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1.
Cytopathology ; 29(3): 267-274, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29578257

RESUMO

OBJECTIVE: To evaluate the performance of an automated DNA-image-cytometry system as a tool to detect cervical carcinoma. METHODS: Of 384 liquid-based cervical cytology samples with available biopsy follow-up were analyzed by both the Imager System and a high-risk HPV test (Cobas). RESULTS: The sensitivity and specificity of Imager System for detecting biopsy proven high-grade squamous intraepithelial lesion (HSIL, cervical intraepithelial neoplasia [CIN]2-3) and carcinoma were 89.58% and 56.25%, respectively, compared to 97.22% and 23.33% of HPV test but additional HPV 16/18 genotyping increased the specificity to 69.58%. The sensitivity and specificity of the Imager System for predicting HSIL+ (CIN2-3+) lesions among atypical squamous cells of undetermined significance samples were 80.00% and 70.53%, respectively, compared to 100% and 11.58% of HPV test whilst the HPV 16/18 genotyping increased the specificity to 77.89%. Among atypical squamous cells-cannot exclude HSIL, the sensitivity and specificity of Imager System for predicting HSIL+ (CIN2-3+) lesions upon follow up were 82.86% and 33.33%%, respectively, compared to 97.14% and 4.76% of HPV test and the HPV 16/18 genotyping increased the specificity to 19.05%. Among low-grade squamous intraepithelial lesion cases, the sensitivity and specificity of the Imager System for predicting HSIL+ (CIN2-3+) lesions were 66.67% and 35.71%%, respectively, compared to 66.67% and 29.76% of HPV test while HPV 16/18 genotyping increased the specificity to 79.76%. The overall results of imager and high-risk HPV test agreed in 69.43% (268) of all samples. CONCLUSIONS: The automated imager system and HPV 16/18 genotyping can enhance the specificity of detecting HSIL+ (CIN2-3+) lesions.


Assuntos
Colo do Útero/patologia , DNA Viral/genética , Lesões Intraepiteliais Escamosas Cervicais/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Escamosas Atípicas do Colo do Útero/patologia , Células Escamosas Atípicas do Colo do Útero/virologia , Biópsia/métodos , Colo do Útero/virologia , Colposcopia/métodos , Feminino , Testes de DNA para Papilomavírus Humano/métodos , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Humanos , Citometria por Imagem/métodos , Pessoa de Meia-Idade , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Sensibilidade e Especificidade , Lesões Intraepiteliais Escamosas Cervicais/virologia , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal/métodos , Adulto Jovem , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
2.
Hong Kong Med J ; 24(1): 48-55, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29302018

RESUMO

INTRODUCTION: Exotic pets are increasingly popular in Hong Kong and include fish, amphibians, reptiles, and arthropods. Some of these exotic animals are venomous and may cause injuries to and envenomation of their owners. The clinical experience of emergency physicians in the management of injuries and envenomation by these exotic animals is limited. We reviewed the clinical features and outcomes of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre. METHODS: We retrospectively retrieved and reviewed cases of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre from 1 July 2008 to 31 March 2017. RESULTS: There were 15 reported cases of injuries and envenomation by exotic pets during the study period, including snakebite (n=6), fish sting (n=4), scorpion sting (n=2), lizard bite (n=2), and turtle bite (n=1). There were two cases of major effects from the envenomation, seven cases with moderate effects, and six cases with mild effects. All major effects were related to venomous snakebites. There were no mortalities. CONCLUSION: All human injuries from exotic pets arose from reptiles, scorpions, and fish. All cases of major envenomation were inflicted by snakes.


