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1.
Hong Kong Med J ; 29(5): 412-420, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37794613

RESUMO

INTRODUCTION: Telemedicine services worldwide have experienced unprecedented growth since the early days of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have shown that telemedicine is an effective alternative to conventional in-person patient care. This study explored the public perception of telemedicine in Hong Kong, specifically among older adults who are most vulnerable to COVID-19. METHODS: Medical students from The Chinese University of Hong Kong conducted in-person surveys of older adults aged ≥60 years. Each survey collected socio-demographic information, medical history, and concerns regarding telemedicine use. Univariate and multivariate logistic regression analyses were conducted to identify statistically significant associations. The primary outcomes were acceptance of telemedicine use during a hypothetical severe outbreak and after the COVID-19 pandemic. RESULTS: There were 109 survey respondents. Multivariate logistic regression analyses revealed that the expectation of government subsidies for telemedicine services was the strongest common driver and the only positive independent predictor of telemedicine use during a hypothetical severe outbreak (P=0.016) and after the COVID-19 pandemic (P=0.003). No negative independent predictors of telemedicine use during a hypothetical severe outbreak were identified. Negative independent predictors of telemedicine use after the COVID-19 pandemic included older age and residence in the New Territories (both P=0.001). CONCLUSION: Government support, such as telemedicine-specific subsidies, will be important for efforts to promote telemedicine use in Hong Kong during future severe outbreaks and after the COVID-19 pandemic. Robust dissemination of information regarding the advantages and disadvantages of telemedicine for the public, especially older adults, is needed.


Assuntos
COVID-19 , Telemedicina , Humanos , Idoso , COVID-19/epidemiologia , Hong Kong/epidemiologia , Pandemias , Estudos Transversais
2.
Hong Kong Med J ; 29(6): 532-541, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37385947

RESUMO

Helicobacter pylori infection causes chronic gastric inflammation that contributes to various gastroduodenal diseases, including peptic ulcer and gastric cancer. Despite broad regional variations, the prevalence of resistance to antibiotics used to manage H pylori infection is increasing worldwide; this trend could hinder the success of eradication therapy. To increase awareness of H pylori and improve the diagnosis and treatment of its infection in Hong Kong, our consensus panel proposed a set of guidance statements for disease management. We conducted a comprehensive review of literature published during 2011 and 2021, with a focus on articles from Hong Kong or other regions of China. We evaluated the evidence using the Oxford Centre for Evidence-Based Medicine's 2011 Levels of Evidence and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system and sought consensus through online voting and a subsequent face-to-face meeting, which enabled us to develop and refine the guidance statements. This report consists of 24 statements regarding the epidemiology and burden, screening and diagnosis, and treatment of H pylori. Key guidance statements include a recommendation to use the test-and-treat approach for high-risk individuals, as well as the confirmation that triple therapy with a proton pump inhibitor, amoxicillin, and clarithromycin remains a valid first-line option for adults and children in Hong Kong.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Adulto , Criança , Humanos , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Hong Kong/epidemiologia , Consenso , Antibacterianos/uso terapêutico
4.
Osteoporos Int ; 27(3): 943-951, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26449355

