The posterior interosseous nerve as a donor source for nerve grafting: a concept revisited.
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Dissection↗
Biomedical subjects
H O Rennekampff
Publications and source records attributed to H O Rennekampff.
Skin assessment of burn wounds covered with a collagen based dermal substitute in a 2 year-follow-up.
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Adult↗
[Evaluating scar development with objective computer-assisted viscoelastic measurement].
In a prospective study we compared the subjective scar assessment by the Vancouver Scar Scale with an objective viscoelastic measurement. Donor sites from the thigh primarily dressed with vaseline gauze (F), biobrane or occlusive dressing(O) were evaluated 0.5 years postoperatively by VSS and with the Cutometer (Courage and Khazaka). VSS of donor sites was 2.74 +/- 0.91 (F), 4.25 +/- 0.77 (B) and 2.57 +/- 0.72(O) (mean +/- sem). All ratings were significant compared to normal mirror-sided skin. Viscoelastic measurements by the Cutometer were near normal compared to uninjured skin. No correlation was found between subscale VSS pliabilty rating and Cutometer readings.
Bandages↗
Bioactive interleukin-8 is expressed in wounds and enhances wound healing.
BACKGROUND: Wound healing is a sequential biological process that involves the integration of chemotaxis of neutrophils, mitosis and migration of keratinocytes, and remodeling of the scar, all of which are regulated by specific soluble mediators. To modulate wound healing specific mediators have to be identified and functionally characterized. Therefore we addressed this study on the polymorphonuclear leukocyte (PMN) attractant interleukin-8 (IL-8) and its function in epidermal wound healing. MATERIALS AND METHODS: Peptide purification, bioassays for PMN chemotaxis, and sequential IL-8 measurements were performed on human wound fluid from burn blisters and skin graft donor sites. Histology for IL-8 immunoreactivity was included. In vitro human keratinocytes were assayed for proliferation, migration, and integrin expression after IL-8 treatment. Wounding experiments with topical IL-8 were performed in a chimeric mouse model. RESULTS: IL-8 was found to be the major bioactive chemoattractant for PMNs in human blister and skin graft donor site wound fluids (mean levels ranging from 173 ng/ml Postoperative Day (POD) 1 to 2130 ng/ml (POD 5)). Released intracellular epidermal IL-8 immunoreactivity at the wound edge was considered as an immediate source of IL-8 while NH(2)-terminal analysis revealed the 77-amino-acid residue form as a second source of IL-8 possibly PMN derived. In vitro experiments on the effect of recombinant human (rh) IL-8 on keratinocyte proliferation revealed a rise in cell number (4.8-fold, ED(50) = 0.6 ng/ml), which was accompanied by an increase in cells in S phase and overexpression of the integrin subunit alpha6. In vivo topically applied IL-8 (1 microg/ml) on human skin grafts in a chimeric mouse model enhanced reepithelialization in IL-8 treated animals over controls due to elevated numbers of mitotic keratinocytes. Wound contraction was significantly diminished by topical IL-8. CONCLUSIONS: These results indicate the sequential function of endogenous IL-8 in all phases of human wound healing. Topical IL-8 may be useful in impaired wound healing.
Animals↗
Role of melanoma growth stimulatory activity (MGSA/gro) on keratinocyte function in wound healing.
Melanoma growth stimulatory activity/gro alpha (MGSA), a member of the alpha-chemokine family, is produced by a variety of dermal and epidermal cells and can act in a paracrine and autocrine fashion. However, little is known about the importance of MGSA in wound healing. In this study, we quantified the levels of MGSA protein in burn blister and donor site wound fluids. We studied the effects of MGSA on proliferation and migration of primary human keratinocytes and modulation of their integrin expression. Blister fluids contained 0.79 ng/ml (range 0.018 to 4.86 ng/ml) MGSA. Substantial increasing amounts of MGSA were found in donor site fluids from day 1 through day 5 with mean levels ranging from 1.77 to 103 ng/ml at postoperative day 5, which correlated with increasing amounts of tumor necrosis factor alpha (r = 0.86), a known stimulus for MGSA production. In vitro proliferation experiments revealed a maximum stimulation (2.6-fold) with 10 ng/ ml MGSA for 7 days over unstimulated keratinocyte controls; the ED50 was 0.2 ng/ml. DNA content analysis revealed an increase in S phase with 10 ng/ml MGSA stimulation. In cultured keratinocytes, MGSA enhanced the mean fluorescence intensity for alpha 6, while no significant change was seen for beta 1, alpha 2 and alpha 5. We also studied the effect of topically applied MGSA (50 ng/cm2) on the healing of meshed split-thickness human skin grafts on athymic mice. In these wounds, MGSA stimulated the rate of epithelialization (P < 0.05) at day 7, and an increased proportion of mitotic keratinocytes was observed. Wound contraction was significantly (P < 0.05) reduced on days 7 and 14 in the MGSA-treated group. These results suggest that MGSA participates in wound healing by stimulating keratinocyte proliferation.
