Displaying publications 81 - 100 of 595 in total

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  1. Non-clinical safety assessment of repeated intramuscular administration of an EV-A71 VLP vaccine in rabbits
    Salmons B, Lim PY, Djurup R, Cardosa J
    Vaccine, 2018 10 29;36(45):6623-6630.
    PMID: 30293762 DOI: 10.1016/j.vaccine.2018.09.062
    A candidate hand, foot, and mouth disease vaccine comprising of human enterovirus A71 (EV-A71) virus-like particles (VLPs) was tested in rabbits to evaluate the potential local and systemic effects of this vaccine. The rabbits received more than double the full human dose and one additional dose according to the n + 1 recommended scheme. The three doses were given mixed with Alhydrogel adjuvant as intramuscular (IM) injections. Vaccinations were well-tolerated, with no indication of overt toxicity in any parameter observed. An EV-A71 specific immune response in the form of antibodies that specifically reacted with the virus capsid proteins VP1 and VP0, the complete VLP, and EV-A71 viruses of different subgenotypes to that of the vaccine could be demonstrated. A boosting effect in the form of higher EV-A71 specific antibody titers was observed after the subsequent doses, and these enhanced titers were shown to be statistically significant in one-way ANOVA analyses. Fortnightly intramuscular administration of EV-A71 VLP vaccine did not result in any test article-related changes in immunotoxicity as defined by increased serum IL-6, and in general IL-6 concentrations remained below the lower limit of quantitation for the majority of animals throughout the study. Although increased indicators of inflammation at the injection site were observed in animals sacrificed immediately after the last vaccination, these largely reversed at the end of the recovery phase. No findings suggestive of systemic or delayed toxicity were recorded in this independently conducted study. In conclusion, repeated IM administration of the EV-A71 VLP vaccine were locally and systemically well-tolerated in rabbits and immunogenic, supporting the clinical development of the vaccine.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  2. Late presentation of Nipah virus encephalitis and kinetics of the humoral immune response
    Wong SC, Ooi MH, Wong MN, Tio PH, Solomon T, Cardosa MJ
    J Neurol Neurosurg Psychiatry, 2001 Oct;71(4):552-4.
    PMID: 11561048
    Nipah virus is a newly discovered paramyxovirus transmitted directly from pigs to humans. During a large encephalitis outbreak in Malaysia and Singapore in 1998-9, most patients presented acutely. A 12 year old child is described who developed encephalitis 4 months after exposure to the virus. She was diagnosed by a new indirect IgG enzyme linked immunosorbent assay (ELISA), which is also described. The late presentation and IgG subclass responses had similarities to subacute sclerosing panencephalitis. Nipah virus should be considered in patients with encephalitis even months after their possible exposure.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  3. Development of a sandwich ELISA to detect virus-like-particles in enterovirus A71 vaccines
    Lim PY, Cardosa MJ
    J Virol Methods, 2019 08;270:113-119.
    PMID: 31100287 DOI: 10.1016/j.jviromet.2019.05.005
    The goal of this paper was to develop a sandwich ELISA that can detect intact human enterovirus A71 (EV-A71) virus-like particles (VLPs) in vaccines. This assay specifically detected EV-A71 viruses from different sub-genogroups as well as EV-A71 VLPs, and treatment of VLPs with high heat and low pH reduced or completely abolished detection of the VLPs suggesting that the ELISA detected assembled particles. Using a purified VLP as a reference standard, a quantitative sandwich ELISA (Q-ELISA) was established which was used to monitor the yield and purity of the VLPs during manufacturing. Coupled with immunogenicity studies, the Q-ELISA was used to evaluate the performance of the VLPs and formalin-inactivated EV-A71 vaccine. This assay has the potential to play an important role in the development of an efficient process to produce and purify the VLPs and in examining the quality of EV-A71 vaccines.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay/methods*
  4. Fulltext Decreased expression of alpha-2-HS glycoprotein in the sera of rats treated with Eurycoma longifolia extract
    Chen Y, Phang WM, Mu AK, Chan CK, Low BS, Sasidharan S, et al.
    Front Pharmacol, 2015;6:211.
