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Biomedical subjects

T J Ryan

Publications and source records attributed to T J Ryan.

At least 415 records · Page 23Linked to original sources
PubMed1978

Angiotensin converting enzyme inhibition in patients with congestive heart failure.

The etiology of afterload elevation in congestive cardiac failure is unclear, but experimental evidence suggests a role for the renin-angiotensin system in maintaining elevated peripheral vascular resistance. The angiotensin converting enzyme inhibitor SQ20,881 was administered to eight patients with congestive cardiac failure (four hypertensives, four normotensives) during or one day after diagnostic cardiac catheterization. Various hemodynamic measurements performed before and during blockade indicate that this agent caused improvement in cardiac function in all patients by decreasing afterload. This improvement correlated with the decrease in total vascular resistance but was independent of the baseline blood pressure and plasma renin activity. These results suggest that inhibition of angiotensin converting enzyme is a worthwhile approach to the treatment of congestive heart failure, although its exact mechanism of action remains unclear.

Aged↗
PubMed1978

ST segment changes post-infarction: predictive value for multivessel coronary disease and left ventricular aneurysm.

To ascertain whether exercise testing might predict multivessel coronary disease and left ventricular aneurysm after a myocardial infarction, 154 patients with a single documented myocardial infarction who had both exercise testing and coronary angiography were grouped according to whether they had greater than or equal to 1 mm ST depression, greater than or equal to 1 mm ST elevation, or neither during exercise testing: 83 patients developed ST depression alone (group 1); 22 patients had ST elevation with concomitant ST depression in other leads (group 2); 19 patients had ST elevation alone (group 3); and 30 patients had no ST changes (group 4). Multivessel disease, defined as greater than or equal to 70% luminal narrowing in two or more coronary vessels, was present in 76% (63 of 83) of group 1, 91% (20 of 22) of group 2, 21% (four of 19) of group 3, and 13% (four of 30) of group 4. A left ventricular aneurysm was present in 31% (26 of 83) of group 1, 68% (15 of 22) of group 2, 79% (15 of 19) of group 3, and 40% (12 to 30) of group 1. We conclude that ST changes during exercise testing in patients after a myocardial infarction can reliably predict the extent of coronary disease and the presence of a left ventricular aneurysm; ST depression with or without ST elevation predicts multivessel disease; ST elevation alone or a negative exercise test suggests single vessel involvement; and ST elevation with or without ST depression predicts left ventricular aneurysm.

Adult↗
PubMed1978

ST-segment elevation during recovery from exercise. A new manifestation of Prinzmetal's variant angina.

Four patients underwent exercise testing because of a history of pain in the chest; all four developed marked elevation of the S-T segment only during recovery after exercise. Three of the four patients showed ST-segment depression during exercise, but ST-segment elevation was absent until two or more minutes after cessation of exercise. ST-segment elevation after exercise was accompanied by hypotension in three patients and by ventricular arrhythmias in one. Subsequent coronary angiographic studies revealed normal or minimally diseased coronary arteries in two patients and significant coronary lesions in the other two. Review of the literature shows that contrary to the prevailing belief, over half of the patients with Prinzmetal's variant angina have electrocardiographic changes diagnostic of ischemia during exercise testing. Over half of the patients with abnormal findings on tests during exercise display ST-segment elevation as a manifestation of ischemia; however, delayed ST-segment elevation of the type seen in these four patients is distinctly uncommon, having previously been described in only three individual case reports. The pathophysiology of this response is uncertain but may relate to rapid alterations in the autonomic balance during recovery after exercise.

Adult↗
PubMed1978

Trifascicular and complete heart block with anterior myocardial infarction. Electrocardiographic patterns and long-term medical management.

A 45-year-old man exhibited various patterns of delay in trifascicular conduction, culminating in complete heart block during acute myocardial infarction. A temporary pacemaker was utilized for the short period of heart block. Delay in ventricular conduction subsided, and the patient refused implantation of a permanent pacemaker. Ventricular irritability, which was detected eight months later, was suppressed with administration of digitalis, guided by testing with acetylstrophanthidin. Neither heart block nor delay in ventricular conduction recurred during 43 months after the infarction. In certain patients with heart block complicating anterior myocardial infarction, long-term prognosis may be dictated by coronary and myocardial residual function, rather than by the hazard of recurrent heart block.

Bundle-Branch Block↗
PubMed1977

Angiotensin II inhibition. Treatment of congestive cardiac failure in a high-renin hypertension.

A patient with intractable congestive cardiac failure secondary to renovascular hypertension and severe coronary artery disease was infused with the competitive antagonist of angiotensin II, saralasin acetate. The infusion produced an impressive increase in cardiac output and left ventricular stroke work index in parallel with a striking decrease in the systemic and pulmonary vascular resistance, the coronary resistance, and the myocardial oxygen consumption. It is suggested that angiotensin inhibition may present advantages over other forms of treatment of congestive cardiac failure in selected cases.

Angiotensin II↗
PubMed1977

Preponderance of lysosomal bodies in cultured fibroblasts from patients with recessive epidermolysis bullosa dystrophica. An electron microscopic study.

