Population structure analysis and association mapping of blast resistance in indica rice (Oryza sativa L.) landraces.

Rice blast caused by Magnaporthe oryzae is one of the most devastating rice diseases worldwide. To understand the genetic diversity of indica landrace accessions and identify simple sequence repeat (SSR) markers that are associated with blast resistance, a population of 276 indica landraces from across the world was constructed. This population was then used to evaluate the blast-resistance phenotype through artificial inoculation under controlled conditions in 2012 and 2013. The genetic diversity and association of the population with resistance were analyzed by examining the phenotype for 160 SSR markers distributed on 12 rice chromosomes. The 276 accessions were classified into seven groups using model- and distance-based cluster analyses. Associations between SSR markers and blast resistance showed that 26 SSR markers were significantly associated with blast resistance in 2012 and 2013 (P < 0.01) and that the phenotypic variation ranged from 2.68 to 13.11%. Nineteen of the markers associated with blast resistance were located in regions where genes or quantitative trait loci (QTLs) have been previously reported, and seven were newly identified in this study. These results indicate that marker-trait association has potential advantages over classical linkage analysis and QTL mapping, and that these markers could be used for marker-assisted selection in rice blast-resistance-breeding programs.

Gamma-glutamyltransferase levels and risk of metabolic syndrome: a meta-analysis of prospective cohort studies.

AIMS: Several epidemiological studies suggested that gamma-glutamyltransferase (GGT) levels may be associated with risk of Metabolic Syndrome (MetS). However, the exact association between them is still not fully clear. We therefore conducted a meta-analysis of prospective cohort studies to comprehensively evaluate the exact association between GGT and risk of MetS. METHODS: The Pubmed, Embase, Science Citation Index (ISI Web of Science) databases were searched to collect all prospective cohort studies on the association between GGT and MetS. Then, the association between GGT and MetS was analysed in qualitative and quantitative manners. RESULTS: Nine prospective cohort studies involving 47,499 participants and 5009 cases of MetS were included. When comparing the risk of MetS between the highest versus the lowest category of GGT levels, the pooled RR of MetS was 1.63 (95% CI: 1.43-1.82; p < 0.000). The second dose-response analysis of GGT levels per 5 U/l increment with risk of MetS showed that the summary RR of MetS was 1.09 (95% CI: 1.06-1.13; p < 0.000). Subgroup analysis suggested that number of adjusted confounding factors may be a potential source of heterogeneity. Sensitivity analyses showed that no single study significantly influenced the pooled RRs. CONCLUSIONS: Our results show that GGT levels are positively associated with risk of MetS independently of alcohol intake. GGT may be a promising marker for predicting MetS. Further studies are needed to confirm our findings and elucidate the underlying mechanisms in future.

A high-resolution radiation hybrid map of the human genome draft sequence.

We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases.

[Study on HIV-1 subtype among elderly male clients and female sex workers of low-cost venues in Guangxi Zhuang Autonomous Region, China].

Objective: To understand HIV-1 subtype characteristics and transmission clusters in elderly male clients and female sex workers (FSWs) of low-cost commercial sex venues in Guangxi Zhuang Autonomous Region, China. Methods: A cross sectional survey was conducted in FSWs and elderly male clients (≥50 years) of low-cost commercial sex venues in 4 cities and 9 counties in Guangxi Zhuang Autonomous Region by convenient sampling in 2012. The blood sample was collected from each case for HIV-1 antibody detection. The pol gene fragments were amplified and sequenced from viral RNA template extracted from plasma samples. The phylogenetic tree was constructed and the subtypes were identified. Results: A total of 4 048 elderly male clients and 784 FSWs were surveyed, and 116 HIV-1 infections were detected, the positive rate was 2.5% (103/4 048) in the clients and 1.7% (13/784) in FSWs. The gene amplification and sequencing of HIV-1 detected in 84 blood samples indicated that 53 pol gene sequences were successfully determined (48 blood samples from elderly male clients and 5 blood samples from FSWs). Among 53 pol sequences, 48(90.6% ), 4(7.5% ), and 1(1.9% ) sequences were identified as CRF01_AE, CRF08_BC, and CRF07_BC, respectively. Two transmission clusters were identified among CRF01_AE, including 4 sub-clusters. One transmission cluster was identified among CRF08_BC. The transmission cluster or sub-cluster were from the infected individuals at same low-cost commercial sex venue, or different low-cost commercial sex venues in the same town, or same place, or adjacent villages and towns. Conclusions: CRF01_AE was the predominant HIV-1 subtype among elderly male clients and FSWs of low-cost commercial sex venues in Guangxi Zhuang Autonomous Region, circulating in same venue or adjacent villages and towns. The HIV-1 positive male clients and FSWs might play an important role in the spread of the strains.

