左旋咪唑对鸡细胞免疫和体液免疫功能的作用

系统研究了左旋咪唑对鸡细胞免疫和体液免疫功能的作用。结果表明左旋咪唑可影响正常鸡的免疫功能 :左旋咪唑可显著促进鸡外周血T淋巴细胞增殖 ,但对B淋巴细胞无明显影响 :2 5～ 1 0mg/kg左旋咪唑可使CD+4/CD+8淋巴细胞比值明显升高 ;左旋咪唑可使鸡体内抗颗粒性、胸腺依赖性抗原SRBC抗体滴度 ,抗可溶性、胸腺依赖性抗原BSA抗体滴度和抗非胸腺依赖性抗原BA抗体滴度均明显升高 ;2 5～ 1 0mg/kg左旋咪唑可使鸡血清总补体活性明显升高。左旋咪唑影响正常鸡回忆性免疫应答反应 :左旋咪唑 ( 1 0mg/kg)可使二次免疫鸡抗SRBC抗体滴度和抗BA抗体滴度回忆性免疫应答反应明显升高 ;但使鸡对抗BSA抗体滴度回忆性免疫应答反应明显降低。     

西咪替丁对鸡回忆性体液免疫应答反应的作用

枯试验系统观察了西咪替丁对鸡回忆性体液免疫应答反应的作用，并与同类咪唑类化合物左旋咪只进行了比较，28日龄鸡，免疫注射绵羊红细胞＋牛血清白蛋白（SRBC＋BSA）悬液，或稀释的布氏杆菌（BA）抗原。56日龄时，以10．0、100．0mg/kg西咪替丁或10．0mg/kg左旋咪唑饮水给药，连用3天，给药第二天同时进行2次免疫注射。结果表明西咪替丁（10．0－100mg/kg)可使二次免疫鸡体内对颗粒性胸腺依赖性抗原SRBC和非胸腺依赖性抗原BA抗体滴度回忆性免疫应答反应明升高，但使鸡对可溶性胸腺依赖性抗原BSA抗体滴回忆性免疫应答反应明显降低。与西咪替丁比较，左旋咪唑（10．0mg/kg)也存在着非常类似的作用。     

甲哨唑对鸡细胞免疫和体液免疫功能的作用

本试验观察了甲硝唑对鸡细胞免疫和体液免疫功能的作用，并与左旋咪唑进行了比较。结果表明2．5－400mg/kg甲哨唑可显著促进鸡外周血T淋巴细胞增殖，但对B淋巴细胞无明显影响；可使CD4^ /CD8^ 淋巴细胞比值明显升高；可使鸡外周血淋巴细胞诱生IL－2活性明显增强；可使鸡体内抗颗粒性胸腺依赖性抗原SRBC抗体滴度、抗可溶性胸腺依赖性抗原BSA抗体滴度和抗非胸腺依赖性抗原BA抗体滴度明显升高；可使鸡血清总补体活性明显升高。与甲硝唑比较，左旋咪唑也存在着非常类似的作用，2．5－10mg/kg左旋咪唑可明显促进外周血T淋巴细胞增殖，可使CD4^ /CD8^ 淋巴细胞比值明显升高；可使鸡外周血淋巴细胞诱生IL－2活性明显增强；可使鸡体内抗SRBC抗体滴度、抗BSA抗体滴度和抗BA抗体滴度均明显升高；10mg/kg左旋咪唑甲硝唑可使血清补体总活性升高。上述结果表明甲硝唑和左旋咪唑两种咪唑类化合物在促进鸡细胞免疫和体液免疫可能存在着相似的作用机制。     

甲硝唑对地塞米松预处理鸡免疫功能的影响

对地塞米松预处理鸡投以10mg／kg剂量的甲硝唑，观察后者对前者作用的影响。结果表明：地塞米松明显抑制由伴刀豆球蛋白A(ConA)引起的鸡外周血淋巴细胞(PBL)产生IL-2活性，而甲硝唑对这种抑制作用有显著的拮抗作用；地塞米松能抑制鸡对绵羊红细胞(SRBC)悬液和牛血清白蛋白(BSA)两种胸腺依赖性抗原的免疫应答和对布鲁氏菌非胸腺依赖性抗原的抗体应答，但甲硝唑会逆转这种抑制作用；甲硝唑能封闭地塞米松对补体产生的抑制作用。对比实验结果同时表明，在拮抗地塞米松对鸡免疫功能负面影响方面，左旋咪唑与甲硝唑作用非常类似。     

