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McGrath, Aleksandra M
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Publications (10 of 12) Show all publications
Bourke, G., McGrath, A. M., Wiberg, M. & Novikov, L. N. (2018). Effects of early nerve repair on experimental brachial plexus injury in neonatal rats. Journal of Hand Surgery, European Volume, 43(3), 275-281
Open this publication in new window or tab >>Effects of early nerve repair on experimental brachial plexus injury in neonatal rats
2018 (English)In: Journal of Hand Surgery, European Volume, ISSN 1753-1934, E-ISSN 2043-6289, Vol. 43, no 3, p. 275-281Article in journal (Refereed) Published
Abstract [en]

Obstetrical brachial plexus injury refers to injury observed at the time of delivery, which may lead to major functional impairment in the upper limb. In this study, the neuroprotective effect of early nerve repair following complete brachial plexus injury in neonatal rats was examined. Brachial plexus injury induced 90% loss of spinal motoneurons and 70% decrease in biceps muscle weight at 28 days after injury. Retrograde degeneration in spinal cord was associated with decreased density of dendritic branches and presynaptic boutons and increased density of astrocytes and macrophages/microglial cells. Early repair of the injured brachial plexus significantly delayed retrograde degeneration of spinal motoneurons and reduced the degree of macrophage/microglial reaction but had no effect on muscle atrophy. The results demonstrate that early nerve repair of neonatal brachial plexus injury could promote survival of injured motoneurons and attenuate neuroinflammation in spinal cord.

Place, publisher, year, edition, pages
Sage Publications, 2018
Keywords
Brachial plexus injury, neonatal rat, spinal cord, motor neuron, cell death
National Category
Orthopaedics Surgery
Identifiers
urn:nbn:se:umu:diva-147362 (URN)10.1177/1753193417732696 (DOI)000429871600005 ()28950736 (PubMedID)
Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2018-06-09Bibliographically approved
McGrath, A. M., Brohlin, M., Wiberg, R., Kingham, P. J., Novikov, L. N., Wiberg, M. & Novikova, L. N. (2018). Long-Term Effects of Fibrin Conduit with Human Mesenchymal Stem Cells and Immunosuppression after Peripheral Nerve Repair in a Xenogenic Model. Cell Medicine, 10, 1-13
Open this publication in new window or tab >>Long-Term Effects of Fibrin Conduit with Human Mesenchymal Stem Cells and Immunosuppression after Peripheral Nerve Repair in a Xenogenic Model
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2018 (English)In: Cell Medicine, ISSN 2155-1790, Vol. 10, p. 1-13Article in journal (Refereed) Published
Abstract [en]

Introduction: Previously we showed that a fibrin glue conduit with human mesenchymal stem cells (hMSCs) and cyclosporine A (CsA) enhanced early nerve regeneration. In this study long term effects of this conduit are investigated. Methods: In a rat model, the sciatic nerve was repaired with fibrin conduit containing fibrin matrix, fibrin conduit containing fibrin matrix with CsA treatment and fibrin conduit containing fibrin matrix with hMSCs and CsA treatment, and also with nerve graft as control. Results: At 12 weeks 34% of motoneurons of the control group regenerated axons through the fibrin conduit. CsA treatment alone or with hMSCs resulted in axon regeneration of 67% and 64% motoneurons respectively. The gastrocnemius muscle weight was reduced in the conduit with fibrin matrix. The treatment with CsA or CsA with hMSCs induced recovery of the muscle weight and size of fast type fibers towards the levels of the nerve graft group. Discussion: The transplantation of hMSCs for peripheral nerve injury should be optimized to demonstrate their beneficial effects. The CsA may have its own effect on nerve regeneration.

National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-60908 (URN)10.1177/2155179018760327 (DOI)000433910200001 ()
Available from: 2012-11-02 Created: 2012-11-01 Last updated: 2018-09-10Bibliographically approved
McGrath, A. M., Lu, J.-Y. C., Chang, T.-J. N., Fang, F. & Chuang, D.-C. C. (2016). Proximal versus distal nerve transfer for biceps reinnervation: a comparative study in a rat’s brachial plexus injury model. Plastic and Reconstructive Surgery Global Open, 4(12), Article ID e1130.
Open this publication in new window or tab >>Proximal versus distal nerve transfer for biceps reinnervation: a comparative study in a rat’s brachial plexus injury model
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2016 (English)In: Plastic and Reconstructive Surgery Global Open, ISSN 2169-7574, Vol. 4, no 12, article id e1130Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: The exact role of proximal and distal nerve transfers in reconstruction strategies of brachial plexus injury remains controversial. We compared proximal with distal nerve reconstruction strategies in a rat model of brachial plexus injury.

