Displaying publications 1621 - 1640 of 4091 in total

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  1. Fulltext Clustering and genetic differentiation of the normocyte binding protein (nbpxa) of Plasmodium knowlesi clinical isolates from Peninsular Malaysia and Malaysia Borneo
    Ahmed MA, Fong MY, Lau YL, Yusof R
    Malar J, 2016;15(1):241.
    PMID: 27118390 DOI: 10.1186/s12936-016-1294-6
    The zoonotic malaria parasite Plasmodium knowlesi has become an emerging threat to South East Asian countries particular in Malaysia. A recent study from Sarawak (Malaysian Borneo) discovered two distinct normocyte binding protein xa (Pknbpxa) types of P. knowlesi. In the present study, the Pknbpxa of clinical isolates from Peninsular Malaysia and Sabah (Malaysian Borneo) were investigated for the presence of Pknbpxa types and natural selection force acting on the gene.
    Matched MeSH terms: Carrier Proteins
  2. Fulltext Understanding the dimorphic lifestyles of human gastric pathogen Helicobacter pylori using the SWATH-based proteomics approach
    Loke MF, Ng CG, Vilashni Y, Lim J, Ho B
    Sci Rep, 2016 05 25;6:26784.
    PMID: 27222005 DOI: 10.1038/srep26784
    Helicobacter pylori may reside in the human stomach as two morphological forms: the culturable spiral form and the viable but non-culturable (VBNC) coccoid form. This bacterium transforms from spiral to coccoid under in vitro suboptimal conditions. However, both spiral and coccoid have demonstrated its infectivity in laboratory animals, suggesting that coccoid may potentially be involved in the transmission of H. pylori. To determine the relevance of the coccoid form in viability and infectivity, we compared the protein profiles of H. pylori coccoids obtained from prolonged (3-month-old) culture with that of 3-day-old spirals of two H. pylori standard strains using SWATH (Sequential Window Acquisition of all Theoretical mass spectra)-based approach. The protein profiles reveal that the coccoids retained basal level of metabolic proteins and also high level of proteins that participate in DNA replication, cell division and biosynthesis demonstrating that coccoids are viable. Most interestingly, these data also indicate that the H. pylori coccoids possess higher level of proteins that are involved in virulence and carcinogenesis than their spiral counterparts. Taken together, these findings have important implications in the understanding on the pathogenesis of H. pylori-induced gastroduodenal diseases, as well as the probable transmission mode of this bacterium.
    Matched MeSH terms: Bacterial Proteins/analysis*; Bacterial Proteins/biosynthesis; Bacterial Proteins/genetics
  3. Fulltext Unmasking Heavily O-Glycosylated Serum Proteins Using Perchloric Acid: Identification of Serum Proteoglycan 4 and Protease C1 Inhibitor as Molecular Indicators for Screening of Breast Cancer
    Lee CS, Taib NA, Ashrafzadeh A, Fadzli F, Harun F, Rahmat K, et al.
    PLoS One, 2016;11(2):e0149551.
    PMID: 26890881 DOI: 10.1371/journal.pone.0149551
    Heavily glycosylated mucin glycopeptides such as CA 27.29 and CA 15-3 are currently being used as biomarkers for detection and monitoring of breast cancer. However, they are not well detected at the early stages of the cancer. In the present study, perchloric acid (PCA) was used to enhance detection of mucin-type O-glycosylated proteins in the serum in an attempt to identify new biomarkers for early stage breast cancer. Sensitivity and specificity of an earlier developed sandwich enzyme-linked lectin assay were significantly improved with the use of serum PCA isolates. When a pilot case-control study was performed using the serum PCA isolates of normal participants (n = 105) and patients with stage 0 (n = 31) and stage I (n = 48) breast cancer, higher levels of total O-glycosylated proteins in sera of both groups of early stage breast cancer patients compared to the normal control women were demonstrated. Further analysis by gel-based proteomics detected significant inverse altered abundance of proteoglycan 4 and plasma protease C1 inhibitor in both the early stages of breast cancer patients compared to the controls. Our data suggests that the ratio of serum proteoglycan 4 to protease C1 inhibitor may be used for screening of early breast cancer although this requires further validation in clinically representative populations.
    Matched MeSH terms: Blood Proteins/metabolism*; Complement C1 Inactivator Proteins/metabolism*
  4. Aptamer-based 'point-of-care testing'