RESUMO

SUMMARY: Falls are a costly public health problem worldwide. The literature is devoid of prospective data that identifies factors among fallers that significantly drive health care resource utilization. We found that cognitive function--specifically, executive functions--and cognitive status are significant determinants of health resource utilization among older fallers. INTRODUCTION: Although falls are costly, there are no prospective data examining factors among fallers that drive health care resource utilization. We identified key determinants of health resource utilization (HRU) at 6 and 12 months among older adults with a history of falls. Specifically, with the increasing recognition that cognitive impairment is associated with increased falls risk, we investigated cognition as a potential driver of health resource utilization. METHODS: This 12-month prospective cohort study at the Vancouver Falls Prevention Clinic (n = 319) included participants with a history of at least one fall in the previous 12 months. Based on their cognitive status, participants were divided into two groups: (1) no mild cognitive impairment (MCI) and (2) MCI. We constructed two linear regression models with HRU at 6 and 12 months as the dependent variables for each model, respectively. Predictors relating to mobility, global cognition, executive functions, and cognitive status (MCI versus no MCI) were examined. Age, sex, comorbidities, depression status, and activities of daily living were included regardless of statistical significance. RESULTS: Global cognition, comorbidities, working memory, and cognitive status (MCI versus no MCI ascertained using the Montreal Cognitive Assessment (MoCA)) were significant determinants of total HRU at 6 months. The number of medical comorbidities and global cognition were significant determinants of total HRU at 12 months. CONCLUSION: MCI status was a determinant of HRU at 6 months among older adults with a history of falls. As such, efforts to minimize health care resource use related to falls, it is important to tailor future interventions to be effective for people with MCI who fall. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01022866.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Disfunção Cognitiva/epidemiologia , Recursos em Saúde/estatística & dados numéricos , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Colúmbia Britânica/epidemiologia , Cognição , Disfunção Cognitiva/psicologia , Estudos de Coortes , Comorbidade , Função Executiva , Feminino , Avaliação Geriátrica/métodos , Humanos , Estudos Longitudinais , Masculino , Limitação da Mobilidade , Testes Neuropsicológicos , Equilíbrio Postural , Estudos Prospectivos , Fatores de Risco
5.
Br J Cancer ; 111(4): 708-15, 2014 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-24921912

RESUMO

BACKGROUND: Neuroblastoma tumour resection goal is maximal tumour removal. We hypothesise that combining surgery with sustained, local doxorubicin application can control tumour growth. METHODS: We injected human neuroblastoma cells into immunocompromised mouse adrenal gland. When KELLY cell-induced tumour volume was >300 mm(3), 80-90% of tumour was resected and treated as follows: instantaneous-release silk film with 100 µg doxorubicin (100IR), controlled-release film with 200 µg (200CR) over residual tumour bed; and 100 and 200 µg intravenous doxorubicin (100IV and 200IV). Tumour volume was measured and histology analysed. RESULTS: Orthotopic tumours formed with KELLY, SK-N-AS, IMR-32, SH-SY5Y cells. Tumours reached 1800±180 mm(3) after 28 days, 2200±290 mm(3) after 35 days, 1280±260 mm(3) after 63 days, and 1700±360 mm(3) after 84 days, respectively. At 3 days post KELLY tumour resection, tumour volumes were similar across all groups (P=0.6210). Tumour growth rate was similar in untreated vs control film, 100IV vs 100IR, and 100IV vs 200IV. There was significant difference in 100IR vs 200CR (P=0.0004) and 200IV vs 200CR (P=0.0003). Tumour growth with all doxorubicin groups was slower than that of control (P: <0.0001-0.0069). At the interface of the 200CR film and tumour, there was cellular necrosis, surrounded by apoptotic cells before reaching viable tumour cells. CONCLUSIONS: Combining surgical resection and sustained local doxorubicin treatment is effective in tumour control. Administering doxorubicin in a local, controlled manner is superior to giving an equivalent intravenous dose in tumour control.


Assuntos
Neoplasias das Glândulas Suprarrenais/terapia , Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Portadores de Fármacos/administração & dosagem , Neuroblastoma/terapia , Neoplasias das Glândulas Suprarrenais/patologia , Animais , Linhagem Celular Tumoral , Terapia Combinada , Preparações de Ação Retardada , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neuroblastoma/patologia , Seda/química , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Eur J Neurol ; 20(4): 616-22, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22672698

