Determination of Chlorinated organic compounds in aqueous matrices

Thirteen pure volatile, semi-volatile and non-volatile chlorinated organic compounds of molecular weights ranging from trichloroethylene (MW = 131.39 g mole -¹) to hexachlorobenzene (MW = 284.78 g mole-¹) were determined in aqueous matrices by GC-ECD. After 10% salt addition, different extraction tests were performed using fibres whose adsorbing phase was based on microsphere carbon particles characterized by a constant size. Five experimental parameters were optimized: extraction temperature and time, position of the fibre in the GC injector port, desorption temperature and time. The optimized analytical protocol was employed to determine the efficiency of a real activated carbon adsorption plant to remove organic chlorinated pollutants from an industrial wastewater at ng l-¹ levels

Ultra-short echo time cardiovascular magnetic resonance of atherosclerotic carotid plaque.

BACKGROUND: Multi-contrast weighted cardiovascular magnetic resonance (CMR) allows detailed plaque characterisation and assessment of plaque vulnerability. The aim of this preliminary study was to show the potential of Ultra-short Echo Time (UTE) subtraction MR in detecting calcification. METHODS: 14 ex-vivo human carotid arteries were scanned using CMR and CT, prior to histological slide preparation. Two images were acquired using a double-echo 3D UTE pulse, one with a long TE and the second with an ultra-short TE, with the same TR. An UTE subtraction (DeltaUTE) image containing only ultra-short T2 (and T2*) signals was obtained by post-processing subtraction of the 2 UTE images. The DeltaUTE image was compared to the conventional 3D T1-weighted sequence and CT scan of the carotid arteries. RESULTS: In atheromatous carotid arteries, there was a 71% agreement between the high signal intensity areas on DeltaUTE images and CT scan. The same areas were represented as low signal intensity on T1W and areas of void on histology, indicating focal calcification. However, in 15% of all the scans there were some incongruent regions of high intensity on DeltaUTE that did not correspond with a high intensity signal on CT, and histology confirmed the absence of calcification. CONCLUSIONS: We have demonstrated that the UTE sequence has potential to identify calcified plaque. Further work is needed to fully understand the UTE findings

A report on a randomly sampled questionnaire survey about renal stone disease in Hong Kong

Objectives: To investigate the prevalence and characteristics of patients with renal stone in Hong Kong, and awareness of corresponding prevention strategies. Design: Telephone public survey. Setting: Hong Kong community. Participants: A public telephone survey concerning the occurrence of renal stone disease and the public awareness of the condition was performed. Respondents whose telephone numbers were randomly selected by computer and the family member of the household who had the closest birthday to that date was chosen for interview. Data collected were further adjusted for the gender and age distribution of the Hong Kong population in mid-2007. Results: A total of 1010 Hong Kong citizens aged 18 years or above were successfully interviewed in November 2007. Among them, 25 respondents themselves had a history of renal stones, yielding a point prevalence of 2.5%. In addition, 70 respondents had family members with a history of renal stones, yielding an estimated household point prevalence of 6.9%. Stone patients were mainly older, male, and imbibed less fluids than the average for all respondents. The public's concepts with regard to the diet necessary and the importance of taking more fluid to prevent stone formation was poor. Conclusion: Hong Kong has a relatively low prevalence of renal stone disease, compared to neighbouring areas. However, the local public and affected patients had little knowledge and awareness about this important health problem.published_or_final_versio

Using bevacizumab in the fight against malignant glioma: First results in Asian patients

Objectives To investigate the efficacy and safety profile of bevacizumab in combination with irinotecan in Hong Kong Chinese patients with recurrent malignant glioma and to determine whether their response differed from that reported in other populations. Design Retrospective study. Setting Two private clinics and a public hospital in Hong Kong. Patients Fourteen individuals who presented with recurrent glioma presenting to the hospital between November 2005 and November 2009. Intervention Salvage therapy with bevacizumab (10 mg/kg) and irinotecan (125 mg/m 2 [340 mg/m 2 for those taking enzyme-inducing antiepileptic drugs]) on a 14-day schedule. Results A radiological response was observed in 12 (86%) of the patients, four (33%) of whom had a complete response. The median progression-free survival was 6 (range, 1-15) months; 71% remained progression-free at 6 months. The median overall survival was 18 (range, 9-61) months. The most common adverse events during the bevacizumab and irinotecan treatment period were haematological; five patients had grade 2/3 adverse events. Pulmonary embolism occurred in two patients, one of whom died. Intracranial haemorrhage was not detected in any of the 14 treated patients. Conclusions Bevacizumab plus irinotecan was at least as effective at treating Chinese patients with recurrent glioma as previously reported in clinical trials in different patient populations.published_or_final_versio

