CQ10-LPSp对紫花苜蓿幼苗内生细菌多样性及其根瘤菌的影响

为了探究成团泛菌CQ10脂多糖（Pantoea agglomerans CQ10 Lipopolysaccharide,CQ10-LPSp）对紫花苜蓿（Medicago sativa L.）幼苗内生细菌多样性及其根瘤菌（Rhizobium）的影响,本试验首先研磨分离‘巨能551’紫花苜蓿幼苗内生细菌,后设置6个不同浓度梯度（0,0.133 5,0.200 3,0.267 0,0.333 8,0.400 5 EU·mL^-1）的CQ10-LPSp与紫花苜蓿互作,再分离并测定了其根系内生细菌的种类和数量以及根瘤菌的数量。结果显示,随着CQ10-LPSp浓度的增大,紫花苜蓿内生根瘤菌的数量呈先升高后降低的变化趋势,在0.267 0 EU·mL^-1 CQ10-LPSp下根瘤菌数量最多,为6.98×10⁷ cfu·g^-1,且该浓度下根系内生细菌种类较种带细菌多样性减少。结果表明,CQ10-LPSp处理下会影响植物内生细菌的种类和数量,且在一定浓度范围内能增加紫花苜蓿内生根瘤菌的数量。本研究结果为开发促进紫花苜蓿内生根瘤菌生长的外源添加剂奠定一定的理论和实践基础。     

Cell death and CD14 expression in resident and inflammatory polymorphonuclear leukocytes from virgin bovine mammary gland

This paper investigates the association between expression of CD14 and occurrence of apoptosis in blood, resident (_RESPMN) and inflammatory (_INFPMN) polymorphonuclear leukocytes (PMN) from heifer mammary glands. The fresh population of _RESPMN contained a statistically significant higher proportion of CD14+, apoptotic and necrotic cells than did populations of _INFPMN and blood PMN. In vitro cultivation of _RESPMN, _INFPMN and blood PMN led to concurrent increase of apoptotic, necrotic and CD14+ cells. A positive correlation was found between the proportions of both apoptotic and necrotic PMN and CD14+ PMN as determined by three-color flow cytometry analysis. Our study confirmed that expression of CD14 in blood PMN, _RESPMN and _INFPMN from heifer mammary glands was accompanied by apoptosis and necrosis.     

Leukocyte and platelet changes following low-dose lipopolysaccharide administration in five dogs

Effects of low-dose LPS (0.1 μg/kg IV) on leukocyte and platelet parameters measured using an Advia 120 hematology analyzer were investigated. Five dogs received a saline sham treatment prior to LPS, and blood was collected before and 3, 6, and 24 h post-treatment. LPS-treated dogs had mild neutrophil toxic change and increased neutrophil bands at 3 and 6 h. Compared to saline-treated controls, total leukocyte, neutrophil, and monocyte counts of LPS-treated dogs were significantly decreased at 3 h and increased at 24 h. Compared to baseline, total leukocyte counts of LPS-treated dogs were significantly decreased at 3 h and increased at 24 h. Mean platelet volume was significantly increased and mean platelet component concentration was decreased at 3 h compared to baseline. Platelet count was significantly decreased at 3 and 6 h; plateletcrit did not change significantly. High dosage is not required in order to detect LPS-mediated hematologic effects in dogs. Low-dose LPS administration causes significant changes in leukocyte and platelet indices in dogs without causing severe clinical signs or death.     

Heat-tolerant versus heat-sensitive Bos taurus cattle: influence of air temperature and breed on the metabolic response to a provocative immune challenge

