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Association of deleted in liver cancer-1 gene polymorphism with increased risk of chronicity of disease among Malaysian patients with hepatitis B infection

Riazalhosseini B, Mohamed R, Devi Apalasamy Y, Mohamed Z

Pharmacogenet Genomics, 2021 Dec 01;31(9):185-190.
PMID: 34320605 DOI: 10.1097/FPC.0000000000000439

OBJECTIVE: The aim of this study is to examine the association between genetic variations in deleted in liver cancer 1 (DLC1) gene with progression of the hepatitis B virus (HBV) infection.
METHODS: A total of 623 subjects were included in this study, of whom, 423 were chronic hepatitis B (CHB) patients without liver cirrhosis or hepatocellular carcinoma (HCC), 103 CHB with either liver cirrhosis ± HCC and 97 individuals who had resolved HBV. Two single-nucleotide polymorphisms rs3739298 and rs532841 of DLC1 gene were genotyped using the Sequenom MassARRAY platform.
RESULTS: Our results indicated significant differences between the chronic HBV and resolved HBV groups in genotype and allele frequencies of DLC1-rs3739298 [odds ratio (OR) = 2.23; 95% confidence interval (CI): 1.24-3.99; P = 0.007] and (OR = 1.54; 95% CI: 1.07-2.22; P = 0.021), respectively. Moreover, haplotype analysis revealed significant associations between chronicity of HBV with TG and GA haplotypes (P = 0.041 and P = 0.042), respectively.
CONCLUSION: A significant association exists between the rs3739298 variant and susceptibility to CHB infection.
Eimeria tenella glucose-6-phosphate isomerase: molecular characterization and assessment as a target for anti-coccidial control

Loo SS, Blake DP, Mohd-Adnan A, Mohamed R, Wan KL

Parasitology, 2010 Jul;137(8):1169-77.
PMID: 20233491 DOI: 10.1017/S0031182010000119

Limitations with current chemotherapeutic and vaccinal control of coccidiosis caused by Eimeria species continue to prompt development of novel controls, including the identification of new drug targets. Glucose-6-phosphate isomerase (G6-PI) has been proposed as a valid drug target for many protozoa, although polymorphism revealed by electrophoretic enzyme mobility has raised doubts for Eimeria. In this study we identified and sequenced the Eimeria tenella G6-PI orthologue (EtG6-PI) from the reference Houghton strain and confirmed its position within the prevailing taxonomic hierarchy, branching with the Apicomplexa and Plantae, distinct from the Animalia including the host, Gallus gallus. Comparison of the deduced 1647 bp EtG6-PI coding sequence with the 9016 bp genomic locus revealed 15 exons, all of which obey the intron-AG-/exon/-GT-intron splicing rule. Comparison with the Weybridge and Wisconsin strains revealed the presence of 33 single nucleotide polymorphisms (SNPs) and 14 insertion/deletion sites. Three SNPs were exonic and all yielded non-synonymous substitutions. Preliminary structural predictions suggest little association between the coding SNPs and key G6-PI catalytic residues or residues thought to be involved in the coordination of the G6-PI's substrate phosphate group. Thus, the significant polymorphism from its host orthologue and minimal intra-specific polymorphism suggest G6-PI remains a valid anti-coccidial drug target.
Fulltext Bioinformatics in Malaysia: hope, initiative, effort, reality, and challenges

Zeti AM, Shamsir MS, Tajul-Arifin K, Merican AF, Mohamed R, Nathan S, et al.

PLoS Comput Biol, 2009 Aug;5(8):e1000457.
PMID: 19714208 DOI: 10.1371/journal.pcbi.1000457
All-optical generation of a 21 GHz microwave carrier by incorporating a double-Brillouin frequency shifter

Shee YG, Mahdi MA, Al-Mansoori MH, Yaakob S, Mohamed R, Zamzuri AK, et al.

