MyMedR

Displaying publications 6101 - 6120 of 8505 in total

Abstract:

Sort:

Outcomes after mastectomy with immediate breast reconstruction for breast cancer in a multiethnic, middle-income Asian setting

See MH, Sinnadurai S, Lai LL, Tan KL, Teh MS, Teoh LY, et al.

Surgery, 2021 12;170(6):1604-1609.
PMID: 34538341 DOI: 10.1016/j.surg.2021.08.001

BACKGROUND: Although immediate breast reconstruction is increasingly becoming popular worldwide, evidence from resource-limited settings is scarce. We investigated factors associated with immediate breast reconstruction in a multiethnic, middle-income Asian setting. Short-term surgical complications, timing of initiation of chemotherapy, and survival outcomes were compared between women undergoing mastectomy alone and their counterparts receiving immediate breast reconstruction.
METHODS: This historical cohort study included women who underwent mastectomy after diagnosis with stage 0 to stage IIIa breast cancer from 2011 to 2015 in a tertiary hospital. Multivariable regression analyses were used to assess factors associated with immediate breast reconstruction and to measure clinical outcomes.
RESULT: Out of 790 patients with early breast cancer who had undergone mastectomy, only 68 (8.6%) received immediate breast reconstruction. Immediate breast reconstruction was independently associated with younger age at diagnosis, recent calendar years, Chinese ethnicity, higher education level, and invasive ductal carcinomas. Although immediate breast reconstruction was associated with a higher risk of short-term local surgical complications (adjusted odds ratio: 3.58 [95% confidence interval 1.75-7.30]), there were no significant differences in terms of delay in initiation of chemotherapy, 5-year disease-free survival, and 5-year overall survival between both groups in the multivariable analyses.
CONCLUSION: Although associated with short-term surgical complications, immediate breast reconstruction after mastectomy does not appear to be associated with delays in initiation of chemotherapy, recurrence, or mortality after breast cancer. These findings are valuable in facilitating shared surgical decision-making, improving access to immediate breast reconstruction, and setting priorities for surgical trainings in middle-income settings.
Fulltext Development of a Polysaccharide-Based Hydrogel Drug Delivery System (DDS): An Update

Pushpamalar J, Meganathan P, Tan HL, Dahlan NA, Ooi LT, Neerooa BNHM, et al.

Gels, 2021 Sep 27;7(4).
PMID: 34698125 DOI: 10.3390/gels7040153

Delivering a drug to the target site with minimal-to-no off-target cytotoxicity is the major determinant for the success of disease therapy. While the therapeutic efficacy and cytotoxicity of the drug play the main roles, the use of a suitable drug delivery system (DDS) is important to protect the drug along the administration route and release it at the desired target site. Polysaccharides have been extensively studied as a biomaterial for DDS development due to their high biocompatibility. More usefully, polysaccharides can be crosslinked with various molecules such as micro/nanoparticles and hydrogels to form a modified DDS. According to IUPAC, hydrogel is defined as the structure and processing of sols, gels, networks and inorganic-organic hybrids. This 3D network which often consists of a hydrophilic polymer can drastically improve the physical and chemical properties of DDS to increase the biodegradability and bioavailability of the carrier drugs. The advancement of nanotechnology also allows the construction of hydrogel DDS with enhanced functionalities such as stimuli-responsiveness, target specificity, sustained drug release, and therapeutic efficacy. This review provides a current update on the use of hydrogel DDS derived from polysaccharide-based materials in delivering various therapeutic molecules and drugs. We also highlighted the factors that affect the efficacy of these DDS and the current challenges of developing them for clinical use.
Transcriptomic Responses to Coaggregation between Streptococcus gordonii and Streptococcus oralis

Choo SW, Mohammed WK, Mutha NVR, Rostami N, Ahmed H, Krasnogor N, et al.

