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  • 1. Arsov, Stefan
    et al.
    Trajceska, Lada
    van Oeveren, Wim
    Smit, Andries J
    Dzekova, Pavlina
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sikole, Aleksandar
    Rakhorst, Gerhard
    Graaff, Reindert
    Increase in skin autofluorescence and release of heart-type fatty acid binding protein in plasma predicts mortality of hemodialysis patients2013In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 37, no 7, p. E114-E122Article in journal (Refereed)
    Abstract [en]

    Advanced glycation end-products (AGEs) are uremic toxins that accumulate progressively in hemodialysis (HD) patients. The aim of this study was to assess the 1-year increase in skin autofluorescence (DAF), a measure of AGEs accumulation and plasma markers, as predictors of mortality in HD patients. One hundred sixty-nine HD patients were enrolled in this study. Skin autofluorescence was measured twice, 1 year apart using an AGE Reader (DiagnOptics Technologies BV, Groningen, The Netherlands). Besides routine blood chemistry, additional plasma markers including superoxide dismutase, myeloperoxydase, intercellular adhesion molecule 1 (ICAM-1), C-reactive protein (hs-CRP), heart-type fatty acid binding protein (H-FABP), and von Willebrand factor were measured at baseline. The mortality of HD patients was followed for 36 months. Skin autofluorescence values of the HD patients at the two time points were significantly higher (P < 0.001) than those of healthy subjects of the same age. Mean 1-year DAF of HD patients was 0.16 +/- 0.06, which was around seven-to ninefold higher than 1-year DAF in healthy subjects. Multivariate Cox regression showed that age, hypertension, 1-year DAF, hs-CRP, ICAM-1, and H-FABP were independent predictors of overall mortality. Hypertension, 1-year DAF, hs-CRP, and H-FABP were also independent predictors of cardiovascular mortality. One-year DAF and plasma H-FABP, used separately and in combination, are strong predictors of overall and cardiovascular mortality in HD patients.

  • 2.
    Forsberg, Ulf
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jonsson, Per
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Christofer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    A high blood level in the air trap reduces microemboli during hemodialysis2012In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 36, no 6, p. 525-529Article in journal (Refereed)
    Abstract [en]

    Previous studies have demonstrated the presence of air microemboli in the dialysis circuit and in the venous circulation of the patients during hemodialysis. In vitro studies indicate that a high blood level in the venous air trap reduces the extent of microbubble formation. The purpose of this study was to examine whether air microbubbles can be detected in the patient's access and if so, whether the degree of microbubble formation can be altered by changing the blood level in the venous air trap. This was a randomized, double-blinded, interventional study of 20 chronic hemodialysis patients. The patients were assigned to hemodialysis with either an elevated or a low blood level in the air trap. The investigator and the patient were blinded to the settings. The numbers of microbubbles were measured at the site of the arteriovenous (AV) access for 2 min with the aid of an ultrasonic Doppler device. The blood level in the air trap was then altered to the opposite setting and a new measurement was carried out after an equilibration period of 30 min. Median (range) for the number of microbubbles measured with the high air trap level and the low air trap level in AV access was 2.5 (0-80) compared with 17.5 (0-77), respectively (P = 0.044). The degree of microbubble formation in hemodialysis patients with AV access was reduced significantly if the blood level in the air trap was kept high. The exposure of potentially harmful air microbubbles was thereby significantly reduced. This measure can be performed with no additional healthcare cost.

