Isolation of a herpesvirus from the cell culture of a malignant melanoma of a ground squirrel (Spermophilus tridecemlineatus).

A subcutaneous neoplastic mass in a 13-lined ground squirrel which metastasized to regional lymph nodes and lung was studied. Histopathologically, the tumor architecture and cellular morphology were compatible with that of a malignant amelanotic melanoma. Ultrastructurally, the neoplastic tissue was composed of oval cells, spindle-shaped cells, and spindle-shaped cells with electron-dense cytoplasmic granules. Virus particles were not seen in these cells. Cell cultures from neoplastic tissue grew in complete monolayers and on initial passages contained a few herpesvirus particles. Secondary monolayer cell culture, when exposed to 5-iodo-2'-deoxyuridine or made into several serial subculture passages, caused the appearance of cytopathic effect and the demonstration of many virus particles. The ground squirrel agent, because it contained DNA, was sensitive to chloroform treated and had herpesvirus characteristics on electron microscopy, was considered a herpesvirus. The buoyant density of the virus was 1.298 g/cm3 and the diameter of the enveloped virus particles was 146 nm. This ground squirrel herpesvirus was antigenically distinct from other known herpesviruses.     

Characterization of West Nile virus (WNV) isolates from Assam,India: Insights into the circulating WNV in northeastern India

West Nile virus (WNV) is a mosquito-borne flavivirus that causes subclinical symptoms, febrile illness with possible kidney infarction and encephalitis. Since WNV was first serologically detected in Assam during 2006, it has become recognized as an important etiological agent that causes acute encephalitis syndrome (AES) in addition to endemic Japanese encephalitis virus (JEV). Therefore, isolating and characterizing the currently circulating strain of WNV is important. The virus was isolated from the cerebrospinal fluid (CSF) of two patients that presented with AES. The genotyping of the isolates HQ246154 (WNIRGC07) and JQ037832 (WNIRTC08) based on the partial sequencing of 921 nucleotides (C-prM-E) of the genome placed them within lineage 5 along with other Indian strains isolated prior to 1982, but the present circulating virus formed a distinct subclade. The derived amino acid sequence alignment indicated substitution in A₈₁T and A₈₄P of the capsid region in HQ246154. A cross-neutralization assay suggested substantial antigenic variation between isolates. The pathogenesis in mice that suggested the circulating WNV was neuroinvasive and comparatively more pathogenic than previous strains from India.     

Mitigation of N2O emission from an alluvial soil by application of karanjin

An incubation experiment was conducted to study N₂O emissions from a Typic Ustochrept, alluvial soil, fertilized with urea and urea combined with different levels of two nitrification inhibitors, viz karanjin and dicyandiamide (DCD). Karanjin [a furano-flavonoid, obtained from karanja (Pongamia glabra Vent.) seeds] and DCD were incorporated at rates of 5, 10, 15, 20 and 25% of applied urea-N (100 mg kg^-1 soil), to the soil adjusted to field capacity moisture content. The highest N₂O flux (366 µg N₂O-N kg^-1 soil day^-1) was obtained on day 1 after incubation from soil fertilized with urea without any inhibitor. The presence of the inhibitors appreciably reduced the mean N₂O flux from the urea-treated soils. The application of karanjin resulted in a higher mitigation of total N₂O-N emission (92-96%) compared to DCD (60-71%). Rates of N₂O flux ranged from 0.9 to 140 µg N₂O-N kg^-1 soil day^-1 from urea combined with different levels of the two inhibitors (coefficient of variation=24-272%). Karanjin (62-75%) was also more effective than DCD (9-42%) in inhibiting nitrification during the 30-day incubation period.     

A Photosynthesis-Based Dry Deposition Modeling Approach

We present a dry deposition modeling approach that includesvegetation-atmosphere interactions through photosynthesis/carbonassimilation relationships. Gas deposition velocity (V _d) is calculated using an electrical resistance-analogapproach in a coupled soil-vegetation-atmosphere transfer (SVAT)model. For this, a photosynthesis-based surface evapotranspirationand gas exchange model is dynamically coupled to an atmospheric model with prognostic soil hydrology andsurface energy balance. The effective surface resistance(composed of aerodynamic, boundary layer, and canopy-basedresistances) is calculated for a realistic and fully interactiveestimation of gaseous deposition velocity over natural surfaces.Based on this coupled framework, the photosynthesis-based gasdeposition approach is evaluated using observed depositionvelocity estimates for ozone over a soybean field (C3photosynthesis pathway) and a corn field (C4 photosynthesispathway). Overall, observed V _d and modeled V _d show good qualitative and quantitative agreement.Results suggest that photosynthesis-based physiologicalapproaches can be adopted to efficiently develop depositionvelocity estimates over natural surfaces. Such a physiologicalapproach can also be used for generalizing results from fieldmeasurements and for investigating the controlling relationshipsamong various atmospheric and surface variables in estimatingdeposition velocity.     

Andrographis paniculata (Burm. f.) Wall. ex Nees (kalmegh), a traditional hepatoprotective drug from India

Andrographis paniculata [(Burm. f.) Wall. ex Nees, family Acanthaceae], commonly known as kalmegh is used both in Ayurvedic and Unani system of medicines for a number of ailments related to digestion, hepatoprotection, hypoglycaemic and as anti-bacterial, analgesic, anti-inflammatory, vermicidal and antipyretic. Although kalmegh is extensively used in Indian Systems of Medicine, but it is not yet cultivated on a large-scale. The supply of herb is met from the wild growing populations which is now under constrain due to over-collection. Considering its value as a drug raw material, genetic variability of A. paniculata was augmented from different geographical regions of India by explorations and was conserved at the National Gene Bank, NBPGR, New Delhi. The therapeutic activity of the herb has been attributed to andrographolide, a bicyclic diterpenoid lactone present in the whole herb. Thirty germplasm collections of A. paniculata were evaluated for bioactive compound andrographolide to find out superior genotype for high drug yield. The andrographolide content in the germplasm was quantitatively analyzed by high performance thin-layer chromatography (HPTLC) at 232 nm. Results indicated wide variability among thirty accessions of A. paniculata for andrographolide content which ranged from 0.72 to 2.99 % on dry weight basis. DIVA-GIS analysis of A. paniculata germplasm for andrographolide content showed that diverse accessions of A. paniculata exist in three Indian states of Orissa, Tamil Nadu and Kerala. Promising accessions having high andrographolide content were identified; IC520361 (2.99 %), IC520395 (2.86 %), IC399125 (2.81 %), IC369404 (2.77 %) and IC520394 (2.61 %). Due to the economic importance of the drug, these promising collections can be exploited for large-scale cultivation for their pharmacologically important constituents mainly andrographolide content and also can serve as potential source for breeding and improvement of cultivars for obtaining higher drug yield.