Displaying publications 21 - 40 of 330 in total

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  1. Fulltext Different IVIG glycoforms affect in vitro inhibition of anti-ganglioside antibody-mediated complement deposition
    Sudo M, Yamaguchi Y, Späth PJ, Matsumoto-Morita K, Ong BK, Shahrizaila N, et al.
    PLoS One, 2014;9(9):e107772.
    PMID: 25259950 DOI: 10.1371/journal.pone.0107772
    Intravenous immunoglobulin (IVIG) is the first line treatment for Guillain-Barré syndrome and multifocal motor neuropathy, which are caused by anti-ganglioside antibody-mediated complement-dependent cytotoxicity. IVIG has many potential mechanisms of action, and sialylation of the IgG Fc portion reportedly has an anti-inflammatory effect in antibody-dependent cell-mediated cytotoxicity models. We investigated the effects of different IVIG glycoforms on the inhibition of antibody-mediated complement-dependent cytotoxicity. Deglycosylated, degalactosylated, galactosylated and sialylated IgG were prepared from IVIG following treatment with glycosidases and glycosyltransferases. Sera from patients with Guillain-Barré syndrome, Miller Fisher syndrome and multifocal motor neuropathy associated with anti-ganglioside antibodies were used. Inhibition of complement deposition subsequent to IgG or IgM autoantibody binding to ganglioside, GM1 or GQ1b was assessed on microtiter plates. Sialylated and galactosylated IVIGs more effectively inhibited C3 deposition than original IVIG or enzyme-treated IVIGs (agalactosylated and deglycosylated IVIGs). Therefore, sialylated and galactosylated IVIGs may be more effective than conventional IVIG in the treatment of complement-dependent autoimmune diseases.
    Matched MeSH terms: Immunoglobulin G/immunology; Immunoglobulin G/metabolism; Immunoglobulin G/pharmacology
  2. Immunological studies in Malaysian patients with rheumatoid arthritis
    Sivapatham G, Gong NC, Pang T
    ASEAN Journal of Clinical Sciences, 1982;3(4):329-33.
    Twenty-one patients with rheumatoid arthritis (RA) were investigated for various immunological parameters, both humoral and cellular. IgG concentration was 1673+/-266 mg/dl, IgM 259+/-108 mg/dl and IgA 302 +/-7 mg/dl. Enumeration of T lymphocytes in peripheral blood revealed a value of 66% with a B cell count of 10%. Additionally, IgG levels, in 5 selected patients, appeared to fall to normal levels in the course of treatament with D-penicillamine. The significance of these findings are discussed.
    Matched MeSH terms: Immunoglobulin G
  3. Fulltext Presence of both dengue specific Ns1 antigen and immunoglobulin m antibody in confirmed dengue patients in Kolkata
    Poddar, S., Hati, A.K., Pal, D., Bhattacharya, N., Mukim, Y.
    JUMMEC, 2018;21(2):10-14.
    MyJurnal
    Purpose: The object of this study was to identify patients with diagnosed dengue infection, who were positive
    for both dengue-specific NS1 antigen and IgM antibody.
    Method: From January 2013 to December 2016, in Central Kolkata in West Bengal in India, patients with
    symptoms of dengue infection, were sent to the laboratory by the physicians for confirmatory diagnosis of
    dengue infection. A total of 4762 patients were seen, and serum samples tested and distributed into seven
    panels, according to the investigations requested. 1436 patients were tested positive.
    Results: 1053 cases were tested for both NS1 and Ig M antibody, 835 for dengue-specific NS1 antigen, IgM and
    IgG antibodies and 218 for NS1 dengue-specific antigen and IgM antibody. Of these, dengue was confirmed in
    34.3 %, with 16.6% positive for both NS1 antigen and IgM antibody. Eleven were diagnosed, with late dengue
    infection, thirty-nine with late primary infections and ten with late secondary dengue infection.
    Conclusions: Many of the patients were reactive for both NS1 antigen and IgM antibody, and they required
    proper attention and strict vigilance with effective monitoring and treatment, not of early dengue infection,
    but of late dengue infection. Unless the serological tests for Ig M and IgG antibodies, and the dengue specific
    viral antigen NS1 are performed simultaneously, these types of cases would not all be detected.
    Matched MeSH terms: Immunoglobulin G
  4. A probable case of vaccine-induced immune thrombotic thrombocytopenia secondary to Pfizer Comirnaty COVID-19 vaccine
    Goh Cy C, Teng Keat C, Su Kien C, Ai Sim G
    J R Coll Physicians Edinb, 2022 Jun;52(2):113-116.