RESUMO

BACKGROUND AND PURPOSE: To investigate the risk of stroke development following a diagnosis of Bell's palsy in a nationwide follow-up study. METHODS AND MATERIALS: Information on Bell's palsy and other factors relevant for stroke was obtained for 433218 eligible subjects without previous stroke who had ambulatory visit in 2004. Of those, 897 patients with Bell's palsy were identified. Over a median 2.9 years of follow-up, 4581 incident strokes were identified. We estimated hazard ratios (HR) and 95% confidence intervals [CI] with Cox proportional hazard models adjusting for age, sex, co-morbidities, and important risk factors. Standardized incidence ratio of stroke amongst patients with Bell's palsy was analyzed. RESULTS: Compared with non-Bell's palsy patients, patients with Bell's palsy had a 2.02-times (95% CI, 1.42-2.86) higher risk of stroke. The adjusted HR of developing stroke for patients with Bell's palsy treated with and without systemic steroid were 1.67 (95% CI, 0.69-4) and 2.10 (95%, 1.40-3.07), respectively. CONCLUSIONS: Patients with Bell's palsy carry a higher risk of stroke than the general population. Our data suggest that these patients might benefit from a more intensive stroke prevention therapy and regular follow-up after initial diagnosis.


Assuntos
Paralisia de Bell/complicações , Paralisia de Bell/tratamento farmacológico , Esteroides/uso terapêutico , Acidente Vascular Cerebral/complicações , Adulto , Paralisia de Bell/epidemiologia , Diabetes Mellitus/epidemiologia , Determinação de Ponto Final , Feminino , Seguimentos , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , Classificação Internacional de Doenças , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Programas Nacionais de Saúde/estatística & dados numéricos , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Risco , Fatores Sexuais , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/mortalidade , Análise de Sobrevida , Taiwan/epidemiologia
7.
Clin Radiol ; 68(4): e213-21, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23332436

RESUMO

AIM: To assess whether the three-dimensional (3D) black-blood motion-sensitized driven equilibrium (MSDE) prepared rapid gradient-echo sequence (3D MERGE) magnetic resonance imaging (MRI) sequence is sensitive enough to detect differences in atherosclerotic plaque size and morphology occurring in the adductor canal and the proximal bifurcation segment. MATERIALS AND METHODS: Fifty pairs of adductor canal and bifurcation segments from 25 patients with intermittent claudication were examined using 3D MERGE. The two-dimensional (2D) transverse section showing the largest plaque burden in each segment was chosen for comparison. Wall and lumen boundaries were segmented from each 2D section and quantified using six metrics: wall area (WA), lumen area (LA), normalized wall index (NWI), maximum wall thickness (MaxWT), minimum wall thickness (MinWT), and eccentricity. RESULTS: The mean LA in the adductor region was significantly lower than that in the bifurcation segment (p < 0.0001). Mean NWI, MaxWT, and eccentricity in the adductor region were significantly higher than those at bifurcation (p < 0.0001, p < 0.0021, and p < 0.0045, respectively). Mean WA and MinWT of the two segments did not show a statistically significant difference. WA in both regions was positively correlated with eccentricity (p < 0.0049 and p < 0.0049, respectively). LA was negatively correlated with eccentricity (p < 0.0017), and NWI was positively correlated with eccentricity only in the adductor region (p < 0.0004). CONCLUSION: The results suggest that compensatory enlargement was limited in the adductor canal when compared to the proximal bifurcation segment. 3D MERGE, as a fast and non-invasive sequence, may assist the evaluation of femoral atherosclerosis by assessing the size and morphology of plaques, knowledge of which can guide clinical treatment.


Assuntos
Aterosclerose/patologia , Artéria Femoral/patologia , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Placa Aterosclerótica/patologia , Idoso , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Sensibilidade e Especificidade
8.
Ann Oncol ; 23(8): 2128-2137, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22241896

