Identification of Novel Hb Guiyang [HBA2: c.151C > A α2 50 (CE8) His- Asn] and Phenotype- Genotype Correlation of Abnormal Hemoglobins in Guizhou, Southwest China.

Purpose: To analyze the composition of abnormal hemoglobin and the relationship between genotype and phenotype by screening abnormal hemoglobin in a subpopulation of Guizhou, China. Patients and Methods: Routine blood evaluation, capillary electrophoresis of hemoglobin, and mutation of α - and ß - thalassemia genes were evaluated in 19,976 individuals for thalassemia screening in Guizhou. Sanger sequencing of HBA1, HBA2 and HBB genes was performed in samples with abnormal bands or unexplained increases of normal bands. The types of abnormal hemoglobin were obtained by sequence analysis. Results: Abnormal hemoglobin was detected in 84 individuals (detection rate, 0.42%). Ten types each of α and ß globin chain variants were detected, including most commonly Hb E, Hb New York and Hb Port Phillip. In this study, the abnormal Hb Mizuho was identified for the first time in a Chinese population, and a novel abnormal hemoglobin Hb Guiyang (HBA2: c.151C > A) was detected for the first time. Except for Hb Mizuho, other abnormal hemoglobin heterozygotes without thalassemia or iron deficiency had no significant hematological changes. Conclusion: This study enriched the molecular epidemiological data of abnormal hemoglobin in Guizhou, China and provided reference data for genetic counseling and prenatal diagnosis of abnormal hemoglobin.

Reference intervals for HbA2 and HbF and cut-off value of HbA2 for ß-thalassemia carrier screening in a Guizhou population of reproductive age.

OBJECTIVE: The aims of this study were to establish the reference intervals for HbA2 and HbF in a Guizhou population of reproductive age, and to determine the cut-off value of HbA2 for ß-thalassemia carrier screening. METHODS: Hemoglobin analysis was performed on 832 individuals without hypochromic microcytic anemia to calculate the reference intervals for HbA2 and HbF. Three hundred and ninety one ß-thalassemia carriers and non ß-thalassemia individuals were analyzed for their HbA2 levels followed by detecting ß-globin gene mutations, then cut-off value of HbA2 for ß-thalassemia carrier screening was determined using ROC curve analysis. RESULTS: The reference interval for HbA2 in overall normal individuals was 2.3%-3.1%, and reference intervals for HbF in normal males and females (including normal females and pregnant women) were 0-0.5% and 0-1.0% respectively. The cut-off values of HbA2 for ß-thalassemia carrier screening in males, non-pregnant women, pregnant women and the overall set were 4.40%, 3.75%, 3.70% and 3.95% respectively. CONCLUSION: Gender and pregnancy status had no obvious influence on reference interval for HbA2. The HbF level was higher in females than in males, but pregnancy status had no obvious influence on HbF level. Cut-off value of HbA2 for ß-thalassemia carrier screening was obviously affected by gender but not by pregnancy status.

[Effect of Blocking PYR Complex Binding to DNA Site by Peptide Nucleic Acid on γ-Globin Gene Expression].

OBJECTIVE: To investigate the effect of blocking polypyrimidine complex binding to DNA site by using peptide nucleic acid (PNA) on γ-globin gene expression. METHODS: PYR-PNA, ß-PNA and RS-PNA (random sequence-PNA) were designed and synthesized, then were transfected into K562 cells with the cationic liposome lipofectamine 2000 used as vector. The expression of γ-globin gene at both the transcriptional and translational level was detected by RT-PCR and the Western blot respectively at 24 h, 48 h and 72 h after transfection with PNAs. RESULTS: Compared with RS-PNA and control groups, the expression of γ-globin gene at mRNA and protein levels in PYR-PNA group was significantly up-regulated(P<0.05), especially at 48 h after tranfection, the levels of mRNA and protein in PYR-PNA group were increased by 2.0 and 2.5 times than those in control group, respectively. CONCLUSION: PYR-PNA can significantly up-regulate the expression of γ-globin gene in K562 cells, this study may provide a new research idea for gene therapy of ß-thalassemia.

The Prevalence and Spectrum of α-Thalassemia in Guizhou Province of South China.

