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Biomedical subjects

J Schwartz

Publications and source records attributed to J Schwartz.

At least 253 records · Page 14Linked to original sources
PubMed1994

Air pollution and hospital admissions for the elderly in Detroit, Michigan.

Several studies in recent years have suggested that exposure to airborne particles and to ozone are associated with increases in respiratory hospital admissions. Few of those studies have used inhalable particles as their measure of exposure, and the studies did not always examine both particle and ozone exposure. This study examined the association between both PM10 and ozone and respiratory hospital admissions for persons 65 yr of age and older in the Detroit, Michigan, metropolitan area during the years 1986 to 1989. After controlling for seasonal and other long-term temporal trends, temperature, and dew point temperature, both PM10 (RR = 1.012, 95% CI = 1.019-1.004) and 24-h ozone concentrations (RR = 1.026, 95% CI = 1.040-1.013) were associated with daily admissions for pneumonia. The relative risks are for a 10-microgram/m3 increase in PM10 and a 5-ppb increase in 24-h ozone concentration and from models including both pollutants. Admissions for COPD other than asthma were associated with PM10 (RR = 1.020, 95% CI = 1.032-1.009) and ozone (RR = 1.028, 95% CI = 1.049-1.007) as well. Asthma admissions were not associated with either pollutant. Controlling for one pollutant did not effect the magnitude of the association with the other pollutant. The magnitude of these relative risks are very similar to those recently reported in Birmingham, Alabama, Ontario, and New York State. This suggests that the associations with both pollutants are likely to be causal.

Aged↗
PubMed1994

Passive smoking exposure in adults and chronic respiratory symptoms (SAPALDIA Study). Swiss Study on Air Pollution and Lung Diseases in Adults, SAPALDIA Team.

The association between passive exposure to tobacco smoke and respiratory symptoms was examined in a sample of 4,197 never-smoking adults. They constituted the never-smoking subsample of a random sample of 9,651 adults (age, 18 to 60 yr) in eight areas in Switzerland. Information on passive smoking exposure and standardized questions on respiratory symptoms were obtained via a questionnaire administered by trained examiners. After controlling for age, sex, body mass index (BMI), study area, atopy, and parental and sibling history, passive smoking exposure was associated with an elevated risk of wheezing apart from colds (odds ratio [OR] = 1.94, 95% CI = 1.39 to 2.70), an elevated risk of bronchitis symptoms (OR = 1.59, 95% CI = 1.17 to 2.15), an elevated risk of symptoms of chronic bronchitis (OR = 1.65, 95% CI = 1.28 to 2.16), an elevated risk of dyspnea (OR = 1.45, 95% CI = 1.20 to 1.76), and an elevated risk of physician diagnosed asthma (OR = 1.39, 95% CI = 1.04 to 1.86). It was not associated with any increased risk of allergic rhinitis including hayfever. Adding a variable for low educational level, excluding subjects whose mother ever smoked or subjects with end-expiratory CO levels > or = 7 ppm, and controlling for paternal smoking during childhood or occupational exposure had little impact on the association. The association of passive smoking exposure with dyspnea, wheeze, and asthma showed evidence of a dose-dependent increase with hours per day of exposure, whereas association with symptoms of bronchitis was stronger with years of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Acute effects of summer air pollution on respiratory symptom reporting in children.

A daily diary of respiratory symptoms was collected from the parents of 1,844 school children in six U.S. cities to study the association between ambient air pollution exposures and respiratory illness. A cohort of approximately 300 elementary school children in each of six communities were asked to keep a daily log of the study child's respiratory symptoms for one year. Daily measurements of ambient sulfur dioxide, nitrogen dioxide, ozone, inhalable particles (PM10), respirable particles (PM2.5), light scattering, and sulfate particles were made, along with integrated 24-h measures of aerosol strong acidity. The analyses were limited to the five warm season months between April and August. Significant associations were found between incidence of coughing symptoms and incidence of lower respiratory symptoms and PM10, and a marginally significant association between upper respiratory symptoms and PM10. There was no evidence that other measures of particulate pollution including aerosol acidity were preferable to PM10 in predicting incidence of respiratory symptoms. Significant associations in single pollutant models were also found between sulfur dioxide or ozone and incidence of cough, and between sulfur dioxide and incidence of lower respiratory symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Somatization in patients with dissociative disorders.

