Browsing by Issue Date, starting with "2005"

Now showing 1 - 20 of 404

Color Doppler ultrasound as an objective assessment tool for chemotherapeutic response in advanced breast cancer
(2005) Seema Singh; Satyajit Pradhan; Ram Chandra Shukla; Mumtaz Ahmad Anson; Anand Kumar
Background: In our part of the world, the majority of the patients with breast cancer present with locally advanced disease and require neo-adjuvant chemotherapy as the primary treatment modality. It is essential to monitor the response to chemotherapy in these patients. Clinical examination as the sole criterion of response assessment is entirely subjective and fallacious. Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) are expensive. The role of Doppler ultrasonography as an imaging modality for this purpose is therefore being evaluated. Methods: A prospective study was undertaken of 25 cases of locally advanced breast carcinoma (LABC) and Color Doppler sonography was used for the sequential assessment of chemotherapeutic response. The response assessed on the basis of clinical examination and Color Doppler was compared with the histological response. The parameters assessed on color Doppler were a change in the number of flow signals, maximum flow velocity (V max), pulsatility index (PI) and resistivity index (RI). Responses were analysed statistically using the Pearson correlation coefficient and Kappa statistics (κ). The sensitivity, specificity, positive predictive & negative predictive values for predicting complete histological response were calculated. Results: Color Doppler showed a sensitivity of 88.88% for predicting complete histological response. The negative predictive value of color Doppler was 92.3%. A significant correlation was obtained between color Doppler & histopathological response. Conclusions: Color Doppler was found to be an objective and effective tool or modality compared with clinical evaluation in sequential response assessment, especially for predicting complete histological response.
Copper, zinc, and Cu/Zn ratio in carcinoma of the gallbladder
(2005) S.K. Gupta; S.P. Singh; V.K. Shukla
Introduction: The exact role of copper and zinc in the etiology of carcinoma of the gallbladder is unclear. Some studies suggest the Cu/Zn ratio is a good indicator of the extent and prognosis in carcinoma of the gastrointestinal tract. The aim of the present study is to estimate the micronutrient profile and Cu/Zn ratio in the serum, tissues, and bile of patients with benign and malignant gallbladder diseases. Methods: The present study was carried out in 60 patients comprising 30 each of carcinoma of the gallbladder and cholelithiasis, and 30 age and sex matched controls. Copper and zinc levels were estimated in blood, bile, and tissue using a Perkin Elmer Model 2380 Atomic absorption Spectrophotometer. Results: The mean serum zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis and in healthy controls (P < 0.001). The mean serum copper levels were significantly higher in patients with carcinoma of the gallbladder as compared to patients with cholelithiasis and healthy controls (P < 0.001). Biliary and tissue zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis. Biliary and tissue copper levels were higher in patients with carcinoma of the gallbladder than in patients with cholelithiasis. The serum Cu/Zn ratio showed a gradual and significant increase from 1.11 in healthy controls to 1.35 in patients with cholelithiasis and 2.12 in patients with carcinoma of the gallbladder. The biliary and tissue Cu/Zn ratios were also significantly increased in patients with carcinoma of the gallbladder than in patients with cholelithiasis (P < 0.001). Conclusions: Our data support an association between lower zinc levels and consequently an increased Cu/Zn ratio and carcinoma of the gallbladder. Whether zinc supplementation has a protective effect in preventing carcinoma of the gallbladder needs to be studied further. © 2005 Wiley-Liss, Inc.
Mixed-ligand Ru(II) complexes with 2,2′-bipyridine and aryldiazo-β-diketonato auxillary ligands: Synthesis, physico-chemical study and antitumour properties
(Elsevier Inc., 2005) Lallan Mishra; Ajay K. Yadaw; Subrato Bhattacharya; Santosh K. Dubey
The complexes of Ru(II)-2,2′-bipyridyl with substituted diazopentane-2,4-diones (L1H-L5H) were synthesized and characterized by elemental analyses, conductance, FAB (fast atom bombardment) mass and spectral (IR, UV/Vis (UV/visible), NMR) studies. Molecular geometry optimization of the complexes was also made. None of the complexes luminesce. However, facilitated oxidation of Ru(II) to Ru(III) was evidenced from their lower reduction potential data. The ligands and their complexes were tested for their antitumour activity against a variety of tumour cell lines. Though activity is found to vary with the type of tumour cell lines used, yet complex 5 with naphtyldiazopentane-2,4-dione as co-ligand was found to be a potential compound as it showed in general significant activity against all cell lines studied. © 2005 Elsevier Inc. All rights reserved.
