Displaying publications 101 - 120 of 144 in total

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  1. Fulltext Hemorrhage in a Fetal Ovarian Cyst
    Hassan R, Chong YC, Khairun Nisa M, Yew CG, Tan PG, Mazlin J
    J Neonatal Surg, 2017 Apr 15;6(2):49.
    PMID: 28770146 DOI: 10.21699/jns.v6i2.505
  2. Fulltext Continental Shelf Sediments of Sarawak, Malaysian Borneo
    Morni WZW, Ab Rahim SAK, Masron T, Rumpet R, Musel J, Hassan R
    ScientificWorldJournal, 2017;2017:4853048.
    PMID: 29075660 DOI: 10.1155/2017/4853048
    Sediment distributions in deep sea influence the benthic community structure and thus play an important role in shaping the marine ecosystem. Several studies on sediment characteristics had been conducted in South China Sea (SCS), but only limited to coastal areas of regions within SCS territories. Therefore, this study was carried out to analyze the benthic sediment profile in an area beyond 12 nautical miles off the coast of Sarawak, southern SCS. Sediment samples were collected from 31 stations, comprising three depth ranges: (I) 20-50 m, (II) 50-100 m, and (III) 100-200 m. The total organic matter (TOM) contents were determined and subjected to dry and wet sieving methods for particle size analysis. TOM contents in the deep area (>50 m) were significantly higher (p = 0.05) and positively correlated (r = 0.73) with silt-clay fraction. About 55% and 82% of stations in strata II and III, respectively, were dominated by silt-clay fractions (<63 μm mean diameter), coherent with TOM data. In addition, sediments in the deep area (>50 m) tend to be poorly sorted, very fine skewed, and platykurtic. Unlike data obtained 20 years ago which reported high content of silt-clay (58%), this study recorded a lower content (35%); therefore, changes in sediment load had been observed in southern SCS.
  3. Fulltext Genomic Alterations, Gene Expression Profiles and Functional Enrichment of Normal-Karyotype Acute Myeloid Leukaemia Based on Targeted Next-Generation Sequencing
    Ambayya A, Razali R, Sulong S, Zulkefli ES, Yap YY, Sathar J, et al.
    Cancers (Basel), 2023 Feb 22;15(5).
    PMID: 36900179 DOI: 10.3390/cancers15051386
    Characterising genomic variants is paramount in understanding the pathogenesis and heterogeneity of normal-karyotype acute myeloid leukaemia (AML-NK). In this study, clinically significant genomic biomarkers were ascertained using targeted DNA sequencing and RNA sequencing on eight AML-NK patients' samples collected at disease presentation and after complete remission. In silico and Sanger sequencing validations were performed to validate variants of interest, and they were followed by the performance of functional and pathway enrichment analyses for overrepresentation analysis of genes with somatic variants. Somatic variants involving 26 genes were identified and classified as follows: 18/42 (42.9%) as pathogenic, 4/42 (9.5%) as likely pathogenic, 4/42 (9.5%) as variants of unknown significance, 7/42 (16.7%) as likely benign and 9/42 (21.4%) as benign. Nine novel somatic variants were discovered, of which three were likely pathogenic, in the CEBPA gene with significant association with its upregulation. Transcription misregulation in cancer tops the affected pathways involving upstream genes (CEBPA and RUNX1) that were deregulated in most patients during disease presentation and were closely related to the most enriched molecular function gene ontology category, DNA-binding transcription activator activity RNA polymerase II-specific (GO:0001228). In summary, this study elucidated putative variants and their gene expression profiles along with functional and pathway enrichment in AML-NK patients.
  4. Prevalence and Distribution of Major β-Thalassemia Mutations and HbE/β-Thalassemia Variant in Nepalese Ethnic Groups
    Lama R, Yusof W, Shrestha TR, Hanafi S, Bhattarai M, Hassan R, et al.
    Hematol Oncol Stem Cell Ther, 2022 Mar 01;15(1):279-284.
    PMID: 33592169 DOI: 10.1016/j.hemonc.2021.01.004
    BACKGROUND: Beta-thalassemia is a genetic disorder that is inherited in an autosomal recessive pattern. This genetic disease leads to a defective beta-globin hemoglobin chain causing partial or complete beta-globin chain synthesis loss. Beta-thalassemia major patients need a continuous blood transfusion and iron chelation to maintain the normal homeostasis of red blood cells (RBCs) and other systems in the body. Patients also require treatment procedures that are costly and tedious, resulting in a serious health burden for developing nations such as Nepal.

