umu.sePublikationer
Ändra sökning
Avgränsa sökresultatet
1234 51 - 100 av 159
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Alfredson, Håkan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Willberg, Lotta
    Öhberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Ultrasound and doppler-guided artthroscopic shaving for the treatment of patellar tendinopathy/jumper´s knee: biological background and description of method2011Ingår i: Anterior knee pain and patellar instability / [ed] Sanchis-Alfonso, Vicente, London: Springer London, 2011, s. 367-371Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Treatment with ultrasound and Doppler-guided arthroscopic shaving of the region with vessels and nerves outside the dorsal tendon has shown promising clinical results in patients with proximal patellar tendinopathy/Jumper´s knee. The results concerning only a limited patient material has been published in a scientific paper. Results on larger materials are under evaluation for later publication. Proper understanding of the ultrasound and Doppler findings, to enable for a precise and minimal arthroscopic shaving procedure on the dorsal side of the tendon, are cornerstones using this new type of treatment.

  • 52.
    Alfredson, Håkan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Zeisig, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Fahlström, Martin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    No normalisation of the tendon structure and thickness after intratendinous surgery for chronic painful midportion Achilles tendinosis.2009Ingår i: British journal of sports medicine, ISSN 1473-0480, Vol. 43, nr 12, s. 948-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To characterise Achilles tendon structure and thickness a minimum of 8 years after intra-tendinous surgery. Material and METHODS: Fourteen patients (16 tendons; 9 men and 5 women, mean age 43 years, range 27-55) surgically treated (intra-tendinous surgery) for chronic painful midportion Achilles tendinosis, were followed with clinical examination and grey-scale ultrasonography for a minimum of 8 years (range 8-16 years, mean 13 years). RESULTS: All patients were satisfied with the result of surgery and were active in Achilles tendon loading activities without restrictions. In all operated tendons, structural abnormalities remained and tendons remained thicker than normal tendons. CONCLUSIONS: Resection of tendinosis is associated with persistent structural abnormalities and thickening of the tendon 13 years after surgery, despite successful clinical outcomes.

  • 53.
    Alfredson, Håkan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Öhberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Neovascularisation in chronic painful patellar tendinosis - promising results after sclerosing neovessels outside the tendon challenge the need for surgery2005Ingår i: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 13, nr 2, s. 74-80Artikel i tidskrift (Refereegranskat)
  • 54.
    Alfredson, Håkan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Öhberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Sclerosing injections to areas of neo-vascularisation reduce pain in chronic Achilles tendinopathy: a double-blind randomised controlled trial2005Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 13, nr 4, s. 338-344Artikel i tidskrift (Refereegranskat)
  • 55.
    Alfredson, Håkan
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Öhberg, Lars
    Umeå universitet, Medicinsk fakultet, Strålningsvetenskaper, Diagnostisk radiologi.
    Zeisig, Ewa
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Lorentzon, Ronny
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Treatment of midportion Achilles tendinosis: similar clinical results with US and CD-guided surgery outside the tendon and sclerosing polidocanol injections.2007Ingår i: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 15, nr 12, s. 1504-1509Artikel i tidskrift (Refereegranskat)
  • 56.
    Andersson, Gustav
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Handkirurgi.
    Backman, Ludvig J.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Christensen, Jens
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Nerve distributions in insertional Achilles tendinopathy - a comparison of bone, bursae and tendon2017Ingår i: Histology and Histopathology, ISSN 0213-3911, E-ISSN 1699-5848, Vol. 32, nr 3, s. 263-270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background/Aim. In a condition of pain in the Achilles tendon insertion there are multiple structures involved, such as the Achilles tendon itself, the retrocalcaneal bursa and a bony protrusion at the calcaneal tuberosity called Haglund's deformity. The innervation patterns of these structures are scarcely described, and the subcutaneous calcaneal bursa is traditionally not considered to be involved in the pathology. This study aimed at describing the innervation patterns of the four structures described above to provide a better understanding of possible origins of pain at the Achilles tendon insertion.

    Methods. Biopsies were taken from 10 patients with insertional Achilles tendinopathy, which had pathological changes in the subcutaneous and retrocalcaneal bursae, a Haglund deformity and Achilles tendon tendinopathy as verified by ultrasound. The biopsies were stained using immunohistochemistry in order to delineate the innervation patterns in the structures involved in insertional Achilles tendinopathy.

    Results. Immunohistochemical examinations found that the subcutaneous bursa scored the highest using a semi-quantitative evaluation of the degree of innervation when compared to the retrocalcaneal bursa, the Achilles tendon, and the calcaneal bone.

    Conclusions. These findings suggest that the subcutaneous bursa, which is traditionally not included in surgical treatment, may be a clinically important factor in insertional Achilles tendinopathy.

  • 57.
    Andersson, Gustav
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Arteries in the area targeted with successful sclerosing injections for Achilles tendinosis are under distinct neural control2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    It has been scientifically demonstrated that there are blood vessels with pathologically high blood flow inside and outside the ventral part of the Achilles tendon in chronic painful tendinosis, but not in pain-free normal Achilles tendons. Injections of local anaesthesia on the outside of the ventral part of the tendon have been found to temporarily abolish the tendon pain, and this has been an inspiration in the development of a new approach in the treatment of tendinosis: Based on ultrasound- (US) and colour Doppler- (CD) guidance, the sclerosing substance polidocanol, for many years used in treatment of varicose veins, was injected targeting the area of high-flow blood vessels just outside the ventral part of the Achilles tendon. The treatment has in pilot studies and a randomized controlled clinical study been shown to cure the pain in about 70-80 % of the patients. Also, follow up examinations, using US and CD, have shown a possible remodeling potential of the tendon. There is some previous information available on the innervation patterns of the human Achilles tendon itself. However, the innervation patterns of the area just outside the ventral part of the tendon, i.e. the area that is targeted by the sclerosing injections (target area), are unknown. This includes a lack of information concerning the nerve-related characteristics of the blood vessels in the area. In this study, therefore, tissue specimens from this target area, obtained during surgical treatment of patients with chronic painful mid-portion Achilles tendinosis, were examined. Histological and immunohistochemical examinations were performed. In the tissue of the target area, in which loose connective tissue and fat cells were frequent constituents, there was a presence of arteries and nerve fascicles. The arteries were of varying dimensions, some being very large. The nerve fascicles were distinguished in sections processed for the pan-neural marker protein gene-product 9.5 (PGP 9.5).  Some of the arteries were supplied by an extensive perivascular innervation, as seen via PGP 9.5 staining. As seen via processing for the rate limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), sympathetic innervation was found to be a constituent of this innervation. There was furthermore a marked occurrence of immunoreactions for the α1-adrenoreceptor in arterial walls. Also, there was a presence of immunoreactions for the substance P (SP)-preferred receptor, the neurokinin-1 (NK-1) receptor in arterial walls. This receptor was particularly detected in the endothelial parts. The study shows that the arteries in the target area are accompanied by nerve fascicles and that there is a presence of a perivascular innervation, as well as a presence of adrenergic and NK-1 receptors in arterial walls, in this region. Thus, arteries in this area are under distinct neural control. The nerve-related characteristics of the area targeted in the successful polidicanol injection treatment for Achilles tendinosis are here for the first time shown.

  • 58.
    Andersson, Gustav
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Nerve-related characteristics of ventral paratendinous tissue in chronic Achilles tendinosis2007Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 15, nr 10, s. 1272-1279Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ultrasound and Doppler examination has shown high blood flow-neovascularisation inside and outside the ventral Achilles tendon in chronic painful tendinosis, but not in pain-free normal Achilles tendons. In patients with Achilles tendinosis, injections with the sclerosing substance polidocanol, targeting the areas with increased blood flow, have been demonstrated to give pain relief. A drawback when interpreting these findings is the fact that the pattern of nerve supply in the target area, i.e. the ventral area of the tendon, is so far unknown. In this study, therefore, tissue specimens from this area, obtained during surgical treatment of patients with chronic painful midportion Achilles tendinosis, were examined. In the examined area, containing loose connective tissue, the general finding was a presence of large and small arteries and nerve fascicles. The nerve fascicles were distinguished in sections processed for the pan-neural marker protein gene-product 9.5. The nerve fascicles contain sensory nerve fibers, as shown via staining for the sensory markers substance P (SP) and calcitonin gene-related peptide, and sympathetic nerve fibers as seen via processing for tyrosine hydroxylase. In addition, there were immunoreactions for the SP-preferred receptor, the neurokinin-1 receptor, in blood vessel walls and nerve fascicles. Some of the blood vessels were supplied by an extensive peri-vascular innervation, sympathetic nerve fibers being a distinct component of this innervation. There was also a marked occurrence of immunoreactions for the alpha1-adrenoreceptor in arterial walls as well as in the nerve fascicles. Altogether, these findings suggest that the area investigated is under marked influence by the nervous system, including sympathetic and sensory components. Thus, sympathetic/sensory influences may be involved in the pain mechanisms from this area. In conclusion, the nerve-related characteristics of the area targeted by the polidicanol injection treatment for Achilles tendinosis, are shown here for the first time.

