Displaying publications 1 - 20 of 240 in total

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  1. Mak JW, Yong HS, Lim PK, Tan MA
    PMID: 3406806
    Biotechnological tools are being used in malaria, filariasis and dengue research. The main emphasis has been on the production of reagents for immunodiagnosis and research. In this respect monoclonal antibodies (McAbs) against various species and stages of the above pathogens have been produced. It is hoped that these McAbs will be useful not only in immunodiagnosis but also for seroepidemiological applications. A DNA probe against Brugia malayi has been tested in Malaysia and was found to be sensitive and specific.
    Matched MeSH terms: Antibodies, Monoclonal
  2. Cross JH
    PMID: 3043701
    There are essentially no reports on the use of modern biotechnological methods on the study of cestode parasites in the Philippines, Indonesia or Malaysia. The only recent reports of cestode studies in these countries have been on reports of new species in animals and on prevalence rates of cestode parasites in humans; Taenia solium and cysticercosis, Taenia saginata and Hymenolepis nana, etc. Reports on the use of biotechnology has emanated from outside the area on cestodes of humans and animals, and some of these methods could be used to study cestodes in this part of the world.
    Matched MeSH terms: Antibodies, Monoclonal
  3. Trépanier P, Minocha HC, Ibrahim AL, Sheikh-Omar AR, Montpetit C, Lecomte J, et al.
    Vet Microbiol, 1988 Dec;18(3-4):219-31.
    PMID: 2852870
    Hemagglutination activity, structural protein profiles and neutralization assays were used in a comparative study of bovine herpesvirus 1 strains from the U.S.A., Canada, Great Britain, Denmark and Malaysia with equine, feline and human herpesviruses in order to further characterize the bovine herpesvirus 1 hemagglutinin. Bovine herpesvirus 1 strains of different geographical origins all showed hemagglutinating activity for mouse erythrocytes; furthermore, feline herpesvirus 1 was also shown to hemagglutinate mouse erythrocytes. Analyses of partly purified viruses showed that a distinctive and specific polypeptides profile is associated with each species of herpesviruses used in our study; strains of bovine herpesvirus 1 from North America, Europe and Southeast Asia however, presented a remarkable similarity as to their electrophoretic protein patterns. A protein similar to the 97-kDa bovine viral hemagglutinin was not identified with the hemagglutinating feline herpesvirus. An important neutralization epitope on the bovine viral hemagglutinin was also not found on feline, equine and human herpesviruses but was identified on all bovine strains tested from North America, Europe and Southeast Asia stressing the importance of the bovine hemagglutinin for eventual prophylactic purposes.
    Matched MeSH terms: Antibodies, Monoclonal
  4. Tan MA, Mak JW, Yong HS
    Trop. Med. Parasitol., 1989 Sep;40(3):317-21.
    PMID: 2617040
    Two out of six monoclonals (McAbs) produced against subperiodic Brugia malayi infective larva (L3) antigens impaired B. malayi L3 motility independently of human buffy coat cells. Scanning electron microscopy studies showed damage to L3 surface and loss of regular cuticular annulations. The two McAbs (BML 1a and BM1 8b) did not affect B. malayi microfilaria (mf). They were IFAT-positive with B. malayi adult and L3 antigens; other McAbs which did not affect mf or L3 motility were IFAT-negative. All six McAbs did not promote cellular adherence of normal human buffy coat cells to mf or L3.
    Matched MeSH terms: Antibodies, Monoclonal/immunology*
  5. Karim QN, Finn GY, Easmon CS, Dangor Y, Dance DA, Ngeow YF, et al.
    Genitourin Med, 1989 Dec;65(6):361-5.
    PMID: 2693334
    A monoclonal antibody raised against Haemophilus ducreyi was tested for its sensitivity and specificity as an immunofluorescence (IF) reagent using simulated vaginal smears containing H. ducreyi, smears taken from skin lesions of mice infected with H. ducreyi and patients from South Africa, Thailand and Malaysia with clinically diagnosed chancroid. The IF test was more sensitive than culture or Gram staining in the simulated smears, theoretically detecting less than 4 organisms/sample. It detected H. ducreyi in 95% of the animal lesions compared with 14% detected by culture. Immunofluorescence testing identified over 90% of culture-positive cases of chancroid but also detected organisms in some culture-negative cases where clinical evidence for the diagnosis was strong. These results suggest that this antibody may provide a simple, rapid and sensitive means of detecting H. ducreyi in cases of chancroid.
