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1.
Eur J Cancer Care (Engl) ; 27(2): e12826, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29377317

ABSTRACT

This study examined the exercise barriers and preferences of head and neck cancer (HNC) survivors in relation to exercise experience. Participants (n = 22; 46.8% response rate) completed retrospective self-report questionnaires on demographic and medical information, exercise barriers and preferences. A subset of participants then completed semi-structured interviews (n = 18). Participants had previously engaged in the ENHANCE trial during, or immediately following, radiation treatment, an average of 22.1 ± 5.8 months before. Retrospective questionnaires revealed that before ENHANCE participation, lack of interest and time were the primary exercise barriers. After participation, there was a significant decrease in typical barriers including lack of interest (p = .008), exercise not a priority (p = .039) and exercise not in routine (p = .004). Number of barriers experienced after ENHANCE participation was negatively correlated with age, quality of life and minutes of resistance exercise training per week. After ENHANCE participation, significant increases were found in preference for exercising at a cancer centre (p = .031) and with other cancer survivors (p = .016). Four higher order themes emerged inductively from interview data analysis pertaining to preferences (i.e., class format) and three higher order themes regarding barriers (physical, psychological and external). By investigating participants' perspectives after ENHANCE participation, key factors for effective HNC exercise programme design were identified.


Subject(s)
Exercise Therapy/psychology , Head and Neck Neoplasms/psychology , Head and Neck Neoplasms/therapy , Patient Preference , Depression/etiology , Exercise/psychology , Female , Humans , Leisure Activities , Male , Middle Aged , Patient Acceptance of Health Care/psychology , Quality of Life , Retrospective Studies , Self Report , Surveys and Questionnaires
2.
Oncogene ; 36(27): 3934-3942, 2017 07 06.
Article in English | MEDLINE | ID: mdl-28192404

ABSTRACT

Despite extensive effort, there has been limited progress in the development of direct RAS inhibitors. Targeting isoprenylcysteine carboxylmethyltransferase (ICMT), a unique enzyme of RAS post-translational modification, represents a promising strategy to inhibit RAS function. However, there lacks direct genetic evidence on the role of ICMT in RAS-driven human cancer initiation and maintenance. Using CRISPR/Cas9 genome editing, we have created Icmt loss-of-function isogenic cell lines for both RAS-transformed human mammary epithelial cells (HME1) and human cancer cell lines MiaPaca-2 and MDA-MB-231 containing naturally occurring mutant KRAS. In both in vitro and in vivo tumorigenesis studies, Icmt loss-of-function abolishes the tumor initiation ability of all major isoforms of mutant RAS in HME1 cells, and the tumor maintenance capacity of MiaPaca-2 and MDA-MB-231 cells, establishing the critical role of ICMT in RAS-driven cancers.


Subject(s)
Protein Methyltransferases/physiology , ras Proteins/genetics , Animals , Antineoplastic Agents, Hormonal/pharmacology , Cell Line, Tumor , Cell Transformation, Neoplastic/metabolism , Humans , Mice, SCID , Mutation, Missense , Protein Isoforms/genetics , Protein Isoforms/metabolism , Tamoxifen/pharmacology , Xenograft Model Antitumor Assays , ras Proteins/metabolism
3.
Curr Oncol ; 23(1): 26-33, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26966401

