Displaying publications 21 - 40 of 92 in total

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  1. Cross-reactive T-cell responses to the nonstructural regions of dengue viruses among dengue fever and dengue hemorrhagic fever patients in Malaysia
    Appanna R, Huat TL, See LL, Tan PL, Vadivelu J, Devi S
    Clin Vaccine Immunol, 2007 Aug;14(8):969-77.
    PMID: 17567768
    Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas in the world. Attempts to develop effective vaccines have been hampered by the lack of understanding of the pathogenesis of the disease and the absence of suitable experimental models for dengue viral infection. The magnitude of T-cell responses has been reported to correlate with dengue disease severity. Sixty Malaysian adults with dengue viral infections were investigated for their dengue virus-specific T-cell responses to 32 peptides antigens from the structural and nonstructural regions from a dengue virus isolate. Seventeen different peptides from the C, E, NS2B, NS3, NS4A, NS4B, and NS5 regions were found to evoke significant responses in a gamma interferon enzyme-linked immunospot (ELISPOT) assay of samples from 13 selected patients with dengue fever (DF) and dengue hemorrhagic fever (DHF). NS3 and predominantly NS3(422-431) were found to be important T-cell targets. The highest peaks of T-cell responses observed were in responses to NS3(422-431) and NS5(563-571) in DHF patients. We also found almost a sevenfold increase in T-cell response in three DHF patients compared to three DF patient responses to peptide NS3(422-431). A large number of patients' T cells also responded to the NS2B(97-106) region. The ELISPOT analyses also revealed high frequencies of T cells that recognize both serotype-specific and cross-reactive dengue virus antigens in patients with DHF.
    Matched MeSH terms: Cross Reactions
  2. Fulltext Evaluation of recombinant Plasmodium knowlesi merozoite surface protein-1(33) for detection of human malaria
    Cheong FW, Lau YL, Fong MY, Mahmud R
    Am J Trop Med Hyg, 2013 May;88(5):835-40.
    PMID: 23509118 DOI: 10.4269/ajtmh.12-0250
    Plasmodium knowlesi is now known as the fifth Plasmodium species that can cause human malaria. The Plasmodium merozoite surface protein (MSP) has been reported to be potential target for vaccination and diagnosis of malaria. MSP-1(33) has been shown to be immunogenic and its T cell epitopes could mediate cellular immune protection. However, limited studies have focused on P. knowlesi MSP-133. In this study, an approximately 28-kDa recombinant P. knowlesi MSP-1(33) (pkMSP-1(33)) was expressed by using an Escherichia coli system. The purified pkMSP-1(33) reacted with serum samples of patients infected with P. knowlesi (31 of 31, 100%) and non-P. knowlesi malaria (27 of 28, 96.43%) by Western blotting. The pkMSP-1(33) also reacted with P. knowlesi (25 of 31, 80.65%) and non-P. knowlesi malaria sera (20 of 28, 71.43%) in an enzyme-linked immunosorbent assay (ELISA). Most of the non-malarial infection (49 of 52 in by Western blotting and 46 of 52 in the ELISA) and healthy donor serum samples (65 of 65 by Western blotting and ELISA) did not react with recombinant pkMSP-1(33).
    Matched MeSH terms: Cross Reactions
  3. Immunological properties of Hypnale hypnale (hump-nosed pit viper) venom: antibody production with diagnostic and therapeutic potentials
    Tan CH, Tan NH, Sim SM, Fung SY, Gnanathasan CA
    Acta Trop, 2012 Jun;122(3):267-75.