RESUMO

BACKGROUND: Racial disparity has been investigated in a number of cancers; however, there remains a comparative paucity of data in Hodgkin's lymphoma (HL). PATIENTS AND METHODS: We examined time-, age-, and gender-specific incidence, disease characteristics, and survival across and within races for adolescent/adult HL (age 10-79 years) diagnosed during 1992-2007 in the SEER 13 registries. RESULTS: A total of 15 662 HL cases were identified [11,211 non-Hispanic whites, 2067 Hispanics, 1662 blacks, and 722 Asian/Pacific Islanders (A/PI)]. Similar to whites, A/PIs had bimodal age-specific incidence, while blacks and Hispanics did not. Further, HL was significantly more common in Hispanics versus whites age>65 years (7.0/1×10(6) versus 4.5/1×10(6), respectively, P<0.01). By place of birth, US-born Hispanics and A/PIs age 20-39 years had higher incidence of HL versus their foreign-born counterparts (P<0.05), however, rates converged age>40 years. Interestingly, from 1992-1997 to 2003-2007, A/PI incidence rates increased >50% (P<0.001). Moreover, this increase was restricted to US-born A/PI. We also identified a number of disease-related differences based on race. Finally, 5-, 10-, and 15-year overall survival rates were inferior for blacks and Hispanics compared with whites (P<0.005 and P<0.001, respectively) and A/PI (P<0.018 and P<0.001, respectively). These differences persisted on multivariate analysis. CONCLUSION: Collectively, we identified multiple racial disparities, including survival, in adolescent/adult HL.


Assuntos
Disparidades nos Níveis de Saúde , Doença de Hodgkin/etnologia , Adolescente , Adulto , Fatores Etários , Idoso , Povo Asiático , População Negra , Criança , Feminino , Hispânico ou Latino , Doença de Hodgkin/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Havaiano Nativo ou Outro Ilhéu do Pacífico , Programa de SEER , Fatores Sexuais , Estados Unidos/epidemiologia , População Branca , Adulto Jovem
9.
Ann Oncol ; 23(9): 2362-2374, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22786757

RESUMO

BACKGROUND: The two most common forms of non-Hodgkin lymphoma (NHL) exhibit different sex ratios: diffuse large B-cell lymphoma (DLBCL) occurs more frequently in men and follicular lymphoma (FL) more frequently in women. Looking among women alone, this pooled analysis explores the relationship between reproductive histories and these cancers. MATERIALS AND METHODS: Self-reported reproductive histories from 4263 women with NHL and 5971 women without NHL were pooled across 18 case-control studies (1983-2005) from North America, Europe and Japan. Study-specific odd ratios (ORs) and confidence intervals (CIs) were estimated using logistic regression and pooled using random-effects meta-analyses. RESULTS: Associations with reproductive factors were found for FL rather than NHL overall and DLBCL. In particular, the risk of FL decreased with increasing number of pregnancies (pooled OR(trend) = 0.88, 95% CI 0.81-0.96). FL was associated with hormonal contraception (pooled OR = 1.30, 95% CI 1.04-1.63), and risks were increased when use started after the age of 21, was used for <5 years or stopped for >20 years before diagnosis. DLBCL, on the other hand, was not associated with hormonal contraception (pooled OR = 0.87, 95% CI 0.65-1.16). CONCLUSIONS: Hormonal contraception is associated with an increased risk of FL but not of DLBCL or NHL overall.


Assuntos
Anticoncepcionais Orais Hormonais/efeitos adversos , Linfoma não Hodgkin/etiologia , Inibição da Ovulação , História Reprodutiva , Estudos de Casos e Controles , Anticoncepcionais Orais Hormonais/administração & dosagem , Feminino , Humanos , Modelos Logísticos , Linfoma não Hodgkin/fisiopatologia , Razão de Chances , Fenômenos Reprodutivos Fisiológicos
10.
Ann Oncol ; 22(5): 1170-1180, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21115603

