Gap junction is one kind of synapse coexisting with chemical synapse in the nervous system. Nowadays with the development of electrophysiological technique,more research began to focus on the role of gap junction in the neural network,especially in the cognitive function. Gap junction collaborates with chemical synapses to induce the neural network activities related to memory and perception,such as gamma and ripple oscillation,which is regarded as the mechanism of the role of gap junction in cognitive function. This review introduces the structure of gap junction,distribution and expression of different kinds of connexins in central nervous system,which are the basic element of gap junction. Furthermore,this review discusses the role of gap junction in cognition related network oscillations and activity-dependent plasticity of gap junction.

Objective To analysis the biomechanical properties of four-rod fixation system for lumbosacral reconstruction after sacrectomy.Methods Two finite element models of lumbosacral area were established according to pelvic CT images:a subtotal saerectomy model and a total sacrectomy model.The range of motion of L3 vertebral body and max yon Mise stress of instruments of a novel four-rod fixation system were evaluated and compared with those of modified Galveston technique(MGT)under conditions of veaebral body and max von Mise stress of instruments of the four-rod fixation system were evaluated and compared with those of MGT under vertical compression.Results In subtotal sacreetomy model,the range of motion of L3 vertebral body in the four-rod fixation system were 4.2 mm,0.49°,0.49°,0.24°and 0.26°compared to 5.5 mm.0.74°,0.74°,0.27°and 0.30°in the MGT.The max von Mise stress of instruments in the four-rod fixation system were 810.7,148.0,148.0,134.6 and 14.4 MPa,compared to 655.0,109.9,109.9,119.1 and 11.4 MPa in the MGT.In total sacrectomy model under veaical compression,the range of motion of L3 vertebral body and max van Mise stress of instruments in the four-rod fixation system were 10.9mm and 2172 MPa compared to 49.1 mm and 4325 MPa in the MGT.Conclnsion Comparing with the MGT.the four-rod fixation system was stiffer and showed a significant increase in the stability of lumbosacral area.When total sacrectomy without bone graft were performed,the max stress of the four-rod fixation system was much lower than that of the MGT,which means smaller risk of instrument failure.When subtotal sacrectomy or bone graft were performed,despite better stability,the higher stress shielding-effect of the four-rod fixation svstem might be unfavorable for bone fusion,which still need to be evaluated by clinical trials.

Granulocyte colony-stimulating factor (G-CSF) has been demonstrated to have neuroprotective effects in rat model with focal cerebral ischemia through anti-apoptotic pathways and by promoting proliferation of neural stem cells. In the present study, we examined the neuroprotective effect of G-CSF in an acute focal cerebral ischemia rat model with lipid metabolism disorder. Eighty male SD rats were randomly divided into normal diet control group (NC group) and high-fat diet group (HFD group) (n = 40 in each). In HFD group, rats were fed on high fat diet to induce atherosclerosis. After 29 days, 4 rats from each group were sacrificed to evaluate the effects of different diets, and the middle cerebral artery occlusion (MCAO) was performed in the rest of the rats. MCAO rats received either G-CSF (50 μg·kg(-1)·mL(-1)) or phosphate buffered saline (PBS) injection through the external jugular vein for 5 days, which was followed by 5-bromo-deoxy uridine (BrdU, i.p., 50 mg/kg) injection for another 7 days. To evaluate the effects of G-CSF treatment on neurological function, the modified neurological severity score (mNSS) was calculated. The vascular distribution, ischemic cells proliferation, cell apoptosis and the expression of vascular endothelial growth factor (VEGF) were measured to determine the effects of G-CSF treatment. Our results showed that G-CSF-treated rats had a lower mNSS than PBS-treated rats in both NC group and HFD group. G-CSF injection promoted endothelial cell proliferation and vascular regeneration, and inhibited cell apoptosis. The serum and tissue levels of VEGF were significantly increased after G-CSF treatment. It is concluded that G-CSF exerts its neuroprotective effect in focal cerebral ischemia rats with hyperlipidemia by enhancing angiogenesis, promoting cells proliferation, decreasing cell apoptosis, and increasing local VEGF expression.

