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Comparative Study 2005; 26(6): 759-762 PubMed PMID: 16380678 Citation  Keywords:  Austria:epidemiology, Educational Status, Employment, Faculty:statistics & numerical data, Female, Humans, Male, Mothers:statistics & numerical data, Parity, Pregnancy, Reproduction:physiology, Seasons, Sex Ratio, Social Class,.   

OBJECTIVES: Environmental and socio-demographic factors can influence the variation of the human sex ratio at birth (SRB = the ratio of males to males plus females). In particular, findings of seasonal, parental education, birth order, and maternal age effects on the SRB are not always in agreement, and a number of works report minimal variation.

SETTING: Here, we investigated the seasonality of SRB in academic and non-academic mothers employed at the University of Vienna, and who gave birth between 1963 and 2000 (n = 1932 births).

METHODS: All data were available from an anonymous employee database.

RESULTS: Both groups, academic and non-academic mothers do not differ between their overall SRB. In academic mothers the SRB is significantly (P = 0.004) increased during the springtime and decreased during the summertime. Although in non-academic mothers the trend is comparable, it is far less pronounced and not significant (P = 0.345). When a multiple logistic model was applied to the data of academic mothers the only significant influencing factor on the SRB is the season, while birth order of children and mothers' age at childbirth has no effect. None of the three independent variables influence the SRB in non-academic mothers.

MAIN FINDINGS: These findings suggest a more flexible SRB rate in academic mothers than in non-academics within the seasons.

CONCLUSION: We conclude that the significant seasonal variation of the SRB in academic women cannot be merely interpreted as an effect of socio-economic status but more likely as the interaction between socio-economic and environmental working conditions....

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Journal Article 2003; 24(3-4): 137-140 PubMed PMID: 14523346 Citation  Keywords:  Animals, Bivalvia:metabolism, Chromatography, High Pressure Liquid, Estradiol:metabolism, Gonads:metabolism, Isomerism, Radioimmunoassay, Reproduction:physiology, Spectrometry, Mass, Electrospray Ionization, Spectrophotometry, Ultraviolet,.   

OBJECTIVES: In earlier studies, we demonstrate that 17-beta -estradiol and an estrogen cell surface receptor can be found on various human cells, i.e., vascular endothelial, monocytes, and granulocytes, where they are coupled to nitric oxide release. We further demonstrated this phenomenon in the marine mussel Mytilus edulis ganglionic tissues. In the present report we sought to determine if estrogen can be found in M. edulis reproductive tissues.

MATERIAL & METHODS: We determined the presence of 17-beta -estradiol via high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA) in the animals gonads. This substance was further identified via nanoelectro-spray ionization quadrupole time of flight mass spectrometry (Q-TOF-MS).

RESULTS: 17-beta -estradiol was identified and quantified in Mytilus gonads. Interestingly, we also determined that estradiol isoforms also were present in this tissue.

CONCLUSION: These data demonstrate that 17-beta-estradiol and an estradiol isoform is present in M. edulis gonadal tissues, suggesting that they have functions related to reproduction. This further suggests that estrogen's association with reproductive activities has a long evolutionary history and that this association began in invertebrates....

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Journal Article 2001; 22(4): 222-228 PubMed PMID: 11524627 Citation  Keywords:  Animals, Circadian Rhythm, Drosophila:physiology, Reproduction:physiology, Species Specificity,.   

: Physiological and behavioral phenomena of many animals are restricted to certain times of the day. Many organisms show daily rhythms in their mating. The daily fluctuation in mating activity of a few insects is controlled by an endogenous clock. The fruitfly, Drosophila, is the most suitable material to characterize the genetic basis of circadian rhythms of mating because some mutants with defective core oscillator mechanism, feedback loops, have been isolated. D. melanogaster wild-type display a robust circadian rhythm in the mating activity, and the rhythms are abolished in period or timeless null mutant flies (per(01) and tim(01)), the rhythms are generated by females but not males. Disconnected (disco) mutants which have a severe defect in the optic lobe and are missing lateral neurons show arrhythmicity in mating activities. Thus, the lateral neurons seem to be essential for the circadian rhythm in mating activity of Drosophila. Furthermore, an anti-phasic relation in circadian rhythms of the mating activity was detected between D. melanogaster and their sibling species D. simulans. The Queensland fruit flies or wild gypsy moth also show species-specific mating rhythm, suggesting that species-specific circadian rhythms in mating activity of insect appear to cause a reproductive isolation....

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