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Biomedical subjects

S Karchmer

Publications and source records attributed to S Karchmer.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Prenatal and perinatal lead exposures alter acoustic cry parameters of neonate.

We performed acoustic analyses on cries elicited from a subset of healthy babies born to the Mexico City Prospective Lead Study at 2 days (n = 75), 15 days (n = 176), and 30 days (n = 166). Lead was measured in maternal blood every 8 weeks during pregnancy from week 12 to delivery and in umbilical cord (1-38 micrograms/dL, 0.05-1.84 mumol/L). Percent nasalization and number of cries decreased in babies born to mothers with higher lead levels in the last two trimesters while median fundamental frequency increased in babies born to mothers with higher lead at 12 weeks of pregnancy, and with higher cord lead in multiple regression analysis. Decreased percent nasalization was related to increased brainstem auditory evoked response latencies and interpeak intervals in a subset of the sample. The results suggest an effect of gestational exposure to lead on apparatus innervated by cranial nerves and/or lead effect on cry mediated by lead-altered auditory function. Altered baby cry and auditory function associated with lead might contribute to developmental delays by affecting early communication between caretaker and baby.

Acoustics↗
PubMedDate not supplied

Secular trend in blood lead levels in a cohort of Mexico City children.

We determined the secular trend in blood lead levels in a cohort of 104 children born in Mexico City between 1987 and 1993. We grouped children by the calendar year in which they reached 6 mo of age and measured blood lead levels every 6 mo until they attained 36 mo of age. The overall geometric mean blood lead level was 9.6 microg/dl (range = 1.5-59.5 microg/dl). A repeated measures analysis of variance revealed a highly significant linear trend in blood lead level with year (p < .001); there was a maximum decrease of 7.6 microg/dl between 1989 and 1993. There was a highly significant quadratic age effect (p < .001); blood lead levels rose between 6 and 18 mo of age and decreased thereafter. There was a marginally significant interaction between age of the child and year. Family use of lead-glazed pottery significantly elevated blood lead levels (p = .028). The downward trend in blood lead levels during the time period of study corresponded to the reduction in various sources of lead exposure.

Child, Preschool↗
PubMedDate not supplied

Electron microscopy of Chlamydia trachomatis infection of the male genital tract.

Semen specimens and testicular and epididymis biopsy from a patient of an infertile marriage were examined by transmission electron microscopy. Intraepithelial vesicles containing C. trachomatis were present in remaining cytoplasmic droplets in spermatozoa, desquamated epithelial cells, and stereocilia from epididymis. Elementary bodies were demonstrated in connective tissue from testes and in Leydig cells. The association between the microorganisms and spermatozoa contribute to the decreased motility and necrospermia. The morphologic alterations in epididymis are responsible for decreased sperm maturation. The damage to Leydig cells can be demonstrated only by electron microscopy.

Adult↗
PubMedDate not supplied

Ultrastructural characteristics of Gardnerella vaginalis infection in the heterosexual couple.

Adhesion and penetration of Gardnerella vaginalis into the male urethral and female vaginal epithelial cells were evaluated in a prospective cohort study of infected females and their sexual partners. Vaginal secretions of 10 women with culture proven G. vaginalis infection and semen samples of their asymptomatic husbands were analyzed with conventional optical and electron microscopy. G. vaginalis was isolated in 50% of the male sexual partners of women harboring the microorganism. G. vaginalis adheres to the plasmatic membrane and penetrates into the cytoplasm of both vaginal and urethral epithelial cells. The ability of G. vaginalis to colonize the male lower genital tract may have clinical relevance with respect to the role of the male partner in the reinfection of women.

Bacterial Adhesion↗
PubMedDate not supplied

[Acid-base equilibrium in healthy newborns. Pattern of normality in Mexico City].

During their spontaneous recovery after birth, the acid-base balance was studied in 32 healthy newborns. The observation period lasted for 4 hours. Determinations were carried out, both in umbilical vessels as in central arterial blood. The most outstanding phenomenon was an increase in acidosis at 30 minutes of life. The metabolic component predominating over the respiratory was a definitely evident fact. At the end of four hours, the acid-base balance reached figures considered normal for the adult.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Hyperlipoproteinemia in children. Correlation between changes in the parents and newborn infant].

The families of 13 children who had presented hyperlipoproteinemia at birth were studied. Total cholesterol, LDL cholesterol, triglycerides and electrophoresis of LP were performed. The parameters studied were divided in three groups: a) Inespecific indicators (alpha-LP, betas/alphas relation). b) Indicators of the beta-LP group (total and LDL cholesterol and beta-LP). c) Indicators of the prebeta-LP group (TG, prebeta-LP and prebeta-1). In all cases at least one of the parents had hyperlipoproteinemia. All the parents, but one, showed alterations in the same group of indicators as their children. Obesity, diabetes mellitus, arterial hypertension, coronary insufficiency, myocardial infarction and cerebrovascular accident where observed in the families of the hiperlipidemic parents, but not on those of the normolipemic parents.

Adult↗
PubMedDate not supplied

[Sources of lead in pregnant women in the Valley of Mexico].

Lead levels in samples of the groups at highest risk to the effects of lead exposure, pregnant women and their infants, are higher than levels known to produce developmental retardation in children in a considerable proportion of the sample tested in Mexico City. Modeling of prenatal factors predicting maternal lead during pregnancy shows the strong effect of the use of low-temperature ceramics on lead level. The data also suggests an important contribution from air lead. The downward trend in lead exposure in pregnant women in the Valley of Mexico over the last 10 years, concurrent with downward trends in air lead is encouraging. However, reducing the manufacture and use of leaded pottery could produce a significant further reduction of lead exposure with a modest program of public education, government regulation and subsidization of lead free pottery.

Adolescent↗