Objective Global brain atrophy was reported as an important structural change in Alzheimer's disease (AD), while it has been detected in the older person with normal cognitive function. Therefore, this study was aimed at investigating the difference of the neural metabolites in the left hippocampus (HIP) and left frontal cortex (FC) among patients who showed global brain atrophy but with different cognitive function. Methods The 33 patients with global brain atrophy confirmed by MRI scan, underwent a comprehensively clinical and neuropsychological assessment including mini-mental state examination (MMSE), activities of daily living scale (ADL) and clock drawing test(CDT). According to the diagnostic and statistical manual of mental disorders, fourth edition(DSM-Ⅳ) and Mayo clinic rochester(MCR), 14 patients were diagnosed as AD, 9 patients as amnestic mild cognitive impairment(aMCI), and 10 patients as normal cognition. Every person was taken a cerebral proton magnetic resonance spectroscopy(1H-MRS) scan to measure the levels of n-acetylaspartate(NAA), choline(Cho), myo-inositol(MI) and Creatine(Cr) in the left HIP and the left FC. Results While compared with the group with normal cognition, the ratio of NAA/Cr in the AD group reduced 10.2% in the left HIP and 5.3% in the left FC, and the ratio of Cho/Cr increased 17.5% in the left HIP and 16.7% in the left FC, and the ratio of MI/Cr increased 39.5% in the left HIP and 19.2% in the left FC. The ratio of NAA/Cr of the left HIP in the AD group was lower than that in the aMCI group at the decrease rate of 6.4%, while the ratio of NAA/Cr of the left FC was not significantly different between the two groups. The AD group had higher ratios of Cho/Cr at the increase rate of 9.3% in the HIP and 12.3% in the FC, and higher MI/Cr ratios at the increase rate of 30% in the HIP and 17% in the FC than in the aMCI group. The aMCI group showed significantly lower ratio of NAA/Cr at the decrease rate of 4.1% and higher ratio of Cho/Cr at the increase rate of 7.5% in the left HIP than in the normal cognition group. Conclusions Among patients with global brain atrophy, the decrement of ratio of NAA/Cr in the left HIP and the increment of the ratio of Cho/Cr and MI/Cr are predictive of the progress from aMCI to AD. Moreover, the decrement of ratio of NAA/Cr in the left HIP and the increment of the ratio of Cho/Cr are helpful to distinguish the aMCI and the persons with normal cognition.

Autophagy is known as cellular degradation of long-lived proteins and organelles, by a double-membranound structure fusing with the lysosome, for recycling intraceUular constituents and reusing nutri-tion. Defective autophagy is closely correlated with tumorigenesis and tumor progress. There are crosstalks between autophay associated/regulative genes and oncogene/anti-oncogene. More over, regulative autophagic cell death may lead to an novol way for cancer therapy.

Objective To get more diagnostic informa ti on from the acute cerebral infarct, We used1HMRS and TCD to investigate the r elationship between the metabolites in the infarct, the infarct volume, blood f low velocity and blood flow to the infarct, and the clinical neurologic deficit. MethodsFifteen patients with acute cerebral infarct underwent1HMRS and TCD examinations. Clinical neurologic deficit score was c ollected from every patient record at the time of the1HMRS and TCD study. Inf arct volume (V/ml) was determined with machine software automatically. A PRESS a cquisition was used for1HMRS. The peak areas of N,Lac,Cr,Cho in the lesi on region were compared with those in the contralateral side. TCD was performed for measuring Vs, Vm of encephalic blood vessels on both sides, and the responsi ble cerebral blood flow was estimated by Vs. ResultsT here were significant decrease of N,Cr,Vm and ECBF in the lesion region when c ompared with the contralateral side( P

