Serum Lipid Profile and Its Relationship with Host Immunity in Carcinomas of the Breast and Uterine Cervix

Carcinomas of the uterine cervix and breast, which have a different etiopathogenesis, are the most common malignancies among Indian women. Between these two cancers a comparative study was undertaken in which serum lipids were assessed along with host immunity. Thirty randomly selected cases each of breast and cervical carcinoma, and 20 matched healthy control women were studied by means of standard procedures. Significantly higher (P < 0.001) mean levels of triglycerides (x = 192.1 mg/dl, SD ± 113.5) and total cholesterol (x = 212.9 mg/dl, SD ± 49.78) were observed in breast cancer as compared to controls or cervical cancer patients. Patients with cervical cancer had low mean values of all lipid fractions. Women with the above malignancies also showed a significantly decreased CD3+ and CD4+ population (P < 0.001), while there was a significant increase in CD8+ cells (P < 0.005) compared to normal controls. Interestingly, a significant relationship (P < 0.05) was observed between CD8+cells and LDL-cholesterol among the cancer patients (r = 0.3652 and r = 0.4298 for carcinomas of breast and cervix, respectively).

Glycoprotein B genotyping in congenital/perinatal Cytomegalovirus infection in symptomatic infants

BACKGROUND

Molecular epidemiological studies on circulating strains of CMV in cogenital/perinatal infections have not been done earlier in this region.

OBJECTIVE

To study the glycoprotein B genotypes in babies with symptomatic congenital/perinatal CMV infection and to assess the possible influence of genotype on the outcome of the infection.

METHODS

Clinical samples (blood and urine) of symptomatic babies are sent to the Virology Department of NCDC, Delhi for the diagnosis of congenital infections. 375 clinical samples of infants (newborn - 6 months old) were included for the study. Serum samples were subjected to ELISA for detection of IgM antibodies against CMV. DNA isolation and amplification of CMV genomic DNA targeting gB gene fragment by nested PCR, was carried out in the samples. The amplified fragment including the cleavage site was subjected to RFLP using restriction enzymes Rsal and Hinf1. They were also verified by sequencing using Big Dye Terminator chemistry.

RESULTS

75 samples out of 375 tested were confirmed positive for CMV infection by serology and PCR. Both RFLP and sequencing of gB gene fragment showed that gB 1, 2 and 3 genotypes were in circulation. gB 3 was the most prevalent genotype in symptomatic infants. Hepatosplenomegaly was the most common feature in gB-3 genotype of CMV. gB2 congenital CMV infection was more commonly associated with long term sequelae.

Resistance-associated mutations in HIV-1 among patients failing first-line antiretroviral therapy

Thirty-five HIV-1 infected patients showing clinical and/or immunological failure to first line antiretroviral therapy (ART) according to WHO criteria were recruited from the ART center of Lok Nayak Hospital, New Delhi to detect the presence of resistance-mutations in reverse transcriptase (RT) and protease (PR) region of pol gene of HIV-1. Plasma viral load (PVL) was estimated. HIV-1 pol gene region encoding complete protease and reverse transcriptase (codons; 1-232 to 1-242) was reverse transcribed, followed by nested PCR. The PCR product was sequenced and analyzed. Plasma samples from 94.3% of patients with PVL >log(10) 3.0 c/mL could be amplified and analyzed. Virologic failure was detected in 65.7% of patients according to WHO criteria (PVL >log(10) 4.0). All patients were found to be infected with subtype C. One or more resistance-mutations were observed among 90.9% of study sequences. Nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations were seen among all patients, with M184V and thymidine analogue mutations (TAM) being most frequently detected (75.6% and 72.7%, respectively). Nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance-mutations were detected in 63.6% of sequences, of which Y181C/I (47.6%), K103N (33.3%) and G190S (28.6%) are the most common. None of the sequences showed major protease inhibitors (PIs) resistance mutation. High prevalence of NRTI and NNRTI drug resistance mutations among the study participants warrants the use of genotypic resistance testing to prevent accumulation of resistance mutations, which would limit future treatment options.

Diagnostic potential of IS6110, 38kDa, 65kDa and 85B sequence-based polymerase chain reaction in the diagnosis of Mycobacterium tuberculosis in clinical samples

PURPOSE

The correlation between the presence of specific gene sequence of M. tuberculosis and specific diagnosis of clinical tuberculosis is not known. This study compared the results of polymerase chain reaction (PCR) amplification of M. tuberculosis specific DNA sequences (IS6110, 65kDa, 38kDa and mRNA coding for 85B protein) from different clinical samples of pulmonary and extrapulmonary tuberculosis.

METHODS

One hundred and seventy-two clinical samples from suspected tuberculosis patients were tested for smear examination, culture (LJ and rapid BACTEC 460 TB system) and PCR. PCR was performed with specific primers for the targets: IS6110, 65 kDa, 38 kDa and 85 B.

