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S J Samuels

Publications and source records attributed to S J Samuels.

At least 55 records · Page 3Linked to original sources
PubMed1991

Reporting of occupational injury and illness in the semiconductor manufacturing industry.

In the United States, occupational illness and injury cases meeting specific reporting criteria are recorded on company Occupational Safety and Health Administration (OSHA) 200 logs; case description data are submitted to participating state agencies for coding and entry in the national Supplementary Data System (SDS). We evaluated completeness of reporting (the percentage of reportable cases that were recorded in the company OSHA 200 log) in the semiconductor manufacturing industry by reviewing company health clinic records for 1984 of 10 manufacturing sites of member companies of a national semiconductor manufacturing industry trade association. Of 416 randomly selected work-related cases, 101 met OSHA reporting criteria. Reporting completeness was 60 percent and was lowest for occupational illnesses (44 percent). Case-description data from 150 reported cases were submitted twice to state coding personnel to evaluate coding reliability. Reliability was high (kappa 0.82-0.93) for "nature," "affected body part," "source," and "type" variables. Coding for the SDS appears reliable; reporting completeness may be improved by use of a stepwise approach by company personnel responsible for reporting decisions.

Accidents, Occupational↗
PubMed1991

The use of a urinary estrone conjugates assay for detection of optimal mating time in the cynomolgus macaque (Macaca fascicularis).

Forty-four female cynomolgus macaques (Macaca fascicularis) were examined to determine the optimum fertile period for mating. Daily urinary estrone conjugates (E1C) were measured, beginning on day 7 of the menstrual cycle, until a 1.5-gold E1C rise above the baseline was detected. The females were bred the next morning. Pregnancies were verified in all animals at day 18 postbreeding, and/or on day 25 postbreeding. Serum progesterone levels were used to correlate the relationship between ovulation and the E1C peak. Forty-four of the 57 cycles indicated a urinary E1C peak between days 10-15 of the menstrual cycle; this peak occurred on the day following the initial 1.5-fold to twofold rise in 90% of the cycles. A single 2-hr mating period the day before, the day of, or the day after the E1C peak resulted in conception in 17 of 44 (38.6%) animals.

Animals↗
PubMed1990

The perinatal impact of cocaine, amphetamine, and opiate use detected by universal intrapartum screening.

Universal urine testing for cocaine, amphetamines, and opiates was performed on 1643 women admitted to an obstetric service for a 1-year period with 20.5% having positive results. There were 299 patients with positive toxicology results matched for race and discharge date with patients having negative toxicology and drug history. Significant differences in age, prior obstetric history, prenatal care, alcohol history, and smoking were noted between groups. There was a significant decrease in birth weight, head circumference, length, and gestational age for the drug-positive group, which was most marked in cocaine and multiple drug users. These differences persisted after we controlled for smoking, prenatal care, and prior preterm births. Differences in birth weight and head circumference remained after we controlled for gestational age. Rates of congenital anomalies and abruptio placental were similar between groups. Perinatal substance abuse is independently associated with growth retardation and prematurity. Multiple risk factors are frequently present, necessitating a comprehensive approach to prenatal care.

Adult↗
PubMed1990

Adverse reproductive outcomes among female veterinarians.

Because female veterinarians are exposed to several known reproductive hazards, the authors conducted a reproductive survey of all female graduates of a US veterinary school (n = 537) and law school (comparison group, n = 794). Analysis was confined to pregnancies completed after the second year of professional school and from 1966 to 1986. Based on one randomly chosen eligible pregnancy per woman (veterinarians, n = 176; lawyers, n = 229), spontaneous abortion rates, adjusted for elective abortions, were 13.3% for the veterinarians and 15.1% for the lawyers; these did not differ significantly. A Cox life table regression model controlling for age, smoking, alcohol use, and prior spontaneous abortion also showed no significant difference in spontaneous abortion rates between the two populations. Using all pregnancies, veterinarians who reported performing five or more radiographic examinations per week had a marginally elevated risk of spontaneous abortion, but the statistical significance disappeared when analysis was limited to one random pregnancy per woman. For one random eligible birth per woman, the mean birth weight did not differ significantly between the veterinarians and lawyers, even after controlling for possible confounders in regression analyses. A higher rate of reportable birth defects was observed among the veterinarians than among the lawyers (relative risk = 4.2, 95% confidence interval 1.2-15.1), but this unexpected result must be considered hypothesis-generating. The authors did not find an overall increased risk for spontaneous abortion or low birth weight infants among veterinarians compared with lawyers, but veterinarians who reported performing five or more radiographic examinations per week may have been at increased risk for spontaneous abortion.

