Aerosol generation with the use of positive pressure ventilation via supraglottic airway devices: an observational study.

The amount of aerosol generation associated with the use of positive pressure ventilation via a supraglottic airway device has not been quantified. We conducted a two-group, two-centre, prospective cohort study in which we recruited 21 low-risk adult patients scheduled for elective surgery under general anaesthesia with second-generation supraglottic airway devices. An optical particle sizer and an isokinetic sampling probe were used to record particle concentrations per second at different size distributions (0.3-10 µm) during use as well as baseline levels during two common activities (conversation and coughing). There was a median (IQR [range]) peak increase of 2.8 (1.5-4.5 [1-28.1]) and 4.1 (2.0-7.1 [1-18.2]) times background concentrations during SAD insertion and removal. Most of the particles generated during supraglottic airway insertion (85.0%) and removal (85.3%) were < 3 µm diameter. Median (IQR [range]) aerosol concentration generated by insertion (1.1 (0.6-5.1 [0.2-22.3]) particles.cm-3 ) and removal (2.1 (0.5-3.0 [0.1-18.9]) particles.cm-3 ) of SADs were significantly lower than those produced during continuous talking (44.5 (28.3-70.5 [2.0-134.5]) particles.cm-3 ) and coughing (141.0 (98.3-202.8 [4.0-296.5]) particles.cm-3 ) (p < 0.001). The aerosol levels produced were similar with the two devices. The proportion of easily inhaled and small particles (<1 µm) produced during insertion (57.5%) and removal (57.5%) was much lower than during talking (99.1%) and coughing (99.6%). These results suggest that the use of supraglottic airway devices in low-risk patients, even with positive pressure ventilation, generates fewer aerosols than speaking and coughing in awake patients.

Peri-operative management of patients with Parkinson's disease.

Patients with Parkinson's disease are at higher risk of peri-operative medical and surgical complications. Multidisciplinary management, early recognition of potential complications, specialised care of medications and intra-operative protection of the vulnerable brain are all important aspects of the peri-operative management of patients with Parkinson's disease. Advances in continuous dopaminergic treatment, development of a peri-operative Parkinson's disease pathway and application of telemedicine are starting to play a role in improving peri-operative care. Management of patients with advanced Parkinson's disease is also evolving, with potential for incorporation of integrated care and changes in the anaesthetic management for deep brain stimulation surgery. There are new methods for localisation of target nuclei and increasing insight on the effects of anaesthetic drugs on microelectrode recordings and clinical outcomes. Parkinson's disease is a progressive disease, but management is improving with better peri-operative care for patients.

Prediction of chemical biodegradability using support vector classifier optimized with differential evolution.

Reliable computer models for the prediction of chemical biodegradability from molecular descriptors and fingerprints are very important for making health and environmental decisions. Coupling of the differential evolution (DE) algorithm with the support vector classifier (SVC) in order to optimize the main parameters of the classifier resulted in an improved classifier called the DE-SVC, which is introduced in this paper for use in chemical biodegradability studies. The DE-SVC was applied to predict the biodegradation of chemicals on the basis of extensive sample data sets and known structural features of molecules. Our optimization experiments showed that DE can efficiently find the proper parameters of the SVC. The resulting classifier possesses strong robustness and reliability compared with grid search, genetic algorithm, and particle swarm optimization methods. The classification experiments conducted here showed that the DE-SVC exhibits better classification performance than models previously used for such studies. It is a more effective and efficient prediction model for chemical biodegradability.

Varicella vaccine uptake and associated factors in children in Hong Kong.

Varicella is a common and highly contagious childhood disease which impacts the public worldwide. Hong Kong children can only be vaccinated against the disease in private practice. The varicella vaccination rate of local children in preschool is uncertain. Therefore a cross-sectional kindergarten-based parent-administered questionnaire survey was conducted in Hong Kong during 2012. Twelve kindergartens were randomly selected from a complete school list from the Education Bureau of Hong Kong. In total, 1285/1538 (83·6%) parents consented to join the study and completed the questionnaires. The overall varicella infection rate was 19·5% and the uptake of varicella vaccination rate was 57·6%. Barriers against varicella vaccination were mostly due to parental uncertainties about the effectiveness of vaccine, lack of recommendations from doctors or government, and adverse side-effects of the vaccine. The government and healthcare professional bodies are strongly recommended to further enhance health education among healthcare professionals, encouraging their active promotion of varicella vaccination for their patients. Furthermore, health education through various stakeholders is crucial to enhance parental awareness of varicella, as well as the effectiveness and safety of varicella vaccine.

