Production and characterization of monoclonal antibodies against a local isolate of classical swine fever virus

Monoclonal antibodies (mAbs) against a classical swine fever virus (CSFV; subgenogroup 1:1) isolate from Assam, India were produced and characterized. Four fusions of myeloma cells (SP2/0Ag) were made with spleenocytes of 8-10 weeks old BALB/C mice immunized with the viral antigen. Several hybridoma clones secreting antibodies to the virus were obtained after four fusions, but five hybridoma clones secreting antibody specific to the virus could be stabilized. All the mAbs belong to the IgG2a isotype. Except one, none of the four mAbs showed cross reaction with bovine viral diarrhoea virus and border disease virus (BDV). One mAb showed cross reaction with BDV. All the four mAbs specific to CSFV showed reactivity with the parental virus in immunoperoxidase test (IPT) and with a single protein band (molecular weight 55 kD approximately) of the virus in western blotting. In neutralization peroxidase linked assay (NPLA) all the mAbs reacted with 13 CSFV local isolates as well as with the cell culture adapted lapinized vaccine virus strain belonging to the subgenogroup 1:1. This is the first report on production and characterization of mAbs against CSFV in India.     

Characterization of intrinsic variability of Mesorhizobium ciceri isolates of cultivated fields

A large number of putative rhizobial isolates were obtained from the root nodules of various chickpea cultivars growing in agricultural research fields. Of these, thirty were selected and characterized for traits, such as, generation time, intrinsic azide resistance and several symbiotic characters.     

Triglyceride Levels and Not Adipokine Concentrations Are Closely Related to Severity of Nonalcoholic Fatty Liver Disease in an Obesity Surgery Cohort

Although nonalcoholic fatty liver disease (NAFLD) is frequent in obesity, the metabolic determinants of advanced liver disease remain unclear. Adipokines reflect inflammation and insulin resistance associated with obesity and may identify advanced NAFLD. At the time of obesity surgery, 142 consecutive patients underwent liver biopsy and had their preoperative demographic and clinical data obtained. Liver histology was scored by the NAFLD activity score, and patients subdivided into four groups. Concentrations of retinol‐binding protein 4 (RBP4), adiponectin, tumor necrosis factor‐α (TNF‐α), and leptin were determined ～1 week prior to surgery and results were related to liver histology. The prevalence of no NAFLD was 30%, simple steatosis 23%, borderline nonalcoholic steatohepatitis (NASH) 28%, and definitive NASH 18%. Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS) prevalence were 39 and 75%, respectively, and did not differ across the four histological groups (P = NS). Triglyceride (TG) and alanine transaminase (ALT) levels, strongly associated with advanced stages of NAFLD and NASH (P = 0.04). TG levels >150 mg/dl, increased the likelihood of NASH 3.4‐fold, whereas high‐density lipoprotein (HDL) levels predicted no NAFLD (P < 0.01). Concentrations of TNF‐α, leptin, and RBP4 did not differ among histological groups and thus did not identify NASH; however, there was a trend for adiponectin to be lower in NASH vs. no NAFLD (P = 0.061). In summary, both TG and ALT levels assist in identification of NASH in an obesity surgery cohort. These findings underscore the importance of fatty acid delivery mechanisms to NASH development in severely obese individuals.     

Isolation and characterization of microcystin producing Microcystis from a Central Indian water bloom

Microcystis aeruginosa Kütz, a well-known microcystin (hepatotoxin) producing cyanobacterium was the dominant bloom-forming organism in a mesotrophic lake at Nagpur in Central India, which was isolated and characterized for morphospecies and microcystin content. Compact spherical colonies, formation of daughter colonies, and clathration of older colonies leading to release of solitary cells, were characteristics of laboratory grown M. aeruginosa. Its growth, monitored as increase in optical density (OD) measured at 678 nm (the wavelength selected using dilution curve technique), exhibited a maximum specific growth rate (μ_max) of 0.34 day⁻¹ which, was attained on the 5th day of the experiment with a doubling time of 3.25 days. Though the morphological characters of the M. aeruginosa under field conditions were not retained under laboratory conditions, the microcystin content and type of variants did match with bloom samples. Reverse phase high performance liquid chromatography (RP-HPLC) analyses revealed that the laboratory grown isolate of Microcystis produced microcystin-RR (732 μg g⁻¹ dry weight biomass) and demethylated microcystin-RR (165 μg g⁻¹ dry weight biomass) variants, which are reported to be less toxic when compared to microcystin-LR. LC/ESI/MS further confirmed the presence of these two variants. Geographical distribution of microcystin variants and their prevailing concentrations need to be considered during formulation of guideline values for drinking and recreational waters.     

An assessment of biopotential of three cyanobacterial isolates from Antarctic for carotenoid production

Specific growth rates and carotenoid contents of three Antarctic and tropical strains of cyanobacteria viz. Anabaena sp., Phormidium sp. and Nostoc sp. were compared in batch and mass cultures to assess bio-potential of Antarctic strains for cost-effective carotenoid production. Antarctic strains though exhibited slightly lower specific growth rates, but contained higher carotenoid contents (per unit dry wt.), than tropical strains. Modification of normal composition of BG-11 culture medium, by altering nitrogen and carbon sources resulted in 25-38% increase in carotenoid content in both types of strains. Mass-culture in indoor and semi-outdoor bio-reactors resulted in 39-113% higher carotenoid content in Antarctic strains, compared to their respective tropical strains. The observations suggest that Antarctic cyanobacteria may have potential as superior strains for maximizing the yield of carotenoids.     

