Constitutive expression of hrap gene in transgenic tobacco plant enhances resistance against virulent bacterial pathogens by induction of a hypersensitive response

Hypersensitive response-assisting protein (HRAP) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpin(Pss)-mediated hypersensitive response (HR). The hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. To assess the function of the hrap gene in plant disease resistance, the CaMV 35S promoter was used to express sweet pepper hrap in transgenic tobacco. Compared with wild-type tobacco, transgenic tobacco plants exhibit more sensitivity to harpin(Pss) and show resistance to virulent pathogens (Pseudomonas syringae pv. tabaci and Erwinia carotovora subsp. carotovora). This disease resistance of transgenic tobacco does not originate from a constitutive HR, because endogenous level of salicylic acid and hsr203J mRNA showed similarities in transgenic and wildtype tobacco under noninfected conditions. However, following a virulent pathogen infection in hrap transgenic tobacco, hsr203J was rapidly induced and a micro-HR necrosis was visualized by trypan blue staining in the infiltration area. Consequently, we suggest that the disease resistance of transgenic plants may result from the induction of a HR by a virulent pathogen infection.     

Total synthesis and evaluation of lamellarin alpha 20-Sulfate analogues

In order to explore the influence of sulfate groups on the bioactivity profiles of marine alkaloids of the lamellarin class, three such alkaloids, lamellarin alpha, lamellarin alpha 13,20-disulfate and lamellarin H, were synthesized and their activities against HIV-1 integrase and cancer cell lines were compared with those of lamellarin alpha 20-sulfate, which is a selective inhibitor of HIV-1 integrase. Lamellarin alpha does not inhibit HIV-1 integrase but shows moderate cytotoxicity with good cell line selectivity. Lamellarin alpha 13,20-disulfate is a moderate inhibitor of both HIV-1 integrase and cancer cell lines. Lamellarin H is a more potent inhibitor of HIV-1 integrase but lacked the specificity required to be medicinally useful.     

A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

Tuberculosis (TB) still holds a major threat to the health of people worldwide, and there is a need for cost-efficient but reliable models to help us understand the disease mechanisms and advance the discoveries of new treatment options. In vitro cell cultures of monolayers or co-cultures lack the three-dimensional (3D) environment and tissue responses. Herein, we describe an innovative in vitro model of a human lung tissue, which holds promise to be an effective tool for studying the complex events that occur during infection with Mycobacterium tuberculosis (M. tuberculosis). The 3D tissue model consists of tissue-specific epithelial cells and fibroblasts, which are cultured in a matrix of collagen on top of a porous membrane. Upon air exposure, the epithelial cells stratify and secrete mucus at the apical side. By introducing human primary macrophages infected with M. tuberculosis to the tissue model, we have shown that immune cells migrate into the infected-tissue and form early stages of TB granuloma. These structures recapitulate the distinct feature of human TB, the granuloma, which is fundamentally different or not commonly observed in widely used experimental animal models. This organotypic culture method enables the 3D visualization and robust quantitative analysis that provides pivotal information on spatial and temporal features of host cell-pathogen interactions. Taken together, the lung tissue model provides a physiologically relevant tissue micro-environment for studies on TB. Thus, the lung tissue model has potential implications for both basic mechanistic and applied studies. Importantly, the model allows addition or manipulation of individual cell types, which thereby widens its use for modelling a variety of infectious diseases that affect the lungs.     

Bacillus enclensis sp. nov., isolated from sediment sample

A novel bacterial strain, designated SGD-1123^T was isolated from Chorao Island, in Goa Province, India. The strain was found to be able to grow at 15–42 °C, pH 5–12 and 0–12 % (w/v) NaCl. The whole cell hydrolysates were found to contain meso-diaminopimelic acid, galactose and arabinose. The major fatty acids were identified as iso-C_15:0 and anteiso-C_15:0, MK-7 was identified as the predominant menaquinone and the predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminolipid. The genomic DNA G+C content was determined to be 44.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolate within the genus Bacillus and further revealed that strain SGD-1123^T had highest sequence similarity with Bacillus aquimaris, and forms a separate clade with its closest relatives i.e. B. aquimaris, Bacillus vietnamensis and Bacillus marisflavi, with which it shares 94.5, 94.1 and 94.1 % similarity respectively. The phylogenetic, chemotaxonomic and phenotypic analyses indicated that strain SGD-1123^T represents a novel species within the genus Bacillus, for which the name Bacillus enclensis is proposed. The type strain is SGD-1123^T (NCIM 5450^T=CCTCC AB 2011125^T).     