Abortion, Incomplete↗
PubMed1990

Sustained and selective attention in children with learning disabilities.

Sustained and selective attention of 30 fourth-, fifth-, and sixth-grade students with learning disabilities (LD) and 20 controls were compared. A continuous performance test (CPT) yielded no differences for students with LD and controls, suggesting similar ability for both groups in sustaining attention and inhibiting impulsive responding. Subjects with LD made more errors than controls on a selective attention task when letter distractors were adjacent to the target letter but not when they were distant, and more correct responses than controls when facilitating letters were adjacent to the target, suggesting that students with LD are less able to narrow the focus of their attention. Longer response times by students with LD indicate that they have slower information-processing skills than controls. Regrouping students according to teacher ratings for attention deficit-hyperactivity disorder (ADHD) yielded the customary impulsive response set on the CPT and more errors on the selective attention task, but no differences on response times for students with ADHD. LD students with ADHD made more errors than LD students without ADHD when letter distractors were adjacent to the target letter.

Adolescent↗
PubMed1990

Markers of exposure to diesel exhaust in railroad workers.

Diesel exhaust is a known mutagen and a potential human carcinogen. Recent epidemiological studies have demonstrated a small increase in the risk of lung cancer from diesel exhaust exposure. However, many epidemiological studies have used crude estimates of exposure, and even accurate measures of exposure may not be accurate estimates of the internal dose received. Measurement of diesel exhaust exposure also has been limited by the absence of a standard marker. This study was undertaken to evaluate the usefulness of urinary mutagenicity as a biological marker of diesel exhaust exposure in the workplace. We measured the exposure of individual railroad workers to diesel exhaust by using personal air samples taken over two consecutive work shifts. Nicotine in the samples was measured to adjust the respirable particle concentrations for active and passive cigarette smoking. Urine samples were collected at the end of the study work shifts and were analyzed for markers of cigarette smoking (nicotine, cotinine) and for mutagenicity, using a sensitive microsuspension assay (micro preincubation assay; Salmonella strain TA98 with or without S9 enzyme). The number of cigarettes smoked on the study shift was recorded, and subjects completed a questionnaire at the end of the second day on personal habits and exposures at home and work. Multiple regression analyses were used to analyze independent determinants of urinary mutagenicity, including a generalized least-squares analysis that divided residual variation into between- and within-person components. Eighty-seven subjects completed 151 two-day protocols; an additional four subjects provided usable data for a single day (n = 306 samples). Respirable particle concentration was not a good marker of diesel exhaust exposure when contamination by environmental tobacco smoke existed in the work location, but respirable particle concentration that was adjusted for environmental tobacco smoke correlated with a priori assessments of diesel exhaust exposure by job grouping. Phenanthrene concentration, as a potential marker, was measured in a subset of personal samples, and correlated with known diesel exhaust exposure by job grouping. A constant ratio of phenanthrene to respirable particles in area samples from diesel exhaust-exposed work locations suggested that phenanthrene is promising as a marker for diesel exhaust. Mutagenic activity was also measured from extracts of respirable particles in a few personal filter samples, and this technique may be useful for further investigation in epidemiological studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants, Occupational↗
PubMed1990

Mechanisms of filtration of morphologically abnormal human sperm by cervical mucus.

It is well known that cervical mucus restricts penetration of morphologically abnormal human sperm, both in vitro and in vivo. However, the mechanisms of such restriction are not well understood. Using videomicrography to simultaneously analyze the motions and morphology of individual human sperm, we analyzed differential penetration of normal and abnormal sperm into fresh human cervical mucus. Abnormal sperm swam slower in mucus than the normal sperm, but their flagellar beat parameters were not commensurately different. Multivariate statistical analysis of the relationship between individual sperm velocity and flagellar beat parameters indicated that the heads of the abnormal sperm experienced greater resistance from the mucus than did normal heads. Differential mucus resistance, more than altered motile vigor, appears to be responsible for the restriction of abnormal sperm during migration through mucus.

Cervix Mucus↗
PubMed1989

A comparison of the usefulness of SpermMar and immunobead tests for the detection of antisperm antibodies.

We compared two testing protocols designed to detect immunoglobulin (Ig) G antibodies on sperm surfaces: (1) SpermMar (Ortho, Raritan, NJ) and (2) Immunobead Testing (Biorad, Richmond, CA). The standard SpermMar (SPMAR) protocol (direct test of unwashed semen) was performed with 47 ejaculates and found to be more sensitive than Immunobead Testing (IBT) on washed sperm, detecting five samples with greater than or equal to 30% bead binding, all of which by IBT had less than 20% bead binding. In contrast, when SPMAR was performed on washed sperm or with an indirect antibody transfer from serum or seminal plasma, SPMAR results gave mostly low values for bead binding in comparison with IBT. Our data suggest that SPMAR be used only in direct assays employing unwashed ejaculates, that it can be easily incorporated into routine semen analysis as a screening test, and that positive results should be confirmed by IBT (IgG and IgA).

