4种因素对NK细胞杀伤活性的影响

为了探讨效应细胞与靶细胞的比例(效靶比)、孵育时间、显色时间以及小牛血清浓度对NK细胞杀伤活性的影响,采用乳酸脱氢酶释放法来测定不同因素对NK细胞杀伤活性的影响,结果表明,最佳效靶比和孵育时间分别为50∶1和2 h。在最优效靶比及孵育时间的基础上,显色0.5 h,小牛血清浓度为50 mL/L时NK细胞活性最高,证明4种因素对NK细胞杀伤活性均有不同程序的影响。     

MTT法检测鸡脾脏和外周血NK细胞杀伤活性的条件优化

选取不同日龄的SPF鸡和肉鸡,用贴壁法从血液和脾脏分离出NK细胞作为效应细胞,选择瘤细胞MDCC-MSB1和MDCC-MSBCU147分别作为靶细胞,二者按比例混合,孵育,利用MTT法检测靶细胞的活力反映效应细胞对靶细胞的杀伤活性,并对效靶比、作用时间进行比较.结果显示,MSB-1和CU147均可作为NK细胞良好的靶细胞,但CU147更稳定;效靶比为20:1～50:1,作用时间8～16 h杀伤效果稳定;50%DMF-20%SDS混合物作为裂解液能够对结晶彻底溶解,优于其他溶解试剂.     

应用CCK8法检测鸡淋巴细胞活性的检测最佳条件研究

为了研究应用CCK-8法检测鸡淋巴细胞增殖的体外培养最佳条件,试验设置了不同种板细胞数、血清浓度、培养时间、孵育时间和检测波长等条件对其进行比较研究。结果表明:1 750 r/min转速的改良鸡外周血淋巴细胞分离方法效果最佳;在体外增殖培养试验中,CCK-8加样4 h后在450 nm波长处检测OD值最理想,培养时间以44 h为最佳;在细胞数量一致的情况下,胎牛血清浓度为5%或者为10%差异不显著(P0.05)。当细胞悬液浓度为1×10~6个/m L时,加入100,50,25,12.5μL不同细胞数,4组间比较均差异显著(P0.05),并且随着细胞悬液浓度的增加OD值增加;最佳铺板细胞的细胞悬液浓度为2.0×10~6~3.0×10~6个/m L,取50~100μL为宜,即最佳细胞铺板数量控制在每孔1.5×10~5~2.0×10~5个/100μL。说明应用CCK-8法检测鸡外周血淋巴细胞活性的最佳条件除种板细胞数不同外,在检测波长、血清浓度、加样后孵化时间等方面与其他动物试验差别不大。     

CD58与山羊早孕因子之间关系的研究

应用猪淋巴细胞Ea花环抑制试验 ,建立了山羊EPF测定的方法 ,检测了山羊妊娠早期血清中EPF的活性并对EPF与CD5 8的活性关系进行了研究。结果证明 :猪淋巴细胞Ea花环抑制试验可应用于山羊EPF活性的测定 ;妊娠早期 ( 1～ 2ld)山羊血清中存在EPF活性 ,第 1,8d有活性峰值 (RIT值分别为 18 8± 1 1,2 1 2± 1 8) ,其余时间EPF活性相对稳定 ,呈现一定规律性变化 ;CD5 8( 1∶10 0 )孵育淋巴细胞后 ,RIT值显著高于HBSS液对照组(P <0 0 5 ) ,CD5 8( 1∶2 ,1∶10 )孵育淋巴细胞后 ,RIT值极显著高于HBSS液对照 (P <0 0 1) ,认为CD5 8活性可以用Ea花环抑制试验进行测定并具有与EPF协同抗淋巴细胞血清使RIT值升高作用相似的功能 ;妊娠山羊血清经CD5 8,CD2 ,HBSS液等处理后孵育淋巴细胞 ,经CD5 8处理组RIT值极显著高于HBSS液处理组 (P <0 0 1) ,经CD2处理组RIT值极显著低于HBSS液处理组 (P <0 0 1)而与HBSS液对照组差异不显著 (P >0 0 5 ) ,表明CD5 8与EPF可共同协同抗淋巴细胞血清抑制Ea花环形成 ,CD2对EPF有一定程度的封闭作用。进一步认为CD5 8与EPF具有一定程度的抗原交叉性。     

