Pre-hospital stroke screening and notification of patients with reperfusion-eligible acute ischaemic stroke using modified Face Arm Speech Time test.

OBJECTIVES: To investigate the effects of pre-hospital stroke screening and notification on reperfusion therapy for patients with acute ischaemic stroke. METHODS: Pre-hospital stroke screening criteria were established based on a modified version of the Face Arm Speech Time (FAST) test. Screening was performed during ambulance transport by emergency medical service (EMS) personnel who completed a 2-hour training session on stroke screening. Temporal trends affecting acute ischaemic stroke investigation and intervention were compared before and after implementation of the pre-hospital screening. RESULTS: From July 2018 to October 2019, 298 patients with suspected stroke were screened by EMS personnel during ambulance transport prior to hospital arrival. Of these 298 patients, 213 fulfilled the screening criteria, 166 were diagnosed with acute stroke, and 32 received reperfusion therapy. The onset-to-door time was shortened by more than 1.5 hours (100.6 min vs 197.6 min, P<0.001). The door-to-computed tomography time (25.6 min vs 32.0 min, P=0.021), door-to-needle time (49.2 min vs 70.1 min, P=0.003), and door-to-groin puncture time for intra-arterial mechanical thrombectomy (126.7 min vs 168.6 min, P=0.04) were significantly shortened after implementation of the pre-hospital screening and notification, compared with historical control data of patients admitted from January 2018 to June 2018, before implementation of the screening system. CONCLUSION: Implementation of pre-hospital stroke screening using criteria based on a modified version of the FAST test, together with pre-arrival notification, significantly shortened the door-to-reperfusion therapy time for patients with ischaemic stroke. Pre-hospital stroke screening during ambulance transport by EMS personnel who complete a 2-hour focused training session is effective for identifying reperfusion-eligible patients with stroke.

Clinical outcome of generalized myasthenia gravis in Hong Kong Chinese.

BACKGROUND: Myasthenia gravis (MG) is an organ-specific autoimmune disease characterized by autoantibody-mediated impairment of skeletal muscle neuromuscular transmission. MG causes significant morbidity and even mortality. We studied the long-term clinical outcome of generalized MG (gMG) patients. METHODS: Records of Chinese gMG patients managed in Queen Mary Hospital from 1997 to 2012 were reviewed. Clinical, serological and radiological characteristics were studied for independent predictors of good long-term clinical outcome. RESULTS: A total of 123 Chinese gMG patients were studied. Their mean onset age was 44.8 years (range 7-83 years), 87 (70.7%) were female, and median follow-up duration was 114 months (interquartile range 67-188 months). Thymoma were detected in 45 patients (36.6%). Acetylcholine receptor autoantibodies were detected in 99 patients (87.6%). Ninety-three patients (75.6%) received immunosuppressant therapy (corticosteroid 75.6%, azathioprine 58.5%, mycophenolate mofetil 5.7%, cyclosporin 5.7%) and 77 (62.6%) received thymectomy. Thirty-five (28.5%) patients experienced MG crisis and two died. Ninety-six (78.0%) patients had good outcome defined by Myasthenia Gravis Foundation of America (MGFA) post-intervention status (PIS) of complete stable remission (CSR), pharmacological remission (PR) or minimal manifestation (MM) at latest follow-up, whereas 24 patients (19.5%) had intermediate outcome defined by MGFA PIS of Improved (I); 3 patients (2.4%) had poor prognosis defined by MGFA PIS of unchanged (U), worse (W), exacerbation (E) or died of MG (D). Azathioprine therapy was the only independent predictor of good outcome (OR 3.57, 95% CI 1.05-12.10, p=0.042). CONCLUSION: 78.0% of gMG patients had good long-term clinical outcome. Azathioprine therapy independently predicted good clinical outcome.

Visit-to-visit systolic blood pressure variability predicts all-cause and cardiovascular mortality after lacunar infarct.

BACKGROUND AND PURPOSE: Both blood pressure (BP) and its variability (BPV) are established risk factors for development of atherosclerotic disease and are associated with an increased risk for cardiovascular and all-cause mortality. The prognostic implications of outpatient clinic visit-to-visit BPV amongst patients with lacunar infarction are nevertheless unknown. METHODS: The clinical outcome of 281 patients with lacunar infarction was prospectively followed up. The average BP and BPV, as determined by the standard deviation of the systolic and diastolic BP, were recorded during a mean 13 ± 6 outpatient clinic visits. RESULTS: The mean age of the population was 70 ± 10 years. After a mean 78 ± 18 months follow-up, 65 patients died (23%), 31% (20/65) due to cardiovascular causes; 14% and 7% developed recurrent stroke and acute coronary syndrome. After adjusting for age, sex, mean systolic and diastolic BP, cardiovascular risk factors and comorbidities, patients with a systolic BPV of the third tertile had significantly higher risk of all-cause mortality [hazard ratio (HR) 1.97, 95% confidence interval (CI) 1.02-3.80, P = 0.04) and cardiovascular mortality (HR 7.64, 95% CI 1.65-35.41, P < 0.01) than those with systolic BPV of the first tertile. Nevertheless, systolic BPV did not predict recurrent stroke or acute coronary syndrome. Diastolic BPV did not predict various adverse clinical outcomes. CONCLUSIONS: Visit-to-visit systolic BPV predicts long-term all-cause and cardiovascular mortality after lacunar infarct, independent of conventional risk factors including average BP control.

