Single-chain VαVß T-cell receptors function without mispairing with endogenous TCR chains.

Transduction of exogenous T-cell receptor (TCR) genes into patients' activated peripheral blood T cells is a potent strategy to generate large numbers of specific T cells for adoptive therapy of cancer and viral diseases. However, the remarkable clinical promise of this powerful approach is still being overshadowed by a serious potential consequence: mispairing of the exogenous TCR chains with endogenous TCR chains. These 'mixed' heterodimers can generate new specificities that result in graft-versus-host reactions. Engineering TCR constant regions of the exogenous chains with a cysteine promotes proper pairing and reduces the mispairing, but, as we show here, does not eliminate the formation of mixed heterodimers. By contrast, deletion of the constant regions, through use of a stabilized Vα/Vß single-chain TCR (scTv), avoided mispairing completely. By linking a high-affinity scTv to intracellular signaling domains, such as Lck and CD28, the scTv was capable of activating functional T-cell responses in the absence of either the CD3 subunits or the co-receptors, and circumvented mispairing with endogenous TCRs. Such transduced T cells can respond to the targeted antigen independent of CD3 subunits via the introduced scTv, without the transduced T cells acquiring any new undefined and potentially dangerous specificities.

Regional variability in symptom-based MELD exceptions: a response to organ shortage?

MELD (model for end-stage liver disease) exception awards affect the liver allocation process. Award rates of specific nonhepatocellular carcinoma exceptions, termed symptom-based exceptions (SBE), differ across UNOS regions. We aimed to characterize the regional variability in SBE awards and examine predictive factors for receiving a SBE in the MELD era. The OPTN liver transplant and waiting list dataset was analyzed for waiting list registrants during the MELD allocation on February 27, 2002, until November 22, 2006. Competing risks proportional hazards regression analysis was used to examine predictors for receiving a SBE in 39 169 registrants. The hazard ratios for receiving a SBE differed significantly across regions when adjusted for multiple variables including age, gender, ethnicity, physiologic MELD score, blood group, functional status, etiology of liver disease, insurer and education level. Utilization of SBE is highly significantly variable across UNOS regions, and does not correlate with organ availability as estimated by the regional mean physiologic MELD score at transplantation. Patients with Medicaid as their primary payer have a lower likelihood of receiving a SBE award, while patients with cryptogenic/NASH cirrhosis or cholestatic liver disease have a higher likelihood of receiving a SBE. Reasons for these regional and demographic disparities deserve further investigation.

Fully covered self-expandable metallic stents in the management of complex biliary leaks: preliminary data - a case series.

Techniques for management of bile leaks include biliary sphincterotomy and stenting. Partially covered self-expandable metallic stents have been used in complex bile leaks, but they are associated with migration and hyperplasia. A fully covered self-expandable metallic stent (CSEMS) with anchoring fins might be effective in treating bile leaks without these complications. The aim of this study was to investigate the safety and efficacy of temporary placement of a CSEMS for resolving complex bile leaks. Thirteen patients with complex bile leaks underwent endoscopic retrograde cholangiopancreatography (ERCP) with temporary placement of a CSEMS following cholecystectomy (n = 8) or liver transplantation (n = 5). All patients had resolution of their bile leaks. Two patients developed a stricture below the confluence. Three patients died from unrelated causes. Two deaths occurred prior to CSEMS removal. Ten of 11 patients had evidence of biliary debris at the time of CSEMS removal. Overall, temporary placement of CSEMS is efficacious atresolving bile leaks. CSEMS are less prone to migration, but are associated with ulcerations, de novo choledocholithiasis, and strictures.

Benign transient hyperphosphatasemia associated with Epstein-Barr virus enteritis in a pediatric liver transplant patient: a case report.

Transient hyperphosphatasemia was found in a 3-year-old male liver transplant recipient. The condition was associated with diarrheal disease due to the Epstein-Barr virus (EBV). Immunosuppression was tapered and valganciclovir prescribed for 3 months, after which the diarrhea resolved and the EBV polymerase chain reaction assays became negative. After 6 months, alkaline phosphatase levels normalized. Isolated elevation of alkaline phosphatase in conjunction with enteric infection is a rare condition. No further diagnostic or therapeutic interventions except treatment of the underlying infection are needed, as this has been shown to be a benign, transient condition.

Donor factors predicting recipient survival after liver retransplantation: the retransplant donor risk index.

The use of extended criteria liver donors (ECD) is controversial, especially in the setting of retransplantation. The aims of this study are to investigate the effects of ECD grafts on retransplantation and to develop a predictive mortality index in liver retransplantation based on the previously established donor risk index. The United Network for Organ Sharing (UNOS) liver transplant dataset was analyzed for all adult, non-status 1, liver retransplantations occurring in the United States since February 2002. All donors were categorized for multiple characteristics of ECD, and using multivariate survival models a retransplant donor risk index (ReTxDRI) was developed. A total of 1327 retransplants were analyzed. There were 611 (46%) recipients who received livers with at least one ECD criterion. The use of ECD grafts in recipients with HCV did not incur worse survival than the non-ECD grafts. The addition of the cause of recipient graft failure to the donor risk index formed the ReTxDRI. After adjusting for multiple recipient factors, the ReTxDRI was predictive of overall recipient survival and was a strongly independent predictor of death after retransplantation (HR 2.49, 95% CI 1.89-3.27, p < 0.0001). The use of the ReTxDRI can improve recipient and donor matching and help to optimize posttransplant survival in liver retransplantation.