In vitro propagation of Lagerstromia parviflora Roxb. from adult tree

A micropropagation protocol based on axillary bud proliferation has been developed from mature Lagerstromia parviflora adult tree. Nodal segments cultured on woody plant medium supplemented with 5.0 microl. BAP and 0.25 microm IAA gave maximum (86.9%) morphogenetic response. Proliferated shoots (10.7 per explants) were elongated to 3.9 cm within 6 weeks. In vitro produced micro-shoots were subjected to an IBA treatment (500 ppm for 2 min. dip) and placed under misting conditions for rooting. Misting beds were prepared with sand: soil (3:1) for 80.6% rooting and was acclimatized. Shoot length seems to be important to induce adventitious roots. The highest (91.7%) rooting was recorded on shoots ranging a length between 3.1-4.0 cm. Rooted and hardened plants were later transferred to poly bags and maintained in shadenet house. The protocol has the realizes capacity to produce 260 plants from a single explants within 10 months multiplication cycle.     

Molecular Phylogenetic Exploration of Bacterial Diversity in a Bakreshwar (India) Hot Spring and Culture of Shewanella-Related Thermophiles

The bacterial diversity of a hot spring in Bakreshwar, India, was investigated by a culture-independent approach. 16S ribosomal DNA clones derived from the sediment samples were found to be associated with gamma-Proteobacteria, cyanobacteria, and green nonsulfur and low-GC gram-positive bacteria. The first of the above phylotypes cobranches with Shewanella, a well-known iron reducer. This phylogenetic correlation has been exploited to develop culture conditions for thermophilic iron-reducing microorganisms.     

Flotation characteristics of cyanobacterium Anabaena flos-aquae for gas vesicle production

Cyanobacterium Anabaena flos-aquae was cultivated in photobioreactors for production of intracellular gas vesicles (GVs), as potential oxygen microcarriers. Natural flotation of the buoyant culture was investigated as a potential means of cell harvesting, because filtration and centrifugation tended to destroy the vesicles. Best flotation was found with actively growing culture and when conducted in the dark. The flotation-related cell properties, including the specific GV content, vesicle-collapsed filament density, and intracellular carbohydrate content, were measured to understand the phenomena. During the batch culture, the specific GV content remained relatively constant at 370 microL/(g dry cells) but the filament density (ranging 1.02 to 1.08 g/cm3) showed a decrease-then-increase profile. The increase began when the growth slowed down because of the reduced light availability at high cell concentrations. The dark flotation was studied with both actively growing (mu approximately 0.2 day-1) and stationary-phase cultures. The specific GV content of the stationary-phase culture remained relatively constant while that of the growing culture increased slightly. The intracellular carbohydrate content of the growing culture decreased much faster and more significantly, from 57 to 10 mg/(g dry cells) in 相似文献   

Autoprotection: Stimulated tissue repair permits recovery from injury

Autoprotection is a phenomenon whereby prior exposure to a small dose of a chemical results in protection against a subsequently administered lethal dose of the same compound. While CCl₄ autoprotection has been studied the most, it has also been demonstrated for other chemicals. Recent studies indicate that the prevailing concept of decreased bioactivation of the normally lethal dose of CCl₄ owing to decreased hepatic microsomal cytochrome P-450

1 Abbreviations used: CD, chlordecone; cyt. P-450, cytochromes P-450; M, mirex; N, normal diet; PB, phenobarbital.

content can not be supported by direct end points of liver injury such as necrosis. These findings suggest a pivotal role for hepatocellular division and tissue healing processes stimulated by the protective dose in the mechanism of autoprotection. Augmentation of hepatocellular regeneration and tissue repair, stimulated by the protective dose, appears to permit timely recovery and restoration of hepatic structure and function. In the absence of the protective dose, hepatocellular division is substantially deficient and it occurs too late to tip the delicate balance between recovery from injury and progression of massive injury in favor of recovery. Abolition of autoprotection by colchicine antimitosis, under conditions where metabolism and disposition of CCl₄ are not altered, is supportive of this concept. Selective colchicine antimitotic suppression of the early phase of hepatocellular division and tissue repair induced by a low dose of CCl₄ results in progression of toxic liver injury, leading to hepatic failure and mortality. Studies have shown that pretreatment with phenobarbital results in postponed low-dose CCl₄-stimulated cell division by 24 hours, which accordingly postpones the optimal autoprotection. These findings provide discrete evidence to suggest that the protective dose-stimulated hepatocellular division and tissue repair underlies the mechanism of autoprotection. These new insights reveal that in contrast to the widely held concept, the ultimate outcome of toxic injury is determined by whether a prompt stimulation of sustainable tissue repair can occur rather than by the magnitude of the injury inflicted by a toxic chemical.