1.An outbreak of gastroenteritis caused by Salmonella enterica serotype Enteritidis traced to cream cakes
Solhan Suhana ; Chan Pei Pei ; Lalitha Kurupatham ; Foong Bok Huay ; Ooi Peng Lim ; James Lyn ; Phua Leslie ; Tan Ai Ling ; Koh Diana ; Goh Kee Tai
Western Pacific Surveillance and Response 2011;2(1):23-30
Introduction:This paper describes the epidemiological, microbiological and environmental investigations conducted during an outbreak of Salmonella gastroenteritis in Singapore.
Methods:A case-control study was undertaken to identify the vehicle of transmission. Microbiological testing was performed on faecal, food and environmental samples. Isolates of Salmonella were further characterized by phage typing and ribotyping.
Results:There were 216 gastroenteritis cases reported from 20 November to 4 December 2007. The causative agent was identified as Salmonella enterica subspecies enterica serotype Enteritidis for 14 out of 20 cases tested. The vehicle of transmission was traced to cream cakes produced by a bakery and sold at its retail outlets ( P < 0.001, OR = 143.00, 95% Cl = 27.23–759.10). More than two-thirds of the 40 Salmonella strains isolated from hospitalized cases, food samples and asymptomatic food handlers were of phage type 1; the others reacted but did not conform to any phage type. The phage types correlated well with their unique antibiograms. The ribotype patterns of 22 selected isolates tested were highly similar, indicating genetic relatedness. The dendrogram of the strains from the outbreak showed distinct clustering and correlation compared to the non-outbreak strains, confirming a common source of infection.
Discussion:The cream cakes were likely contaminated by one of the ingredients used in the icing. Cross-contamination down the production line and subsequent storage of cakes at ambient temperatures for a prolonged period before consumption could have resulted in the outbreak.
2.International health regulations: lessons from the influenza pandemic in Singapore.
Chew Ling LOW ; Pei Pei CHAN ; Jeffery L CUTTER ; Bok Huay FOONG ; Lyn JAMES ; Peng Lim OOI
Annals of the Academy of Medicine, Singapore 2010;39(4):325-323
INTRODUCTIONSingapore's defense against imported novel influenza A (H1N1-2009) comprised public health measures in compliance with the World Health Organization's (WHO) International Health Regulations (IHR), 2005. We report herein on the epidemiology and control of the fi rst 350 cases notified between May and June 2009.
MATERIALS AND METHODSWe investigated the fi rst 350 laboratory-confirmed cases of novel influenza A (H1N1-2009) identified from the healthcare institutions between 27 May and 25 June 2009. Epidemiological details of these cases were retrieved and analysed. Contact tracing and active case finding were also instituted for each reported case, and relevant particulars including flight information were provided to WHO and overseas counterparts.
RESULTSThe fi rst 350 novel influenza A (H1N1-2009) cases comprised 221(63%) imported cases, 124 (35%) locally acquired cases and 5 (2%) cases with unknown source. The imported cases consisted of three waves involving the United States (US), Australia and Southeast Asia. In the fi rst wave, 11 (69%) of the 16 imported cases had visited the US within seven days prior to their onset of illness between 25 May and 4 June 2009. In the second wave, 20 (74%) of the 27 imported cases between 5 June and 12 June had travelled to Melbourne, Australia. In the third wave, 90 (51%) of the 178 imported cases between 13 June and 25 June were acquired from intra-regional travel in Southeast Asia. Specifically, 49 cases were from the Philippines and 40 (82%) of them had travelled to Manila. A total of 667 communications were effected through the IHR mechanism; a majority within 24 hours of disease notification.
CONCLUSIONSingapore experienced an unprecedented need for international cooperation in surveillance and response to this novel Influenza A (H1N1-2009) pandemic. The IHR mechanism served as a useful channel to engage in regional cooperation concerning disease surveillance and data sharing, but requires improvement.
