Lower Neighborhood Socioeconomic Status Associated with Reduced Diversity of the Colonic Microbiota in Healthy Adults

In the United States, there are persistent and widening socioeconomic gaps in morbidity and mortality from chronic diseases. Although most disparities research focuses on person-level socioeconomic-status, mounting evidence suggest that chronic diseases also pattern by the demographic characteristics of neighborhoods. Yet the biological mechanisms underlying these associations are poorly understood. There is increasing recognition that chronic diseases share common pathogenic features, some of which involve alterations in the composition, diversity, and functioning of the gut microbiota. This study examined whether socioeconomic-status was associated with alpha-diversity of the colonic microbiota. Forty-four healthy adults underwent un-prepped sigmoidoscopy, during which mucosal biopsies and fecal samples were collected. Subjects’ zip codes were geocoded, and census data was used to form a composite indicator of neighborhood socioeconomic-status, reflecting household income, educational attainment, employment status, and home value. In unadjusted analyses, neighborhood socioeconomic-status explained 12–18 percent of the variability in alpha-diversity of colonic microbiota. The direction of these associations was positive, meaning that as neighborhood socioeconomic-status increased, so did alpha-diversity of both the colonic sigmoid mucosa and fecal microbiota. The strength of these associations persisted when models were expanded to include covariates reflecting potential demographic (age, gender, race/ethnicity) and lifestyle (adiposity, alcohol use, smoking) confounds. In these models neighborhood socioeconomic-status continued to explain 11–22 percent of the variability in diversity indicators. Further analyses suggested these patterns reflected socioeconomic variations in evenness, but not richness, of microbial communities residing in the sigmoid. We also found indications that residence in neighborhoods of higher socioeconomic-status was associated with a greater abundance of Bacteroides and a lower abundance of Prevotella, suggesting that diet potentially underlies differences in microbiota composition. These findings suggest the presence of socioeconomic variations in colonic microbiota diversity. Future research should explore whether these variations contribute to disparities in chronic disease outcomes.     

Neutron fibre diffraction study of DNA hydration

Interactions with water are crucial to the conformation assumed by the DNA double helix. The location of water around the D conformation has been investigated in a neutron fibre diffraction study which shows that water is ordered in the minor groove of the DNA. The D conformation is important since its occurrence is limited to specific DNA base pair sequences which have been identified as functionally significant. This study is of particular interest because the D conformation has not been reported in single crystal studies of oligonucleotides.     

A direct fuel cell for the production of electricity from lignin

This report describes the use of an anthraquinone mediated fuel cell for the direct production of electrical energy from sulfonated lignin and Kraft Black Liquor. The cell produces the equivalent of 1 kWh for each 2-3 lb sulfonated lignin and 5-8 lb black liquor combustibles. In the case of the sulfonated lignin, chain session occurs during the oxidation process, reducing the molecular weight from ca. 2 x 10(4) to less than 1000 D.     

Metabolism of kinetin by soybean callus

Soybean callus metabolised applied 6-furfurylamino (8^-14C) purine very rapidly to polar compounds, some of which were retained on a Dowex 50 cation exchange resin, and were unaffected by alkaline phosphatase; while others were apparently phosphorylated and were detected in the aqueous fraction. Adenine was detected as an intermediate and it can be concluded that it was formed as a result of the rapid and efficient removal of the furfuryl side chain. The formed adenine was rapidly incorporated into the polar metabolites. Exactly how the presence of this cytokinin stimulates cell division is not apparent from the results.The financial support of the C.S.I.R., Pretoria, and The Natal University Development Fund is gratefully acknowledged.     

The limnology of a thermal lake: Lake Rotowhero,New Zealand: II. General biology with emphasis on the benthic fauna of Chironomids

Nitella hookeri A. BR., a native charophyte of the Rotorua lakes in the North Island of New Zealand, was investigated in terms of its nutrient requirements under laboratory culture in non-arenic conditions. Optimum growth in phosphate, nitrate, ammonia, iron and magnesium occurred at 20 mg l⁻¹ or lower. Higher concentrations of these ions were markedly inhibitory to growth when compared with the optimum. Calcium and potassium gave growth at higher levels and over a wider range of concentrations. Sulphate and sulphur-amino acids do not promote growth above the levels of the basal medium (1.2 mg l⁻¹ sulphur as SO²⁻ ₄). Amino acids did not appear to provide a nitrogen source for the plant. The optimum phosphate concentration was one thousand times higher than previously reported values. This may be due to the presence of arsenic in the vegetative propagules used from Lake Rotoiti. Iron toxicity effects may have resulted from the presence of EDTA. The results are considered in relation to the known levels of nutrients present in lake waters. Only phosphorus appears directly correlated with the natural distribution of the plant but it is suggested that anaerobic lake substrates may contribute iron and ammonia to the plants and further explain their distribution.     

Cloning and expression of ovine placental lactogen

Ovine placental lactogen (oPL) is active in a wide range of GH and PRL assays, a property that it shares with human GH (hGH). In addition, oPL is one of a small number of hormones that bind the human GH receptor with high affinity. In order to compare the sequence of oPL to the sequences of other members of the GH family, full-length cDNA clones have been isolated. These clones predict that the full sequence of oPL contains 198 amino acids preceded by a 38 amino acid signal sequence. The mature oPL sequence includes six cysteine and two tryptophan residues and shows substantially more identity to bovine PL (67%) and oPL (49%) than to mouse (31%) or human (25%) PL or to oGH (28%) or (26%) hGH. Like the natural hormone, oPL expressed in mammalian tissue cells binds with high affinity to a soluble form of the recombinant hGH receptor. Thus, oPL binds to the human receptor in spite of having a sequence that is considerably divergent from hGH. Interestingly, the sequence of oPL differs from hGH at most of the amino acids recently found by mutagenesis studies to be important residues in the binding of hGH to the human receptor.     

Retardation of pubertal development by prenatal long days in goat kids born in autumn.

Goat kids born in spring attain sexual maturity during the first autumn after birth in temperate regions, at about 30 weeks of age. This study observed sexual development in autumn-born kids and the influence of late-summer, prenatal light treatment on onset of puberty. The breeding season of 14 female British Saanen dairy goats was artificially advanced by 4 months, using a treatment of long days during the winter followed by melatonin treatment in spring. Five goats were treated with a photoperiod of 20 h light:4 h dark (lights on 04.00 h) for 62.1 +/- 1.4 days (mean +/- SEM, n = 5) prepartum (14 August to 15 October). The remaining nine goats were kept under a natural photoperiod: 20 kids from these mothers were followed, five males and five females from each group. Testicular development was assessed by means of weekly measurement of scrotal circumference. Blood samples were taken once a week from all kids from 4 weeks of age for 5 months. Plasma was assayed for progesterone in females and testosterone in males. Autumn-born female kids initiated oestrous cyclicity in January, at a mean age of 12.8 +/- 0.8 weeks. Puberty onset was significantly delayed (P less than 0.03, unpaired Student's t test) in females exposed to 20 h light:4 h dark in utero and occurred at a mean age of 16.5 +/- 1.4 weeks. Testicular development was significantly delayed and plasma testosterone concentrations were lower in autumn-born male kids that experienced 20 h light:4 h dark in utero than in kids from mothers in a natural photoperiod.(ABSTRACT TRUNCATED AT 250 WORDS)