Cloning and Sequence Analysis on cDNA of Growth Hormone Releasing Hormone Receptor Gene from Wuzhishan Miniature Pig

[Objective] cDNA of growth hormone releasing hormone （GHRH） receptor gene from Wuzhishan miniature pig was cloned and its sequence was also analyzed. [Method] Using genomic DNA extracted from porcine ear tissues of Wuzhishan miniature pig as the template, three pairs of primers were designed by the reported cDNA sequence of porcine GHRH, and cDNA was also amplified by RT-PCR. After being recovered and purified, PCR products were ligated to pMD18-T and then transformed into Escherichia coli DH5a. The transformation products were analyzed by PCR and double enzyme digestion to screen positive clones, and the positive clones were sequenced after identification in LB liquid medium. [ Result] cDNA of Wuzhishan miniature pig GHRH receptor gene was obtained successfully, and its length was 1 577 bp coding 423 amino acids. BLAST analysis showed that there were only 23 nuoleotides in difference between this fragment and pomine GHRH receptor gene, and its homology was 98%. However, both GHRH receptor genes were constituted by 423 amino acids with the sequence homology of 96%. [ Conclusion] This study provides theoretical basis for further studies on the dwarf mechanism of Wuzhishan miniature pig.

Isolation of Growth Hormone-Releasing Hormone and Its Receptor Genes from Scatophagus argus and Their Expression Analyses

The teleost Scatophagus argus is a species whose females grows faster than males.Growth hormone(gh)mRNA abundance in females pituitary is higher than that in males;however the mechanism underlining such differential is still unknown.Growth hormone(GH)is tightly associated with GH-releasing hormone(Ghrh)in vertebrates.In this study,Ghrh gene(ghrh)and its receptor gene,ghrhr,were isolated from S.argus.Tissue expression analysis showed that ghrh and ghrhr were mainly expressed in hypothalamus while ghrhr was expressed in pituitary and gh was predominantly expressed in pituitary.Twenty cultured S.argus individuals were used to compare ghrh,ghrhr and gh mRNA abundances,120 g and 181 g average weight for male(n=11)and female(n=9),respectively.Real-time PCR indicated that the ghrh and ghrhr mRNA abundances in male hypothalamus were significantly higher than those in female hypothalamus while that of gh mRNA abundance was significantly higher in female pituitary than in male pituitary.The ghrh and ghrhr mRNA abundances were significantly up-regulated in female hypothalamus 3 h after injection of 0.1 mg kg^-1 body weight Ghrh while pituitary ghrhr and gh mRNA abundances were not affected.In female hypothalamus,ghrh and ghrhr m RNA abundances were not affected at 6 h post-injection of 4 mg kg^-1 body weight 17α-methyltes-tosterone(17α-MT)or 17β-Estradiol(E2).In female pituitary,ghrhr m RNA abundance was down-regulated by 17α-MT while that of gh m RNA abundance was up-regulated by E2.Our findings indicated that E2,rather than Ghrh,plays an important role in up-regulating the expression of gh in female S.argus,which should aid to understand the sexual dimorphism of teleost growth.

Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

AIM:To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundicstrips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.

siRNA-targeted inhibition of growth hormone receptor in human colon cancer SW480 cells