OBJECTIVE: This study attempted to determine the prevalence of somatic symptoms, somatization disorder, and medical interventions in patients with dissociative disorders. METHOD: Fourteen psychiatric inpatients with a DSM-III dissociative disorder were matched for age and gender with a comparison group of inpatients who reported few dissociative symptoms. All subjects were interviewed in a blind manner with the Dissociative Disorders Interview Schedule (this semistructured interview schedule includes a section on somatization disorder), and their hospital charts were reviewed to determine somatic symptoms and medical histories. RESULTS: Sixty-four percent of the patients with dissociative disorders met DSM-III criteria for somatization disorder and reported an average of 12.4 somatic symptoms. None of the comparison patients met DSM-III criteria for somatization disorder, and these patients reported an average of 3.1 somatic symptoms. These differences between the two groups were significant. Significant differences were also found in the number of medical hospitalizations and consultations between the two groups. A significant correlation was found between the degree of dissociation and degree of somatization in patients with dissociative disorders. CONCLUSIONS: The authors conclude that somatization disorder is a frequent and serious comorbid disorder among patients with dissociative disorders.

Adult↗
PubMed1994

The relationship of dietary fish intake to level of pulmonary function in the first National Health and Nutrition Survey (NHANES I)

Eicosapentaenoic acid (EPA), which predominates in marine fish, tends to counteract and inhibit the uptake and incorporation of arachidonic acid and membrane phospholipids and dilute arachidonic acid as a potential substrate for oxidation. Thus, fish intake may be protective for the occurrence of asthma and other pulmonary diseases. We wanted to examine the relationship between the effect of chronic dietary intake to fish and its relationship to level of pulmonary function. We performed this analysis using data from the First National Health and Nutritional Examination Survey (NHANES I). A detailed subsample of 2,526 adults had a medical history questionnaire, that included a 24-hour dietary recall, and performed spirometric examination. Log of forced expiratory volume in one second (FEV1) served as a dependent variable in regression analysis which included an adjustment for height, age, cigarette smoking and gender. When added to the regression model including the above variables dietary fish intake showed a protective association with FEV1 (beta = 0.008 +/- 0.004, p = 0.028). When smokers were excluded from the analysis, the effect of fish intake on pulmonary function appeared to increase slightly (beta = 0.0108 +/- 0.006, p = 0.61). These data suggest that chronic dietary intake of fish is associated with higher levels of pulmonary function and is consistent with the hypothesis of an effect of fish oil on arachidonic acid metabolism.

Adult↗
PubMed1994

Total suspended particulate matter and daily mortality in Cincinnati, Ohio.

Recent studies have associated particulate air pollution with daily mortality in a number of U.S. communities. This study sought to replicate those analyses in Cincinnati, Ohio, and to test the strength of the association to the deletion of days with extreme weather conditions and to sensitivity analyses in the analytical approach. This study demonstrates the use of graphical diagnostic procedures to assure adequate control for season and weather and to confirm that the risk is particularly elevated in the elderly and for deaths from pneumonia and cardiovascular disease. Daily total suspended particulate (TSP) concentrations were available in Cincinnati from 1977 to 1982. They were matched to daily counts of nonaccidental deaths, temperature, and dew point temperature. Poisson regression analysis controlled for seasonal and monthly variations and potentially nonlinear relationships to temperature and humidity. TSP was associated with increased risk of mortality. The relative risk for a 100 micrograms/m3 increase in TSP was 1.06 (95% CI = 1.03-1.10). The relative risk for the elderly was higher (1.09), as was the risk for pneumonia (1.18) and cardiovascular disease (1.08). The similarity to recently reported results in Philadelphia is striking. Given the consistent findings from multiple locations, the relationship should be considered causal.

Aged↗
PubMed1994

Secretion of adrenocorticotrophin (ACTH) and ACTH precursors in ovine anterior pituitary cells: actions of corticotrophin-releasing hormone, arginine vasopressin and glucocorticoids.

Although corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) have been extensively characterized as stimulators, and glucocorticoids as inhibitors of ACTH secretion, far less is known about the control of the secretion of ACTH precursors from the anterior pituitary or about the types of corticotrophs involved. The present study was designed to systematically evaluate the actions of stimulatory and inhibitory factors on the secretion of ACTH and ACTH precursors (pro-opiomelanocortin, M(r) 31,000; pro-ACTH, M(r) 22,000) from dissociated ovine anterior pituitary cells. The cells were stimulated for 3 h with CRH (10 nmol/l) and AVP (100 nmol/l), alone or in combination with the synthetic glucocorticoid dexamethasone. In designated wells, cells were treated with dexamethasone, (100 nmol/l), beginning 16-18 h before and continuing through the 3-h secretion experiments in the presence of CRH and AVP. Secretion of ACTH-like peptides from intact cultures was compared with that from cultures which had been pretreated with a cytotoxic CRH conjugate (cytotoxin) to eliminate CRH-target cells specifically. Immunoreactive (ir)-ACTH was measured by radioimmunoassay (RIA); ACTH(1-39) and ACTH precursors were specifically measured by two-site immunoradiometric assays that discriminate between the two. In intact populations of cells, dexamethasone had no effect on basal ACTH(1-39) secretion, but decreased the secretion of ACTH(1-39) in response to CRH or AVP. Pretreatment of cells in the same experiments with cytotoxin (for 18 h, beginning 3.5 days before secretion studies) also had no significant effect on basal ACTH(1-39) secretion, but eliminated the response to CRH and decreased the response to AVP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1994

