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Biomedical subjects

J S Reif

Publications and source records attributed to J S Reif.

78 records · Page 5Linked to original sources

Exposure to tap water during pregnancy.

Studies of disinfection byproducts (DBPs) in drinking water and risk of adverse reproductive outcome have usually relied on approximate measures of exposure. Individual differences in consumption of bottled or filtered water, variability in tap water consumption at home and at work, dermal and inhalation exposure to volatile contaminants, and changes in residency during pregnancy may lead to exposure misclassification. We characterized exposures to tap water and other risk factors among 71 pregnant and 43 non-pregnant women attending public health clinics. Nearly all residences had a municipal water source, but 25% of women drank filtered or bottled water. Fifty percent of the women in our sample reported working outside the home where, on average, one third of their daily water intake took place. Pregnant women consumed more water than non-pregnant women (3.4 vs. 3.0 total l/day), especially cold tap water at home (1.8 vs. 1.3 l/day, 95% CI for the difference=0.1, 0.9). Patterns of showering were similar for both groups of women, but pregnant women were more likely to bathe and to bathe more frequently. The prevalence of smoking was lower among pregnant women (22.5% vs. 32.6%), as was the consumption of alcohol (4.2% vs. 53.5%, 95% CI for the difference=-64.9, -33.7). Thirty-two percent of women had moved during their current pregnancy. The data reaffirm the importance of collecting individual-level data for water consumption and exposure to potential confounders to avoid misclassification bias. This study is the first to target women of low socio-economic status (SES) and therefore of particular interest in studies of adverse reproductive outcomes for which this group is at increased risk.

Adolescent↗

Two-stage evaluation of exposure to mercury and biomarkers of neurotoxicity at a hazardous waste site.

Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were studied in order to determine whether exposures to mercury were greater among persons who resided there than among residents of a comparison area 12-15 miles distant. From a census-based stratified random sample, 469 persons were interviewed and urine samples were obtained for biomonitoring. Mercury was detected in urine from 32 (6.8%) of the 469 persons sample at a detection limit of 5 ppb. Trace levels of mercury (detectable, but nonquantifiable) were found in 80 (17.1%) of the persons sampled. Neither the frequency of detection, the arithmetic mean, nor the geometric mean value for urine mercury was found to be statistically different when persons living near the site were compared to persons from the more distant comparison area. The risk of mercury exposure associated with demographic variables, residence, occupation, hobbies, dietary habits, water supply, housing, and activity patterns was evaluated. In the second stage of the evaluation, the Neurobehavioral Core Test Battery (NCTB) is being used to assess individual functional deficits and nervous system disorders associated with exposure to mercury and other neurotoxic chemicals.

Adolescent↗

Effect of feline immunodeficiency virus infection on Toxoplasma gondii-specific humoral and cell-mediated immune responses of cats with serologic evidence of toxoplasmosis.

Serum samples from 89 cats with serologic evidence of toxoplasmosis were identified by using an enzyme-linked immunosorbent assay (ELISA) that detected Toxoplasma gondii-specific immunoglobulin M (IgM) or T. gondii-specific immunoglobulin G (IgG). Concurrent feline immunodeficiency virus (FIV) infection was detected in 36 cats using an ELISA for detection of FIV-specific IgG. The majority of the cats in both the FIV-seropositive and FIV-seronegative groups were male and > 5 years of age. FIV-seropositive cats were more likely to have T. gondii IgM titers without IgG (P < 0.05) or any T. gondii IgM titer (P < 0.05) than were FIV-seronegative cats. FIV-seronegative cats (1328) had a higher T. gondii IgG geometric mean titer than did FIV-seropositive cats (724) and were more likely to have T. gondii IgG titers > 1:2048 than were FIV-seropositive cats (P < 0.05). Cats with serologic evidence of both T. gondii and FIV infections had persistent T. gondii IgM titers for > 12 weeks. Lymphoblast transformation in response to concanavalin A, T. gondii-specific intracellular antigens, and T. gondii-specific secretory antigens was compared in T. gondii seropositive and FIV-seronegative cats, cats with serologic evidence of T. gondii infection alone, and cats with serologic evidence of concurrent FIV and T. gondii infections. Lymphocytes from all but one cat in the FIV-seropositive group responded to concanavalin A. Whereas lymphocytes from FIV-seronegative cats with serologic evidence of toxoplasmosis responded to T. gondii-specific antigens, four of five of the FIV-seropositive cats with concurrent serologic evidence of toxoplasmosis did not.

Animals↗

Canine exposure to herbicide-treated lawns and urinary excretion of 2,4-dichlorophenoxyacetic acid.

A recent study by Hayes et al. (J. Natl. Cancer. Inst., 83: 1226-1231, 1991) found an increased risk of malignant lymphoma associated with exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) in pet dogs. We conducted a study to determine the extent to which dogs absorb and excrete 2,4-D in urine after contact with treated lawns under natural conditions. Among 44 dogs potentially exposed to 2,4-D-treated lawns an average of 10.9 days after application, 2,4-D concentrations greater than or equal to 10.0 micrograms/l were found in 33 dogs (75%) and concentrations of > or = 50 micrograms/l were found in 17 (39%). Among 15 dogs with no known exposure to a 2,4-D-treated lawn in the previous 42 days, 4 (27%) had evidence of 2,4-D in urine, 1 at a concentration of > or = 50 micrograms/l. The odds ratio for the association between exposure to a 2,4-D-treated lawn and the detection of > or = 50 micrograms/l 2,4-D in urine was 8.8 (95% confidence interval, 1.4-56.2). Dogs exposed to lawns treated within 7 days before urine collection were more than 50 times as likely to have 2,4-D at concentrations > or = 50 micrograms/l than dogs with exposure to a lawn treated more than 1 week previously (odds ratio = 56.0; 95% confidence interval, 10.0-312.2). The highest mean concentration of 2,4-D in urine (21.3 mg/l) was found in dogs sampled within 2 days after application of the herbicide.(ABSTRACT TRUNCATED AT 250 WORDS)

2,4-Dichlorophenoxyacetic Acid↗