1.Sample Preparation and Imaging of Single Adenovirus Particle Using Atomic Force Microscopy in Liquid.
Yan LIANG ; Li CHEN ; Mariska G M van ROSMALEN ; Gijs J L WUITE ; Wouter H ROOS
Chinese Journal of Virology 2015;31(6):601-606
Atomic force microscopy (AFM), as a sophisticated imaging tool with nanoscale resolution, is widely used in virus research and the application of functional viral particles. To investigate single viruses by AFM in a physiologically relevant environment (liquid), an appropriate surface treatment to properly adhere the viruses to the substrate is essential. Here we discuss hydrophobic treated glass coverslips as a suitable substrate for the adhesion of single adenovirus particle (Adenovirus type 5 F35, Ad5F35) when studied with AFM in liquid. From the high resolution AFM images, the orientation of the adhered virus particles can be distinguished. Furthermore, the particles exhibit the expected height of -90 nm. This illustrates that the viruses adhere to the substrate firmly without large deformations. Hence, the described method works well on (fragile) viruses. The described experimental approach can be widely used for AFM studies in liquid of virus structure and mechanics as well as for investigating the interaction of viruses with cellular receptors.
Adenoviridae
;
chemistry
;
Imaging, Three-Dimensional
;
Microscopy, Atomic Force
;
methods
;
Virion
;
chemistry
2.Stratified sampling survey of major human parasitic diseases in Henan province.
B L XU ; H W ZHANG ; Y DENG ; Z L CHEN ; W Q CHEN ; D L LU ; Y L ZHANG ; Y L ZHAO ; X M LIN ; Q HUANG ; C Y YANG ; Y LIU ; R M ZHOU ; P LI ; J S CHEN ; L J HE ; D QIAN
Chinese Journal of Epidemiology 2018;39(3):322-328
Objective: To understand the prevalence of major human parasitic diseases and related factors in Henan province. Methods: This stratified sampling survey was carried out according to the requirement of national survey protocol of major human parasitic diseases, 2014-2015. The prevalence of soil-transmitted helminths infection, taeniasis and intestinal protozoiasis were surveyed in 104 sites selected from 35 counties (districts) and the prevalence of clonorchiasis was surveyed in 62 sites selected from 37 townships. In each survey spot, 250 persons were surveyed. A total of 26 866 persons and 15 893 persons were surveyed. Modified Kato-Katz thick smear was used to detect the eggs of intestinal helminthes. Tube fecal culture was used to identify the species of hookworm. The Enterobius eggs were detected in children aged 3 to 6 years by using adhesive tape. The cyst and trophozoite of intestinal protozoa were examined with physiological saline direct smear method and iodine stain method. Results: The overall infestation rate of intestinal parasites was2.02% in Henan, and the worm infection rate was higher than protozoa infection rate. Fourteen kinds of intestinal parasites were found, including nematode (5 species), trematode (2 species), and protozoan (7 species). The infection rate of Enterobius vermicularis was highest, and Qinba Mountain ecological area had the highest infestation rate of intestinal parasites in 4 ecological areas of Henan. There was no significant difference in intestinal parasite infection rate between males and females (χ(2)=3.630, P=0.057), and the differences in intestinal parasite infection rate among different age groups had significance (χ(2)=124.783, P=0.000 1). The infection rate reached the peak in age group ≤9 years and the major parasite was Enterobius vermicularis. Furthermore the overall human infection rate of parasite showed a downward trend with the increase of educational level of the people (χ(2)=70.969, P=0.000 1), the differences had significance (χ(2)=120.118, P=0.000 1). For different populations, the infection rate of intestinal parasites was highest among preschool children. The infection of intestinal helminth was mainly mild, only 2 severe cases were detected. The infection rate of Clonorchis sinensis in urban residents was only 0.006%. Logistic regression analysis showed that being preschool children (χ(2)=15.765, P=0.000 1) and drinking well water (χ(2)=45.589, P=0.000 1) were the risk factors for intestinal parasite infection, and annual income per capita of farmers was the protective factor against intestinal parasite infection. The infection rates of protozoa and intestinal parasites decreased sharply compared with the results of previous two surveys, and the rate of intestinal helminth infection also dropped sharply compared with the second survey. The numbers of protozoa, helminth and intestinal parasites detected in this survey were all less than the numbers found in the previous two surveys. Conclusions: Compared the results of three surveys in Henan, the infection rate of protozoa and intestinal parasites showed a downward trend. The prevention and treatment of Enterobius vermicularis infection in children should be the key point of parasitic disease control in the future.
Animals
;
Child
;
Child, Preschool
;
Clonorchiasis/epidemiology*
;
Farmers
;
Feces/parasitology*
;
Female
;
Helminthiasis/epidemiology*
;
Helminths
;
Humans
;
Intestinal Diseases, Parasitic/parasitology*
;
Male
;
Prevalence
;
Protective Factors
;
Risk Factors
;
Rural Population
;
Soil Microbiology
;
Surveys and Questionnaires
;
Taeniasis/epidemiology*
;
Trematode Infections/parasitology*
;
Urban Population
;
Water Wells
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.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
;
Seventh
;
Lake
;
Aedes
;
seconds
5.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
6.Characteristics of newly reported HIV/AIDS cases with non-marital but non-commercial heterosexual transmission in Hangzhou, 2015-2017.
