| 11. |
- Dahlin, Lars, et al.
(author)
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Schwann cells, acutely dissociated from a predegenerated nerve trunk, can be applied into a matrix used to bridge nerve defects in rats
- 2007
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In: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 100, s. 57-60
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Journal article (peer-reviewed)abstract
- BACKGROUND: The gold standard to reconstruct a nerve defect is a conventional autologous nerve graft. There may be a lack of such grafts in severe nerve injuries. Alternatives to autologous nerve grafts are needed. METHODS: We have developed a technique where mainly Schwann cells are acutely dissociated from the ends of the severed nerve trunk after nerve injury. The technique does not require long-term cell culture procedures. The obtained cells, which can be dissociated within a few hours, are applied to a silicone tube or a tendon autograft used to bridge a nerve defect. FINDINGS: Dissociated cells from the ends of the severed nerve ends consist of more than 85% of Schwann cells. The remaining cells are ED1 stained macrophages. The cells survive transfer to a silicone tube or a tendon autograft which bridge the nerve defect. Axons do grow through such a graft filled with dissociated cells. CONCLUSION: Our novel model to obtain mainly Schwann cells by dissociation of the cells from the severed nerve ends after injury and add them to a matrix, thereby creating an artificial nerve graft, may be a new technique with potential clinical application in nerve reconstruction.
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| 12. |
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| 13. |
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| 14. |
- Ekström, Per, et al.
(author)
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A calmodulin inhibitor with high specificity, compound 48/80, inhibits axonal transport in frog nerves without disruption of axonal microtubules.
- 1991
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In: Acta physiologica Scandinavica. - 0001-6772. ; 142:2, s. 181-9
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Journal article (peer-reviewed)abstract
- The calmodulin inhibitor compound 48/80 has previously been shown to arrest axonal transport in vitro in the regenerating frog sciatic nerve. The inhibition was limited to the outgrowth region of nerves, which had been allowed to regenerate in vivo for 6 days after a crush lesion, before they were incubated with or without drugs in vitro overnight. The effects of compound 48/80 on the regenerating nerve were further investigated. A concentration of compound 48/80 (50 micrograms ml-1), which effectively inhibits axonal transport, did not cause observable changes of the microtubules of regenerating axons in the outgrowth region as judged by electron microscopy. Furthermore, it was shown that also a lower concentration (25 micrograms ml-1) inhibited axonal transport. As a measure of possible metabolic effects, the level of ATP was assessed in the regenerating nerve after exposure to compound 48/80. Compound 48/80 at 25 micrograms ml-1 did not change the level of ATP in the nerve. The assembly of bovine brain microtubule proteins in a cell-free system was unaffected by 25 micrograms ml-1 of compound 48/80 and slightly inhibited by 50 micrograms ml-1. At higher concentrations (greater than 100 micrograms ml-1) assembly of microtubules appeared stimulated, and microtubule spirals as well as closely aligned microtubules could be seen. These effects appeared to be unrelated to the transport effects. The present results indicate that compound 48/80 arrests axonal transport via mechanisms other than destruction of axonal microtubules or interference with the energy metabolism. It is possible that these mechanisms involve inhibition of calmodulin-regulated events essential to the transport.
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| 15. |
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| 16. |
- Jongsma, Helen, et al.
(author)
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Alteration of PACAP distribution and PACAP receptor binding in the rat sensory nervous system following sciatic nerve transection
- 2000
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In: Brain Research. - 0006-8993. ; 853, s. 96-186
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Journal article (peer-reviewed)abstract
- Pituitary adenylate cyclase activating polypeptide (PACAP) is a widely expressed neuropeptide that has been involved in nerve regeneration, neurone survival and nociception. In this study, the distribution of PACAP and PACAP-receptors were investigated in rat dorsal root ganglia (DRG), spinal cord and medulla oblongata at 3, 7 or 14 days following unilateral sciatic nerve transection using immunohistochemistry, 125I-PACAP-binding and in situ hybridisation. In control (contralateral side) DRG, about 30% of the nerve cell bodies (92% being small) were PACAP-immunoreactive (PACAP-IR). In the spinal cord, PACAP-IR fibres were seen in laminae I-II but not in the gracile nuclei. Following sciatic nerve transection, PACAP-IR fibres appeared in the gracile nuclei and occasionally in the deeper laminae of the dorsal horn consistent with the relative increase in larger PACAP-IR DRG neurones. However, the relative number of small PACAR-IR neurones was significantly lower on the transected side as compared to the control side suggesting a dual reaction for PACAP in the DRG following nerve injury. 125I-PACAP-binding was found in laminae I-II, around the central canal and in the gracile nuclei but not in the DRG. At 14 days after transection, 125I-PACAP-binding density was significantly reduced in the ipsilateral dorsal horn. PACAP-receptor (PAC(1)) mRNA was detected in neurones of the dorsal and ventral horn and in the gracile nuclei with no overt changes observed after transection. Very few DRG nerve cell bodies contained PAC(1) mRNA. The findings are consistent with a role for PACAP both in nociception and regeneration.
