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  1. Fulltext Accumulation of Mitochondrial DNA Microsatellite Instability in Malaysian Patients with Primary Central Nervous System Tumors
    Radzak S, Khair Z, Ahmad F, Idris Z, Yusoff A
    Turk Neurosurg, 2021;31(1):99-106.
    PMID: 33491172 DOI: 10.5137/1019-5149.JTN.27893-20.4
    AIM: To determine the mitochondrial microsatellite instability (mtMSI) status in a series of Malaysian patients with brain tumors. Furthermore, we analyzed whether the mtMSI status is associated with the clinicopathological features of the patients.

    MATERIAL AND METHODS: Forty fresh frozen tumor tissues along with blood samples of brain tumor patients were analyzed for mtMSI by PCR amplification of genomic DNAs, and the amplicons were directly sequenced in both directions using Sanger sequencing.

    RESULTS: Microsatellite analysis revealed that 20% (8 out of 40) of the tumors were mtMSI positive with a total of 8 mtMSI changes. All mtMSI markers were detected in D310 and D16184 of the D-loop region. Additionally, no significant association was observed between mtMSI status and clinicopathological features.

    CONCLUSION: The variations, specifically the mtMSI, suggest that the mitochondrial DNA (mtDNA) can be targeted for genomic alteration in brain tumors. Therefore, the specific role of mtDNA alteration in brain tumor development and prognosis requires further investigation.

  2. Clinoptilolite augmented electrocoagulation process for the reduction of high-strength ammonia and color from stabilized landfill leachate
    Hamid MAA, Aziz HA, Yusoff MS, Rezan SA
    Water Environ Res, 2021 Apr;93(4):596-607.
    PMID: 32991022 DOI: 10.1002/wer.1461
    The high-strength leachate produced from sanitary landfill is a serious issue around the world as it poses adverse effects on aquatic life and human health. Physio-chemical technology is one of the promising options as the leachate normally presents in stabilized form and not fully amendable by biological treatment. In this research, the effectiveness of natural zeolite (clinoptilolite) augmented electrocoagulation process (hybrid system) for removing high-strength ammonia (3,442 mg/L) and color (8,427 Pt-Co) from naturally saline (15 ppt) local landfill leachate was investigated. A batch mode laboratory-scale reactor with parallel-monopolar aluminum electrodes attached to a direct current (DC) electric power was used as an electrocoagulation reactor for performance enhancement purpose. Optimum operational conditions of 146 g/L zeolite dosage, 600 A/m2 current density, 60 min treatment time, 200 rpm stirring speed, 35 min settling duration, and pH 9 were recorded with up to 70% and 88% removals of ammonia and color, respectively. The estimated overall operational cost was 26.22 $/m3 . The biodegradability of the leachate had improved from 0.05 to 0.27 in all post-treatment processes. The findings revealed the ability of the hybrid process as a viable option in eliminating concentrated ammonia and color in natural saline landfill leachate. PRACTITIONER POINTS: Clinoptilolite was augmented on the electrocoagulation process in saline and stabilized landfill leachate (15 ppt). The high strength NH3 -N (3,442 mg/L) and color (8,427 Pt-Co) were 70% and 88% removed, respectively. The optimum conditions occurred at 140 g/L zeolite, 60 mA/cm2 current density, 60 min, and final pH of 8.20. The biodegradability of the leachate improved from 0.05 to 0.27 after the treatment. This hybrid treatment was simple, faster, and did not require auxiliary electrolyte.
  3. Fulltext Enhancement of Live Food Nutritional Status with Essential Nutrients for Improving Aquatic Animal Health: A Review
    Samat NA, Yusoff FM, Rasdi NW, Karim M
    Animals (Basel), 2020 Dec 21;10(12).
