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Biomedical subjects

L Andrews

Publications and source records attributed to L Andrews.

At least 19 recordsLinked to original sources

Financial aspects of the provision of care to AIDS patients at Hartford Hospital.

Data on the provision of care to persons with AIDS at Hartford Hospital are presented for the years 1988 and 1989. Approximately 2% of the total operating loss from uncompensated care at the hospital was due to patients with AIDS during both of those years. While the hospital continues to show a net surplus of revenues over expenses, the operating loss incurred by the hospital for the provision of care to hospitalized case-definition AIDS patients increased by 88.1% between 1988 and 1989.

Acquired Immunodeficiency Syndrome

Biologic markers in ethylene oxide-exposed workers and controls.

Ethylene oxide (EtO) is an alkylating agent and a model direct-acting mutagen and carcinogen. This study has evaluated a panel of biologic markers including EtO-hemoglobin adducts (EtO-Hb), sister-chromatid exchanges (SCEs), micronuclei, chromosomal aberrations (CAs), DNA single-strand breaks (SSB) and an index of DNA repair (ratio of UDS to NA-AAF-DNA binding) in the peripheral blood cells of 34 workers at a sterilization unit of a large university hospital and 23 controls working in the university library. Comprehensive environmental histories were obtained on each subject including detailed occupational and smoking histories. Industrial hygiene data obtained prior to the study and personal monitoring during the 8 years preceding the study showed that workers were subject to low-level exposure near or below the current Occupational Safety and Health Administration (OSHA) standard of 1 ppm (TWA). Personal monitoring data obtained during 2 weeks prior to blood sampling were uniformly less than 0.3 ppm (TWA). After adjusting for smoking, EtO workplace exposure was significantly (p less than 0.001) associated with EtO-Hb (a carcinogen-protein adduct) and 2 measures of SCEs [the average number of SCEs/cell (SCE50) and the number of high frequency cells (SCEHFC)]. There was an apparent suppression of DNA repair capacity in EtO-exposed individuals as measured by the DNA repair index; i.e., the ratio of unscheduled DNA synthesis (UDS) and NA-AAF-DNA binding (p less than 0.01). No association of DNA repair index with smoking was found. Another important finding of this study is the highly significant correlation between EtO-Hb adduct levels and SCEHFC (p less than 0.01) and SCEs (p less than 0.02) which provides evidence of a direct link between a marker of biologically effective dose and markers of genotoxic response. In contrast, micronuclei, CAs and SSBs were not significantly elevated in the workers. The activity of the u-isoenzyme of glutathione-S-transferase (GT) was measured as a possible genetic marker of susceptibility and a modulator of biomarker formation. However, possibly because of confounding by age, no significant relationships were found between GT and any of the exposure-related markers by ANOVA or among other independent variables by regression. This study demonstrates significant effects of low-level EtO exposure, independent of smoking history, near or below 1 ppm on multiple biomarkers and suggests that the current OSHA standard may not be adequately protective. Previously described effects of smoking on EtO-Hb adducts, SCEs and SCEHFC were also seen in this study.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

Properties of the glucose phosphotransferase system of Clostridium acetobutylicum NCIB 8052.

The glucose phosphotransferase system (PTS) of Clostridium acetobutylicum was studied by using cell extracts. The system exhibited a Km for glucose of 34 microM, and glucose phosphorylation was inhibited competitively by mannose and 2-deoxyglucose. The analogs 3-O-methylglucoside and methyl alpha-glucoside did not inhibit glucose phosphorylation significantly. Activity showed no dependence on Mg2+ ions or on pH in the range 6.0 to 8.0. The PTS comprised both soluble and membrane-bound proteins, which interacted functionally with the PTSs of Clostridium pasteurianum, Bacillus subtilis, and Escherichia coli. In addition to a membrane-bound enzyme IIGlc, sugar phosphorylation assays in heterologous systems incorporating extracts of pts mutants of other organisms provided evidence for enzyme I, HPr, and IIIGlc components. The HPr was found in the soluble fraction of C. acetobutylicum extracts, whereas enzyme I, and probably also IIIGlc, was present in both the soluble and membrane fractions, suggesting a membrane location in the intact cell.

Bacillus subtilis

Detection of adducts of deoxyribonucleic acid in white blood cells of roofers by 32P-postlabeling. Relationship of adduct levels to measures of exposure to polycyclic aromatic hydrocarbons.

