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Biomedical subjects

M Rosenthal

Publications and source records attributed to M Rosenthal.

At least 199 records · Page 11Linked to original sources
PubMed1985

Closed chest catheter ablation of an accessory pathway in a patient with permanent junctional reciprocating tachycardia.

This report describes a 23 year old woman with a lifelong history of permanent junctional reciprocating tachycardia refractory to conventional antiarrhythmic medications who was successfully treated with closed chest, transvenous selective ablation of a posteroseptal bypass tract. Two 100 J (stored) direct-current shocks were delivered to the region of the os of the coronary sinus using a quadripolar catheter positioned in the coronary sinus. At a 2 month follow-up interval, the patient is asymptomatic without recurrence of the tachycardia. It is concluded that in patients with permanent junctional reciprocating tachycardia, selective catheter ablation of a posteroseptal accessory pathway is a feasible alternative to a difficult pharmacologic regimen or to ablative surgery.

Adult↗
PubMed1985

Mitochondrial redox responses to cerebral ischaemia produced by four-vessel occlusion in the rat.

Changes in reduction/oxidation (redox) ratios of the initial and terminal members of the mitochondrial respiratory chain (nicotine adenine dinucleotide and cytochrome a,a3) were measured by fluorometry and reflection spectrophotometry in rat cerebral cortex. Three patterns of responses were observed during the transition to global ischaemia produced by electrocoagulation of the vertebral arteries and carotid artery ligation. Most often, arterial occlusion was accompanied by shifts towards reduction of the mitochondrial components followed by partial reoxidation and then further reduction. Less frequently, ischaemia produced reductive shifts of the respiratory chain reactants that rapidly reached maximal values. In some rats, however, arterial, occlusion produced mitochondrial reduction followed by partial or complete reoxidation. ECoG remained suppressed, despite mitochondrial reoxidation, in approximately 1/3 of the latter animals. This study demonstrates that responses to 4-vessel occlusion can vary greatly among animals and suggests that monitoring of signals of ischaemic insult, such as mitochondrial redox status, may offer advantages for assessment of the consequences of ischaemic insult.

Anesthesia, General↗
PubMed1985

Prevalence, detection, and control of hypertension in a biethnic community. The San Antonio Heart Study.

A survey was carried out on a random sample of 1,288 Mexican Americans and 929 Anglos living in three socially distinct neighborhoods in San Antonio, Texas. Hypertension was defined as diastolic blood pressure greater than or equal to 95 mmHg or currently taking antihypertensive medication. Overall age-adjusted prevalence rates of hypertension were similar for Mexican-American and Anglo men (10.0 and 9.8%, respectively); for women, the Mexican-American rate was slightly lower than that for Anglos (7.8 and 9.7%, respectively). After adjustment for obesity differences, Mexican Americans have a tendency toward lower hypertension rates than Anglos of the same socioeconomic level. Only among women was a decline in the prevalence of hypertension with increasing socioeconomic status observed. Mexican Americans have a higher proportion of newly diagnosed hypertension, and, among previously diagnosed cases, a lower proportion are on antihypertensive medication than Anglos. The rates of hypertension control found in this survey are among the highest reported in the United States at the community level. Despite this, Mexican Americans still lag somewhat behind Anglos of the same socioeconomic level in awareness, treatment, and degree of hypertension control, suggesting the possibility of sociocultural barriers to adequate medical care.

Adult↗
PubMed1985

Coffee consumption, diet, and lipids.

Recent reports suggest that coffee consumption is associated with increased serum cholesterol and triglyceride concentrations. The authors examined the association between serum lipids and coffee consumption and other caffeinated beverages as part of a population-based study of 1,228 women and 923 men, aged 25-64 years, in San Antonio, Texas, studied between October 1979 and November 1982. The study confirmed a positive relationship between coffee consumption and both total and low density lipoprotein cholesterol in both sexes which persisted after adjustment for age, ethnicity, obesity, cigarette smoking, and alcohol consumption. Neither tea nor cola consumption was associated with changes in serum lipids, suggesting that caffeine alone does not exert a direct effect on lipid levels. The possibility was examined that the coffee-cholesterol relationship might be due to a more atherogenic diet consumed by heavy coffee drinkers. In men, per cent calories from both total and saturated fat and dietary cholesterol intake increased with increased coffee consumption. Similar trends were not observed in women, however. The positive relationship between coffee and cholesterol may therefore be due to confounding effects of other aspects of the diet.

Adult↗
PubMed1985

Geriatrics: a selected up-to-date bibliography.

