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Biomedical subjects

M V R Reddy

Publications and source records attributed to M V R Reddy.

10 recordsLinked to original sources
PubMed2006

Lymphatic filariasis: possible pathophysiological nexus with oxidative stress.

Wuchereria bancrofti-mediated lymphatic filariasis is widely prevalent. Diversity in immune response presumably may lead to myriad clinical presentations, such as overt chronic filariasis, occult filariasis with atypical systemic manifestation and asymptomatic microfilariae carrier state. Anticipated oxidative stress during inflammatory response to infective conditions might complicate the immune response and thus might alter the disease outcome. The present study was carried out to assess the status of oxidative stress in different clinical presentations of bancroftian filariasis. Twenty-five microfilariae carriers and 30 cases each of chronic filariasis and occult filariasis were compared to 30 endemic normal individuals. Serum malondialdehyde level and superoxide dismutase enzyme activity were measured by spectrophotometric methods and levels of filarial antigen were measured by ELISA. In the filarial cases, the levels of these parameters were assayed again after treatment with diethylcarbamazine citrate (DEC). Results showed significant (P<0.05) association of oxidative stress with chronic and occult filariasis but not with microfilarial carriers. DEC therapy in both clinical cases and carriers resulted in a significant reduction of oxidative stress associated with decreased antigen level (P<0.01). These findings suggest the possible involvement of oxidative stress in filarial disease pathology.

Adult↗
PubMed2006

Immunoprophylactic evaluation of a 37-kDa Brugia malayi recombinant antigen in lymphatic filariasis.

The Brugia malayi filarial antigens recognised preferentially by sera from an endemic normal population are considered to be potential vaccine candidates. By immunoscreening the cDNA library of the infective L3 stage of B. malayi with pooled endemic normal sera, a cDNA clone Bm-SL3 was identified. Analysis of sera from different patient groups with the rBm-SL3 protein showed it to be highly reactive with endemic normal sera compared to its reactivity with microfilaraemic and non-endemic normal sera. The immunoprotective efficacy of the rBm-SL3 antigen against B. malayi filarial infection was evaluated in susceptible host jirds (gerbils) (Meriones unguiculatus). Jirds immunised with the rBm-SL3 antigen showed 68% cytotoxicity against microfilariae and 67-69% cytotoxicity against infective larvae in in-vitro antibody-dependent cellular cytotoxicity assays and in-situ micropore chamber methods. Analysis of IgG subclasses against Bm-SL3 revealed a significant increase in IgG1 and IgG2 antibodies in endemic normal sera compared with other groups. Lymphocyte proliferation to Bm-SL3 was significantly higher in the endemic normal group compared with that in clinical and microfilarial carriers (p < 0.001). Significantly enhanced levels of IFN-gamma in the culture supernatant of peripheral blood mononuclear cells of endemic normal sera after stimulation with Bm-SL3 suggest that the cellular response in this group may have a Th1 bias.

Animals↗
PubMed2005

Isolation and analysis of partial cDNA sequence coding for superoxide dismutase in Wuchereria bancrofti.

Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response.

Amino Acid Sequence↗
PubMed2005

Cloning and expression of a 12 kDa serospecific epitope of Wuchereria bancrofti.

The immunoscreening of a microfilarial cDNA library of Wuchereria bancrofti with microfilaraemic sera revealed many positive clones expressing filarial antigens. One immunoreactive clone, designated PMR1, was shown to encode a protein of 114 amino acid residues. The cDNA fragment was subcloned into an expression vector, Pinpoint XaT. The resulting recombinant (r)PMR1-biotin fusion protein was expressed in Escherichia coli (BL21 [DE3] pLys) and was affinity purified on avidin resin. Analysis of sera of different groups for filarial antibodies against rPMR1 showed it to be highly reactive with microfilaraemic and clinical filarial sera compared to its reactivity with endemic and nonendemic controls. This indicates that the gene sequence of cDNA is expressing an immunodominant epitope, which could be useful in serodiagnosis of lymphatic filariasis.

