Studies with Radioactive Endotoxin II. Clearance of 3H-Labelled Endotoxin from the Blood of Calves

The clearance of ³H-labelled Pseudomonas endotoxin from the blood was studied in a nontolerant and in an endotoxin tolerant state. Calves were rendered tolerant to the toxic effects of the endotoxin by four daily intravenous injections of endotoxin at the dose rate of 5 µg/kg body weight.

Clearance of ³H-endotoxin from the blood of nontolerant calves occurred more slowly than did clearance of ⁵¹Cr-endotoxin and was not significantly (P<0.05) affected by the development of tolerance. The lungs and liver were the major organs involved in the clearance of ³H-endotoxin from the blood of calves. Leukocytes and erythrocytes, but not platelets, were shown to participate in endotoxin clearance in calves. ³H₂O, the control substance used in calves, was not concentrated within any particular organ but rapidly equilibrated with total body water and was slowly excreted.

     

Studies with Radioactive Endotoxin I. Clearance of 51Cr-Labelled Endotoxin from the Blood of Calves

The clearance of ⁵¹Cr-labelled Pseudomonas endotoxin from the blood was studied in calves in a nontolerant and in an endotoxin-tolerant state. Calves were rendered tolerant to the toxic effects of the endotoxin by four daily intravenous injections of endotoxin at the dose rate of 5 µg/kg body weight.

Clearance of a small amount of ⁵¹Cr-endotoxin from the blood of nontolerant calves was almost complete within three minutes of injection and was not significantly faster in tolerant calves. The lungs and liver were the major organs involved in clearance of endotoxin from the blood. The ⁵¹Cr label was slowly excreted by the kidneys. Neither platelets nor leukocytes were demonstrated to participate in endotoxin clearance in calves. ⁵¹CrCl₃ was injected into control calves. Relative to the distribution and loss of labelled endotoxin, the ⁵¹CrCl₃ was cleared slowly from the blood, was distributed uniformly throughout the body and was excreted rapidly.

     

Determination of the Inflammatory Potential of Bioaerosols from a Duck‐Fattening Unit by Using a Limulus Amebocyte Lysate Assay and Human Whole Blood Cytokine Response

Inhalation of bioaerosols from animal houses can induce acute inflammatory reactions in the respiratory tract. Determination of the concentration of airborne endotoxins is widely used to characterize this risk. In this study, the activity of bioaerosol samples from a duck‐fattening unit to induce interleukin‐1β (IL‐1β) in human blood and to react with Limulus Amebocyte Lysate (LAL) was investigated. The activity detected in the whole blood assay correlated well with the endotoxic activity found in the LAL assay (Spearmen's ρ = 0.902). However in all samples, the inflammation‐inducing potential was overestimated by the LAL assay. It is assumed that this overestimation could be, in part, a result of an overestimation of the inflammatory potential of endotoxins originating from Pseudomonadaceae by the LAL assay. Pseudomonadaceae were regularly isolated from the air of the duck‐fattening unit. The results presented here indicate that the whole blood assay can be used besides the LAL assay as an additional method to characterize the inflammation‐inducing potential of bioaerosols.     

黑熊血液有形成分显微及亚微结构的研究

利用光学显微镜和透射电子显微镜技术对5只黑熊血液有形成分进行了系统观察.结果表明:红细胞为圆饼状,直径为7.4μm,胞质均质,电子密度中等,未见有任何细胞器,中性粒细胞胞质内含有大量体积较小、形态多样、电子密度不同的中性颗粒,嗜酸粒细胞胞质内的嗜酸性颗粒含有纵向排列、电子密度高的长方形晶体;嗜碱粒细胞除含有体积较大、内含小粒的嗜碱性颗粒外,还含有数量较多体积较小的颗粒;单核细胞和淋巴细胞与其他种哺乳动物相应细胞形态结构类似;血小板体积较小,直径为3μm,无核,基质内含有两种颗粒,即一种是体积较大,且电子密度较高的致密颗粒,另一种为体积较小,内有芯样结构的特殊颗粒.     