    Gopinath SC, Lakshmipriya T, Chen Y, Phang WM, Hashim U
    Biotechnol Adv, 2016 May-Jun;34(3):198-208.
    PMID: 26876017 DOI: 10.1016/j.biotechadv.2016.02.003
    Aptamers are single-stranded oligonucleotides that can be artificially generated by a method called Systematic evolution of ligands by exponential enrichment (SELEX). The generated aptamers have been assessed for high-performance sensing applications due to their appealing characteristics. With either aptamers alone or complementing with antibodies, several high sensitive and portable sensors have been demonstrated for use in 'point-of-care testing'. Due to their high suitability and flexibility, aptamers are conjugated with nanostructures and utilized in field applications. Moreover, aptamers are more amenable to chemical modifications, making them capable of utilization with most developed sensors. In this overview, we discuss novel, portable, and aptamer-based sensing strategies that are suitable for 'point-of-care testing'.
    Matched MeSH terms: Complement System Proteins
  5. Fulltext Genetic diversity and natural selection in the rhoptry-associated protein 1 (RAP-1) of recent Plasmodium knowlesi clinical isolates from Malaysia
    Rawa MS, Fong MY, Lau YL
    Malar J, 2016;15:62.
    PMID: 26847346 DOI: 10.1186/s12936-016-1127-7
    The Plasmodium rhoptry-associated protein 1 (RAP-1) plays a role in the formation of the parasitophorous vacuole following the parasite's invasion of red blood cells. Although there is some evidence that the protein is recognized by the host's immune system, study of Plasmodium falciparum RAP-1 (PfRAP-1) suggests that it is not under immune pressure. A previous study on five old (1953-1962) P. knowlesi strains suggested that RAP-1 has limited genetic polymorphism and might be under negative selection. In the present study, 30 recent P. knowlesi isolates were studied to obtain a better insight into the polymorphism and natural selection of PkRAP-1.
    Matched MeSH terms: Membrane Proteins
  6. Once-weekly prophylactic treatment vs. on-demand treatment with nonacog alfa in patients with moderately severe to severe haemophilia B
    Kavakli K, Smith L, Kuliczkowski K, Korth-Bradley J, You CW, Fuiman J, et al.
    Haemophilia, 2016 May;22(3):381-8.
    PMID: 26823276 DOI: 10.1111/hae.12878
    Limited data are available on optimal prophylaxis regimens of factor IX (FIX) replacements for patients with haemophilia B.
    Matched MeSH terms: Recombinant Proteins/biosynthesis; Recombinant Proteins/genetics; Recombinant Proteins/therapeutic use
  7. Bisleuconothine A Induces Autophagosome Formation by Interfering with AKT-mTOR Signaling Pathway
    Wong CP, Seki A, Horiguchi K, Shoji T, Arai T, Nugroho AE, et al.
    J Nat Prod, 2015 Jul 24;78(7):1656-62.
    PMID: 26176165 DOI: 10.1021/acs.jnatprod.5b00258
    We have previously reported that bisleuconothine A (Bis-A), a novel bisindole alkaloid isolated from Leuconotis griffithii, showed cytostatic activity in several cell lines. In this report, the mechanism of Bis-A-induced cytostatic activity was investigated in detail using A549 cells. Bis-A did not cause apoptosis, as indicated by analysis of annexin V and propidium iodide staining. Expression of all tested apoptosis-related proteins was also unaffected by Bis-A treatment. Bis-A was found to increase LC3 lipidation in MCF7 cells as well as A549 cells, suggesting that Bis-A cytostatic activity may be due to induction of autophagy. Subsequent investigation via Western blotting and immunofluorescence staining indicated that Bis-A induced formation but prevented degradation of autophagosomes. Mechanistic studies showed that Bis-A down-regulated phosphorylation of protein kinase B (AKT) and its downstream kinase, PRAS40, which is an mTOR repressor. Moreover, phosphorylation of p70S6K, an mTOR-dependent kinase, was also down-regulated. Down-regulation of these kinases suggests that the increase in LC3 lipidation may be due to mTOR deactivation. Thus, the cytostatic activity shown by Bis-A may be attributed to its induction of autophagosome formation. The Bis-A-induced autophagosome formation was suggested to be caused by its interference with the AKT-mTOR signaling pathway.
    Matched MeSH terms: Apoptosis Regulatory Proteins/metabolism; Proto-Oncogene Proteins c-akt/metabolism
  8. Fulltext Prevention of cell-surface attachment and reduction of penicillin-binding protein 2a (PBP2a) level in methicillin-resistant Staphylococcus aureus biofilms by Acalypha wilkesiana
