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S Goldstein

Publications and source records attributed to S Goldstein.

At least 289 records · Page 16Linked to original sources
PubMed1991

SOD-like activity studies of cytokinin-copper(II) complexes.

Using the pulse radiolysis technique it was shown that copper(II) complexes of kinetin and 6-benzylaminopurine (6-BAP) catalyze O2- dismutation very efficiently at physiological pH. The 'turnover' rate constants at pH 7 were determined to be (1.5 +/- 0.3) x 10(9) and (2.2 +/- 0.4) x 10(9) M-1s-1 for 6-BAP and kinetin, respectively. The system was studied at pH 3-10 in the case of 6-BAP, and the results show that this complex catalyzes also HO2 dismutation efficiently.

Adenine↗
PubMed1991

Determination of the superoxide dismutase-like activity of cimetidine-Cu(II) complexes.

Using the direct method of pulse radiolysis to determine the superoxide dismutase like activity of copper(II) cimetidine complexes, it was found that the reaction rate constant with O2-, kcat, was (8.5 +/- 0.5) x 10(8) M-1s-1 independent of the cimetidine concentrations present in excess of 50-200 microM over the metal. The results suggest that either the 1:1 ligand to metal complex does not catalyze O2- dismutation at a comparable rate to that of the 2:1 complex, or that the stability constant of the last species is much higher than that determined earlier by Kimura et al., and only the 2:1 species is present in the solutions. With the indirect methods of cytochrome c and NBT for determining the ability of these complexes to catalyze O2 dismutation, these compounds exhibited a much lower SOD activity, and kcat was determined to be (5.0 +/- 0.3) x 10(6) and (7.6 +/- 0.4) x 10(7) M-1s-1, respectively using the two assays.

Cimetidine↗
PubMed1991

Beta-adrenergic blocking agents in the treatment of patients after a myocardial infarction.

Beta-adrenergic blocking agents have been widely used in ischemic heart disease. They have achieved their greatest benefit in the secondary prevention of recurrent events in patients following acute myocardial infarction (MI). This is a review of the major clinical investigations exploring the effects of beta-adrenergic blocking agents in patients following acute MI and in a variety of patient subsets. These data indicate that the routine use of beta-adrenergic blocking agents in postinfarction patients results in a 25% to 35% decrease in mortality and has increased relative and absolute benefit in patients with ventricular ectopy and left ventricular dysfunction. The adverse effects of beta-adrenergic blocking agents are discussed which indicate that these drugs are well tolerated with little or no side effects. This review supports the observation that beta-adrenergic blocking agents have an important role in the treatment of patients following an acute MI, with the exclusion of those with chronic lung disease and severe left ventricular dysfunction.

Adrenergic beta-Antagonists↗
PubMed1991

Management of cardiogenic shock complicating acute myocardial infarction: The Henry Ford Hospital experience and review of the literature.

Cardiogenic shock complicating acute myocardial infarction (MI) carries a high mortality which in some series prior to 1980 exceeded 80%. Neither the use of inotropic and vasopressor agents nor intraaortic balloon counterpulsation was found to improve survival in this group of patients. Intravenous thrombolytic agents improve survival in patients with acute MI, but their role in cardiogenic shock is unknown. Reports of the use of surgical and mechanical interventions in patients with severe left ventricular dysfunction were examined to determine if there was any benefit to be derived from restoring blood flow to ischemic areas of the myocardium. It was found that urgent placement of intraaortic balloon counterpulsation followed by coronary bypass surgery may improve survival rates and successful coronary angioplasty also appeared to benefit patients with cardiogenic shock. Similar improvement in survival has been reported after successful coronary reperfusion. In surgical series with predominantly nonmechanical causes of shock, survival has varied from 40% to 88%. Data from our five-year experience in the management of MI patients with cardiogenic shock suggest that coronary revascularization with coronary angioplasty or bypass surgery improves survival in patients with cardiogenic shock especially when performed within 24 hours of the onset of shock.

Angioplasty, Balloon, Coronary↗
PubMed1991

Incomplete versus complete myocardial infarction.

Incomplete myocardial infarction (MI), when compared with a complete MI, is characterized by a small infarct size and a large mass of viable but jeopardized myocardium within the perfusion zone of the infarct-related vessel that is manifested clinically by early recurrent infarction. The pathophysiology involves early spontaneous or thrombolytic reperfusion. Clinical (i.e., residual ischemia), electrocardiographic, and echocardiographic findings and magnitude of serum cardiac enzyme elevations should be taken into account in diagnosing an incomplete MI.

Electrocardiography↗
PubMed1991

Recurrent acute suppurative thyroiditis.