    METHODS: A total of 61 individuals clinically diagnosed to have thalassemia were genotyped with multiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Twenty-one major mutations were investigated using allele-specific primers grouped into six different panels.

    RESULTS: The most common mutations found (23%) were IVS 1-5 (G-C) and Cd 26 (G-A) (HbE), followed by 619 deletion, Cd 8/9 (+G), Cd 16 (-C), Cd 41/42 (-TTCT), IVS 1-1 (G-T), Cd 19 (A-G), and Cd 17 (A-T) at 20%, 12%, 8%, 6%, 4%, 3%, and 1%, respectively.

    CONCLUSION: The results of this study revealed that Nepal's mutational profile is comparable to that of its neighboring countries, such as India and Myanmar. This study also showed that thalassemia could be detected across 17 Nepal's ethnic groups, especially those whose ancestors originated from India and Central Asia.

  5. Fulltext Graph-based extractive text summarization method for Hausa text
    Bichi AA, Samsudin R, Hassan R, Hasan LRA, Ado Rogo A
    PLoS One, 2023;18(5):e0285376.
    PMID: 37159449 DOI: 10.1371/journal.pone.0285376
    Automatic text summarization is one of the most promising solutions to the ever-growing challenges of textual data as it produces a shorter version of the original document with fewer bytes, but the same information as the original document. Despite the advancements in automatic text summarization research, research involving the development of automatic text summarization methods for documents written in Hausa, a Chadic language widely spoken in West Africa by approximately 150,000,000 people as either their first or second language, is still in early stages of development. This study proposes a novel graph-based extractive single-document summarization method for Hausa text by modifying the existing PageRank algorithm using the normalized common bigrams count between adjacent sentences as the initial vertex score. The proposed method is evaluated using a primarily collected Hausa summarization evaluation dataset comprising of 113 Hausa news articles on ROUGE evaluation toolkits. The proposed approach outperformed the standard methods using the same datasets. It outperformed the TextRank method by 2.1%, LexRank by 12.3%, centroid-based method by 19.5%, and BM25 method by 17.4%.
  6. Fulltext Exploring Extended White Blood Cell Parameters for the Evaluation of Sepsis among Patients Admitted to Intensive Care Units
    Ho SF, Tan SJ, Mazlan MZ, Iberahim S, Lee YX, Hassan R
    Diagnostics (Basel), 2023 Jul 21;13(14).
    PMID: 37510189 DOI: 10.3390/diagnostics13142445
    Sepsis is a major cause of mortality and morbidity in intensive care units. This case-control study aimed to investigate the haematology cell population data and extended inflammatory parameters for sepsis management. The study included three groups of patients: sepsis, non-sepsis, and healthy controls. Patients suspected of having sepsis underwent a Sequential Organ Failure Assessment (SOFA) evaluation and had blood drawn for blood cultures, complete peripheral blood counts (CBC), and measurements of various markers such as C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6). We observed significant changes in numerous CBC parameters and extended inflammation parameters (EIPs), in addition to significant biochemical