Complete genome sequences of two closely related isolates of Staphylococcus saprophyticus isolated from human fingertips.

Complete genomes of two closely related isolates of Staphylococcus saprophyticus from human fingertips, SZ.YL11 and SZ.PL35w, were established through hybrid assembly. Each possesses a single circular chromosome and a circular plasmid, totaling 2,611,553 and 2,611,619 bp, respectively (with G + C 33.14% for both).

Complete genome sequence of Gluconobacter frateurii ML.ISBL3, an endophytic strain isolated from aerial roots of Syngonium podophyllum.

The endophytic strain Gluconobacter frateurii ML.ISBL3 was isolated from aerial roots of Syngonium podophyllum in Hong Kong. Its complete genome, established through hybrid assembly, comprises a single chromosome of 3,309,710 bp (56.30% G+C).

Complete genome sequence of Klebsiella variicola subsp. variicola ML.9ba2, an endophytic strain isolated from aerial roots of Philodendron erubescens.

The endophytic strain Klebsiella variicola subsp. variicola ML.9ba2 was isolated from aerial roots of Philodendron erubescens in Hong Kong. Its complete genome of 5,682,083 bp (57.29% G+C), comprising a single chromosome and an IncF plasmid, was established through hybrid assembly.

Complete genome sequence of Serratia ureilytica KML.E1, a copper-tolerant strain isolated from a disused tungsten mine.

Serratia ureilytica KML.E1 was recovered from a disused tungsten mine in Hong Kong and can tolerate copper(II) concentrations up to 90 mM. Its complete genome, a single chromosome of 5,094,661 bp (59.68% G+ C), was established through hybrid assembly.

Prevalence of abnormal Papanicolaou smears in female sex workers in Hong Kong.

OBJECTIVE. To investigate the prevalence of pre-cancerous uterine cervix lesions as detected in Papanicolaou (Pap) smears from female sex workers in Hong Kong. DESIGN. Retrospective analysis of laboratory records. SETTING. Private anatomical pathology laboratory, Hong Kong. PATIENTS. Female sex workers undergoing Pap smear examinations at two non-governmental organisations between 2006 and 2012. MAIN OUTCOME MEASURES. Detection of pre-cancerous uterine cervical conditions and their management. RESULTS. A total of 2697 satisfactory Pap smears from female sex workers were performed during the study period from 2006 to 2012. In these subjects, the point prevalence of low-grade squamous intraepithelial lesion and atypical squamous cells of unknown significance was 10.12% (compared with 3.92% for the general population during the same period), whereas that of high-grade squamous intraepithelial lesions and atypical squamous cells of unknown significance with or without high-grade intraepithelial lesions was 2.22% (compared with 0.54% in the general population). For both categories of lesions, the higher prevalence among female sex workers than in the general population was statistically significant. Most patients who had abnormal Pap smears received proper referrals and follow-up management according to recommended guidelines. CONCLUSIONS. Female sex workers in Hong Kong as a group had a significantly higher prevalence of abnormal Pap smears than the general population. Non-governmental organisations providing free-of-charge screening services to these women helped early detection and proper follow-up for those who had abnormal Pap smears, whilst also increasing their awareness of women's health issues.

Angioplasty and stenting for intracranial atherosclerotic stenosis: position statement of the Hong Kong Society of Interventional and Therapeutic Neuroradiology.