Assuntos
Animais Exóticos , Mordeduras e Picadas/epidemiologia , Mordeduras e Picadas/etiologia , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/etiologia , Adolescente , Adulto , Animais , Mordeduras e Picadas/prevenção & controle , Feminino , Peixes , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Centros de Controle de Intoxicações/estatística & dados numéricos , Estudos Retrospectivos , Escorpiões , Serpentes , Ferimentos e Lesões/prevenção & controle , Adulto Jovem
3.
Clin Exp Immunol ; 187(1): 113-123, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27667787

RESUMO

Tolerogenic dendritic cells (tolDC) are a new immunotherapeutic tool for the treatment of rheumatoid arthritis (RA) and other autoimmune disorders. We have established a method to generate stable tolDC by pharmacological modulation of human monocyte-derived DC. These tolDC exert potent pro-tolerogenic actions on CD4+ T cells. Lack of interleukin (IL)-12p70 production is a key immunoregulatory attribute of tolDC but does not explain their action fully. Here we show that tolDC express transforming growth factor (TGF)-ß1 at both mRNA and protein levels, and that expression of this immunoregulatory cytokine is significantly higher in tolDC than in mature monocyte-derived DC. By inhibiting TGF-ß1 signalling we demonstrate that tolDC regulate CD4+ T cell responses in a manner that is at least partly dependent upon this cytokine. Crucially, we also show that while there is no significant difference in expression of TGF-ßRII on CD4+ T cells from RA patients and healthy controls, RA patient CD4+ T cells are measurably less responsive to TGF-ß1 than healthy control CD4+ T cells [reduced TGF-ß-induced mothers against decapentaplegic homologue (Smad)2/3 phosphorylation, forkhead box protein 3 (FoxP3) expression and suppression of (IFN)-γ secretion]. However, CD4+ T cells from RA patients can, nonetheless, be regulated efficiently by tolDC in a TGF-ß1-dependent manner. This work is important for the design and development of future studies investigating the potential use of tolDC as a novel immunotherapy for the treatment of RA.


Assuntos
Artrite Reumatoide/terapia , Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , Tolerância Imunológica , Imunoterapia/métodos , Fator de Crescimento Transformador beta1/metabolismo , Artrite Reumatoide/imunologia , Células Cultivadas , Colecalciferol/farmacologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/transplante , Dexametasona/farmacologia , Fatores de Transcrição Forkhead/metabolismo , Humanos , Imunomodulação , Interleucina-12/genética , Interleucina-12/metabolismo , Ativação Linfocitária , Proteína Smad2/metabolismo
4.
Hong Kong Med J ; 23(1): 13-8, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27909267

RESUMO

INTRODUCTION: There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. METHODS: This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. RESULTS: The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. CONCLUSIONS: Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.


Assuntos
Antivenenos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Venenos de Crotalídeos/antagonistas & inibidores , Adulto , Testes de Coagulação Sanguínea , China , Venenos de Crotalídeos/intoxicação , Voluntários Saudáveis , Hong Kong , Humanos , Mordeduras de Serpentes/terapia , Tailândia , Fatores de Tempo
5.
Curr Oncol ; 23(4): e362-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27536185

RESUMO

PURPOSE: In the present study, we determined the association of pretreatment circulating neutrophils, monocytes, and lymphocytes with clinical outcomes after lung stereotactic body radiotherapy (sbrt). METHODS: All patients with primary lung cancer and with a complete blood count within 3 months of lung sbrt from 2005 to 2012 were included. Overall survival (os) was calculated using the Kaplan-Meier method. Factors associated with os were investigated using univariable and multivariable Cox proportional hazards regression. Fine-Gray competing risk regression was performed to test the association of the neutrophil:lymphocyte (nlr) and monocyte:lymphocyte (mlr) ratios with two types of failure: disease-related failure and death, and death unrelated to disease. RESULTS: Of the 299 sbrt patients identified, 122 were eligible for analysis. The median and range of the nlr and mlr were 3.0 (0.3-22.0) and 0.4 (0.1-1.9) respectively. On multivariable analysis, sex (p = 0.02), T stage (p = 0.04), and nlr (p < 0.01) were associated with os. On multivariable analysis, T stage (p < 0.01) and mlr (p < 0.01) were associated with disease-related failure; mlr (p = 0.03), nlr (p < 0.01), and sbrt dose of 48 Gy in 4 fractions (p = 0.03) and 54 Gy or 60 Gy in 3 fractions (p = 0.02) were associated with disease-unrelated death. Median survival was 4.3 years in the nlr≤3 group (95% confidence interval: 3.5 to not reached) and 2.5 years in the nlr>3 group (95% confidence interval: 1.7 to 4.8; p < 0.01). CONCLUSIONS: In lung sbrt patients, nlr and mlr are independently associated with os and disease-unrelated death. If validated, nlr and mlr could help to identify patients who would benefit most from sbrt.