analysis markers CRP and IL-6 in sepsis cohorts. Multiple logistic regression analyses showed that combining different CBC parameters and EIPs were effective to profile these patients. Two different models have been developed using white blood cell counts and their extended parameters. Our findings indicate that the absolute counts of white blood cells, and the EIPs which reflect their activation states, are important for the prediction and assessment of sepsis, as the body responds to an insult that triggers an immune response. In an emergency situation, having timely updates on patient conditions becomes crucial for guiding the management process. Identifying trends in these specific patient groups will aid early diagnosis, complementing clinical signs and symptoms, especially as CBC is the most commonly ordered test in a diagnostic workup.
  7. Fulltext Clinical and Laboratory Features of JAK2 V617F, CALR, and MPL Mutations in Malaysian Patients with Classical Myeloproliferative Neoplasm (MPN)
    Zulkeflee RH, Zulkafli Z, Johan MF, Husin A, Islam MA, Hassan R
    Int J Environ Res Public Health, 2021 Jul 16;18(14).
    PMID: 34300032 DOI: 10.3390/ijerph18147582
    Mutations of JAK2V617F, CALR, and MPL genes confirm the diagnosis of myeloproliferative neoplasm (MPN). This study aims to determine the genetic profile of JAK2V617F, CALR exon 9 Type 1 (52 bp deletion) and Type 2 (5 bp insertion), and MPL W515 L/K genes among Malaysian patients and correlate these mutations with clinical and hematologic parameters in MPN. Mutations of JAK2V617F, CALR, and MPL were analyzed in 159 Malaysian patients using allele-specific polymerase chain reaction, including 76 polycythemia vera (PV), 41 essential thrombocythemia (ET), and 42 primary myelofibrosis (PMF) mutations, and the demographics of the patients were retrieved. The result showed that 73.6% JAK2V617F, 5.66% CALR, and 27.7% were triple-negative mutations. No MPL W515L/K mutation was detected. In ET and PMF, the predominance type was the CALR Type 1 mutation. In JAK2V617F mutant patients, serum LDH was significantly higher in PMF compared to PV and ET. PV has a higher risk of evolving to post PV myelofibrosis compared to ET. A thrombotic event at initial diagnosis of 40.9% was high compared to global incidence. Only one PMF patient had a CALR mutation that transformed to acute myeloid leukemia. JAK2V617F and CALR mutations play an important role in diagnostics. Hence, every patient suspected of having a myeloproliferative neoplasm should be screened for these mutations.
  8. Prevalence of GP. Mur variant phenotype among Malaysian blood donors
    Hassan SN, Mohamad S, Kannan TP, Hassan R, Wei S, Wan Ab Rahman WS
    Asian J Transfus Sci, 2023;17(2):169-174.
    PMID: 38274953 DOI: 10.4103/ajts.ajts_125_21
    BACKGROUND AND OBJECTIVE: A number of glycophorin variant phenotypes or hybrid glycophorin variants of the MNS blood group system bear multiple immunogenic antigens such as Mia, Mur, and MUT. In the East and Southeast Asian populations, glycoprotein (GP.) Mur is the most common glycophorin variant phenotype expressing those three immunogens. The aim of this study was to detect MNS system glycophorin variant phenotypes (GP. Mur, GP. Hop, GP. Bun, GP. HF, and GP. Hut) among Malaysian blood donors.