ABSTRACT

OBJECTIVES: Adenoid cystic carcinoma (acc) is often treated with surgery, with or without adjuvant radiation therapy (rt). We evaluated disease characteristics, treatments, and potentially prognostic variables in patients with acc. METHODS: Our retrospective analysis considered consecutive cases of acc presenting at a tertiary care hospital between 2000 and 2014. Factors predictive of overall survival (os) and disease-free survival (dfs) were identified by univariate analysis. RESULTS: The 60 patients analyzed had a mean age of 58 years (range: 22-88 years), with a 2:1 female:male ratio. Tumour locations included the major salivary glands (40% parotid, 17% submandibular and sublingual), the oro-nasopharyngeal cavity (27%), and other locations (16%). Of the 60 patients, 35 (58%) received surgery with adjuvant rt; 12 (20%), rt only; 13 (22%), surgery only. Of 18 patients (30%) who experienced a recurrence within 5 years, 3 (5%) developed local recurrence only, and the remaining 15 (25%), distant metastasis. The 5-year os and dfs were 64.5% [95% confidence interval (ci): 45.9% to 78.1%] and 46.2% (95% ci: 29.7% to 61.2%) respectively. In patients without recurrence, 5-year os was 77% (95% ci: 52.8% to 89.9%), and in patients with recurrence, it was 42.7% (95% ci: 15.8% to 67.6%). Patients treated with rt only had a 5-year os of 9.2%. Predictors of 5-year dfs were TNM stage, T stage, nodal status, treatment received, and margin status; age, nodal status, treatment received, and margin status predicted 5-year os. CONCLUSIONS: Despite surgery and rt, one third of patients with acc experience distant recurrence. Patients whose tumours are not amenable to surgery have a poor prognosis, indicating a need for alternative approaches to improve outcomes.

4.
Hong Kong Med J ; 21(5): 401-6, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26234688

ABSTRACT

OBJECTIVE: To identify specific angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in Chinese paediatric patients. DESIGN: Retrospective cross-sectional observational study. SETTING: Four locoregional tertiary neurosurgical centres in Hong Kong: Queen Elizabeth Hospital, Tuen Mun Hospital, Kwong Wah Hospital, and Pamela Youde Nethersole Eastern Hospital. PATIENTS: Patients aged 18 years or younger who underwent pretreatment digital subtraction angiography for brain arteriovenous malformation between 1 January 2005 and 31 July 2013 were included. Patients were divided into haemorrhagic and non-haemorrhagic groups based on the initial presentation. Pretreatment digital subtraction angiographies were independently reviewed by two experienced neuroradiologists. MAIN OUTCOME MEASURES: The following parameters were evaluated for their association with haemorrhagic presentation by univariate and multivariate analyses: nidus location, nidus size, nidus morphology (diffuse or compact); origin and number of arterial feeders; venous drainage; number of draining veins; presence of aneurysms, venous varices, and venous stenosis. RESULTS: A total of 67 children and adolescents (28 male, 39 female) with a mean age of 12 years were included. Of them, 52 (78%) presented with haemorrhage. Arteriovenous malformation size (P=0.004) and morphology (P=0.05) were found to be associated with haemorrhagic presentation by univariate analysis. Small arteriovenous malformation nidus size and diffuse nidal morphology were identified as independent risk factors for haemorrhage by multivariate analysis. CONCLUSION: Smaller arteriovenous malformation size and diffuse nidal morphology are angiographic factors independently associated with haemorrhagic presentation. Bleeding risk is important in determining the therapeutic approach (aggressive vs conservative) and timeframe, particularly in paediatric patients.


Subject(s)
Cerebral Angiography , Cerebral Hemorrhage/etiology , Intracranial Arteriovenous Malformations/complications , Intracranial Arteriovenous Malformations/diagnostic imaging , Adolescent , Angiography, Digital Subtraction , Cerebral Hemorrhage/diagnostic imaging , Child , Child, Preschool , Female , Hong Kong , Humans , Male , Retrospective Studies , Risk Factors
5.
Chem Commun (Camb) ; 51(27): 5828-31, 2015 Apr 07.
Article in English | MEDLINE | ID: mdl-25622026

ABSTRACT

Developing molecular diagnostics in resource-poor settings is challenging. As such, we purpose-built a novel bridging flocculation assay for qualitative evaluation of isothermally amplified DNA by naked eye. The flocculation assay was dependent on pH, DNA polymer amounts and lengths. The method was first applied to the rapid and sensitive detection of important plant pathogens and subsequently extended to other pathogens across the animal kingdom to demonstrate the wide applications of our approach.