Flying Over an Infected Landscape: Distribution of Highly Pathogenic Avian Influenza H5N1 Risk in South Asia and Satellite Tracking of Wild Waterfowl

Highly pathogenic avian influenza (HPAI) H5N1 virus persists in Asia, posing a threat to poultry, wild birds, and humans. Previous work in Southeast Asia demonstrated that HPAI H5N1 risk is related to domestic ducks and people. Other studies discussed the role of migratory birds in the long distance spread of HPAI H5N1. However, the interplay between local persistence and long-distance dispersal has never been studied. We expand previous geospatial risk analysis to include South and Southeast Asia, and integrate the analysis with migration data of satellite-tracked wild waterfowl along the Central Asia flyway. We find that the population of domestic duck is the main factor delineating areas at risk of HPAI H5N1 spread in domestic poultry in South Asia, and that other risk factors, such as human population and chicken density, are associated with HPAI H5N1 risk within those areas. We also find that satellite tracked birds (Ruddy Shelduck and two Bar-headed Geese) reveal a direct spatio-temporal link between the HPAI H5N1 hot-spots identified in India and Bangladesh through our risk model, and the wild bird outbreaks in May-June-July 2009 in China (Qinghai Lake), Mongolia, and Russia. This suggests that the continental-scale dynamics of HPAI H5N1 are structured as a number of persistence areas delineated by domestic ducks, connected by rare transmission through migratory waterfowl.     

Gender distribution in irritable bowel syndrome is proportional to the severity of constipation relative to diarrhea

Background: A significant gender disparity has been observed in individuals with irritable bowel syndrome (IBS), with females outnumbering males, especially in constipation-predominant IBS (C-IBS). However, this observation is based on Rome criteria categorization and does not take into account the severity of constipation or diarrhea.Objective: In a large prospective data set, gender differences across the severity of constipation and diarrhea were examined in patients with IBS.Methods: Consecutive adult patients with Rome I positive IBS who were referred to a tertiary care medical center (Cedars-Sinai Medical Center, Los Angeles, California) in 1999–2003 were given a questionnaire. The questionnaire asked subjects to rate their constipation and diarrhea according to perceived severity using a scale from 0 (none) to 5 (very severe). C-IBS was determined to be present if the severity of constipation was greater than the severity of diarrhea (sevC > sevD). If sevD > sevC, subjects were considered to have diarrhea-predominant IBS (D-IBS). To further categorize their symptoms, subjects were then grouped by the difference between the severity of constipation and diarrhea, creating a range of values from ?5 to +5. For each of these 11 constipation/diarrhea severity values, the female:male ratio was determined. The severity of constipation to diarrhea was compared by Spearman rank correlation.Results: A total of 429 subjects with IBS (325 women: mean [SD] age, 42.5 [0.8] years; 104 men: mean age, 42.2 [1.7] years) completed the questionnaire. Constipation occurred more frequently in women (79.7%) compared with men (61.5%) (odds ratio [OR] = 2.49; 95% CI, 1.55–4.02). The prevalence of diarrhea was similar between the sexes. Whereas C-IBS was more common in women (31.8%) than in men (26.0%) (OR = 2.03; 95% CI, 1.24–3.30), D-IBS was more prevalent in men (62.5%) than in women (36.3%) (OR = 2.39; 95% CI, 1.53–3.75). When the female:male ratio was evaluated across the 11 severity score categories of constipation and diarrhea, the greater the sevC — sevD score, the higher the proportion of women (R = 0.80; P = 0.003).Conclusion: In this study of patients with IBS, the observation of the association of constipation and gender in IBS is extended to indicate that the female:male ratio significantly increases according to the severity of constipation relative to the severity of diarrhea.     

