首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The purpose of this study was to determine the mechanism of the local cytokine-mediated immune response in the skin of chickens. The incorporation of 3H-thymidine into spleen T lymphocytes from 9-to 10-week-old chickens was augmented by the addition of epidermal tissue culture supernatant (ESN) from 11-day-old embryos. The colony formation of neonatal chicken bone marrow cells in the methylcellulose medium was also significantly increased by addition of ESN. When axonal outgrowth in matrigel was investigated, the embryonal sympathetic ganglion was found to grow axons outwards towards the epidermal tissue specimens. The above results suggest that chicken epidermal cells (probably keratinocytes) produce T-cell growth factor (corresponding to IL-1), colony-stimulating factor for macrophages (M-CSF) and granulocytes (G-CSF), and nerve growth factor (NGF).  相似文献   

2.
利用精原细胞-体细胞体外无血清共培养模型研究了促卵泡素(FSH)和表皮生长因子(EGF)对鸡胚精原细胞增殖的作用。结果表明:单独的FSH(10~100ng/mL)或EGF(10~100ng/mL)可显著增加精原细胞的数目以及增殖细胞核抗原的表达。EGF(10ng/mL)联合FSH(10ng/mL)具有加性效应,但更高剂量的EGF(100ng/mL)则降低了FSH的促进作用。因此,FSH联合适量的EGF可促进精原细胞的增殖。  相似文献   

3.
Studies were undertaken to assess the chicken embryo and newly hatched chicken as models for studying the effects of bone-active agents. Initially, 1,25-dihydroxycholecaliferol (1,25[OH]2D3), sodium fluoride (NaF), parathyroid extract, epidermal growth factor, and prostaglandin E2, were tested for lethality over a broad dose range. One or 3 injections of 1,25(OH)2D3 into the yolk sac of chicken embryos resulted in death of embryos given greater than or equal to 0.1 ng/injection, whereas 0.01 ng was tolerated by the embryos. Administering 1,25(OH)2D3 intraperitoneally to newly hatched chickens as a single injection or weekly for 3 weeks resulted in no deaths at doses up to 50 ng. One or 3 IV injections of 800 micrograms of NaF were lethal to embryos, whereas injections of less than or equal to 400 micrograms were tolerated by the embryo. Giving chickens feed and water containing 2.4 g of NaF/kg was lethal, but no deaths occurred when chickens were given feed containing less than or equal to 1.2 g of NaF/kg. Mortality associated with the administration of epidermal growth factor to embryos was inconsistent, in that death occurred in embryos given a single injection of greater than or equal to 250 ng, but no deaths occurred in embryos given 3 injections at similar doses. Parathyroid extract and prostaglandin E2 were not lethal when administered to embryos and chickens in a single-injection or multiple-injection regimen. Overall, lethality in chicken embryos given a particular agent reflected the dose of bone-active agent injected, rather than the number of injections. Three of the bone-active agents were selected to characterize their microscopic bone effects in chicken embryos and chickens.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
OBJECTIVE: To determine the effects of epidermal growth factor (EGF) or insulin-like growth factor (IGF) on tenoblast migration on absorbable suture material using an in vitro model. STUDY DESIGN: An in vitro evaluation of tenoblast migration. ANIMAL OR SAMPLE POPULATION: Segments of the long digital flexor tendon were obtained from Cobb chickens (9-11 weeks old) immediately after the birds were euthanatized. METHODS: Tissue culture explants of tendons containing absorbable suture material were treated with either EGF or IGF. Tenoblast migration was assessed daily using an inverted microscope equipped with bright field and phase optics. Tenoblast migration was assessed according to the following criteria: time of first cell appearance, percent of explant interfaces producing cells, migration distance, and terminal migration index at 120 and 168 hours. RESULTS: EGF had a stimulatory effect on tenoblast migration for cells originating from the endotenon interfaces. No significant effect was noted on migration distance for cells originating from epitenon interfaces. A stimulatory effect on the percentage of interfaces producing cells and a significant decrease in time of first cell appearance were also observed after EGF treatment. IGF-stimulated cell migration distance for epitenon interfaces but this stimulatory effect did not occur at a higher concentration. IGF was inhibitory to percent of epitenon and endotenon interfaces producing cells but decreased time of first cell appearance at low concentration. CONCLUSIONS: Using an in vitro model, EGF had a stimulatory effect on tenoblast migration. IGF was stimulatory at low concentration levels but inhibitory at a higher concentration. Increased migration distance was observed for endotenon interfaces after EGF treatment and for epitenon interfaces after IGF treatment. CLINICAL RELEVANCE: EGF or IGF might enhance tendon repair if they could be delivered to the repair site. Incorporation of EGF or IGF into suture material would allow slow release and prolonged exposure of migrating tenoblasts to growth factors.  相似文献   