    Matched MeSH terms: Antibodies, Monoclonal*
  6. Edwards S, Sands JJ
    DTW. Dtsch. Tierarztl. Wochenschr., 1990 Feb;97(2):79-81.
    PMID: 2178905
    Nineteen monoclonal antibodies (MAbs) with specificity for hog cholera virus (HCV) were prepared. They were used in an immune binding (peroxidase linked) assay to determine the reaction patterns of HCV isolates from Europe, Brazil, USA, Japan and Malaysia, as well as laboratory reference strains of the virus. A further panel of 17 MAbs raised against bovine virus diarrhoea virus (BVDV) was included in the study, together with 5 MAbs raised against a non-HCV pestivirus of porcine origin. All the MAbs were also tested against representative strains of BVDV and border disease virus. Six MAbs were HCV-specific, reacting with all isolates of HCV and none of the ruminant viruses. Among the other HCV MAbs geographical variation in reaction patterns was observed. There was evidence of antigenic distinction between recent European isolates, and archive material originally isolated more than 10 years ago.
    Matched MeSH terms: Antibodies, Monoclonal/immunology*
  7. Dunster LM, Gibson CA, Stephenson JR, Minor PD, Barrett AD
    J Gen Virol, 1990 Mar;71 ( Pt 3):601-7.
    PMID: 2155996
    The ability of passage in HeLa cells to attenuate flaviviruses was investigated for three different strains of the mosquito-borne West Nile (WN) virus and two tick-borne viruses, louping-ill and Langat. One strain of WN virus, Sarawak, was attenuated 4000-fold for adult mice by intraperitoneal or intranasal challenge after six HeLa passages. The HeLa-passaged virus was also found to be antigenically different and temperature-sensitive in its growth characteristics compared with the parent. After six HeLa cell passages the Egypt 101 and Smithburn strains of WN virus lost their ability to infect monkey kidney cells and no longer killed adult mice, although inoculated animals became sick for several days. In contrast, two tick-borne flaviviruses remained as virulent for mice after six HeLa passages as the parent non-HeLa-passaged virus. Neither of the tick-borne viruses exhibited characteristics associated with temperature sensitivity. The results, therefore, indicate that the mosquito-borne, but not tick-borne, flaviviruses can be attenuated by very few passages in HeLa cells. This observation may provide a model system with which to analyse the molecular basis of attenuation and/or virulence of mosquito-borne flaviviruses.
    Matched MeSH terms: Antibodies, Monoclonal
  8. Cecilia D, Gould EA
    Virology, 1991 Mar;181(1):70-7.
    PMID: 1704661
    The Sarawak strain of Japanese encephalitis virus (JE-Sar) is virulent in 3-week-old mice when inoculated intraperitoneally. The nucleotide sequence for the envelope glycoprotein (E) of this virus was determined and compared with the published sequences of four other strains. There were several silent nucleotide differences and five codon changes. Monoclonal antibodies (MAbs) against the E protein of JE-Sar virus were prepared and characterized. MAb-resistant mutants of JE-Sar were selected to determine if mutations in the E protein gene could affect its virulence for mice. Eight mutants were isolated using five different MAbs that identified virus-specific or group-reactive epitopes on the E protein. The mutants lost either complete or partial reactivity with selecting MAb. Several showed decreased virulence in 3-week-old mice after intraperitoneal inoculation. Two (r27 and r30) also showed reduced virulence in 2-week-old mice. JE-Sar and the derived mutants were comparable in their virulence for mice, when inoculated intracranially. Mutant r30 but not r27 induced protective immunity in adult mice against intracranial challenge with parent virus. However, r27-2 did induce protective immunity against itself. Nucleotide sequencing of the E coding region for the mutants revealed single base changes in both r30 and r27 resulting in a predicted change from isoleucine to serine at position 270 in r30 and from glycine to aspartic acid at position 333 in r27. The altered capacity of the mutants to induce protective immunity is consistent with the immunogenicity changes predicted by computer analysis using the Protean II program.
    Matched MeSH terms: Antibodies, Monoclonal
  9. Foo A, Carter R, Lambros C, Graves P, Quakyi I, Targett GA, et al.
    Am J Trop Med Hyg, 1991 Jun;44(6):623-31.