RESULTS

Each PCR test was found to have a much higher positivity than conventional test and BACTEC culture (P < 0.05). Smear positive samples (56) and the samples (36) showing positive results by conventional methods (smear and LJ medium culture) and BACTEC were found to be positive by all PCR protocols. No significant difference was found between the four PCR protocols (P> 0.05). The primer specific for amplifying the 123bp IS6110 fragment gave the highest positivity (83%), followed by 65kDa, 38kDa and 85B RT-PCR in descending order.

CONCLUSIONS

These data suggest that the presence of IS6110 correlates more closely with the diagnosis of clinical tuberculosis than that of 65kDa, 38kDa and 85B proteins.

Occurrence & nucleotide sequence analysis of hepatitis G virus in patients with acute viral hepatitis & fulminant hepatitis

BACKGROUND & OBJECTIVE

Association of hepatitis G virus (HGV) with acute viral hepatitis (AVH) and fulminant hepatitis (FH) is not clearly understood. This study was designed to asses the occurrence of HGV infection and its relationship with other hepatotropic viruses in patients with FH and AVH and also to determine the nucleotide sequence of HGV isolates.

METHODS

The study included 100 patients of FH and 125 of AVH on the basis of clinical examination, liver function test and serology for hepatitis A, B, C and E virus. HGV RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and direct sequencing for 4 randomly selected samples followed by phylogenetic analysis.

RESULTS

Of the 100 patients with FH, 30 were negative for hepatitis viruses A, B, C and E by serology (non A-non E) while 60 were negative in the AVH group. In the non A-non-E hepatitis group, HGV was positive in 16.66 per cent (5/30) cases of FH, 10 per cent (6/60) cases of AVH and 6 per cent (6/100) of healthy controls. The difference in HGV seropositivity between FH and AVH patients was statistically not significant compared to healthy controls, while HBV and HCV infections were significant. The four isolates sequenced seemed to be of same type and close to Chinese strain of HGV (Y13755.1 Y13756.1 Y15407, and U67782) on phylogeny.

INTERPRETATION & CONCLUSION

In HGV infection was not found to be clinically significant as well as nonpathogenic in the patients of FH and AVH and appeared to be an innocent bystander in the course of the disease. The four sequenced HGV isolates showed close pairing with Chinese strains.

Histone as future drug target for malaria

Malaria continues to be a major cause of mortality and morbidity in tropical countries and affecting around 100 countries of the world. As per WHO estimates, 300-500 million are being infected and 1-3 million deaths annually due to malaria. With the emerging knowledge about genome sequence of all the three counterparts involved in the disease of malaria, the parasite Plasmodium, vector Anopheles and host Homo sapien have helped the scientists to understand interactions between them. Simultaneous advancement in technology further improves the prospects to discover new targets for vaccines and drugs. Though the malaria vaccine is still far away in this situation there is need to develop a potent and affordable drug(s). Histones are the key protein of chromatin and play an important role in DNA packaging, replication and gene expression. They also show frequent post-translation modifications. The specific combinations of these posttranslational modifications are thought to alter chromatin structure by forming epigenetic bar codes that specify either transient or heritable patterns of genome function. Chromatin regulators and upstream pathways are therefore seen as promising targets for development of therapeutic drugs.

Prompt laboratory diagnosis in timely containment of a plague outbreak in India

A focal outbreak of pneumonic plague occurred in a hamlet of village Hatkoti, district Shimla, Himachal Pradesh in the first fortnight of February, 2002. A total of 16 cases with 4 deaths were reported. Diagnosis of plague was confirmed by the laboratory in 10 (63%) cases. Y. pestis was isolated from clinical samples of 3 cases and confirmed by bacteriophage lysis. Molecular tests confirmed the presence of Y. pestis specific pla and F1 genes in 4 cases; DNA fingerprinting had identity with the known sequence of plague bacilli. Paired samples from 5 cases showed more than 4 fold rise and 1 case showed more than 4 fold fall in antibodies against F1 antigen of Y. pestis. The present communication emphasises that timely and systematic laboratory investigations give confirmatory diagnosis in shortest possible time which forms the backbone of the outbreak control in a timely fashion and prevents confusion and controversy.

Phenotypic and genotypic detection of ESBL mediated cephalosporin resistance in Klebsiella pneumoniae: Emergence of high resistance against cefepime, the fourth generation cephalosporin

OBJECTIVES

Cephalosporins belonging to second and third generation are commonly used in India for the treatment of Klebsiella pneumoniae. Report on resistance among K. pneumoniae strains to second and third generation cephalosporins are on rise in this country, which has been attributed to emergence of strains expressing extended-spectrum beta-lactamases (ESBLs). The aim of this study was to evaluate the in vitro susceptibility of K. pneumoniae to broad-spectrum cephalosporins particularly to cefepime, a recently introduced fourth generation cephalosporin in relation to ESBL production.

METHODS

This study has been carried out in two phases among K. pneumoniae strains isolated between October 2001 and September 2002 (phase I, before marketing of cefepime in India) and between August 2003 and July 2004 (phase II, after marketing of cefepime in India). Minimum Inhibitory Concentration (MIC) was determined by a commercial strip containing gradient of antimicrobials (Strip E-test). Detection for ESBL production was carried out by DDST, E-test ESBL and PCR.

