Molecular characteristics of extended-spectrum beta-lactamases and qnr determinants in Enterobacter species from Japan

The incidence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide, but screening criteria for detection of ESBLs are not standardized for AmpC-producing Enterobacteriaceae such as Enterobacter species. In this study, we investigated the prevalence of ESBLs and/or AmpC β-lactamases in Japanese clinical isolates of Enterobacter spp. and the association of plasmid-mediated quinolone resistance (PMQR) determinants with ESBL producers. A total of 364 clinical isolates of Enterobacter spp. collected throughout Japan between November 2009 and January 2010 were studied. ESBL-producing strains were assessed by the CLSI confirmatory test and the boronic acid disk test. PCR and sequencing were performed to detect CTX-M, TEM, and SHV type ESBLs and PMQR determinants. For ESBL-producing Enterobacter spp., pulsed-field gel electrophoresis (PFGE) was performed using XbaI restriction enzyme. Of the 364 isolates, 22 (6.0%) were ESBL producers. Seven isolates of Enterobacter cloacae produced CTX-M-3, followed by two isolates producing SHV-12. Two isolates of Enterobacter aerogenes produced CTX-M-2. Of the 22 ESBL producers, 21 had the AmpC enzyme, and six met the criteria for ESBL production in the boronic acid test. We found a significant association of qnrS with CTX-M-3-producing E. cloacae. The 11 ESBL-producing Enterobacter spp. possessing bla(CTX-M), bla(SHV), or bla(TEM) were divided into six unique PFGE types. This is the first report about the prevalence of qnr determinants among ESBL-producing Enterobacter spp. from Japan. Our results suggest that ESBL-producing Enterobacter spp. with qnr determinants are spreading in Japan.     

A conformational restriction approach to the development of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease

Alzheimer's disease (AD) has been treated with acetylcholinesterase (AChE) inhibitors such as donepezil. However, the clinical usefulness of AChE inhibitors is limited mainly due to their adverse peripheral effects. Depression seen in AD patients has been treated with serotonin transporter (SERT) inhibitors. We considered that combining SERT and AChE inhibition could improve the clinical usefulness of AChE inhibitors. In a previous paper, we found a potential dual inhibitor, 1, of AChE (IC50=101 nM) and SERT (IC50=42 nM), but its AChE inhibition activity was less than donepezil (IC50=10 nM). Here, we report the conformationally restricted (R)-18a considerably enhanced inhibitory activity against AChE (IC50=14 nM) and SERT (IC50=6 nM).     

Effect of mixed organic substrate on α-tocopherol production by <Emphasis Type="Italic">Euglena gracilis</Emphasis> in photoheterotrophic culture

Effects of organic carbon sources on cell growth and alpha-tocopherol productivity in wild and chloroplast-deficient W14ZUL strains of Euglena gracilis under photoheterotrophic culture were investigated. In both strains, the increase in cell growth was particularly high when glucose was added as the sole organic carbon source. On the other hand, alpha-tocopherol production per dry cell weight was enhanced by adding ethanol. Ethanol addition also increased the chlorophyll concentration in wild strain and mitochondria activity in W14ZUL strain. For effective alpha-tocopherol production, the effects of mixture of glucose and ethanol were investigated. The results showed that, when a mixture of glucose (6 g/l) and ethanol (4 g/l) was used, alpha-tocopherol productivity per culture broth was 3.89 x 10(-2) mg l(-1) h(-1), which was higher than the value obtained without addition of organic carbon source (0.92 x 10(-2) mg l(-1) h(-1)). In addition, under fed-batch cultivation using an internally illuminated photobioreactor, the alpha-tocopherol production per culture broth was 23.43 mg/l, giving a productivity of 16.27 x 10(-2) mg l(-1) h(-1).     

An angiotensin-I converting enzyme inhibitor from buckwheat (Fagopyrum esculentum Moench) flour

A compound that inhibited angiotensin-I converting enzyme (ACE) activity was isolated from buckwheat powder. This compound is thought to be the hydroxy derivative of nicotianamine and its chemical structure is 2'-hydroxynicotianamine. This compound showed a very high inhibitory activity toward ACE, and the IC(50) was 0.08 microM. Only this hydroxy analog was found in buckwheat powder, at about 30 mg/100g, and no nicotianamine was detected. However, nicotianamine was detected in the buckwheat plant body. 2'-hydroxynicotianamine was also found in other polygonaceous plants.     

