Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Pathog ; 12(9): e1005839, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27662621

RESUMO

Using a unique resource of samples from a controlled human malaria infection (CHMI) study, we identified a novel population of CD4+ T cells whose frequency in the peripheral blood was inversely correlated with parasite burden following P. falciparum infection. These CD4+ T cells expressed the multifunctional ectoenzyme CD38 and had unique features that distinguished them from other CD4+ T cells. Specifically, their phenotype was associated with proliferation, activation and cytotoxic potential as well as significantly impaired production of IFN-γ and other cytokines and reduced basal levels of activated STAT1. A CD38+ CD4+ T cell population with similar features was identified in healthy uninfected individuals, at lower frequency. CD38+ CD4+ T cells could be generated in vitro from CD38- CD4+ T cells after antigenic or mitogenic stimulation. This is the first report of a population of CD38+ CD4+ T cells with a cytotoxic phenotype and markedly impaired IFN-γ capacity in humans. The expansion of this CD38+ CD4+ T population following infection and its significant association with reduced blood-stage parasite burden is consistent with an important functional role for these cells in protective immunity to malaria in humans. Their ubiquitous presence in humans suggests that they may have a broad role in host-pathogen defense. TRIAL REGISTRATION: ClinicalTrials.gov clinical trial numbers ACTRN12612000814875, ACTRN12613000565741 and ACTRN12613001040752.


Assuntos
ADP-Ribosil Ciclase 1/metabolismo , Linfócitos T CD4-Positivos/imunologia , Citotoxicidade Imunológica , Interferon gama/metabolismo , Malária Falciparum/imunologia , Malária Falciparum/patologia , Glicoproteínas de Membrana/metabolismo , Plasmodium falciparum/imunologia , Adulto , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Contagem de Células , Voluntários Saudáveis , Humanos , Ativação Linfocitária , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Parasitemia/imunologia , Parasitemia/patologia
2.
Pancreatology ; 17(2): 321-327, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28153446

RESUMO

BACKGROUND: People with pancreatic cancer have high levels of anxiety and depression and reduced quality of life (QoL), but few studies have assessed these outcomes for patient-carer dyads. We therefore investigated these issues in an Australian population-based study. METHODS: Patients with pancreatic cancer (n = 136) and many of their carers (n = 84) completed the Hospital Anxiety and Depression Scale (HADS) and Functional Assessment of Cancer Therapy QoL questionnaire at a median of three months after diagnosis. Overall QoL and well-being subscales (physical, social, emotional, functional) were compared with general population norms. Intraclass correlation coefficients were used to compare anxiety, depression and QoL scores of patients and their respective carers. RESULTS: Fifteen percent of patients and 39% of carers had HADS scores indicative of anxiety and 15% of patients and 14% of carers of depression, respectively. Overall, 70% of patients and 58% of carers had QoL scores below the Queensland population average. Patients' anxiety, depression, overall QoL, social, emotional and functional wellbeing scores were significantly related to those scores in their carers. Among patients and carers, accessing psychological help was associated with elevated anxiety. Not receiving chemotherapy was associated with elevated depression among patients and younger age was associated with poorer outcomes in carers. CONCLUSIONS: More carers had symptoms of anxiety than patients with pancreatic cancer, but symptoms of depression were similarly common in patients and carers. Further research is needed to assess whether interventions to reduce patients' distress could also improve QoL among carers, or whether carer-focussed interventions are required.


Assuntos
Ansiedade/etiologia , Cuidadores , Depressão/etiologia , Neoplasias Pancreáticas/psicologia , Qualidade de Vida , Idoso , Ansiedade/epidemiologia , Austrália , Depressão/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/terapia
3.
Diabetes Obes Metab ; 19(1): 108-117, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27629433

