Complete genome sequence of bluetongue virus serotype 9: implications for serotyping

The second complete genome of bluetongue virus serotype 9 (BTV-9) is presented in this report. The sequence analysis points to continued circulation in India of a mixed topotype virus apparently belonging to the BTV-9 serotype, and it raises questions about approaches for serotyping bluetongue viruses.     

SPR and ITC determination of the kinetics and the thermodynamics of bivalent versus monovalent sugar ligand–lectin interactions

A kinetic study of the interaction of bivalent and monovalent sugar ligands with a lectin was undertaken with the aid of surface plasmon resonance (SPR) method. The study involved a series of bivalent α-d-mannopyranoside containing sugar ligands, with systematic variation in the distance between the sugar ligands. The detailed kinetic studies showed that bivalent ligands underwent a faster association (k _on) and a slower dissociation (k _off) of the ligand–lectin complexes, in comparison to the monovalent ligand–lectin complexes. The kinetic constants were complemented further by assessing the thermodynamic parameters with the aid of isothermal titration calorimetry (ITC). The initiation of cross-linking of ligand–lectin interactions emerge from the early stages of the complexation. The dynamic light scattering (DLS) and the transmission electron microscopy (TEM) techniques allowed judging the sizes and morphologies of the complex in the solution and solid states, respectively.     

Pregnane glycosides from Caralluma adscendens var. fimbriata

Eleven novel pregnane glycosides, 2-7 and 9-13, of which four, i.e., 10-13, comprised a new pregnane-type genin exhibiting a hydroxymethylene instead of a Me group at C(19), and the known pregnane glycoside stalagmoside V (8) were isolated from whole plants of Caralluma adscendens var. fimbriata, a native Indian succulent plant. Their structures were elucidated by extensive 2D-NMR spectroscopic studies.     

IL10 Variant g.5311A Is Associated with Visceral Leishmaniasis in Indian Population

BackgroundVisceral leishmaniasis (VL) is a multifactorial disease, where the host genetics play a significant role in determining the disease outcome. The immunological role of anti-inflammatory cytokine, Interleukin 10 (IL10), has been well-documented in parasite infections and considered as a key regulatory cytokine for VL. Although VL patients in India display high level of IL10 in blood serum, no genetic study has been conducted to assess the VL susceptibility / resistance. Therefore, the aim of this study is to investigate the role of IL10 variations in Indian VL; and to estimate the distribution of disease associated allele in diverse Indian populations.MethodologyAll the exons and exon-intron boundaries of IL10 were sequenced in 184 VL patients along with 172 ethnically matched controls from VL endemic region of India.

Result and Discussion

Our analysis revealed four variations; rs1518111 (2195 A>G, intron), rs1554286 (2607 C>T, intron), rs3024496 (4976 T>C, 3’ UTR) and rs3024498 (5311 A>G, 3’ UTR). Of these, a variant g.5311A is significantly associated with VL (χ²=18.87; p =0.00001). In silico approaches have shown that a putative micro RNA binding site (miR-4321) is lost in rs3024498 mRNA. Further, analysis of the above four variations in 1138 individuals from 34 ethnic populations, representing different social and linguistic groups who are inhabited in different geographical regions of India, showed variable frequency. Interestingly, we have found, majority of the tribal populations have low frequency of VL (‘A’ of rs3024498); and high frequency of leprosy (‘T’ of rs1554286), and Behcet’s (‘A’ of rs1518111) associated alleles, whereas these were vice versa in castes. Our findings suggest that majority of tribal populations of India carry the protected / less severe allele against VL, while risk / more severe allele for leprosy and Behcet’s disease. This study has potential implications in counseling and management of VL and other infectious diseases.     

Solid-State Stability Issues of Drugs in Transdermal Patch Formulations

The transdermal patch formulation has many advantages, including noninvasiveness, an ability to bypass the first-pass metabolism, low dosage requirements, and prolonged drug delivery. However, the instability of solid-state drugs is one of the most critical problems observed in transdermal patch products. Therefore, a well-characterized approach for counteracting stability problems in solid-state drugs is crucial for improving the performance of transdermal patch products. This review provides insight into the solid-state stability of drugs associated with transdermal patch products and offers a comprehensive update on the various approaches being used for improving the stability of the active pharmaceutical ingredients currently being used.     

Excipient Stability in Oral Solid Dosage Forms: A Review

The choice of excipients constitutes a major part of preformulation and formulation studies during the preparation of pharmaceutical dosage forms. The physical, mechanical, and chemical properties of excipients affect various formulation parameters, such as disintegration, dissolution, and shelf life, and significantly influence the final product. Therefore, several studies have been performed to evaluate the effect of drug-excipient interactions on the overall formulation. This article reviews the information available on the physical and chemical instabilities of excipients and their incompatibilities with the active pharmaceutical ingredient in solid oral dosage forms, during various drug-manufacturing processes. The impact of these interactions on the drug formulation process has been discussed in detail. Examples of various excipients used in solid oral dosage forms have been included to elaborate on different drug-excipient interactions.     

