Initial results from time-resolved LaBr based hard x-ray spectrometer for ADITYA-U tokamak.

Runaway electrons (REs) are passively studied by hard x-ray (HX) emissions generated by REs. A LaBr3(Ce) detector-based HX spectroscopic diagnostic (operational within ∼75 keV to 3.5 MeV) has been set up on the ADITYA-U. The diagnostic acquisition software utility is upgraded to obtain the temporal evolution of the HX spectrum to understand the RE energy distribution in plasma during its various phases. The peak position moves to lower energy for Ohmically heated discharges (200-80 keV), indicating a relative increase in the thermal particle content in the plasma. The peak position of RE energy shows a decreasing tendency with increasing ne with Ne gas puffing and termination of the electron cyclotron resonance pulse.

Silicon drift detector based X-ray spectroscopy diagnostic system for the study of non-thermal electrons at Aditya tokamak.

Silicon drift detector based X-ray spectrometer diagnostic was developed to study the non-thermal electron for Aditya tokamak plasma. The diagnostic was mounted on a radial mid plane port at the Aditya. The objective of diagnostic includes the estimation of the non-thermal electron temperature for the ohmically heated plasma. Bi-Maxwellian plasma model was adopted for the temperature estimation. Along with that the study of high Z impurity line radiation from the ECR pre-ionization experiments was also aimed. The performance and first experimental results from the new X-ray spectrometer system are presented.

Draft Genome Sequence of Pasteurella multocida subsp. multocida B:2 Strain VTCCBAA264 Isolated from Bubalus bubalis in North India.

The Pasteurella multocida subsp. multocida B:2 serotype causes hemorrhagic septicemia in bubalines with high morbidity and mortality in the Indian subcontinent. We report the draft genome sequence of Pasteurella multocida strain VTCCBAA264 isolated from the small-intestine of a buffalo calf that died of high fever.

Prevalence of Serum Antibodies to TORCH Infection in and Around Varanasi, Northern India.

BACKGROUND: The acute infections which are caused by Toxoplasma gondii, Rubella virus, Cytomegalovirus (CMV) and the Herpes Simplex Virus (HSV-2) during pregnancy are often associated with adverse foetal outcomes and reproductive failures. In the Indian context, the exact seroprevalence of these infections is not known due to unavailability of baseline data. AIMS: The present study was undertaken to determine the serological evidence of the acute TORCH infections in women who were in the first trimesters of their pregnancies in and around Varanasi, north India. SETTINGS AND DESIGN: This study was carried out in the Sir Sunderlal Hospital, Varanasi and in the Department of Microbiology, Institute of Medical Sciences, BHU, Varanasi, UP, India. The study population involved pregnant women with bad obstetric histories, who were in the first trimester of their pregnancy. METHODS AND MATERIALS: Sera were collected from the women with Bon and they were tested for the presence of specific IgM antibodies against the TORCH infections by ELISA. STATISTICAL ANALYSIS: A 95% confidence interval was calculated for the positive cases in each of the TORCH components. RESULTS: The specific IgM antibodies were found to be positive in 74(19.4%) cases for toxoplasmosis, in 126 (30.4%) cases for the Rubella virus, in 130 (34.7%) cases for CMV and in 151 samples (33.5%) for the HSV-2 infections. CONCLUSIONS: The study showed a high prevalence of the infections which were caused by the TORCH complex amongst pregnant women with bad obstetric histories. Therefore, all the antenatal cases should be routinely screened for the TORCH infections, for carrying out early interventions to prevent foetal loss.

Squamous cell carcinoma presenting as multiple discharging sinuses on the chin.

Squamous cell carcinoma (SCC) usually presents as a raised, firm, pink to skin-coloured keratotic papule, plaque or ulcer, arising on sun-exposed skin. We report an unusual case of a 65-year-old male patient who presented with a 1-year history of multiple discharging sinuses on his chin, which on investigation was found to be an SCC. A malignancy should be considered in the differential diagnoses of patients presenting with multiple discharging sinuses on the chin. We discuss other possible diagnoses for sinuses presenting on the face.

Vocal cord schwannoma: a rare case report.

Schwannomas of the larynx are rare benign tumors, most commonly involving aryepiglottic folds or false vocal folds. When a tumor involves vocal cord, it causes clinical symptoms like hoarseness of voice and foreign body sensation. We report the CT and magnetic resonance imaging findings in a 19-year-old male patient with vocal cord mass histologically diagnosed as a vocal cord schwannoma.

