Biomedical subjects

Wei Han

Publications and source records attributed to Wei Han.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Methotrexate for treatment of graft versus host disease after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To evaluate the efficacy and safety of low-dose methotrexate in patients with graft versus host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). METHODS: Thirty-one patients with minor or moderate grade acute GVHD (aGVHD), chronic GVHD (cGVHD) or GVHD post donor lymphocyte infusion (post-DLI GVHD) after Allo-HSCT received intravenously administrated methotrexate at a dose of 5 or 10mg every 5 to 7 days until achieving complete or partial responses, treatment failure or intolerable side effects. RESULTS: The overall response rate was 93.8% (15/16 patients) in patients with aGVHD, 75% (12/16 patients) in patients with cGVHD and 100% (2/2 in patients) with post-DLI GVHD. The response rate for GVHD involving organs was 100% in skin, 60% in gut, 71% in liver, 75% in mouth and 100% in eyes. Side effects were minor. During the therapy, the other immunosuppressive agents were reduced. CONCLUSION: Short-term low-dose methotrexate is a tolerable and effective regimen for patients with minor or moderate grade aGVHD, cGVHD or post-DLI GVHD after Allo-HSCT.

Adolescent↗

PubMed2005

[Effect of ABO-incompatibility on allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the effect of ABO mismatch on clinical characteristics in allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: We retrospectively reviewed the clinical courses of 148 recipients of allo-HSCT from ABO-incompatible donors, of whom 85 ABO-compatible recipients were used as control group. RESULTS: In ABO major incompatible group, the time of erythrocyte recovery after bone marrow transplantation (BMT) was delayed and more RBC transfusions were required as compared with ABO major incompatible peripheral blood stem cell transplantation (PBSCT). The incidence of acute graft versus host disease (aGVHD), cytomegalovirus (CMV) infection and survival had no significant difference between ABO-incompatible and ABO-compatible recipients for BMT, PBSCT and BMT+PBSCT. CONCLUSION: ABO-incompatibility has no adverse effect on the outcome of HSCT. Allogeneic PBSCT can reduce red blood cell transfusion requirements and facilitate erythrocyte recovery as compared with BMT.

ABO Blood-Group System↗

PubMed2005

[Analysis of pathogenesis of pneumonia post allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To analyse the clinical features and pathogenesis of pneumonia post allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: Analysis was made of 255 patients of recipients of allo-HSCT from 1998 to 2001. RESULTS: Seventy-two episodes of pneumonia occurred in 66 patients with the morbidity of 25.9%; 50 (75%) patients were cured. Twelve episodes (16.7%) were caused by mixed infection of bacteria and fungi; 22 episodes (30.6%) were caused by cytomegalovirus infection and 36 episodes (50.0%) were classified as idiopathic pneumonia syndrome. The total mortility of pneumonia post allo-HSCT in our institute was 22.7%. The occurrence of chronic graft-versus-host disease was significantly high in idiopathic pneumonia syndrome, in which good response to immune suppressive therapy was observed. CONCLUSION: Pneumonia post allo-HSCT is a common complication, of which pathogenesis includes infection and non-infection. Its clinical outcome could be improved by specific therapy.

Adolescent↗

PubMed2005

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.

Animals↗

PubMed2005

Production and purification of recombinant human BLyS mutant from inclusion bodies.

B lymphocyte stimulator (BLyS), a member of the tumor necrosis factor superfamily, is an important regulator of B cell homeostasis. In BLyS-deficient mice, B cell development is severely perturbed. On the other hand, mice transgenic for BLyS developed autoimmune disorders, such as increased germinal center formation, production of autoantibodies, and Ig deposition in kidneys. The overexpression of BLyS was found in some human autoimmune diseases. These findings suggest that BLyS has a crucial role in the humoral immune response and may be a therapeutic target for some human autoimmune diseases. To construct and express the therapeutic vaccine BLyS, we coupled a foreign immunodominant T-helper epitope to the N terminus of BLyS (named recombinant BLyS mutant, rBLySM) and expressed rBLySM in Escherichia coli. We have developed a purification process of rBLySM from inclusion bodies. A step-down urea concentration strategy was applied to the rBLySM renaturation process. By this strategy, a stable yield of 4.5mg purified rBLySM per gram of cell paste could be obtained.

