The detection and classification of extracellular action potentials(i.e.spike) of various single neurons from extracellular recordings are crucial for extracting neuronal spike sequences and thereby for investigating the mechanisms of neural information processing in the central nervous system.In order to increase the correctness of spike detecting and sorting,a new analysis algorithm for processing multi-channel spike signals recorded from rat hippocampi with silicon microelectrode arrays is presented.Four recording contacts on the electrode array are arranged close enough to simultaneously record spikes emitted from same neurons.Firstly,the algorithm extracts all spikes in the four channel recordings by using a multi-channel threshold detection method.Secondly,the algorithm classifies the spikes based on a principle component analysis for a specifically designed type of compound spike waveforms.The compound spike waveform is formed by linking four spike waveforms of a same neuronal firing in the four recording channels one by one in series.The test results with both synthetic datasets and experimental recordings reveal that compared with corresponding traditional single-channel algorithm,the multi-channel algorithm can significantly enhance both the number of extracted spikes and the correctness of spike classifications.The algorithm can also increase the number of isolated neurons from a single experimental preparation.These results indicate that the novel method is efficient for the automatic detection and classification of neuronal spikes.

Objective To evaluate the value of volumetric brain MRI in multiple system atrophy.Methods Eleven patients diagnosed as multiple system atrophy were recruited,includin 5 parkinsonism dominant(MSA-P)and 6 cerebellar dominant(MSA-C).9 patients with parkinsonism of other types and 6 healthy persons were set as case control and healthy control,respectively.T1 weighted (T1W)sagittal and axial images and T2-weighted(T2W)axial images were obtained from all patients and controls at 3.0T scanner.Diameters of the brain structures were measured infratentorially(brainstem, middle cerebellar peduncles(MCP),dentate and red neelus)and supratentorially(globns pallidus and putamen).Results The transverse diameter of the pons was significantly smaller in MSA patients than in the case and healthy controls((27.6?2.0)mm and(30.5?0.6)mm and(29.9?1.1)mm).The significance could be seen when comparing MSA-C and MSA-P with healthy control.The anteroposterior diameter of the fourth ventricle was significantly dilated in MSA patients than in healthy control((11.9? 2.8)mm and(9.0?2.1)mm).The MRI of MSA-C showed narrower MCP((13.3?1.9)mm and (15.8?1.2)mm and larger fourth ventricle((17.3?2.1)mm and(12.6?2.7)mm)than that of MSA-P.The MRI of MSA-P showed smaller globus pallidus and red neclei.Conclusions The volumetric MRI is a useful means in evaluating the brain structure atrophy in multiple system atrophy.The transverse diameter of the pans,though objectively reflecting the atrophy of the pons,can' t be used to differentiate MSA-P from MSA-C.The atrophy of MCP and the dilated fourth ventricle are common in MSA-C,while the atrophy of red neclei is common in MSA-P.

Animals ; Blood Glucose ; Diet, High-Fat ; Ghrelin ; blood ; Lipids ; blood ; Physical Conditioning, Animal ; Rats

Drug Interactions ; Humans ; Proton Pump Inhibitors ; pharmacology ; Ticlopidine ; analogs & derivatives ; pharmacology

OBJECTIVETo study the effect of melatonin on the gastrointestinal motility and plasma levels of the stress hormone in overtraining rats.

METHODThirty adult SD rats were randomly divided into three groups (n = 10): control group, over-training group, melatonin intervention group. 30 min before each training, rats in the control and over-training groups were fed with normal saline (15 mg/kg) once a day and 5 times per week, while rats in the melatonin intervention group were administrated with melatonin, perfusion in the intervention group (15 mg/kg). Excessive training group and melatonin intervention group rats were subjected to excessive training at 5 times a week for 6 weeks. After 6 weeks, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma motilin (MTL) and calcitonin gene-related peptide (CGRP), cortisol (CORT) and catecholamines (CA) were observed in all groups.

RESULTSCompared with the control group, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma MTL, CORT and CA were increased significantly (P < 0.01) while the content of CGRP was reduced (P < 0.01) in over-training group. After treated with melatonin, this trend was reversed, that was, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma MTL, CORT and CA were surpressed significantly (P < 0.01) while the content of CGRP was improved obviously (P < 0.01) in over-training group.

CONCLUSIONMelatonin plays an important role in protecting gastrointestinal tract from dysfunction, in which MTL, CGRP, CORT and CA are all involved.