    PMID: 33371528 DOI: 10.3390/ani10122457
    At the present time, no artificial larval diet is capable of entirely fulfilling the dietary requirements of several larval fish and crustacean species. Zooplankton live food is the basic foundation of fish larviculture, and successful rearing of fish larvae still heavily depends on an adequate supply of nutritious live food. Despite being important, the production protocols of copepods and cladocerans (Moina) are still underdeveloped in hatcheries. Rotifers and Artemia are the most commonly used live foods. However, these live foods are evidently lacking in crucial nutrient constituents. Hence, through nutrient enrichment, live food with the nutritional profile that meets the requirements of fish larvae can be produced. With the aim to maximize the effectiveness of production to optimize profitability, it is important to evaluate and improve culture techniques for the delivery of micro- and macro-nutrients as feed supplements to larvae in aquaculture systems. Bioencapsulation and enrichment are the evolving techniques in aquaculture that are commonly employed to enhance the nutritional quality of live food by integrating nutrients into them, which subsequently improves the growth, survival, and disease resistance of the consuming hosts. This review aims to highlight some of the approaches and methods used to improve the nutritional quality of live food by modifying their nutrient composition, which could have immense promise in the enhancement of aquatic animal health.
  4. Occurrence and level of emerging organic contaminant in fish and mollusk from Klang River estuary, Malaysia and assessment on human health risk
    Omar TFT, Aris AZ, Yusoff FM, Mustafa S
    Environ Pollut, 2019 May;248:763-773.
    PMID: 30851586 DOI: 10.1016/j.envpol.2019.02.060
    The occurrence, level, and distribution of multiclass emerging organic contaminants (EOCs) in fish and mollusks from the Klang River estuary were examined. The targeted EOCs for this assessment were phenolic endocrine disrupting compounds (bisphenol A, 4-OP, and 4-NP), organophosphorous pesticides (quinalphos, chlorpyrifos, and diazinon), estrogenic hormones (E2, E1, and EE2), and pharmaceutically active chemicals (primidone, sulfamethoxazole, dexamethasone, diclofenac, amoxicillin, progesterone, and testosterone). Results from this study showed that the prevalent contamination of the Klang River estuary by EOCs with diclofenac, bisphenol A, progesterone, and amoxicillin were predominantly detected in fish and mollusks. Among the EOCs, diclofenac and progesterone had the highest concentrations in fish and mollusk samples, respectively. The concentrations of diclofenac and progesterone in fish and mollusk samples range from 1.42 ng/g to 10.76 ng/g and from 0.73 ng/g to 9.57 ng/g, respectively. Bisphenol A should also be highlighted because of its significant presence in both fish and mollusks. The concentration of bisphenol A in both matrices range from 0.92 ng/g to 5.79 ng/g. The calculated hazard quotient (HQ) for diclofenac, bisphenol A, and progesterone without consideration to their degradation byproduct were less than one, thus suggesting that the consumption of fish and mollusks from the Klang River estuary will unlikely pose any health risk to consumers on the basis of the current assessment. Nonetheless, this preliminary result is an important finding for pollution studies in Malaysian tropical coastal ecosystems, particularly for organic micropollutant EOCs, and can serve as a baseline database for future reference.
  5. Occurrence and risk assessment of multiclass endocrine disrupting compounds in an urban tropical river and a proposed risk management and monitoring framework
    Wee SY, Aris AZ, Yusoff FM, Praveena SM
    Sci Total Environ, 2019 Jun 25;671:431-442.
    PMID: 30933799 DOI: 10.1016/j.scitotenv.2019.03.243
    Endocrine disrupting compounds (EDCs) are an emerging environmental concern and commonly occur as a mixture of compounds. The EDC mixture can be more toxic than any single compound. The present study analyses EDCs in surface water in the case of an urban tropical river, the Langat River, using the multiresidue analytical method of solid phase extraction and liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). The Langat River is used as a drinking water source and is treated for Malaysian drinking water supply. A total of 14 EDCs i.e. five hormones, seven pharmaceuticals, one pesticide, and one plasticizer were detected. Caffeine was observed to be highest at 19.33 ng/L, followed by bisphenol A and diclofenac at 8.24 ng/L and 6.15 ng/L, respectively. Using a conservative risk quotient (RQ) method, EDCs were estimated for having negligible risks under acute and chronic exposure (RQ 
  6. Disseminated microsporidiosis: An underdiagnosed and emerging opportunistic disease
    Mohamed Yusoff PS, Osman E, Raja Sabudin RZA
    Malays J Pathol, 2021 Apr;43(1):9-18.
