Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis.

PURPOSE: Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity. METHODS: This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVACEQ ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTILVOT / VTIMV. All-cause mortality data were collected retrospectively. RESULTS: A total of 64 patients with DMS and 24 patients with RMS were identified. MVACEQ was larger in patients with DMS (1.43 ± 0.4 cm2 ) than RMS (0.9 ± 0.3 cm2 ) by ~0.5 cm2 (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVACEQ ≤1.5 and MVACEQ ≤1.0 cm2 (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVACEQ ≤1.0 cm2 and DMSI ≤0.35, suggesting severe stenosis severity. CONCLUSION: Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Multivessel Revascularization Does Not Increase Contrast-Induced Acute Kidney Injury Incidence in Acute Myocardial Infarction: A Meta-Analysis.

BACKGROUND: Recent studies and meta-analysis have shown that complete revascularization (CR) compared with infarct-related artery revascularization (IRA) during percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI) is associated with decreased mortality. However, it is unclear if CR versus IRA in STEMI during indexed hospitalization is associated with risk of contrast-induced acute kidney injury (CI-AKI). METHODS: A database search was conducted for all randomized controlled trials that enrolled STEMI patients and compared CR versus IRA and reported CI-AKI. Comprehensive Meta-Analysis Version 2.0 (Wiley, Chichester) was used to determine summary effect size with a fixed-effect model and expressed as a risk ratio with 95 % confidence intervals. RESULTS: A total of four trials were identified and had a mean follow-up of 24.5 ± 9.9 months, a total sample size of 1537, a mean age of 63.8 ± 1.2 versus 64.2 ± 2.1 years, 31.2 ± 5.3 versus 30.1 ± 4.7 % three-vessel disease, and 33.7 ± 4.1 versus 37.2 ± 4.5 % anterior STEMI in the CR versus IRA groups, respectively. A total of 276.7 ± 25.2 versus 186.7 ± 15.3 mL contrast was used in the CR versus IRA respectively (p = 0.006). There were no statistical significant differences between the two groups in the reported incidence of CI-AKI (1.3 % CR vs. 1.9 % IRA; p = 0.4), major bleeding (1.7 % CR vs. 2.5 % IRA; p = 0.4) and stroke (1.1 % CR vs. 0.4 % IRA; p = 0.24). However, there was a significantly increased incidence of cardiovascular death (2.0 % CR vs. 4.7 % IRA; p = 0.01) and ischemia-driven revascularization (6.2 % CR vs. 18.3 % IRA; p < 0.01). CONCLUSION: In the index hospitalization, CR in STEMI patients is associated with significant risk reduction in cardiac death and revascularization and a non-significant reduced trend of CI-AKI, despite increased use of contrast when compared with IRA.

Perspectives of zebrafish models of epilepsy: what, how and where next?

Epilepsy is a complex brain disorder with multiple underlying causes and poorly understood pathogenetic mechanisms. Animal models have been indispensable tools in experimental epilepsy research. Zebrafish (Danio rerio) are rapidly emerging as a promising model organism to study various brain disorders. Seizure-like behavioral and neurophysiological responses can be evoked in larval and adult zebrafish by various pharmacological and genetic manipulations, collectively emphasizing the growing utility of this model for studying epilepsy. Here, we discuss recent developments in using zebrafish models to study the seizure-like behavior involved in epilepsy, outlining current challenges and strategies for further translational research in this field.

Behavioral and physiological effects of acute ketamine exposure in adult zebrafish.

Ketamine is a non-competitive glutamatergic antagonist used to induce sedation and analgesia. In sub-anesthetic doses, it induces hyperlocomotion, impairs memory and evokes stereotypic circling in rodents. Zebrafish (Danio rerio) emerged as a promising new animal model to screen the effects of psychotropic compounds. Here, we investigated the effects of sub-anesthetic doses of ketamine on anxiety, locomotion, habituation and social behavior of adult zebrafish. Acute 20-min exposure to 20 and 40 mg/L (but not 2 mg/L) of ketamine reduced anxiety, impaired intra-session habituation, evoked circular swimming and disrupted zebrafish shoaling. Additionally, ketamine reduced whole-body cortisol levels and elevated brain c-fos expression in zebrafish. Our findings demonstrate the sensitivity of zebrafish to behavioral and physiological effects of sub-anesthetic doses of ketamine, further supporting the utility of this species as a model for neuropharmacological research, including testing ketamine and related drugs.

Behavioral effects of MDMA ('ecstasy') on adult zebrafish.

3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') is a potent psychedelic drug inducing euphoria and hypersociability in humans, as well as hyperactivity and anxiety in rodents. Adult zebrafish (Danio rerio) have become a widely used species in neurobehavioral research. Here, we explore the effects of a wide range (0.25-120 mg/l) of acute MDMA doses on zebrafish behavior in the novel tank test. Although MDMA was inactive at lower doses (0.25-10 mg/l), higher doses reduced bottom swimming and immobility (40-120 mg/l) and impaired intrasession habituation (10-120 mg/l). MDMA also elevated brain c-fos expression, collectively confirming the usage of zebrafish models for screening of hallucinogenic compounds.