Identification of six novel MYH9 mutations and genotype-phenotype relationships in autosomal dominant macrothrombocytopenia with leukocyte inclusions

The autosomal dominant macrothrombocytopenia with leukocyte inclusions, May-Hegglin anomaly (MHA), Sebastian syndrome (SBS), and Fechtner syndrome (FTNS), are rare platelet disorders characterized by a triad of giant platelets, thrombocytopenia, and characteristic Döhle body-like leukocyte inclusions. The locus for these disorders was previously mapped on chromosome 22q12.3-q13.2 and the disease gene was recently identified as MYH9, the gene encoding the nonmuscle myosin heavy chain-A. To elucidate the spectrum of MYH9 mutations responsible for the disorders and to investigate genotypephenotype correlation, we examined MYH9 mutations in an additional 11 families and 3 sporadic patients with the disorders from Japan. Korea, and China. All 14 patients had heterozygous MYH9 mutations, including three known mutations and six novel mutations (three missense and three deletion mutations). Two cases had Alport manifestations including deafness, nephritis, and cataracts and had R1165C and E1841K mutations, respectively. However, taken together with three previous reports, including ours, the data do not show clear phenotype-genotype relationships. Thus, MHA, SBS, and FTNS appear to represent a class of allelic disorders with variable phenotypic diversity.

The Sma I polymorphism in the von Willebrand factor gene associated with acute ischemic stroke

The von Willebrand factor (vWF) is a highly multimerized glycoprotein that promotes platelet adhesion and aggregation at a high shear rate, and also acts as a carrier of coagulation factor VIII. vWF has been identified as a risk factor for recurrent myocardial infarction in the general population. It has been reported that two polymorphisms of vWF gene promoter and the Thr789Ala polymorphism in vWF gene are associated with arterial thrombosis. The Sma I polymorphism is located in intron 2 of vWF gene. The relevance of this polymorphism to thrombotic disease was investigated by genotypic identification in two case-control studies: 107 patients with acute ischemic stroke, 49 patients with acute myocardial infarction (AMI), and 113 health controls age- and race-matched for each patient. Twenty-eight (26.2%) of the 107 patients with acute ischemic stroke, 8 (16.3%) of 49 patients with AMI, and 11 (9.7%) of 113 controls were found to be homozygous for CC genotype, respectively. The prevalence of the CC genotype in acute ischemic stroke was significantly higher than that of the normal controls (odds ratio [OR]=3.29, 95% confidence interval [CI]=1.54-7.01,.01>P>.001). However, the prevalence of the CC genotype in AMI was not significantly different from that of the normal controls (OR=1.81, 95% CI=0.68-4.82,.30>P>.20). Plasma vWF:Ag was also determined by enzyme-linked immunosorbent assay (ELISA) on the frozen plasma of 122 subjects. The mean plasma vWF:Ag levels of the controls, patients with acute ischemic stroke, and AMI were 0.468, 0.584, and 0.783 U/ml, respectively. The mean level of plasma vWF:Ag did not differ significantly between controls and patients with acute ischemic stroke (P=.195), but had significantly difference between controls and patients with AMI (P=.001). No association was found between the Sma I polymorphism and vWF plasma levels in controls, patients with acute ischemic stroke, or the AMI group (one-way ANOVA, P=.323, P=.315, P=.96). Results show that the Sma I polymorphism is strongly associated with increased risk of acute ischemic stroke, however, no association was observed between this polymorphism and AMI. This polymorphism of vWF may represent a newly identified risk factor for acute ischemic stroke in Chinese. Whether it is the real functional variant associated with acute ischemic stroke remains to be elucidated.

Spontaneous platelet aggregation with congenital giant platelet containing large granules and thick membrane

Inherited giant platelet disorders are a heterogeneous group of disorders. In the current study, a patient was reported with moderate bleeding tendency, giant platelets, and spontaneous platelet aggregation, which were not affected by the administration of aspirin or ticlopidine. The electron microscopy of platelets showed a black and thick plasma membrane with crystal-like fine hairs in the exterior coat and more large and variously shaped granules in the cytoplasm. The expression of glycoprotein (GP) Ib, GP IIb, and GP IIIa on platelet surface was normal, and no mutations in genes for GP Ib alpha, GP Ib beta, and GP IX were detected. These phenomena are so distinguishable from those of Mondreal platelet syndrome and other hereditary giant platelet disorders, that we propose that this patient probably has a novel platelet disorder, which has not yet been reported.

