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Biomedical subjects

F T Thomas

Publications and source records attributed to F T Thomas.

At least 73 records · Page 4Linked to original sources

T cell-specific activity in rabbit anti-human thymocyte globulin. Correlation with immunosuppresive activity in nonhuman primates.

Spotaneous E rosette-forming (T) lymphocytes were monitored in the peripheral blood of rhesus monkeys receiving a 5-day course of rabbit anti-human thymocyte globulin (RATG) after skin allotransplantation. Mean graft survival in RATG-treated recipients was 32.3 +/- 7.6 (SD) days compared with 8.2 +/- 1.7 (SD) days in controls. The percentage and total number of circulating T cells fell precipitously after RATG treatment and recovered slowly. Linear regression analysis showed that the recovery pattern of the total number of circulating T cells, but not the percentage of T cells, was significantly correlated with rejection. Specific antihuman T cell antibody was detected in RATG preparations after extensive absorption with human erythrocytes, platelets, and B lymphoblastoid cells. The cytotoxic titers of B cell-absorbed RATG preparations to human peripheral blood lymphocytes showed a significant correlation with the mean skin allograft survival times obtained in RATG-treated primates. Overall the data suggest that the immunosuppressive potency of RATG in the primate skin graft assay is related in large part to its anti-T cell activity.

Animals↗

Factors in the differential rate of arteriosclerosis (AS) between long surviving renal transplant recipients and dialysis patients.

In this study, the incidence of clinical and autopsy arteriosclerosis (AS) was studied in over 300 renal transplant patients (RTP) followed in our clinic up to 13 years post-transplant. Of 45 RTP followed a mean of 10.45 years, the incidence of clinical AS was 6% or 0.58% per year at risk. The incidence of death from AS was 2.2% over 10 years or 0.22% per year at risk. There was no apparent tendency for increase of the risk incidence with increasing time post-transplantation up to 13 years. This incidence of clinical and death-related AS in long term RTP contrasts sharply with a quite high incidence of both clinical and death-related AS in long-term dialysis patients as reported by Scribner's group and both the European and U.S. Dialysis Registry. Of our RTP surviving a decade or more, 77% have normal serum triglycerides and 92% are normotensive, again contrasting sharply with a 70-80% incidence of hyperlipidemia and a 60-80% incidence of hypertension in long-term dialysis patients. These studies suggest that the high rate of accelerated AS in dialysis patients is largely reversed by successful renal transplantation, probably due to a lowering of both blood pressure and hyperlipidemia in the long-term RT patients. Practically, these results suggest that the superior survival of transplant patients over dialysis patients already evident at 10 year mark will widen further during the second post-transplantation decade.

Adolescent↗

Antibody-dependent cellular cytotoxicity and chronic renal allograft rejection.

Antibody-dependent cell-mediated cytotoxicity (ADCMC) was studied retrospectively in 20 long-term (1.3-11 years) renal allograft recipients. The serum of all seven patients having persistent proteinuria greater than 1 g/24 hr exhibited positive ADCMC activity to donor lymphocytes. All 11 patients having a negative ADCMC test had normal levels of urinary protein (mean + 0.28 +/- 0.06 (SE) g/24 hr). Two patients had a positive ADCMC test but had normal urinary proteins and no evidence of chronic rejection. In the ADCMC positive group, the mean serum creatinine values were significantly higher and the mean creatinine clearance values were significantly lower than in the ADCMC negative group. There was no significant positive correlation between the presence of ADCMC and the number of HL-A mismatches identified or the response to donor lymphocytes in mixed lymphocyte culture tests in the two groups. Two patients had transplant nephrectomy and histologically showed both glomerular and arterial lesions of chronic rejection. Post-transplant ADCMC activity showed a significant correlation with proteinuria, decreased creatinine clearance, and elevated serum creatinine, and suggests that the chronic rejection syndrome may be related to ADCMC activity in the recipient.

Antibody Specificity↗

Subepicardial infarction, myocardial impression, and ventricular penetration by sutureless electrode and leads.

Postmortem examination two weeks following implantation of a demand pacemaker with sutureless electrodes demonstrated that (1) the loops of intrapericardial electrode leads indented the myocardium and produced a circumscribed area of subepicardial necrosis, and (2) one of the electrode coils protruded into the right ventricular cavity. The use of extrapericardial electrode leads and left ventricular implantation sites should avoid these problems.

Electrodes, Implanted↗