Transplantation

About: Transplantation is a research topic. Over the lifetime, 276584 publications have been published within this topic receiving 7961661 citations.

Fulminant and subfulminant liver failure: definitions and causes.

Abstract: Fulminant or subfulminant liver failure, complicated by encephalopathy and in many cases by death is seen to be a syndrome that may result from numerous causes. Although viral hepatitis, drug-induced hepatitis, and hepatitis due to various types of poisonings, in decreasing frequency, account for 90% of all cases, a variety of miscellaneous conditions account for the remainder. Consideration of the possibility of these less common etiologies by the clinician is of considerable importance, since some, including massive malignant involvement (such as leukemia) or acute fulminant Wilson's disease, may respond to specific treatment measures. Thus, unless hepatic transplantation proves to be applicable in FHF of many etiologic diagnosis may continue to have important therapeutic indications in at least some cases with this syndrome.

An entire functional mammary gland may comprise the progeny from a single cell

Abstract: Any epithelial portion of a normal mouse mammary gland can reproduce an entire functional gland when transplanted into an epithelium-free mammary fat pad. Mouse mammary hyperplasias and tumors are clonal dominant populations and probably represent the progeny of a single transformed cell. Our study provides evidence that single multipotent stem cells positioned throughout the mature fully developed mammary gland have the capacity to produce sufficient differentiated progeny to recapitulate an entire functional gland. Our evidence also demonstrates that these stem cells are self-renewing and are found with undiminished capacities in the newly regenerated gland. We have taken advantage of an experimental model where mouse mammary tumor virus infects mammary epithelial cells and inserts a deoxyribonucleic acid copy(ies) of its genome during replication. The insertions occur randomly within the somatic genome. CzechII mice have no endogenous nucleic acid sequence homology with mouse mammary tumor virus; therefore all viral insertions may be detected by Southern analysis provided a sufficient number of cells contain a specific insertional event. Transplantation of random fragments of infected CzechII mammary gland produced clonal-dominant epithelial populations in epithelium-free mammary fat pads. Serial transplantation of pieces of the clonally derived outgrowths produced second generation glands possessing the same viral insertion sites providing evidence for self-renewal of the original stem cell. Limiting dilution studies with cell cultures derived from third generation clonal outgrowths demonstrated that three multipotent but distinct mammary epithelial progenitors were present in clonally derived mammary epithelial populations. Estimation of the potential number of multipotent epithelial cells that may be evolved from an individual mammary-specific stem cell by self-renewal is in the order of 10(12)-10(13). Therefore, one stem cell might easily account for the renewal of mammary epithelium over several transplant generations.

Allogeneic mesenchymal stem cells restore cardiac function in chronic ischemic cardiomyopathy via trilineage differentiating capacity

Abstract: The mechanism(s) underlying cardiac reparative effects of bone marrow-derived mesenchymal stem cells (MSC) remain highly controversial. Here we tested the hypothesis that MSCs regenerate chronically infarcted myocardium through mechanisms comprising long-term engraftment and trilineage differentiation. Twelve weeks after myocardial infarction, female swine received catheter-based transendocardial injections of either placebo (n = 4) or male allogeneic MSCs (200 million; n = 6). Animals underwent serial cardiac magnetic resonance imaging, and in vivo cell fate was determined by co-localization of Y-chromosome (Ypos) cells with markers of cardiac, vascular muscle, and endothelial lineages. MSCs engrafted in infarct and border zones and differentiated into cardiomyocytes as ascertained by co-localization with GATA-4, Nkx2.5, and α-sarcomeric actin. In addition, Ypos MSCs exhibited vascular smooth muscle and endothelial cell differentiation, contributing to large and small vessel formation. Infarct size was reduced from 19.3 ± 1.7% to 13.9 ± 2.0% (P < 0.001), and ejection fraction (EF) increased from 35.0 ± 1.7% to 41.3 ± 2.7% (P < 0.05) in MSC but not placebo pigs over 12 weeks. This was accompanied by increases in regional contractility and myocardial blood flow (MBF), particularly in the infarct border zone. Importantly, MSC engraftment correlated with functional recovery in contractility (R = 0.85, P < 0.05) and MBF (R = 0.76, P < 0.01). Together these findings demonstrate long-term MSC survival, engraftment, and trilineage differentiation following transplantation into chronically scarred myocardium. MSCs are an adult stem cell with the capacity for cardiomyogenesis and vasculogenesis which contribute, at least in part, to their ability to repair chronically scarred myocardium.

A randomized active-controlled trial of mycophenolate mofetil in heart transplant recipients. Mycophenolate Mofetil Investigators.

Abstract: BACKGROUND After heart transplantation, 1-year and 5-year survival rates are 79% and 63%, respectively, with rejection, infection, and allograft coronary artery disease accounting for the majority of deaths. Mycophenolate mofetil (MMF), an inhibitor of the de novo pathway for purine biosynthesis, decreases rejection in animals and in human renal transplantation. METHODS In a double-blind, active-controlled trial, 28 centers randomized 650 patients undergoing their first heart transplant to receive MMF (3000 mg/day) or azathioprine (1.5-3 mg/kg/day), in addition to cyclosporine and corticosteroids. Rejection and survival data were obtained for 6 and 12 months, respectively. Because 11% of the patients withdrew before receiving study drug, data were analyzed on all randomized patients (enrolled patients) and on patients who received study medications (treated patients). RESULTS Survival and rejection were similar in enrolled patients (MMF, n=327; azathioprine, n=323). In treated patients (MMF, n=289; azathioprine, n=289), the MMF group compared with the azathioprine group was associated with significant reduction in mortality at 1 year (18 [6.2%] versus 33 deaths [11.4%]; P=0.031) and a significant reduction in the requirement for rejection treatment (65.7% versus 73.7%; P=0.026). There was a trend for fewer MMF patients to have > or = grade 3A rejection (45.0% versus 52.9%; P=0.055) or require the murine monoclonal anti-CD3 antibody or antithymocyte globulin (15.2% versus 21.1%; P=0.061). Opportunistic infections, mostly herpes simplex, were more common in the MMF group (53.3% versus 43.6%; P=0.025). CONCLUSIONS Substitution of MMF for azathioprine may reduce mortality and rejection in the first year after cardiac transplantation.

Osteonecrosis of the Jaw in Multiple Myeloma Patients: Clinical Features and Risk Factors

Abstract: Purpose To describe the clinical, radiologic, and pathologic features and risk factors for osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients. Patients and Methods A retrospective review of 90 MM patients who had dental assessments, including 22 patients with ONJ. There were 62 men; the median age was 61 years in ONJ patients and 58 years among the rest. Prior MM therapy included thalidomide (n = 67) and stem-cell transplantation (n = 72). Bisphosphonate therapy included zoledronate (n = 34) or pamidronate (n = 17) and pamidronate followed by zoledronate (n = 33). Twenty-seven patients had recent dental extraction, including 12 patients in the ONJ group. Median time from MM diagnosis to ONJ was 8.4 years for the whole group. Results Patients usually presented with pain. ONJ occurred posterior to the cuspids (n = 20) mostly in the mandible. Debridement and sequestrectomy with primary closure were performed in 14 patients; of these, four patients had major infections and four patients had recu...