  • 59.
    Andersson, Gustav
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Presence of substance P and the neurokinin-1 receptor in tenocytes of the human Achilles tendon2008Ingår i: Regulatory Peptides, ISSN 0167-0115, E-ISSN 1873-1686, Vol. 150, nr 1-3, s. 81-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nerve signal substances, such as the tachykinin substance P (SP), may be involved in the changes that occur in response to tendinopathy (tendinosis). It is previously known that the level of SP innervation within tendon tissue is limited, but results of experimental studies have suggested that SP may have stimulatory, angiogenetic and healing effects in injured tendons. Therefore, it would be of interest to know if there is a local SP-supply in tendon tissue. In the present study, the patterns of expression of SP and its preferred receptor, the neurokinin-1 receptor (NK-1 R), in normal and tendinosis human Achilles tendons were analyzed by use of both immunohistochemistry and in situ hybridization. We found that there was expression of SP mRNA in tenocytes, and that tenocytes showed expression of NK-1 R at protein as well as mRNA levels. The observations concerning both SP and NK-1 R were most evident for tenocytes in tendinosis tendons. Our findings suggest that SP is produced in tendinosis tendons, and furthermore that SP has marked effects on the tenocytes via the NK-1 R. It cannot be excluded that the SP effects are of importance concerning the processes of reorganization and healing that occur for tendon tissue in tendinosis. In conclusion, it appears as if SPergic autocrine/paracrine effects occur in tendon tissue during the processes of tendinosis, hitherto unknown effects for human tendons.

  • 60.
    Andersson, Gustav
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Scott, Alexander
    University of British Columbia, Vancouver, Vancouver Coastal Health and Research Institute.
    Gaida, James Edmund
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Stjernfeldt, Johanna Elgestad
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Lorentzon, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Backman, Clas
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Handkirurgi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: contralateral effects suggest the involvement of central neuronal mechanisms2011Ingår i: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, nr 5, s. 399-406Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective To determine whether there are objective findings of tendinosis in a rabbit tendinopathy model on exercised and contralateral (non-exercised) Achilles tendons. Design Four groups of six New Zealand white rabbits per group were used. The animals of one (control) group were not subjected to exercise/stimulation. Interventions Animals were subjected to a protocol of electrical stimulation and passive flexion-extension of the right triceps surae muscle every second day for 1, 3 or 6 weeks. Main Outcome Measures Tenocyte number and vascular density were calculated. Morphological evaluations were also performed as well as in-situ hybridisation for vascular endothelial growth factor (VEGF) messenger RNA. Results There was a significant increase in the tenocyte number after 3 and 6 weeks of exercise, but not after 1 week, in comparison with the control group. This was seen in the Achilles tendons of both legs in experimental animals, including the unexercised limb. The pattern of vascularity showed an increase in the number of tendon blood vessels in rabbits that had exercised for 3 weeks or more, compared with those who had exercised for 1 week or not at all. VEGF-mRNA was detected in the investigated tissue, with the reactions being more clearly detected in the tendon tissue with tendinosis-like changes (6-week rabbits) than in the normal tendon tissue (control rabbits). Conclusions There were bilateral tendinosis-like changes in the Achilles tendons of rabbits in the current model after 3 weeks of training, suggesting that central neuronal mechanisms may be involved and that the contralateral side is not appropriate as a control.

  • 61.
    Backman, Ludvig J
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Andersson, Gustav
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Fong, Gloria
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Department of Physical Therapy, University of British Columbia and Centre for Hip Health and Mobility, Vancouver Coastal Health and Research Institute, Vancouver, British Columbia, Canada.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Scott, A
    University of British Columbia, Vancouver, Vancouver Coastal Health and Research Institute.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alpha-2 adrenergic stimulation triggers Achilles tenocyte hypercellularity: comparison between two model systems2013Ingår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 23, nr 6, s. 687-696Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The histopathology of tendons with painful tendinopathy is often tendinosis, a fibrosis-like condition of unclear pathogenesis characterized by tissue changes including hypercellularity. The primary tendon cells (tenocytes) have been shown to express adrenoreceptors (mainly alpha-2A) as well as markers of catecholamine production, particularly in tendinosis. It is known that adrenergic stimulation can induce proliferation in other cells. The present study investigated the effects of an exogenously administered alpha-2 adrenergic agonist in an established in vivo Achilles tendinosis model (rabbit) and also in an in vitro human tendon cell culture model. The catecholamine producing enzyme tyrosine hydroxylase and the alpha-2A-adrenoreceptor (α(2A) AR) were expressed by tenocytes, and alpha-2 adrenergic stimulation had a proliferative effect on these cells, in both models. The proliferation was inhibited by administration of an α(2A) AR antagonist, and the in vitro model further showed that the proliferative alpha-2A effect was mediated via a mitogenic cell signaling pathway involving phosphorylation of extracellular-signal-regulated kinases 1 and 2. The results indicate that catecholamines produced by tenocytes in tendinosis might contribute to the proliferative nature of the pathology through stimulation of the α(2A) AR, pointing to a novel target for future therapies. The study furthermore shows that animal models are not necessarily required for all aspects of this research.

  • 62.
    Bagge, J.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Nerve ingrowth into tendon tissue in Achilles tendinosis: a Case Report2013Ingår i: International journal of experimental pathology (Print), ISSN 0959-9673, E-ISSN 1365-2613, Vol. 94, nr 4, s. A8-A8Artikel i tidskrift (Övrigt vetenskapligt)
  • 63.
    Bagge, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Gaida, JE
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Physical activity level in Achilles tendinosis is associated with blood levels of pain-related factors: a pilot study2011Ingår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 21, nr 6, s. E430-E438Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Physical activity affects the pain symptoms for Achilles tendinosis patients. Brain-derived neurotrophic factor (BDNF), tumor necrosis factor-alpha (TNF-alpha) and their receptors have been detected in human Achilles tendon. This pilot study aimed to compare serum BDNF and soluble tumor necrosis factor receptor I (sTNFRI) levels in Achilles tendinosis patients and healthy controls and to examine the influence of physical activity, and BMI and gender, on these levels. Physical activity was measured with a validated questionnaire, total physical activity being the parameter analyzed. Physical activity was strongly correlated with BDNF among tendinosis women [Spearman's rho (rho) = 0.90, P < 0.01] but not among control women (rho = -0.08, P = 0.83), or among tendinosis and control men. Physical activity was significantly correlated with sTNFRI in the entire tendinosis group and among tendinosis men (rho = 0.65, P = 0.01), but not in the entire control group or among control men (rho = 0.04, P = 0.91). Thus, the physical activity pattern is related to the TNF and BDNF systems for tendinosis patients but not controls, the relationship being gender dependent. This is new information concerning the relationship between physical activity and Achilles tendinosis, which may be related to pain for the patients. This aspect should be further evaluated using larger patient materials.

  • 64.
    Bagge, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Lorentzon, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Unexpected presence of the neurotrophins NGF and BDNF and the neurotrophin receptor p75 in the tendon cells of the human Achilles tendon2009Ingår i: Histology and Histopathology, ISSN 0213-3911, E-ISSN 1699-5848, Vol. 24, nr 7, s. 839-848Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Neurotrophins are substances that have been shown to be important in growth and remodelling phases in different types of tissue. There is no information concerning the possible occurrences of neurotrophins and their receptors in tendons. In this study, sections of both chronic painful (tendinosis) and pain-free (non-tendinosis) human Achilles tendons were immunohistochemically stained with antibodies against the neurotrophins NGF and BDNF, and their receptors TrkA, TrkB and p75. There were marked immunoreactions for NGF and BDNF in the tendon cells (tenocytes) of both tendinosis and non-tendinosis specimens. The tenocytes were also reactive for the receptor p75, but not for the receptors TrkA and TrkB. In addition, p75 immunoreactions were seen in nerve fascicles and in the walls of arterioles. This is the first study to identify neurotrophins in the tenocytes of human tendon. It is clear from this study that the local cells of tendons are sources of neurotrophins. The neurotrophins may play an important role in the tendon through their interaction with the receptor p75 in the tenocytes. These interactions may regulate tropic modulatory, and apoptotic effects. In conclusion, the observations show a new concept concerning production and function of neurotrophins, namely in the tenocytes of tendons.

  • 65.
    Bjur, Dennis
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Presence of the neuropeptide Y 1 receptor in tenocytes and blood vessel walls in the human Achilles tendon2009Ingår i: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 43, nr 13, s. 1136-1142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: There are still questions concerning the mechanisms of development of chronic pain and impaired function of tendons (tendinosis). Aspects that are known to occur are cell proliferation, angiogenesis and altered blood flow regulation. Neuropeptide NPY (NPY) is widely distributed in the body and has powerful effects in relation to these processes. NPY has its effects via the G-protein-coupled Y receptors. There is no information concerning the presence or absence of NPY receptors in Achilles tendons or other tendons.

