Displaying publications 441 - 460 of 1059 in total

Abstract:
Sort:
  1. Refsum E, Mörtberg A, Dahl J, Meinke S, Auvinen MK, Westgren M, et al.
    Transfus Med, 2017 Feb;27(1):43-51.
    PMID: 27862486 DOI: 10.1111/tme.12375
    OBJECTIVES: To investigate the specificities and level of HLA class I antibodies in selected cases referred for suspected foetal and neonatal alloimmune thrombocytopenia (FNAIT).

    BACKGROUND: FNAIT occurs in 1 : 1-2000 live births, whereas maternal immunisation against human leukocyte antigen (HLA) class I is common. Whether HLA class I antibodies alone can cause FNAIT is debatable.

    MATERIAL AND METHODS: A total of 260 patient samples were referred between 2007 and 2012. Referrals with maternal HLA class I antibodies and no other cause for the neonatal thrombocytopenia were included for analysis (cases, n = 23). HPA-1a negative mothers were excluded. Control groups were screened positive mothers of healthy neonates (controls, n = 33) and female blood donors (blood donors, n = 19). LABScreen single antigen HLA class I beads was used for antibody analysis. Clinical records were reviewed for cases.

    RESULTS: All groups had broad antibody reactivity. Cases had more antibodies with high SFI levels compared with the controls (SFI>9999; medians 26, 6 and 0; P 

    Matched MeSH terms: Histocompatibility Antigens Class I*
  2. Habib A, Azize NA, Yakob Y, Md Yunus Z, Wee TK
    Malays J Pathol, 2016 Dec;38(3):305-310.
    PMID: 28028301 MyJurnal
    Lysinuric protein intolerance (LPI) is an inborn error of dibasic amino acid transport due to a defect in the dibasic amino acid transporter in the renal and intestine and has a heterogenous presentation. Three Malaysian patients with LPI were studied and their biochemical and molecular findings compared. There were differences and similarities in the biochemical and molecular findings. Molecular analysis of SLC7A7 gene revealed a novel mutation c.235G>A; p.(Gly79Arg) in exon three in Patient 1 and a mutation c.1417C>T; p.(Arg473*) in exon 10 in patient 2 and 3. The degree of concentration of dibasic amino acids may determine the type of disease of the cell membrane transport, however, a positive molecular confirmation will secure the diagnosis.
    Matched MeSH terms: Antigens, CD98 Light Chains/genetics*
  3. Mehdi WA, Mehde AA, Raus RA, Yusof F, Abidin ZAZ, Ghazali H, et al.
    Int J Biol Macromol, 2018 Oct 15;118(Pt A):610-616.
    PMID: 29959006 DOI: 10.1016/j.ijbiomac.2018.06.113
    BACKGROUND: It is assumed that genetic factors play crucial role in nephrolithiasis. The present study was conducted to explore the role of Human Transcription Factor-7 like-2 (TCF7L2) β-defensin (DEFB1) and CD14 gene polymorphism in development and progression of nephrolithiasis.

    METHODS: The genotypes of TCF7L2, DEFB1 and CD14 polymorphism were determined in 240 nephrolithiasis patients and 240 healthy controls by restriction digestion method of PCR. The levels of serum TCF7L2, DEFB1, CD14, uric acid and other biochemical parameters were measured both in nephrolithiasis patients and healthy control.

    RESULTS: The patients and control groups showed 30% and 50% 1654 AA DEFB1 genotype respectively. The Allele frequency in case of patient's group was 63.67% while in control group it was 36.33%. The mean serum DEFB1 levels of the patients and control groups attained were 115.66 and 239.43 pg/mL respectively. The allele frequency of TCF7L2 in patients and controls were 44.17% and 70.0% for C-allele, 55.83% and 30.00% for T-allele respectively. The mean of serum TCF7L2 levels were significantly decreased in patients compared to control group.