RESUMO

BACKGROUND: Real world outcomes of addition or switch to insulin therapy in type 2 diabetes (T2DM) patients on glucagon-like paptide-1 receptor agonist (GLP-1RA) with inadequately controlled hyperglycaemia, are not known. MATERIALS AND METHODS: Patients with T2DM (n = 66 583) with a minimum of 6 months of GLP-1RA treatment and without previous insulin treatment were selected. Those who added insulin (n = 39 599) or switched to insulin after GLP-1RA cessation (n = 4706) were identified. Adjusted changes in glycated haemoglobin (HbA1c), weight, systolic blood pressure (SBP), and LDL cholesterol were estimated over 24 months follow-up. RESULTS: Among those who continued with GLP-1RA treatment without adding or switching to insulin, the highest adjusted mean HbA1c change was achieved within 6 months, with no further glycaemic benefits observed during 24 months of follow-up. Addition of insulin within 6 months of GLP-1RA initiation was associated with 18% higher odds of achieving HbA1c <7% at 24 months, compared with adding insulin later. At 24 months, those who added insulin reduced HbA1c significantly by 0.55%, while no glycaemic benefit was observed in those who switched to insulin. Irrespective of intensification with insulin, weight, SBP and LDL cholesterol were significantly reduced by 3 kg, 3 mm Hg, and 0.2 mmol/L, respectively, over 24 months. CONCLUSIONS: Significant delay in intensification of treatment by addition of insulin is observed in patients with T2DM inadequately controlled with GLP-1RA. Earlier addition of insulin is associated with better glycaemic control, while switching to insulin is not clinically beneficial during 2 years of treatment. Non-responding patients on GLP-1RA would benefit from adding insulin therapy, rather than switching to insulin.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Liraglutida/uso terapêutico , Peptídeos/uso terapêutico , Peçonhas/uso terapêutico , Idoso , Glicemia/metabolismo , Preservação de Sangue , Peso Corporal , LDL-Colesterol/metabolismo , Bases de Dados Factuais , Diabetes Mellitus Tipo 2/metabolismo , Substituição de Medicamentos , Quimioterapia Combinada , Registros Eletrônicos de Saúde , Exenatida , Feminino , Seguimentos , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
4.
Dis Colon Rectum ; 60(9): 987-991, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28796738

RESUMO

BACKGROUND: The success of current and proposed strategies to reduce colorectal cancer (CRC) incidence and mortality rates are fundamentally based on measurement accuracy. OBJECTIVE: The aim of this study was to evaluate the densities of colorectal polyps individually measured at colonoscopy and whether measurement bias is a systemic phenomenon among colonoscopists. DESIGN: A population-wide, observational study. SETTING: All hospitals of the government-funded health system in Brisbane, Australia. PATIENTS: Our study investigated measurement bias at colonoscopy through systematic analysis of 8,591 individual polyp measurements recorded from 12,597 colonoscopies. All colonoscopies performed over a 12-month period between December 1, 2014, and November 30, 2015, were included. RESULTS: A total of 12,597 electronic colonoscopy reports were individually reviewed, hospital-by-hospital, and 8,591 individual size measurements from 18,276 detected polyps (47%) were obtained. LIMITATIONS: Our study is limited because the true size of unresected polyps was unknown. We chose not to compare pathologic and histologic sizes as resection specimens sent to pathologists are morphologically different and are measured differently to the pre-resection polyp images seen by endoscopists. CONCLUSIONS: Colonoscopists may be inaccurate in the measurement of polyp size and appear biased towards and against certain size measurements. These findings cast doubt over the validity of international post-polypectomy surveillance guidelines and the safety of optical diagnosis as a potential management paradigm for diminutive colorectal polyps. They also question the historical accuracy of polyp size data and risk estimates upon which these strategies were based.


Assuntos
Pólipos do Colo/diagnóstico , Neoplasias Colorretais , Precisão da Medição Dimensional , Austrália , Competência Clínica , Colonoscopia/educação , Colonoscopia/métodos , Colonoscopia/normas , Neoplasias Colorretais/patologia , Neoplasias Colorretais/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Garantia da Qualidade dos Cuidados de Saúde , Melhoria de Qualidade , Medição de Risco , Carga Tumoral , Pesos e Medidas
5.
Histopathology ; 68(4): 578-87, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26212352

RESUMO

AIMS: Most colorectal polyps are classified readily, but a subset of tubulovillous adenomas (TVA) with prominent serrated architecture causes diagnostic confusion. We aimed to (i) identify histological features that separate serrated TVAs from both conventional TVAs and traditional serrated adenomas (TSA) and (ii) perform a clinicopathological and molecular analysis to determine if the serrated TVA has unique features. METHODS AND RESULTS: We collected 48 serrated TVAs, 50 conventional TVAs and 66 BRAF wild-type TSAs for analysis. For each polyp we performed a clinicopathological assessment, BRAF and KRAS mutation profiling, cytosine-phosphate-guanosine (CpG) island methylator phenotype status, MGMT methylation and immunohistochemical assessment of seven markers [MutL homologue 1 (MLH1), p16, p53, ß-catenin, Ki67, CK7 and CK20]. We found that serrated TVAs can be diagnosed reliably, and have features distinct from both conventional TVAs and TSAs. Compared to conventional TVAs, serrated TVAs are larger, more often proximal, more histologically advanced, show more CpG island methylation and more frequent KRAS mutation. Compared to TSAs they are more often proximal, show less CpG island methylation, more frequent MGMT methylation and more frequent nuclear staining for ß-catenin. CONCLUSIONS: The serrated TVA can be diagnosed reliably and has unique features. It represents a precursor of KRAS mutated, microsatellite stable colorectal carcinoma.


