MyMedR

Rapid thin-layer chromatographic semiquantification of morphine in urine via dabsylation: comparison with EMIT and thin-layer chromatographic-iodoplatinate methods

Wang SY, Tham SY, Poon MK

Clin Chem, 1989 Feb;35(2):329-30.

PMID: 2644060

Quantitative trait loci in Anopheles gambiae controlling the encapsulation response against Plasmodium cynomolgi Ceylon

Zheng L, Wang S, Romans P, Zhao H, Luna C, Benedict MQ

BMC Genet, 2003 Oct 24;4:16.

PMID: 14577840

Anopheles gambiae females are the world's most successful vectors of human malaria. However, a fraction of these mosquitoes is refractory to Plasmodium development. L3-5, a laboratory selected refractory strain, encapsulates transforming ookinetes/early oocysts of a wide variety of Plasmodium species. Previous studies on these mosquitoes showed that one major (Pen1) and two minor (Pen2, Pen3) autosomal dominant quantitative trait loci (QTLs) control the melanotic encapsulation response against P. cynomolgi B, a simian malaria originating in Malaysia.

Activity evaluation of cocoa pod borer sex pheromone in cacao fields

Zhang A, Kuang LF, Maisin N, Karumuru B, Hall DR, Virdiana I, et al.

Environ Entomol, 2008 Jun;37(3):719-24.

PMID: 18559177

The previously identified female sex pheromone of cocoa pod borer, Conopomorpha cramerella, was re-evaluated for its attractive activity in different field conditions. It was found that lures containing 100-mug of synthetic sex pheromone blend, (E,Z,Z)- and (E,E,Z)-4,6,10-hexadecatrienyl acetates, and the corresponding alcohols in a ratio of 40:60:4:6 in a polyethylene vial attracted male C. cramerella moths in Sabah and peninsular Malaysia and in Sumatra and Sulawesi, Indonesia, suggesting that the same pheromone strain existed in a wide stretch of the Indo-Malayan archipelago. Of the three kinds of trap designs tested, the Delta traps were more effective than Pherocon V scale traps. Male captures were not significantly different among traps baited with 100-, 300-, or 1,000-mug doses of sex pheromone. A release rate study of pheromone formulation conducted in the laboratory showed that volatile active ingredients were desorbed from polyethylene vials following first-order kinetics, which indicates a satisfactory "half-life time" of a 100-mug loading is approximately 6 wk under laboratory conditions. A satisfactory attractiveness of the lure with a 100-mug loading was approximately 1-2 mo in the fields.

Thermal death kinetics of Mediterranean, Malaysian, melon, and oriental fruit fly (Diptera: Tephritidae) eggs and third instars

Armstrong JW, Tang J, Wang S

J Econ Entomol, 2009 Apr;102(2):522-32.

PMID: 19449631

The late-aged egg and third-instar life stages of laboratory-reared Malaysian fruit fly, Bactrocera latifrons (Hendel); Mediterranean fruit fly, Ceratitis capitata (Wiedemann); melon fly, B. cucurbitae Coquillett; and oriental fruit fly, B. dorsalis (Hendel), (Diptera: Tephritidae); and the third instars of wild Mediterranean fruit fly were exposed to thermal treatments. A heating block system was used to determine the thermal death kinetics of the four fruit fly species. Treatments consisted of heating the fruit fly life stages to 44, 46, 48, and 50 degrees C and holding for different times ranging from 0 to 120 min depending on the thermal mortality response and time required to obtain 100% mortality for each species and life stage. The 0.5-order kinetic model had the best fit to the survival ratio for all the treatment temperatures and was used to predict lethal times. The thermal death time (TDT) curves showed a tolerance order of Mediterranean fruit fly eggs < or = third instars at 44, 46, and 50 degrees C, third instars < or = eggs at 48 degrees C, and wild third instars < the laboratory-reared third instars. Comparison between Mediterranean fruit fly third instar thermotolerance from Hawaii and Israel showed that Israel Mediterranean fruit fly was more thermotolerant. A comparison of minimum treatment times at a given temperature required to obtain 100% mortality of laboratory-reared Malaysian, Mediterranean (Hawaii and Israel strains), melon, Mexican, and oriental fruit fly eggs or third instars and wild Mediterranean fruit fly (Hawaii strain) eggs or third instars showed that oriental fruit fly was the most thermotolerant among the third instars, and the difference in heat tolerance between third instars and eggs was negligible at 50 degrees C.