Subject(s)
DNA/analysis , Fusarium/genetics , HIV-1/genetics , Influenza A Virus, H1N1 Subtype/genetics , Nucleic Acid Amplification Techniques/methods , Pseudomonas syringae/genetics , Animals , Arabidopsis/microbiology , Cattle , DNA/economics , Flocculation , Fusarium/isolation & purification , HIV-1/isolation & purification , Humans , Influenza A Virus, H1N1 Subtype/isolation & purification , Jurkat Cells , Nucleic Acid Amplification Techniques/economics , Pseudomonas syringae/isolation & purification , Solid Phase Microextraction/methods
6.
Hong Kong Med J ; 20(5): 437-43, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25045883

ABSTRACT

Vesicoureteric reflux is an important association of paediatric urinary tract infection. Fluoroscopic micturating cystourethrography and radionuclide cystography have been employed for detecting and grading vesicoureteric reflux. However, both modalities involve ionising radiation, which can pose significant radiation risk to growing children. They also have a lower detection rate due to intermittent fluoroscopic technique in micturating cystourethrography, and lower spatial resolution in radionuclide cystography. Therefore, newer radiation-free ultrasound-based contrast-enhanced voiding urosonography has been developed in Europe for 15 years. This article aimed to summarise the current literature and discuss the first local pilot study in our institution on detection of vesicoureteric reflux by contrast-enhanced voiding urosonography. Contrast-enhanced voiding urosonography is a valid alternative to micturating cystourethrography in assessing vesicoureteric reflux, based on its superior diagnostic performance, reliability, safety, feasibility, and radiation safety for children. Therefore, it should be incorporated in the guideline for investigating paediatric urinary tract infection.


Subject(s)
Urination , Vesico-Ureteral Reflux/diagnostic imaging , Child , Child, Preschool , Diagnostic Techniques, Urological , Female , Humans , Infant , Infant, Newborn , Male , Sensitivity and Specificity , Ultrasonography
7.
Int J STD AIDS ; 25(1): 52-6, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23970631

ABSTRACT

We studied the use of the INNO-LIA syphilis score assay in the resolution of discordant positive screening results of the Murex ICE Syphilis enzyme immunoassay (EIA) with the confirmatory results of both the Serodia Treponema pallidum particle agglutination (TPPA) and the fluorescent treponemal antibody-absorption (FTA-Abs) assays, for the serological diagnosis of syphilis. This was an observational study on the serum samples received by the Syphilis Laboratory, Hong Kong, during the period from January 2006 to December 2012. A total of 801 serum samples with discordant positive screening EIA results were used. Consensus results of such serum samples were derived from results of the EIA, TPPA and FTA-abs assays. The age range of the individuals was 14 to 104 years (median of 52). There were 369 males and 432 females. Of 378 serum samples, 139 showed agreement among positive results, 23 of 310 showed agreement among indeterminate results and 277 of 465 showed agreement among negative results. The proportions of agreement among positive, indeterminate and negative results were 0.37 (95% CI 0.32-0.42), 0.07 (95% CI 0.05-0.11) and 0.60 (95% CI 0.55-0.64), respectively; kappa 0.55 (95% CI 0.49-0.60). There were 60 serum samples with positive consensus results but negative INNO-LIA syphilis score results and 10 with negative consensus results but positive INNO-LIA syphilis score results. Although the INNO-LIA syphilis score assay can be considered a valid alternative confirmatory test for the serological diagnosis of syphilis, the present study showed that its use in the resolution of discordant positive screening EIA results was moderate. A more extensive characterization of serum samples with discordant reactive screening treponemal test results is necessary.


