Factors affecting outcomes of a semantically-based treatment for anomia

Thesis (B.Sc)--University of Hong Kong, 2008.Includes bibliographical references (leaves 26-27).Also available in print.A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2008.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Etiology in 16 cases of toxic epidermal necrolysis and Stevens-Johnson syndrome admitted within 8 months in a teaching hospital

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Protective effects of lycium barbarum polysaccharides on cerebral edema and blood-brain barrier disruption after ischemic stroke

Young Investigators Symposium I (Y3) - Di YangBACKGROUND: Ischemic stroke is a destructive cerebrovascular disease and one of the leading causes of death worldwide. The long term disability after stroke induces heavy burden both to the patients and the society. Yet, no effective neuroprotective agents are available. The polysaccharides extracted from the fruits of wolfberry, Lycium barbarum (LBP), showed neuroprotective and immune-modulative functions. We aim to evaluate the protective effects of LBP in experimental stroke using a focal cerebral ischemia/reperfusion (I/R) model. METHODS: C57BL/6N mice were subjected to 2 h of middle cerebral artery occlusion (MCAO) followed by 22 h of reperfusion. Prior to ischemia induction, animals were treated with either vehicle (PBS) or LBP daily for 7 days. Mice were evaluated for neurological deficits just before sacrifice. Brains were harvested for infarct size estimation, water content measurement and immunohistochemical analysis as well as Western blot experiments. Evans blue (EB) extravasation experiment was performed to determine blood-brain barrier (BBB) disruption after MCAO. RESULTS: LBP treatment significantly improved neurological scores and decreased infarct size, hemispheric swelling and water content as well as reduced EB extravasation. In addition, fewer apoptotic cells were identified in the LBP-treated brains by TUNEL assay. Immunoreactivity for aquaporin-4 and glial fibrillary acidic protein were also significantly decreased in LBP-treated brains. We further observed a reduction of nuclear factor-κB translocation and IκB expression after LBP treatment. CONCLUSION: Seven-day LBP pre-treatment effectively improved neurological deficits, decreased infarct size and cerebral edema as well as protected the brain from BBB disruption, aquaporin water channel up-regulation and glial activation. The protective effects of LBP might partially act through its anti-inflammatory effects. The present study suggests that LBP may be used as a preventive neuroprotectant for ischemic stroke.postprin

Prevalence and genotypes of α- and β-thalassemia carriers in Hong Kong - Implications for population screening

Background: The thalassemias are common in southern China. We determined the prevalence of heterozygous carriers of these genetic disorders in Hong Kong and assessed the feasibility of a community-based screening program. Methods: An educational and screening program for the thalassemias was carried out in three high schools with a total of 2420 students. Seventy- five percent of the students agreed to undergo screening, which consisted of blood counts, hemoglobin electrophoresis, serum ferritin measurements, and DNA analyses. Results: Of the 1800 blood samples tested, 150 (8.3 percent) had microcytosis (mean corpuscular volume, <80 μm3). Ninety students (5.0 percent) were carriers of α-thalassemia, of whom 81 (4.5 percent) were carriers of the Southeast Asian type of deletion, in which both α-globin genes on the same chromosome 16 are deleted. Sixty-one students (3.4 percent) were carriers of either β-thalassemia or the mutation coding for hemoglobin E. Six students were carriers of both α- and β-thalassemias. On the basis of these figures, the estimated numbers of pregnancies in Hong Kong in which the fetus is at risk for homozygous α-thalassemia and β-thalassemia major or intermedia are 145 and 80 per year, respectively. In Hong Kong the actual numbers of women referred for prenatal diagnoses of these disorders are approximately 95 and 40 per year, respectively. Conclusions: Despite the availability of hospital-based screening and prenatal diagnosis for many years in Hong Kong, many women carrying fetuses at risk for thalassemia are not referred for genetic counseling. A community-based program of education, screening, and counseling is needed in Hong Kong and southern China.published_or_final_versio

Lycium barbarum polysaccharides reduce neuronal damage, blood-retinal barrier disruption and oxidative stress in retinal ischemia/reperfusion injury

Neuronal cell death, glial cell activation, retinal swelling and oxidative injury are complications in retinal ischemia/ reperfusion (I/R) injuries. Lycium barbarum polysaccharides (LBP), extracts from the wolfberries, are good for "eye health" according to Chinese medicine. The aim of our present study is to explore the use of LBP in retinal I/R injury. Retinal I/R injury was induced by surgical occlusion of the internal carotid artery. Prior to induction of ischemia, mice were treated orally with either vehicle (PBS) or LBP (1 mg/kg) once a day for 1 week. Paraffin-embedded retinal sections were prepared. Viable cells were counted; apoptosis was assessed using TUNEL assay. Expression levels of glial fibrillary acidic protein (GFAP), aquaporin-4 (AQP4), poly(ADP-ribose) (PAR) and nitrotyrosine (NT) were investigated by immunohistochemistry. The integrity of blood-retinal barrier (BRB) was examined by IgG extravasations. Apoptosis and decreased viable cell count were found in the ganglion cell layer (GCL) and the inner nuclear layer (INL) of the vehicle-treated I/R retina. Additionally, increased retinal thickness, GFAP activation, AQP4 up-regulation, IgG extravasations and PAR expression levels were observed in the vehicle-treated I/R retina. Many of these changes were diminished or abolished in the LBP-treated I/R retina. Pre-treatment with LBP for 1 week effectively protected the retina from neuronal death, apoptosis, glial cell activation, aquaporin water channel up-regulation, disruption of BRB and oxidative stress. The present study suggests that LBP may have a neuroprotective role to play in ocular diseases for which I/R is a feature. © 2011 Li et al.published_or_final_versio

