Ambient Inclusion Trails (AITs) from the Neoproterozoic Gangolihat Formation,Lesser Himalaya,India

Discovery of well-preserved Ambient Inclusion Trails (AITs) is reported for the first time in India from stromatolitic dolomite unit of the Neoproterozoic Gangolihat Formation, Kumaun Lesser Himalaya. AITs are distinct microtubular structures formed by migration of a mineral in a rock substrate. They exhibit several noncrystallographic morphologies such as curved and helical types among others. Mode of field occurrence, association, and petrographic textures suggest that AITs are indigenous to the host rock. Based on the physico-chemical conditions necessary for the formation of AITs, involvement of a biological process is considered for the genesis of AITs in the Gangolihat Formation.     

Deciphering the diversity of culturable thermotolerant bacteria from Manikaran hot springs

The aim of this study was to analyze and characterize the diversity of culturable thermotolerant bacteria in Manikaran hot springs. A total of 235 isolates were obtained employing different media, and screened for temperature tolerance (40 °C–70 °C). A set of 85 isolates tolerant to 45 °C or above were placed in 42 phylogenetic clusters after amplified ribosomal DNA restriction analysis (16S rRNA-ARDRA). Sequencing of the 16S rRNA gene of 42 representative isolates followed by BLAST search revealed that the majority of isolates belonged to Firmicutes, followed by equal representation of Actinobacteria and Proteobacteria. Screening of representative isolates (42 ARDRA phylotypes) for amylase activity revealed that 26 % of the isolates were positive, while 45 % exhibited protease activity, among which one amylase and six protease producers were tolerant up to 70 °C. BIOLOG-based identification of 13 isolates exhibiting temperature tolerance up to 70 °C, using carbon utilization patterns and sensitivity to chemicals, revealed a high degree of correlation with identification based on 16S rRNA gene sequencing for all isolates, except one (M48). These promising isolates showing a range of useful metabolic attributes demand to be explored further for industrial and agricultural applications.     

Biosynthesis of the Naturally Occurring Nucleoside Antibiotics from Adenosine

Abstract

9-β-D-Arabinofuranosyladenine (ara-A, l), first isolated from the culture filtrates of StreDtomyces antibioticus, has a broad spectrum of activity against DNA viruses in cell culture and is successfully used in therapy of herpes simplex encephalitis, neonatal herpes, herpes zoster and chronic myelogenous leukemia¹. 2′-Chlorodeoxycoformycin (2′CldCF, 2), 2′-amino-Zt-deoxyadenosine (3) and nucleocidin (4) have been isolated from the culture medium of Fctinomadura and S. clavus, respectively.     

Structure of orthenthose

A new tetrasaccharide, orthenthose, has been isolated from the dried twigs of Orthenthera viminea (Family: Asclepiadaceae). By spectral and chemical procedures, this new tetrasaccharide has been shown to be O-α-l-oleandropyranosyl-(1→4)-O-α-l-oleandropyranosyl-(1→4)-O-α-l-oleandropyranosyl-(1→4)-β-l-oleandropyrano se.     

Proton HR-MAS MR spectroscopy of oral squamous cell carcinoma tissues: an ex vivo study to identify malignancy induced metabolic fingerprints

Oral squamous cell carcinoma (SCC) represents more than 90% of all head and neck cancers as reported by Hermans (Cancer Imaging, 5(Spec No A), S52–S57, 2005), which draws attention of investigative research for novel predictive metabolic biomarkers to understand the malignancy induced biochemical perturbations occurring at molecular level. In the present work, proton HR-MAS NMR spectroscopic studies have been performed on resected human oral SCC tumor tissues, its neighboring margins and bed tissues (n = 159), obtained from 36 patients (n = 27 training set; n = 9 unknown test set), for the identification of metabolic fingerprints. The proton NMR spectra were then subjected to chemometric unsupervised PCA and supervised OSC-filtered PCA and PLS-DA multivariate analysis. Application of PLS-DA on orthogonally signal corrected training data-set (n = 120 tissue specimens; 27 patients) allowed >95% correct classification of malignant tissues from benign samples with >98% specificity and sensitivity. The OSC-PLS-DA model thus constructed was used to predict the class membership of unknown tissue specimens (n = 39) obtained from nine patients. These tissue samples were correctly predicted in its respective histological categories with 97.4% diagnostic accuracy. The regression coefficients obtained from OSC-filtered PLS-DA model indicated that malignant tissues had higher levels of glutamate, choline, phosphocholine, lactate, acetate, taurine, glycine, leucine, lysine, isoleucine and alanine, and lower levels of creatine and PUFA, representing altered metabolic processes (lipidogenesis, protein synthesis, and volume regulation) during tumor progression. Thus proton HR-MAS MR spectroscopy could efficiently identify the metabolic perturbations of malignant tumor from non-malignant bed and margins tissue specimens, which may be helpful in understanding the extent of tumor penetration in neighboring tissues.     

