RAPD Analysis to Study Metagenome Diversity in Soil Microbial Community of Arid Zone Plants

The study was conducted by taking six soil samples, two each for Capparis decidua (Ker), Calligonum polygonoides (Phog) collected from Bikaner while third sample, Cuminum cyminum (Cumin) was collected from Jobner. RAPD analysis was done using various decamer primers. The total bands amplified varied from 7 (UBC 153) to 13 (UBC 157). Three primers (UBC 153, 154 and 162) showed 100 % polymorphism. 46 out of 53 polymorphic allelic positions were obtained with 86.7 % polymorphism. The number of bands generated was plant and soil dependent.     

Evaluation of Plant Growth Promoting Rhizobacterial Activity in Soil Samples of Arid Zone Plants

In the present investigation, soil samples of Capparis decidua L., Calligonum polygonoides L., Cuminum cyminum Gmel. were taken from different areas of Rajasthan. The bacterial isolates were evaluated for their plant growth promoting rhizobacterial (PGPR) activity, by nitrogen fixation and phosphate solubilization activity. K3, P40, C63, and C79 were the isolates that showed both activities and C63 and C79 showed very good response among all the isolates selected for each plant species. These PGPR may serve as bioinoculants to increase availability and uptake of mineral nutrients for plants and stimulate growth of plants in arid soils of Rajasthan. Rhizobacterial isolates from C. cyminum C63, C68, and C60 showed positive PGPR activity i.e., increased root and shoot length, mean wet biomass, and percent germination.     

Early Detection of Avian Oncogenic Viruses from Blood of Apparently Healthy Chickens

Viral neoplasms in commercial poultry are mainly caused by members of two families with Marek’s disease virus (MDV) belonging to Herpesviridae and reticuloendotheliosis virus (REV), avian leukosis virus subgroups A to E and avian leukosis virus subgroup J (ALV-J) belonging to Retroviridae. This study was conducted to know the status of neoplasms caused by avian oncogenic viruses in commercial chickens. 25 blood samples were collected from a broiler breeder flock that appeared healthy but chickens from the flock on necropsy showed visceral tumours. PCR was employed on blood DNAs of these chickens for detection of avian oncogenic viruses which eventually detected the presence of multiple oncogenic virus infection in most birds. MDV specific primers that could differentiate between pathogenic and non-pathogenic serotype-1 virus detected MDV in four blood DNAs. REV could be detected from all the 25 blood DNAs and endogenous ALV was detected in 21 blood DNAs signifying the slow transforming nature of the retroviruses that may take months to perpetuate visible tumours. It was concluded that concurrent presence of multiple oncogenic viruses in the same bird is more common than the presence of single virus. Thus, for early disease control programs, this moderately simple PCR diagnostic technique can be utilized to identify the birds undergoing latent infection with avian oncogenic viruses.     

Hyperglycemia exaggerates ischemia-reperfusion-induced cardiomyocyte injury: reversal with endothelin antagonism

OBJECTIVES: We have previously demonstrated an importance of endothelin-1 in diabetic patients undergoing bypass surgery. Recent evidence suggests that cardiomyocytes might also produce endothelin-1, which might directly impair myocyte contractility by increasing intracellular calcium levels. Because hyperglycemia is a potent stimulus of endothelin-1 production, we hypothesized that increased production, action, or both of endothelin-1 might be a mediator of direct cardiomyocyte injury in diabetes. Therefore we studied the effects of endothelin receptor blockers (BQ-123 and bosentan) on hyperglycemia-induced endothelin-1 production and cellular injury after ischemia-reperfusion. METHODS: Using a human ventricular heart cell model of simulated ischemia-reperfusion, we studied the effects of normoglycemia (5 mmol/L, 48 hours) and hyperglycemia (25 mmol/L, 48 hours) on cellular injury and endothelin-1 production. Furthermore, the effects of selective endothelin-A and mixed endothelin-A/B receptor antagonism (with BQ-123 and bosentan, respectively) were evaluated. RESULTS: Cellular injury, as assessed by means of trypan blue uptake, was higher in human ventricular heart cells subjected to hyperglycemia and simulated ischemia-reperfusion injury (P =.01); this effect was prevented with both BQ-123 and bosentan (P =.01). In addition, heart cells from the hyperglycemic group elaborated more endothelin-1 after ischemia-reperfusion (P =.02). CONCLUSIONS: Endothelin-1 production and cellular injury were greater in human ventricular heart cells subjected to hyperglycemic conditions and simulated ischemia-reperfusion. These effects are mediated by endothelin-A receptors because both BQ-123 and bosentan exerted similar degrees of protection. Endothelin receptor blockade is a novel strategy to improve the resistance of the diabetic heart to cardioplegic arrest and reperfusion.     

