Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 91 records · Page 5Linked to original sources

PubMed2004

Search for narrow tt resonances in pp collisions at square root of (s)=1.8 TeV.

A search for narrow resonances that decay into tt pairs has been performed using 130 pb(-1) of data in the lepton + jets channel collected by the Dphi detector in pp collisions at square root of (s)=1.8 TeV. There is no significant deviation observed from the standard-model predictions at a top-quark mass of 175 GeV/c2. We therefore present upper limits at the 95% confidence level on the product of the production cross section and branching fraction to tt for narrow resonances as a function of the resonance mass MX. These limits are used to exclude the existence of a leptophobic top-color particle with mass MX<560 GeV/c2, using a theoretical cross section for a width GammaX=0.012MX.

Journal Article↗

PubMed2004

Upper bound on the decay tau-->microgamma from the Belle detector.

We have performed a search for the lepton-flavor-violating decay tau-->microgamma using a data sample of 86.3 fb(-1) accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of B(tau-->microgamma)<3.1 x 10(-7) at the 90% confidence level.

Journal Article↗

PubMed2004

Measurement of /V(ub)/ using inclusive B-->X(u)lnu decays with a novel X(u)-reconstruction method.

We report the measurement of an inclusive partial branching fraction for charmless semileptonic B decay and the extraction of /V(ub)/. Candidates for B-->X(u)lnu are identified with a novel X(u) reconstruction method based on neutrino reconstruction via missing 4-momentum and a technique called "simulated annealing." Based on 86.9 fb(-1) of data taken with the Belle detector, we obtain DeltaB(B-->X(u)lnu;M(X)<1.7 GeV/c2,q2>8.0 GeV2/c2)=[7.37+/-0.89(stat)+/-1.12(syst)+/-0.55(b-->c)+/-0.24(b-->u)]x10(-4) and determine |V(ub)|=[4.66+/-0.28(stat)+/-0.35(syst)+/-0.17(b-->c)+/-0.08(b-->u)+/-0.58(theory)]x10(-3).

Journal Article↗

PubMed2004

Mucin binding mitogenic lectin from freshwater Indian gastropod Belamyia bengalensis: purification and molecular characterization.

A lectin was purified from the hemolymph of the freshwater Indian gastropod Belamyia bengalensis. The purification involved successive ion-exchange chromatography on Resource Q and gel filtration on Superose 12 column in FPLC system. Homogeneity of the protein was confirmed by polyacrylamide gel electrophoresis. Belamyia bengalensis lectin (BBL) was a monomeric protein with a molecular weight of 33 kDa as demonstrated by gel filtration and SDS-PAGE. It is a glycoprotein containing 6% total sugar and its activity is highly dependent on Ca(2+). BBL agglutinated human erythrocytes and is a blood group non-specific lectin. It agglutinated animal erythrocytes also. Hapten inhibition studies indicated that BBL shows binding specificity only for N-acetyl-D-glucosamine and N-acetyl-D-galactosamine at a high concentration among the mono- and oligosaccharides tested. Among the glycoproteins used for hemagglutination-inhibition assay, porcine submaxillary mucin was found to be the best inhibitor. Chemical modification studies indicated that Lys, Arg, and Trp are essential for the sugar-binding activity of BBL. Circular dichroism spectra revealed high content of alpha-helical structure in the lectin. BBL is a potent mitogen as it stimulated the T-lymphocyte proliferation, specifically the Th1 subset.

Amino Acids↗

PubMed2004

Expectant management of tubal ectopic pregnancy: prediction of successful outcome using decision tree analysis.

