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Biomedical subjects

R J Ferguson

Publications and source records attributed to R J Ferguson.

16 recordsLinked to original sources
PubMed1979

Lidoflazine and physical training in the treatment of stable angina pectoris.

An additive effect in the treatment of angina pectoris by combining lidoflazine and physical training was postulated. Twenty-four patients were randomly divided into placebo and drug groups and subsequently underwent a 6-month physical training program. The drug group had a significantly greater reduction in submaximal heart rate than the placebo group. Similar improvements in symptom-limited exercise capacity were observed in both groups. Resting and maximal exercise coronary sinus blood flow and left ventricular oxygen consumption were not significantly changed with training in either group. Physical training and lidoflazine appear to influence exercise tolerance in the same manner.

Angina Pectoris↗
PubMed1978

Improved efficiency of treadmill exercise testing using a multiple lead ECG system and basic hemodynamic exercise response.

One hundred consecutive men with a normal ECG at rest had a maximal treadmill test using 14 leads during and post-exercise. Coronary arteriography performed the following day revealed coronary stenoses greater than or equal to 70% in 66 patients. Test results obtained from a V5 lead were compared to different lead combinations and were correlated with arteriographic findings. A positive exercise test occurred in 37 men using an isolated V5 lead compared to 50 men (P less than 0.05) using 11 leads, 52 men (P less than 0.05) using a combined CM5, CC5, Cl (inferior) lead system and 58 (P less than 0.001) men using all 14 leads. The predictive value of a positive test varied between 89-95% and was not changed significantly by the addition of multiple leads. The 14 lead ECG was positive in 43/45 (96%) patients with multivessel disease. Parameters which helped to predict multivessel disease using 14 leads were 1) the time that ischemia first appeared 2) the pressure-rate product at the time ischemia first appeared, and 3) the maximum workload that could be attained. In general, the magnitude of ST-segment depression and the time required for a positive ECG to return to normal postexercise were not useful predictors of multivessel disease. We conclude that the use of multiple leads improves the sensitivity and efficiency of the maximal treadmill exercise test. The usefulness of exercise test results can be further improved if multiple leads are combined with physiologic data collected during exercise.

Adult↗
PubMed1977

External counterpulsation: coronary hemodynamics and use in treatment of patients with stable angina pectoris.

External pressure counterpulsation (ECP) has been reported to improve the clinical status of patients with angina pectoris. To document the mechanisms for such an improvement left ventricular oxygen consumption and lactate metabolism, coronary sinus blood flow, and cardiac index were studied in 10 patients with angina pectoris 1) prior to and during ECP; and 2) during right atrial pacing before and after 4 consecutive 2-hour sessions of ECP treatment. During ECP peak early and mean arterial diastolic pressures were significantly raised above control values by 32 and 13% respectively. However, coronary sinus blood flow, left ventricular oxygen consumption and left ventricular lactate extraction, mean systolic arterial pressure and cardiac index were not significantly altered by ECP. Right atrial pacing at 140 beats/min increased coronary sinus blood flow 70% over control values and induced angina and ischemic ST segment changes in 8 patients before and after 4 consecutive treatments of ECP. ECP treatment did not significantly modify the above metabolic and hemodynamic responses at rest or during atrial pacing. Although 5 patients reported improvement in angina symptoms the effect was transitory. No significant improvement over pre ECP-treatment exercise angina threshold was observed immediately following or at 1 and 3 months post treatment. This method of noninvasive circulatory assistance appears to be of doubtful value in the management of patients with stable angina pectoris.

Adult↗
PubMed1977

Catecholamines in coronary sinus during exercise in man before and after training.

Coronary patients exercised on an ergometric bicycle before and after physical training. Plasma catecholamines were sampled simultaneously at the arterial and coronary sinus levels and assayed with a radioenzymatic method. The increase in the level of coronary sinus catecholamines exceeded the increase in the arterial level, indicating a liberation of catecholamines by the myocardium and an activation of the peripheral sympathetic fibers during exercise. With high work loads, these values no longer differed, suggesting that the additional increase in circulating catecholamines originate from extra-myocardial stores, presumably the adrenal medulla. Arterial catecholamine levels were significantly correlated with work loads, heart rate, changes in systolic blood pressure, and rate-pressure product. After physical training, arterial catecholamine increases for various work loads were lower; these lower elevations were associated with diminished responses in heart rate and systolic blood pressure, resulting in a lower rate-pressure product. Physical training results in diminished sympathetic responses for a given level of exercise, which could be associated with the clinical improvement of these patients.

