The T29C polymorphism of the transforming growth factor-β1 (TGF-β1) gene is associated with genetic susceptibility to acute coronary syndrome in Mexican patients

Inflammation plays an essential role in the development and progression of atherosclerotic lesions, and plaque disruption. The TGF-β1 plays an important role in the anti-inflammatory process. The aim of the present study was to evaluate the role of TGF-β1 gene polymorphisms as susceptibility markers for acute coronary syndrome (ACS). Two polymorphisms (TGF-β -509T>C and TGF-β T29C) of the TGF-β gene were analyzed by 5' exonuclease TaqMan genotyping assays in a group of 426 patients with coronary acute syndrome and 551 healthy unrelated controls. A significant difference was observed in the distribution of TGF-β T29C polymorphism between ACS patients and healthy controls (P<10(-3)). According to the co-dominant model, individuals with the TGF-β 29 TT genotype have a 2.5-fold increased risk of developing ACS (P<10(-3)). Multiple logistic analysis showed that the largest risk factor for developing ACS was given by smoking habit, diabetes, hypertension, dyslipidemia, and the TGF-β1 29 TT genotype. The analysis of linkage disequilibrium showed one haplotype (TT) with increased frequency and one haplotype (CC) with decreased frequency in ACS patients when compared to healthy controls. The results suggest that TGF-β1 T29C gene polymorphism could be involved in the risk of developing ACS in Mexican individuals.     

New molecular quantitative PCR assay for detection of host-specific Bifidobacteriaceae suitable for microbial source tracking

Bifidobacterium spp. belong to the commensal intestinal microbiota of warm-blooded animals. Some strains of Bifidobacterium show host specificity and have thus been proposed as host-specific targets to determine the origin of fecal pollution. Most strains have been used in microbial-source-tracking (MST) studies based on culture-dependent methods. Although some of these approaches have proved very useful, the low prevalence of culturable Bifidobacterium strains in the environment means that molecular culture-independent procedures could provide practical applications for MST. Reported here is a set of common primers and four Bifidobacterium sp. host-associated (human, cattle, pig, and poultry) probes for quantitative-PCR (qPCR) assessment of fecal source tracking. This set was tested using 25 water samples of diverse origin: urban sewage samples, wastewater from four abattoirs (porcine, bovine, and poultry), and water from a river with a low pollution load. The selected sequences showed a high degree of host specificity. There were no cross-reactions between the qPCR assays specific for each origin and samples from different fecal origins. On the basis of the findings, it was concluded that the host-specific qPCRs are sufficiently robust to be applied in environmental MST studies.     

Mineral Concentrations in Hair of Belgian Elementary School Girls: Reference Values and Relationship with Food Consumption Frequencies

Although evidence suggests that hair elements may reflect dietary habits and/or mineral intake, this topic remains controversial. This study therefore presents age-specific reference values for hair concentrations of Ca, Cu, Fe, Na, Mg, P and Zn using the LMS method of Cole, and investigates the relationship between dietary habits (i.e. food consumption frequencies) and hair mineral concentrations in 218 Belgian elementary school girls by reduced rank regression (RRR). Hair minerals were quantitatively determined via inductively coupled plasma?Cmass spectrometry after microwave-assisted acid digestion of 6-cm long vertex posterior hair samples. The Children??s Eating Habits Questionnaire??Food Frequency Questionnaire was used to obtain information on food consumption frequency of 43 food items in the month preceding hair collection. The established reference ranges were in line with data for other childhood or adolescent populations. The retained RRR factors explained 40, 50, 45, 46, 44 and 48?% of the variation of Ca, Cu, Fe, Mg, P and Zn concentrations in hair, respectively. Although this study demonstrated that a large proportion of hair mineral variation may be influenced by food consumption frequencies in elementary school girls, a number of food groups known to be rich sources of minerals did not show a relation with certain hair minerals. Future research should focus on mechanisms and processes involved in mineral incorporation and accumulation in scalp hair, in order to fully understand the importance and influence of diet on hair minerals.     

Post-translational redox modification of ADP-glucose pyrophosphorylase in response to light is not a major determinant of fine regulation of transitory starch accumulation in Arabidopsis leaves

ADP-glucose pyrophosphorylase (AGP) is a heterotetrameric enzyme comprising two small and two large subunits that catalyze the production of ADP-glucose linked to starch biosynthesis. The current paradigm on leaf starch metabolism assumes that post-translational redox modification of AGP in response to light is a major determinant of fine regulation of transitory starch accumulation. According to this view, under oxidizing conditions occurring during the night the two AGP small subunits (APS1) are covalently linked via an intermolecular disulfide bridge that inactivates the protein, whereas under reducing conditions occurring during the day NADP-thioredoxin reductase C (NTRC)-dependent reductive monomerization of APS1 activates the enzyme. In this work we have analyzed changes in the redox status of APS1 during dark-light transition in leaves of plants cultured under different light intensities. Furthermore, we have carried out time-course analyses of starch content in ntrc mutants, and in aps1 mutants expressing the Escherichia coli redox-insensitive AGP (GlgC) in the chloroplast. We also characterized aps1 plants expressing a redox-insensitive, mutated APS1 (APS1mut) form in which the highly conserved Cys81 residue involved in the formation of the intermolecular disulfide bridge has been replaced by serine. We found that a very moderate, NTRC-dependent APS1 monomerization process in response to light occurred only when plants were cultured under photo-oxidative conditions. We also found that starch accumulation rates during the light in leaves of both ntrc mutants and GlgC-expressing aps1 mutants were similar to those of wild-type leaves. Furthermore, the pattern of starch accumulation during illumination in leaves of APS1mut-expressing aps1 mutants was similar to that of APS1-expressing aps1 mutants at any light intensity. The overall data demonstrate that post-translational redox modification of AGP in response to light is not a major determinant of fine regulation of transitory starch accumulation in Arabidopsis.     

Origin of mound-field landscapes: a multi-proxy approach combining contemporary vegetation, carbon stable isotopes and phytoliths

Background and aims

Seasonally flooded South American savannas harbor different kinds of mound-field landscapes of largely unknown origin. A recent study used soil carbon-isotope depth profiles and other proxies to infer vegetation history in murundu landscapes in Brazil. Results suggested that differential erosion, not building-up processes (e.g., termite mounds), produced mounds. We tested this approach to inferring mound origin in a mound-field landscape in French Guiana.

Methods

We examined carbon-isotope depth profiles of soil organic matter, phytolith profiles and contemporary vegetation composition in mounds and inter-mounds.

Results

Relative abundance of C3 and C4 plants across habitats was very different from that in murundu landscapes; C3 plants were better represented in inter-mounds than on mounds. Habitat differences in C3/C4 distribution were subtler than in murundu landscapes, limiting inference of vegetation history based on carbon isotopes. Still, carbon-isotope and phytolith depth profiles gave similar pictures of vegetation history, both favoring a building-up hypothesis, corroborating other evidence that these mounds are vestiges of ancient agricultural raised fields.

Conclusions

Carbon-isotope depth profiles are unlikely to be adequate for deciphering origin of mound-field landscapes from vegetation history in seasonally flooded savannas. Including data on current vegetation and phytoliths makes inferences more robust.