左旋咪唑对地塞米松预处理鸡免疫功能的影响

系统观察了左旋咪唑对地塞米松预处理鸡免疫状态的作用.结果表明地塞米松明显抑制鸡免疫功能,抑制鸡外周血淋巴细胞IL-2活性,可使体内抗SRBC抗体滴度、抗BA抗体滴度、抗BSA抗体滴度、血清总补体活性(CH50)降低.10mg/kg左旋咪唑可拮抗地塞米松对鸡外周血淋巴细胞IL-2活性的抑制作用,可拮抗地塞米松对鸡体内抗SRBC抗体、抗BSA抗体和抗BA抗体产生的抑制,也可明显拮抗地塞米松对鸡体内补体产生的抑制作用,使地塞米松抑制免疫鸡外周血淋巴细胞IL-2活性、产生抗体和产生补体恢复至或超过正常鸡水平.     

左旋咪唑对地米塞松预处理鸡免疫功能的影响

系统观察了左旋咪唑对地塞米松预处理鸡免疫状态的作用。结果表明地塞米松明显抑制鸡免疫功能，抑制鸡外周血淋巴细胞IL－2活性，可使体内抗SRBC抗体滴度、抗BA抗体滴度、抗BSA抗体滴度、血清总补体活性（CH50）降低。10mg/kg左旋咪唑可拮抗地塞米松对鸡外周血淋巴细胞IL－2活性的抑制作用，可拮抗地塞米松对鸡体内抗SRBC抗体、抗BSA抗体和抗BA抗体产生的抑制，也可明显拮抗地塞米松对鸡体内补体产生的抑制作用，使地塞米松抑制免疫鸡外周血淋巴细胞IL－2活性、产生抗体和产生补体恢复至或超过正常鸡水平。     

几种化学合成类免疫增强剂在鸡病中的应用

1左旋咪唑左旋咪唑是具有免疫调节作用的人工合成化合物,具有广泛的免疫调节活性,可促进细胞和体液免疫。左旋咪唑能增强鸡体液免疫应答反应,使鸡抗胸腺依赖性抗原抗体滴度、抗非胸腺依赖性抗原抗体滴度均明显升高。     

免疫增强剂的研究应用（下）

5，化学合成类 左旋咪唑左旋咪唑是第一个被发现具有免疫调节作用的人工合成化合物，具有广泛的免疫调节活性，可促进细胞免疫和体液免疫，增强正常鸡体体液免疫应答反应，使鸡抗胸腺依赖性抗原抗体滴度、抗非胸腺依赖性抗原抗体滴度均明显升高。左旋咪唑对鸡新城疫疫苗、马立克疫苗和鸡传染性法氏囊疫苗均有免疫增强作用。     

西咪替丁对鸡新城疫疫苗免疫效果的影响

进行了两个实验:实验一观察药物对鸡ND疫苗初次免疫的影响,结果显示7日龄高母源抗体(9.36log2)雏鸡免疫ND活疫苗前用药,10mg/kg西咪替丁用药鸡免疫后7～14d、100mg/kg西咪替丁用药鸡免疫后7～28d,抗体滴度明显升高;10mg/kg左旋咪唑用药鸡免疫后7～21d,抗体滴度与未用药对照组无明显差别,但28d抗体滴度明显高于未用药对照组。免疫后用药,10mg/kg西咪替丁用药后7d,抗体滴度明显高于空白对照组;用药后14d,各用药组抗体滴度与空白对照组无明显差别;用药后21d,10、100mg/kg西咪替丁和10mg/kg左旋咪唑用药鸡抗体滴度均明显高于空白对照组。实验二观察药物对ND疫苗二次免疫的影响,结果显示10、100mg/kg西咪替丁用药ND疫苗二次免疫后7～28d,鸡血清抗NDV抗体滴度明显高于未用药对照组。10mg/kg左旋咪唑用药组,疫苗二次免疫后7～28d,抗体滴度也明显升高。     