METHODS: In rats, the C6 spinal nerve with a nerve graft (proximal nerve transfer model, n = 30, group A) and 50% of ulnar nerve (distal nerve transfer model, n = 30, group B) were used as the donor nerves. The targets were the musculocutaneous nerve and the biceps muscle. Outcomes were recorded at 4, 8, 12, and 16 weeks postoperatively. Outcome parameters included grooming test, biceps muscle weight, compound muscle action potentials, tetanic contraction force, and axonal morphology of the donor and target nerves.

RESULTS: The axonal morphology of the 2 donor nerves revealed no significant difference. Time interval analysis in the proximal nerve transfer group showed peak axon counts at 12 weeks and a trend of improvement in all functional and physiologic parameters across all time points with statistically significant differences for grooming test, biceps compound action potentials, tetanic muscle contraction force, and muscle weight at 16 weeks. In contrast, in the distal nerve transfer group, the only statistically significant difference was observed between the 4 and 8 week time points, followed by a plateau from 8 to 16 weeks.

CONCLUSIONS: Outcomes of proximal nerve transfers are ultimately superior to distal nerve transfers in our experimental model. Possible explanations for the superior results include a reduced need for cortical adaptation and higher proportions of motor units in the proximal nerve transfers.

Place, publisher, year, edition, pages
Wolters Kluwer, 2016
National Category
Surgery
Identifiers
urn:nbn:se:umu:diva-135059 (URN)10.1097/GOX.0000000000001130 (DOI)28293499 (PubMedID)
Note

Erratum in Plast Reconstr Surg Glob Open. 2017 Apr 24;5(3):e1314

Available from: 2017-05-17 Created: 2017-05-17 Last updated: 2018-06-09Bibliographically approved
Bain, G. I., McGuire, D. T. & McGrath, A. M. (2015). A Simplified Lateral Hinge Approach to the Proximal Interphalangeal Joint. Techniques in Hand & Upper Extremity Surgery, 19(3), 129-132
Open this publication in new window or tab >>A Simplified Lateral Hinge Approach to the Proximal Interphalangeal Joint
2015 (English)In: Techniques in Hand & Upper Extremity Surgery, ISSN 1089-3393, E-ISSN 1531-6572, Vol. 19, no 3, p. 129-132Article in journal (Refereed) Published
Abstract [en]

Proximal interphalangeal joint replacement is an effective treatment for painful arthritis affecting the joint. However, the complication rate is relatively high, with many of these complications related to soft-tissue imbalance or instability. Volar, dorsal, and lateral approaches have all been described with varying results. We describe a new simplified lateral hinge approach that splits the collateral ligament to provide adequate exposure of the joint. Following insertion of the prosthesis the collateral ligament is simply repaired, side-to-side, which stabilizes the joint. As the central slip, opposite collateral ligament, flexor and extensor tendons have not been violated, early active mobilization without splinting is possible, and the risk of instability, swan-neck, and boutonniere deformity are reduced. The indications, contraindications, surgical technique, and rehabilitation protocol are described.

Keywords
Activities of daily living, distal interphalangeal joint, interphalangeal joint, metacarpophalangeal joint, proximal range of motion
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-120762 (URN)10.1097/BTH.0000000000000094 (DOI)26230632 (PubMedID)
Available from: 2016-05-20 Created: 2016-05-20 Last updated: 2018-06-07Bibliographically approved
Bain, G. I., Polites, N., Higgs, B. G., Heptinstall, R. J. & McGrath, A. (2015). The functional range of motion of the finger joints. Journal of Hand Surgery, European Volume, 40(4), 406-411
Open this publication in new window or tab >>The functional range of motion of the finger joints
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2015 (English)In: Journal of Hand Surgery, European Volume, ISSN 1753-1934, E-ISSN 2043-6289, Vol. 40, no 4, p. 406-411Article in journal (Refereed) Published
Abstract [en]

The purpose of this study was to measure the functional range of motion of the finger joints needed to perform activities of daily living. Using the Sollerman hand grip function test, 20 activities were assessed in ten volunteers. The active and passive range of motion was measured with a computerized electric goniometer. The position of each finger joint was evaluated in the pre-grasp and grasp positions. The functional range of motion was defined as the range required to perform 90% of the activities, utilizing the pre-grasp and grasp measurements. The functional range of motion was 19 degrees-71 degrees, 23 degrees-87 degrees, and 10 degrees-64 degrees at the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints, respectively. This represents 48%, 59%, and 60% of the active motion of these joints, respectively. There was a significant difference in the functional range of motion between the joints of the fingers, with the ulnar digits having greater active and functional range. The functional range of motion is important for directing indications for surgery and rehabilitation, and assessing outcome of treatment.

