Relationship between expression of somatostatin and DNA ploidy in breast cancer

AIM: To investigate the relationship between somatostatin and the pathologic type, estrogen receptor,DNA ploidy of nuclei in tumor cells of breast cancer.METHODS: 67 cases of primary breast cancer and 25 cases of benign breast tumor were examined by immunohistochemical stretomyces avidin peroxidase method. 26 cases of breast cancer selected at random were analyzed by flow cytometry.RESULTS: Somatostatin expressed significantly higher in low malignant breast cancer than that in high malignant breast cancer (P<0.05). Most of cancers with positive staining of somatostatin were diploidy,most of cancers with negative staining were aneuploidy,there had significant difference between two groups (P<0.05).CONCLUSION: Somatostatin may delay the progress of breast cancer,and somatostatin levels in cancer tissues may become a useful indicator for assessing prognosis of patients with breast cancer.     

猪生长抑素Ⅱ型受体基因(SSTR2)shRNA的构建与筛选

生长激素(GH)是调控动物生长的重要激素,GH分泌水平的高低主要受正性调控因子生长激素释放因子(GRF)和负性调控因子生长抑素(SS)的双向调节。SS通过生长抑素受体(somatostatin receptor,SSTR)发挥作用,减少GH的分泌水平。本研究设计了3条SSTR2的短发夹RNA(shRNA),构建猪(Sus scrofa)SSTR2真核表达质粒(pcDNA3.1(-)-SSTR2)和SSTR2慢病毒RNA干扰质粒(pshRNA-copGFP lentivector,LV-shRNA),并共转染中国仓鼠(Cricetulus griseus)卵巢细胞系(CHO),通过对转染细胞的荧光观察、Real-time PCR和酶联免疫法(ELISA)检测,结果表明,CHO转染细胞中猪SSTR2 mRNA表达水平不同程度的抑制,分别为90.4%、28.3%和86.3%,(P<0.05)。其中,LV-shRNA1表现出最高的沉默效率:转染效率在80%左右时,猪SSTR2mRNA水平沉默效率为90.4%,蛋白质水平降低了33.3%。本研究成功地筛选到了降低猪SSTR2基因表达的shRNA,为利用shRNA技术下调动物基因表达,构建转基因模型提供思路。     

生长抑素对大鼠乳腺斯钙素基因表达的影响

将泌乳期大鼠分为对照组、CS组和SS组,利用RT-PCR法对大鼠乳腺组织斯钙素基因进行检测,分析生长抑素对大鼠乳腺斯钙素基因表达的影响。结果表明:乳腺中有STC1表达,无STC2表达。生长抑素对泌乳期大鼠乳腺斯钙素基因表达起下调作用,半胱胺作用相反。以上结果提示生长抑素和半胱胺可能参与乳腺钙代谢的调节,且通过STC1发挥作用。     

鸡抗病促生长剂的试验研究

采用ＤＮＡ重组技术和蚀斑技术获得融合基因的重组病毒，制备了鸡生长抑制因子（ＳＳ）免疫原，与鸡传染性ＩＢＤ、ＮＤ免疫原共同高免健康产蛋鸡，使其卵黄中产生高效价的抗鸡ＳＳ、ＩＢＤ、ＮＤ抗体，利用含高效价的卵黄制成鸡抗病促生长剂。实验结果表明，该制剂对人工感染的ＩＢＤ鸡治愈率为９７．５％，预防保护率９８．４％；对流行区自然感染的ＩＢＤ鸡治愈率９６％，预防保护率９７％。对健康肉仔鸡应用，可使其育成出栏时间提前３天，每只平均比对照增重１３５．７ｇ；饲料转化率提高８．３７％。     

生长抑素主动和被动免疫及基因免疫研究进展

生长抑素(somatostatin,SS)是下丘脑释放的14肽激素,在动物体内具有广泛的抑制作用,特别是对生长及免疫反应具有明显的影响,通过耗竭或免疫中和体内的SS水平相应提高生长激素(GH)等水平促进动物生长。文中简要介绍了生长抑素主动和被动免疫的研究进展及基因免疫的作用机理、特点及增强基因免疫的途径;阐述了生长抑素基因疫苗的研究和应用发展前景。     

鹅生长过程中血清生长抑素水平变化的研究

本文研究了四季鹅在生长过程中,外周血液生长抑素(Somatostatin,SS)水平的变化,同时观察了甲状腺激素T_3、T_4和血清脲氮(BUN)水平以及与其增重型的关系。同日孵出的四季鹅分批于2、16、30、44、58、72日龄时称重、采血,用放射免疫法测定血清SS、T_3、T_4水平。结果表明,鹅孵出后,相对增重越高、SS水平则越低,SS与生长速度之间存在着显著负相关(r=-0.82,P<0.05),与T_3变化呈强负相关(r=-0.73,P<0.05),与BUN呈正相关(r=0.91,P<0.01)。提示在鹅生长过程中,SS水平降低时,T_3水平升高,组织中氮沉积增加,使增重速度加快。     

