Displaying publications 1 - 20 of 46 in total

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  1. Liu WJ, Zaki M
    Med J Malaysia, 2004 Dec;59(5):649-58.
    PMID: 15889568 MyJurnal
    This survey aims to identify prevalence, reasons and predictors of noncompliance among renal transplant patients followed up in Hospital Kuala Lumpur (HKL). All adult renal transplant patients who were at least 6 months post transplant were recruited from 10/2001 till 5/2002. Patients who consented were interviewed by a medical doctor or research assistant based on questionnaire. Noncompliers were defined as those who missed or self adjusted any dose of immunosuppressant within the preceding 4 weeks. Inter-rater agreement was assessed prior by Kappa (K) scores and they were acceptable. Out of 304 patients, 246 patients volunteered; of whom 144 (58.5%) were males. Twenty-one (9.3%) were noncompliers. Reasons for noncompliance included forgetfulness (n=8), financial constraints (n=1), fear of rejection (n=1), side effects (n=9), decision not to take (n=6), difficulty in breaking medication into correct dosages (n=1). Significant predictors of noncompliance were longer duration of transplant noncompliance to other drugs, regular use of nonprescription drugs; the lack of symptoms of fat facial cheeks and infection. Surveillance for noncompliance should not be relaxed as its predictors are diverse and persistent, especially in those who are at high risks.
  2. Zeng J, Liu W
    PLoS One, 2024;19(3):e0293156.
    PMID: 38446752 DOI: 10.1371/journal.pone.0293156
    Professional identity has become a central topic in teacher education research and a crucial factor in shaping teachers' self-perception and perspectives on various aspects of their profession, including teacher roles, scholarly research, curriculum design, classroom instruction, instructional methods, and strategies, as well as their interactions within the educational context. Despite the considerable scholarly interest in teacher identity development, relatively few studies have considered how to measure teacher professional identity. This study developed and validated a new measurement of professional identity among Chinese pre-service teachers from an English language education program. A total of 560 pre-service teachers majoring in English language education were invited to participate in a survey and 542 questionnaires were deemed valid and subjected to analysis. Through this analysis, a scale with 17 items was developed, focusing on three different dimensions: professional self-efficacy, career commitment, and professional knowledge. After excluding items with a relatively poor correlation with factor loading, the final scale consisted of 13 items. The results showed that the developed scale has relatively good reliability (α = 0.939) and structural validity (χ2/df = 2.46, p < .001, CFI = 0.978, TLI = 0.971, SRMR = 0.033, RMSEA (90% CI) = 0.071 0.054, 0.089). This study may provide a quantitative instrument for future research to measure professional identity among pre-service teachers, both in Chinese and other contexts.
  3. Liu WJ, Hooi LS
    Med J Malaysia, 2007 Aug;62(3):197-200.
    PMID: 18246906 MyJurnal
    The epidemiology of new patients presenting to Sultanah Aminah Hospital Johor Bahru (HSAJB) with end-stage renal disease (ESRD) in 2003 and 2004 was analysed. Patients with ESRD were prospectively registered in the renal replacement therapy (RRT) database in the nephrology unit. The incidence of ESRD and the RRT provision rate in the district of Johor Bahru were calculated according to gender and race. There were 306 new patients in 2003 and 299 in 2004. Diabetic nephropathy contributed 56.8% new patients in 2003 and 57.9% in 2004. The mean age was 50.8 + 15.1 years in 2003 and 51.3 + 14.2 years in 2004. Males accounted for 53.3% in 2003 and 47.8% in 2004. Haemodialysis was the commonest form of RRT (60.5% in 2003, 69.9% in 2004), followed by continuous ambulatory peritoneal dialysis (30.1% in 2003, 19.4% in 2004) and renal transplantation (5.5% in 2003, 2.3% in 2004). Ninety-one percent of patients in 2003 and 90% in 2004 were alive at the end of the year they presented. The incidence of ESRD in the district of Johor Bahru was estimated as 136 per million population (p.m.p.) in 2003 and 151 p.m.p. in 2004. In the two year period the incidence of ESRD was higher among females (154 p.m.p.) than males (134 p.m.p.). Malays (194 p.m.p.) had higher ESRD incidence compared to Chinese (126 p.m.p.) and Indians (134 p.m.p.). RRT provision in Johor Bahru (92.7%) did not differ significantly with gender or race. The increasing number of patients presenting to HSAJB with ESRD especially those with diabetic nephropathy is a major concern. Prevention strategies at the primary care level may curb the burden of this chronic disease.
