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Biomedical subjects

D Hemon

Publications and source records attributed to D Hemon.

10 recordsLinked to original sources
PubMed1991

Lead-exposed workmen and fertility: a cohort study on 354 subjects.

A cohort study was conducted in a French battery factory in 1977-1982 to explore the relationship between occupational lead exposure and fertility. A total of 354 battery workers, divided into 229 lead-exposed subjects (corresponding with 886 person-years) and 125 non-lead-exposed subjects (corresponding with 598 person-years) were compared, in a person-year analysis, for the risk of infertility. Lead exposure, at any level of absorption, did not appear significantly associated with a reduction in fertility after controlling for potential confounders: age, French origin, educational level, number of children at start of the period, cigarette smoking and exposure to heat. The apparent inconsistency between our results and those of several studies involving biological data and semen analysis is partially explained by recent knowledge relating to predictive value on the pregnancy of semen abnormalities.

Adult↗
PubMed1991

Paternal exposure to mercury and spontaneous abortions.

The potential reproductive toxicity of mercury vapour was investigated by comparing the rate of spontaneous abortions among the wives of 152 workers occupationally exposed to mercury vapour with the rate among the wives of 374 controls in the same plant. The results indicate an increase in the rate of spontaneous abortions with an increasing concentration of mercury in the fathers' urine before pregnancy. At concentrations above 50 micrograms/l the risk of spontaneous abortion doubles (odds ratio (OR) = 2.26; 95% confidence interval (95% CI) = 0.99-5.23). Special care was taken to avoid bias in reporting abortions and known risk factors of spontaneous abortions do not seem to explain the results. Several biological mechanisms might account for them including, in particular, direct action of mercury on the paternal reproductive system and indirect toxicity to the mother or embryo through transport of mercury from the father. These indications could be of practical importance and should therefore be further documented.

Abortion, Spontaneous↗
PubMed1979

[Analysis of the geographical variations of twinning rate in France. An indirect approach to study spontaneous abortions (author's transl)].

The hypothesis of the existence of spatial variations of spontaneous abortion rates has two logical consequences on dizygotic twinning rates: they must be heterogeneously distributed and show a positive correlation with natality. French data available on dizygotic twinning rates from 1950 to 1974 are in agreement with both implications. Although alternative explanations are possible, these findings do reinforce the relevance of dizygotic twinning rate variations as a tool for the assessment of reproduction failures.

Abortion, Spontaneous↗
PubMed1979

Mechanisms of transcription in nucleoli of amphibian oocytes as visualized by high-resolution autoradiography.

In oocytes of Pleurodeles waltlii, the method of Miller and Beatty has been combined with a method of high-resolution autoradiography especially suitable for the study of isolated molecules. In vitro labeling of RNA by tritiated precursors was carried out with increasing incubation times (1, 4, 15, 24, 48, and 72 h). Silver grains were present over ribonucleoprotein fibrils in amounts sufficient for quantitative analysis of nucleolar DNA transcription. Statistical analysis of the data revealed that: (a) The units of any one nucleolus exhibited a large degree of heterogeneity in their number of grains. (b) There was a parallelism between the increasing grain number and the ribonucleoprotein-fibril lengthening as observed along the transcription unit.

Amphibians↗
PubMed1978

Twinning rate and reproduction failures.

Spontaneous abortion of one of the zygotes is shown to explain some of the main epidemiologic features of dizygotic twinning: its decrease at higher maternal ages and its spatial and secular variations. Conversely, the dizygotic twinning rate offers a precious tool for the study of the etiology of reproduction failures.

Abortion, Spontaneous↗
PubMed1977

[Distribution of birth weights and influenza epidemics (author's transl)].

The possible consequences of influenza during pregnancy on the weight of the new born were studied. It was shown that the major 1969-70 winter influenza epidemic in Alsace was followed by a decrease in the mean birth weight registered in Haguenau's maternity hospital. This study confirms previous work on the subject and shows that birth weight can be used as a valuable tool at the epidemiologic scale.

Birth Weight↗
PubMed1976

[Effect of a polyvitamin preparation on the immune response to antibodies. Demonstration of the immunostimulating activity of propylene glycol].

Humoral antibody to sheep erythrocytes was studied by plaque forming cell and hemagglutinin assays in mice receiving a polyvitaminic preparation containing vitamins A, D, E, and C. A statistically significant increase in PFC on days 6, 12 and 18 after immunization, and an increase in hemagglutinin titers was observed in animals treated with this vitamin containing solution. These results are interpreted as an immunostimulating activity of the preparation. Nevertheless, as shown by the results obtained with each component injected separately, a major proportion of the immunostimulating activity seems to be related to propylene glycol, a simple compound contained as an hydrodispersant in the preparation. Further studies of the immunostimulating properties of propylene glycol are now in progress in our laboratory.

Adjuvants, Immunologic↗