    Objective: To clarify the expression patterns of the NPY receptors Y1 and Y2 in normal and tendinosis Achilles tendons of man.

    Methods: Immunohistochemical methods were used. Examination on NPY was carried out in parallel.

    Results: The tenocytes showed strong immunoreactions for the Y1 receptor. The immunoreactions were more intense in the tenocytes of the tendinosis tendons than in those of the non-tendinosis tendons. The rounded/oval tenocytes typically seen in tendinosis tendons exhibited marked Y1 receptor reactions on their exterior. Pronounced Y1 reactions were seen in the smooth muscle of the arterioles of both tendinosis and non-tendinosis tendons. No reactions for the Y2 receptor were noted. NPY was detected in nerve fascicles and in the perivascular innervation.

    Conclusions: The present study shows that there is a morphologic correlate for the occurrence of pronounced NPY effects via the Y1 receptor in both tenocytes, this especially being a fact for tendinosis tendons, and blood vessel walls in the Achilles tendon. The findings are of particular interest as NPY is known to have proliferative, angiogenic and blood vessel regulating effects. The effects of targeting the Y1 receptor in tendinosis is an interesting task to be further evaluated.

  • 66.
    Bjur, Dennis
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    The innervation pattern of the human Achilles tendon: studies of the normal and tendinosis tendon with markers for general and sensory innervation2005Ingår i: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 320, nr 1, s. 201-206Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pain-free normal Achilles tendons and chronic painful Achilles tendons were examined by the use of antibodies against a general nerve marker (protein gene-product 9.5, PGP9.5), sensory markers (substance P, SP; calcitonin gene-related peptide, CGRP), and immunohistochemistry. In the normal tendons, immunoreactions against PGP9.5 and against SP/CGRP were encountered in the paratendinous loose connective tissue, being confined to nerve fascicles and to nerve fibers located in the vicinity of blood vessels. To some extent, these immunoreactions also occurred in the tendon tissue proper. Immunoreaction against PGP9.5 and against SP/CGRP was also observed in the tendinosis samples and included immunoreactive nerve fibers that were intimately associated with small blood vessels. In conclusion, Mechanoreceptors (sensory corpuscles) were occasionally observed, nerve-related components are present in association with blood vessels in both the normal and the tendinosis tendon.

  • 67.
    Bjur, Dennis
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Immunohistochemical and in situ hybridization observations favor a local catecholamine production in the human Achilles tendon2008Ingår i: Histology and Histopathology, ISSN 0213-3911, E-ISSN 1699-5848, Vol. 23, nr 2, s. 197-208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Results of recent studies using immunohistochemistry show evidence of an occurrence of catecholamine production in the cells (tenocytes) of patellar tendons exhibiting tendinopathy (tendinosis). In the present study, antibodies against the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH) and alpha1-adrenoreceptors were applied to sections of specimens of normal and tendinosis Achilles tendons. In situ hybridization using a probe detecting human TH mRNA was also utilized. It was found that sympathetic innervation was very scarce. On the other hand, there were distinct alpha1-adrenoreceptor immunoreactions in blood vessel walls. Interestingly, tenocytes, particularly from tendinosis samples in which the tenocytes showed an abnormal shape (not the typical slender appearance), displayed TH immunoreactions and reactions for TH mRNA. Of further interest was the finding of alpha1-adrenoreceptor immunoreactions in tenocytes. The observations show not only evidence of local catecholamine production at the protein level, which was the case in recent studies for the patellar tendon, but also at the mRNA level. The observations suggest that the tenocytes, especially those with disfigured appearances in tendinosis, can produce catecholamines and also that they can respond to sympathetic transmitters. This is of interest as adrenergic stimulation in other parts of the body is known to induce degenerative/apoptotic and proliferative events, features which are seen in Achilles tendinosis. These observations are completely new findings concerning the human Achilles tendon. It is likely that locally produced catecholamines and the occurrence of autocrine/paracrine effects of these substances are of great relevance during the process of tendinosis.

  • 68.
    Bjur, Dennis
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Observations in favor of a presence of local catecholamine production in the human Achilles tendon - of importance when understanding potential adrenergic effects in Achilles tendinosis.2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The mid-portion of the Achilles tendon is a frequently injured and pathologically affected tendon region. Achilles tendinosis presents with chronic tendon pain and impaired function, and most often occurs in the mid-portion of the tendon. Nerve-related effects are likely to be of great significance in the pathogenesis of this condition, and information on innervation patterns is therefore of importance. However, the available information on these aspects is limited for the human Achilles tendon. Via staining for a general nerve marker it has previously been shown that there is a presence of innervation in the loose paratendinous connective tissue and to some extent also within the tendon tissue proper. This innervation has been found to partly conform to sensory innervation. There is no information at all on the patterns of sympathetic innervation in the human Achilles tendon. This is a drawback as it is crucial to know the basis for adrenergic effects on blood vessel regulation in tendinosis and as efferent sympathetic nerve activities may be related to pain symptoms. In the present study, therefore, specimens of tendon tissue from the human Achilles tendon of both tendinosis patients and normal controls were immunohistochemically examined concerning expression of the rate limiting enzyme in catecholamine production, tyrosine hydroxylase (TH), and of neuropeptide Y (NPY). In normal tendons, TH- and NPY-immunoreactive nerve fibers were occasionally detected in nerve fascicles and in arterial walls in the paratendinous tissue, but were not detected with certainty within the tendon tissue proper. In the specimens of tendinosis affected tendons, TH-and NPY-immunoreactive nerve fibers were almost non-existent. Surprisingly, however, TH-immunoreactions could be seen in the tendon cells (tenocytes) themselves. Sections were also processed for demonstration of α1-, α2a-, and β1- adrenoreceptors. It was hereby seen that there were immunoreactions for adrenergic receptors in the walls of some of the blood vessels, as well as in some of the tenocytes. The observations show that there is a limited sympathetic innervation at the level of the paratendinous tissue and in principle a non-existent such innervation within the tendon tissue proper. On the other hand, as evidenced by findings of TH-immunoreaction in tenocytes, it appears as if there is a local production of catecholamines within the tendon tissue proper itself. Thus, the tenocytes might be an important source of mediators that bind to the adrenergic receptors in the tissue. The observations of adrenergic receptors on tenocytes are furthermore of interest as adrenergic stimulation in other situations can lead to degenerative/apoptotic events and an affection on cell growth. These facts are thus highly interesting when trying to understand how such events can occur in Achilles tendinosis. Similarly, cartilage and menisci have in recent studies been found to harbor cells that express adrenergic receptors, but nevertheless to be very scarcely equipped with nerves. Although there is a very limited sympathetic innervation in the Achilles tendon, our observations show that there is a morphologic correlate for the occurrence of adrenergic actions in the tendon, via effects of locally produced catecholamines.

  • 69.
    Bjur, Dennis
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Presence of a non-neuronal cholinergic system and occurrence of up- and down-regulation in expression of M2 muscarinic acetylcholine receptors: new aspects of importance regarding Achilles tendon tendinosis (tendinopathy)2008Ingår i: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 331, nr 2, s. 385-400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Limited information is available concerning the existence of a cholinergic system in the human Achilles tendon. We have studied pain-free normal Achilles tendons and chronically painful Achilles tendinosis tendons with regard to immunohistochemical expression patterns of the M(2) muscarinic acetylcholine receptor (M(2)R), choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT). M(2)R immunoreactivity was detected in the walls of blood vessels. As evidenced via parallel staining for CD31 and alpha-smooth muscle actin, most M(2)R immunoreactivity was present in the endothelium. M(2)R immunoreactivity also occured in tenocytes, which regularly immunoreact for vimentin. The degree of M(2)R immunoreactivity was highly variable, tendinosis tendons that exhibit hypercellularity and hypervascularity showing the highest levels of immunostaining. Immunoreaction for ChAT and VAChT was detected in tenocytes in tendinosis specimens, particularly in aberrant cells. In situ hybridization revealed that mRNA for ChAT is present in tenocytes in tendinosis specimens. Our results suggest that autocrine/paracrine effects occur concerning the tenocytes in tendinosis. Up-regulation/down-regulation in the levels of M(2)R immunoreactivity possibly take place in tenocytes and blood vessel cells during the various stages of tendinosis. The presumed local production of acetylcholine (ACh), as evidenced by immunoreactivity for ChAT and VAChT and the detection of ChAT mRNA, appears to evolve in response to tendinosis. These observations are of importance because of the well-known vasoactive, trophic, and pain-modulating effects that ACh is known to have and do unexpectedly establish the presence of a non-neuronal cholinergic system in the Achilles tendon.

  • 70.
    Björklund, Emmelie
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Farmakologi.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Fowler, Christopher J.
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Farmakologi.
    Increased expression of cannabinoid CB(1) receptors in achilles tendinosis2011Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, nr 9, s. e24731-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The endogenous cannabinoid system is involved in the control of pain. However, little is known as to the integrity of the cannabinoid system in human pain syndromes. Here we investigate the expression of the cannabinoid receptor 1 (CB(1)) in human Achilles tendons from healthy volunteers and from patients with Achilles tendinosis.