    Santiago C, Lim KH, Loh HS, Ting KN
    BMC Complement Altern Med, 2015;15:79.
    PMID: 25880167 DOI: 10.1186/s12906-015-0615-6
    Formation of biofilm is known to enhance the virulence of methicillin-resistance Staphylococcus aureus (MRSA), which is associated with persistent infections in hospital settings. The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics. We have isolated 9EA-FC-B bioactive fraction from Acalypha wilkesiana Müll. Arg. that reverses ampicillin resistant in MRSA through inhibition of the antibiotic resistant protein, penicillin-binding protein 2a (PBP2a). In this study, we aimed to investigate the effects of 9EA-FC-B on MRSA biofilm forming capacity.
    Matched MeSH terms: Bacterial Proteins/metabolism*; Penicillin-Binding Proteins/metabolism
  9. Genome structure of Sagiyama virus and its relatedness to other alphaviruses
    Shirako Y, Yamaguchi Y
    J Gen Virol, 2000 May;81(Pt 5):1353-60.
    PMID: 10769079
    Sagiyama virus (SAG) is a member of the genus Alphavirus in the family Togaviridae, isolated in Japan from mosquitoes in 1956. We determined the complete nucleotide sequence of the SAG genomic RNA from the original stock virus which formed a mixture of plaques with different sizes, and that from a full-length cDNA clone, pSAG2, infectious RNA transcripts from which formed uniform large plaques on BHK-21 cells. The SAG genome was 11698 nt in length exclusive of the 3' poly(A) tail. Between the complete nucleotide sequences of the full-length cDNA clone, pSAG2, and the consensus sequence from the original stock virus, there were nine amino acid differences; two each in nsP1, nsP2 and E1, and three in E2, some of which may be responsible for plaque phenotypic variants in the original virus stock. SAG was most closely related to Ross River virus among other alphaviruses fully sequenced, with amino acid sequence identities of 86% in the nonstructural proteins and of 83% in the structural proteins. The 3' terminal 280 nt region of SAG was 82% identical to that of Barmah Forest virus, which was otherwise not closely related to SAG. Comparison of the nucleotide sequence of SAG with partial nucleotide sequences of Getah virus (GET), which was originally isolated in Malaysia in 1955 and is closely related to SAG in serology and in biology, showed near identity between the two viruses, suggesting that SAG is a strain of GET.
    Matched MeSH terms: Viral Envelope Proteins/genetics; Viral Nonstructural Proteins/genetics
  10. Sequence and phylogenetic analysis of the fusion protein cleavage site of Newcastle disease virus field isolates from Iran
    Kianizadeh M, Aini I, Omar AR, Yusoff K, Sahrabadi M, Kargar R
    Acta Virol., 2002;46(4):247-51.
    PMID: 12693862
    Nine Newcastle disease virus (NDV) isolates from Newcastle disease (ND) outbreaks in different regions of Iran were characterized at molecular level. Sequence analysis revealed that the isolates shared two pairs of arginine and a phenylalanine at the N-terminus of the fusion (F) protein cleavage site similarly to other velogenic isolates of NDV characterized earlier. Eight of the nine isolates had the same amino acid sequence as VOL95, a Russian NDV isolate from 1995. However, one isolate, MK13 showed 5 amino acid substitutions, of which 3 have been reported for other velogenic NDV isolates. These results suggest that the origin of the outbreaks of ND in different parts of Iran in 1995-1998 is VOL95.
    Matched MeSH terms: Viral Fusion Proteins/genetics; Viral Fusion Proteins/metabolism; Viral Fusion Proteins/chemistry*
  11. Styrylpyrone derivative induces apoptosis through the up-regulation of Bax in the human breast cancer cell line MCF-7
    Chien AL, Pihie AH
    J. Biochem. Mol. Biol., 2003 May 31;36(3):269-74.
    PMID: 12787481
    In the fight against cancer, novel chemotherapeutic agents are constantly being sought to complement existing drugs. Various studies have presented evidence that the apoptosis that is induced by these anticancer agents is implicated in tumor regression, and Bcl-2 family genes play a part in apoptosis following treatment with various stimuli. Here, we present data that a styrylpyrone derivative (SPD) that is extracted from the plant Goniothalamus sp. showed cytotoxic effects on the human breast cancer cell line MCF-7. SPD significantly increased apoptosis in MCF-7 cells, as visualized by phase contrast microscopy and evaluated by the Tdt-mediated dUTP nick end-labeling assay and nuclear morphology. Western blotting and immunostaining revealed up-regulation of the proapoptotic Bax protein expression. SPD, however, did not affect the expression of the anti-apoptotic protein, Bcl-2. These results, therefore, suggest SPD as a potent cytotoxic agent on MCF-7 cells by inducing apoptosis through the modulation of Bax levels.
