The role of carotid stenosis ultrasound scale in the prediction of ischemic stroke.

INTRODUCTION: To improve the accuracy of ultrasound techniques for the assessment of carotid stenosis, we designed a novel carotid artery stenosis ultrasound scale (CASUS), and evaluated its accuracy, reliability, and its value in predicting the occurrence of cardiovascular and cerebrovascular diseases in a prospective study. METHODS: A total of 750 patients with first-time ischemic stroke and hospitalized within 24 h were enrolled in the study. Using color Doppler ultrasound (CDUS), the degree of stenosis and blood flow (BF) in bilateral internal carotid arteries (ICA) and the V1-V3 segment of vertebral arteries (VA) was assessed. Cubic simulation curves for BF and global blood flow (GBF) over the stenosis score (SS), total stenosis score (TSS), and radiological imaging- total stenosis score (RI-TSS) were fitted and compared. The receiver operating characteristic (ROC) curves using TSS, RI-TSS, or GBF to predict various ischemic stroke endpoints were also analyzed and compared. RESULTS: There was a linear relationship between SS and BF both ICA and VA (R2 were 0.734 and 0.783, respectively, both P < 0.05). Both TSS and RI-TSS with GBF showed an inverse "S" curve relationship (R2 was 0.839 and 0.843, all P < 0.05). The AUC values of TSS-based and RI-TSS-based predictions of each endpoint were all greater than 0.7 (all P < 0.05), but the differences of the AUC values between TSS, RI-TSS, and GBF were not statistically significant (all P > 0.05). CONCLUSIONS: The novel CASUS can better reflect the level of cerebral reperfusion in patients with ischemic stroke and can better predict the occurrence of cardiovascular and cerebrovascular diseases.

Silencing of Tctex1 impairs autophagy lysosomal degradation of α-synuclein and cell viability.

Tctex1 is an important element of the dynein motor unit in mammalian cells that helps move targets along microtubules and toward the centrosome for degradation. Here, we analyzed the role of Tctex1 in the α-synuclein autophagy-lysosome degradation pathway using Tctex1-siRNA in SH-SY5Y cells. Results showed that siRNA silencing of Tctex1 suppressed cellular viability and promoted cell apoptosis. Protein and mRNA expression of Tctex1 and dynein decreased after Tctex1 knockdown, whereas α-synuclein, LC3-II, and LAMP2 increased. Consistently, fluorescence intensity of Tctex1 was weaker in siRNA-Tctex1-transfected cells, and that of α-synuclein, LC3-II, and LAMP2 was increased. Tctex1 inhibition reduced cell viability and promoted apoptosis. These results show that Tctex1 plays an important role in α-synuclein autophagic degradation and in maintaining cellular homeostasis.

The E3 ubiquitin ligase seven in absentia homolog 1 may be a potential new therapeutic target for Parkinson's disease.

In this study, we investigated the effect of an antibody against E3 ubiquitin ligase seven in absentia homolog 1 (SIAH-1) in PC12 cells. 1-Methyl-4-phenylpyridinium (MPP(+)) treatment increased α-synuclein, E1 and SIAH-1 protein levels in PC12 cells, and it reduced cell viability; however, there was no significant change in light chain 3 expression. Treatment with an SIAH-1 antibody decreased mRNA expression levels of α-synuclein, light chain 3 and SIAH-1, but increased E1 mRNA expression. It also increased cell viability. Combined treatment with MPP(+) and rapamycin reduced SIAH-1 and α-synuclein levels. Treatment with SIAH-1 antibody alone diminished α-synuclein immunoreactivity in PC12 cells, and reduced the colocalization of α-synuclein and light chain 3. These findings suggest that the SIAH-1 antibody reduces the monoubiquitination and aggregation of α-synuclein, promoting its degradation by the ubiquitin-proteasome pathway. Consequently, SIAH-1 may be a potential new therapeutic target for Parkinson's disease.

Silencing of SIAH1 in SH-SY5Y affects α-synuclein degradation pathway.

