Browsing by Author "Sridhar, R"
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Item Crusade for TB: Bringing Treatment to Masses at their Doorsteps(Indian Council of Medical Research, 2019-01) Natrajan, M; Sridhar, R; Narendran, G; Ramachandran, G; Kumar, VV; Tripathy, SItem Cytologic diagnosis of Enterobius vermicularis eggs in an enterocutaneous fistula.(1999-07-22) Sridhar, R; Kapila, K; Verma, KA middle-aged female underwent a laparotomy for suspected ovarian cancer and developed a discharging sinus in the right iliac fossa. Smears of the discharge showed helminthic eggs which were characterised as those of Enterobius Vermicularis. The possibility of an enterocutaneous fistula was suggested which was subsequently confirmed during a relook laparotomy.Item Detection of Mycobacterium tuberculosis directly from sputum specimens & phenotypic drug resistance pattern of M. tuberculosis isolates from suspected tuberculosis patients in Chennai.(2012-05) Therese, K Lily; Gayathri, R; Dhanurekha, L; Sridhar, R; Meenakshi, N; Madhavan, H N; Manoj, S Edwin; Vinayagam, A KamalaBackground & objectives: mRNA is more rapidly destroyed in cells than rRNA or genomic DNA, an assay targeting bacterial mRNA would provide a better guide to mycobacterial viability than amplification tests directed at DNA or rRNA targets. This study was carried out to standardize reverse transcriptase PCR (RT-PCR) targeting 85B gene for the rapid detection of viable Mycobacterium tuberculosis from sputum specimens of suspected TB patients at Chennai, South India and to detect MDR-TB circulating in this population. Methods: Sputum samples from clinically suspected tuberculosis patients (n=301) and 78 controls were included in the study. The sputum samples were collected in sterile diethyl pyrocarbonate (DEPC) treated containers and transported in ice to the laboratory within 2 h to prevent degradation of RNA. RT-PCR targeting 85B gene, mycobacterial culture and phenotypic drug susceptibility testing for the first line drugs streptomycin (S), isoniazid (H), rifampicin (R), ethambutol (E) and pyrazinamide (Z) were performed by BACTEC microMGIT culture system for all the sputum specimens. Results: All the 78 controls were negative for culture and RT-PCR. Among the 301 sputum specimens from patients, 231 (76.8%) were RT-PCR positive and 70 (23.2%) were negative. There were 166 M. tuberculosis isolates, of which 11 (2.9%) were MDR-TB, 33 (8.7%) were polyresistant, 31 (8.2%) were monoresistant and 91 (30.2%) were sensitive to all five first line anti-tuberculous drugs by phenotypic drug susceptibility testing. Monoresistance was higher with Z [20 (20.8%)], followed by S [6 (3%)]. Interpretation & conclusions: RT-PCR targeting 85B gene of M. tuberculosis was a specific, rapid, reliable technique to detect the M. tuberculosis directly from sputum specimens. Our results showed that 2.9 per cent of M. tuberculosis isolates in the study population of Chennai were MDR.Item Diagnostic appraisal of simultaneous application of two nested PCRs targeting MPB64 gene and IS6110 region for rapid detection of M. tuberculosis genome in culture proven clinical specimens.(2013-10) Therese, K L; Gayathri, R; Dhanurekha, L; Sridhar, R; Meenakshi, N; Madhavan, H NBackground: Early diagnosis of tuberculosis is critical for its effective management and prevention. Several gene amplifi cation methods are used in the detection of tubercle bacilli from clinical specimens. MPB64 gene and IS6110 region have been identifi ed as potential gene targets for the specifi c detection of Mycobacterium tuberculosis from direct clinical specimens. Objective: The present study was conducted to evaluate the diagnostic utility of simultaneous application of two nested polymerase chain reaction (nPCRs) targeting MPB64 and IS6110 region for the detection of M. tuberculosis genome. Materials and Methods: A total of 100 and 354 clinical specimens from the control group and clinically suspected tuberculosis patients, respectively, were included in the study. nPCRs targeting MPB64 and IS6110 region were performed. Results and Conclusion: All of the 100 clinical specimens from the control group were negative for both nPCRs. Out of the 354 clinical specimens, 339 were positive for both culture and nPCRs, 10 and 5 were positive for culture, and nPCR targeting IS6110 and MPB64 regions, respectively. To conclude, nPCRs targeting MPB64 and IS6110 region are reliable and specifi c targets when applied simultaneously on clinical specimens to attain 100% sensitivity for the detection of M. tuberculosis genome.Item Nanoemulsified ethanolic extract of Pyllanthus amarus Schum & Thonn ameliorates CCl4 induced hepatotoxicity in Wistar rats.