奶牛在适应热应激过程中机体产生的代谢变化

当外界环境的温度超过奶牛机体的热适温区时,细胞和组织及新陈代谢都会发生变化,机体对热应激反应的防御系统被激活,表现为开始储存热量、迅速增加蒸发散热。如果持续高温,内分泌系统将会做出一定的调节,促使动物适应这种变化。作者主要阐述了在热应激产生的过程中,奶牛细胞内热应激蛋白,内分泌及能量代谢发生的一些变化,并简述了奶牛对热应激的适应。     

亚慢性染镉对未成年大鼠雌性生殖内分泌毒性研究

通过皮下注射CdCl2,研究了亚慢性染镉对未成年雌性SD大鼠血清性激素（雌二醇E2、孕酮P、卵泡刺激素FSH和黄体生成素LH）水平及生殖器官发育的影响。结果表明：各染镉组体重和卵巢湿重低于对照组（P〈0．05）,高剂量组的子宫系数及湿重低于对照组（P〈0．05）：各染镉组血清中P的水平低于对照组（P〈0．05）;而各染镉组血清的E2、FSH、LH与对照组无差别（P〉0．05）。结论为亚慢性低剂量镉暴露对未成年雌鼠生殖内分泌系统具有明显的毒性作用。     

复方丁氨丙磷溶液的抗冷应激作用及其机理研究

为探讨复方丁氨丙磷溶液的抗冷应激作用及其作用机理,将 45 只 1 日龄肉雏随机分成 3 组,每组 15 只,分别给予生理盐水和不同剂量的复方丁氨丙磷溶液。于第14日龄开始冷暴露,在低温条件下继续饲养 2 周,并观察和检测各项设计指标。结果表明,复方丁氨丙磷溶液能显著降低冷应激肉雏血清肌酸磷酸激酶和碱性磷酸酶活性;显著提高血糖和血清甲状腺素含量,同时降低皮质醇含量;但对血清乳酸脱氢酶活性、胰岛素含量和T3/T4值无显著影响。     

环境激素危害与我国木材保护环境安全对策

简要介绍了环境激素的定义、种类和危害, 论述了木材防腐剂的部分环境激素的危害, 提出了构建我国木材保护环境安全的对策建议。     

Treatment of acute adrenal insufficiency

Hypoadrenocorticism is caused by a lack of endogenous glucocorticoid and mineralocorticoid. These deficiencies can cause a myriad of clinical signs. This disease is uncommon and its clinical presentation is similar to many much more commonly recognized diseases such as renal failure and various gastrointestinal disorders. Severely affected patients may present in a life-threatening adrenocortical crisis, which is characterized by variable degrees of volume depletion and electrolyte abnormalities. The emergency clinician should maintain a high clinical suspicion for hypoadrenocorticism, as early recognition and rapid treatment of hypovolemia and electrolyte abnormalities can be lifesaving. The approach to emergency treatment of hypoadrenocorticism should be to recognize and treat life-threatening arrhythmias, replace intravascular volume and normalize perfusion, correct electrolyte abnormalities and hypoglycemia, administer glucocorticoids, and perform the adrenocorticotrophic hormone stimulation test for definitive diagnosis. Patients with this condition should have a favorable outcome when treated appropriately.     

Decreased sodium:potassium ratios in cats: 49 cases

BACKGROUND: Sodium:potassium (Na:K) ratios are often reported in feline biochemical panels, although the importance of this measurement has not been investigated. OBJECTIVES: The aims of this study were to document the range of feline disease states associated with a decreased Na:K ratio, to determine the prevalence of this biochemical abnormality in a referral hospital population, and to identify any particular disease that was more likely to have a decreased Na:K ratio. METHODS: A group of 49 cats with decreased Na:K ratios was compared with a group of 50 cats with normal Na:K ratios that were randomly selected from the same hospital population. RESULTS: Twelve of the 49 cats (24.5%) had gastrointestinal disease, 10 (20.4%) had urinary disease, 8 (16.3%) had endocrine disease, 8 (16.3%) had cardiorespiratory disease, and 5 (10.0%) had diseases affecting other body systems. Six (12.2%) had artifactually decreased Na:K ratios. No cat was identified with hypoadrenocorticism. Statistical analysis revealed that, although none of these disease states was significantly over- or under-represented in the affected group, a significantly higher proportion of cats with decreased Na:K ratio had body cavity effusions (P = .025). Serum potassium concentrations were significantly higher in the affected group (P < .0001), but there was no significant difference in mean sodium concentration between the 2 groups. CONCLUSIONS: Decreased Na:K ratios frequently occur in cats with diseases other than hypoadrenocorticism, including cats with effusions. These findings should be considered when evaluating cats with this biochemical abnormality.     

