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Biomedical subjects

B K Das

Publications and source records attributed to B K Das.

At least 19 recordsLinked to original sources
PubMed2000

Chronic toxic effects of quinalphos on some biochemical parameters in Labeo rohita (Ham.).

The effect of exposure to sublethal concentrations of the organophosphate pesticide, quinalphos (1.12, 0.22 mg/l) on biochemical parameters of muscle and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied after 15, 30 and 45 days. The muscle protein and RNA levels decreased whereas DNA levels and acid phosphatase were elevated. Similarly, alkaline phosphatase was depleted. The brain acetyl cholinesterase activity was decreased most (-75.43%) in 1.12 mg/l concentration over a period of 45 days. Lactic dehydrogenase levels in brain and liver were elevated whereas in the kidney they were inhibited. Succinic dehydrogenase and adenosine triphosphatase activities were depleted in brain, liver and kidney. The effects have been discussed for different organ tissues in relation to the pesticide.

Acetylcholinesterase↗
PubMed2000

Adenosine deaminase activity and lysozyme levels in children with tuberculosis.

Serum adenosine deaminase (ADA) activity and lysozyme levels were measured in 51 patients with tuberculosis (21 pulmonary, 15 miliary, 11 neurotuberculoma and four abdominal plus osteoarticular) and 20 healthy controls. The mean serum ADA activity and lysozyme levels were significantly raised in children with different forms of tuberculosis in comparison with controls (p < 0.001). The neurotuberculoma cases had the lowest mean enzyme levels and the differences were significant when compared with other forms of tuberculosis. The cut-off serum ADA activity of > or = 42 IU/l and lysozyme level of > or = 20 U/l were diagnostic of tuberculosis with 100 per cent sensitivity. A significant correlation was observed between the two parameters (r = 0.66; p < 0.001). Thus, with compatible clinical presentation, the raised serum level of either ADA or lysozyme can be used as a supportive diagnostic test.

Adenosine Deaminase↗
PubMed1999

SPECT studies of regional cerebral blood flow in 8 patients with Japanese encephalitis in subacute and chronic stage.

OBJECTIVE: There is a paucity of regional cerebral blood flow studies in Japanese encephalitis (JE). In this communication we report clinical, radiological and single photon emission computed tomography findings in subacute and chronic JE patients. MATERIAL AND METHODS: Eight JE patients whose ages ranged between 10 and 50 years underwent neurological evaluation. Varying degree of parkinsonian features were present in all, dystonia in 4 and abulia in 5 patients. They were subjected to cranial CT, MRI and SPECT studies. CT scan revealed low density area in 7 patients and midbrain involvement in 1. MRI was carried out in 3 patients and revealed medial temporal involvement in addition to bilateral thalamic involvement in all. RESULTS: SPECT results on visual analysis revealed thalamic hypoperfusion in all the patients, frontal hypoperfusion was present in 5 and lentiform hypoperfusion in 2 patients. Frontal or lentiform hypoperfusion was not associated with corresponding CT or MRI changes. On semiquantitative measurement, thalamic hypoperfusion was present in 7, frontal hypoperfusion in 3, occipital in 2 and lentiform in 1 patient. CONCLUSION: These results confirm high frequency of thalamic involvement in JE. The hypoperfusion in thalamus, frontal cortex and lentiform area is consistent with the crucial role of thalamus and its connections in the genesis of movement disorders in JE.

Acute Disease↗
PubMed1999

Comparison of enzyme immunoassay and reverse transcriptase PCR for identification of serotype G9 rotaviruses.

