[Scanning aneugen and clastogen by micronuclei analysis using flow cytometry].

OBJECTIVE: To explore a flow cytometry (FCM)-based method for discriminating aneugen- or clastogen-induced micronuclei. METHODS: Cells were stained with anti-CD71-FITC and PI, and the PI fluorescent signal intensity of micronucleated reticulocyte (MN-RET) in the peripheral blood of NIH mouse treated with COL or CP was detected by flow cytometry. RESULTS: The ratio of the median of the intensity of MN-RET fluorescent signals to that of nucleated cell was low in the cyclophosphamide treated mouse, while the median was high in the colchicine treated mouse. CONCLUSION: The flow cytometry-based micronucleus assay can be used to discriminate primarily smaller MN induced by the clastogen exposure from the larger MN induced by an aneugen.

[Relationship between the genotype and hematologic characteristics in the fetuses with thalassemia].

OBJECTIVES: To investigate the relationship between the genotype and the hematologic characteristics in the fetuses with different types of thalassemia. METHODS: Fetal blood samples were taken by cordocentesis, and hemograms from 572 fetuses at the gestational age of 18 to 38 weeks were examined. According to the genotypes of thalassemia, there were 117 fetuses with heterozygous alpha-thalassemia-1, and 60 with homozygous alpha-thalassemia-1. Twenty had beta-thalassemia mild, and 9 had beta-thalassemia major, respectively. The hematological parameters in these groups were compared with reference group in which 366 cases were included. RESULTS: In alpha-thalassemia groups, hemoglobin (Hb), hematocrit (HCT), mean cell volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) significantly decreased (P < 0.001), but in heterozygous alpha-thalassemia-1, red blood cell (RBC) increased. In homozygous alpha-thalassemia-1, RBC decreased significantly (P < 0.001), but white blood cell and nucleated erythrocyte increased (P < 0.001). There were no significant differences between beta-thalassemia and reference group in most hematological parameters except for decrease of MCHC. CONCLUSIONS: In the fetal period, the hemogram of the fetuses with alpha-thalassemia changes significantly, while it does not change in beta-thalassemia. For the couple with heterozygous alpha-thalassemia, hemogram can provide some information for prenatal screening and diagnosis for those fetuses with alpha-thalassemia, especially for homozygous, but genotype detection is necessary for confirming the diagnosis.

[Quantitative analysis of human globin gene expression in beta-thalassemia using real-time RT-PCR].

Whole blood samples were collected from 100 normal healthy adults, from umbilical cord of 33 newborn infants, 111 individuals with beta-thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and 39 with beta-thalassemia major (beta(T)/beta(T),alphaalpha/alphaalpha). Prior to quantitative analysis of globin gene expression, DNA was extracted from all blood samples and used for beta-thalassemia genotype analysis. Different types of beta globin gene mutations were analyzed using reverse dot blotting (RDB) method. Total RNA were extracted and subjected to real-time RT-PCR for quantitative measurement of alpha, beta and gamma globin mRNA using three sets of primers and fluorescent-labeled probes, designed according to the sequences of alpha, beta and gamma human globin gene. Real-time RT-PCR was performed in ABI 7700 system. Following the real-time RT-PCR, the mean values of alpha, beta and gamma globin mRNA were calculated and the ratios of alpha/beta, alpha/(beta + gamma ) and gamma /(beta + gamma ) were determined to characterize the relative expression levels of different globin genes among normal adult, infant, beta-thalassemia minor and beta-thalassemia major patients. The resultant data were analyzed using SPSS 10.0 software to determine statistical significance of human globin gene expression among normal controls and beta-thalassemia patients. Due to vast variations of the mean globin gene mRNA levels among different groups, log conversion of alpha/beta + 1, alpha/(beta + gamma ) + 1 and gamma /(beta + gamma ) +1 was used for statistical analyses and intergroup comparison. The alpha/beta globin gene mRNA ratios were determined to be 4.62+/-1.20, 7.81+/-2.89, 13.51+/-5.12, and 188.24+/-374.04 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta-thalassemia major(beta(T)/beta(T),alphaalpha/alphaalpha) respectively. The alpha/(beta+ gamma ) ratios were 4.43+/-1.17, 0.56+/-0.49, 9.62+/-4.37, and 2.14+/-1.58 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta- thalassemia major(beta(T)/beta(T),alphaalpha/alphaalpha) respectively. The gamma /(beta+ gamma ) ratios were 0.04+/-0.03, 0.92+/-0.06, 0.28+/-0.18, and 0.95+/-0.04 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta- thalassemia major (beta(T)/beta(T),alphaalpha/alphaalpha) respectively. Following statistical analyses, the alpha/beta and alpha/(beta+ gamma ) globin gene mRNA ratios were significantly different among four different groups (normal adult, normal infant, beta- thalassemia minor and beta- thalassemia major). The gamma /(beta + gamma ) globin gene mRNA ratio was significantly different among all groups except for between infant and beta- thalassemia major patients. Human beta globin gene mRNA levels decrease progressively and dramatically from normal adults to beta-thalassemia patients with beta-thalassemia major having the lowest levels. On the other hand, the gamma globin gene mRNA levels increase progressively from normal adult to beta-thalassemia patients with beta-thalassemia major having the highest levels. Infants have relatively lower levels of beta but higher levels of gamma globin gene mRNA as compared to those in normal adults. Thus, the relative expression levels of alpha, beta or gamma globin genes varied but inter-related among different ages of normal individuals and different beta-thalassemia genotypes.

[Study of immunological indicators in peripheral blood for nasopharyngeal carcinoma].

OBJECTIVE: To find reliable diagnostic immunological indicators in peripheral blood for nasopharyngeal carcinoma, and to evaluate the possibility of cancer screening and early diagnosis of the malignancies in the future. METHODS: Plasma samples were obtained from 83 patients with nasopharyngeal carcinoma and from 105 patients with benign diseases. Nine cytokines were selected as the candidates for the indicators and their quantity in the plasma samples determined by enzyme-linked immunosorbent assay, the result of which was analyzed statistically. RESULTS: Interleukin (IL)-4 level was obviously increased, while IL-6, IL-12, transforming growth factor (TGF)-beta, interferon (IFN)-gamma levels significantly reduced (P<0.05) in the plasma from patients with nasopharyngeal carcinoma. CONCLUSION: These cytokins may serve as the indicators in the diagnosis of nasopharyngeal carcinoma.

[Establishment of a method for HLA-DRB genotyping in cord blood by reverse dot-blot hybridization technique].

The HLA system was discovered by virtue of the fact that it was polymorphic. The impetus for its discovery was the search for polymorphic antigens to match for transplantation, by analogy with the human red cell blood groups. The most usually DNA method of HLA typing is sequence specific oligonucleotides (SSO) and PCR sequence specific primers (SSP). SSO technique is perfectly suited for analyzing large number of samples, it is not suitable for individual or small numbers. The SSP method is ideal for typing individual samples, but it is costly and requires high capacity thermal cycles for larger numbers of samples. To set up a simple, quick, cheap and high resolution DNA method, were collected sixty-three cord blood samples from Guangzhou Cord Blood Bank, got DNA from blood by the traditional guanidine hydrochloride distillation method. Each sample was simultaneously typed by SSOP, PCR-SSP and reverse dot-blot hybridization (RDB) methods. All of typed is success. The results of three DNA methods are consistent each other. 60 HLA-DRB1 alleles could be accurately distinguished with the RDB method. Our results show that RDB method is a simple, quick, cheap and high resolution method for HLA-DRB types. It can be used in any HLA typing.