AIM:To determine the effects of RNAi-mediated inhibition of the growth hormone receptor(GHR)gene on tumors and colon cancer cells in vivo.METHODS:Construction of a eukaryotic vector for human GHR expression,the pcDNA 6.2-GW/EmGFPsmall interfering RNAs(siRNAs)-GHR plasmid,was used to inhibit GHR expression.Thirty-six BALB/c nude mice were randomly divided into groups and treated with normal saline(NS),recombinant plasmid(G2),growth hormone(GH),5-fluorouracil(FU),G2+FU or G2+FU+GH.Each nude mouse was subcutaneously inoculated with 1×107human colon cancer SW480 cells;the nude mice were weighed before inoculation and on the 2nd,5th,8th,11th,14thand 17thday after inoculation.All nude mice were sacrificed after 17 d.Each subcutaneous tumor was removed and studied.Tumor volume was measured on the 5th,8th,11th,14thand 17thday after inoculation.The expression of GHR protein in the tumor tissue was detected by Western blotting analysis,and the differences in GHR mRNA expression in the tumor tissue were detected by real-time quantitative reverse transcription-polymerase chain reaction.RESULTS:Compared to the control group,the weights of the inoculated nude mice on the 17thday after inoculation were:G2:21.60±0.71 g,GH:21.64±0.45 g,FU:18.94±0.47 g,FU+G2:19.40±0.60 g,G2+FU+GH:21.04±0.78 g vs NS:20.68±0.66 g,P<0.05;the tumor volumes after the subcutaneous inoculation were:G2:9.71±3.82 mm3,FU:11.54±2.42mm3,FU+G2:11.42±1.11 mm3,G2+FU+GH:10.47±1.02 mm3vs NS:116.81±10.61 mm3,P<0.05.Compared to the GH group,the tumor volumes were significantly decreased in the experimental groups.The GHR protein expression(G2:0.39±0.02,FU:0.40±0.02,FU+G2:0.38±0.01,G2+FU+GH:0.39±0.01 vs NS:0.94±0.02,P<0.05)and the GHR mRNA expression(G2:14.12±0.10,FU:15.15±0.44,FU+G2:16.46±0.27,G2+FU+GH:15.37±0.57 vs NS:12.63±0.14,P<0.05)were significantly decreased and increased,respectively,in the experimental groups.CONCLUSION:Inhibition of GHR in human colon cancer SW480 cells resulted in anti-tumor effects in nude mice.

Growth hormone receptor expression in human primary gastric adenocarcinoma

The aim of this study was to determine the expression of growth hormone receptor（GHR） in patients with pri-mary gastric adenocarcinoma.We investigated 48 specimens of primary gastric adenocarcinoma and their cor-responding normal gastric mucosa.Immunohistochemistry and reverse transcription-polymerase chain reaction（RT-PCR） were used to detect the expression of GHR.Immunohistochemical analyses revealed that GHR was expressed in human primary gastric adenocarcinoma（36/48,75.0%） and appeared to be upregulated,compared to the normal mucosa（28/48,58.3%,P 〈 0.001）.A significant correlation was found between GHR expression and tumor stage（P 〈 0.001） and tumor differentiation（P 〈 0.001）.The average positive rate of ki-67 in GHR-positive tumors was 16.06%,while the positive rate in GHR-negative tumors was 6.17%（P 〈 0.01）.The average apoptosis index（AI） of GHR-positive tumors was 3.36%,which was significantly lower than that（7.33%） of GHR-negative tumors.In addition,27 of 48 cases of tumors had GHR mRNA expression,while only 17 of all 48 cases of normal mucosa did so.Our results indicate that the frequency of GHR was significantly higher in primary gastric adeno-carcinoma than that in normal gastric mucosa.GHR expression was significantly correlated with tumor differen-tiation and tumor grade.This finding supported a possible role of growth hormone in primary gastric adenocarci-noma pathophysiology.

The role of endotoxin,TNF-α,and IL-6 in inducing the state of growth hormone insensitivity

AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-alpha, IL-6, and IL-1, which may play a very important role in inducing the growth hormone insensitivity. The objective of this current study was to investigate the role of endotoxin, TNF-alpha and IL-6 in inducing the growth hormone insensitivity at the receptor and post-receptor levels. METHODS: Spague-Dawley rats were injected with endotoxin, TNF-alpha, and IL-6, respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously. All rats were killed at different time points. The expression of IGF-I, GHR, SOCS-3 and beta-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection, however, liver IGF-I mRNA expression had been obviously down-regulated in endotoxemic rats. Liver GHR mRNA expression also had a predominant down-regulation after endotoxin injection. The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection, being decreased by 53% compared with control rats. For GHR mRNA expression, the lowest expression occurred at 8h and had a 81% decrease. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats. Exogenous GH could enhance IGF-I mRNA expression in control rats, but it did fail to prevent the decline in IGF-I mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression. The liver GHR mRNA expression was obviously down-regulated after TNF-alpha iv injection and had a 40% decrease at 8h, but the liver SOCS-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection. CONCLUSION: The growth hormone insensitivity could be induced by LPS injection, which was associated with down-regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level. The in vivo biological activities of LPS were mediated by TNF-alpha and IL-6 indirectly, and TNF-alpha and IL-6 may exert their effects on the receptor and post-receptor levels respectively.