RESULTS

Antimicrobial resistance profile of K. pneumoniae strains to five cephalosporins as analyzed by WHONET 5 identified 15 different resistance profiles among the 108 phase I isolates, ranging from resistance to none (19.44%) to all the five cephalosporin (8.33%) and eight different resistance profiles among the 99 phase II isolates, ranging from resistance to none (9.1%) to all the five cephalosporins (36.4%). Among the 108 phase I isolates a total of 71 (65.72%) and out of 99 phase II isolates, a total of 87 (88.0%) could be identified as ESBL producers. Among the isolates, regardless of the phase of the isolation, those characterized by production of ESBL showed overall higher frequency of resistance to cephalosporins (range 19.7-85.9% and 51.7-100% in phase I and phase II, respectively) compared to those for ESBL non-producers (range 0-13.5% and 0-25% in phase I and phase II, respectively). Ten randomly selected isolates from the most common resistance phenotypes probably belonged to a single strain as evident by MIC patterns, genotypic characterization and resistance profile to non-cephalosporin group of antimicrobials thereby pointing out the possibility of an outbreak.

CONCLUSIONS

PCR may be regarded as a reliable method for detection of ESBL since in addition to the strains that could be identified as ESBL producers by DDST and E-test ESBL; PCR could demonstrate ESBL production among additional 32 strains (15 in phase I and 17 in phase II). Continued uses of cephalosporin group appear to be a potential risk factor for emergence of ESBL producing K. pneumoniae strains. In addition, as noted in the present study, the rise of resistance to cefepime that has been introduced recently in this country for therapeutic use could be of concern.

Molecular characterization of mutation associated with rifampicin and isoniazid resistance in Mycobacterium tuberculosis isolates

Nucleotide changes in catalase peroxidase (Kat G) gene and gene encoding the beta subunit of RNA polymerase (rpo B), responsible for isoniazid and rifampicin drug resistance were determined in the clinical isolates of Mycobacterium tuberculosis by PCR-RFLP, Line probe assay and DNA sequencing. PCR-RFLP test was performed by HapII cleavage of an amplified fragment of Kat G gene to detect the transversion 315AGC-->ACC(Ser-->Thr) which is associated with INH drug resistance. The Line probe assay kit was evaluated to detect the mutation in 81bp RMP resistance determining region of rpo B gene associated with RMP drug resistance. These results were validated by DNA sequencing and drug susceptibility test. Kat G S 315 T mutation was found in 74.19% strains of M. tuberculosis from Delhi. This mutation was not found in any of the susceptible strains tested. The line probe assay kit and DNA sequencing identified 18 isolates as RMP resistant with specific mutation, while one of the RMP resistant strain was identified as RMP susceptible, with a concordance of 94.73% with the phenotypic drug susceptibility result. Majority (8 of 19, 42.1%) of resistant isolates involved base changes at codon 531 of rpo B gene. Both PCR-RFLP and Line probe assay test can be used in many of the clinical microbiology laboratories for early detection of isoniazid and rifampicin drug resistance in clinical isolates of M. tuberculosis.

Protein antigen b (Pab) based PCR test in diagnosis of pulmonary and extra-pulmonary tuberculosis

BACKGROUND AND OBJECTIVES

Diagnosis of tuberculosis (TB) is largely based on microscopy and culture examination which are either less sensitive, or time consuming. In the present study a PCR (polymerase chain reaction) test based on DNA sequence coding for a 38-kilodalton protein antigen b (Pab) ,specific for Mycobacterium tuberculosis was compared with Ziehl-Neelsen (ZN) stained AFB (acid fast bacilli) smear examination, culture based on conventional Lowenstein-Jensen (LJ) medium and radiometric BACTEC 460 system for the diagnosis of TB using clinical samples obtained from pulmonary and extra-pulmonary cases of TB.

METHODS

Clinical samples obtained from 168 patients of suspected TB (pulmonary and extrapulmonary) were subjected to ZN smear examination, LJ culture, radiometric BACTEC culture and a PCR test by amplifying 419 bp sequence coding for Pab, a glycoprotein of molecular weight 38 kDa.

RESULTS

A significant difference was seen in the sensitivity of different tests, the figures being 74.2 per cent for PCR test, 53.4 per cent for BACTEC culture, 47.1 per cent for LJ medium based culture and 35.2 per cent for ZN smear examination (P<0.05). However, there was no significant difference between different tests as far as specificity was concerned. PCR test sensitivity in pulmonary and extra-pulmonary clinical samples were 74.3 and 71.5 per cent respectively, being significantly higher (P<0.05) when compared with sensitivity of other tests. The mean detection time for M. tuberculosis was 24.0 days by LJ media culture, 12.8 days by BACTEC culture and less than 1 day by smear examination and PCR test.

INTERPRETATION AND CONCLUSION

PCR test is more sensitive than ZN smear examination, LJ medium culture and BACTEC culture for diagnosing TB in pulmonary and extra-pulmonary clinical samples.