5.
为研究儋州鸡生长发育规律和各阶段的生长速度,本试验采用Gompertz、Logistic和Bertalanffy 3种非线性模型对黑色羽系和麻花色羽系儋州鸡0~18周龄体重生长数据进行拟合和分析,选取黑色羽系、麻花色羽系儋州鸡各200只(公、母各半),分别于0、2、4、6、8、10、12、14、16和18周龄晨饲前空腹称重并记录,并利用3种非线性模型对儋州鸡生长曲线进行拟合比较分析。结果显示,2种羽色儋州鸡实测生长曲线基本一致,接近于"S"型,符合正常生长发育规律,2种不同羽色儋州鸡母鸡0~18周龄的体重实测值差异不显著(P>0.05),公鸡0~16周龄的体重实测值差异不显著(P>0.05),而16~18周龄麻花色羽系公鸡体重显著高于黑色羽系公鸡(P<0.05)。3种非曲线模型拟合度(R2)均在0.992以上,均能较好地拟合2个羽系儋州鸡的生长曲线,且模型的预测曲线与实际观测曲线基本吻合,但Gompertz模型曲线吻合度高于Logistic和Bertalanffy模型曲线,且母鸡比公鸡拟合效果好。本研究结果初步揭示了儋州鸡的生长发育规律和各阶段的生长特征,可为儋州鸡选育、生产和产业化发展提供科学依据。  相似文献   

6.
鸡肿瘤坏死因子的诱生及活性检测   总被引:3,自引:0,他引:3  
通过对鸡静脉注射卡介苗 (BCG)和脂多糖 (L PS) ,应用 L92 9细胞检测鸡体外周血清、脾细胞和外周血白细胞肿瘤坏死因子 (TNF)活性 ,表明外周血清 TNF活性最高 ,其次是脾细胞 ,而外周血白细胞 TNF活性最低。本研究也表明在正常鸡的外周血液中有少量的 TNF  相似文献   

7.
Growth factors play critical role in cell proliferation, regulate tissue differentiation and modulate organogenesis. Several growth factors have been identified in the testes of various mammalian species in last few years. In present investigation, the objective was to determine the expression of epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in yak testicular tissue by relative quantitative real time polymerase chain reaction (RT‐PCR), Western blot (WB) and immunohistochemistry (IHC) from mRNA and protein levels. The testicular tissues were collected from male yak at 6 and 24 months old. Results of RT‐PCR and WB showed that the expression quantity of EGF and EGFR at 24 months of age was higher than at 6 months, and the increase rate of EGFR on mRNA and protein levels was higher than the increase rate EGF during post‐natal testes development. Positive staining for EGF and EGFR was very low and mainly localized to Leydig cells testes at 6 months of age with immunohistochemistry, and seminiferous tubules were not observed. At 24 month of age, both the EGF and EGFR could be detected in Leydig cells, peritubular myoid cells, sertoli cells and germ cells of the yak testes. However, EGF and EGFR were localized to preferential adluminal compartment and basal compartment in the seminiferous tubules, respectively. In conclusion, the findings in present studies suggest that EGF and EGFR as important paracrine and/or autocrine regulators in yak testes development and spermatogenesis.  相似文献   

8.
我国鸡传染性支气管炎病毒地方分离株生物学特性的研究   总被引:22,自引:3,他引:19  
从我国新疆维吾尔自治区某鸡场发病症状及病理变化疑似鸡传染性支气管炎的病鸡有出血点病变的腺胃组织中分离病毒,在9-11日龄SPF鸡胚上连续传代9次,通过病毒对鸡胚的致病作用、病毒在电镜下的形态观察、病毒在鸡胚中的增殖动态变化、病毒在CEF中的增殖特性、凝集鸡红细胞的特性以及动物回归试验等来研究我国鸡传染性支气管炎病毒地方流行株的生物学特性。结果表明,该毒株的第一代尿囊液对鸡胚无肉眼可见的致病作用,当继代到第5代后,胚体严重病变;电镜观察该病毒为典型的冠状病毒;病毒在鸡胚中随着接种病毒时间的延长,其效价增高,96小时可达到48小时的1倍,该毒株可在CEF上生长,但不能形成明显的蚀斑;并且经1%胰酶处理后可疑集鸡红细胞;鸡胚的第4代尿囊液病毒回归动物体,可致鸡病变病死鸡肾脏病变尤为明显,呈典型的花斑肾,腺胃则未见肉眼可见的病变,接种鸡、同居鸡和对照鸡之间NDV疫苗免疫后其HI抗体水平无明显差异,但从发病症状来看,IBV对ND疫苗具有干扰作用。  相似文献   

