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1.
Lancet ; 402(10402): 613-626, 2023 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-37385275

RESUMEN

BACKGROUND: Weight reduction is essential for improving health outcomes in people with obesity and type 2 diabetes. We assessed the efficacy and safety of tirzepatide, a glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, versus placebo, for weight management in people living with obesity and type 2 diabetes. METHODS: This phase 3, double-blind, randomised, placebo-controlled trial was conducted in seven countries. Adults (aged ≥18 years) with a body-mass index (BMI) of 27 kg/m2 or higher and glycated haemoglobin (HbA1c) of 7-10% (53-86 mmol/mol) were randomly assigned (1:1:1), using a computer-generated random sequence via a validated interactive web-response system, to receive either once-weekly, subcutaneous tirzepatide (10 mg or 15 mg) or placebo for 72 weeks. All participants, investigators, and the sponsor were masked to treatment assignment. Coprimary endpoints were the percent change in bodyweight from baseline and bodyweight reduction of 5% or higher. The treatment-regimen estimand assessed effects regardless of treatment discontinuation or initiation of antihyperglycaemic rescue therapy. Efficacy and safety endpoints were analysed with data from all randomly assigned participants (intention-to-treat population). This trial is registered with ClinicalTrials.gov, NCT04657003. FINDINGS: Between March 29, 2021, and April 10, 2023, of 1514 adults assessed for eligibility, 938 (mean age 54·2 years [SD 10·6], 476 [51%] were female, 710 [76%] were White, and 561 [60%] were Hispanic or Latino) were randomly assigned and received at least one dose of tirzepatide 10 mg (n=312), tirzepatide 15 mg (n=311), or placebo (n=315). Baseline mean bodyweight was 100·7 kg (SD 21·1), BMI 36·1 kg/m2 (SD 6·6), and HbA1c 8·02% (SD 0·89; 64·1 mmol/mol [SD 9·7]). Least-squares mean change in bodyweight at week 72 with tirzepatide 10 mg and 15 mg was -12·8% (SE 0·6) and -14·7% (0·5), respectively, and -3·2% (0·5) with placebo, resulting in estimated treatment differences versus placebo of -9·6% percentage points (95% CI -11·1 to -8·1) with tirzepatide 10 mg and -11·6% percentage points (-13·0 to -10·1) with tirzepatide 15 mg (all p<0·0001). More participants treated with tirzepatide versus placebo met bodyweight reduction thresholds of 5% or higher (79-83% vs 32%). The most frequent adverse events with tirzepatide were gastrointestinal-related, including nausea, diarrhoea, and vomiting and were mostly mild to moderate in severity, with few events leading to treatment discontinuation (<5%). Serious adverse events were reported by 68 (7%) participants overall and two deaths occurred in the tirzepatide 10 mg group, but deaths were not considered to be related to the study treatment by the investigator. INTERPRETATION: In this 72-week trial in adults living with obesity and type 2 diabetes, once-weekly tirzepatide 10 mg and 15 mg provided substantial and clinically meaningful reduction in bodyweight, with a safety profile that was similar to other incretin-based therapies for weight management. FUNDING: Eli Lilly and Company.


Asunto(s)
Diabetes Mellitus Tipo 2 , Adulto , Humanos , Femenino , Adolescente , Persona de Mediana Edad , Masculino , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Resultado del Tratamiento , Péptidos Similares al Glucagón , Hipoglucemiantes/efectos adversos , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Peso Corporal , Método Doble Ciego
2.
J Endocr Soc ; 7(5): bvad056, 2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-37153701