The Limulus Amoebocyte Lysate test: detection of endotoxin in plasma of swine and cattle. II. In vivo investigations

Endotoxin was detected by the LAL test in the plasma of swine and cattle following in vivo injection of endotoxin in order to evaluate the applicability of the test in veterinary medicine for detection of endotoxemia.Clinical symptoms of endotoxemia occurred after the injection into 3 swine of 0.10–0.25 mg endotoxin/100 kg bwt and after the infusion during 1–1½ h of 2.0–2.2 mg endotoxin/100 kg bwt into 3 calves. The concentration of endotoxin detected by the LAL test in the experimental animals ranged from 0.15 ng to 6.0 ng endotoxin per ml crude plasma. As positive LAL reactions were obtained only in close connection to the administration of endotoxin, clearance of endotoxin to levels below the sensitivity of the test was fast. In spite of the fast clearance, light symptoms of endotoxemia could be seen as long as 24 h after the last sample showing a positive test result. The applied technique for LAL analysis on blood, therefore, was not adequate for detection of endotoxin at sufficiently low concentrations and some possibilities of improving the technique are discussed.Though leukocytosis were found not to influence the outcome of the LAL test on blood, leukocytic mediators released by endotoxin or endotoxin-derived injuries may still have caused the persistence of the symptoms of endotoxemia, and this question is disputed in relation to the benefit of improving the technique.Especielly in the veterinary clinic, great precautions are necessary to obviate false positive test samples resulting from, e.g., external contamination or transient stress caused by excitement, and it is concluded that the possible application of the LAL test for detection of endotoxemia in veterinary medicine is restricted to surveillance of hospitalized animals and to research purposes.     

The Piromen Test as an Assay of Bone Marrow Granulocyte Reserves in the Calf I. Studies on Bone Marrow and Peripheral Blood Leukocytes

The use of Piromen, a polysaccharide complex of Pseudomonas aeroginosa, has been investigated in 21 calves by a test of marrow granulocyte reserves. The maximal increase in peripheral granulocytes (ΔG) was determined following multiple intravenous and sub-cutaneous injections of Piromen at various time intervals and was correlated with the mature marrow granulocytes on bone marrow smear differentials. Five ug Piromen per kg body weight, by the subcutaneous route, was found to give a mean ΔG of 5200/mm³, very similar to the ΔG of 5300/mm³ obtained in man with 0.1 ug/kg intravenous Piromen injections. Clinical effects in calves were minimal with the subcutaneous route as compared to the response following intravenous Piromen injections.     

葛根芩连汤对感染大肠杆菌小鼠血常规、血液内毒素及炎性细胞因子含量的影响

旨在研究葛根芩连汤预防及治疗感染大肠杆菌K_(88)小鼠的血常规、血液内毒素及炎性细胞因子含量的影响。统计小鼠的死亡率,血常规检测小鼠血液中白细胞、红细胞及血小板的变化,以及采用显色基质鲎试剂法和ELISA方法检测感染小鼠血液里内毒素及炎性因子TNF-α、IL-1β、IL-6的含量变化。结果显示,预防试验中葛根芩连汤组小鼠死亡率为20%,治疗试验中葛根芩连汤组死亡率为30%,均极显著地低于模型组(P0.01),且与氟苯尼考组相比没有差异;葛根芩连汤组小鼠血液中白细胞指标均极显著地低于模型组(P0.01),红细胞及血小板指标均极显著地高于模型组(P0.01);葛根芩连汤组小鼠白细胞、中性粒细胞及血小板数目极显著的高于氟苯尼考组(P0.01),葛根芩连汤组小鼠内毒素及TNF-α、IL-1β、IL-6的含量均极显著地低于模型组(P0.01)。结果表明:葛根芩连汤对感染大肠杆菌K_(88)小鼠具有预防与治疗作用,而且在抑制早期炎性因子的释放,降低机体炎症反应水平方面优于氟苯尼考。     

奶牛静脉血内毒素浓度及其与产奶量的相关性

为调查我国当前主流饲喂方式下奶牛静脉血内毒素浓度的范围及内毒素浓度与产奶量的相关性,本试验首先验证了应用鲎试剂法定量奶牛静脉血中内毒素浓度的可行性,在此基础上,分别检测了安徽牧场1(60头,饲粮精粗比45∶55)、江苏牧场(15头,按产奶量高低精粗比分别为20∶80、45∶55、50∶50)和安徽牧场2(14头,饲粮精粗比70∶30)共89头奶牛的尾静脉血中内毒素浓度,并进行了内毒素浓度与产奶量的相关性分析.结果表明:鲎试剂法可有效检测奶牛静脉血中内毒素浓度,3个牧场奶牛静脉血中内毒素浓度高低不等,在0～ 1.50 EU/mL范围内.奶牛静脉血中内毒素浓度与产奶量之间的相关性皆不显著(P＞0.05),但安徽牧场2的相关系数(0.195 2)大于安徽牧场1(0.020 5)和江苏牧场(0.037 6).结果提示,鲎试剂法可用于定量检测奶牛血中内毒素浓度,在我国当前的饲喂方式下,奶牛血液中普遍含有内毒素,静脉血内毒素浓度与产奶量无显著相关性.     