While only four globally important rotavirus G serotypes (1 to 4) have been documented, many studies suggest that serotype G9 viruses may be widely distributed and more important than previously recognized. We have evaluated 10 serotype G9 rotavirus-neutralizing monoclonal antibodies (MAbs) directed to VP7, which bound by direct enzyme immunoassay (EIA) to P1A[8], G9 rotaviruses F45, WI61, and AU32, for their ability to recognize the New Delhi G9 rotavirus 116E. Only one MAb (MAb F45:1) bound to P[11], G9 virus 116E to a high titer by EIA. This MAb was incorporated into an indirect EIA for G serotyping, which was validated with prototype cultivable human rotaviruses of G types 1 to 4 and 9. The EIA was compared with genotyping by reverse transcriptase PCR (RT-PCR) under code for the determination of the G types of rotaviruses obtained from neonates in New Delhi, India. The sensitivities of RT-PCR and EIA (after two additional freeze-thaw cycles) for the typing of G9 rotaviruses were 91 and 86%, respectively, for 24 culture-adapted rotavirus strains. The untypeable culture-adapted rotavirus samples also were unreactive with VP7 group antigen-reactive MAb 60. After two additional freeze-thaw cycles, only 26 of 42 (62%) of stools containing rotavirus typed as G9 by RT-PCR were positive for G9 rotavirus by EIA. Stools containing rotavirus untypeable by EIA contained significantly less MAb 60-reactive VP7 antigen (P = 0. 0001) than the stools containing typeable rotavirus. Thus, RT-PCR genotyping was the more sensitive method for determination of G9 type, but a serotype was readily determined in rotavirus samples containing MAb 60-reactive VP7 antigen by an EIA that incorporates MAb F45:1.

Antibodies, Monoclonal↗
PubMed1999

Characterization of a protein complex containing spliceosomal proteins SAPs 49, 130, 145, and 155.

SF3b is a U2 snRNP-associated protein complex essential for spliceosome assembly. Although evidence that SF3b contains the spliceosomal proteins SAPs 49, 130, 145, and 155 has accumulated, a protein-mediated association between all of these proteins has yet to be directly demonstrated. Here we report the isolation of a cDNA encoding SAP 130, which completes the cloning of the putative SF3b complex proteins. Using antibodies to SAP 130 and other putative SF3b components, we showed that SAPs 130, 145, and 155 are present in a protein complex in nuclear extracts and that these proteins associate with one another in purified U2 snRNP. Moreover, SAPs 155 and 130 interact with each other (directly or indirectly) within this complex, and SAPs 49 and 145 are known to interact directly with each other. Thus, together with prior work, our studies indicate that SAPs 49, 130, 145, and 155 are indeed components of SF3b. The Saccharomyces cerevisiae homologs of SAPs 49 and 145 are encoded by essential genes. We show here that the S. cerevisiae homologs of SAPs 130 and 155 (scSAP 130/RSE1 and scSAP 155, respectively) are also essential. Recently, the SF3b proteins were found in purified U12 snRNP, which functionally substitutes for U2 snRNP in the minor spliceosome. This high level of conservation, together with the prior observation that the SF3b proteins interact with pre-mRNA very close to the branch site, suggest that the SF3b complex plays a critical role near or at the spliceosome catalytic core.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Screening of sputum: an experience in a tertiary care hospital.

In order to reduce the work load on the clinical laboratory, it has been recommended that sputum samples, before accepting for culture, should be looked for the presence of polymorphs and squamous epithelial cells. (An appropriate sample should have more than 25 polymorphs per low power field and less than 10 epithelial cells per low power field; others are labelled as inappropriate). We examined this criteria for it's suitability on 1043 samples received at the clinical bacteriology laboratory at the All India Institute of Medical Sciences (AIIMS) for a period of one year (September, 1996 to August, 1997). Four hundred samples were found appropriate while 643 were inappropriate as per recommended criteria. Amongst the 400 appropriate samples, 215 were culture positive and 185 grew normal flora. However, we found that out of 643 inappropriate samples, 195 were culture positive (p < 0.01, statistically significant). The data was further divided into hospitalized and OPD cases. The distribution of culture positive cases in the appropriate samples was again found to be highly significant. It is apparent from our results that an attempt to process an inappropriate sample does not provide useful information.

