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Biomedical subjects

E E Slater

Publications and source records attributed to E E Slater.

50 records · Page 3Linked to original sources
PubMed1979

Dissection of the aorta.

Our approach to management, both initial and definitive, is summarized in Table 2. Patients with proximal dissection require surgical intervention after medical stabilization, unless prior debilitating illness precludes general anesthesia or prolonged vascular surgery. If myocardial infarction or cerebrovascular accidents has complicated the dissection, results are extremely poor, regardless of therapy. Patients with distal dissection have a good prognosis with medical therapy alone, unless aortic rupture or impending rupture, hematoma progression despite a maximal drug program, vital organ compromise, or inability to control pain or blood pressure medically supervene. Dissecting aneurysm of the aorta, while potentially a promptly fatal event, is amenable to aggressive therapy provided that one is alert to the possibility of this disease. Despite all technical advances, the single most important factor in making the diagnosis of dissecting aortic aneurysm is a strong index of suspicion on the part of the physician.

Aged↗
PubMed1979

Isolation of a renal thiol protease that activates inactive plasma renin.

1. A thiol protease with properties similar to those of cathepsin B (EC 3.4.22.1) has been isolated and purified from human renal cortex. 2. This enzyme can generate renin activity from renin-suppressed and anephric human plasma at pH 5.5. 3. The renin activity thus generated is inhibited completely by antibody to purified human renal renin. This activation therefore represents the release of inactive renin.

Cathepsin B↗
PubMed1978

Purification of human renal renin.

1. Human renal renin has been purified 200 000-fold from cadaver kidney cortex by a method which employs affinity chromatography on aminohexyl peptstatin. 2. The product of this purification has a specific activity of 400 Goldblatt units/mg when compared with Haas human renin standard. 3. This product appears as a single band on sodium dodecyl sulphate gel and polyacrylamide-disc gel electrophoresis. Renin enzymatic activity was recovered after elution from a polyacrylamide-disc gel run at pH 7.8. 4. Yield with this method was 1%.

Chromatography, Affinity↗
PubMed1978

Cardiac risk factors and complications in non-cardiac surgery.

In an attempt to assess cardiac risk in non-cardiac surgery, 1001 patients over 40 years of age who underwent major operative procedures were examined preoperatively, observed through surgery, studied with at least one postoperative electrocardiogram, and followed until hospital discharge or death. Documented postoperative myocardial infarction occurred in only 18 patients; though most of these patients had some pre-existing heart disease, there were few preoperative factors which were statistically correlated with postoperative infarction. Postoperative pulmonary edema was strongly correlated with preoperative heart failure, but 21 of the 36 patients who developed pulmonary edema did not have any prior history of heart failure. Nearly all of these 21 patients were elderly, had abnormal preoperative electrocardiograms, and had intraabdominal or intrathoracic surgery. In the absence of an acute infarction, bifascicular conduction defects, with or without PR interval prolongation, never progressed to complete heart block. Spinal anesthesia protected against postoperative heart failure but not against other cardiac complication. By multivariate regression analysis, postoperative cardiac death was significantly correlated with (a) myocardial infarction in the previous 6 months; (b) third heart sound or jugular venous distention immediately preoperatively; (c) more than five premature ventricular contractions per minute documented at any time preoperatively; (d) rhythm other than sinus, or premature atrial contractions on preoperative electrocardiogram; (e) age over 70 years; (f) significant valvular aortic stenosis; (g) emergency operation; (h) a 33% or greater fall in systolic blood pressure for more than 10 minutes intraoperatively. Notably unimportant factors included smoking, glucose intolerance, hyperlipidemia, hypertension, peripheral atherosclerotic vascular disease, angina, and distant myocardial infarction.

Adult↗
PubMed1978

A large form of renin from normal human kidney.

The apparent molecular size of circulating human plasma renin is 43,000 daltons. In this report, the Stokes' radius of renin extracted from human kidney cortex in low ionic strength buffer in the presence of protease inhibitors was shown to correspond to an apparent molecular weight of 58,000 +/- 3,000. If protease inhibitors are omitted, if the kidney tissue is frozen and thawed multiple times, or if the kidney extract is acidified to pH 2.8, renin activity of an apparent molecular size of 42,000 +/- 3,000 can be identified. Both species of renin bind to an affinity support bearing the substrate analog inhibitor His-Pro-Phe-His-Leu-D-Leu-Val-Tyr. Antibody raised to the higher molecular form of the enzyme inhibits the activity of both forms in an equivalent manner. These observations suggest that the larger form of renin may be a biosynthetic precursor of plasma renin, either in the form of a zymogen or an enzyme-binding protein complex.

Binding Sites↗
PubMed1977

Multifactorial index of cardiac risk in noncardiac surgical procedures.

