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651.
Turpentine-induced acute inflammatory responses in chicks were studied experimentally. Foot pad oedema was measured using a plethysmograph. Skin vascular permeability was evaluated using the Evans blue technique. Turpentine injury induced a typical biphasic response when the two parameters of the inflammatory reaction were studied. Some unexpected alterations of the turpentine-induced inflammatory response were seen when chicks received non-steroidal anti-inflammatory drugs. Pretreatment with promethazine, phenylbutazone, methysergide and indomethacin resulted in a decrease in foot oedema. An inhibitory effect upon vascular permeability was found when promethazine, phenylbutazone and indomethacin were used. Methysergide did not inhibit the increase in vascular permeability of the skin. Possible mechanisms are discussed.  相似文献   
652.
Calves infected with a sporozoite suspension of the Ikeda strain of Theileria sergenti were examined in attempts to detect the schizont stage. A suspension equivalent to the contents of 70-200 ticks was inoculated subcutaneously into 10 splenectomized calves. Schizonts and micromerozoites were found in the prescapular lymph nodes of 5 calves about 8 days after the sporozoite inoculation. Schizonts detected at the time of nuclear division had large and diffuse nuclei, and many of the schizonts were very large and extracellular in lymph node smears. The schizonts were also detected by the direct fluorescent antibody staining.  相似文献   
653.
654.
Yersinia enterocolitica biovar 4 serovar 3 and biovar 2 serovar 5.27 failed to establish in the intestines of pigs when challenged with the homologous or heterologous strains. After inoculation, the serum O-agglutinin titers were 1/10 or less and were not boosted by challenge with either serovar. Y. enterocolitica were not recovered in any specimens at the time of slaughter.  相似文献   
655.
树皮草炭混配基质对生菜生长的影响   总被引:12,自引:0,他引:12  
采用草炭与熟化树皮混配作基质栽培生菜 ,结果表明 :适当增加树皮比例 ,可促进生菜生长发育 ,树皮∶草炭为 7∶3时 ,单位叶面积干鲜质量、叶绿素含量、根数与根质量、产量及净菜率均最高。而树皮含量高于或低于 70 %时 ,生长发育会不同程度延缓。树皮含量越高 ,生菜单株耗水量越低 ,即节水效果越好 ,同时 ,生菜植株中N、K含量随之提高 ,但P、Ca、Mg各处理间无显著差异。  相似文献   
656.
Ghrelin is a gut peptide which participates in growth regulation through its somatotropic, lipogenic and orexigenic effects. Synergism of ghrelin and growth hormone-releasing hormone (GHRH) on growth hormone (GH) secretion has been reported in humans and rats, but not in domestic animals in vivo. In this study, effects of a combination of ghrelin and GHRH on plasma GH and other metabolic parameters, and changes in plasma active and total ghrelin levels were studied in Holstein bull calves before and after weaning. Six calves were intravenously injected with vehicle (0.1% BSA-saline), ghrelin (1 microg/kg BW), GHRH (0.25 microg/kg BW) or a combination of ghrelin plus GHRH at the age of 5 weeks and 10 weeks (weaning at 6 weeks of age). Ghrelin stimulated GH release with similar potency as GHRH and their combined administration synergistically stimulated GH release in preweaning calves. After weaning, GH responses to ghrelin and GHRH became greater compared with the values of preweaning calves, but a synergistic effect of ghrelin and GHRH was not observed. The GH areas under the concentration curves for 2h post-injection were greater in weaned than in preweaning calves (P<0.05) if ghrelin or GHRH were injected alone, but were similar if ghrelin and GHRH were injected together. Basal plasma active and total ghrelin levels did not change around weaning, but transiently increased after ghrelin injection. Basal plasma insulin, glucose and non-esterified fatty acid levels were reduced after weaning, but no changes by treatments were observed. In conclusion, ghrelin and GHRH synergistically stimulated GH release in preweaning calves, but this effect was lost after weaning.  相似文献   
657.