The behavioral effects of the stereoisomers of 4-methylaminorex, a psychostimulant, in the rat.

In this study, we examined the effect of the isomers of the psychostimulant 2-amino-4-methyl-5-phenyl-delta 2-oxazoline (4-methylaminorex or 4-MAX) on behavior in rats. The s.c. administration of the stereoisomers of 4-MAX, trans-4S,5S, cis-4R,5S, cis-4S,5R and trans-4R,5R (0.3-3 mg/kg), produced a dose-dependent increase in locomotor activity. However, at a dose of 10 mg/kg, the isomers of 4-MAX produced an initial increase in locomotor activity followed by the appearance of stereotyped behaviors (continuous sniffing, chewing, head bobbing, etc.) then a subsequent phase of rebound-enhanced locomotor activity all over a time course of 4 hr. The rank order of potency for the stereoisomers of 4-MAX was: 4S,5S > 4R,5S =4S,5R < 4R,5R. To determine what neurotransmitter systems may mediate the action of 4-MAX, the ability of various receptor antagonists to block or attenuate the effect of trans-4S,5S-4-MAX (3 mg/kg s.c.) on locomotor activity was examined. The selective dopamine (DA) D1 antagonist (-)-trans-6,7,7a,8,9,13b-hexahydro-3-chloro-2-hydroxy-N-methyl-5H- benzo- [d]naph-thio[2,1b]azepine (SCH 39166) and the D2 receptor antagonist (-)-eticlopride significantly, attenuated the behavioral action of trans-4S,5S-4-MAX, whereas antagonists to serotonergic and adrenergic receptors were ineffective. These results suggest that the ability of 4S,5S-4-MAX to induce locomotor hyperactivity and stereotypical behaviors and to increase rearing durations is primarily mediated by DA receptors. To determine whether the action of 4-MAX is dependent upon 5-hydroxytryptamine or DA concentrations in nerve terminals, rats were pretreated with either reserpine, alpha-methyl-p-tyrosine or d,l-p-chlorophenylalanine. Both reserpine and alpha-methyl-p-tyrosine pretreatment markedly attenuated the locomotor activity produced by trans-4S,5S-4-MAX. Moreover, L-dopa partially reversed the inhibitory action of alpha-methyl-p-tyrosine on 4S,5S-4-MAX-induced behavioral activation. In contrast, the administration of d,l-p-chlorophenylalanine did not alter the behavioral responses produced by trans-4S,5S-4-MAX. Taken together, our results suggest that 4-MAX may increase several locomotor behaviors by inducing neuronal DA release, which subsequently interacts with dopaminergic receptors.

Animals↗
PubMed1994

Using POSTDOC to recognize biomedical concepts in medical school curricular documents.

Recognition of the biomedical concepts in a document is prerequisite to further processing of the document: medical educators examine curricular documents to discover the coverage of certain topics, detect unwanted redundancies, integrate new content, and delete old content; and clinicians are concerned with terms in patient medical records for purposes ranging from creation of an electronic medical record to identification of medical literature relevant to a particular case. POSTDOC (POSTprocessor of DOCuments) is a computer application that (1) accepts as input a free-text, ASCII-formatted document and uses the Unified Medical Language System (UMLS) Metathesaurus to recognize relevant main concept terms; (2) provides term co-occurrence data and thus is able to identify potentially increasing correlations among concepts within the document; and (3) retrieves references from MEDLINE files based on user identification of relevant subjects. This paper describes a formative evaluation of POSTDOC's ability to recognize UMLS Metathesaurus biomedical concepts in medical school lecture outlines. The "precision" and "recall" varied over a wide range and were deemed not yet acceptable for automated creation of a database of concepts from curricular documents. However, results were good enough to warrant further study and continued system development.

Curriculum↗
PubMed1994

Undergraduate health care informatics education: a needs analysis and proposed curriculum.