Animals↗
PubMed2005

Identification of 38kDa Brugia malayi microfilarial protease as a vaccine candidate for lymphatic filariasis.

A FPLC purified 38kDa protease (Bm mf S-7) isolated from B. malayi microfilarial soluble antigen was identified. It showed pronounced reactivity with sera collected from 'putatively immune' asymptomatic and amicrofilaraemic individuals residing in an endemic area for bancroftian filariasis. Further the immune protective activity of Bm mf S-7 antigen was evaluated in susceptible hosts, jirds (Meriones unguiculatus) against B. malayi filarial infection. The antigen showed 89% cytotoxicity against mf and 87-89% against infective (L3) larvae in in vitro antibody dependent cellular cytotoxicity Assay (ADCC) and in situ micropore chamber methods. Bm mf S-7 immunized jirds after challenge infection showed 81.5% reduction in the adult worm burden. The present study has shown that, the 38kDa microfilarial proteases (Bm mf S-7) could stimulate a strong protective immune response against microfilariae and infective larvae in jird model to block the transmission of filariasis. Analysis of IgG subclasses against Bm mf S-7 revealed a significant increase in IgG2 and IgG3 antibodies in endemic normals. Lymphocyte proliferation to Bm mf S-7 was significantly high in endemic normal group as compared to that in clinical and microfilarial carriers. Significantly enhanced levels of IFN-gamma in the culture supernatant of PBMC of endemic normals followed by stimulation with Bm mf S-7 suggest that the cellular response in this group is skewed towards Th 1 type.

Animals↗
PubMed2004

Adult 175 kDa collagenase antigen of Setaria cervi in immunoprophylaxis against Brugia malayi in jirds.

A 175 kDa antigen fraction with collagenase activity was isolated and purified from somatic extracts of adult Setaria cervi females using column chromatography involving consecutive steps of DEAE-Sepharose CL6B and Sephadex G-100. The optimum pH for 175 kDa collagenase was found to be pH 7.0. Sensitivities to a variety of inhibitors and activators indicated that the 175 kDa coIlagenolytic enzyme was metalloserine in nature. The enzyme hydrolysed a variety of protein substrates such as haemoglobin, casein, azocasein (general substrates) and collagen, FALGPA (furanoyl-acryloyl-leu-gly-pro-ala), the specific substrate of collagenase. The enzyme showed 57% inhibition by jird anti-somatic collagenase antibodies and reacted insignificantly with normal jird sera. Further analysis was undertaken on the immunoprophylactic potential of 175 kDa collagenase in inducing immunity against Brugia malayi (a human filarial parasite) in jirds (Meriones unguiculatus) in vitro and in situ. Immune sera of jirds raised against this antigen promoted partial adherence of peritoneal exudate cells to B. malayi microfilariae (mf) and infective larvae (L3) in vitro and induced partial cytotoxicity to the parasites within 48 h. The anti-S. cervi 175 kDa antigen serum was more effective in inducing cytotoxicity to B. malayi L3, than mf. In the microchambers implanted inside immune jirds, host cells could migrate and adhere to the mf and infective larvae thereby killing them partially within 48 h.

Animals↗
PubMed2003

Seroreactivity of 31 kDa and 41 kDa mycobacterial secretory proteins isolated from culture filtrate in extra pulmonary tuberculosis.