    Methodology: Cannabinoid CB(1) receptor immunoreactivity (CB(1)IR) was evaluated in formalin-fixed biopsies from individuals suffering from painful Achilles tendinosis in comparison with healthy human Achilles tendons.

    Principal Findings: CB(1)IR was seen as a granular pattern in the tenocytes. CB(1)IR was also observed in the blood vessel wall and in the perineurium of the nerve. Quantification of the immunoreactivity in tenocytes showed an increase of CB(1) receptor expression in tendinosis tissue compared to control tissue.

    Conclusion: Expression of cannabinoid receptor 1 is increased in human Achilles tendinosis suggesting that the cannabinoid system may be dysregulated in this disorder.

  • 71.
    Brax-Olofsson, Lisbeth
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Ortopedi.
    Svensson, Olle
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Ortopedi.
    Lorentzon, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Lindström, Inger
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Ortopedi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Periosteal transplantation to the rabbit patella.2007Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 15, nr 5, s. 560-563Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Autologous periosteal transplantation (without chondrocyte cell transplantation) for treating traumatic articular cartilage defects of the patella gives pain relief in uncontrolled clinical studies. To study the whole transplanted area macroscopically and microscopically, animal studies are motivated. In this pilot study, we reproduce the surgical technique for periosteum transplantation on human patella to a rabbit model. A full-thickness cartilage defect of the whole patella was created in eight adult female rabbits. The defect was treated with autologous periosteal transplantation. After surgery, the rabbits were allowed free activity. This is the difference compared to the treatment in humans, where our group uses CPM for 5 days and non-weight-bearing for 12 weeks. After 21 weeks, there was a diffuse synovitis in all transplanted knees, and in five of eight knees there were signs of osteoarthritis in the patello-femoral joint. Histologically, in three animals, small islands of hyaline cartilage surrounded by fibrocartilage were seen in the transplanted area. In the other five animals, fibrocartilage was the predominant tissue. In contrast to previous experimental studies using a rabbit model, we did not achieve hyaline cartilage resurfacing.

  • 72.
    Christensen, Jens
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin. UCLH, ISEH, London, England; Pure Sports Clin, London, England.
    Andersson, Gustav
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Handkirurgi.
    Protease-activated receptors in the Achilles tendon-a potential explanation for the excessive pain signalling in tendinopathy2015Ingår i: Molecular Pain, ISSN 1744-8069, E-ISSN 1744-8069, Vol. 11, artikel-id 13Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background/Aim: Tendinopathies are pathological conditions of tissue remodelling occurring in the major tendons of the body, accompanied by excessive nociceptive signalling. Tendinopathies have been shown to exhibit an increase in the number of mast cells, which are capable of releasing histamine, tryptase and other substances upon activation, which may play a role in the development of tendinopathies. This study set out to describe the distribution patterns of a family of receptors called protease-activated receptors (PARs) within the Achilles tendon. These four receptors (PAR1, PAR2, PAR3, PAR4) are activated by proteases, including tryptase released from mast cells, and are involved in fibrosis, hyperalgesia and neovascularisation, which are changes seen in tendinopathies. Method: In order to study which structures involved in tendinopathy that these proteases can affect, biopsies from patients suffering of mid-portion Achilles tendinosis and healthy controls were collected and examined using immunohistochemistry. Tendon cells were cultured to study in vitro expression patterns. Results: The findings showed a distribution of PARs inside the tendon tissue proper, and in the paratendinous tissue, with all four being expressed on nerves and vascular structures. Double staining showed co-localisation of PARs with nociceptive fibres expressing substance P. Concerning tenocytes, PAR2, PAR3, and PAR4, were found in both biopsies of tendon tissue and cultured tendon cells. Conclusions: This study describes the expression patterns of PARs in the mid-portion of the Achilles tendon, which can help explain the tissue changes and increased pain signalling seen in tendinopathies. These findings also show that in-vitro studies of the effects of these receptors are plausible and that PARs are a possible therapeutic target in the future treatment strategies of tendinopathy.

  • 73.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Distribution of general (PGP 9.5) and sensory (substance P/CGRP) innervations in the human patellar tendon.2006Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 14, nr 2, s. 125-132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is no information on the pattern of blood vessel innervation, and in principle no information on innervation in general, in the human patellar tendon. In the present study, biopsies from the proximal part of normal and pain-free patellar tendons (11 men, mean age 33 years) were examined. The specimens were evaluated by using antibodies against the general nerve marker protein gene-product 9.5 (PGP 9.5) and the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP), and immunohistochemistry. It was observed that the arteries, and to some extent the small vessels, in the loose paratendinous connective tissue were supplied with PGP 9.5- as well as SP- and CGRP-innervations. There was a marked PGP 9.5-like immunoreaction (LI), and to some extent also SP- and CGRP-LI, in the large nerve fascicles in this tissue. In the tendon tissue proper, PGP 9.5-LI was detected in nerve fibers located in the vicinity of some of the blood vessels and in thin nerve fascicles. There was a low degree of SP- and CGRP-innervation in the tendon tissue proper. The observations give a morphologic correlate for the occurrence of nerve-mediated effects in the patellar tendon. Particularly it seems as if there is a marked nerve-mediated regulation of the blood vessels supplying the tendon, at the level where they course in the loose paratendinous connective tissue.

  • 74.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Findings favoring production of non-neuronal acetylcholine with possible autocrine/paracrine effects in chronic painful patellar tendon tendinosis.2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The innervation pattern of the human patellar tendon is largely unknown. That includes the situation for patients suffering from patellar tendon tendinosis (“jumper’s knee”). Concerning the possible occurrence of a cholinergic system in the human patellar tendon, very little information is available.

    In the present study, specimens of pain-free normal (n=16) and chronically painful tendinosis (n=7) tendons were examined by different immunohistochemical and histochemical methods.

    It was found that parts of the tenocytes of the tendinosis tendons displayed immunoreactions for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT). Furthermore, immunoreactions for the M2 muscarinic acetylcholine receptor could be detected in both blood vessel cells and tenocytes, especially in tendinosis specimens. Acetylcholinesterase activity was shown for scarce nerve fibers associated with small blood vessels in both the normal and the tendinosis tendons.

    The observations suggest that, besides the occurrence of a scanty nerve related cholinergic system in the human patellar tendon, there is a local non-neuronal cholinergic system as well, at least in tendinosis tendons. As ChAT and VAChT were detected in tenocytes of these tendons, such tenocytes are likely to produce acetylcholine (ACh) locally, and as both tenocytes and blood vessel cells were found to express the M2 receptor, it is likely that both of these cell types may be influenced by ACh.

    Thus, in conclusion, there appears to be an upregulation of the cholinergic system, and an occurrence of autocrine/paracrine effects in this system, in the tendinosis patellar tendon. This observation is of importance, not only related to the fact that tendinosis patients exhibit marked pain, but also as stimulation of ACh receptors can lead to cell proliferation, effects on collagen accumulation and angiogenesis, all of which are phenomena that occur in tendinosis.

  • 75.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Immunohistochemical and histochemical findings favoring the occurrence of autocrine/paracrine as well as nerve-related cholinergic effects in chronic painful patellar tendon tendinosis.2006Ingår i: Microscopy research and technique (Print), ISSN 1059-910X, E-ISSN 1097-0029, Vol. 69, nr 10, s. 808-819Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pathogenesis of the pain in patellar tendon tendinosis ("jumper's knee") is unclear. We have recently presented new information about the sensory nervous system in the human patellar tendon, but there is very little information regarding the possible occurrence of a cholinergic system in this tendon. In the present study, specimens of pain-free normal tendons and chronically painful tendinosis tendons were examined by different immunohistochemical and histochemical methods. Antibodies against the M(2) receptor, choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT) were applied, and staining for demonstration of activity of acetylcholinesterase (AChE) was also utilized. It was found that immunoreactions for the M(2) receptor could be detected intracellularly in both blood vessel cells and tenocytes, especially in tendinosis specimens. Furthermore, in the tendinosis specimens, some tenocytes were seen to exhibit immunoreaction for ChAT and VAChT. AChE reactions were seen in fine nerve fibers associated with small blood vessels in both the normal control tendons and the tendinosis tendons. The observations suggest that there is both a nerve related and a local cholinergic system in the human patellar tendon. As ChAT and VAChT immunoreactions were detected in tenocytes of tendinosis tendons, these cells might be a source of local acetylcholine (Ach) production. As both tenocytes and blood vessel cells were found to exhibit immunoreactions for the M(2) receptor, it is likely that both of these tissue cells may be influenced by ACh. Thus, in conclusion, there appears to be an upregulation of the cholinergic system, and an occurrence of autocrine/paracrine effects in this system, in the tendinosis patellar tendon.

