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Glucocorticoid receptor (GR) signaling is thought to play a key role in embryogenesis, but its specific developmental effects remain unclear. Cortisol is the primary ligand for GR activation in teleosts, and in zebrafish (Danio rerio), the prehatch embryo content of this steroid is of maternal origin. Using early zebrafish developmental stages, we tested the hypothesis that GR signaling is critical for embryo growth and hatching. In zebrafish, maternal GR mRNA is degraded quickly, followed by zygotic synthesis of the receptor. GR protein is widely expressed throughout early development, and we were able to knockdown this protein using morpholino oligonucleotides. This led to a more than 70% reduction in mRNA abundance of matrix metalloproteinase-13 (mmp13), a glucocorticoid-responsive gene. The GR morphants displayed delayed somitogenesis, defects in somite and tail morphogenesis, reduced embryo size, and rarely survived after hatch. This correlated with altered expression of myogenic markers, including myogenin, myostatin, and muscle-specific myosin heavy chain and troponin genes. A key finding was a 70-90% reduction in the mRNA abundance of bone morphogenetic proteins (BMP), including bmp2a, bmp2b, and bmp4 in GR morphants. Bioinformatics analysis confirmed multiple putative glucocorticoid response elements upstream of these BMP genes. GR morphants displayed reduced expression of BMP-modulated genes, including eve1 and pax3. Zebrafish GR mRNA injection rescued the GR morphant phenotype and reversed the disrupted expression of BMP and myogenic genes. Our results for the first time indicate that GR signaling is essential for zebrafish muscle development, and we hypothesize a role for BMP morphogens in this process. 相似文献
3.
骨髓干细胞分化为肝细胞的多种移植途径 总被引:3,自引:0,他引:3
近年来许多研究证实,人类和啮齿类动物的骨髓细胞可分化为多种细胞类型,包括骨骼肌细胞、心肌细胞、神经细胞和肝细胞等,这些骨髓干细胞的可塑性研究,为肝细胞移植提供了新的供体来源.骨髓干细胞替代肝细胞进行移植具有来源丰富,费用相对低廉,对患者损伤小等优点,且自体骨髓干细胞移植可以完全避免移植排斥反应,同时,骨髓干细胞只有 5-15 μm,移植后不会发生栓塞等并发症.因此骨髓干细胞移植在治疗肝病以及解决供体肝脏来源短缺方面具有广泛的应用前景.本文就骨髓干细胞的移植途径做一综述. 相似文献
4.
目的:目前临床进行隧道法舌根射频治疗时,其作用参数的设置仍缺乏统一的标准,故通过计算机三维重建射频损伤区域,分析猪舌根射频损伤体积与射频能量、时间的关系,从中得出应用舌根隧道法射频治疗的最佳作用能级和作用时间。
方法:实验于2006-06/2007-05在上海交通大学耳鼻喉科研究所完成。将36只实验用猪以射频作用能级1,2,3,4,5,6随机分成6组,每组6头猪,各个猪舌的作用时间分别设置为2,5,10,15,20,25s。用Coblation射频发生仪及Reflex55刀头进行猪舌根射频操作。射频作用后的舌根组织行连续冰冻切片,苏木精-伊红染色后,进行序列组织切片的全貌二维图像采集,对拟重建的结构进行边界提取和图像分割。将提取分割图像导入Image-Pro Solution图像处理软件,利用3D Constructor插件进行三维重建,并根据设定参数进行体积计算。用SPSS10.0统计学软件对所测数据进行统计学分析。
结果:①作用能级固定时,舌根组织射频损伤体积随时间延长而增大,符合Logarithmic回归曲线。②作用时间固定时,舌根组织射频损伤体积随能级增大而增大,符合直线回归。③射频损伤体积随能量增大而增加亦符合Logarithmic回归曲线。④Coblation射频治疗系统在能级6时,在作用10s之前,损伤体积随作用时间增加而迅速增加,其后变化趋势平缓,超过20s后损伤体积无显著增加。
结论:①舌根区域射频治疗时,舌根组织射频损伤体积与时间或能量呈Logarithmic曲线相关,与能级呈直线相关。②Coblation射频治疗系统在能级6时,最佳作用时间范围为10-20s。 相似文献
5.