Amino Acid Sequence↗

PubMed2005

Expression and one-step ion-exchange purification of (AAR)IL-8 (human IL-8 receptor antagonist).

Interleukin-8 (IL-8) is C-X-C chemokine, which is produced by a variety of cells. IL-8 plays an important role in the inflammatory response and may be a therapeutic target for some inflammatory diseases. To develop an IL-8 receptor antagonist, (AAR)IL-8 (IL-8 receptor antagonist) was constructed and successfully expressed in Escherichia coli. (AAR)IL-8 could be easily purified by one-step SP-Sepharose fast flow column after the lysate of recombinant bacterial cells was heated at 70 degrees C for 10 min. The purity of (AAR)IL-8 is more than 95%. This purification process resulted in final purified yields of 4.29 mg (AAR)IL-8/g cell paste. In addition, the purified (AAR)IL-8 can significantly inhibit the chemotaxis that was induced by human IL-8 in vitro and in vivo. These results showed that this purification process is very simple and effective. It could be easily amplified at a larger scale. (AAR)IL-8 might find use as a new therapeutic IL-8 receptor antagonist for some acute and chronic inflammatory diseases.

Amino Acid Substitution↗

PubMed2005

Increased and prolonged pulmonary fibrosis in surfactant protein C-deficient mice following intratracheal bleomycin.

Recent reports have linked mutations in the surfactant protein C gene (SFTPC) to familial forms of pulmonary fibrosis, but it is uncertain whether deficiency of mature SP-C contributes to disease pathogenesis. In this study, we evaluated bleomycin-induced lung fibrosis in mice with genetic deletion of SFTPC. Compared with wild-type (SFTPC+/+) controls, mice lacking surfactant protein C (SFTPC-/-) had greater lung neutrophil influx at 1 week after intratracheal bleomycin, greater weight loss during the first 2 weeks, and increased mortality. At 3 and 6 weeks after bleomycin, lungs from SFTPC-/- mice had increased fibroblast numbers, augmented collagen accumulation, and greater parenchymal distortion. Furthermore, resolution of fibrosis was delayed. Although remodeling was near complete in SFTPC+/+ mice by 6 weeks, SFTPC-/- mice did not return to baseline until 9 weeks after bleomycin. By terminal dUTP nick-end labeling staining, widespread cell injury was observed in SFTPC-/- and SFTPC+/+ mice 1 week after bleomycin; however, ongoing apoptosis of epithelial and interstitial cells occurred in lungs of SFTPC-/- mice, but not SFTPC+/+ mice, 6 weeks after bleomycin. Thus, SP-C functions to limit lung inflammation, inhibit collagen accumulation, and restore normal lung structure after bleomycin.

Animals↗

PubMed2005

Generation and characterization of C305, a murine neutralizing scFv antibody that can inhibit BLyS binding to its receptor BCMA.

B-lymphocyte stimulator (BLyS) is a member of the tumor necrosis factor (TNF) family and a key regulator of B cell response. Neutralizing single-chain fragment variable (scFv) antibody against BLyS binding to its receptor BCMA has the potential to play a prominent role in autoimmune disease therapy. A phage display scFv library constructed on pIII protein of M13 filamentous phage was screened using BLyS. After five rounds of panning, their binding activity was characterized by phage-ELISA. Nucleotide sequencing revealed that at least two different scFv gene fragments (C305 and D416) were obtained. The two different scFv gene fragments were expressed to obtain the soluble scFv antibodies, then the soluble scFv antibodies were characterized by means of competitive ELISA and in vitro neutralization assay. The results indicated that C305 is the neutralizing scFv antibody that can inhibit BLyS binding to its receptor BCMA.

Amino Acid Sequence↗

PubMed2005

Matrix metalloproteinase-activated doxorubicin prodrugs inhibit HT1080 xenograft growth better than doxorubicin with less toxicity.

