Browse publications by year: 2024

  1. Teerapongpisan P, Monkantha T, Yimklan S, Mah SH, Gunter NV, Promnart P, et al.
    J Nat Prod, 2024 Jun 28;87(6):1611-1617.
    PMID: 38805684 DOI: 10.1021/acs.jnatprod.4c00248
    The first phytochemical investigation of the twig extract of Uvaria leptopoda resulted in the isolation and identification of three new tetrahydroxanthene-1,3(2H)-diones, uvarialeptones A-C, two new oxidized hexadiene derivatives, uvarialeptols A and B, together with ten known compounds. Their structures were elucidated by spectroscopic techniques and mass spectrometry. Uvarialeptones A and B were unprecedented tetrahydroxanthene-1,3(2H)-dione dimers which exhibited a cyclobutane ring via [2 + 2] cycloaddition from uvarialeptone C and 9a-O-methyloxymitrone, respectively. The structure of uvarialeptone A was confirmed by X-ray diffraction analysis using Mo Kα radiation. Compound 3 inhibited NO production at an IC50 value of 6.7 ± 0.1 μM.
    MeSH terms: RAW 264.7 Cells; Animals; Nitric Oxide/biosynthesis; Oxidation-Reduction; Xanthenes/pharmacology; Xanthenes/chemistry; Molecular Structure; Crystallography, X-Ray; Mice
  2. Lam WN, Huang J, Tay AHT, Sim HJ, Chan PJ, Lim KE, et al.
    New Phytol, 2024 Aug;243(3):881-893.
    PMID: 38840520 DOI: 10.1111/nph.19876
    Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve higher demographic rates (e.g. growth or survival) or occupy unique environmental niches (e.g. waterlogged conditions) remain poorly understood. Anatomical traits may better predict plant environmental and demographic strategies because they are direct measurements of structures involved in these adaptations. We collected 18 leaf and twig traits from 29 tree species in a tropical freshwater swamp forest in Singapore. We estimated demographic parameters of the 29 species from growth and survival models, and degree of association toward swamp habitats. We examined pairwise trait-trait, trait-demography and trait-environment links while controlling for phylogeny. Leaf and twig anatomical traits were better predictors of all demographic parameters than other commonly measured leaf and wood traits. Plants with wider vessels had faster growth rates but lower survival rates. Leaf and spongy mesophyll thickness predicted swamp association. These findings demonstrate the utility of anatomical traits as indicators of plant hydraulic strategies and their links to growth-mortality trade-offs and waterlogging stress tolerance that underlie species coexistence mechanisms in tropical forest trees.
    MeSH terms: Adaptation, Physiological*; Fresh Water; Species Specificity; Tropical Climate*; Ecosystem; Quantitative Trait, Heritable; Wetlands*; Forests*
  3. Yap KH, Azmin S, Abdul Manan H, Yahya N, Ahmad N, Tajurudin FW, et al.
    Parkinsonism Relat Disord, 2024 Jul;124:107013.
    PMID: 38843619 DOI: 10.1016/j.parkreldis.2024.107013
    INTRODUCTION: Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease characterized by increasingly worsening ataxia and non-ataxia features, negatively impacting patients' quality of life. This study was designed to test formally evaluate whether oral trehalose was effective in SCA3 patients.

    METHODS: In this double-blind, randomized controlled trial, SCA3 patients received either 100 g oral trehalose or 30 g maltose to improve ataxia severity over six months. We also measured other clinical (non-ataxia), patient-reported (quality of life, motivations), and safety endpoints. An unscheduled interim analysis was conducted using two-way ANOVAs to analyze the interaction between time (baseline, 3-months, 6-months) and intervention (Trehalose vs. Placebo).

    RESULTS: Fifteen participants (Trehalose = 7 vs. Placebo = 8) completed the study at the time of interim analysis. There was no interaction effect on the ataxia severity, and available data suggested an estimated sample size of 132 (66 per arm) SCA3 patients required to demonstrate changes in a 6-month trial. There were significant interaction effects for executive function (ƞ2 = 0.28-0.43). Safety data indicated that 100 g oral trehalose was well-tolerated.