An infectious full-length cDNA clone of duck Tembusu virus, a newly emerging flavivirus causing duck egg drop syndrome in China

Li S, Zhang L, Wang Y, Wang S, Sun H, Su W, et al.

Virus Res, 2013 Jan;171(1):238-41.

PMID: 23116594 DOI: 10.1016/j.virusres.2012.10.019

Duck Tembusu virus (TMUV) is a recently identified pathogenic flavivirus that causes severe egg drop and encephalitis in Chinese ducks and geese. It has been found to be most closely related to the mosquito-origin Tembusu virus and chicken Sitiawan virus reported in Malaysia. However, the ecological characteristics and the pathogenesis of duck TMUV are largely unknown. We report the construction of full-length cDNA clone of duck TMUV strain JXSP. The virus genome was reverse transcribed, amplified as seven overlapping fragments and successively ligated into the low copy number vector pWSK29 under the control of a T7 promoter. Transfection of BHK-21 cells with the transcribed RNA from the full-length cDNA clone resulted in production of highly infectious progeny virus. In vitro growth characteristics in BHK-21 cells and virulence in ducklings and BALB/c mice were similar for the rescued and parental viruses. This stable infectious cDNA clone will be a valuable tool for studying the genetic determinants of duck TMUV.

Fulltext Multiple Genome Sequences of Helicobacter pylori Strains of Diverse Disease and Antibiotic Resistance Backgrounds from Malaysia

Rehvathy V, Tan MH, Gunaletchumy SP, Teh X, Wang S, Baybayan P, et al.

Genome Announc, 2013;1(5).

PMID: 24051312 DOI: 10.1128/genomeA.00687-13

Helicobacter pylori causes human gastroduodenal diseases, including chronic gastritis and peptic ulcer disease. It is also a major microbial risk factor for the development of gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. Twenty-one strains with different ethnicity, disease, and antimicrobial susceptibility backgrounds were sequenced by use of Illumina HiSeq and PacBio RS platforms.

Taxonomic study of the genus Promalactis Meyrick, 1908 from Southeast Asia (Lepidoptera: Oecophoridae)

Wang S, Du Z, Li H

Zootaxa, 2013;3669:401-55.

PMID: 26312350

The genus Proinalactis Meyrick, 1908 is reviewed in Southeast Asia. Twenty-seven new species are described based on the specimens collected in Malaysia, Thailand, Brunei, Burma, Philippines. The new species include P. alveiformis sp. nov., P. angusta sp. nov., P. bruneiensis sp. nov., P. conicispinalis sp. nov., P. ellipsoidea sp. nov., P. exiliprocessa sp. nov., P. extumida sp. nov., P. fascisetacea sp. nov., P. flagellaris sp. nov., P. foraininulata sp. nov., P. fortijuxtalis sp. nov., P. lancea sp. nov., P. latuncata sp. nov., P. longisaccata sp. nov., P. lophacantha sp. nov., P. medispinata sp. nov., P. palmifolia sp. nov., P. pectinifera sp. nov., P.sectoralis sp. nov., P. semiovata sp. nov., P. sinualis sp. nov., P. spinosicostalis sp. nov., P. strena sp. nov., P. superimposita sp. nov., P. truncatapicalis sp. nov., P. undulata sp. nov. and P. vulvida sp. nov. Promalactis parasuzukiella Wang, 2006 and P. simniliflora Wang, 2006 are recorded from Southeast Asia for the first time. Three species described by Lvovsky are fully redescribed. Images of adults and genitalia are provided, along with a check list of 71 species from Southeast Asia.