Recurrent acute left-sided suppurative thyroiditis was observed and treated in an eight-year-old girl. Barium swallow performed after the third episode revealed the presence of a pyriform sinus fistula extending to the upper pole of the left lobe. Despite resection of the fistula, she relapsed for a fourth time. The fistula was again seen on esophagogram. A probe was left inside the tract during subsequent surgery, thus facilitating its complete removal. AST occurs most commonly as a result of the persistence of a connection between the throat and the thyroid gland which is otherwise extremely resistant to infection. AST is usually left-sided and not associated with thyroid dysfunction. Recurrences are common unless the congenital fistula is identified and completely excised.

Acute Disease↗
PubMed1991

Temporary migrants in Shanghai households, 1984.

In China, temporary migration is defined as a change in place of residence without a concomitant change in household registration; such mobility therefore encompasses a more heterogeneous set of movements than is usually subsumed under this heading in other nations. Because of China's strict control of permanent migration to large cities, temporary migration has become an important strategy for adjusting to economic changes and to effecting family reunification. The Shanghai Temporary Migration Survey of 1984 focused on one segment of temporary migrants, the 58% living in the households of permanent residents. Multinomial logistic regression suggests the heightened probability that close relatives of the household heads come to Shanghai to visit or to live, and nonrelatives to work. Regression on current and expected duration shows that many intended to stay for a year or more, some for up to 20 years. Their presence in the city places added strains on infrastructure and raises questions about the continued efficacy of China's migration policies.

Adolescent↗
PubMed1990

Effect of beta-adrenergic blocking agents on the circadian occurrence of ischemic cardiovascular events.

Clinical observations suggest that beta-adrenergic blocking agents can modify the circadian occurrence of a variety of ischemic events. Morning awakening is associated with a rapid increase in blood pressure and pulse, serum catecholamine content and platelet activation, at a time of decreased blood thrombolytic activity. Beta-adrenergic blocking agents have the potential to modify many of these events. Current data indicate that these agents modify blood pressure and pulse, but do not prevent their early morning increase. In addition, beta-adrenergic blocking agents decrease ventricular ectopy and its circadian variation. Recent studies in humans indicate, however, that metoprolol does not affect the circadian increase in platelet activity or serum catecholamines. The specific mechanism by which beta blockers affect the circadian occurrence of ischemic events remains uncertain.

Adrenergic beta-Antagonists↗
PubMed1990

A universal primer mixture for sequence determination at the 3' ends of cDNAs.

We have devised a universal primer which can be used to sequence the 3'-ends of cloned cDNAs containing a polyA tail. The primer consists of an equimolar mixture of three primers: 20 T nucleotides followed by either an A, C, or G nucleotide (5'----3'). With this primer mixture and the dideoxynucleotide chain termination method, we determined the 3'-terminal sequence of human beta-actin cDNA in an Okayama-Berg vector, in four parallel sets of reactions containing either a single primer (T20G, T20C, or T20A) or an equimolar mixture of all three primers. Priming with both T20A and the triple mixture gave clearly readable results that agree with the known sequence of the human beta-actin gene, and we have applied this method successfully to several other cDNAs in the Okayama-Berg expression vector. Use of this universal primer mixture facilitates determination of sequences at the 3'-ends of cDNAs while by-passing the polyA tail region.

Actins↗
PubMed1990

Replicative senescence: the human fibroblast comes of age.

Human diploid fibroblasts undergo replicative senescence predominantly because of arrest at the G1/S boundary of the cell cycle. Senescent arrest resembles a process of terminal differentiation that appears to involve repression of proliferation-promoting genes with reciprocal new expression of antiproliferative genes, although post-transcriptional factors may also be involved. Identification of participating genes and clarification of their mechanisms of action will help to elucidate the universal cellular decline of biological aging and an important obverse manifestation, the rare escape of cells from senescence leading to immortalization and oncogenesis.

Cell Cycle↗
PubMed1990

Effects of propranolol in non-Q-wave acute myocardial infarction in the beta blocker heart attack trial.

Although the beneficial effects of long-term therapy with beta-adrenergic blocking agents in patients recovering from acute myocardial infarction (AMI) are established, the effect of this therapy on the cardiac event rate in patients recovering from a non-Q-wave AMI is unknown. This post hoc analysis of the Beta Blocker Heart Attack Trial (BHAT) evaluates the effects of daily administration of propranolol 180 or 240 mg/day after non-Q-wave AMI. The study population consisted of 601 patients with enzymatically proven non-Q-wave AMI, which represented 17% of the BHAT patients. Of these, 310 patients were randomized to receive propranolol and 291 patients to placebo. There were no significant baseline differences between groups. The median follow-up was 24.6 months. Mortality was 7.8% (sudden death 4.8%) in the propranolol group and 7.9% (sudden death 4.8%) in the placebo group (p greater than 0.99, log rank test). Reinfarction rate was 7.4% in the propranolol group and 6.5% in the placebo group (p greater than 0.63, log rank test). The need for coronary bypass surgery was similar in the 2 groups. However, more patients randomized to placebo developed angina. In this post hoc group analysis of the BHAT, propranolol was not shown to be beneficial in reducing the cardiac event rate in patients recovering from a non-Q-wave AMI.

