Home About us Contact
|
Home About us Contact | ||
|
|
||
Human Donors (human + donor)
Selected AbstractsEnhancement of Viability of Fat Grafts in Nude Mice by Endothelial Progenitor CellsDERMATOLOGIC SURGERY, Issue 12 2006CHENGGANG YI MD BACKGROUND A recent discovery showed that endothelial progenitor cells (EPCs) could augment collateral vessel growth to ischemic tissues. OBJECTIVE The objective was to demonstrate the effects of EPCs on the vasculogenesis and survival of free transplanted fat tissues in nude mice. METHODS EPCs from human donors were cultured in vitro for 7 days. Human fat tissues were injected subcutaneously into the scalps of 20 6-week-old nude male mice. EPCs stained with CM-DiI were mixed with the transplanted fat tissues and injected into the mice. EBM-2 medium was used as control group. The animals were euthanized 15 weeks after the procedure. Graft volume were measured, and histologic evaluation was performed. The central part of fat tissues was histologically evaluated 15 weeks after the fat injection. RESULTS The survival volume of the experimental group was significantly greater than that of the control group (p< .05). Less cyst formation and fibrosis was obtained in the experimental group. Histologic evaluation of the central part of fat tissues 15 weeks after the fat injection showed that capillary densities increased markedly in the experimental group mice. CONCLUSION The results indicate that EPCs have the ability to enhance the survival and the quality of the transplanted fat tissues. [source] Failure of immunocompetitive capillary electrophoresis assay to detect disease-specific prion protein in buffy coat from humans and chimpanzees with Creutzfeldt-Jakob diseaseELECTROPHORESIS, Issue 5 2003Larisa Cervenakova Abstract The emergence of a new environmentally caused variant of Creutzfeldt-Jakob disease (vCJD), the result of food-born infection by the causative agent of bovine spongiform encephalopathy (BSE), has stimulated research on a practical diagnostic screening test. The immunocompetitive capillary electrophoresis (ICCE) assay has been reported to detect disease-specific, proteinase-resistant prion protein (PrPres) in the blood of scrapie-infected sheep. We have applied this method to blood from CJD-infected chimpanzees and humans. The threshold of detection achieved with our ICCE was 0.6 nM of synthetic peptide corresponding to the prion protein (PrP) C -terminus, and 2 nM of recombinant human PrP at the optimized conditions. However, the test was unable to distinguish between extracts of leucocytes from healthy and CJD-infected chimpanzees, and from healthy human donors and patients affected with various forms of CJD. Thus, the ICCE assay as presently performed is not suitable for use as a screening test in human transmissible spongiform encephalopathies (TSEs). [source] Localization of SOST/sclerostin in cementocytes in vivo and in mineralizing periodontal ligament cells in vitroJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2010A. Jäger Jäger A, Götz W, Lossdörfer S, Rath-Deschner B. Localization of SOST/sclerostin in cementocytes in vivo and in mineralizing periodontal ligament cells in vitro. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2009.01227.x. © 2009 John Wiley & Sons A/S Background and Objective:, Cementum and bone are rather similar hard tissues, and osteocytes and cementocytes, together with their canalicular network, share many morphological and cell biological characteristics. However, there is no clear evidence that cementocytes have a function in tissue homeostasis of cementum comparable to that of osteocytes in bone. Recent studies have established an important role for the secreted glycoprotein sclerostin, the product of the SOST gene, as an osteocyte-derived signal to control bone remodelling. In this study, we investigated the expression of sclerostin in cementocytes in vivo as well as the expression of SOST and sclerostin in periodontal ligament cell cultures following induction of mineralization. Material and Method:, Immunolocalization of sclerostin was performed in decalcified histological sections of mouse and human teeth and alveolar bone. Additionally, periodontal ligament cells from human donors were cultured in osteogenic conditions, namely in the presence of dexamethasone, ascorbic acid and ,-glycerophosphate, for up to 3 wk. The induction of calcified nodules was visualized by von Kossa stain. SOST mRNA was detected by real-time PCR, and the presence of sclerostin was verified using immunohistochemistry and western blots. Results:, Expression of sclerostin was demonstrated in osteocytes of mouse and human alveolar bone. Distinct immunolocalization in the cementocytes was shown. In periodontal ligament cultures, following mineralization treatment, increasing levels of SOST mRNA as well as of sclerostin protein could be verified. Conclusion:, The identification of SOST/sclerostin in cementocytes and mineralizing periodontal ligament cells adds to our understanding of the biology of the periodontium, but the functional meaning of these findings can only be unravelled after additional in vitro and in vivo studies. [source] Aging stimulates cyclooxygenase-2 expression and prostaglandin E2 production in human periodontal ligament cells after the application of compressive forceJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2007Kotoe Mayahara Background and Objectives:, Some clinical studies show that alveolar crestal bone loss is higher in adults than in young patients during orthodontic treatment, but the causes of such a phenomenon have not been elucidated. It is known that prostaglandin E2 (PGE2) is a proinflammatory agent and one of the potent osteoclast-inducing factors, and is produced by human periodontal ligament cells in