  • 3.
    Fuchs, Gabriel
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Berg, Niclas
    Eriksson, Anders
    Wittberg, Lisa Prahl
    Detection of Thrombosis in the Extracorporeal Membrane Oxygenation Circuit by Infrasound: Proof of Concept2017In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 41, no 6, p. 573-579Article in journal (Refereed)
    Abstract [en]

    As of today, there exist no reliable, objective methods for early detection of thrombi in the extracorporeal membrane oxygenators (ECMO) system. Within the ECMO system, thrombi are not always fixed to a certain component or location in the circuit. Thus, clot fragments of different shapes and consistencies may circulate and give rise to vibrations and sound generation. By bedside sound measurements and additional laboratory experiments (although not detailed herein), we found that the presence of particles (clots or aggregates and fragments of clots) can be detected by analyzing the strength of infra-sound (< 20 Hz) modes of the spectrum near the inlet and outlet of the centrifugal pump in the ECMO circuit. For the few patients that were considered in this study, no clear false positive or negative examples were found when comparing the spectral approach with clinical observations. A laboratory setup provided insight to the flow in and out of the pump, confirming that in the presence of particles a low-amplitude low-frequency signal is strongly amplified, enabling the identification of a clot.

  • 4. Graaff, Reindert
    et al.
    Arsov, Stefan
    Ramsauer, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Koetsier, Marten
    Sundvall, Nils
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Engels, Gerwin E.
    Sikole, Aleksandar
    Lundberg, Lennart
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Rakhorst, Gerhard
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Skin and Plasma Autofluorescence During Hemodialysis: A Pilot Study2014In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 38, no 6, p. 515-518Article in journal (Refereed)
    Abstract [en]

    Skin autofluorescence (AF) is related to the accumulation of advanced glycation end products (AGEs) and is one of the strongest prognostic markers of mortality in hemodialysis (HD) patients. The aim of this pilot study was to investigate whether changes in skin AF appear after a single HD session and if they might be related to changes in plasma AF. Skin and plasma AF were measured before and after HD in 35 patients on maintenance HD therapy (nine women and 26 men, median age 68 years, range 33-83). Median dialysis time was 4h (range 3-5.5). Skin AF was measured noninvasively with an AGE Reader, and plasma AF was measured before and after HD at 460nm after excitation at 370nm. The HD patients had on average a 65% higher skin AF value than age-matched healthy persons (P<0.001). Plasma AF was reduced by 14% (P<0.001), whereas skin AF was not changed after a single HD treatment. No significant influence of the reduced plasma AF on skin AF levels was found. This suggests that the measurement of skin AF can be performed during the whole dialysis period and is not directly influenced by the changes in plasma AF during HD.

  • 5.
    Jonsson, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Karlsson, Lars
    Forsberg, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Gref, Margareta
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Stegmayr, Christofer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Air bubbles pass the security system of the dialysis device without alarming.2007In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 31, no 2, p. 132-139Article in journal (Refereed)
  • 6.
    Jonsson, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Lindmark, Lorentz
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Lars
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lundberg, Lennart
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Formation of Blood Foam in the Air Trap During Hemodialysis Due to Insufficient Automatic Priming of Dialyzers2018In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 42, no 5, p. 533-539Article in journal (Refereed)
    Abstract [en]

    We were encouraged to investigate the reasons for large amounts of foam observed in bloodlines during hemodialysis (HD). Foam was visible in the venous air trap within the Artis Gambro dialysis device. Estimates of the extent of foam were graded (0no foam, 10extensive foam) by two persons that were blind to the type of dialyzer used. Thirty-seven patients were involved in the dialysis procedures. Consecutive dialyses were graded using dialyzers from Fresenius Medical Care (CorDiax dialyzers that were used for high flux HDFX80 and FX100, and for hemodiafiltrationFX1000). The extracorporeal circuit was primed automatically by dialysate using Gambro Artis software 8.15 006 (Gambro, Dasco, Medolla Italy, Baxter, Chicago, IL, USA). The priming volume recommended by the manufacturer was 1100 mL, whereas our center uses 1500 mL. Extensive amounts of blood foam were visual in the air traps. Although the manufacturer recommended extension of priming volume up to 3000 mL, this did not eliminate the foam. Microbubble measurement during HD revealed the air to derive from the dialyzers. When changing to PF210H dialyzers (Baxter) and using a priming volume of 1500 mL, the foam was significantly less (P<0.01). The extent of foam correlated with the size of the FX-dialyzer surface (P=0.002). The auto-priming program was updated to version 8.21 by the manufacturer and the extent of foam in the air trap using FX dialyzers was now reduced and there was no longer a difference between FX and PF dialyzers, although less foam was still visible in the venous air trap during several dialyses. In conclusion, this study urgently calls attention to blood foam development in the venous air trap when using Artis devices and priming software 8.15 in combination with Fresenius dialyzers. Updated auto-priming software (version 8.21) of Artis should be requested to reduce the extent of foam for the Fresenius dialyzers. Other interactions may also be present. We recommend further studies to clarify these problems. Meanwhile caution is warranted for the combined use of dialysis devices and dialyzers with incompatible automatic priming.