维持液pH值、血清对犬瘟热病毒和犬细小病毒TCID50检测的影响

在进行犬瘟热病毒(CDV)、犬细小病毒(CPV)的TCID₅₀检测时,采用不同pH值维持液(pH值7.0和7.4)及血清含量(0和2%),于37℃、含5%二氧化碳的培养箱中培养5 d之后判定结果,分析维持液pH值和血清含量对检测结果的影响。结果表明,pH值7.0和pH值7.4的维持液对CDV和CPV检测结果无明显影响。不同血清含量维持液对检测结果有一定影响,其中,对CDV的TCID₅₀检测,含2%血清的维持液的检测结果高于无血清的,检测时应使用含2%血清的维持液进行检测;对CPV的TCID₅₀检测,含2%血清的维持液和无血清维持液的检测结果完全一致,表明检测时两种血清含量的维持液皆可使用。     

间接免疫荧光染色检测石蜡切片中的鸭病毒性肠炎病毒和抗原定位

差速离心和蔗糖密度梯度离心纯化鸭病毒性肠炎病毒(DEV)免疫兔制备兔抗DEV高免血清后,用DEAE-Sephadex A-50柱层析纯化的兔抗DEVIgG建立了间接免疫荧光染色法(IFA)检测石蜡切片中DEV的方法。IFA的最佳条件为:石蜡切片用10mmol/L pH6.0的柠檬酸缓冲液为微波修复液微波修复10min,胰酶修复20min;10%小牛血清室温封闭30min;加入1∶25的兔抗DEVIgG于4℃孵育过夜;再加入FITC标记的羊抗兔IgG于37℃孵育45min。以建立的IFA对DEV人工皮下感染死亡鸭的各组织器官进行检测,在死亡鸭的脾脏、胸腺、法氏囊、肝脏、食道、十二指肠、直肠及肺脏中检测到DEV抗原。研究表明,IFA检测石蜡切片中的DEV具有直观、特异性强的优点,是对DEV进行检测和抗原定位的良好方法。     

8％残杀威可湿性粉剂对美国白蛾的防效试验

施用8％残杀威可湿性粉剂进行第2代美国白蛾4～5龄幼虫防效试验,结果表明：药后7d,8％残杀威可湿性粉剂2000倍液防效最优,达100％;依次是3 000倍液防效为99.76％,4 000倍液防效为95.91％,5 000倍液防效为75.82％,6 000倍液防效为59.93％,随着浓度的降低防效逐渐递减,其中2 000倍液防效与3 000倍液防效差异不显著,与4 000倍液防效差异显著,与5 000倍液、6 000倍液防效差异极显著;故建议蚕农如单独防治美国白蛾,推荐使用浓度以3000～4000倍液为宜.     

鸭疫里默氏杆菌外膜蛋白A原核表达及间接ELISA方法的建立和初步应用

为建立鸭疫里默氏杆菌(Riemerella anatipestifer,RA)间接酶联免疫吸附试验(ELISA)方法,以RA贵州分离株RAG06基因组为模板扩增并克隆鸭疫里默氏杆菌OmpA基因,构建pET32a-OmpA重组原核表达质粒,转化大肠杆菌BL21(DE3)感受态细胞,重组菌经诱导、超声、纯化后,通过SDS-PAGE和Western blotting分析鉴定获得OmpA重组蛋白大小约57 KD;以OmpA重组蛋白为包被抗原初步建立ELISA方法并优化,经多次方阵检测结果显示,OmpA蛋白以2.243 mg/mL的浓度进行包被,血清以1∶100稀释,抗原包被条件为4℃过夜、封闭条件为37℃120 min、血清反应时间为37℃60 min、酶标抗体工作浓度为1∶1000、酶标抗体反应时间为37℃60 min、显色时间为15 min为最佳条件。确定临界值为0.389。特异性试验表明RA阳性血清有较好反应外,其他血清均无明显反应。批内变异系数2.77%～8.00%,批间变异系数为1.10%～7.80%。当阳性血清稀释比例为1∶1600时,仍可判断为阳性,敏感性较高。应用该方法检测贵州...     