Subject(s)
Antibodies, Bacterial/blood , Syphilis Serodiagnosis/methods , Syphilis/diagnosis , Treponema pallidum/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Hemagglutination Tests , Humans , Immunoblotting , Immunoenzyme Techniques , Immunoglobulin G/blood , Male , Middle Aged , Syphilis/blood , Young Adult
8.
Allergy ; 68(2): 195-203, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23253152

ABSTRACT

BACKGROUND: Allergy is an acquired hypersensitivity reaction of the immune system mediated by cross-linking of allergen-specific IgE-bound high-affinity IgE receptors, leading to immediate mast cell degranulation. Artesunate is a semi-synthetic derivative of artemisinin, an active component of the medicinal plant Artemisia annua. Artesunate is a clinically effective anti-malarial drug and has recently been shown to attenuate allergic asthma in mouse models. This study investigated potential anti-allergic effects of artesunate in animal models of IgE-dependent anaphylaxis. METHODS: Anti-allergic actions of artesunate were evaluated in passive cutaneous anaphylaxis and passive systemic anaphylaxis mouse models, and in ovalbumin-induced contraction of bronchial rings isolated from sensitized guinea pigs. Direct mast cell-stabilizing effect of artesunate was examined in RBL-2H3 mast cell line and in mature human cultured mast cells. Anti-allergic signaling mechanisms of action of artesunate in mast cells were also investigated. RESULTS: Artesunate prevented IgE-mediated cutaneous vascular hyperpermeability, hypothermia, elevation in plasma histamine level, and tracheal tissue mast cell degranulation in mice in a dose-dependent manner. In addition, artesunate suppressed ovalbumin-mediated guinea pig bronchial smooth muscle contraction. Furthermore, artesunate concentration-dependently blocked IgE-mediated degranulation of RBL-2H3 mast cells and human culture mast cells. Artesunate was found to inhibit IgE-induced Syk and PLCγ1 phosphorylation, production of IP(3) , and rise in cytosolic Ca(+2) level in mast cells. CONCLUSIONS: We report here for the first time that artesunate possesses anti-allergic activity by blocking IgE-induced mast cell degranulation, providing a foundation for developing artesunate for the treatment of allergic asthma and other mast cell-mediated allergic disorders.


Subject(s)
Anaphylaxis/drug therapy , Antimalarials/pharmacology , Artemisinins/pharmacology , Mast Cells/drug effects , Mast Cells/immunology , Anaphylaxis/immunology , Animals , Anti-Allergic Agents/pharmacology , Artesunate , Asthma/drug therapy , Asthma/immunology , Asthma/physiopathology , Cell Degranulation/immunology , Disease Models, Animal , Dose-Response Relationship, Drug , Female , Guinea Pigs , Humans , Immunity, Cellular/physiology , Immunoblotting , Immunoglobulin E/immunology , Immunoglobulin E/metabolism , In Vitro Techniques , Mast Cells/physiology , Mice , Random Allocation
9.
Euro Surveill ; 17(45)2012 Nov 08.
Article in English | MEDLINE | ID: mdl-23153475

ABSTRACT

Reliable estimates of the morbidity burden caused by the 2009 pandemic influenza (pH1N1) are important for assessing the severity of the pandemic. Poisson regression models were fitted to weekly numbers of cause-specific hospitalisation in Hong Kong from 2005 to 2010. Excess hospitalisation associated with the 2009 pandemic and seasonal influenza was derived from the model by incorporating the proxy variables of weekly proportions of specimens positive for the pandemic influenza A(H1N1)pdm09, seasonal influenza A (subtypes H3N2 and H1N1) and B viruses. Compared with seasonal influenza, pH1N1 influenza was associated with higher hospitalisation rates for acute respiratory disease (ARD) among children younger than 18 years and adults aged between 18 and 64 years, but among the elderly aged 65 years and older the hospitalisation rates were lower for pH1N1 than for seasonal H3N2 and H1N1 influenza. Hospitalisation rates for chronic diseases associated with pH1N1 influenza were generally higher than those associated with seasonal influenza. The reported hospitalised cases with laboratory-confirmed pandemic infections accounted for only 16% of pH1N1 influenza-associated hospitalisations for ARD in the age group 75 years and older, and 5‒66% of hospitalisations for chronic diseases in those older than 40 years. The 2009 H1N1 influenza pandemic was associated with a dramatically increased risk of hospitalisation among children and young adults. The morbidity burden of pandemic was underreported in old people and in those with chronic conditions.


