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1.
The tools available for monitoring necrotic enteritis caused by Clostridium perfringens in broiler chickens have been limited, particularly for identifying subclinical disease. In this study, a modified enzyme-linked immunosorbent assay was used to quantify levels of specific immunoglobulin G to C. perfringens alpha-toxin in serum from broilers. We found significantly higher antibody levels in broilers with a history of subclinical necrotic enteritis compared with a zinc-bacitracin-treated group with a low level of gut lesions. Furthermore, in 4.5-week-old commercial broiler flocks, there was an association between the occurrence of C. perfringens-associated hepatitis at slaughter and the immune response to alpha-toxin. Practical solutions for defining cut-off levels for positive serum samples at individual and flock levels are proposed, and were found to be useful on a set of samples available from flocks with different histories regarding the occurrence of C. perfringens-associated disease. This serological approach seems promising as a diagnostic tool in research and disease monitoring regarding C. perfringens-associated disease. 相似文献
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3.
Risk factors for the development of wheezing during infancy were studied in 5,953 children. The data for the study were collected from a large prospective investigation of children born in 1959-61, who had attended a one-year follow-up examination. Wheezing was diagnosed when the symptom had been observed at least once during the first year of life, not in conjunction with pneumonia, epiglottitis or acute laryngitis. Logit analysis was used for the purpose of assessing the causal effect of environmental and other factors on the risk of wheezing among infants. The assessment of a risk factor by means of regression technique, requires certain other variables to be included in the regression model. A general rule concerning inclusion of other variables has been formulated and applied to the above data. The study demonstrated that the risk of wheezing was affected by a number of factors--particularly environmental. Poor social environment increases the risk of wheezing, as does the mother's smoking, and placement of the baby in day-care. Boys experienced wheezing more often than girls. Premature infants are more liable to develop wheezing than mature children. Remarkably, children born in the period April through September develop wheezing, but not bronchitis, more often than children born in October through March. 相似文献
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The morphologic effects of androgen deprivation in the different lobes of the rat prostate were examined by light microscopic morphometry. The prostates of Wistar male rats (260-340 g) were fixed in situ by glutaraldehyde perfusion in castrated animals 1 week after gonadectomy and in intact animals. The ventral (VP), dorsal (DP), and lateral (LP) lobes as well as the coagulating gland (CG) were dissected out, weighed, and processed for light microscopy. Using stereologic methods the following parameters were estimated for each lobe: volume fraction of connective tissue, epithelium and glandular lumina, average epithelial height, average epithelial cell volume, and total number of epithelial cells. Castration leads to a 58-76% reduction of the wet weight of all prostatic lobes. The decrease of glandular tissue is greater in VP than in LP, DP, and CG. In VP and LP, there is a 39-45% reduction of the epithelial height, and this effect is less pronounced in DP and CG. For all lobes, the shrinkage of average epithelial cell volume is in the same range (25-30%). Moreover, in VP and LP, there is a 70% reduction of the total number of cells, whereas the reduction is less in DP and CG. It thus seems that the reduction of prostatic epithelial tissue mass upon castration is due to a reduction of the number of cells as well as a reduction of the volume of individual cells. VP and LP appear to be more androgen-dependent than DP and CG. 相似文献
6.
S Schulze J Schierbeck B H Spars? M Bisgaard H Kehlet 《Acta chirurgica Scandinavica》1987,153(4):255-259
Body temperature, P-cortisol, P-glucose, P-transferrin, haematocrit and total and differential leucocyte counts were investigated in 24 men undergoing inguinal herniotomy, but otherwise healthy. The patients were randomized to general anaesthesia (GA, n = 8), epidural analgesia (E, n = 8) or epidural analgesia + indomethacin (E + I, n = 8). The rectal temperature rose significantly after surgery, except in the E + I group, and increase in blood granulocytes was significantly less in these patients than in the GA group. Group E showed intermediate changes. P-transferrin changes were similar in all three groups. Glucose and cortisol showed only slight increase in the GA group and constant values in groups E and E + I. It is concluded that prostaglandins may play a role in mediating the surgical stress response, but that factors other than neural stimuli and prostaglandins are important in releasing postoperative granulocytosis. 相似文献
7.
