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Biomedical subjects

G Nath

Publications and source records attributed to G Nath.

At least 37 records · Page 2Linked to original sources
PubMed1999

Synthesis, antibacterial, antifungal and anti-HIV activities of Schiff and Mannich bases derived from isatin derivatives and N-[4-(4'-chlorophenyl)thiazol-2-yl] thiosemicarbazide.

Isatin, its 5-chloro and 5-bromo derivatives have been reacted with N-[4-(4'-chlorophenyl)thiazol-2-yl] thiosemicarbazide to form Schiff bases and the N-Mannich bases of these compounds were synthesized by reacting them with formaldehyde and three secondary amines. Their chemical structures have been confirmed by means of IR, 1H-NMR data and by elemental analysis. Investigation of antimicrobial activity of compounds was done by agar dilution method against 28 pathogenic bacteria, 8 pathogenic fungi and anti-HIV activity against replication of HIV-1 (IIIB) in MT-4 cells. Among the compounds tested 1-[N,N-dimethylaminomethyl]-5-bromo isatin-3-{1'-[4"-(p-chlorophenyl) thiazol-2"-yl] thio semicarbazone} 10 showed the most favourable antimicrobial activity.

Anti-Bacterial Agents↗
PubMed1999

HIV infection in Varanasi.

A total of 6038 serum samples collected from individuals staying/residing in the eastern part of northern India, were screened for antibodies against HIV. The screening was done by ELISA and followed by confirmation of reactive samples by Western Blot. The seropositivity was detected in 154 (2.6%) persons. The prevalence amongst high risk groups was 68/1000 while it was 2.8/1000 in low risk population. The male to female ratio was 1.8:1 in seropositives. Increase by more than three folds in the prevalence was observed from 1994 (1.5%) to 1997 (5.0%). About 50% of the seropositives were in their third decade of life. Seropositives were predominantly (> 90%) from eastern Uttar Pradesh. Almost all the cases could be linked to Mumbai, one of the largest commercial and industrial centres of India.

Adult↗
PubMed1999

Enteropathogenicity and antimicrobial susceptibility of new Escherichia spp.

To determine the mechanism of enteropathogenicity of the newly described Escherichia species, a total of 50 clinical isolates of Escherichia spp. from diarrhoeal stools were studied. Twelve isolates (24%) were found to be E. vulneris, 6 (12%) E. fergusonii, 2 (4%) E. hermannii, and the rest 30 (60%) were E. coli. Most isolates of the new species were resistant to ampicillin, tetracycline, and co-trimoxazole, but were susceptible to cephalosporins and aminoglycosides. The representative strains of all the new species produced significant fluid accumulation in the rat ileal loops both by live cells and their culture filtrates. E. vulneris, isolated from stools, showed maximum fluid accumulation. Thus, it can be inferred that these species are diarrhoeagenic, but their roles on extra-intestinal infections remain to be determined.

Animals↗
PubMed1998

Pharmacological actions of Abies pindrow Royle leaf.

Petroleum ether (PE), benzene (BE), chloroform (CE), acetone (AE) and ethanolic (EE) extracts (50-200 or 200 mg/kg, i.p. or 200 mg/kg, p.o.) of dried Abies pindrow leaves, given 30-45 min before showed significant anti-inflammatory (both against acute and sub-acute models), analgesic, barbiturate hypnosis potentiation and anti-ulcerogenic acitivities in rats. All the extracts except EE decreased swim stress immobility in mice indicating some degree of anti-depressant activity. Only PE exhibited hypotension in dogs blocked by atropine. Chemically, extracts showed the presence of glycosides, steroids, terpenoids and flavonoids. They had no anti-bacterial effect. However, toxicity studies indicated that the extracts had an extended safety index. The investigations are consonant with some of the uses of this plant in Ayurveda.

Analgesics↗
PubMed1997

Chronic typhoid carriage and carcinoma of the gallbladder.