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| 17. |
- Kerns, JM, et al.
(author)
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A comparison of peripheral nerve regeneration in acellular muscle and nerve autografts
- 2003
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In: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - : Informa UK Limited. - 1651-2073 .- 0284-4311. ; 37:4, s. 193-200
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Journal article (peer-reviewed)abstract
- Regeneration of the rat sciatic nerve through acellular muscle and nerve autografts was evaluated 6-28 days postoperatively by the sensory pinch test, immunocytochemical staining for neurofilaments, and light and electron microscopy. Data points generated by the pinch test were plotted against postoperative time periods and by the use of regression analysis the initial delay period for muscle grafts was determined to 10.3 days. This value was similar to that previously published for acellular nerve grafts (9.5 days), but significantly longer than that for fresh nerve grafts (3.6 days). The calculated regeneration rate (slope of the regression line) for muscle grafts (1.8 mm/day) did not differ significantly ( p >0.05) from that calculated for acellular nerve grafts (2.1 mm/day) or for fresh nerve grafts (1.5 mm/day). The front of regenerating axons shown by axonal neurofilament staining confirmed the pinch test results. Both types of acellular grafts were repopulated with host non-neuronal cells and the muscle graft contained occasional ectopic muscle fibres. Remnants of graft basal laminae were evident at the ultrastructural level. These results indicate the suitability of either acellular muscle or nerve grafts for nerve repair despite their prolonged initial delay periods compared with conventional fresh nerve grafts.
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| 18. |
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| 19. |
- Kjellstrand, P., et al.
(author)
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Perchloroethylene: Effects on body and organ weights and plasma buturylcholinesterase activity in mice
- 1984
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In: Acta Pharmacologica et Toxicologica. - : Wiley. - 0001-6683. ; 54:5, s. 414-424
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Journal article (peer-reviewed)abstract
- The effects of continuous and intermittent inhalation of perchloroethylene (PCE) on plasma butyrylcholinesterase (BuChE) activity, organ weights, liver morphology and motor activity in mice (strain NMRI) were tested. PCE exposure increased plasma BuChE activity in a time- and concentration dependent manner in both sexes. The increase was statistically significant at 37 p.p.m. in animals continuously exposed for 30 days. BuChE increased approximately 1.5 times in females and 2.5 times in males after 120 days exposure to 150 p.p.m. After rehabilitation of animals exposed for 30 days to 150 p.p.m., BuChE levels returned to normal. Liver weight also increased in a time and concentration dependent manner. Both sexes exhibited significant liver enlargement at 9 p.p.m. The increase was about 2.3 in females and 1.9 in males after continuous exposure to 150 p.p.m. for 120 days. After rehabilitation (120 days) of animals exposed to 150 p.p.m. for 30 days, a 10% increase still remained. A decrease in body weight gain was seen in both sexes after exposure to concentrations above 75 p.p.m. Female kidney weight was slightly increased. No clear effect on spleen weight could be detected. When the same time-weighted average concentration was used, intermittent exposure for 30 days had similar effects on liver weight and BuChE activity as continuous exposure, even when exposures lasted for only one hour per day. Liver cell morphology was changed after PCE exposure. The alterations could be observed already at 9 p.p.m. but disappeared after rehabilitation.
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| 20. |
- Kjellstrand, Per, et al.
(author)
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Trichloroethylene: Effects on body and organ weights in mice, rats and gerbils
- 1981
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In: Toxicology. - 0300-483X. ; 21:2, s. 105-115
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Journal article (peer-reviewed)abstract
- The influence of continuous inhalation of 150 ppm trichloroethylene (TCE) on body, liver, spleen, and kidney weights in rats, mice, and mongolian gerbils was tested. An age dependent decrease in body weight gain was observed in female rats exposed to TCE. All 3 spcies showed liver enlargement caused by the exposure. The effect was much more pronounced in mice, in which the increase was 60–80%, than in rats and gerbils where it was only 20–30%. After the end of the TCE-exposure the liver weights of the mice decreased rapidly. After 5 days of rehabilitation to the weight was only 10–20% higher than that of the controls. This difference persisted for at least 25 days. The spleen weight appeared unaffected or somewhat smaller in TCE-exposed animals of all species. An increased kidney weight (15%) was observed in TCE-exposed gerbils. This effect was less pronounced in mice and rats. Effects on the liver have earlier been seen only after exposure to concentrations much higher than that used in the present study. This difference is results in proposed to be due to the different schedules used for the exposure.
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