Matrix metalloproteinase (MMP)-activated prodrugs were formed by coupling MMP-cleavable peptides to doxorubicin. The resulting conjugates were excellent in vitro substrates for MMP-2, -9, and -14. HT1080, a fibrosarcoma cell line, was used as a model system to test these prodrugs because these cells, like tumor stromal fibroblasts, expressed several MMPs. In cultured HT1080 cells, simple MMP-cleavable peptides were primarily metabolized by neprilysin, a membrane-bound metalloproteinase. MMP-selective metabolism in cultured HT1080 cells was obtained by designing conjugates that were good MMP substrates but poor neprilysin substrates. To determine how conjugates were metabolized in animals, MMP-selective conjugates were given to mice with HT1080 xenografts and the distribution of doxorubicin was determined. These studies showed that MMP-selective conjugates were preferentially metabolized in HT1080 xenografts, relative to heart and plasma, leading to 10-fold increases in the tumor/heart ratio of doxorubicin. The doxorubicin deposited by a MMP-selective prodrug, compound 6, was more effective than doxorubicin at reducing HT1080 xenograft growth. In particular, compound 6 cured 8 of 10 mice with HT1080 xenografts at doses below the maximum tolerated dose, whereas doxorubicin cured 2 of 20 mice at its maximum tolerated dose. Compound 6 was less toxic than doxorubicin at this efficacious dose because mice treated with compound 6 had no detectable changes in body weight or reticulocytes, a marker for marrow toxicity. Hence, MMP-activated doxorubicin prodrugs have a much higher therapeutic index than doxorubicin using HT1080 xenografts as a preclinical model.

Animals↗

PubMed2005

In situ visualization of DSBs to assess the extranuclear/extracellular effects induced by low-dose alpha-particle irradiation.

Extranuclear/extracellular effects may have a significant effect on low-dose radiation risk assessment as well as on the shape of the dose-response relationship. Numerous studies using different end points such as sister chromatid exchanges, micronuclei and mutation have shown that this phenomenon exists in many cell types. However, these end points mostly reflect the late events after radiation damage, and little is known about the early response in this phenomenon. DNA double-strand breaks (DSBs) induced by ionizing radiation or carcinogenic chemicals can be visualized in situ using gamma-H2AX immunofluorescence staining, and there is evidence that the number of gamma-H2AX foci can be closely correlated with DSBs induced. Here we used gamma-H2AX as a biomarker to assess the extranuclear/extracellular effects induced by low-dose alpha particles in situ. The results show that a greater fraction of positive cells with DSBs (48.6%) was observed than the number of cells whose nuclei were actually traversed by the 1-cGy dose of alpha particles (9.2%). The fraction of DSB-positive cells was greatly reduced after treatment with either lindane or DMSO. These results suggest that in situ visualization of DSBs can be used to assess radiation-induced extranuclear/extracellular effects soon after irradiation. Moreover, the in situ DSB assay may provide a means to evaluate the spatial effect on unirradiated cells that are located in the neighboring region of cells irradiated by alpha particles.

Alpha Particles↗

PubMed2005

[Application of DHPLC in human genomic SNP screening and genotyping for all-trans-retinol dehydrogenase].

OBJECTIVE: To assess the efficacy of denaturing high-performance liquid chromatography (DHPLC) as a new screening assay for sequence variation in SNP detecting and new approach to SNP genotyping. METHODS: DHPLC was used to screen SNPs in 8 DNA pools each consisting of DNA from 5 individuals, and genotype the identified SNPs in 150 Chinese subjects from Hong Kong. RESULTS: Seventeen SNPs were identified: 12 were novel and 5 were previously reported; 11 were found in screening stage and the other 6 were found in genotyping stage; 2 were only found in Caucasian samples; 3 showed ethnic difference of minor allele frequency(MAF); 7 were common with the MAF>0.05 in Chinese samples. CONCLUSION: The results demonstrated the efficiency of DHPLC in screening SNPs when coupled with DNA pooling strategy, and in genotyping SNPs.

Alcohol Oxidoreductases↗

PubMed2005

[Study on water extraction process of Herba epimedii with microwave technology].

OBJECTIVE: To study, the high polar media-water extraction process of Herba epimedii with the microwave technology. METHOD: The single parameters of extraction process was investigated with dry extract yield and extraction efficiency of icariin as content index. RESULT: Through studying the single parameter, the optimal conditions are as follows: 70% ethanol as wetting solvent, volume of solvent to weight of material equal to 6:1 in wetting, 30 min wetting time, 2.5 min microwave irradiation time, volume of solvent to weight of material equal to 50:1 in extraction process, 10 min microwave-assisted extraction time. CONCLUSION: Compared with conventional methods, microwave-assisted extraction (MAE) after Microwave Pretreament (MP) of raw material was higher extraction efficiency and time-saving.