Fulltext Comparing the genomes of Helicobacter pylori clinical strain UM032 and Mice-adapted derivatives

Khosravi Y, Rehvathy V, Wee WY, Wang S, Baybayan P, Singh S, et al.

Gut Pathog, 2013;5:25.

PMID: 23957912 DOI: 10.1186/1757-4749-5-25

Helicobacter pylori is a Gram-negative bacterium that persistently infects the human stomach inducing chronic inflammation. The exact mechanisms of pathogenesis are still not completely understood. Although not a natural host for H. pylori, mouse infection models play an important role in establishing the immunology and pathogenicity of H. pylori. In this study, for the first time, the genome sequences of clinical H. pylori strain UM032 and mice-adapted derivatives, 298 and 299, were sequenced using the PacBio Single Molecule, Real-Time (SMRT) technology.

Fulltext Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes

Botto F, Alonso-Coello P, Chan MT, Villar JC, Xavier D, Srinathan S, et al.

Anesthesiology, 2014 Mar;120(3):564-78.

PMID: 24534856 DOI: 10.1097/ALN.0000000000000113

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) was defined as prognostically relevant myocardial injury due to ischemia that occurs during or within 30 days after noncardiac surgery. The study's four objectives were to determine the diagnostic criteria, characteristics, predictors, and 30-day outcomes of MINS.

METHODS: In this international, prospective cohort study of 15,065 patients aged 45 yr or older who underwent in-patient noncardiac surgery, troponin T was measured during the first 3 postoperative days. Patients with a troponin T level of 0.04 ng/ml or greater (elevated "abnormal" laboratory threshold) were assessed for ischemic features (i.e., ischemic symptoms and electrocardiography findings). Patients adjudicated as having a nonischemic troponin elevation (e.g., sepsis) were excluded. To establish diagnostic criteria for MINS, the authors used Cox regression analyses in which the dependent variable was 30-day mortality (260 deaths) and independent variables included preoperative variables, perioperative complications, and potential MINS diagnostic criteria.

RESULTS: An elevated troponin after noncardiac surgery, irrespective of the presence of an ischemic feature, independently predicted 30-day mortality. Therefore, the authors' diagnostic criterion for MINS was a peak troponin T level of 0.03 ng/ml or greater judged due to myocardial ischemia. MINS was an independent predictor of 30-day mortality (adjusted hazard ratio, 3.87; 95% CI, 2.96-5.08) and had the highest population-attributable risk (34.0%, 95% CI, 26.6-41.5) of the perioperative complications. Twelve hundred patients (8.0%) suffered MINS, and 58.2% of these patients would not have fulfilled the universal definition of myocardial infarction. Only 15.8% of patients with MINS experienced an ischemic symptom.

CONCLUSION: Among adults undergoing noncardiac surgery, MINS is common and associated with substantial mortality.

Advances in paper-based point-of-care diagnostics

Hu J, Wang S, Wang L, Li F, Pingguan-Murphy B, Lu TJ, et al.

Biosens Bioelectron, 2014 Apr 15;54:585-97.

PMID: 24333570 DOI: 10.1016/j.bios.2013.10.075

Advanced diagnostic technologies, such as polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), have been widely used in well-equipped laboratories. However, they are not affordable or accessible in resource-limited settings due to the lack of basic infrastructure and/or trained operators. Paper-based diagnostic technologies are affordable, user-friendly, rapid, robust, and scalable for manufacturing, thus holding great potential to deliver point-of-care (POC) diagnostics to resource-limited settings. In this review, we present the working principles and reaction mechanism of paper-based diagnostics, including dipstick assays, lateral flow assays (LFAs), and microfluidic paper-based analytical devices (μPADs), as well as the selection of substrates and fabrication methods. Further, we report the advances in improving detection sensitivity, quantification readout, procedure simplification and multi-functionalization of paper-based diagnostics, and discuss the disadvantages of paper-based diagnostics. We envision that miniaturized and integrated paper-based diagnostic devices with the sample-in-answer-out capability will meet the diverse requirements for diagnosis and treatment monitoring at the POC.