OBJECTIVE: To establish whether a decision tree based on a combination of clinical, morphological and biochemical parameters could be constructed to help in the selection of women with tubal ectopic pregnancies for expectant management. METHODS: This was a prospective observational study in a tertiary referral early pregnancy unit in an inner city teaching hospital. The study group consisted of 179 women with ultrasound diagnosis of ectopic pregnancy. Demographic, clinical and ultrasound data were recorded in each case at the initial visit. In addition all women had a blood sample taken for the measurements of serum beta-human chorionic gonadotropin (beta-hCG) and progesterone. Clinically stable women with non-viable pregnancies and no signs of hematoperitoneum were managed expectantly on an outpatient basis until their serum beta-hCG declined to <20 IU/L. Women who developed pelvic pain during follow-up and those with non-declining serum beta-hCG were offered surgery. RESULTS: A total of 107/179 (59.8%) tubal ectopics were considered suitable for expectant management. Ectopic pregnancy resolved spontaneously in 75/107 (70%) women, which was 41.9% of the total number of tubal ectopics. Maternal age, initial serum beta-hCG and progesterone were all significantly different in pregnancies that resolved spontaneously compared to those requiring surgery (P < 0.05). Initial serum beta-hCG level was the best predictor of the outcome of expectant management. These differences enabled a construction of a four-level decision tree to estimate the likelihood of successful expectant management. CONCLUSIONS: There are significant differences in demographic, ultrasound and biochemical findings between spontaneously resolving ectopics and those requiring treatment. Decision tree analysis may be used as a guide to estimate the probability of successful expectant management in individual cases.

Adult↗

PubMed2004

Late-onset fistula presenting as buttock abscess in two patients with ileo-anal J-pouches for ulcerative colitis.

Two cases are described of patients who presented with a buttock abscess 3 and 5 years after restorative proctocolectomy for ulcerative colitis. In both the abscess was secondary to a fistula, which was shown on further investigation to be a track traversing the greater sciatic notch. Both patients had had an ileo-anal J-pouch after a proctectomy which had included a mesorectal excision. The possibility that these unusual fistulae might be more common following removal of the mesorectum rather than a close rectal dissection is explored.

Abscess↗

PubMed2004

Mycobacterium tuberculosis isolate with a distinct genomic identity overexpresses a tap-like efflux pump.

BACKGROUND: One mechanism proposed for drug resistance in Mycobacterium tuberculosis (MTB) is by efflux of the drugs by membrane located pumps. We report a novel and definite association between drug resistance and transcription levels of a tap-like pump (Rv1258c) in a multi-drug resistant MTB patient isolate (ICC154) which possesses a unique genotypic signature. MATERIALS AND METHODS: The isolate ICC154 was tested for drug sensitivity. Over-expression of Rv1258c as a function of drug pressure was analyzed by RT-PCR and the strain was typed using fluorescent amplified fragment length polymorhism (FAFLP). RESULT: In the presence of rifampicin and ofloxacin, this isolate shows increased transcription of the gene Rv1258c. Genotypic fingerprinting revealed the presence of unique FAFLP markers. CONCLUSION: A clear association between drug resistance and overexpression of an efflux protein is evident from our studies. The presence of specific markers has implications in rapid identification of MDR clinical isolates and consequent disease management.

Anti-Bacterial Agents↗

PubMed2004

Corneal pachymetry in normal and keratoconic eyes: Orbscan II versus ultrasound.

PURPOSE: To compare corneal thickness measurements using Orbscan II (OII) and ultrasonic (US) pachymetry in normal and in keratoconic eyes. SETTING: Eye Department, Heartlands and Solihull NHS Trust, Birmingham, United Kingdom. METHODS: Central corneal thickness (CCT) was measured by means of OII and US pachymetry in 1 eye of 72 normal subjects and 36 keratoconus patients. The apical corneal thickness (ACT) in keratoconus patients was also evaluated using each method. The mean of the difference, standard deviation (SD), and 95% limits of agreement (LoA = mean +/- 2 SD), with and without applying the default linear correction factor (LCF), were determined for each sample. The Student t test was used to identify significant differences between methods, and the correlation between methods was determined using the Pearson bivariate correlation. Bland-Altman analysis was performed to confirm that the results of the 2 instruments were clinically comparable. RESULTS: In normal eyes, the mean difference (+/- 95% LoA) in CCT was 1.04 microm +/- 68.52 (SD) (P>.05; r = 0.71) when the LCF was used and 46.73 +/- 75.40 microm (P =.0001; r = 0.71) without the LCF. In keratoconus patients, the mean difference (+/- 95% LoA) in CCT between methods was 42.46 +/- 66.56 microm (P<.0001: r = 0.85) with the LCF, and 2.51 +/- 73.00 microm (P>.05: r = 0.85) without the LCF. The mean difference (+/- 95% LoA) in ACT for this group was 49.24 +/- 60.88 microm (P<.0001: r = 0.89) with the LCF and 12.71 +/- 68.14 microm (P =.0077; r = 0.89) when the LCF was not used. CONCLUSIONS: This study suggests that OII and US pachymetry provide similar readings for CCT in normal subjects when an LCF is used. In keratoconus patients, OII provides a valid clinical tool for the noninvasive assessment of CCT when the LCF is not applied.