    Matched MeSH terms: Proto-Oncogene Proteins/metabolism*; Proto-Oncogene Proteins c-bcl-2*
  12. HLA-DRB genes and antiribosomal P antibodies in systemic lupus erythematosus
    Teh LS, Doherty DG, Williams BD
    Br J Rheumatol, 1994 Dec;33(12):1125-6.
    PMID: 8000739
    Antibodies to the ribosomal P protein are specific for SLE but their prevalence varies in different ethnic groups. In a group of Chinese SLE patients from Malaysia who have a high prevalence of this antibody, we have found an increased frequency of an uncharacterized HLA-DRB gene allele, DR16X, in patients who are positive for anti-P antibodies compared to antibody negative patients (31.3% vs 3.2%, P < 0.01, Pcorr not significant, relative risk = 13.6). DR16X has only been found in south east Asian populations and may be a genetic factor which influences the high prevalence of anti-P antibodies in Chinese.
    Matched MeSH terms: Ribosomal Proteins/immunology*; Protozoan Proteins*
  13. Serum and salivary IgA antibodies against a defined epitope of the Epstein-Barr virus nuclear antigen (EBNA) are elevated in nasopharyngeal carcinoma
    Foong YT, Cheng HM, Sam CK, Dillner J, Hinderer W, Prasad U
    Int J Cancer, 1990 Jun 15;45(6):1061-4.
    PMID: 1693600
    The Epstein-Barr virus nuclear antigen I (EBNA I) is the only latent EBV antigen consistently expressed in malignant tissues of the nasopharynx. A 20-amino-acid synthetic peptide, p107 contains a major epitope of EBNA I. We tested sera from 210 patients with nasopharyngeal carcinoma (NPC) and from 128 normal individuals (NHS) for IgA antibodies to p107 using an enzyme-linked immunosorbent assay (ELISA). Whereas 191/210 (91%) of NPC patients had IgA antibodies to p107, only 17/128 (13.3%) of NHS had such antibodies and only 6/57 (10.5%) of sera from patients with malignancies other than NPC had IgA-p107 reactivity. Thirty-nine salivary samples from 46 NPC patients (84.8%) also contained IgA-p107 antibodies whereas only 3/42 (7.1%) of normal saliva samples were IgA-p107 positive. The results suggest that IgA antibodies to EBNA I may become a useful, easily measurable, marker for NPC.
    Matched MeSH terms: Recombinant Proteins/immunology; Viral Proteins/immunology
  14. Macrolide resistance and genotypic characterization of Streptococcus pneumoniae in Asian countries: a study of the Asian Network for Surveillance of Resistant Pathogens (ANSORP)
    Song JH, Chang HH, Suh JY, Ko KS, Jung SI, Oh WS, et al.
    J Antimicrob Chemother, 2004 Mar;53(3):457-63.
    PMID: 14963068
    To characterize mechanisms of macrolide resistance among Streptococcus pneumoniae from 10 Asian countries during 1998-2001.
    Matched MeSH terms: Bacterial Proteins/genetics; Membrane Proteins/genetics
  15. Recombinant expression of the larval excretory-secretory antigen TES-120 of Toxocara canis in the methylotrophic yeast Pichia pastoris
    Fong MY, Lau YL
    Parasitol Res, 2004 Jan;92(2):173-6.
    PMID: 14655048
    A gene encoding the larval excretory-secretory antigen TES-120 of the dog ascarid worm Toxocara canis was cloned into the methylotrophic yeast Pichia pastoris. Specificity of the recombinant TES-120 antigen produced by the yeast was investigated. Forty-five human serum samples from patients infected with different()parasitic organisms, including 8 cases of toxocariasis, were tested against the recombinant antigen in immunoblot assays. Results from the assays showed that the recombinant TES-120 antigen reacted with sera from toxocariasis patients only. This highly specific recombinant TES-120 antigen can potentially be used for the development of an inexpensive serodiagnostic assay for human toxocariasis.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/immunology*; Recombinant Proteins/metabolism
  16. Protein expression and molecular analysis of c-myc gene in primary breast carcinomas using immunohistochemistry and differential polymerase chain reaction
    Naidu R, Wahab NA, Yadav M, Kutty MK
    Int J Mol Med, 2002 Feb;9(2):189-96.
    PMID: 11786932