RESUMEN

Context: Tirzepatide is a glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist approved for treatment of type 2 diabetes (T2D). SURPASS-1, a phase 3 trial of tirzepatide monotherapy in people with early T2D, enables evaluating effects of tirzepatide on pancreatic beta-cell function and insulin sensitivity (IS) without other background antihyperglycemic medications. Objective: Explore changes in biomarkers of beta-cell function and IS with tirzepatide monotherapy. Design: Post hoc analyses of fasting biomarkers with analysis of variance and mixed model repeated measures. Setting: Forty-seven sites in 4 countries. Patients: Four hundred seventy-eight T2D participants. Intervention: Tirzepatide (5, 10, 15 mg), placebo. Main Outcome Measures: Analyze biomarkers of beta-cell function and IS at 40 weeks. Results: At 40 weeks, markers of beta-cell function improved with tirzepatide monotherapy vs placebo with reductions from baseline in fasting proinsulin levels (49-55% vs -0.6%) and in intact proinsulin/C-peptide ratios (47-49% vs -0.1%) (P < .001, all doses vs placebo). Increases from baseline in homeostatic model assessment for beta-cell function (computed with C-peptide) (77-92% vs -1.4%) and decreases in glucose-adjusted glucagon levels (37-44% vs +4.8%) were observed with tirzepatide vs placebo (P < .001, all doses vs placebo). IS improved as indicated by reductions from baseline in homeostatic model assessment for insulin resistance (9-23% vs +14.7%) and fasting insulin levels (2-12% vs +15%), and increases in total adiponectin (16-23% vs -0.2%) and insulin-like growth factor binding protein 2 (38-70% vs +4.1%) with tirzepatide vs placebo at 40 weeks (P ≤ .031, all doses vs placebo, except for fasting insulin levels with tirzepatide 10 mg). Conclusions: As monotherapy for early T2D, tirzepatide achieved significant improvements in biomarkers of both pancreatic beta-cell function and IS.

3.
Lancet ; 398(10295): 143-155, 2021 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-34186022

RESUMEN

BACKGROUND: Despite advancements in care, many people with type 2 diabetes do not meet treatment goals; thus, development of new therapies is needed. We aimed to assess efficacy, safety, and tolerability of novel dual glucose-dependent insulinotropic polypeptide and GLP-1 receptor agonist tirzepatide monotherapy versus placebo in people with type 2 diabetes inadequately controlled by diet and exercise alone. METHODS: We did a 40-week, double-blind, randomised, placebo-controlled, phase 3 trial (SURPASS-1), at 52 medical research centres and hospitals in India, Japan, Mexico, and the USA. Adult participants (≥18 years) were included if they had type 2 diabetes inadequately controlled by diet and exercise alone and if they were naive to injectable diabetes therapy. Participants were randomly assigned (1:1:1:1) via computer-generated random sequence to once a week tirzepatide (5, 10, or 15 mg), or placebo. All participants, investigators, and the sponsor were masked to treatment assignment. The primary endpoint was the mean change in glycated haemoglobin (HbA1c) from baseline at 40 weeks. This study is registered with ClinicalTrials.gov, NCT03954834. FINDINGS: From June 3, 2019, to Oct 28, 2020, of 705 individuals assessed for eligibility, 478 (mean baseline HbA1c 7·9% [63 mmol/mol], age 54·1 years [SD 11·9], 231 [48%] women, diabetes duration 4·7 years, and body-mass index 31·9 kg/m2) were randomly assigned to tirzepatide 5 mg (n=121 [25%]), tirzepatide 10 mg (n=121 [25%]), tirzepatide 15 mg (n=121 [25%]), or placebo (n=115 [24%]). 66 (14%) participants discontinued the study drug and 50 (10%) discontinued the study prematurely. At 40 weeks, all tirzepatide doses were superior to placebo for changes from baseline in HbA1c, fasting serum glucose, bodyweight, and HbA1c targets of less than 7·0% (<53 mmol/mol) and less than 5·7% (<39 mmol/mol). Mean HbA1c decreased from baseline by 1·87% (20 mmol/mol) with tirzepatide 5 mg, 1·89% (21 mmol/mol) with tirzepatide 10 mg, and 2·07% (23 mmol/mol) with tirzepatide 15 mg versus +0·04% with placebo (+0·4 mmol/mol), resulting in estimated treatment differences versus placebo of -1·91% (-21 mmol/mol) with tirzepatide 5 mg, -1·93% (-21 mmol/mol) with tirzepatide 10 mg, and -2·11% (-23 mmol/mol) with tirzepatide 15 mg (all p<0·0001). More participants on tirzepatide than on placebo met HbA1c targets of less than 7·0% (<53 mmol/mol; 87-92% vs 20%) and 6·5% or less (≤48 mmol/mol; 81-86% vs 10%) and 31-52% of patients on tirzepatide versus 1% on placebo reached an HbA1c of less than 5·7% (<39 mmol/mol). Tirzepatide induced a dose-dependent bodyweight loss ranging from 7·0 to 9·5 kg. The most frequent adverse events with tirzepatide were mild to moderate and transient gastrointestinal events, including nausea (12-18% vs 6%), diarrhoea (12-14% vs 8%), and vomiting (2-6% vs 2%). No clinically significant (<54 mg/dL [<3 mmol/L]) or severe hypoglycaemia were reported with tirzepatide. One death occurred in the placebo group. INTERPRETATION: Tirzepatide showed robust improvements in glycaemic control and bodyweight, without increased risk of hypoglycaemia. The safety profile was consistent with GLP-1 receptor agonists, indicating a potential monotherapy use of tirzepatide for type 2 diabetes treatment. FUNDING: Eli Lilly and Company.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Método Doble Ciego , Polipéptido Inhibidor Gástrico/uso terapéutico , Hipoglucemiantes/uso terapéutico , Peso Corporal/efectos de los fármacos , Femenino , Hemoglobina Glucada/análisis , Humanos , India , Japón , Masculino , Persona de Mediana Edad , América del Norte , Resultado del Tratamiento
4.
Clin Cancer Res ; 27(4): 992-1002, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33046516

