Differential brain expression of the Alzheimer''s amyloid precursor protein.

The expression of the Alzheimer amyloid protein precursor (AAPP) was examined in human, monkey, dog and rat brains. Two proteins, one identified as AAPP695 and the other as AAPP751, were immunoprecipitated from the in vitro translation of human, dog and rat brain polysomes. The AAPP751 to AAPP695 ratio was highest in human, intermediate in dog and lowest in rat brain polysomes. Human cerebral cortex contained higher levels of the AAPP751 mRNA than either dog or rat cortex. AAPP695 was detected in both cerebral cortex and cerebellum of all species examined. In contrast, AAPP751 was detected predominantly in the cortex of human, monkey and to a lesser extent dog brains while it was not detected in rat brain. These findings indicate that the amyloid precursors are differentially expressed in different mammalian brains and suggest that AAPP751 is mainly expressed in the brain regions involved in plaque formation.     

The flagellar apparatus ofDunaliella: Isolation of basal body-flagellar root complex

Summary InDunaliella bioculata, a biflagellate wall-less unicellular alga, the cytoskeleton is organized around the two basal bodies. Each basal body is associated with two dissymetric flagellar roots and numerous micro tubules which constitue a regular frame around the cell. We isolated the basal body-flagellar-root apparatus and studied its ultrastructure after negative staining. The two different flagellar roots are formed of microtubules and bundles of twisted filaments 3,5–4 nm in diameter. The proximal end of each root fans out and envelopes the basal body. We have shown preliminary results on the protein composition of basal body-flagellar roots fraction.     

Extracellular Na+, but not Na+/H+ exchange, is necessary for receptor-mediated arachidonate release in platelets.

The effect of extracellular Na+ removal and replacement with other cations on receptor-mediated arachidonate release in platelets was studied to investigate the role of Na+/H+ exchange in this process. Replacement with choline+, K+, N-methylglucamine+ (which abolished the thrombin-induced pHi rise) or Li+ (which allowed a normal thrombin-induced pHi rise) significantly decreased arachidonate release in response to all concentrations (threshold to supra-maximal) of thrombin and collagen. This inhibition was not reversed by NH4Cl (10 mM) addition, which raised the pHi in the absence of Na+, but, on the contrary, NH4Cl addition further decreased the extent of thrombin- and collagen-induced arachidonate release, as well as decreasing 'weak'-agonist (ADP, adrenaline)-induced release and granule secretion in platelet-rich plasma. No detectable pHi rises were seen with collagen (1-20 micrograms/ml) and ADP (10 microM) in bis-(carboxyethyl)carboxyfluorescein-loaded platelets. Inhibition of thrombin-induced pHi rises was seen with 0.5-5 microM-5-NN-ethylisopropylamiloride (EIPA), but at these concentrations EIPA had little effect on thrombin-induced arachidonate release. At higher concentrations such as those used in previous studies (20-50 microM), EIPA inhibited aggregation/release induced by collagen and ADP in Na+ buffer as well as in choline+ buffer (where there was no detectable exchanger activity), suggesting that these concentrations of EIPA exert 'non-specific' effects at the membrane level. The results suggest that (i) Na+/H+ exchange and pHi elevations are not only necessary, but are probably inhibitory, to receptor-mediated arachidonate release in platelets, (ii) inhibition of receptor-mediated release in the absence of Na+ is most likely due to the absent Na+ ion itself, and (iii) caution should be exercised in the use of compounds such as EIPA, which, apart from inhibiting the Na+/H+ exchanger, have other undesirable and misleading effects in platelets.     

Flow of toxic metals in food-web components of tropical mangrove ecosystem,Southern India

The concentration of heavy metals in water, sediment, and various food-web components like plankton, shrimp, bivalve, and fishes were collected from Muthupet mangrove ecosystem. Heavy metal concentration in water samples was relatively lesser than the biological and sediment samples. Among the heavy metals studied, zinc showed highest concentration ranged from 1.81 to 81.5 mg/kg or mg/L, whereas Cd (0–26.06 mg/kg or mg/L) was found to be lesser in all the samples except a few organisms viz. Anadara sp. (26.06 mg/kg), Coilia sp. (10.09 mg/kg), Anguila sp. (9.14 mg/kg), and Tachysurus maculates (6.95 mg/kg) observed during this study. Pb and Cu were ranged from 10.29 to 14.99 mg/kg and 0.59 to 16.06 mg/kg, respectively. The reported values of heavy metals were several folds higher than permissible levels of international regulatory agencies like WHO, FAO, and USEPA. The order of accumulation of heavy metals in biological samples are as follows: Pb > Cu > Zn > Cd. All the biota showed a higher degree of bioconcentration factor for Zn, in the range of 3.90–34.39. Principal component analysis concluded that Muthupet was contaminated by lithogenic as well as anthropogenic activities.Therefore, field observation and sample analysis clearly indicated that sampling sites were polluted with both point and nonpoint source of pollution.     

The effect of ethanol on the phase behavior of membrane lipids extracted from Clostridium thermocellum strains

The phase behavior of aqueous dispersions of extracted lipids from Clostridium thermocellum wild-type and ethanol-tolerant C919 cells has been examined by DSC. The optimum growth temperature of this anaerobe is 60°C. The wild-type lipids exhibit a broad phase transition centered at 30°C; the C919 mutant lipids show a 10°C lower T_m. The direct addition of growth inhibiting concentrations of ethanol has no significant effect on T_m or headgroup mobility (monitored by ²H-NMR) of either set of lipids. In contrast, wild-type cells adapted to growth in ethanol exhibit a broadened and lower T_m (15–25°C plateau); C919 membrane lipids do not exhibit significantly altered phase behavior when adapted to growth in ethanol. Both wild-type and mutant membranes have fatty acid composition changes upon growth in ethanol, which increases lower-melting components. It is concluded that fatty acid changes which occur upon adaptation of the organism to growth in ethanol are secondary responses and not necessarily direct responses to alter membrane fluidity.     