Tuftsin-mediated immunoprophylaxis against an isolate ofAspergillus fumigatusshows less in vivo susceptibility to amphotericin B

In the present study, we evaluated the immunopotentiating efficacy of tuftsin against experimental murine aspergillosis in both normal and immunodebilitant BALB/c mice. The animals were challenged with an isolate of Aspergillus fumigatus (1x10(8) cfu/mouse) that was showing less susceptibility to lower doses of amphotericin B in murine animal model. Co-administration of the immunomodulator tuftsin and liposomised-amphotericin B was found to be highly effective in the treatment of systemic infection of A. fumigatus in both immunocompetent and leukopenic mice. Moreover, pre-treatment of mice with liposomised-tuftsin prior to challenging them with A. fumigatus infection and subsequent treatment with tuftsin-bearing liposomised-amphotericin B was found to be extremely efficient in successful elimination of fungal pathogen. In another set of experiments, tuftsin-mediated antigen-specific memory antibody response was also assessed by immunizing the animals with A. fumigatus cytosolic antigen. The animals that received a booster 150 days after the first immunization with tuftsin-liposomes-antigen showed more resistance to A. fumigatus infection in comparison with the naïve animals.

Comparative study of PCR, smear examination and culture for diagnosis of cutaneous tuberculosis

Diagnosis of tuberculosis (TB), especially cutaneous TB by conventional laboratory method is unreliable and time consuming. We assessed the utility of Polymerase Chain Reaction (PCR) test vis a vis other laboratory tests in 37 clinical samples of skin biopsy from equal number of patients with different variants of cutaneous TB. The PCR test amplifying 165bp region of 65kDa antigen coding gene specific for M. tuberculosis was performed on skin biopsy samples obtained from cases with a strong clinical evidence of cutaneous TB. The samples were also subjected to other laboratory tests e.g. smear examination, conventional (LJ based culture) and rapid BACTEC culture and histopathological examination for mycobacteria. Significant difference (p<0.05) was observed in the sensitivity of PCR test vis-a-vis other tests e.g. smear examination, LJ and BACTEC culture. PCR test showed a higher sensitivity than histopathological examination but the difference was not found to be statistically significant (p>0.05). PCR test showed the maximum positivity of 79.4% followed by histopathology (73.5%), BACTEC culture (47.5%), LJ media culture (29.4%) and smear examination (5.8%). The sensitivity and specificity of PCR test employing culture as the "gold standard" were 95.2% and 100%. The mean time taken for a positive result in different tests were less than 24 hours for smear examination, 1 day for PCR test, 23.42 days for BACTEC culture and 38.02 days for LJ culture. These results show that PCR amplification of 165bp region of 65kDa antigen coding gene of M. tuberculosis is a rapid and sensitive test for diagnosis of cutaneous TB using skin biopsy samples.

CYP11B2 gene polymorphisms and hypertension in highlanders accustomed to high salt intake

BACKGROUND

High salt intake is the main determinant of hypertension. The alleles, which once had adaptive value in the salt-poor environment, by promoting salt retention, now induce hypertension. It would be interesting to determine whether the variant alleles of the aldosterone synthase gene (CYP11B2), if related to exaggerated expression/altered activity, are associated with hypertension when combined with a salt-rich diet.

OBJECTIVE

To investigate the -344T/C, K173R and intron-2 conversion polymorphisms of CYP11B2 for an association with hypertension in highlanders accustomed to a high salt intake.

DESIGN AND METHODS

Three CYP11B2 polymorphisms were compared with respect to frequencies and clinical characteristics in 190 normotensive highlanders (NHLs) and 100 hypertensive highlanders (HHLs). One-way ANOVA, chi2 test and logistic regression analysis were carried out to investigate the association of these polymorphisms with hypertension.

RESULTS

The HHLs had significantly higher systolic blood pressure (SBP), diastolic blood pressure (DBP) (P < 0.0001), body mass index (BMI) (P = 0.0002), plasma aldosterone levels (P = 0.03) and aldosterone to plasma renin ratio (ARR) (P < 0.0001) and lower plasma renin activity (PRA) (P = 0.007). The -344T/C and K173R polymorphisms were in complete linkage disequilibrium with each other and the intron-2 conversion allele was in absolute association with the T allele. The TC/CC genotypes correlated with higher BMI when compared with TT genotype in the NHLs and the HHLs (P = 0.002 and 0.004, respectively). The intron-2 conversion heterozygotes/homozygotes correlated with higher SBP in the HHLs (P = 0.03) and significantly higher ARR when compared to IwIw (P = 0.02). Genotype combinations between the -344T/C and intron-2 conversion polymorphisms revealed that combinations with TC or CC genotypes inclined towards higher BMI in both the groups (P < 0.05).

CONCLUSIONS

Our findings showed a correlation of C allele with high BMI, suggesting that -344T/C polymorphism is in linkage disequilibrium with a functional polymorphism on the adjacent 11-beta hydroxylase gene. The correlation of the intron-2 conversion allele with high SBP and ARR associates it with hypertension. The intron-2 conversion could be a functional variant, since it has been suggested to lead to overexpression of the gene; however, the presence of another functional variant in linkage disequilibrium within the gene cannot be ruled out.