    CONCLUSIONS: The present findings are first of its class that validates a considerable connection of DEFB1 and TCF7L2 gene polymorphisms with nephrolithiasis and could probably act as indicators to estimate the risk associated to nephrolithiasis.

    Matched MeSH terms: Antigens, CD14/genetics*
  4. Muh F, Lee SK, Hoque MR, Han JH, Park JH, Firdaus ER, et al.
    Malar J, 2018 Jul 27;17(1):272.
    PMID: 30049277 DOI: 10.1186/s12936-018-2420-4
    BACKGROUND: The rapid process of malaria erythrocyte invasion involves ligand-receptor interactions. Inducing antibodies against specific ligands or receptors that abrogate the invasion process is a key challenge for blood stage vaccine development. However, few candidates were reported and remain to be validated for the discovery of new vaccine candidates in Plasmodium knowlesi.

    METHODS: In order to investigate the efficacy of pre-clinical vaccine candidates in P. knowlesi-infected human cases, this study describes an in vitro invasion inhibition assay, using a P. knowlesi strain adapted to in vitro growth in human erythrocytes, PkA1-H.1. Recombinant proteins of P. knowlesi Duffy binding protein alpha (PkDBPα) and apical membrane antigen 1 (PkAMA1) were produced in Escherichia coli system and rabbit antibodies were generated from immune animals.

    RESULTS: PkDBPα and PkAMA1 recombinant proteins were expressed as insoluble and produced as a functional refolded form for this study. Antibodies against PkDBPα and PkAMA1 specifically recognized recombinant proteins and native parasite proteins in schizont-stage parasites on the merozoite organelles. Single and combination of anti-PkDBPα and anti-PkAMA1 antibodies elicited strong growth inhibitory effects on the parasite in concentration-dependent manner. Meanwhile, IgG prevalence of PkDBPα and PkAMA1 were observed in 13.0 and 46.7% in human clinical patients, respectively.

    CONCLUSION: These data provide support for the validation of in vitro growth inhibition assay using antibodies of DBPα and AMA1 in human-adapted P. knowlesi parasite PkA1-H.1 strain.