This is the second annual revision of the Geriatrics Bibliography. Approximately two thirds of the old references have been replaced by more current or more detailed articles. The bibliography has been expanded to include several additional topics and over 200 new references. Since the literature pertinent to geriatrics is growing ever more rapidly, it has been necessary to omit many informative articles from the bibliography. Almost all of the references date from the past four years. Preference is given to recent publications, since they provide a list of the important earlier articles. Some articles were selected to highlight current controversies or changes in viewpoint. An occasional review article is cited to amplify geriatric aspects of common diseases. Most of the references deal specifically with an elderly patient population, studies of which, it will be noted, are confounded by questions of "normal" aging as opposed to the concomitants of aging frequent in our society: inactivity, obesity, malnutrition, and psychosocial trauma. A few articles concern diseases remarkably common in the aged but for which no adequate study specifically from a geriatric viewpoint exists; e.g., monoclonal gammopathy, Paget's disease, pulmonary emboli. The references are divided into categories. The first (I) set deals with some possible causes of aging, the second (II) with physiologic decline accompanying aging, the third (III) with the atypical and nonspecific characteristics of illness among geriatric patients, and the fourth (IV) with non-physician services available to the elderly, including ethical quandaries. The remainder of the references are cited by pertinent medical specialty. Within each category, references are divided by disease process. Articles are further subgrouped by aspects of those diseases such as evaluation or therapy.

Aged↗
PubMed1985

Effect of habitual physical activity on regulation of insulin-stimulated glucose disposal in older males.

The goal of this study was to evaluate the effect of differences in habitual level of physical activity on insulin action in healthy males between 60 and 75 years of age. The study population consisted of 20 non-obese individuals with normal glucose tolerance: 13 older subjects (68 +/- 4 years) not exercising regularly and 7 older subjects (66 +/- 3 years) who exercised regularly. Measurements were made of body mass index (BMI), percentage body fat by underwater weighing, maximal O2 consumption by bicycle ergometry (VO2max), and insulin-stimulated glucose disposal by the insulin clamp technique. The results demonstrated that insulin-stimulated glucose disposal was significantly increased (P less than 0.001) in the normal older subjects who exercised regularly. Furthermore, a direct relationship (r = 0.74, P less than 0.001) existed between maximal aerobic capacity and in vivo insulin action, which was independent of either BMI or percentage body fat. These data are consistent with the view that the extensive variation previously noted in in vivo insulin-stimulated glucose disposal of older subjects is related to differences in habitual physical activity.

Aged↗
PubMed1985

Potassium ion homeostasis and mitochondrial redox status of turtle brain during and after ischemia.

To account for the remarkable capacity of turtle brain to survive without oxygen, microelectrode recordings of extracellular potassium activity (K+o) were made in intact brains of normoxic pentobarbital-anesthetized turtles during and after ischemia. Changes in redox status of brain cytochrome a,a3 were recorded simultaneously by reflection spectrophotometry. Cytochrome a,a3 became fully reduced, and K+o rose at a slow rate for approximately 60 min during complete ischemia. When K+o reached 8-12 mM, an inflection point was observed after which K+o rapidly increased to levels above 30 mM. Full recovery of baseline K+o and cytochrome a,a3 redox state occurred only if brain blood flow was restored within 60 min. These data demonstrate that maintenance of ion homeostasis in turtle brain depends on blood flow and continued delivery of systemic substrates and that viability is threatened if ischemia is prolonged beyond 60 min.

Animals↗
PubMed1985

Water and the psychotic world.

Water, in the acute psychotic state on the behavioral level, represents a means of controlling anxiety and/or a sign for the situation. On the verbal level there is a lack of integration between its value as sign and as symbol. It is not invested with any new significance, and its appearance is not coincidental.

Adult↗
PubMed1985

A comprehensive quality assurance system for practicing dentists.

A comprehensive outcome-oriented quality assurance methodology manual has been developed for use by practicing dentists. The audit consists of four parts. Provision for immediate feedback to providers in order to monitor behavior change is a critical part of the review process as is the emphasis on the appropriateness of care dimension, a relatively unexplored area of quality assurance activity.

Clinical Competence↗
PubMed1985

A multidot immunobinding assay for autoimmune testing: evaluation for the diagnosis and management of connective tissue diseases.

Multidot immunobinding assays were evaluated for applicability to connective tissue diseases. Four groups of human sera [(a) healthy, (b) miscellaneous diseases, (c) rheumatoid arthritis and (d) other connective tissue diseases] were used to obtain profiles comprising antibodies against DNA, various subcellular components and rheumatoid factor (RF). Qualitative correlation with standard tests for antinuclear factor and RF was shown. Statistically significant ranges of titer for groups (c) and (d) were obtained, and monitoring individual patients during the progression of disease was demonstrated.