Subject(s)
Hospitalization/statistics & numerical data , Influenza A Virus, H1N1 Subtype , Influenza A Virus, H3N2 Subtype , Influenza, Human/epidemiology , Pandemics , Seasons , Adolescent , Adult , Aged , Female , Hong Kong/epidemiology , Hospitalization/trends , Humans , Male , Middle Aged
11.
Biochim Biophys Acta ; 1810(9): 867-74, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21635937

ABSTRACT

BACKGROUND: The microelectrode array (MEA) was used to investigate the pharmacological relevance of chloride (Cl-) ions in antigen-dependent mast cell activation and the inhibitory effect of disodium cromoglycate (DSCG) on mast cell activation. METHODS: The movements of ions across the cellular membrane and the potential relationship between Cl- channels and DSCG during immunological activation were investigated using the MEA. The results were then subsequently compared with the amount of histamine released from anti-IgE activated peritoneal mast cells. RESULTS: The inclusion of charybdotoxin (ChTX) in Cl--free buffer showed that the measured field potentials during antigen-stimulated peritoneal mast cell were a combination of Cl- influx and K+ efflux. The delayed onset time of Cl- influx indicated the presence of a delayed outwardly-rectifying Cl- current in the antigen-stimulated peritoneal mast cells. The use of 5-nitro-2-(3-phenylpropylamino) benzoic acid demonstrated that the activated mast cell membrane potential can be stabilised, thereby reducing the amount of histamine released from the anti-IgE activated mast cells. The correlation between the results of the histamine release assay and the electrophysiological measurements demonstrated the importance of Cl- to anti-IgE dependent mast cell activation. The inhibitory effect of DSCG on anti-IgE activated cells, however, did not correlate with the presumed influx of Cl-. CONCLUSIONS: The MEA data suggest that Cl- influx is crucial to IgE-dependent mast cell degranulation. GENERAL SIGNIFICANCE: While the MEA cannot yield information about single channel properties, it is convenient to use and can provide information on the global changes in electrophysiological responses of non-excitable cells.


Subject(s)
Chlorides/pharmacology , Cromolyn Sodium/pharmacology , Mast Cells/drug effects , Mast Cells/immunology , Receptors, IgE/physiology , Animals , Antibodies, Anti-Idiotypic/pharmacology , Charybdotoxin/pharmacology , Chloride Channels/drug effects , Chloride Channels/metabolism , Histamine Release/genetics , Male , Microelectrodes , Nitrobenzoates/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, IgE/drug effects
12.
Br J Pharmacol ; 164(2b): 807-19, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21506953

ABSTRACT

BACKGROUND AND PURPOSE: Adenosine is believed to participate in the pathological development of asthma through a mast cell-dependent mechanism. Our study aimed to pharmacologically characterize the functions of adenosine receptor (AR) subtypes (A1, A(2A) , A(2B) and A3) in primary human cultured mast cells (HCMC). EXPERIMENTAL APPROACH: HCMC were derived from progenitor stem cells in buffy coat and the effects of adenosine receptor ligands on basal and IgE-dependent histamine release were evaluated. KEY RESULTS: Adenosine and analogues alone did not induce HCMC degranulation. When HCMC were activated by anti-IgE after 10 min pre-incubation with adenosine, a biphasic effect on histamine release was observed with enhancement of HCMC activation at low concentrations of adenosine (10⁻9-10⁻7 mol·L⁻¹) and inhibition at higher concentrations (10⁻6-10⁻4 mol·L⁻¹). The potentiating action was mimicked by A1 AR agonists CCPA and 2'MeCCPA, and inhibited by the A1 AR antagonist PSB36. In contrast, the inhibitory action of adenosine was mimicked by the non-specific A2 AR agonist CV1808 and attenuated by A(2B) AR antagonists PSB1115 and MRS1760. The non-selective AR antagonist CGS15943 attenuated both the potentiating and inhibitory actions. CONCLUSIONS AND IMPLICATIONS: We have defined for the first time the contribution of A1 and A(2B) ARs, respectively, to the potentiating and inhibitory action of adenosine on human mast cell activation. With reference to the current trend of developing novel anti-asthmatic agents from AR ligands, our results suggest that inhibition of human mast cell activation would be a mechanism for A1 AR antagonists, but not A(2B) AR antagonists.