    Matched MeSH terms: Antigens, Protozoan/immunology*
  5. Ali AO, Stear A, Fairlie-Clarke K, Brujeni GN, Isa NM, Salisi MS, et al.
    Immunogenetics, 2017 03;69(3):157-163.
    PMID: 27921144 DOI: 10.1007/s00251-016-0962-6
    Understanding the structure of the major histocompatibility complex, especially the number and frequency of alleles, loci and haplotypes, is crucial for efficient investigation of the way in which the MHC influences susceptibility to disease. Nematode infection is one of the most important diseases suffered by sheep, and the class II region has been repeatedly associated with differences in susceptibility and resistance to infection. Texel sheep are widely used in many different countries and are relatively resistant to infection. This study determined the number and frequency of MHC class II genes in a small flock of Texel sheep. There were 18 alleles at DRB1, 9 alleles at DQA1, 13 alleles at DQB1, 8 alleles at DQA2 and 16 alleles at DQB2. Several haplotypes had no detectable gene products at DQA1, DQB1 or DQB2, and these were defined as null alleles. Despite the large numbers of alleles, there were only 21 distinct haplotypes in the population. The relatively small number of observed haplotypes will simplify finding disease associations because common haplotypes provide more statistical power but complicate the discrimination of causative mutations from linked marker loci.
    Matched MeSH terms: HLA Antigens/genetics*
  6. Maspi N, Ghaffarifar F, Sharifi Z, Dalimi A, Khademi SZ
    Malays J Pathol, 2017 Dec;39(3):267-275.
    PMID: 29279589
    Vaccination would be the most important strategy for the prevention and elimination of leishmaniasis. The aim of the present study was to compare the immune responses induced following DNA vaccination with LACK (Leishmania analogue of the receptor kinase C), TSA (Thiol-specific-antioxidant) genes alone or LACK-TSA fusion against cutaneous leishmaniasis (CL). Cellular and humoral immune responses were evaluated before and after challenge with Leishmania major (L. major). In addition, the mean lesion size was also measured from 3th week post-infection. All immunized mice showed a partial immunity characterized by higher interferon (IFN)-γ and Immunoglobulin G (IgG2a) levels compared to control groups (p<0.05). IFN-γ/ Interleukin (IL)-4 and IgG2a/IgG1 ratios demonstrated the highest IFN-γ and IgG2a levels in the group receiving LACK-TSA fusion. Mean lesion sizes reduced significantly in all immunized mice compared with control groups at 7th week post-infection (p<0.05). In addition, there was a significant reduction in mean lesion size of LACK-TSA and TSA groups than LACK group after challenge (p<0.05). In the present study, DNA immunization promoted Th1 immune response and confirmed the previous observations on immunogenicity of LACK and TSA antigens against CL. Furthermore, this study demonstrated that a bivalent vaccine can induce stronger immune responses and protection against infectious challenge with L. major.
    Matched MeSH terms: Antigens, Protozoan/immunology*
  7. Gounder SS, Abdullah BJJ, Radzuanb NEIBM, Zain FDBM, Sait NBM, Chua C, et al.
    Anal Cell Pathol (Amst), 2018;2018:7871814.
    PMID: 30175033 DOI: 10.1155/2018/7871814
    Age-associated changes in natural killer (NK) cell population, phenotype, and functions are directly attributed to the risk of several diseases and infections. It is predicted to be the major cause of the increase in mortality. Based on the surface density of CD56, NK cells are subdivided into two types, such as CD56bright and CD56dim cells, which represent cytokine production and cytotoxicity. In our study, we have examined the age-associated changes in the NK cell population and their subsets at different age groups of males and females (at a range from 41 to 80 years). We found that the total lymphocyte count significantly dropped upon aging in both genders. Although, the level of total immune cells also dropped on aging, and surprisingly the total NK cell population was remarkably increased with the majority of NK cells being CD56dim. Subsequently, we evaluated the proliferation potential of NK cells and our results showed that the NK cell proliferation ability declines with age. Overall, our findings prove that there is an increase in the circulating NK cell population upon aging. However, the proliferation rate upon aging declines when compared to the young age group (<41 yrs).