    CONCLUSION: We performed an unplanned interim analysis due to a slow recruitment rate. The new estimated sample size was deemed unfeasible, leading to premature termination of the clinical trial. In this small, current sample of SCA3 patients, 100 g oral trehalose did not differentially impact on ataxia severity compared to placebo. Interestingly, our findings may suggest an improvement in executive function. Future efforts will require a large multi-country, multi-center study to investigate the potential effect of trehalose.

    MeSH terms: Administration, Oral; Adult; Aged; Double-Blind Method; Female; Humans; Male; Middle Aged; Quality of Life; Severity of Illness Index; Outcome Assessment (Health Care)
  4. Seow SQ, Mohan Viswanathan P, Dodge-Wan D
    Environ Sci Pollut Res Int, 2024 Jun;31(30):43292-43308.
    PMID: 38902441 DOI: 10.1007/s11356-024-33906-6
    Labuan, Miri, Kundasang and Raub regions of Malaysia have very different geological formations and settings that could result in different levels of natural radioactivity. Hence, this study determines the influence of different geological formations on radioactivity in these locations using field measurements, petrology and geochemistry. A total of 141 gamma dose rates and 227 beta flux measurements were collected using Polimaster survey meters (PM1405) in these four regions. The gamma dose rate values range from 0.37 to 0.05 µSv/h with a mean value of 0.11 µSv/h. Beta flux values range from 3.46 to 0.12 CPS with a mean value of 0.57 CPS. Mineralogy and elemental composition of the different rock types were analysed using thin-section petrography, XRD, ICP and pXRF methods. Felsic igneous rocks such as syenite and granite have higher natural radioactivity and contain more radionuclide-bearing minerals such as apatite, zircon, allanite, K-feldspar, titanite, muscovite and biotite. Metamorphic rocks have the second highest natural radioactivity and contain fewer radioactive minerals. The natural radioactivity of sedimentary rocks mostly depends on their clay content. The gamma dose rate maps show that igneous and metamorphic regions around Raub have higher radioactivity compared to the sedimentary-dominated regions around Miri and Labuan. Annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated to evaluate the potential health risk for inhabitants of these regions. Labuan and Miri are considered to be safe zones with respect to natural radioactivity as the results show little to no risk for the public, compared with the Raub region, which is medium to high risk.
    MeSH terms: Background Radiation; Geology; Malaysia; Radiation Monitoring*; Radioactivity*; Risk Assessment
  5. Alhassan M, Jalil AA, Owgi AHK, Hamid MYS, Bahari MB, Van Tran T, et al.
    Environ Sci Pollut Res Int, 2024 Jun;31(30):42640-42671.
    PMID: 38902444 DOI: 10.1007/s11356-024-34021-2
    The current work investigated emerging fields for generating and consuming hydrogen and synthetic Fischer-Tropsch (FT) fuels, especially from detrimental greenhouse gases, CO2 and CH4. Technologies for syngas generation ranging from partial oxidation, auto-thermal, dry, photothermal and wet or steam reforming of methane were adequately reviewed alongside biomass valorisation for hydrogen generation, water electrolysis and climate challenges due to methane flaring, production, storage, transportation, challenges and opportunities in CO2 and CH4 utilisation. Under the same conditions, dry reforming produces more coke than steam reforming. However, combining the two techniques produces syngas with a high H2/CO ratio, which is suitable for producing long-chain hydrocarbons. Although the steam methane reforming (SMR) process has been industrialised, it is well known to consume significant energy. However, coke production via catalytic methane decomposition, the prime hindrance to large-scale implementation of these techniques for hydrogen production, could be addressed by coupling CO with CO2 conversion to alter the H2/CO ratio of syngas, increasing the reaction temperatures in dry reforming, or increasing the steam content fed in steam reforming. Optimised hydrogen production and generation of green fuels from CO2 and CH4 can be achieved by implementing these strategies.
    MeSH terms: Carbon Dioxide*; Hydrogen*; Methane*; Biofuels
  6. Sartika RAD, Wirawan F, Gunawan W, Putri PN, Shukri NHM
    Clin Exp Pediatr, 2024 Jul;67(7):358-367.
    PMID: 38902920 DOI: 10.3345/cep.2023.01375
    BACKGROUND: The exclusive breastfeeding (EBF) rate in Indonesia is lower than expected. Among the key factors affecting breastfeeding practices, paternal support has been suggested.