    MATERIALS AND METHODS: In this cross-sectional study, 144 blood donors were selected under stratified random sampling. The deoxyribonucleic acid was extracted from whole blood samples, followed by a polymerase chain reaction assay. Sanger sequencing was used to identify the specific MNS variants and then validated by a serological crossmatch with known anti-Mur and anti-MUT.

    RESULTS: GP. Mur was identified among Malaysian blood donors with a prevalence of 6.94%, and no other variants of the MNS system were found.

    CONCLUSION: The present study substantiates that GP. Mur is the main variant of the MNS system glycophorin (B-A-B) hybrid in Malaysian blood donors. GP. Mur-negative red blood cells must therefore be considered in the current transfusion policy in order to prevent alloimmunization and immune-mediated transfusion reactions, particularly in transfusion-dependent patients.

  9. Fulltext The Prevalence of TET2 Gene Mutations in Patients with BCR-ABL-Negative Myeloproliferative Neoplasms (MPN): A Systematic Review and Meta-Analysis
    Chia YC, Islam MA, Hider P, Woon PY, Johan MF, Hassan R, et al.
    Cancers (Basel), 2021 Jun 20;13(12).
    PMID: 34203097 DOI: 10.3390/cancers13123078
    Multiple recurrent somatic mutations have recently been identified in association with myeloproliferative neoplasms (MPN). This meta-analysis aims to assess the pooled prevalence of TET2 gene mutations among patients with MPN. Six databases (PubMed, Scopus, ScienceDirect, Google Scholar, Web of Science and Embase) were searched for relevant studies from inception till September 2020, without language restrictions. The eligibility criteria included BCR-ABL-negative MPN adults with TET2 gene mutations. A random-effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses explored results among different continents and countries, WHO diagnostic criteria, screening methods and types of MF. Quality assessment was undertaken using the Joanna Briggs Institute critical appraisal tool. The study was registered with PROSPERO (CRD42020212223). Thirty-five studies were included (n = 5121, 47.1% female). Overall, the pooled prevalence of TET2 gene mutations in MPN patients was 15.5% (95% CI: 12.1-19.0%, I2 = 94%). Regional differences explained a substantial amount of heterogeneity. The prevalence of TET2 gene mutations among the three subtypes PV, ET and MF were 16.8%, 9.8% and 15.7%, respectively. The quality of the included studies was determined to be moderate-high among 83% of the included studies. Among patients with BCR-ABL-negative MPN, the overall prevalence of TET2 gene mutations was 15.5%.
  10. Fulltext HDG-select: A novel GUI based application for gene selection and classification in high dimensional datasets
    Hameed SS, Hassan R, Hassan WH, Muhammadsharif FF, Latiff LA
    PLoS One, 2021;16(1):e0246039.
    PMID: 33507983 DOI: 10.1371/journal.pone.0246039
    The selection and classification of genes is essential for the identification of related genes to a specific disease. Developing a user-friendly application with combined statistical rigor and machine learning functionality to help the biomedical researchers and end users is of great importance. In this work, a novel stand-alone application, which is based on graphical user interface (GUI), is developed to perform the full functionality of gene selection and classification in high dimensional datasets. The so-called HDG-select application is validated on eleven high dimensional datasets of the format CSV and GEO soft. The proposed tool uses the efficient algorithm of combined filter-GBPSO-SVM and it was made freely available to users. It was found that the proposed HDG-select outperformed other tools reported in literature and presented a competitive performance, accessibility, and functionality.
  11. Fulltext Falciparum Malaria Outbreak in Sabah Linked to an Immigrant Rubber Tapper
    Jeffree SM, Ahmed K, Safian N, Hassan R, Mihat O, Lukman KA, et al.
    Am J Trop Med Hyg, 2018 Jan;98(1):45-50.
    PMID: 29141714 DOI: 10.4269/ajtmh.17-0081