    Matched MeSH terms: Antigens, CD56/metabolism
  8. Syamila N, Syahir A, Ikeno S, Tan WS, Ahmad H, Ahmad Tajudin A
    Colloids Surf B Biointerfaces, 2020 Jan 01;185:110623.
    PMID: 31735420 DOI: 10.1016/j.colsurfb.2019.110623
    Bio-nanogate involves synthesized or natural molecules as a 'gate' towards bioreceptors and responds upon the presence of targeted analytes in nanoscale dimension. Development of bio-nanogate improves analyte selectivity and signal response across various types of biosensors. The versatility of PAMAM dendrimers to form conjugates with guest molecules, such as proteins can be utilized in forming a bio-nanogate. PAMAM interaction with peptide bioreceptor for antibody detection is of interest in this study. This study investigated the interaction of synthesized immunogenic 'a' determinant (aD) region of hepatitis B virus surface antigen (HBsAg) with PAMAM G4 and anti-HBsAg antibody, as a potential bio-nanogate for anti-HBsAg detection. The aD peptide fused with maltose binding protein (MBP), was confirmed with Western blotting. Nano-Differential Scanning Fluorimetry (nano-DSF) study revealed that the interaction of MBP-aD with anti-HBsAg indicated a higher thermal stability as compared to its interaction with PAMAM G4. Electrochemical impedance spectroscopy showed that a higher binding constant of MBP-aD interaction with anti-HBsAg (0.92 μM-1) was observed at maximum saturation, as compared with PAMAM G4 (0.07 μM-1). Thermodynamic parameters demonstrated that MBP-aD interacted with anti-HBsAg and PAMAM G4, through van der Waals and hydrogen bonding. These analyses suggest that the weak interaction of MBP-aD and PAMAM G4 may form a potential bio-nanogate. It is hypothesized that the presence of anti-HBsAg has a higher affinity towards MBP-aD which may displace PAMAM G4 in the anti-HBsAg detection system. This interaction study is crucial as an initial platform of using peptide-PAMAM as a bio-nanogate in an antibody detection system.
    Matched MeSH terms: Antigens, Surface/analysis*
  9. Fam SY, Chee CF, Yong CY, Ho KL, Mariatulqabtiah AR, Lau HY, et al.
    Int J Mol Sci, 2019 Oct 03;20(19).
    PMID: 31623310 DOI: 10.3390/ijms20194903
    Virus-like nanoparticles (VLNPs) have been studied extensively as nanocarriers for targeted drug delivery to cancer cells. However, VLNPs have intrinsic drawbacks, in particular, potential antigenicity and immunogenicity, which hamper their clinical applications. Thus, they can be eliminated easily and rapidly by host immune systems, rendering these nanoparticles ineffective for drug delivery. The aim of this study was to reduce the antigenicity of hepatitis B core antigen (HBcAg) VLNPs by shielding them with a hydrophilic polymer, poly(2-ethyl-2-oxazoline) (PEtOx). In the present study, an amine-functionalized PEtOx (PEtOx-NH2) was synthesized using the living cationic ring-opening polymerization (CROP) technique and covalently conjugated to HBcAg VLNPs via carboxyl groups. The PEtOx-conjugated HBcAg (PEtOx-HBcAg) VLNPs were characterized with dynamic light scattering and UV-visible spectroscopy. The colloidal stability study indicated that both HBcAg and PEtOx-HBcAg VLNPs maintained their particle size in Tris-buffered saline (TBS) at human body temperature (37 °C) for at least five days. Enzyme-linked immunosorbent assays (ELISA) demonstrated that the antigenicity of PEtOx-HBcAg VLNPs reduced significantly as compared with unconjugated HBcAg VLNPs. This novel conjugation approach provides a general platform for resolving the antigenicity of VLNPs, enabling them to be developed into a variety of nanovehicles for targeted drug delivery.
    Matched MeSH terms: Hepatitis B Core Antigens/chemistry
  10. Mustaffa-Kamal F, Liu H, Pedersen NC, Sparger EE
    BMC Vet Res, 2019 May 22;15(1):165.
    PMID: 31118053 DOI: 10.1186/s12917-019-1909-6
    BACKGROUND: Feline infectious peritonitis (FIP) is considered highly fatal in its naturally occurring form, although up to 36% of cats resist disease after experimental infection, suggesting that cats in nature may also resist development of FIP in the face of infection with FIP virus (FIPV). Previous experimental FIPV infection studies suggested a role for cell-mediated immunity in resistance to development of FIP. This experimental FIPV infection study in specific pathogen free (SPF) kittens describes longitudinal antiviral T cell responses and clinical outcomes ranging from rapid progression, slow progression, and resistance to disease.

