BaTiO3-Graphene-Affinity Layer–Based Surface Plasmon Resonance (SPR) Biosensor for Pseudomonas Bacterial Detection

Plasmonics - In the present work, a highly sensitive SPR biosensor based on silver (Ag), barium titanate (BaTiO3), graphene, and affinity layer is proposed for the detection of Pseudomonas...     

ThesacB gene cannot be used as a counter-selectable marker inPasteurella multocida

The use of theBacillus subtilis sacB gene as a counter-selectable marker was assessed in serogroup A and B strains ofPasteurella multocida. Expression ofsacB failed to render any of the strains sensitive to sucrose, indicating that thesacB gene can not be used as a positive selection system inP. multocida.     

Diarylheptanoids from Curcuma comosa

Three new diarylheptanoids, designated 1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (1), 1-(3-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)-3-methoxy-(6E)-6-heptene (2), (3R, 5R)-1-(3,4-dihydroxyphenyl)-7-phenyl-heptane-3,5-diol (3) and three known compounds, were isolated from rhizomes of Curcuma comosa. Structures of the compounds were determined by spectroscopic data analysis.     

Genetic structure and diversity of Shorea obtusa (Dipterocarpaceae) in Thailand

Shorea obtusa is a keystone species of the dry deciduous dipterocarp forest in Thailand. In this study, the genetic structure and diversity of this species were evaluated by means of five microsatellite markers. A total of 146 trees were collected from five populations encompassing major forest regions of Thailand. High levels of genetic diversity were found among the five populations with the average He of 0.664. Genetic differentiations between populations, although significant, were low with approximately 3% of genetic variation partitioned among populations. This may indicate that the populations sampled were recently part of a continuous population. A tree constructed using the unweighted pair group method with arithmetic average, based on Nei's genetic distance, divided the populations into three groups. This separation was consistent with the altitudinal zonation of the populations, thus indicating that altitude might play a significant role in the genetic structure of S. obtusa. Areas of high genetic diversity were identified which could be considered priorities for conservation.     

Chroman amide and nicotinyl amide derivatives: inhibition of lipid peroxidation and protection against head trauma

A series of chroman amide and nicotinyl amide derivatives was designed and synthesized for the treatment of traumatic and ischemic CNS injury. Five compounds were significantly more potent inhibitors of lipid peroxidation in vitro than the reference antioxidant, trolox (p < 0.01). Quantitative structure activity studies demonstrated that the inhibitory action was related to the ability to donate electrons, charge on hydroxy group and E(LUMO), to scavenging radicals and to the lipophilicity log P, which determines penetration of membrane lipids. ESR study indicated the ability of 12 to scavenge the hydroxyl radicals. The most promising compound, [(3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2yl)ca rbonyl]-3'-(aminoethyl) indole (12), inhibited ex vivo lipid peroxidation in a head injury model and showed potent in vivo neuroprotective efficacy. Improvement of neurological recovery within 1 h of injury (grip test score) by as much as 200% was observed together with significant anti-anoxia activity. Compound 12 was a potent antagonist of methamphetamine-induced hypermotility resulting from dopamine release in the mouse brain. These results support the importance of cerebroprotective radical-scavenging agents for the treatment of traumatic injury and anoxia as well as provide additional evidence for the role of oxygen radicals and dopamine in brain damage.     

MetGEMs Toolbox: Metagenome-scale models as integrative toolbox for uncovering metabolic functions and routes of human gut microbiome

Investigating metabolic functional capability of a human gut microbiome enables the quantification of microbiome changes, which can cause a phenotypic change of host physiology and disease. One possible way to estimate the functional capability of a microbial community is through inferring metagenomic content from 16S rRNA gene sequences. Genome-scale models (GEMs) can be used as scaffold for functional estimation analysis at a systematic level, however up to date, there is no integrative toolbox based on GEMs for uncovering metabolic functions. Here, we developed the MetGEMs (metagenome-scale models) toolbox, an open-source application for inferring metabolic functions from 16S rRNA gene sequences to facilitate the study of the human gut microbiome by the wider scientific community. The developed toolbox was validated using shotgun metagenomic data and shown to be superior in predicting functional composition in human clinical samples compared to existing state-of-the-art tools. Therefore, the MetGEMs toolbox was subsequently applied for annotating putative enzyme functions and metabolic routes related in human disease using atopic dermatitis as a case study.     

