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Transplantation Procedure (transplantation + procedure)
Selected AbstractsEffects and distribution of the enamel matrix derivative Emdogain® in the periodontal tissues of rat molars transplanted to the abdominal wallDENTAL TRAUMATOLOGY, Issue 1 2002Yoshioki Hamamoto Abstract , The enamel matrix derivative Emdogain® (EMD) has been found to promote regeneration of lost periodontal tissues. We have studied the effects and distribution of EMD in the periodontal tissues of maxillary rat molars transplanted to a subcutaneous position in the abdominal wall. The molars were transplanted with or without EMD either immediately after extraction or after drying for 30 min. After 2 days, 1, 2 or 4 weeks the rats were killed and the teeth were examined by means of light microscopy and immunohistochemistry with anti-amelogenin antibodies. Teeth transplanted immediately after extraction showed formation of alveolar bone separated from the dental roots by a periodontal space, regardless of the use of EMD. Among the teeth that were transplanted with EMD after drying for 30 min, new alveolar bone was formed in five out of eight teeth after 2 and 4 weeks. None of the teeth that were dried for 30 min and transplanted without EMD showed alveolar bone formation. Only one tooth transplanted with EMD showed root resorption after drying, while resorption was noted in all teeth transplanted without EMD. All teeth that were transplanted with EMD and none of the teeth that were transplanted without EMD showed an immunohistochemical reaction for amelogenin. After 2 days, amelogenin was precipitated on all surfaces exposed at the transplantation procedure. Later, the immunoreactive material was redistributed to cells at the root surface, where it was still demonstrable after 4 weeks. In conclusion, EMD is accumulated in cells at the root surface and promotes regeneration of the periodontal tissues of the transplanted teeth. It also seems to promote healing of root resorption. [source] Accuracy of magnetic resonance imaging for preoperative detection of portal vein thrombosis in liver transplant candidatesLIVER TRANSPLANTATION, Issue 11 2006Tilak U. Shah The detection of main portal vein thrombosis (PVT) on preoperative imaging of liver transplant candidates has important technical implications for the transplantation procedure. Data are scarce regarding the accuracy of magnetic resonance imaging (MRI) at detecting PVT. The aim of our study was to compare preoperative findings of the portal vein on MRI to operative findings at liver transplantation. Abdominal MRI and clinical records of 172 consecutive patients who received liver transplants between January 1999 and September 2004 were reviewed. Two radiologists independently evaluated the last abdominal magnetic resonance examinations obtained before liver transplantation, blinded to the original reading, operative findings, and clinical data. Findings on MRI were compared with intraoperative findings at transplantation. Main PVT was detected in 12 patients, in whom 8 were found to have thrombus at surgery, with 6 requiring a jump graft or thrombectomy. Sensitivity and specificity of MRI for detecting main PVT were 100% and 98%, respectively. The cause of discordance between findings on MRI and at transplantation in 2 cases was a diminutive caliber of the main portal vein that was interpreted as recanalized chronic thrombosis on MRI. In conclusion, in our study group MRI detected PVT in all liver transplant recipients requiring jump grafts at transplantation. The major reason for a false-positive MRI was a diminutive but patent portal vein. Liver Transpl 2006. © 2006 AASLD. [source] Transjugular intrahepatic portosystemic shunts: an updateLIVER TRANSPLANTATION, Issue 3 2003Barbara Rosado Transjugular intrahepatic portosystemic shunts (TIPS) have been used in the treatment of complications of portal hypertension. TIPS is used for the control of acute variceal bleeding and for the prevention of vericeal rebleeding when pharmacologic therapy and endoscopic therapy have failed. Patients with refractory ascites with adequate hepatic reserve and renal function who fail to respond to large volume paracentesis may be reasonable candidates for TIPS. Promising indications for TIPS are Budd-Chiari syndrome uncontrolled by medical therapy, severe portal hypertensive gastropathy, refractory hepatic hydrothorax, and hepatorenal syndrome. TIPS cannot be recommended for preoperative portal decompression solely to facilitate liver transplantation. Special care should be taken to insure proper placement of the stent to avoid increasing the technical difficulty of the transplantation procedure. The major limiting factors for TIPS success are shunt dysfunction and hepatic