Drugs, Chinese Herbal↗

PubMed2005

[Treatment of primary trigeminal neuralgia with radiofrequency thermogangliocoagulation: Report of 152 consecutive cases].

PURPOSE: To evaluate the clinical results of primary trigeminal neuralgia treated by RFT and investigate the methods to manage complications. METHODS: 152 cases of primary trigeminal neuralgia were collected from 2001 to 2004, a retrospective study was undertaken to analyze the clinical characters such as effective rate, ineffective rate and the rate of complications of patients treated with RFT. RESULTS: The average age of the 152 cases was 48.9 years old, the rate of male to female was 1:1.3. The effective rate of primary trigeminal neuralgia treated with RFT was 94.1%, the ineffective rate was 2.6%;another 3.3% cases gave up or altered to other methods, the rate of complications was 15.8%. CONCLUSIONS: RFT is an effective method to treat primary trigeminal neuralgia with few severe complications and low mortality rate, which can save the sense of touch partly. Recurrent cases can be retreated with RFT.

Electrocoagulation↗

PubMed2005

Application of phage-displayed single chain antibodies in western blot.

A phage display single chain fragment variable library constructed on pIII protein of M13 filamentous phage was screened using B-lymphocyte stimulator and FP248 as selective molecules. After four rounds of panning, there was a remarkable enrichment in the titer of bound phages. Twenty phage clones were selected from the last round and screened by means of phage-ELISA. With the antibody phages as primary antibodies in Western blot, we developed a method for detecting the specific antigen. The dilutions of antibody phages depend on the affinity between antibody-displayed phage particles and antigens.

Animals↗

PubMed2005

[The experimental study on changes of endothelial nitric oxide synthase and plasminogen activator inhibitor-1 protein in the canine atrial fibrillation model].

OBJECTIVE: To evaluate the changes in the expressions of endothelial nitric oxide synthase (eNOS) and plasminogen activator inhibitor-1 (PAI-1) and the alterations of nitric oxide (NO) concentration in atrial endocardium in atrial fibrillation (AF) in order to investigate the mechanisms that contribute to thrombosis. METHODS: In canine AF was produced with rapid atrial pacing at 400 bpm for 6 weeks, whereas the controls had no atrial pacing. NO production was measured by NO-specific microelectrode. The expression of endocardial eNOS and PAI-1 protein were determined by Western blot analysis and immunohistochemical Staining. Plasma levels of PAI-1 were analysed by Enzyme-linked immunoadsorbent assay. RESULTS: Left atrial NO concentration was decreased in AF than that in controls [(23.4 +/- 5.8)nmol/L vs (63.8 +/- 16.1)nmol/L, P < 0.01]. Endocardial eNOS expression was also significantly decreased (855 +/- 217 vs 2320 +/- 694, P < 0.05), whereas the expression of the PAI-1 was increased (3164 +/- 827 vs 1371 +/- 352, P < 0.01). Neither NO concentration, nor PAI-1, eNOS expression were altered in the right atria at the same time. A significant increase for plasma levels of PAI-1 was also detected in AF group. No correlation was found between eNOS and PAI-1 protein expression (r = 0.217, P > 0.05). CONCLUSION: In the canine model AF was associated with a marked decrease in endocardial NOS expression and NO concentration and with an increase in PAI-1 expression in the left atrium, which may contribute to the thrombosis in AF.

Animals↗

PubMed2005

[Effect of Cilazapril on endothelial cell function and fibrinolysis system in the canine atrial fibrillation models].