    PMID: 26441666 DOI: 10.3389/fphar.2015.00211
    Eurycoma longifolia is a Malaysian native herb that has been widely used as an aphrodisiac and a remedy for andropause. Although the physiological effects of the plant extract were predicted as a result of the alterations in protein expression, the key protein(s) involved in these alterations are still unclear. In the present study, we have investigated the effect of standardized E. longifolia extract on serum protein expression up to 28 days following oral administration in rats. Serum protein profiles were analyzed by 2-dimensional electrophoresis, and altered proteins were identified via mass spectrometry. We observed that alpha-2-HS glycoprotein (AHS) was significantly decreased in the serum of experimentally treated rats compared to pre-treated animals. Moreover, reduction in AHS was confirmed using competitive enzyme-linked immunosorbent assay. AHS expression is known to be associated with insulin resistance and diabetes. Our data indicated that serum AHS was reduced in rats treated with standardized E. longifolia extract, and therefore form a prelude for further investigation into the effects of this natural extract in animal models involving infertility and diabetes.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  5. Fulltext Manilkara zapota (L.) P. Royen Leaf Water Extract Induces Apoptosis in Human Hepatocellular Carcinoma (HepG2) Cells via ERK1/2/Akt1/JNK1 Signaling Pathways
    Tan BL, Norhaizan ME, Chan LC
    Evid Based Complement Alternat Med, 2018;2018:7826576.
    PMID: 30519270 DOI: 10.1155/2018/7826576
    Manilkara zapota (L.) P. Royen, called sapodilla, or locally known as ciku, belongs to the family Sapotaceae. We found that Manilkara zapota leaf water extract has cytotoxic effect against human hepatocellular carcinoma (HepG2) cell line in our earlier study. Therefore, this study aimed to explore the anticancer properties of Manilkara zapota leaf water extract in HepG2 cells. We also aimed to unravel yet undiscovered mechanisms and identified several expressed genes whose functions in cytotoxicity activity of Manilkara zapota leaf water extract in HepG2 cells have not been well-studied. The apoptosis and intracellular reactive oxygen species (ROS) activities were analyzed using Annexin V-propidium iodide staining and dichlorodihydrofluorescein diacetate, respectively, by NovoCyte Flow Cytometer. Bax and Bcl-2 expression were assessed using Enzyme-Linked Immunosorbent Assay. The associated molecular pathways were evaluated by quantitative real-time PCR. Overall analyses revealed that Manilkara zapota leaf water extract can increase percentage of early apoptotic cells, induce the formation of ROS, upregulate c-Jun N-terminal kinase 1 (JNK1) and inducible nitric oxide synthase (iNOS), and reduce Akt1 and vascular endothelial growth factor A (VEGFA) transcriptional activities. Our data suggest that Manilkara zapota leaf water extract can suppress the growth of HepG2 cells via modulation of ERK1/2/Akt1/JNK1 transcriptional expression.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  6. Fulltext Urinary type IV collagen levels in diabetes mellitus
    Sthaneshwar P, Chan SP
    Malays J Pathol, 2010 Jun;32(1):43-7.
    PMID: 20614725 MyJurnal
    Type IV collagen is the principal component of glomerular basement membrane and messangial matrix. Studies have shown increased levels of urinary type IV collagen (uIV) in diabetic patients compared to healthy controls. The concentration of uIV increases gradually as diabetic nephropathy progresses.
    AIM AND METHOD: This study was carried out to determine whether urinary type IV collagen (uIV) can serve as an indicator of diabetic nephropathy. Using a sandwich enzyme immunoassay technique, uIV excretion was determined in 30 type 2 diabetic patients with normoalbuminuria and 20 patients with microalbuminuria.
    RESULTS: uIV excretion was significantly increased in type 2 diabetics, in both normoalbuminuric and microalbuminuric patients, compared with healthy controls. The increase in urinary type IV collagen was well correlated with the amount of urinary albumin but not with HbA1C.