Detection of soluble urokinase receptor by immunoradiometric assay and its application in tumor patients

It has recently been found that tumor cells express large amounts of urokinase receptor (uPAR) on their surface and that the blood soluble uPAR (suPAR) level in cancer patients is increased. However, the significance of suPAR in tumor progression is still unclear. To investigate the significance of suPAR in evaluating clinical status of solid tumor patients, an immunoradiometric assay (IRMA) based on using two monoclonal antibodies (McAbs) to different epitopes of uPAR was established to determine the serum levels of suPAR in normal individuals and solid tumor patients. The detectable range of this suPAR IRMA was 1.95-500 microg/l. The affinity constant was 4.75x10(9) l/mol. The mean rate of recovery was 101.3%, and the mean coefficients of variation for intra- and interassay were 6.40+/-2.57% (mean+/-S.D., n = 11) and 10.48+/-2.65% (n = 5), respectively. The serum suPAR levels were 2.71+/-1.12 microg/l in 62 normal individuals, 3.71+/-1.69 microg/l in 30 patients with benign tumors, and 5.82+/-2.27 microg/l in 124 patients with malignant tumors. The serum suPAR levels of these two types of tumor patients were increased in comparison with that of normal individuals (P values less than.01 and.001). The extent of their increase in malignant tumors was much greater than in benign tumors (P < .001). The serum suPAR levels of patients with malignant tumors were correlated with tumor invasion, metastasis, and surgical intervention. Our data suggest that IRMA for suPAR could be a sensitive and specific assay and that the serum suPAR level would be a valuable index for evaluating the condition and prognosis of tumor patients in clinic.

[Improvement of combination chemotherapy tolerance of human umbilical cord blood CD(34)(+) cells transducted with double drug resistance genes by a bicistronic retroviral vector]

OBJECTIVE

To explore whether human umbilical cord blood hematopoietic progenitor cells transduced with human aldehyde dehydrogenase class 3 (ALDH3) and multidrug resistance gene (MDR1) could increase resistance to 4-hydroxycyclophosphamide (4-HC) and P-glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and transfected the packaging cell lines GP + E86 and PA317 by LipofectAMINE method, using the medium containing VCR and 4-HC for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, cord blood CD(34)(+) cells were enriched with a high-gradient magnetic cell sorting system (MACS), and then repeatedly transfected with supernatant of retrovirus containing human ALDH3 and MDR1 cDNA under stimulation of hematopoietic growth factors. PCR, RT-PCR, Southern blot, Northern blot, FACS and MTT assay were used to evaluate the transfection and expression of the double genes.

RESULTS

The purity of cord blood CD(34)(+) cells was approximately 91% and the recovery rate was 72%. The highest titer of recombinant amphotropic retrovirus in the supernatant was up to 6.5 x 10(5) CFU/ml. The efficiency of gene transduction was 18%, 20% and 16.7% tested by colony formation, PCR and FACS, respectively. Rhodamine 123 efflux showed 16% transduced cells with P-gp function. No helper virus was found by both nested PCR and rescue assay. The MTT analysis showed a 3.5 to 6.8-fold increase of resistance of transducted cells to cyclophosphamide and P-glycoprotein effluxes drug as compared with the nontransduced cells.

CONCLUSION

The efficiency and co-expression of this dual genes transfer system provided a foundation for ameliorating combination chemotherapy toxicity in clinical trial.

[Study of C807T polymorphism of the platelet collagen receptor alpha2 gene coding sequence in Suzhou Han population]

OBJECTIVE

To study the C807T polymorphism of the platelet collagen receptor alpha(2) gene coding sequence in Suzhou Han population. This polymorphism was associated with the expression density of integrin alpha(2)beta(1) on the platelet surface.

