Displaying publications 1 - 20 of 67 in total

Abstract:
Sort:
  1. Wong MM, Lye MS, Cheng HM, Sam CK
    Asian Pac J Allergy Immunol, 2005 Mar;23(1):65-7.
    PMID: 15997877
    The antibody levels to viral capsid antigen (VCA) and early antigen (EA) of Epstein-Barr virus (EBV) in 164 nasopharyngeal carcinoma (NPC) patients from Sarawak, East Malaysia were significantly higher than those in 147 sex, age and ethnically matched healthy controls. As diagnostic markers of NPC, IgG/VCA at reciprocal titers > or =160 was the most sensitive (89%, with 98% specificity), while IgA/EA at > or =5 was the most specific (100%) but the least sensitive (75%). The sensitivity and specificity of IgA/VCA at reciprocal titers > or =10 were 84% and 97%. IgA/VCA has an advantage over IgG/VCA despite the slightly lower sensitivity due to its consistently more distinct fluorescence reaction. The sensitivity and specificity can be marginally improved by a combination of two tests.
  2. Sam CK, Soon SC, Liam CK, Padmaja K, Cheng HM
    Asian Pac J Allergy Immunol, 1998 Mar;16(1):17-20.
    PMID: 9681124
    We investigated the aeroallergens affecting 200 asthmatics from the University Hospital in Kuala Lumpur, Malaysia and found 164 (82%) patients with skin prick test (SPT) reactivity to one or more of a panel of 14 allergens, which included indoor and outdoor animal and plant aeroallergens. Reactivity was most frequent to the indoor airborne allergens, with 159 (79.5%) reacting to either or both house dust mite (Dermatophagoides) species and 87 (43.5%) to cockroach. The SPT reactivity to house dust mites corresponded with the finding that patients found house dust to be the main precipitant of asthmatic attacks.
  3. Cheng HM, Chamley L
    Autoimmun Rev, 2008 Jun;7(6):431-4.
    PMID: 18558357 DOI: 10.1016/j.autrev.2008.03.011
    Natural autoantibodies are normal components of the humoral arm of the immune system found in clinically healthy individuals. There are two subpopulations of natural antibodies, including an overt group of antibodies that are readily detected in unfractionated normal human sera. The other natural antibody subgroup is revealed by physico or biochemical treatment of normal human sera in vitro. Unmasking of this latter cryptic natural autoantibodies (cNA) may occur in vivo by local factors in the tissue environment of disease states. The masking cryptic factors may be immunoglobulin (Ig) or non-Ig in nature. These factors may either be co-inhibitors or co-enhancers of cNA. In the heat-potentiated binding of natural anti-phospholipid antibodies, apolipoprotein H (beta 2-glycoprotein I) appears to act as a co-enhancer. The immuno-relationship between the in vitro and in vivo cNA phenomenon remains to be elucidated.
  4. Chia YY, Kanthimathi MS, Khoo KS, Rajarajeswaran J, Cheng HM, Yap WS
    PMID: 26415532 DOI: 10.1186/s12906-015-0867-1
    Three species of seaweeds (Padina tetrastromatica, Caulerpa racemosa and Turbinaria ornata) are widely consumed by Asians as nutraceutical food due to their antioxidant properties. Studies have shown that these seaweeds exhibit bioactivities which include antimicrobial, antiviral, anti-hypertensive and anticoagulant activities. However, investigations into the mechanisms of action pertaining to the cytotoxic activity of the seaweeds are limited. The aim of this study was to determine the antioxidant and cytotoxic activities of whole extracts of P. tetrastromatica, C. racemosa and T. ornata, including the cellular events leading to the apoptotic cell death of the extract treated-MCF-7 cells. Bioassay guided fractionation was carried out and the compounds identified.
  5. Lee CY, Cheng HM, Sim SM
    Biofactors, 2007;31(1):25-33.