  4. Yap KL, Chong YW, Liu W
    PLoS One, 2020;15(1):e0227982.
    PMID: 31978101 DOI: 10.1371/journal.pone.0227982
    The rapid increase in the usage of the mobile internet has led to a great expansion of cellular data networks in order to provide better quality of service. However, the cost to expand the cellular network is high. One of the solutions to provide affordable wireless connectivity is the deployment of a WiFi access point to offload users' data usage. Nevertheless, the frequent and inefficient handover process between the WiFi AP and cellular network, especially when the mobile device is on the go, may degrade the network performance. Mobile devices do not have the intelligence to select the optimal network to enhance the quality of service (QoS). This paper presents an enhanced handover mechanism using mobility prediction (eHMP) to assist mobile devices in the handover process so that users can experience seamless connectivity. eHMP is tested in two wireless architectures, homogeneous and heterogeneous networks. The network performance significantly improved when eHMP is used in a homogeneous network, where the network throughput increases by 106% and the rate of retransmission decreases by 85%. When eHMP is used in a heterogeneous network, the network throughput increases by 55% and the retransmission rate decreases by 75%. The findings presented in this paper reveal that mobility prediction coupled with the multipath protocol can improve the QoS for mobile devices. These results will contribute to a better understanding of how the network service provider can offload traffic to the WiFi network without experiencing performance degradation.
  5. Liu WJ, Chew TF, Chiu AS, Zaki M
    Med J Malaysia, 2006 Dec;61(5):540-6.
    PMID: 17623953 MyJurnal
    The aims of this retrospective analysis were (i) to examine the trends of quality of life (QoL) scores and (ii) to identify the risk factors for QoL scores among 6908 dialysis patients entering dialysis between 1997 and 2002. The Spitzer QoL Index was the instrument used by the National Renal Registry of Malaysia to assess the QoL amongst dialysis patients. Demographic and biochemical data were analysed to identify risk factors for poor QoL. The median QoL-index score ranged between 9 and 10. Significant risk factors for poor QoL were female gender, age > 40, diabetes, cohort starting dialysis 2001-2002, haemodialysis modality, body mass index < 18.5, albumin < 30g/dL, cholesterol < 3.2 mmol/L, haemoglobin < 10 g/dL, diastolic blood pressure of > 90 mHg, iPTH < 100 pg/ml. The overall QoL of dialysis patients is satisfactory. The negative impact of diabetes and haemodialysis on QoL warrants further evaluation as each factor involves 50% and 90% of our dialysis population.
  6. Chan AYK, Hooi LS, Liu WJ
    Med J Malaysia, 2001 Mar;56(1):82-7.
    PMID: 11503302
    Retrospective analysis was done on 235 recipients, 133 males and 102 females, who were transplanted between 25th September 1979 and 25th June 1999. 85.1% were Chinese, 7.7% were Indians and 7.2% Malays. 23% (54) were living related renal transplants (LRRT) all except 5 done at Hospital Kuala Lumpur. 60% (141) were living unrelated donor renal transplants (LURT) done in India. 17% (40) were cadaveric transplants (CADT) (all done in China except 2 at Hospital Kuala Lumpur and one in London). 97% (228) were first transplants. Primary renal disease was unknown in 69.4%, 17% (40) glomerulonephritis, 5.5% diabetic nephropathy and 8.1% 19 others. All were on prednisolone, 93.2% were on azathioprine and 96.6% were on cyclosporin A. The acute rejection rate was 23.4% (55 episodes). Patient survival was 88% at five years and patients alive with functioning graft was 84% at 5 years. LRRT had significantly better survival compared to LURT. 34 grafts were lost to chronic allograft nephropathy. 46 recipients died (33 died with functioning graft).
  7. Bujang MA, Kuan PX, Sapri FE, Liu WJ, Musa R
    Indian J Nephrol, 2019 8 20;29(4):235-241.
    PMID: 31423056 DOI: 10.4103/ijn.IJN_152_18
    Introduction: Clinical parameters especially co-morbidities among end stage renal disease (ESRD) patients are associated with mortality. This study aims to determine the risk factors that are associated with mortality within three years among prevalent patients with ESRD.