Animals↗
Current concepts in the development of cultured skin replacements.
Current tissue-culture techniques permit the rapid expansion of keratinocyte populations, such that an area of cultured epithelium equivalent to that of the surface of an adult can be obtained from an initial small skin biopsy. Unfortunately, technical obstacles have delayed the widespread clinical use of multilayered sheets of epithelium. These factors include difficulties in preparing and transferring fragile cultured epithelial sheets, as well as frequent unsatisfactory "take" of cultured grafts on the wound bed. As greater understanding of the complex interactions of cells and matrix evolves, so have new techniques in the field of cultured keratinocytes for grafting. We have utilized an animal model that allows us to examine some of these new methods and the factors which influence graft take. It has become clear that adhesion properties of keratinocytes, early delivery of proliferative keratinocytes to the wound, the development of dermal replacements, and improved delivery systems for keratinocytes are important factors which must be considered for the optimal provision of skin replacements.
Animals↗
Wound closure with human keratinocytes cultured on a polyurethane dressing overlaid on a cultured human dermal replacement.
BACKGROUND: Burn excision followed by immediate wound coverage has become the clinical standard for managing extensive burn injuries in much of the world. When sufficient autograft skin to achieve permanent wound closure is unavailable, cell culture technology has made the use of cultured human keratinocyte (HK) sheets clinically feasible. Whereas previous techniques have focused on development of multilayered, differentiated HK sheets, our attention has been drawn to using HK in a highly proliferative, less differentiated state. Time requirements for preparation of multistratified cultured HK are high, and preparatory steps may destroy important integrin adhesion molecules. METHODS: We describe the use of HK cultured to single layer confluence on a polyurethane membrane(HD), with serum-free medium. HK-HD grafts were transplanted to full-thickness wounds on athymic mice (n = 31). A second group of mice (DG-HK-HD), n = 28) received a living human dermal replacement containing cultured fibroblasts before placement of HK-HD. Control mice received HD alone (n = 4). Basement membrane proteins on healed wounds and surface integrins on cultured HK were identified by means of immunostaining and direct microscopic visualization. RESULTS: HK cultured just to the confluent state on polyurethane membrane were positive for integrins alpha(5) and alpha(6), major integrins on proliferating HK. Histologic analysis showed epithelialized wounds in all groups after 21 days. Using an anti-human involucrin antibody we demonstrated the presence of HK in 64.5% of the HK-HD group, 61% of the DG-HK-HD group, and 0% in the HD group. Mice that received the living human dermal replacement containing cultured fibroblasts in combination with HK-HD grafts developed a thick, well-vascularized neodermis. Strong laminin and collagen IV staining was observed in wound areas covered with HK. CONCLUSIONS: These data show that full-thickness wounds can be closed by application of a single layer of proliferating HK cultured on a biocompatible polyurethane membrane. This technique is an alternative to the use of multilayered, differentiated HK sheets. Preparation times for HK-HD grafts should be significantly shorter than required for multilayered HK sheets, technical efforts should be less, and more extensive wound areas could be covered.
Animals↗
Reduction of capsular formation around silicone breast implants by D-penicillamine in rats.
In a controlled study in 109 female rats we evaluated the effect of soluble D-Penicillamine in doses of 10 mg/ml or 100 mg/ml on capsular formation around semipermeable 2 cm3 mini-prostheses. This was compared with methylprednisolone 1 mg/ml or 10 mg/ml, and a group given saline served as controls. The drugs were injected into the lumen. Capsular wet weight and capsular tensile strength were measured after a period of 40 days. Rats given D-Penicillamine showed a significant, dose-dependent, reduction in wet weight and tensile strength compared with the saline group. There was no significant difference between the groups given D-Penicillamine and those given steroids. Topical treatment with diffused D-Penicillamine can significantly reduce the amount of capsular formation around silicone implants. This drug, which is highly specific for the systemic treatment of fibrotic diseases, should be evaluated further to use in reducing capsular formation.