Adult↗
PubMed1975

Assay of cell-mediated cytotoxicity by tritiated thymidine labeled tumor cells.

A microtechnique for quantitating cell-mediated cytotoxicity using tritiated thymidine labeled target cells is presented. Target cell incorporation of tritiated thymidine is augmented by using methotrexate to arrest endogenous thymidine synthesis. Complete solubilization of labeled cells is accomplished by oxidizing samples to tritiated water and carbon dioxide prior to quantitation in a scintillation counter. This versatile technique, using various combinations of lymphocytes, sera and target cells, permits the simultaneous comparison of 500 or more individual samples.

Autoradiography↗
PubMed1975

The host immune response in human osteosarcoma.

A patient's immunologic response to a malignant tumor may be a major factor in determining his ultimate prognosis. An in vitro microcytotoxicity test using cultured tritiated thymidine (3HT) labeled osteosarcoma cells and autologous fibroblasts has been developed to determine the nature of this response. The role of cell mediated and serum factors has been quantitatively evaluated and the following results obtained. Osteosarcoma patients have been demonstrated to possess a normal cellular immune response which exhibits non-specific cytotoxicity in vitro. These patients can not differentiate their tumor cells from autologous fibroblasts, even though they may significantly suppress the growth of homologous tumors or fibroblasts. Serum blocking factors capable of inhibiting lymphocyte mediated cytotoxicity are occasionally noted. A reliable quantitative microcytotoxicity technique is presented which demonstrates that: (1) osteosarcoma is not due to host immuno-incompetence, (2) a common sarcoma antigen does not exist and (3) serum blocking factors may occasionally be present.

Adolescent↗
PubMed1975

Suppression and regeneration of rat bone marrow under the influence of methotrexate. An EM study.

Adult male rats were given daily injections of methotrexate for 12 days, during which time specimens of femoral bone marrow were taken for correlative light- and electron-microscopic study. After 12 days methotrexate was discontinued and specimens were taken the marrow recovered from the effect of methotrexate. Normal rat bone marrow was used as a basis of comparison. As methotrexate was administered, cell division ceased and the immature erythroblasts and myelocytes proceeded in the maturational process and a rapid hypocellularity of the marrow developed. Eosinophilic leukocytes, lymphocytes, large fat cells, erythrocytes, and phagocytic reticuloendothelial cells were the only formed elements remaining after 12 days of methotrexate treatment. Two days after methotrexate was discontinued, myeloblasts, myelocytes and proerythroblasts were plentiful, and on the third day the marrow exhibited an erythroid hyperplasia. By the eighth day all cell types were present though the marrow still was hypocellular. 14 days post methotrexate the marrow returned to normal.

Animals↗
PubMedDate not supplied

The latero-medial inferior pontine syndrome.

A case is presented with a pontine vascular lesion involving the V, VI, VII, and VIII cranial nerves. The diagnostic evaluation included audiometry and electronystagmography as well as arteriography, pneumoencephalography, and brain scan. Total deafness developed in the involved ear and was present for seven weeks before complete recovery occurred. Electronystagmographic findings consistent with a brain stem lesion also resolved following recovery of the patient. Audiometry and electronystagmography are described and documented for the first time in a report of a patient with a latero-medial inferior pontine syndrome. A discussion of some of the unique features of the brain stem vasculature and its relationship to clinical syndromes involving the brain stem is given.

Audiometry↗
PubMedDate not supplied

The ultrastructure of human osteosarcoma: a study of nine cases.

Electron microscopic study of 9 osteosarcomas corroborates the light microscopic observation that cells with osteoblastic, chondroblastic and fibroblastic features occur in osteosarcomas. Two types of multinucleated giant cells were observed, one was osteoclast-like. The other had anaplastic and degenerative changes. The intercellular matrix is composed of collagen fibers, amorphous ground substance with osteoid and tumor bone. Contrary to many previous electron microscopic reports, osteosarcomas contain more than one cell type.

Adolescent↗