NLRP3 inflammasome up-regulates major histocompatibility complex class I expression and promotes inflammatory infiltration in polymyositis.

OBJECTIVE: This study was designed to investigate the role of the nucleotide-binding-domain -and leucine-rich repeat -containing (NLR) family, pyrin-domain-containing 3 (NLRP3) inflammasome in the pathogenesis of polymyositis (PM). METHODS: Immunochemistry was performed to analyze the NLRP3, caspase-1 and interleukin-1 beta (IL-1ß) expression in the muscle tissue of PM patients. Rat model of PM and C2C12 cell were used to investigate the potential role of NLRP3 inflammasome in PM. RESULTS: The percentage of CD 68+ macrophages, and the expression levels of NLRP3, caspase-1 and IL-1ß in the muscle tissue were elevated in 27 PM patients. LPS/ATP treatment resulted in activation of NLRP3 inflammasome and secretion of IL-1ß as well as interferons (IFNs) and monocyte chemotactic protein-1 (MCP-1) in the Raw 264.7 macrophages. Meanwhile, LPS/ATP challenged activation of NLRP3 inflammasome induced overexpression of major histocompatibility complex class I (MHC-I), a key molecular of PM in the co-cultured C2C12 cells. The effect was decreased by treatment of NLRP3 inflammasome inhibitor MCC950 or siRNA of NLRP3 inflammasome. These findings suggested certain levels of IL-1ß rather than IFNs up-regulated MHC-I expression in C2C12 cells. IL-1ß blockade using neutralizing IL-1ß monoclonal antibody or siRNA of IL-1ß suppressed MHC-I overexpression. In vivo, NLRP3 inflammasome inhibition by MCC950 reduced the expression of NLRP3, IL-1ß and MHC-I in the muscle tissue of PM modal rats. Also, it attenuated the intensity of muscle inflammation as well as the CRP, CK, and LDH levels in the serum. CONCLUSION: NLRP3/caspase-1/IL-1ß axis may play an important role in the development of PM. Inhibition of NLRP3 activation may hold promise in the treatment of PM.

Benign paroxysmal positional vertigo in spontaneous intracranial hypotension.

OBJECTIVES: To assess the prevalence and related factors of benign paroxysmal positional vertigo (BPPV) in patients with spontaneous intracranial hypotension (SIH). METHODS: We retrospectively reviewed 156 consecutive inpatients with SIH, and collected the clinical and radiological data. These patients were divided into BPPV group and non-BPPV group according to the clinical manifestation and the results of Dix-Hallpike or supine roll tests during hospitalization period. We performed a univariate analysis and a further multiple logistic regression analysis to identify the related factors of the development of BPPV in SIH patients. RESULTS: BPPV was detected in 18 patients among the total 156 SIH patients (11.54%). The univariate analysis showed a low cerebrospinal fluid (CSF) pressure (P = 0.018), a small pontomesencephalic angle (P = 0.012) and a positive venous distension sign (VDS) (P = 0.045) were associated with the presence of BPPV. But the multivariate analysis only demonstrated a low CSF pressure was related to the presence of BPPV (OR = 1.022, 95% CI: 1.001-1.043, P = 0.044). CONCLUSION: BPPV is common in SIH patients. SIH patients with low CSF pressure may be prone to develop BPPV.

Investigating the role of 99mTc-TRODAT-1 SPECT imaging in idiopathic Parkinson's disease.

OBJECTIVE: To investigate the role of 99mTc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathic Parkinson's disease (PD). METHODS: Thirty-eight patients with primary, tentative diagnosis of PD and eighteen age-matched normal controls were studied with 99mTc-TRODAT-1 SPECT imaging. The regions of interests (ROIs) were drawn manually on cerebellum (CB), occipital cortex (OC) and three transverse plane slice-views of striatums, the semiquantitative BG (background)/[(OC+CB)/2] were then calculated. RESULTS: A lower uptake of 99mTc-TRODAT-1 in striatums were displayed in thirty-six out of thirty-eight PD patients by visual inspection, compared to controls. In twenty-four PD cases with (Hoehn and Yahr scale) HYS stage I, a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affected limbs than in the same regions of the controls, although the striatal uptake was bilaterally reduced. Using Spearman correlation analysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions in the PD group (P<0.05), a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05). However, analysis of variance (ANOVA) did not show any relationship between the decreasing uptake of 99mTc-TRODAT-1 and increasing severity of PD patients, although the specific uptake of 99mTc-TRODAT-1 was continuously decreased in the striatum by visual inspection with the progress of PD from HYS stage I to III. CONCLUSION: 99mTc-TRODAT-1 SPECT imaging may serve as a useful method for improving the correct diagnosis of PD. In assessing the role of 99mTc-TRODAT-1 SPECT in disease severity of PD, UPDRS can offer a comprehensive index, although the Hoehn and Yahr assessment may be available in part.

[An algorithm study on telecardiogram diagnosis based on multivariate autoregressive model and two-lead ECG signals].

OBJECTIVE: In view of the time delay caused by reconstruction of signals at remote sites, a direct classification method with high accuracy suitable for telediagnosis of electrocardiogram (ECG) signals is studied. METHOD: The data for analysis and classification was obtained from MIT-BIH database, including 300 samples each of normal sinus rhythm (NSR), atria premature contraction (APC), premature ventricular contraction (PVC), ventricular tachycardia (VT), ventricular fibrillation (VF) and superventricular tachycardia (SVT). An multivariate autoregressive (MAR) model based technique that could combine the signals of two ECG leads was presented to classify the ECGs directly, including MAR modeling performed on ECGs, and quadratic discrimination function (QDF) based classification by using MAR coefficients and K-L MAR coefficients. RESULT: Besides quick and convenient diagnosis, the accuracy of the proposed classification algorithm was as high as 98.3%-100%. CONCLUSION: The MAR modeling based technique is suitable for telecardiogram diagnosis. Comparing with single-lead ECGs, better classification results can be obtained through the combination of two-lead ECG signals.