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Antibiotic prophylaxis in elective colorectal surgery

Gul YA, Lian LH, Jabar FM, Moissinac K

ANZ J Surg, 2002 Apr;72(4):275-8.
PMID: 11982514

Antibiotics are often administered in elective colorectal surgery to prevent wound infection. The tendency for surgeons to prolong the administration of prophylactic antibiotic therapy in the postoperative period is a well-known fact. The aim of this study was to elucidate the pattern of prophylactic antibiotic utilization in elective colorectal surgery and to determine if evidence-based medicine is employed in relation to this practice.
Fulltext Plasmon-Enhanced Biosensing for Multiplexed Profiling of Extracellular Vesicles

Min J, Son T, Hong JS, Cheah PS, Wegemann A, Murlidharan K, et al.

Adv Biosyst, 2020 12;4(12):e2000003.
PMID: 32815321 DOI: 10.1002/adbi.202000003

Extracellular vesicles (EVs)-nanoscale phospholipid vesicles secreted by cells-present new opportunities for molecular diagnosis from non-invasive liquid biopsies. Single EV protein analysis can be extremely valuable in studying EVs as circulating cancer biomarkers, but it is technically challenging due to weak detection signals associated with limited amounts of epitopes and small surface areas for antibody labeling. Here, a new, simple method that enables multiplexed analyses of EV markers with improved sensitivities is reported. Specifically, plasmon-enhanced fluorescence detection is implemented that amplifies fluorescence signals using surface plasmon resonances excited by periodic gold nanohole structures. It is shown that fluorescence signals in multiple channels are amplified by one order of magnitude, and both transmembrane and intravesicular markers can be detected at the single EV level. This approach can offer additional insight into understanding subtypes, heterogeneity, and production dynamics of EVs during disease development and progression.
Impact of controlled attenuation parameter on detecting fibrosis using liver stiffness measurement

Karlas T, Petroff D, Sasso M, Fan JG, Mi YQ, de Lédinghen V, et al.

Aliment Pharmacol Ther, 2018 Apr;47(7):989-1000.
PMID: 29446106 DOI: 10.1111/apt.14529

BACKGROUND: Liver fibrosis is often accompanied by steatosis, particularly in patients with non-alcoholic fatty liver disease (NAFLD), and its non-invasive characterisation is of utmost importance. Vibration-controlled transient elastography is the non-invasive method of choice; however, recent research suggests that steatosis may influence its diagnostic performance. Controlled Attenuation Parameter (CAP) added to transient elastography enables simultaneous assessment of steatosis and fibrosis.
AIM: To determine how to use CAP in interpreting liver stiffness measurements.
METHODS: This is a secondary analysis of data from an individual patient data meta-analysis on CAP. The main exclusion criteria for the current analysis were unknown aetiology, unreliable elastography measurement and data already used for the same research question. Aetiology-specific liver stiffness measurement cut-offs were determined and used to estimate positive and negative predictive values (PPV/NPV) with logistic regression as functions of CAP.
RESULTS: Two thousand and fifty eight patients fulfilled the inclusion criteria (37% women, 18% NAFLD/NASH, 42% HBV, 40% HCV, 51% significant fibrosis ≥ F2). Youden optimised cut-offs were only sufficient for ruling out cirrhosis (NPV of 98%). With sensitivity and specificity-optimised cut-offs, NPV for ruling out significant fibrosis was moderate (70%) and could be improved slightly through consideration of CAP. PPV for significant fibrosis and cirrhosis were 68% and 55% respectively, despite specificity-optimised cut-offs for cirrhosis.
CONCLUSIONS: Liver stiffness measurement values below aetiology-specific cut-offs are very useful for ruling out cirrhosis, and to a lesser extent for ruling out significant fibrosis. In the case of the latter, Controlled Attenuation Parameter can improve interpretation slightly. Even if cut-offs are very high, liver stiffness measurements are not very reliable for ruling in fibrosis or cirrhosis.
King Edward VII Hall of Residence--a link with the medical school since 1916