    PURPOSE: To explore the role of paternal support in EBF failure among 3-month-old infants.

    METHODS: This sequential mixed-methods study, part of an ongoing cohort study in West Java in early 2022, included 225 infants. The parents of 3-month-old infants were interviewed. Paternal support was assessed using a 15-point validated questionnaire for a total score of 15-60 points. Multivariate binary regression was used to determine adjusted odds ratios (aORs). The qualitative exploration was based on in-depth interviews (IDIs) and forum group discussions (FGDs) following the quantitative survey.

    RESULTS: Of the 225 infants, 52.2% were no longer EBF. High paternal support (greater than the mean score) of breastfeeding was determined in 52.9% of cases (mean± standard deviation, 38.7±6.7 for the overall population vs. 37.5±6.3 and 40.2±6.8 for infants who were and were not EBF at 3 months of age, respectively). Low paternal support was associated with an increased EBF failure rate (aOR, 2.84; 95% confidence interval [CI], 1.46-5.54). Other variables that remained as predictors in the final model were a low birth rate (aOR, 7.35; 95% CI, 1.73-31.20), negative maternal attitude (aOR, 3.31; 95% CI, 1.63-6.75), lower self-efficacy (aOR, 4.82; 95% CI, 2.43-9.57), and lower maternal education level (aOR, 2.87; 95% CI, 1.03- 8.03). The IDIs and FGD observed the importance of the father's support of the mother and EBF. The qualitative exploration revealed a lack of knowledge about EBF as a parental support barrier.

    CONCLUSION: Paternal support is important for EBF. Paternal involvement in EBF planning encouraged themother to continue. Plans that include fathers in breastfeeding education may help increase paternal support.

  7. Saminathan ST, Ahmed WAW, Nawi NM, Tagiling N, Aziz I, Udin Y, et al.
    Asian Spine J, 2024 Jun;18(3):398-406.
    PMID: 38917860 DOI: 10.31616/asj.2022.0451
    STUDY DESIGN: Retrospective study.

    PURPOSE: To compare and correlate technetium-99m methylene diphosphonate uptake between benign and metastatic bone lesions using semiquantitative analysis of maximum standard uptake value (SUVmax) and mean Hounsfield unit (HU) in single-photon emission computed tomography-computed tomography (SPECT-CT).

    OVERVIEW OF LITERATURE: Qualitative interpretation of metastatic bone lesions in breast cancer on bone scintigraphy is often complicated by coexisting benign lesions.

    METHODS: In total, 185 lesions were identified on bone and SPECT-CT scans from 32 patients. Lesions were classified as metastatic (109 sclerotic lesions) and benign (76 lesions) morphologically on low-dose CT. Semiquantitative analysis using SUVmax and mean HU was performed on the lesions and compared. To discriminate benign and metastatic lesions, the correlation between SUVmax and mean HU was determined using the intraclass correlation coefficients.

    RESULTS: The SUVmax was higher in metastatic lesions (20.66±14.36) but lower in benign lesions (10.18±12.79) (p<0.001). The mean HU was lower in metastatic lesions (166.62±202.02) but higher in benign lesions (517.65±192.8) (p<0.001). A weak negative correlation was found between the SUVmax and the mean HU for benign lesions, and a weak positive correlation was noted between the SUVmax and the mean HU on malignant lesions with no statistical significance (p=0.394 and 0.312, respectively). The cutoff values obtained were 10.8 for SUVmax (82.6% sensitivity and 84.2% specificity) and 240.86 for the mean HU (98.7% sensitivity and 88.1% specificity) in differentiating benign from malignant bone lesions.