To determine which preoperative factors might affect the development of cardiac complications after major noncardiac operations, we prospectively studied 1001 patients over 40 years of age. By multivariate discriminant analysis, we identified nine independent significant correlates of life-threatening and fatal cardiac complications: preoperative third heart sound or jugular venous distention; myocardial infarction in the preceding six months; more than five premature ventricular contractions per minute documented at any time before operation; rhythm other than sinus or presence of premature atrial contractions on preoperative electrocardiogram; age over 70 years; intraperitoneal, intrathoracic or aortic operation; emergency operation; important valvular aortic stenosis; and poor general medical condition. Patients could be separated into four classes of significantly different risk. Ten of the 19 postoperative cardiac fatalities occurred in the 18 patients at highest risk. If validated by prospective application, the multifactorial index may allow preoperative estimation of cardiac risk independent of direct surgical risk.

Age Factors↗
PubMed1976

The clinical recognition of dissecting aortic aneurysm.

The clinical, roentgenologic and laboratory findings in 124 patients with dissecting aneurysm of the aorta are reported. In 53 patients the dissection occurred in the ascending aorta ("proximal" dissection), and in 71 patients the site of origin was the descending thoracic aorta ("distal" dissection). Certain distinct clinical differences between the groups were apparent. Although hypertension was an important predisposing factor, it was significantly more common in distal dissection, as was atherosclerosis. Back pain and hypertension on hospital presentation characterized patients with distal dissection. Conversely patients with proximal dissection were younger and had a significantly higher incidence of Marfan's syndrome, cystic medial necrosis, anterior chest pain, pulse deficits, neurologic compromise, aortic insufficiency and congestive heart failure. In both groups, syncope appeared to correlate well with the occurrence of cardiac tamponade. Chest roentgenograms almost always showed an abnormal aortic contour. Aortic angiography, when performed, was usually confirmatory of the diagnosis.

Adult↗
PubMedDate not supplied

Cloning of the gene and cDNA for mammalian beta-adrenergic receptor and homology with rhodopsin.

The adenylate cyclase system, which consists of a catalytic moiety and regulatory guanine nucleotide-binding proteins, provides the effector mechanism for the intracellular actions of many hormones and drugs. The tissue specificity of the system is determined by the particular receptors that a cell expresses. Of the many receptors known to modulate adenylate cyclase activity, the best characterized and one of the most pharmacologically important is the beta-adrenergic receptor (beta AR). The pharmacologically distinguishable subtypes of the beta-adrenergic receptor, beta 1 and beta 2 receptors, stimulate adenylate cyclase on binding specific catecholamines. Recently, the avian erythrocyte beta 1, the amphibian erythrocyte beta 2 and the mammalian lung beta 2 receptors have been purified to homogeneity and demonstrated to retain binding activity in detergent-solubilized form. Moreover, the beta-adrenergic receptor has been reconstituted with the other components of the adenylate cyclase system in vitro, thus making this hormone receptor particularly attractive for studies of the mechanism of receptor action. This situation is in contrast to that for the receptors for growth factors and insulin, where the primary biochemical effectors of receptor action are unknown. Here, we report the cloning of the gene and cDNA for the mammalian beta 2AR. Analysis of the amino-acid sequence predicted for the beta AR indicates significant amino-acid homology with bovine rhodopsin and suggests that, like rhodopsin, beta AR possesses multiple membrane-spanning regions.

Amino Acid Sequence↗
PubMedDate not supplied

Comparison of renin and converting enzyme inhibition in sodium-deficient dogs.

While renin is a highly specific protease, converting enzyme has at least two principal substrates, angiotensin I and bradykinin. Changes in the rate of formation of angiotensin II or degradation of bradykinin can influence the hypotensive action of angiotensin converting enzyme inhibitors. The present study was designed to determine if there were differences in the maximal blood pressure reduction in Na-deficient dogs after angiotensin converting enzyme or renin inhibitor treatment. Five conscious dogs received 0.1, 0.5, and 1.0 mg/kg of i.v. enalaprilat, a potent angiotensin converting enzyme inhibitor, which reduced blood pressure to 75 +/- 4, 71 +/- 5, and 71 +/- 5 mm Hg. Plasma immunoreactive angiotensin II levels were reduced in a dose-related fashion to 35% of control level at the highest dose. Infusion of a maximally effective dose of a statine-containing renin inhibitor (SCRIP) with the high dose of enalaprilat produced no further fall in blood pressure (68 +/- 7 mm Hg), but immunoreactive angiotensin II levels fell to essentially zero in four of five dogs. The order of drug administration was reversed in another experiment in a group of nine dogs in which SCRIP reduced plasma immunoreactive angiotensin II to 25% of control at 0.04 mg/kg/minute (n = 5), with reduction to near zero levels at higher doses. Maximal blood pressure reduction was achieved at 0.32 to 0.64 mg/kg/minute (76 +/- 4 mm Hg); 1 mg/kg of enalaprilat lowered blood pressure an additional 11 +/- 2 mm Hg (p less than 0.01) while not further decreasing immunoreactive angiotensin II levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