2000年 · 第113卷第08期

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. Chin Med J 2000; 113(8): 677-680

Purpose To review the pathogenesis, clinical presentation, diagnostic assessment and treatment regimens of steroid-induced bone loss. Data sources An English-language literature search(MEDLINE 1966-1999)and bibliographic reviews of textbooks and review articles. Study selection Cross-sectional and prospective studies with BMD measurements or fracture rate. Results The greatest rate of bone loss occur during the first 6 to 12 months of steroid therapy, affecting trabecular more than cortical bone. High steroid dosage for a prolonged period, prevalent fracture, hypogonadism, older age, low calcium intake and family history of osteoporosis are risk factors for steroid-induced bone loss. Based on bone density results, patients with osteoporosis or osteopenia with a T-score below-1.5 should receive antiresorptive treatment during steroid therapy. Among the various antiresorptive agents, bisphosphonates have the strongest evidence of preventing steroid-induced bone loss. Conclusion The most important step in the management of steroid-induced osteoporosis is the proper assessment of the individual patient's risk of bone loss, and the selection of appropriate antiresorptive agent for each patient. Chin Med J 2000; 113(8): 681-685

Purpose To review the research on the cultivation of Gastrodia elata Bl, a rare traditional Chinese medicine. Data sources The data come from our previous research and published review articles on G. elata cultivation. Study selection After reviewing the research results on G. elata from 1960 to 1995, we selected the core research on G. elata and a complete cultivation technique of rare traditional Chinese medicine G. elata •Data extraction Some important data were arranged in different tables, and new cultivation methods were reviewed. Results A. mellea has been found to have inhibiting effects on G. elata seed germination. The seeds are able to sprout only when a nutritional relationship exists between G. elata and a fungus of the same genus as M. osmundicola. The sprouted tubers have to set up a symbiotic relationship with A. mellea during their clone propagation period so as to grow normally. Conclusions G. elata has to symbiosize with M. osmundicola and A. mellea so as to complete its life cycle from seed to seed. These findings have revealed the secret of the life cycle of G. elata that has been puzzling biological circles for years. Chin Med J 2000; 113(8):686-692

Objective To characterize effects of the GP Iba mutation(A156V)on its interaction with von Willebrand factor(vWf)under high fluid shear stress. Methods The residue A156 of GP Iba was converted to a valine and the mutant expressed in CHO cells expressing wild-type GP Ibβ and GPIX. The transfected cells were tested for their interaction with a panel of GP Iba antibodies and for rolling on immobilized vWf under high shear. Results The mutation led to surface expression of a GP Iba polypeptide that adopted a different conformation at its N-terminus because binding of the GP Iba antibody AN51, which has a binding epitope it the N-terminal 35 residues, was eliminated, whereas binding of the others(AK2, MB45, and SZ2, all of which bind to regions C-terminal to the AN51 epitope)was normal. Mutant-expressing cells could adhere and roll on immobilized vWf under high fluid shear stress and rolled significantly faster than wild-type cells. Conclusion These studies demonstrate that the mutation A156V results in a conformation change at the N-terminus of GP Ibα, which leads to an increase in the dissociation rate of the bond between the GP Ibα mutant and vWf. Chin Med J 2000; 113(8): 693-698

Objective To explore the correlation between antiphospholipid antibodies(APA), activated protein C resistance(APCR)and antiphospholipid thrombosis(APL-T)syndrome and further investigate the mechanism of thrombosis in APL-T syndrome. Methods ELISA, PTT-LA and APTT±APC methods were used to detect anticardiolipin antibodies(ACA), lupus anticoagulants(LA)and APC R in 20 APL-T syndrome patients. Results Twenty patients were diagnosed as APL-T. ACA-IgG, M and LA are strongly associated with APL-T. The incidence of APCR in APL-T(75%)was significantly higher than that of the normal group(5%). Conclusion There was high prevalence of APCR in APL-T, which was strongly associated with LA. It is proposed that acquired APCR induced by APA is a key to understanding thrombosis in Chinese APL-T patients. Chin Med J 2000; 113(8): 699-701

Objective To investigate the gene frequencies of 5 major human platelet alloantiqens(HPA 1-5)in Chinese population and to assess if polymorphism of HPA was associated with Chinese acute myocardial infarction(AMI)and acute ischemic stroke(AIS). Methods HPA 1-5 genotyping was performed by PCR using allele specific primers and restriction enzyme digestion based on PCR products in 95 AMI cases, 188 AIS cases and 270 normal controls. Gene frequency distribution was tested by Hardy-Weinberg equilibrium and comparison of HPA gene frequencies between the patient and control groups by χ2 test. Results The gene frequencies of HPA 1-5 were the followings: HPA1a: 91%; 1b: 9%; HPA 2a: 94%; 2b: 6%; HPA 3a: 83%; 3b: 17%; HPA 4a: 98%; 4b: 2%; HPA5a: 97%; 5b: 3%. We found there were no significant differences in HPA 1-5 gene frequencies between AMI patients and normal controls. In AIS patient group HPA-2a allele frequency was significant higher than in controls, but this allele gene frequency in two groups(0.94 and 0.99)was very close and too many subjects in these two groups were overlapped. Otherwise no differences was found in other 4 HPA systems between cases and controls. Conclusion Polymorphism of HPA were not inherited risky factors and not associated with Chinese arterial thrombotic diseases such as AMI and AIS. Chin Med J 2000; 113(8): 702-705

