Search PubMed⌕ Search

Biomedical subjects

T J Ryan

Publications and source records attributed to T J Ryan.

At least 379 records · Page 21Linked to original sources
PubMed1981

Derivation of systolic time intervals from Doppler measurement of temporal arterial blood flow.

The carotid pulse method of recording systolic time intervals is limited by significant motion-induced artifact, making it unsuitable for studying patients during exercise. As an approach to overcoming this limitation, a new method utilizing the blood velocity profile of the superficial temporal artery measured by Doppler ultrasound has been developed. When compared with the values obtained from the conventional carotid pulse method, Doppler-derived left ventricular ejection time and preejection period showed excellent correlation (r = 0.99 for both) and the Doppler-derived measurements showed little intra- or interobserver variability. Studies performed during treadmill exercise showed that in 8 of 10 subjects, suitable tracing could be recorded through stage 3 of the Bruce protocol, confirming the enhanced stability of the technique compared with the carotid pulse method.

Adult↗
PubMed1981

The efficacy of an aromatic retinoid, Tigason (etretinate), in the treatment of Darier's disease.

Eighteen patients with Darier's disease were treated for at least 3 months with the oral aromatic retinoid Tigason (etretinate, Ro 10-9359). Seventeen of the 18 patients improved but adverse effects were seen in all patients, and were particularly severe in 6. No haematological or biochemical abnormalities were detected during treatment. We conclude that Tigason is an important advance in the treatment of Darier's disease but adverse effects restrict its use in some patients.

Adolescent↗
PubMed1981

Pityriasis rubra pilaris: epidermal cell kinetics.

Epidermal proliferative kinetics were studied in a patient with pityriasis rubra pilaris. Elevated proliferative indices (flash labelling and mitotic indices) were apparent compared with normal epidermis and measurements of the birth rate indicate that the rate of epidermal cell production was similar to that found in psoriasis, and equalled 11.8 cells/1000 germinative cells/h; this suggests a cell cycle time of 60 h. Contemporaneous measurements of the rate of entry into DNA synthesis showed values similar to the rate of entry into mitosis; hence there is no G2 cell loss as appears to occur in the hyperproliferative psoriatic epidermis.

Aged↗
PubMed1981

Clinical and angiographic predictors of operative mortality from the collaborative study in coronary artery surgery (CASS).

Fifteen institutions participating in the Collaborative Study in Coronary Artery Surgery (CASS) have performed isolated coronary artery bypass surgery upon 6630 patients (1061 women and 5569 men) for coronary artery disease. The overall operative mortality (OM) was 2.3% (range 0.3-6.4%). Mortality increased with age, from 0 in the group 20-29 years old to 7.9% in the group 70 years and older. OM was higher for women in each group, ranging from 2.8% for ages 30-39 years to 12.3% for age 70 years and older (0.8% and 5.8% for men). Clinical manifestations of congestive heart failure were associated with increased OM. Mortality was 1.4% in one-vessel, 2.1% in two-vessel and 2.8% in three-vessel disease (diameter narrowing greater than or equal to 70%). Among 1019 patients with left main coronary artery (LMCA) stenosis, OM ranged from 1.6% in patients with mild stenosis and a right-dominant system to 25% in patients with severe (greater than or equal to 90%) stenosis and left dominance. OM varied with ejection fraction (EF) (1.9% for EF greater than or equal to 50% to 6.7% for EF less than 19%) and left ventricular wall motion score (1.7% for least abnormal to 9.1% for most abnormal). For elective surgery, OM was 1.7%, for urgent surgery 3.5%, and for emergency surgery 10.8%. Mortality was 40.0% among 30 patients with severe LMCA stenosis who underwent emergency revascularization. Advanced age, female sex, symptoms of heart failure, LMCA stenosis, impaired left ventricular function and nonelective surgery are associated with a higher OM. These factors should be considered in the selection of patients for coronary artery surgery.

Adult↗
PubMed1981

Diagnostic quantification of CASS (coronary artery surgery study) clinical and exercise test results in determining presence and extent of coronary artery disease. A multivariate approach.

