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1.
Children (Basel) ; 9(11)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36421180

RESUMO

Childhood acute lymphoblastic leukemia (ALL) survivors who underwent chemotherapy with anthracyclines have an increased cardiovascular risk. The aim of the study was to evaluate left and right cardiac chamber performances and vascular endothelial function in childhood ALL survivors. Fifty-four ALL survivors and 37 healthy controls were enrolled. All patients underwent auxological evaluation, blood pressure measurements, biochemical parameters of endothelial dysfunction, flow-mediated dilatation (FMD) of the brachial artery, mean common carotid intima-media thickness (c-IMT), antero-posterior diameter of the infra-renal abdominal aorta (APAO), and echocardiographic assessment. The ALL subjects had significantly lower FMD (p = 0.0041), higher left (p = 0.0057) and right (p = 0.0021) echocardiographic/Doppler Tei index (the non-invasive index for combined systolic and diastolic ventricular function) as compared to controls. Tricuspid annular plane excursion (TAPSE) was 16.9 ± 1.2 mm vs. 24.5 ± 3.7 mm, p < 0.0001. Cumulative anthracycline doses were related to TAPSE (p < 0.001). The ALL survivors treated with anthracyclines demonstrated systo/diastolic alterations of the right ventricle and reduced endothelial function compared with healthy controls. The early recognition of subclinical cardiac and vascular impairment during follow up is of utmost importance for the cardiologist to implement strategies preventing overt cardiovascular disease considering the growing number of young adults cured after childhood ALL.

2.
Front Psychol ; 13: 1095030, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36726507

RESUMO

Maternal-Fetal Attachment (MFA) delineates the emotional, cognitive, and behavioral aspects that mothers develop toward the unborn baby during pregnancy. The literature indicates that optimal attachment in pregnancy represents a protective factor for the mother-child attachment bond after birth and child development outcomes. To date, there are few studies that have investigated associated factors of MFA. This study sets out to explore the association between perceived parental bonds and maternal-fetal bonding in pregnant women, accounting for factors such as psychological distress, socio-demographic and obstetric characteristics. Methods: In this cross-sectional study, 1,177 pregnant women answered the Parental Bonding Instrument, the Maternal-Fetal Attachment Scale, State-Trait Anxiety Inventory (STAI-Y), and Beck-Depression Inventory (BDI-II). Results: We found out that perceived maternal and paternal care had significant direct effects on maternal-infant bonding during the pregnancy period when controlling for some confounders, including gestational age and mother age among others. Such maternal and paternal perceived care effects were not mediated by levels of psychological distress, which in turn resulted to be a "borderline" significant predictor of prenatal attachment. Interestingly, the gestational age and the mother age emerged to have a significant and synergic nonlinear effect, suggesting the influence on the MFAS of the gestational age depends on the values of the mother age, and likewise, the effect of mother age on MFAS depends on the gestational week. Conclusion: This study expands our knowledge of the intergenerational transmission of attachment pointing out the effects of a woman's perceived bond in relation to her parental figures during the development of the prenatal attachment process. Findings also suggests that parenting support interventions may have benefits that are realized across generations.

3.
J Affect Disord ; 295: 665-672, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34509782

RESUMO

BACKGROUND: Evidence concerning the impact of COVID-19-related stress exposure on prenatal attachment in pregnant women is unknown. In this study we sought to assess the effect of psychological distress and risk perception of COVID-19 on prenatal attachment in a Italian sample of pregnant women. METHODS: 1179 pregnant women completed an anonymous online survey and self-report questionnaires measuring socio-demographic and obstetric characteristics, psychological distress (STAI Form Y-1-2 and BDI-II), prenatal attachment (PAI) and risk perception of COVID-19. Data were collected from March 2020 to April 2020 referring to the national lockdown period. RESULTS: After adjusting for the socio-demographic and obstetric factors in the multivariable analysis, we found out the state anxiety was shown to be a significant predictor (p < 0001) of prenatal attachment. Moreover, the COVID-19-risk perception positively moderate the relationship between trait anxiety and prenatal attachment (p=0008), indicating that when COVID-19-risk perception is high, the effects of trait anxiety on prenatal attachment is attenuated. The synergistic effect between STAI Form Y-1 and COVID-19-risk perception index on PAI is partially mediated by STAI Form Y-2 score. CONCLUSIONS: Findings from this study showed that state anxiety related to COVID-19 outbreak in pregnant women may affect the prenatal attachment process of the expectant mother negatively. However, an adequate and functional perception of COVID-19 could enhance prenatal attachment. These results underline the importance of monitoring the prenatal attachment process and the mother's mental health during pandemics, to safeguard maternal and infant mental health.