Warfarin associated intracerebral hemorrhage in Hong Kong Chinese.

OBJECTIVES: Warfarin-associated intracerebral hemorrhage (WICH) is a serious neurological condition associated with significant mortality and morbidity. We aimed to study the clinical features and factors that predict clinical outcome of Chinese patients with WICH. METHODS: Medical records of patients with spontaneous intracerebral hemorrhage (ICH) admitted to our hospital between July 2001 and June 2010 were reviewed and those with WICH were studied in detail retrospectively. RESULTS: Fifty-one patients with WICH were studied. The mean age was 74.3 ± 10.5 years and 52.9% of the patients were female. The mean international normalized ratio (INR) on presentation was 2.9 ± 1.0. The median ICH volume was 23·3 (10·4-59·3) ml. The mortality rate at 3-6 months for WICH was 62·0%. Multivariate logistic analysis revealed that an initial ICH volume of > 20 ml (OR 34·4, P  =  0·037) and presence of intraventricular hemorrhage (OR 22.9, P  =  0·046) were independently associated with poor outcome. Supratherapeutic INR (INR > 3.0) on admission (P  =  0.724) and complete correction of INR within 24 hours after admission (P  =  0·486) were not independent predictors of poor outcome. The median ICH volumes did not differ between INR groups (18·2 (9·4-61·1) ml for INR ≤ 3 vs 27.3 (13.7-58.5) ml for INR > 3, P  =  0·718). Neurological deterioration (ND) was documented in 19 (63·3%) of the 30 patients included in a smaller sub-cohort, and was associated with poor neurological outcome (OR 20·7, P  =  0·027). Warfarin was resumed in 7 of the 20 survivors. There were two episodes of recurrent WICH and one episode of ischemic stroke during a mean follow-up duration of 5·4 years. In survivors who were not resumed on warfarin, there were two episodes of recurrent ICH and 12 episodes of ischemic vascular events (nine ischemic strokes) during a mean follow-up duration of 2·6 years. CONCLUSION: Warfarin-associated intracerebral hemorrhage is a very serious complication of warfarin therapy with high mortality and morbidity. Initial ICH volume, presence of intraventricular hemorrhage, and ND are independent predictors of clinical outcome.

Garlic intake is an independent predictor of endothelial function in patients with ischemic stroke.

OBJECTIVES: To investigate the effects of garlic on endothelial function in patients with ischemic stroke (ISS). DESIGN: Cross-sectional study. PARTICIPANTS: 125 Chinese patients with prior ISS due to athero-thrombotic disease were recruited from the outpatient clinics during July 2005 to December 2006. MEASUREMENTS: Daily allium vegetable intake (including garlic, onions, Chinese chives and shallots) was ascertained by means of a validated food frequency questionnaire for Chinese and brachial artery flow-mediated dilatation (FMD) was measured using high-resolution ultrasound in all subjects. RESULTS: The mean age of the study population was 65.9±11.1 years and 69% were males. Mean allium vegetable intake and garlic intake of the study population was 7.5±12.7g/day and 2.9±8.8g/day respectively. Their mean FMD was 2.6±2.3%. Daily intake of total allium vegetable (r=0.36, P<0.01) and garlic (r=0.34, P<0.01) significantly correlated with FMD. Using the median daily allium intake as cut-off (3.37g/day), patients with a low allium intake <3.37g/day was noted to have a lower FMD compared to those with a normal allium intake (2.1±2.1% versus 3.0±2.4%, P<0.05). After adjusting for confounding factors, multi-variate analysis identified that daily allium vegetable (B=0.05, 95% confidence interval: 0.02, 0.09, P<0.01) and garlic (B=0.07, 95% confidence interval: 0.02, 0.12, P<0.01) intake, but not onions, Chinese chives and shallots were independent predictors for changes in FMD in patients with ISS. CONCLUSIONS: Daily garlic intake is an independent predictor of endothelial function in patients with ISS and may play a role in the secondary prevention of atherosclerotic events.

Central nervous system inflammatory demyelinating disorders among Hong Kong Chinese.

