OBJECTIVETo analyze related factors which affect GPA mutation frequency of workers exposed to benzene, with the Glycophorin A (GPA) mutation assay and explore the possibility of GPA mutation frequency as an index of predicting the risk of benzene poisoning.

METHODSThe erythrocytes were bound with fluorescent-labeled monoclonal antibody after isolated and fixed from the peripheral blood, and then the GPA mutation assay was performed using the flow cytometry (FCM). The related factors of GPA mutation frequency were analyzed by statistical methods.

RESULTSThe GPA mutation frequency of chronic benzene poisonings was significantly higher than that of their controls (P < 0.05). Significant direct correlation was found between age, length of service, accumulative exposure score and the GPA mutation frequency of workers exposed to benzene (P < 0.01). However, there was significantly inverse correlation between the 3AB index and the GPA mutation frequency (GPAN0: r(s) = -0.589, P < 0.01, GPANN: r(s) = -0.615, P < 0.01). In the multiple factor regression analysis on GPA mutation frequency, benzene exposure and individual susceptibility both entered model of multiple factors analysis, the coefficient of determination of benzene-exposed workers was 0.819.

CONCLUSIONExposure to benzene and individual susceptibility are the most important factors that affect GPA mutation frequency. GPA mutation frequency increases with the benzene exposure and individual susceptibility.

Benzene ; poisoning ; Glycophorin ; genetics ; Humans ; Mutation ; Mutation Rate ; Occupational Exposure

OBJECTIVES: To assess the availability of the glycophorin A (GPA) assay to detect the biological effect of ionizing radiation in workers exposed to low-doses of radiation. METHODS: Information on confounding factors, such as age and cigarette smoking was obtained on 144 nuclear power plant workers and 32 hospital workers, by a self-administered questionnaire. Information on physical exposure levels was obtained from the registries of radiation exposure monitoring and control at each facility. The GPA mutant assay was performed using the BR6 method with modification by using a FACScan flow cytometer. RESULTS: As confounders, age and cigarette smoking habits showed increasing trends with GPA variants, but these were of no statistical significance. Hospital workers showed a higher frequency of the GPA variant than nuclear power plant workers in terms of the NO variant. Significant dose-response relationships were obtained from in simple and multiple linear regression models. The slope of the regression equation for nuclear power plant workers was much smaller than that of hospital workers. These findings suggest that there may be apparent dose-rate effects. CONCLUSION: In population exposed to chronic low-dose radiation, the GPA assay has a potential to be used as an effective biologic marker for assessing the bone marrow cumulative exposure dose.
Biomarkers* ; Bone Marrow ; Glycophorin* ; Linear Models ; Nuclear Power Plants ; Surveys and Questionnaires ; Radiation, Ionizing ; Registries ; Smoking

BACKGROUND: The Polycomb-group gene Bmi-1 is known to be a molecular regulator of self-renewal of normal and leukemic stem cells and be involved in various aspects of cellular proliferation, differentiation, and survival. METHODS: This study evaluated the effects of overexpression of Bmi-1 on human cord blood CD34+ cells. Bmi-1 was introduced into CD34+ cells through lentivirus transduction. Bmi-1 expressing CD34+ cells were applied to colony forming assay, stromal co-culture, and cytokine-stimulatied culture. RESULTS: Ectopic expression of Bmi-1 resulted in the increased number of erythroid colonies in primary and secondary colony forming assay in an erythropoietin dependent manner. In stromal co-culture, Bmi-1-expressing postnatal hematopoietic stem cells seemed to lose the ability of self-renewal, as determined by week 5 cobblestone area-forming cell assay and by week 5 secondary colony assay. In cytokine-stimulated suspension culture of Bmi-1-transduced CD34+ cells, we observed increased erythropoiesis marked by Glycophorin A expression. CONCLUSION: Our data suggest that ectopic expression of Bmi-1 in human hematopoietic stem/progenitor cells may result in the differentiation to the erythroid lineage rather than promoting self-renewal.
Cell Proliferation ; Coculture Techniques ; Erythropoiesis ; Erythropoietin ; Fetal Blood ; Glycophorin ; Hematopoietic Stem Cells ; Humans* ; Lentivirus ; Stem Cells

Fetal nucleated red blood cells (nRBCs) are rare in maternal circulation, but their presence constitutes a potential source of non-invasive prenatal genetic diagnosis. This study was undertaken to establish a non-invasive prenatal genetic diagnosis method using isolated fetal nRBCs. A multi-step method including triple density gradient and magnetic activated cell sorting (MACS) using CD45 and CD71, cytospin centrifugation, K-B staining, and glycophorin A-immuno fluorescence in situ hybridization (GPA-immuno FISH) was performed. The study population included 65 patients from 8 to 41 weeks of gestation, and fetal nRBC was separated from all cases. The number of fetal nRBCs retrieved was 12.8 +/- 2.7 in 8 to 11 gestational weeks, 15.2 +/- 6.5 in 12 to 18 gestational weeks, 16.4 +/- 6.5 in 19 to 23 gestational weeks, 10.6 +/- 3.2 in 24 to 28 gestational weeks, and 5.5 +/- 1.9 in 35 to 41 gestational weeks: the mean number of nRBCs collected from 20 ml of maternal peripheral blood was 13.7 +/- 6.2. The highest value of yield was 45.6% from 12 to 18 weeks gestation. The fetal sex determination confirmed by amniocentesis or chorionic villus sampling showed 100% sensitivity and 91.7% specificity for males; 91.7% sensitivity and 100% specificity for females. We showed that fetal cells can be reliably enriched from maternal blood and that they can be used for detecting specific chromosomes by FISH with a specificity superior to current non-invasive methods.
Erythrocytes/immunology* ; Female ; Fetal Blood/immunology* ; Gestational Age ; Glycophorin ; Human ; Immunomagnetic Separation ; Immunophenotyping ; In Situ Hybridization, Fluorescence* ; Pregnancy ; Prenatal Diagnosis*