METHODS

An amplified 1332 bp fragment of human alpha(2) gene from 110 unrelated individuals was analyzed by Bgl II and Ase I restriction assay. The resulting products were electrophoresed in 8% polyacrylamide gels and stained with ethidium bromide.

RESULTS

The allelic frequencies were 0.291:0.709 for T807 allele: C807 allele in Suzhou Han population. The total theoretical heterozygous rate was 41%. The genotypic frequencies were 0.018:0.546:0.436 for homozygous 807T allele: heterozygous 807C/T allele: homozygous 807C allele.

CONCLUSION

The C807T polymorphism of the platelet collagen receptor alpha2 gene in Suzhou Han population was different from that observed in other populations.

Detection of Red Blood Cell—Bound Immunoglobulin G by Flow Cytometry and its Application in the Diagnosis of Autoimmune Hemolytic Anemia

Detection of autoantibodies to erythrocytes is of fundamental importance in the diagnosis of autoimmune hemolytic anemia (AIHA). The routinely used direct antiglobulin test (DAT) has the disadvantage of low sensitivity. In this study, we investigated the optimal test conditions of measurement of red blood cell (RBC)-bound immunoglobulin (Ig) G by flow cytometry (FCM). We studied 64 patients with AIHA, 30 anemic patients diagnosed with other diseases, and 36 healthy individuals. In 33 AIHA patients who were found to have RBC-bound IgG, both the mean fluorescence intensity (MFI) and percentage of fluorescence-activated RBCs were remarkably increased and results of both were considered positive. In the remaining 31 AIHA patients who had positive results for RBC-bound complement C3d, the MFI and the percentage of fluorescence-activated RBCs was also increased and 17 patients (54.8%) were considered to have a positive result by this method. In anemic patients with negative DATs the results of FCM were always negative. These results could be confirmed by enzyme-linked immunosorbent assay (ELISA), and the values obtained by FCM and ELISA corresponded to titration scores of the DAT. Additionally, in 3 of the other 8 patients who were suspected to have DAT-negative AIHA, RBC-bound IgG was detected by FCM and ELISA. Our investigation demonstrates that FCM is a precise, reliable, and sensitive method of detecting RBC-bound autoantibodies and could be used as a new routine diagnostic technique for AIHA and other immune hemolytic anemias.

A bicistronic retroviral vector to introduce drug resistance genes into human umbilical cord blood CD34+ cells to improve combination chemotherapy tolerance

OBJECTIVE

To study whether human umbilical cord blood CD34+ cells transduced with human aldehyde dehydrogenase class-1 (ALDH-1) and multidrug resistance gene (MDR1) have increases resistance to 4-Hydroperoxycyclo-phosphamide (4-HC) and P-glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH1-IRES-MDR1 was constructed and used to transfect the packaging cell lines GP + E86 and PA317 by LipofectAMINE method, using the medium containing VCR and 4-HC agents for cloning selection and ping-ponging supernatant infection between the ecotropic producer clone and the amphotropic producer clone, we obtained high titer amphotropic PA317 producing cells with high titers up to 5.6 x 10(5) CFU/ml. Cord blood CD34+ cells were transfected repeatedly with supernatant of retrovirus containing human ALDH-1 and MDR1cDNA under the stimulation of hemopoietic growth factors.

RESULTS

Bicistronic retroviral vector construction was verified by restriction endonuclease analysis. Polymerase chain reaction (PCR), reverse transcription (RT)-PCR, Southern blot, Northern blot, fluorescenceactivated cell sorting (FACS) method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analyses showed that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The transgenes recipient cells confered 4-fold stronger resistance to 4-HC and 5.5 to 7.2-fold P-glycoprotein effluxed drug than untransduced cells.

CONCLUSION

The bicistronic retroviral vector-mediated transfer of two different types of drug resistance genes into human cord blood CD34+ cells and co-expression provided an experimental foundation for improving combination chemotherapy tolerance in tumor clinical trial.