This paper describes a needs analysis and resulting curriculum in Health Care Informatics. It is implemented as a track for the BS degree within the Department of Information Systems at the University of Maryland, Baltimore County. The track in Health Care Informatics is an interdisciplinary specialty within the broader field of Information Systems which is itself an interdisciplinary field. The needs analysis shows current thinking by practitioners and educators in the new field of Health Care Informatics. It also presents a survey of undergraduate students to monitor interest in and knowledge of this field. A curriculum design is presented that addresses these needs.

Curriculum↗
PubMed1994

Bifunctional hybrids between the variable domains of an immunoglobulin and the maltose-binding protein of Escherichia coli: production, purification and antigen binding.

Hybrids were constructed between the maltose-binding protein of Escherichia coli (MalE) and the variable domains (V-domains) of D1.3, a mouse antibody directed against hen lysozyme. Each V-domain was fused with the C- or N-terminus of MalE and expressed in E. coli, either alone or associated with the other V-domain, as a heterodimer (Fv) or as a single-chain fragment (scFv). The hybrids were exported into the bacterial periplasm, purified by affinity chromatography on cross-linked amylose and separated from incomplete products by ion-exchange chromatography. Hybrids between MalE and Fv bound the antigen specifically, with affinities increased up to 10-fold when compared to native D1.3. This strongly suggests that MalE contributed to the binding. The affinities and specificities of the different hybrids, as well as their levels of contamination by incomplete products, depended on their fusion pattern with MalE. Hybrids between MalE and either single V-domain also bound hen lysozyme specifically, which shows that each V-domain can recognize the antigen when fused with MalE. The high affinity of VH-MalE (KD = 3 nM) could be due to both participation of MalE in the binding and a conformational adaptation of the lone V-domain.

ATP-Binding Cassette Transporters↗
PubMed1993

The serum response element can mediate induction of c-fos by growth hormone.

The c-fos protooncogene is transcriptionally activated by a wide variety of agents including serum, growth factors, and phorbol esters. This induction is rapid and transient and is mediated through a number of identified promoter elements. Growth hormone (GH) is also known to induce transcription of c-fos in a variety of cell types including NIH 3T3 fibroblasts and 3T3-F442A preadipocytes. To identify DNA sequences in the c-fos gene regulated by GH, this study sought to determine whether induction of c-fos by GH involves previously identified c-fos promoter elements. A plasmid containing a growth factor-sensitive fragment of the upstream region of the c-fos promoter from -361 to -264 bp was tested for GH sensitivity. The fragment was cloned upstream of a human c-fos reporter [designated FOS by Human Gene Mapping 11 (1991)], which included basal promoter elements. In transiently transfected mouse NIH 3T3 fibroblasts, the promoter fragment conferred GH sensitivity on the human c-fos reporter. To identify a specific GH-sensitive DNA sequence in this promoter, a serum response element (SRE)-reporter plasmid was tested and found to be stimulated by GH. GH was effective in inducing expression through the SRE over a range of physiological GH concentrations. Since GH was recently found to synergize with serum factors in inducing c-fos transcription, the effect of GH and serum on SRE function was examined for insight into the mechanism for such synergism. The combined effect of GH and serum to induce reporter expression through the SRE was greater than the added effects of GH and serum, indicating that the synergism between GH and serum in inducing c-fos involves the SRE sequence. These studies identify the SRE as one specific DNA sequence in the c-fos promoter functionally regulated by GH. It is notable that GH is effective at physiological concentrations. Furthermore, synergism in c-fos induction between GH and serum factors is evident through the SRE.

3T3 Cells↗
PubMed1993

Air pollution and daily mortality in Birmingham, Alabama.

Several recent studies have reported associations between common levels of particulate air pollution and small increases in daily mortality. This study examined whether a similar association could be found in the southern United States, with different weather patterns than the previous studies, and examined the sensitivity of the results to different methods of analysis and covariate control. Data were available in Birmingham, Alabama, from August 1985 through 1988. Regression analyses controlled for weather, time trends, day of the week, and year of study and removed any long-term patterns (such as seasonal and monthly fluctuations) from the data by trigonometric filtering. A significant association was found between inhalable particles and daily mortality in Poisson regression analysis (relative risk = 1.11, 95% confidence interval 1.02-1.20). The relative risk was estimated for a 100-micrograms/m3 increase in inhalable particles. Results were unchanged when least squares regression was used, when robust regression was used, and under an alternative filtering scheme. Diagnostic plots showed that the filtering successfully removed long wavelength patterns from the data. The generalized additive model, which models the expected number of deaths as nonparametric smoothed functions of the covariates, was then used to ensure adequate control for any nonlinearities in the weather dependence. Essentially identical results for inhalable particles were seen, with no evidence of a threshold down to the lowest observed exposure levels. The association also was unchanged when all days with particulate air pollution levels in excess of the National Ambient Air Quality Standards were deleted. The magnitude of the effect is consistent with recent estimates from Philadelphia, Steubenville, Detroit, Minneapolis, St. Louis, and Utah Valley.

