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Biomedical subjects

J L Jacobson

Publications and source records attributed to J L Jacobson.

11 recordsLinked to original sources
PubMed1992

Impact of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls on human and environmental health, with special emphasis on application of the toxic equivalency factor concept.

A scientific evaluation was made of the mechanisms of action of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls. Distinction is made between the aryl-hydrocarbon (Ah) receptor-mediated and non-Ah receptor-mediated toxic responses. Special attention is paid to the applicability of the toxic equivalency factor (TEF) concept.

Animals↗
PubMed1992

Visual expectation and dimensions of infant information processing.

Visual expectation was assessed in 103 black 6.5-month-olds using Haith, Hazan, and Goodman's paradigm and related to performance on standard developmental assessments and tests of information processing skill. As expected, percent anticipations was higher and RT lower than in 3.0-month-olds previously tested. Split-half and left-right correlations for the RT measures were moderate and similar to those previously reported, as was split-half reliability for percent anticipations. The 2 RT measures were related to fixation duration on both visual recognition memory (VRM) and cross-modal transfer, suggesting moderate cross-task and cross-age consistency in processing speed. Percent anticipations and baseline RT each contributed independently to the prediction of VRM novelty preference. Data from a factor analysis suggested 3 dimensions of cognitive function: processing speed, developmental level, and memory/attention. These findings suggest that the visual expectation paradigm provides a reliable new approach for assessing cognitive processing efficiency and attention during infancy.

Black or African American↗
PubMed1991

Incidence and correlates of breast-feeding in socioeconomically disadvantaged women.

Although the incidence of breast-feeding has more than doubled in the United States in recent years, this increase has been less evident among blacks and in lower socioeconomic groups. To understand better this lower incidence, cognitive and personality correlates of breast-feeding were examined in two independent lower-class samples: 137 black inner-city mothers and 50 predominantly white mothers. Ego development, depression, and verbal competence were assessed during the first postpartum year. Only 21.9% of the black sample chose to breast-feed, in contrast with 58.0% of the white sample. Although unrelated to depression and social support, breast-feeding was positively associated with ego level and cognitive ability in both samples. Cognitive ability was assessed using the Peabody Picture Vocabulary Test-Revised, which was found to be valid in relation to maternal and infant characteristics for the black socially disadvantaged sample. When compared using multiple regression analysis, the relation of ego maturity to breast-feeding was generally stronger than that of cognitive ability. Women with more ego maturity may breast-feed because of increased feelings of empathy or nurturance or because they are more attuned to current health advisories and able to deviate from community norms to adopt breast-feeding practices more characteristic of the white middle class.

Black or African American↗
PubMed1990

Effects of in utero exposure to polychlorinated biphenyls and related contaminants on cognitive functioning in young children.

Because prenatal exposure to polychlorinated biphenyls (PCBs) and related contaminants has been associated with reduced birth weight, neonatal behavioral anomalies, and poorer recognition memory in infants born to women who have consumed Lake Michigan sports fish, 236 children, previously evaluated for PCB-related deficits in infancy, were assessed at 4 years of age. Prenatal exposure (indicated by umbilical cord serum PCB level) predicted poorer short-term memory function on both verbal and quantitative tests in a dose-dependent fashion. These effects cannot be attributed to a broad range of potential confounding variables, the impact of which was evaluated statistically. Although much larger quantities of PCBs are transferred postnatally via lactation than prenatally across the placenta, exposure from nursing was unrelated to cognitive performance. The data demonstrate the continuation of a toxic impact received in utero and observed initially during infancy on a dimension of cognitive functioning fundamental to learning.

Animals↗
PubMed1989

Determinants of polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), and dichlorodiphenyl trichloroethane (DDT) levels in the sera of young children.

Serum samples from 285 4-year-old Michigan children were evaluated for levels of 11 environmental contaminants. Polychlorinated biphenyls (PCBs) were found in half the samples tested; polybrominated biphenyls (PBBs) in 13-21 percent; dichlorodiphenyl trichloroethane (DDT), in more than 70 percent. Nursing (Mothers' milk) was the principal source of these exposures. Congener-specific analysis documented the presence of at least one highly toxic PCB congener, 2,3',4,4',5-pentachlorobiphenyl. The data demonstrate the multigenerational impact of female exposure to persistent organic environmental contaminants.

Body Burden↗
PubMedDate not supplied

Effects of exposure to PCBs and related compounds on growth and activity in children.

Two hundred thirty-six children from two established cohorts at risk for exposure to polychlorinated biphenyls (PCBs) and related contaminants were evaluated at age 4 years. Prenatal exposure (assessed by cord serum PCB level) was associated with lower weight, an effect consistent with reports of growth retardation in laboratory rats and in children exposed at high levels in Taiwan and at general population levels in Japan. The highest exposed children weighed 1.8 kg less on the average than the least exposed. Contemporary body burden (assessed by 4-year serum PCB level) was associated with reduced activity based on composite ratings provided by the child's mother and two independent examiners. This effect, attributable to lactation exposure, was strongest among the offspring of women with above average milk PCB levels who breast fed for at least 1 year. While the weight deficit is consistent with previous data linking developmental effects of low-dose human PCB exposures specifically to the prenatal period, activity is the first domain found to be affected by lactation at contemporary levels of exposure.

Animals↗
PubMedDate not supplied

Polychlorinated biphenyls and the developing nervous system: cross-species comparisons.

Polychlorinated biphenyls are stable, lipophilic industrial compounds that are present in residue levels in human tissue, wildlife, and freshwater sediment. They are toxic, and are known to cross the placenta and intoxicate the fetus. Two large outbreaks of PCB poisoning have occurred in Asia; women pregnant at or after the exposures had children who were developmentally impaired. Laboratory experiments in rhesus monkeys and rodents, designed to assess neural or developmental effects, show altered activity levels, impaired learning, and delayed ontogeny of reflexes. Children exposed transplacentally to levels considered to be background in the U.S. have hypotonia and hyporeflexia at birth, delay in psychomotor development at 6 and 12 months, and poorer visual recognition memory at 7 months. Allowing for differences in testing, effects are roughly similar across species, but current methods used to calculate allowable or reference doses give results up to 4 orders of magnitude apart, with the lowest level based on the neurotoxicology level coming from the human data.

Animals↗
PubMedDate not supplied

Maternal recall of alcohol, cocaine, and marijuana use during pregnancy.

Alcohol, cocaine, and marijuana use during pregnancy was reported antenatally and at 13 months postpartum by 361 black inner city mothers. The two reports were moderately related for all three substances, but levels reported retrospectively were substantially higher. MAST scores did not differ for the two interviews. Most of the correlations of the antenatal and retrospective reports with maternal and infant characteristics were similar in magnitude; those that differed were somewhat stronger for the antenatal measures. Although the retrospective reports may provide a better indication of mean levels of fetal exposure, they may be less precise in rank ordering among individuals for purposes of correlational analysis. Women with higher MAST scores were particularly prone to report higher levels of both alcohol and cocaine when interviewed retrospectively, and more severely depressed mothers were more likely to report higher levels retrospectively for all three substances. These data suggest that women reporting more than 1.3 drinks/week antenatally (AA/day greater than 0.1) may actually be drinking at levels at risk for alcohol-related birth defects.

Adolescent↗