954 resultados para Cant
Resumo:
AIMS
To examine the allelic variation of three enzymes involved in 6-mercaptopurine/azathioprine (6-MP/AZA) metabolism and evaluate the in?uence of these polymorphisms on toxicity, haematological parameters and metabolite levels in patients with acute lymphoblastic leukaemia (ALL) or in?ammatory bowel disease (IBD).
METHODS
Clinical data and blood samples were collected from 19 ALL paediatric patients and 35 IBD patients who were receiving 6-MP/AZA therapy. All patients were screened for seven genetic polymorphisms in three enzymes involved in mercaptopurine metabolism [xanthine oxidase, inosine triphosphatase (C94?A and IVS2+21A?C) and thiopurine methyltransferase]. Erythrocyte and plasma metabolite concentrations were also determined. The associations between the various genotypes and myelotoxicity, haematological parameters and metabolite concentrations were determined.
RESULTS
Thiopurine methyltransferase variant alleles were associated with a preferential metabolism away from 6-methylmercaptopurine nucleotides (P = 0.008 in ALL patients,P = 0.038 in IBD patients) favouring 6-thioguanine nucleotides (6-TGNs) (P = 0.021 in ALL patients). Interestingly, carriers of inosine triphosphatase IVS2+21A?C variants among ALL and IBD patients had signi?cantly higher concentrations of the active cytotoxic metabolites, 6-TGNs (P = 0.008 in ALL patients,P = 0.047 in IBD patients). The study con?rmed the association of thiopurine methyltransferase heterozygosity with leucopenia and neutropenia in ALL patients and reported a signi?cant association between inosine triphosphatase IVS2+21A?C variants with thrombocytopenia (P = 0.012).
CONCLUSIONS
Pharmacogenetic polymorphisms in the 6-MP pathway may help identify patients at risk for associated toxicities and may serve as a guide for dose
individualization.
Resumo:
Background There is considerable interest in developing coitally indepen- dent, sustained release formulations for long-term administration of HIV microbicides. Vaginal ring devices are at the forefront of this formulation strategy. Methods Non-medicated silicone elastomer vaginal rings were prepared having a range of appropriate dimensions for testing vaginal ?t in pig- tailed and Chinese rhesus macaques. Cervicovaginal proin?ammatory markers were evaluated. Compression testing was performed to compare the relative ?exibility of various macaque and commercial human rings. Results All rings remained in place during the study period and no tissue irritation or signi?cant induction of cervicovaginal proin?ammatory mark- ers or signs of physical discomfort were observed during the 8-week study period. Conclusions Qualitative evaluation suggests that the 25 · 5-mm ring pro- vided optimal ?t in both macaque species. Based on the results presented here, low-consistency silicone elastomers do not cause irritation in maca-
Resumo:
Polymer nanocomposites offer the potential of enhanced properties such as increased modulus and barrier properties to the end user. Much work has been carried out on the effects of extrusion conditions on melt processed nanocomposites but very little research has been conducted on the use of polymer nanocomposites in semi-solid forming processes such as thermoforming and injection blow molding. These processes are used to make much of today’s packaging, and any improvements in performance such as possible lightweighting due to increased modulus would bring signi?cant bene?ts both economically and environmentally. The work described here looks at the biaxial deformation of polypropylene–clay nanocomposites under industrial forming conditions in order to determine if the presence of clay affects processability, structure and mechanical properties of the stretched material. Melt compounded polypropylene/clay composites in sheet form were biaxially stretched at a variety of processing conditions to examine the effect of high temperature, high strain and high strain rate processing on sheet structure
and properties.
A biaxial test rig was used to carry out the testing which imposed conditions on the sheet that are representative of those applied in injection blow molding and thermoforming. Results show that the presence of clay increases the yield stress relative to the un?lled material at typical processing temperatures and that the sensitivity of the yield stress to temperature is greater for the ?lled material. The stretching process is found to have a signi?cant effect on the delamination and alignment of clay particles (as observed by TEM) and on yield stress and elongation at break of the stretched sheet.
Resumo:
AIMS
The aim of this study was to investigate the in?uence of genetic polymorphisms in ABCB1 on the incidence of nephrotoxicity and tacrolimus dosage-requirements in paediatric patients following liver transplantation.
METHODS
Fifty-one paediatric liver transplant recipients receiving tacrolimus were genotyped for ABCB1 C1236>T, G2677>T and C3435>T polymorphisms. Dose-adjusted tacrolimus trough concentrations and estimated glomerular ?ltration rates (EGFR) indicative of renal toxicity were determined and correlated with the corresponding genotypes.
