Phylogenetic analysis, based on EPIYA repeats in the cagA gene of Indian Helicobacter pylori, and the implications of sequence variation in tyrosine phosphorylation motifs on determining the clinical outcome

The population of India harbors one of the world's most highly diverse gene pools, owing to the influx of successive waves of immigrants over regular periods in time. Several phylogenetic studies involving mitochondrial DNA and Y chromosomal variation have demonstrated Europeans to have been the first settlers in India. Nevertheless, certain controversy exists, due to the support given to the thesis that colonization was by the Austro-Asiatic group, prior to the Europeans. Thus, the aim was to investigate pre-historic colonization of India by anatomically modern humans, using conserved stretches of five amino acid (EPIYA) sequences in the cagA gene of Helicobacter pylori. Simultaneously, the existence of a pathogenic relationship of tyrosine phosphorylation motifs (TPMs), in 32 H. pylori strains isolated from subjects with several forms of gastric diseases, was also explored. High resolution sequence analysis of the above described genes was performed. The nucleotide sequences obtained were translated into amino acids using MEGA (version 4.0) software for EPIYA. An MJ-Network was constructed for obtaining TPM haplotypes by using NETWORK (version 4.5) software. The findings of the study suggest that Indian H. pylori strains share a common ancestry with Europeans. No specific association of haplotypes with the outcome of disease was revealed through additional network analysis of TPMs.

Neural stem cells & supporting cells - The new therapeutic tools for the treatment of spinal cord injury.

Stem cells play important role in the development and in the maintenance of specific tissues. They have been identified in majority of the organs like liver, blood, skin and intestine. Role of stem cells in regenerative medicine have been implicated in many chronic diseases. Stem cell research is a new opportunity to those patients whose organs are damaged or diseased. The discovery of stem cells in central and peripheral nervous system is relatively recent. Spinal cord injury is one of the major neurological disaster affecting mostly young lives. Stem cell transplantation in spinal cord injury patients have shown encouraging results. Different sources of stem cells are being exploited for spinal cord injury as well as other neurological disorders.

Prevalence of hepatitis C virus (HCV) coinfection in HIV infected individuals in south India and characterization of HCV genotypes.

PURPOSE: To determine anti-HCV antibodies and genomic subtype of HCV in 1487 confirmed human immunodeficiency virus (HIV) positive samples. METHODS: A total of 1487 confirmed HIV-positive samples were tested for anti-HCV antibodies by using a third generation ELISA kit (Ortho 3.0) and by RT PCR for HCV. HIV and HCV coinfected samples were selected for HCV genotyping by RFLP and subtyping with NS5-type specific primers. RESULTS: A total of 1487 HIV-infected serum samples were screened for HCV infection, of which, a 1443 (97.04%) were negative and 45 (3.02%) were coinfected. HIV-HCV coinfection was predominant in the age group 41-50 years (51.1%). HCV genotyping and subtyping was done for the 45 HCV RNA-positive specimens of which genotype 1 was observed in 31 (68.8%) and genotype 3 was observed in 14 (31.1%) subjects. Further subtyping analysis showed the genotype 1b in 23 (51.1%), 1a in eight (17.7%), 3a in 10 (22.2%) and 3b in four (8.8%) subjects. CONCLUSION: HIV and HCV seroprevalence is higher in South India, and the most prevalent genotype in coinfection was genotype 1b.

Journey from hepatocyte transplantation to hepatic stem cells: a novel treatment strategy for liver diseases.

