Stability or variation? Patterns of lactase gene and its enhancer region distributions in Brazilian Amerindians

Lactase persistence (LP) is the phenotypic trait in which lactase secretion is maintained during adulthood. LP is due to mutations in the LCT enhancer region, located 14‐kb upstream of the gene. In Europeans, the ?13910*T allele is associated with LP. In Africans this allele is rare while other mutations in this same region were related to LP. The LCT is highly polymorphic in human populations, but so far Brazilian Amerindians had not been investigated for these polymorphisms or for the presence of LP mutations. We describe the genetic diversity of the LCT region and the presence of LP enhancer mutations in four native Brazilian populations (Guarani‐Kaiowá, Guarani–Ñandeva, Kaingang, and Xavante). Twelve polymorphisms were genotyped by PCR‐based methods. The ?13910*T allele varied from 0.5% in the Xavante to 7.6% in the Guarani–Ñandeva. These frequencies probably derive from European sources and they correlate with non‐native admixture proportions previously estimated for these groups. But since admixture is virtually absent in the Xavante, we suggest that the presence of the LP allele could have been determined by a de novo mutation. No other mutations in the ?14 kb enhancer region were found. The LCT was highly polymorphic in the present sample showing 15 haplotypes with a heterogeneous distribution among the four Amerindian populations. This diversity could be due to drift, as indicated by the neutrality test performed. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.     

The Influence of Nutrigenetics on the Lipid Profile: Interaction Between Genes and Dietary Habits

Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.     

Restriction site polymorphism in the phosphoglycerate kinase gene on the X chromosome

Summary Using a human phosphoglycerate kinase (PGK) cDNA probe, we have identified a common Pst I restriction site polymorphism on the human X chromosome in all ethnic groups studied. the polymorphic Pst I site was absent in 40.4% of 94 X chromosomes of unrelated subjects. Heterozygous females can only be detected by the combined use of a Pst I digest and a Xba I+Pst I digest due to the presence of autosomal and X-linked bands of the same size in simple Pst I digests. Since 48% of females are heterozygotes for the Pst I polymorphism, this site can serve as a useful genetic marker on the long arm of X chromosome in man.     

Seasonal effects on ovarian folliculogenesis in rhesus monkeys

Reproductive performance is reportedly reduced in some rhesus monkeys during the summer months, even when environmental conditions are controlled. The mechanism(s) underlying this phenomenon remain unknown. We noted that the pattern of folliculogenesis appeared to be altered in rhesus monkeys that continued to exhibit ovulatory menstrual cycles during the "nonbreeding" season. This study was designed to investigate the effect of season on development of the dominant follicle (DF) and upon levels of serum gonadotropins and sex steroids in animals maintained in a controlled environment. Forty-four menstrual cycles were evaluated from October, 1982 to October, 1983. Animals were housed individually in controlled light (12L:12D) and temperature (22-25 degrees C). A DF was identified by laparoscopy on Day 6 of the cycle in only 45% of cycles during the months of May through September, compared with 87.5% the remainder of the year. No effect of season was detected on either the length of the menstrual cycle or luteal phase, mean follicular diameter, or the percentage of ovulatory cycles. During the follicular phase, amounts of follicle-stimulating hormone (FSH) in peripheral sera were depressed, whereas those of luteinizing hormone (LH) were consistently elevated. Amounts of circulating estradiol were similar between groups. However, serum concentrations of progesterone were markedly reduced in the summer. Development of the DF appeared to be delayed in the early follicular phase during the summer months in those rhesus monkeys that had ovulatory menstrual cycles. This delay was accompanied by an alteration in the FSH to LH ratio. Although most cycles were ovulatory, altered follicular development resulted in deficient luteal function.     

Markers of atresia in ovarian follicular components from rhesus monkeys treated with estradiol-17 beta

A new model for the investigation of atresia in rhesus monkeys is presented. This model is based upon the reliable induction of an atresia-like process in the dominant preovulatory follicle (DF) by estradiol-17 beta administered subcutaneously via Silastic capsules for 24 h. Data obtained from follicular contents aspirated from treated animals demonstrated alterations in the putative markers of atresia similar to those described in other models of atresia. Although follicle size and appearance and volume of follicular fluid (FF) were unaltered in treated animals, FF was much more viscous than that aspirated from follicles in untreated animals; this was apparently due to a greater quantity of intercellular matrix that was sensitive to digestion by hyaluronidase. In treated animals, FF concentrations of estrogen (E) and progesterone (P) were depressed 3- and 6.6-fold, respectively. Viability of granulosa cells (GC) from these animals was reduced by 40%, as was their ability to release basal amounts of E and P in vitro. Accumulation of P by GC from treated animals approximated unstimulated control levels when human follicle-stimulating hormone (hFSH) was included in the culture. Therefore, FSH may have a limited capability to "rescue" GC from atresia induced by estradiol. The percentage of cells that bound 125I-hFSH maximally, as measured by autoradiography following 72 h in culture, was not altered by treatment. Oocytes from animals treated with estradiol showed signs of degeneration at aspiration, and deteriorated further in culture. This model is unique in that atresia can be induced in the single DF of a primate species, and thus avoids the disadvantages inherent to studying atresia of heterogeneous follicles in polytocous species.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aspergillus terreus and its toxic metabolites as a food contaminant in some Egyptian Bakery products and grains

A. terreus isolates isolated from some bakery products, corn and rice were found to be able to produce territrems. 90% of theA. terreus isolated from bakery products were able to produce territrem A, with a mean of 0.09 ppm, while 80% ofA. terreus isolates produce territrem B with a mean of 0.24 ppm. On the other hand 31.8% of the isolates ofA. terreus from corn were able to produce territrem A with a mean of 0.44 ppm. ConcerningA. terreus isolates from rice, 66.7% were found to produce territrem A, with a mean of 5.28 ppm, and 77.8% of the isolates produced territrem B with a mean of 1.79 ppm.     

PSP94融合蛋白在大肠杆菌中的表达及其抗前列腺癌活性分析

在从成年人正常前列腺组织中获得人９４个氨基酸的前列腺分泌蛋白（ＰＳＰ９４）ｃＤＮＡ基础上,利用ＰＬ表达系统,实现了人ＰＳＰ９４成熟肽Ｎ 末端带有１９个外源氨基酸的融合蛋白在大肠杆菌中的表达。目的蛋白在细胞中主要以包涵体形式存在,表达量约占菌体总蛋白的３０％,分子量约为１６－５ｋＤ。表达产物在人前列腺癌细胞ＰＣ ３上活性分析表明,该融合蛋白能明显抑制前列腺癌细胞的生长。