MyMedR

Displaying publications 21 - 40 of 117 in total

Abstract:

Sort:

Fulltext Fine-mapping of 150 breast cancer risk regions identifies 191 likely target genes

Fachal L, Aschard H, Beesley J, Barnes DR, Allen J, Kar S, et al.

Nat Genet, 2020 01;52(1):56-73.
PMID: 31911677 DOI: 10.1038/s41588-019-0537-1

Genome-wide association studies have identified breast cancer risk variants in over 150 genomic regions, but the mechanisms underlying risk remain largely unknown. These regions were explored by combining association analysis with in silico genomic feature annotations. We defined 205 independent risk-associated signals with the set of credible causal variants in each one. In parallel, we used a Bayesian approach (PAINTOR) that combines genetic association, linkage disequilibrium and enriched genomic features to determine variants with high posterior probabilities of being causal. Potentially causal variants were significantly over-represented in active gene regulatory regions and transcription factor binding sites. We applied our INQUSIT pipeline for prioritizing genes as targets of those potentially causal variants, using gene expression (expression quantitative trait loci), chromatin interaction and functional annotations. Known cancer drivers, transcription factors and genes in the developmental, apoptosis, immune system and DNA integrity checkpoint gene ontology pathways were over-represented among the highest-confidence target genes.
Development of a battery of tests to measure attitudes and intended behaviours of dental students towards people with disability or those in marginalised groups

Faulks D, Dougall A, Ting G, Ari T, Nunn J, Friedman C, et al.

Eur J Dent Educ, 2018 May;22(2):e278-e290.
PMID: 28940883 DOI: 10.1111/eje.12292

INTRODUCTION: Recommended curricula in Special Care Dentistry (SCD) outline learning objectives that include the domain of attitudes and behaviours, but these are notoriously difficult to measure. The aims of this study were (i) to develop a test battery comprising adapted and new scales to evaluate values, attitudes and intentions of dental students towards people with disability and people in marginalised groups and (ii) to determine reliability (interitem consistency) and validity of the scales within the test battery.
MATERIALS AND METHODS: A literature search identified pre-existing measures and models for the assessment of attitudes in healthcare students. Adaptation of three pre-existing scales was undertaken, and a new scale was developed based upon the Theory of Planned Behaviour (TPB) using an elicitation survey. These scales underwent a process of content validation. The three adapted scales and the TPB scale were piloted by 130 students at 5 different professional stages, from 4 different countries.
RESULTS: The scales were adjusted to ensure good internal reliability, variance, distribution, and face and content validity. In addition, the different scales showed good divergent validity.
DISCUSSION: These results are positive, and the scales now need to be validated in the field.
CONCLUSIONS: It is hoped that these tools will be useful to educators in SCD to evaluate the impact of teaching and clinical exposure on their students.
Quality of life of obese children in Malaysia

Hamzaid H, Talib RA, Azizi NH, Maamor N, Reilly JJ, Wafa SW

Int J Pediatr Obes, 2011 Oct;6(5-6):450-4.
PMID: 21767214 DOI: 10.3109/17477166.2011.590206

BACKGROUND:Quality of life (QoL) is impaired in childhood obesity, but the literature on this is all from Western countries. Aim. To test for impairment of QoL in obese children in Malaysia, using parent-reported and child-reported QoL.
METHODS:Health-related Quality of Life was measured using the Paediatric Quality of Life Inventory version 4.0. Comparison of QoL between a community sample of 90 obese children (as defined by US CDC and Cole-IOTF definitions), median age 9.5 y (interquartile range [IQR] 8.6, 10.5 y) and 90 control children of healthy weight (BMI less than the 85th centile of US reference data), median age 10.0 y (IQR 9.6, 10.5 y). Children were matched pair-wise for age, gender, and ethnic group, and controls were recruited from schools in the same area as obese participants.
RESULTS:For child self-report, the healthy weight group had significantly higher QoL for the physical (median 82.9, IQR 65.7, 90.6), and psychosocial domains (median, 73.3, IQR 64.4, 83.3), and total QoL (median 76.1, IQR 64.1, 84.8) compared to the obese group (median 67.2, IQR 59.4, 81.3; median 62.5, IQR 53.3, 75.4; median 60.9, IQR 50.8, 73.9; all p < 0.001). There were no significant differences between the obese and healthy weight group for parent-reported physical health, psychosocial health, or total QoL.
CONCLUSION:Obese children in Malaysia have markedly poorer QoL than their peers, but this is not evident when parent reports of QoL are used.
Study name: Malaysian Childhood Obesity Treatment Trial (MASCOT)
Study site: Two primary schools, Kuala Lumpur, Malaysia
Fulltext Ants (Hymenoptera: Formicidae) associated with pig carcasses in Malaysia

Heo CC, Mohamad AR, Rosli H, Nurul Ashikin A, Chen CD, John J, et al.