    Overexpression of c-myc protein and amplification of c-myc were investigated by immunohistochemistry and differential polymerase chain reaction (dPCR) in 440 formalin-fixed primary breast carcinoma tissues, respectively. Overexpression of c-myc was detected in 45% (199/440) and amplification of c-myc was observed in 25% (112/440) of the primary breast carcinomas. Immunolocalization of c-myc oncoprotein was demonstrated in 35% (8/23) of the comedo subtype, 17% (3/18) of the non-comedo subtype, 37% (15/41) of the comedo DCIS and 49% (20/41) of the adjacent invasive ductal carcinomas, 21% (4/19) of the non-comedo DCIS and 37% (7/19) of the adjacent invasive lesions, 49% (133/270) of the invasive ductal carcinomas, 33% (11/33) of the invasive lobular carcinomas, 29% (6/21) of the colloid carcinomas and 47% (7/15) of the medullary carcinomas. C-myc was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 24% (10/41) of the adjacent invasive ductal carcinomas, 30% (82/270) of the invasive ductal carcinomas, 21% (7/33) of the invasive lobular carcinomas, 14% (3/21) of the colloid carcinomas and 24% (4/15) of the medullary carcinomas. Amplification of c-myc was noted in 16% (3/9) of the invasive ductal carcinomas but not in the adjacent non-comedo DCIS lesions. A significant association (P<0.05) was observed between in situ components and adjacent invasive lesions for c-myc expression and amplification. Overexpression of c-myc protein was significantly correlated with poorly differentiated (P<0.05) and high proliferation index (Ki-67) (P<0.05) tumors but not with lymph node metastases (P>0.05), patient age (P>0.05) and estrogen receptor status (P>0.05). Significant relationship was also noted between amplification of c-myc and absence of estrogen receptor (P<0.05), high histological grade (P<0.05) and high proliferation index (Ki-67) (P<0.05). No relationship was seen with nodal status (P>0.05) and patient age (P>0.05). Majority of the Malaysian female patients are from younger age group (<50 years old) but overexpression and amplification of c-myc was not statistically associated with patient age (P>0.05) indicating that these alterations may be independent events of patient age. The above observations suggest that overexpression and amplification of c-myc could play an important role in tumor progression from non-invasive to invasive and, also, it may have the potential as a marker of poor prognosis of breast cancer.
    Matched MeSH terms: Proto-Oncogene Proteins c-myc/analysis*; Proto-Oncogene Proteins c-myc/genetics; Proto-Oncogene Proteins c-myc/immunology
  17. Fulltext Removal of failed dental implant with application of concentrated growth factor (CGF): a case report
    Nurul Ain Mohamed Yusof, Mohd Salman Masri, Erni Noor
    Compendium of Oral Science, 2018;5(1):46-53.
    MyJurnal
    Introduction: High survival rates of dental implants were commonly reported even after 10 years of follow up. Nevertheless, complications and failure may occur and the implant would need to be removed. In recent years, the use of autogenous blood products in dental surgery has increased due to its ability to aid the healing of the soft and hard tissues. Clinical case: The case demonstrated the utilisation of concentrated growth factor (CGF) from the patient’s blood for healing following conservative removal of a failed dental implant. Subsequently, the patient showed satisfactory recovery without any infections and clinical complaints. Conclusion: This explantation procedure, together with the use of CGF, may prevent the normal bone resorption and accelerate soft tissue healing. As it is biological in nature having originated from the patient’s blood, it is more readily accepted by the tissues and the risk of infection is low.
    Matched MeSH terms: Intercellular Signaling Peptides and Proteins
  18. Molecular cloning and immunoglobulin E reactivity of a natural rubber latex lecithinase homologue, the major allergenic component of Hev b 4
    Sunderasan E, Bahari A, Arif SA, Zainal Z, Hamilton RG, Yeang HY
    Clin Exp Allergy, 2005 Nov;35(11):1490-5.
    PMID: 16297147 DOI: 10.1111/j.1365-2222.2005.02371.x
    BACKGROUND:
    Hev b 4 is an allergenic natural rubber latex (NRL) protein complex that is reactive in skin prick tests and in vitro immunoassays. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Hev b 4 is discerned predominantly at 53-55 kDa together with a 57 kDa minor component previously identified as a cyanogenic glucosidase. Of the 13 NRL allergens recognized by the International Union of Immunological Societies, the 53-55 kDa Hev b 4 major protein is the only candidate that lacks complete cDNA and protein sequence information.