    PMID: 18806306
    The ability of the antioxidants in the mulberry leaves to protect Sprague-Dawley rats from injuries caused by immobilization stress was studied as an indicator of the tissue bioavailability of antioxidants. Nitrite level, lipid peroxidation and total antioxidant activity (TAA) in the plasma and tissues were measured. There were hypertrophy of the adrenal glands and kidneys, significant increased levels of nitrite in the plasma and adrenal glands, elevated thiobarbituric acid reactive substances (TBARS) in the plasma, kidneys and spleen, and a reduction of TAA in the plasma, liver, adrenal glands, kidneys and spleen of the immobilized rats. Antioxidants in the mulberry leaf extract suppressed the increase of nitrite and TBARS. Adrenal glands appeared to be the target organ of the antioxidants in the leaf extract. The low dose mulberry antioxidants were more effective than pure rutin (4 mg/day) to protect the cells against inflammation and peroxidation induced by stress.
  6. Cheng HM, Foong YT, AbuSamah AJ, Dillner J, Sam CK, Prasad U
    Cancer Immunol Immunother, 1995 Apr;40(4):251-6.
    PMID: 7750123
    The linear antigenic epitopes of the Epstein-Barr virus replication activator protein (ZEBRA), recognised by specific serum IgG in nasopharyngeal carcinoma (NPC), were determined. This was achieved by synthesizing the entire amino acid sequence of ZEBRA as a set of 29, 22-residue peptides with an overlap of 14 amino acids. The ZEBRA peptides were tested in enzyme-linked immunosorbent assay (ELISA) for IgG binding in sera from 37 selected NPC patients who had IgG antibodies to the native ZEBRA protein. The most immunogenic epitope was peptide 1 at the amino-terminal end with 36 of the sera reactive against it. Further analysis of peptide 1, using the multipin peptide-scanning technique, defined a 10-amino-acid sequence FTPDPYQVPF, which was strongly bound by IgG. Two other regions of ZEBRA were also identified as immunodominant IgG epitopes, namely peptide 11 (amino acids 82-103) and peptide 19/20 (amino acids 146-175) with 8-13 of the NPC sera reactive against the peptides. The number of peptides reactive with individual NPC serum varies from 1 to 6 or more and there is some correlation between a greater number of peptide (at least 4) bound and a higher (at least 1:40) titre of serum IgA to viral capsid antigen. The immunodominant ZEBRA peptide 1 could be utilised in IgG ELISA for the detection of NPC.
  7. Mathew A, Cheng HM, Sam CK, Joab I, Prasad U, Cochet C
    Cancer Immunol Immunother, 1994 Jan;38(1):68-70.
    PMID: 8299121
    The BamHI Z EBV replication activator (ZEBRA) protein is involved in the switch from latency to productive cycle of Epstein-Barr virus. A recombinant ZEBRA protein was synthesized and assessed in enzyme-linked immunosorbent assay (ELISA) for serum IgG response in nasopharyngeal carcinoma (NPC) patients. In 100 NPC serum samples that were positive for IgA to the EBV viral capsid antigen (VCA), 75% had IgG anti-ZEBRA antibodies. In contrast, only 3/83 (3.6%) serum samples from healthy donors and 2/50 (4%) from other cancers were positive for IgG to ZEBRA. Interestingly, in a selected group of 100 NPC sera negative for IgA to VCA, 25% contained IgG anti-ZEBRA antibodies. This suggests that the ELISA for IgG anti-ZEBRA may also identify earlier cases of NPC not detected by the conventional immunofluorescence test for IgA to VCA.
  8. Mathew A, Cheng HM, Sam CK, Prasad U
    Clin. Immunol. Immunopathol., 1994 May;71(2):164-8.
