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Biomedical subjects

S Shapiro

Publications and source records attributed to S Shapiro.

At least 415 records · Page 23Linked to original sources

Utilization of health and mental health services. Three Epidemiologic Catchment Area sites.

Utilization of health and mental health services by non-institutionalized persons aged 18 years and older is examined based on interviews with probability samples of 3,000 to 3,500 persons in each of three sites of the National Institute of Mental Health Epidemiologic Catchment Area (ECA) program: New Haven, Conn, Baltimore, and St Louis. In all three ECAs, 6% to 7% of the adults made a visit during the prior six months for mental health reasons; proportions were considerably higher among persons with recent DSM-III disorders covered by the Diagnostic Interview Schedule (DIS) or severe cognitive impairment. Between 24% and 38% of all ambulatory visits by persons with DIS disorders were to mental health specialists. In seeking mental health services, men were more likely to turn to the specialty sector than to the generalist; women used both sectors about equally. The aged infrequently received care from mental health specialists. Visits for mental health reasons varied considerably depending on specific types of DIS disorder.

Adolescent↗

Risk of breast cancer in relation to the use of rauwolfia alkaloids.

In a case-control study of 1881 women with breast cancer and 1523 controls with benign conditions, 65 cases (3.5%) and 64 controls (4.2%) reported having used a drug that contained rauwolfia, giving a rate ratio estimate of 0.8 (95% confidence interval, 0.5-1.1). Use that ended more than a year previously was negatively associated with breast cancer (rate ratio, 0.5; 95% confidence interval, 0.2-0.9). The risk of breast cancer did not vary significantly according to duration of use. Nor did it vary within strata of varying base-line risk, such as age at first pregnancy. The data suggest that rauwolfia alkaloids do not increase the risk of breast cancer.

Adult↗

Human adult endothelial cell growth in culture.

The purpose of the present study was to culture human adult endothelial cells (HAECs) on a long-term basis in the laboratory. Previous inability to accomplish this has been the major impediment to the in vitro study of endothelialization of prosthetic grafts with human cells, a problem of significant clinical relevance. We have been successful in developing a technique that allows HAECs from human adult arteries, veins, and capillaries to proliferate vigorously in culture for up to 80 population doublings. HAECs are grown on a gelatin surface (medium 199 containing 20% fetal calf serum). Heparin and endothelial cell growth factor (ECGF) are required for optimal growth. With this technique, which will be described in detail, over 10(23) HAECs can be produced from each 1 cm2 of vascular tissue. This makes large numbers of HAECs available for high-density seeding on prosthetic grafts prior to implantation. It also permits for the first time with human cells the in vitro study of prosthetic grafts--HAEC interactions and the factors that enhance optimal growth and adherence to prosthetic materials. It is hoped that identification of the factors promoting graft endothelialization in combination with high-density seeding will lower graft thrombogenicity and therefore result in greater graft longevity than has been possible heretofore.

Adult↗

Breast cancer and oral contraceptive use.

The risk of breast cancer in relation to oral contraceptive use was evaluated in a case-control study of 1191 patients with breast cancer and 5026 control patients. For ever-use compared with never-use, the estimated relative risk of breast cancer was 1.0 (95% confidence interval 0.9-1.2). Use of oral contraceptives for five or more years was not associated with breast cancer, regardless of whether use had ended as much as 10 or more years previously, or more recently. Within categories of women whose baseline risk was elevated, including nulligravidae, premenopausal women, and those with benign breast disease or history of breast cancer in first-degree relatives, the relative risk estimates for five or more years of oral contraceptive use approximated 1.0. For any use before first pregnancy, the relative risk estimate was 1.3, and for use lasting three or more years it was 0.9. These data suggest that long-term oral contraceptive use does not increase the risk of breast cancer even after a latent interval in excess of one decade; nor do oral contraceptives appear to increase the risk within categories of women at relatively high baseline risk.

Adult↗

The epidemiological evaluation of drugs.

Depending on the research problem, the epidemiological evaluation of drugs must be based on a combination of research strategies that include experimental methods (controlled trials), and non-experimental methods. Among the latter are correlational studies; spontaneous reporting systems and published case reports; cohort studies; and case-control studies. The spread of computer technology may, by record linkage, facilitate cohort or case-control studies. Comprehensive drug surveillance must be based on the combined use of each research strategy, as appropriate.

Clinical Trials as Topic↗

Alterations of amino acid transmitter systems in spinal cords of chronic paraplegic dogs.

