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Biomedical subjects

L C Paul

Publications and source records attributed to L C Paul.

At least 91 records · Page 5Linked to original sources

Macrophage subpopulations in normal and transplanted heart and kidney tissues in the rat.

The purpose of the present study was to investigate the phenotype of macrophages that infiltrate normal and transplanted rat tissues. The macrophage monoclonal antibodies ED1, ED2, ED3, 52-1D4, ER15, and OX43, together with antibodies against lymphocyte and class II MHC antigens, were used in an indirect immunofluorescence technique with sections of normal tissues and heart and renal grafts that experienced long-term survival or rejection. A small number of ED1- and ED3-positive interstitial cells were detected in normal heart and renal tissues and their number increased dramatically in rejection. Normal heart tissue contained a population of ED2-positive cells with dendritic morphology that was not detected in renal tissue. Following transplantation, a diffuse increase of rounded ED2-positive cells was observed in heart grafts; no ED2-positive cells were detected in grafts removed after 20-30 days from nonimmunosuppressed recipients. Grafts from CsA-treated animals or grafts that survived greater than 50 days in nonimmunosuppressed recipients exhibited the interstitial dendritic pattern of ED2-positive cells. Only very few rounded ED2-positive cells were observed in renal allografts; if present, they were mostly located in the medulla. OX43, which bound in normal tissues to vessel endothelium and a population of macrophages, stained in allografts an additional small population of graft-infiltrating cells, and in F344 renal allografts a population of multinucleated giant cells. We conclude that the posttransplant macrophage infiltration pattern of heart and renal allografts, defined by the monocyte/macrophage antibodies ED1, ED3, 52-1D4, and ER15, is very similar for both types of organs, although the antibody ED2 and the endothelial-macrophage antibody OX43 revealed remarkable differences between the two types of organ allografts.

Animals↗

Renal transplant artery rupture secondary to candida infection.

We report a case of a diabetic renal transplant patient with candiduria who developed repeated elevations in serum creatinine concentration due to an intermittently obstructing candida ball in the urinary tract. After unsuccessful attempts to place a nephrostomy tube for local irrigation and debulking, the renal graft artery ruptured secondary to extensive perirenal candida infection. Percutaneous nephrostomy may increase the risks of renal and extrarenal tissue infection with the potential for fatal complications such as infection of the vascular anastomosis.

Adult↗

Cyclosporine-associated reduction in systolic myocardial function in the rat.

The cardiotoxic effect of cyclosporine in the inbred rat was investigated in the isolated perfused heart model. Diastolic and systolic function was studied in 5 groups of (Lewis x Brown Norway) F1 rats treated with different doses of cyclosporine for different time intervals and in a group which received the vehiculum cremophor. Of the cyclosporine-treated rats, one group was studied four weeks after drug discontinuation to assess reversibility of the effect. To control for the nephrotoxic side effects of cyclosporine, a group of animals that had undergone 1.5-1.75 renal ablation was included. Left ventricular pressures were measured with a balloon catheter; stepwise increases in preload were obtained by small increments in the balloon volume. Over the range of left ventricular volumes studied, no differences were found in diastolic pressure between the groups. Peak systolic pressures were significantly lower in hearts obtained from cyclosporine treated rats which had received 15 or 7.5 mg/kg/24 h subcutaneously for three weeks (P less than 0.05). Our results indicate that cyclosporine treatment resulted in a reversible decrease in myocardial contractile force apparently unrelated to decreases in renal function or to changes in mean arterial pressure.

Analysis of Variance↗

Human papillomavirus type 16 associated with oral squamous carcinoma in a cardiac transplant recipient.

Human papillomavirus type 16 (HPV 16) has been associated with a variety of squamous carcinomas, particularly those involving the anogenital tract. The authors report the development of an oropharyngeal carcinoma in a 43-year-old man approximately 20 months after cardiac transplantation while he was on a maintenance regimen of cyclosporine A and prednisone. The carcinoma was resistant to treatment, and he died of complications related to metastatic disease 3 years posttransplantation. Molecular biologic studies using nonisotopic-labeled viral DNA probes were done. In situ hybridization demonstrated the presence of HPV 16 DNA in the tumor cells. DNA dot blot analysis confirmed the presence of multiple copies of HPV 16 DNA within the tumor cells and their absence from adjacent normal-appearing tissue. Southern blot analysis suggested that the HPV 16 DNA was integrated into the tumor cell genome. With increasing recognition of the carcinogenicity of HPV type 16 infection, a role for this virus in the development of squamous cell malignancies in immunosuppressed organ transplant recipients is likely to be noted with increasing frequency.

Adult↗

Xenoantibodies in the rat against guinea pig tissues.

The role of naturally occurring antibodies in discordant xenograft rejection is poorly defined. This is partly attributable to a lack of information regarding their tissue specificity and titers. Sera from different rat strains were studied for naturally occurring antibodies against guinea pig tissues using immunofluorescence and immunoperoxidase staining techniques. All sera contained IgG and IgM antibodies in low titers against erythrocytes, lymphoid cells, and a variety of tissue structures. Intentional immunizations of adult rats with guinea pig cells resulted in the production of xenoantibody specificities that were not detectable in nonimmunized animals. Immunizations of Munich-Wistar rats with guinea pig skin grafts occasionally resulted in the formation of antibodies that reacted with allogeneic and syngeneic cells of the liver, lung, and lymphoid organs. We conclude that rats have low titers of naturally occurring xenoantibodies against various tissue structures of the guinea pig, but their importance in xenograft rejection remains to be established.

Animals↗

Psychosocial predictors of survival in end-stage renal disease.

Several psychosocial variables were investigated as predictors of 4-year survival in a sample of 97 end-stage renal disease (ESRD) patients undergoing treatment by hemodialysis, continuous ambulatory peritoneal dialysis, or renal transplantation. Hypothesized psychosocial predictors included depression, mood disturbance, life happiness, affect, pessimism, self-esteem, knowledge of renal disease and its treatment, perceived control over important life domains, perceived intrusiveness of ESRD into important life domains, illness-related concerns, difficulties in daily activities, number of regular leisure activities, somatic symptoms of distress, social networks, recent negative life events, and defensive response styles. Methodological controls were incorporated to test the prognostic significance of these variables and included a) exclusion of deaths attributable to "unnatural" causes; b) multivariate statistical controls for physical and demographic determinants of survival; c) widely used standardized psychosocial instruments; and d) temporally aggregated psychosocial measurements to enhance reliability. Hierarchical multiple regression analyses identified four variables as significant and independent predictors of increased survival times in ESRD: a) comparatively fewer serious nonrenal comorbid illnesses; b) younger age; c) regular involvement in an increased number of leisure activities; and d) overall life happiness described as "an even mixture of unhappiness and happiness" (as compared with "very happy"). However, no evidence was obtained to support the hypothesis that increased depressive symptoms and/or moods contribute to compromised survival in ESRD.

Adaptation, Psychological↗