Animals↗
Median sternotomy for high-risk patients with bilateral pulmonary disease: a case report.
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Aged↗
[Usefulness of dynamic thin section CT in detecting lymph node metastasis of lung cancer].
The diagnosis for metastatic lymph nodes of lung cancer by the conventional CT is done only by the size of nodes, therefore, its diagnostic accuracy is questionable. For the purpose of more qualitative diagnosis in order to elevate accuracy of metastatic nodes, we studied a new CT image (Dynamic Thin Section CT) by combining the Thin Section CT with the Dynamic CT, and reviewed on the image of histopathological positive nodes. Firstly, for the preoperative cases of lung cancer, the conventional CT was performed for the whole chest with 10 mm-thickness and 10 mm-interval. Secondary, among them, the Dynamic CT by bolus-injection at the sites of detected hilar and mediastinal lymph nodes was performed. For this method, the Thin Section CT with 2 mm-thickness was used, and the image-detected nodes were isolated by surgery. We studied 25 cases whose images were compared with the histological findings. By the conventional CT sensitivity were 35.7%, specificity 54.5%, and accuracy 44.0%, in regarding the shorter diameter over 1 cm as positive nodes, then under diagnosis were 36%, over diagnosis 20%. Morphological features were reviewed on the image of metastatic lymph nodes in the Dynamic Thin Section CT, and were (1) lump-like lymph nodes, (2) disappearance of the fatty plane around the lymph nodes or uneven and irregular margins, (3) irregular internal structures of enhanced lymph nodes. Moreover, small lymph nodes were clearly detected, and the size was exactly measured.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenocarcinoma↗
Integrin and matrix molecule expression in cultured skin replacements.
Current tissue culture techniques enable human keratinocytes (HK) from a small section of skin to be grown into sheets of epithelium for treating extensive wounds. The additional use of dermal replacements coupled with cultured skin substitutes may improve handling properties and effect ultimate healing results. Adhesion of cultured HK grafts to wounds, and final success rates of HK grafting, are variable and frequently unsatisfactory. To evaluate adhesion molecule (integrin) expression by cultured grafts, as well as matrix molecule distribution, we performed immunohistologic analysis of integrin expression on HK cultured on plastic and a polyurethane membrane, as well as on two dermal substitutes. Multilayered HK sheet grafts were prepared by culturing cells in plastic tissue culture dishes, and HK were cultured to single-layer confluence on polyurethane membranes (Hydroderm; Wilshire Medical Inc., Dallas, Texas). Composite grafts were prepared by seeding proliferating HK on Dermagraft, composed of human neonatal fibroblasts cultured in polyglactin mesh (Advanced Tissue Sciences, La Jolla, Calif.) and on AlloDerm, an acellular human dermis (LifeCell Inc., The Woodlands, Texas). Immunohistologic staining was performed for the integrin subunits alpha 5, alpha 6, and alpha v. Staining for matrix molecules included fibronectin, laminin-1, and laminin-5. HK in cultured epithelial sheets showed integrin alpha 6 expression on basal cells, and only faint alpha 5 and alpha v staining. HK cultured to confluence on Hydroderm reacted with monoclonal antibodies specific for alpha 5, alpha 6, and alpha v. Through HK adhered well to Dermagraft, there was reduced adhesion of HK on AlloDerm that was not accelerated by addition of fibronectin. HK in composite grafts showed distinct reactivity according to the time in culture. HK on Dermagraft lost alpha 5 reactivity by day 17 and only weak alpha v reactivity was seen. Basal keratinocytes on AlloDerm, however, remained alpha 5 and alpha v positive. In both composite grafts, integrin alpha 6 expression was limited to basal keratinocytes.
Biocompatible Materials↗
Growth peptide release from biologic dressings: a comparison.
