| 1. |
- Bertheim, Ulf, et al.
(författare)
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The distribution of hyaluronan in human skin and mature, hypertrophic and keloid scars
- 1994
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 0007-1226 .- 1465-3087. ; 47:7, s. 483-489
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Tidskriftsartikel (refereegranskat)abstract
- A hyaluronan-binding protein (HABP) was used to locate the distribution of HA in normal skin and in various types of scar tissue: mature scar tissue, hypertrophic scar tissue and keloids. The study was intended to establish whether or not a deviant HA distribution could explain the different clinical features of these scar tissues. The distribution of HA was found to differ between the various scar tissues. In normal skin an intense HA-staining was observed in the papillary dermis. In mature scar tissue the distribution of HA resembled that of normal uninjured tissue, but the layer of HA was thinner. In hypertrophic scar tissue, HA occurred mainly as a narrow strip in the papillary dermis. Keloid tissue showed the least HA-staining of the papillary layer and resembled that of the bulging reticular dermis. In contrast, the thickened granular and spinous layer of the keloid epidermis exhibited an intense HA-staining. We suggest that the altered distribution and amount of HA in these different scar tissues may contribute to their different clinical characteristics. This histochemical technique for the demonstration of HA in scar tissue could be of use in clinical work to decide on therapeutic strategies.
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| 2. |
- Hart, Andrew McKay, et al.
(författare)
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Exogenous leukaemia inhibitory factor enhances nerve regeneration after late secondary repair using a bioartificial nerve conduit
- 2003
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Ingår i: British Journal of Plastic Surgery. - : Elsevier. - 0007-1226 .- 1465-3087. ; 56:5, s. 444-450
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Tidskriftsartikel (refereegranskat)abstract
- The clinical outcome of peripheral nerve injuries remains disappointing, even in the ideal situation of a primary repair performed with optimal microsurgical techniques. Primary repair is appropriate for only about 85% of injuries, and outcome is worse following secondarynerverepair, partly owing to the reduced regenerative potential of chronically axotomised neurons. Leukaemiainhibitoryfactor (LIF) is a gp-130 neurocytokine that is thought to act as an ‘injury factor’, triggering the early-injury phenotype within neurons and potentially boosting their regenerative potential aftersecondarynerverepair. At 2–4 months after sciatic nerve axotomy in the rat, 1 cm gaps were repaired using either nerve isografts or poly-3-hydroxybutyrate conduits containing a calcium alginate and fibronectin hydrogel.Regeneration was determined by quantitative immunohistochemistry 6 weeks afterrepair, and the effect of incorporating recombinant LIF (100 ng/ml) into the conduits was assessed. LIF increased the regeneration distance in repairs performed after both 2 months (69%, P=0.019) and 4 months (123%, P=0.021), and was statistically comparable to nerve graft. The total area of axonal immunostaining increased by 21% (P>0.05) and 63% (P>0.05), respectively. Percentage immunostaining area was not increased in the 2 months group, but increased by 93% in the repairs performed 4 months after axotomy. Exogenous LIF, therefore, has a potential role in promoting peripheral nerveregenerationaftersecondaryrepair, and can be effectively delivered within poly-3-hydroxybutyrate bioartificialconduits used for nerverepair.
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| 3. |
- Bertheim, Ulf, et al.
(författare)
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The stromal reaction in basal cell carcinomas : A prerequisite for tumour progression and treatment strategy
- 2004
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 0007-1226 .- 1465-3087. ; 57:5, s. 429-439
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Tidskriftsartikel (refereegranskat)abstract
- Specimens of basal cell carcinomas collected from 28 patients were classified into three groups: superficial, nodular, and infiltrative, according to their microarchitecture. The specimens were then subjected to histological characterization by means of a biotinylated hyaluronan-binding probe (HABP). By using Ki-67 and PCNA the proliferative activity of the BCC tumours was evaluated with immunohistological techniques. In superficial BCC the tumour islands displayed moderate hyaluronan (HA) staining. Feeble proliferation, denoted by modest mitotic activity and weak Ki-67 and PCNA immunoreactivity, occurred within the tumour islands. The surrounding connective tissue resembled normal skin, and no differentiated tumour stroma was observed. In nodular BCC, the HA staining of the tumour strands was weak to moderate, denoting increased proliferative activity. The differentiated surrounding tumour stroma stained strongly for HA. Tumour islands of infiltrative BCC stained weakly to moderately to HA and evidenced intense proliferation. The intensely HA-stained tumour stroma ended abruptly and the adjacent areas were almost devoid of HA. This study showed that the proliferative activity of BCC cells is associated with increased expression of HA in the tumour stroma. Modification of tumour-associated connective tissue indicates a close relationship between the tumour cells and the adjacent matrix. In particular, in infiltrative BCC, such alterations include degeneration and possible modification and remodelling of the surrounding extracellular matrix. These processes involving areas of probable importance for tumour progression, should be considered when deciding the extent of intended surgical resection.