Adolescent ; Adult ; Child ; Disease Notification ; Disease Outbreaks ; prevention & control ; Female ; Guideline Adherence ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; epidemiology ; prevention & control ; International Cooperation ; Male ; Singapore ; epidemiology ; Travel ; World Health Organization ; Young Adult
3.Outbreak of novel influenza A (H1N1-2009) linked to a dance club.
Pei Pei CHAN ; Hariharan SUBRAMONY ; Florence Y L LAI ; Wee Siong TIEN ; Boon Hian TAN ; Suhana SOLHAN ; Hwi Kwang HAN ; Bok Huay FOONG ; Lyn JAMES ; Peng Lim OOI
Annals of the Academy of Medicine, Singapore 2010;39(4):299-294
INTRODUCTIONThis paper describes the epidemiology and control of a community outbreak of novel influenza A (H1N1-2009) originating from a dance club in Singapore between June and July 2009.
MATERIALS AND METHODSCases of novel influenza A (H1N1-2009) were confirmed using in-house probe-based real-time polymerase chain reaction (PCR). Contact tracing teams from the Singapore Ministry of Health obtained epidemiological information from all cases via telephone.
RESULTSA total of 48 cases were identified in this outbreak, of which 36 (75%) cases were patrons and dance club staff, and 12 (25%) cases were household members and social contacts. Mathematical modelling showed that this outbreak had a reproductive number of 1.9 to 2.1, which was similar to values calculated from outbreaks in naïve populations in other countries.
CONCLUSIONThis transmission risk occurred within an enclosed space with patrons engaged in intimate social activities, suggesting that dance clubs are places conducive for the spread of the virus.
Adolescent ; Adult ; Commerce ; Contact Tracing ; methods ; Dancing ; Disease Outbreaks ; Female ; Humans ; Influenza A Virus, H1N1 Subtype ; isolation & purification ; Influenza, Human ; diagnosis ; epidemiology ; Interviews as Topic ; Male ; Models, Statistical ; Polymerase Chain Reaction ; Singapore ; epidemiology ; Travel ; Young Adult
4.Vascular endothelial growth factor and pigment epithelium-derived factor in aqueous humor of patients with choroidal neovascularization.
Jian-ping TONG ; Ye SHEN ; Wai-man CHAN ; Shun-chao LIN ; Zhi-pei PENG
Journal of Zhejiang University. Medical sciences 2006;35(3):311-314
OBJECTIVETo detect the levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in aqueous humor of patients with active choroidal neovascularization (CNV).
METHODSAqueous humor samples were obtained from 32 patients with active CNV. The concentrations of VEGF and PEDF in aqueous humor were measured by enzyme linked immunosorbent assay (ELISA) for quantitative analysis. VEGF and PEDF in 10 samples of aqueous humor from patients with cataract were also detected by the same methods as control.
RESULTThe mean VEGF and PEDF concentrations in aqueous humor of active CNV patients were higher than those in the control group (P=0.000).
CONCLUSIONThe patients with active CNV exhibit significantly higher VEGF and PEDF levels than those in control, indicating that VEGF along with PEDF may modulate the formation of CNV.
Adult ; Aged ; Aged, 80 and over ; Aqueous Humor ; chemistry ; Choroidal Neovascularization ; metabolism ; Eye Proteins ; analysis ; Female ; Humans ; Male ; Middle Aged ; Nerve Growth Factors ; analysis ; Serpins ; analysis ; Vascular Endothelial Growth Factor A ; analysis
5.Neuronal differentiation of PC12 cells induced by sciatic nerve and optic nerve conditioned medium.
Chan DU ; De-mei YANG ; Pei-xun ZHANG ; Lei DENG ; Bao-guo JIANG
Chinese Medical Journal 2010;123(3):351-355
BACKGROUNDPrevious work has shown that optic nerve and sciatic nerve conditional medium had neurotrophic activity on neurons. In order to find if the optic nerve conditioned media (CM) had a similar activity to make PC12 cells differentiate as sciatic nerve CM did, we explored the neurotrophic activity in optic nerve CM in the same in vitro system and compared the neurotrophin expression levels in optic and sciatic nerves under both conditions.
