RESUMO
When a highly salient distractor is present in a search array, it speeds target absent visual search and increases errors during target present visual search, suggesting lowered quitting thresholds (Moher in Psychol Sci 31(1):31-42, 2020). Missing a critical target in the presence of a highly salient distractor can have dire consequences in real-world search tasks where accurate target detection is crucial, such as baggage screening. As such, the current study examined whether emphasizing either accuracy or speed would eliminate the distractor-generated quitting threshold effect (QTE). Three blocks of a target detection search task which included a highly salient distractor on half of all trials were used. In one block, participants received no instructions or feedback regarding performance. In the remaining two blocks, they received instructions and trial-by-trial feedback that either emphasized response speed or response accuracy. Overall, the distractor lowered quitting thresholds, regardless of whether response speed or response accuracy was emphasized in a block of trials. However, the effect of the distractor on target misses was smaller when accuracy was emphasized. It, therefore, appears that while the distractor QTE is not easily eradicated by explicit instructions and feedback, it can be shifted. As such, future research should examine the applicability of these and similar strategies in real-world search scenarios.
Assuntos
Atenção , Percepção Visual , Humanos , Percepção Visual/fisiologia , Atenção/fisiologia , Tempo de ReaçãoRESUMO
INTRODUCTION: The surveillance of antibiotic resistance is critical for the establishment of effective control strategies. The antibiotic resistance situations in private hospitals in Hong Kong have not been systematically described. The objective of the study was to analyse antibiogram data from private hospitals and describe the temporal trends of non-susceptibility percentages in this setting. METHODS: This retrospective descriptive study used antibiogram data from all private hospitals in Hong Kong that had been collected annually for 6 years (2014-2019). Data on six targeted bacteria and their corresponding multidrug-resistant organisms were included. RESULTS: The non-susceptibility percentages of isolates remained stable or decreased during the study period: methicillin-resistant Staphylococcus aureus had a stable prevalence of approximately 20%; extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species had stable prevalences of 20% to 30% and 10% to 20%, respectively; multidrug-resistant Acinetobacter species had prevalences of approximately 2% to 8%, which decreased over time; multidrug-resistant Pseudomonas aeruginosa had prevalences of 0.0% to 0.3%; Streptococcus pneumoniae penicillin and macrolide non-susceptibility percentages were 2% to 9% and 71% to 79%, respectively. These values generally were comparable with findings from public hospitals and Residential Care Homes for the Elderly in Hong Kong. However, the prevalences of carbapenem-resistant Enterobacteriaceae, which are increasing in Hong Kong and other nations, were also increasing in our dataset despite their currently low values (<1% for Escherichia coli and <2% for Klebsiella species). CONCLUSION: The antibiotic resistance landscape among private hospitals in Hong Kong is satisfactory overall; there remains a need for surveillance, antibiotic stewardship, and other infection control measures.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Idoso , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Escherichia coli , Hong Kong/epidemiologia , Hospitais Privados , Humanos , Testes de Sensibilidade Microbiana , Estudos RetrospectivosRESUMO
AIMS: The coronavirus disease 2019 (COVID-19) pandemic represents an unprecedented threat to mental health. Herein, we assessed the impact of COVID-19 on subthreshold depressive symptoms and identified potential mitigating factors. METHODS: Participants were from Depression Cohort in China (ChiCTR registry number 1900022145). Adults (n = 1722) with subthreshold depressive symptoms were enrolled between March and October 2019 in a 6-month, community-based interventional study that aimed to prevent clinical depression using psychoeducation. A total of 1506 participants completed the study in Shenzhen, China: 726 participants, who completed the study between March 2019 and January 2020 (i.e. before COVID-19), comprised the 'wave 1' group; 780 participants, who were enrolled before COVID-19 and completed the 6-month endpoint assessment during COVID-19, comprised 'wave 2'. Symptoms of depression, anxiety and insomnia were assessed at baseline and endpoint (i.e. 6-month follow-up) using the Patient Health Questionnaire-9 (PHQ-9), Generalised Anxiety Disorder-7 (GAD-7) and Insomnia Severity Index (ISI), respectively. Measures of resilience and regular exercise were assessed at baseline. We compared the mental health outcomes between wave 1 and wave 2 groups. We additionally investigated how mental health outcomes changed across disparate stages of the COVID-19 pandemic in China, i.e. peak (7-13 February), post-peak (14-27 February), remission plateau (28 February-present). RESULTS: COVID-19 