14 research outputs found

    Geomechanical model testing of surface rupture and bridge damage produced by discontinuous reverse faults

    Get PDF
    2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Cytochrome P450 CYP1B1 activity in renal cell carcinoma

    Get PDF
    Renal cell carcinoma (RCC) is the most common malignancy of the kidney and has a poor prognosis due to its late presentation and resistance to current anticancer drugs. One mechanism of drug resistance, which is potentially amenable to therapeutic intervention, is based on studies in our laboratory. CYP1B1 is a cytochrome P450 enzyme overexpressed in a variety of malignant tumours. Our studies are now elucidating a functional role for CYP1B1 in drug resistance. Cytochrome P450 reductase (P450R) is required for optimal metabolic activity of CYP1B1. Both CYP1B1 and P450R can catalyse the biotransformation of anticancer drugs at the site of the tumour. In this investigation, we determined the expression of CYP1B1 and P450R in samples of normal kidney and RCC (11 paired normal and tumour and a further 15 tumour samples). The O-deethylation of ethoxyresorufin to resorufin was used to measure CYP1B1 activity in RCC. Cytochrome P450 reductase activity was determined by following the reduction of cytochrome c at 550 nm. The key finding of this study was the presence of active CYP1B1 in 70% of RCC. Coincubation with the CYP1B1 inhibitor alpha-naphthoflavone (10nM) inhibited this activity. No corresponding CYP1B1 activity was detected in any of the normal tissue examined (n = 11). Measurable levels of active P450R were determined in all normal (n = 11) and tumour samples (n = 26). The presence of detectable CYP1B1, which is capable of metabolising anticancer drugs in tumour cells, highlights a novel target for therapeutic intervention

    Network analysis of depressive symptoms in Hong Kong residents during the COVID-19 pandemic

    Get PDF
    In network theory depression is conceptualized as a complex network of individual symptoms that influence each other, and central symptoms in the network have the greatest impact on other symptoms. Clinical features of depression are largely determined by sociocultural context. No previous study examined the network structure of depressive symptoms in Hong Kong residents. The aim of this study was to characterize the depressive symptom network structure in a community adult sample in Hong Kong during the COVID-19 pandemic. A total of 11,072 participants were recruited between 24 March and 20 April 2020. Depressive symptoms were measured using the Patient Health Questionnaire-9. The network structure of depressive symptoms was characterized, and indices of “strength”, “betweenness”, and “closeness” were used to identify symptoms central to the network. Network stability was examined using a case-dropping bootstrap procedure. Guilt, Sad Mood, and Energy symptoms had the highest centrality values. In contrast, Concentration, Suicide, and Sleep had lower centrality values. There were no significant differences in network global strength (p = 0.259), distribution of edge weights (p = 0.73) and individual edge weights (all p values > 0.05 after Holm–Bonferroni corrections) between males and females. Guilt, Sad Mood, and Energy symptoms were central in the depressive symptom network. These central symptoms may be targets for focused treatments and future psychological and neurobiological research to gain novel insight into depression

    The acute effects of cigarette smoke exposure on muscle fiber type dynamics in rats

    No full text
    202008 bcrcVersion of RecordRGCOthersRGC: 1-ZVFMOthers: 5-ZH1NPublishe

    Impact of common contraceptive methods on quality of life and sexual function in Hong Kong Chinese women

    No full text
    The combined oral contraceptive (COC) pills, injectables, intrauterine contraceptive device (IUCD) and female sterilization are the most common contraceptive methods used by women. Women's choice, compliance and satisfaction with specific contraceptive methods are influenced by any impact of the method on their quality of life and sexual function. Anxiety regarding possible adverse effects of the contraceptive methods on their quality of life and sexual function is one of the common concerns. The aim of this prospective observational study was to determine the impact of the abovementioned contraceptive methods on the quality of life and sexual function of the users. A sample of 361 Hong Kong Chinese women who were first-time users of the following contraceptive methods completed the study: COC pills (n=87), injectables (n=67), IUCD (n=96) and female sterilization (n=111). Quality of life and sexual function of the subjects were assessed before and 3-4 months after use of the method by a standardized questionnaire. The questions were adopted from the validated Chinese versions of the World Health Organization Quality of Life (WHOQOL) questionnaire and the Derogatis Sexual Functioning Inventory (DSFI). In the female sterilization group, we found a significantly higher score for sexual satisfaction (p=.004) and sexual drive (p=.003) 3-4 months after sterilization, as well as an improved WHOQOL social domain score (p=.009). However, the other DSFI subscale scores and WHOQOL domain scores were not significantly different (p>.05). No significant difference was demonstrated in all the WHOQOL domain scores and DSFI subscale scores after use of COC pills, injectables and IUCD (p>.05). We conclude that the COC pills, injectables, IUCD and female sterilization all do not have significant adverse impact on quality of life and sexual function. After female sterilization, there is a significant improvement in sexual satisfaction and sexual drive. © 2004 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