  • 76.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    In situ hybridization studies confirming recent findings of the existence of a local nonneuronal catecholamine production in human patellar tendinosis.2007Ingår i: Microscopy research and technique (Print), ISSN 1059-910X, E-ISSN 1097-0029, Vol. 70, nr 10, s. 908-911Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    We have in recent studies presented unexpected immunohistochemical evidence favoring the existence of a local production of catecholamines, and an occurrence of adrenergic receptors on the tendon cells (tenocytes), in the human patellar tendon. This was particularly noticed for tendons from patients suffering from tendinosis (chronic tendon pain), which has led us to propose an involvement of this autocrine/paracrine system in the development of tendinosis, especially since catecholamines have been reported to be modulators of tissue remodeling and pain processes. However, the findings concerning catecholamine production have so far only been noted at the level of protein detection, and for this reason, the aim of the present study was to confirm the previous immunohistochemical results by using in situ hybridization (ISH) technique. A ssDNA probe detecting human mRNA for the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH) was applied. The ISH results revealed that there were clear reactions indicating the existence of mRNA for TH in tenocytes of tendinosis specimens. It was generally noted that disfigured tenocytes were the ones with the most distinct reactions, while normally looking tenocytes hardly displayed any reactions at all. In conclusion, this study presents the first evidence at the mRNA level of the existence of a local nonneuronal production of catecholamines in human patellar tendon tissue. The findings add to recent observations of the occurrence of a local production in tendons of signal substances traditionally related to neurons.

    (c) 2007 Wiley-Liss, Inc.

  • 77.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Marked occurrence of receptors for sympathetic and cholinergic transmitters and for substance P in the blood vessels of the human patellar tendon.2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    INTRODUCTION: Human tendons have generally been considered to be hyponeural. However, in our recent studies of the patellar tendon in both healthy individuals and patients with tendinosis (jumper’s knee), we have noted the presence of general (PGP 9.5) and sensory (substance P [SP]) innervations, especially in the loose paratendinous connective tissue. Furthermore, we have observed a pronounced expression of the neurokinin-1 receptor (the preferred receptor for SP) in blood vessel walls. The findings are of interest as a new successful treatment of tendinosis has emerged in form of doppler guided sclerosing injections (substance: Polidokanol), targeting areas with neovascularisation, and as SP is known to be of importance when neurogenic angiogenesis participates in diseases. AIM: To further investigate the blood vessels of the normal and tendinosis-affected human patellar tendon regarding autonomic innervation. METHODS: Immunohistochemistry and histochemistry, including antibodies against the sympathetic nerve markers tyroxine hydroxylase and neuropeptide Y and against various adrenoreceptors (α1, α2a, β1), as well as stainings for substances related to cholinergic functions such as the muscarinic M2 receptor, acetylcholinesterase and vesicular acetylcholine transporter. RESULTS/CONCLUSIONS: The preliminary results so far, indicate that there is indeed an occurrence of both sympathetic and cholinergic innervations in the tendon, not the least shown via the presence of sympathetic and cholinergic receptors in blood vessel walls; a fact that further supports the theories that blood vessel regulation via neurotransmitters/-modulators might be a key factor in the pathological mechanisms of jumper’s knee.

  • 78.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Studies on the importance of sympathetic innervation, adrenergic receptors, and a possible local catecholamine production in the development of patellar tendinopathy (tendinosis) in man.2007Ingår i: Microscopy research and technique (Print), ISSN 1059-910X, E-ISSN 1097-0029, Vol. 70, nr 4, s. 310-324Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Changes in the patterns of production and in the effects of signal substances may be involved in the development of tendinosis, a chronic condition of pain in human tendons. There is no previous information concerning the patterns of sympathetic innervation in the human patellar tendon. In this study, biopsies of normal and tendinosis patellar tendons were investigated with immunohistochemical methods, including the use of antibodies against tyrosine hydroxylase (TH) and neuropeptide Y, and against alpha(1)-, alpha(2A)-, and beta(1)-adrenoreceptors. It was noticed that most of the sympathetic innervation was detected in the walls of the blood vessels entering the tendon through the paratendinous tissue, and that the tendon tissue proper of the normal and tendinosis tendons was very scarcely innervated. Immunoreactions for adrenergic receptors were noticed in nerve fascicles containing both sensory and sympathetic nerve fibers. High levels of these receptors were also detected in the blood vessel walls; alpha(1)-adrenoreceptor immunoreactions being clearly more pronounced in the tendinosis tendons than in the tendons of controls. Interestingly, immunoreactions for adrenergic receptors and TH were noted for the tendon cells (tenocytes), especially in tendinosis tendons. The findings give a morphological correlate for the occurrence of sympathetically mediated effects in the patellar tendon and autocrine/paracrine catecholamine mechanisms for the tenocytes, particularly, in tendinosis. The observation of adrenergic receptors on tenocytes is interesting, as stimulation of these receptors can lead to cell proliferation, degeneration, and apoptosis, events which are all known to occur in tendinosis. Furthermore, the results imply that a possible source of catecholamine production might be the tenocytes themselves. Microsc. Res. Tech., 2007. (c) 2007 Wiley-Liss, Inc.

  • 79.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Andersson, Gustav
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Extensive expression of markers for acetylcholine synthesis and of M2 receptors in tenocytes in therapy-resistant chronic painful patellar tendon tendinosis - a pilot study.2007Ingår i: Life Sciences, ISSN 0024-3205, E-ISSN 1879-0631, Vol. 80, nr 24-25, s. 2235-2238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have recently obtained evidence favoring the occurrence of an up-regulation of a non-neuronal cholinergic system in chronic painful patellar tendon tendinosis. It seems possible that this up-regulation to a certain degree may be involved in the manifestations of the disease. Today, there is a new, very successful, line of treatment of patellar tendinosis in the form of Doppler guided sclerosing injections. However, a few patients seem resistant to this therapy. Therefore, we have in this pilot study investigated biopsies from the patellar tendon of three such therapy-resistant patients, using immunohistochemistry. In situ hybridization was also applied. Comparisons were made with a material of specimens from both normal (n=16) and tendinosis (n=7) tendons, also previously examined. The study showed that there were extensive immunoreactions for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter, as well as for the M(2) muscarinic acetylcholine receptor, in the overwhelming majority of the tenocytes. The immunoreactions were more pronounced than those generally obtained in the tendinosis tissue of the previously studied patients and clearly more pronounced than those of patellar tendon tissue of controls. Also, for the first time, we here present findings of mRNA for ChAT within tenocytes. In conclusion, it appears as if there is an excessive local acetylcholine (ACh) production and an occurrence of marked ACh effects in cases of severe tendinosis. An excessive production of local ACh might be related to pain sensation and the processes that occur in tendinosis development, such as cell proliferation. Thus, the results of this pilot study suggest that non-neuronal ACh is highly involved in the pathology of therapy-resistant patellar tendinosis.

  • 80.
    Danielson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Andersson, Gustav
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Marked sympathetic component in the perivascular innervation of the dorsal paratendinous tissue of the patellar tendon in arthroscopically treated tendinosis patients.2008Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 16, nr 6, s. 621-6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the recent years, a few studies have shed new light on the innervation patterns of the human patellar tendon, but the area of the loose paratendinous connective tissue dorsal to the proximal tendon proper has yet not been investigated. That is a drawback, since this is the area targeted in promising treatment regimens of chronic painful patellar tendinosis, namely sclerosing Polidocanol injection therapy, and a new surgical method conforming to ultrasound and color Doppler guided arthroscopic shaving, directed at neovessels found in the region. The present study thus aimed at investigating the paratendinous area dorsal to the proximal patellar tendon proper in seven patients being operated for tendinosis. Biopsies were collected through the new arthroscopic technique, approaching the tendon from the dorsal side. Samples were investigated using immunohistochemistry with antibodies delineating general (PGP 9.5), sensory (SP/CGRP), and sympathetic (TH/NPY) nerve patterns, and also antibodies against alpha1- and alpha2A-adrenoreceptors. Both small and large blood vessels had a marked perivascular innervation (PGP 9.5). Surprisingly, this perivascular innervation was found only to a very limited extent to correspond to sensory nerves, while there were marked immunoreactions for sympathetic markers. Adrenoreceptor immunoreactions frequently occurred in blood vessel walls. In conclusion, this study demonstrates, for the first time, the innervation patterns of the area dorsal to the patellar tendon in man. It shows that the area investigated is under marked influence by the sympathetic nervous system. Thus, sympathetic effects are likely to occur for blood vessels of the area, which is interesting since color Doppler has revealed that vessels of this area ("neovessels") display a pathologically high blood flow in tendinosis. The findings are discussed in relation to aspects of vascular regulation, and to pain symptoms of tendinosis.