    CONCLUSIONS: Semiquantitative assessment using SUVmax and HU can complement qualitative analysis. Metastatic lesions had higher SUVmax but lower mean HU than benign lesions, whereas benign lesions demonstrated higher mean HU but lower SUVmax. A weak correlation was found between the SUVmax and the mean HU on malignant and benign lesions. Cutoff values of 10.8 for the SUVmax and 240.86 for the mean HU may differentiate bone metastases from benign lesions.

  8. Al-Ashwal MA, Al-Adhroey AH, Atroosh WM, Al-Subbary AA, Albhri AA, Azlan UW, et al.
    Parasitol Res, 2024 Jun 27;123(6):256.
    PMID: 38935203 DOI: 10.1007/s00436-024-08273-3
    Cutaneous leishmaniasis (CL), a neglected tropical disease, is a major public health concern in Yemen, with Leishmania tropica identified as the main causative agent. This study aims to investigate the occurrence and distribution of Leishmania parasites in domestic and wild animals in CL endemic areas in the western highlands of Yemen. A cross-sectional study was conducted in the Utmah District of western Yemen. Blood and skin scraping specimens were collected from 122 domestic and wild animals and tested for the Leishmania DNA using internal transcribed spacer 1 (ITS1) nested polymerase chain reaction. Phylogenetic analyses were performed on 20 L. tropica sequences obtained from animals in this study and 34 sequences from human isolates (collected concurrently from the same study area) retrieved from the GenBank. Overall, L. tropica was detected in 16.4% (20/122) of the examined animals, including 11 goats, two dogs, two bulls, one cow, one donkey, one rabbit, one rat and one bat. None of the examined cats and sheep was positive. The animal sequences were segregated into four different L. tropica haplotypes, with the majority of the animal (15/20) and human (32/34) sequences composed of one dominant haplotype/genotype. These findings represent the first confirmed evidence of natural L. tropica infections in different kinds of domestic and wild animals in western Yemen, suggesting these animals potentially have a role in the transmission of CL in Yemen. Therefore, a One Health approach is required for the effective prevention and control of this devastating disease among endemic populations.
    MeSH terms: Animals; Cross-Sectional Studies; Humans; Male; Phylogeny*; Yemen/epidemiology; DNA, Protozoan/genetics; Polymerase Chain Reaction/veterinary; Sequence Analysis, DNA; Endemic Diseases/veterinary; DNA, Ribosomal Spacer/genetics; Neglected Diseases/epidemiology; Neglected Diseases/parasitology; Neglected Diseases/veterinary
  9. Lee SY, Tan YH, Lau SY, Mubarak NM, Tan YY, Tan IS, et al.
    Environ Res, 2024 Jun 27;259:119448.
    PMID: 38942255 DOI: 10.1016/j.envres.2024.119448
    Dye wastewater consists of high solids concentrations, heavy metals, minor contaminants, dissolved chemical oxygen demand, and microorganisms. Nanoflowers are nanoparticles that resemble flowers when viewed at a microscopic level. Inorganic metal oxide nanoflowers have been discovered to be a potential source for overcoming this situation. Their flower-like features give them a higher surface area to volume ratio and porosity structure, which can absorb a significant amount of dye. The metal oxide nanoflower synthesized from different synthesis methods is used to compare which one is cost-effective and capable of generating a large scale of nanoflower. This review has demonstrated outstanding dye removal efficiency by applying inorganic nanoflowers to dye removal. Since both adsorption and photocatalytic reactions enhance the dye degradation process, complete dye degradation could be achieved. Meanwhile, the inorganic metal oxide nanoflowers' exemplary reusability characteristics with negligible performance drop further prove that this approach is highly sustainable and may help to save costs. This review has proven the momentum of obtaining high dye removal efficiency in wastewater treatment to conclude that the metal oxide nanoflower study is worth researching.
  10. Arnett S, Chew SH, Leitner U, Hor JY, Paul F, Yeaman MR, et al.
    J Neurol, 2024 Aug;271(8):4794-4812.
    PMID: 38958756 DOI: 10.1007/s00415-024-12452-8
    BACKGROUND: Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

