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Biomedical subjects

T E Morgan

Publications and source records attributed to T E Morgan.

At least 19 recordsLinked to original sources
PubMed1992

Complement C1qB and C4 mRNAs responses to lesioning in rat brain.

These data show the presence of mRNAs for two complement components (C) in the adult rat brain and describe their responses to experimental lesions. Cortical deafferentation caused elevations in striatal C1qB and C4 mRNAs that coincided temporally and overlapped anatomically with the course of degeneration of corticostriatal afferent fibers. By in situ hybridization, C1qB mRNA in the lesioned striatum was colocalized to cells immunoreactive for CR3, a complement receptor found on microglia-macrophages. The mRNA for SGP-2, a putative C inhibitor in rat, showed parallel changes. Similarly, in hippocampus and other brain regions, kainic acid lesions increased C1qB mRNA. The data suggest that microglia-macrophages and possibly other cells in rat brain rapidly up-regulate C-mRNAs in response to deafferentation and local neuron injury. These experimental responses provide models to analyze changes in C components during Alzheimer's disease and other chronic neurodegenerative conditions.

Animals↗
PubMed1991

Long-term effect of thrombolytic therapy on left ventricular ejection fraction after acute myocardial infarction.

To assess the long-term effect of thrombolytic therapy on left ventricular (LV) systolic function, 222 patients with acute myocardial infarction treated with intravenous tissue plasminogen activator within 4 hours of symptom onset underwent assessment of LV ejection fraction (EF) by radionuclide equilibrium angiography at hospital discharge and 1 year later. Mean EF at hospital discharge (46 +/- 12) was similar to that at 1 year (45 +/- 13). Stepwise multivariate linear regression analysis identified EF at discharge and patency of the infarct-related artery before discharge as independent predictors of EF change at 1 year (p = 0.0002 and 0.003, respectively). Random assignments to invasive versus conservative treatment strategies or to early versus delayed beta-blocker therapy did not affect EF change during follow-up. No significant deterioration of EF was observed in patients with larger infarcts. However, EF decreased from 45 +/- 10 at hospital discharge to 39 +/- 12 (p = 0.005) at 1-year follow-up in a subgroup of patients with history of prior infarction. Thus, patients with acute myocardial infarction, treated with intravenous tissue plasminogen activator early after onset of symptoms, appear to have stable LV function between hospital discharge and 1 year follow-up. The change in EF between hospital discharge and 1 year can be predicted from the EF value at discharge, patency of the infarct-related artery before discharge and history of previous myocardial infarction.

Aged↗
PubMed1981

The role of M.D.-Ph.D. training in increasing the supply of physician-scientists.

Since 1968 the number of postdoctoral research fellows with M.D.s or other professional degrees has fallen from about 4100 to 1730 in training each year. By 1980, the number of M.D. postdoctoral fellows entering and completing research training was about 850 per year. During the past 12 years, the number of M.D.-Ph.D. trainees has risen to about 650 in the federal Medical Scientist Training Program (MSTP) and about 500 in nonfederal programs. The attrition rate in non-federal M.D.-Ph.D. programs has been shown to be 44 per cent, and that from the MSTP, 9 per cent. When the length of the training program, the attrition rate, and other factors are considered, present trainees will account for about 150 M.D.-Ph.D. graduates annually in the immediate future. Current training programs can meet only about half the estimated national need for physician researchers. The federal M.D.-Ph.D. program should be expanded to ensure that the country's future research and teaching needs will be met.

Education, Graduate↗
PubMed1980

Bifunctional enzyme activity at the same active site: competitive inhibition kinetics with 3 alpha/20 beta-hydroxysteroid dehydrogenase.

20 beta-Hydroxy-5 alpha-pregnan-3-one (HPO) is a competitive inhibitor of reduction by 3 alpha/20 beta-hydroxysteroid dehydrogenase (3 alpha/20 beta-HSD; E.C.1.1.1.53) of 17 beta-hydroxy-5 alpha-androstan-3-one (DHT; 3 alpha-activity; Ki = 4.6x10(-5)M), and of 6 beta-acetoxyprogesterone (6 beta-AP; 20 beta-activity; Ki = 4.34x10(-5)M). HPO and DHT inhibit affinity alkylation of 3 alpha/20 beta-HSD by 6 beta-bromoacetoxyprogesterone (6 beta-BAP). The facts that 1) enzyme 3 alpha-activity and 20 beta-activity are both competitively inhibited by HPO with practically identical Ki-values, 2) 6 beta-BAP is solely a 20 beta-activity substrate for 3 alpha/20 beta-HSD, 3) one mole of 6 beta-BAP reacts with one mole of 3 alpha/20 beta-HSD to simultaneously inactivate 3 alpha- and 20 beta-activity, and 4) inactivation of 3 alpha/20 beta-HSD by 6 beta-BAP is inhibited by DHT (a C19-steroid) or HPO (a C21-steroid), support the view that the same active site of 3 alpha/20 beta-HSD possesses both 3 alpha- and 20 beta-activity. Bifunctional activity at the same active site is considered for other steroid-specific enzymes in female mammalian reproductive systems.

20-Hydroxysteroid Dehydrogenases↗
PubMed1978

Proliferative serous tumors of the ovary. Histologic features and prognosis.

In reviewing all proliferative serous tumors of the ovary seen at Barnes Hospital from 1950 to 1974, we quantitated histologic characteristics and defined criteria for diagnosis in 55 borderline tumors, 13 well-differentiated cystadenocarcinomas, and 15 cystadenomas with unusual proliferative areas. This last type with focal proliferation behaved in a benign fashion and should be considered a variant of a simple cystadenoma. Stromal invasion was the only histologic feature which consistently distinguished carcinomas from the borderline tumors. The presence in some borderline tumors of severe cellular atypia, marked epithelial disorganization, frequent mitoses, and cribriform glands in the stroma neither signified carcinoma nor indicated poor prognosis. No patient with a Stage I borderline lesion died of tumor. Although the mortality of patients with Stage IIb or Stage III borderline tumors is high, tumor-related deaths rarely occurred before 5 years, and three patients lived more than 10 years. Borderline serous tumors are low-grade malignant neoplasms which differ from overt carcinomas in the excellent prognosis of Stage I lesions and in long survival even with widespread abdominal disease.

Cystadenocarcinoma↗
PubMed1975

Choriocarcinoma and bilateral renal metastases.

A case of choriocarcinoma presenting with metastases to both kidneys is reported. The epidemiologic and pathologic aspects of gestational choriocarcinoma are briefly discussed. Prior reports of renal metastases with choriocarcinoma are reviewed, and the fairly typical clinical presentation for this entity is emphasized.

Adult↗