Hirschsprung disease (HSCR) is a congenital developmental defect of the enteric nervous system known to be associated with the RET-protooncogene and other candidates. Recently, a genome-wide association study has added NRG1, a regulator of the development of the enteric ganglia precursors, as a new candidate gene. The aim of this study is to validate the association of the RET-protooncogene and the NRG1 in HSCR in Thai patients. The study used TaqMan single-nucleotide polymorphism (SNP) genotyping and PCR-restriction fragment length polymorphism for genotyping of 10 SNPs within the RET-protooncogene and four SNPs within the NRG1, in 68 Thai sporadic HSCR cases and 120 ethnic-matched controls. On univariate disease association analysis, 9 of 10 RET-protooncogene SNPs and all four NRG1 SNPs showed an association with HSCR. The rs2435357 (RET-protooncogene) and rs2439305 (NRG1) showed the strongest associations with the disease at P-values of 8.17E-09 (odds ratio (OR)¼6.43, 95% confidence intervals (CI)¼3.33-12.40) and 6.94E-03 (OR¼3.28, 95% CI¼1.28-8.38), respectively. The RET-protooncogene rs2435357 (TT genotype) in combination with the NRG1 rs2439305 (GG genotype) was strongly associated with an increased risk of HSCR with a P-value of 1.99E-04 (OR¼20.34, 95% CI; 2.54-162.78) when compared with a single SNP of the RET-protooncogene or NRG1. Genetic variation of the RET-protooncogene and NRG1 is involved in the risk of HSCR development in the Thai population. Moreover, the study also detected a combined effect of SNPs by SNP-SNP interaction, which may help in predicting HSCR risk.

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Several lines of evidence have pointed out that genetic components have roles in thyrotoxic hypokalemic periodic paralysis (TTPP). In this study, for the first time we performed genome-wide association study (GWAS) in male hyperthyroid subjects in order to identify genetic loci conferring susceptibility to TTPP. We genotyped 78 Thai male TTPP cases and 74 Thai male hyperthyroid patients without hypokalemia as controls with Illumina Human-Hap610 Genotyping BeadChip. Among the SNPs analyzed in the GWAS, rs312729 at chromosome 17q revealed the lowest P-value for association (P=2.09 × 10(-7)). After fine mapping for linkage disequilibrium blocks surrounding the landmark SNP, we found a significant association of rs623011; located at 75 kb downstream of KCNJ2 on chromosome 17q, reached the GWAS significance after Bonferroni's adjustment (P=3.23 × 10(-8), odds ratio (OR)=6.72; 95% confidence interval (CI)=3.11-14.5). The result was confirmed in an independent cohort of samples consisting of 28 TTPP patients and 48 controls using the same clinical criteria diagnosis (replication analysis P=3.44 × 10(-5), OR=5.13; 95% CI=1.87-14.1; combined-analysis P=3.71 × 10(-12), OR=5.47; 95% CI=3.04-9.83).

Effective lignocellulosic biomass saccharification is one of the crucial requirements of biofuel production via fermentation process. Organic acid pretreatments have been gained much interests as one of the high potential methods for promoting enzymatic saccharification of lignocellulosic materials due to their lower hazardous properties and lower production of inhibitory by-products of fermentation than typical chemical pretreatment methods. In this study, three organic acids, including acetic acid, oxalic acid, and citric acid, were examined for improvement of enzymatic saccharification and bioethanol production from oil palm trunk biomass. Based on response surface methodology, oxalic acid pretreated biomass released the maximum reducing sugar of 144 mg/g-pretreated biomass at the optimum condition, which was higher than untreated samples for 2.30 times. The released sugar yield of oil palm trunk also corresponded to the results of FT-IR analysis, which revealed the physical modification of cellulose and hemicellulose surface structures of pretreated biomass. Nevertheless, citric acid pretreatment is the most efficient pretreatment method to improve bioethanol fermentation of Saccharomyces cerevisiae TISTR 5606 at 1.94 times higher than untreated biomass. These results highlighted the selection of organic acid pretreatment as a potential method for biofuel production from oil palm trunk feedstocks.

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Soil contamination by cadmium (Cd) poses a serious environmental and public health concern. Phytoremediation, i.e., the use of plants to remove contaminants from soil, has been proposed for treatment of Cd-contaminated ecosystems. In this study, we demonstrated the potential of Vetiveria zizanioides, commonly known as vetiver, to serve as an effective phytoremediation agent. Two ecotypes, i.e., India and Sri Lanka, were grown in greenhouse pots and in the field. Soils were amended with cow manure, pig manure, bat manure, and an organic fertilizer. Among all amendments, pig manure performed best in both greenhouse and field studies in terms of increasing total V. zizanioides biomass production in both ecotypes. In both greenhouse and in the field, tissue of the Sri Lanka ecotype had higher Cd concentrations than did the India ecotype. In the greenhouse, the presence of Cd did not affect total biomass production or root dry weight. The Sri Lanka ecotype had 2.7 times greater adventitious root numbers and 3.6 times greater Cd accumulation in roots than did the India ecotype. In the field study, the Sri Lanka ecotype offers potential as an excluder species, as it accumulated Cd primarily in roots, with translocation factor values <1 and a bioconcentration coefficient for roots >1 for all experiments except for the pig manure amendment. In addition, the highest Cd concentration in the Sri Lanka ecotype root (71.3 mg kg(-1)) was consistent with highest Cd uptake (10.4 mg plant(-1)) in the cow manure treatment. The India ecotype contained lower root Cd concentrations, and Cd accumulation was slightly higher in shoots compared to roots, with translocation factor (TF) values >1. The India ecotype was therefore not considered as an excluder in the Cd-contaminated soil. With the use of excluder species combined with application of organic amendments, soil contamination by Cd may be treated by alternative remediation methods such as phytostabilization.

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Greenhouse and field experiments were conducted to evaluate the influence of three different organic amendments (cow manure, pig manure, and organic fertilizer) on the Cd phytostabilization potential of Eucalyptus camaldulensis grown on Cd-contaminated soil. The application of all amendments, particularly organic fertilizer, improved plant growth (i.e., height and biomass production) when compared to the control (Cd-contaminated soil alone), in both greenhouse and field experiments. E. camaldulensis treated with organic fertilizer experienced the greatest height (39 cm and 3.8 m) and biomass production (2.0 g and 3.3 kg) in greenhouse and field experiments, respectively. Plants grown on amended soils had lower Cd accumulation than those grown on the Cd soil alone. Among the treatments, organic fertilizer resulted in a translocation factor < 1 and a bioconcentration factor for the root (BCFR) > 1, indicating the potential of this species to stabilize Cd in the roots. The results showed that E. camaldulensis is a promising species for phytostabilization of Cd-contaminated soil. The wood of the mature tree is used in the manufacture of commercial products; given the low Cd uptake by E. camaldulensis, it is feasible to harvest the wood grown on Cd-affected soils for making paper and furniture.