Subject(s)
Adenosine-5'-(N-ethylcarboxamide) , Antibodies, Anti-Idiotypic/pharmacology , Histamine Release/drug effects , Mast Cells/drug effects , Mast Cells/metabolism , Receptor, Adenosine A1/metabolism , Receptors, Adenosine A2/metabolism , Adenosine/pharmacology , Adenosine A1 Receptor Agonists/pharmacology , Adenosine A1 Receptor Antagonists/pharmacology , Adenosine-5'-(N-ethylcarboxamide)/pharmacology , Anti-Asthmatic Agents/pharmacology , Cells, Cultured , Humans , Purinergic P1 Receptor Agonists/pharmacology , Purinergic P1 Receptor Antagonists/pharmacology
13.
J Plast Reconstr Aesthet Surg ; 64(6): e137-45, 2011 Jun.
Article in English | MEDLINE | ID: mdl-20869928

ABSTRACT

BACKGROUND: Despite widespread beliefs regarding the use of topical tocotrienol in the prevention of hypertrophic scars, there is very little evidence from well controlled and randomised clinical trials to justify its benefits for surgical scars. OBJECTIVE: This study was conducted to evaluate the efficacy of topical tocotrienol in preventing the development of hypertrophic scars. METHODS: A prospective, randomised, double-blinded study was performed on 122 patients with recently healed (<2 weeks) surgical scars, who were randomised into either a treatment group with 5% topical tocotrienol or a placebo group. The patients were required to apply the preparation to their scars twice a day for 6 weeks starting at 2 weeks after surgery. Assessments of the scars were performed at weeks 0, 2, 6 and 16 following the onset of topical application using three methods: a clinical assessment using the Patient and Observer Scar Assessment Scale (POSAS), a photographic scar assessment by two independent assessors using a visual analogue scale and laser Doppler imaging (LDI). Data analysis was performed on 85 patients (tocotrienol group: 45 patients; placebo group: 40 patients), who had completed four assessments. RESULTS: There was no statistically significant difference in scar parameters between the tocotrienol and the placebo groups in the POSAS, photographic scar assessment or mean flux of LDI (p>0.05) categories. The mean LDI flux showed a decreasing trend over time, which was positively correlated with vascularity (correlation coefficient=0.325, p=0.008) and total scores (correlation coefficient=0.248, p=0.034) of the observer scar assessment scale on week 0. No significant adverse effect was observed. CONCLUSIONS: Twice-daily application of 5% topical tocotrienol had no significant effect on the appearance and vascularity of scars over 4 months post-surgery. LDI has a promising role as a scar assessment tool.


Subject(s)
Cicatrix, Hypertrophic/prevention & control , Tocotrienols/administration & dosage , Vitamins/administration & dosage , Administration, Topical , Adolescent , Adult , Cicatrix, Hypertrophic/pathology , Double-Blind Method , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Laser-Doppler Flowmetry , Male , Middle Aged , Prospective Studies , Treatment Outcome , Young Adult
14.
Hong Kong Med J ; 16(5): 397-9, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20890006

ABSTRACT

Infantile cortical hyperostosis (Caffey disease) is a rare self-limiting inflammatory bony disease of early infancy. We report a 1-month-old Chinese boy with Caffey disease who presented with painful swelling over his shins bilaterally. Physical abuse was initially suspected, but the radiological findings of periosteal thickening over multiple bones (particularly the mandible), symmetrical involvement, diaphyseal involvement with sparing of the epiphysis, made Caffey disease a likely diagnosis. This report highlights that infantile cortical hyperostosis is an important differential diagnosis for children suspected of being abused, and clinicians should have a high index of suspicion to avoid misdiagnosis.