UNLABELLEDObjective： To study the effect of PD98059, a specific inhibitor of Ras/Raf/MEK/ERK signaling pathway, on the proliferation and apoptisis of bone marrow CD71(+), CD235a(+) nucleated erythrocytes in patients with high altitude polycythemia (HAPC) and the pathogenesis of HAPC.

METHODSThe CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients and controls (patients with simple obsolete stracture) were sorted by using the immunemagnetic beads, then were added with 5, 10, 20 µmol/L of PD98059 and DMSO (as control) and were cultured for 72 h under hypoxia. The cell apoptosis was detected by flow cytometry with Annexin V and PI double staining, the cell proliferation was detected by CCK8 method, at same time the erythroid colong-formation ability of bone marrow mononuclear cells (BMMNC) treated with 5, 10, 20 µmol/L of PD98059 and DMSO was observed.

RESULTSWith the increase of PD98059 concentration, the apoptosis rate of bone marrow CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients was enhanced (r=0.807,P<0.01), while the proliferation rate of CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients dereased (r=0.502,P<0.01). The erythroid colong-formation ability of BMMNC in HAPC patients decreased with the increase of PD98059 concentration (r=0.504,P<0.01). There were statistic differences among different groups at 7 and 14 d.

CONCLUSIONThe MEK specific inhibitor PD98059 can inhibit the proliferation and promote the apoptosis of CD71(+) and CD235a(+) nucleated erythrocytes in HAPC patients, then inhibit the excessive accumulation of erythrocytes.

Altitude Sickness ; Apoptosis ; Bone Marrow ; Bone Marrow Cells ; Cell Proliferation ; Erythroblasts ; Erythrocyte Count ; Erythrocytes ; Flavonoids ; Flow Cytometry ; Glycophorin ; Humans

OBJECTIVETo detect the base sequences of all exons and part of introns in the GYPA gene of the glycophorin GPA and to investigate the polymorphism of M, N alleles in Chinese population.

METHODSA total of 225 blood sample were randomly colleeted from unrelated Chinese volunteers and were detected by serology techniques. The primers were designed by self, the seguencing of GYPA gene related with sample exon 1-7 full length sequences of bases and intron-1-7 partial sequence was performed, the polymorphism of M, N gene mutation in mucleotide sequence was analysed.

RESULTSThe results of M and N genotyping were in agreement with the results of serological detection. The 23rd base of intron-2, the 55th base of intron-3, the 63rd base of intron-4, the 55th, 189th and 190th base of intron-6, the 712th base variation of exon-7 in the gene M and N were used to subdivide the gene M and N into the mutant M103, M201, M202, N101, N102, N103, N104, and N201. At the same time, it was found that 42th and 54th base were mutated, the base T was inserted between 59th and 60th base in the intron-2, the new mutations occurred in the alleles 28, 29, 65 and 102 in intron-3 in this study.

CONCLUSIONThe polymorphism of the the Chinese population's GYPA gene occurs in all the exons and partly in the introns. The gene polymorphism of M and N blood group in Chinese population might provide the theoretical basis for the studies of clinical blood transfusion, human population genetics and molecular biology.

Alleles ; Asian Continental Ancestry Group ; Blood Group Antigens ; Blood Grouping and Crossmatching ; Exons ; Genotype ; Glycophorin ; Humans ; Introns ; Polymorphism, Genetic

Red blood cells that agglutinate with most normal adult sera but never with own sera are termed polyagglutinable and can be separated by patterns of lectin reactivity into various types. Among these polyagglutination, activation of the T cryptantigen occurs when carbohydrate structures on glycophorins A and B lose sialic acid and express the disaccharide Gal beta-l-3 GalNac which reacts with the peanut agglutinin, a lectin from Arachis hypogaea. T activation is a temporary condition due to exposure of the membrane antigen to the action of microbial neuraminidase. In T activated red cells, the following hazards, which are theoretically possible, are spontaneous polyagglutination of red cells in vitro, in vivo and severe blood transfusion reactions. We experienced a case of T activation in 6 month old girl with bacterial meningitis caused by Streptococcus pneumoniae. The reactivity to lectins indicated the patient's red cells were T activated. We report a case of T activation in an infant with the review of literature.
Adult ; Arachis ; Blood Transfusion ; Erythrocytes ; Female ; Glycophorin ; Humans ; Infant ; Lectins ; Membranes ; Meningitis, Bacterial ; N-Acetylneuraminic Acid ; Neuraminidase ; Peanut Agglutinin ; Streptococcus pneumoniae

OBJECTIVETo identify the binding site on glycophorin A (GPA) for EBA-175 to provide clue for developing short peptide vaccine and therapeutic agents against Plasmodium falciparum.