A new mutation, Ala1500-->Glu, responsible for type 2A von Willebrand disease

Two patients (from the same family) with a bleeding disorder were diagnosed with type 2A von Willebrand disease (vWD). The 28th exon of the von Willebrand factor (vWF) gene was obtained by polymerase chain reaction and then screened by denaturing gradient gel electrophoresis. The fragments displaying abnormal melting behavior were directly sequenced. A heterozygous C-->A substitution changing alanine 1500 to glutamic acid at position 4750 in the A2 domain of vWF was found. The structure of recombinant A1500E vWF within transfected COS-7 cells and the secretion of high-molecular-weight (HMW) multimers were similar to wild-type vWF. HMW forms of vWF multimers were absent in plasma but present in platelets. The mutation described here corresponds to the group II type 2A vWD characterized by normal secretion of all vWF multimers.

[In vitro study on transduction of human O(6)-methylguanine-DNA-methyltransferase cDNA into human umbilical cord blood CD34(+) cells]

OBJECTIVE

To explore human umbilical cord blood hematopoietic progenitor cells transduced with human O(6)-methylguanine-DNA-methyltransferase (MGMT) gene increase resistance to 1,3-Bis(2-Chloroethyl)-1-Nitrosourea(BCNU).

METHODS

The present authors obtained a full length cDNA fragment encoding the human MGMT from a patient with cholelithiasis liver tissue by RT-PCR method and confirmed by DNA sequencing. The fragment was cloned into pGEM-T vector and further subcloned into G1Na retrovirus vector. Then the G1Na-MGMT was transfected into the packaging cell lines GP+E86 and PA317 by LipofectAMINE method; using the medium containing BCNU for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, the authors obtained high titer amphotropic PA317 producer clone with the highest titer up to 1.6x10(6) CFU/ml. Cord blood CD34(+) cell were transfected repeatedly with supernatant of retrovirus containing human MGMT cDNA under stimulation of hemopoietic growth factors.

RESULTS

PCR, RT-PCR, Southern blot, Northern blot, Western blot and MTT analyses showed that MGMT gene had been integrated into the genomic DNA of cord blood CD34(+) cells and expressed efficiently in the transfected cells. The transgene recipient cells conferred 4 folds stronger resistance to BCNU than that of the non-transduced.

CONCLUSION

The retrovirus vector-mediated transfer of MGMT drug resistance gene into human cord blood CD34(+) cells and expression could confer the resistance of transgene cells to BCNU toxicity.

von Willebrand disease in China

PURPOSE

To review the molecular pathogenesis in Chinese patients with von Willebrand disease (vWD) and polymorphisms of von Willebrand factor (vWF) in Chinese population.

DATA SOURCES

Both Chinese and English language literature search using MEDLINE (1985-1998), and original articles published in main Chinese and international journals.

STUDY SELECTION AND DATA EXTRACTION

After reviewing of the literature, 19 articles of them were selected that specifically addressed the stated purpose.

RESULTS

The molecular pathogenesis of vWD was variant. Six cases of point mutation have been found in Chinese patients with vWD. The system of site-directed mutagenesis and expression of vWF gene was constructed. The polymorphisms of vWF gene are very different between Chinese and Gaucasians.

CONCLUSION

Combining to gene mutant in vWD patients, the use of site- directed mutagenesis and expression of vWF will help to understand the vWF function. The polymorphisms of vWF gene are useful marker in Chinese for carrier detection and prenatal diagnosis of vWD.

[Study on genetic mutations of the vWF in type 2A von Willebrand disease]

OBJECTIVE

To study the molecular pathological mechanism of the type 2A von Willebrand disease(vWD) and the relationship of the phenotypes with genotypes.

METHODS

A total of 126 patients with the hereditary hemorrhagic disease were examined using bleeding time, vWF:Ag, FVIII:CAg, ristocentin induced platelet agglutination assay(RIPA) and multimer analysis of plasma. The exon 28 of authenticity vWF gene was studied by PCR, denaturing gradient gel electrophoresis(DGGE) and sequencing in the type 2A vWD.

RESULTS

Fourteen cases were diagnosed as type 2A vWD. Four cases of point mutations resulting in single animo acid substitutions, Arg611His, Ala737Glu, Arg834Trp, were identified in 3 families of type 2A vWD. Ala737Glu substitution in vWF is caused by a novel missense mutation.

