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Transplanted Tissue (transplanted + tissue)
Selected AbstractsCollagenase-Assisted Fat Dissociation for Autologous Fat TransferDERMATOLOGIC SURGERY, Issue 10 2008DAVID K. MOSCATELLO PHD BACKGROUND The quality of fat for autologous transfer procedures has been a major focus of research in the past few years. The primary goal of these efforts is to improve the viability and longevity of the graft in human subjects. One possible factor in the permanence of theses transplants is the size of the adipose tissue grafts. OBJECTIVE This study evaluated the effects of collagenase digestion on the viability of human adipose tissue. MATERIALS AND METHODS Samples of fat were obtained from subjects undergoing tumescent liposuction. The tissue was digested in a variety of concentrations of collagenase using optimized methods of processing. The digested fat was also subjected to mock injections through small bore needles. RESULTS Eight subjects completed the study. The viability of the fat using the optimized methods of collagenase digestion was consistently higher than 79%. During the mock injection trials, the viability of fat was improved from approximately 17% to 84% by collagenase digestion. CONCLUSIONS Our results show increased viability of human adipose tissue when digested by collagenase. These techniques can be applied to human autologous lipoaugmentation procedures in an effort to improve longevity of the transplanted tissue. [source] Increasing renal mass improves survival in anephric rats following metanephros transplantationEXPERIMENTAL PHYSIOLOGY, Issue 1 2007Damian Marshall Renal failure and end-stage renal disease are prevalent diseases associated with high levels of morbidity and mortality, the preferred treatment for which is kidney transplantation. However, the gulf between supply and demand for kidneys remains high and is growing every year. A potential alternative to the transplantation of mature adult kidneys is the transplantation of the developing renal primordium, the metanephros. It has been shown previously, in rodent models, that transplantation of a metanephros can provide renal function capable of prolonging survival in anephric animals. The aim of the present study was to determine whether increasing the mass of transplanted tissue can prolong survival further. Embryonic day 15 rat metanephroi were transplanted into the peritoneum of anaesthetized adult rat recipients. Twenty-one days later, the transplanted metanephroi were anastomosed to the recipient's urinary system, and 35 days following anastomosis the animal's native renal mass was removed. Survival times and composition of the excreted fluid were determined. Rats with single metanephros transplants survived 29 h longer than anephric controls (P < 0.001); animals with two metanephroi survived 44 h longer (P < 0.001). A dilute urine was formed, with low concentrations of sodium, potassium and urea; potassium and urea concentrations were elevated in terminal serum samples, but sodium concentration and osmolality were comparable to control values. These data show that survival time is proportional to the mass of functional renal tissue. While transplanted metanephroi cannot currently provide life-sustaining renal function, this approach may have therapeutic benefit in the future. [source] Donor-Derived Mesenchymal Stem Cells Remain Present and Functional in the Transplanted Human HeartAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009M. J. Hoogduijn Mesenchymal stem cells (MSC) are characterized by their multilineage differentiation capacity and immunosuppressive properties. They are resident in virtually all tissues and we have recently characterized MSC from the human heart. Clinical heart transplantation offers a model to study the fate of transplanted human MSC. In this study, we isolated and expanded MSC from heart tissue taken before, and 1 week up to 6 years after heart transplantation. MSC from posttransplantation tissue were all of donor origin, demonstrating the longevity of endogenous MSC and suggesting an absence of immigration of recipient MSC into the heart. MSC isolated from transplanted tissue showed an immunophenotype that was characteristic for MSC and maintained cardiomyogenic and osteogenic differentiation capacity. They furthermore preserved their ability to inhibit the proliferative response of donor-stimulated recipient peripheral blood mononuclear cells. In conclusion, functional MSC of donor origin remain present in the heart for several years after transplantation. [source] Activity of CuZn-superoxide dismutase, catalase and glutathione peroxidase in erythrocytes in kidney allografts during reperfusion in patients with and without delayed graft functionCLINICAL TRANSPLANTATION, Issue 1 2006L Doma Abstract:, Background:, Generation of reactive oxygen species (ROS) is the main mechanism involved in the ischemic/reperfusion damage of the transplanted organ. Oxygen burst is a trigger for complex biochemical events leading to generation of oxygenated lipids and changes in microcirculation. Many markers have been researched to prove the presence of ROS in the transplanted tissue. Some of them, like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are considered to play a major role in graft protection against oxygen stress during reperfusion. Methods:, The aim of this study was to examine the changes of SOD1, CAT and GPx activity in erythrocytes during the first minutes after total graft reperfusion. Forty patients undergoing kidney transplantation at our center were assigned to two groups: with or without delayed graft function (DGF). Before anastomosing kidney vessels with recipient's iliac vessels, the ,0' blood sample was taken from the iliac vein. Next blood samples I, II and III were taken from the graft's renal vein. The reperfusion of the transplanted kidney was evaluated precisely with the thermovision camera. Erythrocyte SOD1, CAT and GPx activity was measured with a spectrophotometric method. Results:, We did not observe statistically significant changes in SOD1, CAT and GPx activity in erythrocytes during the early phase of reperfusion in patients with and without DGF. Conclusions:, Erythrocyte-antioxidative system in graft's vein remain stable during the early phase of reperfusion. The results of the study suggest that further studies on extracellular enzymes are required for the assessment of antioxidant system in the conditions of ischemia/reperfusion. [source] Assessment of parathyroid autotransplantation for preservation of parathyroid function after total thyroidectomyHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2003Magdy I. El-Sharaky MD Abstract Background. Hypoparathyroidism with permanent hypocalcemia is a well-recognized complication after thyroid surgery. Aim. This study was conducted to assess the role of immediate parathyroid autotransplantation in the preservation of parathyroid function after total thyroidectomy. Patients and Methods. Twenty-eight patients had autotransplantation of parathyroid glands resected or devascularized during total thyroidectomy. Data were collected prospectively regarding demographics, indication for surgery, operative procedure, pathologic diagnosis, number of glands transplanted, and subsequent course. Thyroid nodules were evaluated by ultrasonography, radionuclide scanning, and/or fine-needle aspiration cytology. All patients had serum ionized calcium, phosphorus, and intact parathyroid hormone (PTH) levels measured preoperatively and monitored regularly postoperatively for a period of 14 weeks and again at 6 months after operation. Patients were categorized into three groups according to the number of glands transplanted: one (group 1, n = 6), two (group 2, n = 14), or three glands (group 3, n = 8). In three other volunteers, one parathyroid gland was transplanted in the brachioradialis and subjected to electron microscopy 1, 2, and 4 weeks after transplantation. Results. Total thyroidectomy was performed for malignant disease in 16 patients (57.1%) and for benign disease in 12 (42.9%) patients. All patients reverted to asymptomatic normocalcemia without the need for any medications within 4 to 14 weeks. Normal levels of serum markers were regained slower when one gland was transplanted compared with two or three glands (P < .01). Electron microscopic examination showed evidence of ischemic degeneration in the transplanted tissues 1 week postoperatively. Regeneration started by the second week and coincided with normalization of PTH levels. Optimum resting and nearly normal status of parathyroid tissue was achieved by the fourth week. Conclusions. This study showed that active PTH production coincides with regeneration of parathyroid cells and that autotransplantation of at least two resected or devascularized glands during total thyroidectomy nearly eliminates permanent postoperative hypoparathyroidism, thus improving the safety of total thyroidectomy performed for malignant or benign disease. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 799,807, 2003 [source] | ||||||||||