To assess the utility of adducts of deoxyribonucleic acid (DNA) as biomarkers of exposure to carcinogens in an industrial population, a pilot study of roofers occupationally exposed to polycyclic aromatic hydrocarbons was conducted. DNA isolated from white blood cells of roofers and nonoccupationally exposed comparison subjects matched for age, sex, and smoking status was analyzed for DNA adducts with the use of 32P-postlabeling methods. Occupational exposures to polycyclic aromatic hydrocarbons were assessed by personal air sampling and skin wipes. Ten of the 12 roofers, but only 2 of the 12 comparison subjects, had detectable levels of aromatic DNA adducts in the 32P-postlabeling assay. Among the roofers, the post-shift levels of polycyclic aromatic hydrocarbons in the skin wipes were correlated with the DNA adduct levels. These results suggest that 32P-postlabeling assay may be useful for monitoring internal exposures to complex mixtures of aromatic hydrocarbons in industrial populations.

Adult

A pilot study of detection of DNA adducts in white blood cells of roofers by 32P-postlabelling.

To assess the utility of DNA adducts as biomarkers of exposure to carcinogens in an industrial population, a pilot study of roofers occupationally exposed to a mixture of polycyclic aromatic hydrocarbons was conducted. DNA was isolated from peripheral white blood cells of roofers and non-occupationally exposed subjects matched for age, sex and smoking status. Occupational exposures to anthracene, fluoranthene, pyrene, benzanthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[g,h,i]perylene and benzo[k]fluoranthene were assessed by personal breathing zone air sampling and skin wipes. Exposures to benzo[a]pyrene in air of exposed subjects ranged from 0.60 microgram/m3 to 1.39 micrograms/m3, and exposures to total polycyclic aromatic hydrocarbon (the sum of eight hydrocarbons) ranged from 6.0 micrograms/m3 to 13.8 micrograms/m3 on the day before blood collection. In the biomarker studies 10 of 12 roofers, but only 2 of 12 comparison subjects, had detectable levels of aromatic DNA adducts by 32P-postlabelling assay (p less than 0.01). The two non-roofers with detectable adducts had levels at or near the detection limit of 2 adducts per 10(9) nucleotides. In two roofer samples which were studied in a mixing experiment, the major adduct spots did not co-migrate with the guanosine N2 adduct of benzo[a]pyrene diol epoxide. These results suggest that the 32P-postlabelling assay may be useful for monitoring exposures to complex mixtures of aromatic hydrocarbons in industrial populations.

Adult

Normative data on the Kagan Matching Familiar Figures test for adult male incarcerates.

This study presents normative data on the Kagan Matching Familiar Figures test, a measure of impulsivity/reflection, for 200 adult male incarcerates (108 Black, 92 White) in a state correctional system. Also presented are t-tests between groups and correlations between the MFF and a series of demographic and test measures. Low, significant correlations were found between the MFF scores (time, number correct) and race, IQ, education, and reading levels. A comparison with college male and female norms is provided. The value and use of the MFF as a measure of cognitive style are discussed.

Adolescent

Neonatal resuscitation in community hospitals. A regional-based, team-oriented training program coordinated by the tertiary center.

Neonatal resuscitation in community hospitals is problematic because of the lack of on-site personnel with adequate training and experience. Even when efforts are made to transport high-risk mothers to tertiary care centers, the most complex resuscitations must occasionally be performed in all obstetric services. This dilemma can result in increased neonatal morbidity and mortality, and is reflected in the obstetric malpractice crisis. We present an approach to the problem in which a tertiary center actively intervenes to assist regional community hospitals to develop and implement resuscitation team capabilities. Key aspects of the system are training and implementation of hospital shift "Code Pink" teams composed of nonphysician professionals, a regional neonatal resuscitation protocol used by all participants, "mock code" resuscitation drills to maintain skills, and extensive quality assurance both at the local hospital and regional levels.

Clinical Protocols

Endoscopic accessories: friend or foe?

With the variety and number of procedures increasing, it became a constant challenge to supply the needed accessory equipment. A system was developed to provide an adequate supply of accessories while achieving a balance between new patient care standards and cost containment. The system has provided a well organized and highly productive endoscopy unit.

Endoscopy

Sequence and structure of the yeast galactose transporter.