    PMID: 22322247 DOI: 10.1016/j.actatropica.2012.01.016
    Envenomation by hump-nosed pit viper (Hypnale hypnale, Hh) in Sri Lanka has caused significant morbidity and mortality, attributed to 35% of total venomous snakebites. In Southwestern India (Kerala), H. hypnale was increasingly identified as a dangerous and common source of envenomation, second to the Russell's viper but ahead of the cobra bites. Unfortunately, there is still no specific antivenom to date. This study aims to investigate the immunological properties of the venom and to assess the feasibility of specific Hh antivenom production as well as the development of a diagnostic assay. Hh venom elicited satisfactory titers of anti-Hh IgG in rabbits after 3rd immunization. The anti-Hh IgG, isolated with caprylic acid precipitation method, was effective in neutralizing the venom lethality (potency=48 LD(50) per ml IgG) as well as its procoagulant, hemorrhagic and necrotic effects, indicating the possibility to produce the specific antivenom using the common immunization regime. Cross-reactivity studies using indirect ELISA showed that anti-Hh IgG cross-reacted extensively with several Asiatic crotalid venoms, particularly that of Calloselasma rhodostoma (73.6%), presumably due to the presence of venom antigens common to both snakes. Levels of immunological cross-reactivity were vastly reduced with double-sandwich ELISA. Further work demonstrated that the assay was able to distinguish and quantify venoms of H. hypnale, Daboia russelii and Echis carinatus sinhaleyus (three common local viperid) used to spike human sera at various concentrations. The assay hence may be a useful investigating tool for diagnosing biting species and studying the time course profile of venom concentrations in blood.
    Matched MeSH terms: Cross Reactions
  4. Fulltext Cellular immune responses to recurring influenza strains have limited boosting ability and limited cross-reactivity to other strains
    Keynan Y, Card CM, Ball BT, Li Y, Plummer FA, Fowke KR
    Clin Microbiol Infect, 2010 Aug;16(8):1179-86.
    PMID: 20670292 DOI: 10.1111/j.1469-0691.2010.03142.x
    Influenza vaccine provides protection against infection with matched strains, and this protection correlates with serum antibody titres. In addition to antibodies, influenza-specific CD8+ T-lymphocyte responses are important in decreasing disease severity and facilitating viral clearance. Because this response is directed at internal, relatively conserved antigens, it affords some cross-protection within a given subtype of influenza virus. With the possibility of a broader A(H1N1) Mexico outbreak in the fall of 2009, it appeared worthwhile studying the degree of cellular immune response-mediated cross-reactivity among influenza virus isolates. The composition of the 2006-2007 influenza vaccine included the A/New Caledonia/20/1999 strain (comprising a virus that has been circulating, and was included in vaccine preparations, for 6-7 years) and two strains not previously included (Wisconsin and Malaysia). This combination afforded us the opportunity to determine the degree of cross-reactive cellular immunity after exposure to new viral strains. We analysed the antibody responses and the phenotype and function of the T cell response to vaccine components. The results obtained show that antibody responses to A/New-Caledonia were already high and vaccination did not increase antibody or cytotoxic T lymphocyte responses. These data suggest that repeated exposure to the same influenza stain results in limited boosting of humoral and cellular immune responses.
    Matched MeSH terms: Cross Reactions
  5. Fulltext Broad reactive monoclonal antibodies for rapid identification of enteroviruses show cross-reactivity with chikungunya virus infected cells
    Khairul AH, Chem YK, Keniscope C, Rosli J, Hassan S, Mat J, et al.
    Malays J Pathol, 2010 Jun;32(1):49-52.
    PMID: 20614726 MyJurnal
    In the past decade, enterovirus 71 (EV71) and chikungunya (CHIK) virus have re-emerged periodically causing serious public health problems in Malaysia, since their first emergence in 1997 and 1998 respectively. This study demonstrates that CHIK virus causes similar patterns of cytopathic effect in cultured Vero cells as some enteroviruses. They also show positive cross-reaction on direct immunofluorescence staining using monoclonal antibodies meant for typing enteroviruses. Without adequate clinical and epidemiological information for correlation, CHIK virus isolated from patients with acute febrile rash can be wrongly reported as untypeable enterovirus due to its cross-reactivity with commercial pan-enterovirus monoclonal antibodies. This is due to the diagnostic laboratory being unaware of such cross-reactions as it has not been reported previously. Final identification of the virus could be determined with specific antibodies or molecular typing using specific oligonucleotide primers for the CHIK virus.
