Displaying publications 241 - 260 of 517 in total

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  1. Tan WS, McNae IW, Ho KL, Walkinshaw MD
    PMID: 17671358
    Hepatitis B core (HBc) particles have been extensively exploited as carriers for foreign immunological epitopes in the development of multicomponent vaccines and diagnostic reagents. Crystals of the T = 4 HBc particle were grown in PEG 20,000, ammonium sulfate and various types of alcohols. A temperature jump from 277 or 283 to 290 K was found to enhance crystal growth. A crystal grown using MPD as a cryoprotectant diffracted X-rays to 7.7 A resolution and data were collected to 99.6% completeness at 8.9 A. The crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 352.3, b = 465.5, c = 645.0 A. The electron-density map reveals a protrusion that is consistent with the N-terminus extending out from the surface of the capsid. The structure presented here supports the idea that N-terminal insertions can be exploited in the development of diagnostic reagents, multicomponent vaccines and delivery vehicles into mammalian cells.
    Matched MeSH terms: Hepatitis B virus/chemistry*
  2. Ansari AW, Schmidt RE, Shankar EM, Kamarulzaman A
    J Transl Med, 2014;12:341.
    PMID: 25528160 DOI: 10.1186/s12967-014-0341-8
    Even in the era of successful combination antiretroviral therapy (cART), co-infection of Hepatitis C virus (HCV) remains one of the leading causes of non-AIDS-related mortality and morbidity among HIV-positive individuals as a consequence of accelerated liver fibrosis and end-stage liver disease (ESLD). The perturbed liver microenvironment and induction of host pro-inflammatory mediators in response to HIV and HCV infections, play a pivotal role in orchestrating the disease pathogenesis and clinical outcomes. How these viruses communicate each other via chemokine CCL2 and exploit the liver specific cellular environment to exacerbate liver fibrosis in HIV/HCV co-infection setting is a topic of intense discussion. Herein, we provide recent views and insights on potential mechanisms of CCL2 mediated immuno-pathogenesis, and HIV-HCV cross-talk in driving liver inflammation. We believe CCL2 may potentially serve an attractive target of anti-fibrotic intervention against HIV/HCV co-infection associated co-morbidities.
    Matched MeSH terms: Hepatitis C/complications; Hepatitis C/immunology*; Hepatitis C/pathology
  3. Palaniappan S, Ramanaidu S
    Med J Malaysia, 2012 Jun;67(3):326-8.
    PMID: 23082427 MyJurnal
    Matched MeSH terms: Hepatitis, Autoimmune/complications*; Hepatitis, Autoimmune/diagnosis; Hepatitis, Autoimmune/drug therapy
  4. Koh KC
    Malays Fam Physician, 2011;6(1):34-5.
    PMID: 25606219
    This is the photograph of an adult male with Human Immunodeficiency Virus -Hepatitis C virus (HIV-HCV) co-infection. He was on highly active antiretroviral therapy (HAART) for HIV infection. The liver function tests showed hypoalbuminemia and elevated serum transaminases while liver ultrasonography showed coarse echotexture compatible with liver cirrhosis.
    Matched MeSH terms: Hepatitis C
  5. Ho CW, Tan WS, Chong FC, Ling TC, Tey BT
    J Microbiol Biotechnol, 2009 Apr;19(4):416-23.
    PMID: 19421000
    Hepatitis B core antigen (HBcAg) is an important serological marker used in the diagnosis of hepatitis B virus (HBV) infections. In the current study, a fast and efficient preparative purification protocol for truncated HBcAg from Escherichia coli disruptate was developed. The recombinant HBcAg was first captured by anion exchange expanded bed adsorption chromatography integrated with a cell disruption process. This online capture process has shortened the process time and eliminated the "hold-up" period that may be detrimental to the quality of target protein. The eluted product from the expanded bed adsorption chromatography was subsequently purified using size-exclusion chromatography. The results showed that this novel purification protocol achieved a recovery yield of 45.1% with a product purity of 88.2%, which corresponds to a purification factor of 4.5. The recovered HBcAg is still biologically active as shown by ELISA test.