    CONCLUSION: Our findings that uIV is higher in those with microalbuminuria and correlates with albuminuria, support uIV as an indicator of diabetic nephropathy. Whether the increased uIV excretion would predict the impending renal failure needs further confirmation.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  7. Development of a dry-reagent-based nucleic acid-sensing platform by coupling thermostabilised LATE-PCR assay to an oligonucleotide-modified lateral flow biosensor
    Ang GY, Yu CY, Chan KG, Singh KK, Chan Yean Y
    J Microbiol Methods, 2015 Nov;118:99-105.
    PMID: 26342435 DOI: 10.1016/j.mimet.2015.08.024
    In this study, we report for the first time the development of a dry-reagent-based nucleic acid-sensing platform by combining a thermostabilised linear-after-the-exponential (LATE)-PCR assay with a one-step, hybridisation-based nucleic acid lateral flow biosensor. The nucleic acid-sensing platform was designed to overcome the need for stringent temperature control during transportation or storage of reagents and reduces the dependency on skilled personnel by decreasing the overall assay complexity and hands-on time. The platform was developed using toxigenic Vibrio cholerae as the model organism due to the bacterium's propensity to cause epidemic and pandemic cholera. The biosensor generates result which can be visualised with the naked eyes and the limit of detection was found to be 1pg of pure genomic DNA and 10CFU/ml of toxigenic V. cholerae. The dry-reagent-based nucleic acid-sensing platform was challenged with 95 toxigenic V. cholerae, 7 non-toxigenic V. cholerae and 66 other bacterial strains in spiked stool sample and complete agreement was observed when the results were compared to that of monosialoganglioside (GM1)-ELISA. Heat-stability of the thermostabilised LATE-PCR reaction mixes at different storage temperatures (4-56°C) was investigated for up to 90days. The dry-reagent-based genosensing platform with ready-to-use assay components provides an alternative method for sequence-specific detection of nucleic acid without any cold chain restriction that is associated with conventional molecular amplification techniques.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  8. Fulltext Toxoplasma infection in pregnant women: a current status in Songklanagarind hospital, southern Thailand
    Andiappan H, Nissapatorn V, Sawangjaroen N, Chemoh W, Lau YL, Kumar T, et al.
    Parasit Vectors, 2014;7:239.
    PMID: 24886651 DOI: 10.1186/1756-3305-7-239
    Toxoplasmosis, being one of the TORCH's infections in pregnant women, is caused by Toxoplasma gondii, an obligate intracellular protozoan parasite. This parasitic infection in pregnancy congenitally causes severe outcomes to their fetus and newborn. This study aimed to determine the seroprevalence and stages of Toxoplasma infection in pregnant women and its associated risks exposures.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  9. Fulltext Oral immunization of a non-recombinant Lactococcus lactis surface displaying influenza hemagglutinin 1 (HA1) induces mucosal immunity in mice
    Jee PF, Tiong V, Shu MH, Khoo JJ, Wong WF, Abdul Rahim R, et al.
    PLoS One, 2017;12(11):e0187718.
    PMID: 29108012 DOI: 10.1371/journal.pone.0187718
    Mucosal immunization of influenza vaccine is potentially an effective approach for the prevention and control of influenza. The objective of the present study was to evaluate the ability of oral immunization with a non-recombinant Lactococcus lactis displaying HA1/L/AcmA recombinant protein, LL-HA1/L/AcmA, to induce mucosal immune responses and to accord protection against influenza virus infection in mice. The LL-HA1/L/AcmA was orally administered into mice and the immune response was evaluated. Mice immunized with LL-HA1/L/AcmA developed detectable specific sIgA in faecal extract, small intestine wash, BAL fluid and nasal fluid. The results obtained demonstrated that oral immunization of mice with LL-HA1/L/AcmA elicited mucosal immunity in both the gastrointestinal tract and the respiratory tract. The protective efficacy of LL-HA1/L/AcmA in immunized mice against a lethal dose challenge with influenza virus was also assessed. Upon challenge, the non-immunized group of mice showed high susceptibility to influenza virus infection. In contrast, 7/8 of mice orally immunized with LL-HA1/L/AcmA survived. In conclusion, oral administration of LL-HA1/L/AcmA in mice induced mucosal immunity and most importantly, provided protection against lethal influenza virus challenge. These results highlight the potential application of L. lactis as a platform for delivery of influenza virus vaccine.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  10. High occurrence of in vitro apoptosis of lymphocytes induced by serum from systemic lupus erythematosus patients is associated with increased serum levels of anti-C1q autoantibodies
    Hasan SI, Mohd Ashari NS, Mohd Daud K, Che Husin CM
    Int J Rheum Dis, 2013 Aug;16(4):430-6.
