OBJCTIVE :To investigate the fundus ocu]i changes in hypnxie isehemic encepbalnpa ally(HIE)of new[x,rns. METHODS:One hundred and two newblt;~rns suffered from HIE were investi- gated to observe lhe pathological neular fundus changes by di~et ophthabnoseopy after mydria~s. RE- SULTS:Seventy seven ca.~s(154 eyes)were found to have ophthalmoscopic changes in the ~ular fundi including papilledema .white retina vaseolar abnormality and hemorrhage. CONCLUSIONS:In clinical view .the severity of HIE depends on the pathological ebanges of the brain .and ftmdus ahnormalby will be very often in middle and .~vere sufforers of HIE.
Objective To study the effects of several neurotrophic factors and growth factors on the survival of human retinal ganglion cells(RGC)in vitro. Methods RGC were isolated from donor eyes and cultured.RGC in cell culture were identified by morphologic criteria and immunocytochemical staining.Various neurotrophic factors and growth factors were added individually to the cultures.Numbers of RGC in wells in which these agents had been added were compared with those from control wells(cultures without supplements). Results No or very few RGC were present in cell cultures containing medium without supplements or those supplemented with neurotrophin-3(NT-3),nerve growth factor (NGF),epidermal growth factor(EGF)amd plateletderived growth factor(PDGF).Numbers of RGC(per 10 fields)in cell cultures containing brain derived neurotrophic factor(BDNF),ciliary neurotrophic factor(CNTF),neurotrophin-4/5(NT-4/5)and basic fibroblast growth factor(bFGF)wer 4.08,1.23,2.63 and 2.65,respectively,significantly more than found in the control cultures. Conclusions BDNF,NT-4/5,bFGF,CNTF improve survival of human RGC in vitro,while NGF,NT-3,EGF and PDGF do not. (Chin J Ocul Fundus Dis, 1999, 15: 149-152)
Objective To observe the expression of related proteins of retina after subretinal implantation with inactive chips.Methods A total of 27 healthy adult New Zealand white rabbits were randomly divided into three groups: operation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina;shamoperation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina which was taken out immediately;the control group (3 rabbits). Animals were sacrified for immunohistological study 7,15,30 and 60 days after surgery.The rabbits in control group group were sacrified for immunohistological study after bred for 30 days.The expressions of glial fibrillary acidic protein (GFAP) and brain derived neurotrophic facor (BDNF) were observed.Results In operation group, the outer nulear layer of retina thinned, and the cells in the inner nulear layer was disorganized 7,15,and 30 days after the surgery;glial cells proliferated 60 days after surgery; the positive expression of BDNF and GFAP was more than that in the shamoperation and control group.In shamoperation group, the positive expression of BDNF and GFAP was more than that in the control group.No obvious difference of expression of BDNF and GFAP between each time point groups was found.Conclusions The expression of neroprotective related proteins increased after subretinal implantation with inactive chips suggests that limited neuroprotective effects might be led by the implantation.
Due to the high complexity and subject variability of motor imagery electroencephalogram, its decoding is limited by the inadequate accuracy of traditional recognition models. To resolve this problem, a recognition model for motor imagery electroencephalogram based on flicker noise spectrum (FNS) and weighted filter bank common spatial pattern (wFBCSP) was proposed. First, the FNS method was used to analyze the motor imagery electroencephalogram. Using the second derivative moment as structure function, the ensued precursor time series were generated by using a sliding window strategy, so that hidden dynamic information of transition phase could be captured. Then, based on the characteristic of signal frequency band, the feature of the transition phase precursor time series and reaction phase series were extracted by wFBCSP, generating features representing relevant transition and reaction phase. To make the selected features adapt to subject variability and realize better generalization, algorithm of minimum redundancy maximum relevance was further used to select features. Finally, support vector machine as the classifier was used for the classification. In the motor imagery electroencephalogram recognition, the method proposed in this study yielded an average accuracy of 86.34%, which is higher than the comparison methods. Thus, our proposed method provides a new idea for decoding motor imagery electroencephalogram.