Air Pollutants↗
PubMed1993

Particulate air pollution and chronic respiratory disease.

Chronic exposure to particulates has been associated with increased rates of bronchitis and other respiratory ailments, with loss of lung function, and with increased risk of lung cancer. Despite these findings, debate continues about the adverse health effects of exposure to airborne particles at concentrations often seen in urban areas. This issue was examined by looking at reported rates of chronic respiratory illness by standardized questionnaire across 53 urban areas in the United States. Diagnosis of respiratory illness by an examining physician in the First National Health and Nutrition Examination Survey was also considered as an outcome. After controlling for age, race, sex, and cigarette smoking, annual average total suspended particulate concentrations (TSP) were associated with increased risk of chronic bronchitis (odds ratio (OR) = 1.07, 95% confidence interval (CI) 1.02-1.12) and of a respiratory diagnosis by the examining physician (OR = 1.06, 95% CI = 1.02-1.11). The odds ratios are for a 10 micrograms/m3 increase in TSP. When the analysis was restricted to never smokers, the associations remained, with a slight increase in the relative odds associated with airborne particles. Plots of the relative odds by quartiles of TSP exposure, adjusting for covariates, showed dose-dependent increases in risk with increasing exposure. The risk appeared to continue to concentrations below the ambient air quality standard. Given the other recent findings of both acute and chronic effects of particulate pollution, these associations are likely causal.

Adolescent↗
PubMed1993

Vitamin C enhances the development of carcinomas in the hamster buccal pouch experimental model.

Forty young adult male Syrian hamsters (Mesocricetus auratus) were divided into four groups of 10 animals. The animals in group 1 (tumor control) had the right buccal pouches painted three times a week with a 0.5% solution of 7,12 dimethylbenz(a)anthracene in heavy mineral oil USP with the use of a number 4 sable brush. The animals in group 2 (experimental group) had the right buccal pouches painted with the same solution as group 1. In addition, they received 1 mg ascorbic acid in 0.5 ml mineral oil three times a week on days alternating with the other application. The ascorbic acid was administered by mouth with the use of a pipette. The animals in group 3 received 1 mg ascorbic acid in 0.5 ml mineral oil three times weekly, and the animals in group 4 were untreated controls. The animals were killed after 14 weeks. Tumors were counted and measured. Both right and left (control) pouches were photographed, excised, fixed in formalin, sectioned in paraffin, and studied histologically. The animals that received the ascorbic acid (vitamin C) had significantly larger tumors in the right buccal pouch, although actual numbers of gross tumors were only slightly increased. The figures for tumor burden in the animals in groups 1 and 2 were 364 versus 648 mm3. Histologic study revealed that the animals in group 2 had more anaplastic tumors and a significantly greater number of areas of dysplastic leukoplakia than the animals in group 1.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

SCH 38057: a picornavirus capsid-binding molecule with antiviral activity after the initial stage of viral uncoating.

The activity of a new water-soluble molecule, SCH 38057, against picornaviruses is described. SCH 38057 inhibited plaque formation of selected entero- and rhinoviruses in a range of 10.2 to 29.1 microM (50% endpoint) and had a therapeutic index of 10 against poliovirus type 2 (polio 2) in HeLa cells. When administered orally or subcutaneously, SCH 38057 protected mice infected with either coxsackievirus B3 (CVB3) or echovirus-9 from mortality. The molecule provided a low level of protection against thermal inactivation of virus, indicating that SCH 38057 interacts with the picornavirus capsid. Binding studies with [3H]SCH 38057 revealed that the molecule binds to CVB3 and human rhinovirus 14 (HRV14) in a ratio of 29 and 19 molecules per viral particle, respectively. The affinity constant for SCH 38057 binding to CVB3 was 7.0 x 10(-4) M. When added to cultures of infected cells at 3 h after infection, SCH 38057 markedly inhibited viral RNA synthesis. This finding with lack of inhibition of attachment and loss of infectious virus after attachment were interpreted to indicate that, although SCH 38057 binds to the viral capsid, the molecule exerts its antiviral effect after the initial stage of picornavirus uncoating, i.e., after conversion of the 156S infectious viral particle to smaller subviral species.

Animals↗