Cadaveric renal transplantation at the University of Pittsburgh: a two and one-half-year experience with the point system.

From January 1, 1986 to July 30, 1988, 530 consecutive cadaver kidney transplantations were performed with patient selection by a point system that took into account time awaiting an organ, donor-recipient matching, degree of presensitization, and some less important factors. The effect of the system was to diminish judgmental factors in case selection which in the past, had probably operated to the disadvantage of "undesirable" potential recipients, including older ones. Primary 1-year graft survival (74%) and graft survival after retransplantation (71%) were lower than in the earlier time. However, the results with triple-drug therapy using CsA, AZA and P demonstrated 88% 1-year graft survival for primary graft recipients and 74% in highly sensitized patients, with comparable patient mortality. These latter observations provide some assurance that the concepts of equitable access and efficient utilization of a scarce resource are not mutually exclusive

Heat Transfer in Surface-Cooled Objects Subject to Microwave Heating

Several investigators in microwave bioeffects research have exposed biological preparations to intense microwave fields, while at the same time cooling the sample with flowing water. We examine the heat transfer characteristics of this situation, to estimate the maximum temperature increase and thermal time constants that might be encountered in such an experiment. The sample is modeled as a uniform sphere, cylinder, or slab subject to uniform heating, which is located in an unbounded coolant flow. The heat transfer is determined by the Biot and Reynolds numbers (which reflect the geometry, fluid flow, and material thermal properties of the system) the temperature rise is governed by the heat conduction equation coupled with external convection. The results are expressed in terms of nondimensional quantities, from which the thermal response of a heated object of arbitrary size can be determined. At low coolant flow rates, the maximum temperature rise can be biologically significant, even for relatively small objects (of millimeter radius) exposed to moderate levels of microwave energy (with a SAR of ca. 100 mW/g). The results are valid also where the coolant is a gas or a liquid different from water, the only restriction being on the Reynolds number of the flow

Adenoviral Infections in Pediatric Liver Transplant Recipients

Over a 51/2-year period, 22 of 262 children receiving liver transplants developed adenoviral infections. Five had adenoviral hepatitis in the allograft, caused by serotype 5. All five were treated for rejection, either just before or at the time of infection. Liver biopsy specimens had characteristic histological appearance, and diagnosis of adenoviral infection was confirmed with monoclonal antiadenoviral antibodies, electron microscopy, and by culture of liver tissue. In the remaining 17 patients, adenovirus was isolated from urine, stool, throat secretions, and/or blood samples, but none had any detectable visceral infection. Serotypes 1 and 2 predominated, similar to children not receiving transplants during the same time period. Three of the patients with hepatitis are alive and well; two died of liver failure. Adenoviral hepatitis did not recur in the second allograft of a patient who underwent retransplantation for combined rejection and adenoviral hepatitis, and appears, therefore, not to be a contraindication to retransplantation when liver failure ensues. © 1987, American Medical Association. All rights reserved

Evolutionary Search and Theoretical Study of Silicene Grain Boundaries' Mechanical Properties

Defects such as grain boundaries (GBs) are almost inevitable during the synthesis process of 2D materials. To take advantage of the fascinating properties of 2D materials, understanding the nature and impact of various GB structures on the pristine 2D sheet is crucial. In this work, using an evolutionary algorithm search, we predict a wide variety of silicene GB structures with very different atomic structures compared to those found in graphene or hexagonal boron-nitride. Twenty-one GBs with the lowest energy were validated by density functional theory (DFT) - a majority of which were previously unreported to our best knowledge. Based on the diversity of the GB predictions, we found that the formation energy and mechanical properties can be dramatically altered by adatoms positions within a GB and certain types of atomic structures, such as four-atom rings. To study the mechanical behavior of these GBs, we apply strain to the GB structures stepwise and use DFT calculations to investigate the mechanical properties of 9 representative structures. It is observed that GB structures based on pentagon-heptagon pairs are likely to have similar or higher in-plane stiffness and strength compared with the zigzag orientation of pristine silicene. However, an adatom located at the hollow site of a heptagon ring can significantly deteriorate the mechanical strength. For all the structures, the in-plane stiffness and strength were found to decrease with increasing formation energy. For the failure behavior of GB structures, it was found that GB structures based on pentagon-heptagon pairs have failure behavior similar to graphene. We also found that the GB structures with atoms positioned outside of the 2D plane tend to experience phase transitions before failure. Utilizing the evolutionary algorithm, we locate diverse silicene GBs and obtain useful information for their mechanical properties.Comment: 25 pages, 9 figure

Knowledge, skills, and barriers to management of faecal incontinence in Australian primary care: a cross-sectional study

