Polyphosphate kinase 2: a modulator of nucleoside diphosphate kinase activity in mycobacteria.

Mycobacteria encode putative class II polyphosphate kinases (PPKs). We report that recombinant PPK2 of Mycobacterium tuberculosis catalyses the synthesis of GTP from GDP using polyphosphate rather than ATP as phosphate donor. Unlike that of PPK1, this is the favoured reaction of PPK2.

A novel copper chelate modulates tumor associated macrophages to promote anti-tumor response of T cells.

Background: At the early stages of carcinogenesis, the induction of tumor specific T cell mediated immunity seems to block the tumor growth and give protective anti-tumor immune response. However, tumor associated macrophages (TAMs) might play an immunosuppressive role and subvert this anti tumor immunity leading to tumor progression and metastasis.

Methodology/principal Findings: The Cu (II) complex, (chelate), copper N-(2-hydroxy acetophenone) glycinate (CuNG), synthesized by us, has previously been shown to have a potential usefulness in immunotherapy of multiple drug resistant cancers.

Surfactant enhanced ricinoleic acid production using Candida rugosa lipase.

In this study, ricinoleic acid was produced on surfactant enhanced castor oil hydrolysis using Candida rugosa lipase. The most effective surfactant was Span 80. Employing fractional factorial design, the most suitable temperature and surfactant concentration were found to be 31 degrees C and 0.

Modeling of arsenic adsorption kinetics of synthetic and contaminated groundwater on natural laterite.

A simple shrinking core model is applied to predict the adsorption kinetics of arsenite and arsenate species onto natural laterite (NL) in a stirred tank adsorber. The proposed model is a two-resistance model, in which two unknown parameters, external mass transfer coefficient (K(f)) and pore diffusion coefficient (D(e)) are estimated by comparing the simulation concentration profile with the experimental data using a nonlinear optimization technique. The model is applied under various operating conditions, e.

The management of failed second-trimester termination of pregnancy.

Background: Management of failed medical second-trimester termination of pregnancy (TOP) is a challenge with best therapy not determined.

Study Design: This was a cross-sectional study using retrospective record review of all women requesting medical TOP in the second trimester from January to June 2005. A comparative analysis was done to determine differences in demography, surgical methods and complications between two groups: (a) women who successfully aborted (first-admission group) and (b) women who failed to abort during their first admission (repeat-admission group).

A TNF- and c-Cbl-dependent FLIP(S)-degradation pathway and its function in Mycobacterium tuberculosis-induced macrophage apoptosis.

Apoptosis is central to the interaction between pathogenic mycobacteria and host macrophages. Caspase-8-dependent apoptosis of infected macrophages, which requires activation of the mitogen-activated protein (MAP) kinase p38, lowers the spread of mycobacteria. Here we establish a link between the release of tumor necrosis factor (TNF) and mycobacteria-mediated macrophage apoptosis.

Absence of reptation in highly confined polymers.

We present results of mechanical stress relaxation measurements on polymers confined at the air-water interface in the form of a monolayer. Systematic measurements allow, to our knowledge, for the first time, observation of the scaling of the stress relaxation time of the highly confined polymers as a function of both surface concentration and molecular weight. The observed scaling is found to be very close to that expected for motion of unentangled polymer solutions with hydrodynamic interactions.

Buckling in polymer monolayers: molecular-weight dependence.

We present systematic investigations of buckling in Langmuir monolayers of polyvinyl acetate formed at the air-water interface. On compression the polymer monolayers are converted to a continuous membrane with a thickness of approximately 2-3 nm of well-defined periodicity, lambdab. Above a certain surface concentration the membrane undergoes a morphological transition buckling, leading to the formation of striped patterns.

Novel role of Wag31 in protection of mycobacteria under oxidative stress.

Wag31 of Mycobacterium tuberculosis belongs to the DivIVA family of proteins known to regulate cell morphology in Gram-positive bacteria. Here we demonstrate an unrecognized, novel role of Wag31 in oxidatively stressed mycobacteria. We report the cleavage of penicillin-binding protein 3 (PBP3) by the intramembrane metalloprotease Rv2869c (MSMEG_2579) in oxidatively stressed cells.

Role of a second stage partogram in predicting the outcome of normal labour.

Background: Management of the second stage of labour is dictated by arbitrary time limits rather than true measures of progress. No partogram is available for second stage of labour.

Objectives: To evaluate a partogram designed for use for the second stage of labour.

Morphological transitions in polymer monolayers under compression.

We present a systematic investigation of morphological transitions in poly vinylacetate Langmuir monolayers. On compression, the polymer monolayer is converted to a continuous membrane with a thickness of approximately 2-3 nm. Above a certain surface concentration the monolayer, on water, undergoes a morphological transition-buckling, leading to formation of striped patterns of period of lambda(b) approximately 160 nm, as determined from in situ grazing incidence small angle x-ray scattering measurements.

Maximization of bioconversion of castor oil into ricinoleic acid by response surface methodology.

In this study, response surface methodology was applied to optimize process variables like temperature, pH, enzyme concentration (mg/g oil), and buffer concentration (g/g oil) for hydrolysis of castor oil using Candida rugosa lipase. A 2(4) full factorial central composite design was used to develop the quadratic model that was subsequently optimized and the optimal conditions were as follows: temperature 40 degrees C, pH 7.72, enzyme concentration 5.

Complex dynamics in polymer nanocomposites.

