1.Surveillance of Aedes mosquitoes in a university campus in Kuala Lumpur, Malaysia.
O Wan Norafikah ; C D Chen ; H N Soh ; H L Lee ; W A Nazni ; M Sofian Azirun
Tropical biomedicine 2009;26(2):206-15
Ovitrap surveillance was initiated for eight continuous weeks to determine the distribution and abundance of Aedes sp. mosquitoes in the University of Malaya campus, Kuala Lumpur, and the impact of meteorological conditions on the Aedes populations. Two study areas within the campus were selected: Varsity Lake and Seventh Residential College. The abundance of Aedes populations in Varsity Lake was indicated by ovitrap index (OI) which ranged from 60.00% - 90.00%. The mean number of larvae per ovitrap of Aedes albopictus in Varsity Lake ranged from 11.23 +/- 2.42 - 43.80 +/- 6.22. On the other hand, the outdoor OI for Seventh Residential College ranged from 73.33% - 93.33%, respectively, while the mean number larvae per ovitrap for this area ranged from 19.33 +/- 4.55 - 35.27 +/- 5.46, respectively. In addition, the indoor OI of Seventh Residential College ranged from 0.00% - 30.00%, while the mean number of larvae per ovitrap for Ae. albopictus ranged from 0 - 5.90 +/- 3.55. There was no significant difference (p > 0.05) of Ae. albopictus population between Varsity Lake and Seventh Residential College. The studies showed a correlation between OI and mean number of larvae per ovitrap for outdoor Ae. albopictus populations in Varsity Lake and Seventh Residential College (r = 0.794). There was also a correlation between the mean larvae number per ovitrap of Ae. albopictus obtained from eight weeks indoor ovitrap surveillance in Seventh Residential College with rainfall (r = 0.584). However, there was no correlation between the mean larvae number per ovitrap of Ae. albopictus in both study areas with temperature and relative humidity. Aedes aegypti mosquitoes were found neither indoor nor outdoor in both study areas. This study indicated that the principal dengue vector in the university campus was most likely Ae. albopictus.
College
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Seventh
;
Lake
;
Aedes
;
seconds
2.Prophylactic Dual Catheter Technique to Prevent Side Branch Snowplowing Complications during Angioplasty and Stenting.
Leonard LL YEO ; W M WU ; Y L CHEN ; C H YEH ; H F WONG
Journal of Cerebrovascular and Endovascular Neurosurgery 2017;19(1):12-18
OBJECTIVE: Angioplasty and Stenting of intracranial atherosclerotic lesions have a higher complication rate and a large proportion of this is attributable to side branch arterial occlusion from forceful displacement of the atheroma into the ostia or snowplowing effect. This can result in severe disabilities when it result in small infarcts involving eloquent areas in the posterior circulation or the motor tracts. MATERIALS AND METHODS: We present a series of 6 cases utilizing a new dual catheter technique for maintaining the patency of at-risk vessels during angioplasty and stenting. There are several methods previously described to help reduce the incidence of stroke but because they do not have a physical presence in the ostia to protect it, they are unable to guarantee the patency of the vessel. RESULTS: All 6 patients underwent angioplasty and stenting with the technique. The patients were assessed for complications with post-procedure magnetic resonance imaging and no complications were found. CONCLUSION: In this preliminary series, the dual catheter technique appears to safe and effective in preventing occlusion of the adjacent branch arteries. This technique may facilitate the use of the Wingspan stent in the treatment of intracranial atherosclerotic stenotic segments by reducing the risk of peri-procedural stroke.
Angioplasty*
;
Arteries
;
Catheters*
;
Humans
;
Incidence
;
Magnetic Resonance Imaging
;
Plaque, Atherosclerotic
;
Stents*
;
Stroke
3.Quantifying the duration of the preclinical detectable phase in cancer screening: a systematic review
Sandra M. E. GEURTS ; Anne M. W. M. AARTS ; André L. M. VERBEEK ; Tony H. H. CHEN ; Mireille J. M. BROEDERS ; Stephen W. DUFFY
Epidemiology and Health 2022;44(1):e2022008-
OBJECTIVES:
The aim of this study was to provide an overview of published mathematical estimation approaches to quantify the duration of the preclinical detectable phase (PCDP) using data from cancer screening programs.
METHODS:
A systematic search of PubMed and Embase was conducted for original studies presenting mathematical approaches using screening data. The studies were categorized by mathematical approach, data source, and assumptions made. Furthermore, estimates of the duration of the PCDP of breast and colorectal cancer were reported per study population.
