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Biomedical subjects

S Singh

Publications and source records attributed to S Singh.

At least 397 records · Page 22Linked to original sources
PubMed2000

Evaluation of a commercially available ELISA kit for detection of antibodies to Anaplasma marginale and Anaplasma centrale in cattle in Australia and Zimbabwe.

A newly available competitive inhibition ELISA kit for the serological diagnosis of anaplasmosis was evaluated in Australia and Zimbabwe. In Australia the performance of the test was compared with the card agglutination test (CAT). The assay was evaluated using negative sera collected from Anaplasma-free herds, positive sera from experimentally infected cattle and sera from Anaplasma marginale-endemic herds. The sensitivity and specificity of the ELISA in Australia were 100 % and 83,3 %, respectively, and the sensitivity and specificity of the CAT were both 100%. The agreement between the ELISA and CAT in the sera from endemic herds was 86,4 % (kappa = 0,718). The specificity of the ELISA in Zimbabwe was 100%. No meaningful estimate of sensitivity was possible in Zimbabwe because few known positive sera were available for testing, but all eight known positive sera that were available were clearly positive. We conclude that the ELISA is a useful alternative to the CAT for epidemiological studies. The ELISA kits have advantages over the CAT in that the ELISA is more robust and reagents are better standardized, but the kits are expensive.

Agglutination Tests↗
PubMed2000

Use of expanded polytetrafluoroethylene in aesthetic surgery of the face.

Aesthetic surgery procedures and materials available to improve the appearance of various subunits of the face have been evolving for the past several decades. Initially, techniques such as direct excision or placement of autogenous tissue grafts (e.g., fat, fascia, tendon, and dermal fat grafts) were used. Additional options became available with the development of silicone, injectable collagen, and ePTFE. These options for facial augmentation can be done rapidly in an office setting and as an outpatient. An important aspect of treatment is discussing clearly all pertinent options with the patient, and recommending the appropriate option based on the patient's anatomic findings and personal needs. For example, patients desiring lip augmentation but unsure about the result may be best treated with collagen injection, which gives temporary results and lets the patient consider a long-term result provided by ePTFE or autogenous grafts. Use of ePTFE in facial aesthetic surgery gradually has increased over the past two decades. Its use in augmentation of lips, nasolabial creases, and nose is becoming an important treatment modality for aesthetic surgeons.

Biocompatible Materials↗
PubMed2000

Is TB contact screening relevant in a developing country setting? Experiences from eastern Nepal, 1996-1998.

SETTING: A tuberculosis programme run by a non-governmental organisation in eight hill and mountain districts of eastern Nepal. OBJECTIVE: To assess the impact of contact screening on case-finding. DESIGN: A retrospective cohort study of contacts of smear-positive, smear-negative and extra-pulmonary tuberculosis patients diagnosed and registered during 1996-1998 ('index cases'). Contacts, defined as household members identified by index cases, were screened by sputum examination; two positive smears were taken to indicate smear-positive pulmonary disease. RESULTS: Approximately 50% (668) of registered cases identified contacts; 75% (2298) of the contacts identified provided one or more sputum specimens. An overall smear-positive case yield of 0.61% (14) was obtained from contacts tested, all except one of which were contacts of smear-positive index cases. For smear-positive index cases with a smear grading of > or = 2+, the yield was 7.2 times greater (P = 0.04) than for those with a grading of 1+. CONCLUSION: In this setting, sputum examination of household contacts of smear-negative and extrapulmonary tuberculosis cases is not justified. Further assessment is needed to evaluate the utility of testing contacts of smear-positive cases without symptom screening, and whether cost effectiveness can be improved by restricting testing to contacts of cases with high bacterial (> or = 2+) loads.

Cohort Studies↗
PubMed2000

Iodinated natural rubber latex: preparation, characterisation & antibacterial activity assessment.