Objective To set up and to evaluate an acute closed brain injury model in rats. Methods The acute closed brain injury was produced in rats by using an impactor consisting of a stand, a guide tube, a weight and a footplate. Ninetysix SD rats were divided into a control group(n＝32, no impact), a mild injury group(n＝32, impact once at force level of 400 g·cm) and a severe injury group(n＝32, impact once at force level of 800 g·cm) to elucidate the physiological responses, the pathophysiological changes and brain edema after brain injury at different injury levels. Results In the mild injury group and the severe injury group, a sudden rise or reduction of blood pressure, deep and fast breath apnea, and pain reflects inhibition were observed. The responses were more obvious in the severe injury group than in the mild injury group. The water content of the brain increased after 6 hours of injury. The pathological contusion and edema of brain were noted or above the impact force level of 800 g·cm. When the impact force rose to or over 1200g·cm, the animals died of persistent apnea mostly. Conclusion Although the established closed brain injury model with different biomechanical mechanisms as the clinical brain injury, it is in conformity with pathological changes and pathophysiological characteristics of acute clinical brain injury, it can be utilized extensively because of its convenient and practice.
Traditional depression research based on electroencephalogram (EEG) regards electrodes as isolated nodes and ignores the correlation between them. So it is difficult to discover abnormal brain topology alters in patients with depression. To resolve this problem, this paper proposes a framework for depression recognition based on brain function network (BFN). To avoid the volume conductor effect, the phase lag index is used to construct BFN. BFN indexes closely related to the characteristics of “small world” and specific brain regions of minimum spanning tree were selected based on the information complementarity of weighted and binary BFN and then potential biomarkers of depression recognition are found based on the progressive index analysis strategy. The resting state EEG data of 48 subjects was used to verify this scheme. The results showed that the synchronization between groups was significantly changed in the left temporal, right parietal occipital and right frontal, the shortest path length and clustering coefficient of weighted BFN, the leaf scores of left temporal and right frontal and the diameter of right parietal occipital of binary BFN were correlated with patient health questionnaire 9-items (PHQ-9), and the highest recognition rate was 94.11%. In addition, the study found that compared with healthy controls, the information processing ability of patients with depression reduced significantly. The results of this study provide a new idea for the construction and analysis of BFN and a new method for exploring the potential markers of depression recognition.
【摘要】 目的 探討顱腦損傷(BI)死亡的法醫病理學特點,以及繼發性腦干損傷、并發癥的發生與死亡之間的因果關系。方法 從性別、年齡、致傷方式、損傷類型、生存時間、死亡原因等方面,對四川大學華西法醫學鑒定中心1998年1月-2008年12月127例BI死亡尸檢案例進行回顧性統計研究分析。結果 127例法醫病理學檢案中,原發性BI死亡51例(402%),繼發性腦干損傷死亡61例(480%),并發癥死亡15例(118%),其中傷后12 h內死亡者直接死因均為嚴重原發性腦損傷,存活12 h～1周者直接死因以繼發性腦干損傷居多,生存時間超過1周者約半數死于并發癥。結論 在BI案例的死亡原因確定時,應在全面系統的病理學檢驗基礎上,結合案情及臨床資料進行綜合分析。【Abstract】 Objective To explore the characteristics of forensic pathology in traumatic brain injury and the relationships between secondary brainstem damage, complications and the causes of death. Methods 127 cases were reviewed from gender, age, manner of injury, survival time and the direct causes of death from January 1998 to December 2008. Results Of the 127 cases, the key direct cause of death was secondary brainstem damage, followed by severe primarily brain injury and complications. For those who died within 12 hours after injury, the direct cause was severe primarily brain injury; for those who survived between 12 hours to one week, secondary brainstem damage was in the majority of the causes and for those who survive more than one week time, complication was an important cause. Conclusion In the cases of traumatic brain injury, we should take comprehensive and systematic examination of forensic pathology, and refer to clinical data at the same time to determine the direct cause of death.