    PMID: 33903300
    Disseminated microsporidiosis is a life-threatening disease resulting from the haematogenous spread of microsporidia species. The diagnosis is challenging owing to its subtle nonspecific clinical presentation, which usually reflects the underlying organ involved. Therefore, a high index of suspicion is required for early diagnosis. Besides, tools for confirmatory laboratory diagnosis are limited. Currently, there is no direct diagnostic method that can detect the infection without involving invasive procedures. Clinical confirmation of disseminated microsporidiosis is usually based on light and transmission electron microscopy of infected tissue specimens. These are then followed by species detection using polymerase chain reaction (PCR). Disseminated microsporidiosis shows the potential to be cleared up by albendazole or fumagillin if they are detected and treated early. Based on a series of case reports, this review aims to present a current update on disseminated microsporidiosis with emphasis on the clinical manifestations based on the organ system infected, diagnostic approach and treatment of this devastating condition.
  7. Synthesis and in-vitro anti-cancer evaluations of multi-methoxylated asymmetrical diarylpentanoids as intrinsic apoptosis inducer against colorectal cancer
    Leong SW, Chia SL, Abas F, Yusoff K
    Bioorg Med Chem Lett, 2020 04 15;30(8):127065.
    PMID: 32127259 DOI: 10.1016/j.bmcl.2020.127065
    In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.
  8. Fulltext Blood transfusion services amidst the COVID-19 pandemic
    Noordin SS, Yusoff NM, Karim FA, Chong SE
    J Glob Health, 2021 Apr 17;11:03053.
    PMID: 33884188 DOI: 10.7189/jogh.11.03053
  9. Mechanistic insights into carbon dioxide utilization by superoxide ion generated electrochemically in ionic liquid electrolyte
    Halilu A, Hayyan M, Aroua MK, Yusoff R, Hizaddin HF
    Phys Chem Chem Phys, 2021 Jan 21;23(2):1114-1126.
    PMID: 33346756 DOI: 10.1039/d0cp04903d
    Understanding the reaction mechanism that controls the one-electron electrochemical reduction of oxygen is essential for sustainable use of the superoxide ion (O2˙-) during CO2 conversion. Here, stable generation of O2˙- in butyltrimethylammonium bis(trifluoromethylsulfonyl)imide [BMAmm+][TFSI-] ionic liquid (IL) was first detected at -0.823 V vs. Ag/AgCl using cyclic voltammetry (CV). The charge transfer coefficient associated with the process was ∼0.503. It was determined that [BMAmm+][TFSI-] is a task-specific IL with a large negative isovalue surface density accrued from the [BMAmm+] cation with negatively charged C(sp2) and C(sp3). Consequently, [BMAmm+][TFSI-] is less susceptible to the nucleophilic effect of O2˙- because only 8.4% O2˙- decay was recorded from 3 h long-term stability analysis. The CV analysis also detected that O2˙- mediated CO2 conversion in [BMAmm+][TFSI-] at -0.806 V vs. Ag/AgCl as seen by the disappearance of the oxidative faradaic current of O2˙-. Electrochemical impedance spectroscopy (EIS) detected the mechanism of O2˙- generation and CO2 conversion in [BMAmm+][TFSI-] for the first time. The EIS parameters in O2 saturated [BMAmm+][TFSI-] were different from those detected in O2/CO2 saturated [BMAmm+][TFSI-] or CO2 saturated [BMAmm+][TFSI-]. This was rationalized to be due to the formation of a [BMAmm+][TFSI-] film on the GC electrode, creating a 2.031 × 10-9 μF cm-2 double-layer capacitance (CDL). Therefore, during the O2˙- generation and CO2 utilization in [BMAmm+][TFSI-], the CDL increased to 5.897 μF cm-2 and 7.763 μF cm-2, respectively. The CO2 in [BMAmm+][TFSI-] was found to be highly unlikely to be electrochemically converted due to the high charge transfer resistance of 6.86 × 1018 kΩ. Subsequently, O2˙- directly mediated the CO2 conversion through a nucleophilic addition reaction pathway. These results offer new and sustainable opportunities for utilizing CO2 by reactive oxygen species in ionic liquid media.
