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Explants
Kinds of Explants Terms modified by Explants Selected AbstractsTo Explant or Not to Explant: An Invasive and Noninvasive Monitoring Protocol to Determine the Need of Continued Ventricular Assist Device SupportCONGESTIVE HEART FAILURE, Issue 2 2009Satoru Osaki MD Predictors of myocardial recovery after ventricular assist device (VAD) implantation are not well defined. The authors report their current VAD weaning protocol. Between 2003 and 2006, 38 patients received VAD implants. The authors performed 5 tests in 4 patients in whom echocardiography findings suggested myocardial recovery after implant. The protocol consists of assessing symptoms, electrocardiographic findings, hemodynamics, and cardiac function at baseline and as VAD support is weaned. As a result, 3 patients passed the weaning protocol and were explanted. There has been no recurrence of heart failure 667, 752, and 1007 days after explant, respectively. One patient failed the protocol after 151 days of support because of low cardiac index during the protocol. This patient was transplanted. This current experience of VAD weaning protocol is a novel tool to identify candidates for successful VAD explantation. [source] Medium, Explant and Genotype Factors Influencing Shoot Regeneration in Oilseed Brassica spp.JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2003G. X. Tang Abstract The effects of culture media, explants and genotypes on shoot regeneration in oilseed Brassica species were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog medium supplemented with 3 mg l,1 6-benzylaminopurine and 0.15 mg l,1 1-naphthaleneacetic acid. The addition of 2.5 mg l,1 AgNO3 was very beneficial to shoot regeneration in B. napus and Ag2S2O3 (10 mg l,1) was even superior to AgNO3 (2.5 mg l,1). Explant age, explant type and carbon source also significantly affected shoot regeneration. Four-day-old seedlings of cotyledonary explants showed the maximum shoot regeneration frequency and number of shoots per explant. Of the four explants , peduncles, hypocotyls, cotyledons and leaf petioles , cotyledons produced the highest shoot regeneration frequency (56.67 %). Four carbon sources , glucose, maltose, starch and sucrose , were compared for their respective effects on shoot regeneration from cotyledonary explants. Sucrose appeared to be the best carbon source for shoot regeneration with the highest shoot regeneration frequency (76.00 %). Considerable variation in shoot regeneration from cotyledonary explants was observed both between and within Brassica species. The shoot regeneration frequency ranged from 10.00 % for cv. R5 (B. rapa) to 83.61 % for cv. N1 (B. napus). Two B. napus, one B. carinata and one B. juncea cultivars exhibited shoot regeneration frequency higher than 70 %. In terms of the number of shoots produced per explant, B. rapa showed the highest variation, ranging from 5.64 for cv. R3 to 1.33 for cv. R5. Normal plantlets were regenerated from all induced shoots and developed normally. The regenerated plants were fertile and identical with the source plants. [source] Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker ImplantationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002MARTINO MARTINELLI MARTINELLI, M., et al.: Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation. Unnecessary pacemaker implantation may cause significant social and psychological consequences, the inconvenience of periodic office visits, and the expense of pulse generator replacement. Establishing adequate criteria for explanting pacemakers is crucial and has not yet been described. This study presents the results of a study protocol for explanting the pacemaker in patients without a clear indication for pacemaker implantation. Seventy pacemaker users without a clear reason for the implantation were included in the study conducted from August 1986 to November 1998 and were prospectively followed. The investigation consisted of clinical and neurological evaluations, echocardiogram, exercise testing, and tilt table testing. When these tests were negative, the pulse generator energy and stimulation rates were reprogrammed to the lowest values. Periodic Holter monitoring was conducted during follow-up. When asymptomatic for 1 year, patients underwent an electrophysiological evaluation of sinus and atrioventricular junction function and ventricular vulnerability. When the electrophysiological study was negative, pacemaker explantation was performed. Of the 70 patients, 35 had their pacemaker explanted; 3 were excluded due to a positive tilt table test and electrophysiological study, and 3 are waiting for pacemaker explantation. Mean follow-up after pacemaker explantation was 30.3 months, and all patients remained asymptomatic, except for one patient who died of a noncardiac cause. Critical analysis of pacemaker users without a well-established indication is justified because it may allow pacemaker explant in a significant proportion of these patients, and it may bring considerable social, economic, and psychological benefits. [source] PaCE: a technique to avoid subretinal fluid drainage in retinal detachment surgeryACTA OPHTHALMOLOGICA, Issue 1 2006Manzar Saeed Abstract. Purpose:,Subretinal fluid (SRF) drainage and thus the potential complications of this procedure during scleral buckling can be avoided by inducing SRF absorption preoperatively. The technique described in this series is named PaCE (Pneumatic Cryo Explant). Methods:,A total of 22 eyes of 22 patients with primary bullous rhegmatogenous retinal detachment (RRD) were included in this prospective non-comparative case trial. All satisfied specific inclusion criteria similar to those used in previous pneumatic retinopexy (PR) studies. Under direct visualization, 0.3 ml C3F8 100% was injected into the vitreous cavity through the pars plana. Postoperative posturing was encouraged. Retinopexy with either cryotherapy or laser was performed, combined with scleral buckling (SB) when the SRF was absorbed. Avoidance of SRF drainage and persistent reattachment of the retina at the end of the 12-month follow-up was considered a successful outcome. A change in vision by one line (logMAR) was considered significant. Results:,Resolution of SRF before retinopexy and the SB procedure was achieved in 20 of 22 eyes (90.9%) and hence SRF drainage was not required. Visual improvement was achieved in 95% of cases. One eye (4.5%) lost vision due to a total RD after gas injection (further surgery was not carried out). Conclusion:,PaCE should be considered in any suitable case of primary RRD where SRF drainage is deemed necessary. The