METHODSPC12 cells were used to examine the effects of neurotrophins secreted by the sciatic nerve and optic nerve. RT-PCR and real-time QPCR showed that the sciatic nerve and optic nerve produced a range of neurotrophins including nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3).
RESULTSThe effects of sciatic nerve and optic nerve CM on neurite outgrowth were tested against a range of neurotrophins, and they had different neuritogenic activities. Only NGF and sciatic nerve CM had obvious neuritogenic activities, although the concentration of NGF in the sciatic nerve CM was very low.
CONCLUSIONSOur experiment showed that sciatic nerve CM had a higher neurotrophic activity on PC12 cells than optic nerve CM. These results suggested that peripheral nervous system (PNS) and central nervous system (CNS) had different expression levels of neurotrophin, which may in part explain the lack of ability to regenerate the CNS.
Animals ; Brain-Derived Neurotrophic Factor ; genetics ; pharmacology ; Cell Differentiation ; drug effects ; Culture Media, Conditioned ; metabolism ; pharmacology ; Nerve Growth Factor ; genetics ; pharmacology ; Neurotrophin 3 ; genetics ; pharmacology ; Optic Nerve ; metabolism ; PC12 Cells ; cytology ; drug effects ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Sciatic Nerve ; metabolism
6.Study on the adoption of Schwann cell phenotype by bone marrow stromal cells in vitro and in vivo.
Fu-Qiang ZHAO ; Pei-Xun ZHANG ; Xiang-Jun HE ; Chan DU ; Zhong-Guo FU ; Dian-Ying ZHANG ; Bao-Guo JIANG
Biomedical and Environmental Sciences 2005;18(5):326-333
OBJECTIVETo explore the possibilities of bone marrow stromal cells (MSCs) to adopt Schwann cell phenotype in vitro and in vivo in SD rats.
METHODSMSCs were obtained from tibia and femur bone marrow and cultured in culture flasks. Beta-mercaptoethanol followed by retinoic acid, forskolin, basic-FGF, PDGF and heregulin were added to induce differentiation of MSCs'. Schwann cell markers, p75, S-100 and GFAP were used to discriminate induced properties of MSCs' by immunofluorescent staining. PKH-67-labelled MSCs were transplanted into the mechanically injured rat sciatic nerve, and laser confocal microscopy was performed to localize the PKH67 labelled MSCs in the injured sciatic nerve two weeks after the operation. Fluorescence PKH67 attenuation rule was evaluated by flow cytometry in vitro.
RESULTSMSCs changed morphologically into cells resembling primary cultured Schwann cells after their induction in vitro. In vivo, a large number of MSCs were cumulated within the layer of epineurium around the injured nerve and expressed Schwann cell markers, p75, S-100, and GFAP.
CONCLUSIONMSCs are able to support nerve fiber regeneration and re-myelination by taking on Schwann cell function, and can be potentially used as possible substitutable cells for artificial nerve conduits to promote nerve regeneration.
Animals ; Biomarkers ; analysis ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Flow Cytometry ; Fluorescent Antibody Technique, Indirect ; Fluorescent Dyes ; Glial Fibrillary Acidic Protein ; analysis ; Morphogenesis ; Organic Chemicals ; analysis ; Phenotype ; Rats ; Receptor, Nerve Growth Factor ; analysis ; S100 Proteins ; analysis ; Schwann Cells ; cytology ; metabolism ; Sciatic Nerve ; cytology ; injuries ; Stromal Cells ; cytology ; metabolism ; transplantation
7.Lifestyle factors associated with cardiovascular risk among healthcare workers from the tertiary hospitals in Sarawak
Kuan Pei Xuan ; Chan Weng Ken ; Chua Pin Fen ; John Yeo Jui Ping ; Fatin Ellisya Sapri ; Mohamad Adam Hj Bujang ; Asri Said
Malaysian Family Physician 2020;15(1):15-22
Introduction: A cross-sectional study is used to evaluate the lifestyle factors associated with
cardiovascular disease (CVD) risk among healthcare workers in tertiary hospitals in Sarawak, Malaysia.
