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排序方式: 共有269条查询结果,搜索用时 15 毫秒
51.
A computerized method for rapid quantification of gallbladder volume from real-time sonograms 总被引:4,自引:0,他引:4
A computerized method that requires only 1-2 minutes to quantify gallbladder volume from real-time sonograms is described. This time is considerably shorter than that required using the hand-calculation method. There was a highly significant correlation between gallbladder volumes calculated by computer and hand (r = 0.97; P less than .001). 相似文献
52.
Although there have been great advances in cancer diagnosis in recent years, it remains difficult to transfer tumor location information from cross-sectional computed tomographic (CT) scans or magnetic resonance images to the simulation and verification films used in planning radiotherapy. A newly developed system uses radioopaque markers attached to the patient as reference points. These markers are identified on both CT scans and simulation films and their locations entered into the treatment planning computer. The tumor and any desired normal structures are then outlined manually on each CT section. Transparent overlays produced by the computer show the position of the reference markers and tumor outlines for any combination of gantry angles and source-film distance. Because the overlays are scaled to the simulation films, the reference points enable precise alignment of overlay and film. The tumor outline thus appears on the simulation or verification films exactly as it is "seen" by the therapy beam, making field verification straightforward and accurate, even on oblique films. 相似文献
53.
Inthispaper ,wereportedriskfactorsassociatedwithHIVinfectionamongwomenandtheirimplicationsforAIDSpreventioneffortsintheDodomaregion ,Tanzania .1 SUBJECTSANDMETHODS1.1 Thepopulationandsampleselection ThestudywasconductedintheDodomaregion ,whichhasanestimate… 相似文献
54.
Pixel overflow artifacts in SPECT evaluation of the skeleton 总被引:2,自引:0,他引:2
The successful application of single photon emission computed tomography (SPECT) techniques to radionuclide evaluation of the skeleton depends on strict quality control measures, recognition of potential artifacts, and the selection of appropriate cases for specific reprocessing techniques. The application of simple image-processing routines to problems of "hot spot" and bladder pixel overflows facilitated a reduction in the technical inadequacy rate from 19% to 2% for SPECT evaluation of 100 hips, as well as improvement in diagnostic image quality in a variety of additional cases. 相似文献
55.
Dercksen MW; Gerritsen WR; Rodenhuis S; Dirkson MK; Slaper-Cortenbach IC; Schaasberg WP; Pinedo HM; von dem Borne AE; van der Schoot CE 《Blood》1995,85(11):3313-3319
Adhesion molecules play a role in the migration of hematopoietic progenitor cells and regulation of hematopoiesis. To study whether the mobilization process is associated with changes in expression of adhesion molecules, the expression of CD31, CD44, L-selectin, sialyl Lewisx, beta 1 integrins very late antigen 4 (VLA-4) and VLA-5, and beta 2 integrins lymphocyte function-associated 1 and Mac-1 was measured on either bone marrow (BM) CD34+ cells or on peripheral blood CD34+ cells mobilized with a combination of granulocyte colony- stimulating factor (G-CSF) and chemotherapy. beta 1 integrin VLA-4 was expressed at a significantly lower concentration on peripheral blood progenitor cells than on BM CD34+ cells, procured either during steady- state hematopoiesis or at the time of leukocytapheresis. No differences in the level of expression were found for the other adhesion molecules. To obtain insight in which adhesion molecules may participate in the homing of peripheral blood stem cells (PBSCs), the number of CD34+ cells expressing these adhesion molecules present in leukocytapheresis material was quantified and correlated with hematopoietic recovery after intensive chemotherapy in 27 patients. The number of CD34+ cells in the subset defined by L-selectin expression correlated significantly better with time to platelet recovery after PBSC transplantation (r = - .86) than did the total number of CD34+ cells (r = -.55). Statistical analysis of the relationship between the number of CD34+L-selectin+ cells and platelet recovery resulted in a threshold value for rapid platelet recovery of 2.1 x 10(6) CD34+ L-selectin+ cells/kg. A rapid platelet recovery (< or = 14 days) was observed in 13 of 15 patients who received > or = 2.1 x 10(6) CD34+ L-selectin+ cells/kg (median, 11 days; range, 7 to 16 days), whereas 10 of 12 patients who received less double positive cells had a relative slow platelet recovery (median, 20 days; range, 13 to 37 days). The L-selectin+ subpopulation of CD34+ cells also correlated better with time to neutrophil recovery (r = - .70) than did the total number of reinfused CD34+ cells (r = -.51). However, this latter difference failed to reach statistical significance. This study suggests that L-selectin is involved in the homing of CD34+ cells after PBSC transplantation. 相似文献
56.