OBJECTIVE: To investigate the effect of cilazapril on endothelial cell function and fibrinolysis system in the canine atrial fibrillation (AF) models. METHODS: All canines were divided into three groups: (1) Control group, without atrial pacing; (2) Atrial pacing group, in which atrial fibrillation was established by rapid atrial pacing at 400 bpm for 6 weeks; (3) Atrial pacing together with cilazapril group, in which cilazapril was given before and after atrial pacing. Nitric oxide (NO) of atrial endocardium was measured with NO-specific microelectrode. The expression of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) protein in atrium was determined by Western Blot analysis and immunohistochemical staining. Plasma levels of von Willebrand Factor (vWF), PAI-1 and tPA were analyzed by enzyme-linked immunoadsorbent assay. RESULTS: NO production from atrial endocardium was significantly increased in atrial pacing together with cilazapril group than atrial pacing group [(42.6 +/- 9.9) nmol/L vs (23.4 +/- 5.8) nmol/L, P < 0.05], whereas the plasma levels of vWF were decreased [(75.4 +/- 12.8)% vs (125.9 +/- 20.6)%, P < 0.05]. Compared to controls, the expression of atrium tPA protein in atrial pacing together with cilazapril group was significantly upregulated (4052 +/- 857 vs 1936 +/- 421, P < 0.05) and PAI-1 protein was downregulated (2487 +/- 542 vs 3164 +/- 827, P < 0.05). Cilazapril also significantly increased tPA antigen and decreased PAI-1 antigen in plasma. CONCLUSION: Cilazapril can favorably improve endothelial function and resume the balance of fibrinolysis system in AF, which might be of beneficial to hypercoagulated state in AF.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2005

[Reduced intensity of BuCy conditioning regimen for transplantation in the treatment of malignant hematologic diseases].

OBJECTIVE: To evaluate the use of a new reduced intensity of BuCy conditioning regimen for the treatment of malignant hematologic diseases in aged or intolerable patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) from the siblings. METHODS: Twelve patients with acute lymphoblastic leukemia (ALL, n = 4), acute myelogenous leukemia (AML-M(2), n = 2), chronic myelogenous leukemia (CML, n = 4), and myelodysplastic syndromes-refractory anemia with excess blasts (MDS-RAEB, n = 2) were intolerant of conventional myeloablative therapy because of age (older than 50 years) or having severe concurrent diseases. The median age was 49 years (range 42-64 years). Seven were males and five females. Two of the 12 patients were HLA one antigen-mismatched and the rest HLA identical with their donors. The low dosage conditioning regimen consisted of busulfan (2 mg.kg(-1).d(-1) for 3 days), Ara-C (2 g.m(-2).d(-1) for 1 or 2 times), cyclophosphamide (1.0 g.m(-2).d(-1) for 2 days) and anti-T-lymphocyte globulin (ATG 2.5 mg.kg(-1).d(-1) for 4 days, -5 - -2 day). Granulocyte colony-stimulating factor mobilized bone marrow and peripheral blood stem cells (PBSC) were harvested (1 patient using PBSC alone). All patients received cyclosporin A, short-term MTX and mycophenolate mofetil (MMF) for prophylaxis of acute graft-versus-host disease (aGVHD). DNA short tandem repeat (STR) sequence analysis, cytogenetics and molecular-biologic technique were used to analyze chimerism. RESULTS: All the patients were well tolerated the regimen, with no severe regimen related toxicity. In all the 12 patients, absolute neutrophil count > or = 0.5 x10(9)/L was achieved in 11 to 17 (median 15) days and platelet count > 20 x 10(9)/L in 10 to 23 (median 15) days after transplantation. Complete chimerism was achieved in 11 patients and 1 patient was in mixed chimerism at one month after HSCT. With a median follow-up of 14.5 (4.0-24.0) months, 7 of the 12 patients (58.0%) were alive and 5 (42.0%) of the 7 were disease-free. The probabilities of OS and DFS at 12 months were 75.0% and 48.1%. Five patients (41.6%) had aGVHD and four had local chronic GVHD with a cumulative probability of chronic GVHD of 41.5%. CONCLUSION: This reduced intensity conditioning regimen is well tolerated and safe for HSCT in the older patients or patients with severe concurrent medical conditions and can achieve full chimerism and long-term disease-free survival.

Adult↗

PubMed2005

[Construction, Expression, Purification and Antiviral Activity of Fused Interferon-BLA (IFN-BLA).].

A fusion protein, Interferon-BLA (IFN-BLA), was constructed with IFN-beta-1b and IFN-alpha-2b separating by a linker -GGGS-. The laboratory-scale expression conditions in E.coli BL21 CodonPlus (DE3)-RIL had been optimized and IFN-BLA was expressed higher than 35% of total protein in the cells mainly as inclusion body. The inclusion body of IFN-BLA was denatured and refolded by dialysis and purified by ion-exchange chromatography. The overall yield of IFN-BLA was about 45 mg/L with purity higher than 90%. Antiviral activity assay suggested that this newly fused protein may have synergetic or additive antiviral activities.

Antiviral Agents↗