    PMID: 36146992 DOI: 10.1177/14782715221103660
    The accelerated development of various vaccines against COVID-19 was a global effort to curb the COVID-19 pandemic. As a result, several unique vaccine-related adverse events were observed. Vaccine-induced immune thrombotic thrombocytopenia (VITT) has been recognised as a clinically distinct entity with a predisposition for thrombosis at unusual sites with laboratory features of consumptive coagulopathy in addition to anti-PF4 assay seropositivity. The majority of cases reported were associated with adenoviral-based vectors such as ChAdOx1 nCoV-19 (Oxford-AstraZeneca) and Janssen Ad26.COV2.S (Johnson & Johnson). In our online search, we have not found any reports to date of VITT associated with Pfizer-BioNTech Comirnaty mRNA vaccine. We report a case of a previously healthy 76-year-old man who received his first-dose Pfizer Comirnaty vaccine on 11 October 2021 who developed left upper limb swelling on day 2 post-vaccination, which progressively worsened on day 4 post-vaccination. He was confirmed to have left axillary vein thrombosis on computer tomography arteriography/computed tomography venography of left upper limb on day 5 post-vaccination with new onset aphasia with unilateral limb weakness on day 8 post-vaccination. Magnetic resonance imaging/magnetic resonance angiography of the brain confirmed acute left middle cerebral artery thrombosis with infarction. Blood investigations showed thrombocytopenia, elevated D-dimer, hypofibrinogenemia in addition to his unusual sites of thrombosis involving both arterial and venous circulation. His IgG ELISA assay for anti-PF4 antibody was positive.
    Matched MeSH terms: Immunoglobulin G
  5. Characterizing and applying immunoglobulins in snakebite diagnostics: A simple and rapid venom detection assay for four medically important snake species in Southeast Asia
    Lee LP, Tan CH, Khomvilai S, Sitprija V, Chaiyabutr N, Tan KY
    Int J Biol Macromol, 2023 May 01;236:123727.
    PMID: 36863668 DOI: 10.1016/j.ijbiomac.2023.123727
    Snakebite envenoming is a medical emergency requiring urgent and specific treatment. Unfortunately, snakebite diagnostics are scarce, time-consuming and lacking specificity. Hence, this study aimed to develop a simple, quick and specific snakebite diagnostic assay using animal antibodies. Anti-venom horse immunoglobulin G (IgG) and chicken immunoglobulin Y (IgY) were produced against the venoms of four major medically important snake species in Southeast Asia, i.e., the Monocled Cobra (Naja kaouthia), Malayan Krait (Bungarus candidus), Malayan Pit Viper (Calloselasma rhodostoma), and White-lipped Green Pit Viper (Trimeresurus albolabris). Different capture:detection configurations of double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) were constructed using both immunoglobulins, and the horse IgG:IgG-HRP configuration was found to be most selective and sensitive in detecting the corresponding venoms. The method was further streamlined to develop a rapid immunodetection assay, which is able to produce a visual color change within 30 min for discrimination between different snake species. The study shows it is feasible to develop a simple, quick and specific immunodiagnostic assay using horse IgG, which can be derived directly from antisera prepared for antivenom production. The proof-of-concept indicates it is a sustainable and affordable approach in keeping with on-going antivenom manufacturing activities for specific species in the region.
    Matched MeSH terms: Immunoglobulin G
  6. Fulltext Profiling Bartonella infection and its associated risk factors in shelter cats in Malaysia
    Alias NNA, Omar S, Ahmad NI, Watanabe M, Tay ST, Aziz NA, et al.
    J Vet Sci, 2023 May;24(3):e38.
    PMID: 37271506 DOI: 10.4142/jvs.22277
    BACKGROUND: Poor disease management and irregular vector control could predispose sheltered animals to disease such as feline Bartonella infection, a vector-borne zoonotic disease primarily caused by Bartonella henselae.

    OBJECTIVES: This study investigated the status of Bartonella infection in cats from eight (n = 8) shelters by molecular and serological approaches, profiling the CD4:CD8 ratio and the risk factors associated with Bartonella infection in shelter cats.