Growth and characterization of gallium nitride nanowire
(2005) Vipul Srivastava; V. Sureshkumar; P. Puviarasu; K. Thangaraju; R. Thangavel; J. Kumar
The present-day trend towards the development of nanostructures has resulted in several interesting material systems with unique and, in some cases, novel properties. Gallium nitride nanowires and nanodimensional structures have been realized using a simpler approach of vapour phase-assisted deposition. GaN nanodimensional structures have been realized on (0 0 0 1) sapphire substrates by suitable surface treatment procedure using ferrous salt. Growth has been carried out at the substrate temperature of 950 °C. A separate synthesis boat was kept close to the growth substrate and the reaction of Ga to GaN was made in the close proximity of the substrate. Experiments were carried out at different growth temperatures and also by varying the proximity conditions of the substrate. The surface features reveal excellent distribution of nanostructures which are correlated with the growth conditions. © 2004 Elsevier B.V. All rights reserved.
Nucleation and growth of catalyst-free zinc oxide nanostructures
(2005) Jai Singh; Anchal Srivastava; R.S. Tiwari; O.N. Srivastava
This paper deals with the investigations on the nucleation and growth of Zinc Oxide (ZnO) nanostructures in a catalyst free synthesis. The ZnO nanostructures have been formed by evaporation of Zn (99.99%) in O 2 and Ar atmosphere in single zone furnace under two temperature regions, region A (∼1173-1073 K) and region B (∼873-773 K). Through application of XRD and TEM techniques, it has been shown that first ZnO is formed which changes to ZnO x through creation of oxygen vacancies. The ZnO x acts as self-catalyst and leads to formation of various nanostructures. Those observed in the present investigation are nanotetrapods (1D, diameter ∼ 70-450 nm, length ∼ 2-4.5 μm) nanorods (1D, diameter ∼ 45-95 nm, length ∼ 2.5-4.5 μm), nanoflowers(2D, central core diameter ∼ 90-185 nm, length of petals/nanorod ∼ 1.0-3.5 μm) and nanoparticles (3D, size ∼ 0.85-2.5 μm). These nanostructures have been revealed by SEM explorations. Attempts have been made to explain the formation of the various nanostructures in terms of the creation and distribution of the ZnO x, the temperature as well as oxygenation conditions. Copyright © 2005 American Scientific Publishers All rights reserved.
Fructose-2, 6-bisphosphate associated regulatory enzymes develop in concordance in mice brain during early postnatal life
(2005) Pankaj Pandey; Sanjay K. Singh; Surendra K. Trigun
Fructose-2, 6-bisphosphate (fru-2, 6P2), synthesized by 6-phosphofructo-2-kinase (PFK2), regulates glucose metabolism via modulating phosphofructokinase-1 (PFK1) and fructose-1, 6-bisphosphatase (FBPase1) reciprocally in mammalian tissues. How this control system develops in brain is poorly understood. This article presents the postnatal comparative profiles of fru-2, 6P2 and PFK2 & fru-2, 6P2 dependent regulation of PFK1 and FBPase1 in mice brain. Fru-2, 6P2 and PFK2 activity both attained their adult levels in concordance from day1 to 1wk age. Western blot analysis of mice liver and brain & rat liver PFK2 using anti rat liver PFK2/FBPase2 confirmed that both, mice liver and brain isoforms cross- react efficiently with this antibody. In addition, DEAE-eluted brain fractions from different postnatal ages revealed that 1day mice brain expresses a liver type enzyme (∼55 kDa) that is replaced by an adult brain type protein (∼110 kDa) from 1wk onward ages. As compared to 1day mice, significantly decreased Km values of PFK2 at 1wk-10wk ages also suggest the existence of a kinetically different isoform of this enzyme from 1wk onward ages. In vitro effects of fru-2, 6P2 on partially enriched brain PFK1 and FBPase1 suggest that fru-2, 6P2 dependent respective stimulatory and inhibitory responses of both these enzymes increase progressively from day1 to 3wk age. This is well corroborated with the postnatal age-dependent linear increase in PFK1 and decrease in FBPase1 activities in mice brain. The results suggest that fru-2, 6P2 associated regulatory components develop in concordance in mice brain during early postnatal life. © Universitätsverlag Ulm GmbH 2005.
