Smoking and lipid cardiovascular risk factors in Vietnamese refugees in Australia

BACKGROUND: The effects of smoking and sex on lipid risk factors for cardiovascular disease were examined among Vietnamese people newly arrived in Australia. METHODS: Immigrants recruited through Refugee Screening had anthropometric data recorded and blood collected to measure total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) by Reflotron; apolipoprotein A-1 (apo A-1) and apolipoprotein B-100 (apo B) by immunoturbidimetric analyses (Turbitimer); and lipoprotein (a) (LP (a)) by ELISA. A questionnaire determined behavioral variables known to influence cardiovascular risk and Statview, Minitab, and SPSS were employed for data analysis. RESULTS: Lipoprotein profiles of men (n = 242) and women (n = 159) were compared. Crude TC and apo B were similar; HDL, apo A-1, and LP (a) were higher in women, TG was higher in men. After adjustment (age, BMI, WHR, years of smoking, and drinks per week), only apo A-1 and LP (a), were higher in women. "At risk" levels of TC or apo B did not differ by gender; risk of low apo A-1 was higher among men. Smokers had a significant risk (crude and adjusted) of low HDL, low apo A-1, and high LP (a). The sex difference in HDL was removed by a single adjustment for smoking; male smokers had higher LP (a) than male nonsmokers. CONCLUSION: Male and female Vietnamese immigrants had similar adjusted lipid profiles. Smoking had a marked detrimental effect on lipids.     

Selenium-Enriched Foods Are More Effective at Increasing Glutathione Peroxidase (GPx) Activity Compared with Selenomethionine: A Meta-Analysis

Selenium may play a beneficial role in multi-factorial illnesses with genetic and environmental linkages via epigenetic regulation in part via glutathione peroxidase (GPx) activity. A meta-analysis was undertaken to quantify the effects of dietary selenium supplementation on the activity of overall GPx activity in different tissues and animal species and to compare the effectiveness of different forms of dietary selenium. GPx activity response was affected by both the dose and form of selenium (p < 0.001). There were differences between tissues on the effects of selenium supplementation on GPx activity (p < 0.001); however, there was no evidence in the data of differences between animal species (p = 0.95). The interactions between dose and tissue, animal species and form were significant (p < 0.001). Tissues particularly sensitive to changes in selenium supply include red blood cells, kidney and muscle. The meta-analysis identified that for animal species selenium-enriched foods were more effective than selenomethionine at increasing GPx activity.     

Atoh1 null mice show directed afferent fiber growth to undifferentiated ear sensory epithelia followed by incomplete fiber retention.

Inner ear hair cells have been suggested as attractors for growing afferent fibers, possibly through the release of the neurotrophin brain-derived neurotrophic factor (BDNF). Atoh1 null mice never fully differentiate hair cells and supporting cells and, therefore, may show aberrations in the growth and/or retention of their innervation. We investigated the distribution of cells positive for Atoh1- or Bdnf-mediated beta-galactosidase expression in Atoh1 null and Atoh1 heterozygotic mice and correlated the distribution of these cells with their innervation. Embryonic day (E) 18.5 Atoh1 null and heterozygotic littermates show Atoh1- and BDNF-beta-galactosidase-positive cells in comparable distributions in the canal cristae and the cochlea apex. Atoh1-beta-galactosidase-positive but only occasional Bdnf-beta-galactosidase-positive cells are found in the utricle, saccule, and cochlea base of Atoh1 null mutant mice. Absence of Bdnf-beta-galactosidase expression in the utricle and saccule of Atoh1 null mice is first noted at E12.5, a time when Atoh1-beta-galactosidase expression is also first detected in these epithelia. These data suggest that expression of Bdnf is dependent on ATOH1 protein in some but does not require ATOH1 protein in other inner ear cells. Overall, the undifferentiated Atoh1- and Bdnf-beta-galactosidase-positive cells show a distribution reminiscent of that in the six sensory epithelia in control mice, suggesting that ear patterning processes can form discrete patches of Atoh1 and Bdnf expression in the absence of ATOH1 protein. The almost normal growth of afferent and efferent fibers in younger embryos suggests that neither fully differentiated hair cells nor BDNF are necessary for the initial targeted growth of fibers. E18.5 Atoh1 null mice have many afferent fibers to the apex of the cochlea, the anterior and the posterior crista, all areas with numerous Bdnf-beta-galactosidase-positive cells. Few fibers remain to the saccule, utricle, and the base of the cochlea, all areas with few or no Bdnf-beta-galactosidase-positive cells. Thus, retention of fibers is possible with BDNF, even in the absence of differentiated hair cells.     

