Active coping toward predatory stress is associated with lower corticosterone and progesterone plasma levels and decreased methylation in the medial amygdala vasopressin system

An active coping style displayed under stress – which involves proactive investigatory responses toward environmental threats – has been associated with reduced vulnerability to psychiatric illness. However, the neurobiological determinants of coping styles are not well understood. When rats are exposed to a naturalistic stressor (cat fur) in a group, some individuals in the group show robust active investigation of the stimulus while others show a passive response involving retreat, immobility and close aggregation with conspecifics. Here we explored endocrine and epigenetic correlates of these contrasting coping styles. Male Wistar rats (n = 48) were exposed to cat fur in groups of 4 and the passive and active responders were identified and assessed for endocrine and epigenetic differences. Three days after the final cat fur exposure, active responders had substantially lower plasma levels of corticosterone and progesterone than passive responders. Plasma and testicular testosterone levels did not differ between active and passive responders. Active responders had markedly less methylation of the AVP CGCG promoter region located at base 4970 in the posterodorsal region of the medial amygdala but did not differ in the methylation status of the CCGG sequence located at base 2243. This is in agreement with prior research suggesting that AVP and progesterone act in opposition within the medial amygdala to modulate stress-related behaviors. The present study reports striking endocrine and epigenetic differences between active and passive responders, providing insight into potential systems involved in the manifestation of differing coping styles.     

Expression,purification and substrate specificities of 3-nitrotoluene dioxygenase from Diaphorobacter sp. strain DS2

3-Nitotoluene dioxygenase (3-NTDO) is the first enzyme in the degradation pathway of 3-nitrotoluene (3-NT) by Diaphorobacter sp. strain DS2. The complete gene sequences of 3-NTDO were PCR amplified from genomic DNA of Diaphorobacter sp., cloned, sequenced and expressed. The 3-NTDO gene revealed a multi component structure having a reductase, a ferredoxin and two oxygenase subunits. Clones expressing the different subunits were constructed in pET21a expression vector system and overexpressed in E. coli BL21(DE3) host. Each subunit was individually purified separately to homogeneity. The active recombinant enzyme was reconstituted in vitro by mixing all three purified subunits. The reconstituted recombinant enzyme could catalyse biotransformations on a variety of organic aromatics.     

TLR4‐mediated skin carcinogenesis is dependent on immune and radioresistant cells

Skin cancers are the most commonly diagnosed cancers. Understanding what are the factors contributing to skin tumour development can be instrumental to identify preventive therapies. The myeloid differentiation primary response gene (MyD)88, the downstream adaptor protein of most Toll‐like receptors (TLR), has been shown to be involved in several mouse tumourigenesis models. We show here that TLR4, but not TLR2 or TLR9, is upstream of MyD88 in skin tumourigenesis. TLR4 triggering is not dependent on lipopolysaccharide associated to skin‐colonizing bacteria, but on the high mobility group box‐1 protein (HMGB1), an endogenous ligand of TLR4. HMGB1 is released by necrotic keratinocytes and is required for the recruitment of inflammatory cells and for the initiation of inflammation. The expression of TLR4 on both bone marrow‐derived and radioresistant cells is necessary for carcinogenesis. Consistently, a human tissue microarray analysis showed that melanoma and colon cancer display an over‐expression of TLR4 and its downstream adaptor protein MyD88 within tumours. Together, our results suggest that the initial release of HMGB1 triggers a TLR4‐dependent inflammatory response that leads to tumour development.     

Organic acid production and plant growth promotion as a function of phosphate solubilization by Acinetobacter rhizosphaerae strain BIHB 723 isolated from the cold deserts of the trans-Himalayas

An efficient phosphate-solubilizing plant growth–promoting Acinetobacter rhizosphaerae strain BIHB 723 exhibited significantly higher solubilization of tricalcium phosphate (TCP) than Udaipur rock phosphate (URP), Mussoorie rock phosphate (MRP) and North Carolina rock phosphate (NCRP). Qualitative and quantitative differences were discerned in the gluconic, oxalic, 2-keto gluconic, lactic, malic and formic acids during the solubilization of various inorganic phosphates by the strain. Gluconic acid was the main organic acid produced during phosphate solubilization. Formic acid production was restricted to TCP solubilization and oxalic acid production to the solubilization of MRP, URP and NCRP. A significant increase in plant height, shoot fresh weight, shoot dry weight, root length, root dry weight, and root, shoot and soil phosphorus (P) contents was recorded with the inoculated treatments over the uninoculated NP₀K or NP_TCPK treatments. Plant growth promotion as a function of phosphate solubilization suggested that the use of bacterial strain would be a beneficial addition to the agriculture practices in TCP-rich soils in reducing the application of phosphatic fertilizers.     