J F CHEN ; H WU ; X L ZHANG ; Y LUO ; J M DING
Chinese Journal of Epidemiology 2018;39(12):1602-1606
Objective: To describe the characteristics of newly reported HIV/AIDS cases via non-marital or non-commercial heterosexual transmission and to find out the relative factors in Hangzhou, from 2015 to 2017. Methods: Data were collected through the national HIV/AIDS comprehensive control and prevention data system. Study subjects would include those reported HIV/AIDS cases who were residents of Hangzhou and were infected via non-marital heterosexual transmission, between January 1, 2015 and December 31, 2017. Demographic characteristics and behavioral information were collected. χ(2) test was used to compare different characteristics of the non-married heterosexual transmission subjects. Logistic regression was used to assess factors that associated with non-marital but non-commercial HIV heterosexual transmission with SPSS. 20 software used to analyze statistically. Results: Non-marital HIV heterosexual transmission accounted for 38.03% (1 393/3 663) of the total new reported HIV/AIDS cases in 2015-2017. Out of the 1 393 HIV/AIDS cases, those infected through non-marital but non-commercial heterosexual transmission accounted for 50.83% (708/1 393), and those through non-martial commercial transmission was accounted for 49.17% (685/1 393). Male to female ratio was 3.51 ∶ 1 (1 084/309). Male HIV cases reported that their major way of infection was via non-marital commercial transmission (670/1 084, 61.81%), while female patients reported the way was via non-marital non-commercial (294/309, 95.1%). Results from multivariate logistic analysis showed that the related risk factors and ORs for non-marital but non-commercial transmission appeared as: female (aOR=48.25, 95%CI: 26.94- 88.44),<30 year olds (aOR=2.43, 95%CI: 1.31-4.51), 30-39 year olds (aOR=1.92, 95%CI: 1.11- 3.33), 40-49 year olds (aOR=1.80, 95%CI: 1.08-3.00), married or unmarried (vs. divorced or widowed, aOR=1.57, 95%CI: 1.10-2.24; aOR=1.78, 95%CI: 1.15-2.78), high school and above of education level (vs. primary school and under of education level, aOR=1.82, 95%CI: 1.18-2.80), administrative officers or employee (vs. farmers, aOR=2.03, 95%CI: 1.04-1.91). Number of non- marital partners less than 5 (vs. number of non-marital partners more than 5, aOR=10.65, 95%CI: 6.41-17.42). Conclusions: HIV/AIDS cases with non-marital heterosexual transmission accounted for considerable proportion regarding the HIV transmission in Hangzhou from 2015 to 2017. Differences were found in the following factors as non-marital and non-commercial heterosexual transmission with diverse gender, age, marital status, educational level and occupation among of the HIV/AIDS patients.
Female
;
HIV
;
HIV Infections/transmission*
;
Heterosexuality
;
Humans
;
Male
;
Risk Factors
;
Sexual Behavior/psychology*
;
Sexual Partners
;
Single Person
7.BCL2 antagonist of cell death kinases, phosphatases, and ovarian cancer sensitivity to cisplatin.
Nisha BANSAL ; Douglas C MARCHION ; Elona BICAKU ; Yin XIONG ; Ning CHEN ; Xiaomang B STICKLES ; Entidhar Al SAWAH ; Robert M WENHAM ; Sachin M APTE ; Jesus GONZALEZ-BOSQUET ; Patricia L JUDSON ; Ardeshir HAKAM ; Johnathan M LANCASTER
Journal of Gynecologic Oncology 2012;23(1):35-42
OBJECTIVE: The BCL2 family proteins are critical mediators of cellular apoptosis and, as such, have been implicated as determinants of cancer cell chemo-sensitivity. Recently, it has been demonstrated that the phosphorylation status of the BCL2 antagonist of cell death (BAD) protein may influence ovarian cancer (OVCA) cell sensitivity to cisplatin. Here, we sought to evaluate how kinase and phosphatase components of the BAD apoptosis pathway influence OVCA chemo-sensitivity. METHODS: Protein levels of cyclin-dependent kinase 1 (CDK1) and protein phosphatase 2C (PP2C) were measured by immunofluorescence in a series of 64 primary advanced-stage serous OVCA patient samples. In parallel, levels of cAMP-dependent protein kinase (PKA), AKT, and PP2C were quantified by Western blot analysis in paired mother/daughter platinum-sensitive/resistant OVCA cell lines (A2008/C13, A2780S/A2780CP, Chi/ChiR). BAD pathway kinase CDK1 was depleted using siRNA transfection, and the influence on BAD phosphorylation and cisplatin-induced apoptosis was evaluated. RESULTS: OVCA patient samples that demonstrated complete responses to primary platinum-based therapy demonstrated 4-fold higher CDK1 (p<0.0001) and 2-fold lower PP2C (p=0.14) protein levels than samples that demonstrated incomplete responses. Protein levels of PP2C were lower in the platinum-resistant versus that shown in the platinum-sensitive OVCA cell line sub-clones. Levels of PKA were higher in all platinum-resistant than in platinum-sensitive OVCA cell line sub-clones. Selective siRNA depletion of CDK1 increased sensitivity to cisplatin-induced apoptosis (p<0.002). CONCLUSION: BAD pathway kinases and phosphatases, including CDK1 and PP2C, are associated with OVCA sensitivity to platinum and may represent therapeutic opportunities to enhance cytotoxic efficacy.
