Browsing by Author "Singh, B B"
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Item "Abdominal pain in children--a clinical study".(1978-07-01) Rahman, H; Singh, B B; Agarwal, V K; Srivastava, A KItem Analysis of biexponential nuclear magnetic resonance relaxation curves: studies on simulated data.(1993-10-01) Srinivasan, V T; Singh, B BApplication of a Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence to a nuclear spin system consisting of two components, whose spins do not exchange or exchange slowly on the scale of the shorter time constant, results in the nuclear magnetization Mz of the spin system decaying according to the relation Mz = Ma exp(-t/Ta)+Mb exp(-t/Tb)+K+E where Ma,Ta are the intensity and transverse relaxation time of one component, Mb and Tb are the corresponding values for the second component, K is a constant and E is the contribution due to noise. Data simulation according to the above function was carried out with different values for the parameters Ma, Ta, Mb, Tb and K, the noise component being normally distributed with mean zero. For each set of parameters, the data generation was repeated a number of times with a different noise content and in each case, the parameters were estimated using a non-linear least square curve fitting procedure. The mean and percent coefficient of variation (CV) of each parameter was calculated. The value of CV is taken as a measure of the uncertainty in the estimated value of the parameter. It is found that the uncertainty in the estimated values of the parameters is due to the random noise. The range of data points is more critical than the number of data points used in curve fitting. Moreover, the uncertainty associated with each parameter increases with decreasing Ma/Mb ratio and increases with increasing Ta/Tb ratio. Higher signal to noise ratios will be required to analyse data with low Ma/Mb and high Ta/Tb ratios.(ABSTRACT TRUNCATED AT 250 WORDS)Item Antitumor effect of pre-transplantation local hyperthermia and augmentation by dietary unsaturated fat.(1996-09-01) Vartak, S; George, K C; Singh, B BAntitumor effects of pre-transplantation hyperthermia and its correlation to immunological changes in the host animals and enhancement by dietary unsaturated fat have been studied. Leg muscles of mice were locally heated (41 degrees-43 degrees C, 40 min) and fibrosarcoma cells were inoculated into the heated and unheated sites and tumor growth time was determined. Spleen cell activity and plasma levels of interleukins (IL1 and 2) [RIA kits] were assessed. Muscle and tumor fatty acid profiles were modified by feeding mice with unsaturated fat supplemented diet and analysed by GLC. Pre-transplantation hyperthermia suppressed the tumor growth on both heated and unheated contralateral legs of mice. These effects were associated with increased spleen cell activity and plasma levels of IL1 and 2. Diet rich in unsaturated fat altered the fatty acid profiles of the leg muscles and tumors and inhibited tumor growth. It also potentiated the antitumor effect of pre-transplantation hyperthermia. In conclusion, mild local hyperthermia induces both direct and abscopal antitumor effects which may be ascribed to stimulation of host's antitumor immune responses and these effects are augmented by unsaturated fat supplemented diet.Item Assessment of chlorpromazine as radiation sensitizer and protector.(1996-12-01) Huilgol, N G; Chatterjee, N; Singh, B BIn vitro studies of chlorpromazine (CPZ) a popular anti-psychotic drug has shown radiation sensitizing effects at higher celluar concentration and protective effect at a lower concentration. The present study was designed to evaluate both sensitizing and protective effects in the treatment of advanced cancer of the cervix treated with hypofractionated external radiation and intratumoural injection of chlopromazine. Twenty patients were treated with intratumoural CPZ and radiation, while, 23 patients received radiation alone. A 52.94% complete response was noted in CPZ arm while 39.1% complete response in the control. A trend towards improved response is seen in CPZ group. Similarly patients who received CPZ showed significantly low proctitis rates.Item Calcium-dependent metabolic regulations in prokaryotes indicate conserved nature of calmodulin gene.(1998-02-01) Sengupta, L K; Singh, B B; Mishra, R; Pandey, P K; Singh, S; Sengupta, S; Bisen, P SRole of free calcium and calcium binding protein calmodulin as signal molecule in cellular regulation is well established in eukaryotes. However, reports on Ca(2+)-dependent processes and their inhibition by calcium and/or calmodulin antagonists indicate towards the presence of calmodulin in prokaryotes as well. The common evolutionary origin of pro- and eukaryotes and many examples of evolutionary conservation of structure and functions support the contention of such conservation of the role of Ca2+ and calmodulin. Eukaryotic calmodulin (CaM) contains four structurally and functionally similar Ca2+ domains named I, II, III and IV. Each Ca2+ binding loop consists of 12 amino acid residues with ligands arranged spatially to satisfy the octahedral symmetry of Ca2+ binding. Plant calmodulin differ from vertebrate ones in 13 to 14 amino acid positions of which nine occur at -COOH- terminal half. Differences between protozoan and mammalian CaM also occur mostly in the same half. Isolation and characterization, although to a little