CONCLUSION

The molecular pathological mechanism of the type 2A vWD is very variant.

[Intraperitoneal lymphatic chemotherapy for colonic cancer]

OBJECTIVES

To evaluate the effect of intraperitoneal lymphatic chemotherapy with carboplatin and sandostatin on colonic carcinoma and abdominal lymphatic metastasis in patients after radical resection.

METHODS

Patients with colonic cancer were divided into two group: abdominal lymphatic chemotherapy group and control group. The lymphatic chemotherapy group was treated at the introduction stage of anesthesia with carboplatin (200 mg) injected intraperitoneally and sandostatin (0.1 mg x 2) injected subcutaneously, whereas the control group was just treated with carboplatin (200 mg) injected intraperitoneally. The platinum levels in abdominal lymphatic nodes were monitored during operation. The two groups were uninterruptedly given intraperitoneal lymphatic chemotherapy or intraperitoneal chemotherapy. Retroperitoneal lymphatic metastasis was evaluated in each patient by abdominal CT scan after operation.

RESULTS

The platinum levels in abdominal lymphatic nodes increased more significantly at 2, 3 hours in the lymphatic chemotherapy group than in the control group (P < 0.01). There was no difference in the platinum levels of the portal vein between the two groups, and also no difference in the platinum levels between the lymphatic nodes with or without metastasis. The rates of retroperitoneal lymphatic metastasis after resection were significantly lower in the lymphatic chemotherapy group control group (P < 0.01).

CONCLUSION

Intraperitoneal administration of carboplatin combined with sandostatin may elevate the platinum levels in the abdominal lymphatic nodes and reduce the abdominal lymphatic metastasis after radical resection of colonic cancer. It is an effective method for intraperitoneal lymphatic chemotherapy.

[Construction and transient expression of an Ala 737-->Glu mutant of vWF]

OBJECTIVE

To study the functional change of an Ala737-->Glu substitution mutant of vWF and the molecular pathological mechanism of this mutant in the type 2A vWD.

METHODS

The expression plasmid pSVvWF containing full-length cDNA of vWF was used to site direct mutagenesis by polymerase chain reaction (PCR) and transitorily expressed in the COS-7 cells, vWF: Ag in the supernatant and the cell lysate between wild type and pSVAla737Glu vWF were measured. vWF polymers of the platelet of the patient with the mutation and response to DDAVP treatment of the patient were observed.

RESULTS

vWF: Ag level of pSVAla 737Glu vWF was 76.4% and 98.8% of the wild types in the supernatant and cell lysate, respectively. The polymer pattern of extracellular pSVAla737Glu vWF was indistinguishable from that of the wild type, containing all kinds of molecular weight. Increased vWF antigen levels was observed in the patients after DDAVP treatment.

CONCLUSION

This mutant did not change the assembly and secretion of vWF. The mutant of vWF Ala737-->Glu resulted in Group II type 2A vWD.

Spectroelectrochemical investigation of direct electron transfer between resting horseradish peroxidase and its oxidation states promoted by DNA

Direct electron transfer between resting horseradish peroxidase (HRP) and its oxidation states was observed at a gold mesh electrode in a spectroelectrochemical cell in the presence of DNA. The conversion between HRP and the oxidized species induced electrochemically was found to be reversible and parallel to that initiated chemically. DNA played an important role as electron carrier and promoted the electron transfer between HRP and the electrodes. Voltammetric results and CD spectra indicated an interaction between HRP and DNA. Moreover, the secondary structure of HRP was slightly disturbed upon mixing with DNA. The direct spectroelectrochemistry of HRP at a gold mesh electrode presented new information on its bioelectrochemical characteristics.

[Detection of trisomy 8 with interphase fluorescence in situ hybridization in myelodysplastic syndromes]

OBJECTIVE

To explore the value of interphase fluorescence in situ hybridization (FISH) in the detection of trisomy 8 in myelodysplastic syndromes (MDS).

METHODS

Conventional cytogenetics (CC) and interphase FISH using SpectrumGreen labelled chromosome 8 centromere specific probe were simultaneously carried out to detect trisomy 8 in 69 MDS and 6 normal individuals.