    Sabah is a Malaysian state situated in the northern part of Borneo, and it is endemic for malaria. The incidence of malaria is the lowest (0.05/1,000 population) in Penampang districts of Sabah. In June 26, 2012, two Plasmodium falciparum malaria cases were notified to public health department from a village in Penampang. Immediate investigation was initiated to identify the risk factors and to institute control measures. We performed active case finding by asking household members of all houses in the village regarding malaria symptoms and by examining blood smears. Environmental investigation was performed by collecting samples to detect mosquito breeding sites and to identify malaria transmitting vector mosquitoes. A case-control study with a ratio of 1:4 (11 cases and 44 controls) was conducted using self-administered questionnaire. The microscopic examination of blood smear for malarial parasite and entomology sampling was carried out. The malarial attack rate was 2.3%, 6/11 smears have gametocyte, and the case fatality rate was 9.1%. One case was a migrant rubber tapper from Indonesia which happened to be the first case with gametocyte positive. Overall, the incidence of malaria was higher (6/11) among rubber tappers. The odds of cases for those living nearby stagnant water were 7.3 [95% confidence interval: 1.2-43.5] times higher. In conclusion, an outbreak of P. falciparum malaria was introduced into a malaria-free village by a migrant rubber tapper, by whom the imported parasite was introduced to the community via vector Anopheles balabacensis. Living near stagnant water bodies was the risk factor in this outbreak.
  12. Fulltext Anti-D Alloimmunization Following Rhesus-Incompatible Platelet Transfusion in a Myelodysplastic Syndrome Patient
    Hanafi R, Zulkeflee RH, Hassan MN, Saidin NIS, Adzahar S, Hassan R
    Cureus, 2024 Mar;16(3):e57165.
    PMID: 38681415 DOI: 10.7759/cureus.57165
    Patients with myelodysplastic syndrome (MDS) often need platelet transfusions to address thrombocytopenia. The risk of alloimmunization, particularly in Rhesus (Rh) incompatibility between donors and recipients during platelet transfusions, is heightened, especially with whole blood-derived pooled platelets as opposed to apheresis platelets. Although the occurrence of alloimmunization from platelet transfusions is minimal, there is an ongoing debate about whether Rh immune globulin (RhIg) should be administered to Rhesus D (RhD)-negative recipients of RhD-positive platelet units. We present a unique case of anti-D alloimmunization in a 56-year-old patient with underlying MDS following multiple platelet transfusions but never received packed cell transfusion or anti-D immunoglobulin. Some studies advocate for RhIg administration in specific scenarios and for certain patient populations. This case underscores the importance of considering Rhesus compatibility or administering anti-D immunoglobulin in cases where frequent platelet transfusions are required.
  13. Towards understanding the role of nanomedicine in targeting TNFR2 in rheumatoid arthritis
    Lambuk F, Nordin NA, Mussa A, Lambuk L, Ahmad S, Hassan R, et al.
    Immunology, 2024 Aug 27.
    PMID: 39191474 DOI: 10.1111/imm.13855
    Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation of the synovium and progressive joint destruction which significantly affects both quality of life and socioeconomic status. Admittedly, various treatments are available, but they are usually accompanied by various side effects, from mild to severe, and potentially with adverse events. Tumour necrosis factor-alpha (TNF-α) plays a crucial role in the pathophysiology of RA. It promotes inflammatory, apoptosis and necroptosis via TNF receptor-1 (TNFR1) but elicit anti-inflammatory effects via TNFR2. Herein, targeting TNFR2 has gained attention in RA studies. Understanding the role of nanomedicine in modulating TNFR2 signalling may be the instrument in development of RA therapies. Nanotechnology has made a significant progress in treating various conditions of diseases since its inception. Due to this, nanomedicine has emerged as a promising therapeutics approach for RA. Recent studies have demonstrated the potential of nanomedicine in RA theranostics, combining therapy and diagnostics for improved treatment outcomes. Owing to the challenges and advancements in the field of nanotechnology, nanoparticles are seen as an applicable candidate in the treatment of RA. In this review, we provide an overview of the role of nanomedicine in targeting TNFR2 for the treatment of RA and highlight the limitations of current therapies as well as the potential of nanocarriers with controlled drug release and active targeting abilities.
  14. Fulltext Randomized single-blinded study comparing sedation effectiveness and hemodynamic stability of remifentanil vs dexmedetomidine infusion for electrophysiology procedures in patients of National Heart Institute cathlab
    Hassan R, Mutalib AA, Shang CY, Sachdev NS, Rahman FA, Ling ESL
    J Interv Card Electrophysiol, 2024 Nov;67(8):1735-1743.
    PMID: 39110272 DOI: 10.1007/s10840-024-01884-x
    BACKGROUND: While studies comparing the effectiveness of remifentanil and dexmedetomidine are prevalent in other nations, using remifentanil alone is uncommon in Malaysia. This research aims to evaluate the effectiveness of sedation with remifentanil or dexmedetomidine infusion in monitored anesthesia care for electrophysiology procedures.