Objective To investigate the antithrombotic mechanism of glycosaminoglycan(GAG)extracted from sea cucumber. Methods We studied the effects of GAG on the coagulant pathway by measuring cloting time. The antithrombin mechanism of GAG was checked by assaying its effects on the thrombin activity in normal human pooled plasma, purified human heparin cofactorⅡ system and antithrombin Ⅲ system. The effects of GAG on the assembly, dispersion, and structure of fibrin gels as well as on the activity of plasmin were studied by means of turbidimetry, electron microscopy, and chromogenic substrate assay. We studied the effect of GAG on the expsession and transcription of tissue factor(TF)and thrombomodulin(TM)in LPS(lipopolysaccharide)-stimulated human umbilical vein endothelial cells(HUVECs), and used heparin as a control. HUVECs were treated with different concentrations of GAG(1 μg/ml, 5 μg/ml, and 10 μg/ml respectively)and 5 μg/ml heparin as a control together with LPS(1 μg/ml). After incubation for 6 hours, TF and TM were investigated by ELISA and the mRNA study was carried out by RT-PCR. In a clinical trail, a series of variables were observed before and after treatment with GAG in patients recovering from cerebral ischemic stroke or suffering from ischemic heart disease. Results The TT and APTT were significantly prolonged by GAG(0.1 μg/ml). GAG inhibited thrombin activity in the presence of HCII with a second order rate constant of 1.14×107m-1 · min-1, which was 4.6 times higher than that of ATⅢ. GAG significantly inhibited the polymerization of fibrin monomer and enhanced the activity of plasmin in a concentration dependent manner. GAG could impair TF mRNA expression and up-regulate TM mRNA expression. The result of clinical trail showed that the fat metabolism was enhanced in addition to the anticoagulant and the blood viscosity reducing effects. No side-effect was found. Conclusions GAG mainly affected on the intrinsic pathway of blood coagulation. GAG was similar to dermatan sulfate both in the efficiency and in the mechanism of antithrombin. The acceleration of colt lysis by GAG depended on its ability to increase the activity of plasmin, to inhibit the polymerizing of fibrin monomer, and consequently, to alter the architecture of the fibrin net work. This effect on HUVECs appears to be at a transcriptional level and might be relevant for the antithrombotic action of GAG. GAG possess anticoagulant activity in vivo and it is a promising drug for antithrombotic therapy. Chin Med J 2000; 113(8): 706-711

Objective To study the difterentiation-inducing effect of hydroxycamptothecin(HCPT)on hepatoma Hep G2 cells. Methods 3-[4, 5-dimethylthial-2-yl]-3, 5-diphenyl-tetrazolinium bromide(MTT)colorimetric method was used for determining HepG2 cells viability. Alpha-fetoprotein(AFP)and albumin(ALB)levels were determined with Elisa Kits. Results The AFP secretion of HCPT-treated cells was reduced by 44.0%-49.2% while the ALB level was increased markedly. Conclusion Hydroxycamptothecin can induce human hepatoma Hep G2 cells to differentiation. Chin Med J 2000; 113(8): 712-713

Objective To investigate which of the two immunoglobulin(Ig)-like domains, immunoglobulin variable region homologous domain IgV(hB7-1 IgV), or immunoglobulin constant region homologous domain IgC(hB7-1 IgC)on human B7-1 molecule contain the receptor binding sites, and to evaluate if the B7-1 molecule expressed in bacteria has biological activity. Methods PCR was used to amplify three fragments of hB7-1 IgV, hB7-1 IgC and complete extracellular region of human B7-1 containing both the IgV and IgC domains(hB7-1 IgV+IgC). Three recombinants, pQE9-hB7-1 IgV, pQE9-hB7-1 IgC and pQE9-Hb7-1(IgV+IgC)were generated by cloning the PCR products into a prokaryote expression plasmid(pQE-9)and were introduced into the host stain M15. The relevant target hexahistidine-tagged proteins were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7-1 proteins and [3H]-TdR incorporation. Results Three recombinant proteins of human B7-1, hB7-1 IgV, hB7-1 IgC and hB7-1(IgV+IgC)were produced and detected in both soluble and inclusive body forms from engineered bacterial cells. With the presence of anti-CD3 antibody, T lymphocytes proliferated when co-stimulated by bacterially produced hB7-1(IgV+IgC), but not by either hB7-1 IgV or hB7-1 IgC. Conclusions Functional glycoprotein human B7-1 could be produced in bacterial cells. Both extracellular immunoglobulin-like domains are necessary for B7-1 to react with its counter receptors. Chin Med J 2000; 113(8): 714-719

Objective To study the preventive effects of single use of azathioprine and its combination with methylprednisolone on chronic cerebral vasospasm(CVS). Methods A canine model of the"double subarachnoid hemorrhage(SAH)"was established to study the angiogram characteristics of chronic CVS. The effects of azathioprine and its combination with methylprednisolone on the prevention of chronic CVS were observed in a randomized study. The content of malondialdehyde(MDA)and pathological changes in the basilar artery(BA)wall were also analyzed. Results The results were obtained on the 7th day after subcarachnoid hemorrhage. In the azathioprine group, the BA diameter was 87%±26% of the original BA diameter, and the MDA content of BA wall was 0.03±0.01 nmol/mg tissue. In the azathioprine plus methylprednisolone group, it was 93%±20%(BA diameter)and 0.02±0.01 nmol/mg tissue(MDA content). In the control group, the BA diameter was 53%±19% and MDA content was 0.11±0.05 nmol/mg tissue. Pathological examination confirmed the reduction in BA wall damage in the experimental groups. Conclusion Azathioprine has a preventive effect on chronic CVS following SAH. It may suppress the production of free radicals and reduce damage to the BA wall. Combined use of azathioprine with methylprednisolone allows lower dosage and less complication compared with a single agent, and results in a better outcome. Chin Med J 2000; 113(8): 720-724