    Methods: This is a cohort study where prevalent ESRD patients' details were recorded between May 2012 and October 2012. Their records were matched with national death record at the end of year 2015 to identify the deceased patients within three years. Four models were formulated with two models were based on logistic regression models but with different number of predictors and two models were developed based on risk scoring technique. The preferred models were validated by using sensitivity and specificity analysis.

    Results: A total of 1332 patients were included in the study. Majority succumbed due to cardiovascular disease (48.3%) and sepsis (41.3%). The identified risk factors were mode of dialysis (P < 0.001), diabetes mellitus (P < 0.001), chronic heart disease (P < 0.001) and leg amputation (P = 0.016). The accuracy of four models was almost similar with AUC between 0.680 and 0.711. The predictive models from logistic regression model and risk scoring model were selected as the preferred models based on both accuracy and simplicity. Besides the mode of dialysis, diabetes mellitus and its complications are the important predictors for early mortality among prevalent ESRD patients.

    Conclusions: The models either based on logistic regression or risk scoring model can be used to screen high risk prevalent ESRD patients.

  8. Liu W, Wang YT, Tian DS, Yin ZC, Kwang J
    Dis Aquat Organ, 2002 Apr 24;49(1):11-8.
    PMID: 12093036
    The vp28 gene encoding an envelope protein (28 kDa) of white spot syndrome virus (WSSV) was amplified from WSSV-infected tiger shrimp that originated from Malaysia. Recombinant VP28 protein (r-28) was expressed in Escherichia coli and used as an antigen for preparation of monoclonal antibodies (MAbs). Three murine MAbs (6F6, 6H4 and 9C10) that were screened by r-28 antigen-based enzyme-linked immunosorbent assay (ELISA) were also able to recognize viral VP28 protein as well as r-28 on Western blot. Three non-overlapping epitopes of VP28 protein were determined using the MAbs in competitive ELISA; thus, an antigen-capture ELISA (Ac-ELISA) was developed by virtue of these MAbs. Ac-ELISA can differentiate WSSV-infected shrimp from uninfected shrimp and was further confirmed by a polymerase chain reaction (PCR) and Western blot. Approximately 400 pg of purified WSSV sample and 20 pg of r-28 could be detected by Ac-ELISA, which is comparable in sensitivity to PCR assay but more sensitive than Western blot in the detection of purified virus. Hemolymph and tissue homogenate samples collected from a shrimp farm in Malaysia during December 2000 and July 2001 were also detected by Ac-ELISA and PCR with corroborating results.
  9. Zhang Y, Liu W, Lin Y, Ng YK, Li S
    BMC Genomics, 2019 Apr 04;20(Suppl 2):186.
    PMID: 30967119 DOI: 10.1186/s12864-019-5470-2
    BACKGROUND: Recent advances in genome analysis have established that chromatin has preferred 3D conformations, which bring distant loci into contact. Identifying these contacts is important for us to understand possible interactions between these loci. This has motivated the creation of the Hi-C technology, which detects long-range chromosomal interactions. Distance geometry-based algorithms, such as ChromSDE and ShRec3D, have been able to utilize Hi-C data to infer 3D chromosomal structures. However, these algorithms, being matrix-based, are space- and time-consuming on very large datasets. A human genome of 100 kilobase resolution would involve ∼30,000 loci, requiring gigabytes just in storing the matrices.