Polymer nanocomposites offer the potential to create a new type of hybrid material with unique thermal, optical, or electrical properties. Understanding their structure, phase behavior, and dynamics is crucial for realizing such potentials. In this work we provide an experimental insight into the dynamics of such composites in terms of the temperature, wave vector, and volume fraction of nanoparticles, using multispeckle synchrotron x-ray photon correlation spectroscopy measurements on gold nanoparticles embedded in polymethylmethacrylate.

Unusual dynamical arrest in polymer grafted nanoparticles.

We present results of temperature dependent measurements of dynamics of polymer grafted nanoparticles with high grafting density with star polymerlike morphology. We observed for the low grafting density and hence low functionality sample, a dynamically arrested state with lowering of temperature, similar to what was conjectured earlier. However the high grafting density sample shows liquidlike relaxation at all measured temperatures.

Human immunodeficiency virus (HIV) antigens and RNA in HIV-seronegative women with cervical intraepithelial neoplasia.

While investigating whether proteins retrieved by cervicovaginal lavages (CVL) from women with cervical intraepithelial neoplasia (CIN) might correlate with risk of progression to invasive cervical cancer, we unexpectedly identified HIV gag and env glycoprotein in CVL from women with HIV-negative serology. HIV antigens were consistently identified by mass spectrometry (MS) in CVL from 4 women but were absent in CVL from the remaining 16 women. HIV serologies of all 20 patients were negative for both HIV-1 and HIV-2 antibodies.

Helicobacter pylori protein HP0175 transactivates epidermal growth factor receptor through TLR4 in gastric epithelial cells.

The pathophysiology of Helicobacter pylori-associated gastroduodenal diseases, ulcerogenesis, and carcinogenesis is intimately linked to activation of epidermal growth factor receptor (EGFR) and production of vascular endothelial growth factor (VEGF). Extracellular virulence factors, such as CagA and VacA, have been proposed to regulate EGFR activation and VEGF production in gastric epithelial cells. We demonstrate that the H.

Prevalence of Helicobacter pylori Infection in Peptic Ulcer Patients of Highly Endemic Kashmir Valley.

Objective This study aimed to find out prevalence of Helicobacter pylori (H. pylori) in peptic ulcer disease (PUD) which is highly endemic disease in Kashmir.Method This study consisted of 50 PUD patients and 30 asymptomatic volunteers.

Helicobacter pylori associated antral gastritis in peptic ulcer disease patients and normal healthy population of kashmir, India.

Aim: To study the association of Helicobacter pylori infection with chronic antral gastritis in peptic ulcer disease patients and healthy population of Kashmir.

Methods: 50 peptic ulcer patients (duodenal ulcer = 46, gastric ulcer = 2 and combined duodenal and gastric ulcer = 2) and 30 asymptomatic healthy volunteers were included in this study. Peptic ulcer was diagnosed on endoscopic examination.

Trends in racial disparities among the elderly for selected procedures.

The authors examine trends over 1997-2001 in racial or ethnic disparities in the utilization of three costly, referral-sensitive procedures among the elderly-coronary artery bypass grafting (CABG), percutaneous transluminal coronary angioplasty (PTCA), and hip/joint replacement. Using a multivariate framework, they undertake a simultaneous examination of the relationships between patient, local area context, and health systems on these admission types after comparing them to a control group. This period spans the implementation of the Balanced Budget Act and a major Department of Health and Human Services initiative to reduce disparities in cardiovascular and other diseases.

Human artificial chromosome assembly by transposon-based retrofitting of genomic BACs with synthetic alpha-satellite arrays.

The development of methodologies for the rapid assembly of synthetic alpha-satellite arrays recapitulating the higher-order periodic organization of native human centromeres permits the systematic investigation of the significance of primary sequence and sequence organization in centromere function. Synthetic arrays with defined mutations affecting sequence and/or organization may be evaluated in a de novo human artificial chromosome assay. This unit describes strategies for the assembly of custom built alpha-satellite arrays containing any desired mutation as well as strategies for the construction and manipulation of alpha satellite-based transposons.

Positive feedback and noise activate the stringent response regulator rel in mycobacteria.

Phenotypic heterogeneity in an isogenic, microbial population enables a subset of the population to persist under stress. In mycobacteria, stresses like nutrient and oxygen deprivation activate the stress response pathway involving the two-component system MprAB and the sigma factor, SigE. SigE in turn activates the expression of the stringent response regulator, rel.

Human placental extract offers protection against experimental visceral leishmaniasis: a pilot study for a phase-I clinical trial.

An aqueous extract of human placenta (HPE) was found to offer protection against established experimental visceral leishmaniasis in BALB/c mice and hamsters, whether the Leishmania donovani strain involved was one that was sensitive or resistant to pentavalent antimony. Intraperitoneal administration of the extract, into mice or hamsters that had been infected 2 months previously, led to antileishmanial T-cell proliferation among splenic mononuclear cells, the generation of host-protective cytokines (interferon-gamma, tumour necrosis factor and interleukin-12) and the upregulation of the expression of inducible nitric oxide synthase (and subsequent NO generation) in splenocytes. Furthermore, splenic macrophages from the HPE-treated mice showed increased generation of reactive oxygen species and enhanced surface expression of antigens of major histocompatibility complex class II (MHCII), and the extract restored the otherwise-defective antigen-presenting ability of the macrophages.