    PMID: 1713424
    Monoclonal antibodies (MAbs) directed against different epitope regions on three sexual stage-specific gamete surface proteins of Plasmodium falciparum, Pfs 25, Pfs 230, and Pfs 48/45, were used to study the genetic diversity of these epitopes among fresh isolates of P. falciparum from Malaysia, using immunofluorescence microscopy (IFA). Among 45 Malaysian isolates, one epitope of Pfs 25, designated region I, showed evidence of variable reactivity with MAbs among different isolates; the Pfs 25 epitope, region II, was universally recognized by MAbs in all isolates. Two apparently distinct epitope regions of Pfs 230 were defined by MAbs, one of which was universally recognized by MAbs among the 45 isolates; the other was conserved in all but three isolates. The epitope regions of gamete-surface protein Pfs 48/45, designated regions I, IIa, IIb, IIc, III, and IV, were examined for reactivity by IFA in 33 isolates. Epitope regions I, IIb, III, and IV were conserved in all isolates; regions IIa and IIc existed in variant forms.
    Matched MeSH terms: Antibodies, Monoclonal/immunology
  10. Lim YC, Phang KS, Cheong SK
    Malays J Pathol, 1992 Dec;14(2):85-9.
    PMID: 1304629
    With the advent of new monoclonal antibodies that are applicable to formalin-fixed, paraffin embedded sections, immunophenotyping is becoming increasingly important in the diagnosis and classification of lymphomas. However, multiple factors such as fixation, trypsinization and even type of antibodies used have certain effects on the final outcome of the staining procedure. In this paper we report our experience and the problems encountered in our laboratory when we first tried to establish a workable immunostaining protocol for formalin-fixed, paraffin embedded tissue sections using the immunoalkaline phosphatase technique.
    Matched MeSH terms: Antibodies, Monoclonal
  11. Lim PK, Mak JW, Yong HS
    PMID: 1298082
    Two monoclonal antibodies (MAbs), one produced against Plasmodium falciparum (PF-IG8) and the other against P. cynomolgi (PC-IE12) schizont antigens were used in a sandwich ELISA for the detection of circulating plasmodial antigens in sera of patients infected with either P. falciparum, P. vivax or P. malariae. The mean +/- SD optical density (OD) values for the normal control group using PF-108 and PC-1E12 were 0.351 +/- 0.036 and 0.205 +/- 0.044, respectively. Mean OD values for the three infected groups were found to be significantly higher than those of the normal control group for both MAbs. However, ELISA values for individual serum specimens did not correlate with the level of parasitemia in the infected blood. Using a cut-off point of mean OD +/- 3 SD of the normal control group as indicating a positive reading, the specificity of this assay with both MAbs was 100%. The sensitivity of the assay using PF-1G8 was 95% while that obtained with PC-1E12 was 98%.
    Matched MeSH terms: Antibodies, Monoclonal*
  12. Nazaimoon W, Ng ML, Bak K
    Malays J Pathol, 1993 Jun;15(1):75-83.
    PMID: 8277795
    A simple, non-isotopic in-house enzyme-linked immunoabsorbant assay (ELISA) for human growth hormone (GH) was developed. The assay involved using in-house polyclonal anti-GH adsorbed onto 96-well microtitre plates, commercially prepared mouse monoclonal anti-GH, and goat anti-mouse IgG horseradish peroxidase detection system. Results of recovery and parallelism studies ranged from 95%-106% and 98%-101% respectively, of the expected values. The detection limit of the assay was 0.008 mIU/well or the equivalent to 0.4 mIU/L of undiluted serum. Intra- and interassay coefficients of variations were 4.8%-7.9% and 6.5%-8.7% respectively. Serum GH levels measured in this assay correlated well with those measured in established in-house radioimmunoassays (r = 0.985, p < 0.001) and immunoradiometric assay from NETRIA (r = 0.984, p < 0.001).
    Matched MeSH terms: Antibodies, Monoclonal
  13. Rasool NB, Green KY, Kapikian AZ
    J Clin Microbiol, 1993 Jul;31(7):1815-9.