The response of the immune and stress systems have been assessed in response to a lipopolysaccharide (LPS) challenge, yet the role of metabolism in mediating energy requirements during the acute phase response has not been sufficiently studied. This study tested heat-tolerant (Romosinuano [RO]) and heat-sensitive (Angus [ANG]) Bos taurus breeds at different ambient temperatures (T_a) to determine differential metabolic responses to LPS challenge. Twenty-one heifers (ANG: n = 11, 306 ± 26 kg BW; RO: n = 10, 313 ± 32 kg BW) were housed in stanchions in 4 temperature-controlled chambers. Initially, T_a in all 4 chambers was cycling at thermoneutrality (TN; 18.5°C–23.5°C) for a 1-wk adjustment period, followed by an increase in 2 chambers to cycling heat stress (HS; 24°C–38°C) for 2 wk. Five ANG and 5 RO heifers were housed at TN, whereas 6 ANG and 5 RO heifers were housed at HS. On day 19, heifers were fitted with jugular catheters. On day 20, heifers were challenged with LPS (0.5 μg/kg BW; 0 h), and blood samples were collected from −2 to 8 h and at 24 h relative to LPS challenge. Serum was analyzed for glucose, insulin, and NEFA concentrations. In addition, feed intake was measured 3 d before and on the day of the challenge. Feed intake decreased over time (P < 0.001) and was decreased in heifers housed at HS compared with heifers housed at TN (P = 0.013). Glucose concentrations before LPS challenge were greater in RO (P = 0.01) than in ANG heifers and greater in TN-housed heifers (P = 0.02) than in HS heifers. Glucose after LPS challenge initially increased before decreasing below baseline concentrations (P < 0.01) in all heifers. In addition, there was a breed by T_a interaction (P < 0.004), such that HS decreased glucose concentrations in ANG heifers compared with ANG heifers housed at TN (P < 0.001), whereas HS did not affect glucose concentrations after LPS challenge in RO heifers (P = 0.941). Nonesterified fatty acid concentrations before LPS challenge were not affected by breed (P = 0.37) or T_a (P = 0.60). Although NEFA concentration after LPS challenge was unaffected by T_a (P = 0.78), there tended to be a breed by T_a interaction (P = 0.07) such that, when housed at HS, RO heifers had greater serum NEFA concentrations after LPS challenge than ANG heifers (P = 0.009). Insulin concentration before LPS challenge was greater in RO heifers than in ANG heifers (P < 0.01). Insulin after LPS challenge increased (P < 0.01), with RO heifers producing a greater insulin response than ANG heifers (P < 0.01). These data suggest that HS decreases the metabolic response of heat-sensitive ANG heifers in response to LPS challenge, thus providing physiological evidence that may explain differences observed in the acute phase response between heat-sensitive ANG and heat-tolerant RO cattle breeds.     

草鱼脂多糖结合蛋白的分离纯化(英文)

脂多糖结合蛋白(lipopolysaccharide binding proteins ,LBP)是机体对革兰氏阴性菌感染产生的可溶性急性期蛋白,结合并提呈LPS给细胞表面的模式识别受体,激发免疫反应。在本试验中,用低浓度嗜水气单胞菌( Aeromonas hydrophila)感染草鱼(Ctenopharyngodon idellus)24 h后,抽取全血,离心,获得血浆。结合LBP活性检测,经硫酸铵沉淀、CMSephadex C-50阳离子交换层析和DEAE Sephadex A-25阴离子交换层析后,分离纯化得到LBP。该蛋白对异硫氰酸荧光素标记的脂多糖(Fluorescein isothiocyanate labeled li-popolysaccharide ,FITC-LPS)有较强的结合能力。在SDS-PAGE电泳后,考马斯亮蓝染色可见3条明显的带,分子量大约为68、53和48 kDa。同时探索一条简便分离纯化脂多糖结合蛋白的方法,为进一步研究LBP的功能奠定了基础。     

芩连液与白虎汤对气分证家兔胃肠黏膜的病理影响比较

为了比较自拟方芩连液和白虎汤对气分证动物模型的治疗效果,试验通过静脉注射内毒素(LPS)复制家兔气分证模型,并在2种药物治疗前后分别观察了家兔胃肠道黏膜组织的病理变化以及测定了血清免疫球蛋白(IgA)含量。结果表明:静脉注射LPS能致家兔胃肠道黏膜组织产生明显病理损伤,血清IgA含量上升;经白虎汤和芩连液治疗后胃肠道黏膜组织病理损伤显著减轻,但血清IgA含量仍然显著高于正常水平。说明白虎汤和芩连液对LPS引起的胃肠道黏膜组织损伤都具有显著的治愈效果,而对血清IgA的含量无显著影响。     

Effects of lipopolysaccharide binding protein on activation of p38 signaling pathway induced by LPS in macrophages

AIM:To investigate the regulatory effects of lipopolysaccharide binding protein(LBP)on activation of p38 signaling pathway induced by lipopolysaccharide(LPS)in alveolar macrophages.METHODS:The LBP from actue phase rat serum was purified by ammonium sulphate precipitation, Bio-Rex70 resin and the MonoQ column. Rat alveolar macrophages were exposed to LPS (0.01 mg/L or 1 mg/L) the various concentrations of LBP(0 mg/L, 0.01 mg/L, 0.1 mg/L, 1 mg/L and 10 mg/L).Western blotting were used to detect phospho-p38 in alveolar macrophages. RESULTS:SDS-PAGE analysis indicated that the purified preparation of rat LBP showed homogeneity and the molecu-lar weight was 60 kD.The binding of lipopolysaccharide to mononuclear cells were enhanced by purified rat LBP.Stimu-lation of rat alveolar macrophages with LPS at concentration of 0.01 mg/L was LBP dependent.LBP at concentrations up to 1 mg/L was able to increase the activation of p38.However, when LBP concentrations were further increased to 10mg/L, the phosphorylation levers of p38 were lower as compared with that in the presence of 1 mg/L.Stimulation of ratalveolar macrophages with LPS at concentrations of 1 mg/L was LBP-independent.CONCLUSION:The activation of p38 induced by LPS at lower concentration(0.01 mg/L) was LBP-dependent, meanwhile, LPS at higher concentration(1 mg/L) was LBP-independent.     