An unusual foreign body in the larynx in an adult
(2005) Gautam Bir Singh; Raman Abrol; Arjun Dass
[No abstract available]
The various phases of the system Sr1-xCaxTiO 3 - A Raman scattering study
(John Wiley and Sons Ltd, 2005) P. Ranson; R. Ouillon; J.-P. Pinan-Lucarre; Ph. Pruzan; S.K. Mishra; R. Ranjan; D. Pandey
This paper deals with the structural Raman-active and the disorder-induced TO and LO Raman modes in Sr1-xCaxTiO3 (SCT) ceramics. Spectra were recorded at ambient pressure in a wide range of temperatures from 8 K up to ≈500 K. The chemical composition (x) was chosen so as to investigate the phase boundaries which have been previously determined in the x-T phase diagram. An eigenvector analysis is given for all the known phases. The Raman data confirm the occurrence of a double-tilt system of Imma space group lying between the tetragonal I4/mcm and the orthorhombic Pbnm structures for x ≥ 0.06. Higher-order transformation of the antiferroelectric phase (0.20 ≤ x ≤ 0.40) at low temperature is also suggested. The main interesting disorder-induced effects originate from the temperature behaviour of the hard polar modes TO2 and TO4, which appear in the Raman spectra of the paraelectric domain. This behaviour allows one to discuss the precursor range of ferroelectricity in the SCT system in terms of ferroelectric- or antiferroelectric-type dipolar interactions. Copyright © 2005 John Wiley & Sons, Ltd.
The molecular characterization of clinical isolates from Indian Kala-azar patients by MLEE and RAPD-PCR
(2005) Madhumita Manna; Hemanta Kumar Majumder; Shyam Sundar; Amar Nath Bhaduri
Background: Kala-azar is a serious health problem in India. The situation has worsened further due to the occurrence of cases unresponsive to antimonials. About 30-50% patients do not respond to the prevailing regimen of antimonials. The etiological agent for Indian kala-azar has long been known to be Leishmania donovani. Recently, in a somewhat startling report, it was claimed that L. tropica causes nearly 25% of current kala-azar cases in India. It was also suggested that this might be in some way related to the unresponsiveness to pentavalent antimonials in the field. Material/Methods: Two independent molecular characterization techniques, multilocus enzyme electrophoresis (MLEE) and RAPD-PCR, were employed to analyze 15 clinical isolates from confirmed Indian kala-azar patients collected from the eastern part of the country over a period of nearly 20 years. The collection included six Sb5+- unresponsive and one PKDL case. Results: Our observations strongly suggest that all the clinical isolates, including the antimony (Sb5+)-unresponsive and PKDL ones, we studied were identical to the WHO reference strain (DD8) for Leishmania donovani by both the above methods and no strain variation might have occurred in two major epidemic and inter-epidemic periods. We also observed that none of the Sb5+-unresponsive stains we analyzed was related to L. tropica. Conclusions: We conclude that L. donovani may be the causal agent for Indian kala-azar and that L. tropica is most likely not an etiological agent for Indian Kala-azar cases that are unresponsive to antimonials. © Med Sci Monit, 2005.
Microstructural and corrosion studies of 9Cr-1Mo steel in acidic methanol solutions
(2005) V.B. Singh; Archana Gupta
The corrosion behaviour of 9Cr-1Mo ferritic steel has been studied in methanol containing different concentrations of sulphuric, hydrochloric acids and their mixtures using potentiostatic and potentiodynamic techniques at 30°C. The influence of various heat treatments: furnace cooled (FC), air cooled (AC) and water quenched (WQ) on the electrochemical polarization behaviour has also been studied for a few selected compositions of these acids and their mixtures in methanolic solutions. The cathodic reaction is observed to be hydrogen evolution. The alloy showed active, passive and transpassive behaviour in different concentrations of sulphuric acid in methanol. The anodic polarization curves of the alloy revealed a characteristic 'cathodic loop' in methanol at higher concentrations of sulphuric acid (0.1 and 1.0 M). Stable passivity was also observed which became ustable at higher potential due to pitting. Well defined anodic Tafel region followed by a limiting current density region, in different concentrations of methanolic solution of hydrochloric acid, was observed. However, in the mixture of different concentrations of sulphuric acid and hydrochloric acids in methanol and at higher concentration of sulphuric acid (1.0 M) the alloy showed active, passive and transpassive behaviour. Such behaviour was not observed below 1.0 M concentration of either acid in methanol, rather a limiting nature was observed. It seems that in the acidic mixture, the SO2-4 ions act as inhibitor and decreases the adsorption of Cl- ions and at sufficiently high concentration it effectively hinders the adsorption of the Cl- ions on the surface. The anodic polarization curves for FC specimen shifted towards higher current density region and the curves for AC and WQ specimens shifted towards lower current density region in comparison to as-received one in methanolic solution of sulphuric acid. However, the anodic polarization curves for FC, AC and WQ specimen shifted towards higher current density region as compared to as-received specimen in methanolic solution of hydrochloric acid and in the mixture of hydrochloric and sulphuric acids in methanol. Examination of the sample surface was done using scanning electron microscopy (SEM).