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| 4. |
- Lutz, Barbara S., et al.
(författare)
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Selection of donor nerves : an important factor in end-to-side neurorrhaphy
- 2000
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 0007-1226 .- 1465-3087. ; 53:2, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the effects of end-to-side neurorrhaphy on peripheral nerve regeneration usingthe median nerve as recipient nerve and either the antagonistic radial nerve or the agonistic ulnar nerve as donor nerves in rat upper limbs. A perineural window was created in all cases. Motor recovery up to 16 weeks postoperation was tested with the grasping test. No recovery of motor function was evident after end-to-side neurorrhaphy of the median nerve to the antagonistic radial nerve, whereas six of eight rats with end-to-side neurorrhaphy to the agonistic ulnar nerve achieved 367 g±47 g grasping power as compared to 526 g±6 g in end-to-end coapted control animals. No significant difference in flexor digitorum sublimus-motor nerve conduction velocity was found among all three groups. Radial nerve stimulation produced simultaneous contraction of both extensor and flexor muscles of the lower arm that disabled any coordinated movement of the paw. Histology (toluidine blue, acetylcholinesterase-stain) showed multiple regenerated (motor)-axons distal to the coaptation site in the median nerve. Reinnervation of the median nerve solely by the respective donor nerve was demonstrated by a retrograde double labelling technique. These results show that averaged 70% muscle power as compared to end-to-end neurorrhaphy with well coordinated muscle function can be achieved by axonal sprouting through end-to-side neurorrhaphy if an agonistic nerve is used as donor nerve. However, satisfying results are unpredictable. Antagonistic nerves show the ability to induce axonal regeneration, but no useful function can be expected.
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| 5. |
- Mzezewa, S, et al.
(författare)
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HIV infection reduces skin graft survival in burn injuries: a prospective study
- 2003
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 1465-3087 .- 0007-1226. ; 56:8, s. 740-745
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Tidskriftsartikel (refereegranskat)abstract
- Impaired survival of skin grafts has been noted in human immunodeficiency virus (HIV) infected patients, but the reason is not known. Alterations in inflammatory response, which might be recorded as an imbalance in cytokine production, have been implicated. The aim of this study was to determine the impact of HIV infection in patients with burn injuries by comparison of split skin graft survival, T lymphocyte count and cytokine levels in HIV-infected and non HIV-infected patients in relation to healthy and HIV-infected nonburnt volunteers. Fifty-four patients with deep dermal burns were included. Fifteen patients' were HIV-infected. Thirteen healthy and 15 HIV-infected, volunteers were recruited as controls. The burnt surface area was traced on a transparent plastic sheet and converted to area. Graft survival on day of discharge/regraft for non HIV-infected patients was 69%, and in HIV-infected 22%, (p < 0.05). The median length of hospital stay for early excision among non HIV-infected patients was 21 (12-53) days and for HIV-infected, 41 days (p < 0.05). Serum protein levels in HIV-infected patients were elevated compared to non HIV-infected patients (p < 0.05). CD4+ Lymphocytes were depressed in HIV-infected volunteers and HIV-infected burn patients compared to healthy volunteers (p < 0.05). CD8+ lymphocytes were elevated in HIV-infected volunteers compared to non HIV-infected burn patients. Pro-inflammatory cytokine levels of Interleukin-2 (IL-2), Interteukin-6 (IL-6), Interferon-gama (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) were depressed in HIV-infected volunteers compared to healthy volunteers and non HIV-infected burn patients. The pro-inflammatory cytokine IFN-gamma did not increase after burn injury in HIV-infected burns patients as did IL-2, IL-6 and TNF-alpha (p < 0.05). Antiinflammatory cytokine levels of IL-4 were elevated in HIV-infected volunteers compared to healthy volunteers and burn patients (p < 0.05). Conclusion: Graft survival after split skin grafting of burn wounds in HIV-infected patients is impaired and hospital stay is prolonged. HIV infection. result in immune dysregulation, which might be related to impaired skin graft survival. (C) 2003 The British Association of Plastic Surgeons. Published by Elsevier Ltd. ALL rights reserved.
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| 6. |
- Wadström, J, et al.
(författare)
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Modulatory effects of topically administered lidocaine and pentobarbital on traumatic vasospasm in the rabbit ear artery.