As a means of preventing secondary ischaemic stroke, angioplasty and stenting are considered potentially beneficial for patients with severe intracranial atherosclerotic stenosis. However, the role of stenting has been challenged since the publication of the first randomised controlled trial on Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial arterial Stenosis (SAMMPRIS). This indicated that aggressive medical management was superior to stenting using Wingspan to prevent recurrent stroke, because stenting has a high peri-procedural stroke and death rate. In this paper, we review the management of intracranial atherosclerosis, revisit the skepticism on stenting, and state our position on the topic in the form of recommendations. These are based on the prevalence of the disease in Hong Kong, the high risk of recurrent stroke despite medical therapy in the presence of haemodynamic intracranial stenosis without sufficient collaterals, an analysis of the weak points of SAMMPRIS, and results of clinical studies in Hong Kong.

Complete genome sequence of Kosakonia pseudosacchari RX.G5M8, a putative methylotroph isolated from Hong Kong soil.

Kosakonia pseudosacchari RX.G5M8, a putative methylotroph, was isolated from garden soil in Hong Kong. Its complete genome, a single chromosome of 4,953,935 bp (GC content 53.91%), was established through hybrid assembly.

Complete Genome Sequence of Enterobacter roggenkampii RX.G5M56, a C1-Metabolizing Strain from a Freshwater Stream in Hong Kong.

The C1-metabolizing strain Enterobacter roggenkampii RX.G5M56 was isolated from a freshwater stream in Hong Kong. Its complete genome, a single chromosome of 4,772,201 bp (GC content of 56.05%), was established through hybrid assembly.

Sediment metal enrichment and ecological risk assessment of ten ports and estuaries in the World Harbours Project.

Ten global harbours were assessed for sediment quality by quantifying the magnitude of anthropogenic change and ecological risk. Anthropogenic change (enrichment) was high for Derwent River and Sydney estuary, moderate for Santander Harbour, Rio de Janeiro and Dublin Port, slight for Hong Kong, minimal for Darwin. All 10 enrichment indices used showed similar results. Derwent River sediment was rated at high ecological risk, followed by Sydney and Santander estuaries with moderate risk. Auckland and Darwin sediments exhibited minimal ecological risk and sediment in the remaining harbours (Dublin, Hong Kong, Ravenna, Ria de Vigo and Rio de Janeiro) were assessed at slight ecological risk. The extraordinary variety of environments and types/quantities/qualities of data investigated resulted in as much a critique and development of methodology, as an assessment of human impact, including unique techniques for elemental normalisation and contaminant classification. Recommendations for an improved technical framework for sediment quality assessment are provided.

Community-based intervention to optimise falls risk management: a randomised controlled trial.

BACKGROUND: falls are the leading causes of accidental death and fragility fractures in older adults. Interventions that assess and reduce falls risk are underutilised. OBJECTIVE: to evaluate the impact of a multifaceted community-based programme aimed at optimising evidence-based management of patients at risk for fall-related fractures. DESIGN: this was a randomised trial performed from 2003 to 2006. SETTING: community-based intervention in Ontario, Canada. PARTICIPANTS: eligible patients were community-dwelling, aged > or =55 years and identified to be at risk for fall-related fractures. A total of 201 patients were allocated to the intervention group or to usual care. INTERVENTION: components of the intervention included assessment of falls risk, functional status and home environment, and patient education. MEASUREMENTS: primary outcome was the implementation of appropriate falls risk assessment at 6 months. Secondary outcomes included falls and fractures at 6 and 12 months. RESULTS: the mean age of participants was 72 years, and 41% had fallen with injury in the previous year. Compared to usual care, the intervention increased the number of referrals made to physiotherapy [21% (21/101) vs 6.0% (6/100); relative risk (RR) 3.47, 95% confidence interval (CI) 1.46-8.22] and occupational therapy [15% (15/101) vs 0%; RR 30.7, 95% CI 1.86 to >500]. At 12 months, the number of falls in the intervention group was greater than in the usual care group [23% (23/101) vs 11% (11/100); RR 2.07, 95% CI 1.07-4.02]. CONCLUSIONS: compared to usual care, a multi-faceted intervention increased referrals to physiotherapy and occupational therapy but did not reduce risk of falls. Similar falls reduction interventions cannot be recommended based on the results of this study.