RESULTS:
From 689 publications, 34 estimation methods were included. Five distinct types of mathematical estimation approaches were identified: prevalence-to-incidence ratio (n=8), maximum likelihood estimation (n=16), expectation-maximization algorithm (n=1), regression of observed on expected (n=6) and Bayesian Markov-chain Monte Carlo estimation (n=5). Fourteen studies used data from both screened and unscreened populations, whereas 19 studies included only information from a screened population. Estimates of the duration of the PCDP varied between 2 years and 7 years for breast cancer in the Health Insurance Plan study (annual mammography and clinical breast examinations in women aged 40-64 years) and 2 years and 5 years for colorectal cancer in the Calvados study (a guaiac fecal occult blood test in men and women aged 45-74 years).
CONCLUSIONS
Different types of mathematical approaches lead to different estimates of the PCDP duration. We advise researchers to use the method that matches the data available, and to use multiple methods for estimation when possible, since no method is perfect.
4.Post community hospital discharge rehabilitation attendance: Self-perceived barriers and participation over time.
Abel W L CHEN ; Yan Tong KOH ; Sean W M LEONG ; Louisa W Y NG ; Patricia S Y LEE ; Gerald C H KOH
Annals of the Academy of Medicine, Singapore 2014;43(3):136-144
INTRODUCTIONThis study aimed to examine the attendance rates of post-discharge supervised rehabilitation as recommended by the multidisciplinary team at discharge among subacutely disabled adults and the barriers preventing adherence.
MATERIALS AND METHODSPatients were from a community hospital, aged 40 years or older. They had been assessed by a multidisciplinary team to benefit from rehabilitation after discharge, were mentally competent and communicative. We used a sequential qualitative-quantitative mixed methods study design. In the initial qualitative phase, we studied the patient-perceived barriers to adherence to rehabilitation using semi-structured interviews. Emerging themes were then analysed and used to develop a questionnaire to measure the extent of these barriers. In the subsequent quantitative phase, the questionnaire was used with telephone follow-up at 3, 6, 9 and 12 months after discharge.
RESULTSQualitative phase interviews (n = 41) revealed specific perceived financial, social, physical and health barriers. At the start of the quantitative phase (n = 70), 87.1% of the patients viewed rehabilitation as beneficial, but overall longitudinal attendance rate fell from 100% as inpatient to 20.3% at 3 months, 9.8% at 6 months, 6.3% at 9 months and 4.3% at 12 months. The prevalence of physical and social barriers were high initially but decreased with time. In contrast, the prevalence of financial and perceptual barriers increased with time.
CONCLUSIONAttendance of post-hospitalisation rehabilitation in Singapore is low. Self-perceived barriers to post-discharge rehabilitation attendance were functional, social, financial and perceptual, and their prevalence varied with time.
Adult ; Aged ; Aged, 80 and over ; Female ; Health Services Accessibility ; Hospitals, Community ; Humans ; Male ; Middle Aged ; Patient Compliance ; Patient Discharge ; Qualitative Research ; Rehabilitation ; Self Concept ; Surveys and Questionnaires ; Time Factors
5.Progress of research on the association between air pollution and prevalence of major cancers.
Z X YANG ; H M ZENG ; R S ZHENG ; C F XIA ; S W ZHANG ; W Q CHEN
Chinese Journal of Epidemiology 2018;39(4):532-535
Being an undisputed risk factor of cancer, air pollution is posing a huge threat to the health on human beings. In this article, we introduced the composition of air pollution, and the standards on air quality which was set by both World Health Organization and the Chinese government. We also summarized the most recent research findings on the association between air pollution and the risk of lung, breast, bladder and other major cancers.
Air Pollutants/toxicity*
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Air Pollution/adverse effects*
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Humans
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Neoplasms/epidemiology*
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Prevalence
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Research/trends*
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Risk Factors
6.Thrombotic thrombocytopenic purpura in pediatric patients.
