Crack propagation in brittle solid containing 3D surface fracture under uniaxial compression

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Rapid-eye-movement-sleep (REM) associated enhancement of working memory performance after a daytime nap

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M30 Antagonizes Indoleamine 2,3-Dioxygenase Activation and Neurodegeneration Induced by Corticosterone in the Hippocampus

Monoamine oxidases (MAO), downstream targets of glucocorticoid, maintain the turnover and homeostasis of monoamine neurotransmitters; yet, its pathophysiological role in monoamine deficiency, oxidative stress and neuroinflammation remains controversial. Protective effects of M30, a brain selective MAO inhibitor with iron-chelating antioxidant properties, have been shown in models of neurodegenerative diseases. This study aims to examine the neuroprotective mechanism of M30 against depressive-like behavior induced by corticosterone (CORT). Sprague-Dawley rats were given CORT subcutaneous injections with or without concomitant M30 administration for two weeks. CORT-treated rats exhibited depressive-like behavior with significant elevated levels of MAO activities, serotonin turnover, oxidative stress, neuroinflammation and apoptosis in the hippocampus with significant losses of synaptic proteins when compared to the control. The expression and activity of cytokine-responsive indoleamine 2,3-dioxygenase (IDO-1), a catabolic enzyme of serotonin and tryptophan, was significantly increased in the CORT-treated group with lowered levels of serotonin. Besides, CORT markedly reduced dendritic length and spine density. Remarkably, M30 administration neutralized the aberrant changes in the hippocampus and prevented the induction of depressive-like behavior induced by CORT. Our results suggest that M30 is neuroprotective against CORT-induced depression targeting elevated MAO activities that cause oxidative stress and neuroinflammation, resulting in IDO-1 activation, serotonin deficiency and neurodegeneration.published_or_final_versio

Biomedical service - towards the 10th year anniversary

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Women's sexuality after termination of pregnancy in Hong Kong Chinese

Objective: Our aim is to determine sexuality after termination of pregnancy (TOP) in Hong Kong Chinese. Design: This was a prospective study using self-administered questionnaires given before and eight weeks after abortion. Subjects: Women over age 18 years old requesting TOP were invited to participate in the study during the period 6 December 2005 to 28 March 2006. Main outcome measures: Sexual function, couple relationship and psychological well-being like depression and post-traumatic stress disorder (PTSD) were assessed. Contraception was also reviewed. Results: No significant change in the number of women who presented with sexual dysfunctions before and after abortion. However, women reported subjective decrease in sexual functions after TOP, ranging from 9.8% for those with increased vaginal pain to 24.5% for those with decreased sexual desire. Majority of them (74.8%) suffered from at least moderate degree of post-traumatic stress symptoms and 10.2% had symptoms suggestive of the presence of a PTSD. Significant associations were seen in subjective decrease of sexual functions with post-traumatic stress symptoms after termination of pregnancy. On the other hand, 41.6% felt less depressed after abortion. There was no significant change in couple relationship after abortion. Conclusion: Termination of pregnancy did not cause sexual dysfunctions. However, significant proportion of women did suffer from decreased sexual functions subjectively which may be due to stress related to unplanned pregnancy or the TOP. The abortion itself did not cause depression and women who had completed family were less depressed after abortion. Post-traumatic stress was prevalent in those having abortion and the symptoms were associated with the subjective decrease in sexual functions.published_or_final_versio

Are L-myc genotypes prognostic markers in non-small cell lung carcinoma (NSCLC) in our Chinese patients?

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Wnt-C59 arrests stemness and suppresses growth of nasopharyngeal carcinoma in mice by inhibiting the Wnt pathway in the tumor microenvironment

