Technology for sex selection: current status and utilization.

Research focusing on potential users of technology for sex selection and their preference for firstborn sons is reviewed in light of technological advances. Further study of personality characteristics of users is proposed as well as identification of interpersonal dynamics occurring within a couple having divergent preferences for sex of offspring.

Sex selection technology utilization: further implications for sex ratio imbalance.

A survey of 242 undergraduates assessed attitudes toward use of sex selection technology and the choice of sex of first- and second-born offspring among potential users. Of our sample, 31 per cent endorsed use of sex selection technology, with the small subsample of nonwhites more accepting of utilization than were whites. There was a significant preference for first-born sons among all potential users, but nonwhites indicated a stronger preference than did whites. Students from rural areas were more desirous of boys than were urban residents. The desire for gender balance within the family documented in earlier studies did not manifest itself. Choice of gender of second child was independent of preference for first-born, with 54 per cent of the potential users desiring sons as both first and second children.

Alanine is a major end product of metabolism by Giardia lamblia: a proton nuclear magnetic resonance study.

1H-NMR spectroscopy was used to monitor the major metabolic end products released by Giardia lamblia when maintained anaerobically in culture in Diamond's TYI-S-33 medium. Spectra were acquired for the cell-free medium and the resonances of metabolites utilised and produced during cell growth identified by the addition of pure compounds and by difference spectroscopy. The major metabolites produced by the parasite were alanine, ethanol and acetate, with increases in concentrations in the media after 4 days' growth (end of log phase) of 18, 15 and 4 mM, respectively. The production of both alanine and ethanol approximated to cell growth, with ethanol formation lagging behind alanine during log growth but predominating after the parasites entered stationary phase. Acetate was formed at a more constant rate during growth. Glucose utilisation was sufficient to account for only 50% of the total carbon appearing in alanine, ethanol and acetate. The aminotransferase inhibitors L-cycloserine and carboxymethoxylamine inhibited growth and selectively inhibited the production of alanine. Analysis of the amino acid composition of the medium by HPLC showed that the only amino acid produced, apart from alanine, was proline, which increased in concentration in the medium by 4 mM after 4 days. There was also a 7 mM increase in ammonia over the same period. The only amino acids that were utilised were arginine and the components of an unresolved peak comprising serine, asparagine and glutamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic studies of the protozoan parasite, Crithidia luciliae, using proton nuclear magnetic resonance spectroscopy.

Proton nuclear magnetic resonance (NMR) spectroscopy was used to follow glucose metabolism in Crithidia luciliae. Parasites were grown aerobically and anaerobically in culture, with glucose as the major carbon source and 1H NMR spectra were acquired for the cell free medium. The 1H NMR resonances of metabolites utilised and produced during cell growth were identified by difference spectroscopy, and quantitated from standard curves using 3-trimethylsilyl propionate-2,2,3,3-d4 sodium salt as an internal standard. The major metabolites produced by C. luciliae grown aerobically on 8 mM glucose were succinate, pyruvate, acetate and ethanol, in final concentrations in the media when the cells entered stationary phase of 8.5 +/- 0.5, 5.0 +/- 0.3, 2.1 +/- 0.2 and 2.5 +/- 0.6 mM, respectively. The production of succinate and pyruvate, but not acetate and ethanol, followed closely the growth curve of the parasites. Succinate was also measured enzymically and glucose using an autoanalyser. In both cases the results correlated well with the NMR data. The amounts of end products formed were greater than could be accounted for by the utilisation of glucose or any other metabolite observable in the 1H NMR spectra. There was approximately one extra atom of carbon for each molecule of succinate formed, supporting the view that succinate is produced via phosphoenolpyruvate carboxykinase and carbon dioxide fixation. Anaerobically the same major metabolites were produced, but with a decreased ratio of succinate to acetate and ethanol. The formation of glycerol from glucose was not observed under these conditions.

Sex-role orientation as a predictor of preferential cognitive response style.

This study investigated the relationship between sex-role orientation and cognitive preferential response style (N = 60). It attempted to use scores on the Bem Sex Role Inventory (BSRI) to predict the Erlebnistypus (EB) ratio of the Rorschach. Although masculine and androgynous individuals were expected to demonstrate extratensive and intraversive cognitive styles, respectively, no such distinction was apparent. However, feminine individuals did demonstrate significantly an ambitent response style in which neither human movement nor weighted color was dominant. Results were discussed in terms of increased construct validity for both of the measures utilized.

Preference for sex of child among primiparous women.

Primiparous American women (N = 140) were questioned during their third trimester concerning their choice of sex of offspring and their willingness to use sex preselection techniques (if available). Eighty-two women expressed no preference for sex of offspring; of the remaining 58, 33 chose girls and 25 chose boys. Of the 26 women who indicated they would have used preselection technology, 13 chose boys and 13 chose girls. Fifty-three percent of the sample indicated they would not have used preselection techniques; 29% were undecided. These results were at variance with earlier studies that indicated a consistent choice of male firstborns, especially in nonpregnant samples. The discrepancy is discussed in terms of a move from boy preference to no preference and a gradual weakening of societal bias against women.