    RESULTS: We propose a succinct representation of the distance matrices which tremendously reduces the space requirement. We give a complete solution, called SuperRec, for the inference of chromosomal structures from Hi-C data, through iterative solving the large-scale weighted multidimensional scaling problem.

    CONCLUSIONS: SuperRec runs faster than earlier systems without compromising on result accuracy. The SuperRec package can be obtained from http://www.cs.cityu.edu.hk/~shuaicli/SuperRec .

  10. Gao H, Li H, Liu W, Mishra SK, Li C
    Dokl Biochem Biophys, 2021 Sep;500(1):393-401.
    PMID: 34697748 DOI: 10.1134/S1607672921050070
    Andrographolide is a labdane diterpenoid isolated from Andrographis paniculata. The plant extract and andrographolide has long been used in traditional medicine practices mainly for gastrointestinal diseases and improving liver function. Andrographolide has shown various pharmacological properties including anti-inflammatory, antioxidant and anticancer activity. This study evaluated the effect of andrographolide on proliferation of human gastric carcinoma cells in relevance to p53 and Mdm-2 pathways. Andrographolide inhibited the proliferation of SGC7901 and AGS cells in a dose-dependent manner with estimated IC50 values 38 and 44 μM respectively. Effect of andrographolide on p53 activity was ascertained by using a p53 activator (RITA) which showed synergistic inhibition of cell proliferation. While andrographolide when used in combination with a p53 inhibitor (pifithrin-α) showed potent restriction over its response. Andrographolide caused decrease in mitochondrial membrane potential as an indicator of apoptotic activity. Andrographolide activated the expression of p53 protein and gene and downregulated the levels of Mdm-2 (negative regulator of p53). Andrographolide inhibited the colony formation abilities in SGC7901 in a p53-dependent manner followed by induction of mitochondrial intrinsic apoptosis through activation of caspases-9 and -3, cleavage of PARP, and inhibition of pro-apoptotic Bcl-2. Andrographolide induced p53 mediated apoptosis in gastric carcinoma cells which adds to a novel approach in anticancer therapies.
  11. Zhu XQ, Xu YH, Liao CX, Liu WG, Cheng KK, Chen JX
    J Microsc, 2015 Nov;260(2):219-26.
    PMID: 26366638 DOI: 10.1111/jmi.12288
    Nonlinear optical microscopy (NLOM) was used as a noninvasive and label-free tool to detect and quantify the extent of the cartilage recovery. Two cartilage injury models were established in the outer ears of rabbits that created a different extent of cartilage recovery based on the presence or absence of the perichondrium. High-resolution NLOM images were used to measure cartilage repair, specifically through spectral analysis and image texture. In contrast to a wound lacking a perichondrium, wounds with intact perichondria demonstrated significantly larger TPEF signals from cells and matrix, coarser texture indicating the more deposition of type I collagen. Spectral analysis of cells and matrix can reveal the matrix properties and cell growth. In addition, texture analysis of NLOM images showed significant differences in the distribution of cells and matrix of repaired tissues with or without perichondrium. Specifically, the decay length of autocorrelation coefficient based on TPEF images is 11.2 ± 1.1 in Wound 2 (with perichondrium) and 7.5 ± 2.0 in Wound 1 (without perichondrium), indicating coarser image texture and faster growth of cells in repaired tissues with perichondrium (p < 0.05). Moreover, the decay length of autocorrelation coefficient based on collagen SHG images also showed significant difference between Wound 2 and 1 (16.2 ± 1.2 vs. 12.2 ± 2.1, p < 0.05), indicating coarser image texture and faster deposition of collagen in repaired tissues with perichondrium (Wound 2). These findings suggest that NLOM is an ideal tool for studying cartilage repair, with potential applications in clinical medicine. NLOM can capture macromolecular details and distinguish between different extents of cartilage repair without the need for labelling agents.
  12. Guangnan Z, Tao H, Rahman MA, Yao L, Al-Saffar A, Meng Q, et al.
    Work, 2021;68(3):871-879.
    PMID: 33612530 DOI: 10.3233/WOR-203421
    BACKGROUND: An isolated robot must take account of uncertainty in its world model and adapt its activities to take into account such as uncertainty. In the same way, a robot interaction with security and privacy issues (RISAPI) with people has to account for its confusion about the human internal state, as well as how this state will shift as humans respond to the robot.