    Matched MeSH terms: Hepatitis B Core Antigens/genetics; Hepatitis B Core Antigens/isolation & purification*; Hepatitis B Core Antigens/metabolism
  6. Hesham R, Zamberi S, Tajunisah ME, Ariza A, Ilina I
    Med J Malaysia, 2005 Oct;60(4):407-10.
    PMID: 16570700
    Health care workers (HCW) are at higher risk of acquiring blood borne infections such as hepatitis B virus, hepatitis C virus and human immunodeficiency virus from patients. To minimise exposure, Universal Precautions Policy guidelines were introduced. This study looked into one of the aspects of hepatitis B prevention among HCW in the Malaysian context. The objective of this study was to assess hepatitis B vaccine coverage among HCW. A cross sectional study involving pre-tested questionnaires was undertaken from February 2001 to August 2001. Hospital staff in Hospital Kuala Lumpur and Hospital Universiti Kebangsaan Malaysia as well as undergraduate students undergoing clinical attachments were randomly chosen. A total of 625 subjects were enrolled. Only 58.4% had taken a complete hepatitis B vaccination. However, 82.2% have taken at least one dose of the hepatitis B vaccine and were supposed to complete the schedule in due course. Not all HCW were protected against hepatitis B. Preventing hepatitis B in HCW should be one of the priorities of the hospital management as it is definitely cheaper than managing chronic hepatitis B cases.
    Matched MeSH terms: Hepatitis B/prevention & control*; Hepatitis B Vaccines/administration & dosage*
  7. Lee WS, Teh CM, Chan LL
    J Paediatr Child Health, 2005 May-Jun;41(5-6):265-8.
    PMID: 15953326 DOI: 10.1111/j.1440-1754.2005.00608.x
    OBJECTIVES: To estimate the risks of seroconversion of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency viruses (HIV) in children with multitransfused thalassaemia at a thalassaemic clinic in Kuala Lumpur, Malaysia.
    METHODS: Seventy-two children (39 males, median age 11.3 years, 2.5th-97.5th centile: 1.4-19.2 years) with thalassaemia major were studied. The risks of seroconversion of HBV, HCV and HIV were estimated by comparing the seroprevalences of hepatitis B surface antigen (HBsAg), anti-HCV and anti-HIV between a defined starting point and an end point. The end point was the point when latest serological results were available while the starting point was when regular transfusion was commenced, or approximately 5 years before the end point when the duration of transfusion was longer.
    RESULTS: The median duration of the study was 49 months (range 8-69 months, total 2953 patient-months). There were 2605 transfusion episodes and 4154 units of blood transfused (0.88 transfusion episode/patient per month, 1.41 units of blood transfused/patient per month). There were three new seroconversions for anti-HCV but none for HBsAg and anti-HIV. The risk of seroconversion for HCV was one in 1384 units of blood transfused (95% CI: 4000-472). The seroprevalence rates at the starting and end points were: HBsAg (1%, 1%), anti-HCV (10%, 13%) and anti-HIV (0%, 0%), respectively.
    CONCLUSIONS: The estimated risk of acquiring HCV infection in children receiving multiple blood transfusions in this study is surprisingly higher than the generally accepted estimated risk. Other routes of transmission may be important. A prospective, multicentre study to estimate such risks more precisely is needed.
    Matched MeSH terms: Hepatitis B Antibodies/blood*; Hepatitis C Antibodies/blood*
  8. Guan R
    Med J Malaysia, 2005 Jul;60 Suppl B:52-6.
