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Biomedical subjects

S Bloom

Publications and source records attributed to S Bloom.

At least 91 records · Page 5Linked to original sources
PubMed1981

Risk factors for fatal heart attack in young women.

Deaths of 338 women at ages 15-44 years attributed to myocardial infarction (MI) on death certificates during an 18-month period in five metropolitan areas were investigated. Evidence of recent MI or evidence that death occurred suddenly was obtained for about half (163) from records of hospitals or medical examiners or from relatives. A case-control study (involving one deceased control, and one hospitalized living control) of risk factors for heart attack was then conducted using interviews with relatives and abstracts of records of hospitals and physicians identified by the relatives as sources of medical care. Information was obtained on history of prior MI, other heart disease, diabetes, thromboembolism, stroke, hypertension, high cholesterol, obesity, oophorectomy, oral contraception and cigarette smoking. Data are presented on the prevalence of these potential risk factors for the case group and each control group, and for subsets of cases consisting of those without prior heart disease, definite MI only, sudden death only, and white women only. Multivariate analyses identify somewhat different sets of risk factors and different levels of risk for the various subgroups. In general, the risk factors are those that have been reported for men, despite the major difference in level of mortality.

Adolescent↗
PubMed1981

Analysis of dietary data; an interactive computer method for storage and retrieval.

The authors briefly review some problems encountered in collecting and interpreting dietary data and in analyzing them by hand and by computer methods. The use of computers, meant to speed processing, has often delayed processing or merely replaced computation time with coding time. The authors describe a simplified nutrient data base and an interactive retrieval method, Quick Input of Food, which has been developed for direct use by nutritionists with their clients.

Computers↗
PubMed1981

Surface cables of vertebrate muscle cells.

Cardiac and skeletal muscle cells were examined by scanning electron microscopy (SEM) for the presence of cell surface cables. This is the first report of such structures in the non-mammalian species, the pigeon, and in skeletal muscle of any species. They previously been reported from hamster cardiac myocytes. Cables were demonstrated on skeletal and heart muscle cells of both pigeons and hamsters. However, they could be visualized in skeletal muscle and pigeon heart only at short sarcomere lengths induced by homogenizing the tissues with additional CaCl2. Cables in the various preparations varied in length between 160 +/- 93 nm (mean +/- S. D.) and 220 +/- 54 nm. Heart cables has a mean diameter of 60 nm and skeletal muscle cables a mean diameter of 50 nm, as measured in metal-coated SEM preparations prepared simultaneously. This difference was significant (p less than 0.02) in hamsters and and highly significant (p less than 0.001) in pigeons. Cables reached the greatest concentration in hamster heart prepared with added CaCl2 (9.1 +/- 2.4 cables per linear transverse micrometer). The function of the cables, and their chemical nature, are not known. They may represent the anatomic basis for the limited compliance of heart muscle at long sarcomere lengths, and/or they may be a component of the intercellular fibrillar network of the heart.

Animals↗
PubMed1980

Fatal myocardial infarction and the role of oral contraceptives.

The association between use of oral contraceptives (OC) and death from myocardial infarction (MI) in young women was investigated in a collaborative case-control study conducted in the five largest metropolitan areas in the US. Potential cases were identified from computer tapes of the National Center for Health Statistics. Controls were selected from among women who died from, or were hospitalized for, acute conditions other than heart disease or from accidents, and were matched to cases on age, geographic area, and year of death. Information on cause of death, personal characteristics, OC use, and the presence of conditions predisposing to MI was obtained from interviews with relatives and abstracts of hospital, clinic and physician records. Odds ratios as approximations to relative risks for fatal MI in relation to OC use, and the associated 95% confidence limits, were calculated overall and for subgroups determined by demographic and health history characteristics. Odds ratios in the total study population were not significantly different from one. However, odds ratios significantly different from one were found when attention was restricted to white subjects without contraindications to OC use, andincluding only those cases whose deaths were attributed to MI with the greatest degree of certainty. Smoking was found to be a significant risk factor for fatal MI.

Adolescent↗
PubMed1980

Ca2+ flux and beating in leaky heart cells.

Previous work has shown that beating heart muscle cells with leaky sarcolemmae take up Ca2+ from the medium at a rate of 5.4 nmol/min/mg of protein while beating at a rate of 44 b.p.m. In the present work, we have used fragments of myocardium (MF), composed of such cells, to measure Ca2+ effux velocity and to compare influx and efflux rates to contraction frequency. The MF were estimated to be three cells thick, five cells wide, and three cells long, on the average. With MF suspended in fresh Pi-buffered medium containing 8.7 mumol/liter total Ca2+, the initial velocity of Ca2+ uptake (Vi) was much greater than the initial velocity of efflux (Vo). Vi, but not Vo, covaried with beating as a function of temperature and also showed ATP dependence. Thus, uptake, but not efflux, is a controlled process coupled to beating under these conditions. When cells were preloaded with Ca2+ and resuspended in Ca2+-depleted medium (total Ca2+ about 1 mumol/liter), approximating the steady state condition, Vi was reduced while Vo increased proportionally. These data suggest that contraction-activating Ca2+ is derived from extracellular sources during the pre-steady state conditions used here. Derivation from intracellular sites could occur in the steady state. The pre-steady state results conflict with mechanical behavior studies by us and others and, with Ca2+ flux in isolated sarcoplasmic reticulum (SR). The steady state results suggest that this conflict may be due to differences in Ca2+ loading and [Ca2+]i/[Ca2+]o.