RESULTS
The present study revealed a higher incidence of the ABCB1 variant-alleles examined among patients with renal dysfunction (30% reduction in EGFR) at 6 months post-transplantation (1236T allele: 63.3% vs 37.5% in controls,P = 0.019; 2677T allele: 63.3% vs. 35.9%, p = 0.012; 3435T allele: 60% vs. 39.1%,P = 0.057). Carriers of the G2677->T variant allele also had a signi?cant reduction (%) in EGFR at 12 months post-transplant (mean difference = 22.6%; P = 0.031). Haplotype analysis showed a signi?cant association between T-T-T haplotypes and an increased incidence of nephrotoxicity at 6 months post-transplantation (haplotype-frequency = 52.9% in nephrotoxic patients vs 29.4% in controls; P = 0.029). Furthermore, G2677->T and C3435->T polymorphisms and T-T-T haplotypes were signi?cantly correlated with higher tacrolimus dose-adjusted pre-dose concentrations at various time points examined long after drug initiation.
CONCLUSIONS
These ?ndings suggest that ABCB1 polymorphisms in the native intestine signi?cantly in?uence tacrolimus dosage-requirement in the stable phase after transplantation. In addition, ABCB1 polymorphisms in paediatric liver transplant recipients may predispose them to nephrotoxicity over the ?rst year posttransplantation. Genotyping future transplant recipients for ABCB1 polymorphisms, therefore, could have the potential to individualize better tacrolimus immunosuppressive therapy and enhance drug safety
Resumo:
En este artículo se focaliza el recurso de la alegoría como método exegético en la composición de los sermones panegíricos de Juan Espinosa Medrano (Perú, siglo XVII). Se traza el recorrido de la alegoría (y las humanidades en general) en relación –siempre tensa– con el cristianismo a lo largo de su historia; y se llega a la Contrarreforma y el uso exacerbado del método en la predicación barroca; particularmente en la oratoria sagrada de Espinosa Medrano, quien abarca elementos diversos y extraídos de distintas fuentes (filosofía natural, mitología clásica, tradición emblemática, relatos bíblicos), a los que hace funcionar como signos de otra verdad mayor, la sagrada. Si bien las preceptivas sagradas impulsaban una predicación más llana y simple, la profusión de alegorías mitológicas, que el autor resemantiza según su interés de guiar la interpretación, pueden explicarse por varias circunstancias, motivos de estudio en este trabajo.
Resumo:
Objectives: Treatment of epithelial ovarian cancer (EOC) remains a challenge, despite advances in surgery and chemotherapy. Hereditary ovarian cancer is primarily due to germline mutations in the BRCA1 tumour suppressor gene. In addition, sporadic EOC tumours display signi?cant of loss of BRCA1 function due to epigenetic inactivation of the BRCA1 gene. This article reviews the preclinical and clinical evidence to support a role for BRCA1 as a potential predictive biomarker of response to both platinum and taxane based chemotherapy in EOC.
Methods: We conducted a Medline and Pubmed search for reports between 1990 and 2008 using the search terms: BRCA1 and hereditary ovarian cancer, BRCA1 and sporadic ovarian cancer, ovarian cancer and chemotherapy, ovarian cancer and taxanes, ovarian cancer and platinums, ovarian cancer and clinical response, BRCA1 and DNA damage, BRCA1 and DNA repair, BRCA1 and mitotic checkpoint. If reports identi?ed by these criteria referred to other papers not in the initial search, then these were also reviewed if relevant to BRCA1 and ovarian cancer.
Results: The BRCA1 pathway plays a signi?cant role in the development of both hereditary and sporadic EOC. Evidence suggests that BRCA1 is a potential biomarker of response to platinum chemotherapy in EOC with BRCA1 de?ciency predicting for enhanced response. In contrast, initial evidence suggests that loss of BRCA1 function results in reduced response to antimicrotubule-based chemotherapy. The ability of BRCA1 to differentially modulate response to these agents involves loss of BRCA1 mediated DNA repair and mitotic checkpoint control, respectively.
Conclusions: Standard ?rst line treatment of EOC consists of a combination of platinum and taxane chemotherapy, however clinically useful biomarkers for predicting response to these agents have yet to be established. BRCA1 may prove useful as a biomarker in EOC for assigning chemotherapy treatments based on the presence or absence of BRCA1 function.
Resumo:
Objectives: Cilostazol improves walking distance in peripheral arterial disease (PAD) patients. The study objectives were to assess the effects of cilostazol on walking distance, followed by the additional assessment of cilostazol on exercise-induced ischaemiaereperfusion injury in such patients.