RESUMEN

PURPOSE: We report the final analysis of JVDL (NCT02789345), which examined the combination of the EGFR tyrosine kinase inhibitor (TKI) osimertinib plus the VEGFR2-directed antibody ramucirumab in patients with T790M-positive EGFR-mutant non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: This open-label, single-arm phase I study enrolled patients with EGFR T790M-positive NSCLC, who had progressed following EGFR TKI but were third-generation EGFR TKI-naïve. A dose-limiting toxicity (DLT) period with as-needed dose deescalation was followed by an expansion cohort. Patients received daily oral osimertinib and intravenous ramucirumab every 2 weeks until progression or discontinuation. RESULTS: Twenty-five patients were enrolled. No DLTs were observed. Median follow-up time was 25.0 months. Common grade 3 or higher treatment-related adverse events (TRAE) were hypertension (8%) and platelet count decreased (16%); grade 5 TRAE (subdural hemorrhage) occurred in 1 patient. Patients with (N = 10) and without central nervous system (CNS) metastasis (N = 15) had similar safety outcomes. Five patients remain on treatment. Objective response rate (ORR) was 76%. Median duration of response was 13.4 months [90% confidence interval (CI): 9.6-21.2]. Median progression-free survival (PFS) was 11.0 months (90% CI: 5.5-19.3). Efficacy was observed in patients with and without CNS metastasis (ORR 60% and 87%; median PFS 10.9 and 14.7 months, respectively). Exploratory biomarker analyses in circulating tumor DNA suggested that on-treatment loss of EGFR Exon 19 deletion or L858R mutations, detectable at baseline, correlated with longer PFS, but on-treatment loss of T790M did not. Emergent genetic alterations postprogression included C797S, MET amplification, and EGFR amplification. CONCLUSIONS: Ramucirumab plus osimertinib demonstrated encouraging safety and antitumor activity in T790M-positive EGFR-mutant NSCLC.See related commentary by Garon, p. 905.


Asunto(s)
Acrilamidas/administración & dosificación , Compuestos de Anilina/administración & dosificación , Anticuerpos Monoclonales Humanizados/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Acrilamidas/efectos adversos , Anciano , Anciano de 80 o más Años , Compuestos de Anilina/efectos adversos , Anticuerpos Monoclonales Humanizados/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Supervivencia sin Enfermedad , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Mutación , Estadificación de Neoplasias , Supervivencia sin Progresión , Criterios de Evaluación de Respuesta en Tumores Sólidos , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Ramucirumab
5.
BMC Urol ; 20(1): 181, 2020 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-33160359

