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Biomedical subjects

S C Pal

Publications and source records attributed to S C Pal.

At least 19 recordsLinked to original sources
PubMed2002

Anxiolytic and antiemetic activity of Zingiber officinale.

The benzene fraction (BF) of a petroleum ether extract of dried rhizomes of ginger, which contained anticonvulsant principle(s), was screened for anxiolytic and antiemetic activity. Motor coordination was not affected by BF per se, but diazepam-induced motor incoordination was potentiated. Animals treated with BF showed decreased occupancy in the closed arm of the elevated plus maze suggesting the presence of anxiolytic principles in the BF. BF also blocked lithium sulphate-induced conditioned place aversion indicating antiemetic activity. These findings suggest that the fraction (BF) possesses anticonvulsant, anxiolytic and antiemetic activity.

Animals↗
PubMed2002

Antimicrobial activity of extracts of Terminalia catappa root.

The effect against bacteria of petroleum ether (60-80 degrees C), chloroform and methanolic extract of dried root of Terminalia catappa Linn. (combrataceae) was employed by cup plate agar diffusion method. The chloroform extract showed prominent antimicrobial activity against S. aureus and E. coli as compared to other tested microorganisms, while petroleum ether extract was devoid of antimicrobial activity. The methanolic: extract exhibited MIC of 0.065 mg/ml against E. coli. and chloroform extract exhibited MIC of 0.4 mg/ml against S. aureus The chloroform has well as methanolic extracts showed good antimicrobial activity against Gram positive and Gram negative microorganisms.

Alkanes↗
PubMed1995

Nutrient optimization for production of broad spectrum antibiotic by Streptomyces antibioticus SR15.4.

Antibiotic production by Streptomyces antibioticus Sr15.4 was studied under various cultural conditions. During nutrient optimization it was found that the strain utilized glycerol as the best source of carbon at 1.044 molar level, and 0.020 molar arginine as the best source of nitrogen. The strain exhibited significant enhancement in antibiotic production when grown at pH 6.8.

Anti-Bacterial Agents↗
PubMed1994

Multi-drug resistant typhoid fever in hospitalised children. Clinical, bacteriological and epidemiological profiles.

A total of 592 children with clinical diagnosis of typhoid fever admitted to the Dr B. C. Roy Memorial Hospital for Children, Calcutta, India during the period between February 1990 and January 1992, were screened for Salmonella typhi by blood culture. S. typhi was isolated from 221 (37.3%) cases. The majority of the strains (92.3%) showed multi-drug resistant (MDR). They were resistant to chloramphenicol, ampicillin, tetracycline and trimethoprim-sulphamethoxazole. However, all the strains were uniformly (100%) susceptible to gentamicin, amikacin, furazolidone, norfloxacin and ciprofloxacin. Minimum inhibitory concentration of the antimicrobial agents against the resistant strains of S. typhi ranged between 200 and > 1600 micrograms/ml. Phage type 0 was most frequently encountered. The rate of isolation of S. typhi was more or less the same in all the pediatric age groups. The majority of the cases came from lower socio-economic classes with poor personal hygiene. Fever was the main presenting feature in all the cases. Other associated features of the MDR typhoid fever cases, who were uncomplicated during admission, were headache (36.0%), chill and rigor (23.2%), diarrhea (37.2%), anorexia (26.2%), vomiting (23.8%), cough (18.0%) and abdominal pain (19.8%). Hepatosplenomegaly was present in 42.4% cases. However, complications were less frequently encountered among the MDR typhoid fever cases who were uncomplicated during admission and treated as in-patients. Fourteen bacteriologically-confirmed MDR typhoid fever cases had jaundice and another 18 cases had an abnormal state of consciousness during admission. Four (2.0%) bacteriologically-confirmed MDR typhoid fever patients died during the period of observation.

Age Distribution↗
PubMed1993

Biochemical and immunological studies on soluble antigens of Entamoeba histolytica.