Mechanisms underlying the cardioprotective effect of L-cysteine.

In many tissues the availability of L-cysteine is a rate-limiting factor in glutathione production, though this has yet to be fully tested in heart. This study aimed to test the hypothesis that supplying hearts with 0.5 mM L-cysteine would preserve glutathione levels leading to an increased resistance to ischaemia reperfusion. Left ventricular function was measured in isolated perfused rat hearts before, during and after exposure to 45 min global normothermic ischaemia. Control hearts received Krebs throughout, whilst in treated hearts 0.5 mM L-cysteine was added to the perfusate 10 min before ischaemia, and was then present throughout ischaemia and for the first 10 min of reperfusion. Reperfusion injury was assessed from the appearance of lactate dehydrogenase (LDH) in the effluent. In two separate groups of control and treated hearts, ATP and glutathione (GSH) contents were measured at the beginning and end of ischaemia. Hearts treated with 0.5 mM L-cysteine showed a significantly higher recovery of rate pressure product (16,256+/- 1288 mmHg bpm vs. 10,324+/- 2102 mmHg bpm, p < 0.05) and a significantly lower release of LDH (0.54+/- 0.16 IU/g wet weight vs. 1.44+/- 0.31 IU/g wet weight, p < 0.05) compared to controls. Also, the L-cysteine treated group showed significantly better preservation of ATP and GSH during ischaemia in comparison to control. These results suggest that the mechanisms underlying the cardioprotective effects of 0.5 mM L-cysteine may include: increased anaerobic energy production either directly or through reduced degradation of adenine nucleotides; direct scavenging of free radicals; and/or improved antioxidant capacity through glutathione preservation.

Molecular characterization of Vibrio cholerae O139 bengal isolated from water and the aquatic plant Eichhornia crassipes in the River Ganga, Varanasi, India.

A collection of ten strains of Vibrio cholerae O139, comprising six isolates from Eichhornia crassipes, two from water of the River Ganga, and one each from a well and a hand pump, were characterized. All the strains carried the CTX genetic element (ctxA, zot, and ace) except for the st gene and carried structural and regulatory genes for toxin-coregulated pilus (tcpA, tcpI, and toxR), adherence factor (ompU), and accessory colonization factor (acfB); all produced cholera toxin (CT). These strains were resistant to trimethoprim, sulfamethoxazole, streptomycin, and to the vibriostatic agent pteridine. Results obtained by ribotyping and enterobacterial repetitive intergenic consensus sequence-PCR fingerprint analysis indicate that multiple clones of toxigenic-pathogenic V. cholerae O139 were present in the aquatic environment.

Molecular analysis of Vibrio cholerae O1, O139, non-O1, and non-O139 strains: clonal relationships between clinical and environmental isolates.

A total of 26 strains of Vibrio cholerae, including members of the O1, O139, and non-O1, non-O139 serogroups from both clinical and environmental sources, were examined for the presence of genes encoding cholera toxin (ctxA), zonula occludens toxin (zot), accessory cholera enterotoxin (ace), hemolysin (hlyA), NAG-specific heat-stable toxin (st), toxin-coregulated pilus (tcpA), and outer membrane protein (ompU), for genomic organization, and for the presence of the regulatory protein genes tcpI and toxR in order to determine relationships between epidemic serotypes and sources of isolation. While 22 of the 26 strains were hemolytic on 5% sheep blood nutrient agar, all strains were PCR positive for hlyA, the hemolysin gene. When multiplex PCR was used, all serogroup O1 and O139 strains were positive for tcpA, ompU, and tcpI. All O1 and O139 strains except one O1 strain and one O139 strain were positive for the ctxA, zot, and ace genes. Also, O1 strain VO3 was negative for the zot gene. All of the non-O1, non-O139 strains were negative for the ctxA, zot, ace, tcpA, and tcpI genes, and all of the non-O1, non-O139 strains except strain VO26 were negative for ompU. All of the strains except non-O1, non-O139 strain VO22 were PCR positive for the gene encoding the central regulatory protein, toxR. All V. cholerae strains were negative for the NAG-specific st gene. Of the nine non-ctx-producing strains of V. cholerae, only one, non-O1, non-O139 strain VO24, caused fluid accumulation in the rabbit ileal loop assay. The other eight strains, including an O1 strain, an O139 strain, and six non-O1, non-O139 strains, regardless of the source of isolation, caused fluid accumulation after two to five serial passages through the rabbit gut. Culture filtrates of all non-cholera-toxigenic strains grown in AKI media also caused fluid accumulation, suggesting that a new toxin was produced in AKI medium by these strains. Studies of clonality performed by using enterobacterial repetitive intergenic consensus sequence PCR, Box element PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) collectively indicated that the V. cholerae O1 and O139 strains had a clonal origin, whereas the non-O1, non-O139 strains belonged to different clones. The clinical isolates closely resembled environmental isolates in their genomic patterns. Overall, there was an excellent correlation among the results of the PCR, AFLP, and PFGE analyses, and individual strains derived from clinical and environmental sources produced similar fingerprint patterns. From the results of this study, we concluded that the non-cholera-toxin-producing strains of V. cholerae, whether of clinical or environmental origin, possess the ability to produce a new secretogenic toxin that is entirely different from the toxin produced by toxigenic V. cholerae O1 and O139 strains. We also concluded that the aquatic environment is a reservoir for V. cholerae O1, O139, non-O1, and non-O139 serogroup strains.