  • 81.
    Fahlström, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Ultrasound and Doppler findings in the Achilles tendon among middle-aged recreational floor-ball players in direct relation to a match.2010Ingår i: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 44, nr 2, s. 140-143Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: In this study, structure, blood flow and thickness in the Achilles tendon related to tendon-loading activity were investigated. DESIGN: Examination by ultrasound (US) and colour Doppler (CD) immediately before and after 1 h of floor-ball matchplay. SETTING: Sports Medicine Unit, Umeå University, Sweden. PARTICIPANTS: 36 Achilles tendons in 18 middle-aged (mean 39 years) recreational male floor-ball players. MAIN OUTCOME MEASUREMENTS: Structure and high blood flow (HBF)/neovessels (NV) in the tendons were registered. Tendon thickness was measured 3 and 4.5 cm above the upper calcaneus and at the thickest part of the tendon. RESULTS: The US examination showed that 11/36 tendons (30.5%) in nine individuals had structural changes before and after the floor-ball match. In 7/36 tendons (five with structural changes), there were HBF/NV before, and after, the match. In six of these seven tendons, the blood flow was higher after than before the match. In three more tendons (two with structural changes), there were HBF/NV after, but not before, the match. After the match, mean tendon thickness had decreased significantly in both normal tendons and tendons with structural changes at the 3-cm level (6.0 (1.0) mm to 5.8 (0.9) mm; p<0.019), at the 4.5-cm level (5.7 (1.1) mm to 5.5 (1.0) mm; p<0.044), and at the thickest part (6.6 (1.1) mm to 6.3 (1.2) mm; p<0.000). CONCLUSIONS: In about 1/3 of the tendons, there were structural changes, about half of those tendons also had HBF/NV, which was higher after, than before, the match. Mean tendon thickness in both normal tendons and tendons with structural changes had decreased significantly after a 1-h floor-ball match.

  • 82.
    Fahlström, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    Jonsson, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Lorentzon, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Chronic Achilles tendon pain treated with eccentric calf-muscle training2003Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 11, nr 5, s. 327-333Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Injuries involving the Achilles tendon and manifested as chronic tendon pain are common, especially among recreational athletes. In a pilot study on a small group of patients with chronic painful midportion Achilles tendinosis, eccentric calf-muscle training was shown to give good clinical results. The aim of this prospective study was to investigate if the previously achieved good clinical results could be reproduced in a larger group of patients, and also to investigate the effects of eccentric calf-muscle training in patients with chronic insertional Achilles tendon pain. Seventy-eight consecutive patients, having chronic painful Achilles tendinosis at the mid-portion (2–6 cm level) in a total of 101 tendons (55 unilateral and 23 bilateral), and thirty consecutive patients with chronic insertional Achilles tendon pain in 31 tendons (29 unilateral and one bilateral) were treated with eccentric calf-muscle training for 12 weeks. Most patients were recreational athletes. Evaluation of the amount of tendon pain during activity was recorded on a visual analogue scale (VAS), before and after treatment. In 90 of the 101 Achilles tendons (89%) with chronic painful mid-portion Achilles tendinosis, treatment was satisfactory and the patients were back on their reinjury activity level after the 12-week training regimen. In these patients, the amount of pain during activity, registered on the VAS-scale (mean±SD), decreased ignificantly from 66.8±19.4 to 10.2±13.7. On the contrary, in only ten of the tendons (32%) with chronic insertional Achilles tendon pain was treatment satisfactory, with a significant decrease on the VAS-scale (mean±SD), from 68.3±7.0 to 13.3±13.2. Our conclusion is that treatment with eccentric calf-muscle training produced good clinical results in patients with chronic painful mid-portion Achilles tendinosis, but not in patients withchronic insertional Achilles tendon pain.

  • 83.
    Fahlström, Martin
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinsk fakultet, Samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    Lorentzon, Ronny
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Painful conditions in the Achilles tendon region: a common problem in middle-aged competitive badminton players.2002Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 10, nr 1, s. 57-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Overuse injuries are the most frequent type in badminton, generally localized in the legs. An earlier study found 32% of young Swedish elite badminton players to have experienced disabling pain in the Achilles tendon region during the previous 5 years. The present investigation examined the prevalence and characteristics of painful conditions in the Achilles tendon region in 32 middle-aged competitive badminton players by means of questionnaire and physiotherapist's examination. Pain in the Achilles tendon region was reported by 44%, either presently or during the past 5 years, generally localized in the middle portion of the tendon. Symptoms had lasted 2 weeks-1 year (96 days). On the competition days 22% of the reported pain currently in the region. Age was found to be correlated to Achilles tendon pain, but there was no relationship between symptoms of pain and body mass index, gender, training quantity, or years of playing badminton. In conclusion, Achilles tendon pain seems to be relatively common among Swedish middle-aged competitive badminton players, particularly in the older ones.

  • 84.
    Fahlström, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    Lorentzon, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Painful conditions in the Achilles tendon region in elite badminton players.2002Ingår i: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 30, nr 1, s. 51-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this study was to investigate the prevalence and characteristics of painful conditions in the Achilles tendon region in elite badminton players. The study group consisted of 66 players in the Swedish elite division (highest level) in badminton, 41 men (mean age, 24.4 years) and 25 women (mean age, 21.9 years). Twenty-one players (32%) reported the occurrence of a disabling painful condition in the Achilles tendon region during the previous 5 years, and 11 players (17%) had an ongoing painful condition. A majority of the painful conditions (12 of 21, or 57%) were described as involving the midportion of the Achilles tendon. The players who had a painful condition reported a significantly higher weekly training load as measured by the number of hours spent in total training, badminton training, and endurance and strength training. There were no differences in age, sex, and body mass index between the players with and without painful conditions in the Achilles tendon region.

  • 85.
    Fahlström, Martin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    Yeap, Joo Seng
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Söderman, Kerstin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Sjukgymnastik.
    Shoulder pain -- a common problem in world-class badminton players.2006Ingår i: Scandinavian journal of medicine & science in sports, ISSN 0905-7188, Vol. 16, nr 3, s. 168-73Artikel i tidskrift (Refereegranskat)
  • 86.
    Flodgren, Gerd M
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Crenshaw, Albert G
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Idrottsmedicin.
    Fahlström, Martin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Hellström, Fredrik B
    Bronemo, Lars
    Djupsjöbacka, Mats
    Glutamate and prostaglandin E2 in the trapezius muscle of female subjects with chronic muscle pain and controls determined by microdialysis.2005Ingår i: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 9, nr 5, s. 511-515Artikel i tidskrift (Refereegranskat)
  • 87.
    Flodgren, Gerd M
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Crenshaw, Albert G
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Idrottsmedicin.
    Fahlström, Martin
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Hellström, Fredrik B
    Bronemo, Lars
    Djupsjöbacka, Mats
    Glutamate and prostaglandin E2 in the trapezius muscle of female subjects with chronic muscle pain and controls determined by microdialysis.2005Ingår i: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 9, nr 5, s. 511-515Artikel i tidskrift (Refereegranskat)
  • 88.
    Fong, Gloria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.
    Backman, Ludvig J.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Scott, Alex
    Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Oftalmiatrik.
    The Effects of Substance P and Acetylcholine on Human Tenocyte Proliferation Converge Mechanistically via TGF-β12017Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 3, artikel-id e0174101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous in vitro studies on human tendon cells (tenocytes) have demonstrated that the exogenous administration of substance P (SP) and acetylcholine (ACh) independently result in tenocyte proliferation, which is a prominent feature of tendinosis. Interestingly, the possible link between SP and ACh has not yet been explored in human tenocytes. Recent studies in other cell types demonstrate that both SP and ACh independently upregulate TGF-β1 expression via their respective receptors, the neurokinin 1 receptor (NK-1R) and muscarinic ACh receptors (mAChRs). Furthermore, TGF-β1 has been shown to downregulate NK-1R expression in human keratocytes. The aim of this study was to examine if TGF-β1 is the intermediary player involved in mediating the proliferative pathway shared by SP and ACh in human tenocytes. The results showed that exogenous administration of SP and ACh both caused significant upregulation of TGF-β1 at the mRNA and protein levels. Exposing cells to TGF-β1 resulted in increased cell viability of tenocytes, which was blocked in the presence of the TGFβRI/II kinase inhibitor. In addition, the proliferative effects of SP and ACh on tenocytes were reduced by the TGFβRI/II kinase inhibitor; this supports the hypothesis that the proliferative effects of these signal substances are mediated via the TGF-β axis. Furthermore, exogenous TGF-β1 downregulated NK-1R and mAChRs expression at both the mRNA and protein levels, and these effects were negated by simultaneous exposure to the TGFβRI/II kinase inhibitor, suggesting a negative feedback loop. In conclusion, the results indicate that TGF-β1 is the intermediary player through which the proliferative actions of both SP and ACh converge mechanistically.