increased the risk for three mental outcomes: (1) depression (odds ratio [OR] = 1.30, 95% confidence interval [CI]: 1.04-1.62); (2) anxiety (OR = 1.47, 95% CI: 1.16-1.88) and (3) insomnia (OR = 1.37, 95% CI: 1.07-1.77). The highest proportion of probable depression and anxiety was observed post-peak, with 52.9% and 41.4%, respectively. Greater baseline resilience scores had a protective effect on the three main outcomes (depression: OR = 0.26, 95% CI: 0.19-0.37; anxiety: OR = 1.22, 95% CI: 0.14-0.33 and insomnia: OR = 0.18, 95% CI: 0.11-0.28). Furthermore, regular physical activity mitigated the risk for depression (OR = 0.79, 95% CI: 0.79-0.99). CONCLUSIONS: The COVID-19 pandemic exerted a highly significant and negative impact on symptoms of depression, anxiety and insomnia. Mental health outcomes fluctuated as a function of the duration of the pandemic and were alleviated to some extent with the observed decline in community-based transmission. Augmenting resiliency and regular exercise provide an opportunity to mitigate the risk for mental health symptoms during this severe public health crisis.
Assuntos
COVID-19/psicologia , Depressão/epidemiologia , Saúde Mental/estatística & dados numéricos , Pandemias , SARS-CoV-2 , Adulto , Ansiedade/epidemiologia , Ansiedade/psicologia , COVID-19/epidemiologia , China/epidemiologia , Estudos Transversais , Depressão/psicologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/psicologiaRESUMO
OBJECTIVES: Screening questions for sarcopenia used in the community (SARC-F) may be regarded as indicators of exercise tolerance. DESIGN: Observational study. SETTING: We tested the hypothesis that community-living older people who are screened positive for sarcopenia using the SARC-F tool but without a history of heart failure (HF) have a higher prevalence of cardiac abnormalities compared with those who are SARC-F negative. PARTICIPANTS: Participants were recruited from a territory-wide primary care needs assessment for older people based in community centres, and from non-acute hospitals in the same region as the study centre. MEASUREMENTS: Participants with a total score of >=4 and who did not have any history of HF were invited to attend for further cardiac assessment. Grip strength, walking speed, and the 6-minute walk test and echocardiography were carried out. Patients with frailty and at least Grade II diastolic dysfunction were considered to have heart failure with preserved ejection fraction (HFpEF) if they also had concomitant elevated N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) of at least 300 pg/ml. RESULTS: Diastolic dysfunction (DD) was significantly associated with SARC-F score >=4 and higher circulating NT-proBNP levels. ROC curves evaluating the predictive values of SARC-F, HGS and gait speed for DD showed that a combination of SARC-F and HGS or gait speed provided significant incremental value in predicting DD. CONCLUSIONS: Community living older people with sarcopenia detected using a simple questionnaire have a higher prevalence of DD accompanied by elevated NT proBNP. Addition of hand grip strength or walking speed improve the magnitude of the association. SARC-F may be used as a tool to detect early cardiac dysfunction in the community.
Assuntos
Doenças Cardiovasculares/etiologia , Ecocardiografia/métodos , Força da Mão/fisiologia , Peptídeo Natriurético Encefálico/metabolismo , Sarcopenia/complicações , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/patologia , Feminino , Avaliação Geriátrica , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To test the utility of the FRAIL questionnaire as a screening tool for heart failure. DESIGN: Cross sectional study. SETTING: Chinese older people in Hong Kong. PARTICIPANTS: Participants aged 60 years and over were recruited from a territory-wide primary care needs assessment for older people based in community centers as well as two nonacute hospitals. MEASUREMENTS: Questionnaire administered included the five-item FRAIL scale, and information regarding sociodemographic data, smoking and alcohol use, history of cardiovascular disease and diabetes, and heart failure symptoms. Handgrip strength, walking speed and 6 minute walk distance were recorded. Cardiac assessment included electrocardiogram, echocardiography, and blood assay for N-terminal prohormone of B-type natriuretic peptide (NT-proBNP). RESULTS: The prevalence of diastolic dysfunction was high, being 52% in the robust group, increasing to 65% in the pre-frail and 85% in the frail group. This finding is accompanied by a corresponding increase in NT-proBNP from 64.18 pg/ml in the robust group, to 118.57 pg/ml in the pre-frail and 167.98 pg/ml in the frail group. Three of the five components of the FRAIL scale, fatigue, resistance and ambulation, were associated with increased odds ratios of diastolic dysfunction among those aged 75 years and older, while resistance alone was associated with increased odds ratio among those less than 75 years old. CONCLUSION: Frailty is associated with heart failure with preserved ejection fraction (HFpEF), and frailty screening may be used to detect undiagnosed HFpEF. The findings support the proposal that HFpEF be considered a geriatric syndrome.