Natural Rubber (NR) in both its latex and dried form was treated with iodine to make it antibacterial in nature. The NR latex was dried and washed, dissolved in toluene, iodinated and cast into films. In a different approach, NR in its latex form (emulsion) was blended with aqueous solution of povidone-iodine complex (PVP-I) and films were cast. Phase separation of PVP-I was observed in the films prepared using NR latex; whereas the film prepared using NR solution in toluene and molecular iodine were homogeneous, transparent light brown. Solubility assessment of the films revealed that unlike pure NR, the iodinated NR failed to go into solution completely. The films obtained from both the approaches were evaluated for release of iodide ions. On immersion in water, PVP-I blended latex did not retain iodine while sustained release of iodide ion was observed in case of dried NR dissolved in toluene and treated with iodine. The FT-IR spectra of the iodinated films revealed that iodine attaches covalently to the double bonds in the isoprene units of NR. The films were also evaluated for their antibacterial properties and it was observed that the films prepared from both the approaches, acquired antimicrobial properties.

Anti-Bacterial Agents↗
PubMed2000

A study of filarial transmission in a non-endemic area of Pathankot (Punjab).

A filariasis survey was conducted in July 1998 in Pathankot town of Punjab covering a population of 28, 041. A total of 2136 blood smears were collected from migratory and local inhabitants. Microfilaria (Mf) rate and mean Mf density was 1.19 and 15.05 respectively. Disease rate was nil. All the 20 microfilaria carriers detected were known to hall from filaria endemic areas of different states. Mf rate was highest in 20-49 years age-group, whereas Mf density was high in younger age group. Wuchereria bancrofti was the only infection encountered. 10 Men Hour Density of Culex quinquefasciatus ranged between 343 in the North Command unit to 400 in an engineering unit. A total of 339 female Culex quinquefasciatus were dissected. None was found positive for human microfilaria parasite, thus negating any indigenous filariasis transmission in this town. These findings were compared to earlier surveys in the same area and other non-endemic areas. Non-endemic areas continue to be non-endemic for filariasis despite considerable increase in MF rate among migratory population and vector density.

Adolescent↗
PubMed2000

Neurological syndromes following organophosphate poisoning.

Organophosphorous compounds, the anticholinesterases, produce significant morbidity and mortality in India. Although exact estimates are not available, hospital based statistics suggest that nearly half of the admissions to emergency with acute poisoning are due to organophosphates. Following accidental or suicidal exposure, these anticholinesterases lead to three well defined neurological syndromes i.e. initial life threatening acute cholinergic crisis which often requires management in intensive care unit, intermediate syndrome in which cranial nerve palsies, proximal muscle weakness and respiratory muscle weakness are common and patients often require respiratory support and delayed organophosphate induced polyneuropathy. In addition to these three classical neurological syndromes following acute exposure and in some following low dose chronic exposure, several neurobehavioural changes have been observed and these have been termed together as 'chronic organophosphate induced neuropsychiatric disorders' (COPIND). Organo-phosphate compounds produce significant pesticide related illness in developing countries. There is, thus, a need to determine exact extent of the problem and to develop appropriate strategies to manage these cases with available resources in these countries.

Cholinesterase Inhibitors↗
PubMed2000

Inverted-repeat DNA: a new gene-silencing tool for seed lipid modification.

Post-transcriptional gene silencing (PTGS) has been successfully used to modify seed lipids in oilseed crops like soybean, canola and sunflower. Conventionally, PTGS has been induced by transforming the plants with either antisense or co-suppression constructs targeted against key seed lipid biosynthesis genes. A major drawback of this approach has been the recovery of only a modest proportion of silenced individuals from large populations of transgenic plants. In this report we show that inverted-repeat DNA constructs containing an intron encoding RNA with a hairpin structure can induce PTGS with very high frequency.

Arabidopsis↗
PubMed2000

Inhibition of polyunsaturated fatty acid accumulation in plants expressing a fatty acid epoxygenase.