Assuntos
COVID-19 , Angústia Psicológica , Ansiedade/epidemiologia , Controle de Doenças Transmissíveis , Depressão , Feminino , Humanos , Lactente , Itália/epidemiologia , Percepção , Gravidez , Gestantes , SARS-CoV-2 , Estresse Psicológico
4.
Am J Epidemiol ; 190(11): 2384-2394, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34010956

RESUMO

The prevalence of ideal cardiovascular health (CVH) among adults in the United States is low and decreases with age. Our objective was to identify specific age windows when the loss of CVH accelerates, to ascertain preventive opportunities for intervention. Data were pooled from 5 longitudinal cohorts (Project Heartbeat!, Cardiovascular Risk in Young Finns Study, The Bogalusa Heart Study, Coronary Artery Risk Development in Young Adults, Special Turku Coronary Risk Factor Intervention Project) from the United States and Finland from 1973 to 2012. Individuals with clinical CVH factors (i.e., body mass index, blood pressure, cholesterol, blood glucose) measured from ages 8 to 55 years were included. These factors were categorized and summed into a clinical CVH score ranging from 0 (worst) to 8 (best). Adjusted, segmented, linear mixed models were used to estimate the change in CVH over time. Among the 18,343 participants, 9,461 (52%) were female and 12,346 (67%) were White. The baseline mean (standard deviation) clinical CVH score was 6.9 (1.2) at an average age of 17.6 (8.1) years. Two inflection points were estimated: at 16.9 years (95% confidence interval: 16.4, 17.4) and at 37.2 years (95% confidence interval: 32.4, 41.9). Late adolescence and early middle age appear to be influential periods during which the loss of CVH accelerates.


Assuntos
Comportamentos Relacionados com a Saúde , Fatores de Risco de Doenças Cardíacas , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Adulto Jovem
6.
J Clin Med ; 9(11)2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33187300

RESUMO

BACKGROUND: Asthma patterns are not well established in epidemiological studies. AIM: To assess asthma patterns and risk factors in an adult general population sample. METHODS: In total, 452 individuals reporting asthma symptoms/diagnosis in previous surveys participated in the AGAVE survey (2011-2014). Latent transition analysis (LTA) was performed to detect baseline and 12-month follow-up asthma phenotypes and longitudinal patterns. Risk factors associated with longitudinal patterns were assessed through multinomial logistic regression. RESULTS: LTA detected four longitudinal patterns: persistent asthma diagnosis with symptoms, 27.2%; persistent asthma diagnosis without symptoms, 4.6%; persistent asthma symptoms without diagnosis, 44.0%; and ex -asthma, 24.1%. The longitudinal patterns were differently associated with asthma comorbidities. Persistent asthma diagnosis with symptoms showed associations with passive smoke (OR 2.64, 95% CI 1.10-6.33) and traffic exposure (OR 1.86, 95% CI 1.02-3.38), while persistent asthma symptoms (without diagnosis) with passive smoke (OR 3.28, 95% CI 1.41-7.66) and active smoke (OR 6.24, 95% CI 2.68-14.51). CONCLUSIONS: LTA identified three cross-sectional phenotypes and their four longitudinal patterns in a real-life setting. The results highlight the necessity of a careful monitoring of exposure to active/passive smoke and vehicular traffic, possible determinants of occurrence of asthma symptoms (with or without diagnosis). Such information could help affected patients and physicians in prevention and management strategies.

7.
Stat Methods Med Res ; 29(3): 765-777, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30991902

RESUMO

This paper focuses on hypothesis testing in lasso regression, when one is interested in judging statistical significance for the regression coefficients in the regression equation involving a lot of covariates. To get reliable p-values, we propose a new lasso-type estimator relying on the idea of induced smoothing which allows to obtain appropriate covariance matrix and Wald statistic relatively easily. Some simulation experiments reveal that our approach exhibits good performance when contrasted with the recent inferential tools in the lasso framework. Two real data analyses are presented to illustrate the proposed framework in practice.


