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Biomedical subjects

M S Bernstein

Publications and source records attributed to M S Bernstein.

31 records · Page 2Linked to original sources
PubMed1991

An experimental human model of metal fume fever.

OBJECTIVE: To examine the pathogenesis of metal fume fever in humans by studying functional, cellular, and biochemical responses after exposure to zinc welding fume. DESIGN: Clinical experimental study. PARTICIPANTS: We studied 14 welders recruited through public advertisements. INTERVENTIONS: Participants welded galvanized steel. MEASUREMENTS: We measured lung volumes, airflow, diffusing capacity for carbon monoxide, and airway reactivity at baseline as well as either 6 or 20 hours after welding. We carried out bronchoalveolar lavage either 8 hours (early follow-up, 5 participants) or 22 hours (late follow-up, 9 participants) after welding, assaying the fluid for total and differential cell counts and bronchoalveolar lavage supernatant concentrations of interleukin-1 and tumor necrosis factor (TNF). MAIN RESULTS: Changes in pulmonary function and airway reactivity were minimal. Cumulative zinc exposure and polymorphonuclear leukocyte count in bronchoalveolar lavage fluid at late (r = 0.87; P less than 0.01) and early (r = 0.93; P less than 0.05) follow-up were positively correlated. Among the late follow-up group, the mean proportion of polymorphonuclear leukocytes was 37% (range, 19% to 63%), a statistically greater proportion than the 9% (range, 2% to 21%) seen among the early follow-up group (P less than 0.05). We did not detect TNF or more than a trace amount of interleukin-1 in the bronchoalveolar lavage supernatant. CONCLUSIONS: Zinc oxide welding fume was associated with a marked dose-dependent increase in the number of polymorphonuclear leukocytes recovered in bronchoalveolar lavage fluid 22 hours after exposure but was not associated with a clinically significant change in pulmonary function or airway reactivity. Although we did not identify increases in either interleukin-1 or TNF levels in bronchoalveolar lavage fluid, cytokines or a cytokine-like mechanism may mediate the syndrome of metal fume fever.

Adult↗
PubMed1991

Activation of human monocyte--derived macrophages with lipopolysaccharide decreases human immunodeficiency virus replication in vitro at the level of gene expression.

Activation of T lymphocytes infected with the human immunodeficiency virus-1 (HIV-1) results in enhancement of viral replication mediated in part by activation of cellular NF kappa B capable of binding directly to sequences in the viral long terminal repeat, or LTR. Together with CD4+ T cells, macrophages constitute a major target for infection by HIV-1. Unlike lymphocytes, however, stimulation of mononuclear phagocytes is not associated with cell division and proliferation. Human monocyte-derived macrophages transfected with HIV-LTR-CAT constructs demonstrated down-regulation of CAT activity after stimulation with bacterial lipopolysaccharide (LPS) that mapped to a region distinct from NF kappa B binding sites. In contrast, fresh monocytes and the promonocytic U937 cell line both demonstrated up-regulation of HIV-LTR-CAT expression by LPS. Differentiation of U937 by PMA to establish a nondividing phenotype resulted in down-regulation of transfected HIV-LTR-CAT activity by LPS similar to that in mature macrophages. Human monocyte-derived macrophages infected with HIV-1 in vitro demonstrated a decrease in viral p24 release after incubation in LPS that was comparable to the negative regulation that occurred in the transient transfection assays. Factors controlling HIV replication may differ in dividing and nondividing hematopoietic cells and may contribute to restricted viral expression in nondividing cells.

Cells, Cultured↗
PubMed1991

Pregnancy complicated by collagen vascular disease.

Pregnancies complicated by collagen vascular diseases present a challenge to the obstetrician, internist, and other consulting physicians caring for the patient. Although most pregnancies complicated by these disorders result in satisfactory outcomes, a significant number develop manifestations sufficiently serious to require admission to an intensive care unit. Such manifestations include lupus nephritis, CNS lupus, ARDS, massive alveolar hemorrhage, scleroderma renal crisis, pulmonary hypertension, severe myositis, and diffuse vasculitis. Of the numerous therapeutic options available, many may be used to optimize maternal and perinatal outcome.

Autoimmune Diseases↗
PubMed1985

Uptake of taurocholate by freshly isolated hepatocytes from fetal and newborn rabbits.

During early postnatal maturation a significant increase in the rate constant of translocation (Michaelis-Menten constant; Km) for taurocholate uptake occurs in isolated rabbit hepatocytes. This age-dependent change is related to a decrease in the efficiency of uptake for taurocholate and is probably associated with changes in the receptor or its microenvironment within the plasma membrane. Cholic acid conjugates (taurocholic and glycocholic acids) are the predominant bile acids found in the premature and neonatal human. It is therefore of interest that in the fetal and neonatal rabbit we have found a developmentally dependent alteration of taurocholic acid transport.

Animals↗
PubMed1983

Aqueous penetration of oral and topical indomethacin in humans.

Aqueous humor and serum indomethacin levels were determined following administration of the drug orally, as a topical 1% aqueous suspension and as a topical 1% oil suspension. Patients receiving indomethacin orally had a mean aqueous humor level below the lower limit of sensitivity of the assay, which is also below the level known to inhibit prostaglandin synthesis in vitro and a mean serum level of 642 ng/mL. Patients receiving the topical 1% aqueous suspension had a mean aqueous level of 198 ng/mL and no detectable serum level. Patients receiving the topical 1% oil suspension had a mean aqueous level of 429 ng/mL, which was significantly higher than that of the aqueous suspension. Both topical suspensions yield levels that are able to inhibit prostaglandin synthesis. Higher aqueous levels with no detectable blood levels (and thus negligible potential for systemic toxic effects) make the topical route of administration preferable to the oral route.

Administration, Oral↗
PubMed1982

High-performance liquid chromatography-fluorescence analysis for indomethacin and metabolites in biological fluids.

A rapid and sensitive high-performance liquid chromatography-fluorescence method is described for the quantitative analysis of indomethacin and its metabolites in urine. A modified version is also shown for the detection of indomethacin in plasma. The method consists of a single extraction of an acid-buffered plasma sample or single extractions of two buffered aliquots in parallel of urine using ethyl acetate, followed by evaporation of the organic phase. Indomethacin (I) and the metabolite desmethylindomethacin (DMI) were deacylated to their fluorescent products, deschlorobenzoylindomethacin (DBI) and desmethyldeschlorobenzoylindomethacin (DMBI), respectively, prior to chromatography. The chromatographic phase utilized a reversed-phase C18-bonded column with a solvent system comprised of either 22.5% or 26% acetonitrile in 0.25% acetic acid. The elution times for indomethacin metabolites ranged from 12-26 min. The total DBI (including deacylated I) and DMBI (including deacylated DMI) in the extract were each determined using fluorometric detection, with excitation at 288 nm and emission at 390 nm (370 nm cutoff filter). An internal standard of indole-3-propionic acid was used for quantitation. The lower limit of sensitivity for I in plasma was 25 ng/ml.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

The future of clinical engineering in the 1990's.

The problems in hospitals which led to the development of the clinical engineering profession are described along with recent changes in the hospital environment. The authors discuss how the profession is adapting to these changes. Also discussed is the tendency for BMETs to move into clinical engineering roles.

Biomedical Engineering↗
PubMedDate not supplied

Isolated power and line isolation monitors.

Isolated power and line isolation monitor systems are standards in operating rooms and cardiac catheterization suites. They provide the patient and the equipment user with the knowledge of potential hazards. When a potential hazard occurs, appropriate corrective action can take place to prevent unnecessary injury.

Anesthesiology↗