9.
为探究散养对皖南三黄鸡生长性能和肉品质的影响,试验选择80羽4周龄、体重相近、健康无病的的皖南三黄鸡,随机分为笼养组和散养组,笼养组每只鸡单笼,每组40个重复。试验期9周。结果表明:6周龄时散养组体重高于笼养组(P<0.05),试验期散养组胫围高于笼养组(P<0.05);笼养组的肌肉滴水损失率、蒸煮损失率和失水率以及腿肌水分、粗脂肪含量和pH高于散养组(P<0.05);与散养鸡相比,笼养鸡生长速度较快,但散养鸡肌肉系水力高于笼养鸡(P<0.05),表明散养鸡肉品质优于笼养鸡。综上,生产者应该根据自身情况以及不同市场对鸡肉产品的不同要求选用适宜的饲养方式。  相似文献   

10.
鸡传染性支气管炎病毒LH2/01/10的分离鉴定   总被引:1,自引:0,他引:1  
2001年在我国黑龙江省某鸡场疑似鸡传染性支气管炎的发病鸡群中,分离到一株病毒,将该病毒接种10日龄SPF鸡胚,取72h的尿囊液进行电镜观察并用1%胰酶处理,结果发现尿囊液中存在典型的冠状病毒,用胰酶处理过的尿囊液能凝集SPF鸡的红细胞,初步鉴定为鸡的传染性支气管炎病毒。将该病毒尿囊液再次接种10日龄SPF’鸡胚,通过病毒对鸡胚的致病作用、病毒超微形态特征以及病毒凝集鸡红细胞的特性等对该毒株进行研究,结果表明:经胰酶处理后的病毒尿囊液可凝集鸡红细胞。鸡胚的第二代病毒尿囊液(命名为LH2,/01/10)分别接种1日龄和15日龄的SPF鸡,发现对不同日龄的鸡表现不同的致病性,对1日龄接种鸡和同笼饲养的同居对照鸡致病力高,发病率为11/11,致死率分别为4/6和2/5;15日龄接种和同居感染鸡发病率为9/9,致死率分别为1/5和1/4。实验应用反转录一聚合酶链式反应技术对LH2/01/10的膜蛋白基因进行扩增、克隆和序列测定,结果表明该基因具有IBVM基因的共有分子特征.与IBV标准株M41的M基因核苷酸的同源性为90%,氨基酸的同源性为91%。这从分子水平进一步证实引起鸡群死亡的病毒为鸡传染性支气管炎病毒。  相似文献   

11.
以京海黄鸡、AA鸡、尤溪麻鸡、边鸡等4个鸡品种为研究对象,采用PCR-SSCP方法检测胰岛素样生长因子结合蛋白1(insulin-like growth factor-binding protein-1,IGFBP-1)第4外显子的多态性,并分析其对京海黄鸡生长性能的遗传效应。结果显示,在IGFBP-1第4外显子区检测到2处变异(5550T→C、5692AAT插入)。对于P3扩增片段,在尤溪麻鸡群体中检测到AA、AB、BB 3种基因型,在AA鸡和边鸡品种中检测到AA和AB 2种基因型,京海黄鸡中只检测到AA基因型;对于P4扩增片段,在4个鸡品种中均检测到CC、CD、DD 3种基因型。最小二乘分析结果表明,京海黄鸡3种基因型个体的初生重存在显著差异(P<0.05)。  相似文献   

12.
根据NCBI公共数据库获取的家蚕表皮生长因子受体基因序列,设计8对针对表皮生长因子受体基因的特异性引物。提取柞蚕中不同龄期和不同组织中总RNA,以Oligo-dT为引物,反转录为第一链cDNA,经PCR扩增,荧光定量PCR检测,结果表明表皮生长因子受体基因在不同发育阶段中的表达有差异。不同发育阶段和整个眠期的柞蚕中,ApEGFR的mRNA均有表达,但在5龄和3眠期的时候的表达量最高。不同组织中,在柞蚕的丝腺中ApEGFR的mRNA表达量最高,表皮最低。  相似文献   