The soluble antigens of Entamoeba histolytica trophozoites were analysed in detail by biochemical and immunochemical methods. The antigen was highly complex and heterogeneous as revealed by Sephacryl S-300 column chromatography, which showed four distinct fractions. The molecular mass of fractions FI, FII, FIII and FIV was 660, 170, 65 and 13 kDa, respectively. Protein was the major constituent in crude soluble antigen (CSA) and fractions FI and FII (67%, 80% and 90%, respectively). Polysaccharide was predominant in the FIII fraction (59%). Antigenic activity observed after different physico-chemical treatments revealed that CSA and FI antigens were predominantly glycoprotein in nature. However, the antigenicity of FIII antigen was greatly reduced after sodium meta-periodate treatment, whereas no alteration in reactivity was discerned after trypsin treatment. Sodium dodecyl sulphate-polyacryl-amide gel electrophoresis (SDS-PAGE) analysis demonstrated nearly 28 Coomassie blue bands for CSA and 20, 16, 15 and 3 polypeptide bands for the FI, FII, FIII and FIV fractions, respectively. The molecular mass of the polypeptides of these bands ranged from 210 to 20 kDa. Antigenic activity was observed in CSA and in the first three fractions, both in counter immunoelectrophoresis (CIEP) and in enzyme-linked immunosorbent assay (ELISA). However, the highest antigenic activity was noted in fraction FI. Major immunoreactive polypeptides of CSA and FI antigens against whole trophozoite antibody were observed in the 10- to 170-kDa regions. However, major differences in the immunoreactivity of the two antigens were noted at 116 and 14 kDa for FI antigen and at 84, 30 and 20 kDa for CSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

New phage typing scheme for Vibrio cholerae O1 biotype El Tor strains.

The conventional phage typing scheme proposed by S. Basu and S. Mukerjee (Experientia 24:299-300, 1968) has been used routinely for identification of the strains at the Vibrio Phage Reference Laboratory since 1968. However, because of limitations of this scheme, a new phage typing scheme using five newly isolated phages was incorporated into the conventional scheme. A different definition of routine test dilution (almost confluent lysis) was found to be more useful than the one previously used (confluent lysis). The 1,000 strains tested could be clustered into 27 types with the five new phages. With the new scheme of 10 phages (5 new phages and 5 phages of Basu and Mukerjee), the 1,000 strains could be grouped into 146 types. The new phages were different from each other and also from those of Basu and Mukerjee, as revealed by lytic pattern, electron microscopy, restriction endonuclease digestion, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and antiphage antiserum studies. With the new typing scheme, 99.6% of the strains were typeable. Phage type 115 was the most common and includes 119 (11.9%) of the 1,000 strains tested. Next most common were phage types 142 (9.4%), 143 (7.0%), 104 and 116 (both 5.4%), 3 (5.3%), 5 (4.1%), 4 (3.9%), 24 (2.1%), and 100 (1.7%). The larger number of types would be useful for further classification of the strains for epidemiological purposes. This newly developed scheme is highly applicable to, and could be widely adopted for, phage typing of Vibrio cholerae O1 biotype El Tor strains.

Antibodies, Viral↗
PubMed1993

Alpha-amylase production in lactose medium by Bacillus circulans ACB.

Alpha-amylase production by Bacillus circulans ACB was studied in various cultural conditions. During nutrient optimisation, it was found that 2% lactose can be utilized by the strain as source of carbon providing better growth and enzyme yields than starch. Ammonium sulfate of the basal medium can be replaced by ammonium nitrate for better growth and alpha-amylase activity. The strain demonstrated significant enhancement in alpha-amylase production when grown at pH 6.6.

Bacillus↗
PubMed1993

Value of a single Widal test in the diagnosis of typhoid fever.

Results of a single Widal test in patients with bacteriologically confirmed typhoid fever (116), clinically suggestive but culture negative fever (170) and non-typhoidal febrile illness (98) and in normal control children (54) were analysed. Positive Widal test (antibody titre against S. typhi O antigen of 1:160) was recorded in 61.2 per cent of patients with bacteriologically confirmed typhoid fever and in 58.8 per cent with culture negative but clinically suggestive typhoid fever. In contrast, the same titre was observed in 10.2 per cent patients with other febrile illnesses of known etiology and in 1.8 per cent of normal children. Differences in the positivity of Widal test in patients with bacteriologically confirmed typhoid fever and clinically suggestive but culture negative fever were highly significant (P < 0.000001) when compared to that of patients with non-typhoidal febrile illnesses and normal controls. High specificity and positive predictive value in 1:160 dilution makes the Widal test acceptable as a diagnostic tool.

Antibodies, Bacterial↗
PubMed1993

Significance of Cryptosporidium as an aetiologic agent of acute diarrhoea in Calcutta: a hospital based study.

The significance of Cryptosporidium as a causative agent of acute diarrhoea has been assessed in a year long hospital based study. A significantly higher detection of Cryptosporidium (P < 0.01) was observed in cases as compared to controls. Cryptosporidium was detected alone from 3% of acute diarrhoeal patients and from 5.5% in combination with other enteric pathogens. However, only 1.1% of control subjects were positive for Cryptosporidium. The highest detection rate of Cryptosporidium oocysts was in the first two years of life, in both cases and controls. No sex specific predilection for Cryptosporidium was observed in either the cases or controls.

