安全高效防治玉米丝黑穗病种衣剂的研制

通过田间和室内人工模拟低温条件,重复再现了烯唑醇产生药害的症状,首次明确了烯唑醇药剂产生药害的原因,找出了解决的办法.研制出安全、高效防治玉米丝黑穗病的种衣剂"Hc",克服了烯唑醇遇低温易产生药害问题,试验示范防治效果达88.6%。     

Correlation of Serum Cardiac Troponin I and Myocardial Damage in Cattle with Monensin Toxicosis

Background: Cardiac troponin I (cTnI) is used as a biomarker of myocardial injury in people and small animals. Little is known about the diagnostic use of cTnI in cattle.
Hypothesis: Serum cTnI correlates to myocardial function and histopathologic lesions in cattle with monensin-induced myocardial injury.
Animals: Ten healthy cows.
Methods: Experimental study. Animals received 1 dose of monensin PO; 30 mg/kg (n = 1) or 40 mg/kg (n = 1) (Group A) or 50 mg/kg monensin (n = 8) (Group B) of body weight. Repeated measurements were performed of serum cTnI, biochemistry, and ECG and echocardiography until study termination at 80 (Group A) and 144 hours (Group B) after dosing. Semiquantitative histopathologic examinations of the heart were performed in each cow. A scoring system with regard to the magnitude of myocardial injury was established and a total heart score was compared with maximum cTnI concentration measured after monensin administration. Five hearts from healthy cows served as controls.
Results: Increased cTnI (>0.07 ng/mL) was found in 9/10 cows. cTnI was significantly associated with left ventricular shortening fraction ( r ²= 0.51; P = .02) and myocardial histopathologic lesion score ( r ²= 0.49; P = .021). All cows (n = 7) with evidence of myocardial necrosis had a cTnI concentration ≥ 1.04 ng/mL.
Conclusion and Clinical Importance: cTnI is related to myocardial necrosis and severity of myocardial damage in cattle with monensin toxicosis. cTnI could become a useful diagnostic tool in the noninvasive assessment of myocardial injury in cattle with naturally occurring cardiac disease.     

Effect of transmyocardial laser revascularization on myocardial lactatic metabolism and mitochondria of myocardial cells

AIM: We studied the therapeutic effect and mechanism of transmyocardial laser revascularization (TMLR) for the acute myocardial ischemia (AMI). METHODS: 18 dogs were divided randomly and evenly into the control group, the AMI group and the TMLR group. A continuous wave Nd: YAG laser was used for TMLR. Concentration of lactate in artery and coronary sinus (A.Lat and CS.Lat), myocardial metabolic rate of lactate acid (MLR) and myocardial lactate extraction (MLE) were measured before the left anterior descending coronary artery (LAD) ligation and 60 min after the LAD ligation. Myocardial biopsy was made 4 h after the LAD ligation to quantitatively observe the shape and number of mitochondria in myocardial cells by a electric microscope. RESULTS: 60 min after the LAD ligation, CS.Lat were (7.63±4.27) mmol/L in the AMI and (5.78±3.98) mmol/L in the TMLR, respectively (P<0.05); MLR were (0.03±0.01) mmol·100 g^-1 myocardium·min^-1 in the AMI and (0.06±0.02) mmol·100 g^-1 myocardium·min^-1 in the TMLR, respectively (P<0.05); MLE were (12.04±3.04) in the AMI and (21.84±8.49)% in the TMLR, respectively (P<0.05). The volume density of mitochondria were (27.51±7.93)% in the AMI and (31.26±3.85)% in the TMLR, respectively (P>0.05). The area density of mitochondria were (1.25±0.18) μm^-1 in the AMI and (1.64±0.28) μm^-1 in the TMLR, respectively (P<0.01). The number density of mitochondria were (0.10±0.03) μm^-3 in the AMI and (0.18±0.05) μm^-3 in the TMLR, respectively (P<0.01). The average volume of mitochondria were (5.27±2.85) μm³ in the AMI and (2.80±0.54) μm³ in the TMLR, respectively (P<0.05). The average diameter of mitochondria were (2.06±0.36) μm in the AMI and (1.78±0.12)μm in the TMLR, respectively (P＜0.05). CONCLUSION: The study suggests that TMLR may effectively improve myocardial lactatic metabolism and protect the myocardial cells from ischemic injury in dogs with the AMI.