Assuntos
Idoso Fragilizado/estatística & dados numéricos , Insuficiência Cardíaca Diastólica/diagnóstico , Programas de Rastreamento/métodos , Volume Sistólico/fisiologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Estudos Transversais , Feminino , Força da Mão/fisiologia , Insuficiência Cardíaca Diastólica/epidemiologia , Hong Kong/epidemiologia , Humanos , Masculino , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Prevalência , Inquéritos e QuestionáriosRESUMO
The Centre for Health Protection of the Department of Health has convened the Advisory Group on Antibiotic Stewardship Programme in Primary Care (the Advisory Group) to formulate guidance notes and strategies for optimising judicious use of antibiotics and enhancing the Antibiotic Stewardship Programme in Primary Care. Acute pharyngitis is one of the most common conditions among out-patients in primary care in Hong Kong. Practical recommendations on the diagnosis and antibiotic treatment of acute streptococcal pharyngitis are made by the Advisory Group based on the best available clinical evidence, local prevalence of pathogens and associated antibiotic susceptibility profiles, and common local practice.
Assuntos
Antibacterianos/administração & dosagem , Faringite/tratamento farmacológico , Infecções Estreptocócicas/diagnóstico , Streptococcus/isolamento & purificação , Doença Aguda , Gestão de Antimicrobianos/organização & administração , Hong Kong , Humanos , Faringite/microbiologia , Guias de Prática Clínica como Assunto , Atenção Primária à Saúde/normas , Índice de Gravidade de DoençaRESUMO
AIMS: To investigate whether 25-hydroxyvitamin D concentration was associated with incident diabetes in a large cohort of older women. METHODS: Data were analysed from women included in the Study of Osteoporotic Fractures, a cohort of community-dwelling women aged ≥65 years at enrolment. Serum 25-hydroxyvitamin D concentration was assessed at the year 6 visit, as were BMI and other factors associated with vitamin D and/or diabetes. Diabetes status was determined at each subsequent visit by self-report and medication use. Only those without prevalent diabetes at the year 6 visit were included in the present analysis (N = 5463, mean age 76.5 years). RESULTS: During a mean ±sd follow-up of 8.6 ± 4.4 years, incident diabetes was reported in 320 participants. The mean BMI was higher in those with a 25-hydroxyvitamin D concentration <20 ng/ml (<50 nmol/l) than in those with concentrations 20-30 or ≥30 ng/ml [50-74 or ≥75 nmol/l (P < 0.0001)]. A higher 25-hydroxyvitamin D concentration was associated with a 13% lower risk of incident diabetes after adjustment for age and clinic site [hazard ratio 0.87, 95% CI 0.76-0.99, per sd increase in 25-hydroxyvitamin D]; however, the addition of BMI to the model attenuated the estimated effect (hazard ratio 0.97, 95% CI 0.86-1.11). Adjustment for additional potential confounders yielded similar results. CONCLUSIONS: Serum 25-hydroxyvitamin D does not independently predict incident diabetes in older women. Although those with higher 25-hydroxyvitamin D concentrations are less likely to develop diabetes, this is mainly explained by their lower BMI.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Índice de Massa Corporal , Estudos de Coortes , Feminino , Seguimentos , Humanos , Incidência , Estudos Longitudinais , Valor Preditivo dos Testes , Fatores de Risco , Fatores Sexuais , Vitamina D/sangueRESUMO