Endotoxin Concentration in Venous Blood and Its Correlation with Milk Yield of Dairy Cows

为调查我国当前主流饲喂方式下奶牛静脉血内毒素浓度的范围及内毒素浓度与产奶量的相关性,本试验首先验证了应用鲎试剂法定量奶牛静脉血中内毒素浓度的可行性,在此基础上,分别检测了安徽牧场1(60头,饲粮精粗比45∶55)、江苏牧场(15头,按产奶量高低精粗比分别为20∶80、45∶55、50∶50)和安徽牧场2(14头,饲粮精粗比70∶30)共89头奶牛的尾静脉血中内毒素浓度,并进行了内毒素浓度与产奶量的相关性分析.结果表明:鲎试剂法可有效检测奶牛静脉血中内毒素浓度,3个牧场奶牛静脉血中内毒素浓度高低不等,在0～ 1.50 EU/mL范围内.奶牛静脉血中内毒素浓度与产奶量之间的相关性皆不显著(P＞0.05),但安徽牧场2的相关系数(0.195 2)大于安徽牧场1(0.020 5)和江苏牧场(0.037 6).结果提示,鲎试剂法可用于定量检测奶牛血中内毒素浓度,在我国当前的饲喂方式下,奶牛血液中普遍含有内毒素,静脉血内毒素浓度与产奶量无显著相关性.     

Detection and Localization of GLUTs 1, 2, 3 and 5 in Donkey Spermatozoa

GLUTs are a family of proteins that facilitate the transport of glucose and other hexoses through the plasma membrane of the cells. GLUTs are present in mammalian spermatozoon’s membrane in different isoforms and they supply metabolic substrates for all the cell’s activities such as motility, homoeostasis and fertilization. As studies about donkey spermatozoa and their metabolism are lacking, this study was aimed at detecting GLUTs 1, 2, 3 and 5 presence by western blotting technique and at determining their localization on the plasma membrane by indirect immunofluorescence. Each protein showed a typical localization on the sperm cells’ plasma membrane, differencing the one to the other on the basis of the hexose they transport. We also highlighted some differences between GLUTs distribution and molecular weight in donkey spermatozoa and its nearest relative, the horse.     

Endotoxin and Arachidonic Acid Metabolites in Portal,Hepatic and Arterial Blood of Cattle with Acute Ruminai Acidosis

Andersen, P. Haubro, M. Hesselholt and N. Jarlev: Endotoxin and arachidonic acid metabolites in portal, hepatic and arterial blood of cattle with acute ruminai acidosis. Acta vet.scand.1994,35,223-234.– Ruminai acidosis was induced experimentally with 70 g barley / kg body weight in 2 rumen fistulated cows with chronic indwelling catheters in the portal vein, in a hepatic vein and the carotid artery. The cows were followed for 24 and 20h after the overfeeding and evaluated clinically and by clinical chemistry. The 2 cows exerted different responses to the treatment. Both cows showed signs of severe ruminai acidosis. Both cows had endotoxin in portal and hepatic vein blood, but only 1 of the cows convincingly developed a systemic endotoxaemia. A pre-hepatic release of the stable prostacyclin and thromboxane metabolites, 6-ketoprostaglandin F_lα and thromboxane B₂ was demonstrated in this cow. The results of the present study show that endotoxin and arachidonic acid metabolites of pre-hepatic origin may be factors involved in the pathogenesis of ruminai acidosis, and that investigation of the factors affecting translocation of ruminai endotoxin and subsequent clearing in the liver, will be of importance.     

