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81.
TheFirstWorldChineseCongresofDigestionwasheldinBeijingfromOctober20to22,1998inthebeautifulcapitalcityofBeijing.Thespecificaim... 相似文献
82.
We tested whether the in vivo infusion of recombinant, soluble CTLA4 fused with Ig heavy chains, as a surrogate ligand used to block CD28/CTLA4 T-cell costimulation, could prevent efficient T-cell activation and thereby reduce graft-versus-host disease (GVHD). Lethally irradiated B10.BR recipients of major histocompatibility complex disparate C57BL/6 donor grafts received intraperitoneal injections of human CTLA4-Ig (hCTLA4-Ig) or murine CTLA4-Ig (mCTLA4-Ig) in various doses and schedules beginning on day -1 or day 0 of bone marrow transplantation (BMT). In all five experiments, recipients of CTLA4-Ig had a significantly higher actuarial survival rate compared to mice injected with an irrelevant antibody control (L6) or saline alone. Survival rates in recipients of hL6 or PBS were 0% at 29 to 45 days post-BMT. In recipients of CTLA4-Ig, survival rates were as high as 63% mice surviving 3 months post-BMT. However, protection was somewhat variable and recipients of CTLA4-Ig were not GVHD-free by body weight, clinical appearance, and histopathologic examination. There were no significant differences in the survival rates in comparing injection dose, injection duration, or species of CTLA4-Ig (hCTLA4-Ig v mCTLA4- Ig). Splenic and peripheral blood flow cytometry studies of long-term hCTLA4-Ig-injected survivors showed a significant peripheral B-cell and CD4+ T-cell lymphopenia, consistent with GVHD. A kinetic study of splenic reconstitution was performed in mice that received hCTLA4-Ig and showed that mature splenic localized CD8+ T-cell repopulation was not significantly different in recipients of hCTLA4-Ig compared with hL6, despite the significant increase in actuarial survival rate in that experiment. These data suggest that the beneficial effect of hCTLA4-Ig on survival is not mediated by interfering with mature donor- derived T-cell repopulation post-BMT. Neither hCTLA4-Ig nor mCTLA4-Ig interfered with hematopoietic recovery post-BMT. We conclude that CTLA4- Ig (most likely in combination with other agents) may represent an important new modality for GVHD prevention. 相似文献
83.
A comparison between activated protein C and des-1-41-light chain- activated protein C in reactions with type 1 plasminogen activator inhibitor 总被引:2,自引:0,他引:2
This study investigates the role of the gamma-carboxyglutamic acid (gla) containing domain of activated protein C in interactions with both platelet-derived and purified type 1 plasminogen activator inhibitor (PAI-1). The activity of human platelet PAI-1 was neutralized to the same extent by bovine activated protein C and bovine des-1-41- light chain-activated protein C. Both forms of activated protein C formed SDS-stable, divalent-cation independent complexes with platelet PAI-1, as demonstrated by immunoblotting using antibodies directed to either protein C or PAI-1. Since activated protein C neutralized PAI-1, the potential inhibition of the enzyme by PAI-1 was studied. Purified PAI-1 inhibited the amidolytic activity of bovine-activated protein C and bovine des-1-41-light chain-activated protein C with a k2 of 2.85 X 10(4) M-1 sec-1 for both proteins. These data suggest that the gla domain of activated protein C is not required for neutralization of PAI- 1 activity, for complex formation with PAI-1, or for inhibition of the amidolytic activity of activated protein C by PAI-1. 相似文献
84.
