Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 142
Filtrar
1.
Med Image Anal ; 90: 102967, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37778102

RESUMO

Any clinically-deployed image-processing pipeline must be robust to the full range of inputs it may be presented with. One popular approach to this challenge is to develop predictive models that can provide a measure of their uncertainty. Another approach is to use generative modelling to quantify the likelihood of inputs. Inputs with a low enough likelihood are deemed to be out-of-distribution and are not presented to the downstream predictive model. In this work, we evaluate several approaches to segmentation with uncertainty for the task of segmenting bleeds in 3D CT of the head. We show that these models can fail catastrophically when operating in the far out-of-distribution domain, often providing predictions that are both highly confident and wrong. We propose to instead perform out-of-distribution detection using the Latent Transformer Model: a VQ-GAN is used to provide a highly compressed latent representation of the input volume, and a transformer is then used to estimate the likelihood of this compressed representation of the input. We demonstrate this approach can identify images that are both far- and near- out-of-distribution, as well as provide spatial maps that highlight the regions considered to be out-of-distribution. Furthermore, we find a strong relationship between an image's likelihood and the quality of a model's segmentation on it, demonstrating that this approach is viable for filtering out unsuitable images.


Assuntos
Processamento de Imagem Assistida por Computador , Humanos , Probabilidade , Incerteza
2.
Sci Data ; 10(1): 726, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37863915

RESUMO

Microplastics (<5 mm) pollution is a growing problem affecting coastal communities, marine ecosystems, aquatic life, and human health. The widespread occurrence of marine microplastics, and the need to curb its threats, require expansive, and continuous monitoring. While microplastic research has increased in recent years and generated significant volumes of data, there is a lack of a robust, open access, and long-term aggregation of this data. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) now provides a global open access to marine microplastics data on an easily discoverable and accessible GIS web map and data portal ( https://www.ncei.noaa.gov/products/microplastics ). The objective of this data portal is to develop a repository where microplastics data are aggregated, archived, and served in a user friendly, consistent, and reliable manner. This work contributes to NCEI's efforts towards data standardization, integration, harmonization, and interoperability among national and international collaborators for monitoring global marine microplastics. This paper describes the NOAA NCEI global marine microplastics database, its creation, quality control procedures, and future directions.

3.
Eur J Cancer ; 175: 236-245, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36155117

RESUMO

BACKGROUND: The cyclin-dependent kinase 4/6 inhibitor palbociclib has demonstrated efficacy and a manageable safety profile in combination with endocrine therapy in women with oestrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) in international phase 3 trials. The phase 3 PALOMA-4 trial evaluated the efficacy and safety of palbociclib plus letrozole versus placebo plus letrozole in Asian women with ER+/HER2- ABC. METHODS: Postmenopausal women (n = 340) with no prior systemic treatment for advanced disease were randomised 1:1 to palbociclib (125 mg/d orally; 3 weeks on, 1 week off) plus letrozole (2.5 mg/d orally; continuously) or placebo plus letrozole. The primary end-point was investigator-assessed progression-free survival (PFS). Secondary end-points included tumour response and safety. RESULTS: Median (95% CI) PFS was 21.5 (16.6-24.9) months with palbociclib plus letrozole and 13.9 (13.7-16.6) months with placebo plus letrozole (hazard ratio, 0.68 [95% CI, 0.53-0.87]; P = 0.0012). Consistent with the established safety profile, the most common adverse events (AEs) with palbociclib plus letrozole were neutropenia, leukopenia, thrombocytopaenia, and anaemia. Grade 3/4 neutropenia was reported in 84.5% of patients in the palbociclib arm versus 1.2% in the placebo arm. One serious AE of febrile neutropenia in the palbociclib group was reported. CONCLUSIONS: Findings from PALOMA-4 support the efficacy and safety of first-line palbociclib plus letrozole in postmenopausal Asian women with ER+/HER2- ABC. No new safety concerns of palbociclib plus letrozole were identified. TRIAL REGISTRATION: Clinicaltrials. gov, NCT02297438.