Chronic microbial infections and/or their carrier state have been reported to be associated with particular cancers. Since typhoid infections and carcinoma of the gallbladder (the site where salmonella usually persists) are endemic in northern India, it was considered important to explore the relationship between the two. In the present study, a total of 1001 bile specimens collected from cases of carcinoma of the gallbladder (28), cholelithiasis (56) and individuals without biliary pathology (17) were subjected to aerobic cultures that had been enriched for salmonella. Salmonella typhi and S. paratyphi-A could be detected in a significantly higher (P < 0.05) number in patients with carcinoma of the gallbladder as compared with cholelithiasis and control groups. The existence of such an association indicates that detection and eradication of typhoid carriers may lead to a decrease in the incidence of carcinoma of the gallbladder along with typhoid fever.

Bile↗
PubMed1997

Predicting difficult intubation--a comprehensive scoring system.

A study was conducted in an attempt to devise a simple and more accurate method of predicting difficult intubation. Prospective assessments were made in 282 patients and retrospective assessment in 16 patients with regard to 21 anatomical factors which were correlated with the laryngoscopic view at intubation. Twelve factors correlated significantly with difficult intubation. Four of these were eliminated after multifactorial analysis. A scoring system was devised, assigning points to each variable based on its discriminative value. A score of 6 or more correctly identified 22 out of the 23 difficult intubations and there were 50 false positives (sensitivity, specificity and PPV of 96%, 82% and 31% respectively). When negative scoring was done for factors favouring easy intubation, false positives were reduced to 36, but only 20 difficult cases could be identified correctly.

Adult↗
PubMed1997

Pharmacological actions of Pongamia pinnata roots in albino rats.

Pongamia pinnata root has been advocated in Ayurveda for treatment of various inflammatory and infective conditions including ulcers. Sequential petroleum ether, benzene, chloroform, acetone and ethanolic extracts of P. pinnata roots when administered in the dose of 50 mg/kg, i.p. in rats was found to have anti-inflammatory, analgesic activity while pentobarbitone-induced 'sleep time' was reduced by all the extracts except petroleum ether which, however, enhanced it. They were also found to possess antiulcer effects when administered either by i.p. (45 min before) or oral route (45 min before or for 4 days) against restraint-stress or pylorus-ligated gastric ulcers in rats, the maximum protection being afforded by petroleum ether and ethanol extracts. The mechanism of antiulcer effect could either be due to decrease in acid-pepsin secretion and augmentation of mucin secretion as observed with ethanol extract, while petroleum ether extract might be producing the effect by virtue of its anti-stress activity.

Animals↗
PubMed1996

Cerebrospinal fluid adenosine deaminase activity for the diagnosis of tuberculous meningitis in children.

Adenosine deaminase (ADA) activity was measured in the cerebrospinal fluid (CSF) of 27 subjects suffering from tuberculous meningitis (TBM), 19 from bacterial meningitis, 10 from encephalitis, and 10 control subjects. The mean CSF ADA level was significantly raised (P < 0.001) in TBM patients as compared to other study groups. A cut-off CSF ADA level of > 5 IU/1 was considered for the diagnosis of TBM, and the test had sensitivity and specificity of 89 and 92 per cent, respectively. Overall, it was found to be a better test in comparison to any other single test for the diagnosis of TBM. Confirmed TBM patients had significantly higher CSF ADA activity when compared with clinical TBM (P < 0.01) and the levels did not differ significantly among different stages of disease. The ADA level in TBM cases had significant correlation with CSF cell count (P < 0.01), lymphocyte percentage (P < 0.02) and protein concentration (P < 0.02). Thus, the CSF ADA activity assay was found to be a simple, useful and rapid diagnostic test for the early recognition of TBM in children.

Adenosine Deaminase↗
PubMed1996

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.

Aeromonas↗
PubMed1996

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.

Adolescent↗
PubMed1996

Epithelial adherence of Candida albicans is enhanced by passage through rat small intestine.

Seven Candida albicans isolates (four from patients with diarrhoea and three from healthy persons) underwent two passages through rat ileal loop (RIL) to see the effect of consecutive passages on the adherence to rat intestinal epithelium. The isolates from patients with diarrhoea showed a significant enhancement in adherence after the first passage (1.95 x 10(4) cfu/cm2 versus 3.67 x 10(4) cfu/cm2). There was no further increase between the first passage (3.67 x 10(4) cfu/cm2) and the second one (3.61 x 10(4) cfu/cm2). A similar pattern was observed with the three nondiarrhoeal isolates. Animal passage of this fungus probably leads to better interactions between the cell surfaces causing the enhanced adherence.