复方健脾散对肉牛生产性能和消化酶活性及抗氧化功能的影响

选用7月龄,190kg“利鲁”杂交一代小牛18头,平均分为3组,分别在小牛日粮中添加0％（对照组）、2％（试验1组）和4％（试验2纽）的复方健牌散添加剂饲喂至10月龄屠宰,其中,试验2组的日粮中不含有常规微量元素添加剂。通过本试验,研究复方健脾散对小牛的促生长作用;对小牛胃肠道非蛋白酶（瘤胃纤维素酶、胰脂肪酶、胰淀粉酶）和蛋白酶（胃蛋白酶,胰蛋白酶,胰凝乳蛋白酶）活性的影响;对肉牛血清中丙二醛（MDA）含量、谷胱甘肽过氧化物酶（GSH—Px）和总超氧化物歧化酶（T—SOD）活性的影响。结果表明,饲喂复方健脾散对小牛的促生长不显著（P〉0．05）;可以显著提高小牛十二指肠的胰脂肪酶、胰蛋白酶和胃蛋白酶的活性（P〈0．05）,但对瘤胃纤维素酶、胰淀粉酶、胰凝乳蛋白酶的活性影响不显著（P〉0．05）;2％复方健脾散添加水平可显著降低肉牛血清中MDA含量和显著提高T—SOD活力（P〈0．05）;但4％复方健脾散添加水平明显提高GSH—Px活力（P〈0．05）。     

40%灭多威乳油对美国白蛾的防效试验

通过40%灭多威乳油对第2代美国白蛾4～5龄幼虫防效试验表明:药后7d,40%灭多威乳油3 000倍液防效最优,达100%;依次是4 000倍液防效为97.26%,5 000倍液防效为95.96%,6 000倍液防效为776.32%,随着浓度的降低防效逐渐递减,其中3 000倍液与4 000倍液、5 000倍液、6 000倍液防效差异极显著,4 000倍液与5 000倍液防效差异显著,与6 000倍液防效差异极显著;故建议蚕农如单独防治美国白蛾,推广使用浓度以4 000～5 000倍液为宜。     

Bovine natural cell mediated cytotoxicity (NCMC): activation by cytokines

Incubation of bovine peripheral blood mononuclear leukocytes (PBML) with the cytokines (CK) IL-2, alpha-IFN, gamma-IFN or IL-4 resulted in significant increases in natural cell mediated cytotoxicity (NCMC) over endogenous levels, as determined in an 18 h 51Cr-release assay using the human K562 or mouse Yac-1 target cell lines. Endogenous cytotoxic activity of bovine natural effector cells (NEC) using K562 or Yac-1 target cells was minimal (killing less than 8%). After 18 h of incubation with the CK hurIL-2, alpha-bovrIFN, gamma-bovrIFN or hurIL-4, NEC had significant increases in cytotoxic activity for both K562 and Yac-1 target cells. Significant increases in cytotoxic activity were not found after incubation of NEC with IL-1 or beta-IFN. Specific killing varied with CK concentration in a dose dependent manner and was proportional to effector:target cell ratio. Activation of the bovine NEC by CK was rapid, occurring within 6-12 h of incubation with alpha-IFN or gamma-IFN and within 12-18 h of incubation with IL-2. Incubation of bovine PBML with IL-2 and alpha- or gamma-IFN or with alpha-IFN and gamma-IFN showed that these CK do not act in a synergistic manner to increase NCMC in the bovine NEC.     

