Altered exocytosis of inhibitory synaptic vesicles at single presynaptic terminals of cultured striatal neurons in a knock-in mouse model of Huntington's disease.

Huntington's disease (HD) is a progressive dominantly inherited neurodegenerative disease caused by the expansion of a cytosine-adenine-guanine (CAG) trinucleotide repeat in the huntingtin gene, which encodes the mutant huntingtin protein containing an expanded polyglutamine tract. One of neuropathologic hallmarks of HD is selective degeneration in the striatum. Mechanisms underlying selective neurodegeneration in the striatum of HD remain elusive. Neurodegeneration is suggested to be preceded by abnormal synaptic transmission at the early stage of HD. However, how mutant huntingtin protein affects synaptic vesicle exocytosis at single presynaptic terminals of HD striatal neurons is poorly understood. Here, we measured synaptic vesicle exocytosis at single presynaptic terminals of cultured striatal neurons (mainly inhibitory neurons) in a knock-in mouse model of HD (zQ175) during electrical field stimulation using real-time imaging of FM 1-43 (a lipophilic dye). We found a significant decrease in bouton density and exocytosis of synaptic vesicles at single presynaptic terminals in cultured striatal neurons. Real-time imaging of VGAT-CypHer5E (a pH sensitive dye conjugated to an antibody against vesicular GABA transporter (VGAT)) for inhibitory synaptic vesicles revealed a reduction in bouton density and exocytosis of inhibitory synaptic vesicles at single presynaptic terminals of HD striatal neurons. Thus, our results suggest that the mutant huntingtin protein decreases bouton density and exocytosis of inhibitory synaptic vesicles at single presynaptic terminals of striatal neurons, causing impaired inhibitory synaptic transmission, eventually leading to the neurodegeneration in the striatum of HD.

Direct Oral Anticoagulation Versus Warfarin in Left Ventricular Thrombus: Pooled Analysis of Randomized Controlled Trials.

Patients with impaired left ventricular (LV) function can develop LV thrombus, a potentially life-threatening condition due to risk of stroke and embolization. Conventional treatment with vitamin K antagonists (VKAs; e.g., warfarin) puts patients at risk of bleeding, and the use of direct oral anticoagulants (DOACs) appears promising, although data are scant. We searched the published English language literature for randomized controlled trials (RCTs) comparing DOACs with VKAs in LV thrombus. End points were failure to resolve, thromboembolic events (stroke, embolism), bleeding, or any adverse event (composite of thromboembolism or bleeding), or all-cause death. Data were pooled and analyzed in hierarchical Bayesian models. In three eligible RCTs, 141 patients were studied during an average of 4.6 months (53.8 patient-years; n = 71 assigned to DOAC, n = 70 assigned to VKA). A similar number of patients in each treatment arm demonstrated failure to resolve (DOAC: 14/71 vs. VKA: 15/70) and death events (3/71 vs. 4/70). However, patients on DOACs suffered fewer strokes/thromboembolic events (1/71 vs. 7/70; log odds ratio [OR], -2.02 [95% credible interval (CI95 ), -4.53 to -0.31]) and fewer bleeding events (2/71 vs. 9/70; log OR, -1.62 [CI95 , -3.43 to -0.26]), leading to fewer patients on DOACs with any adverse event versus VKAs (3/71 vs. 16/70; log OR, -1.93 [CI95 , -3.33 to -0.75]). In conclusion, pooled analysis of RCT data favors DOACs over VKAs in patients with LV thrombus in terms of both efficacy and safety.

Absorbable Suture Embolization in Distal Coronary Perforation.

Coronary artery perforation is a rare but serious complication during percutaneous coronary intervention. Distal or small vessel perforation is usually treated by coil, fat, or microsphere embolization. We describe 5 cases of distal coronary perforation that were managed successfully by a novel technique that uses absorbable sutures. (Level of Difficulty: Advanced.).