Anthony Stock MRCOG Wong Wai Ming MRCOG Michael Rogers FRCOG Allan MZ Chang PhD 《The Australian & New Zealand journal of obstetrics & gynaecology》1994,34(4):393-398
EDITORIAL COMMENT: We accepted this paper for publication because the authors have explored the possible value of ultrasound versus clinical assessment of fetal size to see whether they can predict the need for Caesarean section when the baby is large. In this study both the ultrasound and the clinical assessment were impressively accurate and fetal femur length was the most accurate of the ultrasound parameters in assessing fetal weight in predicting the need for Caesarean section. However, as the authors indicate, none of these methods of assessment of fetal size are recommended as an absolute indication for Caesarean section. Every obstetrician uses clinical assessment of the fetus when evaluating management of the patient but the need for clinical judgment remains.
Summary: One hundred and five women with singleton pregnancies and cephalic presentation were assessed. Fundal height and a clinical estimate of fetal weight were recorded. The fetal biparietal diameter, abdominal circumference and femur length were measured with ultrasound. Ultrasound estimated fetal weight was calculated using 3 different formulas (Shepard, Campbell and CUHK). The liquor volume was assessed using the amniotic fluid index.
Ultrasound was able to predict Caesarean section with more reliability than clinical assessment of fetal size or weight. The biparietal diameter, fundal height and amniotic fluid index were poor predictors of mode of delivery. The measurements which best predicted the mode of delivery were the fetal femur length and abdominal circumference. Femur length, but not abdominal circumference, was a statistically better predictor of Caesarean section than clinical estimation of fetal weight. There was no improvement in prediction using ultrasound estimated fetal weight. 相似文献
Summary: One hundred and five women with singleton pregnancies and cephalic presentation were assessed. Fundal height and a clinical estimate of fetal weight were recorded. The fetal biparietal diameter, abdominal circumference and femur length were measured with ultrasound. Ultrasound estimated fetal weight was calculated using 3 different formulas (Shepard, Campbell and CUHK). The liquor volume was assessed using the amniotic fluid index.
Ultrasound was able to predict Caesarean section with more reliability than clinical assessment of fetal size or weight. The biparietal diameter, fundal height and amniotic fluid index were poor predictors of mode of delivery. The measurements which best predicted the mode of delivery were the fetal femur length and abdominal circumference. Femur length, but not abdominal circumference, was a statistically better predictor of Caesarean section than clinical estimation of fetal weight. There was no improvement in prediction using ultrasound estimated fetal weight. 相似文献
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7.
Comparing the effects of 8-week treatment with fluoxetine and imipramine on fasting blood glucose of patients with major depressive disorder 总被引:1,自引:0,他引:1
Ghaeli P Shahsavand E Mesbahi M Kamkar MZ Sadeghi M Dashti-Khavidaki S 《Journal of clinical psychopharmacology》2004,24(4):386-388
This study was designed to compare the effects of fluoxetine and imipramine on fasting blood glucose (FBG) in patients with major depressive disorder. Sixty nondiabetic patients with major depressive disorder (based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) entered this randomized, double-blind study. Patients did not receive any medication affecting serum FBG levels for at least 2 weeks before the initiation of the study. Patients were assigned to receive 20 to 40 mg/d of fluoxetine or 75 to 200 mg/d of imipramine for 8 weeks. Pregnant women and patients with diabetes mellitus and a history of any major heart disease were excluded from this study. Additionally, none of the patients should have received electroconvulsive therapy within 6 months before the initiation of the antidepressants. FBG levels were measured at the initiation, as well as 4 and 8 weeks after starting antidepressants. Nineteen patients in the fluoxetine and 24 patients in the imipramine groups completed the study. In the fluoxetine group, FBG level was decreased from 88.5 mg/dL (baseline) to 85.0 mg/dL at week 4 (P = 0.73), and to 79.8 mg/dL at week 8 (P < 0.001). On the other hand, in the imipramine group, FBG level was increased from 86.96 mg/dL (baseline) to 89.71 mg/dL at week 4 (P = 0.079), and to 96.90 mg/dL at week 8 (P < 0.001). This 8-week study showed that FBG levels may decrease in depressive patients receiving fluoxetine and may increase in those patients treated with imipramine. Therefore, it is suggested to measure and monitor FBG before initiation and during treatment with fluoxetine and imipramine. 相似文献
8.
高三尖杉酯碱在大鼠及兔肝微粒体的代谢研究 总被引:1,自引:0,他引:1
采用动物肝微粒体体外代谢法对高三尖杉酯碱进行了代谢转化的研究。应用梯度洗脱—反相HPLC结合二极管陈列检测器对体外代谢体系进行了分析。判定在体外代谢体系中,高三尖杉酯碱主要产生一个代谢产物。用HPLC法制备出一定量代谢物纯品,经光谱分析及与化学制备的对照品相比较,推定其代谢物结构为:2′-羟基-2′(α-乙酸)-6′-甲基-6′-羟基-庚酰三尖杉碱。 相似文献
9.