Animals↗
PubMed1995

Effect of intrathecal saline injection and Valsalva maneuver on cerebral perfusion pressure during transsphenoidal surgery for pituitary macroadenoma.

Cerebrospinal fluid pressure (CSFP) was monitored through a lumbar intrathecal catheter in 32 patients undergoing transsphenoidal excision of pituitary macroadenomas. In the first 20 patients, standardized intermittent Valsalva maneuvers were followed by intrathecal saline injections in 2.5-ml increments. Their effects on CSFP, mean arterial pressure (MAP), and therefore, cerebral perfusion pressure (CPP) were compared. The increase in CSFP produced by one Valsalva maneuver (4 +/- 2 mm Hg) was similar to that produced by a single increment of intrathecal saline (4 +/- 2 mm Hg), but the effect of saline was more sustained. With Valsalva maneuvers, the maximum CSFP produced was 13 +/- 4 mm Hg, and the CPP decreased to 50 +/- 14 mm Hg, whereas with saline, the maximum CSFP was 25 +/- 7 mm Hg, and the CPP decreased to 59 +/- 13 mm Hg. Because the increase in CSFP was greater and better sustained with intrathecal saline, Valsalva maneuvers were omitted in the next 12 patients. Peroperative data, including surgical conditions, and post-operative morbidity, with special reference to low-pressure headache and meningeal infection, were analyzed in all 32 patients. Operative conditions produced with intrathecal saline were judged excellent or good in 75% of patients. However, because this technique can decrease the CPP excessively, we recommend that it be used only with continuous CSFP monitoring.

Adenoma↗
PubMed1995

An outbreak of multidrug resistant. Salmonella typhimurium in a nursery.

A nursery epidemic caused by multidrug resistant Salmonella typhimurium is reported. In total, 21 infants developed symptomatic illness; of these, 17 had septicemia (7 blood culture positive) and 4 had diarrhea alone. Asymptomatic carrier state was identified in 13 infants. Male sex and birth asphyxia increased the risk for symptomatic illness. Fever, lethargy, and diarrhea were the most common clinical features. Amongst the septicemic infants there was no difference in clinical profile whether the blood culture was positive or negative for S. typhimurium. In the symptomatic group, S. typhimurium was isolated from feces in 19 cases and from blood in 7 cases. In both symptomatic and asymptomatic infants, all isolates of S. typhimurium, whether obtained from feces and/or from blood, were resistant to ampicillin, chloramphenicol, and trimethoprim, and a significant number (almost one-fifth) of them also showed resistance to third generation cephalosporins. More than 90% of isolates were sensitive to aminoglycosides and ciprofloxacin. On a combination of third generation cephalosporin (cefotaxime or ceftriaxone) and amikacin, 17 (81%) infants recovered, 2 succumbed to their illness, and 2 failed to improve and required ciprofloxacin. The origin of epidemic was traced to a carrier staff nurse working in nursery.

Anti-Bacterial Agents↗
PubMed1995

Cerebrospinal fluid adenosine deaminase activity and C-reactive protein in tuberculous and partially treated bacterial meningitis.

Adenosine deaminase (ADA) activity measurement and C-reactive protein (C-RP) detection were done in CSF of 27 tuberculous meningitis (TBM) and 8 patients of partially treated bacterial meningitis, apart from routine biochemical tests. Both the groups had comparable CSF cell count, protein and sugar concentrations. The mean CSF ADA activity was significantly raised in TBM as compared to partially treated bacterial meningitis patients (p < 0.05). A cut-off ADA level < or = 5 IU/L and C-RP positively were used for differentiation of partially treated bacterial from TBM cases. Based on this, the sensitivity and specificity of ADA and C-RP were 62.5%, 88.9% and 75%, 100%, respectively. Since both the tests are simple and take lesser time to perform, they can be used as rapid diagnostic tests to remove diagnostic dilemma between the two diseases.

Adenosine Deaminase↗