  • 89.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Andersson, Gustav
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Handkirurgi.
    Further proof of the existence of a non-neuronal cholinergic system in the human Achilles tendon: Presence of the AChR alpha 7 receptor in tendon cells and cells in the peritendinous tissue2015Ingår i: International Immunopharmacology, ISSN 1567-5769, E-ISSN 1878-1705, Vol. 29, nr 1, s. 195-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Human tendon cells have the capacity for acetylcholine (ACh) production. It is not known if the tendon cells also have the potential for ACh breakdown, nor if they show expression of the nicotinic acetylcholine receptor AChR alpha 7 (alpha 7nAChR). Therefore, tendon tissue specimens from patients with midportion Achilles tendinopathy/tendinosis and from normal midportion Achilles tendons were examined. Reaction for the degradative enzyme acetylcholinesterase (AChE) was found in some tenocytes in only a few tendinopathy tendons, and was never found in those of control tendons. Tenocytes displayed more regularly alpha 7nAChR immunoreactivity. However, there was a marked heterogeneity in the degree of this reaction within and between the specimens. alpha 7nAChR immunoreactivity was especially pronounced for tenocytes showing an oval/widened appearance. There was a tendency that the magnitude of alpha 7nAChR immunoreactivity was higher in tendinopathy tendons as compared to control tendons. A stronger alpha 7nAChR immunoreactivity than seen for tenocytes was observed for the cells in the peritendinous tissue. It is likely that the alpha 7nAChR may be an important part of an auto-and paracrine loop of non-neuronal ACh that is released from the tendon cells. The effects may be related to proliferative and blood vessel regulatory functions as well as features related to collagen deposition. ACh can furthermore be of importance in leading to anti-inflammatory effects in the peritendinous tissue, a tissue nowadays considered to be of great relevance for the tendinopathy process. Overall, the findings show that tendon tissue, a tissue known to be devoid of cholinergic innervation, is a tissue in which there is a marked non-neuronal cholinergic system.

  • 90.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Bjur, Dennis
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Rantapää-Dahlqvist, Solbritt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Reumatologi.
    Norrgård, Örjan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Dalén, Tore
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Ortopedi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Novel information on the non-neuronal cholinergic system in orthopedics provides new possible treatment strategies for inflammatory and degenerative diseases2009Ingår i: Orthopedic Reviews, ISSN 2035-8237, Vol. 1, nr 1, s. 39-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Anti-cholinergic agents are used in thetreatment of several pathological conditions.Therapy regimens aimed at up-regulatingcholinergic functions, such as treatment withacetylcholinesterase inhibitors, are also currentlyprescribed. It is now known that not onlyis there a neuronal cholinergic system but alsoa non-neuronal cholinergic system in variousparts of the body. Therefore, interference withthe effects of acetylcholine (ACh) broughtabout by the local production and release ofACh should also be considered. Locally producedACh may have proliferative, angiogenic,wound-healing, and immunomodulatory functions.Interestingly, cholinergic stimulationmay lead to anti-inflammatory effects. Withinthis review, new findings for the locomotorsystem of a more widespread non-neuronalcholinergic system than previously expectedwill be discussed in relation to possible newtreatment strategies. The conditions discussedare painful and degenerative tendon disease(tendinopathy/tendinosis), rheumatoid arthritis,and osteoarthritis.

  • 91.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Bjur, Dennis
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Den kroniskt smärtande senan - histopatologi.2007Ingår i: Idrottsskador - frontlinjen inom behandling och rehablitering, s. 267-274Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    I denna artikel belyses de morfologiska förändringar man ser i Achilles- och patellarsena vid tendinos. Fokus riktas inte minst på nya fynd avseende utseenden för sencellerna (tenocyterna). Vidare ges en kortfattad beskrivning av vad man idag känner till avseende nervrelaterade aspekter för dessa senor hos människa. Det är sannolikt att kunskap om dessa är viktig för att man rätt ska förstå de smärtsymptom som föreligger vid tendinos och även de effekter som nyare tids behandlingar har vid dessa kroniska smärttillstånd.

  • 92.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Bjur, Dennis
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Förändringar i kroniskt smärtande sena.2006Ingår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 25, nr 3, s. 8-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vad känner man till om de förändringar som sker i en kroniskt smärtande sena?

    Hur ser sencellerna ut och hur påverkas nerverna vid tendinos? I denna sammanställning kommer de förändringar man ser i Akilles- och patellarsena vid tendinos att belysas. Fokus riktas inte minst på nya fynd avseende utseenden för sencellerna (tenocyterna). Vidare ges en kortfattad beskrivning av vad man idag känner till avseende nervrelaterade aspekter för dessa senor hos människa. Det är sannolikt att kunskap om dessa är viktig för att man rätt ska förstå de smärtsymptom som föreligger vid tendinos och även de effekter som nyare tids behandlingar har vid dessa kroniska smärttillstånd.

  • 93.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Danielson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Vascular NK-1 receptor occurrence in normal and chronic painful Achilles and patellar tendons: studies on chemically unfixed as well as fixed specimens.2005Ingår i: Regulatory Peptides, ISSN 0167-0115, E-ISSN 1873-1686, Vol. 126, nr 3, s. 173-181Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is not known as to whether the Achilles and patellar tendons contain neurokinin-1 (NK-1) receptors. This is a drawback when considering the fact that pain symptoms are frequent in these and as recent studies show that the pain symptoms might be cured via interference with blood vessel function. In the present study, the human Achilles and patellar tendons were examined concerning immunohistochemical expression of the NK-1 receptor. Chemically unfixed and fixed specimens, TRITC and PAP stainings and a battery of NK-1 receptor antibodies, including antibodies against the C-terminus and the N-terminal region, were utilized. NK-1 receptor immunoreaction could be detected in inner parts of the walls of large blood vessels and in the walls of small blood vessels. To some extent, NK-1 immunoreaction was also detectable in small nerve fascicles and in tenocytes. It was found to be of utmost importance to apply both chemically unfixed and fixed specimens. The use of chemically unfixed tissue was found advantageous in order to depict the immunoreactions in the blood vessel walls. The observations represent new findings and are of relevance as substance P (SP) is known to be of importance where neurogenic angiogenesis contributes to diseases and as SP on the whole has profound effects concerning blood vessel regulation.

  • 94.
    Forsgren, Sture
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Spang, Christoph
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    In mid-portion Achilles tendinosis the plantaris tendon shows the same tendinosis-like morphological features and expression of the non-neuronal cholinergic system as the Achilles tendon itself2013Ingår i: International journal of experimental pathology (Print), ISSN 0959-9673, E-ISSN 1365-2613, Vol. 94, nr 4, s. A3-A3Artikel i tidskrift (Övrigt vetenskapligt)
  • 95.
    Gaida, J
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. School of Primary Health Care, Monash University, Melbourne, Australia.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Cook, J
    School of Primary Health Care, Monash University, Melbourne, Australia.
    Decreased tumour necrosis factor alpha (tnf-a) in serum of patients with achilles tendinopathy: further evidence against the role of inflammation in the chronic stage2014Ingår i: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 48, nr 7, s. 597-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Altered expression of several cytokines and growth factors has been shown in biopsies of tendinopathy tissue. Biopsy studies are however challenged by capacity to obtain i) healthy tissue for comparison, ii) multiple samples to monitor cytokine dynamics, and iii) tissue from recent onset tendinopathy. An alternative is to study cytokines in blood samples. Whether cytokines in blood samples reflect tissue levels and the degree of tendinopathy is unknown.

    OBJECTIVE: To measure serum concentration of six cytokines and growth factors suggested to have a role in tendon response to load among individuals with chronic Achilles tendinopathy and controls.

    DESIGN: In this cross-sectional study, serum cytokine concentrations were measured from fasting blood samples on the BioPlex-200.

    SETTING: Sports Medicine Unit, Umeå University.

    PARTICIPANTS: Participants were recreationally active individuals. Achilles tendinopathy (n=22) was diagnosed on clinical criteria and confirmed with ultrasound examination. The control group (n=10) had no history of tendon pain and had normal ultrasound findings.

    INDEPENDENT VARIABLES: Serum concentration of tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), basic fibroblast growth factor (bFGF), platelet derived growth factor BB (PDGF-BB), interferon gamma (IFN-γ), and vascular-derived endothelial growth factor (VEGF) were the independent variables.

    MAIN OUTCOME MEASUREMENTS: A diagnosis of Achilles tendinopathy (yes/no) was defined as the key outcome variable prior to data collection.

    RESULTS: TNF-α concentration was lower in the tendinopathy group than the control group (P=.018); there were no other group differences.

    CONCLUSIONS: The observations indicate a lowering of the TNF-α concentration in the chronic phase of Achilles tendinopathy. As TNF-α levels are elevated in chronic inflammatory conditions, this reinforces that chronic Achilles tendinopathy is not an inflammatory disorder. Collecting a blood sample to study disease biomarkers leaves the tendon intact and therefore this design can be used to study cytokine dynamics with multiple sampling during disease progression and recovery.