encephalopathy. Because shunt stenosis is the most important cause of recurrent complications of portal hypertension, a surveillance program to monitor shunt patency is mandatory. The MELD score may be useful in predicting post-TIPS survival, and also in counseling patients and their families. [source] Kinetics of PME/Pi in pig kidneys during cold ischemiaNMR IN BIOMEDICINE, Issue 7 2007Dominik von Elverfeldt Abstract Quality assessment of renal grafts via 31P magnetic resonance spectroscopy (MRS) has been investigated since 1986. As ATP concentrations decay rapidly during cold ischemia, the ratio of phosphomonoesters (PME) to inorganic phosphate (PiO) within the organ (PME/PiO) is commonly used as a quality marker and is considered to be the most reliable parameter. MRS did not lead to any delay in the transplantation procedure since it was performed during the time necessary for immunological matching (cross-match). Differences in the time period until transplantation call for extrapolation of the measured ratio to the end of cold ischemia before correlating with graft performance after transplantation. Therefore, quantitative determination of PME/PiO kinetics is essential. As a model for metabolite decay in human renal grafts, pig kidneys obtained from a slaughterhouse were monitored for up to 80,h via 31P MRS at 2,T. By employing chemical shift imaging (CSI) with a spatial resolution of approximately 1,×,1,×,4,cm3, it was possible to reduce partial volume effects significantly. The improved spectral resolution gained through CSI enabled reliable PME/PiO ratios to be determined only from those voxels containing renal tissue. Spectra were fitted automatically using the magnetic resonance user interface (MRUI), with prior knowledge obtained from unlocalized spectra when necessary. A monoexponential time dependence of PME/PiO for histidine,tryptophane,alpha-ketoglutarate (HTK)-perfused kidneys during cold ischemia was observed, and the determined value of the decay constant , was 0.0099,±,0.0012,h,1. In University of Wisconsin solution (UW)-perfused kidneys, an , of 0.0183,±,0.0053,h,1 was determined. Determination of the decay constant enables a usable extrapolation of PME/PiO for quality assessment of UW perfusion and a reliable extrapolation for HTK-perfused human renal grafts. Copyright © 2007 John Wiley & Sons, Ltd. [source] Genome-Wide Transcription Profile of Endothelial Cells After Cardiac Transplantation in the RatAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010B. Mikalsen Transcriptome analyses of organ transplants have until now usually focused on whole tissue samples containing activation profiles from different cell populations. Here, we enriched endothelial cells from rat cardiac allografts and isografts, establishing their activation profile at baseline and on days 2, 3 and 4 after transplantation. Modulated transcripts were assigned to three categories based on their regulation profile in allografts and isografts. Categories A and B contained the majority of transcripts and showed similar regulation in both graft types, appearing to represent responses to surgical trauma. By contrast, category C contained transcripts that were partly allograft-specific and to a large extent associated with interferon-,-responsiveness. Several transcripts were verified by immunohistochemical analysis of graft lesions, among them the matricellular protein periostin, which was one of the most highly upregulated transcripts but has not been associated with transplantation previously. In conclusion, the majority of the differentially expressed genes in graft endothelial cells are affected by the transplantation procedure whereas relatively few are associated with allograft rejection. [source] Positron Emission Tomography in Clinical Islet TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2009O. Eriksson The fate of islets in clinical transplantation is unclear. To elude on this positron emission tomography combined with computed tomography (PET/CT) was performed for 60 min during islet transplantation in five patients receiving six transplants. A fraction of the islets (23%) were labeled with 18F-fluorodeoxyglucose ([18F]FDG) and carefully mixed with unlabeled islets just prior to intraportal transplantation. The peak radioactivity concentration in the liver was found at 19 min after start of islet infusion and corresponded to only 75% of what was expected, indicating that islets are lost during the transplantation procedure. No accumulation of radioactivity was found in the lungs. A nonphysiological peak of C-peptide was found in plasma during and immediately after transplantation in all subjects. Distribution in the liver was heterogeneous with wide variations in location and concentration. Islets found in areas with