Adult↗

PubMed2004

Chemopreventive potential of Azadirachta indica (Neem) leaf extract in murine carcinogenesis model systems.

Numerous laboratory studies reveal that various naturally occurring dietary substances can modify the patho-physiological process of various metabolic disorders and can be an effective preventive strategy for various diseases, including cancer. Indian Neem tree, Azadirachta indica A. Juss. (family: Meliaceae), contains at least 35 biologically active principles and is widely grown all over the tropics. The effect of two different doses (250 and 500 mg per kilogram body weight) of 80% ethanolic extract of the leaves of Azadirachta indica were examined on drug metabolizing Phase-I and Phase-II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase, and lipid peroxidation in the liver of 7-week-old Swiss albino mice. Also anticarcinogenic potential of Azadirachta indica leaf extract was studied adopting protocol of benzo(a)pyrene-induced fore-stomach and 7,12-dimethyl benz(a)anthracene (DMBA)-induced skin papillomagenesis. Our primary findings reveal its potential to induce only the Phase-II enzyme activity associated mainly with carcinogen detoxification in liver of mice. The hepatic glutathione S-transferase (P < 0.005) and DT-diaphorase specific activities (P < 0.01) were elevated above basal level. With reference to antioxidant enzymes the investigated doses were effective in increasing the hepatic glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) activities significantly (from P < 0.005 to P < 0.001). Reduced glutathione measured as non-protein sulphydryl was found to be significantly elevated in liver (P < 0.005) and in extrahepatic organs (from P < 0.005 to P < 0.001) examined in our study. Glutathione S-transferase (GST) and DT-diaphorase (DTD) showed a dose-dependent increase in extrahepatic organs. Chemopreventive response was measured by the average number of papillomas per mouse, as well as percentage of tumor-bearing animals. There was a significant inhibition of tumor burden, in both the tumor model system studied (from P < 0.005 to P < 0.001). Tumor incidence was also reduced by both the doses of Azadirachta indica extract.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2004

Elasticity and adhesion force mapping reveals real-time clustering of growth factor receptors and associated changes in local cellular rheological properties.

Cell surface macromolecules such as receptors and ion channels serve as the interface link between the cytoplasm and the extracellular region. Their density, distribution, and clustering are key spatial features influencing effective and proper physical and biochemical cellular responses to many regulatory signals. In this study, the effect of plasma-membrane receptor clustering on local cell mechanics was obtained from maps of interaction forces between antibody-conjugated atomic force microscope tips and a specific receptor, a vascular endothelial growth factor (VEGF) receptor. The technique allows simultaneous measurement of the real-time motion of specific macromolecules and their effect on local rheological properties like elasticity. The clustering was stimulated by online additions of VEGF, or antibody against VEGF receptors. VEGF receptors are found to concentrate toward the cell boundaries and cluster rapidly after the online additions commence. Elasticity of regions under the clusters is found to change remarkably, with order-of-magnitude stiffness reductions and fluidity increases. The local stiffness reductions are nearly proportional to receptor density and, being concentrated near the cell edges, provide a mechanism for cell growth and angiogenesis.

Animals↗

PubMed2004

Does cardiovascular therapy affect the onset and recurrence of preretinal and vitreous haemorrhage in diabetic eye disease?