Comparison of the conventional diagnostic modalities, bactec culture and polymerase chain reaction test for diagnosis of tuberculosis

PURPOSE

To evaluate the performance of 65 kDa antigen based PCR assay in clinical samples obtained from pulmonary and extrapulmonary cases of tuberculosis.

METHODS

One hundred and fifty six samples were processed for detection of Mycobacterium tuberculosis by ZN smear examination, LJ medium culture, BACTEC radiometric culture and PCR tests.

RESULTS

A significant difference was seen in the sensitivities of different tests, the figures being 74.4% for PCR test, 33.79% for ZN smear examination, 48.9% for LJ culture and 55.8% for BACTEC culture (P< 0.05). However, there was no significant difference (P>0.05) as far as specificity of different tests was concerned. PCR test sensitivity in pulmonary and extrapulmonary clinical samples were 72.7% and 75.9% respectively and found to be significantly higher (P< 0.05) when compared with those of other tests. The mean detection time for M.tuberculosis was 24.03 days by LJ medium culture, 12.89 days by BACTEC culture and less than one day by PCR test.

CONCLUSIONS

PCR is a rapid and sensitive method for the early diagnosis of pulmonary and extrapulmonary tuberculosis.

Identification, expression, modeled structure and serological characterization of Plasmodium vivax histone 2B

Histones play important role in DNA packaging, replication and gene expression. Here, we describe the isolation and characterization of histone 2B (PvH2B) gene from the most common but non-cultivable human malaria parasite Plasmodium vivax. The isolated cDNA clone of PvH2B was allowed to express in Escherichia coli and the recombinant protein was purified by affinity chromatography. The expressed PvH2B protein showed DNA-binding properties on the South-Western analysis and the confocal microscopy localized it in the parasite nucleus. This gene is actively expressed during blood stages of the parasite and all P. vivax patients produced antibodies against the protein. The mRNA of PvH2B was found to contain a poly(A) tail at its 3' end, unlike abundant mRNA of human H2B. The encoded polypeptide is 118 amino acid long contains a nuclear targeting site, a signature motif of H2B and showed 74% homology to its host molecule. The structure of PvH2B showed that it has certain differences from that of its host at critical functional sites (viz acetylation, methylation, trypsin cleavage, DNA-binding and inter-histone interaction) which are required for general gene expression and DNA packaging. The distinctive structural features of P. vivax H2B described here may help in designing the specific antimalarial drugs.

An outbreak of human anthrax in Mysore (India)

Anthrax is a zoonotic disease caused by Bacillus anthracis. Intestinal anthrax though a rare entity mostly ends with fatal outcome. Very few cases of intestinal anthrax are reported. Present outbreak of intestinal anthrax is unique in itself that four cases succumbed to the illness within a span of 48-72 hours in a small hamlet of Mysore district of Karnataka, after consuming diseased deer meat. Confirmation of the diagnosis was carried out at NICD, Delhi by bacteriological culture isolation, biochemical tests, animal pathogenicity and polymerase chain reaction (PCR). This outbreak clearly indicates surveillance of anthrax in animals in endemic areas is an essential part in the control of the disease with intersectoral coordination between the departments of health, animal husbandary, agriculture and forest.

Antimicrobial susceptibility pattern and prevalence of extended spectrum beta-lactamase (ESBLs) producing strains of Klebsiella pneumoniae from a major hospital in New Delhi

Extended spectrum beta-lactamases (ESBLs) are plasmid mediated enzymes capable of hydrolyzing penicillins, broad spectrum-cephalosporins and monobactams. The ESBL producing K. pneumoniae strains are being reported from around the world including India. The present study was taken up to evaluate the ESBL production and in-vitro susceptibility of K. pneumoniae isolates from a hospital. The bacterial isolates collected during 2003 included 51 K. pneumoniae biochemically confirmed isolates from 395 patients admitted in various wards of a major hospital in New Delhi. The isolates were from pus, wound, pleural fluid, urine and tracheal aspirate of patients attending respiratory, urology and burns wards. Antimicrobial susceptibility was carried out by Kirby Bauer's disc diffusion technique using NCCLS criteria. A screening of ESBL production was done by Double-disc synergy test (DDST) and using E-test ESBL strips. The frequency of resistance among K. pneumoniae for the cephalosporins (cefoxitin, cefuroxime, cefotaxime, ceftazidime, and cefepime) and non-cephalosporins (aztreonam, piperacillin, chloramphenicol and trimethoprim-sulfamethoxazole) were in the range of 39.2-88.0% and 51.0-90.2% respectively. 14 different antimicrobial resistance profiles were recognized ranging from resistance to only four (n=6, 11.7%) to as many as ten (n=9, 17.7%). Among the 51 isolates of K. pneumoniae strains, a total of 36 (70.6%) could be identified as ESBL producers, that correlates with the high frequency of multi-drug resistant K. pneumoniae The study shows alarming rise in ESBL production among K. pneumoniae strains and high rate of resistance to a wide range of cephalosporin and non-cephalosporin group of antimicrobials.