Lee HP

Ann Acad Med Singap, 2005 Jul;34(6):159C-162C.
PMID: 16010400

King Edward VII ("KE") had been synonymous with the medical school and its associated hall of residence at Sepoy Lines since the 1910s. After the school became the Medical Faculty, the illustrious name remained with the Hall, which was rebuilt in 1957. For almost 90 years, KE has kept alive the rich history and traditions of a bygone era that embodied the passion and pride of both Singapore and Malaysia. The heroism of some Keviians during the Second World War and other exploits have led to many legends of the Hall. In 1987, it moved to its present location at Kent Ridge, and opened its doors to students from all other faculties. We count many personalities among our alumni, including some of the most prominent physicians in our country. The exuberant hall life, cultural pursuits and achievements of the residents contribute to the strong spirit of endeavour. Keviians over the decades have lived, worked, played and served to uphold the motto that means so much to all of us: TO STRIVE, TO SEEK, TO SERVE.
How sexually permissive are Singaporeans?

Kok LP, Heng BH, Ong YW, Ho ML, Lee HP

Ann Acad Med Singap, 1995 Sep;24(5):679-84.
PMID: 8579309

This paper presents data on two surveys done in 1989 and 1992 that indicated the attitudes of Singaporeans to sexuality. Both surveys revealed that Singaporeans have sexually conservative attitudes and those who have a lower education, are single, above the age of 40, are Malays/Muslims hold more conservative views.
Prevalence and determinants of cervical cancer screening: a community-based study in Singapore

Seow A, Lee HP

Ann Acad Med Singap, 1994 May;23(3):342-7.
PMID: 7944247

A cross-sectional survey of 568 married women aged 21-65 years in the Pasir Panjang Constituency was conducted to determine the prevalence of cervical cancer screening in the community and the factors affecting acceptance of this screening test. Results show that 309 (54.4%) of the respondents had ever had a Pap smear. The women who reported having had a smear were more likely to be below 45 years of age (prevalence ratio 1.47, 95% confidence interval 1.15 to 1.88), Chinese and of a higher socioeconomic status (1.68, 1.33 to 2.12). They were also more likely to have married at a later age (1.68, 1.21 to 2.31) than women who had not had a smear. Age and socioeconomic status remained independent predictors on multivariate analysis. The findings suggest that an important task of public health practitioners is to increase the uptake of screening among older and socially disadvantaged women who are known to be at the highest risk of cervical cancer. In addition, strategies to encourage younger women to continue regular attendance at screening clinics beyond their childbearing years will be important for the future.
Incidence of primary liver cancer in Singapore, 1968-1982

Chia KS, Lee HP, Lee J

Ann Acad Med Singap, 1989 May;18(3):313-6.
PMID: 2549842

Based on data collected by the population-based Singapore Cancer Registry over the period 1968 to 1982, baseline epidemiological characteristics and incidence trends of primary liver cancer were described. This will facilitate the interpretation of future trends, especially in the light of new interventions such as hepatitis B immunisation. The primary liver cancer incidence is four times higher in males than in females, with the incidence peaked in the seventh decade. The incidence rate was higher in the Chinese than in Malays and Indians and marginally higher among foreign born than Singapore born Chinese. A general declining trend in liver cancer incidence was especially notable in the local born Chinese. Misclassification of metastatic carcinomas in the earlier years of cancer registration may have contributed to the initial higher incidence. Definitive decrease in incidence as a result of hepatitis immunisation will only be seen in another two to three decades.
Classification of Chinese cancer patients by dialect group: is it still valid?

Lee HP, Gourley L

Ann Acad Med Singap, 1988 Jul;17(3):431-3.
PMID: 3265301

In Singapore, cancer incidence is documented separately for the different Chinese dialect groups, as a means of providing a possible insight into environmental or genetic factors which may be involved in the aetiological process. Thus, it would be useful to determine whether or not the Chinese population in Singapore still comprises distinct dialect groups. In view of this, an investigation into the dialect group of the parents of 792 hospital in-patients (cases and controls) was carried out. It was found that the vast majority of patients (94.2%), most of whom were born before 1940, had parents of the same dialect group. The percentages of within-dialect marriages were only slightly less for offspring born in Singapore or Malaysia as opposed to China, and decreases with time were small. Thus in 1985-87 Chinese cancer patients and controls in Singapore, of the ages represented in this study may indeed be classified according to their father's dialect and this is likely to be the case for at least the next decade or so. This finding will be of use to cancer epidemiologists as well as others studying Chinese dialect group variations in disease patterns.
Isolation and Identification of novel toxins from a new mosquitocidal isolate from Malaysia, Bacillus thuringiensis subsp. jegathesan

