免疫增强剂对河鲫鱼白细胞吞噬和溶菌酶活性的影响

在饵料中添加不同含量的免疫增强剂(0.2%,0.5%,0.8%)连续投喂21d。在0,1,4,7,14,21d检测河鲫鱼(Carassius auratus)血液白细胞的吞噬活性、血清和体表粘液的溶菌酶活性。结果表明,该免疫增强剂可使河鲫鱼血液中白细胞吞噬活性、血清和体表粘液的溶菌酶活性都有明显提高。在停止投喂后7d,血清溶菌酶的活性逐渐降低与对照组无显著差异(P>0.05),组白细胞吞噬活性依然与对照组存在显著差异(P<0.05)。     

免疫增强剂对河鲫鱼白细胞吞噬和溶菌酶活性的影响

在饵料中添加不同含量的免疫增强剂(0.2%,0.5%,0.8%)连续投喂21d。在0,1,4,7,14,21d检测河鲫鱼(Carassius auratus)血液白细胞的吞噬活性、血清和体表粘液的溶菌酶活性。结果表明,该免疫增强剂可使河鲫鱼血液中白细胞吞噬活性、血清和体表粘液的溶菌酶活性都有明显提高。在停止投喂后7d,血清溶菌酶的活性逐渐降低与对照组无显著差异(P>0.05),但白细胞吞噬活性依然显著差异于对照组(P<0.05)。     

微生态制剂对银鲫免疫机能的影响

饲料中微生态制剂的添加量为1×1011/kg,即可显著提高银鲫血液白细胞吞噬活性和血清溶菌酶活性,投喂微生态制剂后第4天或第7天,PP、PI显著或极显著地高于对照组,而且在停止投喂微生态制剂10d后,试验组的PP和PI仍显著或极显著地高于对照组。投喂微生态制剂后第7天,试验组银鲫溶菌酶的活性显著或极显著高于投喂制剂前及对照组,停止投喂第10天,血清溶菌酶的活性与对照组之间即无显著差异。     

A3α肽聚糖对彭泽鲫生长及非特异免疫机能的影响

为探讨肽聚糖对彭泽鲫非特异免疫功能的影响及促长作用,将不同剂量的A3α肽聚糖添加于饵料中投喂彭泽鲫,测定鲫鱼体重、白细胞吞噬活性、血清和体表粘液溶菌酶活性,以及活菌攻毒后的免疫保护率。结果表明,添加250~550 mg/kg肽聚糖可显著提高彭泽鲫鱼白细胞吞噬活性、体表粘液及血清溶菌酶活性,但对鲫鱼生长均无明显促长效果;鲫鱼口服肽聚糖药饵后抗病能力增强,感染后的死亡率明显降低;在饵料中肽聚糖适宜添加量为250~450 mg/kg。     

免疫增强剂对异育银鲫非特异免疫力的影响

分别用添加1%酵母细胞壁(1号饲料)、1%酵母细胞壁+0.23%Vc+0.02%VE(2号饲料)、1%免疫多糖(3号饲料)的饲料投喂异育银鲫,并于试验后4、11、17、24、31 d测定头肾巨噬细胞吞噬活性、血清溶菌酶活性和血清杀菌活性.结果表明,与对照组相比,3组饲料均能显著提高异育银鲫的头肾巨噬细胞吞噬活性、血清溶菌酶活性和血清杀菌活性,其中3号饲料效果最为显著,其次为2号饲料.     

壳聚糖对异育银鲫生长及非特异性免疫功能的影响

在异育银鲫配合饲料中按0.25%、0.5%、1.0%、2.0%的比例添加壳聚糖,连续投喂60d后,通过测定供试鱼的增重、血细胞的吞噬活性及血清中溶菌酶活性,比较了壳聚糖对异育银鲫促长和非特异性免疫功能的影响.结果表明,添加0.5%、1.0%、2.0%壳聚糖均能显著提高异育银鲫的特定生长率、吞噬细胞的吞噬活性和溶菌酶活性,但它们之间无显著性差异(P>0.05);以0.5%的添加量最为经济实用.     