Assuntos
Neoplasias da Mama , Neutropenia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/patologia , Quinase 4 Dependente de Ciclina , Feminino , Humanos , Letrozol , Neutropenia/tratamento farmacológico , Piperazinas , Pós-Menopausa , Piridinas , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo
4.
Pediatr Pulmonol ; 57(1): 300-307, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34633156

RESUMO

OBJECTIVES: To assess the association of cumulative fluid overload (FO) up to 14 days from the diagnosis of pediatric acute respiratory syndrome (PARDS) with pediatric intensive care unit (PICU) mortality, 28-day mechanical ventilation free days (VFD), and 28-day intensive care unit free days (IFD). We hypothesized that fluid overload, even beyond the acute period, would be associated with increased morbidity and mortality. METHODS: We conducted a retrospective cohort study of PARDS patients admitted to PICU from 2009 to 2015. For repeated admissions, we considered the admission with the highest oxygenation index (OI). Daily FO (%) was calculated as (intake - output)/weight at PICU admission × 100. Peak cumulative FO (CFO) was the highest CFO from the diagnosis of PARDS to Day 14 or to PICU discharge or mortality, whichever was earliest. Rate to peak CFO was the peak CFO divided by the number of days to reach that highest CFO. The association of FO with mortality, VFD and IFD were analyzed with logistic and linear regression models, with the following covariates: Pediatric Index of Mortality 2 score, PARDS severity, and the presence of acute kidney injury (AKI). RESULTS: There were 165 patients included in this study, with a mortality rate of 45.5% (75/165), median age 3.2 years (interquartile range [IQR] 0.7-9.9) and OI 15.8 (IQR 9.5-27.9). Seventy-three (44.2%) patients had severe PARDS and 64 (38.8%) had AKI. AKI (aOR [adjusted odds ratio] 3.19, 95% CI [confidence interval] 1.43-7.09, p = 0.004) and rate to peak cumulative FO (aOR 1.23, 95% CI 1.07-1.42, p = 0.004) were associated with mortality. AKI and peak cumulative FO were associated with decreased VFD and IFD. CONCLUSION: The rate to peak CFO over the first 14 days of PARDS was associated with mortality and peak CFO was associated with decreased VFD and IFD.


Assuntos
Síndrome do Desconforto Respiratório , Desequilíbrio Hidroeletrolítico , Criança , Pré-Escolar , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica , Respiração Artificial , Síndrome do Desconforto Respiratório/diagnóstico , Estudos Retrospectivos , Desequilíbrio Hidroeletrolítico/etiologia
6.
Panminerva Med ; 64(2): 274-288, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34609116

RESUMO

According to the International Diabetes Federation, the number of adults (age of 20-79) being diagnosed with diabetes mellitus (DM) have increased from 285 million in year 2009 to 463 million in year 2019 which comprises of 95% type 2 DM patient (T2DM). Research have claimed that genetic predisposition could be one of the factors causing T2DM complications. In addition, T2DM complications cause an incremental risk to mortality. Therefore, this article aims to discuss some complications of T2DM in and their genetic association. The complications that are discussed in this article are diabetic nephropathy, diabetes induced cardiovascular disease, diabetic neuropathy, diabetic foot ulcer (DFU) and Alzheimer's disease (AD). According to the information obtained, genes associated with diabetic nephropathy (DN) are gene GABRR1 and ELMO1 that cause injury to glomerular. Replication of genes FRMD3, CARS and MYO16/IRS2 shown to have link with DN. The increase of gene THBS2, NGAL, PIP, TRAF6 polymorphism, ICAM-1 encoded for rs5498 polymorphism and C667T increase susceptibility towards DN in T2DM patient. Genes associated with cardiovascular diseases are adiponectin gene (ACRP30) and apolipoprotein E (APOE) polymorphism gene with ξ2 allele. Haptoglobin (Hp) 1-1 genotype and mitochondria superoxide dismutase 2 (SOD2) plays a role in cardiovascular events. As for genes related to diabetic neuropathy, janus kinase (JAK), mutation of SCN9A and TRPA1 gene and destruction of miRNA contribute to pathogenesis of diabetic neuropathy among T2DM patients. Expression of cytokine IL-6, IL-10, miR-146a are found to cause diabetic neuropathy. Besides, A1a16Va1 gene polymorphism, an oxidative stress influence was found as one of the gene factors. Diabetic retinopathy (DR) is believed to have association with monocyte chemoattractant protein-1 (MCP-1) and insulin-like growth factor 1 (IGF1). Over-expression of gene ENPP1, IL-6 pro-inflammatory cytokine, ARHGAP22's protein rs3844492 polymorphism and TLR4 heterozygous genotype are contributing to significant pathophysiological process causing DR, while research found increases level of UCP1 gene protects retina cells from oxidative stress. DFU is manifested by slowing in re-epithelialization of keratinocyte, persistence wound inflammation and healing impairment. Re-epithelialization disturbance was caused by E2F3 gene, reduction of Tacl gene encoded substance P causing persistence inflammation while expression of MMp-9 polymorphism contributes to healing impairment. A decrease in HIF-1a gene expression leads to increased risk of pathogenesis, while downregulation of TLR2 increases severity of wound in DFU patients. SNPs alleles has been shown to have significant association between the genetic dispositions of T2DM and AD. The progression of AD can be due to the change in DNA methylation of CLOCK gene, followed with worsening of AD by APOE4 gene due to dyslipidemia condition in T2DM patients. Insulin resistance is also a factor that contributes to pathogenesis of AD.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Pé Diabético , Nefropatias Diabéticas , Neuropatias Diabéticas , Retinopatia Diabética , Adulto , Doenças Cardiovasculares/complicações , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Pé Diabético/complicações , Pé Diabético/diagnóstico , Pé Diabético/genética , Nefropatias Diabéticas/diagnóstico , Nefropatias Diabéticas/genética , Neuropatias Diabéticas/complicações , Neuropatias Diabéticas/genética , Predisposição Genética para Doença , Genótipo , Humanos , Inflamação , Interleucina-6/genética , Canal de Sódio Disparado por Voltagem NAV1.7/genética , Polimorfismo de Nucleotídeo Único
7.
J Gambl Stud ; 36(2): 477-498, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31620927