    Matched MeSH terms: Cross Reactions
  6. Antibody response to Helicobacter pylori excretory antigen and the cross reaction study
    Sasidharan S, Uyub AM
    J Immunoassay Immunochem, 2009;30(1):70-81.
    PMID: 19117203 DOI: 10.1080/15321810802569477
    Helicobacter pylori is recognized as a major case of gastritis and peptic ulcer and a key factor in the development of gastric cancer, gastric lymphoma, and non-ulcerative dyspepsia in man. The detection of antibodies specific for strains of H. pylori has demonstrated the value of serology for providing evidence of infection. The present study was conducted to detect the antigenic proteins of excretory antigen of H. pylori with Western blotting and examine whether anti-H. pylori IgG and IgA antibodies from H. pylori positive patients cross-react with antigens from other common bacterial pathogens. By using SDS-PAGE, 20 different proteins were found in the excretory antigen. By Western blotting and absorption studies, there were indications that anti-H. pylori IgA antibodies directed against 54 kDa, 50 kDa and 27 kDa cross-reacted with antigens from other bacteria, and that H. pylori proteins of 99 kDa, 88 kDa and 81 kDa possibly shared similar epitope with antigens of other pathogens not tested in the absorption studies. The cross-reactivity occurred in this study was not significantly affect the performance of the in-house ELISA.
    Matched MeSH terms: Cross Reactions
  7. Identification of the major allergens of Charybdis feriatus (red crab) and its cross-reactivity with Portunus pelagicus (blue crab)
    Misnan R, Murad S, Yadzir ZH, Abdullah N
    Asian Pac J Allergy Immunol, 2012 Dec;30(4):285-93.
    PMID: 23393908
    Tropomyosin and arginine kinase have been identified as the major allergens in multiple species of crab. Charybdis feriatus is an important commercial crab in this country.
    Matched MeSH terms: Cross Reactions
  8. Fulltext Laboratory detection of strongyloidiasis: IgG-, IgG4 - and IgE-ELISAs and cross-reactivity with lymphatic filariasis
    Norsyahida A, Riazi M, Sadjjadi SM, Muhammad Hafiznur Y, Low HC, Zeehaida M, et al.
    Parasite Immunol., 2013 May-Jun;35(5-6):174-9.
    PMID: 23448095 DOI: 10.1111/pim.12029
    Enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of IgG, IgG4 and IgE antibodies against Strongyloides stercoralis. A commercial ELISA (IVD Research, USA) was also used, and the sensitivities and specificities of the four assays were determined. Serum samples from 26 patients with S. stercoralis infection and 55 patients with other infections or no infection were analysed. Sensitivities of the IgG4 , IgG, IgE and IgG (IVD) assays were 76.9%, 84.6%, 7.7% and 84.6%, respectively, while the specificities were 92.7%, 81.8%, 100% and 83.6%, respectively. If filariasis samples were excluded, the specificities of the IgG4 -ELISA and both IgG-ELISAs increased to 100% and 98%, respectively. A significant positive correlation was observed between IgG- and IgG4 -ELISAs (r = 0.4828; P = 0.0125). IgG- and IgG- (IVD) ELISAs (r = 0.309) were positively correlated, but was not significant (P = 0.124). Meanwhile there was no correlation between IgG4 - and IgG- (IVD) ELISAs (r = 0.0042; P = 0.8294). Sera from brugian filariasis patients showed weak, positive correlation between the titres of antifilarial IgG4 and the optical densities of anti-Strongyloides IgG4 -ELISA (r = 0.4544, P = 0.0294). In conclusion, the detection of both anti-Strongyloides IgG4 and IgG antibodies could improve the serodiagnosis of human strongyloidiasis. Furthermore, patients from lymphatic filariasis endemic areas who are serologically diagnosed with strongyloidiasis should also be tested for filariasis.