Published: 21 April 2021Background: GPs play an important role in the diagnosis and management of patients with faecal incontinence (FI). However, their confidence and ability in this role are unknown. Aim: This study aimed to investigate the knowledge, skills, and confidence of GPs to manage FI in primary care, and identify barriers to optimal management. Design & setting: A cross-sectional study using self-administered questionnaires of GPs attending health education seminars, which took place across Australian capital cities. Method: Main outcome measures included: (i) clinical exposure to and previous training in FI; (ii) knowledge and skills in screening, diagnosing, and managing FI; and (iii) barriers and facilitators to optimising care. Associations between demographics, training and knowledge and skills were assessed. Results: Some 1285 of 1469 GPs (87.5%) participated (mean 47.7 years [standard deviation {SD} 11.3]). The vast majority reported poor clinical exposure to (88.5%) and training in FI management (91.3%). Subjectively, 69.7% rated their knowledge and skills in screening, assessing, and treating FI as suboptimal. The most commonly reported barrier to FI care was ‘insufficient skills’ (56.1%); facilitators were improved referral pathways (84.6%) and increased training (67.9%). GPs with more training had better knowledge (odds ratio [OR] = 24.62, 95% confidence interval [CI] = 13.32 to 45.51) and skills (OR = 13.87, 95% CI = 7.94 to 24.24) in managing FI. Conclusion: Clinical exposure to and training in FI among GPs was poor. Accordingly, knowledge, skills, and confidence to manage FI was suboptimal. GPs recognise the importance of FI and that increased training and/or education and formalisation of referral pathways may improve the care of patients with FI in primary care.Kheng-Seong Ng, Deanne S Soares, Sireesha Koneru, Ramesh Manocha, Marc Antony Gladma

Childbearing after liver transplantation

Seventeen female patients who underwent orthotopic liver transplantation between June 1973 and June 1987 became pregnant 5 months to 11 years after transplantation. Immunosuppression was maintained with combinations of prednisone, cyclosporine, and azathioprine prior to and during pregnancy. One patient discontinued immunosuppression after knowledge of pregnancy, taking only azathioprine sporadically. Mean age at time of delivery was 26 years. Twelve patients had no alteration in liver function studies; 7 patients demonstrated mild or moderate enzyme elevations prior to delivery, with one case of rejection confirmed by percutaneous liver biopsy. Major problems related to pregnancy were hypertension, anemia, and hyperbilirubinemia. Twenty live births occurred (2 patients had 2 separate pregnancies, one patient had a set of twins); 13 were by caesarian section, 7 by vaginal delivery. Eleven of the 13 caesarian births were premature by gestational age. All vaginal births were term. Toxemia of pregnancy and early rupture of membranes were the principal indications for caesarean section. There were no congenital abnormalities or birth defects and all the children are surviving well. Fifteen of 16 children older than one year all have normal physical and mental development, with one child manifesting immature speech development. Four children are under one year, all with normal milestones thus far. Sixteen of the 17 mothers are alive from 2—18 years after transplantation; the only death was from a lymphoma, almost 4 years after transplantation and 2½ years after delivery. This experience suggests that women undergoing liver transplantation can safely bear children despite an increased risk of premature caesarian births. The effect of chronic immunosuppression of female pediatric patients on their reproductive potential later in adulthood remains to be fully evaluated but the results so far are favorable. © 1990 by Williams & Wilkins

Long-term results after liver transplantation for primary hepatic epithelioid hemangioendothelioma

Background: Hepatic epithelioid hemangioendothelioma (PHEHE) is a multifocal, low-grade malignant neoplasia characterized by its epithelial-like appearance and vascular endothelial histogenesis. The outcome of 16 patients treated with orthotopic liver transplantation (OLT) is the subject of this report. Methods: A retrospective study of 16 patients with HEHE (7 men, 9 women) with ages ranging from 24 to 58 years (mean 37 ± 10.6 years). Follow-up intervals ranged from 1 to 15 years (median of 4.5 years). Results: Actual patient survival at 1, 3, and 5 years was 100, 87.5, and 71.3%, respectively. Disease-free survival at 1, 3, and 5 years was 81.3, 68.8, and 60.2%, respectively. The 90-day operative mortality was 0. Involvement of the hilar lymph nodes or vascular invasion did not affect survival. The 5-year survival of HEHE compares favorably with that of hepatocellular carcinoma at the same stage (stage 4A): 71.3 versus 9.8% (p=0.001) Conclusions: The long-term survival obtained in this series justifies OLT for these tumors even in the presence of limited extrahepatic disease. © 1995 The Society of Surgical Oncology, Inc