potential complications associated with this procedure are relatively less serious and it does not compromise the viability of subsequent procedures. [source] To Explant or Not to Explant: An Invasive and Noninvasive Monitoring Protocol to Determine the Need of Continued Ventricular Assist Device SupportCONGESTIVE HEART FAILURE, Issue 2 2009Satoru Osaki MD Predictors of myocardial recovery after ventricular assist device (VAD) implantation are not well defined. The authors report their current VAD weaning protocol. Between 2003 and 2006, 38 patients received VAD implants. The authors performed 5 tests in 4 patients in whom echocardiography findings suggested myocardial recovery after implant. The protocol consists of assessing symptoms, electrocardiographic findings, hemodynamics, and cardiac function at baseline and as VAD support is weaned. As a result, 3 patients passed the weaning protocol and were explanted. There has been no recurrence of heart failure 667, 752, and 1007 days after explant, respectively. One patient failed the protocol after 151 days of support because of low cardiac index during the protocol. This patient was transplanted. This current experience of VAD weaning protocol is a novel tool to identify candidates for successful VAD explantation. [source] Repulsive guidance of axons of spinal sensory neurons in Xenopus laevis embryos: Roles of Contactin and notochord-derived chondroitin sulfate proteoglycansDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 7 2005Naoko Fujita An immunoglobulin superfamily neuronal adhesion molecule, Contactin, has been implicated in axon guidance of spinal sensory neurons in Xenopus embryos. To identify the guidance signaling molecules that Contactin recognizes in tailbud embryos, an in situ binding assay was performed using recombinant Contactin-alkaline phosphatase fusion protein (Contactin-AP) as a probe. In the assay of whole-mount or sectioned embryos, Contactin-AP specifically bound to the notochord and its proximal regions. This binding was completely blocked by either digestion of embryo sections with chondroitinase ABC or pretreatment of Contactin-AP with chondroitin sulfate A. When the spinal cord and the notochord explants were co-cultured in collagen gel, growing Contactin-positive spinal axons were repelled by notochord-derived repulsive activity. This repulsive activity was abolished by the addition of either a monoclonal anti-Contactin antibody, chondroitin sulfate A or chondroitinase ABC to the culture medium. An antibody that recognizes chondroitin sulfate A and C labeled immunohistochemically the notochord in embryo sections and the collagen gel matrix around the cultured notochord explant. Addition of chondroitinase ABC into the culture eliminated the immunoreactivity in the gel matrix. These results suggest that the notochord-derived chondroitin sulfate proteoglycan acts as a repulsive signaling molecule that is recognized by Contactin on spinal sensory axons. [source] L1, ,1 integrin, and cadherins mediate axonal regeneration in the embryonic spinal cordDEVELOPMENTAL NEUROBIOLOGY, Issue 14 2006Murray Blackmore Abstract Embryonic birds and mammals are capable of axon regeneration after spinal cord injury, but this ability is lost during a discrete developmental transition. We recently showed that changes within maturing neurons, as opposed to changes solely in the spinal cord environment, significantly restrict axon regeneration during development. The developmental changes within neurons that limit axon regeneration remain unclear. One gap in knowledge is the identity of the adhesive receptors that embryonic neurons use to extend axons in the spinal cord. Here we test the roles of L1/NgCAM, ,1 integrin, and cadherins, using a coculture system in which embryonic chick brainstem neurons regenerate axons into an explant of embryonic spinal cord. By in vivo and in vitro methods, we found that brainstem neurons reduce axonal expression of L1 as they mature. Disrupting either L1 or ,1 integrin function individually in our coculture system partially inhibited growth of brainstem axons in spinal cords, while disrupting cadherin function alone had no effect. However, when all three adhesive receptors were blocked simultaneously, axon growth in the spinal cord was reduced by 90%. Using immunohistochemistry and in situ hybridization we show that during the period when neurons lose their regenerative capacity they reduce expression of mRNA for N-cadherin, and reduce axonal L1/NgCAM protein through a post-transcriptional mechanism. These data show that embryonic neurons use L1/NgCAM, ,1 integrin, and cadherin receptors for axon regeneration in the embryonic spinal cord, and raise the possibility that a reduced expression of these essential receptors may contribute to the low-regenerative capacity of older neurons. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] Long-term outcomes of positive fluorescence in situ hybridization tests in primary sclerosing cholangitis,HEPATOLOGY, Issue 1 2010Sanjay Y. Bangarulingam Patients with primary sclerosing cholangitis (PSC) are at increased risk for developing cholangiocarcinoma (CCA). Fluorescence in situ hybridization (FISH) is a cytological test designed to enhance early CCA diagnosis. The long-term outcome of PSC patients with a positive FISH test (polysomy, trisomy/tetrasomy) are unclear. All PSC patients with at least one FISH test were identified and defined to have CCA if they had a positive tissue biopsy, positive cytology, or evidence of cancer in the explant after liver transplantation. A total of 235 PSC patients had at least one FISH test performed, and 56 patients had CCA on histopathology (n = 35) or cytology (n = 21). Overall, 120 of 235 (51%) of PSC patients tested for FISH were positive, but only one third of these positive patients had CCA. Sensitivity and specificity for FISH polysomy were 46% and 88%, and for trisomy/tetrasomy they were 25% and 67%, respectively. Survival analysis showed that patients with FISH polysomy had an outcome similar to patients with CCA; whereas FISH trisomy/tetrasomy patients had an outcome similar to patients with negative FISH tests. The FISH polysomy patients without cancer compared with those with CCA had lower serum bilirubin, lower carbohydrate antigen 19-9 (CA 19-9), lower Mayo risk score, and lower occurrence of dominant strictures. Conclusion: In PSC patients, the presence of a dominant stricture plus FISH polysomy has a specificity of 88% for CCA. Patients with FISH showing trisomy or tetrasomy have a similar outcome to patients with negative FISH. FISH testing should be used selectively in patients with other