    Matched MeSH terms: Cross Reactions
  9. Detection of Legionella pneumophila antigens in patients' sera using monoclonal antibodies
    Normaznah Y, Saniah K, Noor Rain A, Norazah A, Azizah MR, Sabiha P
    Malays J Pathol, 1998 Dec;20(2):95-8.
    PMID: 10879269
    Three monoclonal antibodies (McAb) were produced against soluble antigens of Legionella pneumophila serogroup 1 which was cultured on BCYE agar. The McAbs were all of the IgM isotype. The McAbs were used in the McAb-based ELISA for detection of circulating L. pneumophila antigens in 186 sera collected from patients with symptoms and signs suggestive of atypical pneumonia. The normal reference optical (OD) density value of each of the McAbs was determined using 44 sera collected from healthy blood donors. The antigen positivity rates for the McAbs 1C7.2B, 2B2.10F and 2B2.11E were 11.3%, 7.7% and 22.2% respectively. Antigen positivity of the McAb 2B2.10F was significantly higher in the younger age group (p < 0.05). There is no significant association between the antigen positivity with age and sex for all the McAbs. There was no cross-reaction demonstrated between the McAbs with other bacterial antigens.
    Matched MeSH terms: Cross Reactions
  10. Detection of Angiostrongylus malaysiensis circulating antigen using monoclonal antibody-based enzyme-linked immunosorbent assay (MAb-ELISA)
    Ambu S, Rain AN, Mak JW, Maslah D, Maidah S
    Southeast Asian J. Trop. Med. Public Health, 1997;28 Suppl 1:143-7.
    PMID: 9656366
    Three MAbs 1C4.2D8, 1C4.2C4 and 1C4.1F5 were produced using sonicated adult worm antigens of Angiostrongylus malaysiensis and they were found to be secreters of IgG1. The MAbs 1C4.2C4 and 1C4.2D8 were found to react with antigens of A. malaysiensis and cross-react with the closely related A. cantonensis but not with other helminths. A total of 108 human sera collected from Orang Asli (aborigenes) from Grik, in the State of Perak were tested for A. malaysiensis infection using the MAb-ELISA. MAb 1C4.1F5 and 25 (23%) were positive. Twenty of these positive samples were tested with the MAb 1C4.2D8 and none was found to be positive.
    Matched MeSH terms: Cross Reactions
  11. An extensive study of human IgE cross-reactivity of Blo t 5 and Der p 5
    Kuo IC, Cheong N, Trakultivakorn M, Lee BW, Chua KY
    J Allergy Clin Immunol, 2003 Mar;111(3):603-9.
    PMID: 12642844
    BACKGROUND: Dual sensitization by Blomia tropicalis and Dermatophagoides pteronyssinus mites is common in tropical and subtropical countries. The human IgE cross-reactivity between clinical important group 5 allergens, Blo t 5 and Der p 5, remains controversial.

    OBJECTIVE: This study was undertaken to assess the levels of the IgE cross-reactivity between Blo t 5 and Der p 5 by using sera from a large cohort of asthmatic children in subtropical and tropical countries.

    METHODS: Purified recombinant Blo t 5 and Der p 5 were produced in Pichia pastoris and tested against sera from 195 asthmatic children. The IgE cross-reactivity was examined by direct, inhibitory and competitive human IgE enzyme-linked immunosorbent assay as well as skin prick tests.

    RESULTS: The Blo t 5 IgE responses were 91.8% (134 of 146) and 73.5% (36 of 49) for Taiwanese and Malaysian sera, respectively. The Blo t 5 specific IgE titers were significantly higher than those of Der p 5 (P cross-reactivity was observed. This was further confirmed by the dose-response inhibition studies. Skin prick tests performed on asthmatic children in Thailand also showed differential IgE response to Blo t 5 and Der p 5.