Kawalek MD, Benjamin S, Lee HL, Gill SS

Appl Environ Microbiol, 1995 Aug;61(8):2965-9.
PMID: 7487029

A new mosquitocidal Bacillus thuringiensis subsp., jegathesan, has recently been isolated from Malaysia. Parasporal crystal inclusions were purified from this strain and bioassayed against fourth-instar larvae of Culex quinquefasciatus, Aedes aegypti, Aedes togoi, Aedes albopictus, Anopheles maculatus, and Mansonia uniformis. The 50% lethal concentration of crystal inclusions for each species was 0.34, 8.08, 0.34, 17.59, 3.91, and 120 ng/ml, respectively. These values show that parasporal inclusions from this new subspecies have mosquitocidal toxicity comparable to that of inclusions isolated from B. thuringiensis subsp. israelensis. Solubilized and chymotrypsin-activated parasporal inclusions possessed low-level hemolytic activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the crystals were composed of polypeptides of 77, 74, 72, 68, 55, 38, 35, 27, and 23 kDa. Analysis by Western blotting (immunoblotting) with polyclonal antisera raised against toxins purified from B. thuringiensis subsp. israelensis reveals that proteins in parasporal inclusions of subsp. jegathesan are distinct, because little cross-reactivity was shown. Analysis of the plasmid content of B. thuringiensis subsp. jegathesan indicates that the genes for toxin production may be located on 105- to 120-kb plasmids. Cry- clones that have been cured of these plasmids are nontoxic. Southern blot analysis of plasmid and chromosomal DNA from subsp. jegathesan showed little or low homology to the genes coding for CryIVA, CryIVB, and CryIVD from B. thuringiensis subsp. israelensis.
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Klionsky DJ, Abdelmohsen K, Abe A, Abedin MJ, Abeliovich H, Acevedo Arozena A, et al.

Autophagy, 2016;12(1):1-222.
PMID: 26799652 DOI: 10.1080/15548627.2015.1100356
Fulltext Formation of biofilm by Listeria monocytogenes ATCC 19112 at different incubation temperatures and concentrations of sodium chloride

Lee HY, Chai LC, Pui CF, Mustafa S, Cheah YK, Nishibuchi M, et al.

Braz J Microbiol, 2013;44(1):51-5.
PMID: 24159283 DOI: 10.1590/S1517-83822013005000004

Biofilm formation can lead to various consequences in the food processing line such as contamination and equipment breakdowns. Since formation of biofilm can occur in various conditions; this study was carried out using L. monocytogenes ATCC 19112 and its biofilm formation ability tested under various concentrations of sodium chloride and temperatures. Cultures of L. monocytogenes ATCC 19112 were placed in 96-well microtitre plate containing concentration of sodium chloride from 1-10% (w/v) and incubated at different temperature of 4 °C, 30 °C and 45 °C for up to 60 h. Absorbance reading of crystal violet staining showed the density of biofilm formed in the 96-well microtitre plates was significantly higher when incubated in 4 °C. The formation of biofilm also occurs at a faster rate at 4 °C and higher optical density (OD 570 nm) was observed at 45 °C. This shows that storage under formation of biofilm that may lead to a higher contamination along the processing line in the food industry. Formation of biofilm was found to be more dependent on temperature compared to sodium chloride stress.
Fulltext Neuraxial block and postoperative epidural analgesia: effects on outcomes in the POISE-2 trial†

Leslie K, McIlroy D, Kasza J, Forbes A, Kurz A, Khan J, et al.