CONTEXT: A high prevalence of obesity has recently been reported in postmenopausal women with low trauma fracture, suggesting that higher bone mineral density (BMD) in obese individuals may not be protective against fracture. OBJECTIVE: The aim of this study was to compare BMD and other risk factors for nonvertebral fracture in 1377 obese postmenopausal women. DESIGN: Characteristics of obese women with and without incident nonvertebral fracture were investigated among the prospective cohort in the Study of Osteoporotic Fractures. SETTING: The Study of Osteoporotic Fractures is a multicenter study of 9704 women (>99% Caucasian) aged 65 yr and over who were recruited between September 1986 and October 1988 from population-based listings at four U.S. clinical centers. MAIN OUTCOME MEASURE: The main outcome measure was nonvertebral fracture. RESULTS: BMD T-scores in the spine, femoral neck, and total hip were significantly lower in obese women who experienced fractures than in obese women without fracture: mean differences, -0.56 [95% confidence interval (CI) = -0.73 to -0.39], -0.46 (95% CI = -0.57 to -0.36), and -0.51 (95% CI = -0.62 to -0.39), respectively (P < 0.0001 for all). A previous history of fracture [odds ratio = 1.69 (95% CI = 1.33-2.14); P < 0.0001] and femoral neck BMD [1.62 (95% CI = 1.42-1.85) per sd decrease in BMD; P < 0.0001] were independently associated with incident nonvertebral fracture. CONCLUSIONS: Obese postmenopausal women who sustain nonvertebral fractures have significantly lower BMD on average than obese women without fracture and are more likely to have a past history of fracture. Fractures in obese postmenopausal women thus exhibit some characteristics of fragility fractures.
Assuntos
Fraturas do Quadril/epidemiologia , Obesidade/epidemiologia , Osteoporose/epidemiologia , Traumatismos do Punho/epidemiologia , Idoso , Densidade Óssea , Feminino , Humanos , Incidência , Modelos Logísticos , Prevalência , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
We demonstrate a stable and linear photonic radio frequency (RF) phase shifter based on a differential-group-delay element and the polarization sensitive effect of an optical phase modulator. The phase shift can be tuned continuously over 360 degrees for RF signals over 40GHz with an electrical control voltage from -7.5 to +7.5V.
RESUMO
OBJECTIVE: Radiographic hip osteoarthritis (RHOA) is associated with increased hip areal bone mineral density (aBMD). This study was undertaken to examine whether femoral geometry is associated with RHOA independent of aBMD. METHODS: Participants in the Study of Osteoporotic Fractures in whom pelvic radiographs had been obtained at visits 1 and 5 (mean 8.3 years apart) and hip dual x-ray absorptiometry (DXA) had been performed (2 years after baseline) were included. Prevalent and incident RHOA phenotypes were defined as composite (osteophytes and joint space narrowing [JSN]), atrophic (JSN without osteophytes), or osteophytic (femoral osteophytes without JSN). Analogous definitions of progression were based on minimum joint space and total osteophyte score. Hip DXA scans were assessed using the Hip Structural Analysis program to derive geometric measures, including femoral neck length, width, and centroid position. Relative risks and 95% confidence intervals for prevalent, incident, and progressive RHOA per SD increase in geometric measure were estimated in a hip-based analysis using multinomial logistic regression with adjustment for age, body mass index, knee height, and total hip aBMD. RESULTS: In 5,245 women (mean age 72.6 years), a wider femoral neck with a more medial centroid position was associated with prevalent and incident osteophytic and composite RHOA phenotypes (P < 0.05). Increased neck width and centroid position were associated with osteophyte progression (both P < 0.05). No significant geometric associations with atrophic RHOA were found. CONCLUSION: Differences in proximal femoral bone geometry and spatial distribution of bone mass occur early in hip OA and predict prevalent, incident, and progressive osteophytic and composite phenotypes, but not the atrophic phenotype. These bone differences may reflect responses to loading occurring early in the natural history of RHOA.