Syntaxin 16 Regulates Lumen Formation during Epithelial Morphogenesis

The formation and maintenance of cell-cell junctions, both under physiological and pathological conditions, requires the targeting and trafficking of junctional proteins. Proteins of the syntaxin (Stx)-family localize to a variety of subcellular membranes and contribute to intracellular transport of cargo by regulating vesicle fusion events at these sites. Unlike plasma membrane localized Stxs, the roles of endosome- and Golgi-localized stx proteins in epithelial morphogenesis are less understood. Here we show that Stx16– an endosome- and Golgi-localized target-membrane soluble N-ethylmaleimide attachment protein receptor (t-SNARE) that plays a role in membrane trafficking between these compartments – is essential for lumen development. In cultured Madin Darby Canine Kidney (MDCK) cells, Stx16 was selectively upregulated as sparsely plated cells attained confluency. Stx16-depleted confluent monolayers consistently showed lower transepithelial resistance than control monolayers, and failed to maintain endogenous and ectopically expressed E-cadherin at the adherens junctions due to decreased recycling. We further found that whereas cysts formed by MDCK cells cultured in Matrigel have a single hollow lumen, those formed by stx16-depleted counterparts had multiple lumens, due to abnormal orientiation of the mitotic spindle. Finally, a similar role for stx16 function in vivo is indicated by our analysis of pronephric-duct development in zebrafish expressing the claudinB:lynGFP transgene; lack of stx16 function in this structure (in stx16-morphant embryos) led to the development of enlarged, torturous pronephric ducts with more than one lumen. Taken together, our in vitro and in vivo studies establish a role for Stx16 in maintaining the integrity of cell-cell junctions, and thereby in morphogenesis of the kidney epithelial lumen.     

Mechanism of action of aflatoxin B1 in Bacillus megaterium

Bacillus megaterium cells from various growth phases were equally susceptible to the lethal effects of aflatoxin B1. Known surfactants (EDTA and Tween-80) accentuated the effects of aflatoxin B1. Viability and inulin uptake in aflatoxin B1-exposed cells decreased considerably. The effect was concentration dependent. A straight-line relationship observed in the death curve indicated a single target for aflatoxin B1 action in B. megaterium. Leakage of intracellular constituents in B. megaterium was also concentration dependent, and this can be related to the extent of cell membrane damage.     

Evaluation of ammonium hydroxide as preservative for ground meat

Summary Ammonium hydroxide when added at 0.134 to 0.67m to ground-meat, decreased the total number of aerobic bacteria and, to a lesser extent, Gram-negative bacteria at 37°C, 4°C and –20°C. The plate count at the same pH adjusted with 1m NaOH was considerably more than when 0.4m NH₄OH had been used, indicating that NH₄OH was acting as preservative for ground-meat and not the merely changing the pH. The changes in extract release volume, water holding capacity, soluble protein nitrogen and cook out losses were much less in ground meat containing NH₄OH as compared to control (no preservative) or containing NaOH.

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Resumen La adición de hidróxido amónico a concentraciones de 0.134 a 0.67m disminuyó el número total de bacterias aerobias y en menor proporción la cantidad de bacterias gram negativas a 37°C, 4°C y a –20°C. El conteo efectuado a un mismo pH ajustado con NaOH 1m o bien con NH₄OH 0.4m fue considerablemente superior en el primer caso, indicando que el efecto de NH₄OH no era únicamente debido al cambio de pH sino que extracto liberado, en la capacidad de retención de agua, en las proteinas/nitrógeno soluble y las perdidas por cocción fueron menores en la carne picada que contenía NH₄OH comparada con el control (sin preservativo) o con la que contenía NaOH.

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Résumé L'ajout d'ammoniaque de 0.134 à 0.67m à la viande moulue fait décroître le nombre total de bactéries aérobies et, dans une moindre mesure, de bactéries Gram-négatives, tant à 37°C qu'à 4°C et à –20°C. Le comptage sur boîte de Pétri au même pH, obtenu par ajustement au NaOH 1m, révèle des valeurs considérablement plus élevées que lorsque l'ammoniaque 0.4m est utilisé, indiquant par là que c'est bien l'ammoniaque qui agit en tant que préservatif pour la viande moulue et non le seul changement de pH. Les changements en volume d'extrait relâché, en capacité de rétention d'eau, en azote protéique soluble, sont bien moins prononcés dans le cas de la viande moulue contenant de l'ammoniaque que dans le contrôle sans préservatif ou contenant du NaOH.