6.
Eur J Clin Microbiol Infect Dis ; 34(9): 1827-32, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26071001

RESUMO

The automated high-throughput Abbott RealTime MTB real-time PCR assay has been recently launched for Mycobacterium tuberculosis complex (MTBC) clinical diagnosis. This study would like to evaluate its performance. We first compared its diagnostic performance with the Roche Cobas TaqMan MTB assay on 214 clinical respiratory specimens. Prospective analysis of a total 520 specimens was then performed to further evaluate the Abbott assay. The Abbott assay showed a lower limit of detection at 22.5 AFB/ml, which was more sensitive than the Cobas assay (167.5 AFB/ml). The two assays demonstrated a significant difference in diagnostic performance (McNemar's test; P = 0.0034), in which the Abbott assay presented significantly higher area under curve (AUC) than the Cobas assay (1.000 vs 0.880; P = 0.0002). The Abbott assay demonstrated extremely low PCR inhibition on clinical respiratory specimens. The automated Abbott assay required only very short manual handling time (0.5 h), which could help to improve the laboratory management. In the prospective analysis, the overall estimates for sensitivity and specificity of the Abbott assay were both 100 % among smear-positive specimens, whereas the smear-negative specimens were 96.7 and 96.1 %, respectively. No cross-reactivity with non-tuberculosis mycobacterial species was observed. The superiority in sensitivity of the Abbott assay for detecting MTBC in smear-negative specimens could further minimize the risk in MTBC false-negative detection. The new Abbott RealTime MTB assay has good diagnostic performance which can be a useful diagnostic tool for rapid MTBC detection in clinical laboratories.


Assuntos
Automação Laboratorial/métodos , Ensaios de Triagem em Larga Escala/métodos , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Pulmonar/diagnóstico , Automação Laboratorial/instrumentação , Diagnóstico Precoce , Ensaios de Triagem em Larga Escala/instrumentação , Humanos , Limite de Detecção , Técnicas de Diagnóstico Molecular/instrumentação , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Tuberculose Pulmonar/microbiologia
7.
J Am Chem Soc ; 136(11): 4129-32, 2014 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-24588769

RESUMO

The Au102(p-MBA)44 cluster (p-MBA: para-mercaptobenzoic acid) is observed as a chiral compound comprised of achiral components in its single-crystal structure. So far the enantiomers observed in the crystal structure are not isolated, nor is the circular dichroism spectrum known. A chiral phase transfer method is presented which allows partial resolution of the enantiomers by the use of a chiral ammonium bromide, (-)-1R,2S-N-dodecyl-N-methylephedrinium bromide ((-)-DMEBr). At sufficiently low concentration of (-)-DMEBr, the phase transfer from water to chloroform is incomplete. Both the aqueous and organic phases show optical activity of near mirror image relationship. Differences in the spectra are ascribed to the formation of diastereomeric salts. At high concentrations of (-)-DMEBr, full phase transfer is observed. The organic phase, however, still displays optical activity. We assume that one of the diastereomers has very strong optical activity, which overrules the cancelation of the spectra with opposite sign. Comparison with computations further corroborates the experimental data and allows a provisional assignment of handedness of each fraction.