signs indicating CCA and not as a screening tool in all PSC patients undergoing endoscopic retrograde cholangiopancreatography (ERCP). (HEPATOLOGY 2009.) [source] Excellent outcome following down-staging of hepatocellular carcinoma prior to liver transplantation: An intention-to-treat analysis,,HEPATOLOGY, Issue 3 2008Francis Y. Yao We previously reported encouraging results of down-staging of hepatocellular carcinoma (HCC) to meet conventional T2 criteria (one lesion 2,5 cm or two to three lesions <3 cm) for orthotopic liver transplantation (OLT) in 30 patients as a test of concept. In this ongoing prospective study, we analyzed longer-term outcome data on HCC down-staging in a larger cohort of 61 patients with tumor stage exceeding T2 criteria who were enrolled between June 2002 and January 2007. Eligibility criteria for down-staging included: (1) one lesion >5 cm and up to 8 cm; (2) two to three lesions with at least one lesion >3 cm and not exceeding 5 cm, with total tumor diameter up to 8 cm; or (3) four to five lesions with none >3 cm, with total tumor diameter up to 8 cm. A minimum observation period of 3 months after down-staging was required before OLT. Tumor down-staging was successful in 43 patients (70.5%). Thirty-five patients (57.4%) had received OLT, including two who had undergone live-donor liver transplantation. Treatment failure was observed in 18 patients (29.5%), primarily due to tumor progression. In the explant of 35 patients who underwent OLT, 13 had complete tumor necrosis, 17 met T2 criteria, and five exceeded T2 criteria. The Kaplan-Meier intention-to-treat survival at 1 and 4 years after down-staging were 87.5% and 69.3%, respectively. The 1-year and 4-year posttransplantation survival rates were 96.2% and 92.1%, respectively. No patient had HCC recurrence after a median posttransplantation follow-up of 25 months. The only factor predicting treatment failure was pretreatment alpha-fetoprotein >1,000 ng/mL. Conclusion: Successful down-staging of HCC can be achieved in the majority of carefully selected patients and is associated with excellent posttransplantation outcome. (HEPATOLOGY 2008.) [source] Medium, Explant and Genotype Factors Influencing Shoot Regeneration in Oilseed Brassica spp.JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2003G. X. Tang Abstract The effects of culture media, explants and genotypes on shoot regeneration in oilseed Brassica species were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog medium supplemented with 3 mg l,1 6-benzylaminopurine and 0.15 mg l,1 1-naphthaleneacetic acid. The addition of 2.5 mg l,1 AgNO3 was very beneficial to shoot regeneration in B. napus and Ag2S2O3 (10 mg l,1) was even superior to AgNO3 (2.5 mg l,1). Explant age, explant type and carbon source also significantly affected shoot regeneration. Four-day-old seedlings of cotyledonary explants showed the maximum shoot regeneration frequency and number of shoots per explant. Of the four explants , peduncles, hypocotyls, cotyledons and leaf petioles , cotyledons produced the highest shoot regeneration frequency (56.67 %). Four carbon sources , glucose, maltose, starch and sucrose , were compared for their respective effects on shoot regeneration from cotyledonary explants. Sucrose appeared to be the best carbon source for shoot regeneration with the highest shoot regeneration frequency (76.00 %). Considerable variation in shoot regeneration from cotyledonary explants was observed both between and within Brassica species. The shoot regeneration frequency ranged from 10.00 % for cv. R5 (B. rapa) to 83.61 % for cv. N1 (B. napus). Two B. napus, one B. carinata and one B. juncea cultivars exhibited shoot regeneration frequency higher than 70 %. In terms of the number of shoots produced per explant, B. rapa showed the highest variation, ranging from 5.64 for cv. R3 to 1.33 for cv. R5. Normal plantlets were regenerated from all induced shoots and developed normally. The regenerated plants were fertile and identical with the source plants. [source] Myocardial Failure Caused by Traumatic Dissection of Left Coronary System,Ventricular Recovery with Temporary Circulatory SupportJOURNAL OF CARDIAC SURGERY, Issue 3 2007Alexander Lauten M.D. The dissection involved the left coronary artery including peripheral segments of the coronary circulation. The patient was revascularized; however, she could not be weaned from cardiopulmonary bypass thereafter. An Impella microaxial hemopump was implanted and the patient's left ventricular function markedly improved during the following days. Eight days later hemodynamics had stabilized far enough to explant the device, after explantation the patient remained hemodynamically stable and free of inotropic support. The report intends to emphasize the potential of the myocardium to recover even after extensive infarction under temporary ventricular support and takes the Impella microaxial hemopump into consideration as a device that is technically easy to implant with no injury to the ventricle and thus associated with good properties for weaning. Surgeons should consider the device as short-term support in borderline indications. [source] Stromal cell-derived factor-1 promotes migration of cells from the upper rhombic lip in cerebellar developmentJOURNAL OF NEUROSCIENCE RESEARCH, Issue 13 2010Tao Yu Abstract During cerebellar development, the chemokine stromal cell-derived factor-1, (SDF-1,) has been shown to play an important role in recruiting cells from the upper rhombic lip (URL) and external granule cell layer (EGL). However, its function in cerebellar development is still poorly understood. Our results have demonstrated that SDF-1 is necessary for EGL development, and URL cells stream to the SDF-1 source in vitro. Results of embryonic URL explant assays and transwell assays indicated that SDF-1 induces neural cell migration from the URL region in chemotactic and chemokinetic responses. The time-lapse results showed that the migration speed of granule cell progenitors out of the URL was accelerated by the addition of recombinant SDF-1,. Collectively, our study shows that SDF-1 increases the motility of URL cells in the absence of a gradient and promotes the migration of granule cell progenitors during cerebellar development. © 2010 Wiley-Liss, Inc. [source] Vascular endothelial growth factor enhances migration of astroglial cells in subventricular zone neurosphere culturesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2010Nina Mani Abstract Vascular endothelial growth factor (VEGF) is an endothelial and neuronal survival factor and a mitogen for endothelial cells and astrocytes in both explant and in vivo