    PMID: 7514112
    Inhibition studies were carried out to study possible cross-reactivity between a peptide fragment of the Epstein-Barr virus nuclear antigen, EBNA-1, and keratin/collagen. The 20-amino acid peptide (pAG), derived from a glycine-alanine repeat region of EBNA-1, uniquely makes up about one-third of the viral protein and is a dominant IgA antigenic epitope in patients with nasopharyngeal carcinoma (NPC). A small percentage of normal human sera (NHS) also binds pAG and this reactivity is examined in this study. Ten percent (2/20) and 13.4% (2/15) of IgA-pAG-positive NPC sera and NHS, respectively, were significantly inhibited by keratin in a competitive ELISA system. Conversely, 31.6% (6/19) and 30.8% (4/13) of IgA-keratin-positive NPC sera and NHS, respectively, were significantly inhibited by pAG. This indicated minimum cross-reactivity between IgA serum antibodies to EBNA-1 and keratin. Using collagen as inhibitor, none of 18 and only 2/13 IgA-pAG-positive NPC sera and NHS, respectively, were inhibited. In the collagen ELISA system, only 2/19 (10.5%) and 4/25 (16%) of IgA-collagen-positive NPC sera and NHS, respectively, were inhibited with pAG. Therefore, cross-reactivity with collagen was also low. IgA-pAG-positive NHS may therefore not be a false positive phenomenon, but whether it may represent an early serological profile related to NPC carcinogenesis remains to be determined.
  9. Ong SG, Cheng HM, Soon SC, Goh E, Chow SK, Yeap SS
    Clin Rheumatol, 2002 Sep;21(5):382-5.
    PMID: 12223986 DOI: 10.1007/s100670200102
    The aim of this study was to investigate the incidence of IgG anticardiolipin antibody (ACL) and IgG anti-beta(2) glycoprotein I antibody (anti-beta2GPI) positivity in patients with primary or secondary antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE), to assess the association between IgG ACL and anti-beta2GPI, and the relationship between the presence of ACL and anti-beta2GPI with the clinical manifestations of APS. IgG ACL and IgG anti-beta2GPI levels were measured in 51 SLE patients, 20 patients with SLE and APS (secondary APS) and 11 primary APS patients using commercially available ELISA kits. Relationships between laboratory data and clinical manifestations of the patients were examined. The incidence of IgG ACL positivity was significantly higher in primary (36.4%) and secondary (40%) APS than in SLE (13.7%) patients (P = 0.02). The incidence of IgG anti-beta2GPI positivity was significantly higher in primary (54.5%) and secondary (35%) APS than in SLE (7.8%) patients (P = 0.0006). Mean levels of IgG ACL and anti-beta2GPI were significantly higher in the primary and secondary APS than in the SLE patients (P = 0.002 for both). A significant relationship was found between IgG ACL and IgG anti-beta2GPI (P = 0.01, R(2) = 0.56). There was a significant correlation between the presence of IgG ACL and a history of thrombosis in the combined primary and secondary APS group, but not in SLE patients. In conclusion, in this study IgG ACL and IgG anti-beta2GPI are closely related and mean levels of IgG ACL and IgG anti-beta2GPI are higher in patients with either primary or secondary APS than in SLE patients.
    Study site: Rheumatology Clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
  10. Palanisamy U, Cheng HM, Masilamani T, Subramaniam T, Ling LT, Radhakrishnan AK
    Food Chem, 2008 Jul 1;109(1):54-63.
    PMID: 26054264 DOI: 10.1016/j.foodchem.2007.12.018
    The rind of rambutan, which is normally discarded was found to contain extremely high antioxidant activity when assessed using several methods. Although having a yield of only 18%, the ethanolic rambutan rind extract had a total phenolic content of 762±10mg GAE/g extract, which is comparable to that of a commercial preparation of grape seed extract. Comparing the extract's pro-oxidant capabilities with vitamin C, α-tocopherol, grape seed and green tea, the rind had the lowest pro-oxidant capacity. In addition, the extract at 100μg/ml was seen to limit oxidant-induced cell death (DPPH at 50μM) by apoptosis to an extent similar to that of grape seed. The extracts were not cytotoxic to normal mouse fibroblast cells or splenocytes while the powderised rind was seen to have heavy metals contents far below the permissible levels for nutraceuticals. Our study for the first time reveals the high phenolic content, low pro-oxidant capacity and strong antioxidant activity of the extract from rind of Nephelium lappaceum. This extract, either alone or in combination with other active principles, can be used in cosmetic, nutraceutical and pharmaceutical applications.
