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排序方式: 共有337条查询结果,搜索用时 687 毫秒
91.
Interleukin-12 enhances peripheral hematopoiesis in vivo 总被引:3,自引:1,他引:3
Interleukin 12(IL-12) is a cytokine that supports the proliferation and activation of cytotoxic T lymphocytes and natural killer (NK) cells. Recent evidence has suggested that IL-12 also has hematopoietic activities in vitro. We report studies that show that IL-12 has significant in vivo hematopoietic stimulating activity that includes enhancement of peripheral (splenic) hematopoiesis and mobilization of hematopoietic progenitor cells to the peripheral circulation. A single injection of recombinant murine IL-12 significantly reduced the number of bone marrow (BM) colony-forming unit granulocyte-macrophage (CFU-GM) in a time-dependent manner, while concomitantly stimulating high proliferative potential. In contrast, splenic CFU-GM and HPP were increased in a time- and dose-dependent manner. Chronic administration of IL-12 resulted in significant splenic hyperplasia with increased progenitor cells, increased circulating progenitor cells, and BM hypoplasia with decreased progenitor cells. These data show that IL-12 has significant in vivo hematopoietic effects that include the ability to mobilize progenitor cells to the peripheral circulation, which may prove to be of significant benefit for peripheral blood stem cell transplantation. Thus, IL-12 has potential to be an important agent for clinical transplantation because of its hematopoietic mobilization and its previously shown immune augmenting and therapeutic activities. This combination of hematopoietic and immune functions is unique and not achievable with currently used hematopoietic growth factors. 相似文献
92.
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
93.
Loss of bone mineral density in Chinese pre-menopausal women with systemic lupus erythematosus treated with corticosteroids 总被引:7,自引:1,他引:7
The adverse effect of disease and chronic corticosteroid therapy on bone
mineral density (BMD) in patients with systemic lupus erythematosus (SLE)
has been reported in several studies of Caucasian populations. As the
factors controlling bone homeostasis may be different in Asian populations,
we measured BMD in 52 pre-menopausal Chinese women (mean age 34.1 +/- 8.0
yr) with SLE (mean disease duration 6.4 +/- 4.5 yr) treated with prednisone
(mean daily dose 11.4 +/- 10.8 mg/day). Lumbar spine, hip (total and
subregions) and total body BMDs were measured in the SLE patients using
dual-energy X-ray absorptiometry (DEXA), and compared with those from
healthy controls matched for age, sex and body mass index. Compared to
controls, SLE patients were found to have lower BMD (g/cm2) at several
sites: the lumbar spine (0.98 vs 0.90, P = 0.001), Ward's triangle (0.72 vs
0.67, P = 0.03), total body (1.04 vs 1.01, P = 0.04) and total hip (0.87 vs
0.82, P = 0.05). There was no correlation between BMD at any region and
duration of disease, activity of disease or prednisone therapy (mean daily
dose, cumulative dose or treatment duration). When BMDs were compared
between controls and SLE patients, subgrouped according to those not on
calcium and those arbitrarily receiving calcium supplements (1 g/day),
significantly lower BMDs were found in those not on calcium compared to
both controls and SLE patients on calcium. BMDs in SLE patients on calcium
were not different from those in controls. The low prevalence of
osteoporosis in our SLE patients (4-6%) suggests significant loss of BMD in
Chinese SLE patients on corticosteroid therapy is less than that reported
in Caucasians (12-18%).
相似文献
94.
Elliott MJ; Vadas MA; Eglinton JM; Park LS; To LB; Cleland LG; Clark SC; Lopez AF 《Blood》1989,74(7):2349-2359
Two human hemopoietic growth factors involved in monocytopoiesis, interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were studied for their ability to stimulate blood monocytes and to bind to the monocyte membrane. Both cytokines maintained monocyte/macrophage numbers during long-term culture and increased cell size as compared with controls. Effects on cell numbers were present at low cytokine concentrations (6 to 20 pmol/L), whereas enhanced 3H-thymidine incorporation was observed only at higher concentrations (greater than or equal to 60 pmol/L). Autoradiographic studies showed only 1% to 3% of stimulated monocytes with nuclear grains. These results suggest that the primary mechanism for IL-3 and GM-CSF-induced maintenance of monocyte/macrophage numbers in humans is through an effect on cell survival. Surface receptors for both IL-3 and GM-CSF were studied by using 125I-labeled recombinant human (rh) cytokines and performing Scatchard analyses. Both cytokines showed curvilinear Scatchard plots, and computer analyses favored a two-site binding model. High-affinity binding data for 125I rhIL-3 (Kd 7.7 to 38.2 pmol/L; receptor number/cell 95 to 580) and for 125I rhGM-CSF (Kd 4.7 to 38.9 pmol/L; receptor number/cell 8 to 67) show similar binding affinities for the two cytokines but a lower receptor number/cell for 125I rhGM-CSF. Low-affinity binding characteristics for 125I rhIL-3 (Kd 513 to 939 pmol/L; receptor number/cell 179 to 5,274) and for 125I rhGM- CSF (Kd 576 to 1,120 pmol/L; receptor number/cell 130 to 657) show a similar pattern for the two cytokines. Specificity of 125I rhIL-3 and 125I rhGM-CSF binding to monocytes was established by the ability of the homologous cytokine to inhibit binding and the inability of a range of other cytokines to compete at 100-fold excess molar concentration. It is important, however, that binding of 125I rhIL-3 was partially inhibited by rhGM-CSF and that rhIL-3 partially inhibited binding of 125I rhGM-CSF to the monocyte membrane under conditions shown to prevent receptor internalization. The degree of inhibition varied between 25% and 80% in different experiments, and quantitative inhibition experiments showed that 1,000-fold excess concentrations of competitor failed to inhibit binding of the heterologous ligand completely. These results demonstrate that human IL-3 and GM-CSF have similar effects on growth and survival of human monocytes in vitro and suggest that these and other common biological effects may be mediated either through a common receptor or through distinct receptors associated on the monocyte membrane. 相似文献
95.