Wnt/β-catenin signaling is responsible for the generation of cancer stem cells (CSCs) in many human tumors, including nasopharyngeal carcinoma (NPC). Recent studies demonstrate that Wnt or PORCN inhibitor, Wnt-C59, inhibits tumor growth in MMTV-WNT1 transgenic mice. The effect of Wnt-C59 in human tumors is not clear. In this study, the NPC cell lines investigated manifest heterogeneous responses to Wnt-C59 treatment. Wnt-C59 decreased tumor growth of SUNE1 cells in mice immediately following the administration of Wnt-C59. Mice injected with HNE1 cells did not develop visible tumors after the treatment of Wnt-C59, while control mice developed 100% tumors. Wnt-C59 inhibited stemness properties of NPC cells in a dosage-dependent manner by arresting sphere formation in both HNE1 and SUNE1 cells. Thus, Wnt-C59 has the potential to eradicate CSCs in human tumors. Active β-catenin and Axin2 proteins were strongly expressed in stromal cells surrounding growing tumors, confirming the importance of Wnt signaling activities in the microenvironment being driving forces for cell growth. These novel findings confirm the ability of Wnt-C59 to suppress Wnt-driven undifferentiated cell growth in NPC. Both anti-Wnt signaling and anti-CSC approaches are feasible strategies in cancer therapy.published_or_final_versio

P53 intron 2 polymorphisms and mutations in non-small cell lung carcinoma in Hong Kong

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Comparing the use and content of antenatal care in adolescent and older first-time mothers in 13 countries of west Africa: a cross-sectional analysis of Demographic and Health Surveys

Background West Africa has the highest proportion of married adolescents, and the highest adolescent childbirth rate and maternal death rate in sub-Saharan Africa. However, few studies have focused on the type and quality of health care accessed by pregnant young women in countries in this subregion. Methods We obtained data from Demographic and Health Surveys done between 2010 and 2014, to compare the use, timing, source, and components of antenatal care between adolescent and older first-time mothers in 13 west African countries. The sample included primiparous women who were aged 15–49 years with a livebirth in the 5-year survey recall period, and women were assigned to one of three groups on the basis of age at the time of childbirth: adolescent (10–19 years), young adults (20–24 years), or adults (25 years or older). We calculated the percentage of women who: attended at least one antenatal care visit, completed at least one visit during the first trimester of pregnancy, attended four or more appointments in antenatal care, and received four components of antenatal care (blood pressure measurement, urine tests, blood tests, and information on complications), as well as the sector where the women received care. We primarily report the comparison between adolescents and young adults. Findings In 2016, we acquired data from the Demographic Health Surveys from 13 west African countries between 2010 and 2014 on primiparous women. The study sample was 19 211 women, of whom 10 025 (52%) were adolescents, 6099 (32%) were young adults, and 3087 (16%) were adults. Overall, 17 386 (91%) of 19 211 first-time mothers made use of antenatal care facilities on at least one occasion. 3597 (41%) of 8741 adolescents compared with 8202 (47%) of all 17 386 women began the use of antenatal care during the first trimester. Across west Africa, 5430 (62%) of 8741 adolescents had four or more antenatal care visits compared with 4067 (71%) of 5717 young adults and 2358 (81%) of 2928 adults. Of those who had four or more visits to antenatal care, 2779 (51%) of 5430 adolescents received all the antenatal care components examined compared with 2488 (61%) of 4067 young adults and 1600 (68%) of 2358 adults. Although most women received antenatal care in the public sector, in nine of the 13 countries, the proportion of women that used the private sector was higher in older mothers. Interpretation Although a large percentage of west African adolescents use some antenatal care for their first birth, they seek care later, make fewer visits during pregnancy, and receive fewer components of care than older first-time mothers. Governments must ensure the pregnancy care accessed by adolescent mothers is of high quality and tailored to meet their needs

Adverse effects if TERT-CLPTM1L and double-strand breaks repair contribute to risk for NPC

Epidemiology - Poster Presentations - Proffered Abstracts - Poster Presentations - Molecular and Genetic Epidemiology of Lung, Head and Neck, and Gastrointestinal Cancers: abstract no. 4148This journal suppl. entitled: Proceedings: AACR Annual Meeting 2014; April 5-9, 2014 ...BACKGROUND AND AIMS: The genetic etiology of NPC and mechanisms for inherited susceptibility remain unclear. Only modest low-penetrance effects of cancer-predisposing common variant SNPs were previously identified in the few large-scale NPC association studies reported. Most NPC association studies focused on single or limited candidate genes with modest sample sizes. Systematic and comprehensive study designs for evaluation of higher order gene-gene interactions are scanty. A large-scale NPC case-control SNP association study was performed to examine the genetic risk factors for NPC development. In order to elucidate the ...postprin