Adenosine Triphosphate↗
PubMed1979

Roentgen diagnosis of linear ulcers.

Linear peptic ulcerations are not uncommon lesions of the stomach and duodenum and can be demonstrated by upper gastrointestinal series. This is facilitated by the double contrast technique, but they may also be appreciated via compression methods. The criteria found helpful to establish the presence of a linear ulcer include: (a) contour deformity; (b) niche projection; (c) fuzzy line; and (d) folds radiating to a line (crater). Routine use of these criteria with the double-contrast method enabled the authors to diagnose 42 linear ulcers.

Duodenal Ulcer↗
PubMed1978

The relationship between calcium flux and beating in hyperpermeable heart muscle cells.

Beating hyperpermeable myocardial fragments, suspended in fresh medium, show a Ca uptake rate which greatly exceeds the release rate. Under these conditions, Ca influx and contraction frequency co-vary with temperature. Ca efflux, however, is not temperature responsive. In addition, influx, but not efflux, is ATP-dependent. This implies that influx, but not efflux, is a controlled process, the activity of which has the same determinants as does contraction. However, under conditions approximating the steady state, the Ca influx rate was found to decrease, while the efflux rate increased. This suggests the possibility, at least, that the source of contraction-activating Ca can vary with the prevailing conditions.

Adenosine Triphosphate↗
PubMed1978

Heavy water effects on leaky heart muscle cells and actomyosin.

Heavy water inhibition of skeletal muscle contraction in barnacle and frog is thought to occur through inhibition of Ca release by SR. If this were so, D2O might be useful for studies on control of the inotropic state in mammalian myocardium. We therefore compared selected properties of mechanically disaggregated leaky myocardial fragments, and actomyosin, in D2O and H2O. At equal values of electrode-determined acidity the contraction frequency, initial velocity of 45Ca uptake, and equilibrium (Ca)i/(Ca)o of the myocardial fragments were all less when heavy water was used. For each of these parameters, and for actomyosin superprecipitation, the H2O and D2O acidity-response curves were similar but the D2O curve was shifted to the right. The actomyosin sedimentation rate was less in D2O than in H2O at near neutral acidity but not different under more acidic or basic conditions. Actomyosin ATPase showed an acidity-dependent increased activity in D2O. These results verify that heavy water inhibits contraction in mammalian myocardium, as is the case with invertebrate and frog skeletal muscle. The effect, however, cannot be attributed to inhibition of Ca release from SR.

Actomyosin↗
PubMed1977

Linear and rod-shaped peptic ulcers.

Experience with the routine use of the pharmacologically aided, double-contrast examination to demonstrate various primary and healing ulcers over a six month period is assessed. Thirteen linear or rod-shaped ulcerations were diagnosed. It appears that gastric relaxation and the demonstration of fine mucosal relief are necessary to detect ulcers of linear or rod form.

Contrast Media↗
PubMed1976

Respiratory control in hyperpermeable adult heart muscle cells. Effects of calcium.

Spontaneously beating myocardial fragments prepared by mechanical disaggregation have hyperpermeable sarcolemmae. Such preparations were used to study mitochondrial function in situ. The myocardial fragments suspended in a phosphate-buffered salt solution containing 1-3 mM MgCl2 showed a low rate of oxygen uptake. Addition of succinate, pyruvate plus malate or glutamate was followed by an increase in the rate of O2 uptake. Addition of ADP to fragments engaged in State 4 respiration was followed by initiation of more rapid State 3 respiration, with respiratory control ratios routinely greater than 3 for succinate and glutamate. If the fragments were suspended in the same medium containing 3 mM ATP (a medium in which contractile activity occurs), State 3 was initiated upon addition of substrate. The suspension medium used in these experiments contained about 8 muM calcium as contamination. Addition of calcium chloride to give a final concentration of 0.14 to 0.57 mM stimulated State 4 respiration of the myocardial fragments. In contrast similar additions made during State 3 inhibited respiration. The maximum degree of inhibition brought respiration close to the State 4 rate. If calcium was added prior to ADP, respiratory stimulation by the nucleotide was diminished. Respiratory function of myocardial fragments and of mitochondria isolated from them was similar in terms of response to substrate, ADP, and calcium addition in State 4. Response to calcium in State 3 was different in that inhibition was long-lived only at low [Pi] in the case of mitochondria, but at low or high [Pi] in the case of the fragments.

Animals↗
PubMed1976

Evaluation of routine double contrast views of the anterior wall of the stomach.

Since June 1974, we have performed over 1,500 consecutive double contrast upper gastrointestinal examinations. The double contrast study of the anterior wall has been a useful adjunct to conventional mucosal relief and dosed compression studies. Nevertheless, the low diagnostic yield of the anterior wall examination does not appear to justify including it as part of the routine double contrast upper gastrointestinal study.

Contrast Media↗