    PMID: 16108174
    In the Asia Pacific region Human Immunodeficiency virus (HIV) is often acquired in individuals already infected with hepatitis B virus (HBV). The immune suppression caused by HIV infection reduces cellular immune response against HBV and liver inflammation may improve, but the risk of developing cirrhosis is not. HBV infection does not affect the progression of HIV disease. Anti-retroviral agents may be directly hepatotoxic and cause ALT elevations in patients with chronic hepatitis. Highly active anti-retroviral therapy (HAART) improves immunity and as cytotoxic lymphocyte responses improve, hepatitis flares can occur, usually r within 3 months of initiation of HAART. These hepatitis flares may be followed by normalization of ALT and clearance of HBVDNA. If lamivudine is included in the HAART regime, hepatitis flares may not occur till late and these late flares signal the development of lamivudine resistant HBV strains (90% of HBV/HIV co-infection). Treatment options for chronic HBV infection include interferon (IFN), and nucleoside analogues. Lamivudine, adefovir dipivoxil, tenofovir disoproxil fumarate (DF) are nucleoside analogues with activity against both HBVDNA polymerase and HIV reverse transcriptase. The latter two compounds have added activity against lamivudine resistant HBVDNA. Lamivudine should be avoided in the initial treatment of both hepatitis B as well as HIV because of the high incidence of resistance. Interferon should be considered first for treatment of HBV in HIV co-infected individuals and is usually unsuccessful in the later stages of HIV infection when immune suppression is extreme. As new and improved agents in HAART continue to prolong survival, the use of liver transplantation for cirrhotic patients co-infected with HIV and HBV may increase.
    Matched MeSH terms: Hepatitis B, Chronic/complications; Hepatitis B, Chronic/drug therapy*; Hepatitis B, Chronic/physiopathology
  9. Gane E
    Med J Malaysia, 2005 Jul;60 Suppl B:72-6.
    PMID: 16108179
    Matched MeSH terms: Hepatitis C, Chronic/drug therapy*; Hepatitis C, Chronic/epidemiology; Hepatitis C, Chronic/physiopathology
  10. Merican I
    J Gastroenterol Hepatol, 2000 May;15 Suppl:E71-8.
    PMID: 10921386
    Matched MeSH terms: Hepatitis B, Chronic/complications; Hepatitis B, Chronic/immunology; Hepatitis B, Chronic/therapy*
  11. Kok WL, Yusoff K, Nathan S, Tan WS
    J. Biochem. Mol. Biol. Biophys., 2002 Feb;6(1):55-8.
    PMID: 12186783
    The PreS domain of hepatitis B virus (HBV) is believed to be involved in virion assembly and attachment to a hepatocyte receptor during infection. In order to study the functions of this region, we fused it to the g3p protein of bacteriophage M13 that allows the fusion protein to be displayed at the tip of the filament. The fusion protein was detected by the anti-E tag antibody on a Western blot. The polypeptide in a soluble form was produced by transfecting a non-suppressor E. coli host cell with the recombinant phagemid. The soluble protein was detected in cytoplasm, in the periplasmic space and also in the medium. The functional display of the PreS domain would provide an alternative means to study its interactions with the nuleocapsid and hepatocytes.
    Matched MeSH terms: Hepatitis B Surface Antigens/genetics*; Hepatitis B Surface Antigens/metabolism; Hepatitis B Surface Antigens/chemistry*
  12. Morad Z, Suleiman AB, Kong CT
    Transplant Proc, 1989 Feb;21(1 Pt 2):1825-6.
    PMID: 2652593
    Matched MeSH terms: Hepatitis/etiology*; Hepatitis B Surface Antigens/analysis*
  13. Wong WCW, Lo YR, Jiang S, Peng M, Zhu S, Kidd MR, et al.
    Fam Pract, 2018 12 12;35(6):731-737.
    PMID: 29741661 DOI: 10.1093/fampra/cmy032
    Objective: The study aimed to decentralize hepatitis testing and management services to primary care in China.

