Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND： The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE： To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography （DSA）, magnetic resonance diffusion-weighted imaging （DWI） and magnetic resonance perfusion-weighted imaging （PWI）. DESIGN： Repetitive measure animal experiment. SETTING： Zhongshan Hospital Affiliated to Dalian University. MATERIALS： The experiment was carried out in the Animal Laboratory （Provincial Laboratory）, Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12-15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS： Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging （MRI） was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES： Analytic results of DSA, DWI, PWI and MRI. RESULTS： All 14 experimental piglets were involved in the final analysis. ① DSA： The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI： There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI： There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION： It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.

Clinical implications of the concentration of alveolar nitric oxide in non-small cell lung cancer

To the Editor:Lung cancer,one of the most common types of tumor,is also the leading cause of cancer death,accounting for an estimated 1.8 million deaths worldwide.Early recognition of lung cancer is critical.It has been established that nitric oxide and its byproducts play a role in pathophysiological processes of lung cancer,such as tumor immunity,inflammation,and lung tumor progression.[1]Exhaled nitric oxide(eNO)concentrations can be measured by non-invasive devices.The alveolar concentration of nitric oxide(CaNO)has been proposed as a marker of distal airway inflammation,but its value in nonsmall cell lung cancer(NSCLC)is unknown.