RESULTS

Two hundred interphase cells were counted and cells with three green hybridization spots > 3% was assigned. Eleven cases displayed trisomy 8 by CC and were confirmed in 10 by FISH. In 7 cases, the percentage of trisomy 8 cells was significantly lower by FISH than by CC. Seven cases displayed trisomy 8 by FISH in 58 cases who did not show trisomy 8 by CC. Of the 7 cases, two had 2 and 3 marker chromosomes respectively, 4 had normal karyotypes.

CONCLUSIONS

Interphase FISH was a useful method for the detection of trisomy 8 in MDS, especially in patients with normal karyotype or marker chromosome. It was a important complement to CC.

Expression of the human multidrug resistance gene mdr1 in leukemic cells and its application in studying P-glycoprotein antagonists

OBJECTIVE

To investigate the retrovirus-mediated transfer and expression of multidrug resistance gene (mdr1) in hematopoietic cells and to develop a model for studying the possible reversal of the MDR-mediated phenotype.

METHODS

A retroviral vector HaMDR expressing the human mdr1 gene was packaged by PA317 cells with a titer of up to 8.5 x 10(5) CFU/ml. K562 leukemia cells were infected with MDR retrovirus, and transfectant K562/MDR cells were generated. The integration and expression of the exogenous mdr1 gene in K562/MDR cells were determined by polymerase chain reaction and flow cytometry. The reversal ability of P-glycoprotein (P-gp) antagonists was analyzed by in vitro drug sensitivity, accumulation and efflux of rhodamine 123 (Rh123) in this model.

RESULTS

Transduction with amphotropic MDR retrovirus resulted in integration and expression of the mdr1 gene in the resistant cells, where an aberrant splicing transcript of the mdr1 gene was found. The K562/MDR cells displayed a classic MDR phenotype with a 41-78 fold resistance to vincristine and colchicine in comparison with parental K562 cells. The drug sensitivity of K562/MDR cells to vincristine can be completely restored by cyclosporin A (CsA, 2 mg/L) and Cremophor EL (CRE 132 mg/L), either individually or in combination (P < 0.05). CsA (3 mg/L) can block the efflux pump function of P-gp shown by the significantly increased accumulation and efflux reduction of Rh123 in K562/MDR cells.

CONCLUSIONS

Retroviral vector HaMDR allows transfection with high-level expression of the mdr1 gene in human myeloid progenitor cells K562. The transfected K562/MDR provides a simple, sensitive model for developing antagonists of P-gp and studying their mechanism of action.

Describing paraspinal EMG findings: inadequacy of the single 0-4+ score

OBJECTIVE

Clinical electrodiagnostic textbooks instruct that lumbar radiculopathies typically have paraspinal abnormalities and that these abnormalities should be recorded using a single 0-4+ scale. Recent work demonstrates that that the innervation of the paraspinal muscles is segmental, not homogenous, and that asymptomatic persons may have reproducible ("1+") positive waves or fibrillation potentials.

DESIGN

To assess current use of the 0-4+ scale, a retrospective study of EMG scores in persons diagnosed with radiculopathy at a university laboratory was performed. No specific paraspinal EMG technique was used. Included were 117 consecutive, qualified S-1 radiculopathies and 33 L-5 radiculopathies.

RESULTS

When radiculopathy was defined by "more than one limb muscle abnormal," paraspinal scores were recorded as 0 to 1+ in 83% of L-5 and 63% of S-1 cases (chi2, L-5 vs. S-1, not significant). For more severe radiculopathies (at least one limb muscle with a "2+" score), 0-1+ paraspinal scores were recorded in 76% of L-5 and 57% of S-1 cases (chi2, not significant). A total of 82% of S-1 radiculopathies with no overlapping L-5 innervation had 0-1+ scores.

CONCLUSIONS

These data demonstrate the common use of equivocal paraspinal scores in patients whom electromyographers believe have radiculopathies. Standardized exploration techniques and a more detailed scoring system for the paraspinal muscles may eliminate this discrepancy.