AIMS: To review the role of cardiovascular disease and therapy in the onset and recurrence of preretinal/vitreous haemorrhage in diabetic patients. METHODS: Retrospective case note analysis of diabetic patients with vitreous haemorrhage from the Diabetic Eye Clinic at Birmingham Heartlands Hospital. RESULTS: In total, 54 patients (mean age 57.1, 37 males, 20 type I vs 34 type II diabetic patients) were included. The mean (SD) duration of diagnosed diabetes at first vitreous haemorrhage was significantly longer, 21.9 (7.6) years for type I and 14.8 (9.3) years for type II diabetic patients (P < 0.01, unpaired t-test, two-tailed).Aspirin administration was not associated with a significantly later onset of vitreous haemorrhage. Four episodes were associated with ACE-inhibitor cough. There was a trend towards HMGCoA reductase inhibitor (statin) use being associated with a delayed onset of vitreous haemorrhage: 21.4 years until vitreous haemorrhage (treatment group) vs 16.2 years (nontreatment group) (P = 0.09, two-tailed, unpaired t-test, not statistically significant). During follow-up 56 recurrences occurred, making a total of 110 episodes of vitreous haemorrhage in 79 eyes of 54 patients. The mean (range) follow-up post haemorrhage was 1067 (77-3842) days, with an average of 1.02 recurrences. Age, gender, diabetes type (I or II) or control, presence of hypertension or hypercholesterolaemia, and macrovascular complications were not associated with a significant effect on the 1-year recurrence rate. Aspirin (and other antiplatelet or anticoagulant agents) and ACE- inhibitors appeared to neither increase nor decrease the 1-year recurrence rate. However, statin use was significantly associated with a reduction in recurrence (Fisher exact P < 0.05; two-tailed) with an odds ratio (95% CI) of 0.25 (0.1-0.95). CONCLUSION: In this retrospective analysis, the onset of preretinal/vitreous haemorrhage was not found to be accelerated by gender, hypertension, hypercholesterolaemia, evidence of macrovascular disease, or HbA1c. Neither aspirin nor ACE-inhibitor administration accelerated the onset or recurrence of first vitreous haemorrhage. Statins may have a protective role, both delaying and reducing the recurrence of haemorrhage.

Adult↗

PubMed2004

Surgical treatment and outcome of patients with giant retinal tears.

OBJECTIVE: To report the management and outcome in retinal detachments associated with giant retinal tears (GRTs). METHODS: Retrospective, case note analysis of patients treated between November 1991 and June 2002 at a tertiary referral hospital. RESULTS: The case notes of 29 patients (24 males, 5 females) with a follow-up ranging from five months to 7 years were reviewed. In all, 25 eyes had retinal detachments with macular involvement and 10 patients had myopia more than 6 D. All patients underwent vitrectomy. A total of 23 patients had heavy liquid and 16 had scleral explants; 28 patients had silicone oil and one had C3F8 tamponade. Intraoperative complications included lens trauma and iatrogenic GRT. Six eyes had recurrent retinal detachment and needed multiple surgical procedures. At the last follow-up, 25 patients had anatomically attached retinas. In all, 18 fellow eyes were treated prophylactically. Three patients had total retinal detachment and marked PVR. The visual acuity improved in 20 eyes. CONCLUSION: GRTs are more common in patients with high myopia. With newer techniques of surgical treatment of GRTs, the anatomical and visual outcomes are more favourable.

Adolescent↗

PubMed2004

Clinical features and associated psychopathology in a Tourette syndrome cohort.

OBJECTIVE: This study explored in detail the association between tic symptomatology, related clinical variables, and psychopathology in 91 consecutive adult TS subjects from a UK clinic. METHODS: Consecutive patients from a specialized Tourette clinic who met the DSM-III criteria for TS were evaluated using standardized rating scales for Tourette syndrome and other psychopathology. RESULTS: The male female ratio in our cohort was 1.8:1. Significantly more males had an earlier age at onset of TS and history of birth complications. Obsessive compulsive behaviors in the patient was positively correlated with presence of attention deficit hyperactivity disorder and self-injurious behaviors. With regard to adult psychopathology, principal components factor analysis yielded two factors, 'obsessionality' and 'anxiety/depression', which accounted for 72% of the variance. CONCLUSION: Our results support the high occurrence of anxiety, depression and obsessionality in adult TS subjects.

Adolescent↗

PubMed2004

Electrical properties of Fe-Fe3O4-SiO2 gel nanocomposites.

Nanocomposites containing Fe3O4 and alpha-Fe, respectively, in a SiO2 gel were prepared by subjecting a suitably chosen gel with iron ions to a reduction treatment at 923 K, followed by wet oxidation at the same temperature for 1 hour. The particle sizes of the two phases were estimated to have values in the range of 18 to 25 nm. The dc conductivity of the composites was found to arise due to a variable range hopping mechanism with a density of states calculated as approximately 10(18) eV(-1) cc(-1). The nanoparticles of alpha-Fe are believed to contribute to the latter. The ac conductivity variation as a function of frequency and temperature could be explained because of an overlapping small polaron tunneling mechanism in the Fe3O4 nanoparticles. The density of states estimated in the latter case was approximately 10(18) eV(-1) cc(-1). From the dielectric modulus spectra of the nanocomposites, a Kohlrausch-Williams-Watts (KWW) exponent of approximately 0.30 was extracted. This indicated the presence of a wide distribution of relaxation times in the system.