    Methods: A nationwide representative provider survey amongst community health centres (CHCs) using randomized stratified sampling methods was conducted between September and December 2015. One hundred and eighty CHCs and frontline primary care practitioners from 20 cities across three administrative regions of Western, Central and Eastern China were invited to participate.

    Results: One hundred and forty-nine clinicians-in-charge (79%), 1734 doctors and 1846 nurses participated (86%). Majority of CHCs (80%, 95% CI: 74-87) offered hepatitis B testing, but just over half (55%, 95% CI: 46-65) offered hepatitis C testing. The majority of doctors (87%) and nurses (85%) felt that there were benefits for providing hepatitis testing at CHCs. The major barriers for not offering hepatitis testing were lack of training (54%) and financial support (23%). Multivariate analysis showed that the major determinants for CHCs to offer hepatitis B and C testing were the number of nurses (AOR 1.1) and written policies for hepatitis B diagnosis (AOR 12.7-27.1), and for hepatitis B the availability of reproductive health service.

    Conclusions: Primary care providers in China could play a pivotal role in screening, diagnosing and treating millions of people with chronic hepatitis B and C in China.

    Matched MeSH terms: Hepatitis, Chronic/diagnosis*; Hepatitis, Chronic/epidemiology; Hepatitis, Chronic/therapy*
  14. Ooi A, Tan S, Mohamed R, Rahman NA, Othman RY
    J Biotechnol, 2006 Feb 24;121(4):471-81.
    PMID: 16271415
    A cucumber green mosaic mottle virus (CGMMV) full-length clone was developed for the expression of Hepatitis B surface antigen (HBsAg). The expression of the surface displayed HBsAg by the chimeric virus was confirmed through a double antibody sandwich ELISA. Assessment of the coat protein composition of the chimeric virus particles by SDS-PAGE analysis showed that 50% of the coat proteins were fused to the HBsAg. Biological activity of the expressed HBsAg was assessed through the stimulation of in vitro antibody production by cultured peripheral blood mononuclear cells (PBMC). PBMC that were cultured in the presence of the chimeric virus showed up to an approximately three-fold increase in the level of anti HBsAg immunoglobulin thus suggesting the possible use of this new chimeric virus as an effective Hepatitis B vaccine.
    Matched MeSH terms: Hepatitis B Surface Antigens/biosynthesis*; Hepatitis B Surface Antigens/genetics; Hepatitis B Surface Antigens/immunology
  15. MyJurnal
    This study evaluates the sanitary and physico-chemical quality of Sg. Jarum Mas shellfish waters in order to establish its suitability as a model farm. Seawater and shellfish from nine stations (4 shellfish harvesting waters, 4 surrounding waters and 1 control site) were collected and analyzed monthly from September 2004 - September 2005. The results show that shellfish harvesting waters in Sg. Jarum Mas can be classified as ‘approved’ and ‘conditionally approved’. Hepatitis A virus was not detected in any of the shellfish examined. Dinophysis caudata and Pseuodonitzshia spp. were the most common harmful alga species observed. Harmful species that are known to produce toxins and cause shellfish poisoning such as Alexandrium spp., Gymnodinum spp., Pyrodinium sp. and Prorocentrum spp. were not detected. The physico-chemical characteristics of shellfish waters in Sg. Jarum Mas imply that they are suitable for aquaculture activity of moderately tolerant species such as shellfish.
    Matched MeSH terms: Hepatitis A virus
  16. Yong YK, Saeidi A, Tan HY, Rosmawati M, Enström PF, Batran RA, et al.
    Front Immunol, 2018;9:472.
    PMID: 29616020 DOI: 10.3389/fimmu.2018.00472
    Mucosal-associated invariant T (MAIT) cells, defined as CD161++TCR iVα7.2+ T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3+CD161++TCR iVα7.2+ MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVα7.2+ CD161+ MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4+ T cells and MAIT cells and with CD57 on CD8+ T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iVα7.2+ MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.
    Matched MeSH terms: Hepatitis B; Hepatitis B virus; Hepatitis B, Chronic; Hepatitis A Virus Cellular Receptor 2
  17. Kared H, Martelli S, Tan SW, Simoni Y, Chong ML, Yap SH, et al.
    Front Immunol, 2018;9:686.
    PMID: 29731749 DOI: 10.3389/fimmu.2018.00686
    Repetitive stimulation by persistent pathogens such as human cytomegalovirus (HCMV) or human immunodeficiency virus (HIV) induces the differentiation of natural killer (NK) cells. This maturation pathway is characterized by the acquisition of phenotypic markers, CD2, CD57, and NKG2C, and effector functions-a process regulated by Tim-3 and orchestrated by a complex network of transcriptional factors, involving T-bet, Eomes, Zeb2, promyelocytic leukemia zinc finger protein, and Foxo3. Here, we show that persistent immune activation during chronic viral co-infections (HCMV, hepatitis C virus, and HIV) interferes with the functional phenotype of NK cells by modulating the Tim-3 pathway; a decrease in Tim-3 expression combined with the acquisition of inhibitory receptors skewed NK cells toward an exhausted and cytotoxic phenotype in an inflammatory environment during chronic HIV infection. A better understanding of the mechanisms underlying NK cell differentiation could aid the identification of new immunological targets for checkpoint blockade therapies in a manner that is relevant to chronic infection and cancer.
    Matched MeSH terms: Hepatitis C/immunology*; Hepatitis A Virus Cellular Receptor 2/immunology*
  18. Earnest BS, Men LC, Sukvinder Kaur G, Alias RB, Sunita Devi H
    J Assoc Physicians India, 2010 Feb;58(2):118-20.
    PMID: 20653157
    The neurological manifestations of chronic hepatitis C is most often a peripheral sensory neuropathy characterised by numbness, burning and sensation of "pins and needles". Peripheral motor neuropathy, mononeuropathy, mononeuropathy multiplex and transverse myelitis also occur. Ischemic stroke and transient cerebral ischemia have also been reported. Anterior ischemic optic neuropathy is seen, often following interferon therapy. We report an exceptional case of neuromyelitis optica in chronic hepatitis C infection in the absence of interferon therapy.
    Matched MeSH terms: Hepatitis C Antibodies/immunology*; Hepatitis C, Chronic/complications*
  19. Iakunchykova O, Meteliuk A, Zelenev A, Mazhnaya A, Tracy M, Altice FL
    Int J Drug Policy, 2018 Jul;57:11-17.
    PMID: 29655101 DOI: 10.1016/j.drugpo.2018.03.022
    BACKGROUND: Among the estimated 340,000 people who inject drugs (PWID) in Ukraine, HCV prevalence is approximately 70%. As HCV treatment availability increases, an assessment of the HCV treatment cascade is needed to guide HCV prevention and treatment strategies.