    CONCLUSION: By using a large panel of asthmatic sera and a combination of in vitro and in vivo assays, the major allergen of B tropicalis in tropical and subtropical regions, Blo t 5, exhibits low levels of IgE cross-reactivity with homologous Der p 5. These findings suggest that highly specific clinical reagents are necessary for precise diagnosis and immunotherapeutic treatment of sensitization to group 5 mite allergens.

    Matched MeSH terms: Cross Reactions
  12. Fulltext Geographic distribution of Tick-borne encephalitis virus complex
    Im JH, Baek JH, Durey A, Kwon HY, Chung MH, Lee JS
    J Vector Borne Dis, 2020 1 1;57(1):14-22.
    PMID: 33818450 DOI: 10.4103/0972-9062.308794
    A comprehensive understanding of the geographic distribution of the tick-borne encephalitis virus (TBEV) complex is necessary due to increasing transboundary movement and cross-reactivity of serological tests. This review was conducted to identify the geographic distribution of the TBEV complex, including TBE virus, Alkhurma haemorrhagic fever virus, Kyasanur forest disease virus, louping-ill virus, Omsk haemorrhagic fever virus, and Powassan virus. Published reports were identified using PubMed, EMBASE, and the Cochrane library. In addition to TBEV complex case-related studies, seroprevalence studies were also retrieved to assess the risk of TBEV complex infection. Among 1406 search results, 314 articles met the inclusion criteria. The following countries, which are known to TBEV epidemic region, had conducted national surveillance studies: Austria, China, Czech, Denmark, Estonia, Finland, Germany, Hungary, Italy, Latvia, Norway, Poland, Romania, Russia, Switzerland, Sweden, Slovenia, and Slovakia. There were also studies/reports on human TBEV infection from Belarus, Bulgaria, Croatia, France, Japan, Kyrgyzstan, Netherland, and Turkey. Seroprevalence studies were found in some areas far from the TBEV belt, specifically Malaysia, Comoros, Djibouti, and Kenya. Kyasanur forest disease virus was reported in southwestern India and Yunnan of China, the Powassan virus in the United States, Canada, and east Siberia, Alkhurma haemorrhagic fever virus in Saudi Arabia and east Egypt, and Louping-ill virus in the United Kingdom, Ireland, and east Siberia. In some areas, the distribution of the TBEV complex overlaps with that of other viruses, and caution is recommended during serologic diagnosis. The geographic distribution of the TBEV complex appears to be wide and overlap of the TBE virus complex with other viruses was observed in some areas. Knowledge of the geographical distribution of the TBEV complex could help avoid cross-reactivity during the serologic diagnosis of these viruses. Surveillance studies can implement effective control measures according to the distribution pattern of these viruses.
    Matched MeSH terms: Cross Reactions
  13. Primary assessment of a T. spiralis putative serine protease for early serological detection of experimental trichinellosis
    Sun GG, Lei JJ, Guo KX, Liu RD, Long SR, Zhang X, et al.
    Trop Biomed, 2019 Sep 01;36(3):792-802.
