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Biomedical subjects

U Mittwoch

Publications and source records attributed to U Mittwoch.

At least 55 records · Page 3Linked to original sources
PubMed1984

Effects of gossypol on sperm counts in two inbred strains of mice.

Gossypol acetic acid was administered orally to mice of two inbred strains, BALB/c/O1a and CBA/Gr, at daily doses of 10 or 20 mg/kg for about 4 weeks. Treated mice of both strains showed a reduction in sperm counts. This was more marked in CBA mice, which also had smaller testes size than did BALB/c mice. The treatment had no significant effect on testicular weight but the caput epididymidis and seminal vesicles of treated mice weighed less than those of control mice.

Animals↗
PubMed1981

Retardation of ovarian growth in male-sterile mice carrying an autosomal translocation.

Ovarian volumes in 3- and 5-day-old mice heterozygous for the t(11;19)42H translocation were found to be smaller then those of normal controls. Comparisons between liter mates suggested a slight increase in body weight of the translocation bearers and this effect increased the difference in relative ovarian volumes between t42H/+ ice and controls. It is suggested that the differential effect of the translocation on fertility in males and females might be the result of the higher meiotic requirements inherent in spermatogenesis.

Animals↗
PubMed1980

Antimitochondrial effects of thioacetamide and ethylenethiourea in human and yeast cell cultures.

Cytological studies in the light microscope showed that thioacetamide (TAA) depressed the mitotic index in cultures of skin fibroblasts at the lowest concentrations used (100 μg/ml). At high concentration (1 mg/ml), TAA tended to cause aberration in nuclear morphology. Ethylenethiourea (ETU) had no effect on either mitotic index or nuclear morphology at 1 mg/ml. Fibroblast cultures treated with 1 mg/ml TAA and cultures grown in the presence of 2 mg/ml ETU were studied by electron microscopy. In some TAA-treated cells there was unfolding of the nuclear membrane and enlargement and granulation of the nucleolus, but these effects were not correlated. In all cells, TAA caused severe and characteristic damage to the majority of mitochondria, whether or not there were nuclear aberrations. The organelle showed extensive swelling of the cristae of the inner membrane and an increase in matrix density. Ultrastructure of other cell components appeared to be unaffected by this treatment. In ETU-treated cells some less severe swelling of inner mitochondrial membranes was seen and only in a minority of cells, whilst all other cell structures appeared normal. Similar membrane swelling and increase in matrix density was seen in isolated rat liver mitochondria after incubation with TAA, indicating a direct antimitochondrial effect of the carcinogen.When yeast cells were treated with TAA and ETU, primary antimitochondrial activity of these compounds was apparent from (1) inhibition of growth in non-fermentable medium, (2) selective blockage of mitochondrial protein synthesis and (3) induction of mitochondrial mutations. TAA was much more effective than ETU in all these respects.

Acetamides↗
PubMed1980

Comparison of development of human fetal gonads and kidneys.

Comparative measurements of weight, protein and DNA contents of human fetal gonads and kidneys have shown that, for any crown-rump length investigated, values were greater for testes than ovaries but there were no differences between male and female kidneys. Values were also greater for right gonads than left in both sexes but this asymmetry was not seen in kidneys.

DNA↗
PubMed1980

Additional growth--a link between mammalian testes, avian ovaries, gonadal asymmetry in hermaphrodites and the expression of H-Y antigen.

In human hermaphrodites, testes are preferentially situated on the right and ovaries on the left side. This asymmetry can be related to the results of measurements on the growth of fetal gonads. Testes exceed ovaries in weight, protein and DNA contents in fetuses of the same crown-rump length, and in both sexes, right gonads exceed left gonads in the same criteria. These findings, support the hypothesis that in mammals, a basic growth rate will convert the bipotential gonadal rudiment into an ovary while an increased growth rate is required for testicular development. Relative growth rates of chick embryo gonads are largely, although not entirely, the opposite of those in mammals: during the major period of gonadal differentiation, the ovary exceeds the testes in growth. The expression of H-Y antigen in birds and mammals seems to correspond to the presence of the faster growing gonad. These data do not support the hypothesis that H-Y antigen is the primary determiner of sex but a secondary involvement is likely.

Animals↗
PubMed1979

Early testicular development in sex reversed mice.

A comparison is made of two sets of data bearing on the development of testes in XX, Sxr mice. Although Spoljar and Drews (1978) reported no significant difference in the growth rates of XX and XY testes, nevertheless their data suggest that such a difference may exist. This confirms earlier work by Mittwoch and Buehr (1973), who found the testicular volumes of XX embryos aged 15 and 16 days to be below those of XY embryos.

Animals↗
PubMed1978

Parthenogenesis.

Explore the source record for details and available documents.

Amphibians↗
PubMed1977

Sex and lateral asymmetry of the finger ridge-count.

In a sample 719 individuals, the bimanual difference in ridge-count (right minus left) differed only slightly between the two sexes, the mean difference being 0-621 (females minus males). This is not statistically significant, but further evidence suggests that this difference may be real.

Dermatoglyphics↗
PubMed1977

Effects of topically potent glucocorticoids on human diploid fibroblasts in vitro.

A wide range of concentrations of both cortisol and a topically more potent synthetic derivative, fluocinolone acetonide, was found not to inhibit the growth of cultured human skin fibroblasts; fluocinolone acetonide produced a slight increase in the growth rate. Both steroids had a transient stimulatory effect on fibroblasts, promoting an earlier entry into the period DNA synthesis (S) which was also accompanied by a substantial increase in the length of S.

Cell Division↗
PubMed1977

H-Y antigen and the growth of the dominant gonad.

The evolutionary conservation of H-Y antigen and its expression in the heterogametic sex regardless of whether this is male or female must mean that the antigen is associated with a common denominator underlying the development of mammalian testes and avian ovaries. It is suggested that one such common denominator is an enhanced growth rate of the dominant heterogametic gonad at a critical stage of its development.

Animals↗
PubMed1976

Differential growth of human foetal gonads with respect to sex and body side.

Measurements have been carried out on the gonads of 54 human foetuses, 29 males and 25 females. Crown-rump lengths ranged between 140 and 212 mm. The criteria used were fresh weight, total protein contents and total DNA contents. It was found that for any given crown-rump length class, the mean values of testes exceeded those of ovaries for all three criteria. It was also found that the mean values of right gonads exceeded those of left gonads. Since in true hermaphrodites, testes are preferentially situated on the right and ovaries on the left side, it is concluded that there is a causal relationship between increased growth rate and testicular differentiation. It is suggested that in normal development this function is performed by the Y chromosome.

Body Height↗