Rhodethrin: a novel indole terpenoid ether produced by Rhodobacter sphaeroides has cytotoxic and phytohormonal activities

A novel metabolite was isolated from the culture supernatants of Rhodobacter sphaeroides OU5 when grown on l-tryptophan as sole source of nitrogen under photoheterotrophic conditions. It was identified by IR, NMR (¹H, ¹³C) and MS as an indole terpenoid ether [3-hydroxy-6-(1H-indol-3-yloxy)-4-methylhexanoic acid] and is named as rhodethrin. Rhodethrin at 0.5 μM gave positive test in auxin bioassay and initiated early rooting in tissue-cultured plants than IAA at 5 μM. Rhodethrin has cytotoxic activity against Sup-T₁ lymphoma and Colo-125 cancer cell lines at 10 nM.     

Drug, dosage, activity, studies of antimalarials by physical methods--II

Studies pertaining to drug-DNA interactions in treating a disease efficiently have taken an important place in recent times. Murthy and colleagues were active in correlating the drug activity, with physical parameters like refractivity, susceptibility, molecular electron ionization cross-section and the dosage. The molecular polarizability, diamagnetic susceptibility and molecular electron ionization cross section Q have been evaluated. An analysis of Q in the light of the data available on plasma protein binding, bio availability, Log P and half-Life show semblance of regular dependence of Q on them and hence an effort is made to bring this dependence into a regular mathematical relationship. The dosage of each drug is calculated. A critical look at the results arrived on Q and dosages reveal that a highly active drug with large Q need to be monitored in very small quantities and any minute increase in dosage is resulting in unwanted toxic effects and vice versa. The algebraic formulae enable one to calculate the dosages theoretically from the value of Q and other parameters and the calculated dosage through the formulae agreed favorably well with suggested dosages. For example, in primaquine phosphate, the calculated dosage is 30 mg per day against the suggested practical dosage of 26.3 mg per day. A similar observation is made in mepacrine with theoretical dosage of 60 mg per day as against the suggested practical dosage of 100 mg per day. In short, the molecular structure followed by refraction and susceptibility measurements and Q will throw light on dosage, toxicity of a drug. Thus the present investigations pave way for a new direction of approach for study of drug activity without recourse to techniques involving highly expensive instrumentation and highly theoretical approaches involving quantum mechanical methods.     

Influence of recirculation on the performance of anaerobic sequencing batch biofilm reactor (AnSBBR) treating hypersaline composite chemical wastewater

Influence of recirculation on the performance of anaerobic sequencing batch biofilm reactor (AnSBBR) was studied in the process of treating hypersaline (total dissolved inorganic solids (TDIS) approximately 26 g/l) and low biodegradable (BOD/COD approximately 0.3) composite chemical wastewater. Significant enhancement in the substrate removal efficiency and biogas yield was observed after introducing the recirculation to the system. Maximum efficiency (COD removal efficiency - 51%; SDR - 3.14 kg COD/cum-day) was observed at recirculation to feed (R/F) ratio of 2 (OLR - 6.15 kg C OD/cum-day; HLR - 2.30 cum (liquid)/cum day; UFV(A) - 0.023 m/h). Subsequent increase of R/F to 3 (OLR - 6.15 kg COD/cum-day; HLR - 3.07cum (liquid)/cum-day; UFV(A) - 0.035 m/h) resulted in reduction in COD removal efficiency (32%; SDR - 1.97 kg COD/cum-day). The enhanced performance of the system due to the introduction of recirculation was attributed to the improvement in the mass transfer between the substrate present in the bulk liquid and the attached biofilm. The hydrodynamic behavior due to recirculation mode of operation reduced the concentration gradient (substrate inhibition) of substrate and reaction by-products (VFA) resulting in mixed flow conditions.     

Praziquantel derivatives I: Modification of the aromatic ring

Several analogues of the potent anthelmintic praziquantel were prepared with variation in the aromatic ring. The biological activity of these analogues was evaluated and compared against known analogues. Amination of the ring was tolerated while other variations were not. These results have important implications for drug development for schistosomiasis.