486 research outputs found

    Oxidative stress in patients with laryngeal carcinoma

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    Background : Cancer is a multifactorial disease. Repetitive cumulative damage of cellular organelles by oxy-free radicals are few of the important causative factors. Aim : To assess the role of oxidative stress in the laryngeal cancer patients in Indian population. Setting and Design : Case control study. Materials and Methods : Level of malondialdehyde (MDA) as a marker of oxidative stress was examined in large cohort of control (50) and laryngeal carcinoma patients (155) from North India. Both the controls and laryngeal carcinoma patients were smokers. Results : In control healthy subjects MDA levels were 0.102±0.07 (0.080- 0.303, 95% CI) n mol/ml, as compared to 0.329±0.16 (0.124-0.354, 95% CI) n mol/ml in the cases of laryngeal carcinoma patients. Three times higher serum MDA levels indicated that there was significant oxidative stress in the subjects having laryngeal carcinoma lesions. In addition patients with secondaries were having MDA levels of 0.4±0.02 (0.391-0.408 95% CI) n mol/ml, as compared to 0.57±0.03 (0.558-0.582 95% CI)n mol/ml in group of patients without secondaries. These two values were statistically significant as compared to control values (P< 0.01). Conclusion : These findings suggest that in case of laryngeal carcinoma patients, there is increase in the level of oxidative enzyme MDA. The oxidative stress might be due to the modulation of pro-oxidant or anti-oxidant systems in laryngeal carcinoma

    Oxidative stress in patients with laryngeal carcinoma

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    Background : Cancer is a multifactorial disease. Repetitive cumulative damage of cellular organelles by oxy-free radicals are few of the important causative factors. Aim : To assess the role of oxidative stress in the laryngeal cancer patients in Indian population. Setting and Design : Case control study. Materials and Methods : Level of malondialdehyde (MDA) as a marker of oxidative stress was examined in large cohort of control (50) and laryngeal carcinoma patients (155) from North India. Both the controls and laryngeal carcinoma patients were smokers. Results : In control healthy subjects MDA levels were 0.102\ub10.07 (0.080- 0.303, 95% CI) n mol/ml, as compared to 0.329\ub10.16 (0.124-0.354, 95% CI) n mol/ml in the cases of laryngeal carcinoma patients. Three times higher serum MDA levels indicated that there was significant oxidative stress in the subjects having laryngeal carcinoma lesions. In addition patients with secondaries were having MDA levels of 0.4\ub10.02 (0.391-0.408 95% CI) n mol/ml, as compared to 0.57\ub10.03 (0.558-0.582 95% CI)n mol/ml in group of patients without secondaries. These two values were statistically significant as compared to control values (P&lt; 0.01). Conclusion : These findings suggest that in case of laryngeal carcinoma patients, there is increase in the level of oxidative enzyme MDA. The oxidative stress might be due to the modulation of pro-oxidant or anti-oxidant systems in laryngeal carcinoma

    Mesenteric gastrointestinal stromal tumour presenting as intracranial space occupying lesion

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    BACKGROUND: Gastrointestinal stromal tumours (GIST) usually present with non-specific gastrointestinal symptoms such as abdominal mass, pain, anorexia and bowel obstruction. METHODS: We report a case of a 42 year old male who presented with a solitary intracranial space occupying lesion which was established as a metastasis from a mesenteric tumour. RESULTS: The patient was initially treated as a metastatic sarcoma, but a lack of response to chemotherapy prompted testing for CD117 which returned positive. A diagnosis of mesenteric GIST presenting as solitary brain metastasis was made, and the patient was treated with imatinib. CONCLUSION: We recommend that all sarcomas with either an intraabdominal or unknown origin be routinely tested for CD117 to rule out GIST

    Congenital diaphragmatic hernia and retinoids: searching for an etiology

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    Congenital diaphragmatic hernia (CDH) is a major life-threatening cause of respiratory failure in the newborn. Recent data reveal the role of a retinoid-signaling pathway disruption in the pathogenesis of CDH. We describe the epidemiology and pathophysiology of human CDH, the metabolism of retinoids and the implications of retinoids in the development of the diaphragm and lung. Finally, we describe the existing evidence of a disruption of the retinoid-signaling pathway in CDH