目的:应用激光多谱勒血流仪监测局部血流变化以判断高压电损伤程度。方法:实验于2003-10/2005-01在深圳市第二人民医院烧伤整形科实验室完成。选择健康新西兰兔32只,采用自制电击设备建立电损伤重度损伤模型,将电击区域均分为A,B,C,D,E5个区,依次为肢体远端到近端。在A,B,E区于伤前、伤后0,2,4,24,48,72h,4,5,6,7d测定局部皮肤表面及肌肉中血流值变化情况。结果:①损伤前A、B、E区皮肤表面平均血流值分别为75.74,78.86,84.21PU,表明肢体近端至远端血流值逐渐减少,各点之间血流值差异无显著性意义(P>0.05)。②A区皮肤表面伤后2h血流值明显低于伤后0,4,24,48h,差异有显著性意义[分别为(27.22±22.80),(91.60±74.37),(63.97±44.41),(58.80±52.50),(58.72±39.02)PU,t=2.357,2.856,2.364,2.998,P<0.05],此时组织学表现为细胞水肿明显,有少量中性粒细胞浸润。A区皮肤表面伤后4h血流值增加,但至伤后4d才逐渐恢复到伤前水平。A区肌肉伤后2h血流值低于伤后24h,4d,差异有显著性意义[分别为(83.70±73.30),(135.10±63.07),(160.26±71.32)PU,t=2.383,2.367,P<0.05]。此时组织学表现为肌纤维肿胀,部分横纹消失,肌纤维的胞浆呈红染的疏松水波状和网状结构。③B区皮肤表面伤后4,24h血流值低于损伤前和伤后0h,差异有显著性意义[分别为(50.75±41.69),(47.23±35.36),(78.86±26.47),(83.89±32.77)PU;t=2.324,2.732,2.826,3.189,P<0.05,0.01],组织学表现同A区。B区局部肌肉伤后4h血流值低于伤后0,48,72h,差异有显著性意义[分别为(64.65±34.08),(107.11±36.50),(130.30±75.04),(180.56±72.59)PU,t=2.545,2.712,2.963,P<0.05]。此时组织学表现基本上同A区伤后2h。④E区皮肤表面各时相点之间血流值差异无显著性意义(P>0.05)。组织学表现同A区。E区局部肌肉伤后2h血流值低于伤后0,24,72h,差异有显著性意义[分别为(129.11±65.08),(175.02±71.67),(169.14±71.05),(196.64±67.34)PU,t=2.776,2.521,2.895,P<0.05]。此时组织学表现为肌纤维溶解断裂及中性粒细胞浸润。结论:用激光多谱勒血流仪监测损伤局部血流变化可以判断高压电损伤程度。 相似文献
57.
Cyclic hematopoiesis in gray collie dogs can be cured by lithium treatment. We examined the mechanism of lithium's effect by developing an assay for the canine equivalent of GM-CSF (called GM-CSA). Phytohemagglutinin (PHA)-stimulated canine blood mononuclear cells produce GM-CSA in a dose-dependent manner; this GM-CSA stimulates more neutrophil-containing colonies than does endotoxin-treated dog serum. Production of GM-CSA by PHA-stimulated normal dog cells was not altered by lithium. However, cells from gray collies during their neutrophilic period increased their GM-CSA when lithium (2 mEq/L) was added to low doses of PHA, whereas neutropenic gray collie cells did not. These data suggest that lithium could modulate cyclic hematopoiesis by increasing intramedullary GM-CSA at the time when marrow neutrophilic progenitor cells are at their nadir. 相似文献
58.