    METHODS: A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

    RESULTS: A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p 

    MeSH terms: Female; Humans; Male; Sex Ratio; Age of Onset*
  11. Razali NAM, Salleh WNW, Mohamed MA, Aziz F, Jye LW, Yusof N, et al.
    PMID: 38958863 DOI: 10.1007/s11356-024-34081-4
    The investigations of real industrial wastewater, such as palm oil mill effluent (POME), as a recalcitrant pollutant remain a subject of global water pollution concern. Thus, this work introduced the preparation and modification of g-C3N4 and WO3 at optimum calcination temperature, where they were used as potent visible light-driven photocatalysts in the degradation of POME under visible light irradiation. Herein, g-C3N4-derived melamine and WO3 photocatalyst were obtained at different calcination temperatures in order to tune their light absorption ability and optoelectronics properties. Both photocatalysts were proven to have their distinct phases, crystallinity levels, and elements with increasing temperature, as demonstrated by the ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) results. Significantly, g-C3N4 (580 °C) and WO3 (450 °C) unitary photocatalysts exhibited the highest removal efficiency of POME without dilution due to good crystallinity, extended light absorption, high separation, and less recombination efficiency of electron-hole pairs. Furthermore, surprisingly, the superior energy storage photocatalytic performance with outstanding stability by WO3 achieved an approximately 10% increment during darkness, compared with g-C3N4 under visible light irradiation. Moreover, it has been proven that the WO3 and g-C3N4 photocatalysts are desirable photocatalysts for various pollutant degradations, with excellent visible-light utilization and favorable energy storage application.
  12. Gantumur M, Hossain MI, Shahiduzzaman M, Tamang A, Rafij JH, Shahinuzzaman M, et al.
    ACS Appl Mater Interfaces, 2024 Jul 17;16(28):36255-36271.
    PMID: 38959094 DOI: 10.1021/acsami.4c03591
    This study delves into enhancing the efficiency and stability of perovskite solar cells (PSCs) by optimizing the surface morphologies and optoelectronic properties of the electron transport layer (ETL) using tungsten (W) doping in zinc oxide (ZnO). Through a unique green synthesis process and spin-coating technique, W-doped ZnO films were prepared, exhibiting improved electrical conductivity and reduced interface defects between the ETL and perovskite layers, thus facilitating efficient electron transfer at the interface. High-quality PSCs with superior ETL demonstrated a substantial 30% increase in power conversion efficiency (PCE) compared to those employing pristine ZnO ETL. These solar cells retained over 70% of their initial PCE after 4000 h of moisture exposure, surpassing reference PSCs by 50% PCE over this period. Advanced numerical multiphysics solvers, employing finite-difference time-domain (FDTD) and finite element method (FEM) techniques, were utilized to elucidate the underlying optoelectrical characteristics of the PSCs, with simulated results corroborating experimental findings. The study concludes with a thorough discussion on charge transport and recombination mechanisms, providing insights into the enhanced performance and stability achieved through W-doped ZnO ETL optimization.
  13. Mohan P, Shahul Hamid F
    Mar Pollut Bull, 2024 Aug;205:116654.
    PMID: 38959572 DOI: 10.1016/j.marpolbul.2024.116654
    According to a bibliometric analysis, studies on microplastic pollution in Malaysia are still incomprehensive. This study found microplastic contamination in sediment (97 particles/kg) and water (10,963 particles/m3) samples from Malaysian mangroves. Sediment from Matang and water from Kuala Selangor recorded the highest microplastic concentrations at 140 ± 5.13 particles/kg and 13,350 ± 37.95 particles/m3, respectively. Fragmented, blue, rayon and particles of <0.1 mm microplastic were the most abundant in sediment and water. In an experiment of polypropylene microplastic uptakes, Anadara granosa was found to uptake more 0.1 mm fiber particles. The uptake is strongly correlated to the presence of microplastics in sediment and water. The estimated dietary intake (EDI) indicates that a consumer could ingest 507 microplastic particles/year by consuming contaminated A. granosa. Therefore, mitigating measures are crucial to safeguard aquatic systems and humans from microplastic pollution.
    MeSH terms: Environmental Monitoring*; Malaysia; Polypropylenes; Bibliometrics; Wetlands
  14. Nordin N, Hasbullah NH, Abu Bakar N
    Food Chem, 2024 Nov 15;458:140236.
    PMID: 38959805 DOI: 10.1016/j.foodchem.2024.140236
    Coffee, a globally consumed beverage, has raised concerns in Islamic jurisprudence due to the possible presence of alcohol compounds. This research aims to utilise the sensitivity and reliability of 1H NMR spectroscopy in the quantification of alcohol compounds such as ethanol, furfuryl alcohol, and 5-(hydroxymethyl) furfural (HMF) in commercial instant coffee. Analysis of seven products was performed using advanced 1H Nuclear Magnetic Resonance (NMR) spectroscopy together with Statistical Total Correlation Spectroscopy (STOCSY) and Resolution-Enhanced (RED)-STORM. The analysis of the 100 mg sample revealed the absence of ethanol. The amount of furfuryl alcohol and HMF in the selected commercial instant coffee samples was 0.817 μg and 0.0553 μg, respectively. This study demonstrates the utility of 1H NMR spectroscopy in accurate quantification of trace components for various applications.
    MeSH terms: Ethanol/analysis; Alcohols/analysis; Furaldehyde/analogs & derivatives; Furaldehyde/analysis; Furans/analysis; Islam; Magnetic Resonance Spectroscopy/methods
  15. Wei Rong CW, Salleh H, Nishio H, Lee M
    Sci Total Environ, 2024 Oct 15;947:174348.
    PMID: 38960184 DOI: 10.1016/j.scitotenv.2024.174348
    INTRODUCTION: Global warming appears to initiate and aggravate allergic respiratory conditions via interaction with numerous environmental factors. Temperature, commonly identified as a factor in climate change, is important in this process. Allergic rhinitis, a common respiratory allergy, is on the rise and affects approximately 500 million individuals worldwide. The increasing ambient temperature requires evaluation regarding its influence on allergic rhinitis, taking into account regional climate zones.

