PubMed Health⌕ Search

Biomedical subjects

S Dack

Publications and source records attributed to S Dack.

At least 19 recordsLinked to original sources
PubMed2001

The activity of yeast ADH I and ADH II with long-chain alcohols and diols.

The activities of yeast ADH I and ADH II towards long chain alcohols and diols were studied using rather unusual conditions (1.0 M Tris pH 8.75, approximately 0.3 mg/ml enzyme and [S]<<<K(m) ) where the alcohols are oxidised quantitatively in a first-order manner. Plots of the apparent first-order rate constant versus primary alcohol chain length show double peaks with similar values for ethanol and 1-decanol and relatively low values for 1-butanol through to 1-octanol. With the alpha,omega diols only one peak of activity was observed with 1,14-tetradecanediol, the preferred substrate, being oxidised about the same rate as ethanol. Both enzymes were essentially inactive with short-chain diols (C(2)-C(8)). For all of these assays normalised rates with ADH II were about threefold faster than with ADH I.

Alcohol Dehydrogenase↗
PubMed1987

Morphological aspects of the development of hydrocephalus in a mouse mutant (SUMS/NP).

The SUMS/NP is a mouse mutant with a recessive gene for congenital hydrocephalus. The condition is detectable outwardly at 3 days after birth and affected animals die soon after weaning. The heads of fetuses from 14 to 20 days gestation and at 1, 4, 5, 12 and 18 days after birth have been sectioned for light microscopy and the volume of the lateral ventricles measured in all but the three oldest ages. At 16 days gestation and earlier all fetuses had a relatively large lateral ventricle volume. Hydrocephalus was first detected from volume measurements at 18 days gestation and generally became progressively more severe with age. Hydrocephalic animals, in addition to lateral and third ventricle dilatation, always showed a reduction in the cross-sectional area of the cerebral aqueduct or a total absence of the aqueduct. All hydrocephalics, with the exception of two fetuses, also had cystic cavitation of the forebrain around the lateral ventricles. Electron microscopy of animals with a reduced aqueduct showed the ventral part to be absent in hydrocephalics.

Age Factors↗
PubMed1976

Coronary artery dissection - a complication of cardiac catheterization without sequelae: case report and review of the literature.

This report describes an acute right coronary artery dissection occurring during diagnostic cardiac catheterization. Following catheter manipulation in the vicinity of the aortic valve, the patient complained of mild chest discomfort and had transient electrocardiographic evidence of acute inferior wall myocardial infarction with runs of 2:1 atrioventricular block. Within 5 min, the EKG reverted to precatheterization appearance, and the patient was asymptomatic. Coronary angiography revealed a dissection of the proximal vessel without obstruction. The patient had no clinical sequelae while monitored in the intensive care unit. The patient underwent elective aortic and mitral valve replacement. The area of the dissection was directly visualized, and no abnormality was noted. We review the literature of spontaneous and iatrogenic coronary artery dissections with regard to pathology, diagnosis, and prognosis, and make recommendations for therapy.

Aortic Dissection↗
PubMed1976

Value of Holter monitoring in assessing cardiac arrhythmias in symptomatic patients.

Holter electrocardiographic monitoring in 55 symptomatic patients with syncope, palpitations or dizziness uncovered significant arrhythmias in 30 patients (55 percent). By providing an observation period of at least 24 hours including a period of sleep, the procedure aided detection and diagnosis in both symptomatic and asymptomatic patients of transient arrhythmias or conduction abnormalities not documented by routine electrocardiograms. Bradyarrhythmias accounted for the majority of arrhythmias recorded in 21 or 30 symptomatic patients (70 percent); 15 had sinus bradycardia (35 to 55 beats/min) alone and 6 also had long episodes of sinus arrest of up to 5 seconds. Two had sinus bradycardia with periods of atrioventricular block with Wenckebach phenomenon. Five patients had a tachycardia-bradycardia syndrome; three had other episodic arrhythmias and one had pacemaker failure. In 15 (60 percent) of the 25 patients without arrhythmias, monitoring did not document the cause of symptoms. Holter monitoring is of considerable value in assessing the efficacy and adequacy of drug treatment, especially in patients with known heart disease, and in detecting pacemaker malfunction. However, very long periods of monitoring may be needed to make a diagnosis in those with only sporadic symptoms.

Adult↗
PubMed1975

Myocardial infarction due to coronary atherosclerosis in three young adults with systemic lupus erythematosus.

Three patients, 24, 24 and 25 years of age, with systemic lupus erythematosus had signs of myocardial infarction. Two had serial electrocardiographic changes indicative of infarction without any cardiac symptoms. The third patient had clinical evidence of an acute massive myocardial infarction, which was proved at autopsy to be due to coronary atherosclerosis. This case is presented in detail and the association between systemic lupus erythematosus and myocardial infarction is reviewed. It is postulated that the relation between lupus erythematosus and coronary atherosclerosis is more than coincidental.

Adult↗
PubMed1975

Transient Q waves in Prinzmetal's angina.

Transient abnormal Q waves were seen in two patients with Prinzmetal's angina during episodes of chest pain. The Q waves appeared recurrently while the patients had chest pain and disappeared when it subsided, indicating that Q waves suggestive of myocardial infarction can be seen with severe myocardial ischemia without actual necrosis. We describe these two patients, the various conditions in which transient abnormal Q waves have been reported and the theories offered to explain this electrophysiologic finding.

Angina Pectoris↗
PubMed1975

Disappearance of abnormal Q waves after aortocoronary bypass surgery.

Sixty-one patients were selected from 100 consecutive patients under-going aortocoronary artery bypass. The number of vessels diseased as defined by coronary arteriography and the number of bypass grafts were recorded. Review of the preoperative electrocardiograms showed an infarct pattern in 26 of the 61 patients and analysis of the postoperative electrocardiograms revealed loss of abnormal Q waves in 3 of the 26. The pre- and postoperative clinical course of these three patients is analyzed and the extent of their coronary artery disease and number of bypass grafts compared with those of the 23 patients who had persistence of the infarction pattern and the 17 patients who manifested new Q waves. Possible explanations for the disappearance of abnormal Q waves are discussed.

Aged↗
PubMed1975

Bacterial endocarditis with ruptured sinus of Valsalva and aorticocardiac fistula.

A case is presented of bacterial endocarditis with a ruptured sinus of Valsalva and formation of an aorticocardiac fistula from the right coronary sinus into the right atrium and right ventricle. The pathologic, clinical and surgical aspects of bacterial endocarditis complicated by a ruptured sinus of Valsalva and an aorticocardiac fistula are analyzed. This complication of bacterial endocarditis is still uncommon, but alertness to its diagnosis makes possible early and successful surgical treatment.

Adult↗