Antibodies↗
PubMed1984

Effects of acetazolamide and electrical stimulation on cerebral oxidative metabolism as indicated by the cytochrome oxidase redox state.

The intravenous administration of acetazolamide to rats caused a prompt oxidation of cytochrome a,a3 that was associated with an increase in the rate at which this cytochrome underwent additional oxidation and reductive recovery after electrical stimulation of the cerebral cortex. These effects were not observed in animals made hypercapnic after ventilation with 5% CO2. The speed with which these and other metabolic and physiological events occur, after administering the drug, suggests that acetazolamide exerts its effects by complex mechanisms and that the site of action may be in the region of the blood-brain barrier, an area rich in carbonic anhydrase, and noradrenergic innervation.

Acetazolamide↗
PubMed1984

Oxygen insufficiency during hypoxic hypoxia in rat brain cortex.

To relate cerebral oxygen sufficiency and insufficiency with arterial oxygen tension, reduction/oxidation responses of the initial and terminal members of the mitochondrial respiratory chain (NADH and cytochrome c oxidase) were recorded in situ by optical techniques when increased cerebral energy use was provoked by direct electrical stimulation. Small decreases in paO2, produced by forced ventilation of hypoxic gas mixtures, resulted in decreased amplitude of the characteristic negative shift in extracellular potential which accompanies such stimulation and smaller oxidative response of NADH and cytochrome oxidase. When paO2 fell below 40-50 Torr, stimulation produced reductive rather than oxidative shifts of the mitochondrial respiratory chain components. The data suggest that when arterial oxygen tension is slightly decreased, compensating mechanisms allow brain function to continue with minimal changes in cortical metabolites and high energy phosphate compounds. When arterial oxygen falls below 40-50 Torr, however, compensation can no longer prevent tissue hypoxia during times of increased energy demand. Thus, hypoxemia is not necessarily synonymous with oxygen insufficiency, but oxygen sufficiency must be defined with due regard to the degree of energy demand.

Animals↗
PubMed1984

Concepts of brain oxygen sufficiency during seizures.

To resolve conflicting evidence of oxygen sufficiency or insufficiency during seizures, signals of metabolic and circulatory function were monitored in rat cerebral cortex during recurrent seizures. Early seizures were accompanied by increased blood volume, increased tPO2, and oxidative shifts of cytochrome a,a3, indicative of oxygen sufficiency. Later seizures were accompanied by a smaller increment in blood volume, a fall in tPO2, and shifts toward reduction of cytochrome a,a3, suggesting that cerebral oxygen supply became insufficient to meet demand. Responses suggesting oxygen insufficiency occurred during short duration ictal bursts, interictal spikes or electrocortical stimulation at times when longer duration ictal episodes still were accompanied by responses signalling oxygen sufficiency. These data indicate that there is a progressive dissociation of the normally tight couple between neuronal activity, energy demand, and cerebral blood flow during status epilepticus. Systemic derrangements that often accompanied recurrent seizures also contributed to decreased cerebral oxygenation. These factors may cause the neuronal damage reported to follow prolonged status epilepticus.

Animals↗
PubMed1984

Sex difference in the effects of sociocultural status on diabetes and cardiovascular risk factors in Mexican Americans. The San Antonio Heart Study.

The authors postulated that as Mexican Americans became more affluent and/or acculturated to "mainstream" United States life-style they would progressively lose their "obesity-related" pattern of cardiovascular risk factors which were defined as: obesity, diabetes, hypertriglyceridemia and low levels of high density lipoprotein cholesterol. This hypothesis was tested in 1979-1982 in the San Antonio Heart Study, a population-based study on 1,288 Mexican Americans and 929 Anglos living in three San Antonio neighborhoods: a low-income barrio, a middle-income transitional neighborhood, and a high-income suburb. The study population comprised 25-65-year-old men and nonpregnant women. In Mexican American women, all of the "obesity-related" risk factors fell sharply with rising socioeconomic status. In Mexican American men, by contrast, diabetes was the only "obesity-related" risk factor which fell with rising socioeconomic status. Moreover, it fell less steeply, there being an approximately twofold difference in diabetes prevalence between the barrio and the suburbs in men compared to a fourfold difference in women. Also, total and low density lipoprotein cholesterol rose with rising socioeconomic status in Mexican American men, but not in Mexican American women. "Obesity-related" risk factors were generally higher in Mexican Americans of both sexes than in their Anglo neighbors who were of similar socioeconomic status. These results suggest that cultural factors exert a stronger influence on diabetes and cardiovascular risk factors in Mexican Americans than do purely socioeconomic factors.

Adult↗