Study on pathophysiological and image diagnostic evaluations in calves with Bovine Respiratory Disease Complex.

牛呼吸系统疾病复合体(BRDC)是世界范围内引起犊牛肺炎的重要原因。本研究旨在评价高渗盐水溶液(HSS)和高渗盐水葡聚糖(HSD)的临床药理作用，并评价BRDC的病理生理和影像诊断表现。这些研究的研究结果如下：(1)HSD改善脑循环的效果优于20%甘露醇。(2)建立了符合临床症状和血浆内毒素活性的实验性内毒素模型。(3)肺炎支原体肺炎小牛的Fischer比率显著低于健康小牛。(4)BRDC小牛BALF中锌和钙的含量高于健康小牛。此外，与健康组相比，添加BRDC的犊牛的锌/铜比更高。锌/铜比值的诊断界值为8.676(p(5)支原体感染危重病例支原体感染；支气管内毒素升高。监测血浆内毒素活性有助于判断大肠型乳腺炎的治疗效果和预后。本课题的研究结果为BRDC的发病机制做出了贡献。

Bovine Respiratory Disease Complex (BRDC) is an important cause of calf pneumonia worldwide. The present studies were to evaluate the clinical pharmacological effects of Hypertonic Saline Solution (HSS) and Hypertonic Saline Dextran (HSD), and to evaluate the pathophysiological and image diagnostically findings of BRDC. Research results of these studies are as follows.(1) HSD was superior in cerebral circulation improvement effects to 20% mannitol. Therefore, HSD may be expected as anti brain hypotensive drugs.(2) the experimentally endotoxin model that was matched the clinical symptoms and plasma endotoxin activity was developed.(3) Fischer ratio of Calves with Mycoplasma pneumonia was significantly lower than the healthy calves.(4) Amount of Zn and Ca of BALF obtained from calf with BRDC was larger than healthy calf. Also, Zn/Cu ration of calves with BRDC was higher Zn/Cu ration compared with healthy one. Diagnostic cut-off value in Zn/Cu is 8.676 (p(5) The BRDC severe cases that Mycoplasma infection; endotoxin has increased in the bronchus and trachea. Those endotoxins transferred to plasma from trachea.(6) Monitoring of plasma endotoxin activity was useful to determine the therapeutic effect and prognosis coliform mastitis. Theses results obtained from this project research contributed to the pathogenesis of BRDC.