微生态制剂对银鲫血清溶菌酶活性的影响

通过向水体施用一定量的微生态制剂，研究了银鲫血清溶菌酶活性的变化。结果表明，投喂微生态制剂后7d，实验组银鲫溶菌酶的活性极显著差异于投喂制剂前及对照组，在停止向水体施用微生态制剂后21d，血清溶菌酶的活性与对照组之间即无显著差异。     

中草药对鲤血清和免疫器官溶菌酶活性的影响

用添加刺五加、蒲公英、枸杞子、金银花和大蒜等单方中草药的配合饲料饲喂鲤(Cyprinus carpio L.),在开始饲喂后的第15d和第30d测定其血清和免疫器官(头肾、中肾、脾)的溶菌酶活性。结果显示,15d时,仅脾溶菌酶活性刺五加组和对照组有显著差异。30d时,血清溶菌酶活性蒲公英组、金银花组和大蒜组与对照组差异显著,头肾溶菌酶活性金银花组和对照组差异显著,中肾溶菌酶活性金银花组和大蒜组与对照组差异显著,脾溶菌酶活性所有试验组和对照组相比均有显著差异。     

中草药饲料添加剂对异育银鲫感染Ⅱ型鲤疱疹病毒的影响

分别用添加1%穿心莲、黄芪、板蓝根、大黄4种中草药的定制饲料投喂异育银鲫,而后腹腔注射1mL定量为1.08×10~7个/mL的Ⅱ型鲤疱疹病毒,研究这4种中草药对异育银鲫感染Ⅱ型鲤疱疹病毒的影响。人工感染后采用实时荧光定量PCR的方法测定血液中的Ⅱ型鲤疱疹病毒滴度。试验结果显示,对照攻毒组鱼体临床症状为胸腹部体表大面积充血,鳃部暗红出血,脾脏肿大、内脏出血等体征,为典型的Ⅱ型鲤疱疹病毒发病症状,且用PCR方法能检测出Ⅱ型鲤疱疹病毒基因组片段。投喂含穿心莲、板蓝根、黄芪、大黄的定制饲料,异育银鲫死亡率分别为15%、30%、35%、95%,对照组死亡率为100%。对照组血液中的病毒滴度高于穿心莲、板蓝根、黄芪,大黄与对照组病毒滴度差别较小。研究结果表明,大黄定制饲料抗Ⅱ型鲤疱疹病毒效果相对较差,黄芪与板蓝根抗病毒效果稍强,穿心莲具有较好的抗Ⅱ型鲤疱疹病毒效果,或可作为抗Ⅱ型鲤疱疹病毒的抗病毒饲料产品用于疾病防控。本研究结果为利用中草药药饵防治异育银鲫感染Ⅱ型鲤疱疹病毒提供了一定的理论依据。     

苏云金芽孢杆菌对黄河鲤血液免疫效果研究

研究了苏云金芽孢杆菌对黄河鲤血液免疫应答的影响.将苏云金芽孢杆菌按1.0×10~(11)、3.0×10~(11)、5.0×10~(11) cfu/kg 3个浓度添加在鱼用全价颗粒饲料中,投喂经嗜水气单胞菌疫苗免疫组(A_0～A_3)和未免疫组(B_0～B_3)黄河鲤,分别于0、15、30、40 d时检测各组黄河鲤白细胞吞噬活性、血清溶菌酶活性以及血清凝集抗体效价,并进行攻毒试验.结果表明:添加苏云金芽孢杆菌可使黄河鲤血液中白细胞吞噬活性和血清溶菌酶活性显著提高.添加组与对照组差异显著(P<0.05),添加浓度越高,血液白细胞活性和溶菌酶活性越强.免疫组与未免疫组白细胞吞噬活性差异不显著(P>0.05),而溶菌酶活性差异显著(P<0.05).在停止投喂后10 d,白细胞活性、血清溶菌酶活性逐渐下降,但差异不显著(P>0.05).添加苏云金芽孢杆菌还可提高黄河鲤的凝集抗体效价及攻毒后的存活率,其中,当菌株添加浓度为5.0×10~(11) cfu/kg时,受免疫的黄河鲤免疫保护率最高.即投喂苏云金芽孢杆菌对黄河鲤血液免疫应答有明显促进作用.     