Agglutination Tests↗
PubMed1989

Spontaneous abortions in relation to consumption of tap water: an application of methods from survival analysis to a pregnancy follow-up study.

A previous study of pregnant women whose water supply was potentially contaminated revealed a significant increase in spontaneous abortions among those drinking tap as opposed to bottled water, regardless of exposure to the contamination. The relation between reported prenatal water consumption and risk of spontaneous abortion was therefore analyzed in an independent cohort of pregnancies seen in 1981-1982 at a health maintenance organization in three counties in northern California. The study used a nested case-control design. Since early miscarriages are left-truncated, gestational age at which a pregnancy comes to medical attention may confound results of pregnancy outcome studies. Risk set analyses were therefore conducted in two stages: 1) the life of table-adjusted risk for those drinking mainly bottled water was 8.4%; the risk for those drinking mainly tap water was 12.5%, and 2) the Cox proportional hazards model was used to control for multiple confounders, yielding a hazard ratio for spontaneous abortion of 1.5 (95% confidence interval 1.1-2.0) for consumers of tap water compared with bottled water. Tap water drinkers whose home source of water included ground water had the greatest risk (13.8) and, after controlling for confounders, their hazard ratio was 1.7. Based on external data from comparable studies, bottled water drinkers appeared to have had unusually low risks, and tap water drinkers who received ground water may have had slightly high risks. Inconsistencies in the reporting of tap water consumption suggest recall bias. Causal factors could not be ruled out, however, although no reproductive toxins, either biological or chemical, have yet been identified in the tap water in this area.

Abortion, Spontaneous↗
PubMed1989

Reproductive outcomes of pregnant workers employed at 36 reinforced plastics companies. II. Lowered birth weight.

The authors analyzed the birth weights of infants whose mothers worked during pregnancy in the reinforced plastics industry, where styrene monomer is a primary chemical exposure. Reproductive and work histories were taken by telephone interview from 1535 women employed between 1974 and 1981 at 36 companies. The questionnaire was based on one used by the National Institute for Occupational Safety and Health, and indices of styrene exposure were derived from an historical set of 1500 industrial hygiene samples from the study companies. There was not a significant dose-response trend in decreasing average birth weights. However, women who worked at the most highly exposed jobs--such as laminators, rollers, or spray-up operators at boat manufacturing companies--had offspring with adjusted birth weights of 4% less than the offspring of unexposed women (95% confidence interval = -7.7% to +0.6%) after adjustment for other factors.

Birth Weight↗
PubMed1988

Lessons from a surveillance program of semen quality.

The discovery in 1977 that dibromochloropropane (DBCP) could induce male sterility led to an interest in the surveillance of semen quality in men working in a pesticide manufacturing plant. The program consisted of an initial questionnaire, physical examination, and serial semen analyses. The success of the surveillance was limited by economic considerations and protocol compliance problems. Based on the experience with this program, recommendations for future surveillance efforts are presented.

Humans↗
PubMed1988

The relationship of circulating antisperm antibodies to sperm surface antibodies in infertile men.

The correlation between the amount and location of antisperm antibody binding to the sperm surface and the level measured in the serum has not been previously reported. Hence, the value and limitations of screening blood sera from men with suspected immunologic infertility are not currently known. In this study 70 paired sera and semen samples were assayed by the immunobead test (IBT). A screening protocol for blood sera was constructed to be 100% sensitive for detecting semen specimens with 20% or more of sperm binding IgG or IgA immunobeads. The specificity of this screening protocol was determined to be 79%. Serum IgA was not a good predictor of IgA on the sperm surface. The true positive predictive rate for antisperm antibodies on the sperm surface using circulating antisperm antibodies as a screening assay was estimated to be as low as 35%. There was little correlation between the site of immunobead binding following passive antibody transfer from patients' sera to donor sperm and the site of naturally occurring antibodies on the patients' sperm surface. Although direct assessment of antibodies on the sperm surface is preferred, these data suggest that serum IgG alone can be used as a sensitive screening assay for antisperm antibodies in men. A positive screen dictates that a direct assay on semen should be performed.

Antibodies↗
PubMed1988

Early indicators of male reproductive toxicity.

