With the development of brain research, study of neural coding has attracted more attention. Neural coding by informatics entropy is a very important aspect in the research field. This paper presents an overview of typical entropy coding methods of neuronal spike train including binary string method, direct method, asymptotically unbiased estimator method, inter-spike interval and mutual information method. Related principles and application are reviwed.

OBJECTIVE: To observe monocyte chemoattractant protein 1 (MCP-1) changes in ischemic tissue during the process of angiogenesis induction in ischemic limbs by autologous mesenchymal stem cell (MSC) transplantation.METHODS: Twenty male Sprague-Dawley rats were randomized to 2 groups (n = 10): model and MSC transplantation. Femoral and tibial bone marrow was taken to isolate and culture MSCs by percoll density gradient method. Cells of the 3~(rd) or 4~(th) passage were used for transplantation. Severe bilateral hind limb ischemia was surgically created in each group rats. Two hours after model establishment, MSCs (1×10~(11)/L) were infused into the ischemic region of rats from the MSC transplantation group, and the model group received the same amount of phosphate buffered saline. Collateral artery formation was determined by angiographic analysis and histological assessment. CD68~+ macrophage infiltration was examined by immunohistochemistry. MCP-1 protein expression in the plasma and ischemic tissue was detected by enzyme-linked immunosorbent assay. MCP-1 mRNA expression in ischemic tissue was detected by reverse transcription-polymerase chain reaction.RESULTS: At postoperative 28 days, treatment with MSC transplantation lead to collateral vessel formation, and immunohistochemistry demonstrated that CD68~+ macrophage infiltration was lower compared with the model group. MCP-1 protein and mRNA expression in the plasma and ischemia tissue was significantly lower in the MSC transplantation group than in the model group (P < 0.05).CONCLUSION: Following MSC transplantation, MCP-1 may play an important role in ischemia-induced angiogenesis. This indicates that MCP-1 would become one possible target molecule for modulating inflammatory angiogenesis by MSC Transplantation.

Transient ischemic attack (TIA) is not only an ischemic cerebrovascular disease with high incidence, but also a risk warning signal of cerebral infarction. This article reviewed the correlation of TIA and cerebral infarction, risk factors of transient ischemic attack progressing into cerebral infarction and its score scale.

Attention Deficit Disorder with Hyperactivity ; therapy ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Phytotherapy ; methods

Objective To study the etiology,clinical presentation,MR images,treatment and prog-nosis of spontaneous spinal epidural and subdural hematoma.Methods From1995to2002,6cases diag-nosed as spontaneous spinal epidural and subdural hematoma were reviewed retrospectively.All of the pa-tients were males aging from30to68years with an average of 47years.The onset was acute while the pa-tients were in resting or light activity without prior history of any infection,administration of drugs or trau-ma.One patient had the history of hypertension,and another one was found to have diabetes after admission.The clinical characteristics were sudden pain involving neck,shoulder,chest and back,then dysfunction of motion and sensation of extremities and sphincter within few minutes.4cases of spontaneous spinal epidural hematoma were located at T 5~6 ,T 2~4 ,C 4~5 and C 6 ~T 1 respectively,and2cases of spontaneous spinal subdu ral hematoma at C 7 ~T 1 and C 7 ~T 2 respectively.Results All cases were proved with surgery and pathology.MR imaging showed occupying mass in the posterior or posteriolateral region inside the spinal canal.T 1 -weighted imaging was most useful owing to its typical signal changes with the hematoma.T 2 -weighted gra-dient echo sequence was capable to identify epidural and subdural spinal hematoma.Total laminectomy and hematoma debridement were performed.The outcome was closely related to the interval between the onset and surgery.The patients were followed up from6to18months with an average of 10months.All cases showed no significant improvement of spinal cord function except 5cases with incomplete recovery of sphincter function.Conclusion Spontaneous spinal epidural and subdural hematoma are rare entities.MRI is a most helpful diagnostic tool for this disorder.It should be stressed that early diagnosis and prompt surgical intervention are of great importance for prognosis of spontaneous spinal epidural hematoma.