Methods: PAD patients were prospectively recruited to a double-blinded, placebo-controlled trial. Patients were randomised to receive either cilostazol 100 mg or placebo twice a day. The primary end-point was an improvement in walking distance. Secondary end-points included the assessment of oxygen-derived free-radical generation, antioxidant consumption and other markers of the in?ammatory cascade. Initial and absolute claudication distances (ICDs and ACDs, respectively) were measured on a treadmill. In?ammatory response was assessed before and 30 min post-exercise by measuring lipid hydroperoxide, ascorbate, atocopherol, b-carotene, P-selectin, intracellular and vascular cell-adhesion molecules (I-CAM and V-CAM), thromboxane B2 (TXB2), interleukin-6, interleukin-10, high-sensitive C-reactive protein (hsCRP), albuminecreatinine ratio (ACR) and urinary levels of p75TNF receptor. All tests were performed at baseline and 6 and 24 weeks.
Results: One hundred and six PAD patients (of whom 73 were males) were recruited and successfully randomised from December 2004 to January 2006. Patients who received cilostazol demonstrated a more signi?cant improvement in the mean percentage change from baseline in ACD (77.2% vs. 26.6% at 6 weeks, pZ0.026 and 161.7% vs. 79.0% at 24 weeks, pZ0.048) as compared to the placebo. Cilostazol reduced lipid hydroperoxide levels compared to a placebo-related increase before and after exercise (6 weeks: pre-exercise: 11.8% vs.
Resumo:
Background & aims: Little is known about energy requirements in brain injured (TBI) patients, despite evidence suggesting adequate nutritional support can improve clinical outcomes. The study aim was to compare predicted energy requirements with measured resting energy expenditure (REE) values, in patients recovering from TBI.
Methods: Indirect calorimetry (IC) was used to measure REE in 45 patients with TBI. Predicted energy requirements were determined using FAO/WHO/UNU and Harris–Benedict (HB) equations. Bland– Altman and regression analysis were used for analysis.
Results: One-hundred and sixty-seven successful measurements were recorded in patients with TBI. At an individual level, both equations predicted REE poorly. The mean of the differences of standardised areas of measured REE and FAO/WHO/UNU was near zero (9 kcal) but the variation in both directions was substantial (range 591 to þ573 kcal). Similarly, the differences of areas of measured REE and HB demonstrated a mean of 1.9 kcal and range 568 to þ571 kcal. Glasgow coma score, patient status, weight and body temperature were signi?cant predictors of measured REE (p < 0.001; R2= 0.47).
Conclusions: Clinical equations are poor predictors of measured REE in patients with TBI. The variability in REE is substantial. Clinicians should be aware of the limitations of prediction equations when estimating energy requirements in TBI patients.
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The aim of this study was to investigate the solubility of mefenamic acid (MA), a highly cohesive, poorly water-soluble drug in a copolymer of polyoxyethylene–polyoxypropylene (Lutrol F681), and to understand the effect drug polymer solubility has on in vitro dissolution of MA. Solid dispersions (SD) of MA were prepared by a hot melt method, using Lutrol F681 as a thermoplastic polymeric platform. High-speed differential scanning calorimetry (Hyper-DSC), Raman spectroscopy, powder X-ray diffractometry (PXRD) and hot-stage/?uorescence microscopy were used to assess the solubility of the drug in molten and solid polymer. Drug dissolution studies were subsequently conducted on single-phase solid solutions and biphasic SD using phosphate buffer pH 6.8 as dissolution media. Solubility investigations using Hyper-DSC, Raman spectroscopy and hot-stage microscopy suggested MA was soluble in molten Lutrol F681 up to a concentration of 35% (w/w). Conversely, the solubility in the solidstate matrix was limited to<15% (w/w); determined by Raman spectroscopy, PXRD and ?uorescence microscopy. As expected the dissolution properties of MA were signi?cantly in?uenced by the solubility of the drug in the polymer matrix. At a concentration of 10% (w/w) MA (a single phase solid solution) dissolution of MA in phosphate buffer 6.8 was rapid, whereas at a concentration of 50% (w/w) MA (biphasic SD) dissolution was signi?cantly slower. This study has clearly demonstrated the complexity of drug– polymer binary blends and in particular de?ning the solubility of a drug within a polymeric platform. Moreover, this investigation has demonstrated the signi?cant effect drug solubility within a polymeric matrix has upon the in vitro dissolution properties of solid polymer/drug binary blends.