Myofibrosarcoma of the adrenal gland.

Adrenal masses have varying presentations. Most commonly, adrenal masses are discovered incidentally on CT or MRI during an evaluation for an unrelated complaint. Although the majority of these are nonfunctional cortical adenomas, hormonally active tumors and adrenocortical carcinoma must also be considered in the differential diagnosis. Rarely, retroperitoneal tumors may mimic an adrenal mass. We report a case of a 49-year-old man with anemia and weight loss who was found to have a large retroperitoneal mass arising from the adrenal gland. Surgical treatment involved en bloc resection of the right kidney, adrenal gland, segments 7 and 8 of the liver, and a portion of the right hemidiaphragm. Final pathology revealed a low-grade myofibrosarcoma. We believe that this is the first case report of a myofibrosarcoma of the adrenal gland. Myofibrosarcomas are rare malignant tumors composed of myofibroblasts that arise from the deep soft tissues. These tumors have a predilection for the head and neck, trunk, or extremities. Myofibrosarcomas can be differentiated from other sarcomas by immunohistochemical staining and pathologic features. We will briefly discuss the workup of an adrenal mass and focus on the diagnosis of myofibrosarcoma.

Clonal characterization of a bipotent T cell and NK cell progenitor in the mouse fetal thymus.

We recently described a population of fetal thymocytes with a CD117+NK1.1+CD90lowCD25- phenotype, which were shown to contain committed T cell and NK cell progenitors. However, the characterization of a single cell with a restricted T and NK cell precursor potential was lacking. Here, using an in vitro model for T and NK cell differentiation, we provide conclusive evidence demonstrating the existence of a clonal lineage-restricted T and NK cell progenitor. These results establish that fetal thymocytes with a CD117+NK1.1+CD90lowCD25- phenotype represent bipotent T and NK cell progenitors.

Appropriate timing of elective coronary artery bypass graft surgery following acute myocardial infarction.

BACKGROUND: The appropriate timing of elective coronary artery bypass surgery (CABG) following acute myocardial infarction (AMI) remains uncertain. It is hypothesized that a waiting period allows the myocardium to recover prior to revascularization, thus decreasing morbidity and mortality. This study was designed to determine if a waiting strategy is justified following AMI in patients requiring elective CABG. METHODS: Between 1994 and 1996, 214 patients underwent isolated, nonrepeat, elective CABG. Three groups were evaluated: group I, control, 155 patients with no AMI; group 11, 39 patients with nontransmural AMI; and Group III, 20 patients with transmural AMI. Demographics, intraoperative, and postoperative variables were collected and compared among all groups. RESULTS: Groups were well-matched demographically: group I, patients waited an average of 2.3 days in hospital prior to operation; group II, an average of 4.2 days; and group III, an average of 5.2 days. Except for the use of inotropes, group I 34%, group 11 39%, and group III 70% (P = 0.007), and the intra-aortic balloon pump, group I 0%, group 11 8%, and group III 25% (P = 0.001). There were no differences in complications. Importantly, there was no difference in mortality or postoperative length of stay. The mortality in group I was 2.6%, in group 11 2.6%, and in group III 0%. The length of stay in groups I and II was 8.5 days, and in group III, 8.1 days. CONCLUSION: A waiting period of 3 to 5 days after a nontransmural AMI and 5 to 7 days after a transmural AMI can produce similar postoperative results to non-AMI patients undergoing CABG. Thus, a waiting strategy to allow the myocardium to recover is justified.

Analysis of anthranilic acid by liquid chromatography.

Analytical methods for the assay of anthranilic acid and for determination of the impurities methyl anthranilate, anthranoylanthranilic acid and 3- and 4-aminobenzoic acid are described. A Microbondapak C18 column is used for both the assay and the impurity determination. The assay is based on isocratic development with a mobile phase of 35:65 v v methanol/pH-3 phosphate buffer, with benzoic acid as internal standard. The impurities are separated by gradient elution. The standard deviation of the assay method is about 1% and the limit of detection for the impurities is about 0.01%.

Determination of 2-mercaptobenzothiazole, tolyltriazole and benzotriazole in coolant formulations by liquid chromatography.

An analytical method based on high-performance liquid chromatography is suitable for the determination of corrosion inhibitors in coolant solutions based on ethylene glycol. An isocratic system of methanol/aqueous sodium acetate buffer is used with a Microbondapak C18 column. Recovery is 99+%, with a sensitivity of 0.05% w/w. No sample pretreatment is necessary. Analysis time is 15 min.