Existence of cytotoxic activity against BLV-transformed cells in lymphocytes from normal cattle and sheep

Peripheral blood lymphocytes (PBL) from normal cattle and sheep were tested for their cytotoxic activity against several target cells using a 20-hour 51Cr release assay. The following characteristics of the effector cells were observed; 1) PBL from animals showed cytotoxic activity against two sheep cell lines (FLK and SF-28) that were transformed with bovine leukemia virus. However, normal sheep and bovine cells and Molony leukemia virus-induced mouse lymphoma cell line (YAC-1) were not killed by these cells. 2) A time course study showed that the activity was first observed at 4 to 8 hours and reached a maximum at 20 to 30 hours after incubation. 3) Cytotoxic activity was observed in both adherent and nonadherent cell fractions when PBL were passed through a nylon-wool column. This indicated that the effector cells showed some degree of adherence. 4) Treatment of PBL with carrageenan did not change the cytotoxic activity against target cells, indicating that phagocytic capability is not perhaps necessary for cytotoxicity to take place. These results indicate that the effector cells participating in the cytotoxic reaction resembled natural killer cells or natural cytotoxic cells which are present in murine and human systems. However, analysis of the cell surface markers of the effector cells is yet to be done in future studies.     

Kinetic analysis of cattle anti-Brucella abortus S45/20 non-agglutinating antibodies in antibody-dependent cell-mediated cytotoxicity

Calves inoculated with Brucella abortus S45/20 produced, against surface antigens, non-agglutinating antibodies (NAAb) which were isolated and purified. A kinetic analysis was carried out of NAAb in antibody-dependent cell-mediated cytotoxicity (ADCC) using sheep red blood cells labelled with surface antigen from B. abortus S45/20 as target cells. Three parameters were examined: time of incubation, effector cell:target cell (E:T) ratio and NAAb dose. It was found that the NAAb were not able to mediate ADCC with bovine spleen cells.     

Effects of time, initial composition, and stabilizing agents on the results of canine cerebrospinal fluid analysis

BACKGROUND: Cerebrospinal fluid (CSF) is considered highly labile, but not all samples are analyzed immediately. Changes in the composition of CSF could potentially affect diagnostic test results and thus influence decisions about patient management. There has been little scientific inquiry into how variables such as time, initial composition, and storage conditions affect results of standard laboratory analysis of CSF. OBJECTIVES: The objectives of this study were to determine the effects of time, protein concentration, and presence or absence of exogenous stabilizing agents on standard CSF analysis results. METHODS: Thirty abnormal CSF samples from 26 dogs were evaluated. Samples were divided into aliquots comprising different treatment groups and stored at 4 degrees C. Total nucleated cell count (TNCC), differential cell count (DCC), and cell morphology were evaluated for all groups; protein concentration was measured for selected groups. Unaltered aliquots were analyzed immediately (T0Hr) and at 2, 4, 8, 12, 24, and 48 hours (T2Hr-T48Hr); aliquots with added fetal calf serum (FCS) or hydroxyethyl starch (hetastarch) were analyzed at T48Hr. RESULTS: Significant time-dependent changes were observed in DCC in unaltered samples. Mononuclear cells deteriorated more rapidly than did neutrophils. Based on microscopic examination and subjective scoring of cell morphology, cells were consistently more degenerate by T24Hr compared with T0Hr. Samples with protein concentrations > or =50 mg/dL were less susceptible to cell deterioration than those with lower protein concentrations. Adding either FCS or hetastarch improved sample stability. CONCLUSIONS: Delayed analysis of canine CSF by 4-8 hours is unlikely to alter diagnostic interpretation, especially for samples with protein concentrations > or =50 mg/dL. The likelihood of misinterpretation is higher for samples with low cellularity or low protein concentration. We provide specific recommendations for adding FCS or hetastarch to samples that will not be analyzed within 1 hour.     

