The effect of the substance exin on development of microbial infections and isolation of ethylene in plants

Effects of Exin on infection of tomato, potato, and cabbage plants with Pseudomonas solanacearum and Erwinia carotovora and a fungus Sclerotium rolfsii were studied. The treatment of infected plants with Exin caused no significant effect on the development of the disease. Treatment with streptomycin as a standard for comparison completely inhibited the growth of these microorganisms. Pretreatment with Exin one to eight days before infecting inhibited the development of diseases. The numbers of tomato and potato plants damaged among those infected with P. solanacearum were lower by 10 and 35% respectively. In field experiments (350 plants per variant), treatment with Exin decreased the development of wilt caused by S. rolfsii and P. solanacearum and rot caused by E. carotovora. Treatment with Exin activated the release of ethylene for not less than 30 days. Possible mechanisms of the effects of Exin are discussed.     

Characterization of an unstable allele of the Arabidopsis HY4 locus.

The Arabidopsis HY4 gene encodes the nonessential blue light photoreceptor CRY1. Loss-of-function hy4 mutants have an elongated hypocotyl phenotype after germination under blue light. We previously analyzed 20 independent hy4 alleles produced by fast neutron mutagenesis. These alleles were grouped into two classes based on their genetic behavior and corresponding deletion size: (1) null hy4 alleles that were semidominant over wild type and contained small or moderate-sized deletions at HY4 and (2) null hy4 alleles that were recessive lethal and contained large HY4 deletions. Here we describe one additional fast neutron hy4 mutant, B144, that did not fall into either of these two classes. Mutant B144 was isolated as a heterozygote with an intermediate hy4 phenotype. One allele from this mutant, hy4-B144(Delta), contains a large deletion at HY4 and is recessive lethal. The other allele from this mutant, HY4-B144*, appears to be intact and functional but is unstable and spontaneously converts to a nonfunctional hy4 allele. In addition, HY4-B144* is lethal in homozygotes and suppresses local recombination. We discuss genetic and epigenetic mechanisms that may account for the unusual behavior of the HY4-B144* allele.     

Thioether benzenesulfonamide inhibitors of carbonic anhydrases II and IV: Structure-based drug design,synthesis, and biological evaluation

A novel series of potent thioether benzenesulfonamide inhibitors of carbonic anhydrases II and IV was discovered using structure-based drug design. Synthesis, structure–activity relationship, and optimization of physicochemical properties are described. Low nanomolar potency was achieved, and selected compounds with improved thermodynamic solubility showed promising in vitro inhibition of carbonic anhydrase activity in rabbit iris ciliary body homogenate.     

Is Demography Destiny? Application of Machine Learning Techniques to Accurately Predict Population Health Outcomes from a Minimal Demographic Dataset

For years, we have relied on population surveys to keep track of regional public health statistics, including the prevalence of non-communicable diseases. Because of the cost and limitations of such surveys, we often do not have the up-to-date data on health outcomes of a region. In this paper, we examined the feasibility of inferring regional health outcomes from socio-demographic data that are widely available and timely updated through national censuses and community surveys. Using data for 50 American states (excluding Washington DC) from 2007 to 2012, we constructed a machine-learning model to predict the prevalence of six non-communicable disease (NCD) outcomes (four NCDs and two major clinical risk factors), based on population socio-demographic characteristics from the American Community Survey. We found that regional prevalence estimates for non-communicable diseases can be reasonably predicted. The predictions were highly correlated with the observed data, in both the states included in the derivation model (median correlation 0.88) and those excluded from the development for use as a completely separated validation sample (median correlation 0.85), demonstrating that the model had sufficient external validity to make good predictions, based on demographics alone, for areas not included in the model development. This highlights both the utility of this sophisticated approach to model development, and the vital importance of simple socio-demographic characteristics as both indicators and determinants of chronic disease.     