- 1991
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Ingår i: British Journal of Plastic Surgery. - 0007-1226 .- 1465-3087. ; 44:5, s. 341-7
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Tidskriftsartikel (refereegranskat)abstract
- The effect of topical administration of 2 or 20% lidocaine and of 3% pentobarbital on traumatic vasospasm was studied in the central ear artery of the rabbit. The inner diameter of the artery was measured by in vivo microscopy. Vasospasm was induced by a standardised pinch of a 3.2 mm long arterial segment and lasted for 10-20 min. The drugs were given locally at maximal spasm, 1 min after spasm induction. All treatments caused prompt resolution of the vasospasm. This was followed by a plateau phase when the vessel diameter was reduced to about 60% of the initial pre-spasm value as a result of drug-induced vasoconstriction. The vasoconstriction lasted between 40 min and 24 h, depending on the treatment. Twenty per cent lidocaine was most effective, but caused thrombosis in microvessels surrounding the central ear artery. It is concluded that topical lidocaine and pentobarbital are both effective in resolving traumatic vasospasm but should only be used after careful consideration, since they also cause a general decrease in vascular diameter.
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| 7. |
- Wilson, Andrew D H, et al.
(författare)
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Primary sensory neuronal rescue with systemic acetyl-L-carnitine following peripheral axotomy. A dose-response analysis
- 2003
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 0007-1226 .- 1465-3087. ; 56:8, s. 732-739
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Tidskriftsartikel (refereegranskat)abstract
- The loss of a large proportion of primary sensory neurons after peripheral nerve axotomy is well documented. As a consequence of this loss, the innervation density attained on completion of regeneration will never be normal, regardless of how well the individual surviving neurons regenerate. Acetyl-L-carnitine (ALCAR), an endogenous peptide in man, has been demonstrated to protect sensory neurons, thereby avoiding loss after peripheral nerve injury. In this study we examined the dose-response effect of ALCAR on the primary sensory neurons in the rat dorsal root ganglia (DRG) 2 weeks after sciatic nerve axotomy. Six groups of adult rats (n=5) underwent unilateral sciatic nerve axotomy, without repair, followed by 2 weeks systemic treatment with one of five doses of ALCAR (range 0.5-50 mg/kg/day), or normal saline. L4 and L5 dorsal root ganglia were then harvested bilaterally and sensory neuronal cell counts obtained using the optical disector technique. ALCAR eliminated neuronal loss at higher doses (50 and 10 mg/kg/day), while lower doses did result in loss (12% at 5 mg/kg/day, p<0.05; 19% at 1 mg/kg/day, p<0.001; 23% at 0.5 mg/kg/day, p<0.001) compared to contralateral control ganglia. Treatment with normal saline resulted in a 25% (p<0.001) loss, demonstrating no protective effect in accordance with previous studies.ALCAR preserves the sensory neuronal cell population after axotomy in a dose-responsive manner and as such, has potential for improving the clinical outcome following peripheral nerve trauma when doses in excess of 10 mg/kg/day are employed.
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| 8. |
- Zhang, Cheng-Gang, et al.
(författare)
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Motorneuron protection by N-acetyl-cysteine after ventral root avulsion and ventral rhizotomy
- 2005
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Ingår i: British Journal of Plastic Surgery. - : Elsevier BV. - 0007-1226 .- 1465-3087. ; 58:6, s. 765-773
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Tidskriftsartikel (refereegranskat)abstract
- Motor recovery after proximal nerve injury remains extremely poor, despite advances in surgical care. Several neurobiological hurdles are implicated, the most fundamental being extensive cell death within the motorneuron pool. N-acetyl-cysteine almost completely protects sensory neurons after peripheral axotomy, hence its efficacy in protecting motorneurons after ventral root avulsion/rhizotomy was investigated. In adult rats, the motorneurons supplying medial gastrocnemius were unilaterally pre-labelled with retrograde tracer (true-blue/fluoro-gold), prior to L5 and 6 ventral root avulsion, or rhizotomy. Groups received either intraperitoneal N-acetyl-cysteine (ip, 150 or 750 mg/kg/day), immediate or delayed intrathecal N-acetyl-cysteine treatment (it, 2.4 mg/day), or saline; untreated animals served as controls. Either 4 (avulsion model) or 8 (rhizotomy model) weeks later, the pre-labelled motorneurons' mean soma area and survival were quantified. Untreated controls possessed markedly fewer motorneurons than normal due to cell death (avulsion 53% death; rhizotomy 26% death, P<0.01 vs. normal). Motorneurons were significantly protected by N-acetyl-cysteine after avulsion (ip 150 mg/kg/day 40% death; it 30% death, P<0.01 vs. no treatment), but particularly after rhizotomy (ip 150 mg/kg/day 17% death; ip 750 mg/kg/day 7% death; it 5% death, P<0.05 vs. no treatment). Delaying intrathecal treatment for 1 week after avulsion did not impair neuroprotection, but a 2-week delay was deleterious (42% death, P<0.05 vs. 1-week delay, 32% death). Treatment prevented the decrease in soma area usually found after both types of injury. N-acetyl-cysteine has considerable clinical potential for adjuvant treatment of major proximal nerve injuries, including brachial plexus injury, in order that motorneurons may survive until surgical repair facilitates regeneration.
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| 10. |
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