Opt Lett, 2010 May 1;35(9):1461-3.
PMID: 20436603 DOI: 10.1364/OL.35.001461

An all-optical generation of a microwave carrier at 21 GHz that incorporates a double-Brillouin frequency shifter is presented. The frequency shift of approximately 21 GHz is achieved by generating the second-order Brillouin Stokes signal from the Brillouin pump. This is accomplished through the circulation and isolation of its first-order Stokes signal in the optical fiber. The Brillouin pump signal is heterodyned with its second-order Brillouin Stokes signal at a high-speed photodetector, and the output beating frequency is equal to the offset between these two signals. The generated microwave carrier is measured at 21.3968 GHz, and the carrier phase noise as low as -58.67 dBc/Hz is achieved.
Hepatitis C virus core antigen as alternative diagnostic algorithm for active hepatitis C virus infection among haemodialysis population: Cost implications

Wong XZ, Amirah A, Gan CC, Fatiha S, Maznah D, Yahya R, et al.

Nephrology (Carlton), 2021 May;26(5):463-470.
PMID: 33580732 DOI: 10.1111/nep.13862

AIMS: In Malaysia, majority anti-HCV positive haemodialysis patients do not undergo hepatitis C confirmation due to the high cost of HCV RNA. HCV Core Antigen might be a cost-effective diagnostic test to identify HD patients who have active HCV infection eligible for Direct Acting Anti-viral therapy.
METHODS: A cross-sectional study was conducted to assess the correlation between HCV Ag and HCV RNA and the cost implications of different diagnostic algorithms to diagnose active HCV infection using Anti-HCV, HCV Ag, and HCV RNA. Pre-dialysis blood was tested for both HCV Ag and HCV RNA. HCV Ag was tested with Abbott ARCHITECT HCV Ag test.
RESULTS: Two-hundred twenty-seven haemodialysis patients were recruited from 20 centres with mean age of 57.68 ± 12.48 years, and male constitutes 56.8% (129) of the study population. HCV Ag correlated well with HCV RNA (Spearman test coefficient 0.943, p
Fulltext The complete chloroplast genome sequence of Chengal (Neobalanocarpus heimii, Dipterocarpaceae), a durable tropical hardwood

Lee SY, Ng WL, Hishamuddin MS, Mohamed R

Mitochondrial DNA B Resour, 2019;4(1):19-20.
PMID: 33365402 DOI: 10.1080/23802359.2018.1535848

Known for its durable timber quality, Neobalanocarpus heimii (King) Ashton is a highly sought after tree species endemic to the Malay Peninsula. Due to its scarcity and high value, the tree is classified under the IUCN Red List categories of Vulnerable. In this study, we assembled the complete chloroplast (cp) genome of N. heimii using data from high-throughput Illumina sequencing. The Chengal cp genome is 151,191 bp in size and includes two inverted repeat regions of 23,721 bp each, which is separated by a large single copy region of 83,801 bp and a small single copy region of 19,948 bp. A total of 130 genes were predicted, including 37 tRNA, 8 rRNA, and 85 protein-coding genes. Phylogenetic analysis placed N. heimii within the order Malvales.
Fulltext The complete chloroplast genome of Aquilaria malaccensis Lam. (Thymelaeaceae), an important and threatened agarwood-producing tree species

Lee SY, Ng WL, Mohamed R, Terhem R

Mitochondrial DNA B Resour, 2018 Oct 29;3(2):1120-1121.
PMID: 33474439 DOI: 10.1080/23802359.2018.1519382

Known for its valuable agarwood, Aquilaria malaccensis Lam. is an evergreen tropical forest tree species endemic to the Indo-malesian region. Indiscriminate damaging and harvesting of the trees in the wild have resulted in it being listed in the CITES Appendix II for controlled trade and in the IUCN Red List as 'Vulnerable (VU)'. In this study, the complete chloroplast genome of A. malaccensis was assembled using data from high-throughput Illumina sequencing. The chloroplast genome was 174,832 bp in size, which included two inverted repeat regions of 42,091 bp each, separated by a large single copy region of 87,302 bp and a small single copy region of 3,348 bp. A total of 139 genes were predicted, including 39 tRNA, 8 rRNA, and 92 protein-coding genes. Phylogenetic analysis placed A. malaccensis within the family Thymelaeaceae. The chloroplast genome sequence of A. malaccensis offers a useful resource for future studies on the taxonomy and conservation of the threatened Aquilaria trees.
Fulltext The complete chloroplast genome of Walla Patta, Gyrinops walla (Thymelaeaceae), an agarwood-producing tree species from Sri Lanka

