Synthesis and in vitro antimicrobial activities of 2-hydroxy-6-methyl-7-(arylamino)-1,7-dihydropurin-8-ones

A number of 2-hydroxy-6-methyl-7-(arylamino)-1,7-dihydropurin-8-ones have been synthesized. 3-Oxo-2-(arylhydrazono)butyric acid ethyl ester were acetylated and treated with triethyl amine and formamide in presence of 1,4-dioxane to yield N-(5-acetyl-4-ethoxy-2-oxo-2,5-dihydro-imidazol-1-yl)-N-arylacetamide, which on refluxation with urea and freshly prepared sodium ethoxide yielded the title compound. All the newly synthesized compounds have been characterized by spectroscopic and elemental analysis data. The synthesized compounds were screened against a representative panel of susceptible and resistant Gram-positive and Gram-negative bacteria using a standard antibiotic drug purinthol as control. Quantitative structure-activity relationship has also been interpreted in terms of correlation of biological activity with molecular refractive index parameters (M(R)) and Hammett substituent constant (sigma).     

In vitro cultivation of Plasmodium falciparum: studies with modified medium supplemented with ALBUMAX II and various animal sera

RPNI, a combination of three commercially available growth media (RPMI-1640, NCTC-135 and IMDM) has been found to support long term continuous cultivation of 3D7 strain of Plasmodium falciparum in the presence of 10% bovine calf serum. During the present study, the suitability of this medium was evaluated for the development of P. falciparum in the presence of horse, goat and rabbit sera as well as various concentrations of ALBUMAX II. RPNI medium supplemented with 10% bovine calf serum (RPNI-BCS) was used as control. The cultures were maintained in candle jars protocol and parasitaemia was monitored daily up to day 7. Horse, goat and rabbit sera all supported the development of P. falciparum. Horse serum gave best results in RPNI medium and supported continuous culture up to day 100. The parasitaemia in the presence of ALBUMAX was significantly higher in RPNI than in RPMI-1640. Addition of hypoxanthine in RPMI-1640 caused an increase in parasitaemia whereas no obvious advantage could be observed in RPNI. The findings exhibited that medium RPNI has an edge over conventional RPMI-1640 medium for in vitro cultivation of P. falciparum.     

Overexpression of WsSGTL1 Gene of Withania somnifera Enhances Salt Tolerance,Heat Tolerance and Cold Acclimation Ability in Transgenic Arabidopsis Plants

Background

Sterol glycosyltrnasferases (SGT) are enzymes that glycosylate sterols which play important role in plant adaptation to stress and are medicinally important in plants like Withania somnifera. The present study aims to find the role of WsSGTL1 which is a sterol glycosyltransferase from W. somnifera, in plant’s adaptation to abiotic stress.

Methodology

The WsSGTL1 gene was transformed in Arabidopsis thaliana through Agrobacterium mediated transformation, using the binary vector pBI121, by floral dip method. The phenotypic and physiological parameters like germination, root length, shoot weight, relative electrolyte conductivity, MDA content, SOD levels, relative electrolyte leakage and chlorophyll measurements were compared between transgenic and wild type Arabidopsis plants under different abiotic stresses - salt, heat and cold. Biochemical analysis was done by HPLC-TLC and radiolabelled enzyme assay. The promoter of the WsSGTL1 gene was cloned by using Genome Walker kit (Clontech, USA) and the 3D structures were predicted by using Discovery Studio Ver. 2.5.

Results

The WsSGTL1 transgenic plants were confirmed to be single copy by Southern and homozygous by segregation analysis. As compared to WT, the transgenic plants showed better germination, salt tolerance, heat and cold tolerance. The level of the transgene WsSGTL1 was elevated in heat, cold and salt stress along with other marker genes such as HSP70, HSP90, RD29, SOS3 and LEA4-5. Biochemical analysis showed the formation of sterol glycosides and increase in enzyme activity. When the promoter of WsSGTL1 gene was cloned from W. somnifera and sequenced, it contained stress responsive elements. Bioinformatics analysis of the 3D structure of the WsSGTL1 protein showed functional similarity with sterol glycosyltransferase AtSGT of A. thaliana.

Conclusions

Transformation of WsSGTL1 gene in A. thaliana conferred abiotic stress tolerance. The promoter of the gene in W.somnifera was found to have stress responsive elements. The 3D structure showed functional similarity with sterol glycosyltransferases.     