Partial VP1/2A gene sequence based molecular epidemiology of wild type 1 poliovirus isolates from some parts of India

Genomic variability within the sequences of VP1/2A junction among polioviruses from across the globe has revealed the existence of several endemic genotypes and their epidemiological inter-relationships; but such data on Indian isolates are scanty. The present work was intended to ascertain the persistence and transmission pattern of different genotypes of wild type 1 polioviruses circulating in India. Forty-eight wild type 1 poliovirus isolates obtained from different parts of India during 1996-8 were subjected to RT-PCR and nucleotide sequencing using M13 tailed primers. A 293 base pair region was amplified and sequenced for genetic variation study. Considering the 15% divergence of the sequences from Sabin 1, the isolates from six different states of India confirmed a single dominant genotype 4. Phylogenetic analysis revealed the circulation and active inter-state transmission of many genetically distinct strains of wild poliovirus type 1 belonging to genotype 4. This warrants the need for insisting on more efficient surveillance mechanisms so as to assess the impact of an extensive pulse polio immunization programme in India.

Allelic variation in the cg2 gene does not correlate with chloroquine resistance among Indian Plasmodium falciparum isolates

The cg2 gene of Plasmodium falciparum has been proposed to be associated with chloroquine resistance. Here we describe PCR amplification and sequencing of all the four repeat regions (kappa (kappa), gamma (gamma), psi (psi) and omega (omega)) of this gene, from Indian isolates. There were variant forms for each of these repeat regions (two for kappa and gamma, and three for psi and omega) among the 123 Indian isolates of P. falciparum. Among these isolates certain forms of psi and omega repeats were uniquely present while some of the reported forms of the kappa and omega repeats were absent. The pattern of combination of all four repeat regions of cg2 gene (genotype) was analysed from 52 isolates. A total of 11 different genotypes were observed among these cases, of which 10 were unique to Indian isolates. Certain genotypes were more common than others. The nucleotide sequencing of all the four repeat regions revealed that Indian isolates have some unique repeating units within the gamma and omega domains. Altogether, the PCR and sequencing results showed that there was an unrelatedness between cg2 repeats and chloroquine resistance.

Complete nucleotide sequence of the 6 kb element and conserved cytochrome b gene sequences among Indian isolates of Plasmodium falciparum

The malaria parasite contains a nuclear genome with 14 chromosomes and two extrachromosomal DNA molecules of 6 kb and 35 kb in size. The smallest genome, known as the 6 kb element or mitochondrial DNA, has been sequenced from several Plasmodium falciparum isolates because this is a potential drug target. Here we describe the complete nucleotide sequence of this element from an Indian isolate of P. falciparum. It is 5967 bp in size and shows 99.6% homology with the 6 kb element of other isolates. The element contains three open reading frames for mitochondrial proteins-cytochrome oxidase subunit I (CoI), subunit III (CoIII) and cytochrome b (Cyb) which were found to be expressed during blood stages of the parasite. We have also sequenced the entire cyb gene from several Indian isolates of P. falciparum. The rate of mutation in this gene was very low since 12 of 14 isolates showed the identical sequence. Only one isolate showed a maximum change in five amino acids whereas the other isolate showed only one amino acid change. However, none of the Indian isolates showed any change in those amino acids of cyb which are associated with resistance to various drugs as these drugs are not yet commonly used in India.

Relationship of Xba1 and EcoR1 polymorphisms of apolipoprotein-B gene to dyslipidemia and obesity in Asian Indians in North India

BACKGROUND

Genetic investigation of dyslipidemia and obesity prevalent in the Indian population form the basis of this study.

METHODS AND RESULTS

The frequency of restriction fragment length polymorphisms (Xba1 and EcoR1) of the apolipoprotein-B gene was investigated in a case-control study of 30 hyperlipidemic and 40 normolipidemic subjects. By univariate analysis, old age, higher body mass index, waist-hip ratio and sum of four skinfolds were found to be significantly associated with hyperlipidemia. The frequencies of X- and E+ alleles of the apolipoprotein-B gene were significantly higher in North Indians in the state of New Delhi (0.83 and 0.91, respectively) as compared to the observations made in Caucasians in previous studies, but was similar to the frequency reported in Indians settled in Singapore and the UK. There were no significant differences in the allele or genotype frequencies of either Xba1 or EcoR1 polymorphisms between the hyperlipidemic and normolipidemic groups. On multiple logistic regression analysis considering body mass index, waist-hip ratio, percentage body fat and genotypes as independent variables, no association was observed between the apolipoprotein-B genotypes and serum lipid components. Further, there were no associations between apolipoprotein-B polymorphisms and generalized obesity (as assessed by body mass index, sum of four skinfolds, and percentage total body fat) and abdominal obesity (as measured by waist circumference and waist-hip ratio).

CONCLUSIONS

We conclude that apolipoprotein-B (Xba1 and EcoR1) polymorphisms do not appear to influence serum lipid levels and parameters of generalized andregional obesity in the study sample.