(2012-11) Deepa, V; Sridhar, R; Goparaju, A; Reddy, P Neelakanta; Murthy, P BalakrishnaPhyllanthus amarus (PA) is commonly used in traditional medicine for hepatoprotectivity. The major limitation is that, treatment requires a large quantity of herbal extract for a longer duration. Aim of the present study was to encapsulate ethanolic plant extract for sustained release of constituents in intestine and facilitate maximum absorption. The efficacy was compared for the hepatoprotective activity of nanoencapsulated ethanolic extract of P. amarus (NPA) and PA in carbon tetrachloride (CCl4) induced hepatotoxic male rats. Based on total phenol content (TPC), the loading efficiency of nanocapsules was 89% (pH 7.0) and optimum concentration was 2:18 (mg/mL) for plant extract: olive oil. Scanning electron microscopy (SEM) showed a spherical morphology, photon correlation spectroscopy (PCS) identified mean particle diameter as 213 nm and Fourier transform infrared spectroscopy (FT-IR) revealed that the phytoconstituents were stable. An oral dose of NPA (20 mg/kg body wt.) showed a better hepatoprotective activity than PA (100 mg/kg body wt.) and also repeated dose oral toxicity proved to be safe. These biochemical assessments were supported by rat biopsy examinations. In conclusion, the nanoemulsification method may be applied for poor water-soluble ethanolic herbal extracts to reduce the dosage and time.Item Rapid Detection of Viable M. tuberculosis Directly from Sputum by Reverse Transcriptase PCR Targeting 85B Gene.(2011-06) Ramasubban, Gayathri; Kulandai, Lily Therese; Sridhar, R; Durai, Kannan; Hajib, N Madhavan; Meenakshi, NThis study was carried out to standardize reverse transcriptase PCR (RTPCR) targeting 85B gene for the rapid detection of viable Mycobacterium tuberculosis (M tuberculosis) from sputum specimens. 100 sputum samples from clinically suspected tuberculosis patients were included in the study. The sputum samples were collected in sterile diethyl pyrocarbonate (DEPC) treated containers and transported in ice to the laboratory within 2 hours to prevent degradation of RNA. The following microbiological analysis was performed on the sputum specimens: Ziehl Neelsen staining, Mycobacterial culture by BACTEC TB 460 reader and RT-PCR targeting 85B gene. Out of the 100 sputum samples, 40 sputum samples were Ziehl Neelsen stain positive, 58 sputum samples were culture and RT-PCR positive and 42 were culture and RT-PCR were negative. Among direct smear positive specimens, 3 specimens did not grow in culture and was RT-PCR negative indicating the non-viability of the acid-fast bacilli seen in the direct smear. The results of RT-PCR and culture against control group and clinically diagnosed tuberculosis patients were statistically significant by Chi square test (P<0.001). RT-PCR targeting 85B gene of M tuberculosis standardized in our laboratory for is a rapid, reliable and sensitive technique to detect the viable M tuberculosis directly from sputum specimens.Item Spatial and temporal variations in phytoplankton in coral reef and seagrass ecosystems of the Palk Bay, southeast coast of India.(2010-09) Sridhar, R; Thangaradjou, T; Kannan, LSpatial and temporal behavior of distribution of phytoplankton of the coral reef and seagrass environment of the Palk Bay was studied during April 2002 to March 2003. A total of 133 species of phytoplankton was recorded during the study period, of which, 98 species belong to Bacillariophyceae, 15 species belong to Dinophyceae, 12 species belong to Cyanophyceae and 8 species belong to Chlorophyceae. Diatoms (57.14 to 94.10%) contributed more towards the percentage composition of different groups of phytoplankton at the two stations, followed by dinoflagellates (3.12 to 28.57%), blue-greens (2.43 to 12.5%) and greens (3.7 to 7.69%). Higher phytoplankton population density was recorded during the summer season at both stations (St.1. 62,000 cells l-1 and St.2. 55,000 cells l-1). Coral reef environment was two-fold more productive (2.10-130.21 mg C m-3 hr-1) than the seagrass environment (3.30 - 85.56 mg C m-3 hr -1). Chlorophyll ‘a’ concentration showed higher values at station 1, corresponding to the higher phytoplankton population density recorded at this station along with primary productivity.Item Water quality and phytoplankton characteristics in the Palk Bay, southeast coast of India.(2006-07-04) Sridhar, R; Thangaradjou, T; Kumar, S Senthil; Kannan, LThe present study was carried out to determine the water quality in terms of physicochemical characteristics and plankton distribution in the coastal waters of Kattumavadi, Palk Bay for a period of one year from April 2002 to March 2003. Air and surface water temperatures varied from 28 degrees C to 32.50 degrees C and from 27.5 to 32.0 degrees C while light extinction coefficient (LEC) varied between 0.95 and 1.85. Salinity ranged from 26.0 to 34.5 per thousand and the pH ranged between 7.95 and 8.35. Variation in dissolved oxygen content was from 4.15 to 7.18 ml(-1), and the particulate organic carbon (POC) content varied between 0.49 and 2.28 mgCl(-1). Concentrations of nutrients viz. nitrate (2.15 to 8.28 microM), nitrite (0.12 to 0.62 microM), inorganic phosphate (1.28 to 2.15 microM) and reactive silicate (5.15 to 12.52 microM) also varied independently. Chlorophyll a content ranged from 0.28 to 1.48 mg m(-3) and the primary productivity, from 4.19 to 16.08 mgCm(-3) hr(-1). The present study recorded a total of 43 species of planktonic diatoms and two species of blue-green algae. Population density of phytoplankton varied from 18,000 to 34,000 cells l(-1). Percentage composition, of the diatoms showed minimum values during the monsoon season and the maximum values during the premonsoon season.