RESUMO

Compared to the general population, military personnel are particularly vulnerable to developing gambling problems. The present study examined the presentation of gambling-including gambling frequency, personal thoughts on reducing gambling and recommendations from others to reduce gambling-across these populations. Additionally, the study measured the association between gambling and various psychosocial risk and protective factors-including psychological distress, suicidal ideation, external encouragement to reduce substance use, days out of role, personal wellbeing, resilience, social support and intimate bonds. Data was extracted from the Global Health & Wellbeing Survey, an online self-report survey conducted in Australia, Canada, New Zealand, the United Kingdom and the United States. Of the 10,765 eligible respondents, 394 were military veterans and 337 were active military personnel. Consistent with previous research, a higher proportion of gambling behaviours were observed in both current and ex-serving military samples, compared to the general population. To varying degrees, significant associations were found between the different gambling items and all psychosocial risk and protective factors in the general population sample. However, the military sample yielded only one significant association between gambling frequency and the protective factor 'resilience'. A post hoc stepwise linear regression analysis demonstrated the possible mediating role resilience plays between gambling frequency and other psychosocial risk (psychological distress, and suicidal thoughts and behaviour) and protective factors (personal wellbeing) for the military sample. Given the findings, it is recommended that routine screening tools identifying problem gambling are used within the military, and subsequent resilience focused interventions are offered to at risk personnel.


Assuntos
Jogo de Azar/psicologia , Militares/psicologia , Resiliência Psicológica , Apoio Social , Veteranos/psicologia , Adulto , Austrália , Canadá , Feminino , Jogo de Azar/epidemiologia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Militares/estatística & dados numéricos , Nova Zelândia , Fatores de Proteção , Autorrelato , Transtornos Relacionados ao Uso de Substâncias/psicologia , Ideação Suicida , Inquéritos e Questionários , Reino Unido , Estados Unidos , Veteranos/estatística & dados numéricos
8.
Ann Emerg Med ; 72(5): 591-601, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30172448