    PMID: 33597500
    A putative serine protease of T. spiralis (TsSP) was expressed in Escherichia coli and its potential as a diagnostic antigen was primarily assessed in this study. Anti-Trichinella IgG in serum samples from T. spiralis different animal hosts (mice, rats, pigs and rabbits) were detected on Western blot analysis with rTsSP. Anti-Trichinella antibodies were detected in 100% (30/30) of experimentally infected mice by rTsSP-ELISA. Cross-reactions of rTsSPELISA were not found with sera from mice infected with other parasites (S. erinaceieuropaei, S. japonicum, C. sinensis, A. cantonensis and T. gondii) and sera from normal mice. There was no statistical difference in antibody detection rate among mice infected with the encapsulated Trichinella species (T. spiralis, T. nativa, T. britovi, and T. nelsoni) (P>0.05). The results of rTsSP-ELISA showed that serum specific antibody IgG in mice infected with 100 or 500 T. spiralis muscle larvae (ML) were detectable early at 7-8 dpi, but not detected by ML ES antigen-ELISA prior to 10-12 dpi. Specific anti-Trichinella IgG was detected in 100% (18/18) of infected pigs by rTsSP-ELISA and ES-ELISA, but no specific antibodies was not detected in 20 conventionally raised normal pigs by two antigens. The results showed the rTsSP had the potential for early serodiagnosis of animal Trichinella infection, however it requires to be assayed with early infection sera of swine infected with Trichinella and other parasites.
    Matched MeSH terms: Cross Reactions
  14. Protection against scrub typhus infection engendered by the passive transfer of immune sera
    Robinson DM, Huxsoll DL
    Southeast Asian J. Trop. Med. Public Health, 1975 Dec;6(4):477-82.
    PMID: 818716
    The passive transfer of convalescent sera did not protect the majority of mice against challenge with the homologous strain and was completely ineffective against challenge with strains unrelated by fluorescent antibody techniques. When the immune sera was incubated with the rickettsia in vitro and then inoculated into the mice a dramatic increase occurred in the number of surviving mice. The importance of these data in relation to published results with other species of rickettsia is discussed.
    Matched MeSH terms: Cross Reactions
  15. Validation of an enzyme-linked immunosorbent assay screening method and a liquid chromatography-tandem mass spectrometry confirmation method for the identification and quantification of ketamine and norketamine in urine samples from Malaysia
    Harun N, Anderson RA, Miller EI
    J Anal Toxicol, 2009 8 6;33(6):310-21.
    PMID: 19653934 DOI: 10.1093/jat/33.6.310
    An ELISA and a liquid chromatography-tandem mass spectrometry (LC-MS-MS) confirmation method were developed and validated for the identification and quantitation of ketamine and its major metabolite norketamine in urine samples. The Neogen ketamine microplate ELISA was optimized with respect to sample and enzyme conjugate volumes and the sample preincubation time before addition of the enzyme conjugate. The ELISA kit was validated to include an assessment of the dose-response curve, intra- and interday precision, limit of detection (LOD), and cross-reactivity. The sensitivity and specificity were calculated by comparison to the results from the validated LC-MS-MS confirmation method. An LC-MS-MS method was developed and validated with respect to LOD, lower limit of quantitation (LLOQ), linearity, recovery, intra- and interday precision, and matrix effects. The ELISA dose-response curve was a typical S-shaped binding curve, with a linear portion of the graph observed between 25 and 500 ng/mL for ketamine. The cross-reactivity of 200 ng/mL norketamine to ketamine was 2.1%, and no cross-reactivity was detected with 13 common drugs tested at 10,000 ng/mL. The ELISA LOD was calculated to be 5 ng/mL. Both intra- (n = 10) and interday (n = 50) precisions were below 5.0% at 25 ng/mL. The LOD for ketamine and norketamine was calculated statistically to be 0.6 ng/mL. The LLOQ values were also calculated statistically and were 1.9 ng/mL and 2.1 ng/mL for ketamine and norketamine, respectively. The test linearity was 0-1200 ng/mL with correlation coefficient (R(2)) > 0.99 for both analytes. Recoveries at 50, 500, and 1000 ng/mL range from 97.9% to 113.3%. Intra- (n = 5) and interday (n = 25) precisions between extracts for ketamine and norketamine were excellent (< 10%). Matrix effects analysis showed an average ion suppression of 5.7% for ketamine and an average ion enhancement of 13.0% for norketamine for urine samples collected from six individuals. A comparison of ELISA and LC-MS-MS results demonstrated a sensitivity, specificity, and efficiency of 100%. These results indicated that a cutoff value of 25 ng/mL ketamine in the ELISA screen is particularly suitable and reliable for urine testing in a forensic toxicology setting. Furthermore, both ketamine and norketamine were detected in all 34 urine samples collected from individuals socializing in pubs by the Royal Malaysian Police. Ketamine concentrations detected by LC-MS-MS ranged from 22 to 31,670 ng/mL, and norketamine concentrations ranged from 25 to 10,990 ng/mL. The concentrations of ketamine and norketamine detected in the samples are most ikely indicative of ketamine abuse.