    RESULTS: Differences in disease outcome provided an opportunity to investigate the role of T cell immunity to FIP determined by T cell subset proliferation after stimulation with different viral antigens. Reduced total white blood cell (WBC), lymphocyte and T cell counts in blood were observed during primary acute infection for all experimental groups including cats that survived without clinical FIP. Antiviral T cell responses during early primary infection were also similar between cats that developed FIP and cats remaining healthy. Recovery of antiviral T cell responses during the later phase of acute infection was observed in a subset of cats that survived longer or resisted disease compared to cats showing rapid disease progression. More robust T cell responses at terminal time points were observed in lymph nodes compared to blood in cats that developed FIP. Cats that survived primary infection were challenged a second time to pathogenic FIPV and tested for antiviral T cell responses over a four week period. Nine of ten rechallenged cats did not develop FIP or T cell depletion and all cats demonstrated antiviral T cell responses at multiple time points after rechallenge.

    CONCLUSIONS: In summary, definitive adaptive T cell responses predictive of disease outcome were not detected during the early phase of primary FIPV infection. However emergence of antiviral T cell responses after a second exposure to FIPV, implicated cellular immunity in the control of FIPV infection and disease progression. Virus host interactions during very early stages of FIPV infection warrant further investigation to elucidate host resistance to FIP.

    Matched MeSH terms: Antigens, Viral/immunology
  11. Law CT, Camacho F, Garcia-Alles LF, Gilleron M, Sarmiento ME, Norazmi MN, et al.
    Tuberculosis (Edinb), 2019 01;114:9-16.
    PMID: 30711162 DOI: 10.1016/j.tube.2018.11.002
    Tuberculosis (TB) is the main cause of mortality among all infectious diseases. The presentation of lipids by CD1b molecules and the interactions of the CD1b-lipid complexes with the immune receptors are important for the understanding of the immune response to Mycobacterium tuberculosis (Mtb), and to develop TB control methods. A specific domain antibody (dAbk11) recognizing the complex of CD1b with Mtb sulphoglycolipid (Ac2SGL) had been previously developed. In order to study the interactions of dAbk11 with Ac2SGL:CD1b, the conformation of Ac2SGL within CD1b was first modelled. The orientation of dAbκ11 with Ac2SGL:CD1b was then predicted by a docking experiment and the complex was sampled using molecular dynamics simulation. Data showed that dAbκ11 Tyr32 OH plays a decisive role in interacting with Ac2SGL alkyl tail HO17. The binding free energy calculation showed that Ac2SGL establish strong hydrophobic interactions with dAbκ11. The model also predicted a higher affinity for the natural sulfoglycolipid (Ac2SGL) than the synthetic analogue (SGL12), which was supported by the ELISA data. These results shed light on the likely mechanism of interactions between Ac2SGL:CD1b and dAbκ11, thus making possible to envision the strategies for dAbκ11 optimization for possible future applications.
    Matched MeSH terms: Antigens, CD1/immunology*
  12. Diosdado A, Simón F, Morchón R, González-Miguel J
    Parasit Vectors, 2020 Apr 20;13(1):203.
    PMID: 32312291 DOI: 10.1186/s13071-020-04067-5
    BACKGROUND: Ascaris roundworms are the parasitic nematodes responsible for causing human and porcine ascariasis. Whereas A. lumbricoides is the most common soil-transmitted helminth infecting humans in the world, A. suum causes important economic losses in the porcine industry. The latter has been proposed as a model for the study of A. lumbricoides since both species are closely related. The third larval stage of these parasites carries out an intriguing and complex hepatopulmonary route through the bloodstream of its hosts. This allows the interaction between larvae and the physiological mechanisms of the hosts circulatory system, such as the fibrinolytic system. Parasite migration has been widely linked to the activation of this system by pathogens that are able to bind plasminogen and enhance plasmin generation. Therefore, the aim of this study was to examine the interaction between the infective third larval stage of A. suum and the host fibrinolytic system as a model of the host-Ascaris spp. relationships.

    METHODS: Infective larvae were obtained after incubating and hatching fertile eggs of A. suum in order to extract their cuticle and excretory/secretory antigens. The ability of both extracts to bind and activate plasminogen, as well as promote plasmin generation were assayed by ELISA and western blot. The location of plasminogen binding on the larval surface was revealed by immunofluorescence. The plasminogen-binding proteins from both antigenic extracts were revealed by two-dimensional electrophoresis and plasminogen-ligand blotting, and identified by mass spectrometry.

    RESULTS: Cuticle and excretory/secretory antigens from infective larvae of A. suum were able to bind plasminogen and promote plasmin generation in the presence of plasminogen activators. Plasminogen binding was located on the larval surface. Twelve plasminogen-binding proteins were identified in both antigenic extracts.