    METHODS: This study is a single-center, single-blinded, prospective randomized clinical study. One hundred twenty patients were randomized into two groups (remifentanil vs dexmedetomidine). Demographic characteristics and clinical outcomes, including level of sedation, vital signs, and patient satisfaction were monitored and recorded.

    RESULTS: Group R showed a higher mean observer's assessment of alertness/sedation score (3.9 ± 0.7 vs 3.6 ± 0.8; p = 0.008), mean arterial pressure (92.0 ± 12.0 vs 83.0 ± 13.0 mmHg; p 

  15. Fulltext HOXA4 gene promoter hypermethylation as an epigenetic mechanism mediating resistance to imatinib mesylate in chronic myeloid leukemia patients
    Elias MH, Baba AA, Husin A, Sulong S, Hassan R, Sim GA, et al.
    Biomed Res Int, 2013;2013:129715.
    PMID: 23484077 DOI: 10.1155/2013/129715
    Development of resistance to imatinib mesylate (IM) in chronic myeloid leukemia (CML) patients has emerged as a significant clinical problem. The observation that increased epigenetic silencing of potential tumor suppressor genes correlates with disease progression in some CML patients treated with IM suggests a relationship between epigenetic silencing and resistance development. We hypothesize that promoter hypermethylation of HOXA4 could be an epigenetic mechanism mediating IM resistance in CML patients. Thus a study was undertaken to investigate the promoter hypermethylation status of HOXA4 in CML patients on IM treatment and to determine its role in mediating resistance to IM. Genomic DNA was extracted from peripheral blood samples of 95 CML patients (38 good responders and 57 resistant) and 12 normal controls. All samples were bisulfite treated and analysed by methylation-specific high-resolution melt analysis. Compared to the good responders, the HOXA4 hypermethylation level was significantly higher (P = 0.002) in IM-resistant CML patients. On comparing the risk, HOXA4 hypermethylation was associated with a higher risk for IM resistance (OR 4.658; 95% CI, 1.673-12.971; P = 0.003). Thus, it is reasonable to suggest that promoter hypermethylation of HOXA4 gene could be an epigenetic mechanism mediating IM resistance in CML patients.
  16. Fulltext Contribution of BCR-ABL kinase domain mutations to imatinib mesylate resistance in Philadelphia chromosome positive Malaysian chronic myeloid leukemia patients
    Elias MH, Baba AA, Husin A, Abdullah AD, Hassan R, Sim GA, et al.
    Hematol Rep, 2012 Nov 19;4(4):e23.
    PMID: 23355941 DOI: 10.4081/hr.2012.e23
    Development of resistance to imatinib mesylate (IM) in chronic myeloid leukemia (CML) patients is mediated by different mechanisms that can be classified as BCR-ABL dependent or BCR-ABL independent pathways. BCR-ABL dependent mechanisms are most frequently associated with point mutations in tyrosine kinase domain (TKD) of BCR-ABL1 and also with BCR-ABL gene amplification. Many different types and frequencies of mutations have been reported in different studies, probably due to the different composition of study cohorts. Since no reports are available from Malaysia, this study was undertaken to investigate the frequency and pattern of BCR-ABL kinase domain mutations using dHPLC followed by sequencing, and also status of BCR-ABL gene amplification using fluorescence in situ hybridization (FISH) on 40 IM resistant Malaysian CML patients. Mutations were detected in 13 patients (32.5%). Five different types of mutations (T315I, E255K, Y253H, M351T, V289F) were identified in these patients. In the remaining 27 IM resistant CML patients, we investigated the contribution made by BCR-ABL gene amplification, but none of these patients showed amplification. It is presumed that the mechanisms of resistance in these 27 patients might be due to BCR-ABL independent pathways. Different mutations confer different levels of resistance and, therefore, detection and characterization of TKD mutations is highly important in order to guide therapy in CML patients.
  17. Fulltext Guidelines for nucleic acid detection and analysis in hematological disorders
    Hassan R, Husin A, Sulong S, Yusoff S, Johan MF, Yahaya BH, et al.
    Malays J Pathol, 2015 Aug;37(2):165-73.
    PMID: 26277676 MyJurnal
  18. A non-dominated sorting Differential Search Algorithm Flux Balance Analysis (ndsDSAFBA) for in silico multiobjective optimization in identifying reactions knockout
    Daud KM, Mohamad MS, Zakaria Z, Hassan R, Shah ZA, Deris S, et al.
    Comput Biol Med, 2019 10;113:103390.
    PMID: 31450056 DOI: 10.1016/j.compbiomed.2019.103390
    Metabolic engineering is defined as improving the cellular activities of an organism by manipulating the metabolic, signal or regulatory network. In silico reaction knockout simulation is one of the techniques applied to analyse the effects of genetic perturbations on metabolite production. Many methods consider growth coupling as the objective function, whereby it searches for mutants that maximise the growth and production rate. However, the final goal is to increase the production rate. Furthermore, they produce one single solution, though in reality, cells do not focus on one objective and they need to consider various different competing objectives. In this work, a method, termed ndsDSAFBA (non-dominated sorting Differential Search Algorithm and Flux Balance Analysis), has been developed to find the reaction knockouts involved in maximising the production rate and growth rate of the mutant, by incorporating Pareto dominance concepts. The proposed ndsDSAFBA method was validated using three genome-scale metabolic models. We obtained a set of non-dominated solutions, with each solution representing a different mutant strain. The results obtained were compared with the single objective optimisation (SOO) and multi-objective optimisation (MOO) methods. The results demonstrate that ndsDSAFBA is better than the other methods in terms of production rate and growth rate.
  19. Molecular and serological detection of occult hepatitis B virus among healthy hepatitis B surface antigen-negative blood donors in Malaysia
    Hudu SA, Harmal NS, Saeed MI, Alshrari AS, Malik YA, Niazlin MT, et al.
    Afr Health Sci, 2016 Sep;16(3):677-683.
    PMID: 27917199
    BACKGROUND: Occult hepatitis B infections are becoming a major global threat, but the available data on its prevalence in various parts of the world are often divergent.