RESUMEN

BACKGROUND: To evaluate patient-reported outcomes with ramucirumab plus docetaxel, a regimen which improved progression-free survival in platinum-refractory advanced urothelial carcinoma (aUC). METHODS: RANGE-a randomized, double-blinded, phase 3 trial in patients with platinum-refractory aUC. Ramucirumab (10 mg/kg) plus docetaxel (75 mg/m2) or placebo plus docetaxel were administered every 21 days until disease progression or unacceptable toxicity. Patients received maximum 10 cycles of docetaxel. European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and EuroQoL five-dimensions (EQ-5D-5L) were administered at baseline, start of each cycle, and 30-day follow-up visit. A ≥ 10-point change in QLQ-C30 scores was considered meaningful. Rates of improved/stable scores were compared between treatment arms using Fisher's exact test. Time to deterioration (TtD) was estimated and compared using Kaplan-Meier estimation and log-rank test. RESULTS: Of the 530 patients, ~ 97% patients in each arm provided baseline QLQ-C30 data. On-treatment compliance was ≥ 88% for first 8 cycles. Mean baseline QLQ-C30 scores were similar between arms, with global quality of life (QoL), fatigue, pain, and insomnia having greatest impairment. Postbaseline rates of improved/stable QLQ-C30 scores were similar between treatment arms except for greater improvement in pain score with ramucirumab. TtD of QLQ-C30 scales favored ramucirumab arm. Baseline EQ-5D-5L index and visual analogue scale scores were similar between arms, followed by relatively stable on-treatment scores. EQ-5D-5L scores worsened at post-discontinuation follow-up visit. CONCLUSIONS: Ramucirumab plus docetaxel did not negatively impact QoL compared with docetaxel alone in platinum-refractory aUC. Improved TtD and tumor associated rates of pain favored ramucirumab treatment. CLINICAL TRAIL REGISTRATION: NCT02426125. https://clinicaltrials.gov/ct2/show/NCT02426125 . Date of registration: April 24th 2015.


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Células Transicionales/tratamiento farmacológico , Docetaxel/administración & dosificación , Calidad de Vida , Neoplasias Urológicas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Transicionales/patología , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Urológicas/patología , Ramucirumab
6.
Nucleic Acids Res ; 48(20): 11737-11749, 2020 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-33089330

RESUMEN

Double-stranded DNA viruses use ATP-powered molecular motors to package their genomic DNA. To ensure efficient genome encapsidation, these motors regulate functional transitions between initiation, translocation, and termination modes. Here, we report structural and biophysical analyses of the C-terminal domain of the bacteriophage phi29 ATPase (CTD) that suggest a structural basis for these functional transitions. Sedimentation experiments show that the inter-domain linker in the full-length protein promotes oligomerization and thus may play a role in assembly of the functional motor. The NMR solution structure of the CTD indicates it is a vestigial nuclease domain that likely evolved from conserved nuclease domains in phage terminases. Despite the loss of nuclease activity, fluorescence binding assays confirm the CTD retains its DNA binding capabilities and fitting the CTD into cryoEM density of the phi29 motor shows that the CTD directly binds DNA. However, the interacting residues differ from those identified by NMR titration in solution, suggesting that packaging motors undergo conformational changes to transition between initiation, translocation, and termination. Taken together, these results provide insight into the evolution of functional transitions in viral dsDNA packaging motors.


Asunto(s)
Empaquetamiento del ADN , ADN Viral/metabolismo , Proteínas de Unión al ADN/química , Empaquetamiento del Genoma Viral , Proteínas Virales/química , Fagos de Bacillus/química , Fagos de Bacillus/genética , Microscopía por Crioelectrón , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Esterasas/química , Evolución Molecular , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Unión Proteica , Dominios Proteicos , ARN Viral/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo
7.
Oncologist ; 25(11): e1628-e1639, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32537847

RESUMEN

LESSONS LEARNED: The combination of the antivascular endothelial growth factor receptor 2 monoclonal antibody, ramucirumab, and the type II MET kinase inhibitor, merestinib, is tolerable. Preliminary efficacy data suggest that the combination may provide clinical benefit to patients with metastatic colorectal cancer (mCRC). Further development of this combination would likely necessitate the identification of subsets of patients with mCRC where the clinical benefit is of clinical relevance. BACKGROUND: This study evaluated safety, preliminary efficacy, and pharmacokinetics of ramucirumab plus merestinib in patients with MCR previously treated with oxaliplatin and/or irinotecan. METHODS: Open-label phase Ia/b study comprising 3+3 dose-limiting toxicity (DLT) observation and expansion parts. Treatment was ramucirumab 8 mg/kg on days 1 and 15 and merestinib 80 mg once daily (QD; 28-day cycle). Primary objective was safety and tolerability. Secondary objectives were pharmacokinetics and preliminary antitumor activity. Exploratory objective was biomarker associations. RESULTS: Safety findings: DLT (proteinuria) of 7 phase Ia patients (the expansion part started at the initial recommended dose level); 16 patients (70%) with grade ≥3 treatment-emergent adverse events (TEAEs); 10 patients (43%) with grade ≥3 treatment-related TEAEs. The most common grade ≥3 treatment-related TEAEs were fatigue (4 patients [17%]) and increased blood alkaline phosphatase, diarrhea, and hypertension (2 patients each [9%]). One patient discontinued treatment because of cholestatic hepatitis. Geometric mean trough concentrations at cycle 1, day 15, were ramucirumab, 24.8 µg/mL; merestinib, 130 ng/mL. No complete or partial response was seen; 12 patients (52%) achieved stable disease. Median progression-free survival was 3.3 months (95% confidence interval [CI]: 1.6-4.4). Median overall survival was 8.9 months (95% CI: 3.5-12.7). There were no associations between genetic alterations and efficacy. CONCLUSION: Ramucirumab plus merestinib is tolerable and may have clinical benefit in biomarker-unselected, heavily pretreated patients with mCRC.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Colorrectales , Adolescente , Adulto , Anciano , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Colorrectales/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Ramucirumab
8.
Stat Med ; 39(15): 2017-2034, 2020 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-32185801