The heterotrophic eubacterial and archaeal co-inhabitants of the halophilic Dunaliella salina in solar salterns fed by Bay of Bengal along south eastern coast of India

Halophilic microbes are studied to understand the metabolic pathways adopted by organisms in such extreme environment and for their biotechnological exploitation. In thallosohaline environments worldwide, the autotrophic alga Dunaliella salina Teodoresco is omnipresent, but it is being recently realised that the heterotrophic components vary in different regions. The unexplored eastern coastline of India abutted by Bay of Bengal was investigated for the heterotrophic halophilic microbes in this region. The waters in the salterns – replicas of natural hyper-saline water bodies of that region, were collected at four sites along 650 km of the coastal belt. In cultures set up from these waters, green and pink colonies were observed. The green colonies were found to be those of D. salina while the pink colonies were of heterotrophs. To identify the heterotrophic microbes, light microscopy, 16S rRNA typing and pigment profiling through spectrophotometry and HPLC were done. The cells in pink colonies were rod shaped. 16S rRNA typing of cells in these colonies detected the presence of Halomonas sp. – a eubacterium. The pigment profile of cells in pink cultures matched that of the archaea – Halobacterium; bacterioruberin derivatives were found. Thus, it was concluded that Halomonas and Halobacterium spp. are among the co-inhabitant heterotrophs of D. salina. Cultures of D. salina established from these salterns showed the typical three colours seen in the ponds of different sub-plots of salterns. They were green until 30 days, turning dark orange by 60 days and pink when 90 day old. In the 90 day old cultures, innumerable rod shaped cells were found. These cells were similar to the cells of the waters from the ponds of pink sub-plots of salterns and the pink colonies established from saltern waters in the laboratory. In the old (90 days) laboratory cultures of D. salina, the glycerol and proteins released from degenerating cells and the increase in salt concentration to super saturation levels due to evaporation of water in the medium led to the gregarious appearance of the heterotrophs – the co-inhabitants in natural environment.     

Polytene chromosomes and nucleic acid metabolism during macronuclear development in Euplotes

Polytene chromosomes in two species of Euplotes, E. woodruffi and E. eurystomus, have been described during the macronuclear development following conjugation. In these two species, the giant chromosomes appear briefly in the macronuclear anlagen and disappear completely later. DNA synthesis begins concomitantly with the appearance of the giant chromosomes and reaches a peak at the maximum stage of polyteny. Shortly thereafter DNA begins to break down and the breakdown products leave the macronuclear anlagen, reducing the DNA content in the anlagen to the amount present at the earlier stages of the polytene development of the chromosomes. A later phase of DNA synthesis occurs in the anlagen with the appearance of replication bands comparable to the bands which double the DNA in the somatic macronucleus. These replication bands initiate several rounds of DNA synthesis which finally lead to the development of the vegetative macronucleus. RNA synthesis occurs uniformly on the giant chromosomes and no special RNA producing puffs or other regions are noticed on them.Research supported by American Cancer Society grant E 434 to David M. Prescott and by the Deutsche Forschungsgemeinschaft to Dieter Ammermann.     

Engineered silver nanoparticles are sensed at the plasma membrane and dramatically modify the physiology of Arabidopsis thaliana plants

Silver nanoparticles (Ag NPs) are the world's most important nanomaterial and nanotoxicant. The aim of this study was to determine the early stages of interactions between Ag NPs and plant cells, and to investigate their physiological roles. We have shown that the addition of Ag NPs to cultivation medium, at levels above 300 mg L^?1, inhibited Arabidopsis thaliana root elongation and leaf expansion. This also resulted in decreased photosynthetic efficiency and the extreme accumulation of Ag in tissues. Acute application of Ag NPs induced a transient elevation of [Ca²⁺]_cyt and the accumulation of reactive oxygen species (ROS; partially generated by NADPH oxidase). Whole‐cell patch‐clamp measurements on root cell protoplasts demonstrated that Ag NPs slightly inhibited plasma membrane K⁺ efflux and Ca²⁺ influx currents, or caused membrane breakdown; however, in excised outside‐out patches, Ag NPs activated Gd³⁺‐sensitive Ca²⁺ influx channels with unitary conductance of approximately 56 pS. Bulk particles did not modify the plasma membrane currents. Tests with electron paramagnetic resonance spectroscopy showed that Ag NPs were not able to catalyse hydroxyl radical generation, but that they directly oxidized the major plant antioxidant, l ‐ascorbic acid. Overall, the data presented shed light on mechanisms of the impact of nanosilver on plant cells, and show that these include the induction of classical stress signalling reactions (mediated by [Ca²⁺]_cyt and ROS) and a specific effect on the plasma membrane conductance and the reduced ascorbate.