    CONCLUSIONS: To the best of our knowledge, the present results showed for the first time, the pro-fibrinolytic potential of infective larvae of Ascaris spp., which suggests a novel parasite survival mechanism by facilitating the migration through host tissues.

    Matched MeSH terms: Antigens, Helminth/metabolism*
  13. Yunus MH, Arifin N, Balachandra D, Anuar NS, Noordin R
    Am J Trop Med Hyg, 2019 08;101(2):432-435.
    PMID: 31218996 DOI: 10.4269/ajtmh.19-0053
    The conventional method of detecting Strongyloides stercoralis in fecal samples has poor diagnostic sensitivity. Detection of Strongyloides-specific antibodies increases the sensitivity; however, most tests are ELISAs that use parasite extract which may cross-react with the sera of other helminth infections. To improve the serological diagnosis of strongyloidiasis, this study aimed at developing a sensitive and specific lateral flow rapid dipstick test. Two recombinant proteins, recombinant NIE (rNIE) and recombinant Ss1a (rSs1a), were used in preparing the dipstick, with gold-conjugated antihuman IgG4 as detector reagent. In parallel, the corresponding ELISA was performed. Both assays demonstrated diagnostic sensitivity of 91.3% (21/23) when tested with serum samples of patients with Strongyloides infection, and 100% specificity with 82 sera of asymptomatic (healthy) and those with other parasitic infections. The ELISA and dipstick test results were positively correlated to each other (r = 0.6114, P = 0.0019). The developed lateral flow dipstick test may improve the serodiagnosis of strongyloidiasis and merit further validation studies.
    Matched MeSH terms: Antigens, Helminth/immunology
  14. Muh F, Kim N, Nyunt MH, Firdaus ER, Han JH, Hoque MR, et al.
    PLoS Negl Trop Dis, 2020 06;14(6):e0008323.
    PMID: 32559186 DOI: 10.1371/journal.pntd.0008323
    Malaria is caused by multiple different species of protozoan parasites, and interventions in the pre-elimination phase can lead to drastic changes in the proportion of each species causing malaria. In endemic areas, cross-reactivity may play an important role in the protection and blocking transmission. Thus, successful control of one species could lead to an increase in other parasite species. A few studies have reported cross-reactivity producing cross-immunity, but the extent of cross-reactive, particularly between closely related species, is poorly understood. P. vivax and P. knowlesi are particularly closely related species causing malaria infections in SE Asia, and whilst P. vivax cases are in decline, zoonotic P. knowlesi infections are rising in some areas. In this study, the cross-species reactivity and growth inhibition activity of P. vivax blood-stage antigen-specific antibodies against P. knowlesi parasites were investigated. Bioinformatics analysis, immunofluorescence assay, western blotting, protein microarray, and growth inhibition assay were performed to investigate the cross-reactivity. P. vivax blood-stage antigen-specific antibodies recognized the molecules located on the surface or released from apical organelles of P. knowlesi merozoites. Recombinant P. vivax and P. knowlesi proteins were also recognized by P. knowlesi- and P. vivax-infected patient antibodies, respectively. Immunoglobulin G against P. vivax antigens from both immune animals and human malaria patients inhibited the erythrocyte invasion by P. knowlesi. This study demonstrates that there is extensive cross-reactivity between antibodies against P. vivax to P. knowlesi in the blood stage, and these antibodies can potently inhibit in vitro invasion, highlighting the potential cross-protective immunity in endemic areas.
    Matched MeSH terms: Antigens, Protozoan/immunology*
  15. Sheela DS, Chandramathi S, Suresh K
    Trop Biomed, 2020 Mar 01;37(1):210-217.
    PMID: 33612732
    Blastocystis sp. is an enteric protozoan parasite of humans and many animals. Blastocystis sp. subtype 3 (ST3) proves to be the highest frequency case in most populations around the world and it is further distinguished into symptomatic and asymptomatic isolates based on the clinical symptoms exhibited by infected individuals. Phenotypic and genotypic studies implicate the distinctiveness of this parasite which may describe its pathogenesis. However, the antigenic distinctiveness which describes the antibody mediated cell lysis of this parasite has not been explored. This study was aimed to identify the cross-reactivity and cytotoxicity effect between three isolates of symptomatic and asymptomatic Blastocystis sp. ST3 respectively. Antigen specificity and diversity of this parasite was performed by coculturing sera (10-fold dilution) obtained from mice immunised with Blastocystis sp. symptomatic and asymptomatic antigens and the respective Blastocystis sp. ST3 live cells through complement dependant cell cytotoxicity (CDC) assay. The results obtained has shown that, the sera (at 10-fold diluted concentration) from symptomatic and asymptomatic solubilised antigen immunised mice were able to specifically lyse the respective live parasites with an average percentage of 82% and 86% respectively. There were almost 50% crossreactivity observed between the three isolates of Blastocystis sp. ST3 from symptomatic and asymptomatic group proving high antigen diversity or rather low antigen specificity within the same group. However, there was only 17% cross-reactivity observed between the mice sera and parasitic cells of different groups (symptomatic vs asymptomatic isolates) suggesting high specificity between these two groups. We, for the first time have proven that through CDC analysis there were epitopes dissimilarities between Blastocystis sp. ST3 symptomatic and asymptomatic isolates which may allow the parasite to set up diverse immune modulations such as imbalanced Th1/Th2 responses in an infected host.
    Matched MeSH terms: Antigens, Protozoan/immunology*
  16. Vishalkumar P, Jayaprakash NS, Desai PK, Krishnan V, Vijayalakshmi MA
    Trop Biomed, 2020 Dec 01;37(4):1050-1061.
    PMID: 33612757 DOI: 10.47665/tb.37.4.1050
    OBJECTIVE: To evaluate the sensitivity and the stability of the monoclonal antibodies (Aa3c10, b10c1), against truncated Histidine-rich protein 2 (PfHRP2), developed using smart polymer, poly N-isopropylacrylamide, as adjuvant for malarial diagnostic applications in comparison with the available commercial antibodies.