Effect of sericin on diabetic hippocampal growth hormone/insulin-like growth factor 1 axis

Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.

Optimization of the Purification Methods for Recovery of Recombinant Growth Hormone from Paralichthys olivaceus

This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone （r-fGH） was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield （2.605 mg L^-1） than that from soluble protein （1.964 mg L^-l）. Of the tested recovery methods, addition of renaturing buffer （pH 8.5） into denatured inclusion body yielded the best recovery rate （17.9%）. This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.

Fibroblast growth factor receptor 3 effects on proliferation and telomerase activity in sheep growth plate chondrocytes

Background： Fibroblast growth factor receptor 3 （FGFR3） inhibits growth-plate chondrocyte proliferation and limits bone elongation. Gain-of-function FGFR3 mutations cause dwarfism, reduced telomerase activity and shorter telomeres in growth plate chondroyctes suggesting that FGFR3 reduces proliferative capacity, inhibits telomerase, and enhances senescence. Thyroid hormone （1-3） plays a role in cellular maturation of growth plate chondrocytes and a known target of T3 is FGFR3. The present study addressed whether reduced FGFR3 expression enhanced telomerase activity, mRNA expression of telomerase reverse transcriptase （TERT） and RNA component of telomerase （TR）, and chondrocyte proliferation, and whether the stimulation of FGFR3 by T3 evoked the opposite response. Results： Sheep growth-plate proliferative zone chondrocytes were cultured and transfected with siRNA to reduce FGFR3 expression; FGFR3 siRNA reduced chondrocyte FGFR3 mRNA and protein resulting in greater proliferation and increased TERT mRNA expression and telomerase activity （p 〈 0.0.5）. Chondrocytes treated with T3 significantly enhanced FGFR3 mRNA and protein expression and reduced telomerase activity （p 〈 0.05）; TERT and TR were not significantly reduced. The action of T3 at the growth plate may be partially mediated through the FGFR3 pathway. Conclusions： The results suggest that FGFR3 inhibits chondrocyte proliferation and reducing telomerase activity indicating an important role for telomerase in capacity during bone elongation. by down-regulating TERT expression sustaining chondrocyte proliferative

ENDOCRINE CHANGES OF PARALICHTHYS OLIVACEUS AFTER ORAL ADMINISTRATION WITH EXOGENOUS GROWTH HORMONE

Recombinant salmon growth hormone contained in yeast was given for 5 months to flounder in its diet. Both free and total specific binding sites for the growth hormone were examined in liver membranes of control and treated fish. The association constants of both free and total specific binding sites were of the same order (1 nM 1 ), and no significant difference was found between any two groups in the capacity of their free binding sites. The capacity of total binding sites in the liver of treated fish increased significantly compared with that of control. Insulin like growth factor I (IGF I) levels in the plasma of treated fish increased by 22.61% (P<0.05), compared with that of control. While the T 4 levels in plasma did not increase significantly (from 1.35±0.91 ng/ml to 2.29±1.13 ng/ml), T 3 levels were elevated significantly (from 1.78±1.14 ng/ml to 4.87±1.22 ng/ml, P<0.01), as compared with that of control.

阿贝西利联合非甾体类芳香化酶抑制剂一线治疗HR+/HER2-绝经后晚期乳腺癌患者的效果观察

探讨针对激素受体阳性/人类表皮生长因子受体2阴性(HR+/HER2-)绝经后晚期乳腺癌患者应用阿贝西利联合非甾体类芳香化酶抑制剂一线治疗的效果。以玉林市红十字会医院在2022年1月—2023年4月收治的92例HR+/HER2-绝经后晚期乳腺癌患者为研究对象,采用随机数字表法将其分为对照组(n=46,应用非甾体类芳香化酶抑制剂一线治疗)和研究组(n=46,在对照组基础上应用阿贝西利治疗),对比两组疗效、不良反应发生率、生活质量。研究发现,针对HR+/HER2-绝经后晚期乳腺癌患者应用阿贝西利联合非甾体类芳香化酶抑制剂一线治疗,疗效有所提高,不良反应未增加,安全性较高,患者生活质量显著提高,值得推广。