concentrations of >400 IEQ/cc liver tissue varied between 1% and 32% of the graft in different subjects. No side effects attributed to the PET/CT procedure were found. Clinical outcome in all patients was comparable to that previously observed indicating that the [18F]FDG labeling procedure did not harm the islets. The technique has potential to be used to assess approaches to enhance islet survival and engraftment in clinical transplantation. [source] Toward full restoration of synaptic and terminal function of the dopaminergic system in Parkinson's disease by stem cellsANNALS OF NEUROLOGY, Issue S3 2003Ole Isacson DrMedSci New therapeutic nonpharmacological methodology in Parkinson's disease (PD) involves cell and synaptic renewal or replacement to restore function of neuronal systems, including the dopaminergic (DA) system. Using fetal DA cell therapy in PD patients and laboratory models, it has been demonstrated that functional motor deficits associated with parkinsonism can be reduced. Similar results have been observed in animal models with stem cell-derived DA neurons. Evidence obtained from transplanted PD patients further shows that the underlying disease process does not destroy transplanted fetal DA cells, although degeneration of the host nigrostriatal system continues. The optimal DA cell regeneration system would reconstitute a normal neuronal network capable of restoring feedback-controlled release of DA in the nigrostriatal system. The success of cell therapy for PD is limited by access to preparation and development of highly specialized dopaminergic neurons found in the A9 and A10 region of the substantia nigra pars compacta as well as the technical and surgical steps associated with the transplantation procedure. Recent laboratory work has focused on using stem cells as a starting point for deriving the optimal DA cells to restore the nigrostriatal system. Ultimately, understanding the cell biological principles necessary for generating functional DA neurons can provide many new avenues for better treatment of patients with PD. Ann Neurol 2003;53 (suppl 3):S135,S148 [source] Cell transplantation with a catheter-based approach: an efficient method for the treatment of heart failure with multiple lesionsCELL PROLIFERATION, Issue 6 2006M. Chen At present, popular methods of cell delivery may not be efficient in perfusing cells through the whole myocardium. We have developed a novel catheter-based method for global transplantation of cells. Heart failure was induced in rabbit by intravenous administration of doxorubicin. Autologous bone marrow mononuclear cells were transplanted into failing hearts via the root of the aorta. Bilateral sinus aortae and coronary arteries were visualized by angiography during the cell transplantation procedure; there was no intraprocedural death. Four weeks after cell transplantation, there was an improvement in the mean left ventricular ejection fraction from baseline 72.13% to 81.54% (P = 0.034). Transplanted cells were observed throughout the cardiac layers of left and right ventricles. In conclusion, cell transplantation through the root of the aorta is a useful approach to globally supply cells into the heart. [source] Two-stage liver transplantation: an effective procedure in urgent conditionsCLINICAL TRANSPLANTATION, Issue 1 2010Roberto Montalti Montalti R, Busani S, Masetti M, Girardis M, Di Benedetto F, Begliomini B, Rompianesi G, Rinaldi L, Ballarin R, Pasetto A, Gerunda GE. Two-stage liver transplantation: an effective procedure in urgent conditions. Clin Transplant 2010: 24: 122,126. © 2009 John Wiley & Sons A/S. Abstract:, Temporary portocaval shunt and total hepatectomy is a technique used in the presence of toxic liver syndrome because of fulminant hepatic failure, hepatic trauma, primary non-function (PNF), and eclampsia. We performed this technique on four patients. An indication for anhepatic state was severe hemodynamic instability in three of them. Etiologies of these three patients were as follows: PNF after liver transplantation, ischemic hepatitis after right hepatic artery embolization, and massive reperfusion syndrome during a liver transplantation. In the fourth patient, during the liver transplantation when hepatic artery was ligated, a kidney carcinoma in the donor graft was discovered. We decided to complete the hepatectomy and to construct a temporary portocaval shunt. Mean anhepatic phases were 19 h and 15 min. All patients survived the two-stage liver transplantation procedure without major complications. Our cases demonstrated that temporary portocaval shunt while awaiting urgent liver transplantation could be an effective "bridge" in selected patients who develop toxic liver syndrome; however, a short time between portocaval shunt and transplantation