Subject(s)
Child Abuse/diagnosis , Diagnostic Errors , Hyperostosis, Cortical, Congenital/diagnosis , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , China , Diagnosis, Differential , Humans , Hyperostosis, Cortical, Congenital/diagnostic imaging , Infant , Male , Mandible/diagnostic imaging , Mandible/pathology , Radiography
15.
Int J STD AIDS ; 21(2): 110-3, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20089996

ABSTRACT

We evaluated the performance of two immunoblot assays: the INNO-LIA Syphilis Score (LIA) and the MarDx T. pallidum IgG Marblot Test (TWB), as compared with that of the Murex ICE Syphilis enzyme immunoassay (EIA), the Serodia Treponema pallidum particle agglutination (TPPA) assay and the fluorescent treponemal antibody-absorption (FTA-abs) assay, for the serological diagnosis of syphilis using serum samples of 135 attendees of the social hygiene clinics of the Department of Health in Hong Kong newly diagnosed with syphilis and provided with clinical stages (39 in primary, 20 in secondary, 18 in early latent and 58 in latent of unknown duration) and of 43 normal healthy subjects between October and December 2004. The differences in the overall sensitivities of the LIA assay and the EIA/TPPA/FTA-abs assays were not statistically significant (P > 0.05) whereas the overall sensitivity of the TWB assay was significantly lower (P < 0.05) than the overall sensitivities of the EIA, the TPPA and the FTA-abs assays. The LIA assay had an overall sensitivity of 94.1% (95% CI 88.7-97.0%) whereas the TWB assay 65.2% (95% CI 56.8-72.7%). Both the LIA and the TWB assays have a specificity of 100%. When consensus results were derived from the most predominant results of the EIA, the TPPA and the FTA-abs assays, the LIA assay had a positive agreement with the consensus results of 98.5% (95% CI 94.5-99.6%) whereas the TWB assay 68.2% (95% CI 59.8-75.6%). Therefore, the LIA assay performed significantly better (P < 0.05) than the TWB assay. The LIA assay can be considered to be a valid alternative confirmatory test for the serological diagnosis of syphilis.


Subject(s)
Antibodies, Bacterial/blood , Immunoblotting/methods , Syphilis Serodiagnosis/methods , Syphilis/diagnosis , Treponema pallidum/isolation & purification , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Sensitivity and Specificity , Syphilis/blood , Treponema pallidum/immunology
16.
Hong Kong Med J ; 15(4): 285-7, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19652236

ABSTRACT

Well-documented potential cardiovascular complications associated with the use of contrast media include bradycardia, hypotension, arrhythmia, and conduction disturbances. Rupture of the myocardium after acute myocardial infarction is a known cause of death, but has yet to be recognised as a potential complication of the use of a bolus injection of contrast medium. On the contrary, contrast-enhanced computed tomographic studies have been performed widely for the diagnosis and evaluation of myocardial infarction. We report a case of complicated myocardial rupture after a single bolus injection of contrast medium during a computed tomographic study in an elderly woman with acute myocardial infarction, which led to cardiac tamponade and rapid death. Although rare, this should alert us to the need for cautious use of contrast medium in patients with acute myocardial infarction.