蓝塘仔猪IGF-1水平与组织IGF-1、GHR基因的表达

32头不同日龄(出生、3、21、35d)蓝塘仔猪,由前腔静脉采血后剖杀,取肝脏、背最长肌样品。用RIA法测血液、组织中IGF 1浓度,用放射受体法(RBA)检测肝脏、肌肉组织中GHR结合活性,用实时荧光定量PCR法检测IGF 1、GHRmRNA的表达水平。结果表明:(1)血液中IGF 1在出生日显著高于其它时期(P<0 05)。肌肉组织中IGF 1含量高于肝脏组织,肌肉组织IGF 1含量在3、21、35日龄时都显著高于出生日(P<0 05)。(2)肝脏细胞膜GHR结合活性在出生日显著高于3、21日龄(P<0 05),肝脏细胞膜GHR结合活性高于肌肉组织。(3)肝脏组织IGF 1、GHRmRNA的表达量均显著高于肌肉组织(P<0 05)。肝脏IGF 1mRNA的表达在出生日、21日龄时显著高于3、35日龄(P<0 05),GHRmRNA的表达在出生日显著高于其它日龄(P<0 05)。肌肉IGF 1、GHRmRNA的表达在出生日均显著高于其它日龄(P<0 05)。

GHR基因F279Y位点突变对中国荷斯坦牛泌乳性状的影响

目的:研究中国荷斯坦牛生长激素受体(GHR)基因F279Y位点突变对产奶量及乳成份的影响。方法:以232头中国荷斯坦牛为研究材料,参照DHI生产性能测定方法采集产奶量和乳成份数据;采用单链构象多态性(PCR-SSCP)技术并结合测序确定基因型;用最小二乘法进行关联性分析。结果:中国荷斯坦牛GHR基因F279Y位点A、T等位基因频率分别为0.68和0.32,实验群体极显著偏离Hardy-Weinberg平衡(P<0.01);AA型305 d产奶量显著高于AT型(P<0.05),AT型305 d乳脂量、305 d乳蛋白量和305 d乳糖量在数值上有优于AA型的趋势;因此,等位基因A为高产奶量的优势基因,等位基因T对乳成份具有正效应。结论:GHR基因F279Y突变可作为遗传标记应用于中国荷斯坦牛泌乳性状的标记辅助选择(MAS)育种。

牙鲆GHR基因Promoter区微卫星序列多态性与生长性状关系的初步研究

采用牙鲆GHR基因5’端Promoter区的1个微卫星标记,对胶南和日照2个牙鲆养殖群体进行了群体遗传多样性的研究,并探索该基因多态性位点与牙鲆生长性状之间的相关性。结果表明,2个群体在该座位的等位基因数为12和9个,有效等位基因数为6.26和5.04个,多态信息含量为0.84和0.80。2个群体该座位的Hardy-Weinberg遗传偏离指数均为正值,并没有显示出杂合子缺失,但各基因型分布频率都在一定程度上偏离Hardy-Weinberg平衡(P<0.01)。连锁分析中发现,在胶南群体中,IM基因型对应的个体在全重、全长、体长、头长、体高和眼径形态学数据中均是最大的;在日照群体中,BC基因型对应的个体在全重、全长、体高、尾柄高、尾柄长和眼径数据中均是最大的;而CJ基因型对应的个体在体长和头长这两组数据中是最大的。该结果为研究GHR基因的变异对鱼类生长发育的影响及探索将该基因作为生长遗传标记的可行性奠定了实验基础。