The high-affinity uptake of [3H]serotonin, [3H]glutamate, and [3H]gamma-aminobutyric acid [( 3H]GABA) and the Na+-independent binding of [3H]glutamate and [3H]GABA were studied using spinal cord preparations obtained from normal mongrel dogs and from dogs made paraplegic by midthoracic spinal cord crush. Lumbosacral regions of the spinal cord were removed either before (1 week) or after (3 to 8 weeks) onset of spasticity. A myelin-free synaptosomal fraction was obtained by centrifugation and used for studying high-affinity uptake and for preparing synaptic plasma membranes for Na+-independent binding experiments. For the paraplegic groups, the uptake of 30 nM [3H]serotonin was 66 and 18% of control values after 1 and 3 weeks, respectively. Eadie-Hofstee analysis of [3H]serotonin uptake showed a 90% reduction in Vmax for the paraplegic group relative to control values, thereby indicating the expected loss of descending serotonergic pathways. The high-affinity uptakes of 1 microM [3H]glutamate and [3H]GABA were the same in both the control and nonspastic paraplegic groups after 1 week. However, after 3 weeks, the uptakes of [3H]glutamate and [3H]GABA were 60-70% higher for the spastic group than for the control animals. For both amino acids, Eadie-Hofstee plots revealed no difference in Km and higher Vmax for the spastic group relative to control values. After 1 and 3 weeks, the Na+-independent binding of 5 nM [3H]glutamate was 40-85% higher and the binding of 10 nM [3H]GABA was 40-60% lower for the paraplegic groups relative to the values for the control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Suppression of nitrate utilization by ammonium and its relationship to chloramphenicol production in Streptomyces venezuelae.

Cultures of Streptomyces venezuelae grown in a medium containing glucose with mixtures of ammonium and nitrate as the nitrogen source produced chloramphenicol in a distinct idiophase that followed biomass accumulation. Analysis of fermentation broths showed that ammonium and nitrate were taken up consecutively by the organism. Measurements of nitrate reductase in the mycelium established that the enzyme was constitutive and that its specific activity did not increase during the period when ammonium was exhausted from the medium and nitrate was assimilated. The enzyme was neither repressed nor inhibited by ammonium. Production of chloramphenicol was also delayed until ammonium had been consumed and remained slow until subsequent depletion of nitrate. Arylamine synthetase, the initial enzyme in the pathway of antibiotic biosynthesis, showed no marked change in specific activity during utilization of the two nitrogen sources. The result suggests that the mechanism causing preferential utilization of ammonium does not simultaneously control the onset of chloramphenicol biosynthesis.

Chloramphenicol↗

Excretion of alpha-keto acids by strains of Streptomyces venezuelae.

Cultures of Streptomyces venezuelae released acidic metabolites during nitrogen-limited growth on glucose. The main products were pyruvic acid and alpha-ketoglutaric acid. Variation in the extent of acid production was observed; spores of the parental strain 13s gave approximately 10% of low-producing colonies when plated on acid-base indicator medium. Examination of one low producer, strain PC 51-5, showed that differences in acid production became apparent only in low-glucose media containing manganese. In both strains PC 51-5 and 13s, uptake of alpha-keto-[5-14C]glutaric acid occurred by diffusion and no marked differences in permeability to alpha-ketoglutarate were detected. However, differences were observed in the activity of alpha-ketoglutarate dehydrogenase. In cultures of strain PC 51-5, the specific activity of the enzyme increased throughout growth, whereas in the parental strain activity decreased and could not be detected in older mycelium. Loss of enzyme activity was accompanied by excretion of alpha-ketoglutaric acid and failure to assimilate the product after glucose exhaustion. The results suggest that accumulation of pyruvic and alpha-ketoglutaric acids in S. venezuelae cultures grown in glucose-containing media may be due to regulatory suppression of the dehydrogenases by this carbon source.

Cell Membrane Permeability↗

High-risk young mothers: infant mortality and morbidity in four areas in the United States, 1973-1978.

An examination of the changes in infant mortality and morbidity in four regions in the United States has revealed high levels of health problems among the infants of two groups of mothers: those less than or equal to 17 years and 18-19 year-old multiparas, many of whom began their childbearing under age 18. Despite decreases over the period of observation, neonatal mortality rates remain over one and a half times as high for infants of these mothers as for other mothers, largely due to the relatively high proportion of low birthweight (LBW) infants born to these mothers. Post-neonatal mortality rates also remain high, and may be increasing; this change cannot be explained solely by differences in proportion of LBW infants between these and older mothers. Both the high post-neonatal mortality rates and the type of morbidity experienced by surviving infants is consistent with the socioeconomic disadvantage of young mothers. The data further indicate the limited resources available to these mothers to cope with their children's health needs, and their potential vulnerability to decreases in public programs supporting child health care.