Ursodeoxycholic Acid Enhances Fractional Calcium Absorption in Primary Biliary Cirrhosis

Bone disease is a frequently reported complication in primary biliary cirrhosis (PBC), but its pathogenesis is poorly understood. Calcium malabsorption has been considered as an important contributing factor. Ursodeoxycholic acid (UDCA) is the treatment of choice in PBC, improving survival, but its effect on calcium absorption is unknown. In this study, we have measured fractional calcium absorption, using a single isotope method, in a group of female PBC patients (median age: 60 years, range: 46–78 years) and age-matched female controls (median age: 58 years, range: 36–74). Bone mineral density (BMD) in PBC patients was significantly lower than age-matched controls (g/cm²± SEM; lumbar spine: controls 1.139 ± 0.028, PBC patients 1.004 ± 0.026, p= 0.0028; femoral neck: controls 0.944 ± 0.034, PBC patients 0.819 ± 0.023, p = 0.0032). Twenty two PBC patients, who were not vitamin D-deficient, were off and on UDCA for ~1 month and ~8 weeks, respectively. Fractional calcium absorption in PBC patients prior to UDCA treatment (mean ± SEM, 33.8 ± 2.6%) was significantly lower than controls (52.0 ± 2.4%, p<0.001). Following UDCA therapy, fractional calcium absorption increased significantly (Off UDCA: 33.1 ± 2.6%, On UDCA: 36.6 ± 2.5%, p<0.0058). Osteocalcin levels were significantly raised in the PBC group (mean ± SEM, ng/ml, 41.4 ± 2.02) compared to controls (31.1 ± 2.64, p= 0.002). There were no differences in parathyroid hormone (PTH) or 25-hydroxyvitamin D levels between these two groups or following UDCA therapy. In conclusion, we found that PBC patients display low spinal and femoral neck BMD, reduced fractional calcium absorption, and elevated plasma osteocalcin. The calcium malabsorption is corrected partially by UDCA therapy. Long-term studies are required to determine whether this effect can be sustained, and whether a sustained increase in fractional calcium absorption can translate into a favorable change in bone strength in patients with PBC. Received: 27 November 2001 / Accepted: 11 April 2002     

Detection and molecular typing of methicillin-resistant Staphylococcus aureus from northeastern part of India

BackgroundIn Staphylococcus aureus, methicillin resistance is exhibited by modifications in penicillin-binding protein that minimises the binding affinity to beta-lactam antibiotics. The present study investigated the occurrence of methicillin-resistant S. aureus (MRSA) in community-acquired infections, that is, community-acquired MRSA (CA-MRSA) and in-hospital–acquired infections, that is, hospital-acquired MRSA (HA-MRSA) from Northeast India.MethodsA total of 197 consecutive non-duplicate isolates were collected from Silchar Medical College and Hospital and other private diagnostic laboratories. The isolates were confirmed to be S. aureus at our centre. All isolates were subjected to antibiotic susceptibility testing and were screened for methicillin resistance using cefoxitin disc test. All MRSA were subjected to Polymerase Chain Reaction (PCR) assay for detection of mecA and mecC genes. DNA fingerprinting was performed for determining clonal diversity.ResultsSeventy-one isolates of 127 confirmed S. aureus were found to be methicillin resistant by screening test. mecA gene was detected in 43 isolates, and none of the isolates were positive for mecC gene. Linezolid and teicoplanin showed better activity with susceptibility pattern being 83.6% and 72.44%, respectively, whereas 66.14% were sensitive to vancomycin. Other antibiotic showed low level of activity. Pulsed Field Gel Electrophoresis (PFGE) showed 14 different banding patterns that suggest isolates were of different clonal types.ConclusionmecA was responsible for methicillin resistance in majority of strains. Polyclonal spread of MRSA infection in the study area indicates its diverse origin and possible lateral transfer. Thus, this study is of clinical interest in terms of selection of proper antimicrobial chemotherapy and infection control management.     

Efficient insertion of genes into the mouse germ line via retroviral vectors.

We present a general strategy for the efficient insertion of recombinant retroviral vector DNA into the mouse germ line via infection of preimplantation mouse embryos. Transgenic mice were generated that harbor a replication-competent recombinant retrovirus (delta Mo + Py M-MuLV) that lacks the Moloney murine leukemia virus (M-MuLV)-type enhancer sequence in the long terminal repeat (LTR). Instead, the LTR contains an enhancer element that permits polyoma virus F101 to grow in undifferentiated F9 embryonal carcinoma cells. Expression studies in different tissues of animals transgenic for delta Mo + Py M-MuLV indicate possibilities to target and modulate expression of retroviral recombinants in mice via their LTR enhancer sequences. In addition, 16 transgenic mice were generated that harbor proviral DNA of a defective recombinant retrovirus carrying a mutant dihydrofolate reductase gene.