9.
Neuroimage Clin ; 42: 103590, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38513535

RESUMO

BACKGROUND: Apical ground-glass opacification (GGO) identified on CT angiography (CTA) performed for suspected acute stroke was developed in 2020 as a coronavirus-disease-2019 (COVID-19) diagnostic and prognostic biomarker in a retrospective study during the first wave of COVID-19. OBJECTIVE: To prospectively validate whether GGO on CTA performed for suspected acute stroke is a reliable COVID-19 diagnostic and prognostic biomarker and whether it is reliable for COVID-19 vaccinated patients. METHODS: In this prospective, pragmatic, national, multi-center validation study performed at 13 sites, we captured study data consecutively in patients undergoing CTA for suspected acute stroke from January-March 2021. Demographic and clinical features associated with stroke and COVID-19 were incorporated. The primary outcome was the likelihood of reverse-transcriptase-polymerase-chain-reaction swab-test-confirmed COVID-19 using the GGO biomarker. Secondary outcomes investigated were functional status at discharge and survival analyses at 30 and 90 days. Univariate and multivariable statistical analyses were employed. RESULTS: CTAs from 1,111 patients were analyzed, with apical GGO identified in 8.5 % during a period of high COVID-19 prevalence. GGO showed good inter-rater reliability (Fleiss κ = 0.77); and high COVID-19 specificity (93.7 %, 91.8-95.2) and negative predictive value (NPV; 97.8 %, 96.5-98.6). In subgroup analysis of vaccinated patients, GGO remained a good diagnostic biomarker (specificity 93.1 %, 89.8-95.5; NPV 99.7 %, 98.3-100.0). Patients with COVID-19 were more likely to have higher stroke score (NIHSS (mean +/- SD) 6.9 +/- 6.9, COVID-19 negative, 9.7 +/- 9.0, COVID-19 positive; p = 0.01), carotid occlusions (6.2 % negative, 14.9 % positive; p = 0.02), and larger infarcts on presentation CT (ASPECTS 9.4 +/- 1.5, COVID-19 negative, 8.6 +/- 2.4, COVID-19 positive; p = 0.00). After multivariable logistic regression, GGO (odds ratio 15.7, 6.2-40.1), myalgia (8.9, 2.1-38.2) and higher core body temperature (1.9, 1.1-3.2) were independent COVID-19 predictors. GGO was associated with worse functional outcome on discharge and worse survival after univariate analysis. However, after adjustment for factors including stroke severity, GGO was not independently predictive of functional outcome or mortality. CONCLUSION: Apical GGO on CTA performed for patients with suspected acute stroke is a reliable diagnostic biomarker for COVID-19, which in combination with clinical features may be useful in COVID-19 triage.


Assuntos
COVID-19 , Angiografia por Tomografia Computadorizada , Acidente Vascular Cerebral , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Biomarcadores , Angiografia por Tomografia Computadorizada/métodos , COVID-19/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Prognóstico , Estudos Prospectivos , SARS-CoV-2 , Acidente Vascular Cerebral/diagnóstico por imagem
10.
J Clin Pharm Ther ; 38(5): 405-15, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23815285

RESUMO

WHAT IS KNOWN AND OBJECTIVES: A recently published large, long-term randomized controlled trial (RCT) brought into question the safety of dutasteride after a significantly increased risk of 'cardiac failure' was noted in the dutasteride arm of the trial compared with placebo. Our objective was to perform a meta-analysis to assess the risk of cardiovascular adverse events with the use of dutasteride for the prevention or treatment of prostatic disease. METHODS: We searched MEDLINE and EMBASE, unpublished articles identified through FDA/EMEA websites, study registers of pharmaceutical companies and reference lists of articles. Parallel-group, randomized controlled trials where men received dutasteride for the prevention of prostate cancer or treatment of prostatic hyperplasia against any comparator intervention were included. Heart failure was the primary outcome of interest but we also looked at myocardial infarction and stroke. Fixed-effect meta-analysis of pooled relative risk (RR) ratios of adverse effect outcomes was conducted. RESULTS AND DISCUSSION: In all, 12 RCTs were included in the meta-analysis after detailed screening of 564 citations. The total number of participants was 18,802, and study duration ranged from 6 to 208 weeks. Only two trials provided details on adequate allocation concealment, whereas all the trials stated they were double blind in nature. Dutasteride was not associated with a statistically significant increased risk of heart failure (RR 1·05; 95% confidence interval [CI], 0·71-1·57, I(2) = 20%), myocardial infarction (RR 1·00; 95% CI 0·77-1·30, I(2) = 0%) and stroke (RR, 1·20; 95% CI 0·88-1·64, I(2) = 0%) as compared to controls. WHAT IS NEW AND CONCLUSION: We did not find consistent evidence of a significant association between dutasteride therapy and the risk of cardiovascular adverse events.