RESUMO

STUDY OBJECTIVE: Studies are divided on the short-term association of air pollution with stroke. Singapore is exposed to seasonal transboundary haze. We aim to investigate the association between air pollution and stroke incidence in Singapore. METHODS: We performed a time-stratified case-crossover analysis on all ischemic stroke cases reported to the Singapore Stroke Registry from 2010 to 2015. Exposure on days was compared with control days on which exposure did not occur. Control days were chosen on the same day of the week earlier and later in the same month in the same year. We fitted a conditional Poisson regression model to daily stroke incidence that included Pollutant Standards Index and environmental confounders. The index was categorized according to established classification (0 to 50=good, 51 to 100=moderate, and ≥101=unhealthy). We assessed the relationship between stroke incidence and Pollutant Standards Index in the entire cohort and in predetermined subgroups of individual-level characteristics. RESULTS: There were 29,384 ischemic stroke cases. Moderate and unhealthy Pollutant Standards Index levels showed association with stroke occurrence, with incidence risk ratio 1.10 (95% confidence interval 1.06 to 1.13) and 1.14 (95% confidence interval 1.03 to 1.25), respectively. Subgroup analyses showed generally significant association, except in Indians and nonhypertensive patients. The association was significant in subgroups aged 65 years or older, women, Chinese, nonsmokers and those with history of diabetes, hypertension, and hyperlipidemia. Stratified by age and smoking, the risk diminished in smokers of all ages. Risk remained elevated for 5 days after exposure. CONCLUSION: We found a short-term elevated risk of ischemic stroke after exposure to air pollution. These findings have public health implications for stroke prevention and emergency health services delivery.


Assuntos
Poluição do Ar/análise , Isquemia Encefálica/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Poluição do Ar/efeitos adversos , Isquemia Encefálica/induzido quimicamente , Estudos Cross-Over , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de Risco , Estações do Ano , Singapura/epidemiologia , Acidente Vascular Cerebral/induzido quimicamente
9.
JACC Basic Transl Sci ; 2(6): 688-698, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29445778

RESUMO

The reactive oxygen species-generating enzyme NADPH oxidase 4 (Nox4) is up-regulated in the heart after myocardial infarction (MI). Mice with cardiomyocyte-targeted Nox4 overexpression (TG) displayed increased macrophages in the heart at baseline, with skewing toward an M2 phenotype compared with wild-type controls (WT). After MI, TG mice had a higher proportion of M2 macrophages along with higher survival, decreased cardiac remodeling, and better contractile function than wild-type mice. The post-MI increase in cardiac matrix metalloproteinase-2 activity was substantially blunted in TG mice. These results indicate that cardiomyocyte Nox4 modulates macrophage polarization toward an M2 phenotype, resulting in improved post-MI survival and remodeling, likely through the attenuation of cardiac matrix metalloproteinase-2 activity.

10.
Nat Neurosci ; 19(8): 1041-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27294508

RESUMO

A fast, subcortical pathway to the amygdala is thought to have evolved to enable rapid detection of threat. This pathway's existence is fundamental for understanding nonconscious emotional responses, but has been challenged as a result of a lack of evidence for short-latency fear-related responses in primate amygdala, including humans. We recorded human intracranial electrophysiological data and found fast amygdala responses, beginning 74-ms post-stimulus onset, to fearful, but not neutral or happy, facial expressions. These responses had considerably shorter latency than fear responses that we observed in visual cortex. Notably, fast amygdala responses were limited to low spatial frequency components of fearful faces, as predicted by magnocellular inputs to amygdala. Furthermore, fast amygdala responses were not evoked by photographs of arousing scenes, which is indicative of selective early reactivity to socially relevant visual information conveyed by fearful faces. These data therefore support the existence of a phylogenetically old subcortical pathway providing fast, but coarse, threat-related signals to human amygdala.


Assuntos
Tonsila do Cerebelo/fisiologia , Expressão Facial , Medo/fisiologia , Córtex Visual/fisiologia , Adulto , Mapeamento Encefálico , Face/fisiologia , Feminino , Felicidade , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Tempo de Reação/fisiologia , Análise e Desempenho de Tarefas
11.
Adv Bioinformatics ; 2014: 431696, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25309590

RESUMO

K-ras is an oncogenic GTPase responsible for at least 15-25% of all non-small cell lung cancer cases worldwide. Lung cancer of both types is increasing with an alarming rate due to smoking habits in Malaysia among men and women. Natural products always offer alternate treatment therapies that are safe and effective. Typhonium flagelliforme or Keladi Tikus is a local plant known to possess anticancer properties. The whole extract is considered more potent than individual constituents. Since K-ras is the key protein in lung cancer, our aim was to identify the constituents of the plant that could target the mutated K-ras. Using docking strategies, reported potentially active compounds of Typhonium flagelliforme were docked into the allosteric surface pockets and switch regions of the K-ras protein to identify possible inhibitors. The selected ligands were found to have a high binding affinity for the switch II and the interphase region of the ras-SOS binding surface.