Bacteriological Techniques↗
PubMed1999

Neem (Azadirachta indica) extract as an antibacterial agent against fish pathogenic bacteria.

Aquaneem, an emulsified product prepared from the neem (A. indica) kernel was tested against four pathogenic bacteria of fish (i.e. Aeromonas hydrophila, Pseudomonas fluorescens, Escherichia coli and Myxobacteria spp.) to test its efficacy as an antibacterial agent. Growth inhibitory property of the product at 10, 15 and 20 ppm has been noticed and recorded. The percentage reduction of bacterial cell population was noted to be maximum on 9th day at 20 ppm concentration (i.e. 70.14%, 74.15% and 61.75% for A. hydrophila, P. fluorescens and E. coli respectively) with the only exception of myxobacteria which showed maximum reduction percentage (63.90%) on 15th day. Among all the bacteria tested A. hydrophila, P. fluorescens and Myxobacteria spp. exhibited maximum sensitivity to Aquaneem in terms of percentage reduction of bacterial cell population in comparison to E. coli.

Aeromonas hydrophila↗
PubMed1998

Thermodynamic and kinetic characterization of calf lens gammaF-crystallin.

Gamma-crystallin is reported to be conformationally stable because of its internal structural symmetry, and gammaF (gammaIVa) is the most stable among the various gamma-crystallin gene products. However, there is no detailed report on its thermodynamic and kinetic stability. In the present study, detailed unfolding of gammaF-crystallin was investigated by equilibrium and kinetics methods with fluorescence and far-UV CD spectroscopic measurements. The GdnHCl-induced unfolding curves probed by Trp emission maximum and intensity showed a sharp single-step transition. Upon widening the unfolding transition with the use of urea in 1.5 M GdnHCl, a more proper fit for thermodynamic analysis was obtained. GammaF-Crystallin underwent a straightforward two-state process (N <==> U) without showing any measurable amount of intermediate. The conformational stability, as measured by deltaG(D)H2O (approximately 9 kcal/mol), indicates that gammaF-crystallin is a very stable protein. The high activation energy deltaG++H2O (approximately 24 kcal/mol), calculated from unfolding kinetics monitored by far-UV CD at 218 nm, also indicates that the native and unfolded states are separated by a high activation energy barrier.

Animals↗
PubMed1998

Blood sugar and serum insulin response in protein-energy malnutrition.

Blood sugar and serum insulin levels in the fasting state and following an oral glucose load in children with protein-energy malnutrition (PEM) were studied. Twenty-nine children with PEM (15 marasmus, 7 kwashiorkor, and 7 marasmic kwashiorkor) and eight healthy children aged between 6 and 60 months were the subjects of the study. Fasting samples were collected after a 6 h fast. Post-glucose samples were collected after an oral glucose load of 1.75 g/kg. Serum insulin was estimated by radioimmunoassay and glucose by the glucose oxidase method. In malnourished children, the mean fasting blood glucose levels were significantly lower. Two hours following an oral glucose load, only marasmus and marasmic kwashiorkor patients showed significantly higher blood glucose levels. Similarly, the fasting serum insulin levels were significantly lower in malnourished children. Two hours after the oral glucose load, serum insulin levels increased significantly in malnourished children but fell well short of the control values. The insulin:glucose ratio was consistently low in all cases but was more marked in PEM patients, both in the basal state as well as oral glucose loading

Blood Glucose↗
PubMed1998

Parturient fundal height as a predictor of low birth weight.

The usefulness of parturient fundal height as a predictor of low birth weight (LBW) was studied in 151 singleton pregnancies. The symphysis to fundus (S-F) distance was measured in early labour and was plotted against the birth weight of the newborns. A significant positive correlation was observed between the two parameters (r = +0.740). For the prediction of LBW, the critical limit of the fundal height was 31 cm, meaning that a S-F distance of more than 31 cm is reasonably safe while lesser values predict a higher chance of a LBW infant. From these observations, the use of a colour-coded tape by peripheral health workers and traditional birth attendants is suggested: red for S-F < 28 cm, yellow for S-F = 28-31 cm, and green for S-F > 31 cm. Mothers who have a fundal height in the 'red zone' are at risk of delivering LBW infants.