健胃愈疡颗粒干预下大鼠胃溃疡黏膜乳癌相关肽和血小板活化因子的表达及与胃黏膜疏水性的相关性研究 总被引:1,自引:0,他引:1
目的:观察对胃溃疡复发有较好疗效的健胃愈疡颗粒对溃疡黏膜乳腺癌相关肽和血小板活化因子表达的影响,分析其可能的作用机制。方法:实验于2005-07/2006-07在湘雅医院中心实验室完成。SD大鼠110只,雌雄各半,随机抽签法分为5组,即正常对照组、假手术组、雷尼替丁组、健胃愈疡组,各20只;模型组30只。以Okabe改良法复制大鼠实验性胃溃疡,假手术组仅以生理盐水代替乙酸注入玻管内。造模后24h,雷尼替丁组、健胃愈疡组大鼠分别灌服盐酸雷尼替丁和健胃愈疡颗粒(药物组成为:柴胡、党参、白芍、延胡索、白芨、珍珠层粉、青黛、甘草,湖南湘雅制药有限公司生产)药液10mL/kg,分别相当于2.70,1.62g/kg,1次/d。假手术组、模型组灌服蒸馏水10mL/kg。10d后各组中随机取出10只大鼠剖腹取胃(处死前大鼠禁食24h),90d时将模型组20只大鼠再分为模型复发组和模型非复发组,各10只;除正常对照组、假手术组、模型非复发组大鼠腹腔内注射生理盐水外,其余各组大鼠腹腔内注射白细胞介素1,1μg/kg;在注射48h,大鼠禁食24h后,剖腹取胃。观察其对胃溃疡大鼠胃黏膜氨基己糖及磷脂含量、溃疡指数和胃黏膜血流的影响,并用RT-PCR观察乳癌相关肽乳癌相关肽和血小板活化因子表达的变化。结果:实验动物110只,全部进入结果分析。①模型组10,92d胃黏膜血流均低于正常对照组(P<0.01);健胃愈疡组同期胃黏膜血流均高于模型组(P<0.01)。②健胃愈疡组和雷尼替丁组10d溃疡指数均低于模型组(P<0.01,P<0.05);模型复发组、健胃愈疡组和雷尼替丁组92d溃疡指数均高于模型组(P<0.01);健胃愈疡组10,92d溃疡指数及复发率均低于雷尼替丁组(P<0.05,P<0.01)。③模型组10,92d氨基己糖和磷脂含量均低于正常对照组(P<0.01)。健胃愈疡组10,92d氨基己糖和磷脂含量均高于模型组和雷尼替丁组(P<0.01)。溃疡指数与氨基已糖、磷脂含量呈负相关(r=-0.957,-0.960,P<0.01)。④健胃愈疡组和雷尼替丁组10d乳癌相关肽mRNA表达较正常组和假手术组提高,血小板活化因子mRNA的表达下调(P<0.01),健胃愈疡组两指标表达变化较雷尼替丁组显著(P<0.01);模型复发组、健胃愈疡组和雷尼替丁组92d乳癌相关肽mRNA、血小板活化因子mRNA的表达同组10d比较差异无显著性意义(P>0.05);模型组乳癌相关肽mRNA、血小板活化因子mRNA的表达同组10d比较差异有显著性意义(P<0.01)。结论:健胃愈疡颗粒可提高乳癌相关肽mRNA及下调血小板活化因子mRNA的表达,影响胃黏膜氨基己糖及磷脂含量,可能是其促进溃疡愈合的机制之一。 相似文献
10.
目的:了解我院重症监护病房分离菌株对常用抗生素的耐药现状。方法:采用琼脂双倍稀释法测定从我院重症监护病房分离的230株革兰阴性菌的最低抑菌浓度(MIC),并采用抑制剂增强的纸片扩散法测定大肠埃希菌和肺炎克雷伯菌超广谱β-内酰胺酶(ESBLs)。结果:50株肺炎克雷伯菌和17株大肠埃希菌中ESBLs阳性率为62.1%。阴沟肠杆菌、产ESBLs的大肠埃希菌和肺炎克雷伯菌对三代头孢、庆大霉素、阿米卡星的耐药率≥50%。而对碳青霉烯类非常敏感。铜绿假单胞菌对各种抗菌药物均有一定的耐药性。嗜麦芽寡养单胞菌对碳青霉烯类耐药率达100%。结论:受试的230株革兰阴性菌对三代头孢、复合青霉素、氨基糖苷类和环丙沙星的总耐药率≥30%。CPZ/SB和头孢吡肟、碳青霉烯类耐药率较低。 相似文献