Investigation of ν(N-H) and ν(C-N) stretching modes of propylamine (C3H7NH2) in a binary system C 3H7NH2 + CH3OH via concentration dependent Raman study and ab initio calculations
(2005) Sunil K. Srivastava; Animesh K. Ojha; W. Kiefer; B.P. Asthana
Raman spectra of propylamine (C3H7NH2) and its binary mixtures, C3H7NH2 + CH 3OH with varying mole fractions of the reference system, C 3H7NH2, C were recorded in two widely apart wavenumber regions, 3100-3600 cm-1 and 1225-1325 cm-1. In the former region, the two Raman bands at ∼3305 and ∼3326 cm -1, obtained after the line shape analysis, which were assigned to symmetric ν(NH) and anti-symmetric ν(NH) stretching modes, respectively, show a downshift upon dilution. However, whereas the ν(NH) anti-symmetric mode shows a shift of 18.6 cm-1, the ν(NH) symmetric mode shows a much smaller shift (5.7 cm-1) between neat liquid and high dilution, C = 0.1. This aspect has been explained using the optimized geometries calculated employing ab initio theory (MP2 level) for the neat C 3H7NH2 and its different hydrogen-bonded complexes. The linewidth versus concentration plot for the ν(NH) anti-symmetric stretching mode, however exhibits a distinct maxima at C = 0.4, which has been explained as a slight departure from the concentration fluctuation model. In the latter region, a symmetric peak is observed, which corresponds to ν(CN) stretching mode, which shows an upshift upon dilution and an almost linear concentration dependence. This has also been explained in terms of the parameters obtained from the optimized geometries of the different hydrogen-bonded complexes. © 2004 Elsevier B.V. All rights reserved.
Anterior gastrotomy technique of fashioning pancreaticogastrostomy following pancreatico-duodenectomy for pancreatic head and periampullary cancer
(2005) M. Tewari; H.S. Shukla
[No abstract available]
Study of free radicals in neonates born through meconium stained amniotic fluid deliveries [4]
(2005) B.D. Bhatia; A. Goel
[No abstract available]
Revival of interest in low-dose diuretic therapy in hypertension
(2005) N.K. Singh; A. Agrawal; A. Gogia
[No abstract available]
Evidence for minority male mating success and minority female mating disadvantage in Drosophila ananassae
(2005) Arundhati Som; Bashisth N. Singh
Frequency-dependent mating success was tested for three pairs of wild-type and mutant strains of Drosophila ananassae, MY and yellow body color (y), PN and claret eye color (ca), and TIR and cut wing (ct). The two strains of each pair were chosen for their approximately equal mating propensities. Multiple-choice experiments, using different experimental procedures, were employed. The tests were carried out by direct observation in Elens-Wattiaux mating chambers with five different sex ratios (4:16, 8:12, 10:10, 12:8, and 16:4). There was no assortative mating and sexual isolation between the strains, based on 2 x 2 contingency χ2 analysis and isolation estimate values. Onesided rare male mating advantages were found in two experiments, one for ca males and the other for wild-type males (TIR). However, no advantage was found for rare males in the experiment with MY and y flies. Mating disadvantages for rare females were found for sex-linked mutants (y and ct). Two different observational methods (removal or direct observation of mating pairs) imparted no overall significant effects on the outcome of the frequency-dependent mating tests. ©FUNPEC-RP.
Force-induced triple point for interacting polymers
(2005) Sanjay Kumar; Debaprasad Giri; Somendra M. Bhattacharjee
We show the existence of a force induced triple point in an interacting polymer problem that allows two zero-force thermal phase transitions. The phase diagrams for two different models of mutually attracting but self-avoiding polymers are presented. One of these models has an intermediate phase and it shows a triple point. A general phase diagram with multicritical points in an extended parameter space is also discussed. © 2005 The American Physical Society.