RESUMEN

In propensity score analysis, the frequently used regression adjustment involves regressing the outcome on the estimated propensity score and treatment indicator. This approach can be highly efficient when model assumptions are valid, but can lead to biased results when the assumptions are violated. We extend the simple regression adjustment to a varying coefficient regression model that allows for nonlinear association between outcome and propensity score. We discuss its connection with some propensity score matching and weighting methods, and show that the proposed analytical framework can shed light on the intrinsic connection among some mainstream propensity score approaches (stratification, regression, kernel matching, and inverse probability weighting) and handle commonly used causal estimands. We derive analytic point and variance estimators that properly take into account the sampling variability in the estimated propensity score. Extensive simulations show that the proposed approach possesses desired finite sample properties and demonstrates competitive performance in comparison with other methods estimating the same causal estimand. The proposed methodology is illustrated with a study on right heart catheterization.


Asunto(s)
Cateterismo Cardíaco , Causalidad , Humanos , Puntaje de Propensión
9.
Stat Methods Med Res ; 28(8): 2439-2454, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-29921162

RESUMEN

Inverse probability weighting can be used to estimate the average treatment effect in propensity score analysis. When there is lack of overlap in the propensity score distributions between the treatment groups under comparison, some weights may be excessively large, causing numerical instability and bias in point and variance estimation. We study a class of modified inverse probability weighting estimators that can be used to avoid this problem. These weights cause the estimand to deviate from the average treatment effect. We provide some justification for this deviation from the perspective of treatment effect discovery. We show that when lack of overlap occurs, the modified weights can achieve substantial gains in statistical power compared with inverse probability weighting and other propensity score methods. We develop analytical variance estimates that properly adjust for the sampling variability of the estimated propensity scores, and augment the modified inverse probability weighting estimator with outcome models for improved efficiency, a property that resembles double robustness. Results from extensive simulations and a real data application support our conclusions. The proposed methodology is implemented in R package PSW.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Transfusión de Eritrocitos , Cuidados Intraoperatorios , Tiempo de Internación/estadística & datos numéricos , Modelos Estadísticos , Simulación por Computador , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Método de Montecarlo , Estudios Observacionales como Asunto , Puntaje de Propensión , Proyectos de Investigación , Factores de Riesgo
10.
Stat Med ; 37(26): 3745-3763, 2018 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-29855060

RESUMEN

Propensity score analysis is widely used in observational studies to adjust for confounding and estimate the causal effect of a treatment on the outcome. When the outcome is survival time, there are special considerations on the definition of the causal estimand, point, and variance estimation that have not been thoroughly studied in the literature. We investigate propensity score analysis of survival data with a class of weighting methods. We consider the following estimands in the two-sample context: average survival time, restricted average survival time, survival probability, survival quantile, and the marginal hazard ratio. We propose a unified analytic framework to obtain the point and variance estimators. The proposed methodology properly adjusts for the sampling variability in the estimated propensity scores. Extensive simulations show that the point and variance estimators possess desired finite sample properties and demonstrate better numerical performance than some existing weighting and matching methods commonly used in the literature. The proposed methodology is illustrated with data from a breast cancer study.