Chen J, Lee SY, Munugoda KD, Mohamed R, Subasinghe SMCUP, Liao W

Mitochondrial DNA B Resour, 2021 May 19;6(6):1699-1701.
PMID: 34104743 DOI: 10.1080/23802359.2021.1926362

Gyrinops walla is an important agarwood-producing tree and threatened species from Sri Lanka. Herein, we assembled and characterized the complete chloroplast (cp) genome of G. walla as a genomic resource for conservation purposes. The 175,130 bp long genome is comprised of 87,376 bp large single-copy (LSC) and 3316 bp small single-copy (SSC) regions, which are separated by two inverted repeat (IR) region, each with a size of 42,291 bp. A total of 140 genes were predicted for the cp genome, which includes 94 protein-coding, 38 tRNA, and eight rRNA genes. Phylogenetic analysis showed that G. walla is fully resolved in a sister position to Aquilaria in the family Thymelaeaceae. The data provided will be useful for study on the molecular phylogenetics and evolution of Thymelaeaceae in the future.
Fulltext A New Method for a Piezoelectric Energy Harvesting System Using a Backtracking Search Algorithm-Based PI Voltage Controller

Sarker MR, Mohamed A, Mohamed R

Micromachines (Basel), 2016 Sep 23;7(10).
PMID: 30404344 DOI: 10.3390/mi7100171

This paper presents a new method for a vibration-based piezoelectric energy harvesting system using a backtracking search algorithm (BSA)-based proportional-integral (PI) voltage controller. This technique eliminates the exhaustive conventional trial-and-error procedure for obtaining optimized parameter values of proportional gain (Kp), and integral gain (Ki) for PI voltage controllers. The generated estimate values of Kp and Ki are executed in the PI voltage controller that is developed through the BSA optimization technique. In this study, mean absolute error (MAE) is used as an objective function to minimize output error for a piezoelectric energy harvesting system (PEHS). The model for the PEHS is designed and analyzed using the BSA optimization technique. The BSA-based PI voltage controller of the PEHS produces a significant improvement in minimizing the output error of the converter and a robust, regulated pulse-width modulation (PWM) signal to convert a MOSFET switch, with the best response in terms of rise time and settling time under various load conditions.
Fulltext An Overview of the Strategies for Tin Selenide Advancement in Thermoelectric Application

Md Aspan R, Fatima N, Mohamed R, Syafiq U, Ibrahim MA

Micromachines (Basel), 2021 Nov 27;12(12).
PMID: 34945312 DOI: 10.3390/mi12121463

Chalcogenide, tin selenide-based thermoelectric (TE) materials are Earth-abundant, non-toxic, and are proven to be highly stable intrinsically with ultralow thermal conductivity. This work presented an updated review regarding the extraordinary performance of tin selenide in TE applications, focusing on the crystal structures and their commonly used fabrication methods. Besides, various optimization strategies were recorded to improve the performance of tin selenide as a mid-temperature TE material. The analyses and reviews over the methodologies showed a noticeable improvement in the electrical conductivity and Seebeck coefficient, with a noticeable decrement in the thermal conductivity, thereby enhancing the tin selenide figure of merit value. The applications of SnSe in the TE fields such as microgenerators, and flexible and wearable devices are also discussed. In the future, research in low-dimensional TE materials focusing on nanostructures and nanocomposites can be conducted with the advancements in material science technology as well as microtechnology and nanotechnology.
Prevalence of antibodies to Pseudomonas pseudomallei exotoxin and whole cell antigens in military personnel in Sabah and Sarawak, Malaysia

Embi N, Suhaimi A, Mohamed R, Ismail G

Microbiol. Immunol., 1992;36(8):899-904.
PMID: 1474938

Sera from 420 military personnel serving in Sabah and Sarawk, Malaysia, were tested for antibodies to Pseudomonas pseudomallei exotoxin and whole cell antigens by enzyme-linked immunosorbent assay procedure (ELISA). Data showed that 54.4% of serum samples were positive for antibodies to P. pseudomallei exotoxin and 65.7% were positive for antibodies to the whole cell antigens. Samples gave much lower titers for anti-exotoxin antibodies compared to titers against crude whole cell antigens. The incidence of antibody to exotoxin was highest in the age groups ranging from 26 to 32 years, where the positive rates were higher than 40% and 30% for military personnel serving in Sarawak and Sabah, respectively.
Resistance of Pseudomonas pseudomallei to normal human serum bactericidal action