Use of Leishmania donovani field isolates expressing the luciferase reporter gene in in vitro drug screening
(2005) Ashutosh; Suman Gupta; Ramesh; Shyam Sundar; Neena Goyal
Currently available primary screens for the selection of candidate antileishmanial compounds are not ideal. These techniques are time-consuming, laborious, and difficult to scale and require macrophages, which limit their use for high-throughput screening. We have developed Leishmania donovani field isolates that constitutively express the firefly luciferase reporter gene (luc) as a part of an episomal vector. An excellent correlation between parasite number and luciferase activity was observed. luc expression was stable, even in the absence of drug selection, for 4 weeks. The transfectants were infective to macrophages, and intracellular amastigotes exhibited luciferase activity. The suitability of these recombinant field isolates for in vitro screening of antileishmanial drugs was established. The luciferase-expressing sodium stibogluconate-resistant cell lines offer a model for the screening of compounds for resistance. The system is in routine use at the Central Drug Research Institute, Lucknow, India, for high-throughput screening of newly synthesized compounds. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
A new flavanone, reflexin, from Cuscuta reflexa and its selective sensing of nitric oxide
(2005) V.J. Tripathi; S.B. Yadav; A.K. Upadhyay
A new compound, reflexin, 5-hydroxy-7-methoxy-6-(2,3-epoxy-3-methyl-butyl)- flavanone, is isolated from the stems of Cuscuta reflexa along with three other known compounds. This new compound has good potential for application especially in the photoactivity of reflexin. It was found to be sensitive to glutathione, forming a fluorescent product that is utilized for sensing nitric oxide (NO). The lowest detection limit of NO analysis was found to be 0.05 μM. Copyright © 2005 by Humana Press Inc. All rights of any nature whatsoever reserved.
Spectroscopy of Nb90 at high spin
(2005) A. Chakraborty; Krishichayan; S.S. Ghugre; R. Goswami; S. Mukhopadhyay; N.S. Pattabiraman; S. Ray; A.K. Sinha; S. Sarkar; P. V. Madhusudhana Rao; U. Garg; S.K. Basu; M.B. Chaterjee; M. Saha Sarkar; L. Chaturvedi; A. Dhal; R.K. Sinha; I.M. Govil; R.K. Bhowmik; A. Jhingan; N. Madhavan; S. Muralithar; S. Nath; R.P. Singh; P. Sugathan
Excited states of Nb90 were investigated via prompt and delayed γ decays and the recoil-isomer tagging technique. The level scheme of Nb90 has been extended up to J=19 and Ex=8.4 MeV. Half-lives of the 11- and 17/2- isomeric levels in Nb90,91 were measured to be 0.47±0.01 and 3.3±0.4 μs, respectively. The results are compared with the predictions of large-basis shell model calculations. The effects of truncation of the valence model space on the calculated results are discussed. © 2005 The American Physical Society.
A database on occurence patterns of unusual geological incidents in southwest Peninsular India and its implication on future seismic activity
(2005) N.H. Singh; J. Mathai; V.N. Neelakandan; D. Shankar; V.P. Singh
A series of unusual geological incidents have occurred throughout the Kerala State (southwest Peninsular India) during the year 2001 mainly in two active phases i.e. February to March, and June to November 2001. In the beginning during February-March 2001, oscillations and rise in water levels, wavy formations and spouting up of water in the open wells, cracks in the buildings, perceptible ground fissures, shaking of trees/ bushes and enhanced microearthquake activity have occurred. Collapse of shallow open wells, draining of water, lowering of water level, land subsidence, ground fissures etc., and further increased microearthquake activity were the dominant incidents in various parts of the State during June to November 2001. Interestingly, no such incidents had occurred in the past in this region. The frequency of all the above incidents, including microearthquakes activity, reduced drastically to background level beyond November 2001 except a few earthquakes during 2002 and 2003. The incidents are distributed in a vast area irrespective of geology and topography right from coastal stretch to hinterlands in the Western Ghats of India. This chain of incidents was preceded by two moderate size earthquakes of M ∼ 5 on 12 December 2000 and 7 January 2001 which were not capable to trigger such widespread incidents in the region. The temporal patterns of these incidents clearly indicate the p henomenon of rapid ground vibrations at several occasions possibly due to movement of crustal block along certain active fault. This geological process perhaps lead to uplift and tilt of the ground giving rise to several underground water related anomalies and incidents of land deformations. The temporal patterns of individual incident also did not show any clear inter-relationships indicating that all these incidents were caused by a single internal geological process possibly due to converging trend of tectonic stress through the process of redistribution. It is inferred that these incidents constitute a well defined patterns of precursory sequence to a future large seismic activity in the southwest part of Peninsular India. The existence of the present chain of events can be explained by dilatancy diffusion model. Using the spatial distribution of these incidents including microearthquake activity and past significant earthquakes, an east-west trending potential area (10.7 - 10.9° N; 76.0 - 76.8° E) is delineated in the central Kerala region as the preparatory zone for the location of future earthquake. © 2005 Akadémiai Kiadó, Budapest.