氨氮对凡纳对虾免疫指标的影响

以凡纳对虾(Litopenaeus vannamei)为研究对象,研究氨氮对其免疫指标的影响。实验氨氮质量浓度梯度设置为0.05(对照)、0.5、1.0、1.5、2.0、2.5 mg／L,各氨氮梯度用4g／L的氯化铵溶液来调节。将暂养在自然海水(对照)中的凡纳对虾分别放入各实验梯度中,对虾体长为(8.5±0.5)cm。结果表明,氨氮对凡纳对虾血细胞数量、血清中的酚氧化酶活力、溶菌和抗菌活力的影响显著(F>F0.05),且随着氨氮质量浓度的升高,血细胞数量和溶菌、抗菌活力降低,酚氧化酶活力升高;在0-24 h实验时间内,各处理组(对照组除外)对虾血细胞数量和溶菌、抗菌活力呈下降趋势,酚氧化酶活力呈上升趋势,24 h后稳定在较低水平上。实验说明,随着氨氮水平升高,凡纳对虾免疫力明显下降,对病原菌的易感性提高,因此在养殖过程中,环境氨氮变化幅度不应超过0.5 mg／L,或长时间维持在较高氨氮水平(>0.5 mg／L)。     

Seminal plasma proteins of Atlantic halibut (Hippoglossus hippoglossus L.)

Protein content and properties in the seminal plasma of Atlantic halibut (Hippoglossus hippoglossus) were assayed using spectrophotometric and electrophoretic methods. The protein concentration ranged from 6.4 ± 3.1 to 19.4 ± 3.4 mg ml⁻¹ and anti-proteolytic activity from 585.2 ± 104.6 to 2912.4 ± 367.4 U l^−l. A high correlation between anti-proteolytic activity and protein concentration (r = 0.95), and between sperm concentration and osmolality was found (r = 0.92). There was a significant decrease in anti-proteolytic activity from the first to the second sampling, but not in protein concentration. Anti-proteolytic activity and protein concentration were significantly affected by variations in individual males. Electrophoresis revealed four anti-proteolytic bands and individual differences in bands of proteolytic activity, which were subsequently characterized as metalloproteases and serine proteases.     

不同海洋弧菌中5类溶血素基因的分布及其与溶血活性和磷脂酶活性的相关性

用57株海洋弧菌,包括26株弧菌标准菌株、20株哈维氏弧菌、11株副溶血弧菌(从不同宿主和不同地理环境中分离得到),用PCR法合成5类相应的地高辛标记的溶血素基因探针,利用其进行Southern Blot,检测这5类溶血素基因在57株弧菌中的分布。结果显示,在57海洋株弧菌中,含有TDH、HlyA、TLH、δ-VPH和HLX溶血素基因的菌株分别为2株、2株、49株、3株和30株。另外,1株霍氏格里蒙菌(Grimontia hollisae)和1株副溶血弧菌(V.parahaemolyticus)中分别含有2个TDH溶血素基因。用鱼血平板和卵磷脂平板检测57株弧菌的溶血活性和磷脂酶活性,结果表明,弧菌溶血活性和磷脂酶活性与TLH溶血素基因具有显著相关性,与另外4类溶血素基因的关系不明显。     

北极微生物的分离及抗菌抗肿瘤活性筛选

采用多种培养基对北极地区(海洋沉积物、湖泊沉积物及土壤)微生物进行分离,并采用琼脂平板打孔法和MTT法进行了抗菌、抗肿瘤活性菌株的筛选.共分离极地微生物151株,筛选结果显示,12.4%的菌株有抗菌活性,6.2%菌株有抗肿瘤活性,其中3株同时具有抗菌、抗肿瘤活性,表明极地有良好的微生物药用资源.     