12.
Aliment Pharmacol Ther ; 39(10): 1213-24, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24654657

RESUMO

BACKGROUND: Risks and benefits of protease inhibitor (PI) (telaprevir or boceprevir) triple therapy in hepatitis C virus (HCV)-infected patients with mildly decompensated cirrhosis, including those wait-listed for liver transplantation (LT), are incompletely known. AIM: To assess virological responses and safety of PI triple therapy in patients with mildly decompensated Child-Pugh (CP) CP ≥6 vs. compensated (CP = 5) cirrhosis. METHODS: Multicentre cohort of 160 adults with cirrhosis treated with peginterferon/ribavirin (peg-IFN/RBV) plus telaprevir (69%) or boceprevir (31%), comparing outcomes between those with CP = 5 and CP ≥6. RESULTS: Patients, 47% with CP ≥6 cirrhosis (CP range 6-10), received PI triple therapy for a targeted duration of 48 weeks. The cohort was median age 59 years, 32% female, 59% genotype 1a, 35% previous null/partial responders. Sustained virological response at 12 weeks (SVR12) was achieved by 35% of patients with CP ≥6 vs. 54% of those with CP = 5 (P = 0.02). CP = 5, achievement of rapid virological response and genotype 1b/other, independently predicted SVR12. Compared to those with CP = 5, patients with CP ≥6 had more peg-IFN dose reductions, eltrombopag use, transfusions and hospitalisations to manage adverse events (all P < 0.05). Overall, 67 (42%) discontinued treatment early. Nine wait-listed patients were treated for a median of 97 days (IQR 60-160) prior to liver transplantation and five achieved post-LT SVR. CONCLUSIONS: In the presence of mild decompensation (Child-Pugh ≥6), SVR12 rates with protease inhibitor triple therapy are significantly reduced and adverse events increased. Thus, treatment with protease inhibitor triple therapy, if judged as necessary, should be undertaken with close monitoring and awareness of the significant risks.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Antivirais/administração & dosagem , Antivirais/farmacologia , Estudos de Coortes , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/genética , Humanos , Interferon-alfa/uso terapêutico , Cirrose Hepática/patologia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Prolina/administração & dosagem , Prolina/análogos & derivados , Prolina/farmacologia , Prolina/uso terapêutico , Inibidores de Proteases/administração & dosagem , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Estudos Retrospectivos , Ribavirina/administração & dosagem , Ribavirina/uso terapêutico , Índice de Gravidade de Doença
13.
Clin Exp Rheumatol ; 29(2): 261-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21385541

RESUMO

OBJECTIVES: To explore whether endothelial function is related to bone mineral density (BMD) in patients with systemic lupus erythematosus (SLE). METHODS: Consecutive adult SLE patients and age-, sex-, BMI- and smoking-status-matched healthy controls were studied. Subjects with hypertension, hyperlipidemia, diabetes mellitus, renal impairment, dysthyroidism, history of or treatment for cardiovascular and cerebrovascular disorders, antiphospholipid syndrome, positive antiphospholipid antibodies or bone loss were excluded. Endothelial function was assessed by measuring flow-mediated dilatation (FMD) at the brachial artery and carotid intima-media thickness (IMT) by ultrasound. Lumbar and hip BMD were measured by dual-energy x-ray absorptiometry. Fasting blood samples were assayed for atherogenic index and high sensitivity C-reactive protein (hsCRP). Regression models were constructed to study the relationship between FMD and BMD. RESULTS: One hundred and ten subjects (55 SLE and 55 matched healthy controls) were studied. While there were no differences between SLE patients and controls in menopausal status, blood pressure, atherogenic index, carotid IMT and BMD, SLE patients had significantly poorer FMD even after adjustment for age, gender, smoking and baseline brachial artery diameter. Also, SLE patients with lumbar osteopenia had significantly lower FMD than those with normal BMD. Multivariate regression revealed that lower FMD was associated with lower lumbar BMD and higher serum hsCRP in SLE patients, but these relationships were absent amongst healthy controls. CONCLUSIONS: Lumbar vertebral BMD predicted endothelial reactivity in SLE patients without clinically-overt bone loss and atherosclerosis. Thus, early atherosclerotic disease should be considered in lupus patients especially if vertebral bone loss is evident.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/diagnóstico por imagem , Endotélio Vascular/fisiopatologia , Vértebras Lombares/diagnóstico por imagem , Lúpus Eritematoso Sistêmico/fisiopatologia , Absorciometria de Fóton , Adulto , Aterosclerose/diagnóstico , Aterosclerose/fisiopatologia , Feminino , Humanos , Modelos Logísticos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Vasodilatação/fisiologia
14.
BMC Genomics ; 12: 138, 2011 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-21375780