METHODSWith the recombinant protein of EBA-175 as the target molecule, the mimetic peptides of GPA were screened from a 12-mer random peptide library. Three rounds of biopanning were carried out, and enzyme-linked immunosorbent assay (ELISA), competitive ELISA, Dot-ELISA and Western blotting used to evaluate the binding between the phage-borne peptides and EBA-175. The insert DNA sequences of positive clones were determined and their amino acid sequences deduced.

RESULTSThirty clones from the third round were randomly selected, of which 27 were found positive by sandwich ELISA. Competitive ELISA proved that most of the phage-borne peptides could competitively inhibit the binding of antibody (EBA-175 Ab) with EBA-175. Analysis of DNA and amino acid sequences indicated that 24 positive phage clones contained the conservative sequence of IRR, which was highly homologous with the 114-116 amino acids of GPA.

CONCLUSIONThese phage-displayed peptides can bind with EBA-175, and the amino acid sequence IRR might play an important role in the binding between EBA-175 and GPA.

Antigens, Protozoan ; metabolism ; Binding Sites ; Enzyme-Linked Immunosorbent Assay ; Glycophorin ; chemistry ; Humans ; Peptide Library ; Plasmodium falciparum ; Protozoan Proteins ; metabolism ; Sequence Analysis, DNA ; Sequence Analysis, Protein

PURPOSE: This study was performed to induce proliferation and differentiation of erythroid progenitors from cord blood CD34 cells using extracellular matrix (ECM) and stromal cells. METHODS: Cord blood mononuclear cells were separated using Ficoll-Hypaque and CD34 cells were purified by Mini-MACS column. Cells were cultured in IMDM medium including 10% FBS and several cytokines (EPO, flt3-ligand, SCF and TPO) upto 14 days. ECM like laminin, collagen IV, fibrinogen and fibronectin were used alone or in combination. Stromal cells were derived from BM mononuclear cells for 4 weeks of culture and irradiated before use. On day 14 of stromal coculture of cord blood CD34 cells, flow cytometric analysis were done with fluorescence isothiocyanate-conjugated (FITC) antihuman glycophorin A antibody for erythroid cells. RESULTS: ECM-treated group showed 16.3~31.3 fold increase of the cell numbers on day 14 and there were no difference from cytokines-treated group. Stromal cells induced great amount of fold increase compared with ECM-treated group on day 7 (25.4 fold vs. 2.2~5.4 fold). The cell numbers increased upto 16.4 fold on day 7, 92.8 fold on day 10, and 198.4 fold on day 14 with stromal cells. Erythroid progenitors expressing glycophorin A increased from 2.78% on day 0 to 21.57% on day 7 and 43.87% on day 14. CONCLUSION: Stromal coculture of cord blood CD34 cells induced marked proliferation and differentiation of erythroid cells compared with cytokines or ECM-treated group. Efficient in vitro erythroid culture might have implications for gene therapy in RBC defects or developing blood substitutes for transfusions.
Blood Substitutes ; Cell Count ; Coculture Techniques ; Collagen ; Cytokines ; Erythroid Cells ; Extracellular Matrix* ; Fetal Blood* ; Fibrinogen ; Fibronectins ; Fluorescence ; Genetic Therapy ; Glycophorin ; Laminin ; Stromal Cells*

This study was purposed to investigate the molecular polymorphism of gypa gene in association with MN human blood group in Chinese Han population. The MN phenotypes of 202 random samples from unrelated Chinese Han volunteers were identified by serology techniques. The primer for gypa gene exon 2 were designed and synthesized according to reference sequences of NG-007470 gene from GenBank, the DNA of 202 samples was amplified by PCR, at the same time, the amplified products were analyzed by direct DNA sequencing. The results showed that all samples had 2 base substitutions at 1st and 56th nt of gypa exon 2, among them the MN phenotype heterozygote exited mainly in the form of 1A > C, 22T/C, 34A/G, 35T/G, 56T > C; the MM phenotype homozygote exited mainly in the form of 1A > C, 22C, 34G, 35T, 56T > C; the NN phenotype homozygote exited mainly in the form of 1A > C, 22T, 34A, 35G, 56T > C. It is concluded that the polymorphism of gypa gene in associated with MN blood group in Chinese Han population is decided by 5 nucleotide sites of 1, 22, 34, 35 and 56. The bases of 1 and 56 are non-functional gypa single nucleotide polymorphism.
Asian Continental Ancestry Group ; genetics ; Base Sequence ; Exons ; Genotype ; Glycophorin ; genetics ; Humans ; MNSs Blood-Group System ; genetics ; Molecular Sequence Data ; Polymorphism, Genetic ; Sequence Analysis, DNA