13.
1. Differences in responses to lipolytic agents have been investigated in vitro in abdominal adipose tissue from lines of broiler chickens selected for body weight (GL, a 'fat' line) or for food efficiency (FC, a 'lean' line). 2. Dibutyryl cyclic adenosine monophosphate stimulated in vitro lipolysis, as measured by the glycerol release, by adipose tissue from GL or from FC chickens to the same extent. 3. Glucagon stimulated glycerol release from adipose tissue from FC chickens, but not from GL chickens. 4. Adipose tissue from GL chickens was much more sensitive to chicken growth hormone (GH) compared to FC chickens. 5. It is concluded that the selection criteria applied influenced the number of adipose GH and glucagon receptors, the number of adipose GH receptors being lower and of glucagon receptors being higher in FC chickens compared to GL chickens.  相似文献   

14.
采用PCR-SSCP技术检测边鸡及2个对照鸡群体(京海黄鸡和尤溪麻鸡)肌肉生长抑制素(myostatin,MSTN)基因外显子3的单核苷酸多态性,并与边鸡的生长性状进行相关性分析。结果表明,在MSTN基因外显子3的8527—8528 bp处检测到一个TC的插入。在边鸡和京海黄鸡中只检测到2种基因型(AA和AB基因型),在尤溪麻鸡中检测到3种基因型(AA、AB和BB基因型)。在3个鸡品种中都以A等位基因为优势等位基因。最小二乘分析结果表明,边鸡2种基因型个体的6~16周龄体重均无显著差异(P>0.05)。  相似文献   

15.
MSTN基因外显子3的多态性及其与边鸡生长性状的关联分析   总被引:2,自引:0,他引:2  
采用PCR-SSCP技术检测边鸡及2个对照鸡群体(京海黄鸡和尤溪麻鸡)肌肉生长抑制素(myostatin, MSTN)基因外显子3的单核苷酸多态性,并与边鸡的生长性状进行相关性分析。结果表明,在MSTN基因外显子3的8527—8528 bp处检测到一个TC的插入。在边鸡和京海黄鸡中只检测到2种基因型(AA和AB基因型),在尤溪麻鸡中检测到3种基因型(AA、AB和BB基因型)。在3个鸡品种中都以A等位基因为优势等位基因。最小二乘分析结果表明,边鸡2种基因型个体的6~16周龄体重均无显著差异(P>0.05)。  相似文献   

16.
To stably maintain pregnancy, several genes are expressed in the uterus. In particular, the endometrial expression of genes encoding growth factors appears to play a key role in maternal–foetal communication. The previous studies characterized the endometrial expression kinetics of the genes encoding epidermal growth factor (EGF), its receptor (EGFR), transforming growth factor-alpha (TGF-α), amphiregulin (Areg), heparin-binding (Hb) EGF and calbindin-D9k (CaBP-9k) in pigs during implantation. Here, we further characterized the expression patterns of these molecules during the entire porcine pregnancy. Porcine uteri were collected at pregnancy days (PD) 12, 15, 30, 60, 90 and 110 and subjected to RT-PCR. EGF and EGFR showed similar expression patterns, being highly expressed around implantation and then disappearing. TGF-α and Areg expression levels rose steadily until they peaked at PD30, after which they gradually decreased to PD12 levels. This Areg mRNA expression pattern was confirmed by real-time PCR and similar Areg protein expression patterns were observed. Immunohistochemical analysis of PD60 uteri revealed Areg in the glandular and luminal epithelial cells. Hb EGF was steadily expressed throughout the entire pregnancy, while CaBP-9k was expressed strongly on PD12, and then declined sharply on PD15 before recovering slightly for the remainder of the pregnancy. Thus, the EGF family may play a key role during implantation in pigs. In addition, CaBP-9k may help to maintain uterine quiescence during pregnancy by sequestering cytoplasmic Ca2+.  相似文献   

17.
试验旨在揭示贵州黄鸡慢羽系生长发育规律。选择100只贵州黄鸡慢羽系(公母鸡各50只),于0、2、4、6、8、10、12、14周龄末称重,分别采用Bertalanffy、Logistic、Gompertz 3种非线性生长曲线模型对贵州黄鸡慢羽系0~14周龄体重变化进行拟合分析。结果表明:3种模型均能很好地拟合其生长曲线,拟合度均在0.99以上,其中Logistic模型在贵州黄鸡慢羽系公鸡、母鸡生长曲线中拟合最好,拟合结果最接近实测体重情况,其公鸡拐点体重为1 550.81 g,拐点周龄为10.42,母鸡拐点体重为976.67 g,拐点周龄为9.14。试验结果初步揭示了贵州黄鸡慢羽系的生长发育规律和各阶段的生长特征,为贵州黄鸡慢羽系选育生产和产业化发展提供了科学依据。  相似文献   

