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11.
目的介绍个体成长模型方法对大学新生适应能力中交往主动性的3次测查数据采用普通回归模型和个体成长模型进行分析。结果个体成长模型的拟合度比普通回归模型的拟合度要好,个体成长模型可在个体水平上分析个体随时间产生的变化。结论个体成长模型具有许多优点,熟悉这种重要的分析方法对纵向数据研究者是非常有益处的。 相似文献
12.
金地鼠颊囊癌前病变的细胞增殖动力学研究 总被引:2,自引:0,他引:2
目的研究口腔上皮组织癌和癌前病变的细胞动力学变化特征。方法采用Saley的DMBA涂布诱导法,建立金地鼠颊囊癌前病变模型,并用溴脱氧尿苷流式细胞动力学检测方法,对30只叙利亚种金地鼠进行分组对照研究。结果涂药组光镜下的细胞病变程度随涂药时间延长而逐渐加重,而空白对照组无变化;FCM检测显示涂药组与对照组在S期阳性细胞检出率存在显著差异。即使在光镜下表现为轻度不典型增生时,FCM检测结果也有显著差别。结论金地鼠颊囊癌前病变具有细胞异常增殖的细胞动力学特征 相似文献
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Abstract: A prospective, randomized study was conducted to evaluate the role of vitamin B12 and folinic acid supplementation in preventing zidovudine (ZDV)-induced bone marrow suppression. Seventy-five human immunodeficiency virus (HIV)-infected patients with CD4 + cell counts < 500/mm3 were randomized to receive either ZDV (500 mg daily) alone (group I, n = 38) or in combination with folinic acid (15 mg daily) and intramascular vitamin B12 (1000 μg monthly) (group II, n = 37). Finally, 15 patients were excluded from the study (noncompliance 14, death 1); thus, 60 patients (31 in group I and 29 in group II) were eligible for analysis. No significant differences between groups were found at enrollment. During the study, vitamin B12 and folate levels were significantly higher in group II patients; however, no differences in hemoglobin, hematocrit, mean corpuscular volume, and white-cell, neutrophil and platelet counts were observed between groups at 3, 6, 9 and 12 months. Severe hematologic toxicity (neutrophil count < 1000/mm3 and/or hemoglobin < 8 g/dl) occurred in 4 patients assigned to group I and 7 assigned to group II. There was no correlation between vitamin B12 or folate levels and development of myelosuppression. Vitamin B12 and folinic acid supplementation of ZDV therapy does not seem useful in preventing or reducing ZDV-induced myelotoxicity in the overall treated population, although a beneficial effect in certain subgroups of patients cannot be excluded. 相似文献
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本研究采用先进的三维超声成像技术及多普勒技术对正常育龄妇女月经周期中心血管功能进行研究。结果:月经周期中HR、BP无变化;血清E2是周期性变化,排卵前达高峰。SV、CO、EF在排卵前期升高达峰值,显著高于月经期和黄体期;SVR排卵前期最低,而Ved、Ves无变化。Vmax、A、E在内源性E2高峰时明显加快,而E/A比值无明显变化。结果提示:月经周期中随内源性E2的周期性变化,心脏功能也发生周期性变化。E2高峰时,心输出量、心搏量和射血分数达最高。外周阻力最低,心脏内血流速度加快。 相似文献
17.
本文报道57例白血病血清铜,锌含量的测定结果。白血病治疗前血清铜升高,铜/锌值增大;治疗后,病情缓解者下降,未缓解者则更高。血清锌在治疗前后无何差异。急性淋巴细胞性白血病骨髓中白血病细胞百分数与血清铜浓度呈正相关。检测血清铜,锌对白血病疗效的预测及判断预后有一定意义。 相似文献
18.
为了了解吉林省长白县山区所产卫矛科雷公藤属植物黑蔓的药理作用,扩大它的药用部位和应用范围,我们从无机元素与中药药效有密切关系的角度出发,实验测出黑蔓含有Ba、Si、Cu、Fe、Zn、Sn、Co、Mn、Mg、Ca、Se等无机元素,本文重点对其中人体必需的微量元素Cu、Fe、Zn、Se作了定量分析。 相似文献
19.
Takeshi Sakata Yongmei Wang Bernard P Halloran Hashem Z Elalieh Jay Cao Daniel D Bikle 《Journal of bone and mineral research》2004,19(3):436-446
We showed that unloading markedly diminished the effects of IGF-I to activate its signaling pathways, and the disintegrin echistatin showed a similar block in osteoprogenitor cells. Furthermore, unloading decreased alphaVbeta3 integrin expression. These results show that skeletal unloading induces resistance to IGF-I by inhibiting activation of the IGF-I signaling pathways at least in part through downregulation of integrin signaling. INTRODUCTION: We have previously reported that skeletal unloading induces resistance to insulin-like growth factor-I (IGF-I) with respect to bone formation. However, the underlying mechanism remains unclear. The aim of this study was to clarify how skeletal unloading induces resistance to the effects of IGF-I administration in vivo and in vitro with respect to bone formation. MATERIALS AND METHODS: We first determined the response of bone to IGF-I administration in vivo during skeletal unloading. We then evaluated the response of osteoprogenitor cells isolated from unloaded bones to IGF-I treatment in vitro with respect to activation of the IGF-I signaling pathways. Finally we examined the potential role of integrins in mediating the responsiveness of osteoprogenitor cells to IGF-I. RESULTS: IGF-I administration in vivo significantly increased proliferation of osteoblasts. Unloading markedly decreased proliferation and blocked the ability of IGF-I to increase proliferation. On a cellular level, IGF-I treatment in vitro stimulated the activation of its receptor, Ras, ERK1/2 (p44/42 MAPK), and Akt in cultured osteoprogenitor cells from normally loaded bones, but these effects were markedly diminished in cells from unloaded bones. These results were not caused by altered phosphatase activity or changes in receptor binding to IGF-I. Inhibition of the Ras/MAPK pathway was more impacted by unloading than that of Akt. The disintegrin echistatin (an antagonist of the alphaVbeta3 integrin) blocked the ability of IGF-I to stimulate its receptor phosphorylation and osteoblast proliferation, similar to that seen in cells from unloaded bone. Furthermore, unloading significantly decreased the mRNA levels both of alphaV and beta3 integrin subunits in osteoprogenitor cells. CONCLUSION: These results indicate that skeletal unloading induces resistance to IGF-I by inhibiting the activation of IGF-I signaling pathways, at least in part, through downregulation of integrin signaling, resulting in decreased proliferation of osteoblasts and their precursors. 相似文献
20.