Trop Biomed, 2009 Apr;26(1):106-9.
PMID: 19696735

An observational study was conducted in an oil palm plantation in Tanjung Sepat, Selangor, Malaysia on August until September 2007 to note the decomposition process of pigs and their related faunal succession. We collected six species of ants (Formicidae) from 3 subfamilies: Formicinae (Oecophylla smaragdina and Anoplolepis gracilipes), Myrmicinae (Tetramorium sp. and Pheidologeton sp.) and Ponerinae (Odontoponera sp. and Diacamma sp.) that were associated with pig carcasses placed on the ground. Oecophylla smaragdina, Pheidologeton sp. and Tetramorium sp. were found on a partially burnt pig carcass whereas the other species were recovered from unburned pig carcass. These ants predated on fly eggs, larvae, pupae and adults. Ants could be found at all stages of decomposition starting from fresh until dry stage. Predatory ants can reduce fly population and thus may affect the rate of carcass decomposition but this was not seen in our study. Even though O. smaragdina was seen at all stages of decomposition of the burnt pig, this did not alter much the decomposition process by fly larvae.
Fulltext On the predation of fly, Chrysomya rufifacies (Macquart) by a spider, Oxyopes sp. Latreille (Oxyopidae)

Heo CC, Mohamad AM, John J, Baharudin O

Trop Biomed, 2008 Apr;25(1):93-5.
PMID: 18600210 MyJurnal

During a forensic entomological study conducted in a palm oil plantation in Tg.Sepat, Selangor in September 2007, a spider (Arachnida), Oxyopes sp. (Oxyopidae) was found to predate on a calliphorid fly (Chrysomya rufifacies). The female spider laid a silk thread, or "drag line", behind it as it moved. This spider bites its prey by using a pairs of chelicerae, and injecting venom into the fly. The fly was moving its wing trying to escape, however, it succumbed to the deadly bite.
Fulltext Insect succession on a decomposing piglet carcass placed in a man-made freshwater pond in Malaysia

Heo CC, Mohamad AM, John J, Baharudin O

Trop Biomed, 2008 Apr;25(1):23-9.
PMID: 18600201

This entomological study was conducted in a man-made freshwater pond in a palm oil plantation in Tanjung Sepat, Selangor from 23 July 2007 by using pig (Sus scrofa) as a carcass model. A 1.5 month old piglet (5 kg), which died of asphyxia after being accidentally crushed by its mother, was thrown into a pond. Observation was made for ten days; one visit per day and climatological data were recorded. On the first two days, the piglet carcass sunk to the bottom of the pond. The carcass floated to the surface on the third day but no fly activities were seen. The blow fly, Chrysomya megacephala and Chrysomya rufifacies started to oviposit on the fourth day. Other than adult flies, a spider (Arachnida) was also observed on the carcass. Bubbles accumulated at the mouthpart, and the abdomen was greenish black. A lot of blow fly eggs were seen on the body surface on the fifth day (floating decay), along with first and second instars C. megacephala crawling under the piglet's skin. On the sixth day, adult blow fly, C. megacephala,and C. rufifacies,and muscid flies, Ophyra spinigera and Musca domestica were observed on to the carcass. High numbers of first and second instars of flies were observed wandering around the body surface with C. megacephala larvae being the predominant species. Two prominent maggot masses occurred on seventh and eighth days. Bloated deterioration stage began on day eighth exposing rib bones, humerus bones and intestines. Carcass was partially sinking and the maggot masses were at the water level. On day ninth, the carcass was partially sinking and three maggot masses were observed on the exposed surface. There were very few adult flies, including a scarab beetle was sighted on the carcass at this stage. The carcass along with the maggots sunk on day tenth, leaving an oily layer on the water surface.
Fulltext European polygenic risk score for prediction of breast cancer shows similar performance in Asian women

Ho WK, Tan MM, Mavaddat N, Tai MC, Mariapun S, Li J, et al.