Ismail G, Razak N, Mohamed R, Embi N, Omar O

Microbiol. Immunol., 1988;32(7):645-52.
PMID: 3193910

The effect of human normal serum (HNS) on Pseudomonas pseudomallei was determined. It is apparent from our data that the organism is resistant to the normal serum bactericidal mechanism. Ancillary experiments to confirm this serum-resistant property of P. pseudomallei were done by examining the effects of growth phase conditions of the bacteria (i.e., logarithmic and stationary phases) and different buffered systems used as diluent in our bactericidal assay. Results obtained showed similar degree of resistance to serum bactericidal killing by 5 strains of the organisms tested. The possible survival advantage of serum-resistance property to P. pseudomallei as bacterial pathogens known to invade the blood stream is discussed.
Inhibition of macromolecular synthesis in cultured macrophages by Pseudomonas pseudomallei exotoxin

Mohamed R, Nathan S, Embi N, Razak N, Ismail G

Microbiol. Immunol., 1989;33(10):811-20.
PMID: 2615673

Pseudomonas pseudomallei exotoxin was found to be a potent inhibitor of protein and DNA synthesis in cultured macrophages. Inhibition of DNA synthesis occurred at toxin concentrations as low as 1-2 micrograms/ml and inhibition of 3H-thymidine uptake was almost complete at concentrations of 8 micrograms/ml or more. A close correlation between cell damage and inhibition by DNA synthesis was observed. For protein synthesis, inhibition was obtained at much lower doses (0.06-2.0 micrograms/ml) of the toxin. At similar toxin concentrations, DNA synthesis was marginally affected. Further, it was shown that protein synthesis inhibition occurred almost immediately after incubation, reaching its maximal inhibitory effect of 70% after 6 hr. DNA synthesis, however, was minimally affected by a similar toxin concentration even after 10 hr of incubation. The inhibition of macromolecular synthesis in macrophages by P. pseudomallei exotoxin may be relevant to its modulatory effect on the host defense mechanism.
Transcriptome analysis of Burkholderia pseudomallei T6SS identifies Hcp1 as a potential serodiagnostic marker

Chieng S, Mohamed R, Nathan S

Microb Pathog, 2015 Feb;79:47-56.
PMID: 25616255 DOI: 10.1016/j.micpath.2015.01.006

Burkholderia pseudomallei, the causative agent of melioidosis, is able to survive extreme environments and utilizes various virulence factors for survival and pathogenicity. To compete and survive within these different ecological niches, B. pseudomallei has evolved specialized pathways, including the Type VI secretion systems (T6SSs), that have a role in pathogenesis as well as interbacterial interactions. We examined the expression profile of B. pseudomallei T6SS six gene clusters during infection of U937 macrophage cells. T6SS-5 was robustly transcribed while the other five clusters were not significantly regulated proposing the utility of T6SS-5 as a potential biomarker of exposure to B. pseudomallei. Transcription of T6SS regulators VirAG and BprB was also not significant during infection when compared to bacteria grown in culture. Guided by these findings, three highly expressed T6SS genes, tssJ-4, hcp1 and tssE-5, were expressed as recombinant proteins and screened against melioidosis patient sera by western analysis and ELISA. Only Hcp1 was reactive by both types of analysis. The recombinant Hcp1 protein was further evaluated against a cohort of melioidosis patients (n = 32) and non-melioidosis individuals (n = 20) sera and the data clearly indicates a higher sensitivity (93.7%) and specificity (100%) for Hcp1 compared to bacterial lysate. The detection of anti-Hcp1 antibodies in patients' sera indicating the presence of B. pseudomallei highlights the potential of Hcp1 to be further developed as a serodiagnostic marker for melioidosis.
The re-emerging of orf virus infection: A call for surveillance, vaccination and effective control measures

Bala JA, Balakrishnan KN, Abdullah AA, Mohamed R, Haron AW, Jesse FFA, et al.