Acute Disease↗
PubMed1992

Campylobacter species as a cause of diarrhoea in children in Calcutta.

From 1985 to 1988, 857 children (aged between 1 day and 60 months) admitted to hospital with diarrhoea and 241 controls (aged between 5 days and 60 months) were examined for campylobacters and other enteric pathogens by means of conventional methods. The difference between the isolation rates of campylobacters in those cases in which no other enteric pathogen was found (4.8%) and controls (6.2%) was not significant (P greater than 0.05). Strains of Campylobacter jejuni/coli were isolated throughout the year with higher isolation rates during the summer and monsoon months. Mixed infections were very common. Watery diarrhoea (97.6% cases) was the most common clinical presentation of patients found to be infected solely by C. jejuni/coli. Most patients infected with campylobacters were mildly to moderately dehydrated. Biotype I of C. jejuni and C. coli was the dominant biotype associated with cases and controls. All strains of C. jejuni/coli, regardless of their source, were found to be sensitive to erythromycin. From this study, it appears that enteric infections with campylobacters among children in Calcutta are common but often asymptomatic.

Bacterial Typing Techniques↗
PubMed1992

Virulence traits of Aeromonas strains in relation to species and source of isolation.

The virulence traits of 39 well-defined clinical (29 strains) and environmental (10 strains) isolates of Aeromonas (16 A. hydrophila, 12 A. sobria and 11 A. caviae) were examined by a variety of assays to delineate differences, if any, in the enteropathogenic potential in relation to species and the source of isolation. The distribution of enterotoxin (ent), cytotoxin (cyt) and haemolysin (hae) producing strains of Aeromonas did not correlate to species and source of isolation. The extracellular virulence phenotype Ent+ Cyt+ Hae+ was the most common one among all the three species although unique phenotypes associated prominently with either A. hydrophila or A. sobria were also discernible. None of the cytotoxin or haemolysin producing strains hybridized with the vt1/vt2 or the tdh/trh gene probes, respectively, indicating that these two factors of Aeromonas were distinct. Haemagglutination of human O group erythrocytes was not related to the source of isolation or production of enterotoxin, cytotoxin or haemolysin but appeared to be related to species. The strains which did not exhibit cell-associated haemagglutination belonged to either A. hydrophila or A. caviae. Haemagglutination unaffected by fucose, mannose and galactose was the dominant inhibition pattern exhibited mainly by the clinical haemagglutinating strains of the three species. Only one clinical strain of A. caviae showed a diffuse pattern of adherence to HeLa cells. Expression of the 5 bacterial enzymes by strains of Aeromonas did not fall into a readily discernible pattern in relation to species or source of isolation. From this study, it is clear that the mechanism of the pathogenesis of Aeromonas is a multifactorial one.

Aeromonas↗
PubMed1992

Entero-adherent Escherichia coli is an important diarrhoeagenic agent in infants aged below 6 months in Calcutta, India.

Escherichia coli adherent to HEp-2 and HeLa cells were isolated from the faeces of 43 (19.7%) of 218 hospitalised infants aged below 6 months with acute diarrhoea. No conventional virulence factors, including enterotoxin production--heat-labile (LT) or heat-stable (ST), the verotoxin (VT) or shiga-like toxin (SLT)--or the invasive phenotype (determined by the Sereny test) could be detected among these isolates. Out of the 43 isolates, 16 (37.2%) were of the known enteropathogenic O:K serogroups--enteropathogenic E. coli (EPEC). The remaining 27 (62.8%) isolates showed different types of adherence to HEp-2 and HeLa cells which was diffuse (40.7%), localised (37.0%), or both (22.3%); they were identified as entero-adherent E. coli (EAEC). The EAEC isolates adhered to HEp-2 and HeLa cells in the presence of mannose, lactose, fucose, galactose, and fetuin, indicating that adhesion was not specific for these sugars or glycoprotein. Haemagglutination and the salt aggregation test (SAT) did not correlate with patterns of adherence. The results of this study indicate that LA-EAEC is an important aetiological agent of acute diarrhoea in infants aged below 6 months in Calcutta.

Bacterial Adhesion↗
PubMed1992

Detection of cholera toxin by a highly sensitive bead-enzyme linked immunosorbent assay.