To study the quantitative detection method of T-wave alternans (TWA), we analyzed the relationship between the graphic mode of Poincare scatter and TWA, and proposed 'horizontal search algorithm' to complete graphic processing. Then, based on the shape of Poincare scatter, we took Axial_ratio as the final index. Through Matlab simulation, Axial_ratio was compared with the results of spectral method (SM) and appropriate threshold value was selected to recognize the TWA. The results showed that Axial_ratio could accurately detect the TWA.
Algorithms ; Arrhythmias, Cardiac ; diagnosis ; Electrocardiography ; Humans

The present paper is to analyze the trend of sinus heart rate RR interphase sequence after a single ventricular premature beat and to compare it with the two parameters, turbulence onset (TO) and turbulence slope (TS). Based on the acquisition of sinus rhythm concussion sample, we in this paper use a piecewise linearization method to extract its linear characteristics, following which we describe shock form with natural language through cloud model. In the process of acquisition, we use the exponential smoothing method to forecast the position where QRS wave may appear to assist QRS wave detection, and use template to judge whether current cardiac is sinus rhythm. And we choose some signals from MIT-BIH Arrhythmia Database to detect whether the algorithm is effective in Matlab. The results show that our method can correctly detect the changing trend of sinus heart rate. The proposed method can achieve real-time detection of sinus rhythm shocks, which is simple and easily implemented, so that it is effective as a supplementary method.
Algorithms ; Arrhythmias, Cardiac ; physiopathology ; Electrocardiography ; Heart Rate ; Humans ; Ventricular Premature Complexes ; physiopathology

Objective To compare the changes in optic disc parameters after intraocular pressure (lOP) reduction between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG) eyes, and to determine if there is a difference of lamina eribrosa compliance between POAG and PACG. Design Prospective comparative study. Participants 36 PACG (49 eyes) and 35 POAG (49 eyes). Methods Patients underwent Heidelberg Retina Tomography (HRT Ⅱ) and Humphrey visual field test before IOP reduction. HRT and Humphrey visual field test were repeated one month after the IOP was reduced by laser, anti-glaucomatous medications or surgery treatment. Factors that affected the change in IOP were assessed including age, pretreatment IOP, IOP reduction, initial cup: disc ratio and diagnosis (POAG/PACG). Main outcome measures Changes of HRT parameters including cup area, mean cup depth, cup volume, and rim area after IOP reduction. Results The cup area, mean cup depth and cup volume decreased, and rim area in-creased significantly when the IOP was reduced (P<0.05), but there were no significant differences in the changes between PACG and POAG patients (P>0.05). Changes of these four HRT parameters were related to the amount of IOP reduction and the baseline ratio of cup to disc(P>0.05), but not related to age and pre-treatment IOP (P<0.05). Conclusions The cup became smaller and the rim area in-creased after IOP lowering with treatment in both POAG and PACG, and the magnitude of the change was similar in both groups. The lamina cribrosa compliance may not be different between POAG and PACG. (Ophthalmol CHN, 2009, 18: 264-269)

Objective:To determine the expression of miR-17-92 cluster in osteosarcoma tissue samples and explore its associa-tion with clinical significance. Methods: Quantitative polymerase chain reactiom analysis was used to examine the expression of miR-17-92 cluster in osteosarcoma tissues. Normal bone tissues from 63 patients were matched, and the relationships between the ex-pression of miR-17-92 cluster and the clinicopathological features and prognosis of osteosarcoma were explored. Results:The relative expression of miR-17-92 cluster in osteosarcoma tissues was significantly higher than those in adjacent normal tissues (P<0.05). The high expression of miR-17-92 had a significant correlation with reduced survival (P=0.027). Conclusion:The expression of miR-17-92 cluster closely correlates with the occurrence and progress of osteosarcoma and may be used as an indicator for osteosarcoma prognosis.