Assuntos
Adenoma Viloso/patologia , Neoplasias do Colo/patologia , Adenoma Viloso/genética , Idoso , Biomarcadores Tumorais/análise , Neoplasias do Colo/genética , Análise Mutacional de DNA , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade
6.
Paediatr Respir Rev ; 20: 55-66, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27259460

RESUMO

A systematic review was performed (i) to describe the reported overall rate of progression of CF lung disease quantified as FEV1%predicted decline with age, (ii) to summarise identified influencing risk factors and (iii) to review methods used to analyse CF lung disease progression data. A search of publications providing FEV1%predicted values over age was conducted in PUBMED and EMBASE. Baseline and rate of FEV1%predicted decline were summarised overall and by identified risk factors. Thirty-nine studies were included and reported variable linear rates of lung function decline in patients with CF. The overall weighted mean FEV1%predicted over age was graphically summarised and showed a nonlinear, time-variant decline of lung function. Compared to their peers, Pseudomonas aeruginosa infection and pancreatic insufficiency were most commonly associated with lower baseline and more rapid FEV1%predicted declines respectively. Considering nonlinear models and drop-out in lung disease progression, analysis is lacking and more studies are warranted.


Assuntos
Fibrose Cística/fisiopatologia , Volume Expiratório Forçado/fisiologia , Pulmão/fisiopatologia , Criança , Progressão da Doença , Humanos , Testes de Função Respiratória , Fatores de Risco
7.
Mod Pathol ; 28(3): 414-27, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25216220

RESUMO

The traditional serrated adenoma is the least common colorectal serrated polyp. The clinicopathological features and molecular drivers of these polyps require further investigation. We have prospectively collected a cohort of 200 ordinary and advanced traditional serrated adenomas and performed BRAF and KRAS mutational profiling, CpG island methylator phenotype analysis, and immunohistochemistry for a panel of 7 antibodies (MLH1, ß-catenin, p53, p16, Ki67, CK7, and CK20) on all cases. The mean age of the patients was 64 years and 50% were female. Of the polyps, 71% were distal. Advanced histology (overt dysplasia or carcinoma) was present in 19% of cases. BRAF mutation was present in 67% and KRAS mutation in 22%. BRAF mutant traditional serrated adenomas were more frequently proximal (39% versus 2%; P≤0.0001), were exclusively associated with a precursor polyp (57% versus 0%; P≤0.0001), and were more frequently CpG island methylator phenotype high (60% versus 16%; P≤0.0001) than KRAS mutant traditional serrated adenomas. Advanced traditional serrated adenomas retained MLH1 expression in 97%, showed strong p53 staining in 55%, and nuclear ß-catenin staining in 40%. P16 staining was lost in the advanced areas of 55% of BRAF mutant traditional serrated adenomas compared with 10% of the advanced areas of KRAS mutant or BRAF/KRAS wild-type traditional serrated adenomas. BRAF and KRAS mutant traditional serrated adenomas are morphologically related but biologically disparate polyps with distinctive clinicopathological and molecular features. The overwhelming majority of traditional serrated adenomas retain mismatch repair enzyme function indicating a microsatellite-stable phenotype. Malignant progression occurs via TP53 mutation and Wnt pathway activation regardless of mutation status. However, CDKN2A (encoding the p16 protein) is silenced nearly exclusively in the advanced areas of the BRAF mutant traditional serrated adenomas. Thus, the BRAF mutant traditional serrated adenoma represents an important precursor of the aggressive BRAF mutant, microsatellite-stable subtype of colorectal carcinoma.


Assuntos
Adenoma/genética , Adenoma/patologia , Pólipos do Colo/genética , Pólipos do Colo/patologia , Neoplasias Colorretais/patologia , Idoso , Biomarcadores Tumorais/análise , Neoplasias Colorretais/genética , Metilação de DNA , Análise Mutacional de DNA , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteínas ras/genética
8.
Cardiovasc Diabetol ; 14: 10, 2015 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-25616979

