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The effects of three monoamine antagonists, p-chlorophenylalanine, diethyldithiocarbamate and propranolol on the morphogenesis of newt embryos were studied. Antagonists were administered during late blastula through neurula stages. In a concentration of 1 mM, all three arrested gastrulation and caused disintegration of the embryos. Lower concentrations (0.1-0.5 mM) retarded morphogenetic movements in the gastrulation and caused malformations especially in the anterior parts of the embryos; pigmentation was delayed by 1 or 2 days. In addition, p-CIPhe inhibited yolk granule degradation in the notochord and DEDTC caused notochordal hypertrophy. The results show that interference with synthesis or action of catecholamines and serotonin affects morphogenesis. With the methods used it is not possible to discover exactly how monoamines regulate the morphogenetic events because of the unspecific side effects of the antagonists and the feedback interactions between the monoamines.  相似文献   

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目的:探讨动态增强磁共振成像扫描与超声弹性成像对乳腺癌良恶性肿瘤的诊断价值,为临床诊断提供影像学依据。方法:回顾性分析2009年10月至2013年5月在我院经穿刺或手术病理证实为乳腺癌的59例患者的临床资料,患者术前均行超声与动态增强MR检查。依据病理组织活检和临床随访分别评价动态增强MR和UE对乳腺癌诊断的准确性。结果:DCE-MRI检测共发现病灶59个,55个初步诊断乳腺恶性肿瘤(BI-RADS 4-5),4个诊断为良性(BI-RADS 3),诊断准确率为93.22%(55/59)。UE对59个病灶进行评分,54个评分为乳腺恶性肿瘤,5个评分为良性,诊断率为91.53%(54/59)。UE检测乳腺癌的敏感性明显低于DCE-MRI及DCE-MRI+UE,DCE-MRI检测乳腺癌的特异性明显低于UE及DCE-MRI+UE,差异具有统计学意义(P0.05)。DCE-MRI+UE诊断乳腺癌的准确率为96.61%(57/59),明显高于DCE-MRI或UE单独检测的准确率(P0.05)。结论:动态增强MR诊断乳腺癌的敏感性较高,而超声弹性成像的特异性较好,两者联合可提高诊断准确率,对乳腺癌的早期诊断具有重要的临床应用价值。  相似文献   

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《Theriogenology》1996,45(8):1457-1462
The aim of this study was to determine the influence of hand massage of mares' ovaries on breeding activity and hormonal changes in the winter anestrous period and during the luteal phase of the oestrus cycle. The experiment was conducted on 5 experimental and 5 control mares. In winter, (January) the experimental mares underwent 30-sec daily massage of both ovaries, for 30 d, and in summer (August) from the 6th day of the cycle to the occurrence of estrus. The sexual behavior of all mares was determined each day by individual teasing by a vigorous stallion, and the ovaries were checked by palpation per rectum and with an USG. Every second day blood samples were drawn from each mare to determine progesterone and estradiol in the plasma. Ovarian massage during deep winter anestrus had no significant effect on acceleration of the mares' active breeding season. Nevertheless, a higher concentration of estradiol was observed in the experimental group. These differences occurring on the 11th, 17th and 20th days were found to be significant (P ≤ 0.05). It was shown that during the summer period, in the luteal phase of the cycle, ovarian massage shortened the length of the estrous cycle, and ovulation was brought on somewhat earlier.  相似文献   

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The influences of some factors at the both sides of the solid and liquid phases on the solubilities of L-glutamic acid in α and β-forms in water were examined.

As differences in the conditions of the liquid phase, the effects of co-existing inorganic neutral salts and amino acids on the solubilities were investigated; and as for the inorganic neutral salts applied here, salting-in effects were recognized, the degrees of which were in the following order, i.e., NH4Cl, (NH4)2SO4>KCl>NaCl. The effect in the β-form was larger than that of in the α-form. The influence of co-existing amino acids was very little if the amount was not so much, but the tendency to increase the solubility could be recognized.

As a difference in the condition of the solid phase, the purity of the crystals was picked up, and it was clarified that the crude crystal of L-glutamic acid in α-form gave a larger value of the solubility than the purified one.  相似文献   

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The behaviors of impurities such as amino acids and inorganic salts at the time of crystallization of l-glutamic acid were investigated; and it was concluded that amino acids which co-existed in the solution of l-glutamic acid followed the crystals of l-glutamic acid persistently, and the contamination mechanism would not be clarified by the adherence of mother liquor or the formation of liquid foams in the crystals, or by the mixed crystal formation, but by a physical adsorption on the crystal surfaces.  相似文献   

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以Swaisonine(Sw)作为高尔基体付糖链加工酶系中α-甘露糖苷酶Ⅱ的特异抑制剂,研究N-糖链结构和胰岛素受体(Ins-R)功能的关系.发现Sw不影响细胞生长和3H-亮氨酸参入SMMC7721细胞,但明显促进3H-甘露糖参入细胞总糖蛋白和表面糖蛋白,并使后者的ConA强结合组分显著增加,提示Sw使Ins-R的N-糖链变成杂合型及高甘露糖型。胰岛素结合试验后作Scatchard分析:发现Sw不改变Ins-R的结合容量和每个细胞表面的结合位点数,也不改变结合动力学。再用部分纯化的Ins-R研究自身磷酸化和对外源底物的酪氨酸蛋白激酶活力,也未发现Sw处理和对照细胞间的明显区别,表示Sw也不影响Isn-R的跨膜信息传递,结合已报道的衣霉素使细胞表面Ins-R减少的结果,提示Ins-R运送至细胞膜需要N-糖链存在,但糖链的类型对INS-R的代谢和结合动力学并不重要  相似文献   

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