    OBJECTIVES: This paper discusses RISAPI of our original work in the field, which shows how probabilistic planning and system theory algorithms in workplace robotic systems that work with people can allow for that reasoning using a security robot system. The problem is a general way as an incomplete knowledge 2-player game.

    RESULTS: In this general framework, the various hypotheses and these contribute to thrilling and complex robot behavior through real-time interaction, which transforms actual human subjects into a spectrum of production systems, robots, and care facilities.

    CONCLUSION: The models of the internal human situation, in which robots can be designed efficiently, are limited, and achieve optimal computational intractability in large, high-dimensional spaces. To achieve this, versatile, lightweight portrayals of the human inner state and modern algorithms offer great hope for reasoning.

  13. Yu L, Mei Q, Xiang L, Liu W, Mohamad NI, István B, et al.
    Front Bioeng Biotechnol, 2021;9:629809.
    PMID: 33842444 DOI: 10.3389/fbioe.2021.629809
    Ground reaction force (GRF) is a key metric in biomechanical research, including parameters of loading rate (LR), first impact peak, second impact peak, and transient between first and second impact peaks in heel strike runners. The GRFs vary over time during stance. This study was aimed to investigate the variances of GRFs in rearfoot striking runners across incremental speeds. Thirty female and male runners joined the running tests on the instrumented treadmill with speeds of 2.7, 3.0, 3.3, and 3.7 m/s. The discrete parameters of vertical average loading rate in the current study are consistent with the literature findings. The principal component analysis was modeled to investigate the main variances (95%) in the GRFs over stance. The females varied in the magnitude of braking and propulsive forces (PC1, 84.93%), whereas the male runners varied in the timing of propulsion (PC1, 53.38%). The female runners dominantly varied in the transient between the first and second peaks of vertical GRF (PC1, 36.52%) and LR (PC2, 33.76%), whereas the males variated in the LR and second peak of vertical GRF (PC1, 78.69%). Knowledge reported in the current study suggested the difference of the magnitude and patterns of GRF between male and female runners across different speeds. These findings may have implications for the prevention of sex-specific running-related injuries and could be integrated with wearable signals for the in-field prediction and estimation of impact loadings and GRFs.
  14. Waiho K, Fazhan H, Zhang Y, Zhang Y, Li S, Zheng H, et al.
    Mar Biotechnol (NY), 2019 Jun;21(3):320-334.
    PMID: 30835008 DOI: 10.1007/s10126-019-09882-1
    Although the sexual dimorphism in terms of gonadal development and gametogenesis of mud crab has been described, the internal regulating mechanism and sex differentiation process remain unclear. A comparative gonadal miRNA transcriptomic study was conducted to identify miRNAs that are differentially expressed between testes and ovaries, and potentially uncover miRNAs that might be involved in sex differentiation and gonadal maturation mechanisms of mud crabs (Scylla paramamosain). A total of 10 known miRNAs and 130 novel miRNAs were identified, among which 54 were differentially expressed. Target gene prediction revealed a significant enrichment in 30 KEGG pathways, including some reproduction-related pathways, e.g. phosphatidylinositol signalling system and inositol phosphate metabolism pathways. Further analysis on six differentially expressed known miRNAs, six differentially expressed novel miRNAs and their reproduction-related putative target genes shows that both miRNAs and putative target genes showed stage-specific expression during gonadal maturation, suggesting their potential regulatory roles in sex differentiation and reproductive development. This study reveals the sex-biased miRNA profile and establishes a solid foundation for understanding the sex differentiation and gonadal maturation mechanisms of S. paramamosain.