Anne JH Vochteloo Boudewijn LS Borger van der Burg Wim E Tuinebreijer Mark R de Vries Arthur HP Niggebrugge Rolf M Bloem Andrea B Maier Rob GHH Nelissen Peter Pilot 《Geriatrics & Gerontology International》2013,13(1):190-197
Aim: To compare clinical characteristics and outcome of nonagenarian hip fracture patients with younger patients aged 65–89 years. Methods: This was a cohort follow‐up study of admissions for a hip fracture between 2005–2010 (mean follow up of 3.5 years) in two teaching hospitals in the Netherlands; 230 nonagenarians and 1014 patients aged 65–89 years were included. Clinical characteristics, adverse events, mobility and mortality were compared. Results: Nonagenarians were more likely to be female and anemic (both P < 0.001), and had more trochanteric fractures (P = 0.005). The number of American Society of Anesthesiologists III/VI classified patients did not differ between the two groups. During the hospital stay, adverse events were more frequently observed in nonagenarians compared with younger patients (P < 0.001). The length of stay was significantly longer in nonagenarians (P < 0.001), and the 90‐day readmission rate was similar. Absolute mortality was higher in nonagenarians (P < 0.001), excess mortality, however, was comparable. Before admission, 40.0% of the nonagenarians lived in their own home, and 40.9% had returned 3 months postfracture. The rate of returning to their own home was lower compared with younger patients (P < 0.001). Prefracture mobility was worse in nonagenarians compared with the younger group, but 3 months after discharge, the number of patients that regained prefracture mobility was comparable in both age groups. Conclusions: Nonagenarian hip fracture patients differ significantly from younger patients aged 65–89 years with respect to clinical characteristics and long‐term outcome. However, almost half of the nonagenarians returned to their own home and more than half regained their prefracture level of mobility. Given these findings, prevention strategies for hip fracture and adverse events during hospital stay that focus particularly on frail nonagenarians are highly recommended. Geriatr Gerontol Int 2013; 13: 190–197. 相似文献
96.
Dose-dependent localization of TCDD in isolated centrilobular and periportal hepatocytes 总被引:3,自引:1,他引:2
Santostefano MJ; Richardson VM; Walker NJ; Blanton J; Lindros KO; Lucier GW; Alcasey SK; Birnbaum LS 《Toxicological sciences》1999,52(1):9-19
Dose-response relationships for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)
suggest a differential sensitivity of liver cell types to the induction of
cytochrome P450 gene expression, and that the induction of hepatic protein
CYP1A2 causes sequestration of TCDD. In addition, immunolocalization of
hepatic CYP1A1/1B1/1A2 proteins is not uniform after exposure to TCDD. The
mechanism for the regio-specific induction of hepatic P450s by TCDD is
unknown, but may involve the differential distribution of participants in
the AhR-mediated pathway and/or regional P450 isozymes, as well as,
non-uniform distribution/sequestration of TCDD. Therefore, this study
examined the effects of TCDD in unfractionated, centrilobular and
periportal hepatocytes isolated from female Sprague-Dawley rats acutely
exposed (3 days) to a single oral dose of 0.01-10.0 microg [3H]TCDD/kg. A
dose- dependent increase in concentration of TCDD was accompanied by a
dose- dependent increase in CYP1A1, CYP1A2, and CYP1B1 mRNA expression and
associated enzymes in all liver-cell populations. Centrilobular hepatocytes
showed a 2.7- to 4.5-fold higher concentration of TCDD as compared to the
periportal hepatocytes at doses up to 0.3 microg TCDD/kg. Centrilobular
hepatocytes also exhibited an elevated MROD activity as compared to the
periportal hepatocytes at doses up to 0.3 microg TCDD/kg. Furthermore,
centrilobular hepatocytes showed an elevated concentration of induced
CYP1A2 and CYP1B1 mRNA as compared to periportal hepatocytes within the
0.01- and 0.3-microg TCDD/kg- treatment groups. This is the first study to
demonstrate that a dose- dependent difference in distribution of TCDD
exists between centrilobular and periportal cells that might be related to
regional differences in P450 induction.
相似文献
97.
98.
99.
Nebulized budesonide versus oral steroid in severe exacerbations of childhood asthma 总被引:10,自引:0,他引:10
EE Matthews PD Curtis BI McLain LS Morris ML Turbitt 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(8):841-843
The aim of this study was to assess whether nebulized budesonide may substitute for oral prednisolone in the management of children whose asthma is severe enough to warrant hospital admission, but who have no life threatening features. In a prospective, double-blind, randomized study nebulized budesonide (2 mg 8 hourly) was compared with oral prednisolone (2 mg/kg at entry and again at 24 h) in 46 children admitted to hospital with severe asthma exacerbations. Efficacy variables (including lung function measurements such as the primary outcome variable, Forced Expiratory Volume in 1 second (FEV1) and symptoms) were measured 24 h after treatment initiation. FEV1 improved significantly compared to baseline in patients who received nebulized budesonide compared to the prednislone group. The data show nebulized budesonide to be at least as effective as oral steroid in improving lung function and symptom severity in severe exacerbations of childhood asthma. 相似文献
100.