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651.
The outcome of a five-year radiographic follow-up study of 150 patients with maxillo-mandibular malformations who had undergone Le Fort I osteotomy of the maxilla is reported. A superimposition technique made possible an exact evaluation of the adjustments effected. The results confirm the validity of a study conducted in 1977 and the five-year stability of the maxilla. The importance of the relationship between the Frankfort plane, occlusal plane and the osteotomy line is emphasized. In operations in which Le Fort I osteotomy of the maxilla is combined with a sagittal osteotomy of the mandible the maxilla undergoes minute displacements in the weeks following surgery, which can easily be predicted and allowed for at the planning stage. The long-term stability of the maxilla is assured. 相似文献
652.
Prostaglandins of the E series (PGE) inhibit proliferation of normal bone marrow granulocyte/macrophage progenitors (CFU-GM). Circulating CFU-GM are known to differ from marrow CFU-GM in many characteristics, and in the present study, we compared the effect of PGE1 on circulating and bone marrow progenitors in normals and in patients with chronic myelogenous leukemia (CML). PGE1 caused a dose-dependent inhibition of normal marrow CFU-GM. Circulating CFU-GM were inhibited only at concentrations of 10(-5) mol/L or greater, and progenitor proliferation was, in fact, significantly stimulated at PGE1 concentrations between 10(-8) and 10(-6) mol/L. Bone marrow CFU-GM from patients with CML were inhibited in a manner similar to that of normal bone marrow. Circulating cells from patients with CML were, however, less sensitive to PGE1 inhibition than CML bone marrow cells and demonstrated a pattern intermediate between normal circulating and normal marrow progenitors. These studies suggest that peripheral blood and bone marrow contain different progenitor cell populations. 相似文献
653.
Smith FO; Broudy VC; Zsebo KM; Lampkin BC; Buckley CV; Buckley JD; Opie T; Woods WG; Hammond GD; Bernstein ID 《Blood》1994,84(3):847-852
The prognostic significance of c-kit receptor expression on leukemic blast cells was determined in 122 children with acute myeloid leukemia (AML) entered onto Childrens Cancer Group protocol 213. Clinical and laboratory characteristics as well as outcome were analyzed according to the percentage of blast cells expressing c-kit receptors and the relative number of c-kit receptors per cell as determined by indirect immunofluorescence. c-kit receptor expression was strongly associated with the expression of the CD34 antigen. However, contrary to findings in adult patients with AML, c-kit receptor expression by childhood AML blast cells was not predictive of a poor response to therapy. 相似文献
654.
Alsina M; Boyce B; Devlin RD; Anderson JL; Craig F; Mundy GR; Roodman GD 《Blood》1996,87(4):1495-1501
Osteolytic bone destruction and its complications, bone pain, pathologic fractures, and hypercalcemia, are a major source of morbidity and mortality in patients with multiple myeloma. The bone destruction in multiple myeloma is due to increased osteoclast (OCL) activity and decreased bone formation in areas of bone adjacent to myeloma cells. The mechanisms underlying osteolysis in multiple myeloma in vivo are unclear. We used a human plasma cell leukemia cell line, ARH-77, that has disseminated growth in mice with severe combined immunodeficiency (SCID) and expresses IgG kappa, as a model for human multiple myeloma, SCID mice were irradiated with 400 rads and mice were injected either with 10(6) ARH-77 cells intravenously (ARH-77 mice) or vehicle 24 hours after irradiation. Development of bone disease was assessed by blood ionized calcium levels, x-rays, and histology. All ARH-77, but none of control mice that survived irradiation, developed hind limb paralysis 28 to 35 days after injection and developed hypercalcemia (1.35 to 1.46 mmol/L) a mean of 5 days after becoming paraplegic. Lytic bone lesions were detected using x-rays in all the hypercalcemic mice examined. No lytic lesions or hypercalcemia developed in the controls. Controls or ARH-77 mice, after developing hypercalcemia, were then killed and bone marrow plasma from the long bones were obtained, concentrated, and assayed for bone-resorbing activity. Bone marrow plasma from ARH-77 mice induced significant bone resorption in the fetal rat long bone resorption assay when compared with controls (percentage of total 45Ca released = 35% +/- 4% v 11% +/- 1%). Histologic examination of tissues from the ARH-77 mice showed infiltration of myeloma cells in the liver and spleen and marked infiltration in vertebrae and long bones, with loss of bony trabeculae and increased OCL numbers. Interestingly, cultures of ARH-77 mouse bone marrow for early OCL precursors (colony-forming unit-granulocyte- macrophage [CFU-GM]) showed a threefold increase in CFU-GM from ARH-77 marrow versus controls (185 +/- 32 v 40 +/- 3 per 2 x 10(5) cell plated). Bone-resorbing human and murine cytokines such as interleukin- 6 (IL-6), IL-1 alpha or beta, TGF-alpha, lymphotoxin, and TNF alpha were not significantly increased in ARH-77 mouse sera or marrow plasma, compared with control mice, although ARH-77 cells produce IL-6 and lymphotoxin in vitro. Conditioned media from ARH-77 cells induced significant bone resorption in the fetal rat long bone resorption assay when compared with untreated media (percentage of total 45Ca released = 22% +/- 2% v 11% +/- 1%). This effect was not blocked by anti-IL-6 or antilymphotoxin (percentage of total 45Ca released = 19% +/- 1% and 22% +/- 1%, respectively). Thus, we have developed a model of human multiple myeloma bone disease that should be very useful to dissect the pathogenesis of the bone destruction in multiple myeloma. 相似文献
655.