A bead-enzyme linked immunosorbent assay (bead-ELISA) for detection and quantification of cholera toxin (CT) in broth cultures of Vibrio cholerae O1 has been developed. Under optimal buffer and pH conditions the bead-ELISA could consistently detect 40 pg/ml of CT. None of the ingredients of commonly used media for in vitro culture of V. cholerae O1 hindered the performance of the bead-ELISA. Evaluation of the sensitivity and specificity of the bead-ELISA against the commonly used reversed passive latex agglutination (RPLA) test for detection of CT was performed using a collection of 239 strains of V. cholerae O1 (including both biotypes and serotypes) which were examined by a gene probe encoding for the A1 subunit of CT. Although both the assays were highly specific, the bead-ELISA was more sensitive than the RPLA. Quantification of CT by the bead-ELISA revealed that the concentration of CT produced by the strains of V. cholerae O1 which were negative by the RPLA was lower than 1 ng/ml and therefore below the minimum detection ability of the RPLA. The bead-ELISA is a simple, specific and highly sensitive assay for routine detection of CT and is recommended for routine use in clinical microbiology laboratories.

Antigen-Antibody Reactions↗
PubMed1992

Reassessment of the prevalence of heat-stable enterotoxin (NAG-ST) among environmental Vibrio cholerae non-O1 strains isolated from Calcutta, India, by using a NAG-ST DNA probe.

A collection of 521 environmental isolates of Vibrio cholerae which were previously examined by the suckling mouse assay and found to be negative for the heat-stable enterotoxin NAG-ST were reassessed by a recently developed DNA probe for NAG-ST. A total of 12 (2.3%) of the isolates hybridized with the NAG-ST probe. By using a cholera toxin (CT) DNA probe, the CT gene was detected in six of the strains in the collection, although none of the isolates of V. cholerae non-O1 hybridized with both of the toxin probes. All of the NAG-ST and CT probe-positive strains were hemolysin positive. Thirty-fold-concentrated supernatants of the three representative NAG-ST DNA probe-positive V. cholerae non-O1 strains gave positive fluid accumulation ratios in the suckling mouse assay even after heating (100 degrees C for 5 min) and also inhibited the binding of a NAG-ST monoclonal antibody to the bound NAG-ST in a competitive enzyme-linked immunosorbent assay (ELISA). Likewise, all six CT probe-positive V. cholerae non-O1 strains produced in vitro CT when examined by the CT bead ELISA. HindIII digest patterns of chromosomal DNA from the representative NAG-ST gene-positive strains were visually indistinguishable. Between the groups of NAG-ST probe-positive strains examined, there was a variation in the hybridizable fragments, with one group of strains exhibiting a hybridizable fragment similar to that of the NRT 36 reference strain; a smaller HindIII fragment hybridized with the NAG-ST probe in the other group of strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Taxonomical implications of the emergence of high frequency of occurrence of 2,4-diamino-6,7-diisopropylpteridine-resistant strains of Vibrio cholerae from clinical cases of cholera in Calcutta, India.

Of the 110 consecutive isolates of Vibrio cholerae recovered from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India, between July 1989 and October 1990, 90 and 82.7% were resistant to 10 and 150 micrograms of 2,4-diamino-6,7-diisopropylpteridine (O/129), respectively. Additionally, all O/129-resistant strains of V. cholerae were multiply resistant to antimicrobial agents. Except in the cases of four strains, resistance to O/129 was invariably linked with resistance to co-trimoxazole. Although O/129 susceptibility is still a useful test for Vibrio identification, resistance of V. cholerae to this compound in local areas might occasionally pose a problem.

Cholera↗
PubMed1992

Evaluation of the bead enzyme-linked immunosorbent assay for detection of cholera toxin directly from stool specimens.

A highly sensitive bead enzyme-linked immunosorbent assay (bead ELISA) for detection of cholera toxin (CT) was evaluated for direct detection of CT from stool specimens of patients with acute secretory diarrhea. Of the 75 stool samples examined, 59 yielded biochemically, and serologically confirmed strains of Vibrio cholerae O1. The bead ELISA was positive for CT in stool supernatants in 50 (84.7%) of the 59 samples from which V. cholerae O1 was isolated. In addition, the bead ELISA was positive for three stool specimens which were negative by culture. The free CT present in 48 of the 50 stool samples positive by culture for V. cholerae O1 and for CT by bead ELISA was completely absorbed by anti-CT immunoglobulin G. All of the 59 strains of V. cholerae O1 biotype eltor isolated in this study produced in vitro CT. The concentration of CT present in the bead ELISA-positive stool samples ranged between 26 pg/ml and greater than 100 ng/ml. This evaluation study demonstrates that the bead ELISA is a sensitive and simple method for direct detection of CT in nonsterile stool samples, and we recommend routine use of this assay for detection of CT in stool samples and culture supernatants in clinical and reference laboratories.

Cholera Toxin↗