Blood cleansing cells in head kidney and spleen in Buenos Aires tetra, Hyphessobrycon anisitsi (Eigenmann), (Characidae: Teleostei)

The general structure and cell types in kidney and spleen in Buenos Aires tetra, Hyphessobrycon anisitsi, family Characidae, are described. The capability and capacity of these organs to clean foreign ferritin from the blood stream are analysed and compared. Head kidney was mainly composed of neutrophils, macrophages, lymphocytes and other white blood cells, whereas unmatured and matured red blood cells were few in number. Spleen often contained much red pulp, that is mainly matured red blood cells between splenic cords, often with some macrophages and neutrophils in the latter. Occasionally, this pulp contained large volumes of unmatured red blood cells, particularly in the periphery of the spleen. The splenic white pulp consisted of ellipsoids composed of an inner endothelial layer covered by a thick sheet of white blood cells, which in the periphery consisted mainly of macrophages. Erythrocytes occupied nearly the entire splenic volume in some specimens, whereas up to half of this volume was filled by ellipsoid macrophages, neutrophils, lymphocytes and other white blood cells in other specimens. The macrophages and sinusoidal endothelial cells in kidney and spleen from ferritin-injected specimens were tightly packed by yellow-brown granules or Prussian blue precipitations, in tissue treated with Mallory stain or acid ferrocyanide, respectively, suggesting a large uptake of foreign ferritin. In the present tetra large amounts of white blood cells are developed in head kidney, where macrophages and sinusoidal endothelial cells play important roles in the cleansing of scavenger and foreign molecules and particles from the blood stream. The spleen seems primarily to be a site for iron recycling and production and storage of red blood cells. Sometimes, however, it was rich in macrophages, neutrophils, lymphocytes and other white blood cells, suggesting functions like blood cleansing and non-specific and specific defence in such specimens.     

Model to predict septicemia in diarrheic calves

The difficulty in distinguishing between septicemic and nonsepticemic diarrheic calves prompted a study of variables to predict septicemia in diarrheic calves <28 days old that were presented to a referral institution. The prevalence of septicemia in the study population was 31%. Variables whose values were significantly different (P < .10) between septicemic and nonsepticemic diarrheic calves were selected using stepwise, forward, and backward logistic regression. Variables identified as potentially useful predictors were used in the final model-building process. Two final models were selected: 1 based on all possible types of predictors (laboratory model) and 1 based only on demographic data and physical examination results (clinical model). In the laboratory model, 5 variables retained significance: serum creatinine > 5.66 mg/dL (>500 micromol/L) (odds ratio [OR] = 8.63, P = .021), toxic changes in neutrophils > or = 2+ (OR = 2.88, P = .026), failure of passive transfer (OR = 2.72, P = .023), presence of focal infection (OR = 2.68. P = .024), and poor suckle reflex (OR = 4.10, P = .019). Four variables retained significance in the clinical model: age < 5 days (OR = 2.58, P = .006), presence of focal infection (OR = 2.45, P = .006), recumbency (OR = 2.98, P = .011), and absence of a suckling reflex (OR = 3.03, P = .031). The Hosmer-Lemeshow goodness-of-fit chi-square statistics for the laboratory and clinical models had P-values of .72 and .37, respectively, indicating that the models fit the observed data reasonably well. The laboratory model outperformed the clinical model by a small margin at a predictabilty cutoff of 0.5, however, the predictive abilities of the 2 models were quite similar. The low sensitivities (39% and 40%) of both models at a predicted probability cutoff of 0.5 meant many septicemic calves were not being detected by the models. The specificity of both models at a predicted probability cutoff of 0.5 was >90%, indicating that >90% of nonsepticemic calves would be predicted to be nonsepticemic by the 2 models. The positive and negative predictive values of the models were 66-82%, which indicated the proportion of cases for which a predictive result would be correct in a population with a prevalence of septicemia of 31%.     

Correlations between phytohemagglutinin response and leukocyte profile,and bactericidal capacity in a wild rodent

phytohemagglutinin (PHA)‐induced swelling is widely used to investigate cell‐mediated and innate immunity across different vertebrate taxa. However, its physiological mechanism is still an open question due to the complexity of the involved immune components. In the present study, we measured the synchronous variations of PHA response, the proportion of different subtypes of leukocytes, as well as serum bactericidal capacity in circulation blood at 6, 12 and 24 h after PHA versus PBS injection in striped hamster, Cricetulus barabensis. First, the results showed that PHA responses reached a peak at 6 h postinjection, then sharply declined at 12 h and 24 h postinjection. Serum bactericidal capacity was higher at 6 h and 12 h than at 24 h. The proportion of different subtypes of leukocytes, as well as the ratio of neutrophils to lymphocytes did not display significant changes across different time points. Second, PHA response was positively correlated with the proportion of neutrophils and serum bactericidal capacity. The proportion of monocytes was negatively correlated with that of eosinophils and neutrophils. The proportion of basophils was negatively correlated with that of lymphocytes. Our results indicate that earlier enhanced PHA response is important for the striped hamster to cope with changing environmental conditions due to its small body mass, and the increased components of innate immunity in circulation blood may contribute to the enhancement of PHA swelling response.     