extent, of CaM-like proteins from bacteria and cyanobacteria and their comparison with CaMs from diverse origin suggest high degree of conservation. Non-bulky amino acids like glycine, alanine and serine with low specific rotation are present in greater number in the primitive form of calmodulin and have been significantly reduced in highly evolved form of calmodulin, suggesting that their requirement was insignificant and were eliminated from EF hand structure during evolution. However, amino acids like glutamate/glutamine and aspartate/asparagine were highly conserved and did not show any major change in their frequency since their positions are too significant in calcium binding domain. While the number of positively charged amino acids like arginine and leucine was increased, histidine containing weakly ionized group and having a significant buffering capacity was reduced to a major extent, further suggesting that the acidic nature of calmodulin protein has been maintained during evolution. Thus it is now clear that the entire superfamily of Ca2+ binding proteins have arisen from a common genetic ancestry. Two successive tandem duplications of gene encoding a single domain containing protein of 30-40 residues gave rise to a four domain molecule from which this family was then derived.Item Clinical Profile and Outcome of Swine Flu in Indian Children.(2011-05) Das, Rashmi Ranjan; Sami, Abdus; Lodha, Rakesh; Jain, Richa; Broor, S; Kaushik, S; Singh, B B; Ahmed, M; Seth, Rachna; Kabra, Sushil KObjective: To describe the clinical characteristics and outcome of Indian children infected with 2009 H1N1 influenza virus. Study design: Retrospective chart review. Setting: Outpatient department and hospitalized patients in a tertiary care hospital. Methods: Clinical details of 85 children (positive for the 2009 H1N1 virus infection tested by real-time reversetranscriptase– polymerase-chain-reaction assay) were analyzed from medical charts. Results: Of the 85 (55 boys) children positive for 2009 H1N1 virus infection, 64.7% were between 5 years to 16 years, and 35.3% were below 5 years age. The mean age of these children was 7.5±3.5 yr. Contact history was positive only in 22 (26%) cases. High grade fever was the most common symptom, followed by cough and rhinorrhea. Twenty-nine (34%) patients had an underlying co-morbid condition. Of the 34 patients who underwent chest radiography during evaluation, 18 children (52.9%) had findings consistent with lower respiratory tract infection. Antiviral therapy was initiated in 76 patients. Hospitalization was required in 30 (35.3%) children. Risk factors for hospitalization included underlying co-morbid condition, respiratory distress, vomiting, wheezing, diarrhea, hypotension and infiltrates/consolidation on chest radiograph. Mean length of hospitalization was 131+76 hours, irrespective of underlying disease. Three children developed Acute Respiratory Distress Syndrome and died. Conclusions: Clinical features and routine laboratory investigations in children with swine origin influenza were non-specific. Children with co-morbid condition, respiratory distress, vomiting, wheezing, diarrhea, hypotension and infiltrates/consolidation on chest radiograph were at higher risk of hospitalization.Item A clinical study to assess chlorpromazine as hypoxic cell sensitizer in head & neck cancer treated with conventional radiation.(1998-09-05) Huilgol, N G; Chatterjee, N; Singh, B BA randomized prospective study was conducted to evaluate the effectiveness of chlorpromazine as a sensitizer of radiation in advanced head and neck cancers. Patients with unresectable laryngopharyngeal cancers except glottic cancers, with histologically proven squamous cell carcinoma staged III and IV were accrued for the study. Patients received radiation to a total dose of 6000 cGy in six weeks in both the groups except that patients in the study group received 50 mgs Chlorpromazine (CPZ) in divided doses. Fourteen of 20 patients showed complete response in the control group whereas 34 of 38 patients in chlorpromazine treated group had complete regression of the tumour (p = 0.016). The survival was (p = 0.08) better in patients receiving CPZ. This preliminary study shows beneficial effects of chlorpromazine. No adverse effects due to chlorpromazine in conjunction with radiation were documented.Item Cytotoxic & radiosensitizing effects of chlorpromazine hydrochloride in sarcoma 180A.(1980-08-01) Shenoy, M A; Singh, B BItem Effect of dielectric discharge on drug treated mammalian cells.(1981-06-01) Mishra, K P; Binh, L D; Singh, B BItem Effects of transient high electric fields on rat thymocytes.(1984-02-01) Srinivasan, V T; George, K C; Singh, B BItem Hyperthermia--a new dimension in cancer treatment.(1990-08-01) Singh, B BItem Investigation with chitosan-oxalate oxidase-catalase conjugate for degrading oxalate from hyperoxaluric rat chyme.