Multivariate linear discriminant function analysis on maximal exercise treadmill and angiographic data from 500 men with definite angina, 584 men with probable angina and 267 men with nonspecific chest pain identified independent predictors of presence and extent of coronary disease. We used the discriminant function to develop a clinical risk index and a clinical and exercise risk index for each patient subset. Probability curves were generated to predict the presence and extent of coronary disease. In definite angina cases, exercise testing provided more diagnostic information than clinical data alone. However, in the 10% of cases with the smallest risk indexes, half of the patients had coronary disease and one-quarter had multivessel disease. In men with probable angina, exercise testing added substantially more diagnostic information than clinical data. The probability of multivessel disease was reduced to less than 10% for 30% of patients with probable angina, an important diagnostic contribution. Exercise testing in men with nonspecific chest pain was of limited value because disease prevalence was already low.

Angina Pectoris↗
PubMed1981

Acute regional circulatory and renal hemodynamic effects of converting-enzyme inhibition in patients with congestive heart failure.

The acute effects of the angiotensin converting-enzyme inhibitor captopril on regional blood flow, renal hemodynamics and sodium excretion were studied in 12 patients with severe congestive heart failure. Converting-enzyme inhibition decreased systemic vascular resistance by 27% and increased cardiac index by 16%. Estimated hepatic blood flow decreased 17%, but renal blood flow increased 60%. The ratio of renal-systemic blood flow increased from 0.10 +/- 0.01 to 0.14 +/- 0.02 (p = 0.031). Although renal plasma flow increased from 202.8 +/- 28.8 to 323.7 +/- 42.7 ml/min (p less than 0.008), the glomerular filtration rate did not change significantly from the mean pretreatment value of 82.1 +/- 12.3 ml/min. The filtration fraction decreased from 41.3 +/- 3.8% to 33.4 +/- 4.5% (p = 0.050), while urinary sodium excretion doubled, from 34.5 +/- 9.6 to 68.2 +/- 19.6 muEq/min. The plasma renin activity increased from 12.6 +/- 5.0 to 29.9 +/- 8.4 ng/ml/hr (p = 0.030) as plasma aldosterone concentration decreased from 30.5 +/- 6.5 to 11.3 4/- 1.2 ng/dl (p = 0.010) and norepinephrine concentrations decreased from 774 +/- 105 to 618 +/- 85 pg/ml (p = 0.020). We conclude that converting-enzyme inhibition reverses renal vasoconstriction in congestive heart failure and redistributes regional blood flow. The natriuresis may be mediated by one or more of the following: improved renal plasma flow, reduction in filtration fraction, suppression of hyperaldosteronism, and lowering of circulatory catecholamine concentrations.

Acute Disease↗
PubMed1981

Is micropapular sarcoidosis tuberculosis?

Three cases of micropapular sarcoidosis are reported. Two of the cases have a history of tuberculosis and all three cases have atypical patterns of Kveim and Mantoux reactivity. The similarities between this form of sarcoidosis and lichen scrofulosorum or lichenoid tuberculid are observed and the evidence is presented for a tuberculoid aetiology in certain forms of sarcoidosis.

Aged↗
PubMed1980

Successful use of a paracorporeal left ventricular assist device in man.

A paracorporeal left ventricular assist device (LVAD) with a capacity to pump 8 L/min of blood was employed in a clinical trial, and this report details the first survivor. A 60-year-old man could not be separated from the pump oxygenator following coronary artery bypass grafting, and, therefore, an LVAD was employed. Almost the entire left ventricular workload was assumed by the mechanical pump so that the myocardium was allowed to rest and recover. The LVAD support was continued for 105 hours. It provided satisfactory total body perfusion with maintenance of good hemodynamics--without serious deleterious effects on hematologic factors. The patient is alive and active without cardiac symptoms 16 months after his operation. The total experience with 13 LVAD implantations warrants continuation of the clinical trials in selected patients.

Angina Pectoris↗
PubMed1980

The altered baroreceptor response to nitroglycerin in congestive heart failure.

The use of nitroglycerin as a vasodilator in the treatment of congestive heart failure has demonstrated that the hemodynamic response is related to the degree of left ventricular dysfunction. Little emphasis has been placed on the mechanisms responsible for the variability in heart rate response to nitroglycerin. To study this problem, 33 patients with a variety of chronic cardiac disorders were given 0.4 mg of nitroglycerin sublingually. An increase in heart rate of less than 3 beats/min to sublingual nitroglycerin allowed a clear identification of a group of patients who had a left ventricular end-diastolic pressure greater than 18 mmHg or pulmonary artery mean pressure greater than 22 mmHg, and who had improvement in hemodynamic parameters following nitroglycerin. This alteration in baroreceptor sensitivity appears to be related to the level of left ventricular filling pressure, and can be used as a simple bedside means of identifying a group of patients who benefit the most from the vasodilator action of nitroglycerin.

Female↗