Assuntos
Densidade Óssea/fisiologia , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/fisiopatologia , Fraturas do Quadril/epidemiologia , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/fisiopatologia , Osteoporose/complicações , Absorciometria de Fóton , Idoso , Estudos de Coortes , Progressão da Doença , Feminino , Fraturas do Quadril/fisiopatologia , Humanos , Modelos Logísticos , Osteoartrite do Quadril/epidemiologia , Osteófito/diagnóstico por imagem , Osteófito/fisiopatologia , Osteoporose/fisiopatologia , Fenótipo , Prevalência , Fatores de RiscoRESUMO
Two neutrally buoyant intruder particles in a granular bed fluidized by vertical, sinusoidal vibration are known to interact with each other over a range of about five intruder diameters. Using molecular dynamics simulations, we investigate in detail the spatial and temporal nature of this interaction. We show that the force of attraction between intruders can be calculated from the local density and kinetic energy using a simple equation of state. Moreover, the interaction can be changed from attractive to repulsive by reducing the coefficient of restitution between the intruders and host particles, one of the key results of this work.
RESUMO
CONTEXT: Osteoprotegerin (OPG) is a soluble decoy receptor for receptor activator nuclear factor kappa-beta that blocks osteoclastic bone resorption. OBJECTIVE: We investigated the association between a Lys3Asn polymorphism in the OPG gene and bone mineral density (BMD), and the risk of fracture in 6695 women aged 65 yr and older participating in the Study of Osteoporotic Fractures. DESIGN: BMD was measured using either single-photon absorptiometry (Osteon Osteoanalyzer; Dove Medical Group, Los Angeles, CA) or dual-energy x-ray absorptiometry (Hologic QDR 1000; Hologic, Inc., Bedford, MA). Incident fractures were confirmed by physician adjudication of radiology reports. Genotyping was performed using an immobilized probe-based assay. RESULTS: Women who were homozygous for the minor G (Lys) allele had significantly lower BMD at the intertrochanter, distal radius, lumbar spine, and calcaneus than those with the C (Asn) allele. There were 701 incident hip fractures during 13.6-yr follow-up (91,249 person-years), including 362 femoral neck and 333 intertrochanteric hip fractures. Women with the C/C (Asn-Asn) genotype had a 51% higher risk of femoral neck fracture (95% confidence interval, 1.13-2.02) and 26% higher risk of hip fracture (95% confidence interval, 1.02-1.54) than those with the G/G (Lys-Lys) genotype. These associations were independent of BMD. Intertrochanteric fractures were not associated with the Lys3Asn polymorphism. CONCLUSION: These results require confirmation but suggest a role for the OPG Lys3Asn polymorphism in the genetic susceptibility to hip fractures among older white women.
Assuntos
Fraturas do Quadril/etiologia , Osteoprotegerina/genética , Polimorfismo Genético , Idoso , Densidade Óssea , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Estudos Prospectivos , Fatores de RiscoRESUMO
UNLABELLED: Clinical performance of osteoporosis risk assessment tools was studied in women aged 67 years and older. Weight was as accurate as two of the tools to detect low bone density. Discriminatory ability was slightly better for the OST risk tool, which is based only on age and weight. INTRODUCTION: Screening performance of osteoporosis risk assessment tools has not been tested in a large, population-based US cohort. METHODS: We conducted a diagnostic accuracy analysis of the Osteoporosis Self-assessment Tool (OST), Osteoporosis Risk Assessment Instrument (ORAI), Simple Calculated Osteoporosis Risk Estimation (SCORE), and individual risk factors (age, weight or prior fracture) to identify low central (hip and lumbar spine) bone mineral density (BMD) in 7779 US women aged 67 years and older participating in the Study of Osteoporotic Fractures. RESULTS: The OST had the greatest area under the receiver operating characteristic curve (AUC 0.76, 95% CI 0.74, 0.77). Weight had an AUC of 0.73 (95% CI 0.72, 0.75), which was >or=AUC values for the ORAI, SCORE, age or prior fracture. Using cut points from the development papers, the risk tools had sensitivities >or=85% and specificities Assuntos
Osteoporose Pós-Menopausa/diagnóstico
, Fatores Etários
, Idoso
, Idoso de 80 Anos ou mais
, Algoritmos
, Peso Corporal
, Densidade Óssea
, Técnicas de Apoio para a Decisão
, Métodos Epidemiológicos
, Terapia de Reposição de Estrogênios
, Feminino
, Fraturas Ósseas/etiologia
, Fraturas Ósseas/fisiopatologia
, Humanos
, Osteoporose Pós-Menopausa/complicações
, Osteoporose Pós-Menopausa/fisiopatologia
RESUMO
