猪小肠抗菌肽对雏鸡的促生长作用及其机理初探

【目的】测定猪小肠抗菌肽对雏鸡生长指标的影响，在结构上初步探讨猪小肠抗菌肽促进雏鸡生长发育的机理。【方法】选择体重基本一致的雏鸡60只，随机平均分为2组。试验组，在7、14、21、28、35、42日龄每只雏鸡分别肌肉注射猪小肠抗菌肽0.1ml（100 μg·ml-1）；对照组，在相应日龄每只雏鸡分别肌肉注射灭菌生理用水0.1ml，在相同饲养条件下进行6周试验。在7日龄和49日龄，采用组织切片检测鸡十二指肠和空肠的绒毛长度、隐窝深度和黏膜厚度。【结果】试验组雏鸡平均日耗料量（29.82±1.05）g，对照组雏鸡平均日耗料量（28.85±0.79）g，二者无差异（P>0.05）；试验组雏鸡平均日增重为（13.54±0.20）g，对照组雏鸡平均日增重为（11.10±0.19）g，二者差异极显著（P<0.01）；试验组料重比为2.27±0.04，对照组料重比为2.60±0.05，二者差异极显著（P <0.01）。在49日龄，试验组鸡十二指肠和空肠绒毛长度及其绒毛长度/隐窝深度比值（V/C）高于对照组鸡，二者差异显著（P<0.05），试验组鸡十二指肠和空肠黏膜厚度与对照组鸡相比，差异不显著（P>0.05）。【结论】猪小肠抗菌肽可改善鸡十二指肠和空肠的结构，提高雏鸡生长速度和饲料转化率。     

Protective role of heat-shock protein 70 in gastric mucosal lesion induced by endotoxin in cirrhotic rats with portal hypertensive gastropathy

AIM: To investigate the protective role of heat-shock protein 70 (HSP70) in the pathogenesis of gastric mucosal damage in cirrhotic rats with portal hypertensive gastropathy (PHG).METHODS: The rat model of liver cirrhosis with PHG was established by injection with tetrachloride.The animals were divided into normal control group, PHG group, PHG+heat treatment group, PHG+BPI21 group and PHG+endotoxin groups.The endotoxin used in the experiment was at the dose of 3 mg/kg and endotoxin antagonist BPI21 was at the dose of 2 mg/kg.HSP70 was induced by pre-treating the animals with mild whole-body heating.The levels of HSP70 and tumor necrosis factor alpha (TNF-α) in the gastric mucosa were measured by ELISA.Furthermore, the pathological changes of the gastric mucosa were observed under microscope with HE staining.RESULTS: Compared with the normal control rats, the rats in PHG group showed obvious gastric pathological lesion, decrease in HSP70 production and increase in TNF-α level in the gastric mucosa, and increased endotoxin concentration in the plasma.Compared with PHG+endotoxin group, the gastric mucosal lesion in PHG+BPI21 group was significantly attenuated, accompanied by the increase in HSP70 production and decrease in TNF-α level in the gastric mucosa.Heat treatment increased HSP70 production and decreased TNF-α concentration in the PHG rats, thus attenuating the gastric mucosal damage.CONCLUSION: HSP70 alleviates the gastric mucosal lesion induced by endotoxin in cirrhotic rats with PHG and decreases the concentration of TNF-α in gastric mucosa, indicating a protective role of HSP70 in the pathogenesis of gastric mucosal damage in PHG.     

Mucosa-associated lymphoid tissue lymphoma of the third eyelid conjunctiva in a dog

A 4-year-old, neutered female Cocker Spaniel was presented to the veterinary clinic for protrusion of the left third eyelid. When the third eyelids from both eyes were everted, lobulated masses were present on the bulbar surface. The left third eyelid had a larger protrusion. There was no apparent associated ocular or systemic involvement. The tumor of left third eyelid was removed and referred for histological examination. Histologically, there were proliferations of lymphoid follicles surrounded by lymphoid cells forming a marginal zone. Those lymphoid cells occasionally infiltrated into conjunctival epithelium. A few apoptotic bodies with karyopyknotic and karyorrhexic nuclei were observed in the germinal center of lymphoid follicles. Mitotic figures were rare. On immunohistochemistry, tumor cells expressed CD79a but not CD3. A diagnosis of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the third eyelid was established based on the histological and immunophenotypical features. At the 1-year follow-up, there was no evidence of recurrence of the mass at the area of excision of the left third eyelid and the remaining tumor of the right third eyelid was still a similar size. The dog still showed no significant findings, except those of the tumor, and no evidence of systemic involvement. To the authors' knowledge, this is the first reported case of MALT lymphoma of the third eyelid in a dog.     