Assuntos
Inibidores de 5-alfa Redutase/efeitos adversos , Inibidores de 5-alfa Redutase/uso terapêutico , Azasteroides/efeitos adversos , Azasteroides/uso terapêutico , Doenças Cardiovasculares/induzido quimicamente , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Dutasterida , Humanos , Masculino , Doenças Prostáticas/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Risco
11.
Hong Kong Med J ; 19(5): 416-23, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23603777

RESUMO

OBJECTIVE: The clinical features of patients with psoas abscess in a local setting, including the microbiology, incidence and aetiologies, have not been well described. This study aimed to review such clinical features and patient outcomes. DESIGN: Retrospective case series. SETTING: Regional hospital, Hong Kong. PATIENTS: Adults (aged ≥18 years) with psoas abscess admitted to Tuen Mun Hospital from 1 January 2006 to 31 December 2010 were included. The clinical presentations, aetiologies, microbiology, treatments, hospital stays, intensive care unit admissions, and outcomes of these patients were reviewed. RESULTS: The series entailed 42 patients, five of whom developed their psoas abscess after admission and seven were intravenous drug abusers. The most common presenting symptom in community-onset cases was back, hip, or thigh pain (43% [16/37]). Fever was present at presentation in 41% (15/37) of these patients, four of whom presented with fever only. The diagnosis was made by computed tomography in 95% (40/42) of these cases. In all, 23 abscesses were considered secondary; the most common aetiology being infective spondylitis or spondylodiscitis. The commonest causative organism for a primary psoas abscess was methicillin-sensitive Staphylococcus aureus, while for secondary abscesses they were more commonly from the gastro-intestinal and genitourinary tracts. Overall in-hospital mortality rate was 14% (6/42). Secondary psoas abscess patients had longer hospital stays (mean, 62 vs 34 days; P=0.007). CONCLUSION: Psoas abscess is an uncommon condition. Most patients presented with only non-specific symptoms leading to difficulty in making an early diagnosis. In more than half of these patients, the psoas abscesses were secondary, the aetiology of which differed from reported overseas experience.


Assuntos
Febre/etiologia , Abscesso do Psoas/patologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Febre/epidemiologia , Hong Kong , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Dor/epidemiologia , Dor/etiologia , Abscesso do Psoas/microbiologia , Abscesso do Psoas/terapia , Estudos Retrospectivos , Infecções Estafilocócicas/terapia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
12.
Sleep Med ; 101: 50-57, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36334501

RESUMO

OBJECTIVE: To explore the impact of the COVID-19 pandemic on the sleep-wake patterns of preschool children. METHODS: A cohort of preschoolers established before the COVID-19 pandemic was invited to participate in this study. Data including children's demographics, their own and parental sleep-wake patterns, physical activities, and screen time were collected through an online questionnaire from August to September 2020. A comparison was made on the collected data from the same cohort of children before and during the pandemic. RESULTS: The cohort which was established before the pandemic consisted of 3720 preschoolers. For this current study, 642 (17%) participated, and 497 (13%) children who fulfilled the eligibility criteria were included in the final analysis. They showed a delay in their bedtime and wake time on both weekdays and weekends with a 15-30 min increase in nocturnal sleep duration. However, with a reduction in nap time, the average daily sleep duration was shortened by 16.3 ± 64.3 min (p < 0.001) and 27.5 ± 72.9 min (p < 0.001) during weekdays and weekends, respectively. Screen time was increased while outdoor activity duration was decreased. Parental sleep/wake times were also delayed with an increase in sleep duration. Children's sleep habits were associated with screen time and parental sleep/wake patterns. CONCLUSION: Despite school suspension during the COVID-19 pandemic, preschoolers were not sleeping longer. Screen time and parental sleep/wake patterns were the major factors driving the preschoolers' sleep habits. Health education is required to control screen time in children and to promote sleep hygiene among all family members.