    METHODS: A detailed search of PubMed, EMBASE, Scopus, Web of Science, MEDLINE, and CINAHL Plus databases, was conducted, encompassing observational studies published from 1991 to 2023. Original studies examining the relationship between increasing temperature and allergic rhinitis were assessed for eligibility followed by a risk of bias assessment. Random effects meta-analysis was utilized to measure the association between a 1 °C increase in temperature and allergic rhinitis-related outcomes.

    RESULTS: 20 studies were included in the qualitative synthesis, with nine of them subsequently selected for the quantitative synthesis. 20 included studies were rated as Level 4 evidence according to the Oxford Centre for Evidence-Based Medicine, and the majority of these reported good-quality evidence based on the Newcastle-Ottawa Quality Rating Scale. Using the Risk of Bias In Non-Randomized Studies of Exposure tool, the majority of studies exhibit a high risk of bias. Every 1 °C increase in temperature significantly raised the risk of allergic rhinitis-related outcomes by 29 % (RR = 1.26, 95 % CI: 1.11 to 1.50). Conversely, every 1 °C rise in temperature showed no significant increase in the odds of allergic rhinitis-related outcomes by 7 % (OR = 1.07, 95 % CI: 0.95 to 1.21). Subsequent subgroup analysis identified climate zone as an influential factor influencing this association.