Animals ; Calcitonin Gene-Related Peptide ; blood ; Catecholamines ; blood ; Fatigue ; Gastrointestinal Motility ; Hydrocortisone ; blood ; Melatonin ; pharmacology ; Motilin ; blood ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Stress, Physiological

ObjectiveTo investigate the expression levels of the red blood cell surface receptors and oxidative stress of patients with hemodialysis,evaluate the immune function of the red blood cells,and identify the cause of infection and high prevalence of tumor in patients with hemodialysis.MethodsForty-five long-term hemodialysis patients from our blood purification center was chosen as the treatment group.Forty-five healthy individuals conducting physical examination at the same period was chosen as the control group.The flow cytometric method was used to detect CD35 surface receptors numbers of the red blood cell.The red blood cells wreath experiments were used to measure the adhesive function.The ELASA method was used to test the changes of oxidative stress index:SOD,MDA,CAT and GSH-PX.ResultsCompared to the normal control group,the treatment group had significantly lower levels of CD35 [ ( 28.62 ±6.95 ) AU vs.( 19.71 4.89) AU,t =5.441,P ＜0.01 ],impaired adhesive function red blood cells[ (0.63 ±0.07) vs.(0.44 ±0.04),t =0.41,P ＜0.05].For the levels of oxidative stress index,MDA [ ( 6.18 ± 0.16 ) μmol/L vs ( 13.47 ± 0.39 ) μmol/L ] was significantly higher in the treatment group than in the normal control group( t =13.14,P ＜ 0.05 ),and SOD( 34 202.00 ± 1634.00) U/( g · Hb),CAT ( 21.70 ± 0.84 ) U/ml and GSH-PX ( 444.00 ± 10.31 ) U/ml were significantly lower in the treatment group than in the normal control group [ SOD:(24 652.00 ± 2179.00)U/( g · Hb),CAT:( 14.80 ± 1.13 ) U/ml,GSH-PX:( 217.89 ± 13.70 ) U,t =20.246,9.496,27.195,P ＜0.05 ].ConclusionPatients with hemodialysis had lower numbers of red blood cell surface receptors CD35 and impaired immune function of adhesion,and higher oxidative stress levels.This may be the cause of infection and tumor of patients with hemodialvsis.

Objective To investigate the expression of PTPN13 in human gastric cancer and gastric cancer SGC-7901celllineanditsassociationwithproliferationandinvasion.Methods 106casesgastriccancertissuesamples and matched normal peritumorial tissues were collected .SGC-7901 cells were cultured and divided into two groups including pcDNA3.1-PTPN13 transfection group and without transfection group .Immunohistochemical technique was used to detecte protein expression of PTPN 13.The association of PTPN13 expression with tumor location , tumor size , depth of invasion and tumor metastasis were analyzed .The survival rate of patients with different PT-PN13 expression was calculated by Kaplan-Meier curves.CCK-8 assay was used to estimate the proliferation chan-ges.Using Trans-well assay analyzed the invasion of SGC-7901 cells.Moreover, Western blot was performed to de-tect the markers of EMT including E-cadherin, Snail and MMP9.Results Immunohistochemistry showed the expression rate of PTPN13 in gastric cancer tissues was lower than normal tissue (31 %vs 83%, P<0.05).The expression of PTPN13 in patients was related to with different tumor size , depth of invasion and tumor metastasis (P<0.05).The 2-year survival rate of patients with negative PTPN13 expression were lower.Overexpression reduced both proliferation and invasion in SGC-7901 cells.Up-regulated PTPN13 may increase E-cadherin level but decreases the level of Snail and MMP9 .Conclusions PTPN13 plays a role in gastric cancer tissue and cells as a tumor suppressor.Lower PTPN13 may predict a poor prognosis.PTPN13 may be used as therapy target in gastric cancer.

Acute Disease ; Adult ; Female ; Herbicides ; poisoning ; Humans ; Male ; Middle Aged ; Paraquat ; poisoning ; Retrospective Studies ; Young Adult

Problem-based learning is a student-centered teaching mode,which is based on creating question circumstances.In our clinical teaching,we put up questions based on real cases and inspire students'enthusiasm,activity and creativity.The results show the PBL can elevate students' clinical ability and also can promote teachers'capability.

Objective　To study the effect of aluminum on learning and memory and the synaptic interface constructure in hippocampus CA3 area in rats. Methods　The electrical maze were used to test the behavioral reaction of rats. Some parameters of synaptic interface structure were measured by the method of ultrastructural quantitative analysis in hippocampus CA3 area in the rats. Results　The time coming through the E-maze prolonged siginificantly in the experimental group compared with the normal control (P＜0.01), meanwhile the cyto-apparatus demonstrated the pathogenetic changes. Amounts of synapse obviously reduced and the post-synaptic density turned thinner in experimental group than in the control group (P＜0.01). Conclusion　Aluminum can cause the malfunction on learning and memory, which related to the plastic of synapse.