  10. Fulltext Occurrence of multiclass endocrine disrupting compounds in a drinking water supply system and associated risks
    Wee SY, Aris AZ, Yusoff FM, Praveena SM
    Sci Rep, 2020 10 20;10(1):17755.
    PMID: 33082440 DOI: 10.1038/s41598-020-74061-5
    Contamination by endocrine disrupting compounds (EDCs) concerns the security and sustainability of a drinking water supply system and human exposure via water consumption. This study analyzed the selected EDCs in source (river water, n = 10) and supply (tap water, n = 155) points and the associated risks. A total of 14 multiclass EDCs was detected in the drinking water supply system in Malaysia. Triclosan (an antimicrobial agent) and 4-octylphenol (a plasticizer) were only detected in the tap water (up to 9.74 and 0.44 ng/L, respectively). Meanwhile, chloramphenicol and 4-nonylphenol in the system were below the method detection limits. Bisphenol A was observed to be highest in tap water at 66.40 ng/L (detection: 100%; median concentration: 0.28 ng/L). There was a significant difference in triclosan contamination between the river and tap water (p 
  11. In vitro and in silico evaluations of diarylpentanoid series as α-glucosidase inhibitor
    Leong SW, Abas F, Lam KW, Yusoff K
    Bioorg Med Chem Lett, 2018 02 01;28(3):302-309.
    PMID: 29292226 DOI: 10.1016/j.bmcl.2017.12.048
    A series of thirty-four diarylpentanoids derivatives were synthesized and evaluated for their α-glucosidase inhibitory activity. Eleven compounds (19, 20, 21, 24, 27, 28, 29, 31, 32, 33 and 34) were found to significantly inhibit α-glucosidase in which compounds 28, 31 and 32 demonstrated the highest activity with IC50 values ranging from 14.1 to 15.1 µM. Structure-activity comparison shows that multiple hydroxy groups are essential for α-glucosidase inhibitory activity. Meanwhile, 3,4-dihydroxyphenyl and furanyl moieties were found to be crucial in improving α-glucosidase inhibition. Molecular docking analyses further confirmed the critical role of both 3,4-dihydroxyphenyl and furanyl moieties as they bound to α-glucosidase active site in different mode. Overall result suggests that diarylpentanoids with both five membered heterocyclic ring and polyhydroxyphenyl moiety could be a new lead design in the search of novel α-glucosidase inhibitor.
  12. Purification of the extra-cellular domain of Nipah virus glycoprotein produced in Escherichia coli and possible application in diagnosis
    Eshaghi M, Tan WS, Chin WK, Yusoff K
    J Biotechnol, 2005 Mar 30;116(3):221-6.
    PMID: 15707682
    The glycoprotein (G) of Nipah virus (NiV) is important for virus infectivity and induction of the protective immunity. In this study, the extra-cellular domain of NiV G protein was fused with hexahistidine residues at its N-terminal end and expressed in Escherichia coli. The expression under transcriptional regulation of T7 promoter yielded insoluble protein aggregates in the form of inclusion bodies. The inclusion bodies were solubilized with 8 M urea and the protein was purified to homogeneity under denaturing conditions using nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography. The denatured protein was renatured by gradual removal of the urea. Light scattering analysis of the purified protein showed primarily monodispersity. The purified protein showed significant reactivity with the antibodies present in the sera of NiV-infected swine, as demonstrated in Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Taken together, the data indicate the potential usefulness of the purified G protein for structural or functional studies and the development of immunoassay for detection of the NiV antibodies.
  13. Fulltext Antioxidant capacities and total phenolic contents increase with gamma irradiation in two types of Malaysian honey
    Hussein SZ, Yusoff KM, Makpol S, Yusof YA
    Molecules, 2011 Jul 27;16(8):6378-95.
