Event-related potentials P₃₀₀ with memory function and psychopathology in first-episode paranoid schizophrenia / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the variability of event-related potentials P(300) and the relationship with memory function/psychopathology in patients with first-episode paranoid schizophrenia.</p><p><b>METHODS</b>Thirty patients with first-episode paranoid schizophrenia (patient group) and twenty health subjects (control group) were enrolled in the study. The auditory event-related potentials P₃₀₀ at the scalp electrodes Cz, Pz and Wechsler Memory Scale (WMS) were examined in both groups, Positive And Negative Syndrome Scale (PANSS) was evaluated in patient group.</p><p><b>RESULTS</b>In comparison with control group, patients had longer latency of P₃₀₀ [(390.6 ± 47.6)ms at Cz and (393.3 ± 50.1)ms at Pz] (P<0.01), lower amplitude of P₃₀₀ [(7.7 ± 3.4) μV at Cz and (8.5 ± 3.9)μV at Pz] (P<0.05-0.01). The memory quotient (88.1 ± 10.0) scores and short-term memory, immediate memory in patient group were damaged significantly (P<0.05-0.01). In patient group, the latency of P300 was correlated positively with PANSS scores and negatively with WMS scores (P<0.05-0.01).</p><p><b>CONCLUSION</b>First-episode paranoid schizophrenia has memory deficit, which can be evaluated comprehensively by P₃₀₀ and WMS. The longer latency of P₃₀₀ might be associated with the increased severity of first-episode paranoid schizophrenia.</p>

Chronic mild stress stimulates nitric oxide production in rat brain cortex and hippocampus / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the nitric oxide (NO) levels in rat brain cortex and hippocampus after chronic mild stress.</p><p><b>METHODS</b>Sixteen male Sprague-Dawley rats were allocated into control group and model group randomly. Model rats were induced by consecutive chronic mild stress; weight gain, open field test and sucrose solution consumption were investigated before and after procedure. Nitric oxide contents in prefrontal cortex and hippocampus were determined by spectrophotometric assays.</p><p><b>RESULT</b>Decreased locomotion, loss of interest and anhedonia were observed in chronic mild stress rat model group. Nitric oxide contents in prefrontal cortex and hippocampus were significantly higher in chronic mild stress group [(31.00 +/-2.55)nmol/mg.pro and (38.11 +/-1.73)nmol/mg.pro, respectively] than those in control group [(26.97 +/-1.38)nmol/mg.pro and (36.06 +/-0.87)nmol/mg.pro, respectively] (P <0.05).</p><p><b>CONCLUSION</b>Chronic stress can stimulate NO release, and dysfunction of nitric oxide pathway may be involved in development of depression.</p>

Imbalanced free radicals and antioxidant defense systems in schizophrenia: a comparative study / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To examine changes of blood oxidative-antiovidative level in schizophrenic patients and its relationship with clinical symptoms.</p><p><b>METHODS</b>Forty-six Chinese patients met DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-IV) criteria for schizophrenia and fifty age- and sex-matched healthy controls were enrolled in the present study. Baseline psychiatric symptom severity was assessed with brief psychiatric rating scale, positive and negative syndrome scale on the blood draw day. Fresh blood samples were collected to measure levels of nitric oxide and lipid peroxide in plasma as well as activities of superoxide dismutase, catalase and glutathione peroxidase in red blood cells by spectrophotometric assays simultaneously.</p><p><b>RESULTS</b>Comparison of the biochemical parameters indicated that the level of nitric oxide and lipid peroxide increased in patient group, which represented a positive correlation with positive scale scores; while the activities of three critical enzymes decreased and showed a negative linear correlation.</p><p><b>CONCLUSION</b>This study showed that there are dysregulation of free radical metabolism and poor activities of the antioxidant defense systems in schizophrenic patients. Excess free radicals formation may play a critical role in the etiology of schizophrenia. Using antioxidants might be an effective therapeutic approach to partially alleviate or prevent the symptoms of schizophrenia.</p>