18.
为研究IGFBP-3基因表达与鸡生长性状的相关性,以生长速度差异较大的花山麻鸡和清远麻鸡两个黄羽肉鸡品种为研究素材,用实时荧光定量PCR法检测胚胎期和出雏后两个品种鸡胸肌和肝脏中IGFBP-3基因的表达规律,并将其与体重、胸肌重和肝脏重进行相关性分析。结果表明,在9胚龄时两个品种鸡胸肌和肝脏中均可检测到IGFBP-3基因表达,同一胚龄或日龄品种内组织间比较,胚胎期两个品种鸡胸肌IGFBP-3 mRNA表达量均高于肝脏,出雏后肝脏IGFBP-3 mRNA表达量迅速上升,胸肌IGFBP-3 mRNA表达量下降,两个品种鸡肝脏IGFBP-3 mRNA表达量均极显著高于胸肌(P<0.01);组织中IGFBP-3 mRNA表达量与组织重量和体重相关研究表明,两个品种鸡肝脏IGFBP-3 mRNA表达量与其胸肌重、肝脏重和体重呈显著或极显著正相关(P<0.05;P<0.01),胸肌IGFBP-3 mRNA表达量与其胸肌重、肝脏重和体重均呈极显著负相关(P<0.01)。研究结果揭示,IGFBP-3 mRNA在鸡中的表达具有品种、年龄和组织特异性,出雏前肝脏并不是鸡产生IGFBP-3的主要器官,出雏后鸡IGFBP-3可能主要由肝脏合成,肝脏中IGFBP-3 mRNA水平差异是导致两个品种鸡出雏后体重和胸肌重差异的重要因素。  相似文献   

19.
为观察表皮生长因子 ( epidermalgrowth factor,EGF)对成年水牛晶状体上皮细胞增殖作用的影响。将不同浓度 EGF作用于体外培养的成年水牛晶状体上皮细胞 ,采用 MTT法测定细胞的增殖能力。结果 :EGF在浓度为 1ng/ m L和 1 0 ng/ m L作用的前 3 d促增殖作用逐渐加强 ,呈现时间依赖性 ,且在第 3 d达到最大促增殖效果。不同浓度的 EGF对晶状体上皮细胞的增殖作用不同 ,浓度在 1 0 ng/ m L作用 2 4h后即有明显的促增殖作用 ( P <0 .0 5) ,而作用72 h后最低的有效浓度为 1 ng/ m L,而且 2 50ng/ m L EGF有最大促增殖作用。结论 :EGF是诱导成年水牛晶状体上皮细胞增殖的重要因素。  相似文献   

20.
Lippia javanica leaves may have nutraceutical bioactivity and thus could be a viable alternative to antibiotic growth promoters in poultry diets. To test this hypothesis, a feeding trial was carried out to determine the effects of dietary inclusion of Lippia javanica leaf meal (LJ) on growth performance, blood parameters, carcass characteristics and meat quality of indigenous Potchefstroom Koekoek (PK) chickens. The leaf meal was used to dilute a commercial chicken grower diet at a rate of 25 or 50 g/kg diet. Two additional experimental diets, a positive control (commercial chicken grower diet with antibiotics, CON+) and a negative control (commercial chicken grower diet without antibiotics, CON–), were also formulated. Feed intake and growth performance were measured over a period of 13 weeks before slaughtering for carcass and meat quality measurements. Blood was collected in week 11 to determine haematological and serum biochemical parameters. Diet had no effect on overall FCE but significantly (P?<?0.05) affected bilirubin, alanine aminotransferase (ALT), aspartate transaminase (AST), sodium, potassium, cholesterol and magnesium levels in blood. When included at 50 g/kg, LJ increased carcass weight (P?<?0.05). Meat from CON– (6.07) and LJ50 (6.08) chickens had a higher pH than from CON+ (5.9) and LJ25 (5.8) chickens. Breast muscle in CON– chickens had higher (P?<?0.05) lightness (L*) value (53.2) compared to chickens fed on other diets. It was observed that meat from LJ25 chickens had the highest for redness value (2.3). It was concluded that L. javanica leaf meal can be included up to 50 g/kg in Potchefstroom koekoek chicken diets without causing negative effects on the birds’ feed intake, utilisation and weight gain. Diet-induced changes observed in blood parameters and meat quality fell within the expected normal ranges for indigenous chickens.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号