Assuntos
COVID-19 , Pandemias , Humanos , Pré-Escolar , COVID-19/epidemiologia , Sono , Higiene do Sono , Inquéritos e Questionários
13.
J Am Chem Soc ; 134(32): 13316-22, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22816317

RESUMO

Ligand exchange reactions are widely used for imparting new functionality on or integrating nanoparticles into devices. Thiolate-for-thiolate ligand exchange in monolayer protected gold nanoclusters has been used for over a decade; however, a firm structural basis of this reaction has been lacking. Herein, we present the first single-crystal X-ray structure of a partially exchanged Au(102)(p-MBA)(40)(p-BBT)(4) (p-MBA = para-mercaptobenzoic acid, p-BBT = para-bromobenzene thiol) with p-BBT as the incoming ligand. The crystal structure shows that 2 of the 22 symmetry-unique p-MBA ligand sites are partially exchanged to p-BBT under the initial fast kinetics in a 5 min timescale exchange reaction. Each of these ligand-binding sites is bonded to a different solvent-exposed Au atom, suggesting an associative mechanism for the initial ligand exchange. Density functional theory calculations modeling both thiol and thiolate incoming ligands postulate a mechanistic pathway for thiol-based ligand exchange. The discrete modification of a small set of ligand binding sites suggests Au(102)(p-MBA)(44) as a powerful platform for surface chemical engineering.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Solventes/química , Termodinâmica
14.
Org Biomol Chem ; 10(29): 5498-513, 2012 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-22688971

RESUMO

The Simmons-Smith cyclopropanation is a widely used method to synthesize cyclopropanes from alkenes using methylene iodide and a zinc reagent. A novel class of organozinc species, RXZnCH(2)Y, has been found to efficiently cyclopropanate alkenes, including traditionally unreactive unfunctionalized alkenes. The reactivity and selectivity of this class of organozinc reagents can be regulated by tuning the electronic and/or steric nature of the RX group attached to Zn. During recent years, this class of organozinc reagent has been widely used in organic synthesis as a reagent for cyclopropanation and other useful synthetic transformations. Catalytic, asymmetric versions of this reaction have been developed providing high enantiomeric excess for unfunctionalized olefins.

15.
Hong Kong Med J ; 18(1): 40-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22302910

RESUMO

OBJECTIVE: To compare the relative efficacy of the green pit viper antivenom from Thailand and Agkistrodon halys antivenom from China. DESIGN. In-vivo experimental study. SETTING: A wildlife conservation organisation, a university, a poison information centre, and a regional hospital in Hong Kong. MAIN OUTCOME MEASURES: Pre- and post-antivenom lethal dose 50 (LD50) of the Cryptelytrops albolabris venom, median effective dose (ED50) of green pit viper antivenom and Agkistrodon halys antivenom against a lethal dose of the venom. SUBJECTS. Adult mice. RESULTS: The intraperitoneal LD50 of the venom from locally caught Cryptelytrops albolabris was 0.14 microL. After post-exposure treatment with 10 microL of antivenom, it was elevated to 0.36 microL and 0.52 microL by the green pit viper antivenom and the Agkistrodon halys antivenom, respectively. The ED50 was 32.02 microL for green pit viper antivenom and 6.98 microL for Agkistrodon halys antivenom. Both green pit viper antivenom and Agkistrodon halys antivenom ameliorated the lethality of Cryptelytrops albolabris venom in mice. CONCLUSION: The overall superior neutralisation capacity of Agkistrodon halys antivenom over green pit viper antivenom may be related to the geographic proximity of the venoms used for antivenom preparation. The results point towards the need for further comparison of the two antivenoms on protein or immunoglobulin weight basis, and with respect to non-lethal clinically significant toxicities.