Engineering physical microenvironment for stem cell based regenerative medicine

Han YL, Wang S, Zhang X, Li Y, Huang G, Qi H, et al.

Drug Discov Today, 2014 Jun;19(6):763-73.

PMID: 24508818 DOI: 10.1016/j.drudis.2014.01.015

Regenerative medicine has rapidly evolved over the past decade owing to its potential applications to improve human health. Targeted differentiations of stem cells promise to regenerate a variety of tissues and/or organs despite significant challenges. Recent studies have demonstrated the vital role of the physical microenvironment in regulating stem cell fate and improving differentiation efficiency. In this review, we summarize the main physical cues that are crucial for controlling stem cell differentiation. Recent advances in the technologies for the construction of physical microenvironment and their implications in controlling stem cell fate are also highlighted.

Fulltext Pedunculated subcutaneous lipoma in the popliteal fossa causing eczema

Wang SY, Ong KO

Med J Malaysia, 2015 Feb;70(1):33-5.

PMID: 26032527

Pedunculated subcutaneous lipoma in the popliteal fossa extending through the superficial fascia causing chronic irritant dermatitis of the adjacent skin with "psoriatic-like" plaque. To the author's knowledge, no similar case has been reported in the literature.

Paper-based sample-to-answer molecular diagnostic platform for point-of-care diagnostics

Choi JR, Tang R, Wang S, Wan Abas WA, Pingguan-Murphy B, Xu F

Biosens Bioelectron, 2015 Dec 15;74:427-39.

PMID: 26164488 DOI: 10.1016/j.bios.2015.06.065

Nucleic acid testing (NAT), as a molecular diagnostic technique, including nucleic acid extraction, amplification and detection, plays a fundamental role in medical diagnosis for timely medical treatment. However, current NAT technologies require relatively high-end instrumentation, skilled personnel, and are time-consuming. These drawbacks mean conventional NAT becomes impractical in many resource-limited disease-endemic settings, leading to an urgent need to develop a fast and portable NAT diagnostic tool. Paper-based devices are typically robust, cost-effective and user-friendly, holding a great potential for NAT at the point of care. In view of the escalating demand for the low cost diagnostic devices, we highlight the beneficial use of paper as a platform for NAT, the current state of its development, and the existing challenges preventing its widespread use. We suggest a strategy involving integrating all three steps of NAT into one single paper-based sample-to-answer diagnostic device for rapid medical diagnostics in the near future.

Fulltext The complete methylome of Helicobacter pylori UM032

Lee WC, Anton BP, Wang S, Baybayan P, Singh S, Ashby M, et al.

BMC Genomics, 2015;16:424.

PMID: 26031894 DOI: 10.1186/s12864-015-1585-2

The genome of the human gastric pathogen Helicobacter pylori encodes a large number of DNA methyltransferases (MTases), some of which are shared among many strains, and others of which are unique to a given strain. The MTases have potential roles in the survival of the bacterium. In this study, we sequenced a Malaysian H. pylori clinical strain, designated UM032, by using a combination of PacBio Single Molecule, Real-Time (SMRT) and Illumina MiSeq next generation sequencing platforms, and used the SMRT data to characterize the set of methylated bases (the methylome).

Fulltext A returning migrant worker with avian influenza A (H7N9) virus infection in Guizhou, China: a case report

Wang D, Tang G, Huang Y, Yu C, Li S, Zhuang L, et al.

J Med Case Rep, 2015;9:109.