    PMID: 21796076 DOI: 10.3390/molecules16066378
    Two types of monofloral Malaysian honey (Gelam and Nenas) were analyzed to determine their antioxidant activities and total phenolic and flavonoid contents, with and without gamma irradiation. Our results showed that both types of honey can scavenge free radicals and exhibit high antioxidant-reducing power; however, Gelam honey exhibited higher antioxidant activity (p < 0.05) than Nenas honey, which is in good correlation (r = 0.9899) with its phenolic contents. Interestingly, we also noted that both irradiated honeys have higher antioxidant activities and total phenolic and flavonoid contents compared to nonirradiated honeys by Folin-Ciocalteu and UV-spectrophotometry methods, respectively. However, HPLC analysis for phenolic compounds showed insignificant increase between irradiated and nonirradiated honeys. The phenolic compounds such as: caffeic acid, chlorogenic acid, ellagic acid, p- coumaric acid, quercetin and hesperetin as indicated by HPLC method were found to be higher in Gelam honey versus Nenas honey. In conclusion, irradiation of honey causes enhanced antioxidant activities and flavonoid compounds.
  14. Improved peroxide biosensor based on Horseradish Peroxidase/Carbon Nanotube on a thiol-modified gold electrode
    Kafi AKM, Naqshabandi M, Yusoff MM, Crossley MJ
    Enzyme Microb Technol, 2018 Jun;113:67-74.
    PMID: 29602389 DOI: 10.1016/j.enzmictec.2017.11.006
    A new 3-dimensional (3D) network of crosslinked Horseradish Peroxidase/Carbon Nanotube (HRP/CNT) on a thiol-modified Au surface has been described in order to build up the effective electrical wiring of the enzyme units with the electrode. The synthesized 3D HRP/CNT network has been characterized with cyclic voltammetry and amperometry which results the establishment of direct electron transfer between the redox active unit of HRP and the Au surface. Electrochemical measurements reveal that the high biological activity and stability is exhibited by the immobilized HRP and a quasi-reversible redox peak of the redox centre of HRP was observed at about -0.355 and -0.275V vs. Ag/AgCl. The electron transfer rate constant, KSand electron transfer co-efficient α were found as 0.57s-1and 0.42, respectively. Excellent electrocatalytic activity for the reduction of H2O2was exhibited by the developed biosensor. The proposed biosensor modified with HRP/CNT 3D network displays a broader linear range and a lower detection limit for H2O2determination. The linear range is from 1.0×10-7to 1.2×10-4M with a detection limit of 2.2.0×10-8M at 3σ. The Michaelies-Menten constant Kapp M value is estimated to be 0.19mM. Moreover, this biosensor exhibits very high sensitivity, good reproducibility and long-time stability.
  15. Fulltext Effect of different cloning strategies in pET-28a on solubility and functionality of a staphylococcal phage endolysin
    Tham HY, Song AA, Yusoff K, Tan GH
    Biotechniques, 2020 09;69(3):161-170.
    PMID: 32787565 DOI: 10.2144/btn-2020-0034
    Endolysins have been studied intensively as an alternative to antibiotics. In this study, endolysin derived from a phage which infects methicillin-resistant Staphylococcus aureus (MRSA) was cloned and expressed in Escherichia coli pET28a. Initially, the endolysin was cloned using BamHI/XhoI, resulting in expression of a recombinant endolysin which was expressed in inclusion bodies. While solubilization was successful, the protein remained nonfunctional. Recloning the endolysin using NcoI/XhoI resulted in expression of soluble and functional proteins at 18°C. The endolysin was able to form halo zones on MRSA plates and showed a reduction in turbidity of MRSA growth. Therefore, cloning strategies should be chosen carefully even in an established expression system as they could greatly affect the functionality of the expressed protein.
  16. Fulltext Paternal Fenitrothion Exposures in Rats Causes Sperm DNA Fragmentation in F0 and Histomorphometric Changes in Selected Organs of F1 Generation
    Yusoff NA, Taib IS, Budin SB, Mohamed M
    Toxics, 2021 Jul 05;9(7).