    CONCLUSION: It is inconclusive to definitively suggest a harmful effect of increasing temperature exposure on allergic rhinitis, due overall very low certainty of evidence. Further original research with better methodological quality is required.

    MeSH terms: Hot Temperature; Humans; Temperature; Climate Change; Global Warming; Observational Studies as Topic
  16. Lim SJ, Noor NDM, Sabri S, Ali MSM, Salleh AB, Oslan SN
    Microb Pathog, 2024 Aug;193:106773.
    PMID: 38960213 DOI: 10.1016/j.micpath.2024.106773
    Meyerozyma guilliermondii (Candida guilliermondii) is one of the Candida species associated with invasive candidiasis. With the potential for expressing industrially important enzymes, M. guilliermondii strain SO possessed 99 % proteome similarity with the clinical ATCC 6260 isolate and showed pathogenicity towards zebrafish embryos. Recently, three secreted aspartyl proteinases (SAPs) were computationally identified as potential virulence factors in this strain without in vitro verification of SAP activity. The quantification of Candida SAPs activity in liquid broth were also scarcely reported. Thus, this study aimed to characterize M. guilliermondii strain SO's ability to produce SAPs (MgSAPs) in different conditions (morphology and medium) besides analyzing its growth profile. MgSAPs' capability to cleave bovine serum albumin (BSA) was also determined to propose that MgSAPs as the potential virulence factors compared to the avirulent Saccharomyces cerevisiae. M. guilliermondii strain SO produced more SAPs (higher activity) in yeast nitrogen base-BSA-dextrose broth compared to yeast extract-BSA-dextrose broth despite insignificantly different SAP activity in both planktonic and biofilm cells. FeCl3 supplementation significantly increased the specific protein activity (∼40 %). The BSA cleavage by MgSAPs at an acidic pH was proven through semi-quantitative SDS-PAGE, sharing similar profile with HIV-1 retropepsin. The presented work highlighted the MgSAPs on fungal cell wall and extracellular milieu during host infection could be corroborated to the quantitative production in different growth modes presented herein besides shedding lights on the potential usage of retropepsin's inhibitors in treating candidiasis. Molecular and expression analyses of MgSAPs and their deletion should be further explored to attribute their respective virulence effects.
    MeSH terms: Animals; Candida/genetics; Candida/metabolism; Candida/pathogenicity; Culture Media/chemistry; Saccharomycetales/genetics; Saccharomycetales/metabolism; Saccharomycetales/pathogenicity; Fungal Proteins/genetics; Fungal Proteins/metabolism; Virulence
  17. Fu J, Yap JX, Leo CP, Chang CK
    Int J Biol Macromol, 2024 Aug;274(Pt 2):133510.
    PMID: 38960270 DOI: 10.1016/j.ijbiomac.2024.133510
    The biodegradable, nontoxic, and renewable carboxymethyl cellulose (CMC) hydrogel has been developed into a green adsorbent. However, the weak chemical interaction limits its adsorption capability and reusability. This work incorporated lignin with complex structure and ZnO nanoparticles with photocatalytic properties into CMC hydrogel beads to improve the removal of methylene blue (MB) through chemical interaction. Scanning electron microscopic images and Fourier-transform infrared spectra confirmed the compatibility between lignin and ZnO nanoparticles as well as the increment of active sites for dye removal. The MB adsorption on CMC hydrogel beads was more significantly affected by the temperate and initial concentration compared to contact time, pH, and adsorbent dosage. The MB adsorption capacity of CMC hydrogel was improved to 276.79 mg/g after incorporating lignin and ZnO nanoparticles. The adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model, indicating chemical adsorption. After 6 cycles, the adsorption capacity was reduced by about 15 %. The UV irradiation could recover and improve MB adsorption capacity of CMC hydrogel beads containing ZnO nanoparticles due to the introduction of reactive oxygen species.
    MeSH terms: Adsorption; Catalysis; Hydrogen-Ion Concentration; Kinetics; Water Pollutants, Chemical/chemistry; Water Purification/methods; Photochemical Processes
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