    METHODS: Bartonella deoxyribonucleic acid (DNA) was detected through polymerase chain reaction (PCR) targeting 16S-23S rRNA internal transcribed spacer gene, followed by DNA sequencing. Bartonella IgM and IgG antibody titre, CD4 and CD8 profiles were detected using indirect immunofluorescence assay and flow cytometric analysis, respectively.

    RESULTS: B. henselae was detected through PCR and sequencing in 1.0% (1/101) oral swab and 2.0% (1/50) cat fleas, while another 3/50 cat fleas carried B. clarridgeiae. Only 18/101 cats were seronegative against B. henselae, whereas 30.7% (31/101) cats were positive for both IgM and IgG, 8% (18/101) cats had IgM, and 33.7% (34/101) cats had IgG antibody only. None of the eight shelters sampled had Bartonella antibody-free cats. Although abnormal CD4:CD8 ratio was observed in 48/83 seropositive cats, flea infestation was the only significant risk factor observed in this study.

    CONCLUSIONS: The present study provides the first comparison on the Bartonella spp. antigen, antibody status and CD4:CD8 ratio among shelter cats. The high B. henselae seropositivity among shelter cats presumably due to significant flea infestation triggers an alarm of whether the infection could go undetectable and its potential transmission to humans.

    Matched MeSH terms: Immunoglobulin G
  7. Fulltext SARS-CoV-2 S-RBD IgG & Neutralizing antibodies among different categories of health care workers post third dose BNT162b2 mRNA COVID-19 vaccine
    Wan Shuaib WMA, Badaruddin IA, Mansor M, Salleh SA, Hassan MR, Lindong S, et al.
    Hum Vaccin Immunother, 2023 Dec 15;19(3):2266931.
    PMID: 37828861 DOI: 10.1080/21645515.2023.2266931
    Neutralizing antibodies (NTAb) play a significant role in preventing and protecting against SARS-CoV-2 virus infection. Identifying NTAb is undoubtedly imperative in understanding the immunity toward COVID-19 better. However, it is interesting to note that the production of NTAb varies among individuals, especially among healthcare workers (HCWs), as they are exposed to the virus daily. Hence, we would like to investigate factors affecting the production of S-RBD IgG and NTAb among different categories of HCWs, particularly after receiving the third dose of the BNT162b2 mRNA COVID-19 Vaccine. A total of 361 HCWs from our hospital were prospectively enrolled and had their S-RBD IgG and NTAb titers measured. They were studied in relation to the degree of exposure to COVID-19, breakthrough infections, gender, age, race, household income, housing type, household number, and education levels. HCWs with the highest risk of exposure to COVID-19, breakthrough infections, and male gender displayed the highest median titers of both S-RBD IgG and NTAb, and the differences were statistically significant (p 
    Matched MeSH terms: Immunoglobulin G
  8. Fulltext Polymethacrylate Coated Electrospun PHB Fibers as a Functionalized Platform for Bio-Diagnostics: Confirmation Analysis on the Presence of Immobilized IgG Antibodies against Dengue Virus
    Hosseini S, Azari P, Jiménez-Moreno MF, Rodriguez-Garcia A, Pingguan-Murphy B, Madou MJ, et al.
    Sensors (Basel), 2017 Oct 09;17(10).
    PMID: 28991214 DOI: 10.3390/s17102292
    In this article, a combination of far field electrospinning (FFES) and free-radical polymerization has been used to create a unique platform for protein immobilization via the physical attachment of biomolecules to the surface of the fiber mats. The large specific surface area of the fibers with its tailored chemistry provides a desirable platform for effective analyte-surface interaction. The detailed analysis of protein immobilization on a newly developed bio-receptive surface plays a vital role to gauge its advantages in bio-diagnostic applications. We relied on scanning electron microscopy (SEM), diameter range analysis, and X-ray photoelectron spectroscopy (XPS), along with thermal gravimetric analysis (TGA), water-in-air contact angle analysis (WCA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) to study our developed platforms and to provide valuable information regarding the presence of biomolecular entities on the surface. Detailed analyses of the fiber mats before and after antibody immobilization have shown obvious changes on the surface of the bioreceptive surface including: (i) an additional peak corresponding to the presence of an antibody in TGA analysis; (ii) extra FTIR peaks corresponding to the presence of antibodies on the coated fiber platforms; and (iii) a clear alteration in surface roughness recorded by AFM analysis. Confirmation analyses on protein immobilization are of great importance as they underlay substantial grounds for various biosensing applications.