PMID: 25962780 DOI: 10.1186/s13256-015-0580-1

Human infection with avian influenza A (H7N9) virus was first reported on March, 2013 in the Yangtze River Delta region of China. The majority of human cases were detected in mainland China; other regions out of mainland China reported imported human cases, including Hong Kong SAR, Taiwan (the Republic of China) and Malaysia, due to human transportation. Here, we report the first human case of H7N9 infection imported into Guizhou Province during the Spring Festival travel season in January 2014.

Fulltext Quaternary ammonium salt of chitosan: preparation and antimicrobial property for paper

Liu P, Meng W, Wang S, Sun Y, Ashraf MA

Open Med (Wars), 2015;10(1):473-478.

PMID: 28352739 DOI: 10.1515/med-2015-0081

A series of 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was prepared by the reaction of chitosan with glycidyl trimethyl ammonium chloride. Structure of HACC was characterized by FT IR and 1H NMR spectroscopies, and it was proved that substitution reaction mainly occurs on the N element. Antimicrobial activities of HACC was examined against S. aureus, E. coli, and A. niger. Results indicatd that the inhibitory effects of HACC solutions were varied with HACC concentration, quaternization degrees, pH values, metal ions, and heat treatment. The antimicrobial properties of handsheets prepared from HACC were studied by the inhibition zone method, and the sheets had good antimicrobial properties against S. aureus and E. coli, and low inhibition rate against A. niger.

Congenital Tuberculosis Complicated by Hemophagocytic Lymphohistiocytosis

Osowicki J, Wang S, McKenzie C, Marshall C, Gard J, Ke Juin W, et al.

Pediatr Infect Dis J, 2016 Jan;35(1):108-10.

PMID: 26398869 DOI: 10.1097/INF.0000000000000932

We present the case of a male infant with congenital tuberculosis in a nonendemic setting complicated by hemophagocytic lymphohistiocytosis, who was treated successfully with antituberculous therapy and corticosteroids. We review the pediatric literature concerning the unusual association of these 2 rare conditions.

Measurement of differential cross sections for Higgs boson production in the diphoton decay channel in pp collisions at [Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016 01 11;76:13.

PMID: 26855607

A measurement is presented of differential cross sections for Higgs boson (H) production in pp collisions at [Formula: see text][Formula: see text]. The analysis exploits the [Formula: see text] decay in data corresponding to an integrated luminosity of 19.7[Formula: see text] collected by the CMS experiment at the LHC. The cross section is measured as a function of the kinematic properties of the diphoton system and of the associated jets. Results corrected for detector effects are compared with predictions at next-to-leading order and next-to-next-to-leading order in perturbative quantum chromodynamics, as well as with predictions beyond the standard model. For isolated photons with pseudorapidities [Formula: see text], and with the photon of largest and next-to-largest transverse momentum ([Formula: see text]) divided by the diphoton mass [Formula: see text] satisfying the respective conditions of [Formula: see text] and [Formula: see text], the total fiducial cross section is [Formula: see text][Formula: see text].

Study of B Meson Production in p+Pb Collisions at √[S(NN)]=5.02 TeV Using Exclusive Hadronic Decays

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2016 Jan 22;116(3):032301.

PMID: 26849587 DOI: 10.1103/PhysRevLett.116.032301

The production cross sections of the B^{+}, B^{0}, and B_{s}^{0} mesons, and of their charge conjugates, are measured via exclusive hadronic decays in p+Pb collisions at the center-of-mass energy sqrt[s_{NN}]=5.02 TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6 nb^{-1}. The production cross sections are measured in the transverse momentum range between 10 and 60 GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in Pb+Pb collisions.

Search for Narrow Resonances Decaying to Dijets in Proton-Proton Collisions at sqrt[s]=13 TeV

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2016 Feb 19;116(7):071801.

PMID: 26943527 DOI: 10.1103/PhysRevLett.116.071801

A search for narrow resonances in proton-proton collisions at sqrt[s]=13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 fb^{-1}. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W^{'} bosons below 2.6 TeV. These results significantly extend previously published limits.

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