Br J Anaesth, 2016 Jan;116(1):100-12.
PMID: 26209855 DOI: 10.1093/bja/aev255

BACKGROUND: We assessed associations between intraoperative neuraxial block and postoperative epidural analgesia, and a composite primary outcome of death or non-fatal myocardial infarction, at 30 days post-randomization in POISE-2 Trial subjects.
METHODS: 10 010 high-risk noncardiac surgical patients were randomized aspirin or placebo and clonidine or placebo. Neuraxial block was defined as intraoperative spinal anaesthesia, or thoracic or lumbar epidural anaesthesia. Postoperative epidural analgesia was defined as postoperative epidural local anaesthetic and/or opioid administration. We used logistic regression with weighting using estimated propensity scores.
RESULTS: Neuraxial block was not associated with the primary outcome [7.5% vs 6.5%; odds ratio (OR), 0.89; 95% CI (confidence interval), 0.73-1.08; P=0.24], death (1.0% vs 1.4%; OR, 0.84; 95% CI, 0.53-1.35; P=0.48), myocardial infarction (6.9% vs 5.5%; OR, 0.91; 95% CI, 0.74-1.12; P=0.36) or stroke (0.3% vs 0.4%; OR, 1.05; 95% CI, 0.44-2.49; P=0.91). Neuraxial block was associated with less clinically important hypotension (39% vs 46%; OR, 0.90; 95% CI, 0.81-1.00; P=0.04). Postoperative epidural analgesia was not associated with the primary outcome (11.8% vs 6.2%; OR, 1.48; 95% CI, 0.89-2.48; P=0.13), death (1.3% vs 0.8%; OR, 0.84; 95% CI, 0.35-1.99; P=0.68], myocardial infarction (11.0% vs 5.7%; OR, 1.53; 95% CI, 0.90-2.61; P=0.11], stroke (0.4% vs 0.4%; OR, 0.65; 95% CI, 0.18-2.32; P=0.50] or clinically important hypotension (63% vs 36%; OR, 1.40; 95% CI, 0.95-2.09; P=0.09).
CONCLUSIONS: Neuraxial block and postoperative epidural analgesia were not associated with adverse cardiovascular outcomes among POISE-2 subjects.
Fulltext Non-Hodgkin's lymphoma in an Asian population: 1968-1992 time trends and ethnic differences in Singapore

Seow A, Lee J, Sng I, Fong CM, Lee HP

Cancer, 1996 May 1;77(9):1899-904.
PMID: 8646691

BACKGROUND: Non-Hodgkin's lymphoma has increased in incidence in many countries, particularly in the West. Advances in diagnostic methods and the understanding of the disease over time pose a challenge to the interpretation of these trends. The aim of this study was to determine if the disease has increased in Singapore, a newly industrialized Asian country, and to examine the possible factors that may account for any observed changes.
METHODS: Data from the population-based Singapore Cancer Registry for the period 1968 to 1992 were reviewed to determine time trends based on sex and ethnic group. The Poisson regression model was fitted to the cross-tabulated data to obtain the adjusted incidence density ratios.
RESULTS: A total of 1988 cases of non-Hodgkin's lymphoma were included in the analysis. There was an overall increase in incidence among both Chinese and Malaysians. However, the rate of increase was greater in females (age-standardized rate from 1.8 per 100,000 in 1968-1972 to 4.5 per 100,000 in 1988-1992) than in males (3.2 per 100,000 to 5.9 per 100,000 in the same time periods). Between ethnic groups, Malay females were at higher overall risk compared with their Chinese counterparts (incidence density ratio 1.32; 95% confidence interval, 1.08-1.61). Although a substantial proportion of patients diagnosed with Hodgkin's disease between 1968 and 1972 were reclassified on review, using present criteria, as having non-Hodgkin's lymphoma, it is unlikely that this, and other recent changes in histologic interpretation, could have accounted for an increase of this magnitude.
CONCLUSIONS: Non-Hodgkin's lymphoma has increased in incidence among the Chinese and Malay populations in Singapore. The pattern of increase differs from that of the common cancer sites, and suggests the need to look for environmental and genetic factors that have not yet been elucidated.
p53 Status does not affect photodynamic cell killing induced by hypericin

Lee HB, Ho AS, Teo SH

Cancer Chemother Pharmacol, 2006 Jul;58(1):91-8.
PMID: 16211395

Given that p53 is a tumor suppressor that plays a central role in the cellular response to DNA damage and that more than 50% of all cancers have mutated p53, the wider utility of photodynamic therapy (PDT) in the treatment of cancer will depend on an understanding of whether p53 status modulates response to PDT. In this study, we investigated the photosensitivity of isogenic cell lines that differ only in their p53 status to PDT using hypericin as the photosensitizer.
Fulltext Methods for Systematic Identification of Membrane Proteins for Specific Capture of Cancer-Derived Extracellular Vesicles

Zaborowski MP, Lee K, Na YJ, Sammarco A, Zhang X, Iwanicki M, et al.