Hemolytic assay for goat (caprine) and swine (porcine) complement

Optimal conditions for assaying hemolytic complement of goat (caprine) and swine (porcine) sera were determined. Effects of the following were tested: pH, ionic strength, calcium and magnesium ion concentrations, time and temperature of incubation, and ethylenediamine tetracetate concentration. Guinea pig erythrocytes sensitized with goat or cattle antibodies were the most sensitive target cells for goat complement. Sheep and cattle erythrocytes sensitized with rabbit hemolysin were the best target cells for swine complement. Barbital buffer, pH 7.3, ionic strength of 90 nmM relative salt concentration, containing 0.5 mM CaCl2 and 1 mM MgCl2 was the best for swine complement assay. Goat complement lysed best in a barbital buffer, pH 8, ionic strength of 90 to 120 mM of relative salt concentration, in presence of 0.5 mM CaCl2 and 1 mM MgCl2. The optimal incubation temperature was 37 degrees C for both complements. The complement dependent lysis required 75 minutes to reach its maximum. Ethylenediamine tetracetate in 4 mM concentration completely inhibited lysis by both species complements. The CH50 for goat sera varied between 18 and 75 per ml, in swine sera between 75 and 210 per ml.     

猪卵母细胞在玻璃化冷冻液中的培养效果

本试验的目的是要选择较好的用于猪卵母细胞玻璃化冷冻的玻璃化冷冻液，玻璃化液由ＴＣＭ－１９９、ｍＰＢＳ、Ｋｉｅｖ液分别加２０％的犊牛血清与３种抗冷冻剂（丙三醇、１，２──丙二醇和乙二醇）组成。猪卵母细胞采自屠宰厂的卵巢并培养在ＴＣＭ－１９９＋２０％犊牛血清、ｍＰＢＳ＋２０％犊牛血清和Ｋｉｅｖ＋２０％犊牛血清中，在３７℃、湿度１００％条件下培养至少５个小时。５小时后逐渐加入抗冷冻剂，使其终浓度达５０％。培养５分钟后，将猪卵母细胞依次移至抗冷冻剂浓度为２５％，１２．５％和０％的培养液中，培养５分钟，而后进行台盼蓝死活染色。结果表明猪卵母细胞在各组培养后的存活率没有显著性差异（Ｐ＞０．０５），但乙二醇结果优于其它抗冷冻剂，而ＴＣＭ－１９９好于其它两类培养液。     

Granzyme B-mRNA expression by equine lymphokine activated killer (LAK) cells is associated with the induction of apoptosis in target cells

Lymphokine-activated killer (LAK) cells are a subset of cytotoxic cells capable of lysing freshly isolated tumor cells. While LAK activity is typically measured using the (51)Cr-release assay, here we used a non-radioactive flow cytometric method to demonstrate equine LAK activity. Equine peripheral blood mononuclear cells (PBMC) were stimulated in vitro with recombinant human interleukin 2 (hIL-2) to generate LAK cells. An equine tumor cell line, EqT8888, labeled with carboxyfluorescein succinimidyl ester (CFSE) was used as target cells. Following incubation of the targets with different concentrations of LAK cells, Annexin V was added to identify the early apoptotic cells. With increasing effector to target cell ratios, EqT8888 apoptosis was increased. We also measured interferon-gamma, granzyme B and perforin mRNA expression in the LAK cell cultures as possible surrogate markers for cytotoxic cell activity and found granzyme B mRNA expression correlated best with LAK activity. Also, we found that the reduced LAK activity of young horses was associated with decreased granzyme B mRNA expression. Our results indicate that fluorescence-based detection of LAK cell activity provides a suitable non-radioactive alternative to (51)Cr-release assays and mRNA expression of granzyme B can be used as surrogate marker for these cytotoxic cells.     