Resumo:
These results cover dating undertaken since the last published list of dated building from Ireland (Brown (2002)); one English church building is also included in the list. Thanks are due to the owners of the buildings and especially to everyone who assisted in taking of the samples: Phil Barrett, Sapphire Mussen, Charles Lyons, Jon Pilcher and Mike Baillie, Amanda Pedlow, Caimin O’Brien and Martin Timoney. Most of the descriptions of the buildings are taken from the National Inventory of Architectural Heritage http://www.buildingofi reland.ie/. The correlation values were generated by CROSS84 (Munro, 1984), which provides a signifi cance level for the date to be correct; *** (extremely signifi cant), ** (very signifi cant), * (signifi cant), nsm (not signifi cant). Estimated felling date ranges are based on the Belfast sapwood estimate of 32 ± 9 years. Date ranges have been calculated by adding and subtracting 9 years from the calculated estimated felling dates. Timbers from the following buildings could not be dated. Cork: St Finbarre’s Cathedral (W 675 715); Dublin: Christchurch Cathedral (O 152 341); Galway: Cloghan Castle (M 972 119); Kilkenny: Rothe House (S 506 563); Offaly: Boveen House (S 075 956); Waterford: Christchurch Cathedral (S 616 121). Generally only single oak samples were recovered from these structures. References: D.Brown, ‘Dendrochronological dating building from Ireland’, VA 33 (2002), 71–3; M. Munro, ‘An improved algorithm for crossdating tree-ring series’, Tree-Ring Bulletin 44 (1984), 17–27.
Resumo:
This essay examines Tim Loane’s political comedies, Caught Red-Handed and To Be Sure, and their critique of the Northern Irish peace process. As “parodies of esteem”, both plays challenge the ultimate electoral victors of the peace process (the Democratic Unionist Party and Sinn Féin) as well as critiquing the cant, chicanery and cynicism that have characterised their political rhetoric and the peace process as a whole. This essay argues that Loane’s transformation of these comedic pantomime horses into Trojan ones loaded with a ruthless polemical critique of our ruling political elites is all the more important in the context of a self-censoring media that has stifled dissent and debate by protecting the peace process from inconvenient truths. From these close and contextual readings of Loane’s plays, wider issues relating to the political efficacy of comedy and its canonical relegation below ‘higher forms’ in Irish theatre historiography will also be considered.
Resumo:
OBJECTIVES: To characterize the population pharmacokinetics of metronidazole in preterm neonates.
PATIENTS AND METHODS: Data were collected prospectively from 32 preterm neonates who received intravenous metronidazole for the treatment of or prophylaxis against necrotizing enterocolitis. Dried
blood spots (n 203) on ?lter paper were analyzed by highperformance liquid chromatography, and the data were subjected to pharmacokinetic analysis performed by using nonlinear mixed-effect modeling.
RESULTS: A 1-compartment model best described the data. Signi?cant covariates were weight (WT) and postmenstrual age (PMA). The ?nal population models for metronidazole clearance (CL) and volume of distribution (V) were: CL 0.0247 (WT/1.00)0.75 (1 0.107 [PMA 30]) and V 0.726 WT, where CL is in liters per hour, WT is in kilograms, PMA is in weeks, and V is in liters. This model predicts that the half-life of metronidazole decreases rapidly from 40 hours at 25 weeks’ PMA to 19 hours at 32 weeks’ PMA, after which it starts to plateau. This decrease in half-life is the result of a 5-fold increase in CL compared with only a 2.5-fold increase in V during the same period.
CONCLUSIONS: Currently, there are no speci?c dose recommendations for metronidazole in preterm neonates. However, a dosing scheme for preterm neonates that takes into consideration both the weight and PMA has been suggested and should avoid administration of doses that are excessive or more frequent than necessary.
Resumo:
Background Almost without exception, research into the range and quality of childcare provision, and its correlates with children’s development, comes from the perspective of adults. Parents, childcare workers, teachers and the general public have all been asked for their views on childcare. In contrast, there is a dearth of information on attitudes to childcare provision and its correlates from the perspective of the children themselves.
Methods A total of 3657 Primary 7 children, who are 10 or 11 years of age, completed the KIDSCREEN-27 health-related quality of life (HRQoL) measure along with questions on their childcare provision as part of an online survey carried out in schools.
Results Most children receiving childcare from people other than their parents were completely happy with their care. Childcare was related to poorer HRQoL for girls on four of the ?ve KIDSCREEN domains, although the effect sizes were small. For both boys and girls, there were statistically signi?cant, although modest, correlations between happiness with childcare and scores on all ?ve domains of the KIDSCREEN-27.
Conclusions Overall, the ?ndings suggest that most children are happy with their care and that any differences between the HRQoL of those who are cared for by their parents and those who are not are small to moderate.
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This paper considers the ways in which structural model parameter variability can in?uence aeroelastic stability. Previous work on formulating the stability calculation (with the Euler equations providing the aerodynamic predictions) is exploited to use Monte Carlo, Interval and Perturbation calculations to allow this question to be investigated. Three routes are identi?ed. The ?rst involves variable normal mode frequencies only. The second involves normal mode frequencies and mode shapes. Finally, the third, in addition to normal mode frequencies and mode shapes, also includes their in?uence on the static equilibrium. Previous work has suggested only considering route 1, which allows signi?cant gains in computational e?ciency if reduced order models can be built for the aerodynamics. However, results in the current paper show that neglecting route 2 can give misleading results for the ?utter onset prediction.