新生牛血清中大肠杆菌噬菌体检测方法的建立

本研究用大肠杆菌标准噬菌体株选择确定的大肠杆菌C-3000作为宿主菌,采用增殖法和噬斑法与双层琼脂平板法,对多个厂家的新生牛血清进行了大肠杆菌噬菌体检测,建立了兽用生物制品细胞培养用新生牛血清中大肠杆菌噬菌体的检测方法。     

Toxoplasmosis III. Studies Using the Complement-Fixation Test and Fluorescence-Inhibition Test with Sera of Experimentally Exposed Birds

The direct, modified direct and indirect complement-fixation tests and the fluorescence-inhibition test were investigated using sera from pigeons, chickens and turkeys which had been exposed to Toxoplasma gondii. The direct CF test was suitable for use with pigeon sera.

The indirect CF method effectively demonstrated antibodies in chicken and turkey sera. FI tests were less sensitive than the CF methods.

     

Tumor Necrosis Factor and Interleukin-6 Activity and Endotoxin Concentration in Peritoneal Fluid and Blood of Horses with Acute Abdominal Disease

The purpose of this study was to evaluate the diagnostic and prognostic significance of tumor necrosis factor-alpha (TNF) and interleukin-6 (IL-6) activities and endotoxin concentration in blood and peritoneal fluid of 155 adult horses with acute abdominal disease (colic). Samples also were obtained from 20 healthy adult horses. Blood and peritoneal fluid supernatant TNF and IL-6 activities and endotoxin concentration were significantly greater in horses with colic, compared with healthy horses. In horses with colic, the peritoneal fluid endotoxin concentration and TNF and IL-6 activities were significantly greater than those in blood. Within the colic group, peritoneal fluid IL-6 activity was the analyte that was most frequently increased. Blood and peritoneal fluid supernatant TNF and IL-6 activities were significantly greater when endotoxin was detected in the same sample. Blood and peritoneal fluid IL-6 activity was significantly greater in horses with inflammatory or strangulating lesions, compared with horses having nonstrangulating or noninflammatory lesions. Compared with all other data categories, diagnostic accuracy for nonsurvival was greatest (80%) when blood IL-6 activity exceeded 60 units/mL. The results of this study indicate that endotoxin was present in the peritoneal cavity of at least one third of horses with any acute disease of the abdomen. In horses presented for colic, blood or peritoneal fluid IL-6 activity was more useful than either TNF activity or endotoxin concentration for distinguishing lesion type. Although diagnostic accuracy for the prediction of nonsurvival was good for all of the analytes, negative values were more useful in the prediction of a favorable outcome than were abnormally increased values in the prediction of mortality.     

Studies on the replacement policies in dairy cattle. III. Influence of variation in reproduction and production

The optimum policy of insemination and replacement of dairy cows was determined by the dynamic programming technique. The model used in the previous study was extended to allow variation in time of conception. From 2 to 7 months after calving three alternatives were considered for an open cow namely (a) inseminating the cow, with a calculated probability of success, (b) leaving her open, and (c) replacing her immediately. When it was profitable to leave a cow open, the optimum time for replacement during the lactation period was determined.The minimum production level for insemination to be the optimum choice depended on the stage of lactation and the parity of the cow. In the optimum situation the average calving interval was 371 days, while 13% of the cows had an interval of 14 months or longer.The optimum policy was greatly affected by changes in the replacement heifer price. Changes in the probability of conception and persistency of milk production had significant but smaller effects. In herds with a smaller decline in production after the peak, insemination should be continued for longer than in herds with a larger decline.The relation between production and calving interval that resulted from the optimum policy was determined. When a measure of milk production was used that was not affected by gestation, the average correlation was 0.09. The correlation increased to 0.35 when the total 305-day production was used.     

Studies on the pathogenesis of tibial dyschondroplasia in chickens. III. Effect of body weight.

Surgical severance of the gastrocnemius and flexor tendons on the posterior aspect of the tibiotarsal-tarsometatarsal joint in one leg resulted in unilateral lameness in chickens that were susceptible to tibial dyschondroplasia. Perotic-like deformation developed in the operated leg, while the tibiotarsus in the unoperated leg was thicker and bowed in an anterior direction. In nine of 43 chickens with tibial dyschondroplasia the severity of the lesion differed markedly between the operated and unoperated legs. The more severe lesion was in the operated leg in 6 birds, and in the unoperated leg in 3 birds. No evidence was found to support the hypothesis that weight-bearing may be important in the pathogenesis of tibial dyschondroplasia.