A new rhodamine‐based fluorescent chemodosimeter for mercuric ions in water media

A new rhodamine–ethylenediamine–nitrothiourea conjugate (RT) was synthesized and its sensing property as a fluorescent chemodosimeter toward metal ions was explored in water media. Analytical results from absorption and fluorescence spectra revealed that the addition of Hg²⁺ ions to the aqueous solution of the chemodosimeter RT caused a distinct fluorescence OFF–ON response with a remarkable visual color change from colorless to pink; however, no clear spectral and color changes were observed from other metal ions including: Zn²⁺, Cu²⁺, Cd²⁺, Pb²⁺, Ag⁺, Fe²⁺, Cr³⁺, Co³⁺, Ni²⁺, Ca²⁺, Mg²⁺, K⁺ and Na⁺. The sensing results and the molecular structure suggested that a Hg²⁺‐induced a desulfurization reaction and cyclic guanylation of the thiourea moiety followed by ring‐opening of the rhodamine spirolactam in RT are responsible for a distinct fluorescence turn‐on signal, indicating that RT is a remarkably sensitive and selective chemodosimeter for Hg²⁺ ions in aqueous solution. Hg²⁺ within a concentration range from 0.1 to 25 μM can be determined using RT as a chemodosimeter and a detection limit of 0.04 μM is achieved. Copyright © 2014 John Wiley & Sons, Ltd.     

Glycosyl Phosphatidylinositol Anchor Biosynthesis Is Essential for Maintaining Epithelial Integrity during Caenorhabditis elegans Embryogenesis

Glycosylphosphatidylinositol (GPI) is a post-translational modification resulting in the attachment of modified proteins to the outer leaflet of the plasma membrane. Tissue culture experiments have shown GPI-anchored proteins (GPI-APs) to be targeted to the apical membrane of epithelial cells. However, the in vivo importance of this targeting has not been investigated since null mutations in GPI biosynthesis enzymes in mice result in very early embryonic lethality. Missense mutations in the human GPI biosynthesis enzyme pigv are associated with a multiple congenital malformation syndrome with a high frequency of Hirschsprung disease and renal anomalies. However, it is currently unknown how these phenotypes are linked to PIGV function. Here, we identify a temperature-sensitive hypomorphic allele of PIGV in Caenorhabditis elegans, pigv-1(qm34), enabling us to study the role of GPI-APs in development. At the restrictive temperature we found a 75% reduction in GPI-APs at the surface of embryonic cells. Consequently, ~80% of pigv-1(qm34) embryos arrested development during the elongation phase of morphogenesis, exhibiting internal cysts and/or surface ruptures. Closer examination of the defects revealed them all to be the result of breaches in epithelial tissues: cysts formed in the intestine and excretory canal, and ruptures occurred through epidermal cells, suggesting weakening of the epithelial membrane or membrane-cortex connection. Knockdown of piga-1, another GPI biosynthesis enzymes resulted in similar phenotypes. Importantly, fortifying the link between the apical membrane and actin cortex by overexpression of the ezrin/radixin/moesin ortholog ERM-1, significantly rescued cyst formation and ruptures in the pigv-1(qm34) mutant. In conclusion, we discovered GPI-APs play a critical role in maintaining the integrity of the epithelial tissues, allowing them to withstand the pressure and stresses of morphogenesis. Our findings may help to explain some of the phenotypes observed in human syndromes associated with pigv mutations.     

The role of carbohydrate-binding module (CBM) repeat of a multimodular xylanase (XynX) from Clostridium thermocellum in cellulose and xylan binding

A non-cellulosomal xylanase from Clostridium thermocellum, XynX, consists of a family-22 carbohydratebinding module (CBM22), a family-10 glycoside hydrolase (GH10) catalytic module, two family-9 carbohydrate-binding modules (CBM9-I and CBM9-II), and an S-layer homology (SLH) module. E. coli BL21(DE3) (pKM29), a transformant carrying xynX', produced several truncated forms of the enzyme. Among them, three major active species were purified by SDS-PAGE, activity staining, gel-slicing, and diffusion from the gel. The truncated xylanases were different from each other only in their C-terminal regions. In addition to the CBM22 and GH10 catalytic modules, XynX(1) had the CBM9-I and most of the CBM9-II, XynX(2) had the CBM9-I and about 40% of the CBM9-II, and XynX(3) had about 75% of the CBM9-I. The truncated xylanases showed higher binding capacities toward Avicel than those toward insoluble xylan. XynX(1) showed a higher affinity toward Avicel (70.5%) than XynX(2) (46.0%) and XynX(3) (42.1%); however, there were no significant differences in the affinities toward insoluble xylan. It is suggested that the CBM9 repeat, especially CBM9-II, of XynX plays a role in xylan degradation in nature by strengthening cellulose binding rather than by enhancing xylan binding.