    METHODS: Opioid dependent PWID were interviewed and tested for HIV and HCV in five Ukrainian cities from January 2014 to March 2015. Logistic regression was used to examine the independent correlates of two cascade steps: a) anti-HCV positive status awareness; b) chronic HCV confirmation; and of c) annual HCV testing for PWID.

    RESULTS: Among 1613 PWID, 1002 (62.1%) had anti-HCV positive test result, of which 568 (56.7%) were aware of it before the study and 346 (34.5%) reported previous confirmatory testing for chronic HCV. Independent correlates of being aware they had anti-HCV positivity included: current [AOR: 3.08; 95%CI: 2.16-4.40] or prior [AOR: 1.85; 95%CI: 1.27-2.68] opioid agonistic treatment (OAT) experience, relative to no prior OAT, living in Lviv [AOR: 0.50; 95%CI: 0.31-0.81] or Odesa [AOR: 2.73; 95%CI: 1.51-4.93] relative to Kyiv and being aware of having HIV [AOR: 4.10; 95%CI: 2.99-5.62]. Independent correlates of confirming HCV infection among those who were aware of their anti-HCV positive status included: current OAT [AOR: 2.00; 95%CI: 1.24-3.23], relative to prior OAT, the middle income category [AOR: 1.74, 95%CI: 1.15-2.63], relative to the lowest, and receiving ART [AOR: 4.54; 95%CI: 2.85-7.23]. Among 1613 PWID, 918 (56.9%) were either HCV negative or not aware of their HCV positive status, of which 198 (21.6%) reported recent anti-HCV test (during last 12 month). Recent anti-HCV test in this group was associated with current [AOR: 7.17; 95%CI: 4.63-11.13] or prior [AOR: 2.24; 95%CI: 1.32-3.81] OAT experience, relative to no prior OAT.

    CONCLUSION: Encouraging PWID to participate in OAT may be an effective strategy to diagnose and link PWID who are HCV positive to care. Among HIV negative participants, regular HCV testing may be ensured by participation in OAT. More studies are needed to assess HCV treatment utilization among PWID in Ukraine and OAT as a possible way to retain them in treatment.

    Matched MeSH terms: Hepatitis C/complications; Hepatitis C/epidemiology*; Hepatitis C/psychology*
  20. Tam YJ, Allaudin ZN, Lila MA, Bahaman AR, Tan JS, Rezaei MA
    BMC Biotechnol, 2012 Oct 05;12:70.
    PMID: 23039947 DOI: 10.1186/1472-6750-12-70
    BACKGROUND: Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells.

    RESULTS: The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively.

    CONCLUSIONS: The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

    Matched MeSH terms: Hepatitis B Surface Antigens/genetics*; Hepatitis B Surface Antigens/isolation & purification; Hepatitis B Surface Antigens/metabolism
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