Subject(s)
Cardiac Tamponade/etiology , Contrast Media/administration & dosage , Heart Rupture/etiology , Injections/adverse effects , Myocardial Infarction/diagnostic imaging , Aged, 80 and over , Fatal Outcome , Female , Humans , Tomography, X-Ray Computed
17.
J Appl Microbiol ; 107(2): 368-78, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19302312

ABSTRACT

Current models to study Legionella pathogenesis include the use of primary macrophages and monocyte cell lines, various free-living protozoan species and murine models of pneumonia. However, there are very few studies of Legionella spp. pathogenesis aimed at associating the role of biofilm colonization and parasitization of biofilm microbiota and release of virulent bacterial cell/vacuoles in drinking water distribution systems. Moreover, the implications of these environmental niches for drinking water exposure to pathogenic legionellae are poorly understood. This review summarizes the known mechanisms of Legionella spp. proliferation within Acanthamoeba and mammalian cells and advocates the use of the amoeba model to study Legionella pathogenicity because of their close association with Legionella spp. in the aquatic environment. The putative role of biofilms and amoebae in the proliferation, development and dissemination of potentially pathogenic Legionella spp. is also discussed. Elucidating the mechanisms of Legionella pathogenicity development in our drinking water systems will aid in elimination strategies and procedural designs for drinking water systems and in controlling exposure to Legionella spp. and similar pathogens.


Subject(s)
Amoeba/microbiology , Biofilms , Legionella/pathogenicity , Water Microbiology , Acanthamoeba/microbiology , Animals , Eukaryota , Fresh Water/microbiology , Humans , Legionella/growth & development , Legionellosis/prevention & control
18.
Br J Pharmacol ; 156(8): 1279-86, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19302592

ABSTRACT

BACKGROUND AND PURPOSE: Although the mast cell is a source of nitric oxide (NO), the effect of NO on human mast cells has not been defined. This study investigated if exogenous NO could affect human mast cell activation. EXPERIMENTAL APPROACH: Effects of different NO donors on immunoglobulin E (IgE)-dependent activation of human-cultured mast cells (HCMC) derived from precursors in buffy coat were investigated by measuring histamine release. Intracellular NO in HCMC was monitored with confocal microscopy using the fluorescent NO indicator 4-amino-5-methylamino-2', 7'-difluorofluorescein. KEY RESULTS: Diethylamine NONOate (DEA/NO) and MAHMA NONOate (NOC-9), both have rapid NO release rates, only inhibited anti-IgE-induced histamine release when added to HCMC at the time of activation. NO donors with slower NO release kinetics were ineffective even after 30 min incubation. Confocal microscopy revealed that the effectiveness of NO donors was dependent on the availability of adequate NO inside HCMC during activation. The inhibitory action of DEA/NO was diminished by the NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl but potentiated by the anti-oxidant, N-acetylcysteine (NAC). Furthermore, co-incubation with NAC allowed previously ineffective NO donors to suppress HCMC activation and thus suggested that NAC could increase the availability of NO from NO donors. CONCLUSIONS AND IMPLICATIONS: Our results demonstrated that NO was able to modulate human mast cell activation but only when enough NO was present at the time of cell activation. Our findings explain the controversy over the effectiveness of NO on mast cell degranulation and supports the possibility that NO donors could be beneficial for treating allergic inflammation.


Subject(s)
Anti-Allergic Agents/pharmacology , Anti-Inflammatory Agents/pharmacology , Cell Degranulation/drug effects , Histamine Release/drug effects , Immunoglobulin E/immunology , Mast Cells/drug effects , Nitric Oxide Donors/pharmacology , Nitric Oxide/metabolism , Acetylcysteine/pharmacology , Anti-Allergic Agents/metabolism , Anti-Inflammatory Agents/metabolism , Antibodies , Antioxidants/pharmacology , Benzoates/pharmacology , Cells, Cultured , Dose-Response Relationship, Drug , Humans , Hydrazines/metabolism , Hydrazines/pharmacology , Imidazoles/pharmacology , Kinetics , Mast Cells/immunology , Mast Cells/metabolism , Nitric Oxide Donors/metabolism , Nitroprusside/metabolism , Nitroprusside/pharmacology , S-Nitroso-N-Acetylpenicillamine/metabolism , S-Nitroso-N-Acetylpenicillamine/pharmacology , Superoxide Dismutase/metabolism
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