Asunto(s)
Puntaje de Propensión , Análisis de Supervivencia , Anciano , Anciano de 80 o más Años , Algoritmos , Sesgo , Neoplasias de la Mama , Femenino , Humanos , Persona de Mediana Edad , Estudios Observacionales como Asunto , Evaluación de Resultado en la Atención de Salud
11.
Biom J ; 59(2): 331-343, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27983754

RESUMEN

Atrial fibrillation (AF) is an abnormal heart rhythm characterized by rapid and irregular heartbeat, with or without perceivable symptoms. In clinical practice, the electrocardiogram (ECG) is often used for diagnosis of AF. Since the AF often arrives as recurrent episodes of varying frequency and duration and only the episodes that occur at the time of ECG can be detected, the AF is often underdiagnosed when a limited number of repeated ECGs are used. In studies evaluating the efficacy of AF ablation surgery, each patient undergoes multiple ECGs and the AF status at the time of ECG is recorded. The objective of this paper is to estimate the marginal proportions of patients with or without AF in a population, which are important measures of the efficacy of the treatment. The underdiagnosis problem is addressed by a three-class mixture regression model in which a patient's probability of having no AF, paroxysmal AF, and permanent AF is modeled by auxiliary baseline covariates in a nested logistic regression. A binomial regression model is specified conditional on a subject being in the paroxysmal AF group. The model parameters are estimated by the Expectation-Maximization (EM) algorithm. These parameters are themselves nuisance parameters for the purpose of this research, but the estimators of the marginal proportions of interest can be expressed as functions of the data and these nuisance parameters and their variances can be estimated by the sandwich method. We examine the performance of the proposed methodology in simulations and two real data applications.


Asunto(s)
Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Biometría/métodos , Modelos Logísticos , Fibrilación Atrial/cirugía , Ablación por Catéter , Simulación por Computador , Electrocardiografía , Humanos , Prevalencia
12.
Cancer Cell ; 29(5): 711-722, 2016 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-27165743

RESUMEN

An individual's sex has been long recognized as a key factor affecting cancer incidence, prognosis, and treatment responses. However, the molecular basis for sex disparities in cancer remains poorly understood. We performed a comprehensive analysis of molecular differences between male and female patients in 13 cancer types of The Cancer Genome Atlas and revealed two sex-effect groups associated with distinct incidence and mortality profiles. One group contains a small number of sex-affected genes, whereas the other shows much more extensive sex-biased molecular signatures. Importantly, 53% of clinically actionable genes (60/114) show sex-biased signatures. Our study provides a systematic molecular-level understanding of sex effects in diverse cancers and suggests a pressing need to develop sex-specific therapeutic strategies in certain cancer types.


Asunto(s)
Genoma Humano/genética , Genómica/métodos , Neoplasias/genética , Neoplasias/metabolismo , Proteómica/métodos , Variaciones en el Número de Copia de ADN , Metilación de ADN , Femenino , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , MicroARNs/genética , Mutación , Neoplasias/clasificación , Factores Sexuales
13.
Cell Rep ; 14(8): 2017-2029, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26904950

RESUMEN

Ring NTPases are a class of ubiquitous molecular motors involved in basic biological partitioning processes. dsDNA viruses encode ring ATPases that translocate their genomes to near-crystalline densities within pre-assembled viral capsids. Here, X-ray crystallography, cryoEM, and biochemical analyses of the dsDNA packaging motor in bacteriophage phi29 show how individual subunits are arranged in a pentameric ATPase ring and suggest how their activities are coordinated to translocate dsDNA. The resulting pseudo-atomic structure of the motor and accompanying functional analyses show how ATP is bound in the ATPase active site; identify two DNA contacts, including a potential DNA translocating loop; demonstrate that a trans-acting arginine finger is involved in coordinating hydrolysis around the ring; and suggest a functional coupling between the arginine finger and the DNA translocating loop. The ability to visualize the motor in action illuminates how the different motor components interact with each other and with their DNA substrate.


Asunto(s)
Adenosina Trifosfatasas/química , Fagos de Bacillus/ultraestructura , ADN Viral/química , ADN/química , Subunidades de Proteína/química , Proteínas Virales/química , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/química , Arginina/química , Fagos de Bacillus/genética , Fagos de Bacillus/metabolismo , Bacillus subtilis/virología , Cápside/metabolismo , Cápside/ultraestructura , Microscopía por Crioelectrón , Cristalografía por Rayos X , ADN/genética , ADN/metabolismo , Empaquetamiento del ADN , ADN Viral/genética , ADN Viral/metabolismo , Expresión Génica , Hidrólisis , Modelos Moleculares , Dominios Proteicos , Estructura Secundaria de Proteína , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo , Ensamble de Virus
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