A comparative analysis of dynamic grids vs. virtual grids using the A3pviGrid framework

With the proliferation of Quad/Multi-core micro-processors in mainstream platforms such as desktops and workstations; a large number of unused CPU cycles can be utilized for running virtual machines (VMs) as dynamic nodes in distributed environments. Grid services and its service oriented business broker now termed cloud computing could deploy image based virtualization platforms enabling agent based resource management and dynamic fault management. In this paper we present an efficient way of utilizing heterogeneous virtual machines on idle desktops as an environment for consumption of high performance grid services. Spurious and exponential increases in the size of the datasets are constant concerns in medical and pharmaceutical industries due to the constant discovery and publication of large sequence databases. Traditional algorithms are not modeled at handing large data sizes under sudden and dynamic changes in the execution environment as previously discussed. This research was undertaken to compare our previous results with running the same test dataset with that of a virtual Grid platform using virtual machines (Virtualization). The implemented architecture, A3pviGrid utilizes game theoretic optimization and agent based team formation (Coalition) algorithms to improve upon scalability with respect to team formation. Due to the dynamic nature of distributed systems (as discussed in our previous work) all interactions were made local within a team transparently. This paper is a proof of concept of an experimental mini-Grid test-bed compared to running the platform on local virtual machines on a local test cluster. This was done to give every agent its own execution platform enabling anonymity and better control of the dynamic environmental parameters. We also analyze performance and scalability of Blast in a multiple virtual node setup and present our findings. This paper is an extension of our previous research on improving the BLAST application framework using dynamic Grids on virtualization platforms such as the virtual box.     

Linkage analysis of three families with arrythmogenic right ventricular cardiomyopathy in India

BACKGROUND:

Arrythmogenic Right Ventricular Cardiomyopathy (ARVC) is a primary myocardial disorder morphologically characterized by subtle to severe replacement of the right ventricular myocardium by fatty and fibrous tissue. ARVC is known to be highly prevalent in European population with recent reports implicating it to be a major cause of sudden death in young individuals even from American and Asian population.

AIM:

To implicate or exclude TMEM43 (ARVC-5), DSP(ARVC-8) genes and the yet to be identified gene at ARVC-6 locus in the pathogenesis in three families affected with ARVC from India.

MATERIALS AND METHODS:

Three families comprising of 42 affected/unaffected members were included in the study. Three microsatellite markers, D3S3613 (ARVC5) D10S1664 (ARVC6), D6S309 (ARVC8) were genotyped by PCR-based native PAGE. Two-point Linkage analysis was performed using LINKAGE program version 5.2

RESULTS AND DISCUSSION:

LOD scores from linkage analysis for the microsatellite marker D10S1664 (ARVC-6) in families KS and REV have shown positive value hinting the involvement of this locus in the etiology of ARVC, while linkage analysis in the SB family ruled out involvement of DSP, TMEM43 and ARVC-6, as negative LOD scores were obtained with all three loci. Therefore, linkage analysis carried out in the present study indicates that ARVC-6 (cumulative LOD score is equal to plus 1.203376 at θ is equal to 0.05) could be the locus harboring the mutated gene in two out of three families.     

Vaccinia virus infection induces dendritic cell maturation but inhibits antigen presentation by MHC class II

Vaccinia virus (VV) infection is known to inhibit dendritic cells (DC) functions in vitro. Paradoxically, VV is also highly immunogenic and thus has been used as a vaccine. In the present study, we investigated the effects of an in vivo VV infection on DC function by focusing on early innate immunity. Our data indicated that DC are activated upon in vivo VV infection of mice. Splenic DC from VV-infected mice expressed elevated levels of MHC class I and co-stimulatory molecules on their cell surface and exhibited the enhanced potential to produce cytokines upon LPS stimulation. DC from VV-infected mice also expressed a high level of interferon-beta. However, a VV infection resulted in the down-regulation of MHC class II expression and the impairment of antigen presentation to CD4 T cells by DC. Thus, during the early stage of a VV infection, although DC are impaired in some of the critical antigen presentation functions, they can promote innate immune defenses against viral infection.     

t-plasminogen activator inhibitor-1 polymorphism in idiopathic pulmonary arterial hypertension

AIM:

The aim of the present study was to identify the possible genotypic association of 3’UTR Hind III polymorphism of Plasminogen activator Inhibitor-1 (PAI-1) gene with idiopathic pulmonary arterial hypertension (IPAH).

BACKGROUND:

IPAH is a disorder with abnormally raised mean pulmonary arterial pressure and increase in the resistance to blood flow in pulmonary artery. One of the pathological features seen is development of intraluminal thrombin deposition leading to thrombosis. Plasminogen activator inhibitor-1 is an important inhibitor of the fibrinolytic system; its up-regulation may suppress fibrinolysis and result in an increased risk of thrombosis.

METHOD:

Blood samples from 54 IPAH patients and 100 healthy voluntary donors were analyzed by PCR-RFLP method for 3’UTR Hind III polymorphism.

RESULTS AND DISSCUSSION:

A significant association of Hd2 allele with the disease was observed. Raised mean level of right ventricular systolic pressure was observed in the Hd2/Hd2 genotypic patients, strengthening the role of Hd2 allele in the disease progression. Our data suggests an association of Hd2/Hd2 genotype, which may lead to the up-regulation of PAI-1 gene leading to increased levels of PAI-1, which is seen in IPAH. PAI-1 competes with plasminogen activators and hinders the normal mechanism of plasminogen activation system and leads to thrombosis and formation of plexiform lesions in the lung tissue, further strengthening its role in tissue remodeling and disease progression.