苦菜中单宁提取工艺及其抗便秘作用研究

对单宁的提取工艺做了研究，对料液比、温度、提取时间分别进行了单因素试验和L₉(3³)正交试验，并且对单宁的抗便秘防腹泻功能进行了研究。结果显示最佳工艺为料液比1∶60、温度45℃、提取时间6 h，提取率(相对于被提取的苦菜质量)为3.60%。经动物试验显示：苦菜单宁能够较强地促进小鼠小肠的蠕动，明显减少排便次数，说明苦菜单宁对便秘和腹泻有双向治疗作用，且抗便秘作用优于苦菜果胶和苦菜多糖。     

Antibacterial Mechanism of Chitosan–Gentamicin and Its Effect on the Intestinal Flora of Litopenaeus vannamei Infected with Vibrio parahaemolyticus

To explore the application of chitosan–gentamicin conjugate (CS-GT) in inhibiting Vibrio parahaemolyticus (V. parahaemolyticus), which is an important pathogen in aquatic animals worldwide, the antimicrobial activity of CS-GT and the effects of a CS-GT dose on the intestine histopathology and intestinal flora of V. parahaemolyticus-infected shrimps were explored. The results showed that CS-GT possessed broad-spectrum antibacterial activity, with minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and half inhibitory concentration (IC₅₀) of 20.00 ± 0.01, 75.00 ± 0.02 and 18.72 ± 3.17 μg/mL for V. parahaemolyticus, respectively. Further scanning electron microscope and cell membrane damage analyses displayed that the electrostatic interaction of CS-GT with cell membrane strengthened after CS grafted GT, resulting in leakage of nucleic acid and electrolytes of V. parahaemolyticus. On the other hand, histopathology investigation indicated that high (100 mg/kg) and medium (50 mg/kg) doses of CS-GT could alleviate the injury of a shrimp’s intestine caused by V. parahaemolyticus. Further 16S rRNA gene sequencing analysis found high and medium dose of CS-GT could effectively inhabit V. parahaemolyticus invasion and reduce intestinal dysfunction. In conclusion, CS-GT possesses good antibacterial activity and could protect shrimps from pathogenic bacteria infection.     

纳米硒对齐口裂腹鱼生长、肌肉成分、血清生化及抗氧化指标的影响

为探究饲喂富硒酵母强化卤虫无节幼体对大口黑鲈仔鱼的生长、存活率、脂肪酸组成、肝肠组织结构以及抗逆性的影响,设置了0 (Y-se0)、5 (Y-se5)、10 (Y-se10)、15 (Y-se15)、20 mg/L (Y-se20)酵母硒添加浓度对卤虫无节幼体进行硒营养强化,并使用强化后的卤虫饲喂养殖在玻璃缸中的3 000尾大口黑鲈仔鱼(2.1 mg/尾,200尾/缸) 20 d。饲养实验结束后,将每缸10尾仔鱼放入35 °C恒温水浴缸中进行急性温度胁迫试验。结果显示：① Y-se15组的存活率、终末体重、体长以及特定生长率均显著高于对照组,肥满度(CF)在各组间无显著差异。② Y-se5组EPA含量显著低于对照组,Y-se5及Y-se15组DHA/EPA值显著高于对照组。③ Y-se10、Y-se15和Y-se20组肝脏中过氧化氢酶(CAT)活性显著高于对照组,所有处理组肝脏中,谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组,丙二醛(MDA)含量显著低于对照组,处理组和对照组间总超氧化物歧化酶(T-SOD)活性无显著差异。④ Y-se15组肝脏组织空泡化现象较轻,酵母硒添加组的肠道绒毛长度显著高于对照组。⑤ Y-se15组在35 °C应激条件下,存活时间显著高于对照组。研究表明,卤虫无节幼体强化液酵母硒添加浓度为15 mg/L时可显著提高大口黑鲈仔鱼生长、存活率及DHA/EPA水平,增强机体抗氧化以及抗应激能力,改善鱼体健康状况。本研究初步探究了饲喂酵母硒强化卤虫无节幼体对大口黑鲈仔鱼的影响,旨在为进一步完善水生动物苗种开口饵料营养强化技术提供参考,促进水产养殖业高质量发展。