大熊猫生长激素受体(GHR)cDNA的克隆与序列分析

根据已报道的若干物种GHR基因cDNA序列设计引物 ,利用RT -PCR技术首次从大熊猫肝脏组织总RNA中扩增出GHR基因编码区全长cDNA序列 ,克隆于pGEM R○-T载体后进行测序和序列分析。结果表明 ,大熊猫GHR的ORF为 1917bp ,编码 6 38个氨基酸的前体蛋白 ,由 18个氨基酸的信号肽和 6 2 0个氨基酸的成熟肽组成 ,与人、狗、猪GHR结构相似 ,大熊猫GHR成熟肽由 2 4 6个氨基酸的胞外区、 2 4个氨基酸的跨膜区和 35 0个氨基酸的胞内区组成 ,并具GHR的特征性结构。序列相似性比较显示 ,大熊猫GHR与哺乳类GHR具有 6 9%～ 93%的高序列相似性 ,与爬行类和鸟类的序列相似性也达到 6 0 % ,而与鱼类的序列相似性较低 ,仅为 30 %左右。与其它哺乳动物GHR相比 。

版纳微型猪近交系GHR基因克隆及生物信息学分析

目的获得版纳微型猪近交系(BMI)生长激素受体基因(GHR)序列,通过生物信息学分析预测GHR功能并进行GHR mRNA多组织表达谱分析。方法以版纳微型猪近交系的肝脏组织为材料提取RNA,RTPCR方法扩增GHR基因编码区序列,将序列连接至pMD18-T载体进行克隆、测序和生物信息学分析;半定量PCR检测GHR mRNA在BMI不同组织中表达量的差异。结果克隆出了BMI GHR编码区序列,提交GenBank获得登录号KC999114。该基因CDS长1917 bp,编码638个氨基酸。生物信息学分析表明,与长白猪的GHR序列相比BMI存在4处氨基酸替换,分别为p.E381D、p.A409S、p.L556V和p.A580G,均发生在胞内域。GHR基因多组织表达谱分析显示:GHR mRNA几乎在各组织中均有表达,在肌肉中表达量最高,在小肠、心、肝、神经纤维、脾、卵巢中表达量较高,在肺、胃、大脑、胰和肾中的表达量较低。结论成功克隆了版纳微型猪近交系GHR全长编码区序列,进行了生物信息学功能分析和组织表达谱分析,为进一步阐明版纳微型猪近交系生长矮小机理奠定了基础。

HR+/HER2-乳腺癌与HR+/HER2+乳腺癌临床特征和内分泌治疗时长的比较

目的比较免疫组化激素受体阳性、人表皮生长因子阴性(HR+/HER2-)乳腺癌患者和激素受体阳性、人表皮生长因子受体阳性(HR+/HER2+)乳腺癌患者的临床特征和内分泌治疗时长。方法回顾性分析青岛大学附属医院收治的36例HR+/HER2-乳腺癌患者和22例HR+/HER2+乳腺癌患者的临床资料,比较两组患者的年龄、月经状态、骨转移、肺转移、肝转移、淋巴结转移、总转移数、BMI、BI-RADS分级、ECOG评分,以及总线数、一线、二线、三线及以上内分泌治疗时长。结果两组患者年龄、月经状态、肺转移、肝转移、淋巴结转移、总转移数、BMI、BI-RADS分级、ECOG评分,以及总线数、一线、二线、三线及以上内分泌治疗时长比较,差异均无统计学意义(P>0.05);HR+/HER2+组患者骨转移发生率高于HR+/HER2-组(P<0.05),HR+/HER2-组患者三线及以上内分泌治疗时长长于HR+/HER2+组(P<0.05)。结论HR+/HER2+乳腺癌可积极选用内分泌治疗或与HER2靶向药物联合治疗,从而避免使用化疗,减轻化疗所带来的不良反应。