Regulation of hematopoiesis II: the role of polyamine inhibition on helper or suppressor influences of the thymus 总被引:1,自引:0,他引:1
We have previously suggested in murine model systems, that two cell subpopulations with differing proliferative capacity, from the thymus, modify the growth of erythroid progenitor cells in vitro. In order to further characterize these populations, we have specifically inhibited polyamine biosynthesis; this pathway is essential for the process of cell replication. Thus, alpha-difluoromethyl ornithine (DFMO) was used to block the conversion of ornithine to putrescine, the first and rate- limiting step in polyamine biosynthesis. We observed a threefold increase in hematopoietic progenitors (CFU-S and CFU-E) from bone marrow in animals treated with DFMO. We further examined the effect of DFMO on accessory "helper" and "suppressor" cells from the thymus and observed an increase in helper activity with an elimination of suppressor activity. All of these effects of DFMO were specific for inhibition of polyamine biosynthesis, since simultaneous addition of the depleted biosynthetic product, putrescine, restored suppressor activity. We conclude that polyamine biosynthesis is required acutely for accessory cell regulation of hematopoiesis. 相似文献
656.
657.
Alpha and gamma oscillation amplitudes synergistically predict the perception of forthcoming nociceptive stimuli 下载免费PDF全文
Yiheng Tu Zhiguo Zhang Ao Tan Weiwei Peng Yeung Sam Hung Massieh Moayedi Gian Domenico Iannetti Li Hu 《Human brain mapping》2016,37(2):501-514
Ongoing fluctuations of intrinsic cortical networks determine the dynamic state of the brain, and influence the perception of forthcoming sensory inputs. The functional state of these networks is defined by the amplitude and phase of ongoing oscillations of neuronal populations at different frequencies. The contribution of functionally different cortical networks has yet to be elucidated, and only a clear dependence of sensory perception on prestimulus alpha oscillations has been clearly identified. Here, we combined electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) in a large sample of healthy participants to investigate how ongoing fluctuations in the activity of different cortical networks affect the perception of subsequent nociceptive stimuli. We observed that prestimulus EEG oscillations in the alpha (at bilateral central regions) and gamma (at parietal regions) bands negatively modulated the perception of subsequent stimuli. Combining information about alpha and gamma oscillations predicted subsequent perception significantly more accurately than either measure alone. In a parallel experiment, we found that prestimulus fMRI activity also modulated the perception of subsequent stimuli: perceptual ratings were higher when the BOLD signal was higher in nodes of the sensorimotor network and lower in nodes of the default mode network. Similar to what observed in the EEG data, prediction accuracy was improved when the amplitude of prestimulus BOLD signals in both networks was combined. These findings provide a comprehensive physiological basis to the idea that dynamic changes in brain state determine forthcoming behavioral outcomes. Hum Brain Mapp 37:501–514, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
658.
Migraine in childhood and adolescence. A critical study of the diagnostic criteria and of the influence of age on clinical findings 总被引:1,自引:0,他引:1
JLD Gherpelli LM Nagae Poetscher AMMH Souza EMB Bosse GD Rabello A Diament M Scaff 《Cephalalgia : an international journal of headache》1998,18(6):333-341
We studied 253 children aged <15 years. Phase 1 included 193 children with migraine (1.1 and 1.2) divided into two groups (<10 and ≥ 10 years). We studied the relationship between age and migraine type, headache characteristics, and associated symptoms of the International Headache Society (IHS) definition. A higher frequency of migraine with aura, pulsatile quality, and unilateral location was observed in older children. In phase 2 we studied 176 children with headache (excluding migraine with aura), comparing diagnostic criteria, definition items, sensitivity, and specificity. The results showed that item B of the definition was the most frequent cause of exclusion in the 1.7 diagnostic group. Compared with Vahlquist and the IHS, the Prensky criteria were the most sensitive. Sensitivity was >70% for pain of moderate/severe intensity, duration between 2 and 48 h, isolated photophobia, isolated phonophobia, and aggravation with physical activity. Specificity was >70%, for nausea, vomiting, phonophobia and photophobia, isolated photophobia, aggravation with physical activity, and isolated phonophobia. Based on three alternative definitions, each modifying one item of the IHS definition, the sensitivity and specificity of these alternative definitions were compared with the "extended" criteria (children with migraine without aura and migrainous disturbance, according to the IHS criteria, grouped together). Exclusion of headache duration increased sensitivity by 10%, compared to restrictive IHS criteria, without decreasing specificity. 相似文献
659.
Forty patients with advanced hematologic malignancies or severe aplastic anemia received marrow grafts from partially mismatched, unrelated marrow donors. All patients were administered conventional prophylaxis for acute graft-v-host disease (GVHD) consisting of methotrexate and low-dose glucocorticoids. All but two patients who survived at least 30 days showed durable engraftment. Six patients survive 17+ to 36+ months following transplantation. Severe acute GVHD was seen in 47% of the patients; however, no direct correlation between GVHD and the degree of mismatching could be determined. Fatal infections were seen in 29 patients, and in the majority the infection occurred after the granulocyte count had risen to greater than 500 cells/microL. We conclude that the problems encountered in this pilot study can potentially be solved, and that further studies with this type of marrow grafting are warranted. 相似文献
660.
人参的分析——Ⅳ.人参皂甙的高效液相色谱测定 总被引:13,自引:0,他引:13
本文报道了人参中六种主要皂甙(Rb_1,Rb_2,Rc,Rd,Re,Rg)的HPLC测定法,用氨基键合相柱,示差折光检测,流动相为甲醇中乙腈—乙二醇—醋酸铵(0.14 mol/L)(30:70:5:10.6),同时还改进了纯化方法,此法快速、重现性好,与薄层比色法比较结果基本一致。 相似文献