Adult↗
PubMed1998

Blood glucose and serum insulin response in protein-energy malnutrition following nutritional rehabilitation.

Fifteen children with protein-energy malnutrition and eight healthy children between the ages of 6 months and 60 months were studied for blood glucose and serum insulin levels in the fasting state and 120 minutes following oral glucose load. The measurements were repeated after normalization of the body weight following 6 weeks of nutritional rehabilitation. The fasting blood glucose increased significantly in the post-treatment period and became comparable to the control value. The abnormal blood glucose response to oral glucose load also normalized. The serum insulin level rose significantly (p < 0.001) in the post-treatment period but failed to normalize. The response to oral glucose load was similar. The observed lower insulin response, despite normoglycemia, after 6 weeks of nutritional rehabilitation indicates persistence of hormonal imbalance which may need a longer duration of rehabilitation for full recovery.

Blood Glucose↗
PubMed1998

Lack of maternal antibodies to P serotypes may predispose neonates to infections with unusual rotavirus strains.

Rotavirus (RV) strains infecting newborns often have unique neutralization antigens (P serotypes) on their outer capsids that are distinct from those found on RV strains that cause diarrhea in older children. We examined the hypothesis that unusual RV strains preferentially infect newborns because the newborns lack maternal neutralizing antibodies to these strains. To test this hypothesis, sera and saliva samples collected from neonates infected with 116E-like (P[11]G9) strains in the maternity ward of the All India Institute of Medical Sciences (AIIMS) hospital in New Delhi were tested for neutralizing antibodies against common RV strains and those infecting newborns and these titers were compared with those of newborns who did not become infected (controls). The infected neonates had significantly lower levels of cord blood neutralizing antibodies to 116E than the controls, suggesting that immunity to neonatal RV infection is acquired transplacentally through maternal antibodies. Further, this study confirmed the immunogenicity of the AIIMS neonatal strain 116E, a vaccine candidate, in its ability to evoke a potent RV-specific immunoglobulin A and neutralizing antibody response in serum and saliva among the infected babies. Our findings have important implications for the development of an effective RV vaccine. In India, where G9 strains are common in the community, the use of 116E as a vaccine, together with the rhesus tetravalent vaccine, may provide a broader protection against all the circulating RV serotypes, including serotype G9, which is not represented in the current rhesus RV tetravalent vaccine (G1-G4).

Antibodies, Viral↗
PubMed1998

Fluorescence and immunochemical studies of advanced glycation-related lens pigments.

PURPOSE: To establish whether advanced glycation is the major mechanism for yellowing of lens proteins. METHODS: Synchronous fluorescence (SF) and immunochemical assays were used to study glycation in vitro and in vivo. In the in vitro study, advanced glycation end products (AGEs) were prepared and used as antigens to induce antibodies to AGEs. The in vitro AGEs and classified nuclear cataracts were analyzed by SF and immunochemical assays. RESULTS: In vitro AGEs generated from various glycating agents and carrier proteins displayed strong SF above 350 nm; the spectra were well resolved with major bands at 380 nm and 420 nm. Samples from human lenses manifested a band at 395 nm in addition to the two bands shown by in vitro AGEs. SF intensity is greater for the water-insoluble (WI) than water-soluble (WS) fraction, but both increased with increasing nuclear color. The immunoreactivity data also showed that the WI fraction contained more AGEs than the WS fraction and that the amount of AGEs increased with increasing nuclear color. CONCLUSIONS: Fluorescence and immunoassays indicated that pigmented AGEs contributed to yellowing of the crystalline lens nucleus.

Animals↗