injury models. In the CNS, interplay between the vasculature and neural stem progenitor (NSP) cells is required for the maintenance of angiogenic/neurogenic coordination in the germinal niche in the subventricular zone (SVZ) of the lateral ventricle. Using an in vitro SVZ neurosphere (NS) model, this study aimed to understand the direct effects of VEGF and its receptor signaling on neonatal NSP cell growth and migration. Our data indicate that VEGF administration, compared with untreated or brain-derived neurotrophic factor-treated NS, significantly increased growth and migratory capacity of glial fibrillary acidic protein (GFAP)+ and nestin+ NSP cells and in secondary cultures induced a stellate astrocyte morphology. Blockade of both VEGF, which is normally expressed in some NS cells, and its flt-1 receptor signaling by neutralizing antibodies caused morphological changes specifically in GFAP+ cells and disrupted sphere formation and outward migration. These cells did not appear as conventional polygonal astrocytes; their process growth was severely restricted, and overall migration was reduced by up to 76% of control cultures. Blockade of VEGF's flk-1 receptor reduced VEGF expression and caused a lesser, though significant, decrease (29%) in NSP (GFAP+) cell migration. The results show that both VEGF and, in particular, flt-1 receptor signaling are critical to the proper configuration of the NS and its subsequent development. VEGF is also an important growth and migratory factor particularly for GFAP+ cells developing in SVZ-derived NS in culture. © 2009 Wiley-Liss, Inc. [source] Increased accumulation of superficial zone protein (SZP) in articular cartilage in response to bone morphogenetic protein-7 and growth factorsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2007Afshin Khalafi Abstract The purpose of this study was to investigate the role of bone morphogenetic proteins (BMPs), such as BMP-7, growth factors, and cytokines, in the accumulation of superficial zone protein (SZP) in bovine articular cartilage. Calf superficial articular cartilage discs and chondrocytes were obtained for explant and monolayer culture systems, respectively. Dose- and time-dependent actions of BMP-7 on SZP accumulation were investigated in both explant and monolayer culture systems. In addition, actions of various morphogens and growth factors [BMP-2, BMP-4, fibroblast growth factor 2 (FGF-2), insulin-like growth factor 1 (IGF-1), platelet-derived growth factor (PDGF), and transforming growth factor , (TGF-,1)], and cytokines [interleukin (IL)-1,, IL-1,, and tumor necrosis factor (TNF-,)] alone, and in combination with BMP-7, on SZP accumulation were investigated in monolayer culture systems. SZP accumulation was quantified in both the cartilage and the medium using SDS-PAGE and subsequent immunoblotting. In both explant and monolayer cultures, BMP-7 increased SZP accumulation in a dose- and time-dependent fashion (p,<,0.05). Furthermore, SZP accumulation was significantly increased in monolayer cultures by FGF-2, IGF-1, PDGF, and TGF-,1 (p,<,0.05). Both IL-1, and TNF-, significantly reduced SZP accumulation (p,<,0.05). The inhibition of SZP accumulation by TNF-, was partially alleviated by concurrent treatment with BMP-7. The results of this investigation provide novel insights into the role of morphogens, especially BMP-7, growth factors, and cytokines in the accumulation of SZP in articular cartilage. This information has clinical implications because stimulation of SZP may ameliorate the pathology of joint function in arthritis. Furthermore, tissue engineering approaches to articular cartilage may depend on the optimal synthesis and assembly of SZP in the superficial zone to ensure functional tissue architecture. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007 [source] Post-transplant recurrent hepatitis C: immunohistochemical detection of hepatitis C virus core antigen and possible pathogenic implicationsLIVER INTERNATIONAL, Issue 6 2008Mário G. Pessôa Abstract Introduction: The mechanisms by which severe cholestatic hepatitis develops after liver transplantation are not fully understood. Reports on immunohistochemical distribution of hepatitis C virus (HCV) antigens are still scarce, but recently, HCV immunostaining was suggested for early diagnosis of cholestatic forms of recurrent hepatitis C in liver grafts. After purification, Rb246 pab anticore (aa1-68) yielded specific, granular cytoplasmic staining in hepatocytes. Signal amplification through the Envision-Alkaline Phosphatase System avoided endogenous biotin and peroxidase. Aims/Methods: Rb246 was applied to liver samples of explants of 12 transplant recipients, six with the most severe form of post-transplantation recurrence, severe cholestatic hepatitis (group 1) and six with mild recurrence (group 2). We also assessed immuno-reactivity at two time-points post-transplantation (median 4 and 22 months) in both groups. HCV-core Ag was semiquantified from 0 to 3+ in each time point. Serum HCV-RNA was also measured on the different time points by branched DNA. Results: In the early post-transplant time point, one patient had a mild staining (1+), two patients had a moderate staining (2+) and the other three had no staining in group 1, compared with five patients with no staining (0) and one patient with mild staining (1+) in group 2. Late post-transplant liver samples were available in nine patients, and two out of four samples in group 1 showed a mild staining, compared with no staining patients in five patients in group 2. Strikingly, on the explant samples, HCV immunostaining was strongly positive in group 1, and mildly positive in group 2. Two out of five samples showed 3+ staining, and three samples showed 2+ staining in group 1; two out of five samples showed no staining, two samples showed 1+ staining and one sample showed 2+ staining in group 2. Serum HCV-RNA was significantly higher in group 1, on both time-points post-transplantation. HCV-core Ag was not directly associated with serum HCV-RNA on the different time points. Conclusion: These preliminary results suggest that strong HCV immunostaining in the explant is predictive of more severe disease recurrence. [source] Seventh Day Syndrome , acute hepatocyte apoptosis associated with a unique syndrome of graft loss following liver transplantation,LIVER INTERNATIONAL, Issue 1 2001Muhammed Ashraf Memon Abstract:Aim: The aim of this study is to describe a unique 7th day syndrome (7DS), quite different from other causes of post-transplantation allograft dysfunction in a group of orthotopic liver transplant (OLT) patients who needed retransplantation. Methods: A