    Intravenous pharmacokinetics, oral bioavailability, dose proportionality and in situ permeability of anti-malarial lumefantrine in rats

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    <p>Abstract</p> <p>Background</p> <p>Despite the wide spread use of lumefantrine, there is no study reporting the detailed preclinical pharmacokinetics of lumefantrine. For the development of newer anti-malarial combination(s) and selection of better partner drugs, it is long felt need to understand the detailed preclinical pharmacokinetics of lumefantrine in preclinical experimental animal species. The focus of present study is to report bioavailability, pharmacokinetics, dose linearity and permeability of lumefantrine in rats.</p> <p>Methods</p> <p>A single dose of 10, 20 or 40 mg/kg of lumefantrine was given orally to male rats (N = 5 per dose level) to evaluate dose proportionality. In another study, a single intravenous bolus dose of lumefantrine was given to rats (N = 4) at 0.5 mg/kg dose following administration through the lateral tail vein in order to obtain the absolute oral bioavailability and clearance parameters. Blood samples were drawn at predetermined intervals and the concentration of lumefantrine and its metabolite desbutyl-lumefantrine in plasma were determined by partially validated LC-MS/MS method. <it>In-situ </it>permeability study was carried in anaesthetized rats. The concentration of lumefantrine in permeability samples was determined using RP-HPLC.</p> <p>Results</p> <p>For nominal doses increasing in a 1:2:4 proportion, the C<sub>max </sub>and AUC<sub>0-∞ </sub>values increased in the proportions of 1:0.6:1.5 and 1:0.8:1.8, respectively. For lumefantrine nominal doses increasing in a 1:2:4 proportion, the C<sub>max </sub>and the AUC<sub>0-t </sub>values for desbutyl-lumefantrine increased in the proportions of 1:1.45:2.57 and 1:1.08:1.87, respectively. After intravenous administration the clearance (Cl) and volume of distribution (Vd) of lumefantrine in rats were 0.03 (± 0.02) L/h/kg and 2.40 (± 0.67) L/kg, respectively. Absolute oral bioavailability of lumefantrine across the tested doses ranged between 4.97% and 11.98%. Lumefantrine showed high permeability (4.37 × 10<sup>-5 </sup>cm/s) in permeability study.</p> <p>Conclusions</p> <p>The pharmacokinetic parameters of lumefantrine and its metabolite desbutyl-lumefantrine were successfully determined in rats for the first time. Lumefantrine displayed similar pharmacokinetics in the rat as in humans, with multiphasic disposition, low clearance, and a large volume of distribution resulting in a long terminal elimination half-life. The absolute oral bioavailability of lumefantrine was found to be dose dependent. Lumefantrine displayed high permeability in the <it>in-situ </it>permeability study.</p

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Lipid Raft-Dependent FcεRI Ubiquitination Regulates Receptor Endocytosis through the Action of Ubiquitin Binding Adaptors

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    The best characterized role for ubiquitination of membrane receptors is to negatively regulate signaling by targeting receptors for lysosomal degradation. The high affinity receptor for IgE (FcepsilonRI) expressed on mast cells and basophils is rapidly ubiquitinated upon antigen stimulation. However, the nature and the role of this covalent modification are still largelly unknown. Here, we show that FcepsilonRI subunits are preferentially ubiquitinated at multiple sites upon stimulation, and provide evidence for a role of ubiquitin as an internalization signal: under conditions of impaired receptor ubiquitination a decrease of receptor entry is observed by FACS analysis and fluorescence microscopy. We also used biochemical approaches combined with fluorescence microscopy, to demonstrate that receptor endocytosis requires the integrity of specific membrane domains, namely lipid rafts. Additionally, by RNA interference we demonstrate the involvement of ubiquitin-binding endocytic adaptors in FcepsilonRI internalization and sorting. Notably, the triple depletion of Eps15, Eps15R and Epsin1 negatively affects the early steps of Ag-induced receptor endocytosis, whereas Hrs depletion retains ubiquitinated receptors into early endosomes and partially prevents their sorting into lysosomes for degradation. Our results are compatible with a scenario in which the accumulation of engaged receptor subunits into lipid rafts is required for receptor ubiquitination, a prerequisite for efficient receptor internalization, sorting and delivery to a lysosomal compartment

    Interaction of the Transcription Start Site Core Region and Transcription Factor YY1 Determine Ascorbate Transporter SVCT2 Exon 1a Promoter Activity

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    Transcription of the ascorbate transporter, SVCT2, is driven by two distinct promoters in exon 1 of the transporter sequence. The exon 1a promoter lacks a classical transcription start site and little is known about regulation of promoter activity in the transcription start site core (TSSC) region. Here we present evidence that the TSSC binds the multifunctional initiator-binding protein YY1. Electrophoresis shift assays using YY1 antibody showed that YY1 is present as one of two major complexes that specifically bind to the TSSC. The other complex contains the transcription factor NF-Y. Mutations in the TSSC that decreased YY1 binding also impaired the exon 1a promoter activity despite the presence of an upstream activating NF-Y/USF complex, suggesting that YY1 is involved in the regulation of the exon 1a transcription. Furthermore, YY1 interaction with NF-Y and/or USF synergistically enhanced the exon 1a promoter activity in transient transfections and co-activator p300 enhanced their synergistic activation. We propose that the TSSC plays a vital role in the exon 1a transcription and that this function is partially carried out by the transcription factor YY1. Moreover, co-activator p300 might be able to synergistically enhance the TSSC function via a “bridge” mechanism with upstream sequences

    Poly(Glycerol Adipate-co-ω-Pentadecalactone) Spray-Dried Microparticles as Sustained Release Carriers for Pulmonary Delivery

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    Purpose The aim of this work was to optimize biodegradable polyester poly(glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL, microparticles as sustained release (SR) carriers for pulmonary drug delivery. Methods Microparticles were produced by spray drying directly from double emulsion with and without dispersibility enhancers ( L -arginine and L -leucine) (0.5–1.5%w/w) using sodium fluorescein (SF) as a model hydrophilic drug. Results Spray-dried microparticles without dispersibility enhancers exhibited aggregated powders leading to low fine particle fraction (%FPF) (28.79 ± 3.24), fine particle dose (FPD) (14.42 ± 1.57 μg), with a mass median aerodynamic diameter (MMAD) 2.86 ± 0.24 μm. However, L -leucine was significantly superior in enhancing the aerosolization performance ( L- arginine:%FPF 27.61 ± 4.49–26.57 ± 1.85; FPD 12.40 ± 0.99–19.54 ± 0.16 μg and MMAD 2.18 ± 0.35–2.98 ± 0.25 μm, L -leucine:%FPF 36.90 ± 3.6–43.38 ± 5.6; FPD 18.66 ± 2.90–21.58 ± 2.46 μg and MMAD 2.55 ± 0.03–3.68 ± 0.12 μm). Incorporating L -leucine (1.5%w/w) reduced the burst release (24.04 ± 3.87%) of SF compared to unmodified formulations (41.87 ± 2.46%), with both undergoing a square root of time (Higuchi’s pattern) dependent release. Comparing the toxicity profiles of PGA-co-PDL with L -leucine (1.5%w/w) (5 mg/ml) and poly(lactide-co-glycolide), (5 mg/ml) spray-dried microparticles in human bronchial epithelial 16HBE14o- cell lines, resulted in cell viability of 85.57 ± 5.44 and 60.66 ± 6.75%, respectively, after 72 h treatment. Conclusion The above data suggest that PGA-co-PDL may be a useful polymer for preparing SR microparticle carriers, together with dispersibility enhancers, for pulmonary delivery
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