Chinese traditional medicine and abnormal sex ratio at birth in China

A study of the abnormal sex ratio at birth in China reveals that it is not an entirely new phenomenon that emerged since the 1980s, but is simply more visible at present. Deliberate intervention to determine the sex of children has existed in the past few decades, at least in certain groups. Apart from modern medical methods, traditional Chinese medical practice is shown to be highly accurate in identifying the sex of a fetus. This may lead to sex-selective abortion and an abnormal sex ratio at birth. The possible causes of the abnormal sex ratio at birth include not only the real imbalance due to the disturbance of social factors, but also a spurious one attributable to the undercounting of female births. The real magnitude of the imbalance has been exaggerated by statistical error. The phenomenon is a complicated one reflecting the comprehensive socioeconomic setting. Among these factors, the stage of the fertility transition is one of the most decisive.     

Cloning, expression and characterization of a UDP-galactose 4-epimerase from Escherichia coli

The gene galE encoding UDP-galactose 4-epimerase was cloned into E. coli BL21(DE3) from the chromosomal DNA of E. coli strain K-12. High expression of the soluble recombinant epimerase was achieved in the cell lysate. In order to evaluate the use of this epimerase in enzymatic synthesis of important -Gal epitopes (oligosaccharides with a terminal Gal1,3Gal sequence), a new radioactivity assay (1,3-galactosyltransferase coupled assay) was established to characterize its activity in producing UDP-galactose from UDP-glucose. Approximately 2700 units (100 mg) enzyme with a specific activity of 27 U mg^–1 protein could be obtained from one liter of bacterial culture. The epimerase was active in a wide pH range with an optimum at pH 7.0. This expression system established a viable route to the enzymatic production of -Gal oligosaccharides to support xenotransplantation research.     

Determination of genetic relationships among five indigenous Chinese goat breeds with six microsatellite markers

Microsatellite variation was analyzed in five Chinese indigenous goat breeds, which include four Cashmere breeds (Tibetan, Neimonggol, Liaoning, Taihang) and one Hubei local breed (Matou) used for meat production. Five ovine and one bovine microsatellites, selected from eight ovine microsatellites and five bovine microsatellites were suitable for use in this study. With these six microsatellites, allele frequencies, heterozygosity, polymorphism information content (PIC) and effective allele number were calculated. A neighbor-joining tree was constructed using Nei's standard genetic distance (1978). In the tree, Neimonggol and Liaoning were grouped together, then with Taihang; while Tibetan and Matou individually had their own branch. The genetic relationship of five breeds corresponds to their history and geographic origins.     

Effect of Dietary Lipids on Phospholipase D Activity in Rat Brain

Phospholipase D (PLD) is emerging as a major player in many novel signaling pathways. Based on recent studies correlating membrane composition with enzyme function, we speculated that feeding of dietary lipids to the newborns has a major impact on brain PLD activity. To test this hypothesis, the rat dams were fed fat-free powder containing either safflower oil or fish oil, and a control powdered chow. The pups were weaned onto the diet and sacrificed at 30 days of age. PLD activity was measured by transphosphatidylation assays using rat brain membranes. This study shows that microsome GTPS-dependent PLD activity in rats fed safflower oil or fish oil was significantly reduced by 38% and 30% respectively compared to controls. Oleate-dependent PLD activity in the safflower oil group, however, was significantly increased by 38%. In contrast, synaptosome membrane (P2) GTPS-dependent PLD activity in rats consuming safflower oil was significantly increased by 29%, but there was no difference in oleate-dependent PLD activity. Likewise, no difference was observed in microsome oleate-dependent PLD and P2 GTPS-dependent PLD activity between the fish oil and the control groups. These results indicate that dietary lipid intake appears to modulate phospholipid metabolism and differential expression of PLD isozymes in the brain.