    PMID: 34357902 DOI: 10.3390/toxics9070159
    The adverse effects of maternal pesticides exposure on the progeny is very well established. However, the impact of paternal exposure to pesticides such as Fenitrothion (FNT) on the histomorphometry of progeny's organs in unexposed mothers are much less well studied. Therefore, this study aims to evaluate the effects of paternal FNT exposure on the sperm quality of the parent rat and its effects on the histomorphometry of the progeny's organs. Randomly, male Sprague Dawley rats (n = 24) categorized as F0 were distributed equally into three groups namely Control, FNT-10, and FNT-20. Control received 1 mL/kg corn oil while FNT-10 and FNT-20 received 10 mg/kg and 20 mg/kg of FNT, respectively, via oral force feeding for 28 consecutive days. At the end of the study, male rats were mated with unexposed female rats and the male rats were sacrificed to obtain sperm for sperm characterization and DNA damage evaluation. Meanwhile, the rats' progeny (F1) namely pControl, pFNT-10, and pFNT-20 were left to grow until postnatal day 70 before being sacrificed to obtain the matured organs for histology and morphometric analysis. Our results showed that both doses of FNT reduced sperm quality and caused DNA fragmentation in F0 rats compared with the control group (p < 0.05). The number of Leydig cells as well as the diameter of the seminiferous tubules and glomerulus of the pFNT-20 group had significantly decreased (p < 0.05) compared with the pControl group. The Bowman's space of the pFNT-20 group had significantly increased (p < 0.05) compared with the pFNT-10 and pControl groups. Therefore, paternal exposure to FNT reduced the sperm quality and increased sperm DNA fragmentation in F0 male Sprague Dawley rats and altered the histology and morphometry of the selected organs in the F1 progeny.
  17. Fulltext Life Cycle of Edible Jellyfish Acromitus hardenbergi Stiasny, 1934 (Scyphozoa: Rhizostomeae) Inhabiting a Brackish-Water Environment
    Miyake H, Honda S, Nishikawa J, Yusoff FM
    Animals (Basel), 2021 Jul 20;11(7).
    PMID: 34359266 DOI: 10.3390/ani11072138
    The edible jellyfish Acromitus hardenbergi Stiasny, 1934 is harvested throughout the year at the mouth of the Perak River, Malaysia. Although this species is an important fishery resource in the local area, limited biological studies have been carried out on it. The aim of the present study was to elucidate the life cycle of this unique brackish-water jellyfish in order to conserve the species and develop sustainable jellyfish fisheries. Mature medusae were collected at the mouth of the Perak River. Embryonic and larval development after fertilization was completed within 24 h until the planula stage and within 48 h until the polyp stage. Primary polyps had a long stalk with a small stolon at the base of the calyx. Fully developed polyps were bowl-or goblet-shaped but became an elongated stalk under starved conditions. Asexual reproduction was accomplished only by means of budding, and no podocysts were produced. Strobilation was mono-disc type. These characteristics may be adaptations to the dynamic environmental conditions in the estuary of the Perak River, where salinity fluctuates widely due to strong inflows of highly turbid freshwater coupled with tidal changes. This study suggests that polyps of A. hardenbergi expand their population not by podocysts, but by budding as quickly as possible and forming one large ephyra by mono-disc strobilation without the residuum, because the polyp cannot remain for a long time at its settlement place in the sediment-rich environment with drastic salinity change.
  18. Inhibition of Autophagy Does Not Affect Innate Cytokine Production in Human Lung Epithelial Cells During Respiratory Syncytial Virus Infection
    Azman AF, Chia SL, Sekawi Z, Yusoff K, Ismail S
    Viral Immunol, 2021 04 09;34(6):421-426.
    PMID: 33835870 DOI: 10.1089/vim.2020.0217
    Human respiratory syncytial virus (RSV) is one of the major causes of childhood acute lower respiratory tract infection worldwide. Autophagy is an intracellular pathway involved in nutrient recycling. Recently, autophagy has been reported to play a role in regulating host cytokine response to several viruses, including vesicular stomatitis virus and human immunodeficiency virus. Previous in vivo studies using mouse model has shown that inhibition of autophagy reduces RSV-induced cytokine production. However, the role of autophagy in modulating RSV-induced cytokine response in human cells has not been reported. We investigated the role of autophagy in regulating the production of the cytokines C-X-C motif ligand 8 (CXCL8) and C-C motif ligand 5 (CCL5), in RSV-infected human bronchial epithelium BEAS-2B cells. Fluorescent microscopic analysis showed that RSV infection induced autophagosome formation in BEAS-2B cells. This autophagy inducing ability of RSV was further confirmed by flow cytometry. The effects of pharmacological inhibition of autophagy by SAR405 or chloroquine on cell death and cytokine release were quantified using lactate dehydrogenase assay and enzyme-linked immunosorbent assay (ELISA), respectively. We found that SAR405 or chloroquine did not cause cell death. Importantly, ELISA analysis showed that pharmacological inhibition of autophagy by SAR405 or chloroquine did not affect the productions of both CXCL5 and CXCL8. In contrast to the previous studies using mouse model, our data suggest that pharmacological inhibition of autophagy may not be a suitable strategy in controlling RSV-induced airway inflammation.