Electric Conductivity↗

PubMed2004

Gravitational effects on structure development in quenched complex fluids.

When binary liquid mixtures are cooled rapidly from a homogeneous phase into a two-phase system, domains of the two equilibrium phases form and grow (coarsen) with time. In the absence of an external forcing due to gravity or an imposed shear flow, a dynamic scaling regime emerges in which the domain morphology is statistically self-similar at different times with a length-scale that grows with time. In the presence of gravity, however, multiple length scales develop, with the system coarsening more rapidly in the direction of the force. The late-time behavior of such a system is characterized in this study by the calculation of anisotropic growth laws. Gravitation effects significantly affect scaling laws, even with small density mismatch, and the growth mechanism has some similarities to the sedimentation process. However, very few numerical studies have been made of such effects; this is one of the first.

Diffusion↗

PubMed2004

Effect of tight glycaemic control on fetal complications in diabetic pregnancies.

AIMS: To find the incidence of fetal complications in Indian diabetic mothers with tight glycaemic control (TC), its comparison with other levels of glycaemic control, i.e., acceptable control (AC), uncontrolled (UC), and relevant international data. METHODS: A total of 240 mothers with diabetes mellitus (DM) and pregnancy were risk-matched and selected from the Antenatal Clinic of NRS Medical College, 176 of whom had gestational diabetes mellitus (GDM) and 64 had pregestational diabetes mellitus (PGDM), and were put on exercise, diet and or insulin therapy. Glycaemic parameters monitored include fasting plasma glucose (FPG), 2 hr. postprandial plasma glucose (PPPG) and HbA1C. TC had - FPG < 70 mg/dl, PPPG < 100 mg/dl, HBA1C < 6.5%; AC with FPG 70-95 mg/dl, 2 hr. PPPG 100-120, HBA1C 6.5-7.5% and UC had FPG > 95 mg/ dl, 2 hr. PPPG > 120 mg/dl and HBA1C > 7.5%. Fetal parameters monitored included large-for-date babies (LGA), small-for-date babies (SFD), birth asphyxia, perinatal death, neonatal hypoglycemia, neonatal hypocalcaemia and congenital anomalies. RESULTS: (i) LGA-AC had the best results (0% vs. 12.5 and 22.29%); (ii) SFD-TC and AC had worst results (16.7% and 18.18% vs. 0%); (iii) Birth asphyxia-AC fared worse 18.18% vs. 4.16% and 0%; (iv) perinatal death and congenital anomalies showed significant reduction with tight control (4.16% and 0% respectively); (v) Neonatal hypoglycemia is lowered in TC compared with UC while neonatal hypocalcaemia does not show any alteration. For PGDM patients there is little intra-group variability of the parameters. The UC subgroups of GDM fared better than PGDM as far as all complications and congenital anomalies were concerned. Compared with international data, there is a dichotomy of the results of GDM and PGDM. CONCLUSION: For GDM patients all parameters may not be uniformly affected by the same degree of glycaemic control. A tight control may not be theonly factor to decide on the outcomes for PGDM patients.

Adolescent↗

PubMed2003

Measurement of time-dependent CP-violating asymmetries in B0-->phiK(0)S, K+K-K0(S), and eta'K0(S) decays.

We present an improved measurement of CP-violation parameters in B0-->phiK(0)(S), K(+)K(-)K(0)(S), and eta(')K(0)(S) decays based on a 140 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B-->phiK(0)(S) decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.

Journal Article↗

PubMed2003

Evidence for B0-->pi0pi0.

We report evidence for the decay B0-->pi(0)pi(0). The analysis is based on a data sample of 152x10(6) BBmacr; pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. We detect a signal for B0-->pi(0)pi(0) with a significance of 3.4 standard deviations, and measure the branching fraction to be [1.7+/-0.6(stat)+/-0.2(syst)]x10(-6).

Journal Article↗