The effects of Ganoderma lucidum on initial events related to the Bacillus Calmette-Guérin efficacy and toxicity on high-risk uroepithelial cells : an in vitro preliminary study

Author name used in this publication: Yuen, John Wai-Man.2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Synergistic cytotoxic effects of ganoderma lucidum and bacillus calmette guérin on premalignant urothelial HUC-PC cells and its regulation on proinflammatory cytokine secretion

Author name used in this publication: John Wai-man YuenAuthor name used in this publication: Mayur-Danny I. Gohel2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Hepatocyte-specific activation of NF-κB does not aggravate chemical hepatocarcinogenesis in transgenic mice

The NF-κB signalling pathway plays important roles in liver organogenesis and cardnogenesis. Mouse embryos deficient in IKKβ die in mid-gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF-κB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF-κB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKβ was expressed in a hepatocyte-specific manner. Using electrophoretic mobility shift assay, we documented increased NF-κB activities and up-regulated levels of NF-κB downstream target genes, Bcl-xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF-κB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild-type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF-κB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF-κB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF-κB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases. Copyright © 2008 Pathological Society of Great Britain and Ireland.postprin

Final report of the Construction Industry Institute, Hong Kong research project on reinventing the Hong Kong construction industry for its sustainable development

Author name used in this publication: Andrew N. BaldwinAuthor name used in this publication: Y. H. ChiangAuthor name used in this publication: Joyce W. S. CheungAuthor name used in this publication: Joanne W. S. NgConstruction Industry Institute-Hong Kong Report, no. 132008-2009 > Academic research: not refereed > Research book or monograph (author)Other Versio

Angiotensin II type 1 receptor-dependent oxidative stress mediates endothelial dysfunction in type 2 diabetic mice

The mechanisms underlying the effect of the renin-angiotensin-aldosterone system (RAAS) inhibition on endothelial dysfunction in type 2 diabetes are incompletely understood. This study explored a causal relationship between RAAS activation and oxidative stress involved in diabetes-associated endothelial dysfunction. Daily oral administration of valsartan or enalapril at 10mg/kg/day to db/db mice for 6 weeks reversed the blunted acetylcholine-induced endothelium-dependent dilatations, suppressed the upregulated expression of angiotensin II type 1 receptor (AT1R) and NAD(P)H oxidase subunits (p22phox and p47phox), and reduced reactive oxygen species (ROS) production. Acute exposure to AT1R blocker losartan restored the impaired endothelium-dependent dilatations in aortas of db/db mice and also in renal arteries of diabetic patients (fasting plasma glucose level ≥7.0 mmol/l). Similar observations were also made with apocynin, diphenyliodonium, or tempol treatment in db/db mouse aortas. DHE fluorescence revealed an overproduction of ROS in db/db aortas which was sensitive to inhibition by losartan or ROS scavengers. Losartan also prevented the impairment of endothelium-dependent dilatations under hyperglycemic conditions that were accompanied by high ROS production. The present study has identified an initiative role of AT1R activation in mediating endothelial dysfunction of arteries from db/db mice and diabetic patients. © 2010 Mary Ann Liebert, Inc.published_or_final_versio

Influenza viruses in healthy wild birds in Hong Kong

Poster Presentations: Animal Influenza EcologyWild waterfowl are considered the natural reservoir of influenza A viruses. The recent outbreak of highly pathogenic avian influenza (HPAI) H5N1 in Asia which has now spread as far as Africa highlights the importance of defining the influenza virus gene pool in these birds and understanding the potential role played by migratory waterfowl in such HPAI outbreaks. Seventy-three influenza viruses were isolated from 16,724 samples collected from feral waterfowls or their fecal droppings during 2003-7 at Mai Po Marshes and Lok Ma Chau in Hong Kong. A diversity of influenza viruses representing hemagglutinin subtypes of H1, H2, H4, H5, H6, H7, H8, H9, H10 and H11; neuramidinase subtypes of N1, N2, N3, N4, N6, N7, N8 and N9, were isolated. Seventy-two of these 73 positive isolates were collected during the winter period coinciding with the southern migration of waterfowl along the East Asian flyway. No HPAI H5N1 viruses were isolated from healthy birds sampled in this study, though H5N1 viruses have been isolated from dead wild birds found in Hong Kong. Phylogenetic analyses of the HA gene of the H5 viruses isolated in the study showed that they clustered with other LP H5 viruses isolated from Hokkaido, Mongolia and Siberia but they seemed not to be very closely related to the HP H5N1. Six of 150 blood sample collected from wild ducks and one of 43 from shorebirds were tested to have antibody by neutralization tests for H5 subtype hemagglutinin.postprin