Place, publisher, year, edition, pages
Sage Publications, 2015
Keywords
Activities of daily living, distal interphalangeal joint, interphalangeal joint, metacarpophalangeal joint, proximal range of motion
National Category
Surgery
Identifiers
urn:nbn:se:umu:diva-103135 (URN)10.1177/1753193414533754 (DOI)000352651500013 ()24859993 (PubMedID)
Available from: 2015-05-27 Created: 2015-05-18 Last updated: 2018-06-07Bibliographically approved
Jonsson, S., Wiberg, R., McGrath, A. M., Novikov, L. N., Wiberg, M., Novikova, L. N. & Kingham, P. J. (2013). Effect of delayed peripheral nerve repair on nerve regeneration, Schwann cell function and target muscle recovery. PLoS ONE, 8(2), Article ID e56484.
Open this publication in new window or tab >>Effect of delayed peripheral nerve repair on nerve regeneration, Schwann cell function and target muscle recovery
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2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 2, article id e56484Article in journal (Refereed) Published
Abstract [en]

Despite advances in surgical techniques for peripheral nerve repair, functional restitution remains incomplete. The timing of surgery is one factor influencing the extent of recovery but it is not yet clearly defined how long a delay may be tolerated before repair becomes futile. In this study, rats underwent sciatic nerve transection before immediate (0) or 1, 3, or 6 months delayed repair with a nerve graft. Regeneration of spinal motoneurons, 13 weeks after nerve repair, was assessed using retrograde labeling. Nerve tissue was also collected from the proximal and distal stumps and from the nerve graft, together with the medial gastrocnemius (MG) muscles. A dramatic decline in the number of regenerating motoneurons and myelinated axons in the distal nerve stump was observed in the 3- and 6-months delayed groups. After 3 months delay, the axonal number in the proximal stump increased 2-3 folds, accompanied by a smaller axonal area. RT-PCR of distal nerve segments revealed a decline in Schwann cells (SC) markers, most notably in the 3 and 6 month delayed repair samples. There was also a progressive increase in fibrosis and proteoglycan scar markers in the distal nerve with increased delayed repair time. The yield of SC isolated from the distal nerve segments progressively fell with increased delay in repair time but cultured SC from all groups proliferated at similar rates. MG muscle at 3- and 6-months delay repair showed a significant decline in weight (61% and 27% compared with contra-lateral side). Muscle fiber atrophy and changes to neuromuscular junctions were observed with increased delayed repair time suggestive of progressively impaired reinnervation. This study demonstrates that one of the main limiting factors for nerve regeneration after delayed repair is the distal stump. The critical time point after which the outcome of regeneration becomes too poor appears to be 3-months.

Place, publisher, year, edition, pages
Public Library of Science, 2013
National Category
Other Basic Medicine
Identifiers
urn:nbn:se:umu:diva-68439 (URN)10.1371/journal.pone.0056484 (DOI)000315157200136 ()23409189 (PubMedID)
Available from: 2013-04-19 Created: 2013-04-19 Last updated: 2018-06-08Bibliographically approved
McGrath, A. (2012). Development of biosynthetic conduits for peripheral nerve repair. (Doctoral dissertation). Umeå: Umeå University
Open this publication in new window or tab >>Development of biosynthetic conduits for peripheral nerve repair
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Peripheral nerve injuries are often associated with significant loss of nervous tissue leading to poor restoration of function following repair of injured nerves. Although the injury gap could be bridged by autologous nerve graft, the limited access to donor material and additional morbidity such as loss of sensation and scarring have prompted a search for biosynthetic nerve transplants.

The present thesis investigates the effects of a synthetic matrix BD™ PuraMatrix™ peptide (BD)hydrogel, alginate/fibronectin gel and fibrin glue combined with cultured rat Schwann cells or human bone marrow derived mesenchymal stem cells (MSC) on neuronal regeneration and muscle recovery after peripheral nerve injury in adult rats.

In a sciatic nerve injury model, after 3 weeks postoperatively, the regenerating axons grew significantly longer distances within the conduits filled with BD hydrogel if compared with the alginate/fibronectin gel. The addition of rat Schwann cells to the BD hydrogel drastically increased regeneration distance with axons crossing the injury gap and entering into the distal nerve stump. However, at 16 weeks the number of regenerating spinal motoneurons was decreased to 49% and 31% in the BD hydrogel and alginate/fibronectin groups respectively. The recovery of the gastrocnemius muscle was also inferior in both experimental groups if compared with the nerve graft. The addition of the cultured Schwann cells did not further improve the regeneration of motoneurons and muscle recovery.