    METHODS: Two hybridoma clones (Aa3c10, b10c1) were used for the production of ascites in BALB/c mice. Purification of monoclonal antibodies from the ascites was carried out using affinity columns. The thermal stability study of monoclonal antibodies was done by storing it at 37°C and 45°C for thirty days. The stored antibodies were analyzed using SDS-PAGE and flow-through device where the antigenantibody interaction was visualized by Protein A colloidal gold solution. Sensitivity was determined by endpoint dilution ELISA and the dissociation constant by competitive ELISA. Sensitive pair optimization was done by sandwich ELISA using biotinylated antibodies. Prototype preparation for lateral flow assay had a colloidal gold-based detection system.

    RESULTS: Thermal stability experiments showed that both mAbs (Aa3c10; b10c1) are stable up to thirty days at 45°C while the commercially available mAbs were stable up to fifteen days only. Compared to commercial antibodies, the mAb Aa3c10, showed the highest sensitivity in end-point titre. In sensitive pair optimization, it was observed that the mAb, b10c1, as a detector and the mAb, Aa3c10, as a capture antibody showed the highest absorbance to detect 50pg/ml PfHRP2 antigen. The prototype formulation of lateral flow assay using the mAbs (Aa3c10; b10c1) showed good reactivity with WHO panel and no false-positive results were observed with twenty clinically negative samples and five P. vivax positive samples.

    CONCLUSIONS: The novel monoclonal antibodies (Aa3c10, b10c1) against truncated PfHRP2, could be a strong potential candidates that can be included in making RDTs with better sensitivity and stability.

    Matched MeSH terms: Antigens, Protozoan/immunology*
  17. Wong XZ, Amirah A, Gan CC, Fatiha S, Maznah D, Yahya R, et al.
    Nephrology (Carlton), 2021 May;26(5):463-470.
    PMID: 33580732 DOI: 10.1111/nep.13862
    AIMS: In Malaysia, majority anti-HCV positive haemodialysis patients do not undergo hepatitis C confirmation due to the high cost of HCV RNA. HCV Core Antigen might be a cost-effective diagnostic test to identify HD patients who have active HCV infection eligible for Direct Acting Anti-viral therapy.