α-Thalassemia (α-thal) is one of the most prevalent genetic diseases in the world and is especially frequent in tropical and subtropical regions, including South China. The aim of this study was to investigate the prevalence and spectrum of α-thal in Guizhou Province as this information was unknown. A total of 40 α-thal carriers were determined in 1219 newborn umbilical cord blood samples by hemoglobin (Hb) electrophoresis combined with DNA analysis, which revealed that the carrier rate of α-thal in Guizhou Province was 3.28%. One thousand and forty-five individuals referred to our hospital were tested for α-thal mutations. Two hundred and twenty-four cases were determined as α-thal carriers or patients. A total of 11 genotypes and five different α-thal mutations were identified in these 224 cases. Of these mutations, more than 96.0% were deletions, including - -(SEA) (65.89%), -α(3.7) (rightward) (22.87%) and -α(4.2) (leftward) (7.74%). The other two nondeletional mutations, Hb Constant Spring (Hb CS, α(CS)α, HBA2: c.427T > C) and Hb Quong Sze [Hb QS, α(QS)α, HBA2: c.377T > C (or HBA1)] account for 2.71% and 0.78%, respectively. The results of this study will be useful in genetic counseling and prenatal diagnosis (PND) of α-thal in Guizhou Province.

[Analysis on effectiveness of platelet transfusion in 1786 patients].

This study was aimed to observe and analyze the effectiveness of platelet transfusion. The platelet count of 1786 patients before transfusion and on 20-24 hours after transfusion was determined by using Auto-Hematology Analyzer, the percent platelet recovery (PPR) was calculated, the platelet transfusion efficiency (PTE) was evaluated by PPR and hemorrhage presentation after platelet transfusion, and the PTE was statistically analyzed according to disease cause, transfusion frequency, platelet type and once transfusion amount. The results showed that the total PTE of 1786 patients was 52.5%. The comparison of PTE among groups of disease cause showed that PTE in leukemia and aplastic anemia (AA) was lowest, as compared with that of other diseases (P < 0.05), while PTE in operation group was highest. The comparison of PTE among groups of transfusion frequency revealed also statistical difference (P < 0.01), meanwhile PTE decreased with increasing of transfusion frequency. The comparison of PTE among groups of platelet type (platelet phoresis or platelet concentrate) showed statistical difference (P < 0.01). The comparison of PTE among groups of platelet concentrate of once transfusion amount showed no statistical difference (P > 0.05). It is concluded that the PTE closely relates with disease cause of patients, moreover transfusion frequency also associates with PTE, the more frequency of transfusion, the higher possibility of transfusion refractoriness. The PTE of platelet pheresis is obviously superior to that of platelet concentrate, while PTE of platelet concentrate not significantly relates with once adequate or not.

[Impact of five genetic polymorphisms on inter-individual variation in warfarin maintenance dose].

OBJECTIVE: To investigate the effect of genetic polymorphisms in VKORC1, CYP2C9, GGCX, EPHX1, APOE genes on inter-individual variation in warfarin maintenance dose. METHODS: Two hundred and forty-nine patients with stable warfarin dose were enrolled in this study, and the clinical data and blood samples of the patients were collected. Genotypes for the 5 genes were determined by using PCR and denaturing high performance liquid chromatography (DHPLC) assay. The warfarin maintenance doses were compared among patients with different genotypes of the 5 genes, and a warfarin stable dosing algorithm was derived based on genetic and non-genetic factors. RESULTS: Of the 5 genes, VKORC1, CYP2C9 and GGCX were associated with warfarin stable dose. The multiple linear regression analysis indicated that VKORC1, CYP2C9 and GGCX genes, age and weight, had significant influence on inter-individual variation in warfarin stable dose, which contributed 30.2%, 22.8%, 1.5%, 4.7% and 6.7% respectively. The warfarin stable dosing algorithm acquired from the optimal regression model could explain 57.8% variation in warfarin dose. CONCLUSION: This study suggested that genetic factors are the major determinants of the warfarin maintenance dose, and warfarin stable dosing algorithm may be useful for helping clinicians to prescribe warfarin with greater safety and efficiency.

Influence of GGCX genotype on warfarin dose requirements in Chinese patients.

INTRODUCTION: It has been widely accepted that genetic factors were the major sources of the variation in warfarin dose. This study is intended to investigate whether the 3261G>A variation in GGCX gene influences stable warfarin dose in Chinese patient population. MATERIALS AND METHODS: A total of 217 patients with stable warfarin dose were enrolled. Genomic DNA was extracted from each subject and the genotype of GGCX 3261G>A was determined by using of denaturing high-performance liquid chromatography (DHPLC). Least significant difference tests (LSDs) were used to compare dose with genotypes. Analysis of variance (ANVOA) was used to calculate the proportion of warfarin dose that could be explained by variation in genotype. RESULTS: In the total of 217 subjects, 84 patients (38.7%) were GG homozygote, whereas 117 (53.9%) were GA heterozygote and 16 (7.4%) were AA homozygote. Patients with the GGCX 3261AA genotype had a significantly higher average daily maintenance dose (3.39 ± 1.40 mg) than those with the GG genotype (2.69 ± 1.07 mg; P=0.027), and GGCX 3261G>A explains 2.3% of the univariate warfarin dose variance. CONCLUSION: GGCX 3261G>A may affect warfarin dose requirements, and showed a small but significant effect on warfarin dose in a Chinese patient population.