response to orthodontic force. The aim of this study was to investigate age-related change in the biosynthetic capacity of PGE2 and its regulatory gene, cyclooxygenase 2 (COX-2) from periodontal ligament cells in response to mechanical stress. Methods:, Compressive force of 2 g/cm2 was applied for 3,48 h to periodontal ligament cells obtained from human donors aged 9,50 years, and COX-2 mRNA expression in and PGE2 production by the periodontal ligament cells in response to the compressive force were examined. Results:, Application of a compressive force of 2 g/cm2 for 3,48 h significantly stimulated these factors in both time- and age-dependent manners. Furthermore, these increases were dramatically larger in periodontal ligament cells obtained from donors over the age of 35. Conclusions:, Periodontal ligament cells obtained from old donors have significantly greater COX-2 expression and PGE2 production in response to compressive force than those from younger donors. The turning point of aging, where significantly larger amounts of theses factors begin production, appears to be around the age of 35. These results may be positively related to the acceleration of alveolar crestal bone loss during orthodontic treatment in adult patients. [source] Differential expression of Bordetella pertussis iron transport system genes during infectionMOLECULAR MICROBIOLOGY, Issue 1 2008Timothy J. Brickman Summary Temporal expression patterns of the Bordetella pertussis alcaligin, enterobactin and haem iron acquisition systems were examined using alcA,, bfeA, and bhuR,tnpR recombinase fusion strains in a mouse respiratory infection model. The iron systems were differentially expressed in vivo, showing early induction of the alcaligin and enterobactin siderophore systems, and delayed induction of the haem system in a manner consistent with predicted changes in host iron source availability during infection. Previous mixed infection competition studies established the importance of alcaligin and haem utilization for B. pertussis in vivo growth and survival. In this study, the contribution of the enterobactin system to the fitness of B. pertussis was confirmed using wild-type and enterobactin receptor mutant strains in similar competition infection experiments. As a correlate to the in vivo expression studies of B. pertussis iron systems in mice, sera from uninfected and B. pertussis -infected human donors were screened for antibody reactivity with Bordetella iron-repressible cell envelope proteins. Pertussis patient sera recognized multiple iron-repressible proteins including the known outer membrane receptors for alcaligin, enterobactin and haem, supporting the hypothesis that B. pertussis is iron-starved and responds to the presence of diverse iron sources during natural infection. [source] Albumin depletion of human plasma also removes low abundance proteins including the cytokinesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2005Jill Granger Abstract The use of proteomics for efficient, accurate, and complete analysis of clinical samples poses a variety of technical challenges. The presence of higher abundance proteins in the plasma, such as albumin, may mask the detection of lower abundance proteins such as the cytokines. Methods have been proposed to deplete the sample of these higher abundance proteins to facilitate detection of those with lower abundance. In this study, a commercially available albumin depletion kit was used to determine if removal of albumin would measurably reduce detection of lower abundance cytokine proteins in human plasma. The Montage® Albumin Deplete Kit (Millipore) was used to deplete albumin from LPS-stimulated whole blood from 15 normal human donors. Albumin depletion was measured using the BCG reagent and SDS-PAGE, and cytokine recovery was determined by a microassay immunoassay that measures both pro- and anti-inflammatory cytokines. Average albumin depletion from the samples was 72%. However, several cytokines were also significantly reduced when the albumin was removed from the plasma. Additionally, there was a variable reduction in cytokine recovery from a known mixture of cytokines in a minimal amount of plasma that were loaded onto the columns. These data demonstrate that there may be a non-specific loss of cytokines following albumin depletion, which may confound subsequent proteomic analysis. [source] Kidney Injury Molecule-1 is an Early Noninvasive Indicator for Donor Brain Death-Induced Injury Prior to Kidney TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009W. N. Nijboer With more marginal deceased donors affecting graft viability, there is a need for specific parameters to assess kidney graft quality at the time of organ procurement in the deceased donor. Recently, kidney injury molecule-1 (Kim-1) was described as an early biomarker of renal proximal tubular damage. We assessed Kim-1 in a small animal brain death model as an early and noninvasive marker for donor-derived injury related to brain death and its sequelae, with subsequent confirmation in human donors. In rat kidney, real-time PCR revealed a 46-fold Kim-1 gene upregulation after 4 h of brain death. In situ hybridization showed proximal tubular Kim-1 localization, which was confirmed by immunohistochemistry. Also, Luminex assay showed a 6.6-fold Kim-1 rise in urine after 4 h of brain death. In human donors, 2.5-fold kidney injury molecule-1 (KIM-1) gene upregulation and 2-fold higher urine levels were found in donation after brain death (DBD) donors compared to living kidney donors. Multiple regression analysis showed that urinary KIM-1 at brain death diagnosis was a positive predictor of recipient serum creatinine, 14 days (p < 0.001) and 1 year (p < 0.05) after kidney transplantation. In conclusion, we think that Kim-1 