Synthesis, cytotoxicity, and structure-activity relationship (SAR) studies of andrographolide analogues as anti-cancer agent

A series of analogues of andrographolide, prepared through chemo-selective functionalization at C14 hydroxy, have been evaluated for in vitro cytotoxicities against human leukemic cell lines. Two of the analogues (6a, 9b) exhibited significant potency. Preliminary studies on structure-activity relationship (SAR) revealed that the α-alkylidene-γ-butyrolactone moiety of andrographolide played a major role in the activity profile. The structures of the analogues were established through spectroscopic and analytical data.     

Azaindole N-methyl hydroxamic acids as HIV-1 integrase inhibitors-II. The impact of physicochemical properties on ADME and PK

HIV-1 integrase is one of three enzymes encoded by the HIV genome and is essential for viral replication, and HIV-1 IN inhibitors have emerged as a new promising class of therapeutics. Recently, we reported the discovery of azaindole hydroxamic acids that were potent inhibitors of the HIV-1 IN enzyme. N-Methyl hydroxamic acids were stable against oxidative metabolism, however were cleared rapidly through phase 2 glucuronidation pathways. We were able to introduce polar groups at the β-position of the azaindole core thereby altering physical properties by lowering calculated log D values (c Log D) which resulted in attenuated clearance rates in human hepatocytes. Pharmacokinetic data in dog for representative compounds demonstrated moderate oral bioavailability and reasonable half-lives. These ends were accomplished without a large negative impact on enzymatic and antiviral activity, thus suggesting opportunities to alter clearance parameters in future series.     

Overexpression of γ-tocopherol methyl transferase gene in transgenic Brassica juncea plants alleviates abiotic stress: Physiological and chlorophyll a fluorescence measurements

Tocopherols (vitamin E) are lipid soluble antioxidants synthesized by plants and some cyanobacteria. We have earlier reported that overexpression of the γ-tocopherol methyl transferase (γ-TMT) gene from Arabidopsis thaliana in transgenic Brassica juncea plants resulted in an over six-fold increase in the level of α-tocopherol, the most active form of all the tocopherols. Tocopherol levels have been shown to increase in response to a variety of abiotic stresses. In the present study on Brassica juncea, we found that salt, heavy metal and osmotic stress induced an increase in the total tocopherol levels. Measurements of seed germination, shoot growth and leaf disc senescence showed that transgenic Brassica juncea plants overexpressing the γ-TMT gene had enhanced tolerance to the induced stresses. Analysis of the chlorophyll a fluorescence rise kinetics, from the initial “O” level to the “P” (the peak) level, showed that there were differential effects of the applied stresses on different sites of the photosynthetic machinery; further, these effects were alleviated in the transgenic (line 16.1) Brassica juncea plants. We show that α-tocopherol plays an important role in the alleviation of stress induced by salt, heavy metal and osmoticum in Brassica juncea.     

A multiattribute utility evaluation of different methods for the detection of enteric protozoa causing diarrhea in AIDS patients

Background  

Enteric protozoa and sporozoa have emerged as important opportunistic parasites and can cause fatal infections in AIDS patients. The line of treatment being different for them necessitates an accurate and prompt identification of these to avoid empirical treatment. In this study which is the first of its kind from India we did a comprehensive evaluation of different techniques, comparing them on the basis of the attributes like yield, cost, time taken, expertise and infrastructure. For the first time combination of Calcoflour White and DAPI, a nuclear stain, were used to identify Microsporidia spp. Thus, a diagnostic protocol was devised for rapid, sensitive and cost effective identification of the opportunistic enteric protozoa.     

Removal of chromium by some multipurpose tree seedlings of Indian thar desert

An experiment was conducted to study the potential of chromium (Cr) phytoaccumulatory capabilities of four tree species viz., Anogeissus latifolia, Terminalia arjuna, Tecomella undulata, and Salvadora persica Possibility of enhancement of Cr uptake by citric acid and vesicular arbuscular mycorrhizal fungi (VAM) amendments were also tried. Cr is a major pollutant of the environment. Chromium can exist in oxidation states from III to VI, but the most stable and common forms of Cr are trivalent and hexavalent species. Cr(VI) was more toxic to the tree growth in terms of collar diameter (CD) increment in all the tree species than Cr(lll). Roots accumulated more Cr than shoots in all the tree species. There was more than 10 fold increase in root Cr content in comparison with shoot Cr content in all the trees at all the concentration of Cr and all sources of Cr. Citric acid significantly increased the Cr content in the tissues of roots in all the species under both speciation of Cr. The highest increase in Cr content brought by 20 mM citric acid addition was in A. latifolia Results suggest that Anogeissus latifolia is a potential Cr accumulator with citric acid as soil amendment.