Double-Blind Method↗
PubMed1990

Effect of empiric antiarrhythmic therapy in resuscitated out-of-hospital cardiac arrest victims with coronary artery disease.

The effect of empiric antiarrhythmic therapy with quinidine and procainamide on long-term mortality was examined in 209 patients with coronary artery disease resuscitated after out-of-hospital cardiac arrest. The antiarrhythmic agent used was determined by the patient's private physician without knowledge of the study ambulatory electrocardiogram. Of the 209 patients, procainamide was prescribed in 45 (22%), quinidine in 48 (23%) and no antiarrhythmic therapy in 116 (55%). Digoxin therapy was initiated in 101 patients. The 2-year total survival rate for the quinidine, procainamide and nontreated patients was 61, 57 and 71% (p less than 0.05), and for sudden death was 69, 69 and 89% (p less than 0.01), respectively. These observations suggest that empiric antiarrhythmic therapy in survivors of out-of-hospital cardiac arrest did not affect total mortality and was associated with an increased frequency of sudden death.

Aged↗
PubMed1990

Synthesis, cellular uptake of, and cell photosensitization by a porphyrin bearing a quinoline group.

A tetraphenyl porphine linked to a 7-chloroquinoline (5,10,15,20-tetraphenyl-1-3-[4-(4-aminobutyl)7-chloroquinoline] propioamidoporphine, TPPQ) was synthesized and examined as a potential photosensitizer for photodynamic therapy (PDT) of proliferative diseases. With respect to haematoporphyrin, TPPQ is a good in vitro photodynamic sensitizer producing singlet oxygen in 1% Triton X100 solutions. As with other hydrophobic porphyrins used in PDT, blood lipoproteins strongly bind TPPQ. Thus one low density lipoprotein (LDL) can incorporate 25 TPPQ molecules and 17 TPPQ molecules are taken up by one high density lipoprotein (HDL). Cell delivery of TPPQ using HDL or human serum albumin (HSA) as carrier is rather weak. However, an efficient TPPQ delivery to human skin fibroblasts is observed, partly aided by receptor-mediated endocytosis of LDL. Fluorescence spectroscopy shows that the cellular localization of TPPQ is both carrier and time dependent. During its delivery with LDL, TPPQ does not significantly impair the endocytosis of LDL-receptor complexes. After delivery with LDL, TPPQ is as efficient as other haematoporphyrin derivatives used in the PDT of cancers in photosensitizing human skin fibroblasts.

Aminoquinolines↗
PubMed1990

Effects of cigarette smoking and propranolol in survivors of acute myocardial infarction.

The effect of propranolol on mortality and reinfarction after acute myocardial infarction (AMI) in cigarette smokers and nonsmokers was studied in the Beta Blocker Heart Attack Trial. Cigarette smokers (n = 2,332) were 5 years younger than nonsmokers and had a lower incidence of diabetes mellitus, systemic hypertension, previous AMI and cardiomegaly. Among cigarette smokers, the placebo group had a higher total mortality rate than the propranolol group (11.0 vs 7.4%, p less than 0.0008) and more sudden cardiac deaths (7.1 vs 4.6%, p less than 0.009). In nonsmokers the placebo group had a mortality (7.9 vs 7.1%, p greater than 0.64) similar to the propranolol group. After baseline adjustment, cigarette smokers were estimated to have 1.6 times the risk of dying as compared to nonsmokers (p less than 0.0007). Adjusting for baseline differences, both treatment with propranolol and nonsmoking were predictors of survival. No detectable nonsmoking/propranolol interaction could be identified. In survivors of AMI a beneficial effect of propranolol is observed for cigarette smokers. Nevertheless, cigarette smoking continues to be a risk factor for mortality after AMI even for those receiving propranolol.

Double-Blind Method↗
PubMed1990

Absence of reverse transcriptase activity in human diploid fibroblasts.

The reverse flow of genetic information from RNA transcripts to DNA has been postulated to be the mechanism for the generation of pseudogenes, dispersed repetitious DNA families, and small extrachromosomal circular DNAs in eukaryotic cells. We were unable to detect reverse transcriptase-like activity in several strains of cultured human cells, with or without induction by a variety of chemical and physical agents known to induce latent retroviruses.

Cells, Cultured↗