Development and evaluation of a positive youth development course for university students in Hong Kong

Author name used in this publication: Y. H. ChuiAuthor name used in this publication: S. W. LitAuthor name used in this publication: Yida Y. H. ChungAuthor name used in this publication: S. W. Ngai2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Temporal transcriptome changes induced by MDV in marek's disease-resistant and -susceptible inbred chickens

<p>Abstract</p> <p>Background</p> <p>Marek's disease (MD) is a lymphoproliferative disease in chickens caused by Marek's disease virus (MDV) and characterized by T cell lymphoma and infiltration of lymphoid cells into various organs such as liver, spleen, peripheral nerves and muscle. Resistance to MD and disease risk have long been thought to be influenced both by genetic and environmental factors, the combination of which contributes to the observed outcome in an individual. We hypothesize that after MDV infection, genes related to MD-resistance or -susceptibility may exhibit different trends in transcriptional activity in chicken lines having a varying degree of resistance to MD.</p> <p>Results</p> <p>In order to study the mechanisms of resistance and susceptibility to MD, we performed genome-wide temporal expression analysis in spleen tissues from MD-resistant line 6₃, susceptible line 7₂and recombinant congenic strain M (RCS-M) that has a phenotype intermediate between lines 6₃and 7₂after MDV infection. Three time points of the MDV life cycle in chicken were selected for study: 5 days post infection (dpi), 10dpi and 21dpi, representing the early cytolytic, latent and late cytolytic stages, respectively. We observed similar gene expression profiles at the three time points in line 6₃and RCS-M chickens that are both different from line 7₂. Pathway analysis using Ingenuity Pathway Analysis (IPA) showed that MDV can broadly influence the chickens irrespective of whether they are resistant or susceptible to MD. However, some pathways like cardiac arrhythmia and cardiovascular disease were found to be affected only in line 7₂; while some networks related to cell-mediated immune response and antigen presentation were enriched only in line 6₃and RCS-M. We identified 78 and 30 candidate genes associated with MD resistance, at 10 and 21dpi respectively, by considering genes having the same trend of expression change after MDV infection in lines 6₃and RCS-M. On the other hand, by considering genes with the same trend of expression change after MDV infection in lines 7₂and RCS-M, we identified 78 and 43 genes at 10 and 21dpi, respectively, which may be associated with MD-susceptibility.</p> <p>Conclusions</p> <p>By testing temporal transcriptome changes using three representative chicken lines with different resistance to MD, we identified 108 candidate genes for MD-resistance and 121 candidate genes for MD-susceptibility over the three time points. Genes included in our resistance or susceptibility genes lists that are also involved in more than 5 biofunctions, such as <it>CD8α</it>, <it>IL8</it>, <it>USP18</it>, and <it>CTLA4</it>, are considered to be important genes involved in MD-resistance or -susceptibility. We were also able to identify several biofunctions related with immune response that we believe play an important role in MD-resistance.</p

Gene expression signatures of morphologically normal breast tissue identify basal-like tumors

INTRODUCTION: The role of the cellular microenvironment in breast tumorigenesis has become an important research area. However, little is known about gene expression in histologically normal tissue adjacent to breast tumor, if this is influenced by the tumor, and how this compares with non-tumor-bearing breast tissue. METHODS: To address this, we have generated gene expression profiles of morphologically normal epithelial and stromal tissue, isolated using laser capture microdissection, from patients with breast cancer or undergoing breast reduction mammoplasty (n = 44). RESULTS: Based on this data, we determined that morphologically normal epithelium and stroma exhibited distinct expression profiles, but molecular signatures that distinguished breast reduction tissue from tumor-adjacent normal tissue were absent. Stroma isolated from morphologically normal ducts adjacent to tumor tissue contained two distinct expression profiles that correlated with stromal cellularity, and shared similarities with soft tissue tumors with favorable outcome. Adjacent normal epithelium and stroma from breast cancer patients showed no significant association between expression profiles and standard clinical characteristics, but did cluster ER/PR/HER2-negative breast cancers with basal-like subtype expression profiles with poor prognosis. CONCLUSION: Our data reveal that morphologically normal tissue adjacent to breast carcinomas has not undergone significant gene expression changes when compared to breast reduction tissue, and provide an important gene expression dataset for comparative studies of tumor expression profiles

Fears about treatment among young drug abusers in Hong Kong

Author name used in this publication: Yida Y.H. Chung2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Sonographic features of anal atresia at 12 weeks

Anorectal atresia results from abnormal development of the anorectal septum. Prenatal diagnosis is difficult but the condition may be suspected by the sonographic demonstration of a dilated colon. We present the sonographic features of a fetus with anal atresia and a ventricular septal defect at 12 weeks of gestation. This case illustrates that a dilated colon may be present in association with fetal anal atresia as early as 12 weeks.link_to_subscribed_fulltex

Multiple myeloma with testicular involvement

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Thermocoagulation of fetal sacrococcygeal teratoma