    PMID: 23992264 DOI: 10.1111/1756-185X.12062
    BACKGROUND: The ethiopathogenesis of increased apoptosis of lymphocytes in systemic lupus erythematosus (SLE) is still incompletely understood but anti-C1q autoantibodies have been shown to induce apoptosis in lymphocytes from healthy donors and certain cell lines.
    AIM: This study was undertaken to investigate the relationship between peripheral lymphocyte apoptosis and serum levels of anti-C1q autoantibodies in SLE patients.
    METHODS: The sera of 124 patients with SLE involving 62 active SLE and 62 inactive SLE, fulfilling America College of Rheumatology (ACR) classification criteria for SLE (1997) were incubated with peripheral blood lymphocytes of healthy donors. The results were compared with 124 sex- and age-matched normal controls. Apoptotic lymphocytes (AL) were detected by flow cytometry using annexin V and propidium iodide binding. Anti-C1q autoantibodies were detected by an enzyme-linked immunoassay kit for all SLE patients.
    RESULTS: Results demonstrated that the percentage of AL in the peripheral blood of active SLE patients was significantly higher (n = 62, 34.95 ± 12.78%) than that of the inactive SLE patients (n = 62, 30.69 ± 10.13%, P = 0.042, 95%CI = 0.16-8.36) and normal controls (n = 124, 27.92 ± 10.22%, P = 0.001, 95%CI = 3.33-10.73). The percentage of AL significantly correlated with serum levels of anti-C1q autoantibodies in the active SLE patients (r = 0.263, P = 0.039) but not in the inactive SLE patients (r = 0.170, P = 0.185).
    CONCLUSION: The results of this study suggest that increased serum levels of anti-C1q autoantibodies are responsible for apoptosis and may play a pathogenic role in SLE patients, especially in active disease.
    KEYWORDS: anti-C1q; apoptosis; flowcytometry; systemic lupus erythematosus
    Study site: Medical outpatient clinic and medical wards, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  11. Fulltext Association of anti-CLIC2 and anti-HMGB1 autoantibodies with higher disease activity in systemic lupus erythematosus patients
    Syahidatulamali CS, Wan Syamimee WG, Azwany YN, Wong KK, Che Maraina CH
    J Postgrad Med, 2017 9 2;63(4):257-261.
    PMID: 28862243 DOI: 10.4103/jpgm.JPGM_499_16
    BACKGROUND: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by numerous autoantibodies. In this study, we investigated the presence of anti-chloride intracellular channel 2 (anti-CLIC2) and anti-high mobility group box 1 (anti-HMGB1) autoantibodies in SLE patients (n = 43) versus healthy controls ([HCs] n = 43), and their association with serological parameters (antinuclear antibody [ANA], anti-double-stranded DNA [anti-dsDNA], and C-reactive protein [CRP]) and disease activity using Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score (active or inactive).

    SETTINGS AND DESIGN: Case-control study at Rheumatology Clinic of Universiti Sains Malaysia Hospital.

    SUBJECTS AND METHODS: The sera of SLE patients and HCs were tested for the presence of anti-CLIC2 and anti-HMGB1 autoantibodies using human recombinant proteins and ELISA methodologies. Other serological parameters were evaluated according to routine procedures, and patients' demographic and clinical data were obtained.

    STATISTICAL ANALYSIS: Mann-Whitney U-test, Chi-square test, Fisher's exact test, and receiver operating characteristic analysis.

    RESULTS: Anti-CLIC2 autoantibody levels were significantly higher in SLE patients compared to HCs (P = 0.0035), whereas anti-HMGB1 autoantibody levels were not significantly elevated (P = 0.7702). Anti-CLIC2 and anti-HMGB1 autoantibody levels were not associated with ANA pattern, anti-dsDNA, and CRP. Interestingly, SLEDAI score (≥6) was associated with anti-CLIC2 (P = 0.0046) and with anti-HMGB1 (P = 0.0091) autoantibody levels.