Granulocyte colony-stimulating factor (G-CSF) is widely used to mobilize peripheral blood stem cells, and expected to restore cardiac function for patients with coronary artery diseases as a consequence of progression of atherosclerosis. Safety issues related to the administration of G-CSF to these patients, however, are still under study. The animal model for atherosclerosis was produced by feeding miniature swine a high-cholesterol diet for 3 months. G-CSF (5 or 10 microg/kg/day) was given to the animal model by daily subcutaneous injections for 10 days and 20 main arteries were evaluated pathologically. In addition, the general toxicological effects were studied on clinical signs, body weight, hematology, blood chemistry and pathology. In the G-CSF-treated groups, a variety of changes related to the major pharmacological activity of G-CSF including an increase in white blood cell (WBC) counts were observed. In many arteries, atherosclerotic lesions similar to Type I-V of the proposed classification by the American Heart Association were observed. No effects of the G-CSF treatment were seen on the histopathological findings, incidence, severity or distribution of atherosclerotic lesions. In addition, no infiltration of neutrophils to the lesions was observed. These findings suggest that the administration of G-CSF causes neither exacerbation or modification of atherosclerotic lesions nor adverse changes despite that a sufficient increase in WBC counts could be achieved in the peripheral blood.  相似文献   
658.
The present 12-month feeding study was carried out with rat groups fed a diet supplemented with meat or milk (meat/milk) derived from the progeny of clones produced by somatic cell nuclear transfer (SCNT) technology. It was conducted to obtain data concerning the chronic toxicities of these edible products during the process of development and reproduction in rats fed such products. The rats were subjected to clinical observations for general health condition and examinations such as sensory/reflex function, grip strength, motor activity, body weight, food consumption, ophthalmology and urinalysis. Moreover, sexually matured rats fed the test diets were mated and examined for items such as the reproductive performances of the dams and health of their pups. After the feeding period, factors related to rat health status, based on the findings for hematology, blood biochemistry, necropsy, organ weight and histology, were examined. There were no biologically significant differences in these factors between the rat groups fed meat/milk powder supplemented diets derived from the progeny and those fed meat/milk powder supplemented diets derived from conventionally bred cattle. Therefore, the present chronic toxicity study suggests that meat and milk derived from the progeny of SCNT cattle might be equivalent to those derived from conventionally bred cattle in use as dietary supplements for rats.  相似文献   
659.
660.
Two neuropeptides, neuropeptide B (NPB) and prolactin-releasing peptide (PrRP), have been suggested to play important roles in control of the hypothalamic-pituitary-adrenal (HPA) axis in rodents. The aim of the present study was to clarify the central actions of NPB or PrRP in sheep. Ovariectomized ewes were surgically implanted with a cannula directed to the lateral ventricle. They received intracerebroventricular (icv) administration of 400 mul of artificial cerebrospinal fluid, NPB (0.05, 0.5 or 5 nmol), PrRP (0.5, 5 or 50 nmol) or corticotropin-releasing hormone (CRH, 0.5 or 5 nmol) through the cannula, and blood samples were taken 30 and 0 min prior to and 15, 30, 60 and 90 min after the injection. Cortisol concentrations in plasma were determined by enzyme immunoassay. Administration of 0.5 nmol NPB resulted in a significant increase in the cortisol concentration compared with the vehicle control, whereas the cortisol concentration after lower or higher doses of NPB did not differ from the control value. Thus, an icv injection of NPB produced a bell-shaped dose-response of cortisol concentration. Administration of PrRP had no significant effect on the cortisol concentrations at any dose examined. Icv injection of CRH dose-dependently increased plasma cortisol concentrations. These results demonstrate that central NPB stimulates cortisol secretion, suggesting that this neuropeptide plays some roles in control of the HPA axis in sheep. On the other hand, unlike its role in rodents, PrRP is unlikely to be involved in control of the HPA axis in this species.  相似文献   
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