Seven in absentia homolog (SIAH) is a ubiquitin ligase that monoubiquitinates α-synuclein. Lewy bodies are characteristically rich in monoubiquitinated α-synuclein. We aimed to determine the effect of siRNA-SIAH1 on α-synuclein autophagy and UPS degradation in SH-SY5Y. SIAH1 expression was measured with real-time quantitative PCR and Western Blot. Cell proliferation was measured by CCK-8 assay; cell apoptosis assayed by flow cytometry. Relative protein expressions were measured by Western Blot. mRNA levels of relative protein were measured by real-time quantitative PCR. The expression of α-synuclein, LC3-II and SIAH1 were observed by confocal microscopy. We found: (1) Transfection efficiency of SIAH1-siRNA into SH-SY5 measured approximately 89% by flow cytometry. (2) siRNA silencing of SIAH1 promoted cellular proliferation and suppressed apoptosis. (3) Protein and mRNA expression of α-synuclein, LC3-II and p53 decreased after SIAH1 knockdown. E1 protein and mRNA levels increased after SIAH1 siRNA. These data show silencing SIAH1 increased cell proliferation and inhibited apoptosis in SH-SY5Y neuroblastoma cells. SIAH1 knockdown enhanced the clearance of non-aggregated α-synuclein by UPS. SIAH1 is a potential target for treatment of Parkinson's disease.

Proxies of cognitive reserve and their effects on neuropsychological performance in patients with mild cognitive impairment.

Cognitive reserve (CR) modulates the relationship between clinical and pathological phenotypes by restricting the negative effect of cerebral lesions on cognition, according to the CR hypothesis. In this study, we evaluated 18 healthy subjects and 21 patients with mild cognitive impairment (MCI) using conventional MRI, magnetic resonance spectroscopy (MRS), the Mini-Mental State Examination (MMSE), the Wechsler Memory Scale (WMS), and the Montreal Cognitive Assessment (MoCA). The MMSE, WMS and MoCA assessments were repeated 1year later. The MRS analysis results showed that the N-acetyl-aspartate peak area (NAA; t=5.122, P<0.001) and the NAA/creatine (Cr), NAA/myo-inositol (mI) and NAA/choline (Cho) ratios were significantly changed in patients with MCI compared with the control subjects (all P<0.01). The MoCA was significantly related to the NAA/Cho ratio (R=0.443), the NAA/Cr ratio (R=0.533), and the NAA peak area (R=0.814; all P<0.05), but was unrelated to the NAA/mI ratio (R=0.400, P=0.072). We found that the hippocampal volume was significantly correlated with the MoCA, WMS and MMSE (R=0.704, 0.677, 0.542 respectively; all P<0.05). Education level had a positive effect on changes in the MoCA, MMSE, and WMS 1year later. We believe that MoCA and WMS results, MRI hippocampal volume and other related indicators (NAA peak area, NAA/Cr ratio, NAA/mI ratio, and NAA/Cho ratio) may reflect the degree of CR capacity, and that the number of years of education can significantly affect the changes in cognitive function in patients with MCI. Therefore, increasing levels of education and life skills training can help increase CR, reduce the risk of MCI, and slow down the appearance of clinical manifestations and clinical progress in patients with MCI.

The changes of brainstem auditory evoked potentials (BAEP) after vertebrobasilar artery ischemia in rabbits.

Brainstem auditory evoked potentials (BAEPs) have been used as a valuable neurophysiologic index of neuronal dysfunction in the level of the brainstem. BAEPs are also useful in subdividing evoked potentials into normal, slight, or pronounced in patients with vertebrobasilar insufficiency. We investigated the changes of BAEP after vertebrobasilar artery ischemia in rabbits and its significance in clinical work. A brainstem ischemic model was made by unilateral extracranial occlusion of vertebral artery to monitor BAEPs at 0, 10, 20, 30, 40, 50, and 60 min after occlusion. We found that peak latencies (PL) of I, III, and most notably V were gradually extended. In addition, we observed a significant (P < 0.05) delay of interpeak latencies (IPL) of waves I­III, III­V, and I­V after occlusion. This delay became more significant in IPL I­V 60 min after occlusion. Our results also demonstrate that the amplitude of I and V had no obvious change (P < 0.05). In the rabbit with bilateral extracranial occlusion of vertebral artery, BAEP waveforms disappeared 10 min after occlusion. Our results showed that vertebrobasilar insufficiency caused brainstem ischemia, which induced BAEP abnormity. Taken together, our findings suggest that BAEP has important significance for the clinical diagnosis of vertebrobasilar insufficiency. Therefore, early detection of neuronal change after transient cerebral ischemia is important in initiating treatment within the therapeutic window.