    Matched MeSH terms: Immunoglobulin G
  9. Fulltext Comparing the effect of oral supplementation of vitamin E, injective vitamin E and selenium or both during late pregnancy on production and reproductive performance and immune function of dairy cows and calves
    Kafilzadeh F, Kheirmanesh H, Karami Shabankareh H, Targhibi MR, Maleki E, Ebrahimi M, et al.
    ScientificWorldJournal, 2014;2014:165841.
    PMID: 25045726 DOI: 10.1155/2014/165841
    The object of this study was to determine the effect of prepartum supplementation of vitamin E with or without injective vitamin E and selenium (Se) on productive and reproductive performances and immune function in dairy cows. Sixty multiparous Holstein dairy cows were divided randomly into three groups at the end of gestation. Cows in each group received one of three treatments: (1) a single intramuscular (im) injection of vit. E + selenium 3 weeks prepartum; (2) daily supplementation of oral vit. E given from 3 weeks prepartum to parturition; (3) injective vit. E + Se with daily supplementation of oral vit. E. Blood samples were collected from cows at calving and from calves at 0 and 7 days of age. Concentration of IgG in serum of cows and calves as well as in colostrum was determined. No significant differences among treatments occurred in the concentrations of IgG, animal, and calf production and reproduction performance. Due to the lack of significant difference between injection and oral supplementation, it is recommended to replace the injection with oral supplementation.
    Matched MeSH terms: Immunoglobulin G/blood; Immunoglobulin G/metabolism
  10. Seroprevalence of toxoplasmosis among migrant workers from different Asian countries working in Malaysia
    Chan BT, Amal RN, Hayati MI, Kino H, Anisah N, Norhayati M, et al.
    Southeast Asian J. Trop. Med. Public Health, 2008 Jan;39(1):9-13.
    PMID: 18567437
    A serologic study of Toxoplasma antibodies among 501 foreign migrant workers in Malaysia was conducted in a plantation and detention camp. The highest prevalence rate of 46.2% was among Nepalese workers. Statistical analysis indicated the IgG positivity rate among local residents was significantly higher than the migrants studied (p < 0.05). The IgM positivity rate showed no significant difference between the two groups (p > 0.05). No significant difference in the prevalence rate was noted between the migrants and the local workers when grouped by agricultural and non-agricultural occupations (p > 0.05). The continuous introduction of these infections may influence the epidemiology and further compromise efforts in control and prevention. It is therefore important to monitor of non-notifiable diseases.
    Matched MeSH terms: Immunoglobulin G/analysis; Immunoglobulin G/blood
  11. Antibodies against malondialdehyde (MDA) in MRL/lpr/lpr mice: evidence for an autoimmune mechanism involving lipid peroxidation
    Yahya MD, Pinnas JL, Meinke GC, Lung CC
    J Autoimmun, 1996 Feb;9(1):3-9.
    PMID: 8845052
    Previous studies have shown that lipid peroxidative processes may play a role in disease pathogenesis in lupus-prone MRL/lpr mice. Studies were thus performed to determine if an immune response against malondialdehyde (MDA), a highly reactive byproduct of lipid peroxidation, was present in these mice. By using MDA-modified mouse serum albumin (MSA) as antigens in ELISA, we found that these mice produce high levels of MDA-specific antibodies in the complement-fixing IgG2a and IgG2b subclasses. Anti-MDA antibodies were also found in MRL/+ mice but in significantly lower levels. The specificity of these antibodies was verified by inhibition ELISA. MDA may contribute to disease pathogenesis in these mice by altering the immunogenicity of self molecules, eliciting an immune response and forming immune complexes that may deposit in tissues.
    Matched MeSH terms: Immunoglobulin G/analysis; Immunoglobulin G/biosynthesis
  12. Distribution of immunoglobulin classes and IgG subclasses against a culture filtrate antigen of Burkholderia pseudomallei in melioidosis patients
    Chenthamarakshan V, Kumutha MV, Vadivelu J, Puthucheary SD
    J Med Microbiol, 2001 Jan;50(1):55-61.