OBJECTIVE: To determine the association between changes in serum levels of cartilage oligomeric matrix protein (COMP) and serum N-telopeptide crosslinks (NTX) over a 6-year interval with the development and progression of radiographically apparent hip osteoarthritis (RHOA) in a community sample of elderly women over 8.3 years of follow-up. METHODS: Pelvic radiographs were obtained a mean of 8.3 years apart in Caucasian women > or =65 years of age enrolled in the Study of Osteoporotic Fractures. From a cohort of 5928 subjects, we randomly sampled study subjects ( approximately 170 per group) to perform two nested case-control studies, one of RHOA incidence and the other of RHOA progression. Baseline and year 6 serum COMP and serum NTX levels were measured by enzyme linked immunosorbent assay in duplicate and percentage change in serum levels was calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) for 1 standard deviation (SD) change in the serum COMP and NTX level differences were calculated using logistic regression analysis and used to predict the development or progression of RHOA, adjusting for potential covariates. RESULTS: The percentage change in the level of serum COMP from baseline to year 6 was found to be a risk factor for the development of incident RHOA [adjusted OR of 1.58 per 1 SD increase (95% CI: 1.19-2.09)], and reduction of progression of RHOA [adjusted OR of 0.74 per 1 SD increase (95% CI: 0.58-0.96)]. Quartile analysis of serum COMP changes revealed that the three highest quartiles of change in serum COMP were associated with (1) a five-fold greater risk of developing incident RHOA [adjusted OR=5.42 (95% CI: 2.80-10.60)], and (2) a 50% decreased risk of developing progression of RHOA [adjusted OR=0.48 (95% CI: 0.30-0.80)]. No significant association was found between changes in serum NTX levels from baseline to year 6 with either incident RHOA or the progression of existing RHOA. CONCLUSION: Measurement of serum COMP at two distinct timepoints may be a method of identifying patients at risk for developing incident RHOA and those with baseline RHOA that will not rapidly progress.
Assuntos
Proteínas da Matriz Extracelular/sangue , Glicoproteínas/sangue , Osteoartrite do Quadril/diagnóstico , Idoso , Biomarcadores/sangue , Proteína de Matriz Oligomérica de Cartilagem , Estudos de Casos e Controles , Colágeno Tipo I/sangue , Progressão da Doença , Feminino , Seguimentos , Humanos , Proteínas Matrilinas , Osteoartrite do Quadril/sangue , Osteoartrite do Quadril/diagnóstico por imagem , Peptídeos/sangue , Prognóstico , RadiografiaRESUMO
AIMS: A phase II trial was initiated to evaluate the efficacy and toxicity of combination chemotherapy with irinotecan (CPT-11) plus capecitabine in patients with metastatic colorectal cancer. PATIENTS AND METHODS: Patients received a combination of CPT-11 plus capecitabine. CPT-11 was infused intravenously on day 1 every 2 weeks and oral capecitabine was taken twice daily for 5 days every 7 days. Efficacy and toxicities were assessed. RESULTS: Between 2004 and 2005, 43 patients were enrolled. The overall response rate was 51.35%. With a median follow-up of 13 months, the median time to progression was 10 months (95% confidence interval 7.6-12.3 months); the median survival was 15 months (95% confidence interval 13.9-16.9 months). The most common grade 3 haematological and non-haematological toxicities were neutropenia (5.4%), diarrhoea (8.1%) and hand-foot syndrome (2.7%). CONCLUSIONS: CPT-11 plus capecitabine with a 14 day cycle showed a comparable response with international phase II data with a 3 weekly regimen and was well tolerated as a first-line palliative chemotherapy in patients with metastatic colorectal cancer. The data should be interpreted with caution due to the limited sample size and should be further confirmed by a phase III randomised trial.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Camptotecina/análogos & derivados , Neoplasias Colorretais/tratamento farmacológico , Desoxicitidina/análogos & derivados , Fluoruracila/análogos & derivados , Adulto , Idoso , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Capecitabina , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Irinotecano , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Terapia de Salvação , Taxa de SobrevidaRESUMO
We present results of computer simulations for neutrally buoyant intruders in a vertically vibrated three-dimensional granular bed of smaller host particles. Under sinusoidal excitation, pairs of intruders interact over a distance of several intruder diameters; a group of intruders forms a cluster. The strength of the interaction grows as the number of intruders is increased. We show that the tendency to cluster may be manipulated through the use of nonsinusoidal excitation, which allows partial mixing. Finally, we investigate the effects of walls on the clustering of intruders.