Serum lipids, lipoproteins and sex-hormone binding globulin in breast cancer

Serum levels of various lipid parameters, i.e., triglycerides, total cholesterol, alpha lipoprotein or high density lipoprotein (HDL)-cholesterol and beta lipoprotein or low density lipoprotein (LDL)-cholesterol were measured in a total of 138 histologically proven cases of breast cancer along with 146 control women. The mean levels of serum triglycerides, total cholesterol and LDL-cholesterol were found to be significantly higher in breast cancer cases as compared to controls. However, lower mean levels of serum HDL-cholesterol and sex-hormone binding glubulin (SHBG) were observed in breast cancer patients than the control subjects. The results indicate a probable relation between serum lipids and the activity of sex-hormones. Moreover, the study reflects an overall disturbance of lipid metabolism in the pathological process of breast cancer.

Evaluation of oxidative stress in some cases of argimone oil poisoning during a recent outbreak of epidemic dropsy in India

The study was designed to evaluate the oxidative stress and modulation of anti-oxidant enzymes in 10 accidental argimone oil poisoning cases admitted in a hospital in Delhi, India during a recent outbreak of epidemic dropsy in 1998. Serum malondialdehyde (MDA) level, oxygen free-radical scavenging enzymes such as superoxide dismutase (SOD) and catalase (CAT), and glutathione (GSH) and related enzymes, e.g. glutathione reductase (GR), glutathione peroxidase (GPx), gamma glutamyl transpeptidase (GGT) and glutathione-S-transferase (GST) in erythrocytes were assayed. The sanguinarine level in serum was measured by high-performance liquid chromatography. The serum MDA level was higher and the GSH level in erythrocytes was lower in argimone oil poisoning cases than those in controls. There was a significant decrease in SOD and GPx activities in erythrocytes of epidemic dropsy cases but no changes were observed in CAT, GR and GST assay. The depletion of GSH in erythrocytes, serum MDA level and clinical severity were dependent on serum sanguinarine level. The results indicate that sanguinarine (argimone oil) poisoning creates an oxidative stress in humans. The oxidative stress and differential modulation of anti-oxidant enzymes by sanguinarine might play a pathogenic role in epidemic dropsy, which suggests the incorporation of anti-oxidant drugs in the treatment protocol of the disease.

Influence of dietary ginger (Zingiber officinales Rosc) on oxidative stress induced by malathion in rats

Pesticide chemicals may induce oxidative stress leading to generation of free radicals and alterations in antioxidants or oxygen free radical (OFR) scavenging enzymes. Hence, the effect of subchronic malathion (O,O-dimethyl-S-1,2, bis ethoxy carbonyl ethyl phosphorodithioate) exposure was evaluated on lipid peroxidation, glutathione and related enzymes and OFR scavenging enzymes in albino rats. Administration of malathion (20 ppm) for 4 weeks increased the malondialdehyde (MDA) levels in serum, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in erythrocytes and glutathione reductase (GR) and glutathione S-transferase (GST) in serum. However, it decreased the glutathione (GSH) level in whole blood. Concomitant dietary feeding of Zingiber officinales Rosc (ginger 1%, w/w) significantly attenuated malathion induced lipid peroxidation and oxidative stress in these rats. These results indicate the possible involvement of free radicals in organophosphate-induced toxicity and highlight the protective action of ginger, an indigenous medicinal plant product.

Partial nucleotide sequencing and molecular evolution of epidemic causing Dengue 2 strains

To study the genetic variability and to detect evolutionary changes and movement of dengue 2 (DEN-2) strains, nucleotide sequencing of the envelope protein gene and the nonstructural protein 1 gene junction was performed for 9 isolates from the 1996 Delhi epidemic and 1 isolate from the 1967 Delhi epidemic. The epidemic strains had a divergence of 10%-11% from the 1967 strains, but were quite similar to DEN-2 isolates from Seychelles, Somalia, and Torres Strait. In addition, the sequence data were compared to the prototype DEN-2 strain, New Guinea C, and other published DEN-2 sequences from different parts of the world. The phylogenetic analysis by the Molecular Evolutionary Genetics Analysis program suggests that the 1996 Delhi isolates of DEN-2 were genotype IV. The 1967 isolate was similar to a 1957 isolate of DEN-2, P9-122, from India, and was classified as genotype V. This study indicates that earlier DEN-2 strains of genotype V have been replaced by genotype IV.

Biochemical effects of some pesticides on lipid peroxidation and free-radical scavengers

Oxidative stress was studied in blood samples obtained from lindane, malathion and propoxur poisoning cases admitted to the Guru Teg Bahadur Hospital, Delhi and evaluated for lipid peroxidation, oxygen free radical (OFR) scavenging enzymes, and glutathione (GSH) and related enzymes. Acetylcholine esterase (AChE), gamma glutamyl transpeptidase (GGT) and GSH level were also assayed in lymphocytes. The level of thiobarbituric acid reacting substances and activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and GGT were increased and GSH level was decreased in pesticide poisoning. Apparently lindane (at the concentration examined) was more potent than malathion and propoxur in producing alteration in lipid peroxidation, GSH related parameters and OFR scavenging enzymes. However, AChE activity and GSH level in lymphocytes of malathion poisoning cases were reduced and GGT activity was enhanced in comparison to control subjects. The present results suggest that OFR scavenging enzymes were induced while combating oxidative stress in a differential manner in organochlorine, organophosphate and carbamate poisoning. Increased lipid peroxidation, coupled with altered levels of GSH and OFR scavenging enzymes in the blood are discussed in the light of oxidative stress.