[Study of platelet membrane glycoproteins and its fibrinogen binding reaction in patients with cerebral infarction and diabetes mellitus]

OBJECTIVE

To investigate the change of platelet membrane glycoproteins and its fibrinogen binding reaction in patients with cerebral infarction and type II diabetes mellitus (DM), and assess their value in the study of thrombosis and pro-thrombosis state.

METHODS

By flow cytometry, the platelet glycoprotein (GP) I b, GP II b, GP III a, GP II b- III a complex and P-selectin expression as well as fibrinogen binding reaction were analyzed in 85 patients with type II DM and 28 with cerebral infarction, and compared with that in 30 normal subjects.

RESULTS

The platelet membrane GP II b- III a complex, P-selectin expression and fibrinogen binding reaction were higher, while the platelet surface GP I b was lower in the patients with cerebral infarction and type II DM with vascular disease than those in normal group. The GP II b and GP III a were not significantly changed. There was no difference of these parameters between the type II DM without vascular disease patients and normal group.

CONCLUSION

The platelet fibrinogen binding reaction, P-selectin and GP II b- III a complex expression were increased while the GP I b decreased in patients with cerebral infarction and type II DM with vascular disease.

A recombinant antibody-targeted plasminogen activator with high affinity for activated platelets increases thrombolytic potency in vitro and in vivo

To increase thrombolytic specificity of urokinase (uPA), we engineered a recombinant chimeric plasminogen activator SZ51Hu-scuPA, which consists of a humanized monoclonal antibody (SZ-51Hu) specifically against P-selectin on activated human platelet and a single-chain urokinase (scuPA). The cDNA, encoding scuPA amino acids 1-411, was inserted in 5' end to 3' end orientation immediately after the CH3 of SZ-51Hu heavy-chain sequence in the expression vector alphaLys30. The resulting construct alphaLys30-SZ51VH/Hu-scuPA was used to transfect into SP2/0 murine myeloma cell line, which was pretransfected with SZ51Hu light chain. The fusion protein SZ51Hu-scuPA was expressed at 5 mg/L in the supernatant of cell culture. The fusion protein purified by affinity chromatography had a molecular weight of 160 kDa with fibrinolytic activity of 39,000 IU/mg and its affinity to activated human platelet was 67% of the parent murine mAb SZ-51. The thrombolytic property of the fusion protein was first characterized in an in vitro system, which consists of a 125I-fibrin-labeled human plasma clot containing different concentrations of human platelets suspended in citrated human plasma. Fifty percent lysis was reached with SZ51Hu-scuPA in 1 hour at a concentration of 20 IU/mL or in 2 hours at a concentration of 10 IU/ mL, which was much faster than uPA at the same concentration. The maximal lysis of the clots by SZ51Hu-scuPA was 4.1 to 8.4 times more potent than that by uPA. The fusion protein was further characterized in the hamster pulmonary embolism model with clots prepared from fresh platelet-rich human plasma containing 125I-labeled fibrinogen. The thrombolytic activity of SZ51-scuPA was 3.9 times more potent than that of uPA at 2,000 IU/kg in this model. Almost no significant fibrinogen breakdown was observed either in vitro and in vivo.

Hemostasis and thrombosis research in China

PURPOSE

To highlight the development and achievements of hemostasis and thrombosis research in China over the past 50 years.

DATA SOURCES

Both Chinese and English language literature search using MEDLINE (1990-1998), and original articles published in the main Chinese and international journals.

STUDY SELECTION

After reviewing all the main articles on thrombosis and hemostasis, 20 of them were selected that specifically addressed the stated purpose. DATE EXTRATION: The content that could present the progress in hemostasis and thrombosis in China was selected.

RESULTS

Monoclonal antibodies have widely been used in basic research and laboratory diagnosis. Several novel gene mutations of coagulation factors have been identified. Some drugs of traditional Chinese medicine have proved to be efficient in treatment of thrombotic diseases.

CONCLUSIONS

Significant achievements in basic, clinical and pharmacological research in the field of hemostasis and thrombosis have been made in China in the past 50 years. Some new discoveries in platelet membrane glycoproteins and coagulation factors research are believed to be contributions to the international scientific community. However, a specific effort using advanced techniques should be made for future development, especially in molecular biology research.