西咪替丁对鸡新城疫疫苗免疫效果的影响

进行了两个实验：实验一观察药物对鸡ND疫苗初次免疫的影响，结果显示7日龄高母源抗体（9.36log2)雏鸡免疫ND活疫苗前用药，10mg/kg西咪替丁用药鸡免疫后7－14d,100mg/kg西咪替丁用药鸡免疫后7－28d，抗体滴度明显升高；10mg/kg左旋咪唑用药鸡免疫后7－21d，抗体滴度与未用药对照组无明显差别，但28d抗体滴度明显高于未用药对照组。免疫后用药，10mg/kg西咪替丁用药后7d，抗体滴度明显高于空白对照组；用药后14d，各用药组抗体滴度与空白对照组无明显差别；用药后21d,10,100mg/kg西咪替丁和10mg/kg左旋咪唑用药鸡抗体滴度均明显高于空白对照组。实验二观察药物对ND疫苗二次免疫的影响，结果显示10，100mg/kg西咪替丁用药ND疫苗二次免疫后7－28d，鸡血清抗NDV抗体滴度明显高于未用药对照组。10mg/kg左旋咪唑用药组，疫苗二次免疫后7－28d，抗体滴度也明显升高。     

Interference with the humoral immune response in diverse genetic lines of chickens. II. The effect of colloidal carbon

Two experiments were conducted to study the difference in humoral immune responses between lines of chickens selected for high (H) or low (L) antibody production to sheep red blood cells (SRBC). Prior to i.v. immunization with SRBC or Brucella abortus (BA), chicks of both lines were injected with either 2, 3 or 4 ml carbon suspension (59 mg carbon/ml) per kg body weight; controls were not injected. In both the H and L line, a higher dose of carbon showed a more progressive depression of the total antibody titer to SRBC during the initial stage of the primary response. The 2ME-resistant antibody titers to SRBC showed the same tendency during the latter phase of the primary response. However, chicks treated with 3 ml carbon had lower 2ME-resistant antibody titers than any other group. Following i.m. reimmunization with SRBC, the previous treatment with carbon doses enhanced total antibody titers throughout the secondary response, when compared to the controls. The 3 ml carbon-treated chicks had the highest total anti-SRBC titers in the secondary response. The secondary 2ME-resistant anti-SRBC titers were not affected by the carbon doses. Carbon treatment did not affect the antibody titers to BA. No differences between the H and L line were found in the effects of carbon on the humoral immune responses to SRBC or BA.     

Quantification of percutaneous absorption of metronidazole and levamisole in the fire-bellied toad (Bombina orientalis)

Spot-on application has proved to be an effective way to reach therapeutic doses of metronidazole and levamisole in fire-bellied toads. The percutaneous absorption of metronidazole and levamisole was quantified, using an aqueous solution of 1.008 mg/ml of metronidazole and an aqueous solution of 3.767 mg/ml of levamisole. High Performance Liquid Chromatography (HPLC) analysis of the percutaneous absorption revealed that of the amount applied, 75% of metronidazole and 90% of levamisole was absorbed. This resulted during 3 days of application in dosages of 23 mg/kg BW of metronidazole and 94 mg/kg BW of levamisole. Of the absorbed substances, 48% of metronidazole and 9% of levamisole were excreted in urine and faeces as unmetabolised substances.     