Assuntos
Projetos de Pesquisa , Simulação por Computador
8.
Respir Med ; 158: 33-41, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31585374

RESUMO

BACKGROUND: Few population-based studies on the effects of environmental exposure variation exist. AIM: Assessing respiratory symptom/disease incidence related to risk factor exposure changes. METHODS: A longitudinal general population sample from two surveys (PISA2:1991-1993; PISA3:2009-2011; no. = 970), aged ≥20 years at baseline, completed a questionnaire on respiratory symptoms/diseases, risk factor exposure and performed spirometry. 18-year follow-up cumulative incidence of respiratory symptoms/diseases and longitudinal changes (persistence, incidence, remittance) in risk factor exposure were computed. RESULTS: Cumulative incidence values were: 3.2% (corresponding to a 1.8‰/year incidence rate), asthma; 6.6% (3.8‰/year), asthma attacks; 4.5% (2.6‰/year), wheeze; 31.7% (21.0‰/year), allergic rhinitis-AR; 7.6% (4.4‰/year), chronic obstructive pulmonary disease-COPD; 16.1% (9.7‰/year), usual cough; 18.5% (11.3‰/year), usual phlegm; 30.7% (20.1‰/year), dyspnoea 1+; 13.9% (8.3‰/year), airway obstruction. The following associations emerged among respiratory symptom/disease cumulative incidence and risk factor exposure changes: a two-to-five fold higher risk for COPD, phlegm, cough, dyspnoea, asthma attacks, airway obstruction in persistent smokers; a two-to-three fold higher risk for COPD in remittent smokers; a two-fold higher risk for AR, phlegm and a four-fold higher risk for asthma in subjects with persistent occupational exposure; a two-fold higher risk for cough, phlegm, dyspnoea, AR in subjects with incident occupational exposure; a two-fold higher risk for AR, asthma attacks, COPD in subjects with incident traffic exposure. CONCLUSIONS: Our study showed noteworthy respiratory symptom/disease incidence values and indicated that life-style and environmental exposure changes can differently influence onset. This information could be useful for primary prevention strategies in order to reduce the chronic disease burden in the general population.


Assuntos
Transtornos Respiratórios/epidemiologia , Transtornos Respiratórios/etiologia , Adulto , Idoso , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fumar/efeitos adversos , Inquéritos e Questionários , Fatores de Tempo , Adulto Jovem
9.
World J Pediatr ; 15(5): 465-470, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31055782

RESUMO

BACKGROUND: Vitamin D (25-OHD) has a role in bone health after treatment for cancer. 25-OHD deficiency has been associated with risk factors for cardiovascular disease, but no data focusing on this topic in childhood cancer survivors have been published. We investigated the 25-OHD status in children treated for acute lymphoblastic leukemia (ALL), and evaluated its influence on vascular function. METHODS: 25-OHD levels were evaluated in 52 ALL survivors and 40 matched healthy controls. Patients were grouped according to 25-OHD level (< 20 ng/m or ≥ 20 ng/ml). Auxological parameters, biochemical and hemostatic markers of endothelial function (AD, HMW-AD, ET-1, vWFAg, TAT, D-dimers, Fbg, and hs-CRP), ultrasound markers of vascular endothelial function (flow-mediated dilatation, FMD, common carotid intima-media thickness, C-IMT, and antero-posterior diameter of infra-renal abdominal aorta, APAO) were evaluated in the patients. RESULTS: Cases showed higher prevalence of 25-OHD deficiency than controls (p = 0.002). In univariate analysis via mean comparisons, 25-OHD deficient (< 20 ng/ml) patients showed higher C-IMT values compared to the 25-OHD non-deficient (≥ 20 ng/ml) group (P = 0.023). Significant differences were also found for ET-1 (P = 0.035) and AD-HMW (P = 0.015). In the multiple regression models controlling for some confounders, 25-OHD still was associated with C-IMT (P = 0.0163), ET-1 (P = 0.0077), and AD-HMW (P = 0.0008). CONCLUSIONS: Childhood ALL survivors show higher prevalence of 25-OHD deficiency as compared to controls. The 25-OHD levels appear to be linked to indicators of endothelial and vascular dysfunction. Careful monitoring of 25-OHD balance may help to prevent cardiovascular diseases in childhood ALL survivors, characterized by high cardiovascular risk.