  • 96.
    Gaida, James E.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. University of Canberra Research Institute for Sport and Exercise (UCRISE); Discipline of Physiotherapy, University of Canberra.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering. Institute of Sport Exercise and Health, University College Hospital London.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Cook, Jill L.
    A pilot study on biomarkers for tendinopathy: lower levels of serum TNF-alpha and other cytokines in females but not males with Achilles tendinopathy2016Ingår i: BMC Sports Science Medicine and Rehabilitation, ISSN 2052-1847, Vol. 8, artikel-id 5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Achilles tendinopathy is a painful musculoskeletal condition that is common among athletes, and which limits training capacity and competitive performance. The lack of biomarkers for tendinopathy limits research into risk factors and also the evaluation of new treatments. Cytokines and growth factors involved in regulating the response of tendon cells to mechanical load have potential as biomarkers for tendinopathy. Methods: This case-control study compared serum concentration of cytokines and growth factors (TNF-alpha, IL-1 beta, bFGF, PDFG-BB, IFN-gamma, VEGF) between individuals with chronic Achilles tendinopathy and controls. These were measured in fasting serum from 22 individuals with chronic Achilles tendinopathy and 10 healthy controls. Results were analysed in relation to gender and physical activity pattern. Results: TNF-alpha concentration was lower in the entire tendinopathy group compared with the entire control group; none of the other cytokines were significantly different. TNF-alpha levels were nevertheless highly correlated with the other cytokines measured, in most of the subgroups. Analysed by gender, TNF-alpha and PDGF-BB concentrations were lower in the female tendinopathy group but not the male tendinopathy group. A trend was seen for lower IL-1 beta in the female tendinopathy group. Physical activity was correlated with TNF-alpha, PDGF-BB and IL-1 beta to varying extents for control subgroups, but not for the female tendinopathy group. No correlations were seen with BMI or duration of symptoms. Conclusions: This pilot study indicates a lower level of TNF-alpha and PDGF-BB, and to some extent IL-1 beta among females, but not males, in the chronic phase of Achilles tendinopathy. It is suggested that future studies on tendinopathy biomarkers analyse male and female data separately. The lack of correlation between cytokine level and physical activity in the female tendinopathy group warrants further study.

  • 97. Gaida, James E
    et al.
    Alfredson, Håkan
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Kiss, Zoltan S
    Bass, Shona L
    Cook, Jill L
    Asymptomatic Achilles tendon pathology is associated with a central fat distribution in men and a peripheral fat distribution in women: a cross sectional study of 298 individuals.2010Ingår i: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 11, nr 41, s. 1-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Adiposity is a modifiable factor that has been implicated in tendinopathy. As tendon pain reduces physical activity levels and can lead to weight gain, associations between tendon pathology and adiposity must be studied in individuals without tendon pain. Therefore, the purpose of this study was to determine whether fat distribution was associated with asymptomatic Achilles tendon pathology. METHODS: The Achilles tendons of 298 individuals were categorised as normal or pathological using diagnostic ultrasound. Fat distribution was determined using anthropometry (waist circumference, waist hip ratio [WHR]) and dual-energy x-ray absorptiometry. RESULTS: Asymptomatic Achilles tendon pathology was more evident in men (13%) than women (5%) (p = 0.007). Men with tendon pathology were older (50.9 +/- 10.4, 36.3 +/- 11.3, p < 0.001), had greater WHR (0.926 +/- 0.091, 0.875 +/- 0.065, p = 0.039), higher android/gynoid fat mass ratio (0.616 +/- 0.186, 0.519 +/- 0.142, p = 0.014) and higher upper-body/lower body fat mass ratio (2.346 +/- 0.630, 2.022 +/- 0.467, p = 0.013). Men older than 40 years with a waist circumference >83 cm had the greatest prevalence of tendon pathology (33%). Women with tendon pathology were older (47.4 +/- 10.0, 36.0 +/- 10.3, p = 0.008), had less total fat (17196 +/- 3173 g, 21626 +/- 7882 g, p = 0.009), trunk fat (7367 +/- 1662 g, 10087 +/- 4152 g, p = 0.003) and android fat (1117 +/- 324 g, 1616 +/- 811 g, p = 0.005). They had lower central/peripheral fat mass ratios (0.711 +/- 0.321 g, 0.922 +/- 0.194 g, p = 0.004) than women with normal tendons. Women with tendon pathology were more often menopausal (63%, 13%, p = 0.002). CONCLUSIONS: Men with Achilles tendon pathology were older and had a central fat distribution. Women with tendon pathology were older and had a peripheral fat distribution. An interaction between age and waist circumference was observed among men.

  • 98. Gaida, James E
    et al.
    Alfredson, Lotta
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Kiss, Zoltan S
    Wilson, Andrew M
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap.
    Cook, Jill L
    Midportion Achilles tendinopathy: a cardiovascular disease? Response.2010Ingår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, nr 1, s. 215-215Artikel i tidskrift (Refereegranskat)
  • 99.
    Gaida, James Edmund
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin. University of Canberra, Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise (UCRISE), Canberra, ACT, Australia.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin. Institute of Sport Exercise and Health, University College Hospital London, London, UK.
    Scott, A.
    Mousavizadeh, R.
    Forsgren, Sture
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Anatomi.
    Apolipoprotein A1 distribution pattern in the human Achilles tendon2018Ingår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 28, nr 5, s. 1506-1513Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metabolic factors such as cholesterol appear to play an important role in the development of Achilles tendinopathy. There is, however, no morphologic proof explaining the link between high cholesterol and tendinopathy. As apolipoprotein A1 (Apo-A1) is essential for reverse cholesterol transport, it may be related to cholesterol overload in tendon. Nothing is known about Apo-A1 expression in tendon tissue. We examined the distribution of Apo-A1 protein in biopsies from normal and tendinopathy-affected human Achilles tendons, and APOA1 mRNA production from cultured human hamstring tenocytes. Specific immunoreactions for Apo-A1 were detected. The tenocytes showed specific Apo-A1 immunoreactions. These reactions were usually distinct in the tendinopathy specimens. While the tendinopathy specimens often showed granular/small deposit reactions, the slender tenocytes of control specimens did not show this pattern. The magnitude of Apo-A1 immunoreactivity was especially marked in the tendinopathy specimens, as there is a high number of tenocytes. Reactions were also seen in the walls of blood vessels located within the tendon tissue proper of both the normal and tendinopathy tendons and within the peritendinous/fatty tissue of the tendinopathy tendons. The reactions were predominantly in the form of deposit reactions within the smooth muscle layer of the vessel walls. Cultured hamstring tenocytes produced APOA1 mRNA. We demonstrated the presence of Apo-A1 in human tendon tissue. This suggests there may be a link between Achilles tendinopathy and cholesterol metabolism. We hypothesize that Apo-A1 may be important for tenocyte and blood vessel function within tendons.

  • 100.
    Gaida, James Edmund
    et al.
    School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, AUSTRALIA.
    Alfredson, Lotta
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Kiss, Zoltan Steven
    Victoria House Medical Imaging, Prahran, Victoria, AUSTRALIA.
    Wilson, Andrew Michael
    Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, AUSTRALIA.
    Alfredson, Håkan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Idrottsmedicin.
    Cook, Jill Leigh
    Centre for Physical Activity and Nutrition Research, Deakin University, Burwood, Victoria, AUSTRALIA.
    Dyslipidemia in Achilles tendinopathy is characteristic of insulin resistance2009Ingår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 41, nr 6, s. 1194-1197Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    UNLABELLED: Overuse is considered to be a main causative factor for tendinopathies; however, recent reports indicate that tendinopathy is also common among both overweight and inactive individuals. These factors are associated with abdominal obesity, dyslipidemia, hypertension, and insulin resistance. We hypothesized that these features would be associated with tendinopathy.

    PURPOSE: To compare lipid profile between participants with Achilles tendinopathy and matched controls.

    METHODS: Fasting serum lipids were measured among 60 participants with chronic painful midportion Achilles tendinopathy (54% male) and 60 control subjects matched for gender, age (+/-10 yr), and body mass index (+/-2 kg x m(-2)).

    RESULTS: The participants with Achilles tendinopathy showed evidence of underlying dyslipidemia. They had higher triglyceride (TG) levels (P = 0.039), lower %HDL-C (P = 0.016), higher TG/HDL-C ratio (P = 0.036), and elevated apolipoprotein B concentration (P = 0.017) in comparison to the well-matched control group.

    CONCLUSIONS: This pattern of dyslipidemia is characteristic of the dyslipidemia displayed by individuals with insulin resistance and is common in the metabolic syndrome. Two additional aspects of tendinopathy research support a connection with the metabolic syndrome. First, tendinopathy has been associated with greater waist circumference, as has the metabolic syndrome. Second, insulin resistance has been associated with fat deposition in muscle (primarily intracellular), whereas fat deposition in tendon has been found among those with tendon pain.If tendinopathy is confirmed to be associated with dyslipidemia and the metabolic syndrome in larger studies, it may be appropriate to redefine our concept of tendinopathy to that of a cardiovascular disease (CVD). In this case, we may be able to draw considerably on CVD research to improve our understanding of tendinopathy, and perhaps treating CVD risk factors will improve the treatment of tendinopathy.

1234 51 - 100 av 159
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf