22 research outputs found

    Who shares and who doesn't? Results of the UK Sharing Economy Consumer Survey 2017

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    The survey, which was conducted in July 2017, captures 1220 responses, and is based on a representative sample of UK population based on gender, income level, education level, and place of residence in the UK. It was structured to ask questions about informants’ current usage of, opinions about, and future intentions to use the following sharing categories: places to stay (e.g. Airbnb, Beds on Board), rides (e.g. Uber, Liftshare), rental cars (e.g. Easycar, Zipcar), parking (e.g. JustPark, Your Parking Space), services (e.g. Parcelly, TaskRabbit), meals (e.g. MealSharing, Eatwith), pre-owned goods (e.g. eBay, Gumtree) and funding (e.g. Justgiving, Crowdcube)

    Evaluation of existing limited sampling models for busulfan kinetics in children with beta thalassaemia major undergoing bone marrow transplantation

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    Busulfan pharmacokinetic parameters are useful in predicting the outcome of allogeneic bone marrow transplantation (BMT). Standard pharmacokinetic measurements require multiple blood samples. Various limited sampling models (LSM) have been proposed for reducing the sample number required for these measurements, essentially for patients with malignant disorders undergoing BMT. This study was undertaken to evaluate the existing LSM for busulfan pharmacokinetics to find out the most suitable method for patients with thalassaemia major undergoing BMT. Busulfan levels in plasma samples were analysed by HPLC. The AUC calculated by non-compartmental analysis using the program 'TOPFIT' was compared with previously published LSMs. Our seven sample pharmacokinetic data for AUC calculation was compared with the published LSMs. The three sample models suggested by Chattergoon et al and Schuler et al showed significant agreement with AUC TOPFIT (R2 = 0.98 and 0.94, respectively) in our clinical context. Other models resulted in significant over or under representation of observed values (Vassal's model R2 = 0.61; Chattergoon's two sample model R2 = 0.84; four sample model R2 = 0.83; Schuler's two sample model R2 = 0.79). By these data the three sample LSM proposed by Chattergoon et al and Schuler et al are suitable for calculation of the AUC in patients with thalassaemia major undergoing BMT conditioned with oral busulfan

    Glutathione S-transferase activity influences busulfan pharmacokinetics in patients with beta thalassemia major undergoing bone marrow transplantation

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    Busulfan, at a dose of 16 mg/kg, is widely used in combination with cyclophosphamide as a conditioning regimen for patients undergoing bone marrow transplantation. Wide interindividual variation in busulfan kinetics and rapid clearance of the drug have been reported, especially in children. Some of the factors contributing to interpatient variability have been identified. They include circadian rhythms, age, disease, drug interaction, changes in hepatic function, and busulfan bioavailability. In this study, we demonstrate that hepatic glutathione S-transferase (GST) activity correlates negatively with busulfan maximum and minimum concentrations (Pearson's correlation r = -0.74 and -0.77, respectively) and positively with busulfan clearance (Pearson's correlation r = 0.728) in children with thalassemia major in the age range of 2 to 15 years. We also found that plasma alpha GST levels were 5 to 10 times higher in patients with thalassemia than in normal controls and age-matched leukemic patients, either reflecting extensive liver damage, elevated expression of the enzyme, or both in thalassemic patients. Plasma alpha GST concentrations showed a similar correlation with busulfan kinetic parameters to that observed for hepatic GST. The status of hepatic GST activity accounts, at least in part, for the observed interindividual variation in busulfan kinetics, while the observed association with plasma alpha GST is difficult to explain at present

    Glutathione S-transferase M1 polymorphism: a risk factor for hepatic venoocclusive disease in bone marrow transplantation

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    Hepatic venoocclusive disease (HVOD) in bone marrow transplantation (BMT) is attributed to toxicity of cytoreductive agents, especially busulfan and cyclophosphamide, in the conditioning therapy. Busulfan, as well as the metabolites of cyclophosphamide, are conjugated with glutathione (GSH), catalyzed by enzymes of the glutathione S-transferase (GST) family. To assess the impact of polymorphisms of the GST genes, GSTM1 and GSTT1, on the risk of HVOD, we evaluated 114 consecutive patients with -thalassemia major undergoing BMT. There was a significantly increased incidence of HVOD in patients with the GSTM1-null genotype compared with those with the GSTM1-positive genotype (46.5% vs 18.3%; P = .001). Pharmacokinetic analysis in these patients showed that the clearance of busulfan was higher and first-dose steady-state concentration was lower among those with HVOD (0.403 ± 0.06 vs 0.33 ± 0.071 L/h/kg, Student t test P value = .000 01; and 508 ± 125 vs 656 ± 255 ng/mL, t test P value = .001, respectively). We conclude that the GSTM1-null genotype predisposes to HVOD, and the sinusoidal endothelial cells and hepatocyte damage may be mediated by metabolites of busulfan through depletion of the cellular GSH pool

    Randomized trial of two different conditioning regimens for bone marrow transplantation in thalassemia - the role of busulfan pharmacokinetics in determining outcome

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    In total, 94 patients with homozygous beta thalassemia were randomized to two different conditioning regimens: busulfan 600 mg/m2+cyclophosphamide 200 mg/kg or busulfan 16 mg/kg+cyclophosphamide 200 mg/kg and antilymphocyte globulin (47 in each group), for bone marrow transplantation, to see whether increased myeloablation or increased immunosuppression would reduce rejection. Busulfan pharmacokinetics in determining outcome was evaluated. There was no significant difference in engraftment, graft-versus-host disease, rejection, and overall and disease-free survival in the two groups. Systemic exposure to busulfan was significantly higher in the 600 mg/m2 group, but in both groups there was a wide interindividual variation in the busulfan kinetics. Six patients rejected the graft, two in the busulfan 600 mg group and four in busulfan 16 mg group (P=0.677 CI -0.17, 0.07), but in five patients (pharmacokinetic data not available in one patient) who rejected the graft busulfan first dose trough level (Cmin-1) was below 150 ng/ml while it was above this level in the 66 of 68 patients with successful engraftment (P0.001). This randomized trial shows that rejection is influenced by busulfan levels and suggests that monitoring of busulfan levels and dose adjustment based on first-dose kinetics may reduce the risk of rejection