Surgical recanalisation of thrombosed M2 trunk after coil embolisation of a ruptured middle cerebral artery aneurysm.

Thromboembolic events are known complications of endovascular coiling of intracerebral aneurysms. We report a case of a 50-year-old patient whose ruptured middle cerebral artery aneurysm was treated with endovascular coiling, which was complicated by occlusion of the inferior M2 trunk during the procedure. An emergency craniotomy was performed to enable coil retrieval, evacuation of the thrombus and clipping of the aneurysm. All the middle cerebral artery branches were recanalised and the patient recovered with no neurological deficits. Our experience suggests that an emergency salvage operation for thrombosis after endovascular coiling is a treatment option offering a good clinical outcome.

Development of human single-chain antibodies against SARS-associated coronavirus.

The outbreak of severe acute respiratory syndrome (SARS), caused by a distinct coronavirus, in 2003 greatly threatened public health in China, Southeast Asia as well as North America. Over 1,000 patients died of the SARS virus, representing 10% of infected people. Like other coronaviruses, the SARS virus also utilizes a surface glycoprotein, namely the spike protein, to infect host cells. The spike protein of SARS virus consists of 1,255 amino acid residues and can be divided into two sub-domains, S1 and S2. The S1 domain mediates the binding of the virus to its receptor angiotensin-converting enzyme 2, which is abundantly distributed on the surface of human lung cells. The S2 domain mediates membrane fusion between the virus and the host cell. Hence two strategies can be used to block the infection of the SARS virus, either by interfering with the binding of the S1 domain to the receptor or by blocking the fusion of the virus with the cell membrane mediated by the S2 domain. Several antibodies against the S1 domain have been generated and all of them are able to neutralize the virus in vitro and in vivo using animal models. Unfortunately, point mutations have been identified in the S1 domain, so that the virus isolated in the future may not be recognized by these antibodies. As no mutation has been found in the S2 domain indicating that this region is more conserved than the S1 domain, it may be a better target for antibody binding. After predicting the immunogenicity of the epitopes of the S2 domain, we chemically synthesized two peptides and also expressed one of them using a recombinant DNA method. We screened a phage displaying library of human single-chain antibodies (ScFv) against the predicted epitopes and obtained a human ScFv which can recognize the SARS virus in vitro.

Characteristics of false-negative ThinPrep cervical smears in women with high-grade squamous intraepithelial lesions.

OBJECTIVE: To examine the cellular characteristics and other possible factors affecting the correct prediction of ThinPrep cervical smears from patients with high-grade squamous intraepithelial lesions. DESIGN: Retrospective study. SETTING: Private anatomical pathology service, Hong Kong. PATIENTS: Patients (n=98) with biopsy-confirmed high-grade squamous intraepithelial lesion of the uterine cervix encountered between 2004 and 2006. MAIN OUTCOME MEASURES: Correct prediction of the cervical ThinPrep Papanicolaou tests. RESULTS: There were no significant differences in age, hormonal status, degree of inflammation, and the presence or absence of endocervical/metaplastic cells between the true-positive and false-negative groups. There was a significant difference in the number of abnormal cells present and the screening time between the two groups. Approximately 79% (34/43) false-negative smears had 100 or less abnormal cells, while only 11% (5/45) true-positive smears had 100 or less abnormal cells (P<0.001). The true-positive smears were also more likely to contain koilocytic cells and abnormal cells with hyperchromatic nuclei. CONCLUSIONS: The number of abnormal cells present, the presence or absence of koilocytic cells, and the presence or absence of abnormal cells with nuclear hyperchromasia appeared to be independent factors affecting the correct prediction of smears from patients with high-grade squamous intraepithelial lesions.

Acute and chronic toxicities of tributyltin to various life stages of the marine polychaete Hydroides elegans.

