[Correlation study on chemical constitutes of cardiac glycosides in Taxillus chinensis and its Nerium indicum host by UPLC-Q-TOF-MS/MS].

To build up an identification method on cardiac glycosides in Taxillus chinensis and its Nerium indicum host, and evaluate the influence on medicine quality from host to T. chinensis, ultra-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass-mass spectrometry(UPLC-Q-TOF-MS/MS)was applied. The samples of T. chinensis(harvested from N. indicum)and its N. indicum host were collected in field. The samples of T. chinensis(harvested from Morus alba)and its M. alba host was taken as control substance. All samples were extracted by ultrasonic extraction in 70% ethanol. Chromatographic separation was performed on an ACQUITY UPLC HSS T3 C_(18)(2.1 mm×100 mm,1.8 µm)column at 40 ℃. Gradient elution was applied, and the mobile phase was consisted of 0.1% formic acid water and acetonitrile. The 0.5 µL of sample solution was injected and the flow rate of the mobile phase was kept at 0.6 mL·min~(-1) in each run. It was done to identify cardiac glycosides and explore the chemical composition correlation in T. chinensis and its N. indicum host by analyzing positive and negative ion mode mass spectrometry data, elemental composition, cardiac glycoside reference substance and searching related literatures. A total of 29 cardiac glycosides were identified, 28 of it belonged to N. indicum host, 5 belonged to T. chinensis(harvested from N. indicum host), none of cardiac glycoside was identified in T. chinensis(harvested from M. alba host). The result could provide a reference in evaluating the influence in T. chinensis medicine quality from host. It was rapid, accurate, and comprehensive to identify cardiac glycosides in T. chinensis and its N. indicum host by UPLC-Q-TOF-MS/MS.

White Matter Lesions Predict Recurrent Vascular Events in Patients with Transient Ischemic Attacks.

BACKGROUND: White matter lesions (WMLs) are common findings in brain magnetic resonance imaging (MRI) and are strongly associated with stroke incidence, recurrence, and prognosis. However, the relationship between WMLs and transient ischemic attacks (TIAs) is not well established. This study aimed to determine the clinical significance of WMLs in patients with TIA. METHODS: A total of 181 consecutive inpatients with first-ever TIA were enrolled. Brain MRIs within 2 days of symptom onset were used to measure WML volumes. Recurrent vascular events within 1 year of TIA onset were assessed. The relationship between WMLs and recurrent risk of vascular events was determined by a multivariate logistic regression. RESULTS: WMLs were identified in 104 patients (57.5%). Age and ratio of hypertension were significantly different between patients with and without WMLs. The incidence of vascular events in patients with WMLs significantly increased in comparison to those without WMLs (21.15% vs. 5.19%, 95% confidence interval [CI]: 1.18-15.20, P = 0.027) after controlling for confounders. Furthermore, distributions of WML loads were found to be different between patients who developed vascular events and those who did not. WML volumes were demonstrated to be correlated with recurrent risks, and the fourth quartile of WML volumes led to an 8.5-fold elevation of recurrent risk of vascular events compared with the first quartile (95% CI: 1.52-47.65, P = 0.015) after adjusting for hyperlipidemia. CONCLUSION: WMLs occur frequently in patients with TIA and are associated with the high risk of recurrent vascular events, suggesting a predictive neuroimaging marker for TIA outcomes.

Mitochondrial dysfunction and cerebral metabolic abnormalities in patients with mitochondrial encephalomyopathy subtypes: Evidence from proton MR spectroscopy and muscle biopsy.

AIMS: Accumulated evidence indicates that cerebral metabolic features, evaluated by proton magnetic resonance spectroscopy (1 H-MRS), are sensitive to early mitochondrion dysfunction associated with mitochondrial encephalomyopathy (ME). The metabolite ratios of lactate (lac)/Cr, N-acetyl aspartate (NAA)/creatine (Cr), total choline (tCho)/Cr, and myoinositol (mI)/Cr are measured in the infarct-like lesions by 1 H-MRS and may reveal metabolic changes associated with ME. However, the application of this molecular imaging technique in the investigation of the pathology of ME subtypes is unknown. METHODS: In this study, cerebral metabolic features of pathologically diagnosed ME cases, that is, 19 mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS); nine chronic progressive external ophthalmoplegia (CPEO); and 23 healthy controls, were investigated using 1 H-MRS. Receiver operating characteristics (ROC) analysis was used to evaluate the diagnostic power of the cerebral metabolites. Histochemical evaluation was carried out on muscle tissues derived from biopsy to assess the abnormal mitochondrial proliferation. The association between cerebral metabolic and mitochondrial cytopathy was examined by correlation analysis. RESULTS: Patients with MELAS or CPEO exhibited a significantly higher Lac/Cr ratio and a lower NAA/Cr ratio compared with controls. The ROC curve of Lac/Cr ratio indicated prominent discrimination between MELAS or CPEO and healthy control subjects, whereas the NAA/Cr ratio may present diagnostic power in the distinction of MELAS from CPEO. Lower NAA/Cr ratio was associated with higher Lac/Cr in MELAS, but not in CPEO. Furthermore, higher ragged-red fibers (RRFs) percentages were associated with elevated Lac/Cr and reduced NAA/Cr ratios, notably in MELAS. This association was not noted in the case of mI/Cr ratio. CONCLUSIONS: Mitochondrial cytopathy (lactic acidosis and RRFs on muscle biopsy) was associated with neuronal viability but not glial proliferation, notably in MELAS. Mitochondrial neuronopathy and neuronal vulnerability are considered significant causes in the pathogenesis of MELAS, particularly with regard to stroke-like episodes.