A heterotopic primate model for facial composite tissue transplantation.
ABSTRACT The purpose of this study was to develop a nonhuman primate model for heterotopic composite tissue facial transplantation in which to study the natural history of facial transplantation and evaluate immunosuppressive regimens.A composite oromandibular facial segment transplant based on the common carotid artery was evaluated. Flaps from 7 cynomolgus monkeys were transplanted to the groins of 7 recipients at the superficial femoral artery and vein. The immunosuppressive regimen consisted of thymoglobulin, rapamycin, and tacrolimus. Allograft survival ranged from 6 to 129 days. Histology performed in the long-term survivor at the time of necropsy revealed extensive inflammation and necrosis of the allograft skin; however, muscle and bone elements were viable, with minimal inflammation. This heterotopic facial transplantation model avoids the potential morbidity of mandibular resection and orthotopic facial transplantation. Our work also concurs with the work of other groups who found that the skin component is the most antigenic.
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ABSTRACT: Tacrolimus hydrate (FK506), isolated from Streptomyces tsukubaensis, is an immensely used immunosuppressive agent. It was evaluated for its effects on meiotic chromosomes in testes, epididymal spermatozoa and fertility in male mice. The study under different parameters constituted sub acute (seven days) administration (gavage) of FK506 at doses of 4, 8 and 16 mg/kg/day body weight. The results obtained in present study revealed that, FK506 significantly induced spermatozoa abnormalities, lowered fertility and increased embryonic loss. The observed changes related to spermatogenic dysfunction reflected statistically significant increased aberrations in the meiotic chromosomes. These aberrations seemed to be induced by the inhibitory effect of the drug on the signal transduction pathways in the cells and interference in the transcription processes and proliferation of cells. Further studies are warranted to evaluate the safe dose and duration of therapy to determine the exact mode of action of FK506 induced germ cell toxicity.
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ABSTRACT: Currently, only a few large animal models, including swine, dog, and nonhuman primate, are described for composite face transplantation studies and the literature lacks reports on the large animal model of composite auricular transplantation. Large animal models offer better understanding of the immunological mechanisms and major histocompatibility complex characterization and, for this reason, are preferred to the small animal models for the assessment of new immunosuppressive tolerance induction protocols. Thus, the aim of this study was to demonstrate feasibility of dissection and exploration of vascular territories of the hemifacial and auricle transplantation models in the sheep cadavers. Ten cadaver sheep heads were studied. The vascular territories of the composite hemifacial flap and composite auricle flap were defined by anatomical dissection. Methylene blue staining and laser-assisted indocyanine green angiography using SPY Elite System were used for vascular territories assessment. The dissection of cadaver sheep heads confirmed that the hemifacial flap and auricle flap can be raised on the same pedicle consisting of the common carotid artery and jugular vein. An adequate vascular network was observed in the flaps after injection of methylene blue dye via the arterial pedicle. Laser-assisted indocyanine green angiography identified vascular territories of the hemifacial and auricular vascular network. We described a new hemifacial and an auricular transplantation models in the sheep cadavers and have confirmed presence of the adequate vascular network as demonstrated by the laser-assisted angiography. This study introduces 2 new large animal models into the armamentarium of vascular composite allotransplantation.Annals of plastic surgery 04/2014; 72(4):469-74. DOI:10.1097/SAP.0000000000000122 · 1.29 Impact Factor
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ABSTRACT: PURPOSE: To evaluate the effects of vitamin K1 on wound healing in the left colon of rats with experimental biliary obstruction. METHODS: Sixteen male rats, divided into four groups of four animals each (L, M, LK, and MK), underwent colostomy followed by bowel suture in the left colon. Seven days before, animals in the L and LK groups had undergone common bile duct ligation. The animals in groups MK and LK received vitamin K1 supplementation. On day 7 after bowel suture, repeat laparotomy was performed for evaluation of colonic healing by burst pressure measurement and collection of samples for histopathological analysis. Changes in body weight were evaluated in the four groups. RESULTS: Weight loss was lower in animals supplemented with vitamin K. No significant differences were observed in burst pressure among the four groups (p>0.05). Histological analysis showed more hemorrhage and congestion in the biliary obstruction groups. Supplemented animals exhibited increased collagen formation and less edema and abscess formation. CONCLUSION: Vitamin K supplementation attenuated weight loss and improved colonic wound healing in rats.Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 08/2014; 29(8):522-527. DOI:10.1590/S0102-86502014000800007 · 0.48 Impact Factor