Experiments were performed to determine the acute and chronic toxicities of tributyltin (TBT) (nominal concentrations) to polychaete Hydroides elegans. Firstly, static tests were performed to examine the lethal effect of TBT on five life stages of H. elegans. The 48-h LC(50) (95% CI) for the eggs, 2-cells, trochophores, juveniles and adults was 0.18 (0.15-0.20), 0.97 (0.77-1.23), 2.36 (2.11-2.65), 2.86 (2.63-3.12) and 4.36 (4.04-4.71) microg TBT l(-1), respectively. Secondly, a 17-d static renewal chronic test was conducted to study sensitivity of the early development (egg to juvenile) to TBT. The survivorship, percent settlement and time to reach settlement were significantly reduced at 0.01 microg TBT l(-1). Effects of TBT on the juvenile growth and maturation were also studied through a 44-d chronic test. Lower survivorship and reduced tube growth were observed only at >or= 1 microg TBT l(-1), however, only H. elegans exposed to or= 0.1 microg TBT l(-1). Our results indicate that the early development of H. elegans is highly sensitive to TBT and this polychaete can be routinely employed as a test organism for both acute and chronic ecotoxicity bioassays in tropical and subtropical regions such as southern China.

Breast pathology in complications associated with polyacrylamide hydrogel (PAAG) mammoplasty.

OBJECTIVE: To study the tissue pathology of breast lesions associated with hydrophilic polyacrylamide gel injection augmentation mammoplasty. DESIGN: Retrospective study. SETTING: Private anatomical pathology practice, Hong Kong. PATIENTS: Eight patients who underwent lumpectomy of the breast due to complications of hydrophilic polyacrylamide gel injection for augmentation mammoplasty. MAIN OUTCOME MEASURES: Identification of hydrophilic polyacrylamide gel in breast tissue and associated pathological changes. RESULTS: We reviewed the pathological changes in breast tissue associated with hydrophilic polyacrylamide gel injection in eight cases retrieved from our archive. Microscopically, the hydrophilic polyacrylamide gel appeared as pools of pale violet gelatinous material of variable size, between the interstices of connective tissue and fat cells. The larger pools were often surrounded by cellular reactions consisting of histiocytic cells and foreign body-type multinucleated giant cells. Inflammatory reaction featuring infiltration by lymphocytes and plasma cells in the adjacent breast tissue was observed in samples from four patients, and a sample from another patient showed acute inflammation with abscess formation. There was no evidence of abnormal cellular proliferation, atypia or malignant change in the stromal connective tissue or ductal-acinic epithelial components of the breast tissue. CONCLUSIONS: Hydrophilic polyacrylamide gel injection for augmentation mammoplasty can give rise to a breast lump and inflammation. Pathologically, this complication is associated with fibrosis, foreign body reaction, and inflammation.

Clinical relevance of intra-operative sentinel lymph node examination in breast cancer management.

OBJECTIVES: To determine the sensitivity, accuracy, and clinical relevance of intra-operative examination of sentinel lymph nodes in breast cancer management. DESIGN: Retrospective study. SETTING: Private anatomical pathology practice. PARTICIPANTS: Three hundred breast cancer patients who underwent axillary sentinel lymph node biopsies for intra-operative assessment between January 2004 and March 2006. MAIN OUTCOME MEASURES: Correct identification of metastatic carcinoma in sentinel lymph nodes during intra-operative examination, sparing patient a second surgery. RESULTS: The intra-operative diagnosis of sentinel lymph node biopsies from 300 consecutive patients were compared with the final pathological diagnoses. The final pathology results showed metastatic carcinoma in 74 patients, of whom 63 (85%) were correctly diagnosed during frozen section examination. There was no false-positive case (positive predictive value 100%). The sensitivity for detecting macro- and micro-metastases were 95% and 50%, respectively (P<0.01). The sensitivity for detecting metastases in T1 and T2/above tumours were 72% and 90%, respectively (P<0.05). CONCLUSIONS: Intra-operative examination is a reliable and sensitive method for the detection of sentinel lymph node metastasis. Eighty-five percent of the patients with metastatic disease were correctly diagnosed and spared a second operation for axillary dissection. The disadvantage of missing a positive lymph node is by far outweighed by the advantage of a single stage operation in case of a positive diagnosis. The benefit of intra-operative examination was slightly less in patients with smaller tumours.