Effect of higher levels of dietary selenium on production performance and immune responses in growing Japanese quail

1. The effect of increasing dietary selenium (Se) on production performance and immune responses in growing (0 to 6 weeks) Japanese quail was investigated. 2. One-day-old chicks (240) were randomly selected and divided into 12 groups with 20 chicks in each group (3 dietary treatments x 4 replicates). The basal diet contained 0.2 mg Se/kg and the two experimental diets were supplemented with 0.5 and 1.0 mg Se/kg. 3. Body weight gain, food intake and food conversion ratio and mortality were not affected by Se supplementation. 4. On d 28, antibody responses to inoculated sheep red blood cells were determined. Antibody titres were significantly higher after feeding the two Se-supplemented diets. 5. During week 4, the response to intradermally injected phytohaemagglutinin, an index of the in vivo cell-mediated immune response, was shown to be increased in the groups fed on the Se-supplemented diets. 6. After 6 weeks, the relative weights of the bursa of Fabricius and thymus were greater in the chicks given the Se-supplemented diets but there was no effect on the relative weight of spleen and liver. 7. It is concluded that supplementing the diet with Se has a beneficial effect on immune responses but does not affect production performance in growing Japanese quail.     

Effects of dietary supplements of selenium, vitamin E or combinations of the two on antibody responses of broilers

1. The effects of selenium and vitamin E supplementation on some immune parameters were investigated in broilers. 2. Broiler chicks were fed on maize-soybean diets with different concentrations of vitamin E (0-200 mg/kg) and selenium (0-0.2 mg/kg diet) either alone or in combinations from 1 to 42 d of age. 3. Chicks were immunised against Newcastle disease virus (NDV) vaccine at 21 d of age and haemagglutination inhibition (HI) titres were determined after 10 d. 4. Chicks receiving supplements of 200 mg vitamin E/kg and 0.2 mg selenium/kg produced significantly higher HI antibody titres. This was associated with an increased serum concentration of total immunoglobulins and circulatory immune complexes. 5. The chicks given 200 mg vitamin E/kg and 0.2 mg selenium/kg had significantly heavier spleen and bursa. 6. These results suggested that vitamin E and selenium have synergistic effects on immune responses.     

Transient enhancement of the serum antibody response to Brucella abortus strain 19 in cattle treated with levamisole

Two experiments were done on 57 steers. These cattle were allotted to 8 groups (4 groups/experiment) and vaccinated with 1 to 3 X 10(9) colony-forming units of Brucella abortus strain 19. Cattle in 3 of the 4 groups/experiment were given 6 mg of levamisole/kg, subcutaneously, either at the time of vaccination (day 0), 7 days later, or at both times. Serum antibody titers to B abortus were measured sequentially for 28 days in experiment 1 and for 56 days in experiment 2, using the card test, Rivanol test, complement-fixation test, fluorometric immunoassay, and an enzyme-linked immunosorbent assay. In general, the highest mean antibody titers, as determined by all serologic tests, occurred in steers treated with levamisole at 7 days after vaccination or in those treated at the time of vaccination and 7 days later. By the card test on day 56, there was a significantly (P less than 0.05) greater number of seropositive cattle among those given levamisole 7 days after seropositive cattle among those given strain 19 alone. Simultaneous administration of strain 19 and levamisole did not alter antibody responses to B abortus.     

Effect of supplementation of vitamin E, selenium and their different combinations on the performance and immune response of broilers

1. The effect of dietary vitamin E, selenium (Se) and their different combinations on body weight gain, food consumption, food conversion efficiency, leukocyte migration inhibition and antibody production was determined in broilers. 2. Chicks were fed on maize-soya bean based diets with concentrations of supplemental vitamin E varying from 0 to 300 IU/kg and selenium concentrations varying from 0 to 1 mg/kg either alone or in combination from 1 to 42 d of age. 3. The chicks were immunised for Newcastle Disease Virus (NDV) vaccine at 21 d. Per cent leukocyte migration inhibition (LMI) was studied on 42 d. Antibodies to NDV in serum were determined at 10 and 21 d post immunisation (PI). 4. Chicks receiving Se, 1 mg/kg and vitamin E 300 IU/kg had significantly higher cellular immune responses in terms of per cent LMI. 5. Maximum body weight gain and best efficiency of food utilisation were obtained in chicks fed diets containing 0.50 mg/kg Se and 300 IU/kg vitamin E. 6. Significantly higher antibody titres (HI and ELISA) at 10 d PI were attributed to 0.06 mg/kg and 150 IU/kg Se and vitamin E, respectively. 7. These data suggest that optimum growth and immune response may be achieved at supplemental level of Se of 0.06 mg/kg and vitamin E at 150 IU/kg. The vitamin E level is higher than that recommended by NRC (1984, 1994).     