  15. Wu Q, Miao G, Li X, Liu W, Ikhwanuddin M, Ma H
    Mol Biol Rep, 2018 Dec;45(6):1913-1918.
    PMID: 30203240 DOI: 10.1007/s11033-018-4339-9
    The blue swimming crab (Portunus pelagicus) is a valuable marine fishery resource in Indo-West Pacific Ocean. So far, rare genetic resource of this species is available. In this report, the restriction-site associated DNA (RAD) approach was employed to mine the genomic information and identify molecular markers in P. pelagicus. A total of 0.82 Gbp clean data were generated from the genome of individual "X2A". De novo assembly produced 85,796 contigs with an average length of 339 bp. A total of 45,464 putative SNPs and 17,983 microsatellite loci were identified from the genomes of ten individuals. Furthermore, 31 pairs of primers were successfully designed, with 16 of them exhibiting polymorphism in a wild population. For these polymorphic loci, the expected and observed alleles per locus ranged from 1.064 to 7.314 and from 2 to 11, respectively. The expected and observed heterozygosity per locus ranged from 0.0615 to 0.819 and from 0.0626 to 1.000, respectively. Nine loci showed high informative with polymorphism information content (PIC) > 0.5. Five loci significantly deviated from Hardy-Weinberg equilibrium in the samples analyzed. No linkage disequilibrium was found among the 16 polymorphic microsatellite loci. This study provided massive genetic resource and polymorphic molecular markers that should be helpful for studies on conservation genetics, population dynamics and genetic diversity of P. pelagicus and related crab species.
  16. Tao Y, Han Y, Liu W, Peng L, Wang Y, Kadam S, et al.
    Ultrason Sonochem, 2019 Apr;52:193-204.
    PMID: 30514598 DOI: 10.1016/j.ultsonch.2018.11.018
    In this work, sonication (20-kHz) was conducted to assist the biosorption of phenolics from blueberry pomace extracts by brewery waste yeast biomass. The adsorption capacity of yeast increased markedly under ultrasonic fields. After sonication at 394.2 W/L and 40 °C for 120 min, the adsorption capacity was increased by 62.7% compared with that under reciprocating shaking. An artificial neural network was used to model and visualize the effects of different parameters on yeast biosorption capacity. Both biosorption time and acoustic energy density had positive influences on yeast biosorption capacity, whereas no clear influence of temperature on biosorption process was observed. Regarding the mechanism of ultrasound-enhanced biosorption process, the amino and carboxyl groups in yeast were considered to be associated with the yeast biosorption property. Meanwhile, ultrasound promoted the decline of the structure order of yeast cells induced by phenolic uptake. The interactions between yeast cells and phenolics were also affected by the structures of phenolics. Moreover, the mass transfer process was simulated by a surface diffusional model considering the ultrasound-induced yeast cell disruption. The modeling results showed that the external mass transfer coefficient in liquid phase and the surface diffusion coefficient under sonication at 394.2 W/L and 40 °C were 128.5% and 74.3% higher than that under reciprocating shaking, respectively.
  17. Moorthy V, Liu W, Chan SP, Chew STH, Ti LK
    J Diabetes, 2020 Jan;12(1):58-65.
    PMID: 31210000 DOI: 10.1111/1753-0407.12961
    BACKGROUND: Although diabetes is associated with ethnicity and worse cardiac surgery outcomes, no research has been done to study the effect of both diabetes and ethnicity on cardiac surgery outcomes in a multiethnic Southeast Asian cohort. Hence, this study aimed to delineate the association of ethnicity on outcomes after cardiac surgery among diabetics in a multiethnic Southeast Asian population.