    OBJECTIVE: This study aimed to detect occult hepatitis B virus in hepatitis B surface antigen-negative serum using anti-HBc as a marker of previous infection.

    PATIENT AND METHODS: A total of 1000 randomly selected hepatitis B surface antigen-negative sera from blood donors were tested for hepatitis B core antibody and hepatitis B surface antibody using an ELISA and nested polymerase chain reaction was done using primers specific to the surface gene (S-gene).

    RESULTS: Of the 1000 samples 55 (5.5%) were found to be reactive, of which 87.3% (48/55) were positive for hepatitis B surface antibody, indicating immunity as a result of previous infection however, that does not exclude active infection with escaped mutant HBV. Nested PCR results showed the presence of hepatitis B viral DNA in all the 55 samples that were positive for core protein, which is in agreement with the hepatitis B surface antibody result.

    CONCLUSION: This study reveals the 5.5% prevalence of occult hepatitis B among Malaysian blood donors as well as the reliability of using hepatitis B core antibody in screening for occult hepatitis B infection in low endemic, low socioeconomic settings.

  20. Influence of citric acid on the physical and biomineralization ability of freeze/thaw poly(vinyl alcohol) hydrogel
    Wahid MNA, Abd Razak SI, Abdul Kadir MR, Hassan R, Nayan NHM, Mat Amin KA
    J Biomater Appl, 2018 07;33(1):94-102.
    PMID: 29716417 DOI: 10.1177/0885328218771195
    This work reports the modification of freeze/thaw poly(vinyl alcohol) hydrogel using citric acid as the bioactive molecule for hydroxyapatite formation in simulated body fluid. Inclusion of 1.3 mM citric acid into the poly(vinyl alcohol) hydrogel showed that the mechanical strength, crystalline phase, functional groups and swelling ability were still intact. Adding citric acid at higher concentrations (1.8 and 2.3 mM), however, resulted in physically poor hydrogels. Presence of 1.3 mM of citric acid showed the growth of porous hydroxyapatite crystals on the poly(vinyl alcohol) surface just after one day of immersion in simulated body fluid. Meanwhile, a fully covered apatite layer on the poly(vinyl alcohol) surface plus the evidence of apatite forming within the hydrogel were observed after soaking for seven days. Gel strength of the soaked poly(vinyl alcohol)/citric acid-1.3 mM hydrogel revealed that the load resistance was enhanced compared to that of the neat poly(vinyl alcohol) hydrogel. This facile method of inducing rapid growth of hydroxyapatite on the hydrogel surface as well as within the hydrogel network can be useful for guided bone regenerative materials.
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