Acute liver failure (ALF) carries high morbidity and mortality (>80%) even in the best centres. Orthotopic liver transplantation (OLTx) is the only viable approach to the treatment of ALF. This has significantly improved the survival in these patients. The major limitations of OLTx are non availability of the donor liver, requirement of a major surgical procedure, high cost and longterm immunosuppression. Isolated hepatocyte transplantation is emerging as an appealing method for the treatment of ALF because of its technical simplicity and easy availability of cells. Transplantation of allogenic/xenogenic hepatocytes transplantation in experimentally induced ALF has shown an increased survival rate. Clinical studies in acute, chronic liver failure and metabolic disorders have also been undertaken in a few centres and have shown encouraging results. To maintain the continuous supply of cells, xenogenic source of hepatocytes (porcine, rabbit, canine) have offered a hope. A major concern regarding the use of xenogenic donors is the risk of transmission of zoonosis and immunogenicity. Recently, Porcine endogenous retrovirus (PERV) has been shown to infect human tissue in vitro. The problem of immunogenicity of xenogenic hepatocytes can be overcome to some extent by immunoisolation, encapsulation technique, which may also provide protection to the hepatocytes during cryopreservation. The knowledge of adult hepatic stem from tissue offered a new hope for the treatment of various chronic and metabolic diseases. Further, the transdifferentiation potentiality of haematopoietic stem cells to hepatic lineage has strengthened cell therapy.

Prevalence, risk factors and genotype distribution of HCV and HBV infection in the tribal population: a community based study in south India.

Viral hepatitis caused by the hepatitis C virus (HCV) and hepatitis B virus (HBV) represents a major public health problem in India. These viruses share common modes of transmission, such as parenteral routes. We aimed to assess the exposure of a tribal population to these viruses in south India. The present study was carried out on serum samples from 890 individuals (526 males and 324 females) belonging to the Lambada tribe residing in the state of Andhra Pradesh, south India. Anti-HCV antibody and hepatitis B surface antigen (HBsAg) status in the sera were analyzed using commercially available enzyme immunoassays (Abbott Labs, Chicago, IL). HCV-RNA and HBV-DNA in the sera was tested by reverse transcriptase polymerase chain reaction (RT-PCR) and PCR, respectively. The infecting genotype of HCV was determined using type-specific primers corresponding to the NS5 region of the virus. Out of the 890 samples, 18 (2.02%; male 11/526; female 7/364) were positive for HCV-RNA by RT-PCR and, 17 of them were positive for anti-HCV antibody. Genotyping of HCV isolates from the 18 individuals positive for HCV-RNA revealed that 66.67% (12/18) were infected with type 1 of HCV and its variants; while in the remaining (6/18), the infecting genotype was found to be type 3 and its variants. A total of 46 samples (5.16%; males 28/526; female 18/364) were positive for HBsAg; while 11 were positive only for HBV-DNA, 9 were positive for both hepatitis B e antigen (HBeAg) and HBV-DNA. Cultural practices such as tattooing, traditional medicine (e.g. blood-letting), rituals (e.g. scarification), body-piercing etc are the potential sources of spread of infection in this tribe. None of the samples analyzed revealed co-infection with the 2 viruses.

Genetic fine structure analysis of helicobacter pylori isolates before and after treatment.

BACKGROUND: Eradication of H. pylori infection cures peptic ulcer disease and conversely, relapse is associated with reappearance of H. pylori infection. However, it is not clear whether the recurrence of ulcers following H. pylori eradication is due to recrudescence (identical strain) of the previous infection or as a result of exogenous reinfection (different strain) by another strain. The aim of the present study was to analyze the FAFLP patterns of pre and post treatment H. pylori samples to check if the recurrence was due to recrudescence or reinfection. MATERIALS AND METHODS: 24 of 30 duodenal ulcer (DU) subjects screened for H. pylori infection were positive for H. pylori infection. The treatment regime included pantoprazole, ciprofloxacin and amoxicillin. The patients were called for a repeat endoscopy after one month and screened for H. pylori infection. FAFLP analysis and PCR for the cagA and vacA gene was performed for the pre and post treatment samples. RESULTS: Of the 24 positive H.pylori patients, only 6 were negative after treatment and the remaining 18 were positive for H.pylori infection. The analysis of the pre and post treatment samples of the 18 patients showed that the FAFLP profiles of the initial and follow-up pools were similar to one another. CONCLUSION: It can be concluded that in the present series of patients, reinfection was due to recrudescence of infection due to incomplete eradication. The study also suggests that DNA fingerprinting by FAFLP provides discriminatory and complementary data for identifying strains of H. pylori while monitoring therapy.

Roxatidine in duodenal ulcer.