  • 7.
    Jonsson, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Bernd G
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Current leakage in hemodialysis machines may be a safety risk for patients.2000In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 24, no 12, p. 977-981Article in journal (Refereed)
  • 8. Ladyzynski, Piotr
    et al.
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. European Society of Artificial Organs.
    Vienken, Jörg
    Malchesky, Paul S
    Jan Maria Wojcicki (1946-2013): scientist, organizer, friend2014In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 38, no 4, p. 271-273Article in journal (Other academic)
  • 9. Matsuda, Kenichi
    et al.
    Fissell, Rachel
    Ash, Stephen
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Long-Term Survival for Hemodialysis Patients Differ in Japan Versus Europe and the USA. What Might the Reasons Be?2018In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 42, no 12, p. 1112-1118Article in journal (Other academic)
  • 10.
    Ramsauer, Bernd
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Department of Nephrology, Skaraborgs Hospital, Skövde.
    Graaff, Reindert
    Sikole, Aleksandar
    Trajceska, Lada
    Lundström, Sara
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Arsov, Stefan
    Hadimeri, Henrik
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Skin Autofluorescence, a Measure of Cumulative Metabolic Stress and Advanced Glycation End Products, Decreases During the Summer in Dialysis Patients2019In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 43, no 2, p. 173-180Article in journal (Refereed)
    Abstract [en]

    Tissue advanced glycation end products (AGEs) are a measure of cumulative metabolic and oxidative stress and cytokine-driven inflammatory reactions. AGEs are thought to contribute to the cardiovascular complications of hemodialysis (HD) patients. Skin autofluorescence (SAF) is related to the tissue accumulation of AGEs and rises with age. SAF is one of the strongest prognostic markers of mortality in these patients. The content of AGEs is high in barbecue food. Due to the location in northern Sweden, there is a short intense barbecue season between June and August. The aim of this study was to investigate if seasonal variations in SAF exist in HD patients, especially during the barbecue season. SAF was measured noninvasively with an AGE Reader in 34 HD-patients (15 of those with diabetes mellitus, DM). Each time the median of three measures were used. Skin-AF was measured before and after each one HD at the end of February and May in 31 patients (22 men/9 women); the end of May and August in 28 (20 m/8 w); the end of August and March in 25 (19 m/6 w). Paired statistical analyses were performed during all four periods (n = 23, 17 m/6 w); as was HbA1c of those with DM. There was at a median 5.6% increase in skin-AF during the winter period (February-May, P = 0.004) and a 10.6% decrease in the skin-AF during the summer (May-August, P < 0.001). HbA1c in the DM rose during the summer (P = 0.013). In conclusion, skin-AF decreased significantly during the summer. Future studies should look for favorable factors that prevent skin-AF and subsequently cardiovascular diseases.

  • 11.
    Stegmayr, Bernd
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Forsberg, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jonsson, Per
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Stegmayr, Christofer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    The sensor in the venous chamber does not prevent passage of air bubbles during hemodialysis2007In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 31, no 2, p. 162-166Article in journal (Refereed)
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