    CONCLUSION: Our findings support the potential of using anti-CLIC2 autoantibodies as a novel biomarker for SLE patients. Both anti-CLIC2 and anti-HMGB1 autoantibody levels demonstrated potential in monitoring SLE disease activity.

    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay/methods
  12. Fulltext Telomerase activation in neoplastic cell immortalization and tumour progression
    Looi LM, Ng MH, Cheah PL
    Malays J Pathol, 2007 Jun;29(1):33-5.
    PMID: 19105326 MyJurnal
    The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  13. Generation and characterization of a high-affinity monoclonal antibody for MUC1 measurement in breast cancer
    Hamid SS, Cheah SH
    Hybridoma (Larchmt), 2011 Apr;30(2):137-43.
    PMID: 21529286 DOI: 10.1089/hyb.2010.0091
    Breast mucin is secreted by breast tumor cells and serves as a marker for breast cancer. Thus, antibodies against breast mucin will be valuable in the development of immunotherapy and laboratory diagnostic tests. Monoclonal antibodies (MAbs) against breast cancer-associated antigen were generated and characterized. Balb/c mice were immunized with breast cancer-associated antigen CA15-3, and subsequently splenocytes from immunized mice were fused with myeloma cells. After fusion, culture supernatants from hybridomas surviving HAT medium were screened by enzyme-linked immunosorbent assay (ELISA). A total of eight hybridomas producing MAbs against breast cancer showed significant levels of antibody activity against CA15-3. Two selected stable hybridomas were adapted into CELLine CL 350 bioreactors, and the MAbs produced were characterized for their subclass, specificity, and affinity. The MAbs were of high specificity and affinity as shown by ELISA. The MAbs produced may represent a powerful tool and are considered promising reagents for use in diagnosis and detection of early stage of the disease.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  14. Fulltext Detection of Human Papillomavirus 16-Specific IgG and IgM Antibodies in Patient Sera: A Potential Indicator of Oral Squamous Cell Carcinoma Risk Factor
    Kerishnan JP, Gopinath SC, Kai SB, Tang TH, Ng HL, Rahman ZA, et al.
    Int J Med Sci, 2016;13(6):424-31.
    PMID: 27279791 DOI: 10.7150/ijms.14475
    The association between human papillomavirus type 16 (HPV16) and oral cancer has been widely reported. However, detecting anti-HPV antibodies in patient sera to determine risk for oral squamous cell carcinoma (OSCC) has not been well studied. In the present investigation, a total of 206 OSCC serum samples from the Malaysian Oral Cancer Database & Tissue Bank System, with 134 control serum samples, were analyzed by enzyme-linked immunosorbant assay (ELISA) to detect HPV16-specific IgG and IgM antibodies. In addition, nested PCR analysis using comprehensive consensus primers (PGMY09/11 and GP5(+)/6(+)) was used to confirm the presence of HPV. Furthermore, we have evaluated the association of various additional causal factors (e.g., smoking, alcohol consumption, and betel quid chewing) in HPV-infected OSCC patients. Statistical analysis of the Malaysian population indicated that OSCC was more prevalent in female Indian patients that practices betel quid chewing. ELISA revealed that HPV16 IgG, which demonstrates past exposure, could be detected in 197 (95.6%) OSCC patients and HPV16-specific IgM was found in a total of 42 (20.4%) OSCC patients, indicating current exposure. Taken together, our study suggest that HPV infection may play a significant role in OSCC (OR: 13.6; 95% CI: 3.89-47.51) and HPV16-specific IgG and IgM antibodies could represent a significant indicator of risk factors in OSCC patients.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  15. Identification of potential glycoprotein biomarkers in oral squamous cell carcinoma using sweet strategies
    Wong YL, Anand R, Yuen KM, Mustafa WMW, Abraham MT, Tay KK, et al.
    Glycoconj J, 2021 02;38(1):1-11.