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are post-transcriptional regulators of mRNA expression and are involved in numerous cellular processes. Consequently, miRNAs are an important component of gene regulatory networks and an improved understanding of miRNAs will further our knowledge of these networks. There is a many-to-many relationship between miRNAs and mRNAs because a single miRNA targets multiple mRNAs and a single mRNA is targeted by multiple miRNAs. However, most of the current methods for the identification of regulatory miRNAs and their target mRNAs ignore this biological observation and focus on miRNA-mRNA pairs. RESULTS: We propose a two-step method for the identification of many-to-many relationships between miRNAs and mRNAs. In the first step, we obtain miRNA and mRNA clusters using a combination of miRNA-target mRNA prediction algorithms and microarray expression data. In the second step, we determine the associations between miRNA clusters and mRNA clusters based on changes in miRNA and mRNA expression profiles. We consider the miRNA-mRNA clusters with statistically significant associations to be potentially regulatory and, therefore, of biological interest. CONCLUSIONS: Our method reduces the interactions between several hundred miRNAs and several thousand mRNAs to a few miRNA-mRNA groups, thereby facilitating a more meaningful biological analysis and a more targeted experimental validation.


Assuntos
MicroRNAs/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro/genética , Algoritmos , Análise por Conglomerados , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Modelos Lineares , Análise Multivariada
15.
J Laryngol Otol ; 124(12): 1284-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20573293

RESUMO

OBJECTIVE: This study aimed (1) to investigate the relationship between the presence of lymph node central necrosis, viewed on pre-operative computed tomography imaging, and the occurrence of histopathologically determined metastatic lymph node extracapsular spread and (2) to determine whether a larger scale study would be valuable. MATERIALS AND METHODS: Pre-operative computed tomography scans, surgical records and post-operative histopathological analysis results were reviewed for 19 consecutive neck dissections performed in 17 patients with head and neck squamous cell carcinoma. RESULTS: A total of 20/26 (77 per cent) lymph nodes with central necrosis had extracapsular spread on histopathological analysis. Twenty of 21 (95 per cent) lymph nodes with extracapsular spread had central necrosis on pre-operative computed tomography. Thirty-four of 40 (85 per cent) lymph nodes without extracapsular spread had no evidence of central necrosis on computed tomography. Only three of 12 (25 per cent) patients with lymph node central necrosis identified on pre-operative computed tomography were found to have actual necrosis on final histopathological analysis. CONCLUSIONS: Lymph node central necrosis viewed on pre-operative computed tomography scans is a useful indicator of metastatic lymph node extracapsular spread, with a sensitivity of 95 per cent, a specificity of 85 per cent, a positive predictive value of 69 per cent and a negative predictive value of 98 per cent. Lymph node diameter is not a sensitive indicator of extracapsular spread.


Assuntos
Linfonodos/patologia , Idoso , Carcinoma/diagnóstico por imagem , Carcinoma/secundário , Carcinoma/terapia , Carcinoma de Células Escamosas , Diagnóstico Diferencial , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/secundário , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Linfonodos/diagnóstico por imagem , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Pescoço , Necrose , Estadiamento de Neoplasias , Neoplasias de Células Escamosas/diagnóstico por imagem , Neoplasias de Células Escamosas/secundário , Neoplasias de Células Escamosas/terapia , Projetos Piloto , Estudos Retrospectivos , Sensibilidade e Especificidade , Carcinoma de Células Escamosas de Cabeça e Pescoço , Tomografia Computadorizada por Raios X
16.
J Viral Hepat ; 16(2): 141-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19175868