    METHODS: A cross-sectional study was conducted to assess the correlation between HCV Ag and HCV RNA and the cost implications of different diagnostic algorithms to diagnose active HCV infection using Anti-HCV, HCV Ag, and HCV RNA. Pre-dialysis blood was tested for both HCV Ag and HCV RNA. HCV Ag was tested with Abbott ARCHITECT HCV Ag test.

    RESULTS: Two-hundred twenty-seven haemodialysis patients were recruited from 20 centres with mean age of 57.68 ± 12.48 years, and male constitutes 56.8% (129) of the study population. HCV Ag correlated well with HCV RNA (Spearman test coefficient 0.943, p 

    Matched MeSH terms: Hepatitis B Core Antigens/blood*
  18. Lee M, Harrison BA, Lewis GE
    Am J Trop Med Hyg, 1990 Apr;42(4):314-9.
    PMID: 2184690 DOI: 10.4269/ajtmh.1990.42.314
    A modified version of the standard 2-site sporozoite enzyme-linked immunosorbent assay (ELISA) using 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate chromogen solution was adapted for rapid detection and identification of Plasmodium falciparum and P. vivax circumsporozoite (CS) proteins. The TMB-ELISA was evaluated using sporozoites from experimentally infected mosquitoes and laboratory colonized uninfected mosquitoes. Our data indicate comparable sensitivity levels between the TMB-ELISA and the standard ELISA, i.e., 50 P. falciparum or P. vivax sporozoites/50 microliters of test solution. Reactions inherent to the method were specific and background reactivity was minimal. The TMB-ELISA is rapid (1 hr), simple, uses a minimal amount of monoclonal antibodies, and is suitable for use in a wide range of laboratories.
    Matched MeSH terms: Antigens, Protozoan/analysis*
  19. Lim TS, LaBarre DD, Lewis GE
    Jpn. J. Med. Sci. Biol., 1988 Apr;41(2):57-68.
    PMID: 3149355 DOI: 10.7883/yoken1952.41.57
    The optimal conditions for the determination of exposure to scrub typhus by the whole blood lymphocyte transformation assay was 7 days culture of 10% blood in RPMI 1640 medium supplemented with 10% human AB-negative serum and L-glutamine with 50-200 micrograms protein/ml of Karp, Kato, or Gilliam strain membrane antigen. A simple exponentially decaying linear model shows the decrease in lymphocyte viability, the ability of sensitized cells to be stimulated with PHA mitogen, and the corresponding decrease in stimulation by scrub typhus antigens with increasing time of preincubation on ice. The lower limit of stimulation index for the detection of scrub typhus by whole blood lymphocyte transformation assay was 4.0 with a type I error of 1%.
    Matched MeSH terms: Antigens, Bacterial/immunology
  20. Chua KH, Puah SM, Chew CH, Tan SY, Lian LH
    Ann Hum Biol, 2010 Apr;37(2):274-80.
    PMID: 19951233 DOI: 10.3109/03014460903325185
    In this study, we investigated the polymorphisms of the exon 1 (+49A/G), promoter sites (-1722T/C, -1661A/G, -318C/T), and 3'-untranslated region (3'-UTR) (+6230 A/G) of the CTLA-4 gene in systemic lupus erythematosus (SLE) affected patients. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of these five markers in 130 SLE patients and 130 healthy controls. Of the five tested polymorphisms, there was no statistical significant difference between the genotypic and allelic frequencies of patients with SLE and controls. Hence, we propose that the CTLA-4 gene does not play a major role in the genetic susceptibility to the development of SLE in the Malaysian population.
    Matched MeSH terms: Antigens, CD/genetics*
Filters
Contact Us

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

External Links