Low Folate and Selenium in the Mouse Maternal Diet Alters Liver Gene Expression Patterns in the Offspring after Weaning

During pregnancy, selenium (Se) and folate requirements increase, with deficiencies linked to neural tube defects (folate) and DNA oxidation (Se). This study investigated the effect of a high-fat diet either supplemented with (diet H), or marginally deficient in (diet L), Se and folate. Pregnant female mice and their male offspring were assigned to one of four treatments: diet H during gestation, lactation and post-weaning; diet L during gestation, lactation and post-weaning; diet H during gestation and lactation but diet L fed to offspring post-weaning; or diet L during gestation and lactation followed by diet H fed to offspring post-weaning. Microarray and pathway analyses were performed using RNA from colon and liver of 12-week-old male offspring. Gene set enrichment analysis of liver gene expression showed that diet L affected several pathways including regulation of translation (protein biosynthesis), methyl group metabolism, and fatty acid metabolism; this effect was stronger when the diet was fed to mothers, rather than to offspring. No significant differences in individual gene expression were observed in colon but there were significant differences in cell cycle control pathways. In conclusion, a maternal low Se/folate diet during gestation and lactation has more effects on gene expression in offspring than the same diet fed to offspring post-weaning; low Se and folate in utero and during lactation thus has persistent metabolic effects in the offspring.     

An HIV RNase H inhibitory 1,3,4,5-tetragalloylapiitol from the African plant Hylodendron gabunensis

A new compound, 1,3,4,5-tetragalloylapiitol ( 1), was isolated from the aqueous extract of the plant Hylodendron gabunensis and was found to be a potent inhibitor of RNase H enzymatic activity. The structure of 1 was elucidated by NMR analyses to be an apiitol ( 2) sugar moiety substituted with four gallic acid residues. Optical rotation measurements of the free sugar following basic hydrolysis indicated that the 3 S absolute configuration was the same as that of d-apiitol. Compound 1 inhibited HIV-1, HIV-2, and human RNase H with IC 50 values of 0.24, 0.13, and 1.5 microM, respectively, but it did not show inhibition of E. coli RNase H at 10 microM.     

Improved in situ detection method for telomeric tandem repeats in metaphase spreads and interphase nuclei.

Peptide nucleic acid technology (PNA) has become an extremely useful tool and promises to impact on molecular biology and diagnostics. These synthetic DNA analogues pair with DNA and RNA molecules according to Watson and Crick base pairing rules. This paper describes a sensitive and quick fluorescent in situ hybridisation (ISH) technique to determine DNA telomere repeat sequences (TTA GGG)n using epifluorescence microscopy. Telomeres are special, repeated structures at the end of each eukaryotic chromosome and serve as protective caps to prevent DNA rearrangements and fusion of chromosomes. A model system has been developed, using stimulated peripheral blood lymphocytes, which facilitates simultaneous detection of telomeres in metaphase as well as in interphase nuclei. A fluorescein isothiocyanate labelled PNA probe (18 mer) directed against complementary telomeric sequences at the end of each chromosome is used. In addition, a simple, easy to perform PNA-ISH protocol is described that overcomes common hybridisation problems encountered using DNA and RNA oligoprobes. Furthermore, the usefulness of a chromogenic immunocytochemical detection system is shown for PNA-ISH.     

A simple microplate algal assay technique for aquatic toxicity assessment

A simple, miniaturized algal assay procedure using microplates has been developed to assess aquatic toxicity with the green alga, Selenastrum capricornutum. Cell count-generated EC₅₀ data comparisons with the classic assay using flasks have indicated good agreement between the two methods following toxic assessment of various wastewater samples and metal solutions. Parametric comparisons (ATP us cell counts) with the microplate method show equally good correlation. The technique is highly versatile in conducting basic algal bioassays for varying times (4-hour, 4-day, 8-day EC₅₀'s) and with differing parameters, depending on set objectives. Other interesting features of the microplate technique include handling rapidity, economy, space-saving convenience, and automation potential.