RESUMO

BACKGROUND: Rituximab has been associated with hepatitis B virus reactivation (HBV-R). However, the characteristics and scope of this association remain largely undefined. METHODS: We completed a comprehensive literature search of all published rituximab-associated HBV-R cases and from the Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) MedWatch database. Literature and FDA cases were compared for completeness, and a meta-analysis was completed. RESULTS: One hundred and eighty-three unique cases of rituximab-associated HBV-R were identified from the literature (n = 27 case reports, n = 156 case series). The time from last rituximab to reactivation was 3 months (range 0-12), although 29% occurred >6 months after last rituximab. Within FDA data (n = 118 cases), there was a strong signal for rituximab-associated HBV-R [proportional reporting ratio = 28.5, 95% confidence interval (CI) 23.9-34.1; Empiric Bayes Geometric Mean = 26.4, 95% CI 21.4-31.1]. However, the completeness of data in FDA reports was significantly inferior compared with literature cases (P < 0.0001). Among HBV core antibody (HBcAb(+)) series, the pooled effect of rituximab-based therapy showed a significantly increased risk of HBV-R compared with nonrituximab-treated patients (odds ratio 5.73, 95% CI 2.01-16.33; Z = 3.33, P = 0.0009) without heterogeneity (χ(2) = 2.12, P = 0.5473). CONCLUSIONS: The FDA AERS provided strong HBV-R safety signals; however, literature-based cases provided a significantly more complete description. Furthermore, meta-analysis of HBcAb(+) series identified a more than fivefold increased rate of rituximab-associated HBV-R.


Assuntos
Anticorpos Monoclonais Murinos/efeitos adversos , Antineoplásicos/efeitos adversos , Vírus da Hepatite B , Hepatite B/induzido quimicamente , Transtornos Linfoproliferativos/tratamento farmacológico , Adulto , Sistemas de Notificação de Reações Adversas a Medicamentos , Idoso , Idoso de 80 Anos ou mais , Feminino , Hepatite B/complicações , Humanos , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/virologia , Masculino , Pessoa de Meia-Idade , Recidiva , Rituximab , Estados Unidos , United States Food and Drug Administration , Adulto Jovem
11.
Ann Rheum Dis ; 69(1): 297-300, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19103635

RESUMO

OBJECTIVES: Studying post-infliximab gene expression changes could provide insights into the pathogenesis of ankylosing spondylitis (AS). METHODS: Gene expression changes were screened by microarray on peripheral blood RNA of 16 AS patients at baseline and 2 weeks post-infliximab, and selected results were confirmed by quantitative real-time (qRT)-PCR. Corresponding serum-soluble LIGHT (sLIGHT) was estimated by ELISA and the fold change in sLIGHT was correlated to the fold change in erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and the Bath AS disease activity index. RESULTS: Post-infliximab, 69% of the patients (11/16) achieved an ASAS20 response. Six candidate genes were differentially expressed by microarray; four of which were validated by qRT-PCR. sLIGHT showed the most significant difference. There was good correlation of baseline sLIGHT with CRP (R = 0.60; p = 0.01) and ESR (R = 0.51; p = 0.04). The fold change in sLIGHT correlated with change in both CRP (R = 0.71, p = 0.002) and ESR (R = 0.77, p<0.001). CONCLUSION: LIGHT is significantly downregulated by infliximab. sLIGHT correlated well with changes in inflammatory markers.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Proteínas Sanguíneas/metabolismo , Espondilite Anquilosante/tratamento farmacológico , Adulto , Biomarcadores/sangue , Sedimentação Sanguínea , Proteína C-Reativa/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Infliximab , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Índice de Gravidade de Doença , Espondilite Anquilosante/sangue , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/sangue , Adulto Jovem
12.
J Clin Invest ; 102(10): 1776-82, 1998 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9819362

RESUMO

The basic mechanisms underlying reactive arthritis and specifically the joint injury that follows intra-articular Chlamydia trachomatis infection have not been defined. The present study addresses this question through the development of an experimental model. Stable cell lines were generated from synoviocytes harvested from the knee joints of Lewis rats. The synoviocytes were cocultivated with C. trachomatis to allow invasion by the microbe and were then transferred by intra-articular injection into the knee joints of Lewis rats. The ensuing arthritis could be subdivided into an early phase (

Assuntos
Artrite Reativa/microbiologia , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis , Membrana Sinovial/microbiologia , Animais , Artrite Reativa/metabolismo , Artrite Reativa/patologia , Proteínas da Membrana Bacteriana Externa/análise , Western Blotting , Infecções por Chlamydia/metabolismo , Infecções por Chlamydia/patologia , Chlamydia trachomatis/isolamento & purificação , Doença Crônica , Ciprofloxacina/uso terapêutico , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Injeções Intra-Articulares , Injeções Intramusculares , Injeções Subcutâneas , Lipopolissacarídeos/análise , Masculino , Microscopia de Fluorescência , Ratos , Ratos Endogâmicos Lew , Baço/metabolismo , Baço/microbiologia , Membrana Sinovial/citologia , Membrana Sinovial/metabolismo , Membrana Sinovial/patologia , Tetraciclina/uso terapêutico , Fatores de Tempo
14.
J Hum Hypertens ; 31(7): 479-482, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28124684