Antiperoxidation activity of triterpenoids from rhizome of Anemone raddeana

Four triterpenoid compounds hederacolchiside E (1), hederasaponin B (2), raddeanoside 20 (3) and raddeanoside 21 (4) were isolated from ethanol extracts of rhizome of Anemone raddeana Regel. The effects of these triterpenoids on superoxide generation, tyrosyl phosphorylation of proteins and translocation of cytosolic compounds, such as p47^phox, p67^phox and Rac to the cell membrane in human neutrophils was investigated. The superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was slightly suppressed by hederasaponin B, raddeanoside 20 and raddeanoside 21 in a concentration dependent manner. The superoxide generation induced by arachidonic acid (AA) was suppressed by hederasaponin B and raddeanoside 21 significantly. fMLP- and AA-induced tyrosyl phosphorylation and translocation of the cytosolic proteins: p47^phox, p67^phox, and Rac to the cell membrane were suppressed in parallel with the suppression of stimulus-induced superoxide generation.     

双黄连注射液对中性粒细胞磷酸二酯酶4B基因表达的影响

本试验以主要在中性粒细胞中表达的磷酸二酯酶4B基因为靶基因,研究双黄连注射液的抗炎机制.采用半定量RT-PCR法检测双黄连注射液在不同时间对磷酸二酯酶4B基因表达的影响.结果发现双黄连注射液与中性粒细胞共孵育1 h时对磷酸二酯酶4B基因表达无明显的影响,当孵育到3 h时即可极显著抑制磷酸二酯酶4B基因的表达(P＜0.01).本试验结果表明,双黄连注射液能在基因转录水平上抑制中性粒细胞内磷酸二酯酶4B基因的表达,提示其能使cAMP含量升高而抑制中性粒细胞等炎症细胞的活化,从而发挥抗炎作用.     

奶牛外周血中性粒细胞分离方法的优化

用400g/L聚蔗糖和760g/L复方泛影葡胺按一定比例配制成细胞分层液,以确定奶牛中性粒细胞及其他主要血细胞的漂浮密度。然后用自制的60%和75%的Percoll细胞分离液摸索出3种中性粒细胞的分离方法,即Percoll梯度离心法、Dextran作用下的红细胞自然沉降法和裂解红细胞法。对12头健康、泌乳中期荷斯坦奶牛外周血样本进行分离试验。结果表明,中性粒细胞的回收率分别为92.17%±3.328%,90.28%±1.348%,88.79%±3.223%,3种分离方法差异显著(P<0.05);台盼蓝染色活细胞率>97%,中性粒细胞形态改变<9%。     

Mechanisms and functions of the oxygen radicals producing respiration of phagocytes

Respiratory burst is due to the activation of a membrane bound NADPH oxidase induced by perturbation of the plasma membrane during phagocytosis or following interaction between the cell surface and a number of environmental stimuli. It refers to the increase in the non-mitochondrial O2 consumption with a concomitant production of different reactive species (superoxide anion, hydrogen peroxide, hydroxyl radical, singlet oxygen ...). The effects of the respiratory burst depend on the intensity and combination of the different actions which are defensive, toxic, activatory and modulatory of the inflammatory process.     

Descriptive results from a longitudinal study of airway inflammation in British National Hunt racehorses

Reasons for performing study: Rates of airway inflammation in young racehorses decrease with time but it is not clear whether this is associated with increasing age or time exposed to the training environment. The structure of the British National Hunt (NH) population allowed closer examination of this relationship. Objectives: To compare rates of inflammatory airway disease diagnosed by tracheal sampling (trIAD), and its components, in NH racehorses by age and training history and with published rates in young racehorses. Methods: A prospective, longitudinal study was conducted on 5 NH yards over 2 years. Period sample prevalences of nasal discharge, tracheal mucus, airway neutrophilia and trIAD (defined by a combination of tracheal mucus and airway neutrophilia) were estimated and compared between horses with different ages and time in training. Results: Horses new to training had twice the odds of visible tracheal mucus as ex‐flat trained horses (OR 2.0; 95% CI: 1.4–2.8; P<0.001) but no significantly increased odds of airway neutrophilia (OR 1.3; 95% CI: 0.8–1.9; P = 0.3) and inconclusive evidence of increased odds of trIAD (OR 1.8; CI: 0.9–3.5; P = 0.08). However, a lower median time in training was significantly associated with the presence of visible mucus (P<0.001), increased mucus (P = 0.005) and trIAD (P = 0.03). No disease measure varied significantly with age. Conclusions: Tracheal mucus and trIAD, but not neutrophilia detected in tracheal wash samples, were less prevalent in horses that had been exposed to the training environment for longer, explaining previously reported associations with age. Potential relevance: Neutrophil proportion in tracheal wash samples is not as useful a clinical tool as measures of visible tracheal mucus for identifying horses requiring treatment or changes in management. The inclusion of tracheal wash neutrophils in the assessment of equine airways, or at least their relative weighting in definitions of trIAD, should be re‐evaluated.     

Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.