Fetal sacrococcygeal teratoma can lead to a high output cardiac failure resulting in hydrops fetalis. One of the prenatal therapeutic options is to occlude the feeding vessels by radiofrequency ablation. We present a case of fetal sacrococcygeal teratoma diagnosed at 13 weeks of gestation. The tumour increased in size more than 100-fold over 5 weeks causing polyhydramnios and cardiac and placental enlargement. Thermocoagulation was performed at 18 weeks' gestation by passing an insulated electric wire through an 18-gauge needle placed close to the feeding vessels of the tumour at its neck. Blood supply to the tumour was successfully reduced. However, fetal death was diagnosed 2 days after the procedure. We speculate that it may be safer to limit the extent of coagulation in one attempt but to repeat the procedure at a later stage when necessary. Copyright © 2002 John Wiley & Sons, Ltd.link_to_subscribed_fulltex

Puncture Depth and the Mechanical Stability of Microneedles

Microneedles penetrating less than 1mm beneath the skin can deliver the drugs directly without piercing blood vessels or damaging nerves. The mechanical stability and the puncture behaviour were investigated experimentally by inserting steel needles into silicone rubber and pig skin. Puncture tests revealed that the length of needle buried in the flesh is less than 50% of the nominal insertion depth when the insertion depth is less 1mm. The mechanical stability of the buried needle-flesh assembly, characterized by the force needed to retract the needle, decreased with buried depth and needle diameter. Analysis of the load data suggested that a 100-micron diameter microneedle buried 100 microns deep in pig skin would have a retraction force of 0.1mN, which is only 1% of the retraction force of a conventional needle inserted 5mm into the skin. This suggests that the usage of microneedles in arrays is necessary to increase stability and to enable stable drug delivery.link_to_subscribed_fulltex

Comparison of systemic responses of radiofrequency ablation, cryotherapy, and surgical resection in a porcine liver model

Background: The degree of systemic response after hepatic radiofrequency ablation (RFA) has not been well investigated. Methods: An in vivo study was conducted on 23 domestic swine. Different hepatic procedures (RFA, cryotherapy, hepatic pedicle ligation, and hepatectomy) were performed on the medial lobe of the liver (30% of the liver volume). Systemic responses in terms of systemic inflammatory marker changes and end-organ functions were determined. Results: During the early postoperative period, the systemic inflammatory marker concentrations (tumor necrosis factor-α and interleukin-1β) in the RFA group were significantly lower than in the cryotherapy group but significantly higher than in the control group. The corresponding concentrations in the hepatectomy group remained similar to those in the control group. The pattern of changes of serum inflammatory marker concentrations in the pedicle ligation group followed the pattern in the RFA group. The serum intracellular content concentrations (lactate dehydrogenase and urate) of the cryotherapy group peaked at 6 hours after operation, which was significantly later than in the other groups. Liver function, renal function, and coagulation profiles remained normal in the RFA group. However, the renal function deteriorated in the cryotherapy group on day 1. Both platelet count and activated clotting time showed significant derangement in the cryotherapy group compared with the control group. There was more severe interstitial pneumonitic change of the porcine lung after cryotherapy than after RFA. Conclusions: The systemic responses of RFA were significantly less severe than those of cryotherapy in this porcine model. However, the increase in serum inflammatory markers and pneumonitis after RFA was substantial when compared with hepatectomy. © 2004 The Society of Surgical Oncology, Inc.link_to_subscribed_fulltex

Porcine liver: Morphologic characteristics and cell viability at experimental radiofrequency ablation with internally cooled electrodes

PURPOSE: To evaluate morphologic characteristics and cell viability of radiofrequency ablation zones in porcine liver. MATERIALS AND METHODS: Approval of the study protocol was obtained from the Ethics Committee on Use of Live Animals for Teaching and Research at University of Hong Kong. Internally cooled electrodes were used to produce 120 ablated zones ex vivo and 60 ablated zones in vivo with single electrodes (1-, 2-, and 3-cm exposed lengths) or clustered electrodes (1.0-, 2.0-, and 2.5-cm exposed lengths) at 4, 8, 12, and 16 minutes of ablation (ex vivo) and 8 and 12 minutes of ablation (in vivo). Morphologic measurements of each ablated zone were performed. Cell viability in each ablated zone was assessed qualitatively with histochemical staining and quantitatively with measurement of intracellular adenosine 5′-triphosphate (ATP) concentration. RESULTS: Exposed length of electrode (coefficient = 0.79, standard error = 0.04, P < .001), duration of ablation (coefficient = 0.14, standard error = 0.01, P < .001), and clustered electrode design (coefficient = 1.21, standard error = 0.05, P < .001) were independent factors that affected minimal transverse diameter and volume of ablated zone in ex vivo study. Similar morphologic characteristics existed among ablated zones in in vivo study. Mean distance of ablation beyond the electrode tip remained constant (ex vivo, 1.0 cm ± 0.08 [standard deviation]; in vivo, 0.5 cm ± 0.05) regardless of different ablation conditions. Histochemical staining revealed no viable hepatocytes from center to margins of white zone in each ablated area. Mean intracellular ATP concentration in margins of white zone (9.5 × 10-12 mol/μg DNA ± 1.43) was lower than that in red zone (4088 × 10-12 mol/μg DNA ± 65.97, P < .001) and in adjacent normal liver (4528 × 10-12 mol/μg DNA ± 52.74, P < .001). CONCLUSION: Distance of ablation beyond the tip of the electrode remained constant (ex vivo, 1.0 cm; in vivo, 0.5 cm) with different conditions of ablation. Complete and uniform cellular destruction was achieved in the white zone of ablated area. © RSNA, 2005.link_to_subscribed_fulltex