Melanie STEELE ; Howard H W CHEN ; Jeremy STEELE ; Anthony K C CHAN ; Keith K LAU
Chinese Journal of Contemporary Pediatrics 2012;14(11):803-810
Although thrombotic thrombocytopenic purpura (TTP) is rarely seen in pediatric patients, failure to recognize this condition often leads to severe consequences and poor outcomes. Classic features of TTP include thrombocytopenia, microangiopathic hemolytic anemia, acute kidney injury, fever, and central nervous system involvement. However, patients suffering from this condition may not present with all of the symptoms simultaneously. Therefore, it is of utmost importance for healthcare providers to have a high index of suspicion. Laboratory investigations may reveal the presence of schistocytes on peripheral blood smear, negative Coombs test, high lactate dehydrogenase levels and severely low platelet counts. The etiology of TTP is mainly due to insufficient cleavage of the large multimers of von Willebrand factor (vWF) secondary to decreased activity of ADAMTS13 (a disintegrin and metalloprotease with Thrombospondin type 1 repeats, member 13). TTP can be broadly classified into familial TTP (Upshaw Schulman syndrome) and non-familial TTP. Familial TTP is due to a congenital deficiency of ADAMTS13. Its mainstay of therapy is initiation of plasmapheresis during the acute phase, followed by regular fresh frozen plasma (FFP) infusions. Alternatively, non-familial TTP is due to a decrease in ADAMTS13 activity secondary to the presence of anti-ADAMTS13 antibodies. Once again, the primary treatment is plasmapheresis; however, recent anecdotal data also supports the use of rituximab in select cases.
ADAM Proteins
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genetics
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ADAMTS13 Protein
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Antibodies, Monoclonal, Murine-Derived
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therapeutic use
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Child
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Humans
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Plasmapheresis
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Purpura, Thrombotic Thrombocytopenic
;
etiology
;
therapy
;
Rituximab
7.Patent blue dye in lymphaticovenular anastomosis.
Yan Lin YAP ; Jane LIM ; Timothy W H SHIM ; Shenthilkumar NAIDU ; Wei Chen ONG ; Thiam Chye LIM
Annals of the Academy of Medicine, Singapore 2009;38(8):704-706
INTRODUCTIONLymphaticovenular anastomosis (LVA) has been described as a treatment of chronic lymphoedema. This microsurgical technique is new and technically difficult. The small caliber and thin wall lymphatic vessels are difficult to identify and easily destroyed during the dissection.
MATERIALS AND METHODSWe describe a technique of performing lymphaticovenular anastomosis with patent blue dye enhancement. Our patient is a 50-year-old lady who suffers from chronic lymphoedema of the upper limb after mastectomy and axillary clearance for breast cancer 8 years ago.
RESULTSPatent blue dye is injected subdermally and is taken up readily by the draining lymphatic channels. This allows for easy identification of their course. The visualisation of the lumen of the lymphatic vessel facilitates microsurgical anastomosis. The patency of the anastomosis is also demonstrated by the dynamic pumping action of the lymphatic within the vessels.
CONCLUSIONPatent blue dye staining during lymphaticovenular anastomosis is a simple, effective and safe method for mapping suitable subdermal lymphatics, allowing for speedier dissection of the lymphatic vessels intraoperatively. This technique also helps in the confirmation of the success of the lymphaticovenular anastomosis.
Anastomosis, Surgical ; methods ; Coloring Agents ; Female ; Humans ; Lymphatic Metastasis ; Lymphatic Vessels ; Lymphedema ; etiology ; surgery ; Mastectomy ; adverse effects ; Microsurgery ; methods ; Middle Aged ; Rosaniline Dyes ; Sentinel Lymph Node Biopsy
8.The inhibitory effect of tamoxifen on human dermal fibroblast-populated collagen lattices.
Dahai HU ; Xiongxiang ZHU ; Mingda XU ; Bi CHEN ; A H MARGARET ; W C GEORGE
Chinese Journal of Plastic Surgery 2002;18(3):160-162
OBJECTIVETo investigate the potential therapeutic effect of tamoxifen in treating abnormal skin scar contraction.
METHODSFibroblast-populated collagen lattices, which were made by embedding human dermal fibroblasts within type I collagen forming a three-dimensional culture system, were used as an invitro model. Then media either without or with addition of tamoxifen from 1 mumol/L to 50 mumol/L were added to the collagen lattices. Lattice areas were measured at intervals to assess the influence of tamoxifen on the lattice contraction. To visualize changes in the morphology and vitality of fibroblasts, MTT was added to the lattices.
RESULTSTamoxifen had an inhibitory effect on lattice contraction by a dose- and time-dependent pattern. 5 mumol/L or less of tamoxifen didn't show any influence on lattice contraction but 30 mumol/L or higher completely inhibited contraction. At intermediate concentrations from 10 mumol/L to 20 mumol/L the degree of lattice contraction was dose- and time-dependent, which was demonstrated by the reversibility of inhibition. Both the inhibition of contraction and the reversibility of inhibition appeared to correlate with changes in fibroblast morphology.
CONCLUSIONTamoxifen could inhibit the contraction of fibroblast-populated collagen lattices, indicating that tamoxifen may have potential effect on abnormal scar contraction in vivo.