Nat Commun, 2020 07 31;11(1):3833.
PMID: 32737321 DOI: 10.1038/s41467-020-17680-w

Polygenic risk scores (PRS) have been shown to predict breast cancer risk in European women, but their utility in Asian women is unclear. Here we evaluate the best performing PRSs for European-ancestry women using data from 17,262 breast cancer cases and 17,695 controls of Asian ancestry from 13 case-control studies, and 10,255 Chinese women from a prospective cohort (413 incident breast cancers). Compared to women in the middle quintile of the risk distribution, women in the highest 1% of PRS distribution have a ~2.7-fold risk and women in the lowest 1% of PRS distribution has ~0.4-fold risk of developing breast cancer. There is no evidence of heterogeneity in PRS performance in Chinese, Malay and Indian women. A PRS developed for European-ancestry women is also predictive of breast cancer risk in Asian women and can help in developing risk-stratified screening programmes in Asia.
Fulltext Physiological responses of rosewoods Dalbergia cochinchinensis and D. oliveri under drought and heat stresses

Hung TH, Gooda R, Rizzuto G, So T, Thammavong B, Tran HT, et al.

Ecol Evol, 2020 Oct;10(19):10872-10885.
PMID: 33072302 DOI: 10.1002/ece3.6744

Dalbergia cochinchinensis and D. oliveri are classified as vulnerable and endangered, respectively, in the IUCN Red List and under continued threat from deforestation and illegal harvesting for rosewood. Despite emerging efforts to conserve and restore these species, little is known of their responses to drought and heat stress, which are expected to increase in the Greater Mekong Subregion where the species co-occur and are endemic. In this study of isolated and combined drought and heat effects, we found that D. oliveri had an earlier stomatal closure and more constant midday water potential in response to increasing drought level, suggesting that D. oliveri is relatively isohydric while D. cochinchinensis is relatively anisohydric. Heat shock and drought had synergistic effects on stomatal closure. Our results indicate contrasting relationships in water relations, photosynthetic pigment levels, and total soluble sugars. An increase in chlorophyll a was observed in D. cochinchinensis during drought, and a concomitant increase in carotenoid content likely afforded protection against photo-oxidation. These physiological changes correlated with higher total soluble sugars in D. cochinchinensis. By contrast, D. oliveri avoided drought by reducing chlorophyll content and compromising productivity. Anisohydry and drought tolerance in D. cochinchinensis are adaptations which fit well with its ecological niche as a pioneering species with faster growth in young trees. We believe this understanding of the stress responses of both species will be crucial to their effective regeneration and conservation in degraded habitats and in the face of climate change.
Fulltext Range-wide differential adaptation and genomic offset in critically endangered Asian rosewoods

Hung TH, So T, Thammavong B, Chamchumroon V, Theilade I, Phourin C, et al.

Proc Natl Acad Sci U S A, 2023 Aug 15;120(33):e2301603120.
PMID: 37549265 DOI: 10.1073/pnas.2301603120

In the billion-dollar global illegal wildlife trade, rosewoods have been the world's most trafficked wild product since 2005. Dalbergia cochinchinensis and Dalbergia oliveri are the most sought-after rosewoods in the Greater Mekong Subregion. They are exposed to significant genetic risks and the lack of knowledge on their adaptability limits the effectiveness of conservation efforts. Here, we present genome assemblies and range-wide genomic scans of adaptive variation, together with predictions of genomic offset to climate change. Adaptive genomic variation was differentially associated with temperature and precipitation-related variables between the species, although their natural ranges overlap. The findings are consistent with differences in pioneering ability and in drought tolerance. We predict their genomic offsets will increase over time and with increasing carbon emission pathway but at a faster pace in D. cochinchinensis than in D. oliveri. These results and the distinct gene-environment association in the eastern coastal edge of Vietnam suggest species-specific conservation actions: germplasm representation across the range in D. cochinchinensis and focused on hotspots of genomic offset in D. oliveri. We translated our genomic models into a seed source matching application, seedeR, to rapidly inform restoration efforts. Our ecological genomic research uncovering contrasting selection forces acting in sympatric rosewoods is of relevance to conserving tropical trees globally and combating risks from climate change.
THE SUNGEI BULOH LEPROSARIUM

JOHN JC

Indian J Dermatol, 1965 Jan;10:62-4.
PMID: 14266440
Fulltext Genome- and transcriptome-wide association studies of 386,000 Asian and European-ancestry women provide new insights into breast cancer genetics

Jia G, Ping J, Shu X, Yang Y, Cai Q, Kweon SS, et al.

Am J Hum Genet, 2022 Dec 01;109(12):2185-2195.
PMID: 36356581 DOI: 10.1016/j.ajhg.2022.10.011

By combining data from 160,500 individuals with breast cancer and 226,196 controls of Asian and European ancestry, we conducted genome- and transcriptome-wide association studies of breast cancer. We identified 222 genetic risk loci and 137 genes that were associated with breast cancer risk at a p
Fulltext An assessment of health-care students' attitudes toward patients with or at high risk for HIV: implications for education and cultural competency

Jin H, Earnshaw VA, Wickersham JA, Kamarulzaman A, Desai MM, John J, et al.