    PMID: 11192506 DOI: 10.1099/0022-1317-50-1-55
    The class and subclass distribution of antibody response to the culture filtrate antigen (CFA) of Burkholderia pseudomallei was examined in the sera of 45 septicaemic and 17 localised melioidosis cases and 40 cases clinically suspected of melioidosis and the results were compared with those from high-risk and healthy control groups. The geometric mean titre index (GMTI) values for all classes and subclasses of immunoglobulins examined were higher for sera from the proven and clinically suspected melioidosis cases than for the control groups. However, the highest response in the three patient groups was that of IgG with GMTIs ranging from 219.4 to 291.6 and the lowest was for IgM with GMTIs of 22.5, 24.3 and 28.7. The IgA response was intermediate with GMTIs ranging from 119.2 to 170. The GMTIs were highest for IgG in septicaemic and localised infections and for IgA and IgM in localised infections. As regards IgG subclass distribution, IgG1 and IgG2 were the predominant subclasses produced against the CFA in contrast to IgG3 and IgG4, which were produced in low amounts. None of the sera from the control groups had any significant titres of antibodies.
    Matched MeSH terms: Immunoglobulin G/blood; Immunoglobulin G/classification
  13. A New Plant Expression System for Producing Pharmaceutical Proteins
    Abd-Aziz N, Tan BC, Rejab NA, Othman RY, Khalid N
    Mol Biotechnol, 2020 Apr;62(4):240-251.
    PMID: 32108286 DOI: 10.1007/s12033-020-00242-2
    In the past decade, interest in the production of recombinant pharmaceutical proteins in plants has tremendously progressed because plants do not harbor mammalian viruses, are economically competitive, easily scalable, and capable of carrying out complex post-translational modifications required for recombinant pharmaceutical proteins. Mucuna bracteata is an essential perennial cover crop species widely planted as an underground cover in oil palm and rubber plantations. As a legume, they have high biomass, thrive in its habitat, and can fix nitrogen. Thus, M. bracteata is a cost-efficient crop that shows ideal characteristics as a platform for mass production of recombinant protein. In this study, we established a new platform for the transient production of a recombinant protein in M. bracteata via vacuum-assisted agro-infiltration. Five-week-old M. bracteata plants were vacuum infiltrated with Agrobacterium tumefaciens harboring a plasmid that encodes for an anti-toxoplasma immunoglobulin (IgG) under different parameters, including trifoliate leaf positional effects, days to harvest post-infiltration, and the Agrobacterium strain used. Our results showed that vacuum infiltration of M. bracteata plant with A. tumefaciens strain GV3101 produced the highest concentration of heterologous protein in its bottom trifoliate leaf at 2 days post-infiltration. The purified anti-toxoplasma IgG was then analyzed using Western blot and ELISA. It was demonstrated that, while structural heterogeneity existed in the purified anti-toxoplasma IgG from M. bracteata, its transient expression level was two-fold higher than the model platform, Nicotiana benthamiana. This study has laid the foundation towards establishing M. bracteata as a potential platform for the production of recombinant pharmaceutical protein.
    Matched MeSH terms: Immunoglobulin G/biosynthesis*; Immunoglobulin G/genetics; Immunoglobulin G/immunology; Immunoglobulin G/isolation & purification
  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: Immunoglobulin G/blood*; Immunoglobulin G/immunology
  15. Fulltext Seropositivity of dengue antibodies during pregnancy
    Mohamed Ismail NA, Wan Abd Rahim WE, Salleh SA, Neoh HM, Jamal R, Jamil MA
    ScientificWorldJournal, 2014;2014:436975.
    PMID: 25587564 DOI: 10.1155/2014/436975
    Malaysia a dengue endemic country with dengue infections in pregnancy on the rise. The present study was aimed at determining dengue seroprevalence (IgG or IgM) during pregnancy and its neonatal transmission in dengue seropositive women.
    Matched MeSH terms: Immunoglobulin G/blood; Immunoglobulin G/immunology
  16. Fulltext Lateral flow test using Echinococcus granulosus native antigen B and comparison of IgG and IgG4 dipsticks for detection of human cystic echinococcosis
    Khalilpour A, Sadjjadi SM, Moghadam ZK, Yunus MH, Zakaria ND, Osman S, et al.
    Am J Trop Med Hyg, 2014 Nov;91(5):994-9.
    PMID: 25200268 DOI: 10.4269/ajtmh.14-0170
    Cystic echinococcosis (CE) caused by infection with Echinococcus granulosus is of major concern for humans in many parts of the world. Antigen B was prepared from E. granulosus hydatid fluid, and Western blots confirmed eight batches showing a band corresponding to the 8-/12-kDa subunit with positive serum and no low-molecular mass band (< 15 kDa) with negative serum. The batches were pooled and used to prepare lateral flow immunoglobulin G4 (IgG4) and IgG dipsticks. Diagnostic sensitivity was determined using serum samples from 21 hydatidosis patients, and diagnostic specificity was established using sera from 17 individuals infected with other parasites and 15 healthy people. IgG4 dipstick had a diagnostic sensitivity of 95% (20 of 21) and a specificity of 100% (32 of 32). The IgG dipstick had a sensitivity of 100% (21 of 21) and a specificity of 87.5% (28 of 32). Thus, both IgG and IgG4 dipsticks had high sensitivities, but IgG4 had greater specificity for the diagnosis of human CE.