is a promising novel marker for the early, organ specific and noninvasive detection of brain death-induced donor kidney damage. [source] Effect of interleukin-1, on osteogenic protein 1,induced signaling in adult human articular chondrocytesARTHRITIS & RHEUMATISM, Issue 1 2009Amel M. Elshaier Objective Two major receptor-activated Smad (R-Smad) signaling pathways, bone morphogenetic protein (BMP) and MAPK, were examined in a model of interleukin-1, (IL-1,),induced cartilage degeneration to investigate the effect of IL-1, on osteogenic protein 1 (OP-1) signaling in adult human articular chondrocytes. Methods Chondrocytes from the ankles of 26 normal human donors were cultured in high-density monolayers in serum-free medium. The effect of IL-1, on BMP receptors was studied by reverse transcription,polymerase chain reaction and flow cytometry. Phosphorylation of R-Smads was tested in cells treated with IL-1, (10 ng/ml), OP-1 (100 ng/ml), or the combination of IL-1, and OP-1. Cell lysates were analyzed by Western blotting with polyclonal antibodies against 2 R-Smad phosphorylation sites (BMP- and MAPK-mediated) or with total, nonphosphorylated R-Smad as a control. To identify which MAPKs play a role in IL-1, activation of the linker region, chondrocytes were preincubated with specific MAPK inhibitors (PD98059 for MAP/ERK, SP600125 for JNK, and SB203580 for p38). Results IL-1, reduced the number of activin receptor,like kinase 2 (ALK-2) and ALK-3 receptors, inhibited expression of Smad1 and Smad6, delayed and prematurely terminated the onset of OP-1,mediated R-Smad phosphorylation, and affected nuclear translocation of R-Smad/Smad4 complexes. The alternative phosphorylation of R-Smad in the linker region via the MAPK pathway (primarily p38 and JNK) was observed to be a possible mechanism through which IL-1, offsets OP-1 signaling and the response to OP-1. Conversely, OP-1 was found to directly inhibit phosphorylation of p38. Conclusion These findings describe new mechanisms of the crosstalk between OP-1 and IL-1, in chondrocytes. The study also identifies potential targets for therapeutic interventions in the treatment of cartilage-degenerative processes. [source] Indentation testing of human cartilage: Sensitivity to articular surface degenerationARTHRITIS & RHEUMATISM, Issue 12 2003Won C. Bae Objective To determine, for clinical indentation testing of human articular cartilage, the effects of aging and degeneration on indentation stiffness and traditional indices of cartilage degeneration; the relationship between indentation stiffness and indices of degeneration; and the sensitivity and specificity of indentation stiffness to cartilage degeneration. Methods Osteochondral cores from femoral condyles of cadaveric human donors were harvested. Samples were distributed into experimental groups based on donor age (young [20,39 years], middle [40,59 years], and old [,60 years]), and a macroscopic articular surface appearance that was either normal or mildly degenerate, without deep erosion. Samples were analyzed for indentation stiffness, cartilage thickness, India ink staining (quantitated as the reflected light score), and Mankin-Shapiro histopathology score. Results Indentation stiffness, India ink staining, and the histopathology score each varied markedly between normal-sample and degenerate-sample groups but varied relatively little between normal samples obtained from different age groups. A decrease in indentation stiffness (softening) correlated with a decrease in the reflectance score and an increase in the overall histopathology score, especially the surface irregularity component of the histopathology score. Receiver operating characteristic analysis suggested that the indentation testing could accurately detect cartilage degeneration as indicated by macroscopic appearance, India ink staining, and histopathology score. Conclusion The indentation stiffness of the normal to mildly degenerate samples tested in this study was sensitive to mild degeneration at the articular surface and was insensitive to changes associated with normal aging or to slight variations in cartilage thickness. This suggests that indentation testing may be a useful clinical tool for the evaluation of early-stage degenerative changes in articular cartilage. [source] Three-yr follow-up of a type 1 diabetes mellitus patient with an islet xenotransplantCLINICAL TRANSPLANTATION, Issue 3 2007R.A. Valdés-González Abstract:, In order to alleviate the shortage of human donors, the use of porcine islets of Langerhans for xenotransplantation in diabetic patients has been proposed as a solution. To overcome rejection, we have developed a procedure for protecting the islets by combining them with Sertoli cells and placing them in a novel subcutaneous device, that generates an autologous collagen covering. A type 1 diabetic woman was closely monitored for 10 months, and then transplanted in two devices with two months of difference and a third time after 22 months. Here we present a three-yr follow-up. The close monitoring induced a rapid decrease in exogenous insulin requirements, which stabilized between 19 and 28 IU/d for nine months. After transplantation, the requirements reduced further to below 6 IU/d and for some weeks she was insulin free. Glycosylated hemoglobin levels decreased concomitantly. Porcine insulin could be detected in the serum after a glucose challenge and insulin positive cells inside a removed device after two yr. No complications have arisen and no porcine endogenous retrovirus infection has been detected through PCR and RT-PCR. This case demonstrates the feasibility of using the xenotransplantation of porcine cells to alleviate metabolic complications and insulin requirements in type 1 diabetic patients. [source] | |||||||||||||