AIDS Care, 2014;26(10):1223-8.
PMID: 24625279 DOI: 10.1080/09540121.2014.894616

Stigma perpetuated by health-care providers has been found to be a barrier to care for vulnerable populations, including HIV-infected, people who inject drugs (PWIDs), and men who have sex with men (MSM) in multiple clinical contexts and remains unexamined among professional health-care students in Malaysia. This cross-sectional, anonymous, and Internet-based survey assessed the attitudes of medical and dental students toward HIV-infected, PWID, and MSM patients. Survey invitation was emailed to 3191 students at 8 professional schools; 1296 (40.6%) responded and scored their attitudes toward these patient groups using a feeling thermometer, indicating their attitudes on a sliding scale from 0 (most negative) to 100 (most positive). Compared to general patients (mean = 76.50), the mean scores for HIV-infected (mean = 54.04; p < 0.001), PWID (mean = 37.50; p < 0.001), and MSM (mean = 32.13; p < 0.001) patients were significantly lower and significantly different between each group comparison. Within group differences, most notably religion, ethnicity, and personally knowing someone from these populations were associated with significant differences in attitudes. No differences were noted between pre-clinical and clinical year of training. Health-care students represent the next generation of clinicians who will be responsible for future HIV prevention and treatment efforts. Our findings suggest alarmingly negative attitudes toward these patients, especially MSM, necessitating prompt and effective interventions designed to ameliorate the negative attitudes of health-care students toward vulnerable populations, specifically HIV-infected, PWID, and MSM patients in Malaysia.
Site site: online surveys at seven universities: University of Malaya, National University of Malaysia, International Islamic University Malaysia, Universiti Malaysia Sarawak, Penang International Dental College, Universiti Teknologi MARA Malaysia, and Universiti Sains Malaysia.
Flexural properties of poly(methyl methacrylate) resin reinforced with oil palm empty fruit bunch fibers: a preliminary finding

John J, Ann Mani S, Palaniswamy K, Ramanathan A, Razak AA

J Prosthodont, 2015 Apr;24(3):233-8.
PMID: 24976147 DOI: 10.1111/jopr.12191

PURPOSE: The purpose of this preliminary study was to evaluate the flexural properties of poly(methyl methacrylate) (PMMA) reinforced with oil palm empty fruit bunch (OPEFB) fiber.
MATERIALS AND METHODS: The flexural strength and flexural modulus of three OPEFB fiber-reinforced PMMA were compared with a conventional and a commercially available reinforced PMMA. The three test groups included OPEFB fibers of 0.5 mm thickness, 2.0 mm thickness, and OPEFB cellulose.
RESULTS: All test group specimens demonstrated improved flexural strength and flexural modulus over conventional PMMA. Reinforcement with OPEFB cellulose showed the highest mean flexural strength and flexural modulus, which were statistically significant when compared to the conventional and commercially reinforced PMMA used in this study. OPEFB fiber in the form of cellulose and 0.5 mm thickness fiber significantly improved flexural strength and flexural modulus of conventional PMMA resin. Further investigation on the properties of PMMA reinforced with OPEFB cellulose is warranted.
CONCLUSIONS: Natural OPEFB fibers, especially OPEFB in cellulose form, can be considered a viable alternative to existing commercially available synthetic fiber reinforced PMMA resin.
Measuring service quality of public dental health care facilities in Kelantan, Malaysia

John J, Yatim FM, Mani SA

Asia Pac J Public Health, 2011 Sep;23(5):742-53.
PMID: 20460281 DOI: 10.1177/1010539509357341

This study investigates patients' expectations and perceptions of service quality in public dental health care and measures their "satisfaction gap." This descriptive study involved 481 dental outpatients in Kelantan, Malaysia. A modified SERVQUAL 20-item instrument was used to assess patients' expectations before and perceptions after receiving dental treatment. The "satisfaction gap" was then measured.
RESULTS: showed that patients visiting for management of dental pain were more satisfied (P = .007) than those visiting with appointment. The most significant service quality dimensions were related to responsiveness, assurance, and empathy of the dental health care providers. There was a significant difference between the patients' expectations and their perceptions of service provided (P < .01) with regard to all dimensions. In conclusion, dental service providers should give emphasis to the compassionate and emotional aspects of care and to remember that they are integral components of quality service.
Fulltext Oral health care in the elderly population in Malaysia--a review