    Matched MeSH terms: Immunoglobulin G/blood; Immunoglobulin G/immunology
  17. Adaptation of a commercial ELISA to determine the IgG avidity in sheep experimentally and naturally infected with Neospora caninum
    Syed-Hussain SS, Howe L, Pomroy WE, West DM, Smith SL, Williamson NB
    Vet Parasitol, 2014 Jun 16;203(1-2):21-8.
    PMID: 24582279 DOI: 10.1016/j.vetpar.2014.01.003
    Recent reports indicate Neospora caninum has a possible role in causing abortions in sheep in New Zealand. Knowledge about the epidemiology of neosporosis in sheep is limited. This study aimed to adapt and validate a commercially available ELISA assay as an IgG avidity assay to discriminate between acute (primary and re-inoculated) and chronic N. caninum infections in sheep. In addition, it was used to compare the antibody avidity values between lambs from ewes inoculated with N. caninum either during the pregnancy or in the previous year. The avidity assay was undertaken by using 6M urea for the first wash after incubation with the primary antibody in the commercial ELISA (Chekit* Neospora antibody test kit, IDEXX Laboratories, Australia). Sequential serum samples were obtained from naïve ewes (n=16) experimentally inoculated with live N. caninum tachyzoites. All ewes were seropositive by two weeks post-inoculation and remained seropositive for 20 weeks post-inoculation. There was a linear relationship between time after inoculation and avidity values (p<0.05) over the first 24 weeks. In Week 4, all animals had avidity values <35% and by Week 8, 8/16 animals had avidity values of >35%. These results suggest that an avidity value of <35% indicates a recent primary infection while a value of >35% is indicative of a chronic infection. The assay was then validated using samples from other groups of experimentally inoculated sheep as well as samples from naturally infected ewes. When comparing sample to positive ratio (S/P) and avidity values from lambs born from recently inoculated ewes with those from ewes inoculated the previous year and re-inoculated in the current year, it was possible to differentiate the lambs at 2 weeks of age. Lambs from recently inoculated ewes had low S/P and avidity values at 2 weeks of age which increased by 12 weeks of age. In comparison, lambs from re-inoculated ewes had high S/P and avidity values at 2 weeks of age, due to maternal antibody influence but values were similar to those from lambs that were born from recently inoculated ewes at 12 weeks of age. Avidity values for four naturally infected ewes were all >60% indicating chronic infection. These results suggest that the assay is able to discriminate between recent and chronic infection in sheep as well as able to differentiate lambs with maternal immunity compared to their own de novo immunity. As such it can be utilized to understand the kinetics of N. caninum infection in sheep.
    Matched MeSH terms: Immunoglobulin G/blood; Immunoglobulin G/immunology*
  18. 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: Immunoglobulin G/isolation & purification; Immunoglobulin G/therapeutic use
  19. Fulltext Seroprevalance of brucellosis among suspected cases in Malaysia
    Jama'ayah MZ, Heu JY, Norazah A
    Malays J Pathol, 2011 Jun;33(1):31-4.
    PMID: 21874749 MyJurnal
    Brucellosis is a zoonotic disease which can be transmitted by direct or indirect contact with infected animal or their products. It is an important public health problem but little is known on brucellosis in the Malaysian population. The aim of this study was to determine the presence of Brucella antibodies using commercial Brucella IgG and IgM ELISA kits (Vircell, SL, Barcelona Spain). A total of 184 sera from suspected patients were received from 16 hospitals in Malaysia over the years 2004 to 2009. Only 10 serum samples (5.4%) were positive for Brucella antibodies in which 5 showed the presence of both IgM and IgG. Most of the positive patients were occupationally involved with animals. This study suggests the seroprevalance of brucellosis among individuals who have contact with infected animals in Malaysia is low.
    Matched MeSH terms: Immunoglobulin G/analysis; Immunoglobulin G/blood
  20. 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: Immunoglobulin G/blood; Immunoglobulin G/immunology
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