    OBJECTIVE:
    We sought to clone the transcript encoding the Hev b 4 major protein, and characterize the native protein and its recombinant form in relation to IgE binding.

    METHODS:
    The 5'/3' rapid amplification of cDNA ends method was employed to obtain the complete cDNA of the Hev b 4 major protein. A recombinant form of the protein was over-expressed in Escherichia coli. The native Hev b 4 major protein was deglycosylated by trifluoromethane sulphonic acid. Western immunoblots of the native, deglycosylated and recombinant proteins were performed using both polyclonal antibodies and sera from latex-allergic patients.

    RESULTS:
    The cDNA encoding the Hev b 4 major protein was cloned. Its open reading frame matched lecithinases in the conserved domain database and contained 10 predicted glycosylation sites. Detection of glycans on the Hev b 4 lecithinase homologue confirmed it to be a glycoprotein. The deglycosylated lecithinase homologue was discerned at 40 kDa on SDS-PAGE, this being comparable to the 38.53 kDa mass predicted by its cDNA. Deglycosylation of the lecithinase homologue resulted in the loss of IgE recognition, although reactivity to polyclonal rabbit anti-Hev b 4 was retained. IgE from latex-allergic patients also failed to recognize the non-glycosylated E. coli recombinant lecithinase homologue.