    PMID: 8394376
    The distribution of rotavirus G (VP7) serotypes circulating in four locations in Malaysia, representing three geographical areas, was evaluated in 341 RNA-positive stool specimens obtained discontinuously between 1977 and 1988 from infants and young children under the age of five years who were hospitalized with acute gastroenteritis. A total of 306 specimens (256 stool suspensions and 50 that were adapted to growth in tissue culture) that were rotavirus positive by the confirmatory enzyme-linked immunosorbent assay (ELISA) were examined for serotype by ELISA utilizing monoclonal antibodies to rotavirus G serotype 1, 2, 3, 4, or 9. One hundred eighty (59%) of the 306 specimens could be serotyped; of these 180 specimens, 71% were serotype 4, 15% were serotype 1, 4% were serotype 2, and 4% were serotype 3. Serotype 9 rotavirus was not detected. Most (71%) of the specimens tested were obtained in 1988, when serotype 4 predominated in three locations in West Malaysia; no single serotype was predominant in a limited number of specimens from East Malaysia.
    Matched MeSH terms: Antibodies, Monoclonal
  14. Se Thoe SY, Wong KK, Pathmanathan R, Sam CK, Cheng HM, Prasad U
    Gynecol Oncol, 1993 Aug;50(2):168-72.
    PMID: 8397152
    Epstein-Barr virus (EBV) receptors (EBV/C3d receptors) were detected, using the monoclonal antibody HB5, on 23 ectocervical and 5 endocervical biopsies of the uterine cervix. Elevated IgA titers against the viral capsid antigen and early antigen of EBV were also found in the cervical secretions from cervical carcinoma patients (83%), compared with samples from patients with cervical intraepithelial neoplasia (75%), herpes simplex virus-infected patients (0%), and gynecologic patients with nonmalignant conditions (0%). EBV DNA was present in 63% of cervical carcinoma biopsies detected by in situ hybridization. These observations suggest a positive association between EBV and carcinoma of the cervix.
    Matched MeSH terms: Antibodies, Monoclonal/biosynthesis
  15. Kurup VP, Kumar A, Kelly KJ, Fink JN
    J Allergy Clin Immunol, 1993 Nov;92(5):638-43.
    PMID: 8227854 DOI: 10.1016/0091-6749(93)90005-z
    Several hybridomas were produced against antigens extracted from the latex sap of Hevea brasiliensis. One of the monoclonal antibodies (LA-E3) reacted with antigens demonstrating binding to patient sera on crossed enzyme immunoelectrophoresis. This monoclonal antibody reacted with 2 of 10 glove extracts studied and with both Malaysian and Indian latex plant extracts. The antigens purified with monoclonal antibody affinity chromatography demonstrated specific IgE in the sera of patients with latex allergy as determined by ELISA. This monoclonal antibody can thus be utilized to obtain reliable antigens useful in the diagnosis of latex sensitivity, although additional antigens will likely be necessary to enhance sensitivity and specificity.
    Matched MeSH terms: Antibodies, Monoclonal/chemistry*
  16. Soeyoko SS
    PMID: 7973941
    Wuchereria bancrofti, Brugia malayi and Brugia timori are the causative agents of lymphatic filariasis in Indonesia but in some endemic areas, B malayi is more commonly found. Diagnosis of filariasis is normally based on clinical, parasitological and immunological examinations but those methods have limitations. The discovery of monoclonal antibodies is expected to provide a new dimension to the efforts in the development of specific and sensitive immunological tests for the various stages of filariasis infection. This preliminary report, using monoclonal antibodies and dot-blot assay in human lymphatic filariasis showed that 75% of sera from microfilaremic patients with clinical signs, 40% of sera from amicrofilaraemic patients with clinical signs, 88.8% of sera from microfilaremic patients without clinical signs and 19.6% of sera from amicrofilaremic patients without clinical signs have circulating antigens.