Assuntos
Endotélio Vascular/fisiopatologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Sobreviventes , Deficiência de Vitamina D/complicações , Adolescente , Biomarcadores/análise , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Fatores de Risco , Adulto Jovem
10.
Clin Exp Med ; 18(3): 355-361, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29623491

RESUMO

Hereditary angioedema (HAE) is a rare autosomic-dominant disorder characterized by a deficiency of C1 esterase inhibitor which causes episodic swellings of subcutaneous tissues, bowel walls and upper airways that are disabling and potentially life-threatening. We evaluated n = 17 patients with confirmed HAE diagnosis during attack and remission state and n = 19 healthy subjects. The samples were tested for a panel of IL (Interleukin)-17-type cytokines (IL-1ß, IL-6, IL-10, granulocyte-macrophage colony stimulating factor (GM-CSF), IL-17, IL-21, IL-22, IL-23) and transforming growth factor-beta (TGF-ß) subtypes. Data indicate that there are variations of cytokine levels in HAE subjects comparing the condition during the crisis respect to the value in the remission phase, in particular type 17 signature cytokines are increased, whereas IL-23 is unmodified and TGF-ß3 is significantly reduced. When comparing healthy and HAE subjects in the remission state, we found a significant difference for IL-17, GM-CSF, IL-21, TGF-ß1 and TGF-ß2 cytokines. These results confirm and extend our previous findings indicating that in HAE there is operating an inflammatory activation process, which involves also T helper 17 (Th17) cytokines and TGF-ß isoforms, associated with localized angioedema attacks and characterized by elevated bradykinin levels.


Assuntos
Angioedemas Hereditários/diagnóstico , Angioedemas Hereditários/imunologia , Regulação da Expressão Gênica/imunologia , Interleucina-17/imunologia , Células Th17/imunologia , Fator de Crescimento Transformador beta/imunologia , Adolescente , Adulto , Idoso , Angioedemas Hereditários/genética , Angioedemas Hereditários/patologia , Bradicinina/genética , Bradicinina/imunologia , Brônquios/imunologia , Brônquios/patologia , Estudos de Casos e Controles , Criança , Proteína Inibidora do Complemento C1/genética , Proteína Inibidora do Complemento C1/imunologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Interleucina-17/genética , Interleucina-23/genética , Interleucina-23/imunologia , Interleucinas/genética , Interleucinas/imunologia , Intestinos/imunologia , Intestinos/patologia , Masculino , Pessoa de Meia-Idade , Tela Subcutânea/imunologia , Tela Subcutânea/patologia , Células Th17/patologia , Fator de Crescimento Transformador beta/genética , Interleucina 22
11.
JAMA Cardiol ; 3(5): 427-431, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29562081

RESUMO

Importance: Given that hypertension remains a leading risk factor for chronic disease globally, there are substantial ongoing efforts to define the optimal range of blood pressure (BP). Objective: To identify a common threshold level above which BP rise tends to accelerate in progression toward hypertension. Design, Setting, and Participants: This longitudinal, community-based epidemiological cohort study of adults enrolled in Framingham, Massachusetts, included 1252 participants (mean [SD] age, 35.3 [2.7] years) from the Framingham Original Cohort, of whom 790 (63.1%) were women. Each participant contributed up to 28 serial examinations of standardized resting BP measurements between 1948 and 2005. Exposures: Age and systolic BP. Main Outcomes and Measures: Via a segmented mixed model, we identified significant change points in the association between advancing age and increasing systolic BP among individuals categorized by their age at hypertension onset. Results: Individuals maintained a relatively stable resting systolic BP level prior to hypertension onset. Systolic BP level began to rise at a more rapid rate after reaching a level of 123.2 mm Hg (95% CI, 122.7-130.1 mm Hg) in people with onset at 40 to 49 years; 122.0 mm Hg (95% CI, 120.3-123.9 mm Hg) in those with onset between 50 and 59 years, 124.9 mm Hg (95% CI, 120.2-127.9 mm Hg) in those with onset between 60 and 69 years, and 120.5 mm Hg (95% CI, 118.0-123.2 mm Hg) in those with onset between 70 and 79 years (P = .29 for between-group heterogeneity). Conclusions and Relevance: We observed that individuals in the community generally maintained a systolic BP of less than 120 to 125 mm Hg, above which systolic BP increased at a relatively rapid rate toward overt hypertension. This trend was consistent whether the hypertension manifested earlier or later in life. Thus, a resting systolic BP that chronically exceeds the range of approximately 120 to 125 mm Hg may represent an important threshold of underlying vascular remodeling and signal incipient hypertension irrespective of age. Further investigations are needed to unravel the sequence of hemodynamic and vascular changes occurring prior to hypertension onset.