(1997-08-01) Ramakrishnan, V; Lathika, K M; D'Souza, S J; Singh, B B; Raghavan, K GEnteric hyperoxaluria manifests due to hyperabsorption of dietary oxalate, secondary to a variety of chronic gastrointestinal disorders. The potential use of chitosan immobilized oxalate oxidase-catalase conjugate to deplete the oxalate content of food materials, while they are in the digestive tract has been evaluated by treating rat stomach chyme with such an enzyme preparation. Oxalate oxidase, obtained from beet stem, was adsorbed on chitosan along with catalase and then cross linked with glutaraldehyde to stabilize the derivative. This chemical modification of oxalate oxidase brought about a shift in its optimal pH from 4.2 to 3.8 with a marginal increase in its K(m). Compared to native enzyme, the modified oxalate oxidase exhibited increased storage stability, higher thermal stability and enhanced resistance to proteolytic digestion and heavy metal inactivation. These improved properties of the immobilized oxalate oxidase possibly render it suitable for oral administration under hyperoxaluric conditions.Item Nuclear matrix bound DNA polymerase-beta in mouse fibrosarcoma: effect of gamma-radiation.(1996-09-01) Nair, C K; Mukherjee, A; Singh, B BNuclear matrices isolated from the mouse fibrosarcoma tumour cells contain the eukaryotic replicative enzyme DNA polymerase-alpha and the presumptive repair enzyme DNA polymerase-beta. Exposure of tumors to various doses of gamma-radiation (1.95 to 6.5 Gy) causes a 2-fold increase in the levels of only DNA polymerase-beta in the nuclear matrix. The increase in the levels of this enzyme is not discernible if the matrices are isolated 24 hr after irradiation. The rise in the levels of the repair enzyme DNA polymerase-beta could be indicative of radiation stress response of the tumour cells and their repair ability.Item OK-432: an effective sclerosing agent for the treatment of lymphangiomas of head and neck.(2007-07-08) Baskota, D K; Singh, B B; Sinha, B KOBJECTIVE: The basic objective of this study was to find out the efficacy of OK-432 for the conservative treatment of lymphangiomas of head and neck regions at the Department of ENT-Head & Neck Surgery of Tribhuvan University Teaching Hospital (TUTH), Kathmandu, Nepal. METHODS: It was a hospital based prospective, cross-sectional, case series, conducted among the patients suffering from different lymphangiomas of head and neck regions and treated with intra-lesional injection of OK-432, from March, 2005 to September 2006. Altogether eleven patients were enrolled in this modality of treatment out of which one patient was excluded from the study, which was treated surgically due to very ugly scar at the site of lesion resulting from previous surgery for the same. The data were analyzed by using simple mathematical tools like percentage and frequency. RESULTS: Out of ten patients treated with intralesional injection of OK-432, absolute response, i.e. total resolution of swelling was found in nine patients (90%) after the first dose. Remaining one patient also responded well on the treatment but some residual swelling was in situ for which second dose was given. After the second dose it was also totally resolved. In this way we achieved 100% response after the second dose of OK-432. CONCLUSION: The results of this study so far indicate that OK-432 is an effective and safe tool for the treatment of lymphangioma of head and neck region. As the procedure can be done in an out patient department, without hospitalization and has got minimal side effects, it can be proposed as the first line treatment of lymphangiomas of head and neck.Item Potentiation of radiation response of a mouse fibrosarcoma by phenothiazine drugs.(1984-06-01) George, K C; Singh, B BItem Proton spin-lattice relaxation studies and elemental analysis of human lymph nodes afflicted with lymphoma.(1984-08-01) Gopalakrishna, S; Ranade, S S; Srinivasan, V T; Singh, B B; Panday, V K; Talwalkar, G VItem Radioprotective effect of whole-body hyperthermia on mice exposed to lethal doses of total-body gamma irradiation.(1996-09-01) Patil, M S; Kaklij, G S; Poduval, T B; Singh, B BThe whole-body hyperthermia (40 degrees C, 1 hr) 20-48 hr prior to total-body irradiation (TBI) with 9 Gy gamma rays gave 80% protection as assessed by survival of the animals. However this was reduced to 50% when mice were irradiated 7 or 15 days after hyperthermia. The local hyperthermia (42 degrees C, 1 hr) given prior to irradiation, on the other hand, did not show any protective effect. The whole-body or local hyperthermia given after TBI had no protective effect on survival of animals.Item Radiosensitizing and radioprotective effects of phenothiazines.(1985-02-01) Maniar, H S; Singh, B BItem Resealing of electrically hemolysed rat & human erythrocytes.(1983-12-01) Mishra, K P; Bedekar, V W; Singh, B BItem Sample size for collecting germplasms--a polyploid model with mixed mating system.(2003-03-25) Sapra, R L; Narain, Prem; Chauhan, S V S; Lal, S K; Singh, B BThe present paper discusses a general expression for determining the minimum sample size (plants) for a given number of seeds or vice versa for capturing multiple allelic diversity. The model considers sampling from a large 2 k-ploid population under a broad range of mating systems. Numerous expressions/results developed for germplasm collection/regeneration for diploid populations by earlier workers can be directly deduced from our general expression by assigning appropriate values of the corresponding parameters. A seed factor which influences the plant sample size has also been isolated to aid the collectors in selecting the appropriate combination of number of plants and seeds per plant. When genotypic multiplicity of seeds is taken into consideration, a sample size of even less than 172 plants can conserve diversity of 20 alleles from 50,000 polymorphic loci with a very large probability of conservation (0.9999) in most of the cases.