RESUMO

BACKGROUND: To evaluate the association of treatment with glucagon-like peptide-1 (GLP-1) receptor agonist exenatide and/or insulin on macrovascular outcomes in patients with type 2 diabetes (T2DM). METHODS: We conducted a retrospective longitudinal pharmaco-epidemiological study using large ambulatory care data to evaluate the risks of heart failure (HF), myocardial infarction (MI) and stroke in established T2DM patients who received a first prescription of exenatide twice daily (EBID) or insulin between June 2005 and May 2009, with follow-up data available until December 2012. Three treatment groups were: EBID with oral antidiabetes drugs (OADs) (EBID, n = 2804), insulin with OADs (Insulin, n = 28551), and those who changed medications between EBID and insulin or had combination of EBID and insulin during follow-up, along with OADs (EBID + insulin, n = 7870). Multivariate Cox-regression models were used to evaluate the association of treatment groups with the risks of macrovascular events. RESULTS: During a median 3.5 years of follow-up, cardiovascular event rates per 1000 person-years were significantly lower for the EBID and EBID + insulin groups compared to the insulin group (HF: 4.4 and 6.1 vs. 17.9; MI: 1.1 and 1.2 vs. 2.5; stroke: 2.4 and 1.8 vs. 6.1). Patients in the EBID/EBID + insulin group had significantly reduced risk of HF, MI and stroke by 61/56%, 50/38% and 52/63% respectively, compared to patients in the insulin group (p < 0.01). CONCLUSIONS: Treatment with exenatide, with or without concomitant insulin was associated with reduced macrovascular risks compared to insulin; although inherent potential bias in epidemiological studies should be considered.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Peptídeos/administração & dosagem , Peçonhas/administração & dosagem , Idoso , Doenças Cardiovasculares/fisiopatologia , Estudos de Coortes , Diabetes Mellitus Tipo 2/fisiopatologia , Quimioterapia Combinada , Exenatida , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
9.
Cardiovasc Diabetol ; 14: 100, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26249018

RESUMO

BACKGROUND: The aim of the study was to evaluate the effect of delay in treatment intensification (IT; clinical inertia) in conjunction with glycaemic burden on the risk of macrovascular events (CVE) in type 2 diabetes (T2DM) patients. METHODS: A retrospective cohort study was carried out using United Kingdom Clinical Practice Research Datalink, including T2DM patients diagnosed from 1990 with follow-up data available until 2012. RESULTS: In the cohort of 105,477 patients mean HbA1c was 8.1% (65 mmol/mol) at diagnosis, 11% had a history of cardiovascular disease, and 7.1% experienced at least one CVE during 5.3 years of median follow-up. In patients with HbA1c consistently above 7/7.5% (53/58 mmol/mol, n = 23,101/11,281) during 2 years post diagnosis, 26/22% never received any IT. Compared to patients with HbA1c <7% (<53 mmol/mol), in patients with HbA1c ≥7% (≥53 mmol/mol), a 1 year delay in receiving IT was associated with significantly increased risk of MI, stroke, HF and composite CVE by 67% (HR CI: 1.39, 2.01), 51% (HR CI: 1.25, 1.83), 64% (HR CI: 1.40, 1.91) and 62% (HR CI: 1.46, 1.80) respectively. One year delay in IT in interaction with HbA1c above 7.5% (58 mmol/mol) was also associated with similar increased risk of CVE. CONCLUSIONS: Among patients with newly diagnosed T2DM, 22% remained under poor glycaemic control over 2 years, and 26% never received IT. Delay in IT by 1 year in conjunction with poor glycaemic control significantly increased the risk of MI, HF, stroke and composite CVE.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Tempo para o Tratamento , Idoso , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etiologia , Bases de Dados Factuais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Serviços Preventivos de Saúde , Atenção Primária à Saúde , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Reino Unido
10.
Crit Care ; 19: 28, 2015 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-25632974

RESUMO

INTRODUCTION: The aim of this study was to explore the impact of augmented creatinine clearance and differing minimum inhibitory concentrations (MIC) on piperacillin pharmacokinetic/pharmacodynamic (PK/PD) target attainment (time above MIC (fT>MIC)) in critically ill patients with sepsis receiving intermittent dosing. METHODS: To be eligible for enrolment, critically ill patients with sepsis had to be receiving piperacillin-tazobactam 4.5 g intravenously (IV) by intermittent infusion every 6 hours for presumed or confirmed nosocomial infection without significant renal impairment (defined by a plasma creatinine concentration greater than 171 µmol/L or the need for renal replacement therapy). Over a single dosing interval, blood samples were drawn to determine unbound plasma piperacillin concentrations. Renal function was assessed by measuring creatinine clearance (CLCR). A population PK model was constructed, and the probability of target attainment (PTA) for 50% and 100% fT>MIC was calculated for varying MIC and CLCR values. RESULTS: In total, 48 patients provided data. Increasing CLCR values were associated with lower trough plasma piperacillin concentrations (P < 0.01), such that with an MIC of 16 mg/L, 100% fT>MIC would be achieved in only one-third (n = 16) of patients. Mean piperacillin clearance was approximately 1.5-fold higher than in healthy volunteers and correlated with CLCR (r = 0.58, P < 0.01). A reduced PTA for all MIC values, when targeting either 50% or 100% fT>MIC, was noted with increasing CLCR measures. CONCLUSIONS: Standard intermittent piperacillin-tazobactam dosing is unlikely to achieve optimal piperacillin exposures in a significant proportion of critically ill patients with sepsis, owing to elevated drug clearance. These data suggest that CLCR can be employed as a useful tool to determine whether piperacillin PK/PD target attainment is likely with a range of MIC values.


