有机硒对种公牛精子活力、免疫力和血液生化指标的影响

试验选用5头成年种公牛作试验牛，采用分期试验，试验前期饲喂基础日粮，试验中期和后期添加一定量的有机硒，试验期采集种公牛的精液进行精子活力的检测，并分别采取血样进行血常规检测和免疫球蛋白G（IgG）的测定.试验结果表明：在种公牛日粮中添加一定量的有机硒能显著提高种公牛的精子活力和免疫力（P〈0.05），但对血常规主要指标无显著的影响。     

Effects of antibiotic treatment on the inflammatory mediator expression in peritoneum and the peritoneal transport function in the rat with acute bacterial peritonitis

AIM: To observe the effect of antibiotic treatment on the inflammatory mediator expression in peritoneum and the peritoneal transport function in rats with acute peritonitis, and explore its mechanisms. METHODS: Eighty-six SD rats were randomly divided into three groups. Control group (n=28) were treated with PBS (ip), peritonitis group (n=28) and treatment group (n=28) were challenged with the E.coli (ip), but at 3 h and 9 h gentamicin was given (ip) in treatment group. Seven rats of every group were randomly sacrificed at 24 h, 48 h, 72 h and 7 d. Peritoneal equilibration test (PET) was did before they were killed. Leukocyte count, pathological changes and the expression of CD45, NF-κB， IL-1β， TNF-α in peritoneum were examined. RESULTS: (1)The blood leukocytes in peritonitis group decreased strikingly, but did not change obviously in other two groups. The peritoneal fluid leukocytes in peritonitis group increased significantly from 24 h to 72 h, while in treatment group, it enhanced more strikingly than peritonitis group at 24 h, and recovered earlier. (2) Both in peritonitis group and treatment group, the expression of activated NF-κB, IL-1β, TNF-α and CD45 increased significantly, but the treatment group was lower than model group at 48 h and 72 h. The mRNA level of IL-1β and TNF-α had the same trend as their protein expression. (3) Compared with the control group, UF and D/D0 Glu decreased significantly in model group and treatment group, and D/PTP increased dramatically. The D/P TP in treatment group lowered obviously compared with peritonitis group, while the net UF and D/D0 Glu had not significant difference between treatment group and model group. CONCLUSION: Antibiotic treatment can partly decrease the expression of inflammatory mediators in peritoneum of rats with acute peritonitis and also can improve the protein transport ability to some extent, but can not improve the peritoneal ultrafiltration and the glucose transport function.     

1999年四川省小麦条锈病大流行原因分析及治理对策

11999年小麦条锈病流行特点　　1)见病早，侵染时间长。秋苗上病害始见期早于常年，一般提早10d到3个月。　　2)扩散蔓延速度快。1月4日统计全省发病面积为3.0万hm2，到1月底即发展到6.7万hm2。3月3日达16.7万hm2，3月底增至38万hm2，4月23日为58.5万hm2。其扩散蔓延速度之快实属历史罕见。　　3)病害垂直扩散迅速，病情严重。乐至县3月初调查，病田率为64.3％，病株率平均11.9％，病叶率平均3.85％，分别较1周前上升2.0倍、20.0倍、24.7倍。3月23日调查，病株率又上升1.6倍，病叶率上升3.6倍，平均严重程度达21.8％。　　4)流行区域大，所…     

美国优良牧草引种及其利用初探

本文论述从美国俄勒岗淋巴恩布莱格公司引进３６个优良牧草品种，并在福建省上杭县试种筛选的过程。探索在本地区栽培管理这批优良牧草技术及预测在我国南方利用发展前景。     

Protective effects of oral microencapsulated Mycoplasma hyopneumoniae vaccine prepared by co-spray drying method

The efficacy of Mycoplasma hyopneumoniae oral vaccine was investigated in microsphere dosage form. A co-spray drying process was used to apply an encapsulating material, Eudragit L30 D-55, to microspheres containing Mycoplasma hyopneumoniae antigens. The microspheres were generally effective (>93%) with protein release at pH 7.4, but almost none were released at pH 1.2, for 3 hr in an in vitro dissolution test. An SPF-swine model was used to evaluate the effectiveness of the microspheres as an oral vaccine, and the related immune responses. The serum's systemic IgG against M. hyopneumoniae was evoked by ELISA analysis, after a 2nd immunization of all pigs. The vaccinated groups' mean lesion score was significantly lower after the Mycoplasma hyopneumoniae challenge than that of the nonvaccinated/challenged groups (P<0.05). This study strongly suggests that the oral microspheres vaccine prepared by a co-spray drying method can provide effective protection against M. hyopneumoniae infection in pigs.     

Oral immunization using formalin-inactivated Actinobacillus pleuropneumoniae antigens entrapped in microspheres with aqueous dispersion polymers prepared using a co-spray drying process

Oral-vaccine microspheres based on formalin-inactivated Actinobacillus pleuropneumoniae serotype 1 (AP-1) antigens and enteric-coated polymers were prepared using a co-spray drying process. We evaluated using this for a peroral vaccine. We measured specific-antibody titers and protection from challenge in mouse and pig models. In mice (24 per group), a subcutaneous aluminum-adjuvant vaccine or oral vaccination with three doses of AQ6-AP microspheres provided similar protection against intranasal challenge with 5 x 10(8) colony-formation units (cfu) of AP-1 bacterial culture broth. Two weeks after four oral vaccinations with 600 mg of AQ6-AP microsphere acetate solution (containing formalin-inactivated AP-1 antigens of 1.0 x 10(10) cfu bacterial broth), pigs (9 per group) were challenged intranasally with 1 ml of AP-1 bacterial culture broth (5 x 10(9) cfu). The clinical signs, percentage of pig survival ratio, lung lesion areas, and microscopic examinations indicated that the oral AQ6-AP vaccine provided more protection than vaccinating pigs intramuscularly with AP-1 aluminum vaccine.     