Synthesis and antimicrobial activity of 1-aryl-2-amino-3-(4-arylthiazol-2-yl)/(benzothiazol-2-yl)guanidines.

The synthesis of fifteen new 1-aryl-2-amino-3-(4-arylthiazol-2-yl)/(benzothiazol-2-yl)gua nidines is described. They were screened for their antimicrobial susceptibility by the standard disc diffusion method of the World Health Organization (WHO) and the activities compared with that of standard strain of Escherichia coli NCTC 10418. The sensitive aminoguanidines were further subjected to the minimum inhibitory concentration (MIC) test.

Analogue-resistant mutants of Azotobacter chroococcum derepressed for nitrogenase activity and early ammonia excretion having potential as inoculants for cereal crops.

Spontaneous mutants resistant to methionine sulfoximine (Msx), methyl alanine (Mal) and methyl ammonium chloride (Mac) were derived from A. chroococcum strain A103. Msx and Mal-resistant mutants expressed 1.73 to 10.98% of the fully derepressed nitrogenase activity when grown in Burk's medium containing ammonium acetate. Mac-resistant mutants did not express nitrogenase activity in ammonium acetate supplemented medium. The mutants excreted ammonia even after 2 days of growth and some mutants excreted more ammonia as compared to the parent. Selected mutants were inoculated on wheat (Triticum aestivum) and barley (Hordeum vulgare) under field conditions. Majority of the derepressed mutants increased grain yield of wheat and barley varying from 1.2 to 33.3%. However, host-dependent effects on grain yield were observed with different mutants. Two mutants, Mal 27 and Mac 19 showed significant increase in grain yields of both the crops. The results suggest that metabolic analogue-resistant mutants of Azotobacter have potential for use as a biofertilizer for cereal crops.

Significance of Cryptosporidium in acute diarrhoea in North-Eastern India.

In a hospital-based study, stool samples from 2095 patients of all ages were examined for different fungal, protozoal and bacterial enteropathogens over a period of 2 years (July 1994-June 1996). Cryptosporidium was detected in 151 specimens (7.2%) and was the third commonest pathogen found. The highest prevalence of this organism was in the group aged 16-45 years and during the rainy months (July-Oct.). Diarrhoea caused by the protozoon was of mild to moderate severity and features of dysentery were absent. Amongst other enteropathogens, Candida albicans was the most frequently isolated, followed by enteropathogenic and enterotoxigenic Escherichia coli, Salmonella spp., Campylobacter jejuni, Entamoeba histolytica, Giardia duodenalis (lamblia), Shigella spp., Vibrio cholerae and Aeromonas spp.

Haemolysin produced by Vibrio cholerae non-O1 is not enterotoxic.

Of 28 isolates of Vibrio cholerae non-O1 (10 from diarrhoeal patients and 18 from environmental sources) examined for haemolytic activity and its correlation, if any, with enterotoxic activity, 24 showed haemolysis. The four non-haemolytic isolates showed haemolysis after consecutive passages through rabbit ileal loops (RILs). The titres of haemolytic activity were 4-64 HU/ml irrespective of their source. Eight (28.5%) of the non-O1 isolates caused fluid accumulation; six (25%) were haemolytic and two (50%) non-haemolytic. The remaining isolates showed enterotoxic activity after one-to-three consecutive passages through RILs irrespective of their haemolytic character and source. Environmental isolates caused significantly more fluid accumulation than the diarrhoeal isolates. All these isolates reverted to their original non-toxigenic character on repeated subculture or on storage in the laboratory, but continued to show haemolytic activity. The results of the present study indicate that V. cholerae non-O1 strains are potentially enterotoxigenic independent of their haemolytic character and source, and enterotoxin, not haemolysin, is the factor most likely to be responsible for their enterotoxic activity.