Appl Environ Microbiol, 2021 10 28;87(22):e0155821.
PMID: 34469191 DOI: 10.1128/AEM.01558-21

Cell-cell adhesion between oral bacteria plays a key role in the development of polymicrobial communities such as dental plaque. Oral streptococci such as Streptococcus gordonii and Streptococcus oralis are important early colonizers of dental plaque and bind to a wide range of different oral microorganisms, forming multispecies clumps or "coaggregates." S. gordonii actively responds to coaggregation by regulating gene expression. To further understand these responses, we assessed gene regulation in S. gordonii and S. oralis following coaggregation in 25% human saliva. Coaggregates were formed by mixing, and after 30 min, RNA was extracted for dual transcriptome sequencing (RNA-Seq) analysis. In S. oralis, 18 genes (6 upregulated and 12 downregulated) were regulated by coaggregation. Significantly downregulated genes encoded functions such as amino acid and antibiotic biosynthesis, ribosome, and central carbon metabolism. In total, 28 genes were differentially regulated in Streptococcus gordonii (25 upregulated and 3 downregulated). Many genes associated with transporters and a two-component (NisK/SpaK) regulatory system were upregulated following coaggregation. Our comparative analyses of S. gordonii-S. oralis with different previously published S. gordonii pairings (S. gordonii-Fusobacterium nucleatum and S. gordonii-Veillonella parvula) suggest that the gene regulation is specific to each pairing, and responses do not appear to be conserved. This ability to distinguish between neighboring bacteria may be important for S. gordonii to adapt appropriately during the development of complex biofilms such as dental plaque. IMPORTANCE Dental plaque is responsible for two of the most prevalent diseases in humans, dental caries and periodontitis. Controlling the formation of dental plaque and preventing the transition from oral health to disease requires a detailed understanding of microbial colonization and biofilm development. Streptococci are among the most common colonizers of dental plaque. This study identifies key genes that are regulated when oral streptococci bind to one another, as they do in the early stages of dental plaque formation. We show that specific genes are regulated in two different oral streptococci following the formation of mixed-species aggregates. The specific responses of S. gordonii to coaggregation with S. oralis are different from those to coaggregation with other oral bacteria. Targeting the key genes that are upregulated during interspecies interactions may be a powerful approach to control the development of biofilm and maintain oral health.
Fulltext Development of Virtual Surveys for the COVID-19 Wave of the AGELESS Longitudinal Study in Malaysia

Aravindhan K, Mat S, Hamid TA, Shahar S, Abdul Majeed AB, Teh PL, et al.

Gerontology, 2021 Aug 17.
PMID: 34515120 DOI: 10.1159/000517946

BACKGROUND: Rapid population aging occurring in developing nations necessitates innovation to ensure we continue to gain ground on aging research despite pandemic threats. While developed nations have resorted to virtual communications, this is challenging in developing nations due to poor internet connectivity and digital literacy.
OBJECTIVES: The aim of this study was to determine the feasibility of virtual data collection for a longitudinal study of aging assessing cognitive frailty in a middle-income Southeast Asian country.
METHODS: The Transforming Cognitive Frailty into Later-Life Self-Sufficiency (AGELESS) longitudinal study of aging involved community-dwelling participants aged 60 years and above. A semi-structured focus group discussion was conducted via videoconferencing with selected representatives from existing participants. The survey instrument was compiled during a hybrid meeting and refined using a virtual Delphi process involving 51 AGELESS investigators. The final draft survey and recruitment strategy were then piloted among selected participants.
RESULTS: Twelve individuals participated in the virtual focus group interview. Smartphone, tablet computer, laptops, and desktop personal computers were used for information gathering, communication, banking, shopping, leisure, religion, and education, within this group. The survey instrument was redacted from 362 items in 18 sections to 141 items in 12 sections through 3 virtual Delphi rounds facilitated by email, social media messaging, and videoconferencing which attracted 213 comments. Of 45 participants selected for the pilot survey, 30 were successfully contacted after one attempt and 18 completed the survey. Cognitive frailty was present in 13%, cognitive impairment in 20%, frailty in 20%, and 47% were robust.
CONCLUSION: A virtual survey instrument was developed for the AGELESS longitudinal survey of aging which was vital for determining the effects of the COVID-19 pandemic on our older population as well as sustaining research into aging despite barriers posed by the pandemic.
Bioefficacy of mosquito mat vaporizers and associated metabolic detoxication mechanisms in Aedes aegypti (Linnaeus) in Selangor, Malaysia: A statewide assessment

Azratul-Hizayu T, Chen CD, Lau KW, Azrizal-Wahid N, Tan TK, Lim YAL, et al.

Trop Biomed, 2021 Sep 01;38(3):327-337.
PMID: 34508340 DOI: 10.47665/tb.38.3.073

This study aims to examine the efficacy of mosquito mat vaporizers on Aedes aegypti and their associated metabolic detoxication mechanisms. For this purpose, Aedes aegypti (Linnaeus) was collected from nine districts in Selangor, Malaysia and tested with mosquito vaporizing mat bioassays. The same populations were also subjected to biochemical assays to investigate activities of detoxifying enzymes, namely non-specific esterase (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO). The efficacy of Ae. aegypti on the active ingredients tested in decreasing order were d- allethrin > dimefluthrin > prallethrin with PBO > prallethrin. The results further indicated significant enhancement mean levels of EST, GST and MFO in pyrethroid-resistant populations. The mortality rate of Ae. aegypti in response to pyrethroid active ingredients was associated with MFO activity, suggesting it is an important detoxification enzyme for the populations tested. In view of the presence of resistance against household insecticide products, pyrethroid efficacy on Ae. aegypti populations needs to be monitored closely to ensure the implementation of an effective vector control program in Malaysia.
Toxic bloom of Pseudo-nitzschia cuspidata (Bacillariophyceae) and domoic acid contamination of bivalve molluscs in Malaysia Borneo

Teng ST, Abdullah N, Hanifah AH, Tan SN, Gao C, Law IK, et al.

Toxicon, 2021 Sep 30;202:132-141.
PMID: 34600910 DOI: 10.1016/j.toxicon.2021.09.018

In March 2018, an algal bloom of Pseudo-nitzschia was detected, for the first time, in a semi-enclosed lagoon in Miri, Sarawak, Malaysia Borneo. The plankton samples were collected for cell enumeration and species identification by electron microscopy and molecular characterization. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was performed to detect and quantify the neurotoxin domoic acid (DA) in both the plankton and shellfish samples. The abundance of Pseudo-nitzschia cells ranged from 5.6 × 105 to 3.5 × 106 cell L-1 during the bloom event. Morphological observation of the cells by transmission electron microscopy showed that the plankton samples comprised a single Pseudo-nitzschia morphotype resembling P. cuspidata. The ITS2 sequence-structure phylogenetic inference further supported the species identity as Pseudo-nitzschia cuspidata. Low levels of DA were detected in the plankton samples, with cellular DA, particulate DA, and dissolved DA of 257-504 fg DA cell-1, 676 ng L-1, and 15 ng L-1, respectively. The amount of DA, 8 μg g-1 tissue, was found present in the shellfish sample (Magallana sp.) which is below the regulatory limit of 20 μg DA g-1 tissue. The study documented, for the first time, DA contamination in shellfish that associated with bloom of P. cuspidata in the Western Pacific region.
Potentially inappropriate prescribing in a falls clinic using the STOPP and START criteria

Chiam R, Saedon N, Khor HM, A/P Subramaniam S, Binti Mohmad Nasir SS, Binti Abu Hashim NFI, et al.

Int J Clin Pharm, 2021 Oct 09.
PMID: 34626298 DOI: 10.1007/s11096-021-01329-9

Background Potentially inappropriate prescribing is increasingly common in older patients with falls. However, published indicators to assess inappropriate prescribing remains unestablished in many countries. Objective This study determined the burden and profile of potentially inappropriate prescribing among patients attending a falls clinic using the STOPP/START criteria and evaluated the factors for falls potentially associated to inappropriate prescribing. Setting University of Malaya Medical Centre Falls Clinic. Method Data of individuals aged ≥ 65 years referred to the falls and syncope clinic were extracted from the falls registry. Potentially inappropriate prescribing was determined with the STOPP/START version 2 criteria. The relationship between potentially inappropriate prescribing with polypharmacy (≥ 5 medications), comorbidities and clinical variables were determined using Pearson's chi-square and potential confounders adjusted for with multivariate regression. Main outcome measure Potentially inappropriate medicines and/or omitted medicines using STOPP/START criteria. Results Data from 421 individuals, aged 77.8 ± 6.7 years and 53.4% women, were included. Potentially inappropriate prescribing was present in 311 (73.9%). Potentially inappropriate medicines use accounted for 84.6% of the 325 prescriptions. 361/659 instances (54.8%) were falls-risk-increasing drugs, with vasodilators (49.3%) being the main potentially inappropriate medicine identified. Of the 177/421 with polypharmacy, 169/177 (95.5%) were exposed to ≥ one potentially inappropriate medicine. 129 instances of potentially omitted medicines were observed in 109 prescriptions (25.9%). Conclusion STOPP/START criteria are useful to identify potentially inappropriate prescribing at the falls and syncope clinic. This finding has important implications for medication review strategies at falls clinic. Future research should determine whether identifying potentially inappropriate prescribing may reduce adverse falls outcomes among patients in this setting.
Incidence, progression and risk factors of age-related cataract in Malays: The Singapore Malay Eye Study

Tan AG, Tham YC, Chee ML, Mitchell P, Cumming RG, Sabanayagam C, et al.

Clin Exp Ophthalmol, 2020 07;48(5):580-592.
PMID: 32255547 DOI: 10.1111/ceo.13757

IMPORTANCE: Long-term data on age-related cataract, a leading cause of blindness and visual impairment, is scarce in Asian populations.
BACKGROUND: We report the 6-year incidence and progression of age-related cataract and associated risk factors in Malay adults living in Singapore.
DESIGN: Population-based cohort study.
PARTICIPANTS: A total of 3280 Malays aged 40+ years participated in baseline examinations of the Singapore Malay Eye Study (2004-2006). Six years later, 1901 (72.1% of eligible) baseline participants were re-examined.
METHODS: Cataract was assessed using lens photos, taken during eye examinations, following the Wisconsin Cataract Grading System.
MAIN OUTCOMES AND MEASURES: Incidence and progression of cortical, nuclear and posterior subcapsular (PSC) cataract. Poisson regression models and generalized estimating equations models (with Poisson link) were used to assess factors associated with cataract incidence and progression, respectively, adjusting for age, sex and other risk factors.
RESULTS: Age-adjusted 6-year incidence of cortical, nuclear and PSC cataract was 14.1%, 13.6% and 8.7%, respectively, and was strongly age-related (P for trend
Fulltext Stochastic Modelling of Respiratory System Elastance for Mechanically Ventilated Respiratory Failure Patients

Lee JWW, Chiew YS, Wang X, Tan CP, Mat Nor MB, Damanhuri NS, et al.

Ann Biomed Eng, 2021 Dec;49(12):3280-3295.
PMID: 34435276 DOI: 10.1007/s10439-021-02854-4

While lung protective mechanical ventilation (MV) guidelines have been developed to avoid ventilator-induced lung injury (VILI), a one-size-fits-all approach cannot benefit every individual patient. Hence, there is significant need for the ability to provide patient-specific MV settings to ensure safety, and optimise patient care. Model-based approaches enable patient-specific care by identifying time-varying patient-specific parameters, such as respiratory elastance, Ers, to capture inter- and intra-patient variability. However, patient-specific parameters evolve with time, as a function of disease progression and patient condition, making predicting their future values crucial for recommending patient-specific MV settings. This study employs stochastic modelling to predict future Ers values using retrospective patient data to develop and validate a model indicating future intra-patient variability of Ers. Cross validation results show stochastic modelling can predict future elastance ranges with 92.59 and 68.56% of predicted values within the 5-95% and the 25-75% range, respectively. This range can be used to ensure patients receive adequate minute ventilation should elastance rise and minimise the risk of VILI should elastance fall. The results show the potential for model-based protocols using stochastic model prediction of future Ers values to provide safe and patient-specific MV. These results warrant further investigation to validate its clinical utility.
Forecasting plastic waste generation and interventions for environmental hazard mitigation

Fan YV, Jiang P, Tan RR, Aviso KB, You F, Zhao X, et al.

J Hazard Mater, 2022 02 15;424(Pt A):127330.
PMID: 34600379 DOI: 10.1016/j.jhazmat.2021.127330

Plastic waste and its environmental hazards have been attracting public attention as a global sustainability issue. This study builds a neural network model to forecast plastic waste generation of the EU-27 in 2030 and evaluates how the interventions could mitigate the adverse impact of plastic waste on the environment. The black-box model is interpreted using SHapley Additive exPlanations (SHAP) for managerial insights. The dependence on predictors (i.e., energy consumption, circular material use rate, economic complexity index, population, and real gross domestic product) and their interactions are discussed. The projected plastic waste generation of the EU-27 is estimated to reach 17 Mt/y in 2030. With an EU targeted recycling rate (55%) in 2030, the environmental impacts would still be higher than in 2018, especially global warming potential and plastic marine pollution. This result highlights the importance of plastic waste reduction, especially for the clustering algorithm-based grouped countries with a high amount of untreated plastic waste per capita. Compared to the other assessed scenarios, Scenario 4 with waste reduction (50% recycling, 47.6% energy recovery, 2.4% landfill) shows the lowest impact in acidification, eutrophication, marine aquatic toxicity, plastic marine pollution, and abiotic depletion. However, the global warming potential (8.78 Gt CO2eq) is higher than that in 2018, while Scenario 3 (55% recycling, 42.6% energy recovery, 2.4% landfill) is better in this aspect than Scenario 4. This comprehensive analysis provides pertinent insights into policy interventions towards environmental hazard mitigation.
Fulltext Are Malaysian Youths Overdependent on the Internet?: A Narrative Review

Nik Jaafar NR, Bahar N, Ibrahim N, Baharudin A, Wan Ismail WS, Sim ST, et al.

Front Psychiatry, 2021;12:710790.
PMID: 34484002 DOI: 10.3389/fpsyt.2021.710790

Overdependence on the internet is a grave concern that has enveloped Malaysian youths which could lead to a variety of sequelae. This narrative review aims to determine the definition of internet overdependence and its associated factors, as well as the potential preventive and treatment strategies for internet overdependence. From the literature, internet overdependence is regarded as a 3-factor model encompassing salience, self-control failure, and serious consequences. Sociodemographic factors such as age, gender, and ethnicity, as well as psychosocial factors such as depression, anxiety, stress, and loneliness, were found to be associated with internet overdependence among Malaysian youths. A multimodal treatment approach is recommended by the implementation of various types of treatments, integrating disciplines such as pharmacology, psychotherapy, and family counseling. Despite various terminologies being used and unclear conceptualization of its nomenclature, overdependence on the internet is prevalent among youths in Malaysia. Future research should go toward establishing a clear definition of its terminology and attaining more robust evidence on treatment strategies.
Fulltext Streptomyces sp.-A Treasure Trove of Weapons to Combat Methicillin-Resistant Staphylococcus aureus Biofilm Associated with Biomedical Devices

Pusparajah P, Letchumanan V, Law JW, Ab Mutalib NS, Ong YS, Goh BH, et al.

Int J Mol Sci, 2021 Aug 28;22(17).
PMID: 34502269 DOI: 10.3390/ijms22179360

Biofilms formed by methicillin-resistant S. aureus (MRSA) are among the most frequent causes of biomedical device-related infection, which are difficult to treat and are often persistent and recurrent. Thus, new and effective antibiofilm agents are urgently needed. In this article, we review the most relevant literature of the recent years reporting on promising anti-MRSA biofilm agents derived from the genus Streptomyces bacteria, and discuss the potential contribution of these newly reported antibiofilm compounds to the current strategies in preventing biofilm formation and eradicating pre-existing biofilms of the clinically important pathogen MRSA. Many efforts are evidenced to address biofilm-related infections, and some novel strategies have been developed and demonstrated encouraging results in preclinical studies. Nevertheless, more in vivo studies with appropriate biofilm models and well-designed multicenter clinical trials are needed to assess the prospects of these strategies.
Chronic Subdural Hematoma Drainage Under Local Anesthesia with Sedation versus General Anesthesia and Its Outcome

Wong HM, Woo XL, Goh CH, Chee PHC, Adenan AH, Tan PCS, et al.

World Neurosurg, 2022 01;157:e276-e285.
PMID: 34648987 DOI: 10.1016/j.wneu.2021.10.074

BACKGROUND: Burr hole drainage is the criterion standard treatment for chronic subdural hematoma (CSDH), a common neurosurgical condition. However, apart from the surgical technique, the method of anesthesia also has a significant impact on postoperative patient outcome. Currently, there are limited studies comparing the use of local anesthesia with sedation (LA sedation) versus general anesthesia (GA) in the drainage of CSDH. The objective of this study was to compare the morbidity and mortality outcomes of using LA sedation versus GA in CSDH burr hole drainage.
METHODS: This retrospective study presents a total of 257 operations in 243 patients from 2 hospitals. A total of 130 cases were operated under LA sedation in hospital 1 and 127 cases under GA in hospital 2. Patient demographics and presenting features were similar at baseline.
RESULTS: Values are shown as LA sedation versus GA. Postoperatively, most patients recovered well in both groups with Glasgow Outcome Scale scores of 4-5 (96.2% vs. 88.2%, respectively). The postoperative morbidity was significantly increased by an odds ratio of 5.44 in the GA group compared with the LA sedation group (P = 0.005). The mortality was also significantly higher in the GA group (n = 5, 3.9%) than the LA sedation group (n = 0, 0.0%; P = 0.028). The CSDH recurrence rate was 4.6% in the LA sedation group versus 6.3% in the GA group. No intraoperative conversion from LA sedation to GA was reported.
CONCLUSIONS: This study demonstrates that CSDH drainage under LA sedation is safe and efficacious, with a significantly lower risk of postoperative mortality and morbidity when compared with GA.
Fulltext Clinical and epidemiological characteristics of patients seeking COVID-19 testing in a private centre in Malaysia: Is there a role for private healthcare in battling the outbreak?

Chow YP, Chin BHZ, Loo JM, Moorthy LR, Jairaman J, Tan LH, et al.

PLoS One, 2021;16(10):e0258671.
PMID: 34648575 DOI: 10.1371/journal.pone.0258671

OBJECTIVE: This cross-sectional observational study summarized the baseline characteristics of subjects who underwent COVID-19 molecular testing in a private medical centre located in the state of Selangor in Malaysia between 1 Oct 2020 and 31 Jan 2021. We compared the baseline characteristics between subjects who were tested positive and negative of SARS-CoV-2 infection, and identified risk factors which may be predictive of SARS-CoV-2 positivity.
METHODS AND FINDINGS: A total of 36603 subjects who were tested for COVID-19 infection via molecular assays at Sunway Medical Centre between Oct 1, 2020 and Jan 31, 2021, and consented to participate in this observation study were included for analysis. Descriptive statistics was used to summarize the study cohort, whereas logistic regression analysis was used to identify risk factors associated with SARS-CoV-2 positivity. Among the reasons listed for COVID-19 screening were those who needed clearance for travelling, clearance to return to work, or clearance prior to hospital admission. They accounted for 67.7% of tested subjects, followed by the self-referred group (27.3%). Most of the confirmed cases were asymptomatic (62.6%), had no travel history (99.6%), and had neither exposure to SARS-CoV-2 confirmed cases (61.9%) nor exposure to patients under investigation (82.7%) and disease clusters (89.2%). Those who presented with loss of smell or taste (OR: 26.91; 95% CI: 14.81-48.92, p<0.001), fever (OR:3.97; 95% CI: 2.54-6.20, p<0.001), running nose (OR: 1.75; 95% CI:1.10-2.79, p = 0.019) or other symptoms (OR: 5.63; 95% CI:1.68-18.91, p = 0.005) were significantly associated with SARS-CoV-2 positivity in the multivariate logistic regression analysis.
CONCLUSION: Our study showed that majority of patients seeking COVID-19 testing in a private healthcare setting were mainly asymptomatic with low epidemiological risk. Consequently, the average positivity rate was 1.2% compared to the national cumulative positivity rate of 4.65%. Consistent with other studies, we found that loss of smell or taste, fever and running nose were associated with SARS-CoV-2 positivity. We believe that strengthening the capacity of private health institutions is important in the national battle against the COVID-19 pandemic, emphasizing the importance of public-private partnership to improve the quality of clinical care.
The Cross-Sectional Relations of COVID-19 Fear and Stress to Psychological Distress among Frontline Healthcare Workers in Selangor, Malaysia

Subhas N, Pang NT, Chua WC, Kamu A, Ho CM, David IS, et al.

Int J Environ Res Public Health, 2021 Sep 28;18(19).
PMID: 34639482 DOI: 10.3390/ijerph181910182

Previous pandemics have demonstrated short and long-term impacts on healthcare workers' mental health, causing knock-on effects on patient care and professional functioning. Indeed, the present COVID-19 pandemic has created unprecedented disruption in social interactions and working conditions. Malaysia has been under the Recovery Movement Control Order since June 2020; however, with the upsurge of cases, healthcare workers face pressure not only from working in resource-deprived settings but also from the increasing patient load. The primary objective of the present study was to examine the cross-sectional relationship of COVID-19 fear and stress to psychological distress (operationalized as anxiety and depression) in healthcare workers. The present sample included 286 frontline healthcare workers from three hospitals in Selangor, Malaysia. Self-administered questionnaires containing sociodemographic and occupational items, the Malay versions of the Coronavirus Stress Measure scale, the Fear of Coronavirus-19 scale, the Generalized Anxiety Disorder-7, and the Patient Health Questionnaire-9 were distributed via online platforms. Hierarchical multiple regression findings suggest that age, shift work, and COVID-19 stress consistently predicted anxiety and depression among frontline healthcare workers after adjusting for sociodemographic and occupational variables. The present findings suggest that frontline healthcare workers are not only inoculated against COVID-19 itself but also against the psychological sequelae of the pandemic.
Fulltext Early Spatiotemporal Patterns and Population Characteristics of the COVID-19 Pandemic in Southeast Asia

Zhu M, Kleepbua J, Guan Z, Chew SP, Tan JW, Shen J, et al.

Healthcare (Basel), 2021 Sep 16;9(9).
PMID: 34574997 DOI: 10.3390/healthcare9091220

This observational study aims to investigate the early disease patterns of coronavirus disease 2019 (COVID-19) in Southeast Asia, consequently providing historical experience for further interventions. Data were extracted from official websites of the WHO and health authorities of relevant countries. A total of 1346 confirmed cases of COVID-19, with 217 recoveries and 18 deaths, were reported in Southeast Asia as of 16 March 2020. The basic reproductive number (R0) of COVID-19 in the region was estimated as 2.51 (95% CI:2.31 to 2.73), and there were significant geographical variations at the subregional level. Early transmission dynamics were examined with an exponential regression model: y = 0.30e0.13x (p < 0.01, R2 = 0.96), which could help predict short-term incidence. Country-level disease burden was positively correlated with Human Development Index (r = 0.86, p < 0.01). A potential early shift in spatial diffusion patterns and a spatiotemporal cluster occurring in Malaysia and Singapore were detected. Demographic analyses of 925 confirmed cases indicated a median age of 44 years and a sex ratio (male/female) of 1.25. Age may play a significant role in both susceptibilities and outcomes. The COVID-19 situation in Southeast Asia is challenging and unevenly geographically distributed. Hence, enhanced real-time surveillance and more efficient resource allocation are urgently needed.
Fulltext A Novel Para-Amino Salicylic Acid Magnesium Layered Hydroxide Nanocomposite Anti-Tuberculosis Drug Delivery System with Enhanced in vitro Therapeutic and Anti-Inflammatory Properties

Saifullah B, Arulselvan P, El Zowalaty ME, Tan WS, Fakurazi S, Webster TJ, et al.

Int J Nanomedicine, 2021;16:7035-7050.
PMID: 34703226 DOI: 10.2147/IJN.S297040

Introduction: Mycobacterium tuberculosis infections are associated with severe local inflammatory reactions, which may be life-threatening and lead to tuberculosis pathogenesis and associated complications. Inorganic nanolayers have been vastly exploited for biomedical applications (especially in drug delivery) because of their biocompatible and biodegradable nature with the ability to release a drug in a sustained manner. Herein, we report a new nanodelivery system of inorganic nanolayers based on magnesium layered hydroxides (MgLH) and a successfully intercalated anti-tuberculosis drug para-aminosalicylic acid (PAS).
Methods: The designed anti-tuberculosis nanodelivery composite, MgLH-PAS, was prepared by a novel co-precipitation method using MgNO3 as well MgO as starting materials.
Results: The designed nano-formulation, PAS-MgLH, showed good antimycobacterial and antimicrobial activities with significant synergistic anti-inflammatory effects on the suppression of lipopolysaccharide (LPS) stimulated inflammatory mediators in RAW 264.7 macrophages. The designed nano-formulation was also found to be biocompatible with human normal lung cells (MRC-5) and 3T3 fibroblast cells. Furthermore, the in vitro release of PAS from PAS-MgLH was found to be sustained in human body simulated phosphate buffer saline (PBS) solutions of pH 7.4 and pH 4.8.
Discussion: The results of the present study are highly encouraging for further in vivo studies. This new nanodelivery system, MgLH, can be exploited in the delivery of other drugs and in numerous other biomedical applications as well.
Phenotypic profile of Aedes albopictus (Skuse) exposed to pyrethroid-based mat vaporizers and underlying detoxification mechanisms: A statewide report in Selangor, Malaysia

Azratul-Hizayu T, Chen CD, Lau KW, Azrizal-Wahid N, Tan TK, Lim YAL, et al.

Parasitol Int, 2022 Feb;86:102483.
PMID: 34678492 DOI: 10.1016/j.parint.2021.102483

This study examines the biological efficacy of four mosquito mat vaporizers each containing different active ingredients: prallethrin with PBO, dimefluthrin, prallethrin, and d-allethrin. The glass chamber assay was used to evaluate their efficacy on Aedes albopictus (Skuse) (Diptera: Culicidae) from nine districts in Selangor, Malaysia. Aedes albopictus exhibited different knockdown rates, with 50% knockdown times, KT50, varying from 1.19 to 2.00 min, 1.22 to 2.20 min, 1.39 to 5.85 min, and 1.39 to 1.92 min for prallethrin with PBO, dimefluthrin, prallethrin and d-allethrin, respectively. In general, all populations of Ae. albopictus were completely knocked down after exposure to all active ingredients except Hulu Selangor population, which showed 96.00% knockdown against d-allethrin. On the contrary, mortality rates were observed from 84.00-100.00%, 84.00-100.00%, 90.67-100.00% and 90.67-100.00% in populations tested with prallethrin with PBO, dimefluthrin, prallethrin and d-allethrin, respectively. Moreover, significant correlations between mortality rates of prallethrin with PBO vs dimefluthrin (r = 0.836, P = 0.003), prallethrin with PBO vs prallethrin (r = 0.760, P = 0.011), and prallethrin vs d-allethrin (r = 0.694, P = 0.026) were also observed, suggesting cross-resistance among pyrethroids. d-allethrin was found to be high in insecticidal activity, followed by prallethrin, prallethrin with PBO, and dimefluthrin. In consistent with mortality due to insecticide exposure, elevated levels of enzyme activities were also demonstrated in Sabak Bernam, Hulu Selangor, Gombak, Petaling, Hulu Langat and Klang populations.
Fulltext Complete mitochondrial genomes and phylogenetic relationships of the genera Nephila and Trichonephila (Araneae, Araneoidea)

Yong HS, Song SL, Chua KO, Wayan Suana I, Eamsobhana P, Tan J, et al.

Sci Rep, 2021 May 21;11(1):10680.
PMID: 34021208 DOI: 10.1038/s41598-021-90162-1

Spiders of the genera Nephila and Trichonephila are large orb-weaving spiders. In view of the lack of study on the mitogenome of these genera, and the conflicting systematic status, we sequenced (by next generation sequencing) and annotated the complete mitogenomes of N. pilipes, T. antipodiana and T. vitiana (previously N. vitiana) to determine their features and phylogenetic relationship. Most of the tRNAs have aberrant clover-leaf secondary structure. Based on 13 protein-coding genes (PCGs) and 15 mitochondrial genes (13 PCGs and two rRNA genes), Nephila and Trichonephila form a clade distinctly separated from the other araneid subfamilies/genera. T. antipodiana forms a lineage with T. vitiana in the subclade containing also T. clavata, while N. pilipes forms a sister clade to Trichonephila. The taxon vitiana is therefore a member of the genus Trichonephila and not Nephila as currently recognized. Studies on the mitogenomes of other Nephila and Trichonephila species and related taxa are needed to provide a potentially more robust phylogeny and systematics.
Fulltext Semi-analytical modelling and evaluation of uniformly doped silicene nanotransistors for digital logic gates

Chuan MW, Wong KL, Riyadi MA, Hamzah A, Rusli S, Alias NE, et al.

PLoS One, 2021;16(6):e0253289.
PMID: 34125874 DOI: 10.1371/journal.pone.0253289

Silicene has attracted remarkable attention in the semiconductor research community due to its silicon (Si) nature. It is predicted as one of the most promising candidates for the next generation nanoelectronic devices. In this paper, an efficient non-iterative technique is employed to create the SPICE models for p-type and n-type uniformly doped silicene field-effect transistors (FETs). The current-voltage characteristics show that the proposed silicene FET models exhibit high on-to-off current ratio under ballistic transport. In order to obtain practical digital logic timing diagrams, a parasitic load capacitance, which is dependent on the interconnect length, is attached at the output terminal of the logic circuits. Furthermore, the key circuit performance metrics, including the propagation delay, average power, power-delay product and energy-delay product of the proposed silicene-based logic gates are extracted and benchmarked with published results. The effects of the interconnect length to the propagation delay and average power are also investigated. The results of this work further envisage the uniformly doped silicene as a promising candidate for future nanoelectronic applications.

Filters

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

External Links