A fusion protein was synthesized consisting of the murine granulocyte- macrophage colony-stimulating factor (mGM-CSF) gene spliced to a truncated form of the diphtheria toxin (DT390) gene coding for a molecule that retained full enzymatic activity, but excluded the native binding domain. The DT390-mGM-CSF hybrid gene was cloned into a vector under the control of an inducible promoter and the protein expressed in Escherichia coli. After induction, a protein was purified from inclusion bodies in accord with the deduced molecular weight of DT390 mGM-CSF. Cell-free studies of the adenosine diphosphate-ribosylating activity of DT390 mGM-CSF showed results that were similar to those of native DT. The DT390 mGM-CSF immunotoxin inhibited FDCP2.1d, a murine myelomonocytic tumor line expressing the GM-CSF receptor with an IC50 (concentration inhibiting 50% activity) of 5 x 10(-11) mol/L. The fusion toxin was specifically cytotoxic and directed by the GM-CSF portion of the molecule because addition of a monoclonal antibody directed against GM-CSF inhibited its ability to kill the cell line. Cell lines that do not express GM-CSF receptor were not inhibited by the fusion toxin. DT390 mGM-CSF was also able to specifically inhibit normal committed bone marrow (BM) progenitor cells as measured in clonal colony-forming unit granulocyte-macrophage assays. Together, these findings indicate that DT390 mGM-CSF may be useful as a novel tool for purging BM of contaminating leukemia cells or in vivo for eliminating residual leukemia cells. Also, it can be used to determine whether committed and/or noncommitted BM progenitor cells express the GM-CSF receptor. 相似文献
85.
Rakesh Mehra Kushaljit Singh Sodhi Akshay Saxena BR Thapa Niranjan Khandelwal 《Gut and liver》2015,9(3):388-394
Background/Aims
Studies in adults suggest that constipation may not be a purely colonic pathology and may be a component of a generalized gastrointestinal (GI) motor disorder in which proximal GI motility can be impaired. Pediatric data are scarce, and the natural history of the disorder remains undefined. We aimed to evaluate gallbladder motility in a subset of Asian children with chronic functional constipation.Methods
Abdominal ultrasound was performed on 105 children, including 55 patients (aged 3 to 13 years) with chronic functional constipation who met the inclusion criteria and 50 age- and gender-matched controls. The gallbladder contractility index was calculated based on the preprandial and postprandial gallbladder areas. Preprandial and postprandial values for gallbladder volume and wall thickness were evaluated.Results
The mean value of the contractility index for the patients (15.77±24.68) was significantly lower than the mean value for the controls (43.66±11.58) (p=0.001). The mean postprandial gallbladder volumes and areas were larger in children with gallbladder hypomotility (p<0.05). The mean duration of constipation (4.8 months) was significantly higher (p=0.004) in the children with gall-bladder hypomotility.Conclusions
Gallbladder motility is significantly impaired in children with chronic functional constipation. This study contributes to the understanding of the underlying pathophysiology, which will enable advancement in and improved management of children with chronic constipation and associated gallbladder hypomotility. 相似文献86.
Real-time analysis of shear-dependent thrombus formation and its blockade by inhibitors of von Willebrand factor binding to platelets 总被引:12,自引:6,他引:12
Alevriadou BR; Moake JL; Turner NA; Ruggeri ZM; Folie BJ; Phillips MD; Schreiber AB; Hrinda ME; McIntire LV 《Blood》1993,81(5):1263-1276
Two likely mechanisms for the initiation of arterial platelet thrombus formation under conditions of elevated fluid shear stresses are: (1) excessive adhesion and aggregation of platelets from rapidly flowing blood onto the exposed sub-endothelium of injured, atherosclerotic arteries; or (2) direct, fluid shear stress-induced aggregation of platelets in constricted arteries with intact endothelial cells. Mechanism (1) was simulated using a parallel plate flow chamber, fibrillar collagen type I-coated slides, and mepacrine-labeled (fluorescent) platelets in whole blood anticoagulated with citrate, hirudin, unfractionated porcine heparin, or low molecular weight heparin flowing for 1 to 2 minutes at wall shear rates of 100 to 3,000 seconds-1 (4 to 120 dynes/cm2). The precise sequence of interactions among von Willebrand factor (vWF), glycoprotein (GP)Ib, and GPIIb-IIIa during platelet adhesion and subsequent aggregation were resolved by direct real-time observation using a computerized epifluorescence video microscopy system. Adhesion at high shear rates was the result of the adsorption of large vWF multimers onto collagen and the binding of platelet GPIb to the insolubilized vWF. Aggregation occurred subsequently and required the binding of ligands, including vWF via its RGD binding domain, to GPIIb-IIIa. Mechanism (2) was modeled by producing shear stresses of 90 to 180 dynes/cm2 in a rotational cone and plate viscometer, which aggregates platelets from platelet-rich- plasma (PRP) anti-coagulated with citrate, hirudin, or either type of heparin in reactions that require large vWF multimers, Ca2+, adenosine diphosphate, and both GPIb and GPIIb-IIIa. Both vWF-mediated shear- aggregation in PRP and platelet-collagen adhesion in flowing whole blood (anticoagulated with citrate and hirudin) are inhibited by two potentially useful anti-arterial thrombotic agents: polymeric aurin tricarboxylic acid (ATA; 28.5 to 114 micrograms/mL), which binds to vWF and inhibits its attachment of GPIb, and a recombinant vWF fragment (rvWF445-733; 30 to 200 micrograms/mL) that binds to platelet GPIb (in the absence of any modulator) and blocks attachment of vWF multimers. Unfractionated heparin, but not low molecular weight heparin, apparently binds to rvWF445-733 and counteracts the inhibitory effects of the vWF fragment in vitro on shear-aggregation and platelet-collagen adhesion. 相似文献
87.