(+)-Pinoresinol is a putative hypoglycemic agent in defatted sesame (Sesamum indicum) seeds though inhibiting α-glucosidase

Defatted sesame seeds have been reported for hypoglycemic effect in mice and T2DM women. An attempted to identify active components responsible for this effect was conducted using α-glucosidase-guided fractionation, resulting in the isolation of various lignans. Of compounds isolated, only (+)-pinoresinol showed inhibitory activity against rat intestinal maltase with an IC(50) value of 34.3μM. The kinetic study indicated that enzymatic hydrolysis of maltose is inhibited by (+)-pinoresinol through competitive and noncompetitive manners. However, a lower dissociation constant (k(i) 288M) of EI complex suggested that competitive inhibition is predominant over noncompetitive mode (k'(i)1342M).     

Prevalence and genotypic relatedness of carbapenem resistance among multidrug-resistant P. aeruginosa in tertiary hospitals across Thailand

ABSTRACT: BACKGROUND: Increased infection caused by multidrug resistant (MDR) Pseudomonas aeruginosa has raised awareness of the resistance situation worldwide. Carbapenem resistance among MDR (CR-MDR) P. aeruginosa has become a serious life-threatening problem due to the limited therapeutic options. Therefore, the objectives of this study were to determine the prevalence, the antibiotic susceptibility patterns and the relatedness of CR-MDR P. aeruginosa in tertiary hospitals across Thailand. METHODS: MDR P. aeruginosa from eight tertiary hospitals across Thailand were collected from 2007--2009. Susceptibility of P. aeruginosa clinical isolates was determined according to the Clinical and Laboratory Standards Institute guideline. Selected CR-MDR P. aeruginosa isolates were genetically analyzed by pulsed-field gel electrophoresis. RESULTS: About 261 clinical isolates were identified as MDR P. aeruginosa and approximately 71.65% were found to be CR-MDR P. aeruginosa. The result showed that the meropenem resistance rate was the highest reaching over 50% in every hospitals. Additionally, the type of hospitals was a major factor affecting the resistance rate, as demonstrated by significantly higher CR-MDR rates among university and regional hospitals. The fingerprinting map identified 107 clones with at least 95% similarity. Only 4 clones were detected in more than one hospital. CONCLUSIONS: Although the antibiotic resistance rate was high, the spreading of CR-MDR was found locally. Specific strains of CR-MDR did not commonly spread from one hospital to another. Importantly, clonal dissemination ratio indicated limited intra-hospital transmission in Thailand.     

Manganese-based complexes of radical scavengers as neuroprotective agents

Manganese was incorporated in the structure of the selected antioxidants to mimic the superoxide dismutase (SOD) and to increase radical scavenging ability. Five manganese complexes (1-5) showed potent SOD activity in vitro with IC(50) of 1.18-1.84 microM and action against lipid peroxidation in vitro with IC(50) of 1.97-8.00 microM greater than their ligands and trolox. The manganese complexes were initially tested in vivo at 50 mg/kg for antagonistic activity on methamphetamine (MAP)-induced hypermotility resulting from dopamine release in the mice brain. Only manganese complexes of kojic acid (1) and 7-hydroxyflavone (3) exhibited the significant suppressions on MAP-induced hypermotility and did not significantly decrease the locomotor activity in normal condition. Manganese complex 3 also showed protective effects against learning and memory impairment in transient cerebral ischemic mice. These results supported the brain delivery and the role of manganese in SOD activity as well as in the modulation of brain neurotransmitters in the aberrant condition. Manganese complex 3 from 7-hydroxyflavone was the promising candidate for radical implicated neurodegenerative diseases.