RESUMO
PURPOSE: This study evaluated the association between polymorphisms in the estrogen receptor (ER) alpha gene (ESR1) and prevalent and incident radiographic hip osteoarthritis (RHOA) in a large, well-defined prospective cohort of elderly Caucasian women. METHODS: Prevalent and incident RHOA was evaluated from all available pelvis X-rays obtained from the Study of Osteoporotic Fractures at baseline and after a mean of 8.3 years. Evaluable DNA samples were available from 4746 of these subjects. RHOA cases were defined by published methods. The ESR1 polymorphisms at intron I (Pvu II for a T/C substitution and Xba I for an A/G substitution) were genotyped in the context of a multiplex polymerase chain reaction (PCR) amplification followed by allele-specific single nucleotide polymorphism (SNP) detection with immobilized oligonucleotide probes in linear arrays. Multiple logistic regression was performed to estimate odds ratios (ORs) and 95% confidence intervals (95% CI) associated with the T/C and A/G polymorphisms. RESULTS: RHOA was present in 12.1% of subjects, of whom 325 had joint space narrowing (JSN) score > or =3 and 130 had an osteophyte score > or =2 and JSN score > or =2. There was a significant reduction in the odds of prevalent RHOA for individuals with the C/C compared to T/T genotype at the Pvu II site with an OR of 0.71 (95% CI: 0.55-0.92) (P=0.01). Adjustments for age, weight, height, hip Bone mineral density (BMD) and estrogen use did not alter the relationship between the C/C genotype and reduced risk of RHOA, with an OR of 0.71 (95% CI: 0.54-0.94) (P=0.01). The risk of incident RHOA was reduced for the Pvu II C/C compared to the T/T genotype (P=0.11). Also, the reduced risk of incident RHOA in C/C subjects varied by estrogen use. There was no association between the Xba I G/G or G/A genotypes and RHOA with OR of 0.82 (95% CI: 0.61-1.10) (P=0.19) compared to women with A/A genotype. CONCLUSIONS: We conclude that the C/C genotype of the ER alpha Pvu II polymorphism was associated with a modestly reduced risk of prevalent and incident RHOA in elderly Caucasian women. Additional work is required to understand how the intron I ESR1 polymorphism may alter joint degeneration.
Assuntos
Receptor alfa de Estrogênio/genética , Osteoartrite do Quadril/etnologia , Osteoartrite do Quadril/genética , População Branca/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Feminino , Predisposição Genética para Doença/epidemiologia , Genótipo , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/etnologia , Fraturas do Quadril/genética , Humanos , Incidência , Íntrons/genética , Osteoartrite do Quadril/diagnóstico por imagem , Polimorfismo Genético , Prevalência , Estudos Prospectivos , RadiografiaRESUMO
OBJECTIVES: To determine whether older women with abdominal aortic calcification had a greater cardiovascular and all-cause mortality, as such data are limited in older adults. DESIGN: Prospective cohort study with a mean follow-up of 13 years. SETTING: Community-based sample with four US clinical centres. SUBJECTS: A total of 2056 women aged > or =65 years with abdominal aortic calcification assessed on baseline radiographs. MAIN OUTCOME MEASURE: Mortality rate (all, cardiovascular, cancer or other cause) adjudicated from death certificates and hospital records. RESULTS: The prevalence of abdominal aortic calcification increased with age, ranging from 60% at age 65-69 years to 96% at 85 years and older. Participants with aortic calcification were more likely to die during follow-up of any cause (47% vs. 27%) or a cardiovascular-specific cause (18% vs. 11%, both P < 0.001) than those without aortic calcification. In age-adjusted analyses, aortic calcification was associated with a greater rate of all-cause and cause-specific mortality (cardiovascular, cancer, and other, all P < or = 0.01). In analyses adjusted for age and cardiovascular risk factors, aortic calcification was associated with an increased rate of all-cause mortality (HR: 1.37, 95% CI: 1.15-1.64), and noncardiovascular noncancer mortality (HR: 1.57, 95% CI: 1.17-2.11). The associations between aortic calcification and cancer mortality (HR: 1.44, 95% CI: 1.00-2.08) or cardiovascular mortality (HR: 1.18, 95% CI: 0.88-1.57) showed a similar pattern without reaching statistical significance, but was slightly stronger for mortality from coronary heart disease (HR: 1.53, 95% CI: 0.91-2.56). CONCLUSIONS: Abdominal aortic calcification in older women is associated with increased mortality. Future research should examine potential mechanisms for this association.