In situ hybridization for the detection of chicken anaemia virus in experimentally-induced infection and field outbreaks 总被引:1,自引:0,他引:1
A double stranded DNA probe, biotinylated by random primingj was used for in situ hybridization of chicken anaemia virus (CAV) in thymus tissue. Hybridization was visualized with an alkaline phosphatase conjugated streptavidin biotin complex and the substrate New Fuchsin. The test was performed on both uninfected and CAV-, adenovirus- or infectious bursal disease virus-infected specified pathogen free White Leghorn chickens. In addition, both healthy commercial broilers and broilers with blue wing disease or with colisepticemia, were tested. Genomic CAV was detected in all CAV-infected and blue wing-diseased chickens. With the exception of one chicken with colisepticemia, which showed a unexpectedly positive reaction, all control chickens tested negative in the test developed. 相似文献
8.
Leukotrienes and Prostaglandins in Asthma 总被引:1,自引:0,他引:1
H. Bisgaard 《Allergy》1984,39(6):413-420
Leukotrienes and prostaglandins possess properties which are central in the asthmatic reaction. They are bronchoconstrictors, they inhibit the mucociliary clearance, increase blood flow and permeability and thereby induce edema formation, and they attract and activate leukocytes. They are formed partly by allergic reactions and partly by a large number of other more non-specific reactions. Finally, the concentration of prostanoids has been found increased in the asthmatic reaction in vivo. The leukotrienes have not been traced in vivo in asthmatic attacks so far, but have been found in vivo in man in a specific type I allergic conjunctival reaction. Much evidence suggests that these mediators are relevant in asthmatic diseases, even though prostaglandin inhibitors have no effect in asthma. There still remains the need to investigate the influence on asthmatic diseases by as yet unavailable leukotriene blocking agents. Even though leukotrienes are judged today to be important mediators in asthma, it does not seem reasonable to expect that a single mediator is responsible for asthmatic diseases. Rather, it seems quite likely that asthma is caused by a complex interplay of a large number of mediators, circulating hormones, nervous mechanisms, receptor abnormalities, intracellular metabolic defects, etc. Despite this complexity, investigations in recent years have increased the knowledge of the biochemistry and human physiological effects of leukotrienes and prostaglandins which has created an improved understanding of the asthmatic reaction's pathophysiology, contributed a pharmacological rationale for previously used therapy, and stimulated new perspectives for specific pharmacological research. 相似文献
9.
The music of speech: music training facilitates pitch processing in both music and language 总被引:7,自引:0,他引:7
The main aim of the present experiment was to determine whether extensive musical training facilitates pitch contour processing not only in music but also in language. We used a parametric manipulation of final notes' or words' fundamental frequency (F0), and we recorded behavioral and electrophysiological data to examine the precise time course of pitch processing. We compared professional musicians and nonmusicians. Results revealed that within both domains, musicians detected weak F0 manipulations better than nonmusicians. Moreover, F0 manipulations within both music and language elicited similar variations in brain electrical potentials, with overall shorter onset latency for musicians than for nonmusicians. Finally, the scalp distribution of an early negativity in the linguistic task varied with musical expertise, being largest over temporal sites bilaterally for musicians and largest centrally and over left temporal sites for nonmusicians. These results are taken as evidence that extensive musical training influences the perception of pitch contour in spoken language. 相似文献
10.
S. Aabo J. P. Christensen M. S. Chadfield B. Carstensen J. E. Olsen M. Bisgaard 《Avian pathology》2002,31(1):41-47
The aim of the present study was to compare the invasion of selected zoonotic Salmonella serotypes of poultry in an in vivo chicken intestinal loop model and also in vitro in epithelial cell cultures. Invasion was measured relative to a reference strain, Salmonella Typhimurium 4/74 inv H201::Tn phoA . Two serotypes demonstrated intracellular log 10 counts that differed significantly from all other serotypes tested: Salmonella Enteritidis PT4 being 1.5 log 10 colony forming units (CFU) (31-fold) higher, and Salmonella Tennessee being 0.7 log 10 CFU (fivefold) lower than the reference strain ( P h 0.0001). A group of serotypes, which can be vertically transmitted, showed significantly higher intracellular counts (fourfold to eightfold) than the reference strain. The group included S. Typhimurium 4/74, S. Typhimurium DT104 (poultry and porcine isolates), S. Enteritidis PT1, S. Enteritidis PT6, S. Enteritidis PT8, and Salmonella Berta. The serotypes Salmonella Hadar, Salmonella Virchow, S. 4,12:b:-, S. Typhimurium DT41, and Salmonella Infantis, most of which are considered horizontally transmitted, did not show significantly different intracellular counts from the reference strain. Results from the cell culture invasion studies agreed with the in vivo data, with the exception of S. Berta and the poultry isolate of S. Typhimurium DT104. 相似文献