[Clinical applications of dosing algorithm in the predication of warfarin maintenance dose].

OBJECTIVE: To evaluate the feasibility of clinical application for genetic based dosing algorithm in the predication of warfarin maintenance dose in Chinese population. METHODS: The clinical data were collected and blood samples harvested from a total of 126 patients undergoing heart valve replacement. The genotypes of VKORC1 and CYP2C9 were determined by melting curve analysis after PCR. They were divided randomly into the study and control groups. In the study group, the first three doses of warfarin were prescribed according to the predicted warfarin maintenance dose while warfarin was initiated at 2.5 mg/d in the control group. The warfarin doses were adjusted according to the measured international normalized ratio (INR) values. And all subjects were followed for 50 days after an initiation of warfarin therapy. RESULTS: At the end of a 50-day follow-up period, the proportions of the patients on a stable dose were 82.4% (42/51) and 62.5% (30/48) for the study and control groups respectively. The mean durations of reaching a stable dose of warfarin were (27.5 ± 1.8) and (34.7 ± 1.8) days and the median durations were (24.0 ± 1.7) and (33.0 ± 4.5) days in the study and control groups respectively. Significant differences existed in the durations of reaching a stable dose between the two groups (P = 0.012). Compared with the control group, the hazard ratio (HR) for the duration of reaching a stable dose was 1.786 in the study group (95%CI 1.088 - 2.875, P = 0.026). CONCLUSION: The predicted dosing algorithm incorporating genetic and non-genetic factors may shorten the duration of achieving efficiently a stable dose of warfarin. And the present study validates the feasibility of its clinical application.

[Effect of ginkgo biloba extract on plasma vascular endothelial growth factor during peri-operative period of cardiac surgery].

OBJECTIVE: To investigate the effect and clinical value of ginkgo biloba extract (Ginaton) on the plasma vascular endothelial growth factor (VEGF) in patients during peri-operative period of cardiac surgery. METHODS: Twenty patients scheduled to receive cardiac operation were randomly assigned to 2 groups by a digital table. For the 10 patients in the control group, the cardiopulmonary bypass (CPB) was established in routine and received cold (4 degrees C) St. Thomas' cardioplegia perfusion (15 mL/kg) via aortic root after ascending aorta blocking, as for the 10 patients in the Ginaton group, the same was done but with 0.5 mg/kg of Ginaton added to the cardioplegia perfusion. Plasma VEGF contents were detected by ELISA at different time points, i.e., before and after anesthesia induction (T1, T2), after aorta intubation (T3), 0.5 h after aorta clamping (T4), 0.5 h after aorta declamping (T5), immediate after terminating the operation (T6), 6 h after operation (T7), and 24 h after operation (T8). RESULTS: In the control group, VEGF level began to rise at T, and reached the peak at T7(P < 0.01), while in the Ginaton group, it reached the peak early at T, (P < 0.01), and began to drop at T (P < 0.01). CONCLUSION: Ginaton could induce the production of VEGF, which may be one of the mechanisms for its myocardial protection.

[Effects of Ginaton on the markers of myocardial injury during cardiopulmonary bypass].

OBJECTIVE: To evaluate the effects of Ginaton (Ginkgo biloba leaf extract) on the myocardial injury markers (MIMs) during cardiopulmonary bypass (CPB). METHODS: Forty patients with congenital heart diseases, scheduled to take atrial septum or ventricular septum repairing operation, were randomly divided into the Ginaton group and the control group, 20 cases in each group. Patients in both groups received St. Thomas' cardioplegic perfusion via radix aortae, while Ginaton (0.5 mg/kg) was added into the perfusion for the Ginton group. Cardiac surgery were started after complete heart arrest. Central venous blood was obtained before and at 0, 6th, 12th, 24th and 48th hour after operation for detection of serum C reaction protein (CRP) by immunoturbidimetry, as well as creation kinase-MB isoenzyme (CK-MB), cardiac troponin T (cTnT) and cardiac troponin I (cTnI) with enzyme-linked immunosorbent assay (ELISA). RESULTS: There was no difference in serum concentration of CRP, CK-MB, cTnT and cTnI between the two groups before operation (P > 0.05). These indexes increased immediately after operation in both groups ( P < 0.05). They reached the peak value 12 hrs after CPB and reduced to normal level 48 hrs post-operation in the control group, with the value significantly higher than that in the Ginaton group at all the corresponding time points (P < 0.05, or P < 0.01). CONCLUSION: Perfusion with Ginaton during CPB could significantly decrease the release of MIMs and improve post-CPB cardiac function recovery, exerting favorable myocardium-protective effects.