    Clinical and prognostic significance of human papillomavirus in a Chinese population of cervical cancers

    No full text
    Objective: To investigate the clinical and prognostic significance of human papillomavirus (HPV) in a Chinese population of cervical cancers. Methods: We studied 121 cervical cancer tissue samples from patients treated at our hospital. Identification and typing of HPV were done by polymerase chain reaction (PCR) using consensus primers MY11 and MY09 followed by direct DNA sequencing. The results were correlated with various clinical and prognostic parameters. Results: We found HPV DNA in 95 (78.5%) cases, including HPV-16 in 59 (48.8%) and HPV-18 in 14 (11.6%) cases. χ 2 analysis revealed no significant correlation between the presence of HPV DNA and age at diagnosis, clinical stage, histologic type, tumor grading, 2-year and 5-year survival rate. Of the factors evaluated, age at diagnosis and histologic type were found to have a statistically significant relationship with HPV type. The mean age of the HPV-18 group was 48.6 years compared to 57.1 years for the HPV-16 group (p = 0.045) and 58.2 years for the HPV-negative group (p = 0.04). HPV-18 was detected more often in adenocarcinomas (AC) than in squamous cell carcinomas (SCC). Conversely HPV-16 was detected significantly more often in SCC (p < 0.0001). The HPV-negative group also had a higher incidence of SCC (p = 0.007). HPV-18-positive patients seemed to have more nodal involvement than both HPV-16-positive patients (45.5 vs. 20.8%) and HPV-negative patients (45.5 vs. 18.2%); however, it did not reach statistical significance. Conclusions: These observations suggest that the presence of HPV DNA does not bear any clinical or prognostic significance in a Chinese population of cervical cancers. HPV-18 is found more often in younger patients and is associated with AC. Copyright © 2001 S. Karger AG, Basel.link_to_subscribed_fulltex

    The role of microsatellite instability in cervical intraepithelial neoplasia and squamous cell carcinoma of the cervix

    No full text
    Objectives. This study was conducted to define the role of microsatellite instability (MSI) in cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC) of the cervix. We also tested the validity of using markers recommended for MSI study in colonic carcinoma by the National Cancer Institute (NCI) for cervical neoplasm. Methods. Twenty normal cervical, 24 low-grade CIN (CIN-L), 59 high-grade CIN (CIN-H), and 93 SCC tissues were examined for MSI after microdissection. A polymerase chain reaction based MSI detection was performed using five markers recommended by the NCI for colonic cancer (panel one) as well as five other markers (panel two) found to be informative in earlier studies. High-frequency MSI (MSI-H) was defined as instability in ≥2 of 5 loci if one panel was used and ≥30% of loci when more than five loci were used. Low-frequency MSI (MSI-L) was diagnosed if instability was noted but did not meet the criteria of MSI-H. Findings were correlated with clinicopathologic information. Results. The combined use of panel one and two markers showed no MSI in normal cervical or CIN-L tissue, MSI-L in 1 CIN-H (1.7%), MSI-L in 16 (17.2%), and MSI-H in 11 (11.8%) SCC, respectively. The NCI-recommended panel alone detected 19 of 27 MSI-positive SCC. MSI-positive was not related to patient age, disease stage, and tumor grade. The overall survival of MSI-positive patients was significantly worse than that of microsatellite stable patients (P = 0.02). An increasing trend of MSI-H rate with higher disease stages was noted (P = 0.035) but MSI-H was not associated with poor prognosis. Conclusions. The NCI recommended panel of markers might not be useful in MSI study for SCC and using more than five markers improves the MSI detection. MSI is rare in cervical dysplasia but is present in a subset of SCC. The association between MSI-positivity and prognosis awaits future confirmation. © 2003 Elsevier Science (USA). All rights reserved.link_to_subscribed_fulltex
    corecore