Zinc, copper and iron utilisation by chicks fed various concentrations of zinc

1. Zinc, iron and copper interactions were examined in chicks (New Hampshire X Single Comb White Leghorn) grown individually in stainless steel cages and fed on purified diets with three concentrations of zinc: control (37 mg Zn/kg), moderate (100 mg Zn/kg) and excess (2000 mg Zn/kg) in three studies. 2. Chicks given either moderate or excess zinc excreted more than twice as much 65Zn from a test diet as those fed on the control diet. Thus chicks given the moderate amount of zinc had concentrations of zinc in tissues similar to those of controls but chicks given excess zinc accumulated zinc in their tissues. 3. The specific activity of 65Zn in the tissues, especially in the bursa of Fabricius, of chicks given excess zinc was not reduced as much as would be predicted. Thus, ingestion of excess zinc appeared to reduce tissue turnover of 65Zn, especially in the bursa. However, humoral immune responses, as measured by antibody titres to sheep red blood cells, were not affected. 4. Chicks given excess zinc or pair-fed on the control diet retained less 59Fe from a test diet than chicks given control or moderate concentrations of zinc ad libitum. The iron concentrations in tibiae of chicks given excess zinc were depressed.     

Immunostimulatory effects of the muramyl dipeptide analogue LK415 in chickens immunized with a vaccine strain of infectious bursal disease virus

The effects of muramyl dipeptide (MDP) synthetic analogue LK415 on the immune response of chickens immunized with a live vaccine against infectious bursal disease (IBD) were studied in two independent trials, using levamisole hydrochloride as comparative immunostimulant. Groups of five-week-old commercial chickens (Isa Brown) were immunized orally with 10 doses of the vaccine strain of IBDV (Winterfield strain). The chickens were then given four injections of the MDP analogue LK415 in a dosage of either 0.25 mg/kg body weight (b.w.) or 2.5 mg/kg b.w. or levamisole at a daily dose of 15 mg/kg b.w. for four consecutive days, starting from the day of immunization. Histological examinations of bursal tissue collected on days 2, 4 and 7 postimmunization (p.i.) showed a lower degree of destruction of bursal follicles and earlier renewal of bursal tissue in LK415-treated chickens compared to levamisole-treated and untreated immunized groups. Compared to the other groups, the LK415-treated chickens showed a significantly higher antibody response to IBDV on days 14 and 28 p.i. (P < 0.01) as measured by commercial ELISA. The present study indicates some potent immunostimulatory effects of the MDP analogue LK415 on the chicken immune system.     

桦木酸对小鼠免疫器官抗氧化能力的影响

本试验旨在研究桦木酸(BA)对小鼠免疫器官抗氧化能力的影响.选取健康的昆明系小鼠28只,随机分为4组(每组7只),每天每只分别按每千克体重0、0.25、0.50、1.00 mg的剂量给予BA,BA混悬于0.2 mL1％可溶性淀粉溶液中.以灌胃方式给予,每天灌胃1次,连续灌胃14 d后,检测各组小鼠脾脏和胸腺中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GHS-Px)活性,丙二醛(MDA)含量以及总抗氧化能力(T-AOC).结果表明:BA可使小鼠脾脏和胸腺中SOD、GSH-Px活性以及T-AOC升高,MDA含量降低.其中,每千克体重灌胃0.50 mg BA能显著或极显著提高脾脏和胸腺中GSH-Px活性和T-AOC(P＜0.05或P＜0.01),显著或极显著降低胸腺和脾脏中MDA含量(P＜0.05或P＜0.01);每千克体重灌胃1.00 mg BA能显著或极显著提高脾脏和胸腺中SOD活性、T-AOC以及脾脏中GSH-Px活性(P＜0.05或P＜0.01),极显著降低胸腺和脾脏中MDA含量(P＜0.01).由此得出,BA能有效地增强小鼠免疫器官的抗氧化能力.