Factors Modulating Apoptosis: an in-vitro Study in Swine Granulosa Cells

The aim of this study was to investigate the effects of some endocrine and intra‐ovarian factors on the activation/inhibition of apoptosis in swine granulosa cells. Upon incubation in a 10% FCS‐supplemented M199, granulosa cells from small (< 3 mm) follicles programmed their death after 24–48 h of culture; in the absence of FCS, apoptosis was reduced after 24 h of culture. Cells cultured in the presence of FCS were treated with db‐cAMP, LH, FSH, Insulin‐like Growth Factor‐I IGF‐I or PMSG to verify the role of these substances in apoptotic death: all these molecules inhibited apoptosis after 48 h of incubation. A further aim of the study was to investigate the possible involvement of nitric oxide (NO), an intra‐ovarian modulator, in the regulation of granulosa cell apoptosis and its possible role in the modulation of steroidogenesis. After a 48 h incubation with a substrate of NO synthesis ( l ‐arginine, 0.1 and 1 m m ), a NO donor [S‐nitroso‐N‐acetyl‐penicillamine (SNAP) , 0.2 and 1 m m ] or a NO synthase inhibitor [N^ω‐nitro‐ l ‐arginine‐methyl‐ester (NAME, 1 and 5 m m )], the onset of apoptotic death was evaluated: l . arginine and NAME did not induce any significant variation of apoptosis, whereas 1 m m SNAP exerted a protective action. A significant stimulatory effect of l ‐arginine on NO production, associated with a suppressive action on estradiol 17β concentrations was observed; NAME exerted an inhibitory effect on NO production, associated with an increase in estradiol secretion; estradiol 17β production was markedly inhibited by SNAP. In summary, the depletion of FCS could induce a cell cycle arrest in G₀ whereas apoptosis could be the consequence of cell cycle progression mediated by FCS; gonadotropins and IGF‐I could also act as survival factors. NO appeared to represent a ‘trophic’ signal for the follicle, whose involvement in the regulation of ovarian function is substantiated by its modulatory action on steroidogenesis.     

A porcine intrauterine 4-mda component with transforming growth factor-beta activity suppresses natural killer cell responses

A 4-MDa component, recovered from uterine luminal secretions of gilts on d 15 of pregnancy, was assessed for suppression of the lytic responses from natural killer (NK) and lymphokine-activated killer (LAK) effector cells. Each cell type originated from preparations of peripheral blood lymphocytes (PBL), and the LAK cells were generated from the incubation of PBL with interleukin-2. The PBL and LAK cells were cultured for 5 d with and without the 4-MDa component. Following culture, the cells were incubated (22 h) with NK-sensitive K-562 target cells at varying effector:target cell ratios (25:1 to 200:1). Lytic activity was assessed with the chromium-51 release assay. Additional experiments were conducted in order to determine whether suppressor activity of the 4-MDa component was time-dependent and associated with transforming growth factor-beta2 (TGF-beta2). For effector:target cell ratios combined, the 4-MDa component suppressed the lytic activity of PBL but failed to affect the LAK cells. Suppression of NK-mediated lysis occurred by d 3 of the 5-d culture period. In addition, suppressor activity of the 4-MDa component was reversed by a neutralization antibody to TGF-beta2. In conclusion, the 4-MDa component with TGF-beta2 activity suppressed the lytic responses of porcine NK cells.     

替米考星淀粉微球的制备及缓释性能的研究

以可溶性淀粉为原料,N,N′-亚甲基双丙烯酰胺为交联剂,采用包埋法制备了替米考星淀粉微球,通过L9(34)正交试验设计,以载药量和包封率的综合得分为指标,优化了替米考星淀粉微球的制备工艺;分别用激光粒度分布仪、扫描电镜和综合热分析仪对载药微球进行了表征。结果表明最佳工艺条件为：淀粉4 g、替米考星0.02 g、交联剂0.95 g、乳化剂0.75 g、反应时间1 h;影响因素的大小依次为：交联剂的质量＞替米考星和淀粉的投料质量比＞反应时间＞乳化剂的质量;按优化工艺参数制得的载药微球的总载药量2.24%,包封率为89.6%;替米考星载药微球具有一定缓释效果,其制备方法合理可行。