Assuntos
Antibacterianos/administração & dosagem , Creatinina/metabolismo , Estado Terminal/terapia , Taxa de Depuração Metabólica , Piperacilina/administração & dosagem , Terapia de Substituição Renal/estatística & dados numéricos , Adulto , Idoso , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Creatinina/sangue , Creatinina/farmacologia , Feminino , Humanos , Testes de Função Renal , Masculino , Piperacilina/farmacocinética , Piperacilina/farmacologia
11.
Genes Chromosomes Cancer ; 53(7): 537-48, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24677610

RESUMO

Formalin fixation and embedding of clinical tissue samples in paraffin is a common method for archiving biological material. These samples are often well annotated and provide an invaluable resource for research. However, this process of fixation and storage of tissue leads to DNA damage and fragmentation. The use of DNA from formalin fixed, paraffin-embedded (FFPE) tissue to interrogate methylation levels on a genome-wide scale can pose challenges. We compared fresh and matched FFPE tissue DNA samples using the Illumina Infinium HD Human Methylation 450K BeadChip platform with a companion application for repair and "restoration" of DNA from FFPE tissue. Our results showed good correlation between fresh and FFPE sample data. FFPE DNA captured 99% of the CpG sites on the array on average. Significant cancer subgroups based on the CpG island methylator phenotype (CIMP) were clearly distinguished for both fresh and FFPE sample sets with cluster and scaling analysis. The DNA methylation status for the five standard CIMP panel genes which was evaluated for all samples by the MethyLight assay was correctly assigned in both fresh and FFPE samples by the array data. We conclude that the "restoration" method followed by assay on the Infinium HD Human Methylation 450K microarray can produce good quality data for DNA from FFPE samples.


Assuntos
Neoplasias Colorretais/metabolismo , Metilação de DNA , Fixadores , Formaldeído , Genoma Humano , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Ilhas de CpG , Dano ao DNA , Humanos , Inclusão em Parafina , Fixação de Tecidos/métodos
12.
Clin Gastroenterol Hepatol ; 12(12): 2092-103.e1-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24582567

RESUMO

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD), characterized by accumulation of hepatic triglycerides (steatosis), is associated with abdominal obesity, insulin resistance, and inflammation. Although weight loss via calorie restriction reduces features of NAFLD, there is no pharmacologic therapy. Resveratrol is a polyphenol that prevents high-energy diet-induced steatosis and insulin resistance in animals by up-regulating pathways that regulate energy metabolism. We performed a placebo-controlled trial to assess the effects of resveratrol in patients with NAFLD. METHODS: Overweight or obese men diagnosed with NAFLD were recruited from hepatology outpatient clinics in Brisbane, Australia from 2011 through 2012. They were randomly assigned to groups given 3000 mg resveratrol (n = 10) or placebo (n = 10) daily for 8 weeks. Outcomes included insulin resistance (assessed by the euglycemic-hyperinsulinemic clamp), hepatic steatosis, and abdominal fat distribution (assessed by magnetic resonance spectroscopy and imaging). Plasma markers of inflammation, as well as metabolic, hepatic, and antioxidant function, were measured; transcription of target genes was measured in peripheral blood mononuclear cells. Resveratrol pharmacokinetics and safety were assessed. RESULTS: Eight-week administration of resveratrol did not reduce insulin resistance, steatosis, or abdominal fat distribution when compared with baseline. No change was observed in plasma lipids or antioxidant activity. Levels of alanine and aspartate aminotransferases increased significantly among patients in the resveratrol group until week 6 when compared with the placebo group. Resveratrol did not significantly alter transcription of NQO1, PTP1B, IL6, or HO1 in peripheral blood mononuclear cells. Resveratrol was well-tolerated. CONCLUSIONS: Eight weeks administration of resveratrol did not significantly improve any features of NAFLD, compared with placebo, but it increased hepatic stress, based on observed increases in levels of liver enzymes. Further studies are needed to determine whether agents that are purported to mimic calorie restriction, such as resveratrol, are safe and effective for complications of obesity. Clinical trials registration no: ACTRN12612001135808.