Development of an improved synthetic medium for a better production of the new cholera toxin and its immunological relationship with the toxin produced by Vibrio cholerae O139 strains.

An improved synthetic medium (M4) comprising syncase medium supplemented with sodium chloride (1%) and sucrose (0.5%) pH adjusted to 7.4 was developed for a better production of the new cholera toxin (NCT). The culture filtrates prepared in the M4 medium caused significantly (P > 0.05) more fluid accumulation than that in syncase medium. Crude toxin, prepared in the M4 medium with V. cholerae O1 strains (X-392 and 2740-80) caused a reaction similar to that of the same amount of NCT (32 micrograms) prepared in the syncase medium. The neutralization of the optimal loop reacting dose of the NCT prepared in the M4 medium by anti-NCT raised against syncase prepared toxin indicates the release of the same kind of toxin in both media. These observations indicate that the modified M4 medium may be used for NCT preparation and further characterization. All the strains of Vibro cholerae O139 used in this study produced a toxin antigenically similar to NCT.

Diarrhoea associated with Candida spp.: incidence and seasonal variation.

To study the incidence and seasonal variation of diarrhoea associated with Candida, 978 diarrhoeal stool specimens from patients of all age groups were examined by microscopy and culture. Candida spp. was the sole pathogen (unassociated with other diarrhoeagenic bacteria, protozoa, or helminths) in 15.3% of the total cases. Candida albicans (94.9%) was the predominant species isolated. The incidence was highest among the infants aged 0-12 months (37.1%), followed by a decline in the rest of the children aged less than 5 years with a second peak in the people aged over 5 years, including adults. The paediatric age group had a significantly higher incidence in the summer season compared to the rainy (p < 0.05) or winter (p < 0.01) months. Thus, there was a definite age and seasonal variation in the incidence of diarrhoea caused by the overgrowth of Candida in the Varanasi region of the Indian subcontinent.

Biochemical characterisation, enteropathogenicity and antimicrobial resistance plasmids of clinical and environmental Aeromonas isolates.

One hundred and eight strains of Aeromonas from clinical and environmental samples were speciated. Seven species were identified, the most prevalent of which was A. hydrophila. Experimental studies in an animal model with 36 representative strains of different species revealed that all strains could cause significant fluid accumulation in rabbit ileal loops. Of 107 strains showing single or multiple antimicrobial resistance, the highest incidence of resistance was shown for beta-lactam antibiotics other than cefotaxime. Transferable resistance plasmids, encoding resistance to ampicillin, cephalexin, cefoxitin, erythromycin and furazolidone, either alone or in combination, were detected in 35 strains. A further proportion of strains could be cured of one or more resistance markers, including resistance to nalidixic acid, and this was accompanied by the loss of plasmid DNA. The plasmids ranged in size between 85.6 and > 1 50 kb.

HLA sharing, anti-paternal cytotoxic antibodies and MLR blocking factors in women with recurrent spontaneous abortion.

OBJECTIVE: To study the prevalence of HLA sharing between spouses and its correlation with presence of antipaternal cytotoxic antibody (APCA) and mixed lymphocyte reaction (MLR) blocking factors in recurrent spontaneous aborters (RSA). DESIGN: Study was carried out at Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGI), Lucknow, from 1988-1992. Hundred couples with 3 or more consecutive recurrent spontaneous abortions and equal number of age, parity and ethinically matched normal controls were selected for studying HLA, APCA and MLR blocking factors. Meta-analysis was performed using standard formula and significance was tested by Chi-square analysis. RESULTS: Significant HLA sharing was observed in couples with RSA at A and DR loci compared to normal controls (p < 0.001). Twenty-seven point eight percent of couples with RSA were positive for APCA compared to 49% of controls (p < 0.01). MLR blocking factors were detected in 26% couples with RSA compared to 78% in controls (p < 0.001). An inverse correlation between HLA sharing and APCA and MLR positivity was demonstrated. CONCLUSION: The study supports that greater HLA sharing between spouses, associated with lack of an appropriate immune response to them could be responsible for RSA.