Assuntos
Antivenenos/farmacologia , Venenos de Crotalídeos/antagonistas & inibidores , Mordeduras de Serpentes/complicações , Animais , Antivenenos/administração & dosagem , China , Relação Dose-Resposta a Droga , Hong Kong , Dose Letal Mediana , Camundongos , Camundongos Endogâmicos C57BL , Centros de Controle de Intoxicações , Tailândia
16.
Hong Kong Med J ; 17(5): 381-5, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21979475

RESUMO

OBJECTIVE. To review the clinical characteristics of patients presenting after centipede bites in Hong Kong. DESIGN. Descriptive case series. SETTING. Emergency departments of two public hospitals in Hong Kong. PATIENTS. Patients presenting after centipede bites between 2006 and 2010. MAIN OUTCOME MEASURES. Demographics, time and locations of bites, symptoms and signs, treatments and outcomes. RESULTS. A total of 46 relevant patient records were retrieved. The bites were frequently at night, indoors, on lower limbs, and consistently resulted in pain. The majority of the victims were treated with analgesia, anti-histamines, and antibiotics. One patient developed necrosis and five re-attended for delayed pruritus and relapsed/recurrent swelling. CONCLUSIONS. Centipede bites are usually uncomplicated, but may lead to necrosis or delayed hypersensitive reactions.


Assuntos
Artrópodes , Mordeduras e Picadas/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgésicos/uso terapêutico , Animais , Antibacterianos/uso terapêutico , Mordeduras e Picadas/complicações , Mordeduras e Picadas/patologia , Crioterapia , Feminino , Antagonistas dos Receptores Histamínicos/uso terapêutico , Hong Kong , Humanos , Hidroterapia , Masculino , Pessoa de Meia-Idade , Manejo da Dor , Estudos Retrospectivos , Esteroides/uso terapêutico , Fatores de Tempo , Adulto Jovem
17.
Top Curr Chem ; 291: 201-32, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21494947

RESUMO

Organo-catalyzed asymmetric epoxidation has received much attention in the past 30 years and significant progress has been made for various types of olefins. This review will cover the advancement made in the field of chiral ketone and chiral iminium salt-catalyzed epoxidations.


Assuntos
Alcenos/química , Compostos de Epóxi/química , Iminas/química , Cetonas/química , Catálise , Compostos de Epóxi/síntese química , Sais/química , Estereoisomerismo
18.
Hong Kong Med J ; 16(1): 36-43, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20124572

RESUMO

OBJECTIVE: To review the clinical features and management of patients with injuries related to the Chinese cobra (Naja atra). DESIGN: Retrospective study. SETTING: Two acute hospitals in Hong Kong. MAIN OUTCOME MEASURES: The nature of injuries, envenoming features, complications, response to antivenom therapy, and outcome. RESULTS: Eighteen patients were recruited during the 5-year study period. Fifteen of them were snake-bitten, the remaining three suffered ocular injuries. Of the 15 patients with cobra bites, 14 (93%) presented with local swelling. No patient developed severe neurotoxic symptoms. Two patients had laboratory features of haemolysis. Fourteen patients received antivenom therapy and five of them subsequently underwent surgical interventions for extensive local tissue damage and necrosis. There was no fatality. CONCLUSION: Bites from Chinese cobra result in serious local complications with extensive tissue necrosis and minimal neurotoxic symptoms. There is an apparent trend of favourable outcomes following the early administration of antivenom to patients without early signs of irreversible tissue damage. Further research is needed to evaluate the effectiveness of early antivenom use in Chinese cobra bites in order to minimise extent of tissue damage.