Classical multiple sclerosis (CMS) and neuromyelitis optica spectrum disorders (NMOSD) are distinct central nervous system inflammatory demyelinating disorders (CNS IDD). Early diagnosis of CNS IDD is important as appropriate immunotherapies to optimize prognosis. We studied the diagnoses of CNS IDD among Hong Kong Chinese in a hospital-based setting. Consecutive Chinese patients who presented to our hospital with clinically isolated syndrome and subsequently diagnosed to have CNS IDD from 1980 to 2010 were reviewed. Patients with known diagnosis of CNS IDD referred for further care were excluded. Serial sera were assayed for aquaporin-4 autoantibodies (AQP4 Ab), at least 3 assays within 2-5years. A total of 210 patients diagnosed to have CNS IDD with disease duration of at least 2years were studied. Among 198 patients with serial sera available, 40 (20.2%, 20 had NMO and 20 other NMOSD) were AQP4 Ab-positive. Four patients who were AQP4 Ab-negative on the initial assay converted to AQP4 Ab-positive on repeated assays. The diagnoses of 210 patients were CMS in 88 (41.9%), NMOSD 47 (22.4%, 27 NMO, 20 other NMOSD), single attack of myelitis 23 (11.0%), single attack of optic neuritis 21 (10.0%), relapsing myelitis 10 (4.8%), acute disseminated encephalomyelitis (ADEM) 9 (4.3%), relapsing optic neuritis in 6 (2.9%), opticospinal multiple sclerosis 3 (1.4%) and single attack of brainstem encephalitis 3 (1.4%). Compared to CMS, NMOSD patients had older onset age, lower frequencies of brain MRI abnormalities and CSF OCB, higher frequency of LETM, higher CNS inflammation attack frequency in the first 2years, worse clinical outcome with higher EDSS score and mortality rate. This hospital-based study suggests that CMS (41.9%) and NMOSD (22.4%) are the most common CNS IDD among Hong Kong Chinese. NMOSD has worse clinical outcome than CMS. Detection of AQP4 Ab facilitates early diagnosis and prompts immunotherapies of NMOSD.

Destruction of organic pollutants in reusable wastewater using advanced oxidation technology.

This work studied the destruction of various M-EDTA complexes and trace organic pollutants in treated reusable wastewater under advanced oxidation using UV irradiation and ozonation. Effect of dosage of hydrogen peroxide and acidity of reaction matrices on oxidation efficiencies were investigated. The rate constant of mineralization presents a decreasing trend as Fe(III)-EDTA > Fe(II)-EDTA > Al(III)-EDTA > Pb(II)-EDTA > Na(I)-EDTA > Zn(II)-EDTA > Cu(II)-EDTA. The mineralization efficiencies using ozone alone are 15%, 40% and 15% for the water samples after reverse osmosis (RO), microfiltration (MF) and superfiltration (SF) processes, respectively. The presence of hydrogen peroxide in photochemical reaction matrixes can effectively enhance the mineralization of organic carbon species. When 150 mg l(-1) of H2O2 was added in the effluents, the mineralization markedly increased to 80%, 92% and 89%, respectively.

Photochemical degradation of 1,3-dinitrobenzene in aqueous solution in the presence of hydrogen peroxide.

A study on the destruction of 1,3-dinitrobenzene (1,3-DNB) in aqueous solution was carried out under ultraviolet (UV) irradiation alone and UV irradiation in the presence of hydrogen peroxide (H2O2). The combination of UV and H2O2 is significantly effective in degrading 1,3-DNB in terms of initial reaction rate and the mineralization of organic carbons. The photodegradation process can be influenced in certain extent by increasing the content of H2O2 and the acidity of reaction matrices. It was found that a variety of phenolic intermediates and inorganic acid were formed via hydroxyl radicals attacking the parent compound. The UV/H2O2 oxidation of 1,3-DNB was characterized by pseudo-zero order reaction for the degradation of 1,3-DNB with a 20 times enhanced rate constant of 1.36 x 10(-7) Ms(-1) and the initial rate constant was dependent on the initial concentration of 1,3-DNB.

Destruction of model organic pollutants in water using ozone, UV and their combination (Part I).

The experimental results showed that ozone (O3) oxidation is an effective means to destroy phenolic organic pollutants present in water. High removal efficiencies can be readily achieved for most of the model compounds fortified in aqueous matrices within a reasonable time frame. This study also included the oxidation of phenolic compounds using ozone in combination with ultraviolet (UV) irradiation. The extent of mineralization measured in terms of the losses in total organic carbon is promoted by the joint action of ozone and UV in comparison with using ozone alone.

Sonochemical degradation for toxic halogenated organic compounds.

This paper describes the degradation of p-chlorophenol using three different ultrasonic devices. The dissipated power in the reaction matrix was measured based on calorimetric method. The study showed that hydrogen peroxide can improve the sonochemical reaction and gases dissolved in reaction matrix can affect the process to a small extent. The reaction mechanism and kinetics of degradation were also investigated.

Determination of manganese in water samples by flame atomic absorption spectrometry after cloud point extraction.

Cloud point extraction has been used for the preconcentration of manganese, after the formation of a complex with 1-(2-thiazolylazo)-2-naphthol (TAN), and later analysis by flame atomic absorption spectrometry using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The chemical variables affecting the separation phase and the viscosity affecting the detection process were optimized. Under the optimum conditions (i.e., pH = 9.2, [TAN] = 2.0 x 10(-5) mol l-1, [Triton X-114] = 0.05%, added methanol volume = 0.2 ml), preconcentration of 50 ml of sample solution permitted the detection of 0.28 ppb for manganese. The enhancement factor was 57.6. The proposed method has been applied to the determination of manganese in water samples.