Earlier, we described the isolation of a Crepis palaestina cDNA (Cpal2) which encoded a Delta12-epoxygenase that could catalyse the synthesis of 12,13-epoxy-cis-9-octadecenoic acid (18:1E) from linoleic acid (18:2). When the Cpal2 gene was expressed under the control of a seed-specific promoter in Arabidopsis, plants were able to accumulate small amounts 18:1E and 12,13-epoxy-cis-9,15-octadec-2-enoic acid in their seed lipids. In this report we give results obtained from a detailed analysis of transgenic Arabidopsis plants containing the Cpal2 gene. The seeds from these plants accumulate varying levels of 18:1E, but show a marked increase in 18:1 and equivalent decrease in 18:2 and 18:3. We further observed that the co-expression of a C. palaestina Delta12-desaturase in Arabidopsis appears to return the relative proportions of the C(18) seed fatty acids to normal levels and results in a 2-fold increase in total epoxy fatty acids.

Arabidopsis↗
PubMed2000

Chelation in metal intoxication. XLIV: Efficacy of alpha-mercapto-beta-(5-substituted, 2-furyl) acrylic acids in mobilizing intracellularly bound cadmium in rat.

The efficacy of alpha-mercapto-beta-(2-furyl) acrylic acid (MFA), alpha-mercapto-beta-(5-sodiumsulfonate, 2-furyl) acrylic acid (MSFA) and alpha-mercapto-beta-(5-acetoxymethyl, 2-furyl) acrylic acid (MAFA) to mobilize intracellularly bound cadmium in liver and kidney was investigated in rats pre-exposed to cadmium. MFA was effective in reducing cadmium levels of hepatic and renal supernatant cytosolic fraction (SCF) while MSFA and MAFA were effective in lowering cadmium levels of renal SCF and hepatic SCF respectively. All the chelating agents also enhanced the excretion of cadmium more in feces than in urine. However, substitution on the furan ring lowered cadmium mobilizing efficacy of the parent compound, MFA. The treatment with MFA did not affect the status of endogenous zinc and copper while the treatment with MSFA and MAFA enhanced their excretion. MSFA increased hepatic and renal zinc and renal copper while MAFA increased their copper levels.

Acrylates↗
PubMed2000

Serum lactate dehydrogenase in diagnosis of megaloblastic anaemia.

The present study was carried out in 75 patients of macrocytic anaemia categorised on bone marrow examination (into megaloblastic and non-megaloblastic anaemia) to evaluate the efficacy of total serum LDH levels and LDH isoenzyme pattern in the diagnosis of megaloblastic anaemia. 25 healthy adults were taken as controls. From this study it can be concluded that total serum LDH levels more than 3000 IU/L are diagnostic of megaloblastic anaemia. Reversed LDH isoenzyme pattern (LDH1 > LDH2) by chloroform inhibition test is an adjuvant in the diagnosis where total serum LDH levels are between 451-3000 IU/L and it will also differentiate megaloblastic anaemia from haemolytic anaemia.

Adolescent↗
PubMed2000

Pulmonary manifestations in malaria.

Malaria, a major killer of mankind, apart from classical ague presentation, may present with respiratory manifestations. This may be misdiagnosed and important time may be lost in instituting antimalarials leading to higher morbidity and mortality. Present work was undertaken to study the clinical presentations of malaria with special reference to respiratory system and to evaluate the effect of antimalarials to such atypical presentation. One hundred slide positive cases of malaria were taken and detailed for respiratory involvement. Response to antimalarials was seen in these cases and associated complications (if any) were looked for. Mean age of the cases was 29.3 years with a male predominance. Positivity of peripheral smear read as: P vivax(53%), P falciparum (36%) and mixed infection (11%). Twenty-six patients had presented with respiratory manifestations-bronchitis (15), pneumonia (4), asthmatic bronchitis (1), adult respiratory distress syndrome (ARDS) (4) and pulmonary tuberculosis (2). Of these 26 cases, presenting symptoms noticed were cough (77%), dyspnoea (32%), expectoration (29%) and chest pain (15%). Twenty-five (96%) of these 26 patients were positive for P falciparum. Response to antimalarials was not significantly different in these 26 patients as compared to the rest (74 cases). All patients developing ARDS expired. The present study concludes that malarial atypical respiratory presentations are far higher in incidence than reported in literature. Peripheral smear examination in all patients of high grade fever with chills and rigors and having respiratory manifestations may unmask malarial infection and warrant early antimalarial treatment resulting in decreased morbidity and mortality.

Adult↗