    PMID: 33547992 DOI: 10.1007/s10719-021-09973-z
    The prevalence of oral squamous cell carcinoma (OSCC) is high in South and Southeast Asia regions. Most OSCC patients are detected at advanced stages low 5-year survival rates. Aberrant expression of glycosylated proteins was found to be associated with malignant transformation and cancer progression. Hence, identification of cancer-associated glycoproteins could be used as potential biomarkers that are beneficial for diagnosis or clinical management of patients. This study aims to identify the differentially expressed glycoproteins using lectin-based glycoproteomics approaches. Serum samples of 40 patients with OSCC, 10 patients with oral potentially malignant disorder (OPMD), and 10 healthy individuals as control group were subjected to two-dimensional gel electrophoresis (2-DE) coupled with lectin Concanavalin A and Jacalin that specifically bind to N- and O-glycosylated proteins, respectively. Five differentially expressed N- and O-glycoproteins with various potential glycosylation sites were identified, namely N-glycosylated α1-antitrypsin (AAT), α2-HS-glycoprotein (AHSG), apolipoprotein A-I (APOA1), and haptoglobin (HP); as well as O-glycosylated AHSG and clusterin (CLU). Among them, AAT and APOA1 were further validated using enzyme-linked immunosorbent assay (ELISA) (n = 120). It was found that AAT and APOA1 are significantly upregulated in OSCC and these glycoproteins are independent risk factors of OSCC. The clinical utility of AAT and APOA1 as potential biomarkers of OSCC is needed for further evaluation.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  16. Fulltext CD4+CD25hiCD127low regulatory T cells are increased in oral squamous cell carcinoma patients
    Lim KP, Chun NA, Ismail SM, Abraham MT, Yusoff MN, Zain RB, et al.
    PLoS One, 2014;9(8):e103975.
    PMID: 25153698 DOI: 10.1371/journal.pone.0103975
    Regulatory T cells (Tregs), a subset of CD4+ T cells plays a pivotal role in regulating the immune system. An increase in Treg numbers enables cancer progression by dampening the immune system and allowing tumor cells to evade immune detection and destruction. An increase in Treg numbers and expression of inhibitory cytokines including TGF-β and IL-10 are mechanisms by which Tregs exert their immune suppressive function. However, the presence of Tregs and inhibitory cytokines in oral cancer patients is still unclear. In this study, the presence of circulating Tregs in 39 oral cancer patients and 24 healthy donors was examined by studying the presence of the CD4+CD25hiCD127low cell population in their peripheral blood mononuclear cells using flow cytometry. Serum levels of TGF-β and IL-10 were measured by ELISA. T cell subsets of OSCC patients were found to differ significantly from healthy donors where a decrease in CD8+ cytotoxic T cells and an increase in Tregs (CD4+CD25hiCD127low) were observed. Further, the ratio of CD8+ T cells/Tregs was also decreased in patients compared to healthy donors. The presence of Tregs was accompanied by a decrease in IL-10 but not TGF-β secretion in OSCC patients when compared to donors; in addition, the analysis also revealed that an increased presence of Tregs was accompanied by better patient survival. Amongst OSCC patients, smokers had significantly higher levels of TGF-β. It is apparent that the immune system is compromised in OSCC patients and the characterization of the Treg subpopulation could form a basis for improving our understanding of the perturbations in the immune system that occur during OSCC tumorigenesis.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  17. Fulltext An in-house ELISA method for quantification of circulating tissue factor
    Tay SP, Cheong SK
    Malays J Pathol, 2002 Jun;24(1):45-51.