Longitudinal data were analyzed for seminal characteristics of rhesus monkeys and beagles. The monkeys were exposed to DBCP; the beagles were exposed to acute or chronic whole body gamma irradiation. The semen was analyzed for volume and sperm concentration. Sperm were measured for percent motility, swimming speed, and head dimensions. Abnormalities of the sperm tail were also noted. All treatments resulted in measurable effects on the semen parameters. Sperm production, as evaluated by seminal sperm concentration or total sperm numbers in the ejaculate, was as informative of testicular toxicity as any other parameter or combination of parameters. A consistent finding was that changes in sperm output occurred concomitantly with changes in sperm motility.

Animals↗
PubMed1988

An assay using embryo aggregation chimeras for the detection of nonlethal changes in X-irradiated mouse preimplantation embryos.

We have developed a short-term in vitro assay for the detection of sublethal effects produced by very low levels of ionizing radiation. The assay utilizes mouse embryo aggregation chimeras consisting of one irradiated embryo paired with an unirradiated embryo whose blastomeres have been labeled with fluorescein isothiocyanate (FITC). X irradiation (from 0.05 to 2 Gy) and chimera construction were performed with four-cell stage embryos, and the chimeras were cultured for 40 h to the morula stage. The morulae were partially dissociated with calcium-free culture medium and viewed under phase contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution of irradiated (unlabeled) and control (FITC labeled) embryos per chimera. In chimeras where neither embryo was irradiated, the ratio of the unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.50 (17.8 +/- 5.6 cells per unlabeled embryo and 17.4 +/- 5.5 cells per FITC-labeled partner embryo). However, in chimeras formed after the unlabeled embryos were irradiated with as little as 0.05 Gy, the ratio of unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.43 (P less than 0.01). The apparent decreases in cell proliferation were not observed in irradiated embryos that were merely cocultured with control embryos, regardless of whether the embryos were zona enclosed or zona free. We conclude that very low levels of radiation induce sublethal changes in cleaving embryos that are expressed as a proliferative disadvantage within two cell cycles when irradiated embryos are in direct cell-to-cell contact with unirradiated embryos.

Animals↗
PubMed1988

Prospective surveillance of semen quality in the workplace.

We performed a prospective surveillance of semen quality among workers in the plant where 1,2-dibromo-3-chloropropane was first recognized as an occupational cause of impaired semen quality and of infertility. All male employees of the Agricultural Chemical Division were required to participate. Ninety-seven workers (92% participation) provided 258 semen samples over the 4 years of the program. Most samples were analyzed at the plant with a mini-laboratory designed for the study. Motility and shape measures were made objectively. Sixty-six subjects (68%) were non-azoospermic. Generalized multiple regression showed no significant predictors for any response, with the exception of the motility measures, which were reduced with longer times between ejaculation and assay. Between- and within-person standard deviations and correlations were calculated. Comparison of this population with fertile artificial insemination donors (16 men, 498 ejaculates) revealed generally higher ejaculate-to-ejaculate standard deviations in the worker samples. This is probably due to less well controlled conditions of sperm collection in the workplace setting. For cross-sectional studies, one ejaculate per worker is recommended as sufficient; for estimating an individual worker's mean, even three ejaculates may not provide enough precision.

Environmental Exposure↗
PubMed1987

Reproductive effects of chlorpromazine exposure to female mice: cell proliferation disadvantage revealed by the Chimera Embryo Assay.

Administration of chlorpromazine-HCl at 5 to 15 mg/kg bodyweight to pregnant CD-1 mice at 24 h after human chorionic gonadotropin (hCG) (20-23 h after mating) inhibited blastocyst formation and reduced the cell number of embryos recovered at 95 h after hCG. When embryos are recovered at the two- to four-cell stage (48-50 h after hCG) and cultured for an additional 47 h (to 95 h after hCG) or 72 h (to 120 h after hCG), blastocyst formation and embryo cell number were similarly reduced. When the dose range was reduced to 0.5 to 2 mg/kg bodyweight, no significant effect of the drug was observed on blastocyst formation or on embryo cell number. However, when aggregation chimeras were formed between embryos recovered from drug-exposed females and from untreated females, a decrease in cell proliferation rate of the embryo from the drug-exposed female was observed at a dose of 2 mg/kg bodyweight. This result indicates that exposing pregnant mice to chlorpromazine-HCl at doses as low as 2 mg/kg bodyweight can induce a potential for decreased cleavage rate in their pre-implantation embryos that can be revealed by challenging those embryos by direct contact with embryos from nonexposed females. Finally, when four-cell stage embryos recovered from untreated females cultured in the presence of chlorpromazine (0.1-25 mM), blastocyst formation and embryo cell number were significantly reduced in a dose-dependent manner. This last result suggests that in vivo the drug may act directly on the embryo from the pronuclear stage to the early morula stage of development.

Animals↗