RESUMO

Perisinusoidal hepatic stellate cells (HSC) are the principal fibrogenic cells in the liver. In animal models, HSC apoptosis is the predominant clearance mechanism of activated HSC, although data evaluating whether the same processes occur in humans are limited. We conducted a cross-sectional study to evaluate the association between HSC apoptosis and fibrosis stage in subjects with chronic hepatitis C virus (HCV) infection (n = 44) and HCV-negative controls with normal liver histology (n = 9). We used immunohistochemical techniques to identify activated (alpha-smooth muscle actin+), proliferative (Ki-67+) and apoptotic (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP nick end-labelling+) HSC in liver biopsy specimens from all subjects. The same pathologist enumerated positive cells per high-power field (HPF, x 200) in 20 periportal/lobular areas. HSC apoptosis was decreased in HCV-positive subjects compared with controls (median 0.4, range 0.0-3.1 vs 1.1, 0.2-3.5 cells/HPF, P = 0.02). Among HCV-positive subjects, HSC apoptosis was decreased in those with moderate to advanced fibrosis (P = 0.04) compared with those with mild fibrosis. By multivariate analysis, HSC apoptosis decreased by an average of 0.14 cells/HPF (95% confidence interval 0.01-0.28 cells/HPF) per increase in fibrosis stage (P = 0.04). While the number of activated and proliferative HSC was significantly increased in HCV-infected subjects compared with that in uninfected controls, the numbers of these cells did not differ between HCV-infected subjects with mild vs moderate/advanced fibrosis. In conclusion, the number of apoptotic HSC was significantly decreased in HCV-infected subjects with advanced fibrosis. In chronic HCV infection, inhibition of HSC apoptosis may be one mechanism by which fibrosis progresses.


Assuntos
Apoptose , Células Estreladas do Fígado/patologia , Hepatite C Crônica/patologia , Cirrose Hepática/patologia , Fígado/patologia , Adulto , Idoso , Animais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Estatística como Assunto
17.
Hypertension ; 51(2): 319-25, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18180403

RESUMO

Oxidative stress plays an important role in the development of cardiac remodeling after myocardial infarction (MI), but the sources of oxidative stress remain unclear. We investigated the role of Nox2-containing reduced nicotinamide-adenine dinucleotide phosphate oxidase in the development of cardiac remodeling after MI. Adult Nox2(-/-) and matched wild-type (WT) mice were subjected to coronary artery ligation and studied 4 weeks later. Infarct size after MI was similar in Nox2(-/-) and WT mice. Nox2(-/-) mice exhibited significantly less left ventricular (LV) cavity dilatation and dysfunction after MI than WT mice (eg, echocardiographic LV end-diastolic volume: 75.7+/-5.8 versus 112.4+/-12.3 microL; ejection fraction: 41.6+/-3.7 versus 32.9+/-3.2%; both P<0.05). Similarly, in vivo LV systolic and diastolic functions were better preserved in Nox2(-/-) than WT mice (eg, LV dP/dt(max): 7969+/-385 versus 5746+/-234 mm Hg/s; LV end-diastolic pressure: 12.2+/-1.3 versus 18.0+/-1.8 mm Hg; both P<0.05). Nox2(-/-) mice exhibited less cardiomyocyte hypertrophy, apoptosis, and interstitial fibrosis; reduced increases in expression of connective tissue growth factor and procollagen 1 mRNA; and smaller increases in myocardial matrix metalloproteinase-2 activity than WT mice. These data suggest that the Nox2-containing reduced nicotinamide-adenine dinucleotide phosphate oxidase contributes significantly to the processes underlying adverse cardiac remodeling and contractile dysfunction post-MI.


Assuntos
Glicoproteínas de Membrana/metabolismo , Infarto do Miocárdio/fisiopatologia , NADPH Oxidases/metabolismo , Remodelação Ventricular , Animais , Apoptose , Cateterismo Cardíaco , Cardiomegalia/etiologia , Cardiomegalia/metabolismo , Ecocardiografia , Fibrose , Metaloproteinase 2 da Matriz/genética , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miocárdio/patologia , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/deficiência , NADPH Oxidases/genética , RNA Mensageiro/metabolismo , Coloração e Rotulagem , Análise de Sobrevida , Tirosina/análogos & derivados , Tirosina/metabolismo
18.
J Chemother ; 19(4): 451-4, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17855191

RESUMO

The authors report and discuss a case of a mucinous carcinoma of the appendix, a rare entity with a distinct natural history that poses diagnostic and therapeutic challenges. Mucinous peritoneal carcinomatosis is most commonly associated with primary tumors of the appendix and colon. Typically, spread remains confined to the abdominal cavity. Imaging assessment of these mucinous lesions is difficult, while tumor markers (CEA and CA19.9) may be surrogates for extent of disease. Treatment consists of surgical debulking, sometimes coupled with intraperitoneal drug delivery, but recurrence is universal. New treatment approaches are needed. Mucin genes are regulated in part by epidermal growth factor receptor signaling. Therefore, we initiated a phase II study of cetuximab for mucinous peritoneal carcinomatosis, that was part of this patient's treatment.