Development of the Chinese nutrition screen (CNS) for use in institutional settings.

OBJECTIVES: To develop and validate a nutritional screening tool (CNS) for elderly Chinese subjects in the institutional setting. DESIGN: Using the MNA as a guide, a questionnaire was developed appropriate for the Chinese health care system, diet, food customs and culture, using physician assessment for comparison. PARTICIPANTS: 200 men and 200 women aged 65 years or older, approximately equally distributed by age between two cities in China (Hong Kong and Shanghai), were recruited from hospitals and old age homes for the reliability study. 340 men and 527 women were recruited for the validity study. RESULTS: The CNS compared with physician assessments based on two groups, normal or at risk with less than normal nutritional status, had kappa coefficients of 0.5 overall and were as high as 0.8 in Shanghai. CNS was able to identify about 90% of all persons with normal nutritional status and had about a 60% chance of correctly identifying a person at risk with a less than normal nutritional status. CONCLUSION: The CNS can be used in a 2-group classification to identify those who have a normal nutritional status (CNS > or = 21). Those who do not fall into this group should have their nutritional status evaluated in greater detail (CNS score < or = 20). The applicability of screening tools may vary depending on the site and the population characteristics.

[Effects of captopril on platelet-derived growth factor ligand and receptor gene expression of vascular wall after balloon angioplasty].

A predominant fibromuscular plaque was produced by balloon catheter denuding angioplasty of both iliac arteries and feeding cholesterol in 16 New Zealand white rabbits. Balloon angioplasty was performed in model animals. Captopril-treated (n = 8, captopril 12.5 mg.kg-1/d) group which received captopril 7 days before to 4 wk after angioplasty were examined by dot blot hybridization. The results showed that captopril can inhibit platelet-derived growth factor ligand and receptor gene expression of vascular wall after balloon angioplasty.

Role of stromal-derived factor-1/CXCR4 in neo-intimal repair.

Neo-intimal hyperplasia is one of the major causes of restenosis in which stromal cell-derived factor-1 (SDF-1α) and its receptor CXCR4 play an important role. In a rat common carotid artery balloon injury model, the number of CD34(+)CXCR4(+) cells was significantly increased immediately after injury (p < 0.01), followed by a gradual decrease to baseline seven days after the injury. Furthermore, the plasma (SDF-1α) level was markedly elevated, and peaked 24 hours after injury (p < 0.01), followed by a rapid decrease to baseline level seven days after the injury. In the injured common carotid artery, the mRNA expression of (SDF-1α) was elevated immediately after injury, followed by a gradual decline, but that of CXCR4 was increased four days after injury. Immuno-histochemistry displayed CXCR4-positive staining one day after injury, which then gradually increased and continued for at least one month. In addition, administration of AMD3100 (200 ng/kg, i.p.), a CXCR4 antagonist, did not affect the number of CD34(+)CXCR4(+) cells, the elevated level of plasma (SDF-1α) and expression of (SDF-1α) mRNA. The expression of CXCR4 mRNA and protein however was markedly decreased, and detectable CXCR4-positive cells occurred four days after injury, followed by a decreased intensity of staining. We also found that, three months after balloon injury, stenosis of the carotid artery intima in the group that received AMD3100 was significantly less than in the untreated group (p < 0.05). Therefore, (SDF-1α)/CXCR4 played a crucial role in the intimal hyperplasia, and restenosis may have be attenuated after inhibition of CD34(+)CXCR4(+) cells in the intima.

An E. coli gene emrD is involved in adaptation to low energy shock.

E. coli adapt to uncouplers in the presence of a non-fermentable carbon source. Adaptation is accompanied by the restoration of the proton motive force and ATP. A collection of uncoupler-sensitive Tn,lacZ,kan fusion strains was obtained by ampicillin enrichment in the presence of TSA. One of the fusion strains was induced by uncouplers. The fusion gene emrD was mapped to min. 83.1, cloned and sequenced. EmrD is a member of the major facilitator family of pmf-dependent translocases and is homologous to a number of bacterial multidrug resistance pumps. Resistance to some uncouplers including TTFB was not affected by emrD, and growth recovery to this uncoupler was very sluggish. It is suggested that EmrD is a new bacterial multidrug resistance pump that participates in a low energy shock adaptive response.