A profile of the online dissemination of national influenza surveillance data

<p>Abstract</p> <p>Background</p> <p>Influenza surveillance systems provide important and timely information to health service providers on trends in the circulation of influenza virus and other upper respiratory tract infections. Online dissemination of surveillance data is useful for risk communication to health care professionals, the media and the general public. We reviewed national influenza surveillance websites from around the world to describe the main features of surveillance data dissemination.</p> <p>Methods</p> <p>We searched for national influenza surveillance websites for every country and reviewed the resulting sites where available during the period from November 2008 through February 2009. Literature about influenza surveillance was searched at MEDLINE for relevant hyperlinks to related websites. Non-English websites were translated into English using human translators or Google language tools.</p> <p>Results</p> <p>A total of 70 national influenza surveillance websites were identified. The percentage of developing countries with surveillance websites was lower than that of developed countries (22% versus 57% respectively). Most of the websites (74%) were in English or provided an English version. The most common surveillance methods included influenza-like illness consultation rates in primary care settings (89%) and laboratory surveillance (44%). Most websites (70%) provided data within a static report format and 66% of the websites provided data with at least weekly resolution.</p> <p>Conclusion</p> <p>Appropriate dissemination of surveillance data is important to maximize the utility of collected data. There may be room for improvement in the style and content of the dissemination of influenza data to health care professionals and the general public.</p

Pulmonary vasoconstrictor action of KCNQ potassium channel blockers

KCNQ channels have been widely studied in the nervous system, heart and inner ear, where they have important physiological functions. Recent reports indicate that KCNQ channels may also be expressed in portal vein where they are suggested to influence spontaneous contractile activity. The biophysical properties of K+ currents mediated by KCNQ channels resemble a current underlying the resting K+ conductance and resting potential of pulmonary artery smooth muscle cells. We therefore investigated a possible role of KCNQ channels in regulating the function of pulmonary arteries by determining the ability of the selective KCNQ channel blockers, linopirdine and XE991, to promote pulmonary vasoconstriction. Linopirdine and XE991 both contracted rat and mouse pulmonary arteries but had little effect on mesenteric arteries. In each case the maximum contraction was almost as large as the response to 50 mM K+. Linopirdine had an EC50 of around 1 μM and XE991 was almost 10-fold more potent. Neither removal of the endothelium nor exposure to phentolamine or α,β-methylene ATP, to block α1-adrenoceptors or P2X receptors, respectively, affected the contraction. Contraction was abolished in Ca2+-free solution and in the presence of 1 μM nifedipine or 10 μM levcromakalim

Male germ cell-specific protein Trs4 binds to multiple proteins

Temperature-related sequence 4 (Trs4) has been identified as a testis-specific gene with expression sensitive to the abdominal temperature changes induced by artificial cryptorchidism. In murine testes, Trs4 mRNA was detected in round spermatids and its protein was localized mainly in the elongating spermatids as well as in the acrosomes and tails of mature spermatozoa. Using a yeast two-hybrid screening system, we identified Rshl-2, Gstmu1, and Ddc8 as putative binding partners of the Trs4 protein in mouse testes. Their interactions were confirmed by in vivo and in vitro binding assays. Further studies demonstrated that Ddc8, a newly identified gene with unknown functions, displayed a similar expression pattern with Trs4 in mouse testes. In particular, Trs4, Ddc8, and Rshl-2 proteins were co-localized to the tails of mature spermatozoa. These results suggested that Trs4 might be involved in diverse processes of spermiogenesis and/or fertilization through interactions with its multiple binding partners. © 2009 Elsevier Inc.postprin

Brain tissue volume changes following weight gain in adults with anorexia nervosa

Objective: To measure brain volume deficits among underweight patients with anorexia nervosa (AN) compared to control participants and evaluate the reversibility of these deficits with short-term weight restoration. Method: Brain volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) were examined in 32 adult women with AN and compared to 21, age and body mass index-range matched control women. Results: Patients with AN had a significant increase in GM (p = .006, η2 = 0.14) and WM volume (p = .001, η2 = 0.19) following weight restoration. Patients on average had lower levels of GM at low weight (647.63 ± 62.07 ml) compared to controls (679.93 ± 53.31 ml), which increased with weight restoration (662.64 ± 69.71 ml), but did not fully normalize. Discussion: This study suggests that underweight adult patients with AN have reduced GM and WM volumes that increase with short-term weight restoration

iCartiGD: the Integrated Cartilage Gene Database

BACKGROUND: Diseases of cartilage, such as arthritis and degenerative disc disease, affect the majority of the general population, particularly with ageing. Discovery and understanding of the genes and pathways involved in cartilage biology will greatly assist research on the development, degeneration and disorders of cartilage. DESCRIPTION: We have established the Integrated Cartilage Gene Database (iCartiGD) of genes that are known, based on results from high throughput experiments, to be expressed in cartilage. Information about these genes is extracted automatically from public databases and presented as a single page report via a web-browser. A variety of flexible search options are provided and the chromosomal distribution of cartilage associated genes can be presented. CONCLUSION: iCartiGD provides a comprehensive source of information on genes known to be expressed in cartilage. It will remain current due to its automatic update capability and provide researchers with an easily accessible resource for studies involving cartilage. Genetic studies of the development and disorders of cartilage will benefit from this database