RESUMO

A pocket-size cuffless electronic device for self-measurement of blood pressure (BP) has been developed (Freescan, Maisense Inc., Zhubei, Taiwan). The device estimates BP within 10 s using three embedded electrodes and one force sensor that is applied over the radial pulse to evaluate the pulse wave. Before use, basic anthropometric characteristics are recorded on the device, and individualized initial calibration is required based on a standard BP measurement performed using an upper-arm BP monitor. The device performance in providing valid BP readings was evaluated in 313 normotensive and hypertensive adults in three study phases during which the device sensor was upgraded. A formal validation study of a prototype device against mercury sphygmomanometer was performed according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 2013 protocol. The test device succeeded in obtaining a valid BP measurement (three successful readings within up to five attempts) in 55-72% of the participants, which reached 87% with device sensor upgrade. For the validation study, 125 adults were recruited and 85 met the protocol requirements for inclusion. The mean device-observers BP difference was 3.2±6.7 (s.d.) mm Hg for systolic and 2.6±4.6 mm Hg for diastolic BP (criterion 1). The estimated s.d. (inter-subject variability) were 5.83 and 4.17 mm Hg respectively (criterion 2). These data suggest that this prototype cuffless BP monitor provides valid self-measurements in the vast majority of adults, and satisfies the BP measurement accuracy criteria of the ANSI/AAMI/ISO 2013 validation protocol.


Assuntos
Determinação da Pressão Arterial/instrumentação , Autocuidado/instrumentação , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Cancer Res ; 60(19): 5365-70, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11034072

RESUMO

We have examined the presence of loss of heterozygosity (LOH) on chromosome 3p in histologically normal nasopharyngeal epithelia (NP), dysplastic lesions, and carcinoma of the nasopharynx from different ethnic and geographic regions. Microdissected normal NP from noncancerous individuals and nasopharyngeal carcinoma (NPC) samples from both the high-risk group (southern Chinese in Hong Kong) and two low-risk groups for NPC (central/northern Chinese in Anhui/Beijing and Caucasians in Toronto) were included. All NPC samples showed high incidence of 3p deletion (81-100%). High frequencies of LOH on 3p were also detected in normal NP (73.9%) and dysplastic lesions (75%) from the southern Chinese. Significant lower frequency of LOH on 3p was noted in normal NP from the low-risk groups (20%) than those from high-risk groups (P = 0.0003). The presence of such genetic alterations in the histologically normal NP and dysplastic lesions suggests that it is an early event in tumor development. The higher frequency of 3p LOH found in normal NP from southern Chinese compared with those from low-risk groups may be related to the distinct cancer incidence among these populations.


Assuntos
Carcinoma/genética , Deleção Cromossômica , Cromossomos Humanos Par 3/genética , Neoplasias Nasofaríngeas/genética , Nasofaringe/ultraestrutura , Lesões Pré-Cancerosas/genética , Adulto , Idoso , China , Epitélio/fisiologia , Epitélio/ultraestrutura , Feminino , Hong Kong , Humanos , Perda de Heterozigosidade , Masculino , Pessoa de Meia-Idade , Nasofaringe/patologia , Nasofaringe/fisiologia , Fatores de Risco
17.
Geobiology ; 14(5): 499-508, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27384464