Roxatidine acetate is a new H2-receptor antagonist. A randomized double-blind clinical trial in fifty-three patients with endoscopically proven duodenal ulcers > 5 mm in diameter was undertaken to compare safety and efficacy of roxatidine with that of ranitidine. Twenty-six patients received roxatidine (75 mg bid) while 27 patients received ranitidine (150 mg bid) for 4 weeks. One patient in each group did not come for follow up. Roxatidine and ranitidine had comparable ulcer healing rates (22/25 vs 22/26); roxatidine, however, resulted in greater reduction in the number and severity of night time pain episodes (p < 0.05). No adverse event was reported during 4 weeks of treatment with roxatidine. Thus roxatidine achieves the primary therapeutic goal of relief of pain better than ranitidine.

Effect of histamine and glucose on encystation of Entamoeba histolytica in vitro.

Isolates of Entamoeba histolytica grown and maintained in modified Boeck and Drbohlav's medium were used to examine the effect of histamine and glucose on encystation process in vitro. This revealed that 60-74% of the active and motile trophozoites of E. histolytica encysted within 72 hours in the presence of histamine and glucose, in contrast to 10-20% encystment in controls (with out histamine and glucose); a highly significant difference (P < 0.001). These observations also suggest the possibility of active role of histamine and glucose in encystation of E.histolytica in vivo.

Leucocyte migration inhibition index responses of patients of amoebic liver abscess to various antigens of Entamoeba histolytica.

The whole amoebic lysate (WAL), Sephadex G-200 eluted fraction-I. (F-I), detergent dissected membrane proteins (DDMP), amoebic membrane glycoprotein (AMG) and amoebal RNA were extracted from E. histolytica. Amoebal RNA recognized 98.21% where as F-I, AMG, DDMP and WAL recognised 92.85, 91.07, 89.28 and 75% of total 56 clinically proven and amoebic serology positive amoebic liver abscess cases respectively. Intensity of recognition of individual fraction i.e., leucocyte migration inhibition index of each fraction was found to be highly significant (P < 0.001) when compared to whole amoebic lysate. This indicate the leucocyte migration inhibition index responses of patients of amoebic liver abscess to various antigenic fractions of E. histolytica with variations.

A comparative study of different isolated fractions of Entamoeba histolytica in amoebic liver abscess.

Fifty six patients with amoebic liver ubscess were assessed for antibody production and lymphokine release using different antigenic fractions such as sephadex G-200 eluted fraction-I (F-I), shed of bile salt treated amoebae (SBSTA), amoebic membrane glycoprotein (AMG), amoebic RNA and whole amoebic lysate (WAL). Antibody production in response to WAL, F-I, SBSTA, AMG and RNA was assessed by indirect haemagglutination assay. Five and 53 fold increased titres of IHA was observed with F-I and SBSTA respectively compared to WAL. The difference between mean titres of F-I, SBSTA and WAL was found to be highly significant (P < 0.001). Amoebic RNA did not show pronounced antibody titres. Lymphokine release by T lymphocytes in response to F-I, SBSTA, AMG, RNA and WAL was assessed by leukocyte migration inhibition (LMI) test. A highly increased release of LMIF by RNA, AMG, F-I and SBSTA was observed compared to whole amoebic lysate. The difference between the means of the purified fractions and WAL, to release of LMIF was found to be highly significant (P 0.001). These findings suggest that SBSTA, F-I and AMG fractions might have an important role as a potent antigen in inducing humoral and cell mediated immunity in patients with amoebic liver abscess and these findings also confirm the multiple antigenicity of E. histolytica.

Detection of antibodies to serum IgA and IgG in peptic ulcer cases by indirect haemagglutination test.

Autoantibodies to serum IgA and IgG were detected in 206 peptic ulcer patients (196 duodenal ulcer and 10 gastric ulcer) and 52 healthy age and sex-matched controls by indirect haemagglutination test. A significantly increased mean titre of autoantibodies to serum IgA was observed in the peptic ulcer patients. Forty-eight (24.61%) duodenal ulcer cases had autoantibody titre values above mean +/- 2 SD of controls. Titres of autoantibodies to serum IgG were significantly increased only in the gastric ulcer cases. The results suggest an immunologic abnormality in a sizeable fraction of these cases.