Microb Pathog, 2018 Jul;120:55-63.
PMID: 29709684 DOI: 10.1016/j.micpath.2018.04.057

Orf disease is known to be enzootic among small ruminants in Asia, Africa, and some other parts of the world. The disease caused by orf virus is highly contagious among small ruminant species. Unfortunately, it has been neglected for decades because of the general belief that it only causes a self-limiting disease. On the other hand, in the past it has been reported to cause huge cumulative financial losses in livestock farming. Orf disease is characterized by localized proliferative and persistent skin nodule lesions that can be classified into three forms: generalized, labial and mammary or genitals. It can manifest as benign or malignant types. The later type of orf can remain persistent, often fatal and usually causes a serious outbreak among small ruminant population. Morbidity and mortality rates of orf are higher especially in newly infected kids and lambs. Application of antibiotics together with antipyretic and/or analgesic is highly recommended as a supportive disease management strategy for prevention of subsequent secondary microbial invasion. The presence of various exotic orf virus strains of different origin has been reported in many countries mostly due to poorly controlled cross-border virus transmission. There have been several efforts to develop orf virus vaccines and it was with variable success. The use of conventional vaccines to control orf is a debatable topic due to the concern of short term immunity development. Following re-infection in previously vaccinated animals, it is uncommon to observe the farms involved to experience rapid virus spread and disease outbreak. Meanwhile, cases of zoonosis from infected animals to animal handler are not uncommon. Despite failures to contain the spread of orf virus by the use of conventional vaccines, vaccination of animals with live orf virus is still considered as one of the best choice. The review herein described pertinent issues with regard to the development and use of potential effective vaccines as a control measure against orf virus infection.
Comparative expression of pro-inflammatory and apoptotic biosignatures in chronic HBV-infected patients with and without liver cirrhosis

Barathan M, Riazalhosseini B, Iyadorai T, Vellasamy KM, Vadivelu J, Chang LY, et al.

Microb Pathog, 2021 Dec;161(Pt A):105231.
PMID: 34619310 DOI: 10.1016/j.micpath.2021.105231

The interplay of immune mediators is paramount to optimal host anti-viral immune responses, especially against chronic hepatitis B virus (HBV) infection. Here, we investigated the dynamic changes in host immune responses in chronic HBV-infected individuals with and without liver cirrhosis by examining the signatures of apoptosis and plasma levels of pro-inflammatory cytokines, chemokines, and cytotoxic proteins. A total of 40 chronic HBV patients with and without liver cirrhosis were studied for plasma levels of immune mediators, and signatures of apoptosis in peripheral blood mononuclear cells (PBMCs). The intracellular concentrations of reactive oxygen species (ROS) in patients with chronic HBV with liver cirrhosis was relatively higher as compared to chronic HBV patients. The onset of apoptosis was sustained due to ongoing liver inflammation in concert with plasma TNF-α and IL-6 levels. Plasma VEGF was upregulated among chronic HBV patients with liver cirrhosis, whereas CCL2, CCL5 and granzyme B levels were down-regulated. High levels of ROS, IL-6 and TNF-α correlated with ongoing inflammation among chronic HBV patients with liver cirrhosis, which likely attributed to the expression of biosignatures of apoptosis and activation in immune cells.
A genome level survey of Burkholderia pseudomallei immunome expressed during human infection

Su YC, Wan KL, Mohamed R, Nathan S

Microbes Infect., 2008 Oct;10(12-13):1335-45.
PMID: 18761419 DOI: 10.1016/j.micinf.2008.07.034

Burkholderia pseudomallei is the etiological agent of melioidosis, a severe infectious disease of humans and animals. The role of the bacterium's proteins expressed in vivo during human melioidosis continues to remain an enigma. This study's aim was to identify B. pseudomallei target proteins that elicit the humoral immune response in infected humans. A small insert genomic expression library was constructed and immunoscreened to identify peptides that reacted exclusively with melioidosis patients' sera. Sero-positive clones expressing immunogenic peptides were sequenced and annotated, and shown to represent 109 proteins involved in bacterial cell envelope biogenesis, cell motility and secretion, transcription, amino acid, ion and protein metabolism, energy production, DNA repair and unknown hypothetical proteins. Western blot analysis of three randomly selected full-length immunogenic polypeptides with patients' sera verified the findings of the immunome screening. The patients' humoral immune response to the 109 proteins suggests the induction or significant upregulation of these proteins in vivo during human infection and thus may play a role in the pathogenesis of B. pseudomallei. Identification of B. pseudomallei immunogens has shed new light on the elucidation of the bacterium's pathogenesis mechanism and disease severity. These immunogens can be further evaluated as prophylactic and serodiagnostic candidates as well as drug targets.
Fulltext Geopolymer Ceramic Application: A Review on Mix Design, Properties and Reinforcement Enhancement

Mohd Mortar NA, Abdullah MMAB, Abdul Razak R, Abd Rahim SZ, Aziz IH, Nabiałek M, et al.

