Subclinical target organ damage in normotensive and prehypertensive patients.

BACKGROUND: Prehypertension is a risk factor for the development of hypertension and other cardiovascular diseases. The objective of this study was to evaluate for the evidence of subclinical target organ damage in two groups of subjects without hypertension. METHODS: This was a prospective cross-sectional study. Subjects seeking care for various clinical conditions in the hospital were invited for the survey. The subjects' were divided in to two groups according to their blood pressure: prehypertension (systolic blood pressure 120 to 139 mm Hg or diastolic blood pressure, 80 to 89 mm Hg) and normotension (systolic blood pressure, <120 mm Hg and diastolic blood pressure, <80 mm Hg). Urine albumin excretion and other biochemical analyses were performed using standard methods. RESULTS: We recruited a total of 3300 subjects, the prehypertension group included 1100 individuals and the normotension group was composed of 2200 persons. The prevalence of microalbuminuria in subjects in the prehypertension group was 6.8% and in those who are the in the optimal BP group was 3.6% (P<0.001). Subjects in the prehypertension group had a mean B-type natriuretic peptide (BNP) level of 98 (72) pg/mL compared with 43.6 (20) pg/mL found among subjects in the normotension group (<0.001). In the logistic regression model, tobacco smoking aOR 2.7 (95% CI.; 1.7-5.8), higher uric acid level aOR 2.2 (1.7-3.2), microalbuminuria 7.6 (4.9-14.7) and a higher BNP level aOR 2.5 (1.8-7.6) were significantly associated with the occurrence of prehypertension. CONCLUSIONS: Microalbuminuria, BNP level and hyperuricemia were significantly associated with prehypertension.

Sampling and Complementarity Effects of Plant Diversity on Resource Use Increases the Invasion Resistance of Communities.

BACKGROUND: Although plant diversity is postulated to resist invasion, studies have not provided consistent results, most of which were ascribed to the influences of other covariate environmental factors. METHODOLOGY/PRINCIPAL FINDINGS: To explore the mechanisms by which plant diversity influences community invasibility, an experiment was conducted involving grassland sites varying in their species richness (one, two, four, eight, and sixteen species). Light interception efficiency and soil resources (total N, total P, and water content) were measured. The number of species, biomass, and the number of seedlings of the invading species decreased significantly with species richness. The presence of Patrinia scabiosaefolia Fisch. ex Trev. and Mosla dianthera (Buch.-Ham. ex Roxburgh) Maxim. significantly increased the resistance of the communities to invasion. A structural equation model showed that the richness of planted species had no direct and significant effect on invasion. Light interception efficiency had a negative effect on the invasion whereas soil water content had a positive effect. In monocultures, Antenoron filiforme (Thunb.) Rob. et Vaut. showed the highest light interception efficiency and P. scabiosaefolia recorded the lowest soil water content. With increased planted-species richness, a greater percentage of pots showed light use efficiency higher than that of A. filiforme and a lower soil water content than that in P. scabiosaefolia. CONCLUSIONS/SIGNIFICANCE: The results of this study suggest that plant diversity confers resistance to invasion, which is mainly ascribed to the sampling effect of particular species and the complementarity effect among species on resources use.

Linkage analysis of twelve candidate gene loci regulating water and sodium metabolism and membrane ion transport in essential hypertension.

To investigate the relationship between 12 candidate genes responsible for water regulation, sodium metabolism and membrane ion transport and essential hypertension (EH) in the Chinese. Linkage analysis of EH was performed in 95 Chinese nuclear families including 477 subjects using a technique of fluorescence-based gene scanning with 12 microsatellite markers. Markers were selected on the chromosomal regions covering 12 candidate genes responsible for regulating water and sodium metabolism and membrane ion transport. These candidate genes included sodium hydrogen exchanger 3, sodium hydrogen exchanger 5, chloride bicarbonate exchanger 3, sodium calcium exchanger 1, mineralocorticoid receptor, plasma membrane calcium ATPase 2, ATPase,Na/K transporting alpha, a-adducin, SA gene, kidney epithelial sodium channel-gamma, vasopressin receptor 1A, and 11beta-hydroxysteroid dehydrogenase type 2 genes. Two-point non-parametric linkage analysis (NPL), maximum LOD score analysis and transmission/disequilibrium test (TDT) were performed using the GENEHUNTER software package. The NPL analysis and LOD score suggested a significant linkage at D12S398 (Z = 2.08, p<0.05 and LOD score = 1.26, p<0.01, respectively). TDT indicated a significant disequilibrium of transmission at the locus chi2 = 9.00, p < 0.005). No significant linkages were found at the other loci tested (p > 0.05 or LOD < -1). In conclusion, D12S398, a marker near the vasopressin receptor 1A gene (V1AR), showed a positive linkage with EH based on the results of three statistical methods (NPL, LOD score, and TDT). This region warrants further exploration.