Gene and protein interaction network analysis in the epithelial-mesenchymal transition of Hertwig's Epithelial Root Sheath reveals periodontal regenerative drug targets – An in silico study

Background and aimHertwig’s Εpithelial Root Sheath (HΕRS) has a major function in the developing tooth roots. Earlier research revealed that it undergoes epithelial–mesenchymal transition, a vital process for the morphogenesis and complete development of the tooth and its surrounding periodontium. Few studies have demonstrated the role of HERS in cementogenesis through ΕMΤ. The background of this in-silico system biology approach is to find a hub protein and gene involved in the EMT of HERS that may uncover novel insights in periodontal regenerative drug targets.Materials and methodsThe protein and gene list involved in epithelial–mesenchymal transition were obtained from literature sources. The protein interaction was constructed using STRING software and the protein interaction network was analyzed. Molecular docking simulation checks the binding energy and stability of protein-ligand complex.ResultsResults revealed the hub gene to be DYRK1A(Hepcidin), and the ligand was identified as isoetharine. SΤRIΝG results showed a confidence cutoff of 0.9 in sensitivity analysis with a condensed protein interaction network. Overall, 98 nodes from 163 nodes of expected edges were found with an average node degree of 11.9. Docking results show binding energy of −4.70, and simulation results show an RMSD value of 5.6 Å at 50 ns.ConclusionIsoetharine could be a potential drug for periodontal regeneration.     

Examination into the taxonomic position of Bacillus thermotolerans Yang et al., 2013, proposal for its reclassification into a new genus and species Quasibacillus thermotolerans gen. nov., comb. nov. and reclassification of B. encimensis Dastager et al., 2015 as a later heterotypic synonym of B. badius

Two novel Gram-staining positive, rod-shaped, moderately halotolerant, endospore forming bacterial strains 5.5LF 38TD and 5.5LF 48TD were isolated and taxonomically characterized from a landfill in Chandigarh, India. The analysis of 16S rRNA gene sequences of the strains confirmed their closest identity to Bacillus thermotolerans SgZ-8T with 99.9% sequence similarity. A comparative phylogenetic analysis of strains 5.5LF 38TD, 5.5LF 48TD and B. thermotolerans SgZ-8^T confirmed their separation into a novel genus with B. badius and genus Domibacillus as the closest phylogenetic relatives. The major fatty acids of the strains are iso-C_15:0 and iso-C_16:0 and MK-7 is the only quinone. The major polar lipids are diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The digital DNA-DNA hybridization (DDH) and ortho average nucleotide identity (ANI) values calculated through whole genome sequences indicated that the three strains showed low relatedness with their phylogenetic neighbours. Based on evidences from phylogenomic analyses and polyphasic taxonomic characterization we propose reclassification of the species B. thermotolerans into a novel genus named Quasibacillus thermotolerans gen. nov., comb. nov with the type strain SgZ-8^T (= CCTCC AB2012108^T = KACC 16706^T). Further our analyses also revealed that B. encimensis SGD-V-25^T is a later heterotypic synonym of Bacillus badius DSM 23^T.     

Metabolic effects of oral contraceptives in monkeys fed adequate protein & low proein diets

The effects of 2 oral contraceptives, Ovulen and Norlestrin, were studied in monkeys fed adequate protein and low protein diets. The experiment was carried out in parts. In the first one, the administration of contraceptives was cyclic and similar to that employed in human subjects. In the other experiments, the contraceptives were given continuously and an attempt was made to exaggerate the deleterious effects of the oral contraceptive on the liver by including small doses of a known hepatotoxic agent, aflatoxin (AT). In Experiment 1, 45 female monkeys were divided into 2 groups of 20 and 25 and received an adequate protein (16%) and low protein diet (4%) respectively. Each monkey was fed 1/5 of a tablet of Ovulen or Norlestrin orally for 3 weeks, and then administration was discontinued for 1 week. In Experiment 2, 35 female monkeys were divided into 7 groups of 5 each. All the animals recieved 4% protein diet. 5 groups were tube fed at the rate of 100 cal/kg body weight, while 2 groups were given diet ad libitum. Group I received the diet alone while groups II-V received 10 mcg AT, 25 mcg AT, 10 mcg AT plus 1/5 Ovulen tablets, and 25 mcg AT plus 1/5 Ovulen tablet respectively daily. Groups VI and VII received the diet ad libitum but were orally fed 75 mcg AT and 75 mcg AT plus 1/5 Ovulen tablet respectively. Serum glutamic-oxalacetic transaminase activity and alkaline phosphatase activity were studied at regular intervals after the administation of oral contraceptives in the experiments. Serum proteins and hemoglobin were also determined. Monkeys fed oral contraceptives showed increased serum glutamic-oxalacetic transaminase and alkaline phosphatase activities irrespective of the level of protein in the diet. Livers of animals receiving oral contraceptives were morphologically similar to the controls fed respective diets. The experiments were conducted for a period of almost 2 years.