RESUMO

Observations of modern microbes have led to several hypotheses on how microbes precipitated the extensive iron formations in the geologic record, but we have yet to resolve the exact microbial contributions. An initial hypothesis was that cyanobacteria produced oxygen which oxidized iron abiotically; however, in modern environments such as microbial mats, where Fe(II) and O2 coexist, we commonly find microaerophilic chemolithotrophic iron-oxidizing bacteria producing Fe(III) oxyhydroxides. This suggests that such iron oxidizers could have inhabited niches in ancient coastal oceans where Fe(II) and O2 coexisted, and therefore contributed to banded iron formations (BIFs) and other ferruginous deposits. However, there is currently little evidence for planktonic marine iron oxidizers in modern analogs. Here, we demonstrate successful cultivation of planktonic microaerophilic iron-oxidizing Zetaproteobacteria from the Chesapeake Bay during seasonal stratification. Iron oxidizers were associated with low oxygen concentrations and active iron redox cycling in the oxic-anoxic transition zone (<3 µm O2 , <0.2 µm H2 S). While cyanobacteria were also detected in this transition zone, oxygen concentrations were too low to support significant rates of abiotic iron oxidation. Cyanobacteria may be providing oxygen for microaerophilic iron oxidation through a symbiotic relationship; at high Fe(II) levels, cyanobacteria would gain protection against Fe(II) toxicity. A Zetaproteobacteria isolate from this site oxidized iron at rates sufficient to account for deposition of geologic iron formations. In sum, our results suggest that once oxygenic photosynthesis evolved, microaerophilic chemolithotrophic iron oxidizers were likely important drivers of iron mineralization in ancient oceans.


Assuntos
Cianobactérias/metabolismo , Compostos de Ferro/metabolismo , Oxigênio/metabolismo , Plâncton/metabolismo , Proteobactérias/metabolismo , Água do Mar/microbiologia , Sedimentos Geológicos/química , Oxirredução
18.
Am J Clin Nutr ; 69(1): 147-52, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9925137

RESUMO

BACKGROUND: The role of dietary protein intake in osteoporosis remains controversial. Protein is an important structural component of bone and protein supplementation improves the medical outcome of hip fracture patients, but it is unknown whether protein intake can reduce the incidence risk of hip fracture. OBJECTIVE: The relation between intake of protein and other nutrients and subsequent incidence of hip fracture was evaluated. DESIGN: Nutrient intake was assessed with a food-frequency questionnaire in a cohort of Iowa women aged 55-69 y at baseline in 1986. Incident hip fractures were ascertained through follow-up questionnaires mailed to participants in 1987 and 1989 and verified by physician reports. RESULTS: Forty-four cases of incident hip fractures were included in the analyses of 104338 person-years (the number of subjects studied times the number of years of follow-up) of follow-up data. The risk of hip fracture was not related to intake of calcium or vitamin D, but was negatively associated with total protein intake. Animal rather than vegetable sources of protein appeared to account for this association. In a multivariate model with inclusion of age, body size, parity, smoking, alcohol intake, estrogen use, and physical activity, the relative risks of hip fracture decreased across increasing quartiles of intake of animal protein as follows: 1.00 (reference), 0.59 (95% CI: 0.26, 1.34), 0.63 (0.28, 1.42), and 0.31 (0.10, 0.93); P for trend = 0.037. CONCLUSION: Intake of dietary protein, especially from animal sources, may be associated with a reduced incidence of hip fractures in postmenopausal women.


Assuntos
Dieta , Proteínas Alimentares/administração & dosagem , Fraturas do Quadril/prevenção & controle , Pós-Menopausa , Idoso , Análise de Variância , Estudos de Coortes , Proteínas Alimentares/uso terapêutico , Feminino , Fraturas do Quadril/epidemiologia , Humanos , Incidência , Iowa/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários
19.
Cancer Epidemiol Biomarkers Prev ; 8(1): 53-60, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9950240