John J, Mani SA, Azizah Y

Med J Malaysia, 2004 Aug;59(3):433-9.
PMID: 15727396

One of the undeniable facts about living is that everyday we are getting older. By 2050, it is projected that one out of every five Malaysians will be 60 or older. The economic challenge of this demographic change will affect development and the financial implications of sustaining well being of this group are formidable and complex. This population group has extensive oral disease, medical problems that complicate their oral care, and unique dental treatment challenges. The authors discuss the problem of oral healthcare among the aged, its impediments and propose some approaches for improvement to better serve the needs of this group of vulnerable members of our nation.
Fulltext Microplastics in mangroves and coral reef ecosystems: a review

John J, Nandhini AR, Velayudhaperumal Chellam P, Sillanpää M

Environ Chem Lett, 2021 Oct 07.
PMID: 34642583 DOI: 10.1007/s10311-021-01326-4

Microplastic pollution has recently been identified as a major issue for the health of ecosystems. Microplastics have typically sizes of less than 5 mm and occur in various forms, such as pellets, fibres, fragments, films, and granules. Mangroves and coral reefs are sensitive and restricted ecosystems that provide free ecological services such as coastal protection, maintaining natural cycles, hotspots of biodiversity and economically valuable goods. However, urbanization and industrial activities have started contaminating even these preserved ecosystems. Here we review sources, occurrence, and toxicity of microplastics in the trophic levels of mangrove and coral reef ecosystems. We present detection methods, such as microscopic identification and spectroscopy. We discuss mitigating measures that prevent the entry of microplastics into the marine environment.
Fulltext Levels and Correlates of Objectively Measured Sedentary Behavior in Young Children: SUNRISE Study Results from 19 Countries

Kariippanon KE, Chong KH, Janssen X, Tomaz SA, Ribeiro EHC, Munambah N, et al.

Med Sci Sports Exerc, 2022 Jul 01;54(7):1123-1130.
PMID: 35142711 DOI: 10.1249/MSS.0000000000002886

PURPOSE: There is a paucity of global data on sedentary behavior during early childhood. The purpose of this study was to examine how device-measured sedentary behavior in young children differed across geographically, economically, and sociodemographically diverse populations, in an international sample.
METHODS: This multinational, cross-sectional study included data from 1071 children 3-5 yr old from 19 countries, collected between 2018 and 2020 (pre-COVID). Sedentary behavior was measured for three consecutive days using activPAL accelerometers. Sedentary time, sedentary fragmentation, and seated transport duration were calculated. Linear mixed models were used to examine the differences in sedentary behavior variables between sex, country-level income groups, urban/rural settings, and population density.
RESULTS: Children spent 56% (7.4 h) of their waking time sedentary. The longest average bout duration was 81.1 ± 45.4 min, and an average of 61.1 ± 50.1 min·d-1 was spent in seated transport. Children from upper-middle-income and high-income countries spent a greater proportion of the day sedentary, accrued more sedentary bouts, had shorter breaks between sedentary bouts, and spent significantly more time in seated transport, compared with children from low-income and lower-middle-income countries. Sex and urban/rural residential setting were not associated with any outcomes. Higher population density was associated with several higher sedentary behavior measures.
CONCLUSIONS: These data advance our understanding of young children's sedentary behavior patterns globally. Country income levels and population density appear to be stronger drivers of the observed differences, than sex or rural/urban residential setting.
Search for displaced supersymmetry in events with an electron and a muon with large impact parameters

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2015 Feb 13;114(6):061801.
PMID: 25723204

A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at √[s]=8 TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7 fb(-1). Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-μ final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-μ final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to cτ=2 cm, excluding masses below 790 GeV at 95% confidence level.
Study of vector boson scattering and search for new physics in events with two same-sign leptons and two jets

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2015 Feb 6;114(5):051801.
PMID: 25699433

A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4 fb(-1) collected with the CMS detector. Candidate events are selected with exactly two leptons of the same charge, two jets with large rapidity separation and high dijet mass, and moderate missing transverse energy. The signal region is expected to be dominated by electroweak same-sign W-boson pair production. The observation agrees with the standard model prediction. The observed significance is 2.0 standard deviations, where a significance of 3.1 standard deviations is expected based on the standard model. Cross section measurements for W(±)W(±) and WZ processes in the fiducial region are reported. Bounds on the structure of quartic vector-boson interactions are given in the framework of dimension-eight effective field theory operators, as well as limits on the production of doubly charged Higgs bosons.
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.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links