The growth-promoting effects of the tubular conduits prepared from fibrin glue were also studied following repair of short and long peripheral nerve gaps. Retrograde neuronal labeling demonstrated that fibrin glue conduit promoted regeneration of 60% of injured sensory neurons and 52% of motoneurons when compared with the autologous nerve graft. The total number of myelinated axons in the distal nerve stump in the fibrin conduit group reached 86% of the nerve graft control and the weight of gastrocnemius and soleus muscles recovered to 82% and 89%, respectively. When a fibrin conduit was used to bridge a 20 mm sciatic nerve gap, the weight of gastrocnemius muscle reached only 43% of the nerve graft control. The morphology of the muscle showed a more atrophic appearance and the mean area and diameter of fast type fibres were significantly worse than those of the corresponding 10 mm gap group. In contrast, both gap sizes treated with nerve graft showed similar fiber size.

The combination of fibrin conduit with human MSC and daily injections of cyclosporine A enhanced the distance of regeneration by four fold and the area occupied by regenerating axons by three fold at 3 weeks after nerve injury and repair. In addition, the treatment also significantly reduced the ED1 macrophage reaction. At 12 weeks after nerve injury the treatment with cyclosporine A alone or cyclosporine A combined with hMSC induced recovery of the muscle weight and the size of fast type fibres to the control levels of the nerve graft group.

In summary, these results show that a BD hydrogel supplemented with rat Schwann cells can support the initial phase of neuronal regeneration across the conduit. The data also demonstrate an advantage of tubular fibrin conduits combined with human MSC to promote axonal regeneration and muscle recovery after peripheral nerve injury.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2012. p. 55
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1518
Keywords
Biosynthetic conduit, Mesenchymal stem cells, Nerve graft, Nerve tissue engineering, Peripheral nerve injury, Schwann cells
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-60915 (URN)978-91-7459-476-8 (ISBN)
Public defence
2012-11-27, BiA201, Biologihuset, Umeå Universitet, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2012-11-06 Created: 2012-11-02 Last updated: 2018-06-08Bibliographically approved
McGrath, A. M., Brohlin, M., Kingham, P. J., Novikov, L. N., Wiberg, M. & Novikova, L. N. (2012). Fibrin conduit supplemented with human mesenchymal stem cells and immunosuppressive treatment enhances regeneration after peripheral nerve injury. Neuroscience Letters, 516(2), 171-176
Open this publication in new window or tab >>Fibrin conduit supplemented with human mesenchymal stem cells and immunosuppressive treatment enhances regeneration after peripheral nerve injury
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2012 (English)In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 516, no 2, p. 171-176Article in journal (Refereed) Published
Abstract [en]

To address the need for the development of bioengineered replacement of a nerve graft, a novel two component fibrin glue conduit was combined with human mesenchymal stem cells (MSC) and immunosupressive treatment with cyclosporine A. The effects of MSC on axonal regeneration in the conduit and reaction of activated macrophages were investigated using sciatic nerve injury model. A 10mm gap in the sciatic nerve of a rat was created and repaired either with fibrin glue conduit containing diluted fibrin matrix or fibrin glue conduit containing fibrin matrix with MSC at concentration of 80×10(6)cells/ml. Cells were labeled with PKH26 prior to transplantation. The animals received daily injections of cyclosporine A. After 3 weeks the distance of regeneration and area occupied by regenerating axons and ED1 positives macrophages was measured. MSC survived in the conduit and enhanced axonal regeneration only when transplantation was combined with cyclosporine A treatment. Moreover, addition of cyclosporine A to the conduits with transplanted MSC significantly reduced the ED1 macrophage reaction.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
Peripheral nerve injury, Nerve conduit, Bone marrow, Mesenchymal stem cells, Regeneration
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-53882 (URN)10.1016/j.neulet.2012.03.041 (DOI)000304520300002 ()22465323 (PubMedID)
Available from: 2012-04-04 Created: 2012-04-04 Last updated: 2018-06-08Bibliographically approved
Pettersson, J., McGrath, A., Kalbermatten, D., Novikova, L., Wiberg, M., Kingham, P. & Novikov, L. (2011). Muscle recovery after repair of short and long peripheral nerve gaps using fibrin conduits. Neuroscience Letters, 500(1), 41-46
Open this publication in new window or tab >>Muscle recovery after repair of short and long peripheral nerve gaps using fibrin conduits
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2011 (English)In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 500, no 1, p. 41-46Article in journal (Refereed) Published
Abstract [en]