Assuntos
Fármacos Gastrointestinais/uso terapêutico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Estilbenos/uso terapêutico , Gordura Abdominal/patologia , Adulto , Idoso , Austrália , Humanos , Resistência à Insulina , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Placebos/administração & dosagem , Resveratrol , Resultado do Tratamento
14.
J Pharmacokinet Pharmacodyn ; 39(2): 147-60, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22270321

RESUMO

This study is to assess pharmacokinetic (PK) sampling time schedules and trial size requirements of drug-drug interaction (DDI) studies for CYP2C9, based on S-warfarin population PK models. S-warfarin plasma concentrations from eight DDI studies were utilized to develop S-warfarin population PK models. Optimal PK sampling times were obtained that minimized mean squared error of geometric mean of the area under the concentration-time curve (AUC(0-∞)). The powers and type I error rates of testing the equivalences of the geometric means of AUC(0-∞) only and AUC(0-∞) and maximum concentration (C (max)), jointly, were assessed via simulation for two-by-two cross-over designs. The results were compared to those from three bioequivalence sample size calculation methods. Two-compartment population PK models with first order absorption were established for non-Asian and Asian subjects. The optimal PK sampling times of size 17 per individual per period were found to be 0.0, 0.5, 1.0, 2.0, 4.0, 6.0, 10.0, 12.0, 16.0, 24.0, 36.0, 48.0, 60.0, 72.0, 96.0, 120.0, 144.0 h post a single oral dose of 25 mg warfarin. For non-Asian subjects, the minimum numbers of subjects required per trial with the optimal PK sampling schedule to achieve 80% power and 5% type I error rate, ranged from 6 to 19 for the equivalence of AUC(0-∞) and C (max) jointly. It has been demonstrated that appropriately selected PK sampling time points can greatly increase the corresponding power of the study without increasing the number of subjects, especially when the true ratio is near the default bioequivalence boundary (0.8-1.25).


Assuntos
Hidrocarboneto de Aril Hidroxilases/metabolismo , Povo Asiático , Modelos Biológicos , Varfarina/farmacocinética , Área Sob a Curva , Hidrocarboneto de Aril Hidroxilases/genética , Povo Asiático/genética , Estudos Cross-Over , Citocromo P-450 CYP2C9 , Interações Medicamentosas/fisiologia , Feminino , Humanos , Masculino
15.
Gene ; 683: 12-17, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30291871

RESUMO

BACKGROUND AND OBJECTIVE: Genetic modifiers contribute to variable disease phenotype in cystic fibrosis (CF). We explored the association between mutations in the hemochromatosis (HFE) gene and disease severity in adults with CF. METHODS: HFE genotyping was performed in 163 adults with CF attending a single centre. Results were correlated with lung disease severity, prevalence of CF-related diabetes (CFRD) and history of meconium ileus (MI) or distal intestinal obstruction syndrome (DIOS). RESULTS: Subjects with the C282Y substitution in the HFE protein (C282Y mutation) had a lower FEV1 percentage predicted (54% versus 66%, p = 0.029) and accelerated rate of FEV1 decline (-110 mL versus -80 mL per year respectively, p < 0.001) compared to subjects with a normal HFE genotype. C282Y substitutions were associated with increased rates of CFRD (58% versus 33%, p = 0.026) and a trend towards increased MI or DIOS (38% versus 19%, p = 0.05). H63D HFE substitutions were associated with a more rapid rate of decline in forced vital capacity (p = 0.01) and increased risk of MI or DIOS (p = 0.02). CONCLUSIONS: In subjects with CF, the C282Y HFE substitution was associated with worse lung function, and increased rates of CFRD and gastrointestinal complications. The H63D HFE substitution also impacted on disease phenotype, but to a lesser extent. The results support a role for HFE gene mutations as modifiers of CF phenotype.