    Matched MeSH terms: Cross Reactions
  16. Fulltext Blo t 2: Group 2 allergen from the dust mite Blomia tropicalis
    Reginald K, Pang SL, Chew FT
    Sci Rep, 2019 Aug 22;9(1):12239.
    PMID: 31439916 DOI: 10.1038/s41598-019-48688-y
    Blomia tropicalis has been recognized as a cause of allergic diseases in the tropical and subtropical regions. Here we report the immuno-characterization of its group 2 allergen, Blo t 2. Allergen Blo t 2 was amplified from the cDNA of B. tropicalis using degenerate primers, expressed in Escherichia coli as a recombinant protein and purified to homogeneity. The mature protein of Blo t 2 was 126 amino acids long with 52% sequence identity to Der p 2 and apparent molecular mass of 15 kDa. Circular dichroism spectroscopy showed that Blo t 2 is mainly a beta-sheeted protein. We confirmed the presence of three disulfide bonds in recombinant (r) Blo t 2 protein using electrospray mass spectrometry. Thirty-four percent of dust-mite allergic individuals from the Singapore showed specific IgE binding to rBlo t 2 as tested using immuno dot-blots. IgE-cross reactivity assays showed that Blo t 2 had between 20-50% of unique IgE-epitopes compared to Der p 2. IgE binding of native and recombinant forms of Blo t 2 were highly concordant (r2 = 0.77, p 
    Matched MeSH terms: Cross Reactions
  17. A filtration-based rapid test using a partially purified third-stage larval antigen to detect specific antibodies for the diagnosis of gnathostomiasis
    Ma A, Wang Y, Liu XL, Zhang HM, Eamsobhana P, Yong HS, et al.
    J Helminthol, 2019 Jan;93(1):26-32.
    PMID: 29144215 DOI: 10.1017/S0022149X17001080
    Human gnathostomiasis is an emerging food-borne parasitic disease caused by nematodes of the genus Gnathostoma. Currently, serological tests are commonly applied to support clinical diagnosis. In the present study, a simple and rapid filtration-based test, dot immune-gold filtration assay (DIGFA) was developed using a partially purified antigen of Gnathostoma third-stage larvae (L3). A total of 180 serum samples were tested to evaluate the diagnostic potential of DIGFA for gnathostomiasis. The diagnostic sensitivity and specificity were 96.7% (29/30) and 100% (25/25), respectively. The cross-reactivity with sera from other helminthiasis patients ranged from 0 to 4%, with an average of 1.6% (2/125). DIGFA using a partially purified L3 antigen was not only simple and rapid, but also more accurate than standard assays for the diagnosis of human gnathostomiasis. DIGFA may represent a promising tool for application in laboratories or in the field, without requiring any instrumentation.
    Matched MeSH terms: Cross Reactions
  18. Immunofluorescence-based biosensor for the determination of dengue virus NS1 in clinical samples
    Darwish NT, Sekaran SD, Alias Y, Khor SM
    J Pharm Biomed Anal, 2018 Feb 05;149:591-602.