Adolescent↗

Lack of an elevated risk of malignant melanoma in relation to oral contraceptive use.

Epidemiologic and laboratory data suggest an effect of oral contraceptives (OC) on the risk of malignant melanoma. This relationship was explored in a hospital-based case-control study of 160 women with malignant melanoma and 640 matched controls, all of whom were white and 20-59 years of age. A total of 63 cases (39%) had used OC compared with 270 controls (42%), yielding a relative risk estimate of 0.9 (95% confidence interval: 0.6-1.3). When a number of potential confounding factors were simultaneously controlled, the relative risk estimate was 0.8 (0.5-1.3). For use that lasted 5 or more years the estimate was 0.9 (0.5-1.6). The level of tumor invasion was not related to OC use. The evidence from this study suggests that OC, even when used for 5 or more years, do not increase the risk of malignant melanoma.

Canada↗

Ecologic correlates of cancer mortality patterns in an industrialized urban population.

Cancer mortality data for the period 1968-80 were analyzed to examine whether the high cancer burden for the city of Philadelphia was "evenly" distributed spatially and, if not, whether this distribution could be associated with socioeconomic variables and air pollution. Areas with significantly higher-than-expected rates tended to cluster; lung cancer and non-lung cancers showed distinctive cluster patterns, which were evident only for males; female rates for any cancer or groups of cancers were almost uniformly distributed over the neighborhoods. Both the high lung cancer and the high non-lung cancer clusters were characterized by low socioeconomic status, but only the high lung cancer clusters exhibited high levels of air pollution. These neighborhood characteristics suggested that socioeconomic variables explain non-lung cancer mortality patterns; socioeconomic variables, together with air pollution, could be responsible for the observed lung cancer patterns. The uniform distribution of female lung cancer rates suggested that air pollution by itself cannot be a prominent factor in lung cancer mortality.

Breast Neoplasms↗

Birth defects in relation to Bendectin use in pregnancy. II. Pyloric stenosis.

To test the hypothesis that the use of Bendectin in pregnancy increases the risk of pyloric stenosis, we determined rates of antenatal Bendectin exposure among 325 infants with pyloric stenosis and among two control groups comprising infants with other defects; one consisted of 3,153 infants with other conditions, and the other, a subset of that group, consisted of 724 infants with defects that may have had their origins at any time in pregnancy. Comparisons between the cases and the two control series yielded estimated relative risks of 0.9 (95% confidence interval, 0.6 to 1.2) and 1.0 (0.7 to 1.4), respectively. The findings from this large case-control study suggest that Bendectin does not increase the risk of pyloric stenosis.

Abnormalities, Drug-Induced↗

Myocardial infarction in women under 50 years of age.

Risk factors for first nonfatal myocardial infarction (MI) in women younger than age 50 years were evaluated in a case-control study of 255 women with MI and 802 controls. The relative risk of MI increased with the amount smoked. The estimated risk of MI for current smokers of 35 or more cigarettes per day was ten times that of women who never smoked; an estimated 65% of MIs were attributable to cigarette smoking. The relative risk of MI increased markedly with increasing levels of total plasma cholesterol and decreasing levels of high-density lipoproteins, and the effects of the two factors appeared to be independent. Other factors significantly associated with MI were hypertension, angina pectoris, diabetes mellitus, blood group A, and a history of MI or stroke before age 60 years in a mother or sibling. Factors not significantly associated with MI were obesity, history of preeclamptic toxemia, and type A personality. Women who were postmenopausal appeared to have a lower risk of MI than premenopausal women of similar ages. Of the identified risk factors, the most prominent was cigarette smoking, a habit that is amenable to change.

ABO Blood-Group System↗

Lack of relation of oral clefts to diazepam use during pregnancy.

The hypothesis that in utero exposure to diazepam increases the risk of oral-cleft anomalies was evaluated in a case-control study, in which 445 infants with cleft lip with or without cleft palate and 166 with cleft palate without cleft lip (cleft palate alone) were compared with 2498 control infants having other birth defects. For exposure to diazepam during lunar months 1 through 4 relative to no exposure during pregnancy, the estimated relative risks were 1.0 for cleft lip with or without cleft palate (95 per cent confidence interval, 0.5 to 2.1) and 0.8 for cleft palate alone (0.3 to 2.7). After control for all identified potential confounding factors, the corresponding estimates were 0.8 (0.4 to 1.7) and 0.8 (0.2 to 2.5), respectively. The findings were unchanged when maternal suspicion that diazepam might be a teratogen was taken into account. The data suggest that first-trimester exposure to diazepam does not materially affect the risk of cleft lip with or without cleft palate or of cleft palate alone.

Cleft Lip↗