绵羊皮肤中GHR、IGF-1和IGF-1R基因表达的发育性变化及品种特点

采用相对定量反转录多聚酶链式反应（RT-PCR）方法，以18S rRNA作内标，研究了罗米丽（Romilly Hillys）×中国美利奴（新疆军垦型）杂交一代优质细毛羊和哈萨克粗毛羊皮肤中生长激素受体（GHR）、胰岛素样生长因子1（IGF-1）和胰岛素样生长因子1受体（IGF-1R）mRNA发育性变化并进行了品种间比较。分别于30、60、90、135、180和255日龄称重、采毛样，并于30、90、135和255日龄采皮样。结果表明：粗毛羊和细毛羊体重、羊毛生长的发育模式没有明显的差异，30-135日龄体重迅速增加，135～255日龄增重十分缓慢；30-135日龄羊毛日增长逐渐增加，135-180日龄羊毛生长十分缓慢，而180-255日龄又上升到较高水平。粗毛羊皮肤中GHRmRNA在30～90曰龄显著增加（P〈0．05），90日龄达到高峰，此后显著下降（P〈0．05）；细毛羊在135日龄时GHR mRNA极显著地升高（P〈0．01），此后又极显著地下降。粗毛羊皮肤中IGF-1、IGF-1R mRNA30—90日龄上升，90日龄之后极显著下降（P〈0．01）：细毛羊皮肤中IGF—1、IGF-1R mRNA出生时较高，然后逐渐下降。品种之间比较，细毛羊GHR mRNA出现高峰晚于粗毛羊，135日龄高峰时显著地高于粗毛羊；粗毛羊IGF—1、IGF-1RmRNA在90日龄出现高峰，并极显著或显著地高于细毛羊；粗毛羊90日龄前GHR、IGF-1和IGF-1RmRNA高于细毛羊，之后低于细毛羊。结果提示：绵羊皮肤中GHR，IGF-1和IGF-1R基因表达有特定的发育模式，并存在品种差异。

激素受体阳性/人表皮生长因子受体2阳性晚期乳腺癌生物学特点及治疗进展

激素受体阳性(hormone receptor-positive,HR+)/人表皮生长因子受体2阳性(human epidermal growth factor receptor 2-positive,HER2+)晚期乳腺癌是一种异质性较高的肿瘤亚型,各大指南对于HER2+晚期乳腺癌,不论HR阳性或阴性,均建议在抗HER2治疗基础上首选联合化疗,专门针对HR+/HER2+晚期乳腺癌的临床研究不多,其最佳治疗特别是后线治疗选择仍存在争议。晚期乳腺癌很难治愈,兼顾不同治疗手段比如化疗与内分泌治疗的疗效和患者的生活质量等显得非常重要。加之近几年针对HR+的细胞周期蛋白依赖性激酶4/6 (cyclin-dependent kinase 4/6 inhibitor,CDK4/6)抑制剂等靶向药物和针对HER2+乳腺癌的新型抗HER2靶向药物和抗体药物偶联物(antibody-drug conjugate,ADC)的应用,为HR+/HER2+晚期乳腺癌的治疗带来了诸多选择和疗效以及安全性的不确定性。本文综述HR+/HER2+晚期乳腺癌分子生物学和临床病理特点、研究进展和治疗选择,为临床医生治疗决策提供参考。

Ghrelin对大鼠小肠转运及消化间期移行性复合肌电活动的作用及机制

目的探讨ghrelin对大鼠小肠转运和消化间期移行性复合肌电活动(MMC)的影响及作用机制。方法大鼠禁食24h,观察静脉给予不同剂量ghrelin对小肠转运的影响,及静脉给予ghrelin受体拮抗剂(D-Lys3)GHRP-6对ghrelin作用的影响。采用多道生理记录仪在大鼠清醒、禁食状态下监测消化间期MMC,观察静脉给予ghrelin对胃肠MMC的影响。分别给予阿托品、酚妥拉明、普萘洛尔、L-精氨酸及(D-Lys3)GHRP-6,探讨ghrelin对MMC的作用机制。结果静脉给予ghrelin剂量依赖性地促进小肠转运,此作用可被(D-Lys3)GHRP-6阻断。静脉给予ghrelin促进胃肠MMC。阿托品、L-精氨酸和(D-Lys3)GHRP-6不同程度地抑制ghrelin的促动力效应;酚妥拉明和普萘洛尔对ghrelin的促动力作用无显著影响。结论Ghrelin可促进胃肠运动,这可能是通过胆碱能通路起作用,与NO通路关系密切,ghrelin受体GHS-R参与其促动力作用。