Assuntos
Doenças da Aorta/complicações , Calcinose/mortalidade , Doenças Cardiovasculares/mortalidade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças da Aorta/mortalidade , Calcinose/complicações , Doenças Cardiovasculares/etiologia , Estudos de Coortes , Feminino , Humanos , Estudos Prospectivos , Análise de SobrevidaRESUMO
OBJECTIVE: To examine the association of the Arg200Trp and Arg324Gly variants of FRZB with the risk and phenotype of radiographic osteoarthritis (OA) of the hip and serum levels of Frizzled-related protein (FRP) in a prospective cohort of elderly Caucasian women. METHODS: Radiographic hip OA status of patients was defined by the presence of severe joint space narrowing (JSN) (feature grade>or=3), a summary grade>or=3, or definite osteophytes (grade>or=2) and JSN (grade>or=2) in the same hip. Genotypes were obtained in 569 patients with radiographic OA of the hip and in 1,317 and 4,136 controls for the Arg200Trp and Arg324Gly variants, respectively. Serum FRP levels were measured by enzyme-linked immunosorbent assay. Multivariate logistic regression was performed. RESULTS: The minor allele frequency for the Arg200Trp polymorphism was 0.12 in the control group compared with 0.14 in the group with radiographic OA of the hip (P=0.12), and the minor allele frequency for the Arg324Gly variant was 0.083 in the control group compared with 0.088 in the group with radiographic OA of the hip (P=0.63). The multilocus genotypes available in 1,886 subjects suggested that inheritance of both minor alleles was a risk factor for developing OA characterized by JSN (P<0.01). Patients with radiographic OA of the hip who were homozygous for the Arg200Trp minor allele had higher serum FRP levels than controls who were homozygous for the major allele. CONCLUSION: Our data confirm findings of another study, that a rare haplotype with both Arg200Trp and Arg324Gly FRZB variants contributes to the genetic susceptibility to hip OA among Caucasian women, and that these polymorphisms may contribute to increased serum levels of proteins as biomarkers of OA.
Assuntos
Glicoproteínas/sangue , Osteoartrite do Quadril/sangue , Osteoartrite do Quadril/etiologia , Idoso , Feminino , Genótipo , Glicoproteínas/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/genética , Estudos Prospectivos , Radiografia , Fatores de RiscoRESUMO
OBJECTIVE: To examine the association of baseline concentrations of serum cartilage oligomeric matrix protein (COMP) and serum N-telopeptide crosslinks (NTX) with the development and progression of radiographic hip osteoarthritis (RHOA) in elderly women. METHODS: Pelvic radiographs were obtained a mean of 8.3 years apart from white women > or =65 years of age enrolled in the Study of Osteoporotic Fractures. Random sampling from a cohort of 5,928 subjects was performed, with subjects ( approximately 200 per group) assigned to nested case-control studies, one focusing on RHOA incidence and the other on RHOA progression. Baseline serum levels of COMP and NTX were measured by enzyme-linked immunosorbent assay in duplicate. Odds ratios (ORs) and 95% confidence intervals (95% CIs), indicating the likelihood of baseline serum COMP and NTX levels to be predictive of the development or progression of RHOA, were calculated using logistic regression analysis, with adjustment for potential covariates. RESULTS: At baseline, incident cases of RHOA were associated with higher serum levels of COMP and NTX (P < 0.05 for each) compared with the no RHOA control group. Higher baseline serum COMP and NTX levels were associated with an increased risk of incident RHOA compared with the no RHOA group, with an adjusted OR of 1.31 per SD increase in COMP (95% CI 1.02-1.68) and adjusted OR of 1.38 per SD increase in NTX (95% CI 1.07-1.79). In this community-based cohort, progression of RHOA was modest. However, there was a trend toward increased risk of RHOA progression with higher baseline COMP and NTX levels. CONCLUSION: These data suggest that serum levels of COMP and NTX are modest risk markers for the development of RHOA in a community-based cohort of elderly white women.