Assuntos
Substituição de Aminoácidos , Fibrose Cística/genética , Fibrose Cística/fisiopatologia , Proteína da Hemocromatose/genética , Adulto , Feminino , Estudos de Associação Genética , Humanos , Masculino , Índice de Gravidade de Doença , Capacidade Vital
16.
Cell Mol Gastroenterol Hepatol ; 8(2): 269-290, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30954552

RESUMO

BACKGROUND & AIMS: Colorectal cancer is an epigenetically heterogeneous disease, however, the extent and spectrum of the CpG island methylator phenotype (CIMP) is not clear. METHODS: Genome-scale methylation and transcript expression were measured by DNA Methylation and RNA expression microarray in 216 unselected colorectal cancers, and findings were validated using The Cancer Genome Atlas 450K and RNA sequencing data. Mutations in epigenetic regulators were assessed using CIMP-subtyped Cancer Genome Atlas exomes. RESULTS: CIMP-high cancers dichotomized into CIMP-H1 and CIMP-H2 based on methylation profile. KRAS mutation was associated significantly with CIMP-H2 cancers, but not CIMP-H1 cancers. Congruent with increasing methylation, there was a stepwise increase in patient age from 62 years in the CIMP-negative subgroup to 75 years in the CIMP-H1 subgroup (P < .0001). CIMP-H1 predominantly comprised consensus molecular subtype 1 cancers (70%) whereas consensus molecular subtype 3 was over-represented in the CIMP-H2 subgroup (55%). Polycomb Repressive Complex-2 (PRC2)-marked loci were subjected to significant gene body methylation in CIMP cancers (P < 1.6 × 10-78). We identified oncogenes susceptible to gene body methylation and Wnt pathway antagonists resistant to gene body methylation. CIMP cluster-specific mutations were observed in chromatin remodeling genes, such as in the SWItch/Sucrose Non-Fermentable and Chromodomain Helicase DNA-Binding gene families. CONCLUSIONS: There are 5 clinically and molecularly distinct subgroups of colorectal cancer. We show a striking association between CIMP and age, sex, and tumor location, and identify a role for gene body methylation in the progression of serrated neoplasia. These data support our recent findings that CIMP is uncommon in young patients and that BRAF mutant polyps in young patients may have limited potential for malignant progression.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Ilhas de CpG , Metilação de DNA , Epigenoma , Mutação , Adenocarcinoma/classificação , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Fatores Etários , Idoso , Neoplasias Colorretais/classificação , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/metabolismo , Epigenômica , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Oncogenes/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Análise de Sequência de RNA
17.
J Am Geriatr Soc ; 65(9): 2029-2036, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28832897

RESUMO

OBJECTIVES: To determine whether geriatric triage decisions made using a comprehensive geriatric assessment (CGA) performed online are less reliable than face-to-face (FTF) decisions. DESIGN: Multisite noninferiority prospective cohort study. Two specialist geriatricians assessed individuals sequentially referred for an acute care geriatric consultation. Participants were allocated to one FTF assessment and an additional assessment (FTF or online (OL)), creating two groups-two FTF (FTF-FTF, n = 81) or online and FTF (OL-FTF, n = 85). SETTING: Three acute care public hospitals in two Australian states. PARTICIPANTS: Admitted individuals referred for CGA. INTERVENTION: Nurse-administered CGA, based on the interRAI Acute Care assessment system accessed online and other online clinical data such as pathology results and imaging enabling geriatricians to review participants' information and provide input into their care from a distance. MEASUREMENTS: The primary decision subjected to this analysis was referral for permanent residential care. Geriatricians also recorded recommendations for referrals and variations for medication management and judgment regarding prognosis at discharge and after 3 months. RESULTS: Overall percentage agreement was 88% (n = 71) for the FTF-FTF group and 91% (n = 77) for the OL-FTF group. The difference in agreement between the FTF-FTF and OL-FTF groups was -3%, indicating that there was no difference between the methods of assessment. Judgements made regarding diagnoses of geriatric syndromes, medication management, and prognosis (with regard to hospital outcome and location at 3 months) were found to be equally reliable in each mode of consultation. CONCLUSION: Geriatric assessment performed online using a nurse-administered structured CGA system was no less reliable than conventional assessment in making clinical triage decisions.


Assuntos
Avaliação Geriátrica/métodos , Internet , Encaminhamento e Consulta , Idoso , Austrália , Feminino , Hospitalização , Humanos , Masculino , Prognóstico , Estudos Prospectivos , Reprodutibilidade dos Testes , Inquéritos e Questionários , Telemedicina , Triagem/métodos
18.
PLoS One ; 11(4): e0152700, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27070549

RESUMO

When a dataset is imbalanced, the prediction of the scarcely-sampled subpopulation can be over-influenced by the population contributing to the majority of the data. The aim of this study was to develop a Bayesian modelling approach with balancing informative prior so that the influence of imbalance to the overall prediction could be minimised. The new approach was developed in order to weigh the data in favour of the smaller subset(s). The method was assessed in terms of bias and precision in predicting model parameter estimates of simulated datasets. Moreover, the method was evaluated in predicting optimal dose levels of tobramycin for various age groups in a motivating example. The bias estimates using the balancing informative prior approach were smaller than those generated using the conventional approach which was without the consideration for the imbalance in the datasets. The precision estimates were also superior. The method was further evaluated in a motivating example of optimal dosage prediction of tobramycin. The resulting predictions also agreed well with what had been reported in the literature. The proposed Bayesian balancing informative prior approach has shown a real potential to adequately weigh the data in favour of smaller subset(s) of data to generate robust prediction models.