  19. Fulltext Increase in tumour-infiltrating lymphocytes with regulatory T cell immunophenotypes and reduced zeta-chain expression in nasopharyngeal carcinoma patients
    Yip WK, Abdullah MA, Yusoff SM, Seow HF
    Clin Exp Immunol, 2009 Mar;155(3):412-22.
    PMID: 19220831 DOI: 10.1111/j.1365-2249.2008.03793.x
    The pathological significance of the mechanisms of tumour immune-evasion and/or immunosuppression, such as loss of T cell signalling and increase in regulatory T cells (T(regs)), has not been well established in the nasopharyngeal carcinoma (NPC) microenvironment. To evaluate the T(reg) immunophenotypes in tumour-infiltrating lymphocytes (TILs), we performed a double-enzymatic immunostaining for detection of forkhead box P3 (FoxP3) and other markers including CD4, CD8, and CD25 on 64 NPC and 36 non-malignant nasopharyngeal (NP) paraffin-embedded tissues. Expression of CD3 zeta and CD3 epsilon was also determined. The prevalence of CD4(+)FoxP3(+) cells in CD4(+) T cells and the ratio of FoxP3(+)/CD8(+) were increased significantly in NPC compared with those in NP tissues (P < 0.001 and P = 0.025 respectively). Moreover, the ratio of FoxP3(+)/CD25(+)FoxP3(-) in NPC was significantly lower than that in NP tissues (P = 0.005), suggesting an imbalance favouring activated phenotype of T cells in NPC. A significant negative correlation between the abundance of FoxP3(+) and CD25(+)FoxP3(-) cells (P < 0.001) was also identified. When histological types of NPC were considered, a lower ratio of FoxP3(+)/CD25(+)FoxP3(-) was found in non-keratinizing and undifferentiated carcinomas. Increased CD4(+)FoxP3(+)/CD4(+) proportion and FoxP3(+)/CD8(+) ratio were associated with keratinizing squamous cell carcinoma. A reduced expression of CD3 zeta in TILs was found in 20.6% of the NPC tissues but none of the NP tissues. These data provide evidence for the imbalances of T(reg) and effector T cell phenotypes and down-regulation of signal-transducing molecules in TILs, supporting their role in suppression of immune response and immune evasion of NPC.
  20. A simple 18S rDNA approach for the identification of cultured eukaryotic microalgae with an emphasis on primers
    Khaw YS, Khong NMH, Shaharuddin NA, Yusoff FM
    J Microbiol Methods, 2020 05;172:105890.
    PMID: 32179080 DOI: 10.1016/j.mimet.2020.105890
    Any forms of valorization of microorganisms would require accurate identity recognition to ensure repeatability, reproducibility and quality assurance. This study aimed to evaluate the effectiveness of different primers for identifying cultured eukaryotic microalgae using a simple 18S rDNA approach. A total of 34 isolated microalgae and one culture collection were utilized in the search for an effective molecular identification method for microalgae. Ammonium formate was applied to marine microalgae prior to DNA extraction. The microalgal DNA was extracted using a commercial kit and subjected directly to PCR amplification using four different published 18S rDNA primers. The DNA sequences were analysed using Basic Local Alignment Search Tool (BLAST) and phylogenetic trees to determine the microalgae identity. The identity was further validated with conventional morphological taxonomic identification, and the relationship of microalgal morphology and genetic materials was also determined. The microalgal DNA was successfully amplified, including marine species without prior cleaning. In addition, the ss5 + ss3 primer pair was found to be an ideal primer set among the tested primers for identifying microalgae. Overall, molecular identification showed relative matching with morphological identification (82.86%). This study is important because it serves as a platform to develop a standardized eukaryotic microalgae identification method. In addition, this method could help to ease the eukaryotic microalgae identification process and enrich the current reference databases such as GenBank.
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