Despite rapid advances in molecular genetics for detection of mycobacteria, it is clear that interest in serodiagnosis remains high, especially for those situations in which a specimen may not contain the infecting agent in particular in extrapulmonary tuberculosis. Immune response to excretory-secretory (ES) proteins of Mycobacterium tuberculosis (M.tb) has been of diagnostic interest in tuberculosis. In earlier study from our laboratory, a secretory protein M.tb ES-31 has been shown to have diagnostic potential in pulmonary tuberculosis. Further, another M.tb H37Ra ES protein (ES-41) was isolated and purified by trichloroacetic acid solubilization followed by Fast Performance Liquid Chromatography (FPLC). These two protein fractions viz ES-31 and ES-41 secreted by M.tb H37 Ra bacilli were employed in stick indirect penicillinase ELISA to study seroreactivity in extra pulmonary tuberculosis namely tuberculous lymphadenopathy, tuberculous meningitis, abdominal tuberculosis and bone & joint tuberculosis. While using ES-31 antigen 88% (22/25) of tuberculous lymphadenopathy and 90% (9/10) of tuberculous meningitis cases showed positive reaction for tuberculous IgG antibody, ES-41 showed 80% positivity in both groups. In abdominal and bone & joint tuberculosis cases, ES-41 antigen showed better sensitivity of 81.5% (22/27) and 84.6% (22/26) respectively in IgG antibody detection compared to 70% (19/27) and 69.2% (18/26) shown by ES-31. This study is of interest that different antigen protein fractions of M.tb exhibit differential seroreactivity, as ES-31 protein showed good potential in detecting tuberculous IgG antibodies in tuberculous lymphadenopathy (TBLN) & tuberculous meningitis (TBM), while ES-41 in abdominal and bone & joint tuberculosis cases.

Antibodies, Bacterial↗
PubMed2003

Analysis of IgG subclasses and IgE antibodies across the clinical spectrum of bancroftian filariasis in an endemic area.

Analysis of immune response in individuals with different clinical manifestations living in filaria endemic area will be of interest to understand the immunological events associated with the disease development in filaria infected endemic population. The levels of four IgG subclasses and IgE antibodies against Brugia malayi microfilarial excretory-secretory (Bm mf ES) antigen as well as circulating filarial antigen level were evaluated in 84 individuals belonging to different groups in an endemic area for bancroftian filariasis. Microfilaraemics showed significantly elevated levels of IgG4 and IgG3 antibodies compared to endemic normals (P < 0.02). As many as 70% of this group were positive for IgG4 & IgG3 antibodies. While Acute filarial cases had pronounced IgG1 antibodies(P < 0.001), the Grade I chronic cases showed higher levels of IgG3 and IgG4 antibodies (P < 0.02), Occult filarial cases had higher levels of IgG4 and IgG3 (P < 0.02) and also of IgG4 antibodies (P < 0.001). IgE antibodies were found to be elevated in microfilaraemics as well as other clinical filarial groups. Circulating filarial antigen was detected in 95% of microfilaraemics, 60% of acute cases, 75% to 90% of different grades of chronic filarial cases, 100% of occult cases and none of the endemic normals.

Animals↗
PubMedDate not supplied

Risk factors for acute myocardial infarction in a rural population of central India: a hospital-based case-control study.

BACKGROUND: There is a paucity of data on the relative importance of various traditional risk factors for coronary artery disease among rural Indians. We conducted a prospective case-control study to determine the risk factors for acute myocardial infarction in a rural population of central India. METHODS: We recruited 111 consecutive patients admitted to our hospital with a first episode of acute myocardial infarction and 222 age- and sex-matched controls. Demographics, anthropometric measures, lipids, blood glucose, smoking and other lifestyle factors were compared among cases and controls. Multivariate analyses were used to identify the risk factors independently associated with acute myocardial infarction. RESULTS: Elevated fasting blood glucose (odds ratio [OR] 8.9; 95% confidence interval [CI] 4.5, 17.9), abnormal waist-hip ratio (OR 3.0; 95% CI 1.7, 5.4) and income (OR 4.0 and 5.9 for the high- and middle-income categories, compared to the lowest category) were independently associated with the first episode of acute myocardial infarction. Abnormal triglycerides (OR 1.7; 95% CI 0.9, 3.1) and current smoking (OR 1.9; 95% CI 0.9, 4.0) were risk factors but were not statistically significant. CONCLUSION: Reduction in blood glucose levels and truncal obesity may be important in controlling the burden of coronary artery disease in rural Indians.

Acute Disease↗