Cicatrix ; drug therapy ; Collagen ; physiology ; Dose-Response Relationship, Drug ; Fibroblasts ; drug effects ; physiology ; Humans ; Skin ; cytology ; drug effects ; Tamoxifen ; pharmacology ; therapeutic use ; Time Factors
9.Epidemiological and pathogenic characteristics of mumps in Fujian province, 2005-2017.
D LI ; Z F CHEN ; X H YANG ; W Y PAN ; Q WANG ; S H ZHANG ; N X ZHENG ; L F HUANG ; Y ZHOU
Chinese Journal of Epidemiology 2018;39(10):1356-1361
Objective: To understand the epidemiological and etiological characteristics of mumps in Fujian province, 2005-2017. Methods: All the reported mumps cases were collected through the National Notifiable Disease Information Management System, 2005-2017. Active search and interviews were conducted to collect the information on vaccination of mumps. Throat swab specimens were collected for cells culture, genotyping and gene sequence analysis on mumps virus (MuV). Results: A total of 83 959 cases of mumps were reported in Fujian province from 2005 to 2017, with an average annual incidence of 17.6 per 100 000. Since 2007, the incidence appeared increasing but then decreasing, reaching the lowest level (7.5 per 100 000), after the setup of a monitoring program. Annually, the onset time of mumps showed an obvious two seasonal peaks, one from April to July, with a weakening trend, and the other from October to January with a rising trend. Most of the mumps cases occurred among students, kindergarten and scattered children (89.2%, 5 814/6 517), children aged 5-9 years (38.8%, 2 527/6 517), with cases reported from every region. Program from the pathogen surveillance showed that the transmission chain of G genotype mumps virus did exist in Fujian. Data from the sequence analysis revealed that mutations in the nucleotide of G genotype strain in 2015 had led to mutation of 6 amino acid sites in the SH gene coding region, resulting in the differences appearing in both nucleotide and amino acid homology with type A vaccine strain. Conclusions: The incidence of mumps decreased annually, in Fujian. Prevention programs should focus on primary and secondary school students. In Fujian province, we also noticed the transmission chain of mumps G genotype with some amino acid mutations in the SH gene coding region. Monitor programs on both epidemiologic and etiology, should be strengthened.
Child
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Child, Preschool
;
China/epidemiology*
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Genotype
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Humans
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Incidence
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Mumps/epidemiology*
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Mumps virus/pathogenicity*
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Phylogeny
;
Sequence Analysis
10.Suicidal ideation in medical students: who is at risk?
Angela P C FAN ; Russell O KOSIK ; Greg A MANDELL ; Dong Trieu TRAN ; Hao Min CHENG ; Chen Huan CHEN ; Tung-Pying SU ; Allen W H CHIU
Annals of the Academy of Medicine, Singapore 2012;41(9):377-382
INTRODUCTIONSuicide is one of the most tragic problems medical schools are facing today. It is an issue that has not escaped medical schools in either developing or developed nations. To combat this trend, medical educators require efficient and effective strategies for the immediate identification of students who are at an elevated risk of harming themselves.
MATERIALS AND METHODSNational Yang Ming University medical students were surveyed on various demographic, academic, personal, and extracurricular subjects as well as assessed for suicidal ideation. In addition, students completed the Chinese Health Questionnaire (CHQ, a translated and modified version of the General Health Questionnaire, GHQ), and the Taiwanese Depression Questionnaire (TDQ, a translated and modified version of the Center for Epidemiologic Studies' Depression Scale, CES-D).
RESULTSThe rate of suicidal ideation was significantly higher in second year students as opposed to fi rst year students (P <0.01). Students of lower socioeconomic status (P = 0.04), with non-inflammatory joint pain (P = 0.02), with headache (P = 0.047), with sleep disorders (P = 0.04), who scored as depressed on the TDQ (P <0.01), and/or who scored abnormally on the CHQ (P <0.01) were all significantly more likely to have experienced suicidal ideation.
CONCLUSIONA number of groups at high risk for suicidal ideation, and thus in greater need of support, were identified. Suicide intervention programmes and depression counselling should target older students and students of lower socioeconomic status. Students presenting to university clinics with non-inflammatory joint pain, headache, and/or sleep disorders should be evaluated for suicidal tendencies. The TDQ and CHQ are potentially valuable screening tests for early detection of potential suicidal students.
Adaptation, Psychological ; Adult ; Depression ; epidemiology ; psychology ; Female ; Humans ; Male ; Psychometrics ; Risk Assessment ; methods ; Social Class ; Statistics as Topic ; Stress, Psychological ; epidemiology ; psychology ; Students, Medical ; psychology ; Suicidal Ideation ; Surveys and Questionnaires ; Young Adult