Apoptosis
;
Blotting, Western
;
CDC2 Protein Kinase
;
Cell Death
;
Cell Line
;
Cisplatin
;
Cyclic AMP-Dependent Protein Kinases
;
Fluorescent Antibody Technique
;
Humans
;
Ovarian Neoplasms
;
Phosphoprotein Phosphatases
;
Phosphoric Monoester Hydrolases
;
Phosphorylation
;
Phosphotransferases
;
Platinum
;
Proteins
;
RNA, Small Interfering
;
Transfection
8.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
9.Ultrasonography of intrauterine devices.
Kristina M NOWITZKI ; Matthew L HOIMES ; Byron CHEN ; Larry Z ZHENG ; Young H KIM
Ultrasonography 2015;34(3):183-194
The intrauterine device (IUD) is gaining popularity as a reversible form of contraception. Ultrasonography serves as first-line imaging for the evaluation of IUD position in patients with pelvic pain, abnormal bleeding, or absent retrieval strings. This review highlights the imaging of both properly positioned and malpositioned IUDs. The problems associated with malpositioned IUDs include expulsion, displacement, embedment, and perforation. Management considerations depend on the severity of the malposition and the presence or absence of symptoms. Three-dimensional ultrasonography has proven to be more sensitive in the evaluation of more subtle findings of malposition, particularly side-arm embedment. Familiarity with the ultrasonographic features of properly positioned and malpositioned IUDs is essential.
Contraception
;
Contraceptive Devices, Female
;
Hemorrhage
;
Humans
;
Intrauterine Devices*
;
Pelvic Pain
;
Recognition (Psychology)
;
Ultrasonography*
10.Pulmonary vein isolation alone and combined with renal sympathetic denervation in chronic kidney disease patients with refractory atrial fibrillation.
Márcio G KIUCHI ; Shaojie CHEN ; Gustavo R E SILVA ; Luis M R PAZ ; Tetsuaki KIUCHI ; Ary G DE PAULA FILHO ; Gladyston L L SOUTO
Kidney Research and Clinical Practice 2016;35(4):237-244
BACKGROUND: Atrial fibrillation (AF) commonly occurs in association with chronic kidney disease (CKD), resulting in adverse outcomes. Combining pulmonary vein isolation (PVI) and renal sympathetic denervation (RSD) may reduce the recurrence of AF in patients with CKD and hypertension. We considered that RSD could reduce the recurrence of AF in patients with CKD by modulating sympathetic hyperactivity. Our goal was to compare the impact of PVI + RSD with that of PVI alone in patients with concurrent AF and CKD. METHODS: This was a single-center, prospective, longitudinal, randomized, double-blind study. Forty-five patients with controlled hypertension, symptomatic paroxysmal AF and/or persistent AF, stage 2 or 3 CKD, and a dual-chamber pacemaker were enrolled from January 2014 to January 2015. We assessed the 30-second recurrence of AF recorded by the pacemaker, 24-hour ambulatory blood pressure measurements, estimated glomerular filtration rate, albuminuria, echocardiographic parameters, and safety of RSD. RESULTS: No patient developed procedural or other complications. The ambulatory blood pressure measurements did not differ within the PVI + RSD group or between the PVI + RSD and PVI groups throughout the study. Significantly more patients in the PVI + RSD group than in the PVI group were free of AF at the 12-month follow-up evaluation. The PVI group had an unacceptable response to ablation with respect to changes in echocardiographic parameters, whereas these parameters improved in the PVI + RSD group. CONCLUSION: PVI + RSD were associated with a lower AF recurrence rate than PVI alone; it also improved renal function and some echocardiographic parameters. These encouraging data will serve as baseline information for further long-term studies on larger patient populations.
Albuminuria
;
Atrial Fibrillation*
;
Blood Pressure
;
Double-Blind Method
;
Echocardiography
;
Follow-Up Studies
;
Glomerular Filtration Rate
;
Humans
;
Hypertension
;
Prospective Studies
;
Pulmonary Veins*
;
Recurrence
;
Renal Insufficiency, Chronic*
;
Sympathectomy*