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D C Dafoe

Publications and source records attributed to D C Dafoe.

121 records · Page 7Linked to original sources
PubMed1984

The importance of immunologic factors in the pathogenesis of encephalomyocarditis virus induced diabetes in mice.

The pathogenesis of EMC virus induced diabetes has generally been thought to be caused by direct cytopathic effect of the virus on beta cells with susceptibility or resistance dictated primarily by the density of viral receptors on the beta cells of different individuals. The histological finding of insulitis, our demonstration of a protective effect of immunosuppression with ALS or anti-theta antibody and silica supports host immune factors as important determinants of susceptibility. A critical role of the immune system might be mediated by autoimmune destruction of EMC-virus infected beta cells. In susceptible strain mice treated with low dose cyclophosphamide to deplete suppressor cells, which may halt the autoimmune process and allow recovery, a prolonged period of hyperglycemia was demonstrated as compared to controls. Bone marrow exchanged between susceptible and resistant strains was also found to alter susceptibility. "B mice", deficient in T lymphocytes, when infected with EMC virus had a decreased incidence of diabetes. Susceptibility to EMC diabetes may be dictated by the autoaggressive response of host immune system to beta cells altered by EMC virus infection.

Animals↗
PubMed1983

Mycobacterial infections in renal allograft recipients.

Primary mycobacterial infections developed in five of 565 patients who had transplants during a 15-year period. All had negative PPDs and normal chest roentgenograms; none had tuberculosis before transplantation. Atypical mycobacteria were cultured in three of five infections. All were treated with a multiple-drug regimen, including isoniazid, rifampin, ethambutol, and streptomycin sulfate. In four of five patients, there were serious drug-related complications. No major initial alteration of immunosuppressive therapy was necessary in any of the patients. During the study, a treatment policy was followed that included one year of isoniazid treatment of all recipients with a positive PPD, history of tuberculosis, chest x-ray film suggestive of tuberculosis, or PPD-positive donor. An additional 14 transplant recipients were treated in accordance with this policy without complications or subsequent mycobacterial infections (32-month average follow-up). Despite the low incidence of mycobacterial infection in this series, the potential lethality and morbidity mandate constant vigilance.

Adult↗
PubMed1982

Percutaneous transluminal angioplasty treatment of renal transplant artery stenosis.

Since June 1979, percutaneous transluminal angioplasty (PTA) has been the procedure of choice for renal transplant artery stenosis (RTAS) at the Hospital of the University of Pennsylvania. Of 241 renal allograft recipients, 17 (7%) when studied by arteriogram because of suspected RTAS proved to have significant stenosis (the mean reduction in luminal width for the group being 68%) and underwent PTA. RTAS was equally prevalent in cadaver and related kidney allografts and was no less common in HLA-identical related donor grafts, arguing against the importance of immune factors in etiology. RTAS was equally prevalent whether the anastomotic technique was end to end or end to side. However, when RTAS occurred after end to side anastomoses, it was usually postanastomotic. Fifteen of 17 of the attempts at dilation by PTA were successful by angiographic analysis. Thirteen of the 15 successfully dilated patients had long-term allograft survival and in all of these instances blood pressure (BP) was decreased after PTA. After a mean of 67 weeks, BP decreased from a systolic of 184 +/- 24 mm Hg pre-PTA to 135 +/- 15 mm Hg (P less than 0.001) and from a diastolic of 115 +/- 10 mm Hg pre-PTA to 87 +/- 11 mm Hg (P less than 0.001). The majority of patients continue to require antihypertensive drugs but in a less vigorous regimen than pre-PTA. Serum creatinine level fell following PTA from 1.9 +/- 0.6 to 1.7 +/- 0.5 mg/100 ml (P less than 0.01). Repeat angiographic study was done in nine patients, an average of 61 weeks after PTA, and no recurrent RTAS was identified. Three minor complications of PTA occurred but none led to long-term sequelae. Thus, we believe PTA of RTAS is relatively safe, carrying less mortality and morbidity than operative treatment, and is capable of improving BP control and renal allograft function.

Adult↗
PubMed1982

Invited commentary: an overview of pancreas transplantation--biologic aspects.

The clinical results of vascularized pancreas transplants have improved somewhat during the last 5 years, the but technical problems of handling the pancreatic duct remain difficult. Clinical isolated islet allografts have rarely if ever succeeded. Rejection appears to be a more severe problem in pancreas or islet transplants than in other pancreas transplants. Nevertheless, if nonendocrine cells can be completely removed, transplanted beta-cells might have prolonged survival, since they probably lack Ia antigens that may be necessary to evoke an immune response. An additional biologic problem is the possible destruction (independent of rejection) of transplanted islet cells by autoimmune insulitis. This has been found to occur in spontaneously diabetic rats who received transplanted islets. Study of this animal model may provide important clues to the etiology and treatment or prevention of diabetes.

Animals↗