635 research outputs found
IDENTIFICATION OF LEAD COMPOUNDS WITH COBRA VENOM DETOXIFICATION ACTIVITY IN ANDROGRAPHIS PANICULATA (BURM. F.) NEES THROUGH IN SILICO METHOD
Objective: To validate the cobra venom detoxification activity in Andrographis paniculata and identification of lead molecules.Methods: The structures of phytochemicals were procured from databases or created by ChemSketch and CORINA. Of the14 cobra venom proteins selected as receptor molecules, the 3D structures of phospholipase A2 and cobrotoxin were retrieved from protein data bank and serine protease, L-amino acid oxidase and acetylcholinesterase were modelled. The structures of remaining nine proteins were retrieved from SWISSMODEL repository. The active sites of the receptor molecules were detected by Q-site Finder and Pocket Finder. Docking was carried out by AutoDock 4.2. To avoid error in lead identification, top ranked five hit molecules obtained in AutoDock were again docked by iGEMDOCK, FireDock and HEX server. The results were analyzed following Dempster-Shafer theory. The molecular property and biological activity of the lead molecules were predicted by molinspiration.Results: Docking results in AutoDock revealed that the plant having phytochemicals for detoxifying all venom proteins but only one potential hit molecule against each of the following proteins viz., cobramin A, cobramin B, long neurotoxin 1, long neurotoxin 2, long neurotoxin 3, long neurotoxin 4 and long neurotoxin 5 and several hit molecules (6-12) were obtained against phospholipase A2, cobrotoxin, cytotoxin 3, acetylcholinesterase, L-aminoacid oxidase, proteolase and serine protease. Therefore, in latter case lead molecules were identified through Dempster-Shafer theory. The theoretical prediction of drug likeliness and bioactivity of the molecules highlighted the plant as the best source of anti-cobra venom drug.Conclusion: The results substantiated its traditional use and further investigation on biological system is essential for evolving novel drug.Keywords: Andrographis paniculata, Cobra, Docking, Venom, Protein, Neurotoxin, Snake bit
Explicating the Conditions Under Which Multilevel Multiple Imputation Mitigates Bias Resulting from Random Coefficient-Dependent Missing Longitudinal Data
Random coefficient dependent (RCD) missingness is a non-ignorable mechanism through which missing data can arise in longitudinal designs. RCD, for which we cannot test, is a problematic form of missingness that occurs if subject-specific random effects correlate with propensity for missingness or dropout. Particularly when covariate missingness is a problem, investigators typically handle missing longitudinal data by using single-level multiple imputation procedures implemented with long-format data, which ignores within-person dependency entirely, or implemented with wide-format (i.e., multivariate) data, which ignores some aspects of within-person dependency. When either of these standard approaches to handling missing longitudinal data is used, RCD missingness leads to parameter bias and incorrect inference. We explain why multilevel multiple imputation (MMI) should alleviate bias induced by a RCD missing data mechanism under conditions that contribute to stronger determinacy of random coefficients. We evaluate our hypothesis with a simulation study. Three design factors are considered: intraclass correlation (ICC; ranging from .25 to .75), number of waves (ranging from 4 to 8), and percent of missing data (ranging from 20% to 50%). We find that MMI greatly outperforms the single-level wide-format (multivariate) method for imputation under a RCD mechanism. For the MMI analyses, bias was most alleviated when the ICC is high, there were more waves of data, and when there was less missing data. Practical recommendations for handling longitudinal missing data are suggested
Studies on intra-specific variations in the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae) under different geographical regions
Studies on intraspecific variations in insect pests are an important tool for preparation of management strategy in different geographical regions. In this paper we tried to establish that these variations are also found in the diamondback moth (P. xylostella) populations under north Indian conditions with respect to reproductive biology.The pest populations were collected from five different geographical regions viz. Hisar (800feet), Kangra (2200feet), Solan (4200 feet), Theog (7500feet) and Kinnaur (9000feet) and then reared under laboratory conditions at 25±1oC on cauliflower. The life table analysis revealed that the female from the Kangra population laid maximum eggs (332.16 eggs/female) whereas the number of eggs laid by the female from the Hisar, Solan, Theog and Kinnaur population was 189.53, 207, 252 and 270 eggs/female, respectively. The doubling time (DT) was observed to be the lowest for Kangra (3.12 days) and maximum for the Hisar (4.59 days) population, whereas weekly multiplication rate was minimum for the Solan (2.252) and maximum for the kangra (4.73) population. The true generation time was the lowest for the Kangra (18.54 days) and highest for the Hisar (24.38 days) population. The true intrinsic rate of increase (rm) was found to be maximum (0.222 female progeny/female/day) for the Kangra whereas for the Kinnaur, Theog, Solan and Hisar population it was 0.203, 0.202, 0.182 and 0.151 female progeny/female/day thereby indicating that the Kangra population is more prolific as compared to the population from other geographical regions. The results are indicative of geographical variations among different populations of P. xylostella
Characterization of haemocytes of the Indian edible oyster, Crassostrea madrasensis (Preston)
The haemocytes of the Indian edible oyster Crassostrea
madrasensis were characterized using light and
electron microscopy. The light microscopic study
was conducted by staining a monolayer of the haemocytes
with Geimsa. Cells without granules and
with a large nucleus occupying much of the cytoplasmic
area were grouped as hyalinocytes. Those
with lesser amounts of basophilic cytoplasmic granules
were characterized as semigranulocytes and
those with large amounts of a mixture of acidophilic
and basophilic granules were termed as granulocytes.