Methods: A questionnaire-based survey using the Simple Lifestyle Indicator Questionnaire (SLIQ) was
administered to, and anthropometric measurements were collected from, 494 healthcare workers.
Results: Te mean age of the subjects was 32.4±8.4, with a range of 19 to 59 years. Te subjects were
from the allied health (45.5%), management and professional (25.1%) and executive (29.4%) felds.
Overall, 47.4% of the subjects were of normal weight, 30.2% were overweight, 17.2% were obese and
5.2% were underweight. Te mean number of working hours per week for the subjects was 47.6±14.0
with the highest working hours found among the management and professional group, followed by
the executive and allied health groups. Overall, 39.7% of the healthcare workers worked ofce hours,
36.6% worked within the shift system, 20.9% worked ofce hours and were on-call and the remaining
2.8% worked a mixture of ofce hours and shifts. Based on the SLIQ score, 58.1% were classifed as
at intermediate risk for CVD, 38.5% were in the healthy category and 3.4% were in the unhealthy
category. Factors associated with a healthier lifestyle were being female (Odds Ratio [OR]= 12.1; CI=
3.2- 46.4), professional (mean score= 6.70), in the allied health group (mean score=7.33) and in the
normal BMI group (OR= 9.3, CI= 1.8- 47.0).
Conclusion: In our study, healthcare workers had an intermediate risk of developing CVD in the
future. Tus, there is a need to intervene in the lifestyle factors contributing to CVD.
8.Leveraging social networking sites for disease surveillance and public sensing: the case of the 2013 avian influenza A(H7N9) outbreak in China
Zhang Emma Xuxiao ; Yang Yinping ; Di Shang Richard ; Simons Joseph John Pyne ; Quek Boon Kiat ; Yin Xiao Feng ; See Wanhan ; Oh Olivia Seen Huey ; Nandar Khine Sein Tun ; Ling Vivienne Ruo Yun ; Chan Pei Pei ; Wang Zhaoxia ; Goh Rick Siow Mong ; James Lyn ; Tey Jeannie Su Hui
Western Pacific Surveillance and Response 2015;6(2):66-72
We conducted in-depth analysis on the use of a popular Chinese social networking and microblogging site, Sina Weibo, to monitor an avian influenza A(H7N9) outbreak in China and to assess the value of social networking sites in the surveillance of disease outbreaks that occur overseas. Two data sets were employed for our analysis: a line listing of confirmed cases obtained from conventional public health information channels and case information from Weibo posts. Our findings showed that the level of activity on Weibo corresponded with the number of new cases reported. In addition, the reporting of new cases on Weibo was significantly faster than those of conventional reporting sites and non-local news media. A qualitative review of the functions of Weibo also revealed that Weibo enabled timely monitoring of other outbreak-relevant information, provided access to additional crowd-sourced epidemiological information and was leveraged by the local government as an interactive platform for risk communication and monitoring public sentiment on the policy response. Our analysis demonstrated the potential for social networking sites to be used by public health agencies to enhance traditional communicable disease surveillance systems for the global surveillance of overseas public health threats. Social networking sites also can be used by governments for calibration of response policies and measures and for risk communication.