retrospective analysis of 594 consecutive OLT over an 8-year period revealed that 10 patients developed allograft dysfunction approximately 7 days following an initially normal graft function. Results: The features included: (a) severe liver failure; (b) sudden peak of extremely high liver enzymes at approximately day 7; (c) serial liver biopsy findings of central lobular hemorrhage with minimal inflammatory cell infiltrate and (d) an explant with no evidence of vascular thrombosis. The biochemical and morphometric pathological data of these patients were compared with data of patitents who had early acute rejection (AR), hepatic artery thrombosis (HAT), primary non-function (PNF), severe sepsis and no dysfunction. Lastly, serial liver core biopsies and explants were tested for evidence of apoptosis, which revealed a significantly higher number of apoptotic hepatocytes in 7DS compared to all control groups. Conclusions: Seventh Day Syndrome is a distinct entity associated with early graft dysfunction characterized by a marked apoptosis of hepatocytes. Fas receptor activation or other pathways of program cell death may be implicated in occurrence of 7DS. [source] Risk factors for recurrence of autoimmune hepatitis after liver transplantation,,LIVER TRANSPLANTATION, Issue 10 2009Aldo J. Montano-Loza Autoimmune hepatitis has been reported to recur after liver transplantation. The aim of our study was to evaluate the risk factors associated with recurrence of autoimmune hepatitis. Forty-six patients that underwent liver transplantation because of end-stage liver disease secondary to autoimmune hepatitis were studied. Recurrence of autoimmune hepatitis was diagnosed in 11 of the 46 (24%) patients, and the overall 5-year probability of recurrence was 18%. By univariate Cox analysis, the features before liver transplantation associated with a higher risk of recurrence were concomitant autoimmune disease [hazard ratio (HR), 3.74; 95% confidence interval (CI), 1.05,13.36; P = 0.04], high aspartate aminotransferase (HR, 1.09; 95% CI, 1.03,1.14; P = 0.002), high alanine aminotransferase (HR, 1.09; 95% CI, 1.03,1.20; P = 0.003), and high immunoglobulin G (IgG; HR, 1.25; 95% CI, 1.11,1.41; P = 0.0003). Moreover, patients with recurrence had a higher frequency of moderate to severe inflammatory activity (HR, 5.3; 95% CI, 1.55,18.79; P = 0.008) and plasma cell infiltration in the liver explant (HR, 5.8; 95% CI, 1.52,22.43; P = 0.01). In the multivariate Cox analysis, only the presence of moderate to severe inflammation (HR, 6.9; 95% CI, 1.76,26.96; P = 0.006) and high IgG levels before liver transplantation (HR, 7.5; 95% CI, 1.45,38.45; P = 0.02) were independently associated with the risk of autoimmune hepatitis recurrence. In conclusion, patients with concomitant autoimmune disease, high aspartate aminotransferase, alanine aminotransferase, and IgG before the transplant, or moderate to severe inflammatory activity or plasma cell infiltration in the liver explant have a higher risk of recurrent disease. These findings suggest that recurrence of autoimmune hepatitis may reflect incomplete suppression of disease activity prior to liver transplantation. Liver Transpl 15:1254,1261, 2009. © 2009 AASLD. [source] Sirolimus-based immunosuppression following liver transplantation for hepatocellular carcinomaLIVER TRANSPLANTATION, Issue 5 2008Michael A. Zimmerman Experience with sirolimus (SRL)-based immunosuppression following orthotopic liver transplantation (OLT) is rapidly accumulating. In combination with calcineurin inhibitors (CNIs), SRL may reduce the incidence of acute rejection and lower overall required drug levels. This study sought to quantify long-term outcome following OLT in patients with cirrhosis and concomitant hepatocellular carcinoma (HCC) who were treated with an SRL-based regimen as a primary therapy. From January 2000 to June 2007, 97 patients underwent OLT for end-stage liver disease and HCC at the University of Colorado Health Sciences Center. Of those, 45 patients received SRL, in addition to CNIs, as a component of their primary immunosuppression regimen post-OLT. Conversely, 52 patients received the standard immunosuppression regimen including CNIs, mycophenolate mofetil, and corticosteroids. The 2 treatment groups were compared with respect to the following variables: age, gender, tumor stage by explant, grade, size, presence of vascular invasion, focality, Child's class, baseline creatinine, and warm and cold ischemic times. The 2 groups were comparable by all factors save for cold ischemic time, which was significantly longer in the CNI-treated group. Overall survival at 1 and 5 years post-OLT for patients treated with SRL was 95.5% and 78.8%, respectively. Conversely, survival in patients treated with CNIs exclusively at the same time intervals was 83% and 62%. Although there was no difference in the incidence of major complications, the SRL group experienced a modest improvement in renal function. Cumulatively, these data suggest a potential survival benefit with SRL-based therapy in patients undergoing OLT for end-stage liver disease and concomitant malignancy. Liver Transpl 2008. © 2008 AASLD. [source] Outcome of patients with hepatocellular carcinoma listed for liver transplantation within the Eurotransplant allocation system,LIVER TRANSPLANTATION, Issue 4 2008Michael Adler Although hepatocellular carcinoma (HCC) has become a recognized indication for liver transplantation, the rules governing priority and access to the waiting list are not well defined. Patient- and tumor-related variables were evaluated in 226 patients listed primarily for HCC in Belgium, a region where the allocation system is patient-driven, priority being given to sicker patients, based on the Child-Turcotte-Pugh (CTP) score. Intention-to-treat and posttransplantation survival rates at 4 years were 56.5 and 66%, respectively, and overall HCC recurrence rate was 10%. The most significant predictors of failure to receive a transplant in due time were baseline CTP score equal to or above 9 (relative risk [RR] 4.1; confidence interval [CI]: 1.7,9.9) and , fetoprotein above 100 ng/mL (RR 3.0; CI: 1.2,7.1). Independent predictors of posttransplantation mortality were age equal to or above 50 years (RR 2.5; CI: 1.0,3.7) and United Network for Organ Sharing pathological tumor nodule metastasis above the Milan criteria (RR 2.1; CI: 1.0,5.9). Predictors of recurrence (10%) were , fetoprotein above 100 ng/mL (RR 3.2; CI:1.1,10) and vascular involvement of the tumor on the explant (RR 3.6; CI: 1.1,11.3). Assessing the value of the pretransplantation staging by imaging compared to explant pathology revealed 