Fibroblasts of skin explants from three normal men and six patients with recessive epidermolysis bullosa dystrophica (EBD-R) were cultured in Dulbecco's medium, grown to confluence, sectioned and studied with the electron microscope. The normal control fibroblasts from the 6th to 13th passage (secretory phase) showed irregular or lobed nuclei with centrally scattered chromatin. They also had prominent RER, Golgi complexes, variously shaped mitochondria and cytoskeletal microfibrils. Their peripheral cytoplasm exhibited many vacuoles and a small number of these were autophagic lysosomes. In addition to the ultrastructural features described in the control fibroblasts, the EBD-R cells from the 6th passage contained remarkable numbers of strongly electron dense lysosomal bodies through their entire cytoplasm with very few empty vacuoles. It is speculated that the accumulation of these lysosomes may be connected with a primary metabolic cellular defect in the dermal fibroblasts of patients with EBD-R akin to that described in mucopolysaccharide storage diseases.

Adult↗
PubMed1977

Post-kala-azar dermal leishmaniasis.

Ten patients with post-kala-azar dermal leishmaniasis (2 females, 8 males-aged 17-47 years) are described. Two of them had macular lesions in which very few Leishman-Donovan bodies were seen and who responded well to treatment with stibophen. Five patients had both macular and nodular lesions, Leishman-Donovan bodies being present in nodules but not in macules. Treatment with stibophen caused partial regression of nodules. Nodular lesions were found in three patients, who did not have macules. They contained numerous Leishman-Donovan bodies and treatment produced only temporary improvement. The variable response to treatment with stibophen may have been due to differences in parasitic load. The difficulty in distinguishing this disease from leprosy is discussed.

Adolescent↗
PubMed1977

Vasculitis.

Explore the source record for details and available documents.

Blood Vessels↗
PubMed1977

Atypical multicentric reticulohistiocytosis with paraproteinemia.

Two women had multiple subcutaneous nodules that showed features of multicentric reticulohistiocytosis (MR). Neither had joint symptoms. Both had a raised erythrocyte sedimentation rate, an immunoglobulin G paraproteinemia, and raised levels of nonhepatic serum alkaline phosphatase. The skin lesions have been followed up, using light and electron microscopy, immunoperoxidase, and histochemical methods. The material in the giant cells stained positively for gamma heavy chain determinants: the light chain type in each case was that of the paraprotein. An attempt to reproduce the skin lesions in one patient by intradermal injection of her paraprotein failed.

Aged↗
PubMed1976

Specificity of thrombin: evidence for selectivity in acylation rather than binding for p-nitrophenyl alpha-amino-p-toluate.

The lysyl ester analogue p-nitrophenyl alpha-amino-p-toluate hydrobromide was synthesized, and its reactions with thrombin, trypsin, and plasmin were studied by stopped-flow and conventional methods. Kinetic parameters were compared with those determined for the arginyl ester analogue, p-nitrophenyl p-guanidinobenzoate hydrochloride, with these enzymes. By following nitrophenol release or proflavin absorption changes in the stopped-flow spectrophotometer, the constants Ks (enzyme-substrate binding), k2 (acylation), and k3 (deacylation) were determined. The major findings were: (1) Ks values were similar regardless of the substrate or the enzyme; (2) k3 was approximately the same for the reaction of the lysyl ester analogue with any enzyme; (3) k2 for the lysyl ester analogue was 1100 times greater with trypsin than with thrombin; and (4) k2 with thrombin was 60 times greater for the arginyl than for the lysyl ester analogue. The results suggest that the limited cleavage of lysyl bonds by thrombin is due in part to restricted acylation rather than substrate binding. The active site of thrombin, compared with that of trypsin, appears to have a more stringent requirement for the spatial relationship between the cationic group and the bond cleaved in substrates.

Acylation↗
PubMed1976

Vectorial characteristics of ventricular extrasystoles stimulated during cardiac catheterization.

Ventricular extrasystoles (VES) from different areas of the ventricular muscle mass were obtained by mechanical stimulation of inflow and outflow regions of the right ventricle (RV) and apical and basal portions of the left ventricle (LV) during cardiac catheterization. Cube system vectorcardiogram (VCG) patterns of VES from each location were analyzed to determine the specificity of vector orientation from each site. Transverse plane VCG distinguished between nonseptal LVES and RVES, while a combination of transverse and either sagittal or frontal planes permitted further localization of septal VES to inflow or outflow regions of the RV and apical and basal areas of the LV.

Adult↗
PubMed1976

The blood vessels of the skin.

During the last 25 years, cutaneous biologists have been particularly interested in abnormal cutaneous vascular patterns, the profusion of capillary anastomoses, the leakiness of venules, clotting, fibrinolysis, and blood viscosity. As a result, the effects of hypoxia and the factors that encourage new vessel proliferation are better understood than before. Only when the biologic behavior of the two extremes of growth from hypoplasia to hyperplasia is studied and compared can the blood supply of a tissue be understood. Hyperplastic tissues are seen in wounds, psoriasis, cancer, and in selected sites of chronic stasis and hypoxia where the vessels are extremely permeable, where blood cells easily escape, and where lymphatics dilate and proliferate. The proliferation of other tissues, such as endothelium, epithelium, mast cells, and probably of locally infective organisms, is also encouraged in hyperplasia. Moreover, fibrinolysis does not occur and fibrin is deposited, the electrostatic charge on the internal vascular surface becomes more positive, and the organ is more vulnerable to subsequent injury. Atrophic or hypoplastic tissues have a reduced cellular turnover and are less hypoxic. The vessels are less permeable, blood cells do not escape, there is only a slight tendency to clot, and fibrinolysis is often increased. Lymphatics are sparse and infection is not a feature. The electrostatic charge on the internal surface of the vessel is negative.

Animals↗