A comparative evaluation of immunotoxicity of malathion after subchronic exposure in experimental animals

The effects of sub-chronic doses of malathion exposure on humoral and cell-mediated immune (CMI) responses were studied in male albino mice, rats and rabbits using sheep red blood cells (SRBC), tetanus toxoid and ovalbumin as antigens. The humoral immune response was assessed by estimating serum immunoglobulin (IgM and IgG) concentrations, antibody titre against antigens and splenic-plaque forming cells (PFC). The CMI response was studied by using the leucocyte migration inhibition (LMI) and macrophage migration inhibition (MMI) tests. In general there were (a) attenuation in antigen induced antibody response, (b) suppression of PFC, and (c) marked inhibition of LMI and MMI factors. Sub-chronic malathion exposure induced differential degrees of humoral and CMI suppression in these experimental animals. However, both cellular and humoral immune responses were decreased in a dose-time dependent pattern and a consistent trend was observed. The threshold level of the malathion for inducing immune suppression depends on the animal species, type of antigen used, and the method of immunological assay. In view of the widespread use of malathion a comparative assessment of immune responses using different experimental animals and antigens is an important aspect of its safety evaluation.

Influence of subchronic exposure to lindane on humoral immunity in mice

Lindane suppressed both primary and secondary antibody responses to sheep red blood cell (SRBC) in albino mice, the effects being more pronounced on the secondary than the primary response. However, a longer duration of pesticide exposure induced similar degrees of immunosuppression on both responses. The sequential study of plaque forming cells (PFC) kinetics revealed that suppression of plaque formation not only occurred at peak days but also on pre and post peak days, and there was no delay in peak antibody formation. Moreover, reduction in the primary PFC was not associated with decrease in the antibody response to SRBC. The results indicate that lindane suppresses both primary and secondary humoral immune responses in a time and dose dependent manner, and suggest a threshold susceptibility to exposure.

A comparative evaluation of immunotoxicity of DDT and its metabolites in rats

Effects of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (DDE), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) and 2,2-bis(p-chlorophenyl) acetic acid (DDA) were comparatively evaluated on humoral and cell mediated immune (CMI) responses in rats. Rats were given a diet containing 200 ppm of the various test compounds for 6 weeks and were subsequently immunized with ovalbumin. DDT, DDE and DDD, all induced differential degrees of humoral and cellular immune suppression. There were (a) increases in albumin/globulin ratios, (b) suppression of IgM and IgG levels, and (c) attenuations in ovalbumin induced antibody responses. In CMI studies, there were marked inhibitions of (a) leucocyte and macrophage migration factors, and (b) delayed type hypersensitivity (DTH) reaction. Whereas, these effects were most marked with DDE and DDD, DDA did not elicit such immunomodulatory effects. It is inferred that suppression of immune responses by immediate DDT metabolites, DDE (and DDD and not DDA) is an important determinant of the toxicity of DDT (DDE > DDD > DDT) and the influence of this environmental pollutant in health and disease.

Resolution of enzyme bands of Plasmodium knowlesi as a function of substrate concentration

An extra band of isoenzyme lactate dehydrogenase (LDH) was obtained in case of Plasmodium knowlesi free parasite as compared to normal monkey blood. This extra band could be resolved due to the decreasing amount of substrate concentration. Agarose electrophoresis technique was used to separate the isoenzyme bands.

Isolation of buffalo muscle aldolase and comparison of its properties with those of rabbit muscle aldolase

Fructose-1,6-bisphosphate aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phyosphate-lyase, EC 4.1.2.13) was isolated from buffalo muscle by fractionation with ammonium sulphate and subsequent purification by phosphocellulose column chromatography using a linear salt gradient. As judged by gel filtration and electrophoresis in polyacrylamide gel, the enzyme was homogeneous with respect to size and charge. The molecular weight and Stokes radius of the enzyme were determined from its elution profile on a calibrated Sephadex column and the respective values were 162000 and 4.55 nm. The diffusion coefficient and frictional ratio were computed to be 4.8-10(7) cm2-s-1 and 1.27, respectively. The molecular weight of the polypeptide chain as measured by aodium dodecyl sulphate polyacrylamide gel electrophoresis was 40750. This taken together with the native molecular weight suggested a four-subunit model for the protein. The N- AND C-terminal residues of polypeptide chains were identified to be proline and tyrosine, respectively. At pH 8.0 the Michaelis-Menten constant and maximum attainable velocity were found to be 8.1 muM and 27 muM Fru-1,6-P2 split/min per mg, respectively. The buffalo muscle aldolase was found to be similar to rabbit muscle aldolase in physico-chemical properties. However, the two enzymes differ significantly in pH optimum; the p optima of the buffalo and rabbit enzymes were determined under identical conditions to be 8.0 and 8.6, respectively.