Cell Rep, 2019 Apr 02;27(1):255-268.e6.
PMID: 30943406 DOI: 10.1016/j.celrep.2019.03.003

Analysis of cancer-derived extracellular vesicles (EVs) in biofluids potentially provides a source of disease biomarkers. At present there is no procedure to systematically identify which antigens should be targeted to differentiate cancer-derived from normal host cell-derived EVs. Here, we propose a computational framework that integrates information about membrane proteins in tumors and normal tissues from databases: UniProt, The Cancer Genome Atlas, the Genotype-Tissue Expression Project, and the Human Protein Atlas. We developed two methods to assess capture of EVs from specific cell types. (1) We used palmitoylated fluorescent protein (palmtdTomato) to label tumor-derived EVs. Beads displaying antibodies of interest were incubated with conditioned medium from palmtdTomato-expressing cells. Bound EVs were quantified using flow cytometry. (2) We also showed that membrane-bound Gaussia luciferase allows the detection of cancer-derived EVs in blood of tumor-bearing animals. Our analytical and validation platform should be applicable to identify antigens on EVs from any tumor type.
Fulltext Increased Resilience Weakens the Relationship between Perceived Stress and Anxiety on Sleep Quality: A Moderated Mediation Analysis of Higher Education Students from 7 Countries

Du C, Zan MCH, Cho MJ, Fenton JI, Hsiao PY, Hsiao R, et al.

Clocks Sleep, 2020 Sep;2(3):334-353.
PMID: 33089208 DOI: 10.3390/clockssleep2030025

High levels of perceived stress and anxiety among university students are a global concern and are known to negatively influence sleep. However, few studies have explored how stress response styles, like psychological resilience and rumination, might alter these relationships. Using validated tools, perceived stress, anxiety, stress response styles, and sleep behaviors of undergraduate and graduate students from seven countries during the height of the COVID-19 pandemic were characterized in order to examine the relationships between these factors using mediation and moderation analyses. Students enrolled in universities in China, Ireland, Malaysia, Taiwan, South Korea, the Netherlands, and the United States were recruited in May 2020. A total of 2254 students completed this cross-sectional study. Perceived stress and anxiety were negatively associated with sleep quality through the mediation of rumination. Increased psychological resilience weakened the relationships between perceived stress and anxiety on sleep quality. The majority of students reported that COVID-19 negatively influenced their mental health and sleep quality but not sleep duration. Based on these results, university students would likely benefit from sleep education and mental health promotion programs that include trainings to increase psychological resilience and reduce rumination, particularly during times of increased stress.
Fulltext Health Behaviors of Higher Education Students from 7 Countries: Poorer Sleep Quality during the COVID-19 Pandemic Predicts Higher Dietary Risk

Du C, Zan MCH, Cho MJ, Fenton JI, Hsiao PY, Hsiao R, et al.

Clocks Sleep, 2021 Jan 15;3(1):12-30.
PMID: 33467418 DOI: 10.3390/clockssleep3010002

Health behaviors of higher education students can be negatively influenced by stressful events. The global COVID-19 pandemic presents a unique opportunity to characterize and compare health behaviors across multiple countries and to examine how these behaviors are shaped by the pandemic experience. Undergraduate and graduate students enrolled in universities in China, Ireland, Malaysia, South Korea, Taiwan, the Netherlands and the United States (USA) were recruited into this cross-sectional study. Eligible students filled out an online survey comprised of validated tools for assessing sleep quality and duration, dietary risk, alcohol misuse and physical activity between late April and the end of May 2020. Health behaviors were fairly consistent across countries, and all countries reported poor sleep quality. However, during the survey period, the COVID-19 pandemic influenced the health behaviors of students in European countries and the USA more negatively than Asian countries, which could be attributed to the differences in pandemic time course and caseloads. Students who experienced a decline in sleep quality during the COVID-19 pandemic had higher dietary risk scores than students who did not experience a change in sleep quality (p = 0.001). Improved sleep quality was associated with less sitting time (p = 0.010). Addressing sleep issues among higher education students is a pressing concern, especially during stressful events. These results support the importance of making education and behavior-based sleep programming available for higher education students in order to benefit students' overall health.
[Clostridium bifermentans serovar malaysia, a new anaerobic bacterium pathogen to mosquito and blackfly larvae]