The previously cloned GAL2 gene of the Saccharomyces cerevisiae galactose transporter has been sequenced. The nucleotide sequence predicts a protein with 574 amino acids (Mr, 63,789). Hydropathy plots suggest that there are 12 membrane-spanning segments. The galactose transporter shows both sequence and structural homology with a superfamily of sugar transporters which includes the human HepG2-erythrocyte and fetal muscle glucose transporters, the rat brain and liver glucose transporters, the Escherichia coli xylose and arabinose permeases, and the S. cerevisiae glucose, maltose, and galactose transporters. Sequence and structural motifs at the N-terminal and C-terminal regions of the proteins support the view that the genes of this superfamily arose by duplication of a common ancestral gene. In addition to the sequence homology and the presence of the 12 membrane-spanning segments, the members of the superfamily show characteristic lengths and distributions of the charged, hydrophilic connecting loops. There is indirect evidence that the transporter is an N-glycoprotein. However, its only N-glycosylation site occurs in a charged, hydrophilic segment. This could mean that this segment is part of a hydrophilic channel in the membrane. The transporter has a substrate site for the cyclic AMP-dependent protein kinase which may be a target of catabolite inactivation. The transporter lacks a strong sequence enriched for proline (P), glutamate (E), aspartate, serine (S), and threonine (T) and flanked by basic amino acids (PEST sequence) even though it has a short half-life. Mechanisms for converting the poor PEST to a possible PEST sequence are considered. Like the other members of the superfamily, the galactose transporter lacks a signal sequence.

Amino Acid Sequence

Health hazards of fire fighters: exposure assessment.

There is growing concern over the detrimental health effects to firefighters produced by exposure to combustion byproducts of burning materials. To assess the types and levels of exposure encountered by firefighters during their routine occupational duties, members of the Buffalo Fire Department were monitored during firefighting activities with personal, portable, ambient environmental sampling devices. The results indicate that firefighters are frequently exposed to significant concentrations of hazardous materials including carbon monoxide, benzene, sulphur dioxide, hydrogen cyanide, aldehydes, hydrogen chloride, dichlorofluoromethane, and particulates. Furthermore, in many cases of the worst exposure to these materials respiratory protective equipment was not used owing to the visual impression of low smoke intensity, and thus these levels represent actual direct exposure of the firefighters. Many of these materials have been implicated in the production of cardiovascular, respiratory, or neoplastic diseases, which may provide an explanation for the alleged increased risk for these illnesses among firefighters.

Air Pollutants, Occupational

Nomarski evaluation of rod outer segment renewal in a hereditary retinal degeneration. Comparison with autoradiographic evaluation.

Differential interference contrast (Nomarski) optics and autoradiography were used to estimate independently the rate of outer segment renewal in the early stages of progressive rod-cone degeneration (PRCD) in dogs. We have found that significant reductions in renewal rate are demonstrable using the two methods of analysis: autoradiography = 34% reduction; Nomarski method = 18% reduction. Nomarski analysis of affected rod outer segments (ROS) demonstrated optical periodicities (light/dark bands) extending from the base to the tip of the outer segment. Nineteen percent of the cells, however, showed areas where the light/dark bands were not apparent. These homogeneous, "optically silent" regions were interpreted to possibly represent areas where the disc orientation was not perpendicular to the long axis of the ROS.

Animals

An outbreak of fume fever in an electronics instrument testing laboratory.

An apparent outbreak of fume fever was identified among six workers in an electronics instrument testing laboratory during a routine thermal evaluation of conductivity on electrical cable. The employees experienced characteristic symptoms of fume fever. Three employees required hospitalization; they demonstrated fever, leukocytosis with a left shift, and significant arterial-alveolar oxygen gradients, all of which resolved over several hours. To prevent future occurrences, an attempt was made to delineate the etiologic agent by exactly reproducing the circumstances of the event and analyzing for the evolution of metal fumes or pyrolysis products of polymers. The pertinent findings included overall poor ventilation in the laboratory and the development of significant chloride air contamination during the test. This latter finding raises the possibility that a chloropolymer contaminant was the etiologic agent.

Electronics

A common thread.

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Grief

Direct visualization of enveloped Epstein-Barr Herpesvirus in throat washing with leukocyte-transforming activity.

Mature enveloped virions belonging to the herpes class were found in a concentrated, partially purified specimen of throat washings from a patient undergoing immunosuppressive therapy for prevention of renal homograft rejection. This throat washing contained a high titer of biologically active Epstein-Barr virus and no other human herpesviruses. Epstein-Barr virions were not detected in throat washings from patients with mononucleosis that had only low titers of transforming activity.

Adolescent

The last night.

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Aged