Protective effects of somatostatin and octreotide on hepatocytes

AIM: To investigate the protective effect of somatostatin (SST) and octreotide (OCT) on rat hepatocytes. METHODS: The primary hepatocytes were pretreated with different concentrations of SST and OCT. The levels of alanine minotransferase (ALT) and aspartate aminotransferase (AST) in culture supernatant were analyzed by the model of ethanol/carbon tetrachloride (CCl4)-induced hepatocyte injury. Additionally, 75 Sprague-Dawley rats were divided into 5 groups at random, including normal control, model control, SST-treated model groups at high, medium and low doses (200 μg·kg-1·d-1, 100 μg·kg-1·d-1 and 50 μg·kg-1·d-1, respectively). Except for the normal controls, all rats were injected with 40% CCl4 subcutaneously for 8 weeks to establish hepatic fibrosis. Meanwhile, rats of SST-treated model groups were given at different doses of SST twice a day in the same way. Thereafter, the liver function and apoptosis index of hepatocytes were detected by standard enzyme method, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), respectively. RESULTS: Compared with those of injury model group, the hepatocytes pretreated with SST (10-8-10-6 mol/L) and OCT (10-7-10-5 mol/L) exhibited significantly decreased levels of ALT and AST in the culture supernatant. Furthermore, most indices of liver function including ALT, AST, alkaline phosphatase (ALP), total bilirubin (TBIL) and albumin (ALB) improved obviously in all SST-treated groups, especially in the group treated with low dose of SST. The apoptosis index of hepatocytes in the fibrotic liver was also reduced greatly by the treatment with low dose of SST. CONCLUSION: SST and OCT may protect hepatocytes against CCl4-induced injury, inhibit hepatocyte apoptosis, and improve the liver function. These findings suggest them a potential efficiency in the prevention of hepatic fibrosis.     

不同剂量半胱胺对肉用仔鸡增重及血液生长抑素、生长激素含量的影响

将８０只３０日龄红布罗鸡随机分为４组，半胱胺（ｃｙｓｔｅａｍｉｎｅ，ＣＳ）的添加量分别为０（对照）、１００、１５０、２００ｍｇ／ｋｇ体重。至５８日龄称重、宰杀、颈静脉采血，并用放免法对血液生长抑素（ＳＳ）和生长激素（ＧＨ）含量进行分析。结果：（１）与对照组相比，ＣＳ１００组净增重提高６．２％（Ｐ＜０．０５），其它剂量组增重无明显变化；（２）口服ＣＳ不改变仔鸡采食量，但饲料转化率ＣＳ１００、ＣＳ１５０、ＣＳ２００组分别提高５．７％、３．３％、６．３％；（３）与对照组相比，ＣＳ１００、ＣＳ１５０、ＣＳ２００组的血液ＳＳ含量分别下降７０．７％（Ｐ＜０．０５）、７６．２％（Ｐ＜０．０２５）和７６．１％（Ｐ＜０．０１），但ＧＨ水平只在ＣＳ１００组有明显升高（Ｐ＜０．０５），结果提示ＣＳ对仔鸡的作用同哺乳动物一样也呈现剂量依赖性     

生长抑素对泌乳大鼠乳腺发育的作用

给泌乳SD大鼠皮下注射生长抑素及其耗竭剂,用RT-PCR法和放射免疫法检测大鼠乳腺中相关基因的表达水平及乳腺和血清生长抑素的水平,探讨生长抑素与相关因子间的关系。结果表明：生长抑素能提高大鼠血清和乳腺生长抑素的含量,下调ERα、PR、GHR、PRLR基因的表达,上调Leptin和LEPR基因的表达;其耗竭剂的作用相反,降低血清和乳腺中生长抑素的含量,上调ERα、PR、GHR、PRLR基因的表达,下调Leptin和LEPR基因的表达。说明生长抑素通过调节乳腺中相关因子的表达对大鼠乳腺发育起作用。     

Growth hormone excess and the effect of octreotide in cats with diabetes mellitus

In this prospective study 16 cats with diabetes mellitus were examined for concurrent acromegaly by measuring plasma growth hormone (GH) and insulin-like growth factor-I concentrations, and magnetic resonance imaging (MRI) of the pituitary fossa. Additionally, the effects of octreotide administration on the plasma concentrations of glucose, GH, α-melanocyte-stimulating hormone (α-MSH), adrenocorticotrophic hormone (ACTH), and cortisol were measured.Five cats were diagnosed with hypersomatotropism. The pituitary was enlarged in these 5 cats and in 2 other cats. Six cats that required a maximum lente insulin dosage ≥1.5 IU/kg body weight per injection had pituitary enlargement and 5 of these cats had acromegaly. Plasma concentrations of GH, ACTH, and cortisol decreased significantly after single intravenous administration of the somatostatin analogue octreotide in the acromegalic cats. The effect on GH concentrations was more pronounced in some of the acromegalic cats than in others. In the non-acromegalic cats only ACTH concentrations decreased significantly. In both groups plasma glucose concentrations increased slightly but significantly, whereas α-MSH concentrations were not significantly affected.In conclusion, the incidence of hypersomatotropism with concomitant pituitary enlargement appears to be high among diabetic cats with severe insulin resistance. Some of these cats responded to octreotide administration with a pronounced decrease in the plasma GH concentration, which suggests that octreotide administration could be used as a pre-entry test for treatment with somatostatin analogues.