Increased plasma fructosamine concentrations in laminitic horses

Reasons for performing study: The use of plasma fructosamine concentration ([fructosamine]) as a marker of abnormal glucose homeostasis in laminitic horses has not been investigated. Hypothesis: Plasma fructosamine concentration may be higher amongst laminitic horses than normal horses; this might relate to underlying insulin resistance. Objectives: 1) To compare [fructosamine] between laminitic and normal horses. 2) To investigate associations between [fructosamine] at presentation in laminitic horses with a) single sample markers of insulin resistance and b) outcome. Methods: Plasma fructosamine concentration, fasting serum insulin concentration (insulin) and fasting plasma glucose concentration (glucose) were measured in 30 horses that presented with laminitis. Clinical details and follow‐up data were recorded. Plasma fructosamine concentration was also measured in 19 nonlaminitic control horses. Results: Laminitic horses had significantly higher mean [fructosamine] than normal horses (P<0.001). Thirteen of 30 laminitic horses had fasting hyperinsulinaemia, 2/30 had fasting hyperglycaemia. Statistically significant univariable correlations were identified between [fructosamine] and [glucose], [insulin] and the proxies RISQI and MIRG. Trends for association between [fructosamine] and negative outcome did not reach statistical significance. Conclusions and potential relevance: Increased mean [fructosamine] in laminitic horses may represent abnormal glycaemic control and [fructosamine] may become a clinically useful marker.     

复方丁氨丙磷溶液的抗热应激作用及其机理研究

为探讨复方丁氨丙磷溶液的抗热应激作用及作用机理,以黄羽肉鸡为对象,检测各处理组肉鸡生产性能,体温及血清T3、T4、胰岛素和皮质醇等内分泌激素,血清肌酸磷酸激酶、碱性磷酸酶、乳酸脱氢酶和血糖等生化指标.将45只1日龄肉鸡仔鸡随机分成3组,每组15只,分别给予生理盐水和不同剂量的复方丁氨丙磷溶液.于14日龄开始热暴露,在高温条件下继续饲养2周,并观察和检测各项指标.试验结果表明,复方丁氨丙磷溶液能明显降低热应激肉仔鸡直肠温度,显著提高T3/T4值和胰岛素含量,能极显著降低血清肌酸磷酸激酶、碱性磷酸酶和乳酸脱氢酶活性,同时提高血糖含量,而对血清皮质醇含量无显著影响.因此,复方丁氨丙磷溶液可通过调整肉仔鸡血清部分激素含量和改变血清部分生化指标来发挥其抗应激作用.     

牛磺鹅去氧胆酸对家禽和小鼠抗热应激作用研究

为探讨牛磺鹅去氧胆酸(taurochenodeoxycholic acid,TCDCA)对热应激条件下AA肉鸡、海兰褐仔鸡及昆明种小白鼠的抗热应激作用,试验检测了TCDCA对热应激条件下AA肉鸡死亡率、海兰褐仔鸡体增重及对热应激小鼠采食量、饮水量、增重、血清中皮质醇和甲状腺素(T3)含量、肝脏组织中热休克蛋白70(HSP70) mRNA表达的影响。结果表明,0.1和0.2 g/kg TCDCA可显著降低热应激AA肉鸡死亡率(P<0.05);0.05、0.1和0.2 g/kg TCDCA可极显著增加热应激海兰褐仔鸡的体增重(P<0.01);0.1 g/kg TCDCA能显著提高热应激小鼠的采食量和饮水量(P<0.05),而对其体增重无显著影响(P>0.05);0.05、0.1和0.2 g/kg TCDCA可使热应激小鼠血清T3含量显著降低(P<0.05);0.1和0.2 g/kg TCDCA可使热应激小鼠血清皮质醇含量显著升高(P<0.05);0.05、0.1和0.2 g/kg TCDCA可显著抑制热应激小鼠肝脏中HSP70 mRNA的表达(P<0.05)。综上所述,TCDCA具有抗热应激作用。