Assuntos
Adenocarcinoma Mucinoso/diagnóstico , Adenocarcinoma Mucinoso/cirurgia , Neoplasias do Apêndice/diagnóstico , Neoplasias do Apêndice/cirurgia , Apêndice , Adenocarcinoma Mucinoso/patologia , Idoso , Neoplasias do Apêndice/patologia , Apêndice/patologia , Antígeno CA-19-9/análise , Antígeno Carcinoembrionário/análise , Evolução Fatal , Feminino , Humanos
19.
Gene Ther ; 14(15): 1166-74, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17508007

RESUMO

Our previous studies suggest that replication-defective Sindbis vectors might be promising agents for specific tumor targeting and detection. However, the effects of innate and/or adaptive anti-viral immunity, in particular, the IFN-I/STAT1 signaling pathway, may impact their therapeutic potential. Using a bioluminescent imaging system, we demonstrate that although most normal cells are not permissively transduced by replication-defective Sindbis vector, transduction of liver non-sinusoidal endothelial occurs the first time IFN-I/STAT1 signaling deficient mice are inoculated with the vector. Transduction of some cells is not surprising since STAT1 knockout animals show significant delay in IFN responses such as the production of IFN-alpha/beta and transcriptional activation of several anti-viral genes (IRF7, RIG-I, PKR, TLR3, USP18, ISG15). However, beyond the initial vector transduction, which resolves rapidly, secondary inoculums of Sindbis vectors do not transduce any liver cells, suggesting that an alternative antiviral pathway may protect against further transduction. Other known signaling pathways were examined using mice lacking functional TLR3, tumor necrosis factoralphaR or nuclear factor-kappa B (p50). Surprisingly, none of those pathways seem to play a significant role in anti-Sindbis responses. Thus it appears that in vivo, in contrast to the ready transduction of tumor cells, transduction of normal cells by replication-defective Sindbis vector is limited, possibly by a novel mechanism.


Assuntos
Infecções por Alphavirus/imunologia , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Interferon Tipo I/genética , Neoplasias/terapia , Sindbis virus/genética , Animais , Vetores Genéticos/imunologia , Imunidade , Imunidade Inata , Interferon Tipo I/imunologia , Fígado/imunologia , Fígado/virologia , Luminescência , Camundongos , Camundongos Knockout , NF-kappa B/genética , Neoplasias/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Receptor 3 Toll-Like/genética , Transdução Genética/métodos
20.
Heart ; 93(8): 903-7, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16670100

RESUMO

Substantial evidence suggests the involvement of oxidative stress in the pathophysiology of congestive heart failure and its antecedent conditions such as cardiac hypertrophy and adverse remodelling after MI. Oxidative stress describes an imbalance between antioxidant defences and the production of reactive oxygen species (ROS), which at high levels cause cell damage but at lower levels induce subtle changes in intracellular signalling pathways (termed redox signalling). ROS are derived from many sources including mitochondria, xanthine oxidase, uncoupled nitric oxide synthases and NADPH oxidases. The latter enzymes are especially important in redox signalling, being implicated in the pathophysiology of hypertension and atherosclerosis, and activated by diverse pathologically relevant stimuli. We review the contribution of ROS to heart failure pathophysiology and discuss potential therapies that may specifically target detrimental redox signalling. Indeed, drugs such as ACE inhibitors and statins may act in part through such mechanisms. A better understanding of redox signalling mechanisms may enable the development of new targeted therapeutic strategies rather than the non-specific antioxidant approaches that have to date been disappointing in clinical trials.


Assuntos
Insuficiência Cardíaca/metabolismo , Hipertrofia Ventricular Esquerda/metabolismo , Miocárdio/metabolismo , Transdução de Sinais/fisiologia , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/patologia , Humanos , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/terapia , Miocárdio/patologia , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Remodelação Ventricular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...