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Z Stein

Publications and source records attributed to Z Stein.

At least 55 records · Page 3Linked to original sources
PubMed1992

Cognitive assessment of human immunodeficiency virus-exposed children.

OBJECTIVE: To determine (1) the level of impairment in cognitive and motor functioning in human immunodeficiency virus (HIV)-exposed and HIV-infected preschool and school-age children; (2) cognitive strengths and weaknesses that characterize HIV-infected children; and (3) potential contributions of serostatus, neurologic impairment, and prenatal drug-exposure to cognitive functioning. DESIGN: Cross-sectional, single-blind study. SETTING: Pediatric neurology clinic at a large metropolitan hospital in New York, NY. PARTICIPANTS: Forty-one HIV-infected and eight seroreverter school-age children. INTERVENTIONS: The McCarthy Scales of Children's Abilities were administered to all children, as was the Neurologic Examination for Children. MEASUREMENTS/MAIN RESULTS: The obtained mean of the sample on the McCarthy Scales' General Cognitive Index was in the Borderline range, with 44% of the subjects scoring in the Mentally Retarded range. The most severe cognitive deficits were found on the Quantitative, Verbal, and Memory scales (Borderline range). Children infected with HIV with neurologic impairment performed significantly worse than did seroverters and neurologically normal HIV-infected children. There were no significant differences in cognitive functioning due to gender, ethnicity, and prenatal drug exposure. CONCLUSIONS: Cognitive deficits were detected in HIV-infected and seroreverted children. The presence of neurologic dysfunction in HIV-infected children markedly intensified these deficits.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Genetic risk factors for perinatally acquired HIV-1 infection.

This study evaluates genetic influence on susceptibility to perinatal HIV-1 infection among 106 Black infants from New York and San Francisco born to mothers infected with HIV-1. Genes tested by molecular techniques are HLA class II loci DRB1, DPB1 and DQA1; HLA class III loci complement C4A and C4B; alpha and beta interferons; and the constant region of the T-cell receptor beta chain. Of the 106 infants analysed, 54 are infected with HIV and 52 remain uninfected at age 15 months and older. Genotypes in the HLA region appear to influence risk of HIV infection. Specifically, infants with the amino acid sequence -asp-glu-ala-val- at DPB1 positions #84-87 are more likely to be infected (P = 0.001) and infants with the allele DQA1*0102 are less likely to be infected (P = 0.031). Combinations of these two risk factors show a strong dose response (P = 0.0005). HLA DPB1 and DQA1 may play a direct role in immune response associated with HIV-1 infection, or the critical region may be located between these two genes. Characterisation of other class II HLA genes in these infants will allow more precise determination of the role of HLA loci in susceptibility to HIV-1 infection.

Alleles↗
PubMed1991

Exact random-walk models in crystallographic statistics. VI. P.D.F.'s of magnitude of [E] for all plane groups and most space groups.

An exact calculation of the probability density function (p.d.f.) of magnitude of [E], the magnitude of the normalized structure factor, can be developed in terms of Fourier and Fourier-Bessel series whose coefficients can be expressed in terms of the characteristic function. This article provides the formulae for atomic contributions to such characteristic functions. The results presented in this study are applicable to all the plane groups and to 206 three dimensional space groups. Only the space groups isomorphous to the cubic point groups 432, 43m and m3m were omitted due to the complexity of the resulting expressions and the small deviations of the corresponding densities from the central-limit-theorem approximation, which have been observed in simulations for extreme atomic heterogeneities. Representative derivations illustrating the problems and techniques of their solution are provided. All the theoretical results have been computed numerically and compared with simulated distributions. Some results of these computations are illustrated in the accompanying paper, Part VII of this series [Rabinovich, Shmueli, Stein, Shashua & Weiss (1991). Acta Cryst. A47, 336-340].

Fourier Analysis↗
PubMed1991

Exact random-walk models in crystallographic statistics. VII. An all-space-group study of the effects of atomic heterogeneity on the P.D.F.'s of magnitude of [E].