34% accuracy, absence of carcinoma in 8.3%, overstaging in 36.2%, and understaging in 10.4%. Allocation rules for HCC should consider not only tumor characteristics but also the degree of liver impairment. Patients older than 50 years with a stage above the Milan criteria at transplantation have a poorer prognosis after transplantation. Liver Transpl 14:526,533, 2008. © 2008 AASLD. [source] A prospective study on downstaging of hepatocellular carcinoma prior to liver transplantation,LIVER TRANSPLANTATION, Issue 12 2005Francis Y. Yao In patients with hepatocellular carcinoma (HCC) exceeding conventional (T2) criteria for orthotopic liver transplantation (OLT), the feasibility and outcome following loco-regional therapy intended for tumor downstaging to meet T2 criteria for OLT are unknown. In this first prospective study on downstaging of HCC prior to OLT, the eligibility criteria for enrollment into a downstaging protocol included 1 lesion >5 cm and ,8 cm, 2 or 3 lesions at least 1 >3 cm but ,5 cm with total tumor diameter of ,8 cm, or 4 or 5 nodules all ,3 cm with total tumor diameter ,8 cm. Patients were eligible for living-donor liver transplantation (LDLT) if tumors were downstaged to within proposed University of California, San Francisco (UCSF) criteria.13 A minimum follow-up period of 3 months after downstaging was required before cadaveric OLT or LDLT, with imaging studies meeting criteria for successful downstaging. Among the 30 patients enrolled, 21 (70%) met criteria for successful downstaging, including 16 (53%) who had subsequently received OLT (2 with LDLT), and 9 patients (30%) were classified as treatment failures. In the explant of 16 patients who underwent OLT, 7 had complete tumor necrosis, 7 met T2 criteria, but 2 exceeded T2 criteria. No HCC recurrence was observed after a median follow-up of 16 months after OLT. The Kaplan-Meier intention-to-treat survival was 89.3 and 81.8% at 1 and 2 yr, respectively. In conclusion, successful tumor downstaging can be achieved in the majority of carefully selected patients, but longer follow-up is needed to further access the risk of HCC recurrence after OLT. (Liver Transpl 2005;11:1505,1514.) [source] Resection prior to liver transplantation for hepatocellular carcinoma: A strategy of optimizing the role of resection and transplantation in cirrhotic patients with preserved liver functionLIVER TRANSPLANTATION, Issue 6 2004FRCS (Edin), Ronnie T. Poon MS Objective To evaluate the feasibility and postoperative course of liver transplantation (LT) in cirrhotic patients who underwent liver resection prior to LT for HCC. Summary Background Data Although LT provides longer survival than liver resection for treatment of small HCCs, donor shortage and long LT wait time may argue against LT. The feasibility and survival following LT after hepatic resection have not been previously examined. Methods Between 1991 and 2001, among 107 patients who underwent LT for HCC, 88 met Mazzafero's criteria upon pathologic analysis of the explant. Of these, 70 underwent primary liver transplantation (PLT) and 18 liver resection prior to secondary liver transplantation (SLT) for recurrence (n = 11), deterioration of liver function (n = 4), or high risk for recurrence (n = 3). Perioperative and postoperative factors and long-term survival were compared. Results Comparison of PLT and SLT groups at the time of LT revealed similar median age (53 vs. 55 years), sex, and etiology of liver disease (alcohol/viral B/C/other). In the SLT group, the mean time between liver resection and listing for LT was 20 months (range 1-84 months). Overall time on LT waiting list of the two groups was similar (3 vs. 5 months). Pathologic analysis after LT revealed similar tumor size (2.2 vs. 2.3 cm) and number (1.6 vs. 1.7). Perioperative and postoperative courses were not different in terms of operative time (551 vs. 530 minutes), blood loss (1191 vs. 1282 mL), transfusion (3 vs. 2 units), ICU (9 vs. 10 days) or hospital stay (32 vs. 31 days), morbidity (51% vs. 56%) or 30-day mortality (5.7% vs. 5.6%). During a median follow-up of 32 months (3 to 158 months), 3 patients recurred after PLT and one after SLT. After transplantation, 3- and 5-year overall survivals were not different between groups (82 vs. 82% and 59 vs. 61%). Conclusions In selected patients, liver resection prior to transplantation does not increase the morbidity or impair long-term survival following LT. Therefore, liver resection prior to transplantation can be integrated in the treatment strategy for HCC. (Ann Surg 2003;238:885,893.) (Liver Transpl 2004;10:813,815.) [source] Characterization of heat shock protein 90 in the shrimp Metapenaeus ensis: Evidence for its role in the regulation of vitellogenin synthesisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2008Long Tao Wu Abstract Estrogen hormones play a vital role in the regulation of female reproductive maturation. In oviparous vertebrates, the synthesis of vitellogenin (VTG) is tightly controlled by estrogen hormone signal transduction pathway, which is mediated by estrogen receptor and heat shock protein 90 (Hsp90). In order to investigate whether a similar mechanism exists in crustaceans, the Hsp90 gene was cloned and isolated from the shrimp Metapenaeus ensis by homology cloning strategy. The Hsp90 is 2,524 bp in length, containing an open reading frame of 2,163 bp that encodes a 720 amino acid polypeptide (83 kD). The Hsp90 -coding region is interrupted by four introns. MeHsp90 is differentially expressed in eyestalk, ovary, and hepatopancreas at different ovarian maturation stages, and consistently expressed in other tissues including heart, gill, gut, muscle, and central nervous system. In vitro ovary explant assay reveals that MeHsp90 expression in immature ovary can be induced by the addition of exogenous estradiol-17,, but expression in fully mature ovary exhibits no response to estradiol-17, treatment. In situ hybridization shows that MeHsp90 is highly expressed in previtellogenic oocytes and its expression decreases with the progress of maturation, and finally stops in late-vitellogenic oocytes. Our results indicate a strong correlation between estrogen hormones and Hsp90 expression in shrimp, suggesting that the expression of VTG may be under the regulation of estrogen hormones through a mechanism similar to that in vertebrates. The result provides insights on the control of vitellogenesis in invertebrates. Mol. Reprod. Dev. 75: 952,959, 2008. © 2008 Wiley-Liss, Inc. [source] Biomechanical findings in rats undergoing fascial reconstruction with graft materials suggested as an alternative to polypropylene ,,NEUROUROLOGY AND