In vivo and in vitro comparisons of spray-drying and solvent- evaporation preparation of microencapsulated Mycoplasma hyopneumoniae for use as an orally administered vaccine for pigs

OBJECTIVE: To evaluate the efficacy of an orally administered vaccine of Mycoplasma hyopneumoniae that was prepared by spray drying or solvent evaporation. ANIMALS: Thirty 6-week-old, crossbred, specific-pathogen-free (SPF) pigs. PROCEDURE: Pigs were randomly allocated into 5 groups and housed in an SPF facility. Pigs in 2 groups (groups AQ and CAP) were fed M hyopneumoniae enteric-coated vaccine on days 0, 10, and 20. A third group (group IM) received an IM injection of M hyopneumoniae vaccine with aluminium hydroxide as an adjuvant on days 0, 10, and 20. The last 2 groups (non-vaccinated-challenged [NV-C] and nonchallenged [NC]) were fed a sham treatment. All 24 pigs in groups AQ, CAFP IM, and NV-C were challenge exposed with 5 ml of a 10% pneumonic lung suspension administered on day 40 via intubation of the trachea. All pigs were slaughtered and the lungs removed and examined for lesions on day 68. RESULTS: In vitro studies indicated that these 2 microencapsulation techniques formed an effective shell and protected mycoplasmal antigen from gastric acid. Results of inoculation and challenge tests indicated that microencapsulated M hyopneumoniae were sufficiently potent to induce an immune response and provide good protection. CONCLUSIONS AND CLINICAL RELEVANCE: Orally administered microencapsulated M hyopneumoniae vaccines induced an immune response and reduced the severity of lung lesions in challenge-exposed pigs. Results suggest that this novel method can be applied to other antigens, because the spray-drying process yielded an orally administered M hyopneumoniae vaccine that induced a good immune response.     

Effect of tumor infiltrating lymphocytes on the expression of MHC molecules in canine transmissible venereal tumor cells

Canine transmissible venereal tumor (CTVT) can be allo-transplanted across major histocompatibility complex barriers. The expression of MHC molecules is usually low in the progression (P) stage and then greatly increases during tumor regression (R). We investigated the effects of tumor infiltrating lymphocytes (TIL) on the expression of MHC molecules of CTVT cells. Isolated, viable CTVT cells were inoculated at each of 12 sites (1 x 10(8) CTVT cells per site) on the back of six, mixed-breed dogs. Tumor masses were collected every 2-3 weeks and prepared for histopathologic, immunocytochemistry, flow cytometry and immunoblotting studies. The level of MHC expression on tumor cells from different stages of growth was measured. Initially, expression of MHC I and II molecules in P phase CTVT was low. Twelve weeks post-inoculation (PI), expression increased dramatically and it continued to increase during R phase. Tumor growth slowed after 12 weeks PI and tumors entered R phase around 17 weeks PI. We hypothesize that CTVT evades host immunosurveillance and grows progressively for 12 weeks, when it becomes vulnerable and subject to the host's anti-tumor immune responses. We further demonstrated that R phase, but not P phase, TIL were closely associated with the over-expression of MHC I and II molecules by CTVT cells. The number and proportion of TIL were higher in R phase tumors. Supernatants, from R phase co-cultures (CTVT+TIL) and TIL only, promoted MHC I and II expression on P phase CTVT cells. After culturing alone for 1 month, expression of MHC classes I and II molecules in R phase CTVT cells decreased to the level of P phase CTVT cells. However, the above-mentioned supernatants restored their expression of MHC I and II molecules. In contrast, supernatants from P phase TIL or CTVT cells increased expression slightly or had no effect. Therefore, TIL, not CTVT cells, produce the effective substance (s) to promote the expression of MHC molecules by the tumor cells. Heat treated supernatant was unable to promote the expression of MHC I and II molecules by CTVT cells. In conclusion, TIL isolated from R phase CTVT secreted a heat-sensitive, soluble substance(s) that triggered over-expression of MHC I and II after 12 weeks PI. This caused the tumor to enter R phase and helped stop CTVT growth. Our findings will facilitate the understanding and further investigation of the mechanisms that initiate host immune surveillance against tumors.     

Individual and combined antioxidant effects of seven phenolic agents in human erythrocyte membrane ghosts and phosphatidylcholine liposome systems: importance of the partition coefficient

Antioxidant activities of seven phenolic agents against Fe(2+)-induced lipid oxidation were compared with alpha-tocopherol, beta-carotene, and vitamin C in human erythrocyte membrane ghosts and liposome systems. The antioxidant activity of five test flavonoids followed the order catechin > epicatechin > rutin > quercetin > myricetin in both systems (p < 0.05), which was negatively correlated with their partition coefficients. The antioxidant interaction of these phenolic agents with alpha-tocopherol, beta-carotene, or vitamin C in inhibiting Fe(2+)-induced lipid oxidation was examined. Synergistic effects were present in the combinations of alpha-tocopherol plus caffeic acid, catechin, or epicatechin as well as in all combinations of vitamin C plus phenolic antioxidants. On the basis of the stronger individual and combined effects present in caffeic acid, catechin, and epicatechin, the application of these three phenolic agents with or without alpha-tocopherol, beta-carotene, and vitamin C may provide stronger protective benefits against lipid oxidation, which may be helpful for oxidation-related diseases prevention.