Exact expressions have been found for the probability density functions (p.d.f.'s) of the magnitude of the normalized structure factor for all the two-dimensional and most three-dimensional space groups [Part VI: Rabinovich, Shmueli, Stein, Shashua & Weiss (1991). Acta Cryst. A47, 328-335]. The results of that investigation are used in the present article to examine some effects of atomic heterogeneity, in the various space-group symmetries, on the p.d.f.'s. Some typical comparisons are made between p.d.f.'s based on the central limit theorem and p.d.f.'s computed from exact formulae. In addition, the exact results are compared to histograms of simulated values of magnitude of [E]. It is found that the p.d.f.'s for some space groups are influenced rather strongly by the presence of outstandingly heavy scatters, but they are quite insensitive to the presence of such scatterers in other space groups. The often made general statement 'The presence of outstandingly heavy scatterers may invalidate the indications of Wilson's statistics' is made more precise here, insofar as it depends on the particular space group.

Fourier Analysis↗
PubMed1991

Caffeine and spontaneous abortion of known karyotype.

We tested associations of caffeine from beverages with spontaneous abortions of known karyotype. Spontaneous abortions (cases) were classified as chromosomally normal (n = 510) or chromosomally aberrant (n = 389) and, within the latter category, by type of aberration (237 trisomies, 54 monosomies X, 49 triploidies, 49 others). Controls registered for prenatal care before 22 weeks gestation and delivered at 28 weeks or later (n = 1,423). Caffeine intake in the perifertilization period did not differ among case groups and controls. For the highest category, 225+ mg/day, odds ratios (OR), adjusted for payment group and maternal age, were 1.0 for chromosomally normal cases, 0.9 for trisomies, 1.6 for monosomies X, and 0.8 for triploidies. Caffeine intake during pregnancy was tested for associations with chromosomally normal loss using the chromosomally aberrant cases to provide a robust comparison group. Although the proportion of subjects with intake of 225+ mg/day of caffeine intake in the perifertilization period does not influence the risk of chromosomally normal loss or trisomy. For monosomy X and triploidy, no strong associations were observed, but numbers were insufficient to rule out moderate effects. For caffeine intake during pregnancy, we found little evidence to support an influence on chromosomally normal loss.

Abortion, Spontaneous↗
PubMed1991

Marijuana and spontaneous abortion of known karyotype.

We tested whether marijuana use in the 2 months before the last menstrual period and during pregnancy affects the risk of spontaneous abortions of known karyotype. Spontaneous abortions (cases) were defined as chromosomally normal (n = 567) or chromosomally aberrant (n = 393) and, within the latter, by type of aberration (212 trisomies, 71 monosomies X, 49 triploidies, 61 others). Controls were women with prenatal care before 22 weeks gestation and delivering at 28 weeks or later (n = 2042). In comparison with controls, adjusted odds (OR) of reported marijuana use in chromosomally normal cases were 1.1 (95% confidence interval (CI) 0.7, 1.5) and in chromosomally aberrant cases combined 1.2 (95% CI 0.7, 1.9). With respect to specific aberrations, use in the perifertilisation period did not differ significantly from that in controls for trisomies (adjusted OR = 0.8, 95% CI 0.4, 1.8), monosomies X (adjusted OR = 1.8, 95% CI 0.7, 4.3), and triploidies (adjusted OR = 1.3, 95% CI 0.4, 4.5). Comparison of karyotype groups with each other yielded similar results. Our data do not support causal associations of marijuana use, at the levels represented in our sample, with either chromosomally normal or trisomic spontaneous abortion. With monosomy X and triploidy, no statistically significant associations were detected although numbers were insufficient to rule out moderate effects.

Abortion, Spontaneous↗
PubMed1987

Cigarettes, alcohol and marijuana: varying associations with birthweight.