    Matched MeSH terms: Antibodies, Monoclonal*
  17. Abdullah WO, Oothuman P, Yunus H
    PMID: 7973943
    In Peninsular Malaysia, only Wuchereria bancrofti and Brugia malayi are reported to cause human filariasis. Brugia pahangi infects many of the same animal hosts as the zoonotically transmitted subperiodic B. malayi. There is a well-recognized need for improved diagnostic techniques for lymphatic filariasis. Parasite antigen detection is a promising new approach, and it will probably prove to be more sensitive and specific than clinical, microscopic and antibody-based serological methods. We recently generated monoclonal antibodies (MAb XC3) from in vitro culture products of adult B. pahangi (B.p. IVP). Filarial antigenemia was quantitated in various hosts including the sera from 6 Malaysian Aborigines with acute lymphatic filariasis. In hosts infected with brugian filariasis and dirofilariasis, antigenemia was scored ranging from 90 ng/ml to 960 ng/ml. None of the control animal and human sera had antigenemia above 90 ng/ml. In addition, MAb XC3 and B.p. IVP were applied in several seroepidemiological surveys among household cats in Kuala Selangor in order to correlate information gathered for future studies of possible cases of human infection. Out of the 81 cats surveyed, 10 (12.35%) and 5 (6.17%) were parasitologically positive for B. pahangi and B. malayi, respectively. However, 21 (25.92%) were antigenemia positive when serologically investigated with MAb XC3. Antifilarial antibodies to B.p. IVP by direct ELISA showed very high cross-reactivity with non-filarial gut worm infections. 16 (19.75%) cats had reciprocal titers ranging from 320 to 2,560. Only 1 (1.23%) cat from this group was antigenemic.
    Matched MeSH terms: Antibodies, Monoclonal*
  18. Adams SC, Broom AK, Sammels LM, Hartnett AC, Howard MJ, Coelen RJ, et al.
    Virology, 1995 Jan 10;206(1):49-56.
    PMID: 7530394
    Previous studies have found Kunjin (KUN) virus isolates from within Australia to be genetically homogenous and that the envelope protein of the type strain (MRM61C) was unglycosylated and lacked a potential glycosylation site. We investigated the extent of antigenic variation between KUN virus isolates from Australia and Sarawak using an immunoperoxidase assay and a panel of six monoclonal antibodies. The glycosylation status of the E protein of each virus was also determined by N glycosidase F (PNGase F) digestion and limited sequence analysis. The results showed that KUN viruses isolated within Australia oscillated between three antigenic types defined by two epitopes whose expression was influenced by passage history and host cell type. In contrast an isolate from Sarawak formed a stable antigenic type that was not influenced by passage history and was distinct from all Australian isolates. PNGase F digestions of KUN isolates indicated that 19 of the 33 viruses possessed a glycosylated E protein. Nucleotide sequence of the 5' third of the E gene of selected KUN isolates revealed that a single base change in PNGase F sensitive strains changed the tripeptide N-Y-F (amino acids 154-156 of the published sequence) to the potential glycosylation site N-Y-S. Further analysis revealed that passage history also had a significant influence on glycosylation.
    Matched MeSH terms: Antibodies, Monoclonal/immunology
  19. Khairullah NS, Lam SK
    PMID: 8629057
    In 1990 and 1991, six laboratories located in the WHO Western Pacific Region (WPR) and South East Asian Region (SEAR) were selected, based on their experience in the immunofluorescence antibody technique (IFAT), to participate in the evaluation of a WHO monoclonal antibody (Mab) kit to detect respiratory syncytial (RS) virus, influenza A virus, influenza B virus, parainfluenza virus and adenovirus. Despite differences in the initial standardization procedures, the WHO monoclonal antibodies were found to be of high quality, sensitivity and specificity when tested on clinical specimens. The constant supply of affordable high quality reagents from WHO would enable their use in clinical virological laboratories in the developing countries as well as promote the utilization of IFAT as an adjunct to cell culture isolation in the diagnosis of acute respiratory viral infections.
    Matched MeSH terms: Antibodies, Monoclonal*
  20. Khairullah NS
    Malays J Pathol, 1996 Jun;18(1):27-30.
    PMID: 10879221
    Two different preparations of monoclonal antibodies developed against respiratory viruses have been evaluated by the immunofluorescence antibody technique. The Chemicon monoclonal antibodies were found to be more efficient at picking up positive specimens with a high sensitivity and specificity than Imagen monoclonal antibodies. However, the overall concordance rate of the monoclonal antibodies was 92.3%-100%. Generally, when compared with cell culture isolation, the immunofluorescence antibody technique was found to be more sensitive. The high quality of the Chemicon monoclonal antibodies contribute to their value in providing definitive diagnosis, within a few hours of specimen collection, thus allowing early management of patients, their contacts and control of hospital infection.
    Matched MeSH terms: Antibodies, Monoclonal*
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