     

鳜胃肠道和肝脏主要消化酶活性的研究

试验测定了鳜胃、肠道、肝脏和幽门盲囊中蛋白酶、淀粉酶和脂肪酶等3种主要消化酶的活性及温度对这些酶活性的影响。结果表明:从鳜的胃、肠、肝脏和幽门盲囊中均可检测出蛋白酶、淀粉酶和脂肪酶的活性,且在温度为(37±1)℃和pH为7.5(胃pH5.4)条件下,鳜消化道中蛋白酶活性大小顺序为:幽门盲囊>肠>胃>肝脏;淀粉酶活性大小顺序为:肝脏>幽门盲囊>胃>肠;脂肪酶活性大小顺序为:幽门盲囊>肠>肝脏>胃。鳜胃、肠、肝脏和幽门盲囊中蛋白酶的最适温度分别为50℃、50℃、40℃和55℃,淀粉酶的最适温度分别为50℃、25℃、40℃和50℃,脂肪酶的最适温度分别为20℃、40℃、40℃和25℃。     

不同粗精比日粮对绵羊小肠中瘤胃微生物蛋白质利用的影响

用4只装有瘤胃瘘管、十二肠瘘管和回肠瘘管的去势(公母各半)萨福克羊体重平均为(45.5±5.2)kg,在不同粗精比日粮条件下 ,研究瘤胃细菌、纤毛虫体蛋白质在小肠内的利用率。结果表明 :到达十二指肠的瘤胃细菌和纤毛虫的量 ,随日粮中精饲料水平的提高而显著减少(P<0.05)。与此相反 ,过瘤胃饲料蛋白质的量则显著增加(P<0.05)。小肠内的细菌利用率显著受日粮变化的影响 ,而纤毛虫利用率则不易受日粮影响且显著地高于细菌的利用率(P<0.05)。小肠内被吸收的细菌和纤毛虫对微生物氮的贡献率在全试验组中平均为50 %。     

大豆凝集素在不同种属动物小肠中残留、结合和内吞特点的比较研究

选取5种动物为试验对象,生理年龄均在1/2性成熟期,每种动物4头,猪(长白,70 d)、羊(小尾寒羊,60 d)、狗(比格犬,80 d)、兔(日本大耳白,75 d)和鸡(爱拔益加,75 d)。采用体内原位结扎灌注肠段的方法研究不同浓度大豆凝集素(SBA)在不同种属动物小肠中的残留、结合和内吞特点。动物禁食24 h后,注入麻醉剂,剪去腹部体毛,打开腹腔,结扎空肠前段,(各种动物以空肠前段1/3处相对位置开始结扎)。用30 m L(39±1)℃的生理盐水冲洗隔离的肠段,以冲洗肠段内残余的食糜,分别结扎4段5 cm长的肠段,用注射器分别输入含不同浓度SB(A 0、0.5、1.0 m g/m L和3.0 m g/m L)的Krebs液。灌注时间8 h。试验结束后,采用间接抑制ELISA方法检测3个指标:灌注液中SBA的残留率,肠黏膜表面SBA的结合率,进入小肠壁的SBA的内吞率。结果表明:大豆凝集素在动物小肠中的结合特点存在种属差异;比较而言,SBA在猪和狗小肠中的内吞率和结合率高于羊,兔和鸡的内吞率也较大,且SBA的不同浓度对其在小肠壁上的内吞也有较大影响,低浓度时SBA的结合率和内吞率较大。     

暗纹东方鲀不同养殖模式下的微生物群落结构

为探究暗纹东方鲀不同养殖模式下环境及肠道的细菌群落结构特征,实验采用Illumina Miseq高通量测序方法对传统养殖与立体种养2种模式下水体、底泥及暗纹东方鲀肠道细菌的16S rRNA的2个高变区(V3～V4)进行测序分析,利用冗余分析(redundancy analysis,RDA)方法来分析水体菌群与环境因子的...