    PMID: 16329555
    Tissue Factor (TF) is a low molecular weight transmembrane glycoprotein that initiates the clotting protease cascade. It is considered to be the principal regulator of the extrinsic coagulation pathway, hemostasis and thrombosis, as well as inflammation and cellular immune response. An in-house two-step direct sandwich ELISA (enzyme-linked immunosorbent assay) for immunological quantification of plasma TF was successfully developed. The assay employed a monoclonal antibody against human TF (1:400 dilution; 1250 ng/ml) and peroxidase-conjugated anti-TF IgG (1:1000 dilution; 2000 ng/ml) as capture and detecting antibodies respectively, whilst tetramethylbenzidine/H2O2 were utilized as substrates. Titration curves of recombinant TF were linear within 10 to 4000 pg/ml, with a detection limit of 36.31 pg/ml. It demonstrated low intra- (2.50 - 9.23 CV%) and inter-assays (5.65 - 13.57 CV%) variability, as well as satisfactory analytical recovery (91.55 - 103.95%) and good parallelism. The assay developed was intended to be applied for measurement of plasma TF levels in patients with thrombotic disorders.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay/methods*
  18. Fulltext Characterization of Der f 22 - a paralogue of the major allergen Der f 2
    Reginald K, Tan CL, Chen S, Yuen L, Goh SY, Chew FT
    Sci Rep, 2018 08 06;8(1):11743.
    PMID: 30082894 DOI: 10.1038/s41598-018-30224-z
    We previously identified an expressed sequence tag clone, Der f 22, showing 41% amino acid identity to published Der f 2, and show that both genes are possible paralogues. The objective of this study was to characterize the genomic, proteomic and immunological functions Der f 22 and Der f 2. The full-length sequence of Der f 2 and Der f 22 coded for mature proteins of 129 and 135 amino acids respectively, both containing 6 cysteine residues. Phylogenetic analysis of known group 2 allergens and their homologues from our expressed sequence tag library showed that Der f 22 is a paralogue of Der f 2. Both Der f 2 and Der f 22 were single gene products with one intron. Both allergens showed specific IgE-binding to over 40% of the atopic patients, with limited of cross-reactivity. Both allergens were detected at the gut region of D. farinae by immunostaining. Der f 22 is an important allergen with significant IgE reactivity among the atopic population, and should be considered in the diagnostic panel and evaluated as future hypoallergen vaccine therapeutic target.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  19. Early expression of local cytokines during systemic Candida albicans infection in a murine intravenous challenge model
    Chin VK, Foong KJ, Maha A, Rusliza B, Norhafizah M, Chong PP
    Biomed Rep, 2014 Nov;2(6):869-874.
    PMID: 25279161
    Local cytokine production is a significant indicator for disease pathogenesis or progression. Previous studies on cytokine production during systemic Candida albicans (C. albicans) infection were solely on kidney or single cell type interaction with C. albicans. Therefore, the present study aimed to assess the early cytokine expression of various target organs (kidney, spleen and brain) over a 72-h time course during systemic C. albicans infection. The local cytokine profiles of the target organs during systemic C. albicans infection were measured by cytometric bead array and ELISA analysis. The results demonstrated that interleukin-6 (IL-6) and IL-2 were statistically significant (P<0.05) in the spleen at 24 and 72 h post-infection, whereas in the kidney, IL-6 and tumor necrosis factor-α (TNF-α) were statistically significant (P<0.05) at 24 and 72 h post-infection and CXCL-1 and transforming growth factor-β (TGF-β) were statistically significant (P<0.05) at 72 h post-infection. In the brain, IL-6 and TNF-α were statistically significant (P<0.05) at 24 and 72 h post-infection, whereas TGF-β was statistically significant (P<0.05) at 72 h post-infection. These findings demonstrate that host immune responses were varied among target organs during systemic C. albicans infection. This could be important for designing targeted immunotherapy against this pathogen through immunomodulatory approaches in future exploratory research.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
  20. Fulltext Rodent Species Distribution and Hantavirus Seroprevalence in Residential and Forested areas of Sarawak, Malaysia
    Hamdan NE, Ng YL, Lee WB, Tan CS, Khan FA, Chong YL
    Trop Life Sci Res, 2017 Jan;28(1):151-159.
    PMID: 28228923 MyJurnal DOI: 10.21315/tlsr2017.28.1.11
    Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential (n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) (p < 0.001 of Zar-t test based on the Shannon index). Rattus rattus and Sundamys muelleri were present at high frequencies in both localities. An enzyme-linked immunosorbent assay (ELISA) showed that hantavirus-targeting antibodies were absent from 53 tested serum samples. This is the first report of hantavirus seroprevalence surveillance in rodent populations in Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia.
    Matched MeSH terms: Enzyme-Linked Immunosorbent Assay
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