    Pharmacokinetics of oral busulphan in children with beta thalassaemia major undergoing allogeneic bone marrow transplantation

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    The pharmacokinetics of busulphan were studied in 23 thalassaemic children undergoing BMT. Patients received busulphan at a dose of either 16 mg/kg with cyclophosphamide and ATG (Group A) or 600 mg/m2 (with cyclophosphamide alone) (Group B) in 16 divided doses every 6 h over 4 days. Busulphan levels were analyzed by a modified GC-MS method. The dose of busulphan/kg for patients in group B was 64% (range 56-71%) higher than that for patients in group A. The mean AUC, Css, Cmax and MRV were significantly higher in group B as compared with group A for both doses 1 and 13. There was no significant difference in Vd/F, T1/2 and Kel between the two groups. A significant decrease in AUC and Css was found between 1st and 13th doses in group B, but not in group A. The Cl/F values in group A were significantly higher than those in group B after dose 1, but not after dose 13. No increase in toxicity due to the higher dose of busulphan was noted. We conclude that busulphan at 600 mg/m2 results in much higher systemic exposure to the drug as compared to 16 mg/kg, without increase in toxicity in children with beta thalassaemia major

    Can we avoid filter bubbles or only burst them? a natural experiment investigating filter bubbles in non-personalised content feeds

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    While the amount of information available has exponentially increased, our cognitive abilities to process information have not improved. Hence, social media platforms employ algorithmic filtering to keep information load at manageable levels. Algorithmic filtering leads to algorithmic distortion, creating phenomena such as filter bubbles and echo chambers, resulting in information blindness. This paper investigates whether filter bubbles exist even before personalisation due to users’ actions to combat information overload. Through a natural experiment and a quantitative study on clickstream data from an information curation app, we investigate the presence of filter bubbles in a non-personalised content feed. We have built five multiple regression models using a within-person approach to answer our hypotheses. We find that the position of content shown has a statistically significant effect on consumption, thereby creating a filter bubble effect. We develop further nuances of such filter bubbles in polarised topics and by end-user interests

    Coexistence of a novel &#946;-globin gene deletion (codons 81-87) with the codon 30 (g&#8594;c) mutation in an indian patient with &#946;<SUP>0</SUP>-thalassemia

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    We identified and characterized a novel &#946;0-thalassemia mutation due to the deletion of 22 bases from codons 81 through 87, found in a compound heterozygous state with codon 30 (G&#8594;C) in a patient originating from West Bengal State, India. The deletion causes a shift in the reading frame of the coding sequence and creates a stop codon at position 81. Direct and inverted repeat sequences present in the deleted region might be involved in the origin of this mutation. The patient had moderate anemia and did not require blood transfusions (thalassemia intermedia)

    Association of methylenetetrahydrofolate reductase gene polymorphisms & colorectal cancer in India

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    Background & objectives: Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, 677C -> T and 1298 A -> C have shown to impact several diseases including cancer. This case-control study was undertaken to analyse the association of the MTHFR gene polymorphisms 677 C -> T and 1298 A -> C and risk of colorectal cancer (CRC).Methods: One hundred patients with a confirmed histopathologic diagnosis of CRC and 86 age and gender matched controls with no history of cancer were taken for this study. DNA was isolated from peripheral blood samples and the genotypes were determined by PCR-RFLP. The risk association was estimated by compounding odds ratio (OR) with 95 per cent confidence interval (CI). Results: Genotype frequency of MTHFR 677 CC, CT and TT were 76.7, 22.1 and 1.16 per cent in controls, and 74,25 and 1.0 per cent among patients. The 'T' allele frequency was 12.21 and 13.5 per cent in controls and patients respectively. The genotype frequency of MTHFR 1298 AA, AC, and CC were 25.6, 58.1 and 16.3 per cent for controls and 22, 70 and 8 per cent for patents respectively. The 'C' allele frequency for 1298 A -> C was 43.0 and 45.3 per cent respectively for controls and patients. The OR for 677 CT was 1.18 (95% CI 0.59-2.32, P = 0.642), OR for 1298 AC was 1.68 (95% CI 0.92-3.08, P = 0.092) and OR for 1298 CC was 0.45(95% CI 0.18-1.12, P = 0.081). The OR for the combined heterozygous state (677 CT and 1298 AC) was 1.18(95% CI 0.52-2.64, P =0.697).Interpretation & conclusion: The frequency of the MTHFR 677 TT genotype is rare as compared to 1298 CC genotype in the population studied. There was no association between 677 C -> T and 1298 A -> C polymorphisms and risk of CRC either individually or in combination. The homozygous state for 1298 A -> C polymorphism appears to slightly lower risk of CRC. This needs to be confirmed with a larger sample size

    A novel &#946;-thalassemia mutation in an asian Indian

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    A novel 7 bp deletion in exon 2 of the &#946;-globin gene in a 9-year-old boy originating from the eastern part of India is described. This deletion causes a shift in the reading frame of the &#946;-globin coding sequences, and consequently, a premature translation termination due to the creation of a stop codon at position 86. A slipped strand mispairing during DNA replication repair is proposed as the potential mechanism in generating this small deletion
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