9. Correlation between gut microbiota and FGF21 in mice with insulin resistance
Ye WANG ; Xue HAN ; Xiao-Ting SHA ; Chan-Yue WANG ; Lin-Lin LI ; Pei-Pei ZHANG ; Lin-Lin LI
Chinese Pharmacological Bulletin 2021;37(3):337-342
Aim To study the effect of normal glucose tolerance fecal microbiota transplantation ( FMT) on the gut microbiota in mice with insulin resistance(IR) and its correlation with FGF21 , and to explore the possible mechanisms of gut microbiota affecting IR.Methods After the establishment of IR model with high-fat diet feeding, 30 successful IR model mice were randomly divided into three groups; insulin resistance ( IR ) group, IR + metformin( Met) group, and IR + glucose tolerance normal fecal microbiota transplantation (FMT)group, and blank control(Control) group, with 10 mice in each group.After eight weeks of administration, the body mass and fasting blood glucose of mice at 8th week were recorded, then the number of target bacteria in fecal samples and the mRNA expression levels of FGF21 and its receptors in liver, colon and ileum tissues were detected by Real-time quantitative PCR( RT-qPCR).Results ® Compared with control group, the body mass and fasting blood glucose increased in IR group mice, while the mRNA expression levels of FGF21/p-Klolho/FGFRl/FGFR4 in liver, colon and ileum tissues were down-regulated.The levels of Bacteroules and R.sarlorii were reduced in fecal samples, and the levels of P.distasonis, M.schaedleri and R.gnavus increased.These indices were reverted by Met and FMT treatment.(2) The expression of FGF21 was negatively correlated with FBG, P.distasonis , M.schaedleri and R.gnavus, and positively correlated with Bacteroides and B.sartorii.Conclusions FMT can increase the expression level of FGF21 and regulate gut microbiota, and the two are closely related , which may be one of the important mechanisms of FMT in improving insulin resistance.
10.Oral Lovastatin Attenuates Airway Inflammation and Mucus Secretion in Ovalbumin-Induced Murine Model of Asthma.
Chian Jiun LIOU ; Pei Yun CHENG ; Wen Chung HUANG ; Cheng Chi CHAN ; Meng Chun CHEN ; Ming Ling KUO ; Jiann Jong SHEN
Allergy, Asthma & Immunology Research 2014;6(6):548-557
PURPOSE: Lovastatin is an effective inhibitor of cholesterol synthesis. A previous study demonstrated that lovastatin can also suppress airway hyperresponsiveness (AHR) in murine model of asthma. We aimed to investigate the effect of lovastatin on mucus secretion and inflammation-associated gene expression in the lungs of murine model of asthma. METHODS: Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) by intraperitoneal injection, and orally administered lovastatin from days 14 to 27 post-injection. Gene expression in lung tissues was analyzed using real-time polymerase chain reaction. AHR and goblet cell hyperplasia were also examined. BEAS-2B human bronchial epithelial cells were used to evaluate the effect of lovastatin on the expression of cell adhesion molecules, chemokines, and proinflammatory cytokines in vitro. RESULTS: We showed that lovastatin inhibits the expression of Th2-associated genes, including eotaxins and adhesion molecules, in the lungs of murine model of asthma. Mucin 5AC expression, eosinophil infiltration and goblet cell hyperplasia were significantly decreased in the lung tissue of murine model of asthma treated with lovastatin. Furthermore, lovastatin inhibited AHR and expression of Th2-associated cytokines in bronchoalveolar lavage fluid. However, a high dose (40 mg/kg) of lovastatin was required to decrease specific IgE to OVA levels in serum, and suppress the expression of Th2-associated cytokines in splenocytes. Activated BEAS-2B cells treated with lovastatin exhibited reduced IL-6, eotaxins (CCL11 and CCL24), and intercellular adhesion molecule-1 protein expression. Consistent with this, lovastatin also suppressed the ability of HL-60 cells to adhere to inflammatory BEAS-2B cells. CONCLUSIONS: These data suggest that lovastatin suppresses mucus secretion and airway inflammation by inhibiting the production of eotaxins and Th2 cytokines in murine model of asthma.
Animals
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Asthma*
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Bronchoalveolar Lavage Fluid
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Cell Adhesion Molecules
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Chemokines
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Cholesterol
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Cytokines
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Eosinophils
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Epithelial Cells
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Female
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Gene Expression
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Goblet Cells
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HL-60 Cells
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Humans
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Hyperplasia
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Immunoglobulin E
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Inflammation*
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Injections, Intraperitoneal
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Intercellular Adhesion Molecule-1
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Interleukin-6
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Lovastatin*
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Lung
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Mice
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Mucin 5AC
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Mucus*
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Ovalbumin
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Ovum
;
Real-Time Polymerase Chain Reaction