Biologic dressings are believed to stimulate wound healing in a variety of wound types. Cryopreserved allograft skin (CAS) is used as a biologic dressing for excised wounds, partial-thickness wounds, and meshed split-thickness skin grafts, and the use of allogenic or autologous cultured epithelial sheets (CES) has been reported to enhance healing of skin ulcers and deep partial-thickness wounds. However, limitations of allograft skin include bacteriologic and viral safety, limited availability, cost, and ease of handling. Previously we have reported the successful use of human keratinocytes cultured to single-layer confluence on Hydroderm polyurethane membranes (HD/HK) for grafting of full-thickness wounds. In this study we evaluated the release of five different growth peptides (transforming growth factors alpha and beta (TGF-alpha, TGF-beta), interleukin-6, interleukin-8, and melanoma growth stimulatory activity from CAS, CES, and HD/HK grafts. Highest levels of TGF-alpha were found for HD/HK (728 +/- 115 pg/10 cm2 of membrane) followed by CES (491 +/- 137 pg/10 cm2; NS). No TGF-alpha was detectable for CAS, and 3.7-fold, and 25-fold higher levels of interleukin-6 were found for CES (257 +/- 12.7 U/10 cm2) compared with HD/HK and CAS, respectively. Interleukin-8 had similar levels for CES (0.65 +/- 0.7 ng/10 cm2) and HD/HK (0.88 +/- 0.12 ng/10 cm2), whereas melanoma growth stimulatory activity was elevated in CES (2314 +/- 97 pg/10 cm2) compared with HD/HK (1071 +/- 55 pg/10 cm2). TGF-beta was barely detectable for CES and HD/HK. Cryopreserved allograft showed high levels of TGF-beta (5.2 +/- 1.6 ng/10 cm2). Overall mitogenic activity of the supernatants on keratinocyte cultures was assessed. Highest proliferation was seen for CES supernatants followed by HD/HK (NS). Supernatants from CAS had an antiproliferative effect on keratinocytes. We conclude that a single layer of keratinocytes cultured on a polyurethane membrane facilitates keratinocyte proliferation similar to CES, whereas cryopreserved allograft has no mitogenic effect on keratinocytes.
Analysis of Variance↗
Acellular human dermis promotes cultured keratinocyte engraftment.
In full-thickness skin injury, loss of dermis may result in compromised wound repair, including contracture, hypertrophic scarring, and wound breakdown. This report examines the effect of an acellular dermal matrix on in vivo skin repair. Human keratinocytes cultured onto a synthetic hydrophilic dressing were applied with (N = 9) and without (N = 11) an acellular dermal matrix to full-thickness skin defects on athymic mice. Host cells progressively repopulated the acellular dermal component of the grafts. All animals with dermal matrix revealed fully differentiated epidermis by postoperative day 21. Human keratinocytes persisted in all animals grafted with dermal matrix, compared to only 63.6% of those animals without a dermal component. Planimetric analysis revealed significantly reduced wound contraction (p = 0.016) in animals receiving the dermal matrix. Histologic, immunohistochemical, and electron microscopic analyses also were performed. These studies suggest that an acellular dermal matrix can effectively direct regeneration of normal skin morphology.
Animals↗
Evaluation of amniotic membrane as adhesion prophylaxis in a novel surgical gastroschisis model.
Adhesions are a leading cause of bowel obstruction and infertility. The coverage of peritoneal defects, as in gastroschisis, is still a crucial problem. Despite biodegradable substitutes and synthetic implants such as PTFE membrane, a satisfactory replacement for gastroschisis has not been identified. The amniotic membrane, which is available at birth with a low antigenicity, was evaluated as a peritoneal substitute. Viable, partially viable, and inversed-used amniotic membranes were compared in a rat model. A full-thickness abdominal wall defect was made and the amniotic membrane sutured into this defect. The skin was closed over the amniotic membrane. Reoperation was performed 3 weeks after initial surgery, and the adhesion formation was measured by computerized area calculation. Viable amniotic membrane showed 0 to 3% area adhesion formation, while partially viable (50%) amniotic membrane demonstrated 33% area adhesion formation. Inversed-used amniotic membrane, with the stromal side directed toward the abdominal cavity, showed 70% of the amniotic membrane area to be covered with adhesions. The same amount was found in the control group, in which no substitute was sutured into the defect. This animal model is suitable for the straightforward evaluation of peritoneal substitutes with regard to adhesion formation. It is easy to perform and mimics surgical needs. Viable amniotic membrane proved to be an excellent antiadhesive tissue.
Abdominal Muscles↗