    CONCLUSION:
    The IgE epitopes of the Hev b 4 lecithinase homologue reside mainly in its carbohydrate moiety, which also account for the discrepancy between the observed molecular weight of the protein and the value calculated from its cDNA.
    Matched MeSH terms: Plant Proteins/immunology; Recombinant Proteins/immunology
  19. Detection of immunoglobulin antibodies in the sera of patients using purified latex allergens
    Kurup VP, Yeang HY, Sussman GL, Bansal NK, Beezhold DH, Kelly KJ, et al.
    Clin Exp Allergy, 2000 Mar;30(3):359-69.
    PMID: 10691894
    BACKGROUND: Latex allergy is largely an occupational allergy due to sensitization to natural rubber latex allergens present in a number of health care and household products. Although several purified allergens are currently available for study, information on the usefulness of these purified, native or recombinant allergens in the demonstration of specific immunoglobulin (Ig) E in the sera of patients is lacking.

    OBJECTIVE: To evaluate the purified latex allergens and to demonstrate specific IgE antibody in the sera of health care workers and spina bifida patients with clinical latex allergy.

    METHODS: Two radioallergosorbent and an enzyme-linked immunosorbent assay (ELISA) using latex proteins Hev b 1, 2, 3, 4, 6 and 7 along with two glove extracts and Malaysian nonammoniated latex (MNA) were evaluated to demonstrate IgE in the sera of health care workers and spina bifida with latex allergy and controls with no history of latex allergy.

    RESULTS: ELISA using the purified latex allergens demonstrated specific IgE in 32-65% health care workers and 54-100% of spina bifida patients with latex allergy. The corresponding figures for RAST were 13-48 and 23-85 for RAST-1 and 19-61 and 36-57 for RAST-2. These results were comparable with the results obtained with glove extracts and crude rubber latex proteins.

    CONCLUSIONS: When used simultaneously, latex proteins Hev b 2 and Hev b 7 reacted significantly with specific serum IgE in 80% of health care workers and 92% of spina bifida patients with latex allergy by ELISA technique, while this combination gave lower positivity when the RASTs were used. By the addition of Hev b 3, specific IgE was detected in all spina bifida patients with latex allergy. Both RASTs failed to show specific IgE in the control subjects, while the ELISA showed significant latex-specific IgE in 22% of controls.

    Matched MeSH terms: Plant Proteins/immunology; Recombinant Proteins/immunology
  20. Allergen concentration in natural rubber latex
    Yeang HY, Hamilton RG, Bernstein DI, Arif SA, Chow KS, Loke YH, et al.
    Clin Exp Allergy, 2006 Aug;36(8):1078-86.
    PMID: 16911364 DOI: 10.1111/j.1365-2222.2006.02531.x
    BACKGROUND:
    Hevea brasiliensis latex serum is commonly used as the in vivo and in vitro reference antigen for latex allergy diagnosis as it contains the full complement of latex allergens.

    OBJECTIVE:
    This study quantifies the concentrations of the significant allergens in latex serum and examines its suitability as an antigen source in latex allergy diagnosis and immunotherapy.

    METHODS:
    The serum phase was extracted from centrifuged latex that was repeatedly freeze-thawed or glycerinated. Quantitation of latex allergens was performed by two-site immunoenzymetric assays. The abundance of RNA transcripts of the latex allergens was estimated from the number of their clones in an Expressed Sequence Tags library.

    RESULTS:
    The latex allergens, Hev b 1, 2, 3, 4, 5, 6, 7 and 13, were detected in freeze-thawed and glycerinated latex serum at levels ranging from 75 (Hev b 6) to 0.06 nmol/mg total proteins (Hev b 4). Hev b 6 content in the latex was up to a thousand times higher than the other seven latex allergens, depending on source and/or preparation procedure. Allergen concentration was reflected in the abundance of mRNA transcripts. When used as the antigen, latex serum may bias the outcome of latex allergy diagnostic tests towards sensitization to Hev b 6. Tests that make use of latex serum may fail to detect latex-specific IgE reactivity in subjects who are sensitized only to allergens that are present at low concentrations.

    CONCLUSION:
    Latex allergy diagnostics and immunotherapy that use whole latex serum as the antigen source may not be optimal because of the marked imbalance of its constituent allergens.
    Matched MeSH terms: Plant Proteins/analysis; Plant Proteins/genetics; Plant Proteins/immunology*
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