de Barjac H, Sebald M, Charles JF, Cheong WH, Lee HL

C. R. Acad. Sci. III, Sci. Vie, 1990;310(9):383-7.
PMID: 1972899

A strain of Clostridium bifermentans individualized as serovar malaysia (C.b.m.) according to its specific H antigen is toxic to mosquito and blackfly larvae when given orally. The toxicity occurs in sporulated cells which contain, in addition to spores, proteinic parasporal inclusion bodies and feather-like appendages; the amino acid content of the inclusion bodies is similar to that of Bacillus thuringiensis serovar israelensis (B.t.i.) and B. sphaericus crystals. The toxicity to Anopheles stephensi is as high as that of B.t.i. and the best strains of B. sphaericus. Culex pipiens is somewhat less susceptible, and Aedes aegypti much less. Pure parasporal inclusion bodies, isolated by ultracentrifugation on sucrose gradients, are highly toxic to mosquito larvae. The larvicidal power is destroyed by heating at 80 degrees C or by treatment with 50 mM NaOH. It is preserved by freeze-drying. The innocuity to mice of the sporulated cells is shown by different routes of administration: force-feeding, percutaneous, subcutaneous, intraperitoneal or intravenous injections. The potential for the biological control of mosquito and blackfly larvae is suggested.
Fulltext Modelling the Effect of a Novel Autodissemination Trap on the Spread of Dengue in Shah Alam and Malaysia

Liang Y, Ahmad Mohiddin MN, Bahauddin R, Hidayatul FO, Nazni WA, Lee HL, et al.

Comput Math Methods Med, 2019;2019:1923479.
PMID: 31481976 DOI: 10.1155/2019/1923479

In this paper, we will start off by introducing the classical Ross-Macdonald model for vector-borne diseases which we use to describe the transmission of dengue between humans and Aedes mosquitoes in Shah Alam, which is a city and the state capital of Selangor, Malaysia. We will focus on analysing the effect of using the Mosquito Home System (MHS), which is an example of an autodissemination trap, in reducing the number of dengue cases by changing the Ross-Macdonald model. By using the national dengue data from Malaysia, we are able to estimate λ, which represents the initial growth rate of the dengue epidemic, and this allows us to estimate the number of mosquitoes in Malaysia. A mathematical expression is also constructed which allows us to estimate the potential number of breeding sites of Aedes mosquitoes. By using the data available from the MHS trial carried out in Section 15 of Shah Alam, we included the potential effect of the MHS into the dengue model and thus modelled the impact MHS has on the spread of dengue within the trial area. We then extended our results to analyse the effect of the MHSs on reducing the number of dengue cases in the whole of Malaysia. A new model was constructed with a basic reproduction number, R0,MalaMHS, which allows us to identify the required MHSs coverage needed to achieve extinction in Malaysia. Numerical simulations and tables of results were also produced to illustrate our results.
Fulltext A Deep Neural Network for Simultaneous Estimation of b Jet Energy and Resolution

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, et al.

Comput Softw Big Sci, 2020;4(1):10.
PMID: 33196702 DOI: 10.1007/s41781-020-00041-z

We describe a method to obtain point and dispersion estimates for the energies of jets arising from b quarks produced in proton-proton collisions at an energy of s = 13 TeV at the CERN LHC. The algorithm is trained on a large sample of simulated b jets and validated on data recorded by the CMS detector in 2017 corresponding to an integrated luminosity of 41 fb - 1 . A multivariate regression algorithm based on a deep feed-forward neural network employs jet composition and shape information, and the properties of reconstructed secondary vertices associated with the jet. The results of the algorithm are used to improve the sensitivity of analyses that make use of b jets in the final state, such as the observation of Higgs boson decay to b b ¯ .

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