Assuntos
Pressão Sanguínea/fisiologia , Hipertensão/fisiopatologia , Adulto , Fatores Etários , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Hipertensão/etiologia , Estudos Longitudinais , Masculino , Massachusetts , Pessoa de Meia-Idade , Fatores Sexuais
12.
Stat Methods Med Res ; 27(5): 1365-1375, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-27510370

RESUMO

This paper focuses on inferential tools in the logistic regression model fitted by the Firth penalized likelihood. In this context, the Likelihood Ratio statistic is often reported to be the preferred choice as compared to the 'traditional' Wald statistic. In this work, we consider and discuss a wider range of test statistics, including the robust Wald, the Score, and the recently proposed Gradient statistic. We compare all these asymptotically equivalent statistics in terms of interval estimation and hypothesis testing via simulation experiments and analyses of two real datasets. We find out that the Likelihood Ratio statistic does not appear the best inferential device in the Firth penalized logistic regression.


Assuntos
Modelos Logísticos , Tamanho da Amostra , Interpretação Estatística de Dados , Humanos , Funções Verossimilhança , Modelos Estatísticos , Estatística como Assunto
13.
Clin Trials ; 14(5): 483-488, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28670909

RESUMO

INTRODUCTION: Bias may occur in randomized clinical trials in favor of the new experimental treatment because of unblinded assessment of subjective endpoints or wish bias. Using results from published trials, we analyzed and compared the treatment effect of hepatitis C antiviral interferon therapies experimental or control. METHODS: Meta-regression of trials enrolling naïve hepatitis C virus patients that underwent four therapies including interferon alone or plus ribavirin during past years. The outcome measure was the sustained response evaluated by transaminases and/or hepatitis C virus-RNA serum load. Data on the outcome across therapies were collected according to the assigned arm (experimental or control) and to other trial and patient-level characteristics. RESULTS: The overall difference in efficacy between the same treatment labeled experimental or control had a mean of +11.9% (p < 0.0001). The unadjusted difference favored the experimental therapies of group IFN-1 (+6%) and group IFN-3 (+10%), while there was no difference for group IFN-2 because of success rates from large multinational trials. In a meta-regression model with trial-specific random effects including several trial and patient-level variables, treatment and arm type remained significant (p < 0.0001 and p = 0.0009 respectively) in addition to drug-schedule-related variables. CONCLUSION: Our study indicates the same treatment is more effective when labeled "experimental" compared to when labeled "control" in a setting of trials using an objective endpoint and even after adjusting for patient and study-level characteristics. We discuss several factors related to design and conduct of hepatitis C trials as potential explanations of the bias toward the experimental treatment.


Assuntos
Antivirais/uso terapêutico , Viés , Hepatite C/tratamento farmacológico , Interferons/uso terapêutico , Variações Dependentes do Observador , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Adulto , Estudos de Casos e Controles , Humanos , Pessoa de Meia-Idade , Projetos de Pesquisa , Resultado do Tratamento
15.
PLoS One ; 7(6): e38363, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22761680

RESUMO

BACKGROUND: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal's behaviour, which contributes to an understanding of species' responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. METHODOLOGY/PRINCIPAL FINDINGS: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007-2009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. CONCLUSIONS/SIGNIFICANCE: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal's perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions based on convention or common practice.


Assuntos
Migração Animal/fisiologia , Comportamento Animal , Ecossistema , Elefantes/fisiologia , Chuva , Estações do Ano , Animais , Meio Ambiente , Feminino , África do Sul , Temperatura
16.
OMICS ; 15(5): 267-72, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21332389