    PMID: 29197806 DOI: 10.1016/j.jpba.2017.11.064
    The sharp increase in incidence of dengue infection has necessitated the development of methods for the rapid diagnosis of this deadly disease. Here we report the design and development of a reliable, sensitive, and specific optical immunosensor for the detection of the dengue nonstructural protein 1 (NS1) biomarker in clinical samples obtained during early stages of infection. The present optical NS1 immunosensor comprises a biosensing surface consisting of specific monoclonal NS1 antibody for immunofluorescence-based NS1 antigen determination using fluorescein isothiocyanate (FITC) conjugated to IgG antibody. The linear range of the optical immunosensor was from 15-500ngmL-1, with coefficient of determination (R2) of 0.92, high reproducibility (the relative standard deviation obtained was 2%), good stability for 21days at 4°C, and low detection limit (LOD) at 15ngmL-1. Furthermore, the optical immunosensor was capable of detecting NS1 analytes in plasma specimens from patients infected with the dengue virus, with low cross-reaction with plasma specimens containing the Japanese encephalitis virus (JEV) and Zika virus. No studies have been performed on the reproducibility and cross-reactivity regarding NS1 specificity, which is thus a limitation for optical NS1 immunosensors. In contrast, the present study addressed these limitations carefully where these two important experiments were conducted to showcase the robustness of our newly developed optical-based fluorescence immunosensor, which can be practically used for direct NS1 determination in any untreated clinical sample.
    Matched MeSH terms: Cross Reactions/immunology
  19. Limited diagnostic value of two commercial rapid tests for acute leptospirosis detection in Malaysia
    Chang CH, Riazi M, Yunus MH, Osman S, Noordin R
    Diagn Microbiol Infect Dis, 2014 Dec;80(4):278-81.
    PMID: 25241641 DOI: 10.1016/j.diagmicrobio.2014.08.012
    This study evaluated 2 rapid leptospirosis serological tests, Leptorapide® (Linnodee, Northern Ireland) and VISITECT®-LEPTO (Omega Diagnostics, Scotland, UK), which are commonly used in Malaysia. A total of 183 samples comprised 113 sera from leptospirosis patients, and 70 sera from other infections and healthy controls were used. The leptospirosis sera were grouped into 2 serum panels, i.e., Group I (MAT+, PCR+) and Group II (MAT+). When inconclusive results were interpreted as positives, both tests showed lower diagnostic sensitivities (≤ 34%) with Group I sera, as compared to Group II sera (Leptorapide®, 93%; VISITECT®-LEPTO, 40%). When inconclusive results were interpreted as negatives, the 2 tests showed ~20% sensitivity with both serum panels. The diagnostic specificity of VISITECT®-LEPTO (94%) was superior to Leptorapide® (69%). Since both tests had misdiagnosed a large proportion of Group I patients and showed many inconclusive results among Group II patients, they have limited diagnostic value in detecting acute leptospirosis.
    Matched MeSH terms: Cross Reactions
  20. A mouse IgM monoclonal antibody recognizes breast and colon cancer
    Bakar AF, Alitheen NB, Keong YS, Hamid M, Ali SA, Ali AM
    Hybridoma (Larchmt), 2009 Jun;28(3):199-203.
    PMID: 19519247 DOI: 10.1089/hyb.2007.0531
    Hybridoma clone C3A8, which is a fusion product between splenic lymphocytes of Balb/c mice immunized with MCF7 breast carcinoma cells and SP2/0 myelomas, was produced and characterized. A stable clone that secreted IgM monoclonal antibody (MAb) with kappa light chain was obtained through limiting dilutions. Cell-ELISA screening, flow cytometry analysis, and immunofluorescence staining revealed that the MAb C3A8 had bound specifically and strongly to MCF7 and HT29 but cross reacted weakly or not on HeLa cell line. The MAb C3A8 reacted positively with paraffin-embedded tissues of human breast and colon cancers but there were no positive reactions on normal tissues. Western blot analysis showed the MAb recognized a 55 kDa protein, which was present in the extract of MCF7 and HT29 cell lines. Our results demonstrated that MAb C3A8 could be used for basic and clinical research of breast and colon cancers.
    Matched MeSH terms: Cross Reactions
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