Peripheral nerve injuries with loss of nervous tissue are a significant clinical problem and are currently treated using autologous nerve transplants. To avoid the need for donor nerve, which results in additional morbidity such as loss of sensation and scarring, alternative bridging methods have been sought. Recently we showed that an artificial nerve conduit moulded from fibrin glue is biocompatible to nerve regeneration. In this present study, we have used the fibrin conduit or a nerve graft to bridge either a 10 mm or 20 mm sciatic nerve gap and analyzed the muscle recovery in adult rats after 16 weeks. The gastrocnemius muscle weights of the operated side were similar for both gap sizes when treated with nerve graft. In contrast, muscle weight was 48.32 ± 4.96% of the contra-lateral side for the 10 mm gap repaired with fibrin conduit but only 25.20 ± 2.50% for the 20 mm gap repaired with fibrin conduit. The morphology of the muscles in the nerve graft groups showed an intact, ordered structure, with the muscle fibers grouped in fascicles whereas the 20 mm nerve gap fibrin group had a more chaotic appearance. The mean area and diameter of fast type fibers in the 20 mm gap repaired with fibrin conduits were significantly (P < 0.01) worse than those of the corresponding 10 mm gap group. In contrast, both gap sizes treated with nervegraft showed similar fiber size. Furthermore, the 10 mm gaps repaired with either nerve graft or fibrin conduit showed similar muscle fiber size. These results indicate that the fibrin conduit can effectively treat short nerve gaps but further modification such as the inclusion of regenerative cells may be required to attain the outcomes of nerve graft for long gaps.

Place, publisher, year, edition, pages
Amsterdam: , 2011
Keywords
autograft; biosynthetic conduit; muscle fiber; nerve injury; regeneration
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-42426 (URN)10.1016/j.neulet.2011.06.002 (DOI)
Available from: 2011-04-07 Created: 2011-04-07 Last updated: 2018-06-08Bibliographically approved
McGrath, A. M., Novikova, L. N., Novikov, L. N. & Wiberg, M. (2010). BD™ PuraMatrix™ peptide hydrogel seeded with Schwann cells for peripheral nerve regeneration. Brain Research Bulletin, 83(5), 207-213
Open this publication in new window or tab >>BD™ PuraMatrix™ peptide hydrogel seeded with Schwann cells for peripheral nerve regeneration
2010 (English)In: Brain Research Bulletin, ISSN 0361-9230, E-ISSN 1873-2747, Vol. 83, no 5, p. 207-213Article in journal (Refereed) Published
Abstract [en]

This study investigated the effects of a membrane conduit filled with a synthetic matrix BD™ PuraMatrix™ peptide (BD) hydrogel and cultured Schwann cells on regeneration after peripheral nerve injury in adult rats. After sciatic axotomy, a 10mm gap between the nerve stumps was bridged using ultrafiltration membrane conduits filled with BD hydrogel or BD hydrogel containing Schwann cells. In control experiments, the nerve defect was bridged using either membrane conduits with alginate/fibronectin hydrogel or autologous nerve graft. Axonal regeneration within the conduit was assessed at 3 weeks and regeneration of spinal motoneurons and recovery of muscle weight evaluated at 16 weeks postoperatively. Schwann cells survived in the BD hydrogel both in culture and after transplantation into the nerve defect. Regenerating axons grew significantly longer distances within the conduits filled with BD hydrogel when compared with the alginate/fibronectin hydrogel and alginate/fibronectin with Schwann cells. Addition of Schwann cells to the BD hydrogel considerably increased regeneration distance with axons crossing the injury gap and entering into the distal nerve stump. The conduits with BD hydrogel showed a linear alignment of nerve fibers and Schwann cells. The number of regenerating motoneurons and recovery of the weight of the gastrocnemius muscle was inferior in BD hydrogel and alginate/fibronectin groups compared with nerve grafting. Addition of Schwann cells did not improve regeneration of motoneurons or muscle recovery. The present results suggest that BD hydrogel with Schwann cells could be used within biosynthetic conduits to increase the rate of axonal regeneration across a nerve defect.

Keywords
Peripheral nerve injury, Tissue engineering, Regeneration, Biomaterial, Retrograde labeling, Nerve repair
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-41350 (URN)10.1016/j.brainresbull.2010.07.001 (DOI)000284514300005 ()20633614 (PubMedID)
Available from: 2011-03-23 Created: 2011-03-23 Last updated: 2018-06-08Bibliographically approved
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