Flower Bud Culture of Shallot (Allium cepa L. Aggregatum group) with Cytogenetic Analysis of Resulting Gynogenic Plants and Somaclones

Unpollinated flower culture was applied for induction of gynogenesis and somatic organogenesis in three shallot strains, ‘Dili-white’, ‘Yogya’ and ‘Dili-red’, from Indonesia. Chromosome surveys were performed on the plants obtained. From a total of 6,812 flowers, 89 plantlets were obtained by gynogenesis, of which 10 could be acclimated. Most of the plantlets were induced from ‘Dili-white’. Of the gynogenetic plants examined, two were haploid (2n = 8), four were naturally doubled haploid (2n = 16) and the remaining four were mixoploid (2n = 8, 16 or 2n = 16, 32, 64). ‘Dili-red’ showed the highest frequency of somatic organogenesis. Fifty-nine directly regenerated plants and 293 callus-derived plants were obtained from somatic organogenesis from the cultured flowers. Based on the chromosome number, frequencies of somaclonal variation were high both in the directly regenerated plants and the callus-derived plants. The frequency of tetraploid plants (2n = 32) in the former (50%) was higher than in the latter (33%). From these results we conclude that unpollinated flower culture is an effective method for chromosome doubling simultaneously with haploid induction in shallot.     

Photobioreactors for mass cultivation of algae

Algae have attracted much interest for production of foods, bioactive compounds and also for their usefulness in cleaning the environment. In order to grow and tap the potentials of algae, efficient photobioreactors are required. Although a good number of photobioreactors have been proposed, only a few of them can be practically used for mass production of algae. One of the major factors that limits their practical application in algal mass cultures is mass transfer. Thus, a thorough understanding of mass transfer rates in photobioreactors is necessary for efficient operation of mass algal cultures. In this review article, various photobioreactors that are very promising for mass production of algae are discussed.     

Association of a polymorphism of ABCB1 with obesity in Japanese individuals

The aim of the present study was to identify gene polymorphisms that confer susceptibility to obesity. A total of 5448 unrelated Japanese individuals from two independent populations were examined: subject panel A comprised 4252 individuals who visited participating hospitals; subject panel B comprised 1196 community-dwelling elderly individuals. The genotypes for 95 polymorphisms of 67 candidate genes were determined. The χ² test revealed that six polymorphisms were related (p < 0.05) to the prevalence of obesity in subject panel A; after application of Bonferroni's correction, however, only the 2677G → A/T polymorphism (rs2032582) of the ATP-binding cassette, subfamily B, member 1 gene (ABCB1) was significantly associated (p = 0.0003) with obesity. Subsequent multivariable logistic regression analysis also revealed that the 2677G → A/T polymorphism of ABCB1 was significantly associated with obesity. For validation of this association, the 2677G → A/T polymorphism of ABCB1 was examined in subject panel B and again found to be significantly associated with obesity. Body mass index was significantly (p = 0.01) greater for individuals with the variant T allele of this polymorphism than for those with the GG genotype in the combined subject panels A and B. Our results suggest that the ABCB1 genotype may prove informative for assessment of genetic risk for obesity in Japanese individuals.     

Reducing effect of feeding powdered nacre of Pinctada maxima on the visceral fat of rats

An abdominal fat accumulation complicated by high blood triglycerides is regarded as a risk factor of metabolic syndrome. Feeding powdered nacre, mother of pearl, from Pinctada maxima, resulted in reduced body weight, visceral fat amount, and blood triglyceride level without influencing the food intake, body length, or amount of muscular tissue, suggesting that nacre powder specifically could decrease visceral fat.     

A putative cation channel, NCA-1, and a novel protein, UNC-80, transmit neuronal activity in C. elegans

Voltage-gated cation channels regulate neuronal excitability through selective ion flux. NALCN, a member of a protein family that is structurally related to the α1 subunits of voltage-gated sodium/calcium channels, was recently shown to regulate the resting membrane potentials by mediating sodium leak and the firing of mouse neurons. We identified a role for the Caenorhabditis elegans NALCN homologues NCA-1 and NCA-2 in the propagation of neuronal activity from cell bodies to synapses. Loss of NCA activities leads to reduced synaptic transmission at neuromuscular junctions and frequent halting in locomotion. In vivo calcium imaging experiments further indicate that while calcium influx in the cell bodies of egg-laying motorneurons is unaffected by altered NCA activity, synaptic calcium transients are significantly reduced in nca loss-of-function mutants and increased in nca gain-of-function mutants. NCA-1 localizes along axons and is enriched at nonsynaptic regions. Its localization and function depend on UNC-79, and UNC-80, a novel conserved protein that is also enriched at nonsynaptic regions. We propose that NCA-1 and UNC-80 regulate neuronal activity at least in part by transmitting depolarization signals to synapses in C. elegans neurons.