and careful intensive care managements are mandatory. [source] Tube thoracostomy during allogeneic stem cell transplantation does not carry an increased risk for infections or bleedingCLINICAL TRANSPLANTATION, Issue 1 2004D Barkan Abstract:, Background:, Candidates for stem cell transplantation may occasionally suffer from massive pleural effusions related to their disease and require tube thoracostomy. The additional risk of this procedure during allogeneic transplantation procedure is not known. Methods:, Four high-risk patients transplanted in our institution during a 2-yr period had chest drainage by tube thoracostomy. The characteristics of the fluid, the clinical course, and the outcome were assessed. Results:, A total of nine chest drains were inserted (range 1,5). No bleeding complications related to the procedure were noted. None of the patients developed any clinical signs of local infection at the tube insertion site or within the pleural fluid. All cultures taken from the drained fluid or from the insertion wound were negative. Conclusions:, Tube thoracostomy in itself does not seem to pose additional risks in the transplant procedure, despite all patients in this series being considered to be at high-risk for complications. [source] Enhancement of In Vitro Hair Shaft Elongation in Follicles Stored in Buffers That Prevent Follicle Cell ApoptosisDERMATOLOGIC SURGERY, Issue 1 2004Walter Krugluger MD Background. Viability and survival of stored micrografts during hair follicle transplantation are important limitations of micrograft transplantation procedures. In this study, we investigated the effect of different storage solutions and inhibitors of apoptotic cell death (ACD) on hair follicle cell viability by measuring in vitro hair shaft elongation (HSE) for 5 days. Methods. Micrografts from informed patients undergoing routine micrograft transplantation were stored for 5 hours at room temperature in phosphate-buffered salt solution (PBS) or HEPES-buffered Dulbecco's modified Eagle's medium (DMEM), containing different concentrations of the ACD-inhibitors aminoguanidine (AMG), hormones (insulin, hydrocortisone), 14,15-epoxy-eicosatrienoic acid (14,15-EET), or combinations of these. Results. In vitro, HSE was significantly increased in micrografts stored in DMEM compared with PBS (2.3%±0.6% vs. 28.4%±3.9%, P<0.0001). DMEM supplemented with AMG (10 ,g/mL) or 14,15-EET (1 ng/mL) further increased in vitro HSE (33.9%±7.1%, p=0.01, and 32.8%±6.1%, P=0.02, respectively). Evaluation of ACD in stored micrografts, performed by determination of cytoplasmic histone-associated DNA fragments, confirmed the results found by HSE. ACD was detectable after a 36-hour culture in serum-containing medium and was higher in micrografts stored in PBS compared with micrografts stored in DMEM (A405nm/A492nm: 1.63±0.21 vs. 1.42±0.07, respectively; P<0.01). The addition of AMG further decreased serum-induced ACD in the micrografts (DMEM 1.42±0.07 vs. DMEM/AMG 0.90±0.11, P<0.0001). Conclusion. Our study demonstrated an important role of ACD in micrograft transplantation surgery. Preconditioning of micrografts with storage buffers containing inhibitors of ACD could prevent serum-induced ACD after transplantation and might increase the viability of micrografts and the clinical outcome in micrograft transplantation. [source] Experimental model of heterotopic uterus transplantation in the laboratory ratMICROSURGERY, Issue 3 2003Lucian P. Jiga M.D. The present study describes a standardized experimental model of whole-uterus-and-ovaries heterotopic allotransplantation in the laboratory rat. Fifteen transplantation procedures were done. The anatomy of the pelvic region was studied with an additional 20 dissections, noting the topographical and vascular anatomy of the uterus, fallopian tubes, and ovarian vessels. Recipients were randomized into three groups. The average operative time was 150 min. The postoperative survival rate was 100%. Postoperative vascular anastomosis patency was 100%, and 26% at 72 hr. Recipients were euthanized at 24 hr (group I), 48 hr (group II), and 72 hr (group III); grafts were harvested and examined macroscopically, and fixed in formaline for histopathological and immunocytochemical analysis. Failure in 74% of the grafts at 72 hr was due to early thrombosis, starting from the capillary bed and progressing towards the main feeding pedicles. More studies must be undertaken to further understand the rejection mechanisms in transplanted reproductive organs. The efficiency, feasibility, and safety for such an operation in humans remain to be proven. We consider the present model a suitable tool to study all the above-mentioned goals. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:246,250 2003 [source] | ||||||||||