Objective To observe the effects of IFNα-2b on keloid fibroblasts in cell prolifera-tion, apoptosis, expression of hTERT and bcl-2 mRNA and to explore its anti-keloid mechanism. Methods Primary cultures of dermal fibroblasts derived from 8 keloid and 8 normal skin samples were established, strains of fibroblasts at passages 3 to 4 were used in this study. Keloid and normal skin fibroblasts in culture medium in vitro were given IFNα-2b and were obsevered in different time. The proliferation of the fibroblasts was measured by MTT assay, the apoptosis was analysed by flow cytometry(FCM), and the expression of hTERT and bcl-2 mRNA were obsevered by semi-qnantitativere verse transcriptase-polymerase chain reaction (RT-PCR). The data were analyzed by statistical software (SPSS11. 5). Results IFNα-2b could inhibit the growth of keloid and nomal skin fibroblasts. The suppression of keloid and nomal skin fibroblasts was time-dependent. After the effect of 10 000 U/ml INFα-2b on cultured fibroblast of keloid and normal skin,the fibroblasts apoptosis was induced and the expression of hTERT and bcl-2 mRNA was lower than that of controlled group . The result was significantly different between control group and treatment group and was related with the treatment time of INFα-2b (P<0.01). Conclusions As a negative regulatory factor,interferon α-2b can suppress growth and proliferation of keloid fibroblasts and induce apoptosis. Decreasing the telomerase activity of keloid fibroblasts may be one of the most important mechamisms. That IFNa-2b inhibited telomerase activity in keloid fibroblasts is an important pathway that may play a key role in the anti- keloid therapy.

Objective To study the expression of PTEN,Fas and DCR3 in human gastric cancer and evaluate their effects on carcinogenesis,cell proliferation,invasion and metastasis of gastric carcinoma,as well as clinical significance.Methods The expression of PTEN,Fas and DCR3 were detected by immunohistochemical method (streptavidin-peroxidase) in the tissues of 75 primary gastric carcinomas and 15 gastric ulcers.Results The positive expression rate of DCR3 in gastric carcinoma tissues was significantly higher than that in normal tissues,and the expression of PTEN and Fas was obviously lower than that in normal tissues (P<0.01).The expression of DCR3 was negatively correlated with Fas and PTEN respectively (r=-0.720,P<0.001; r=-0.336,P<0.001).There was a positive correlation between PTEN and Fas.The expression of PTEN,Fas and DCR3 was closely correlated with lymph node metastasis,clinical stage,histological differentiation grade and tumor depth of gastric cancer,but not related to sex,age and tumor size (P>0.05).Conclusion PTEN,DCR3 and Fas have mutual restrictive relationships in the process of invasion and metastasis in gastric cancer.Detecting the expression of PTEN,Fas and DCR3 in gastric cancer is helpful to judge the malignant biological behavior of gastric cancer at a different angle,which may be considered as reliability index in clinic diagnosis,judging curative effect and monitoring the prognosis of gastric carcinoma.

Radionuclide imaging was widely used in the diagnosis and treatment of skeletal diseases.It is of early diagnostic value in metastatic osteosarcoma，osteomyelitis and Paget's disease,and early affirmative value in vitality of transplanted bone.It also demonstrates a significant analgesic effect on theosteosarcoma and metastatic osteosarcoma.

To investigate the relationship between endothelium dysfunction and experimental vasospasm, twenty-eight New Zealand white rabbits were randomly allocated into three groups: sham operation control group(Group 1, n=8), balloon endothelial denudation + normal diet group (Group 2, n=8) and balloon endothelial denudation + hypercholesterol diet group (Group 3, n=12). Angiography was performed to detect the vasospasm induced by ergonovine and endothelium-dependent vasodilator response induced by acetylcholine before and immediately after denudation and 8 week later. Visible vasospasm was induced at the denuded sites in group 3, and endothelium dysfunction was also found in the same locations. Positive correlation was showed between vasospasm and endothelium dysfunction. Endothelium dysfunction resulted from balloon endothelial denudation and hypercholesterolemia may play an important role in the pathogenesis of experimental vasospasm.

Objective To investigate the early effects of intervention with tanakan on retinal function in diabetic retinopathy(DR) after laser photocoagulation. Methods Prospective random controlled study was performed on 60 Patients (60 eyes) from 23 to 69 years old with DR(phase Ⅲ～Ⅳ). The multifocal electroretinograms (MERG) were tested with VERIS Ⅳ before , the 3rd day and the 7th day after photocoagulation. Results No significant differences were found in the latencies and response densities of N1,P1 and N2 between the two groups before photocoagulation. Compared with that before photocoagulation, three days after photocoagulation the latencies in tanakan group had no significant change. The response densities of N1,P1 and N2 reduced and the changes were much smaller than that in control. Three days after photocoagulation ,the response densities of P1 and N2 in the central macula 5? area were much higher and the latencies of P1 and N2 were significantly shorter than that in control group. There were no significant differences in the response densities in the 7th day and the differences in the latencies between two groups still existed. Conclusion Tanakan may be effective in preventing the retina from damage of retinal photocoagulation in some degree in DR.