Materials (Basel), 2022 Oct 28;15(21).
PMID: 36363159 DOI: 10.3390/ma15217567

Geopolymers have been intensively explored over the past several decades and considered as green materials and may be synthesised from natural sources and wastes. Global attention has been generated by the use of kaolin and calcined kaolin in the production of ceramics, green cement, and concrete for the construction industry and composite materials. The previous findings on ceramic geopolymer mix design and factors affecting their suitability as green ceramics are reviewed. It has been found that kaolin offers significant benefit for ceramic geopolymer applications, including excellent chemical resistance, good mechanical properties, and good thermal properties that allow it to sinter at a low temperature, 200 °C. The review showed that ceramic geopolymers can be made from kaolin with a low calcination temperature that have similar properties to those made from high calcined temperature. However, the choice of alkali activator and chemical composition should be carefully investigated, especially under normal curing conditions, 27 °C. A comprehensive review of the properties of kaolin ceramic geopolymers is also presented, including compressive strength, chemical composition, morphological, and phase analysis. This review also highlights recent findings on the range of sintering temperature in the ceramic geopolymer field which should be performed between 600 °C and 1200 °C. A brief understanding of kaolin geopolymers with a few types of reinforcement towards property enhancement were covered. To improve toughness, the role of zirconia was highlighted. The addition of zirconia between 10% and 40% in geopolymer materials promises better properties and the mechanism reaction is presented. Findings from the review should be used to identify potential strategies that could develop the performance of the kaolin ceramic geopolymers industry in the electronics industry, cement, and biomedical materials.
Fulltext Innovative strategies for the elimination of viral hepatitis at a national level: A country case series

Schröeder SE, Pedrana A, Scott N, Wilson D, Kuschel C, Aufegger L, et al.

Liver Int, 2019 10;39(10):1818-1836.
PMID: 31433902 DOI: 10.1111/liv.14222

Viral hepatitis is a leading cause of morbidity and mortality worldwide, but has long been neglected by national and international policymakers. Recent modelling studies suggest that investing in the global elimination of viral hepatitis is feasible and cost-effective. In 2016, all 194 member states of the World Health Organization endorsed the goal to eliminate viral hepatitis as a public health threat by 2030, but complex systemic and social realities hamper implementation efforts. This paper presents eight case studies from a diverse range of countries that have invested in responses to viral hepatitis and adopted innovative approaches to tackle their respective epidemics. Based on an investment framework developed to build a global investment case for the elimination of viral hepatitis by 2030, national activities and key enablers are highlighted that showcase the feasibility and impact of concerted hepatitis responses across a range of settings, with different levels of available resources and infrastructural development. These case studies demonstrate the utility of taking a multipronged, public health approach to: (a) evidence-gathering and planning; (b) implementation; and (c) integration of viral hepatitis services into the Agenda for Sustainable Development. They provide models for planning, investment and implementation strategies for other countries facing similar challenges and resource constraints.
Fulltext Hemorrhagic cardiac tamponade: rare complication of radiofrequency ablation of hepatocellular carcinoma

Loh KB, Bux SI, Abdullah BJ, Raja Mokhtar RA, Mohamed R

Korean J Radiol, 2012 Sep-Oct;13(5):643-7.
PMID: 22977334 DOI: 10.3348/kjr.2012.13.5.643

Local treatment for hepatocellular carcinoma (HCC) has been widely used in clinical practice due to its minimal invasiveness and high rate of cure. Percutaneous radiofrequency ablation (RFA) is widely used because its treatment effectiveness. However, some serious complications can arise from percutaneous RFA. We present here a rare case of hemorrhagic cardiac tamponade secondary to an anterior cardiac vein (right marginal vein) injury during RFA for treatment of HCC.

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