    METHODS: Perioperative data from 3008 adult patients undergoing elective cardiac surgery from 2008 to 2011 at the two main heart centers in Singapore was analyzed prospectively, and confirmatory analysis was conducted with the generalized structural equation model.

    RESULTS: Diabetes was significantly associated with postoperative acute kidney injury (AKI) and postoperative hyperglycemia. Postoperative AKI, Malay ethnicity, and blood transfusion were associated with postoperative dialysis. Postoperative AKI and blood transfusion were also associated with postoperative arrhythmias. In turn, postoperative dialysis and arrhythmias increased the odds of 30-day mortality by 7.7- and 18-fold, respectively.

    CONCLUSIONS: This study identified that diabetes is directly associated with postoperative hyperglycemia and AKI, and indirectly associated with arrhythmias and 30-day mortality. Further, we showed that ethnicity not only affects the prevalence of diabetes, but also postoperative diabetes-related outcomes.

  18. Li XP, Lin D, Zhang Y, Chen SQ, Bai HQ, Zhang SN, et al.
    Trop Biomed, 2020 Mar 01;37(1):116-126.
    PMID: 33612723
    Several bioactive molecules isolated from the saliva of blood-sucking arthropods, such as mosquitoes, have been shown to exhibit potential anticoagulant function. We have previously identified a 30kDa allergen named Aegyptin-like protein (alALP), which is highly homologous to Aegyptin, from the salivary glands of female Aedes albopictus (Asian tiger mosquito). In this study, we identified the conserved functional domain of alALP by using bioinformatic tools, and expressed the His-tagged alALP recombinant protein in sf9 insect cells by generation and transfection of a baculoviral expression plasmid carrying the fulllength cDNA of alALP. We purified this recombinant protein and examined its function on the inhibition of blood coagulation. The results showed that the purified His-alALP prolonged the Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) in vitro as well as the Bleeding Time (BT) in vivo, which suggest that alALP could be a novel anticoagulant.
  19. Liu W, Zhang J, Hashim JH, Jalaludin J, Hashim Z, Goldstein BD
    Environ Health Perspect, 2003 Sep;111(12):1454-60.
    PMID: 12948883
    Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.
  20. Lake NJ, Phua J, Liu W, Moors T, Axon S, Lek M
    J Neuromuscul Dis, 2023 Mar 31.
    PMID: 37005889 DOI: 10.3233/JND-221552
    BACKGROUND: Recessive pathogenic variants in LAMA2 resulting in complete or partial loss of laminin α2 protein cause congenital muscular dystrophy (LAMA2 CMD). The prevalence of LAMA2 CMD has been estimated by epidemiological studies to lie between 1.36-20 cases per million. However, prevalence estimates from epidemiological studies are vulnerable to inaccuracies owing to challenges with studying rare diseases. Population genetic databases offer an alternative method for estimating prevalence.

    OBJECTIVE: We aim to use population allele frequency data for reported and predicted pathogenic variants to estimate the birth prevalence of LAMA2 CMD.

    METHODS: A list of reported pathogenic LAMA2 variants was compiled from public databases, and supplemented with predicted loss of function (LoF) variants in the Genome Aggregation Database (gnomAD). gnomAD allele frequencies for 273 reported pathogenic and predicted LoF LAMA2 variants were used to calculate disease prevalence using a Bayesian methodology.

    RESULTS: The world-wide birth prevalence of LAMA2 CMD was estimated to be 8.3 per million (95% confidence interval (CI) 6.27 -10.5 per million). The prevalence estimates for each population in gnomAD varied, ranging from 1.79 per million in East Asians (95% CI 0.63 -3.36) to 10.1 per million in Europeans (95% CI 6.74 -13.9). These estimates were generally consistent with those from epidemiological studies, where available.

    CONCLUSIONS: We provide robust world-wide and population-specific birth prevalence estimates for LAMA2 CMD, including for non-European populations in which LAMA2 CMD prevalence hadn't been studied. This work will inform the design and prioritization of clinical trials for promising LAMA2 CMD treatments.

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