RESUMO

The transcription factor Yin Yang 1 (YY1) can favor several aspects of tumorigenesis. In turn, Raf-1 Kinase Inhibitor Protein (RKIP) inhibits the oncogenic activities of MAPK and NF-κB pathways and promotes drug-induced apoptosis. Mutual influences between YY1 and RKIP may exist, and there are already separate evidences that relevant increases in YY1 and reductions in RKIP occur in hepatocellular carcinoma (HCC). However, the levels of the two factors have never been concomitantly examined in HCC. We evaluated by RT-PCR the mRNA levels of YY1, YY1AP, RKIP, and survivin in 35 clinical HCCs (91% HCV-related), in their adjacent cirrhotic tissues and in 6 healthy livers. Immunohistochemical analyses were also performed. The ratio of YY1 to RKIP mRNA was constantly profoundly inverted in the tumors compared with the adjacent nontumoral tissues. A similar result occurred frequently at protein level. Hyperactivation of YY1 in tumors was corroborated by its nuclear localization and the finding that in the tumors there were also increases in YY1AP, a YY1 coactivator not expressed in normal liver, and in survivin, as a possible target of YY1. The frequent alteration in the YY1-RKIP balance might represent a marker of malignant progression and be exploited for therapeutic interventions in HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Fator de Transcrição YY1/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Inibidoras de Apoptose/genética , Fígado/metabolismo , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Proteína de Ligação a Fosfatidiletanolamina/genética , RNA Mensageiro/genética , Survivina , Fatores de Transcrição/genética , Fator de Transcrição YY1/genética
17.
Stat Methods Med Res ; 20(4): 401-14, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20223783

RESUMO

In this article we propose a parsimonious parameterisation to model the so-called erosion of the covariate effect in the Cox model, namely a covariate effect approaching to zero as the follow-up time increases. The proposed parameterisation is based on the segmented relationship where proper constraints are set to accomodate for the erosion. Relevant hypothesis testing is discussed. The approach is illustrated on two historical datasets in the survival analysis literature, and some simulation studies are presented to show how the proposed framework leads to a test for a global effect with good power as compared with alternative procedures. Finally, possible generalisations are also presented for future research.


Assuntos
Modelos de Riscos Proporcionais , Simulação por Computador/estatística & dados numéricos , Seguimentos , Humanos , Cirrose Hepática Biliar/epidemiologia , Nefrite Lúpica/epidemiologia , Dinâmica não Linear
18.
Bioinformatics ; 27(2): 161-6, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21088029

RESUMO

MOTIVATION: Knowing the exact locations of multiple change points in genomic sequences serves several biological needs, for instance when data represent aCGH profiles and it is of interest to identify possibly damaged genes involved in cancer and other diseases. Only a few of the currently available methods deal explicitly with estimation of the number and location of change points, and moreover these methods may be somewhat vulnerable to deviations of model assumptions usually employed. RESULTS: We present a computationally efficient method to obtain estimates of the number and location of the change points. The method is based on a simple transformation of data and it provides results quite robust to model misspecifications. The efficiency of the method guarantees moderate computational times regardless of the series length and the number of change points. AVAILABILITY: The methods described in this article are implemented in the new R package cumSeg available from the Comprehensive R Archive Network at http://CRAN.R-project.org/package=cumSeg.


Assuntos
Genômica/métodos , Neoplasias da Mama/genética , Linhagem Celular , Linhagem Celular Tumoral , Hibridização Genômica Comparativa , Simulação por Computador , Feminino , Humanos , Modelos Estatísticos , Análise de Sequência com Séries de Oligonucleotídeos
19.
Stat Med ; 29(18): 1947-57, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20680987

RESUMO

We propose a simple and flexible framework for the crossing hazards problem. The method is not confined to two-sample problems, but may also work with continuous exposure variables whose effect changes its sign at some time-point of the observed follow-up time. Penalized partial likelihood estimation relies upon the assumption of a smooth hazard ratio via low-rank basis splines with a conventional difference penalty to ensure smoothness, and additional ad hoc penalties to obtain restricted estimates useful in the context of crossing hazards. The framework naturally also leads to a statistical test that has good power for revealing a global effect under several alternatives, including crossing hazards. We provide the results from a real-data analysis and from some simulations to illustrate empirically the performance of the proposed approach as compared with the possible alternatives.


Assuntos
Modelos de Riscos Proporcionais , Análise de Sobrevida , Algoritmos , Biometria , Feminino , Humanos , Funções Verossimilhança , Masculino
20.
Stat Med ; 29(18): 1958-60; author reply 1961, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20680988

RESUMO

We discuss some issues relevant to paper of Clegg and co-authors published in Statistics in Medicine; 28, 3670-3682. Emphasis is on computation of the variance of the sum of products of two estimates, slopes and breakpoints.


Assuntos
Interpretação Estatística de Dados , Dinâmica não Linear , Algoritmos , Feminino , Humanos , Masculino , Grupos Raciais , Fatores de Tempo
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