The relations of cigarette smoking, alcohol drinking and marijuana use during pregnancy to birthweight were examined in two prospectively studied pregnancy cohorts (Phases I and II). After analytic adjustment in ordinary least squares regressions for other factors that influence birthweight, cigarette smoking during at least half the pregnancy was associated with a significant decrease in mean birthweight (159 grams in Phase I, 202 grams in Phase II). In Phase II only, beer drinking was associated with a significant decrement of 8.4 grams in estimated birthweight per ounce of absolute alcohol per month. Neither wine nor liquor drinking in the Phase II data nor any of the three beverages in the Phase I data was associated with significant decrements in predicted birthweight. Furthermore, with one exception (drinking once a week in Phase II only), alcohol drinking, defined as the number of occasions per month on which any alcoholic beverage was consumed, was not associated with a change in birthweight. Regarding marijuana use, the data are not consistent between the two phases. In the Phase I data, no coherent trend in association with birthweight was observed. In the Phase II data, marijuana use 2-3 times per week, 4-6 times per week and daily was associated with increasing decrements in estimated birthweight: 127 g, 143 g and 230 g respectively. The inconsistent findings for alcohol drinking and marijuana use between phases stand in marked contrast to the consistent findings for cigarette smoking.

Adult↗
PubMed1987

Biological markers in reproductive epidemiology: prospects and precautions.

We begin by defining "biological markers" for the purposes of the present review, distinguishing markers from other types of information, such as subject reports or conventional clinical data. We find the distinctions to be hazy. Next, from the standpoint of epidemiologists, we set out circumstances in which exposure markers might be needed, suggesting requirements for useful markers. We give two instances (lead, PCB), drawn from studies of female reproduction, where the use of exposure markers is compared to environmental or anamnestic data. Effect markers are considered in turn. It is argued that their usefulness (if they are to be more informative than exposure markers) depends on their sensitivity and specificity in relation to the disease outcome. Also, their timeliness, and the use that can be made of the gain in time, for individuals and populations is discussed. In this context, we consider markers of events before and around fertilization; more specifically, we consider those events that precede the clinical marker of the first missed period. In returning to the potential uses of biological markers in discovering or interpreting female reproductive disorders that might be owed to environmental causes, we compare markers of the pre- and peri-implantation phases with markers of the postimplantation phase, drawing on experience with studies of chromosome anomaly in spontaneous abortion. Finally, we suggest other sensitive reproductive processes for which biological markers might usefully be developed.

Abortion, Spontaneous↗
PubMed1987

Mild mental retardation and severe mental retardation compared: experiences in eight less developed countries.

Frequencies of Severe Mental Retardation (SMR) and Mild Mental Retardation (MMR) were obtained from pilot surveys of severe childhood disability in 8 less developed countries. Approximately 1,000 children aged 3 to 9 years were surveyed in each location. The surveys used a Ten Question (TQ) door-to-door interview, usually of the mother, as a screening procedure and a systematic medical and psychological assessment for the diagnosis. Diagnostic categories of SMR (IQ less than or equal to 55) and MMR (IQ greater than 55, less than or equal to 70) were assigned by well trained local psychologists, using formal and informal techniques of assessment. Contrasting frequencies and distributions for MMR compared with SMR are shown for each location. No consistent pattern for MMR versus SMR emerged, neither regarding frequency, male/female ratio, average age nor socio-economic status of household. By contrast, MMR did differ from SMR consistently regarding consanguinity of parents, the presence of associated impairments and the positive report of symptoms at interview. Also, the families of all MR children were lower in SES than comparison families. An interpretation of these findings is offered: the more severely disabled children tend to be assessed as SMR, but so do other children who might, in better circumstances, be assessed as MMR. The relevance of this interpretation is discussed, in terms of assessment and of rehabilitation, and as a guide to further epidemiologic studies.

Asia, Southeastern↗
PubMed1987

Does the karyotype of a spontaneous abortion predict the karyotype of a subsequent abortion? Evidence from 273 women with two karyotyped spontaneous abortions.