The effective classification of multi-task motor imagery electroencephalogram (EEG) is helpful to achieve accurate multi-dimensional human-computer interaction, and the high frequency domain specificity between subjects can improve the classification accuracy and robustness. Therefore, this paper proposed a multi-task EEG signal classification method based on adaptive time-frequency common spatial pattern (CSP) combined with convolutional neural network (CNN). The characteristics of subjects' personalized rhythm were extracted by adaptive spectrum awareness, and the spatial characteristics were calculated by using the one-versus-rest CSP, and then the composite time-domain characteristics were characterized to construct the spatial-temporal frequency multi-level fusion features. Finally, the CNN was used to perform high-precision and high-robust four-task classification. The algorithm in this paper was verified by the self-test dataset containing 10 subjects (33 ± 3 years old, inexperienced) and the dataset of the 4th 2018 Brain-Computer Interface Competition (BCI competition Ⅳ-2a). The average accuracy of the proposed algorithm for the four-task classification reached 93.96% and 84.04%, respectively. Compared with other advanced algorithms, the average classification accuracy of the proposed algorithm was significantly improved, and the accuracy range error between subjects was significantly reduced in the public dataset. The results show that the proposed algorithm has good performance in multi-task classification, and can effectively improve the classification accuracy and robustness.
ObjectiveTo investigate the effect of sex on learning and memory ability of newborn mice with hypoxic-ischemic brain injury.MethodsFifty C57BL/6 mice aged 10 days were divided into hypoxia-ischemia group and sham group according to the random number table method, and there were 28 in the hypoxic-ischemic group and 22 in the sham group with half female and half male respectively. In the ischemia-hypoxia group, the left common carotid artery was ligated and then the mice were placed in 34℃ hypoxia chambers with 8% oxygen and 92% nitrogen mixture for 45 minutes. In the sham group, only the skin of the left neck was cut and sutured. After 2 months, Y maze test and Morris water maze test were used to evaluate the learning and memory ability of mice.ResultsThe success rate of the hypoxic-ischemic group was 71.4% (20/28), and that of the sham group was 100.0% (22/22), a total of 42 mice were enrolled in the experiment. In Y maze test, there were differences in entries and total distance of new arms between the two groups (entries: F=16.068, P<0.001; total distance: F=8.532, P=0.007); compared between different groups in the same gender, the entries and total distance of new arms in the hypoxic-ischemic group were lower than those in the sham group with statistically significant differences (entries in males: P=0.001, entries in females: P=0.012; total distance in males: P=0.010, total distance in females: P=0.046). Compared between males and females in the same group, the entries and total distance of new arms of females were higher than those of males in the hypoxic-ischemic group, with statistically significant differences (P=0.039, 0.043). In Morris water maze test, the escape latency of positioning navigation in the hypoxic-ischemic group was higher than that in the sham group, and males showed more obviously poor performance (P<0.001); in the experiment of space exploration, differences were found in the duration of stay and the target quadrant entries between the two groups (duration of stay: F=8.297, P<0.001; entries: F=4.042, P=0.014), and there were statistically significant differences in the same gender males and females in the hypoxic-ischemic group and the sham group (duration of stay in males: P=0.003, duration of stay in females: P=0.038; entries in males: P=0.006, entries in females: P=0.041). Compared between males and females in the same group, the duration of stay and the target quadrant entries of females were higher than those of males in the hypoxic-ischemic group, with statistically significant differences (duration of stay: P=0.018; entries: P=0.032).ConclusionsThe learning and memory ability of newborn mice may be slightly impaired after hypoxic ischemic brain injury. There is significant difference in the effect on learning and memory ability between different genders, and the effect on males is higher than that on females.
ObjectiveTo analyze insulin resistance in patients with cerebral infarction and its correlation with plasma homocysteine level. MethodsA total of 100 cerebral infarction patients diagnosed between July 2013 and August 2014 and 100 healthy physical examination subjects were included in our research. The plasma homocysteine level was detected; the levels of fasting plasma glucose and fasting insulin were detected at the same time. ResultsPlasma homocysteine level (34.95±14.55) μmol/L in patients with cerebral infarction was significantly higher than that of the control group (8.84±2.27) μmol/L (P<0.05). Insulin resistance index (6.24±3.15) in patients with cerebral infarction was significantly higher than that of the control group (2.19±0.63) (P<0.05). The plasma homocysteine level in the infarction group with insulin resistance was significantly higher than that in the infarction group without insulin resistance (P<0.05). The plasma homocysteine level in the infarction group without insulin resistance was significantly higher than that of the patients with insulin resistance in the control group (P<0.05). In the cerebral infarction group, insulin resistance index was positively correlated with plasma homocysteine level (r=0.600, P<0.01). ConclusionInsulin resistance and plasma homocysteine level play important roles in clinical cerebral infarction. Improving insulin resistance and decreasing plasma homocysteine level may be effective ways to reduce the incidence of cerebral infarction.