MPP+ impairs autophagic clearance of alpha-synuclein by impairing the activity of dynein.

Increasing evidence suggests that dynein has an important role in the clearance of misfolded proteins by autophagy. Here we show that treatment of cells with 1-methyl-4-phenylpyridinium (MPP) cause alpha-synuclein overexpression and aggregation, leading to the accumulation of autophagic vacuoles and the recruitment of LC3-II to these vacuoles in the cytoplasm. After MPP treatment, dynein expression decreased and was mainly aggregated at the periphery of cytoplasm and lost its colocalization with alpha-synuclein and lamp1, indicating that dynein lost its function in the aggresome formation and failed to return autophagosome and lysosomes to the center of the cell for degradation. We consider that dynein plays an important role in the autophagic clearance of aggregate-prone proteins.

[Isolation and identification of Japanese encephalitis virus in Liaoning Province].

BACKGROUND: To study arboviruses carried by mosquitoes in Liaoning Province in 2002. METHODS: Totally 4927 mosquitoes were collected from Liaoning Province in July 2002. Virus strains were isolated by inoculating BHK-21, C6/36 and Vero cells. The newly isolated strains were identified by serological (ELISA and IFA) and molecular methods (Real-Time PCR and RT-PCR). RESULTS: Two strains were isolated from mosquitoes causing cytopathogenic effect (CPE) on cells and were fatal to suckling mice. Serological tests showed that both were positive for the antibody to JEV. The PrM and E gene were cloned and sequenced. The phylogenetic analysis showed that the new isolates belonged to genotype I, JEV. Sequence analysis showed that the homology of nucleotide sequences and amino acid (AA) sequences between the two strains was 100%. Compared with the nucleotide sequences between the two strains and the standard JEV vaccine strain SA14-14-2, the difference was up to 4.11%, and the difference of AA was 0.6%. CONCLUSION: Two strains of JEV were isolated and identified in Liaoning province, both belonged to genotype I JEV.

[Arbovirus survey in some regions in Heilongjiang province].

BACKGROUND: Mosquitoes were collected in Heilongjiang province in 2002, four virus strains were isolated by inoculation of homogenates onto BHK cell lines. The viruses were identified. Multiple alignment and phylogenetic analysis were carried out by Clustal X (1.8) program.Amino acid (AA) analysis was carried out by GENEDOS (3.2). RESULTS: Biological characters of four newly isolated strains were examined and it was found that all of them could produce cytopathogenic effect (CPE) in BHK cells, killing sucking mice. Serological tests showed that all of these stains reacted positively to JEV antibodies. PrM and E gene regions were amplified and sequenced. Phylogenic analysis showed that all the newly isolated JEV strains belong to genotype III. Using the vaccine strains (SA14-14-2) as control, analysis of the E gene of the new strains and two JEV strains (47, Ha-3) isolated previously from Heilongjiang province showed that these new strains' nucleotide sequence had a homology of up to 99.9% and the amino acid sequence homology up to 99.8%, respectively. Compared with the standard JE vaccine strain SA-14-14-2 and the four new strains, the nucleotide sequence homology was 97.3% and amino acid sequence homology was between 96.8% and 97.0%, respectively. Compared with vaccine strain, there were seven common variations in all the four newly isolated strains. CONCLUSION: Four JE virus strains were isolated in Heilongjiang province. As compared to the vaccine strain, six variations were found in the newly isolated strains at the eight sites relevant to the virulence of the virus.