免疫应激对断奶仔猪免疫和神经内分泌激素的影响

试验研究了免疫应激对断奶仔猪免疫和神经内分泌激素的影响。选用 6头体重为 (7.6± 0 .3)kg的(2 8± 3)d的达兰断奶仔猪 ,绝食 12h后 ,随机选取 4头猪从腹膜注射 2 0 0 μg/kg(BW)的脂多糖 (LPS) ,另 2头注射等量生理盐水作对照。于注射后 0、1、2和 3h ,分别采血测定血浆白细胞介素 1β(IL 1β)、前列腺素E2 (PGE2 )、皮质醇、生长激素 (GH)和类胰岛素生长因子 I(IGF I)的含量。结果表明 :(1)注射LPS激活了应激轴 :与对照组相比 ,LPS提高了注射后 1h(P <0 .10 )、2h(P <0 .0 1)和 3h(P <0 .0 1)的IL 1β水平 ,提高了注射后 1h(P <0 .0 5 )和 3h(P <0 .0 1)的皮质醇和PGE2 水平 ;(2 )注射LPS抑制了生长轴 :LPS降低了注射后 3h的GH水平 (P <0 .10 ) ,降低了注射后 2h (P <0 .0 5 )和 3h(P <0 .0 1)的IGF I水平。结果显示 ,免疫应激激活了仔猪应激轴 ,而抑制了生长轴 ,在一定程度上揭示了免疫应激抑制生长的机制     

Endotoxin release after antimicrobial treatment in sick foals is mediated by antimicrobial class

The objective of this study was to determine whether treatment with antimicrobials leads to increased serum endotoxin concentrations in sick foals and to further determine whether an effect of class of antimicrobial on endotoxin release occurs in sick foals in vivo. This was a prospective, observational study at a university equine hospital. Twenty-four foals aged 12 hours to 12 days admitted to the hospital in 2004 and 2005 were used. Blood was collected from all foals at time 0 (admission) and at 30 minutes, 8 hours, 12 hours, and 24 hours after treatment with an antimicrobial. The choice of antimicrobial was determined by the clinician caring for the foal, and any other treatment, as deemed necessary for appropriate care of the foal, was employed. For each serum sample, the endotoxin concentration was determined using the limulus amebocyte lysate assay. Those foals that received a beta-lactam alone, more specifically the cephalosporin ceftiofur, showed a significant increase in endotoxin concentration 12 hours after antibiotic administration (P = .005). An increase in serum endotoxin concentration was not seen in the first 24 hours after antimicrobial administration when foals were treated with a combination of beta-lactam and aminoglycoside antimicrobials. In conclusion, a significant increase in endotoxin concentration as a consequence of ceftiofur administration occurs in sick foals. Administration of a combination of a beta-lactam antimicrobial and an aminoglycoside did not result in a significant increase in endotoxin release. Consideration of these findings should be made when choosing antimicrobial therapy for the sick foal.     

Improvement and evaluation of chronic bronchitis modeling methods in mice

AIM: To explore a more accurate and reliable pathological model of the chronic bronchitis, which has improved from the former single-factor modeling method of the disease.METHODS: The mice in complex group were treated with lipopolysaccharide(LPS) by tracheal injection on the 1st day and nasal drops on the 14th day, and from the 2nd day to 30th day, the animals were given passive smoking and sulfur dioxide(SO₂) inhalation(except on the 14th day). The mice in SO₂ group were exposed to SO₂ 2 min per day, while in smoking group, the mice were exposed to smoke for about 1 h per day(4 cigarettes each time until one pack of cigarettes were burning up). In LPS group, the mice had tracheal injection of LPS on the 1st day and nasal drops of LPS on the 14th day and 30th day. Every modeling process lasted for 30 days. After modeling, the improvement of chronic bronchitis model was evaluated by testing the general conditions of the mice, analyzing leukocyte count in bronchoalveolar lavage fluid(BALF), and observing the morphological changes of the bronchial and lung tissues.RESULTS: After modeling, the mice in every model group experienced symptoms including wet nose, cough, dry and lusterless hair, arched back and curled-up body, showing inactive, and slow down in response. The mice in complex group gained the lowest weight compared to other groups. From each model group, the inflammatory cells infiltrated evidently around the bronchial walls, especially in the bronchial cavity, and the mucilage secretion in the airway increased. The total number of leukocytes in BALF increased significantly in complex group. The inflammatory cell count in the lung tissue indicated that the mice in complex group had significantly higher levels of inflammatory cell infiltration. Besides, the comparison between smoke group and LPS group was statistically significant.CONCLUSION: Smoking, SO₂ inhalation and LPS injection induce bronchial lung disease in mice, and the complex chronic bronchitis mouse model is a better model with the pathological changes of bronchus, lung tissue and BALF, and pathogenesis of chronic bronchitis.