At least two spontaneous abortions were karyotyped in 273 women during cytogenetic surveys in New York City and Honolulu. These pairs were analyzed using maximum-likelihood logistic-regression analysis to adjust for maternal age and location. There was a significantly increased risk for a chromosomally normal spontaneous abortion after a previous abortion with a normal karyotype. There was no increased risk for trisomy in a second spontaneous abortion following either a previous trisomic abortion or an abortion with another abnormal karyotype. This is unexpected, given the increased risk for trisomy found among live births and at prenatal diagnosis in young women with a previous trisomic birth. The most likely explanation is that the increased recurrence risk for trisomy is restricted to trisomy for only one or a few chromosomes, for reasons such as parental trisomy mosaicism. These data predict no increased risk of chromosome abnormality in future pregnancies after either (1) spontaneous abortions with trisomies of a kind that are always lethal in utero or (2) multiple early abortions in the presence of normal parental karyotypes.

Abortion, Habitual↗
PubMed1986

Vaginal spermicides and spontaneous abortion of known karyotype.

The relationship between spermicide use and spontaneous abortion was examined in a New York City case-control study carried out during 1974-1982. In a series of matched sample analyses, case groups categorized by karyotype of the abortus were compared to a control group of prenatal patients with respect to spermicide use. Spermicide use was defined in terms of proximity to the date of conception of the study pregnancy and duration of the episode of use most recent to the study pregnancy. There was no association between spermicide use defined either in terms of recency or duration of use and chromosomally normal abortions, which comprise about 60% of all spontaneous abortions. Similarly, there was no association between spermicide use and the various types of chromosomally abnormal abortions, with the exception of trisomic abortion. Spermicide use for more than one year at any time prior to conception was more common in the cases aborting trisomic conceptions than in the control group (odds ratio = 1.9, confidence limits = 1.2, 3.0). There was evidence to suggest that the association varied with maternal age and phase of entrance into the study.

Abortion, Spontaneous↗
PubMed1986

Induced abortion and the chromosomal characteristics of subsequent miscarriages (spontaneous abortions).

Data from a case-control study of miscarriages (spontaneous abortions) were used to test whether single and multiple induced abortions are associated with miscarriage in subsequent euploid (chromosomally normal) pregnancies. Cases and controls were identified in three New York City hospitals between April 1974 and November 1982. It was hypothesized that, if induced abortion increased the risk of subsequent miscarriage, an association would be observed with euploid but not aneuploid (chromosomally abnormal) miscarriage. The frequencies of single and multiple induced abortions among euploid cases and aneuploid cases were compared with those among controls. Among both private and public patients, the proportion of women reporting a single induced abortion was similar in euploid cases and in aneuploid cases compared to controls. Among public patients only, the proportions reporting multiple induced abortions were also similar in euploid cases and in aneuploid cases compared to controls (odds ratios = 0.9 and 1.0, respectively). In contrast, among private patients, the proportion reporting multiple induced abortions was raised among euploid cases (odds ratio = 2.2, 95% confidence interval = 1.3-3.7), although not among aneuploid cases. This association was strongest when the first induced abortion was carried out before 1973, at a young age, or with a procedure other than suction curettage. In public patients, the associations with miscarriage did not vary with characteristics of the first induced abortion, but multiple induced abortion histories when the first two induced abortions occurred before 1973 were in excess among euploid cases compared to controls. These results suggest that, for both private and public patients, neither single nor multiple induced abortions as now performed are likely to increase the risk of miscarriage in subsequent pregnancies. They also suggest a mechanical origin for some miscarriages.

Abortion, Induced↗
PubMed1986

"Serious" mental retardation in developing countries: an epidemiologic approach.

In this paper we first present methods and preliminary results of pilot surveys of "serious" mental retardation (IQ less than or equal to 55); the surveys included screening and diagnostic components and were carried out in the less-developed world. Next we discuss two problems raised by these surveys: one is the diagnosis of a case and its clinical dimensions, and the other is the interpretation of prevalence. In the next section we illustrate epidemiological approaches to the analysis of such data, in particular their relevance to prevention. Lastly, we propose that the two-stage survey approach developed in the course of the pilot work can provide a valuable basis for planning and prevention, if certain key conditions can be met.

Bangladesh↗