URODYNAMICS, Issue 3 2010M.L. Konstantinovic Abstract Aims Graft materials used for pelvic floor reinforcement should still be considered as investigational and, therefore, evaluated experimentally and within clinical trials. The present report describes our biomechanical findings in rats implanted with selected novel implant materials, which in recent years have been suggested as alternatives to plain polypropylene (PP) meshes. Methods Full thickness abdominal wall defects were primarily repaired by the implant of interest. Experiments involved eight different implant materials: two partly degradable synthetic implants, that is, a hybrid of polyglactin 910 with PP (Vypro II) and collagen coated PP (Pelvitex); two non-cross linked (Surgisis, InteX,n LP) and two cross-linked materials (Pelvicol, Pelvisoft) and two porous modifications of InteX,n LP and Pelvicol implants. At different time points (7, 14, 30, and 90 days), the implants and surrounding host tissue (explant) were harvested and tensiometry was performed. Tensile strength and location of breakage were recorded. Results In general resorbable non-cross linked collagen matrices and porous materials were weaker after 90 days; similar behavior was seen for implant materials alone and their construction with the surrounding native tissue. Both non-porous and porous modification of InteX,n LP appeared at 90 days as a very thin layer of collagen that was two-thirds, respectively one-third of the initial thickness. Conclusions In experimental conditions, sufficient strength was obtained only after 3 months, and PP containing constructs appeared as the strongest though reconstruction with Pelvicol showed comparable outcomes. Lower values for strength of non-cross linked and porous collagen materials are questioning their efficacy for pelvic floor reconstruction. Neurourol. Urodynam. 29:488,493, 2010. © 2009 Wiley-Liss, Inc. [source] Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker ImplantationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002MARTINO MARTINELLI MARTINELLI, M., et al.: Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation. Unnecessary pacemaker implantation may cause significant social and psychological consequences, the inconvenience of periodic office visits, and the expense of pulse generator replacement. Establishing adequate criteria for explanting pacemakers is crucial and has not yet been described. This study presents the results of a study protocol for explanting the pacemaker in patients without a clear indication for pacemaker implantation. Seventy pacemaker users without a clear reason for the implantation were included in the study conducted from August 1986 to November 1998 and were prospectively followed. The investigation consisted of clinical and neurological evaluations, echocardiogram, exercise testing, and tilt table testing. When these tests were negative, the pulse generator energy and stimulation rates were reprogrammed to the lowest values. Periodic Holter monitoring was conducted during follow-up. When asymptomatic for 1 year, patients underwent an electrophysiological evaluation of sinus and atrioventricular junction function and ventricular vulnerability. When the electrophysiological study was negative, pacemaker explantation was performed. Of the 70 patients, 35 had their pacemaker explanted; 3 were excluded due to a positive tilt table test and electrophysiological study, and 3 are waiting for pacemaker explantation. Mean follow-up after pacemaker explantation was 30.3 months, and all patients remained asymptomatic, except for one patient who died of a noncardiac cause. Critical analysis of pacemaker users without a well-established indication is justified because it may allow pacemaker explant in a significant proportion of these patients, and it may bring considerable social, economic, and psychological benefits. [source] Spinal Cord Stimulation for Chronic Visceral Abdominal PainPAIN MEDICINE, Issue 3 2010Leonardo Kapural MD Abstract Background., Spinal cord stimulation (SCS) may reduce pain scores and improve function in patients with chronic visceral abdominal pain. We thus present our large clinical experience in SCS for visceral abdominal pain. Methods., We trialed spinal cord stimulation in 35 patients, each of whom was shown by retrograde differential epidural block to have either visceral pain (n = 32) or mixed visceral and central pain (n = 3). SCS trials lasted 4 to 14 days (median 9 days). SCS lead tips were mostly positioned at T5 (n = 11) or T6 (n = 10). Results., Thirty patients (86%) reported at least 50% pain relief upon completion of the trial. Among these, pretrial visual analog scale (VAS) pain scores averaged 8.2 ± 1.6 (SD) and opioid use averaged 110 ± 119 mg morphine sulfate equivalents. During the trial, VAS pain scores decreased to 3.1 ± 1.6 cm (P < 0.001, Mann,Whitney Rank Sum Test) and opioid use decreased to 70 ± 68 mg morphine equivalent a day (P = 0.212). Five patients failed the trial, one was lost to follow-up, and 19 were followed for the whole year. Seven patients were either followed for less than a year (n = 3) or the SCS system was removed due to infection or lead migration (n = 4). One patient despite the successful trial felt no improvements at 6 months after the implant and requested an explant of the SCS device. Among the 28 patients who received permanent implant, 19 were followed at least a year. Their VAS pain scores remained low (3.8 ± 1.9 cm; P < 0.001) at 1 year, as did opioid use (38 ± 48 mg morphine equivalents; P = 0.089). Conclusions., Spinal cord stimulation may be a useful therapeutic option for patients with severe visceral pain. [source] Ultraviolet B radiation suppresses Langerhans cell migration in the dermis by down-regulation of ,4 integrinPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 3 2006Motoko Hamakawa Background/Purpose: Ultraviolet B (UVB) radiation affects the migration and function of epidermal Langerhans cells (LC) and causes immunosuppression of contact hypersensitivity. It is known that LC leaves the epidermis after exposure to UVB. To know the behavior of LC in the dermis after UVB radiation, we studied the effect of UVB radiation on the expression of integrin families on freshly isolated or cultured murine LC. We also examined whether UVB radiation affects the migration of LC to secondary lymphoid tissue chemokine (SLC/6Ckine). Methods: Integrin expressions of murine LC cultured in epidermal cell suspension were analyzed using flowcytometry. We used murine LC sorted flowcytometrically for binding assay to extracellular matrix and for migration assay to chemokine. Skin explant assay and