Fibronectin in artery subendothelium is important for platelet adhesion 总被引:10,自引:1,他引:10
The role of subendothelial fibronectin in platelet interaction with subendothelium was studied. Human umbilical artery subendothelium was exposed to flowing blood containing 111In-labeled platelets in an annular perfusion chamber. Platelet adhesion was determined from the 111In radioactivity on the vessel wall. When perfusions were performed for five minutes at a wall shear rate of 1,800 s-1, platelet adhesion was the same whether normal plasma or fibronectin-free plasma was used. Preincubation of subendothelium with rabbit anti-human fibronectin serum, however, resulted in a marked inhibition of platelet adhesion. Preincubation with normal rabbit serum had no effect. Platelet adhesion was also diminished when the vessel wall was preincubated with anti- fibronectin IgG fraction or F(ab')2 fragment. After the latter preincubations, frozen sections of 4 micron were incubated with fluorescein isothiocyanate-conjugated goat anti-rabbit IgG, F(ab')2 fragment specific. Fluorescence was seen throughout the subendothelium both before and after perfusion. No fluorescence was seen when subendothelium was preincubated with normal rabbit IgG or F(ab')2 or with anti-fibronectin IgG that had been absorbed with purified fibronectin. After absorption of anti-fibronectin IgG with purified fibronectin, the inhibiting effect on platelet adhesion was also no longer present. Preincubation of the vessel wall with anti-fibronectin IgG reduced platelet adhesion significantly at a wall shear rate of 800 s-1. This effect was even greater at 1,800 s-1. At low shear rate (400 s-1), there was no inhibition. 相似文献
59.
Dale DC; Bonilla MA; Davis MW; Nakanishi AM; Hammond WP; Kurtzberg J; Wang W; Jakubowski A; Winton E; Lalezari P 《Blood》1993,81(10):2496-2502
Patients with idiopathic, cyclic, and congenital neutropenia have recurrent severe bacterial infections. One hundred twenty-three patients with recurrent infections and severe chronic neutropenia (absolute neutrophil count < 0.5 x 10(9)/L) due to these diseases were enrolled in this multicenter phase III trial. They were randomized to either immediately beginning recombinant human granulocyte colony- stimulating factor (filgrastim) (3.45 to 11.50 micrograms/kg/d, subcutaneously) or entering a 4-month observation period followed by filgrastim administration. Blood neutrophil counts, bone marrow (BM) cell histology, and incidence and duration of infection-related events were monitored. Of the 123 patients enrolled, 120 received filgrastim. On therapy, 108 patients had a median absolute neutrophil count of > or = 1.5 x 10(9)/L. Examination of BM aspirates showed increased proportions of maturing neutrophils. Infection-related events were significantly decreased (P < .05) with approximately 50% reduction in the incidence and duration of infection-related events and almost 70% reduction in duration of antibiotic use. Asymptomatic splenic enlargement occurred frequently; adverse events frequently reported were bone pain, headache, and rash, which were generally mild and easily manageable. These data indicate that treatment of patients with severe chronic neutropenia with filgrastim results in a stimulation of BM production and maturation of neutrophils, an increase in circulating neutrophils, and a reduction in infection-related events. 相似文献
60.
Characterization of endogenous cytokine concentrations after high-dose chemotherapy with autologous bone marrow support 总被引:3,自引:0,他引:3
Endogenous cytokines are thought to mediate numerous biologic processes and may account for some adverse effects experienced following the administration of recombinant proteins. This study describes the pattern of endogenous cytokine exposure following high-dose chemotherapy. Blood concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), macrophage colony-stimulating factor (M-CSF), and erythropoietin (EPO) were measured by enzyme-linked immunosorbent assay (ELISA) methods in 68 patients receiving the same ablative chemotherapy regimen (cyclophosphamide, cisplatin, carmustine). Patients were grouped according to cellular support (autologous bone marrow [BM] CSF-primed peripheral blood progenitor cells [PBPCs]) and prescribed growth factor (recombinant human granulocyte or granulocyte-macrophage colony-stimulating factor [rHuG- CSF or rHuGM-CSF]). Leukocyte reconstitution was most accelerated in the groups treated with PBPCs and rHuG-CSF. IL-6, M-CSF, and TNF-alpha concentrations were higher in the groups treated with rHuGM-CSF and without PBPCs. Maximal endogenous cytokine concentrations occurred approximately 12 days after BM reinfusion. High concentrations of EPO occurred in patients experiencing significant hypotension despite routine transfusions for hematocrit < 42%. High M-CSF and IL-6 levels were associated with increased platelet transfusion requirements. Concentrations of all four cytokines were significantly higher in patients experiencing renal or hepatic toxicity, with elevations occurring in a predictable sequence and M-CSF elevations occurring first. This report shows that endogenous cytokine concentrations may be influenced by either cellular or CSF support and are associated with differences in platelet reconstitution and organ toxicity. 相似文献