Assuntos
Elapidae , Mordeduras de Serpentes/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antivenenos/uso terapêutico , Transtornos da Coagulação Sanguínea/etiologia , Criança , Venenos Elapídicos/toxicidade , Feminino , Hemólise , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Necrose , Mordeduras de Serpentes/complicações , Fatores de Tempo
19.
Hong Kong Med J ; 16(4): 246-51, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20683065

RESUMO

OBJECTIVE: To investigate the prevalence and characteristics of abusive drug exposure among non-fatal motor vehicle driver casualties presenting to a designated trauma centre in Hong Kong. DESIGN: Cross-sectional study. SETTING: Designated trauma centre/regional accident and emergency department in Hong Kong. SUBJECTS: Non-fatal motor vehicle driver casualties who presented to the trauma centre from 1 January 2007 to 31 December 2007. MAIN OUTCOME MEASURES: Screening of abusive drug exposure using commercial bedside urine immunoassay kits. RESULTS: Drug screening was performed in 395 injured drivers, 10% of whom tested positive for the drugs of interest. Ketamine was the most commonly detected abusive substance (found in 45% of the subjects). A significantly higher proportion of young drivers (aged <25 years) screened positive (odds ratio=2.3; 95% confidence interval, 1.0-5.2; P=0.04), with the rate being 21%. The presence of these drugs in urine was related to the time of occurrence of the crash; those occurring between midnight and dawn revealed a trend towards a higher proportion of casualties testing drug-positive (odds ratio=2.2; 95% confidence interval, 0.9-5.3; P=0.07). There were no significant differences in the frequency of persons testing positive for the screened drugs with respect to gender, class of motor vehicle driven, or the day of the week on which the crash occurred. CONCLUSIONS: The prevalence of drugged driving among non-fatal casualties in our series of Hong Kong drivers was 10%. The frequency of such drivers testing positive for drugs was significantly higher in persons aged less than 25 years. These findings indicate a need to amend existing laws and implement on-site drug screening for suspected drugged drivers.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Detecção do Abuso de Substâncias , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adulto , Fatores Etários , Estudos Transversais , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Prevalência , Fatores de Tempo , Centros de Traumatologia , Adulto Jovem
20.
Ann R Coll Surg Engl ; 102(9): 737-743, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32820638

RESUMO

INTRODUCTION: Open thyroidectomy is the most common approach to thyroid surgery. However, 'scarless' (in the neck) endoscopic thyroidectomy, consisting of endoscopic and robotic surgery, is progressively being adopted for its perceived cosmetic benefits. This study aims to determine the patient's preferred surgical approach and to identify the factors that influence their decision. MATERIALS AND METHODS: A pilot study consisting of 100 patients with a surgical thyroid disorder were prospectively recruited from a single tertiary centre. An interviewer-administered survey was conducted. Demographic, socioeconomic status, scar perception and an adapted body image scale were evaluated to identify factors that shaped the patient's perception of the surgical approach. RESULTS: The mean age of participants was 54.5 ± 13.0 years; 72% were women and 87% Chinese. Of the 100 patients, 75 patients considered scarless endoscopic thyroidectomy as their preferred surgical approach while 25 patients opted for open thyroid surgery. Improvement in scar perception score between scarless endoscopic thyroidectomy and open thyroid surgery is associated with an increased willingness to choose scarless endoscopic thyroidectomy. The mean body image scale score was 6.9 ± 2.8, indicating no statistical difference between the surgical approaches. On multivariate analysis, improvement in scar perception score (odds ratio 3.38, 95% confidence interval 1.11-10.29) and having surgeon recommendation (odds ratio 6.38, 95% confidence interval 1.80-22.63) were independently associated with interest in scarless endoscopic thyroidectomy. CONCLUSION: Patients interest in undergoing scarless endoscopic thyroidectomy is driven by improved scar perception and surgeon's recommendation compared with open thyroid surgery.


Assuntos
Cicatriz/etiologia , Endoscopia/efeitos adversos , Preferência do Paciente/estatística & dados numéricos , Tireoidectomia/efeitos adversos , Atitude Frente a Saúde , Cicatriz/prevenção & controle , Cicatriz/psicologia , Estudos Transversais , Endoscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Preferência do Paciente/psicologia , Projetos Piloto , Estudos Prospectivos , Inquéritos e Questionários , Doenças da Glândula Tireoide/cirurgia , Tireoidectomia/métodos
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