蜈蚣藻多糖降血糖及降血脂活性的研究

本文通过建立四氧嘧啶高血糖小鼠模型和高脂饲料高血脂小鼠模型,进行摄入不同剂量的蜈蚣藻多糖的动物实验,以测定的小鼠空腹血糖值、大鼠血脂水平[胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL—C）、低密度脂蛋白胆固醇（LDL—C）]以及肝脏的生化指标值,探讨蜈蚣藻多糖的降血糖、降血脂活性效果。结果表明蜈蚣藻多糖能显著降低高血糖小鼠的空腹血糖值及高血脂小鼠的TC,TG,LDL—C含量,提高HDL—C含量。蜈蚣藻多糖具有降血糖、降血脂等功效。     

甲基盐霉素对鲤白细胞吞噬活性和溶菌酶活力的影响

选用60 g左右健康正常的鲤540尾,随机平均分为6组,每组设3个重复。试验设6种处理,即基础饲料中分别添加甲基盐霉素0(对照组)、10、20、40、80、160 mg/kg。研究了甲基盐霉素对鲤白细胞吞噬活性和溶菌酶活性的影响。试验结果表明,饲料中添加10 mg/kg甲基盐霉素对鲤白细胞吞噬活性和溶菌酶活性影响不显著,而添加20~160 mg/kg甲基盐霉素对鲤白细胞吞噬活性和溶菌酶活性有一个从促进到抑制的转变,剂量越高,这个转变越快,并且随饲喂时间的延长,其抑制作用越来越强。     

Interaction of grammistins with lipids and their antibacterial activity

ABSTRACT: Grammistins are hemolytic and ichthyotoxic peptides in the skin secretion of soapfishes and are structurally characterized by their abundance in amphiphilic α-helicity. In the present study, their interaction with lipids and lipid vesicles as well as antibacterial activity were examined using four grammistins (Gs 1 and Gs 2 from Grammistes sexlineatus and Pp 1 and Pp 3 from Pogonoperca punctata ). The hemolytic activity of grammistins was inhibited by phospholipids but not by cholesterol. Moreover, grammistins released carboxyfluorescein entrapped within liposomes made of phosphatidylcholine. In contrast, grammistins were found to have antibacterial activity with a broad spectrum against nine species of bacteria, including both Gram-negative and Gram-positive groups. The potency of their antibacterial activity was not related to that of hemolytic activity, suggesting that grammistins bind to membrane phospholipids but lyse erythrocyte and bacterial membranes via different mechanisms. Conclusively, grammistins are new members of the family of cell non-selective membrane-lytic peptides with amphiphilic α-helices, being similar to pardaxins, which are secreted from the skin of soles, and to melittin, which is derived from bee venom.     

Biological activities of synthetic grammistins and analogous peptides

Grammistins, peptide toxins isolated from the skin secretions of two species of soapfishes Grammistes sexlineatus and Pogonoperca punctata, are new members of the family of linear membrane-lytic antibacterial peptides characterized by the abundance of amphiphilic α-helices. As the first step toward future use of grammistins to examine the mode of membrane lysis and design new antibiotics, C-terminally free and amidated forms were chemically synthesized for each of five grammistins (Gs 1, Gs 2, Pp 1, Pp 2b and Pp 3), and evaluated for hemolytic and antibacterial activities. No difference in biological activities was observed between C-terminally free and amidated forms of Gs 1, while the C-terminally amidated forms of the other grammistins exhibited much higher activities than the C-terminally free forms. Comparison with the biological activities of natural grammistins, together with our preliminary cloning experiments, showed that natural grammistins, except for Gs 1, are C-terminally amidated. As for Pp 1, six analogous peptides were further synthesized. Determination of their biological activities revealed that the amphiphilic α-helical structure and positive charge are important for the hemolytic and antibacterial activities, respectively, of Pp 1.