Assuntos
Teorema de Bayes , Conjuntos de Dados como Assunto , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Modelos Teóricos , Tobramicina/administração & dosagem , Adulto Jovem
19.
J Diabetes ; 8(3): 354-62, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25929583

RESUMO

BACKGROUND: The cardiovascular and mortality risk in patients with incident type 2 diabetes (T2D) in relation to smoking status and concurrent use of metformin is not well known. METHODS: A cohort study was performed in 82,205 incident T2D patients from the U.K. Clinical Practice Research Datalink. In the present study, the risks of myocardial infarction (MI), stroke, and mortality in incident T2D patients were evaluated in relation to their smoking status with and without concurrent use of metformin. RESULTS: Over a median 5.4 years of follow-up, of patients without a history of cardiovascular disease (CVD) before a diagnosis of diabetes (n = 63,166), current smokers with and without metformin had an 8% (hazard ratio [HR] 1.08; 95% confidence interval [CI] 0.81, 1.45) and 32% (HR 1.32; 95% CI 1.07, 1.65) increased risk of MI or stroke, respectively, compared with non-smokers without metformin treatment. The respective HRs (95% CI) for mortality in these patients were 0.96 (0.83, 1.11) and 1.86 (1.68, 2.07). The HR for mortality among ex-smokers with and without concurrent metformin treatment was 0.92 (95% CI 0.83, 1.11) and 1.19 (95% CI 1.10, 1.30), respectively. Similar beneficial modifiable effects of metformin among ex- and current smokers were observed in patients with CVD before diagnosis of diabetes (n = 19,039). CONCLUSIONS: In T2D patients, concurrent treatment with metformin attenuates the observed higher cardiovascular and mortality risk in ex- and current smokers. In addition to smoking cessation support, treatment with metformin, particularly in ex- and current smokers, should be encouraged.


Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Diabetes Mellitus Tipo 2/complicações , Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Fumar/efeitos adversos , Idoso , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fumar/mortalidade , Taxa de Sobrevida
20.
Cancer Epidemiol ; 45: 145-150, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27810486

RESUMO

PURPOSE: Family history of pancreatic adenocarcinoma is an established risk factor for the disease. However, associations of pancreatic cancer with other familial cancers are less clear. We analyzed data from the Queensland Pancreatic Cancer Study (QPCS), an Australian population-based case-control study, to investigate associations between family history of various cancer types and risk of pancreatic cancer. MATERIALS AND METHODS: Our study included 591 pancreatic cancer patients and 646 controls, all of whom self-reported the histories of cancer in their first-degree relatives. We used logistic regression to estimate adjusted odds ratios (ORs) and their 95% confidence intervals (CIs). Based on our results, we conducted a systematic literature review using the Medline (OVID) database to identify articles pertaining to the association between family history of melanoma and risk of pancreatic cancer. A meta-analysis including associations in five published studies, unpublished results from a study co-author and the QPCS results was then performed using the DerSimonian and Laird random-effects model. RESULTS: Cases were more likely than controls to report a family history of pancreatic cancer (OR 2.20, 95% CI 1.16-4.19) and melanoma (OR 1.74, 95% CI 1.03-2.95), but not of breast, ovarian, respiratory, other gastrointestinal or prostate cancer. Meta-analysis of melanoma family history and pancreatic cancer risk yielded an OR of 1.22 (95% CI 1.00-1.51). CONCLUSIONS: Our results yield further evidence of increased risk of pancreatic cancer in those with family histories of the disease. We also provide suggestive evidence of an association between family history of melanoma and risk of pancreatic cancer.


Assuntos
Adenocarcinoma/etiologia , Predisposição Genética para Doença , Neoplasias/etiologia , Neoplasias Pancreáticas/etiologia , Adenocarcinoma/epidemiologia , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Razão de Chances , Neoplasias Pancreáticas/epidemiologia , Queensland/epidemiologia , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA