Browse publications by year: 2023

  1. Li A, Wang Q, Huang Y, Hu L, Li S, Wang Q, et al.
    Virus Res, 2023 Apr 15;328:199080.
    PMID: 36882131 DOI: 10.1016/j.virusres.2023.199080
    Chinese sacbrood virus (CSBV) is the most severe pathogen of Apis cerana, which leads to serious fatal diseases in bee colonies and eventual catastrophe for the Chinese beekeeping industry. Additionally, CSBV can potentially infect Apis mellifera by bridging the species barrier and significantly affect the productivity of the honey industry. Although several approaches, such as feeding royal jelly, traditional Chinese medicine, and double-stranded RNA treatments, have been employed to suppress CSBV infection, their practical applicabilities are constrained due to their poor effectiveness. In recent years, specific egg yolk antibodies (EYA) have been increasingly utilized in passive immunotherapy for infectious diseases without any side effects. According to both laboratory research and practical use, EYA have demonstrated superior protection for bees against CSBV infection. This review provided an in-depth analysis of the issues and drawbacks in this field in addition to provide a thorough summary of current advancements in CSBV studies. Some promising strategies for the synergistic study of EYA against CSBV, including the exploitation of novel antibody drugs, novel TCM monomer/formula determination, and development of nucleotide drugs, are also proposed in this review. Furthermore, the prospects for the future perspectives of EYA research and applications are presented. Collectively, EYA would terminate CSBV infection soon, as well as will provide scientific guidance and references to control and manage other viral infections in apiculture.
    MeSH terms: Animals; Bees; Egg Yolk; Virus Diseases*; Beekeeping
  2. Lee ZY, Ortiz-Reyes L, Lew CCH, Hasan MS, Ke L, Patel JJ, et al.
    Ann Intensive Care, 2023 Mar 07;13(1):14.
    PMID: 36882644 DOI: 10.1186/s13613-023-01116-x
    BACKGROUND: A recent landmark randomized controlled trial (RCT) in septic patients demonstrated an increased risk of death and persistent organ dysfunction with intravenous Vitamin C (IVVC) monotherapy, which represents a disparate result from previous systematic reviews and meta-analyses (SRMA). We performed an updated SRMA of IVVC monotherapy to summarize and explore heterogeneity across current trials and conduct trial sequential analysis (TSA) to guard against type-I or type-II statistical errors.

    METHODS: RCTs evaluating IVVC in adult critically ill patients were included. Four databases were searched from inception to 22 June 2022 without language restrictions. The primary outcome was overall mortality. Random effect meta-analysis was performed to estimate the pooled risk ratio. TSA for mortality was performed using the DerSimonian-Laird random effect model, alpha 5%, beta 10%, and relative risk reduction (RRR) of 30%, 25%, and 20%.

    RESULTS: We included 16 RCTs (n = 2130). IVVC monotherapy is associated with significant reduction in overall mortality [risk ratio (RR) 0.73, 95% confidence interval (CI) 0.60-0.89; p = 0.002; I2 = 42%]. This finding is supported by TSA using RRR of 30% and 25%, and sensitivity analysis using fixed-effect meta-analysis. However, the certainty of our mortality finding was rated low using GRADE due to the serious risk of bias and inconsistency. In a priori subgroup analyses, we found no differences between single vs multicenter, higher (≥ 10,000 mg/day) vs lower dose and sepsis vs non-sepsis trials. Post-hoc, we found no differences in subgroup analysis of earlier ( 4 days) vs shorter treatment duration, and low vs other risk of bias studies. IVVC may have the greatest benefit in trials that enrolled patients above (i.e., > 37.5%; RR 0.65, 95% CI 0.54-0.79) vs below (i.e., ≤ 37.5%; RR 0.89, 95% CI 0.68-1.16) median control group mortality (test for subgroup differences: p = 0.06), and TSA supported this.

    CONCLUSIONS: IVVC monotherapy may be associated with mortality benefits in critically ill patients, particularly in patients with a high risk of dying. Given the low certainty of evidence, this potentially life-saving therapy warrants further studies to identify the optimal timing, dosage, treatment duration, and patient population that will benefit most from IVVC monotherapy. PROSPERO Registration ID: CRD42022323880. Registered 7th May 2022.

  3. Khan PA, Johl SK, Kumar A, Luthra S
    Environ Sci Pollut Res Int, 2023 Apr;30(19):55237-55254.
    PMID: 36882655 DOI: 10.1007/s11356-023-26262-4
    The current production and conception have impacted the environmental hazards. Green innovation (GI) is the ideal solution for sustainable production, consumption, and ecological conservation. The objective of the study is to compare comprehensive green innovation (green product, process, service, and organization) impact on firm financial performance in Malaysia and Indonesia, along with the first study to measure the moderation role of the corporate governance index. This study has addressed the gap by developing the green innovation and corporate governance index. Collected panel data from the top 188 publicly listed firms for 3 years and analyzed it using the general least square method. The empirical evidence demonstrates that the green innovation practice is better in Malaysia, and the outcome also shows that the significance level is higher in Indonesia. This study also provides empirical evidence that board composition has a positive moderation relationship betwixt GI and business performance in Malaysia but is insignificant in Indonesia. This comparative study provides new insights to the policymakers and practitioners of both countries to monitor and manage green innovation practices.
    MeSH terms: China; Commerce*; Data Collection; Humans; Indonesia; Malaysia
  4. Ahmed Meelad R, Abd Hamid IJ, Zainudeen ZT, Hashim IF, Azizuddin MNA, Mangantig E, et al.
    J Clin Immunol, 2023 Jul;43(5):999-1006.
    PMID: 36882668 DOI: 10.1007/s10875-023-01463-1
    PURPOSE: Primary immunodeficiency disease (PID) affects various aspects of a patient's life. However, the health-related quality of life (HRQOL) of PID among Malaysian patients is poorly described. This study aimed to determine the quality of life of PID patients and their respective parents.

    METHOD: This cross-sectional study was performed from August 2020 to November 2020. Patients with PID and their families were invited to answer the PedsQL Malay version (4.0) questionnaire, the tool used to assess the HRQOL. A total of 41 families and 33 patients with PID answered the questionnaire. A comparison was performed with the previously published value of healthy Malaysian children.

    RESULT: Parents of respondents recorded a lower mean of total score than the parents of healthy children (67.26 ± 16.73 vs. 79.51 ± 11.90, p-value = 0.001, respectively). PID patients reported lower mean total score to healthy children (73.68 ± 16.38 vs. 79.51 ± 11.90, p-value = 0.04), including the psychosocial domain (71.67 ± 16.82 vs. 77.58 ± 12.63, p-value = 0.05) and school functioning (63.94 ± 20.87 vs. 80.00 ± 14.40, p-value = 0.007). No significant difference of reported HRQOL when comparing between subgroup of PID on immunoglobulin replacement therapy and those without immunoglobulin replacement (56.96 ± 23.58 vs. 65.83 ± 23.82, p-value 0.28). Socioeconomic status was found to be predictive of the lower total score of PedsQL in both parent and children reports.

    CONCLUSION: Parents and children with PID, especially those from middle socioeconomic status, have lower HRQOL and school function impairment than healthy children.

    MeSH terms: Child; Cross-Sectional Studies; Humans; Malaysia/epidemiology; Parents*; Quality of Life*; Surveys and Questionnaires
  5. Madin JS, Baird AH, Connolly SR, Dornelas MA, Álvarez-Noriega M, McWilliam MJ, et al.
    Ecology, 2023 Mar 07.
    PMID: 36882893 DOI: 10.1002/ecy.4017
    Scleractinian corals are colonial animals with a range of life-history strategies, making up diverse species assemblages that define coral reefs. We tagged and tracked ~30 colonies from each of 11 species during seven trips spanning 6 years (2009-2015) to measure their vital rates and competitive interactions on the reef crest at Trimodal Reef, Lizard Island, Australia. Pairs of species were chosen from five growth forms in which one species of the pair was locally rare (R) and the other common (C). The sampled growth forms were massive (Goniastrea pectinata [R] and G. retiformis [C]), digitate (Acropora humilis [R] and A. cf. digitifera [C]), corymbose (A. millepora [R] and A. nasuta [C]), tabular (A. cytherea [R] and A. hyacinthus [C]) and arborescent (A. robusta [R] and A. intermedia [C]). An extra corymbose species with intermediate abundance, A. spathulata was included when it became apparent that A. millepora was too rare on the reef crest, making the 11 species in total. The tagged colonies were visited each year in the weeks prior to spawning. During visits, two or more observers each took two or three photographs of each tagged colony from directly above and on the horizontal plane with a scale plate to track planar area. Dead or missing colonies were recorded and new colonies tagged to maintain ~30 colonies per species throughout the 6 years of the study. In addition to tracking tagged corals, 30 fragments were collected from neighboring untagged colonies of each species for counting numbers of eggs per polyp (fecundity); and fragments of untagged colonies were brought into the laboratory where spawned eggs were collected for biomass and energy measurements. We also conducted surveys at the study site to generate size structure data for each species in several of the years. Each tagged colony photograph was digitized by at least two people. Therefore, we could examine sources of error in planar area for both photographers and outliners. Competitive interactions were recorded for a subset of species by measuring the margins of tagged colony outlines interacting with neighboring corals. The study was abruptly ended by Tropical Cyclone Nathan (Category 4) that killed all but nine of the more than 300 tagged colonies in early 2015. Nonetheless, these data will be of use to other researchers interested in coral demography and coexistence, functional ecology, and parametrizing population, community, and ecosystem models. The data set is not copyright restricted, and users should cite this paper when using the data.
  6. Tang ASO, Ahmad Asnawi AW, Koh AZY, Chong SL, Liew PK, Selvaratnam V, et al.
    Am J Case Rep, 2023 Mar 08;24:e938868.
    PMID: 36882990 DOI: 10.12659/AJCR.938868
    BACKGROUND Plasma cell leukemia (PCL) is an aggressive form of plasma cell neoplasm. We report the first case of primary PCL successfully treated with upfront novel agents consisting of Venetoclax and daratumumab in combination with intensive chemotherapy and allogeneic transplantation. CASE REPORT A 59-year-old woman presented with epistaxis, gum bleeding, and blurred vision. On examination, she appeared pale, with multiple petechiae and hepatomegaly. Fundoscopy revealed retinal hemorrhages. Laboratory investigations revealed bicytopenia and leukocytosis, with mild coagulopathy and hypofibrinogenemia. Elevated globulin and calcium levels were also observed. Serum protein electrophoresis demonstrated IgG lambda paraproteinemia, with a serum-free light chain kappa-to-lambda ratio of 0.074. A skeletal survey revealed the presence of lytic lesions. Bone marrow investigations confirmed the presence of lambda-light-chain-restricted clonal plasma cells. FISH detected t(11;14) and 17p13.1 deletion. Therefore, a final diagnosis of primary PCL was made. The patient received 1 cycle of bortezomib, cyclophosphamide, and dexamethasone (VCD) and 5 cycles of Venetoclax-VCD, followed by an unsuccessful stem cell mobilization. One cycle of daratumumab in combination with bortezomib, lenalidomide, and dexamethasone (VRD) was then given. The patient achieved complete remission. She underwent allogeneic stem cell transplantation of an HLA-matched sibling donor. Post-transplant marrow assessment showed disease remission and absence of t(11;14) and 17p deletions. She was administered pamidronate and lenalidomide maintenance. She remained clinically well with a good performance status and no active graft-versus-host disease 18 months after transplant. CONCLUSIONS The success of our patient in achieving complete remission has highlighted the efficacy and safety of this novel therapy in the front-line management of PCL.
    MeSH terms: Bortezomib; Dexamethasone; Female; Humans; Transplantation, Homologous
  7. Kaur S, Ng CM, Tang SY, Kok EY
    Chronobiol Int, 2023 Apr;40(4):406-415.
    PMID: 36883329 DOI: 10.1080/07420528.2023.2186120
    This study aimed to examine the association between chronotype, eating jetlag, and eating misalignment with weight status among Malaysian adults during the COVID-19 restriction. This online cross-sectional study included 175 working adults recruited from March to July 2020. The chronotype was assessed using Morningness Eveningness Questionnaire (MEQ) while eating jetlag and mealtime variability were measured using Chrononutrition Profile Questionnaire (CPQ). Multiple linear regression demonstrated that lower breakfast frequency (β = -0.258, p = .002) and longer eating duration (β = 0.393, p 
    MeSH terms: Adult; Circadian Rhythm*; Cross-Sectional Studies; Humans; Surveys and Questionnaires; Sleep; Jet Lag Syndrome
  8. Azfaralariff A, Mat Lazim A, Amran NH, Mukhtar NH, Bakri ND, Azrihan NN, et al.
    Waste Manag Res, 2023 Jul;41(7):1219-1226.
    PMID: 36883418 DOI: 10.1177/0734242X231155395
    In recent years, the environmental pollution of microplastics (MPs) has increasingly drawn our attention. MPs are small fragments of plastics that are commonly dispersed in the environment. The accumulation of environmental MPs is due to population growth and urbanization, while natural disasters such as hurricanes, flooding and human activity may influence their distribution. The leaching of chemicals from MPs raises a significant safety problem and environmental approaches aimed at reducing the use and recycling of plastics, with the replacement by bioplastics and wastewater treatment developments are called for. This summary also helps in demonstrating the connection between terrestrial and freshwater MPs and wastewater treatment plants as the major contributors to environmental MPs by discharges of sludge and effluent. More research on the classification, detection, characterization and toxicity of MPs are essential to enable greater options and solutions. Control initiatives need to intensify the comprehensive study of MP waste control and management information programmes in the fields of institutional engagement, technological research and development, legislation and regulation. A comprehensive quantitative analysis approach for MPs should be created in the future, and more reliable traceability analysis methods should be built to examine further its environmental activity and existence, where this should be done to improve scientific research on MP pollution in terrestrial, freshwater and marine environments and hence, develop more scientific and rational control policies.
    MeSH terms: Environmental Monitoring; Environmental Pollution; Humans; Plastics/analysis; Plastics/toxicity; Plastics/chemistry
  9. Fu X, Du B, Meng Y, Li Y, Zhu X, Ou Z, et al.
    PMID: 36883483 DOI: 10.1039/d2em00480a
    Rhinitis is one of the most prevalent chronic diseases globally. Microbiome exposure affects the occurrence of rhinitis. However, previous studies did not differentiate allergic rhinitis (AR) and non-allergic rhinitis (NAR) in the microbial association analysis. In this study, we investigate 347 students in 8 junior high schools, Terengganu, Malaysia, who were categorized as healthy (70.9%), AR (13.8%) and NAR (15.3%) based on a self-administered questionnaire and skin prick tests of pollen, pet, mould and house dust mite allergens. Classroom microbial and metabolite exposure in vacuumed dust was characterized by PacBio long-read amplicon sequencing, quantitative PCR and LC-MS-based untargeted metabolomics. Our findings indicate a similar microbial association pattern between AR and NAR. The richness in Gammaproteobacteria was negatively associated with AR and NAR symptoms, whereas total fungal richness was positively associated with AR and NAR symptoms (p < 0.05). Brasilonema bromeliae and Aeromonas enteropelogenes were negatively associated with AR and NAR, and Deinococcus was positively associated with AR and NAR (p < 0.01). Pipecolic acid was protectively associated with AR and NAR symptoms (OR = 0.06 and 0.13, p = 0.009 and 0.045). A neural network analysis showed that B. bromeliae was co-occurring with pipecolic acid, suggesting that the protective role of this species may be mediated by releasing pipecolic acid. Indoor relative humidity and the weight of vacuum dust were associated with AR and NAR, respectively (p < 0.05), but the health effects were mediated by two protective bacterial species, Aliinostoc morphoplasticum and Ilumatobacter fluminis. Overall, our study reported a similar microbial association pattern between AR and NAR and also revealed the complex interactions between microbial species, environmental characteristics, and rhinitis symptoms.
  10. Chen L, Jiang Q, Jiang C, Lu H, Hu W, Yu S, et al.
    Food Funct, 2023 Mar 20;14(6):2870-2880.
    PMID: 36883533 DOI: 10.1039/d2fo02524h
    Obesity has been reported to be associated with dysbiosis of gut microbiota. Sciadonic acid (SC) is one of the main functional components of Torreya grandis "Merrillii" seed oil. However, the effect of SC on high-fat diet (HFD)-induced obesity has not been elucidated. In this study, we evaluated the effects of SC on lipid metabolism and the gut flora in mice fed with a high-fat diet. The results revealed that SC activates the PPARα/SREBP-1C/FAS signaling pathway and reduces the levels of total cholesterol (TC), triacylglycerols (TG), and low-density lipoprotein cholesterol (LDL-C), but increases the level of high-density lipoprotein cholesterol (HDL-C) and inhibits weight gain. Among them, high-dose SC was the most effective; the TC, TG and LDL-C levels were reduced by 20.03%, 28.40% and 22.07%, respectively; the HDL-C level was increased by 8.55%. In addition, SC significantly increased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels by 98.21% and 35.17%, respectively, decreased oxidative stress, and ameliorated the pathological damage to the liver caused by a high-fat diet. Furthermore, SC treatment altered the composition of the intestinal flora, promoting the relative abundance of beneficial bacteria such as Lactobacillus and Bifidobacterium, while simultaneously decreasing the relative abundance of potentially harmful bacteria such as Faecalibaculum, norank_f_Desulfovibrionaceae, and Romboutsia. Spearman's correlation analysis indicated that the gut microbiota was associated with SCFAs and biochemical indicators. In summary, our results suggested that SC can improve lipid metabolism disorders and regulate the gut microbial structure.
    MeSH terms: Gastrointestinal Microbiome*; Animals; Cholesterol, LDL; Mice, Inbred C57BL; Obesity/etiology; Obesity/microbiology; Triglycerides/pharmacology; Lipid Metabolism; Mice; Diet, High-Fat/adverse effects
  11. Isa N, Osman MS, Abdul Hamid H, Inderan V, Lockman Z
    Int J Phytoremediation, 2023;25(5):658-669.
    PMID: 35858487 DOI: 10.1080/15226514.2022.2099345
    This study describes the synthesis of silver nanoparticles (AgNPs) using shortleaf spikesedge extract (SSE) to reduce AgNO3. Visual observation, in addition to analyses of UV-vis, EDX, XRD, FTIR, and TEM was employed to monitor the formation of AgNPs. The effects of SSE concentration, AgNO3 concentration, reaction time, pH, and temperature on the synthesis of AgNPs were studied based on the surface plasmon resonance (SPR) band. From the TEM image, highly-scattered AgNPs of quasi-spherical shape with an average particle size of 17.64 nm, were observed. For the catalytic study, the reduction of methylene blue (MB) was evaluated using two systems. A detailed batch study of the removal efficiency (%RE) and kinetics was done at an ambient temperature, various MB initial concentrations, and varying reaction time. Employing the electron relay effect in System 2, the batch study clearly highlighted the significant role of AgNPs in boosting the catalytic activity for MB removal. At 30-100 mg/L initial concentrations, MB was reduced by 100% in a very short reaction time between 1.5 and 5.0 mins. The kinetic data best fitted the pseudo-first-order model with a maximum reaction rate of 2.5715 min-1. These findings suggest the promising application of AgNPs in dye wastewater treatment.The SSE-driven AgNPs were prepared using unwanted dried biomass of shortleaf spikesedge extract (SSE) as a reducing as well as stabilizing agent. Employing the electron relay effect, the batch study clearly highlighted the significant role of SSE-driven AgNPs in boosting the catalytic activity for MB removal. At 30-100 mg/L initial concentrations, MB was reduced by 100% in a very short reaction time between 1.5 and 5.0 mins. In this sense, SSE-driven AgNPs acted as an electron relay point that behaves alternatively as acceptor and donor of electrons. The findings revealed the good catalytic performance of SSE-driven AgNPS, proving their viability for dye wastewater treatment.
    MeSH terms: Biodegradation, Environmental; Catalysis; Methylene Blue; Plant Extracts; Silver; Water; Surface Plasmon Resonance*; Metal Nanoparticles*
  12. Nayak SB, Pamidi N, Packirisamy V, Vasudeva SK
    Anat Cell Biol, 2023 Mar 31;56(1):141-144.
    PMID: 36263505 DOI: 10.5115/acb.22.109
    Knowledge of variations of renal vessels is of utmost importance in retroperitoneal surgeries and kidney transplant surgeries. We report concurrent variations of the right renal vessels, observed in an adult male cadaver during dissection classes. The right kidney was supplied by three renal arteries, out of which two entered the kidney through the hilum and the other one entered through the lower pole of the kidney. There were five renal veins, emerging independently from the hilum and opening separately through five openings into the inferior vena cava. Among the veins, only one emerged anterior to the renal pelvis and the other four emerged behind it. Four of them terminated into the posterolateral aspect of the inferior vena cava, whereas one terminated into its anterior aspect. Fourth vein from above, received the right testicular vein. The renal hilum was clogged with the presence of seven vessels and renal pelvis.
  13. Aluh DO, Aigbogun O, Anyachebelu OC
    J Immigr Minor Health, 2023 Apr;25(2):315-323.
    PMID: 36271302 DOI: 10.1007/s10903-022-01404-x
    Immigrant status, especially a few years post arrival, is a major risk factor for depression in populations that have been adequately studied. While information on depression among Asian migrants, including those from India, China and Philippines, in Canada have been reported in previous studies, there is inadequate information about depression among Nigerian immigrants who make up the largest percentage of African migrants and black population residing in Canada. A cross-sectional study was conducted among 187 Nigerian immigrants in Canada. Participants completed the Patient Health Questionnaire (PHQ-9). Descriptive and multivariate logistic regression analyses were carried out using IBM SPPS. About half (51.7%, n = 91) of the participants screened positive to the PHQ-9. Being female, unmarried, not being at all satisfied with the decision to migrate, and having stayed for more than 10 years in Canada significantly increased the risk of screening positive to depression. More than half of the participants screened positive for depression, suggesting an important mental health concern and the potential need for intervention. This population differed from other immigrant populations from previous studies because the absence of social support, satisfaction with employment status, and perceived discrimination did not significantly predict a positive screen for depression in this study.
    MeSH terms: Canada/epidemiology; Cross-Sectional Studies; Depression*; Employment; Female; Humans; Male; Emigrants and Immigrants*
  14. Preece ND, van Oosterzee P, Lawes MJ
    J Environ Manage, 2023 Jun 15;336:117645.
    PMID: 36871451 DOI: 10.1016/j.jenvman.2023.117645
    Successful cost-effective reforestation plantings depend substantially on maximising sapling survival from the time of planting, yet in reforestation programs remarkably little attention is given to management of saplings at the planting stage and to planting methods used. Critical determinants of sapling survival include their vigour and condition when planted, the wetness of the soil into which saplings are planted, the trauma of transplant shock from nursery to natural field soils, and the method and care taken during planting. While some determinants are outside planters' control, careful management of specific elements associated with outplanting can significantly lessen transplanting shock and improve survival rates. Results from three reforestation experiments designed to examine cost-effective planting methods in the Australian wet tropics provided the opportunity to examine the effects of specific planting treatments, including (1) watering regime prior to planting, (2) method of planting and planter technique, and (3) site preparation and maintenance, on sapling survival and establishment. Focusing on sapling root moisture and physical protection during planting improved sapling survival by at least 10% (>91% versus 81%) at 4 months. Survival rates of saplings under different planting treatments were reflected in longer-term survival of trees at 18-20 months, differing from a low of 52% up to 76-88%. This survival effect was evident more than 6 years after planting. Watering saplings immediately prior to planting, careful planting using a forester's planting spade in moist soil and suppressing grass competition using appropriate herbicides were critical to improved plant survival.
    MeSH terms: Australia; Poaceae; Soil*; Trees*; Water
  15. Musa SM, Siew SW, Tay DD, Ahmad HF
    Microbiol Resour Announc, 2023 Apr 18;12(4):e0105522.
    PMID: 36877039 DOI: 10.1128/mra.01055-22
    Here, we present a 7.62-Mbp genome sequence of Paenibacillus sp. nov. strain J5C2022, a Gram-positive facultatively anaerobic bacterium that was isolated from 4-month-old fruit pickle brine and sequenced using the Illumina platform.
  16. Peter OJ, Panigoro HS, Abidemi A, Ojo MM, Oguntolu FA
    Acta Biotheor, 2023 Mar 06;71(2):9.
    PMID: 36877326 DOI: 10.1007/s10441-023-09460-y
    This paper is concerned with the formulation and analysis of an epidemic model of COVID-19 governed by an eight-dimensional system of ordinary differential equations, by taking into account the first dose and the second dose of vaccinated individuals in the population. The developed model is analyzed and the threshold quantity known as the control reproduction number [Formula: see text] is obtained. We investigate the equilibrium stability of the system, and the COVID-free equilibrium is said to be locally asymptotically stable when the control reproduction number is less than unity, and unstable otherwise. Using the least-squares method, the model is calibrated based on the cumulative number of COVID-19 reported cases and available information about the mass vaccine administration in Malaysia between the 24th of February 2021 and February 2022. Following the model fitting and estimation of the parameter values, a global sensitivity analysis was performed by using the Partial Rank Correlation Coefficient (PRCC) to determine the most influential parameters on the threshold quantities. The result shows that the effective transmission rate [Formula: see text], the rate of first vaccine dose [Formula: see text], the second dose vaccination rate [Formula: see text] and the recovery rate due to the second dose of vaccination [Formula: see text] are the most influential of all the model parameters. We further investigate the impact of these parameters by performing a numerical simulation on the developed COVID-19 model. The result of the study shows that adhering to the preventive measures has a huge impact on reducing the spread of the disease in the population. Particularly, an increase in both the first and second dose vaccination rates reduces the number of infected individuals, thus reducing the disease burden in the population.
    MeSH terms: Animals; Computer Simulation; Models, Theoretical; Vaccination; Pandemics/prevention & control
  17. Ali R, Wan Mohamad Ali WN, Wilson Putit P
    JMIR Res Protoc, 2023 Mar 06;12:e39798.
    PMID: 36877567 DOI: 10.2196/39798
    BACKGROUND: Malaria is still a public health threat. From 2015 to 2021, a total of 23,214 malaria cases were recorded in Malaysia. Thus, effective intervention and key entomological information are vital for interrupting or preventing malaria transmission. Therefore, the availability of malaria vector information is desperately needed.

    OBJECTIVE: The objective of our study is to update the list of human and zoonotic malaria vectors in Malaysia. This work will include (1) the characterization of the key behavioral traits and breeding sites of malaria vectors and (2) the determination of new and potential malaria vectors in Malaysia. The findings of our scoping review will serve as decision-making evidence that stakeholders and decision makers can use to strengthen and intensify malaria surveillance in Malaysia.

    METHODS: The scoping review will be conducted based on the following four electronic databases: Scopus, PubMed, Google Scholar, and Science Direct. A search strategy was conducted for articles published from database inception to March 2022. The criteria for article inclusion were any malaria vector-related studies conducted in Malaysia (with no time frame restrictions) and peer-reviewed studies. The PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) will be used to guide our systematic approach. Data from published research literature will be extracted by using a standardized data extraction framework, including the titles, abstracts, characteristics, and main findings of the included studies. To assess the risk of bias, articles will be screened independently by 2 reviewers, and a third reviewer will make the final decision if disagreements occur.

    RESULTS: The study commenced in June 2021, and it is planned to be completed at end of 2022. As of early 2022, we identified 631 articles. After accessing and evaluating the articles, 48 were found to be eligible. Full-text screening will be conducted in mid-2022. The results of the scoping review will be published as an open-access article in a peer-reviewed journal.

    CONCLUSIONS: Our novel scoping review of malaria vectors in Malaysia will provide a comprehensive evidence summary of updated, relevant information. An understanding of the status of Anopheles as malaria vectors and the knowledge generated from the behavioral characteristics of malaria vectors are the key components in making effective interventions for eliminating malaria.

    INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/39798.

  18. Khor LA, A Wahid UNI, Ling LL, Liansim SMS, Oon J, Balakrishnan MN, et al.
    PLoS One, 2023;18(3):e0282733.
    PMID: 36877714 DOI: 10.1371/journal.pone.0282733
    INTRODUCTION: Tuberculosis remains a major health problem globally and in Malaysia, particularly in the state of Sabah. Delayed sputum conversion is associated with treatment failure, drug-resistant tuberculosis and mortality. We aimed to determine the prevalence of delayed sputum conversion among smear positive pulmonary tuberculosis (PTB) patients and its associated factors in Sabah, Malaysia.

    METHODS: A retrospective follow up study on all patients newly diagnosed with smear positive pulmonary tuberculosis from 2017 to 2019 was conducted at three government health clinics in Sabah, utilizing data from a national electronic tuberculosis database and medical records. Descriptive statistics and binary logistic regression were applied for data analysis. The outcome of the study was the sputum conversion status at the end of the two-month intensive treatment phase with either successful conversion to smear negative or non-conversion.

    RESULTS: 374 patients were included in the analysis. Our patients were generally younger than 60 years old with no medical illness and varying proportions of tuberculosis severity as judged by radiographic appearance and sputum bacillary load upon diagnosis. Foreigners constituted 27.8% of our sample. 8.8% (confidence interval: 6.2-12.2) did not convert to smear negative at the end of the intensive phase. Binary logistic regression showed that older patients ≥60 years old (adjusted odds ratio, AOR = 4.303), foreigners (AOR = 3.184) and patients with higher sputum bacillary load at diagnosis [2+ (AOR = 5.061) and 3+ (AOR = 4.992)] were more likely to have delayed sputum smear conversion.

    CONCLUSION: The prevalence of delayed sputum conversion in our study was considerably low at 8.8% with age ≥60 years old, foreigners and higher pre-treatment sputum bacillary load associated with delayed conversion. Healthcare providers should take note of these factors and ensure the patients receive proper follow up treatment.

    MeSH terms: Firmicutes; Bacillus*; Follow-Up Studies; Humans; Lactobacillus casei*; Malaysia/epidemiology; Middle Aged; Retrospective Studies; Sputum; Prevalence
  19. Lau TV, Puah SM, Tan JMA, Merino S, Puthucheary SD, Chua KH
    Microb Pathog, 2023 Apr;177:106059.
    PMID: 36878334 DOI: 10.1016/j.micpath.2023.106059
    Aeromonas dhakensis possesses dual flagellar systems for motility under different environments. Flagella-mediated motility is necessary for biofilm formation through an initial attachment of bacteria to the surface, but this has not been elucidated in A. dhakensis. This study investigates the role of polar (flaH, maf1) and lateral (lafB, lafK and lafS) flagellar genes in the biofilm formation of a clinical A. dhakensis strain WT187 isolated from burn wound infection. Five deletion mutants and corresponding complemented strains were constructed using pDM4 and pBAD33 vectors, respectively, and analyzed for motility and biofilm formation using crystal violet staining and real-time impedance-based assays. All mutants were significantly reduced in swimming (p 
    MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Cell Movement; Flagella/genetics; Flagella/metabolism; Gentian Violet*; Biofilms
  20. Saeed M, Ilyas N, Bibi F, Shabir S, Jayachandran K, Sayyed RZ, et al.
    Chemosphere, 2023 May;324:138311.
    PMID: 36878368 DOI: 10.1016/j.chemosphere.2023.138311
    A novel kinetic model has been developed to explain the degradation of total petroleum hydrocarbons. Microbiome engineered biochar amendment may result in a synergistic impact on degradation of total petroleum hydrocarbons (TPHs). Therefore, the present study analyzed the potential of hydrocarbon-degrading bacteria A designated as Aeromonas hydrophila YL17 and B as Shewanella putrefaciens Pdp11 morphological characterized as rod shaped, anaerobic and gram-negative immobilized on biochar, and the degradation efficiency was measured by gravimetric analysis and gas chromatography-mass spectrometry (GC-MS). Whole genome sequencing of both strains revealed the existence of genes responsible for hydrocarbon degradation. In 60 days remediation setup, the treatment consisting of immobilization of both strains on biochar proved more efficient with less half-life and better biodegradation potentials compared to biochar without strains for decreasing the content of TPHs and n-alkanes (C12-C18). Enzymatic content and microbiological respiration showed that biochar acted as a soil fertilizer and carbon reservoir and enhanced microbial activities. The removal efficiency of hydrocarbons was found to be a maximum of 67% in soil samples treated with biochar immobilized with both strains (A + B), followed by biochar immobilized with strain B 34%, biochar immobilized with strain A 29% and with biochar 24%, respectively. A 39%, 36%, and 41% increase was observed in fluorescein diacetate (FDA) hydrolysis, polyphenol oxidase and dehydrogenase activities in immobilized biochar with both strains as compared to control and individual treatment of biochar and strains. An increase of 35% was observed in the respiration rate with the immobilization of both strains on biochar. While a maximum colony forming unit (CFU/g) was found 9.25 with immobilization of both strains on biochar at 40 days of remediation. The degradation efficiency was due to synergistic effect of both biochar and bacteria based amendment on the soil enzymatic activity and microbial respiration.
    MeSH terms: Bacteria/genetics; Bacteria/metabolism; Biodegradation, Environmental; Hydrocarbons/metabolism; Soil/chemistry; Soil Microbiology; Microbiota*
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