immnohistochemical staining for ,cords formation' were performed as previously described. Results: Twenty and 40 mJ/cm2 of UVB radiation down-regulated the expression of ,4 integrin on 24 h-cultured LC, but not that of ,6, ,1, or ,4 integrin. The number of cultured LC adhered to fibronectin, a ligand for ,4 integrin, was decreased after UVB irradiation, while that to laminin, a ligand for ,6 integrin, was not influenced. UVB radiation reduced the number of migrating LC to SLC. Furthermore, skin sheet explant experiments showed that UVB radiation inhibited the ,cords' formation in dermal vessels of the 48 h-cultured skin. Conclusions: These data suggest that UVB radiation may suppress the migration of LC from the dermis to lymphatic vessels. UVB radiation may downregulate the adherence of LC to dermal fibronectin and migration to SLC, and consequently suppress the migration of LC from the UVB-irradiated dermis to lymphatics. [source] In vitro chromosome doubling of Miscanthus sinensisPLANT BREEDING, Issue 5 2002K. K. Petersen Abstract The aim was to develop an efficient chromosome doubling method for Miscanthus sinensis to enable the production of triploids and so avoid seed dispersal to the environment. Antimitotic treatments with colchicine or oryzalin were tested in M. sinensis cl. MS-88-110 on: (1) in vitro shoots and plants established in soil; (2) during propagation of embryogenic callus; and (c) during the initial stages of callus induction. All systems produced chromosome-doubled plants. A higher percentage of tetraploids was found after antimitotic treatment at the explant or callus level compared with treatment of in vitro shoots or plants established in soil. In general, oryzalin was more toxic to plant material than colchicine. A higher frequency of chimeras was found among plants with altered ploidy level when the target was formed shoot buds compared with adventitious shoot formation from callus. Antimitotic treatment of embryogenic callus from shoot apices also resulted in a high degree of albinism. [source] Hepatocyte growth factor protects auditory hair cells from aminoglycosidesTHE LARYNGOSCOPE, Issue 10 2009Yayoi S. Kikkawa MD Abstract Objectives/Hypothesis: To examine the effect of hepatocyte growth factor (HGF) for protection of auditory hair cells against aminoglycosides and its molecular mechanisms. Study Design: Experimental study. Methods: We quantitatively assessed protective effects of HGF on mouse cochlear hair cells against neomycin toxicity using explant culture systems. To understand mechanisms of hair cell protection by HGF, we examined the expression of c-Met, HGF receptor, and 4-hydroxynonenal (a lipid peroxidation marker) in the cochlea by means of immunohistochemistry and Western blotting. Results: The application of HGF to cochlear explant cultures significantly reduced the hair cell loss induced by neomycin. Immunohistochemistry showed c-Met expression in normal auditory hair cells, and its increase in response to neomycin-induced damage. Immunostaining for 4-hydroxynonenal suggested that HGF acted by attenuating the lipid peroxidation of auditory epithelia induced by neomycin. Conclusions: These findings demonstrate that a functional HGF/c-Met coupling is present in the cochlea, and HGF application exerts protective effects on hair cells, indicating the potential of HGF as a therapeutic agent for sensorineural hearing loss. Laryngoscope, 2009 [source] Hepatitis C Virus Compartmentalization and Infection Recurrence after Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009S. Ramirez Hepatitis C virus (HCV) compartmentalization may have important implications in the pathogenesis of HCV infection. The aim of this study was to investigate the presence and relevance of HCV compartmentalization in the setting of liver transplantation (LT). We collected samples of serum, peripheral blood mononuclear cells (PBMC), perihepatic lymph nodes (PLN) and liver explant at the time of LT, and serum and PBMC after transplantation from 57 HCV-infected cirrhotic patients undergoing LT: 38 individuals received antiviral treatment before LT and 19 were untreated controls. HCV-RNA levels were determined by real-time PCR and the hypervariable region 1 (HVR-1) was sequenced. HCV-RNA was detected in all samples from control patients. In virological responders, recurrence after LT was associated with residual HCV-RNA in the liver explant. Within the entire cohort, 47% of patients harbored differences in direct sequences from distinct compartments. Quasispecies analysis revealed that in most cases, HVR-1 sequences recovered after infection recurrence were identical or closely related to those isolated from the liver explant and serum at the time of LT. Our study shows that a significant proportion of HCV-infected cirrhotic patients exhibit compartmentalization. Viral variants originating within the liver appear to be the main cause of HCV recurrence after LT. [source] Plant regeneration through the direct induction of shoot buds from petiole explants of Jatropha curcas: a biofuel plantANNALS OF APPLIED BIOLOGY, Issue 3 2010N. Kumar An efficient and reproducible method for the regeneration of Jatropha curcas plants has been developed. The method employed direct induction of shoot buds from petiole explants, without the formation of an intervening callus using a Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). The best induction of shoot buds (58.35%) and the number of shoot buds per explant (10.10) were observed when in vitro petiole explants were placed horizontally on MS medium supplemented with 2.27 µM TDZ after 6 weeks. The induced shoot buds were transferred to MS medium containing 10 µM kinetin (Kn), 4.5 µM 6-benzyl aminopurine (BAP) and 5.5 µM ,-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA and indole-3-butyric acid (IBA). MS medium supplemented with 2.25 µM BAP and 8.5 µM IAA was found to be the best combination for shoot elongation and 3.01,3.91 cm elongation was achieved after 6 weeks. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. The orientation (horizontal or vertical) and source (in vitro or in vivo) of explants also significantly influenced plant regeneration. The elongated shoots could be rooted on half-strength MS medium supplemented with 2% sucrose, different concentrations and combinations of IBA, IAA and NAA, and 0.25 mg L,1 activated charcoal. Half-strength MS medium supplemented with 2% sucrose, 15 µM IBA, 5.7 µM IAA, 5.5 µM NAA and 0.25 mg L,1 activated charcoal was found to be the best for promoting rooting. The rooted plants could be established in soil with more than 90% survival. [source] | ||||||||||||||||||||||||||||||||||