  11. Se Thoe SY, Wong KK, Pathmanathan R, Sam CK, Cheng HM, Prasad U
    Gynecol Oncol, 1993 Aug;50(2):168-72.
    PMID: 8397152
    Epstein-Barr virus (EBV) receptors (EBV/C3d receptors) were detected, using the monoclonal antibody HB5, on 23 ectocervical and 5 endocervical biopsies of the uterine cervix. Elevated IgA titers against the viral capsid antigen and early antigen of EBV were also found in the cervical secretions from cervical carcinoma patients (83%), compared with samples from patients with cervical intraepithelial neoplasia (75%), herpes simplex virus-infected patients (0%), and gynecologic patients with nonmalignant conditions (0%). EBV DNA was present in 63% of cervical carcinoma biopsies detected by in situ hybridization. These observations suggest a positive association between EBV and carcinoma of the cervix.
  12. Kario K, Tomitani N, Wang TD, Park S, Li Y, Shin J, et al.
    Hypertens Res, 2023 Dec;46(12):2561-2574.
    PMID: 37605071 DOI: 10.1038/s41440-023-01397-6
    Recent innovations in digital technology have enabled the simultaneous accumulation, and the linking and analysis of time-series big data relating to several factors that influence blood pressure (BP), including biological indicators, physical activity, and environmental information. Various approaches can be used to monitor BP: in the office/clinic; at home; 24-h ambulatory recording; or with wearable and cuffless devices. Of these, home BP monitoring is a reliable and convenient method, and is recommended for hypertension management by current national and international guidelines. This recommendation is based on evidence showing that home BP is an important predictor of cardiovascular, cerebrovascular and kidney disease in patients with hypertension. In addition, lifetime personalized health record (PHR)-based home BP with telemonitoring combined with co-interventions has been shown to lower BP more effectively than the traditional approach based on office BP. Thus, home BP represents a key metric for personalized anticipation medicine, from digital healthcare to digital medicine. This paper summarizes the latest evidence on home BP monitoring and proposes a Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network consensus on a home BP-centered approach to the management of hypertension.
  13. Cheng HM, Wang F
    Immunol Invest, 1989 11 1;18(9-10):1121-7.
    PMID: 2613288
    Non-reactive SLE sera in an ELISA for anticardiolipin antibody (aCL) retested positive in the immunoassay when the sera were first heat-inactivated at 56 degrees C for 30 minutes. This was not a false positive phenomenon since the positive ELISA reactivity of the heated SLE sera was markedly reduced by inhibition with the cardiolipin antigen. Furthermore, the heat-potentiated ELISA reaction was abolished by prior IgG depletion of the SLE sera with Protein A preparation. The unmasked aCL in the heat-treated SLE sera also exhibited selective binding in ELISA to other negatively-charged phospholipids, namely phosphatidylserine and phosphatidic acid but not against either phosphatidylcholine or phosphatidyl-ethanolamine. The data strongly indicate an interaction between antiphospholipid antibodies and heat-sensitive serum component(s), a reduction of the latter resulting in the ELISA detection of the autoantibody.
  14. Cheng HM, Sam CK
    Immunol Lett, 1990 Oct;26(1):7-10.
    PMID: 2276764
    The anti-phospholipid antibody (aPL) in 26 heat-inactivated normal human sera (NHS) was tested for IgG subclass in ELISA. The specific antibody in NHS included all four IgG antibody subclasses, as well as IgA. The incidence of IgG subclasses ranged from 50% (13/26) for IgG1 to 92% (24/26) for IgG2. Specific IgA anti-phospholipid antibody (aPL) was detected by ELISA in 38% (28/73) of normal human saliva. The salivary IgA aPL bound preferentially to anionic phospholipids including cardiolipin, phosphatidylserine and phosphatidic acid but not to phosphatidylcholine or sphingomyelin. Unlike aPL in normal human sera, aPL in saliva was predominantly not associated with the previously described heat-labile inhibitor of aPL. This may indicate a role of salivary IgA aPL in local immunity by binding to cross-reactive bacterial cell surface components including phospholipids.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links