Ultrastructural studies also revealed the
presence of three types of haemocytes. Scanning
electron microscopic studies were used to study the
spreading behaviour of the haemocytes. Cytochemical
studies revealed the presence of acidphosphatase,
peroxidase and prophenol oxidase in the cells
Modulation of selected hemolymph factors in the Indian edible oyster Crassostrea madrasensis (Preston) upon challenge by Vibrio alginolyticus
Juveniles of Crassostrea madrasensis (mean weight 85.5 ± 2.3 g) were exposed to live cells of Vibrio alginolyticus (1.2 x 106
cells g-1) by intramuscular injection. Hemolymph samples were collected at different time intervals to study the modulations
in the cellular and humoral factors. There was an increase in total hemocyte count, percentage granulocytes, serum protein,
serum acid phosphatase, serum phenol oxidase and serum lysozyme in response to bacterial challenge upto three to five days
post-injection. A decrease in the ability of hemocytes to phagocytose yeast cells was also noted. The hemolymph parameters
of the test group became similar to that of control animals within two weeks of exposure to live bacterial cells
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Microbial growth in simulated martian environments
In this study, four new simulants have been developed, and their associated fluid chemistries have been derived for use in a series of microbiological simulation experiments. These experiments will determine if aqueous environments on Mars, past or present, could potentially support microbial life and identify any key geochemical biosignatures that may arise as a result of that life
Small-angle neutron scattering studies on water soluble complexes of poly(ethylene glycol)-based cationic random copolymer and SDS
The interaction of cationic random copolymers of methoxy poly(ethylene glycol) monomethacrylate and (3-(methacryloylamino)propyl) trimethylammonium chloride with oppositely charged surfactant, sodium dodecyl sulphate, and the influence of surfactant association on the polymer conformation have been investigated by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCPSDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were analysed using the log-normal distribution of the polydispersed spherical aggregate model for the local structure in these complexes. For all the systems the median radius and the polydispersity were found to be in the range of 20 ± 2 Å and 0.6 ± 0.05, respectively
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Testing the habitability of distinct simulated martian environments
Habitability of martian waters would have been partially determined by the chemistry arising from interactions with martian lithologies. In this study, the habitability of groundwater chemistries (based on basaltic, iron- and sulfur-enriched lithologies) and the resulting variation in biosignatures was investigated, with microbes from anaerobic estuarine sediment used as an inoculum. The microbial community was monitored by cell counts and 16S rRNA gene profiling. Changes in fluid and precipitate chemistries were measured using ICP-OES and IC, with changes over geological timescales modelled using CHIM-XPT. The fluid chemistries were shown to be habitable, with distinct patterns in cell abundance and growth phases between the chemistries. However, the same genera dominated (Acetobacterium, Desulfovibrio and Desulfosporomusa) regardless of the initial fluid chemistry. In the biotic test group, changes in fluid chemistry were the same in the three chemistries, with an enhanced concentration of aluminium and iron and the removal of sulfate. However, geochemical modelling of the fluids under abiotic conditions over geological timescales revealed similar changes to those in the biotic test groups. Therefore, these samples require further analysis to assess whether we can identify any potentially unambiguous biosignatures that could develop between geologically distinct sites
Studies on lipase enzyme production by indigenously isolated Bacillus Cereus (BAIT GCT 127002 ) and Bacillus Cereus (BAIT GCT 127001)
Microbial lipases holds a prominent place among biocatalysts that act on carboxylic ester bonds. This present study involves about eight strains isolated form slaughter house waste water,Coimbatore producing lipase.Among those strains , two bacterial strains exhibiting high lipase production were identified as Bacillus Cereus (BAIT GCT 127002 ) and Bacillus Cereus (BAIT GCT 127001 ) by both biochemical analysis and 16S rRNA sequencing. Initial studies were done for optimizing lipase production using many components such as time course,Carbon sources ,pH and innoculum volume which revealed maximum lipase acitivity (43.37 U/ml) at 24 hours, using palm oil , at pH 8 and innoculum volume of 1 ml by Bacillus Cereus (BAIT GCT 127002 ).Further the percentage removal of oil from oil stained fabric was determined using partially purified lipase with or without detergents and the results indicated 20% ,30% removal with use of crude lipase and commercial detergent respectively.Hence, lipase from Bacillus Cereus(BAIT GCT 127002 )   can be regarded as an ideal ingredient that can be used in the laundry detergents. 
Maintenance of haemocytes of edible oyster, Crassostrea madrasensis (Preston) in artificial media
The haemocytes of Crassostrea madrasensis were maintained in Hank's balanced
salt solution (HBSS), HBSS with 10% foetal calf serum (FCS), tissue culture
media M 199, and M 199 with 10% FCS. Total counts of viable haemocytes were
taken at 0 hr, 24 hrs, 48 hrs, and 72 hrs. HBSS and HBSS with 10% FCS were
found to maintain cell viability upto 72 hrs without much reduction in the count
of viable cells. In M199 and M199 with 10% FCS, it was found that a substantial
increase of small hyalinocytes occurred at 24 hrs and 48 hrs. This was followed by
a steep fall in the number of viable cells at 72 hrs in both the media. The HBSS,
HBSS with 10% FCS, M199 and M199 with 10% FCS were found to be good for
maintaining the cells in viable state. However, only M 199 and M 199 with 10%
FCS indicated multiplication of haemocytes
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