RESUMO

A family history of prostate cancer has been associated with prostate cancer risk in most prior studies, and more limited data suggest that a family history of breast cancer may also be important; however, there are no data from a population-based cohort study of prostate cancer incidence that adjusts for major confounders. We conducted follow-up through 1995 on 1557 men, ages 40-86 years, who were randomly selected (81% response rate) as cancer-free controls for a population-based case-control study conducted in Iowa from 1987-1989. Family history of cancer in parents and siblings was obtained using a mailed questionnaire. Incident cancers and deaths were ascertained through linkages to state and national databases; 101 incident cases of prostate cancer were identified. At baseline, 4.6% of the cohort reported a family history of prostate cancer in a brother or father, and this was positively associated with prostate cancer risk after adjustment for age [relative risk (RR) = 3.2; 95% confidence interval (CI), 1.8-5.7] or after multivariate adjustment for age, alcohol, and dietary factors (RR = 3.7; 95% CI, 1.9-7.2). Risk was greater if a brother had prostate cancer (RR = 4.5; 95% CI, 2.1-9.7) than if a father had prostate cancer (RR = 2.3; 95% CI, 1.0-5.3). Also at baseline, 9.6% of the cohort had a family history of breast and/or ovarian cancer in a mother or sister, and this was positively associated with prostate cancer risk (age-adjusted RR = 1.7; 95% CI, 1.0-3.0; multivariate RR = 1.7; 95% CI, 0.9-3.2). Men with a family history of both prostate and breast/ovarian cancer were also at increased risk of prostate cancer (RR = 5.8; 95% CI, 2.4-14). There was no association with a family history of colon cancer. Exclusion of well-differentiated, localized tumors did not alter these findings. These data from an incidence study confirm that a family history of prostate cancer is a strong prostate cancer risk factor after adjustment for dietary and other risk factors, and suggest that selection and recall bias have not had an important influence on most case-control study results. These data also support the idea that a family history of breast cancer may also be a prostate cancer risk factor.


Assuntos
Neoplasias da Próstata/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas , Neoplasias da Mama/genética , Estudos de Casos e Controles , Estudos de Coortes , Neoplasias do Colo/genética , Intervalos de Confiança , Fatores de Confusão Epidemiológicos , Bases de Dados como Assunto , Comportamento Alimentar , Feminino , Seguimentos , Humanos , Incidência , Iowa , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neoplasias Ovarianas/genética , Fatores de Risco , Inquéritos e Questionários
20.
Clin Exp Metastasis ; 13(6): 492-8, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7586807

RESUMO

Proteolytic activity is important for tumor growth and metastasis. Plasminogen and urokinase-type plasminogen activator (u-PA) constitute one of the most extensively studied proteolytic systems believed to participate in these processes. u-PA cleaves plasminogen to plasmin, which in turn degrades surrounding extracellular matrix and allows tumor cells to migrate to other areas. The specific receptor for u-PA (u-PAR) has also been implicated as an essential modulator in this pathway. Eleven paired samples of colorectal cancers and normal mucosal tissues from the same patients were removed at surgery. The tissues were homogenized and the supernatants assayed for u-PAR immunoreactivity, u-PAR antigen concentration, u-PAR binding activity and u-PA activity. Immunoblot analysis showed that a major u-PAR species of approximately 55 kDa was present in all tissues. In addition, a protein band of approximately 41 kDa, which crossreacted with anti-u-PAR antibodies, was also found in the tumors. This protein band was either absent, or present in relatively small amounts in the normal colorectal tissues. Cross-linking experiments showed that the approximately 55 kDa band only, and not the approximately 41 kDa band, was able to bind either single chain urokinase-type plasminogen activator (scu-PA) or the amino terminal fragment of urokinase (ATF). The tumor samples also exhibited highly elevated u-PA activity and u-PAR antigen relative to the corresponding normal tissues. Elevated u-PA activity appeared to correlate with elevated u-PAR antigen in colorectal cancers, but not in the normal tissues. These increases were also associated with increase of the u-PAR-related, low-molecular-weight protein in the tumor samples. The measurement of u-PAR and the u-PAR-related protein, in addition to u-PA activity, could have diagnostic or prognostic value in this type of cancer.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Colorretais/metabolismo , Receptores de Superfície Celular/metabolismo , Western Blotting , Humanos , Peso Molecular , Receptores de Superfície Celular/química , Receptores de Superfície Celular/imunologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
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