Comparison of the traditional and situational choice questions in the physiological examination / 基础医学与临床

Objective Evaluating the effect of situational questions for qualifying the students'abilities in physiolo-gy examination .Methods Comparing the difficulty coefficients and discrimination indexes between situational and traditional choice questions .Results Compared with the traditional choice questions , the difficulty coefficient of situational questions increased , while the discrimination indexes were more reasonable .The discrimination indexes of situational understanding questions were higher than those of the traditional memory and understanding questions . There were no difference between discrimination indexes of the situational application questions and those of tradi -tional application questions .Conclusions Situational questions not only improved the quality of examinations , but also facilitate evaluating students'learning ability .

Mitochondrial inhibition induces glutamate excitotoxicity mediated motoneuron death / 中华神经科杂志

Objective To study the relation between mitochondria damage and glutamate excitotoxicity in motor neuron disease.Methods Organotypic cerebral cultures were prepared from prefrontal brain of neonatal SD rats. Mitochondria was damaged by malonate sodium, and a NMDA receptor antagonist, MK-801 of 0.025,0.050,0.075,0.100 mmol/L, was respectively added into the cerebral cultures simultaneously in the protective experiment. The morphology of motor neurons was shown by Nissl and anti-high molecular weight filament (anti-NFH) immunohistochemical staining, and number of motor neurons was counted. The concentration of MDA in culture medium was measured by MDA assay. Results After exposed to malonate sodium (0, 1, 3, 5 and 7 mmol/L) for 1 week, the number of motor neurons in cerebral slices showed a dose-dependent decrease (49.78?4.30, 47.89?6.81, 25.67?6.18, 4.44?3.40, 1.22?1.99). The group treated with 3 mmol/L malonate sodium was selected as damage group. In protective experiment, the number of motor neurons in 0.050, 0.075 and 0.100 mmol/L MK-801-treated groups was significantly increased as compared with damage group, still less than that of controls. However, there was no difference of number of motor neurons among these three groups. The concentration of MDA in culture medium in normal control and 3, 5 mmol/L malonate sodium was (13.47?0.49), (15.87?0.74), (20.52?0.74) mmol/L. When treating cerebral cultures with 0.050 mmol/L MK-801 and 5 mmol/L malonate sodium simultaneously, the MDA was decreased to 14.45?0.78, close to normal level. Conclusion Glutamate excitotoxicity plays a role in motor neuron diseases caused by mitochondria damage, there exists a close relationship between glutamate exicitotoxicity and mitochondria damage.