Bluman EM; Schnier GS; Avalos BR; Strout MP; Sultan H; Jacobson FW; Williams DE; Carson WE; Caligiuri MA 《Blood》1996,88(10):3887-3893
88.
Unrelated donor bone marrow transplantation: influence of HLA A and B incompatibility on outcome 总被引:2,自引:9,他引:2
Davies SM; Shu XO; Blazar BR; Filipovich AH; Kersey JH; Krivit W; McCullough J; Miller WJ; Ramsay NK; Segall M 《Blood》1995,86(4):1636-1642
We have studied the outcome of 211 consecutive unrelated donor (URD) bone marrow transplants (BMT) performed at the University of Minnesota (Minneapolis, MN) between May 1985 and December 1992. Ninety patients (43%) received marrow matched serologically at HLA A, B, and DR loci; 86 (41%) received marrow with a major and 32 (15%) marrow with a minor serologic mismatch at the HLA A or B locus. Multivariate analysis revealed that older age had an adverse effect on survival. In younger (age less than 18 years) recipients, survival after fully matched (A, B, and DR sub-type) or major mismatched (A or B locus), DR subtype- matched donor BMT was not significantly different (P = .4; survival: 53% v 41%, respectively, at 3 years). For adults, survival after matched donor BMT was significantly better than that with mismatched donors (P < .01; survival: 30% v 10%, respectively, at 3 years). Formal quality of life assessment by telephone interview demonstrated similar functional status in survivors of URD and related donor (RD) BMT at least 2 years post-BMT. URD BMT provides effective therapy for a variety of lethal hematopoietic diseases that rivals outcome of RD transplant in some cases. Use of URD marrow with a major mismatch at one HLA A or B locus is well tolerated in young, but not in older, recipients. These observations should be used to improve donor selection and counseling for URD BMT candidates. 相似文献
89.
Eighteen patients with agnogenic myeloid metaplasia with myelofibrosis were studied for clinical and laboratory evidence of immunologic dysfunction. Clinical findings included the presence of arthritis, vasculitis, and erythema nodosum. Laboratory abnormalities included the presence of circulating immune complexes, antinuclear antibodies, positive direct Coombs tests, elevated latex fixations, and a circulating lupus type anticoagulant. Total hemolytic complement was markedly depressed in four patients. Analysis of complement (C) components C1-C9 and factor B demonstrated significant reduction of only C3 and factor B. By crossed-immunoelectrophoresis, both C3 and factor B, but not C4, were cleaved, indicating that C activation was occurring predominantly via the alternative pathway. The control proteins beta 1H and C3b inactivator were decreased in three of four patients with hypocomplementemia. These data suggest that immunologic mechanisms associated with activation of the complement system play an important role in the disease process of some patients with agnogenic myeloid metaplasia with myelofibrosis. 相似文献
90.
Knox SJ; Wilson FD; Greenberg BR; Shifrine M; Rosenblatt LS; Reeves JD; Misra H 《Blood》1981,57(6):1043-1048
In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x-irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST (patients, D37 = 198 R; normals, D37 = 309 R, p = 0.057) and colony formation assay (patients, D37 = 53 R; normals, D37 = 109 R, p = 0.016). No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed. 相似文献