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https://www.readbyqxmd.com/read/28724776/inhibitory-circuits-of-the-mammalian-main-olfactory-bulb
#1
Shawn D Burton
Synaptic inhibition critically influences sensory processing throughout the mammalian brain, including the main olfactory bulb (MOB), the first station of sensory processing in the olfactory system. Decades of research across numerous laboratories have established a central role for granule cells (GCs), the most abundant GABAergic interneuron type in the MOB, in the precise regulation of principal mitral and tufted cell (M/TC) firing rates and synchrony through lateral and recurrent inhibitory mechanisms. In addition to GCs, however, the MOB contains a vast diversity of other GABAergic interneuron types, and recent findings suggest that, while fewer in number, these oft-ignored interneurons are just as important as GCs in shaping odor-evoked M/TC activity...
July 19, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28720600/is-the-mechanism-of-re-expansion-pulmonary-oedema-in-a-heart-lung-interaction
#2
Candy Masego Mokotedi, Martin Balik
The mechanism of re-expansion pulmonary oedema (Re-PE) is unclear. There are multiple variables in play when evaluating the response to evacuation of pleural fluid. We present an educational case of a critically ill patient admitted for respiratory failure who was fully dependent on ventricular pacing set at a constant rate throughout the episode of Re-PE. The transthoracic echocardiography (TTE) showed an ejection fraction of 38%, moderate mitral regurgitation (MR), mildly dilated right ventricle and moderate pulmonary hypertension...
July 18, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28707559/viscoelastic-properties-of-mitral-valve-leaflets-an-analysis-of-regional-variation-and-frequency-dependency
#3
Jonathan Baxter, Keith G Buchan, Daniel M Espino
The aim of this study was to determine the regional variation in viscoelastic properties of mitral valve leaflets over a range of physiological and patho-physiological frequencies. This included comparisons to be made between anterior and posterior leaflets, anterior leaflet clear and rough zones, and radial and circumferential leaflet orientation. Dynamic mechanical analysis was used to determine frequency-dependent viscoelastic properties. The valve leaflets were dissected from eight porcine hearts. The leaflets were loaded under a sinusoidal tensile displacement, with a mean dynamic peak to trough strain of 11%, applied to all leaflet samples at nine different frequencies, ranging from 0...
July 1, 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28699262/recurrent-myocardial-infarction-in-a-47-year-old-woman-with-a-mechanical-mitral-valve-prosthesis-atherosclerosis-embolism-or-spasm
#4
Bimmer E Claessen, Thomas P W van den Boogert, Jan J Piek
We present a case of a 47-year-old woman with a mechanical mitral valve prosthesis and recurrent myocardial infarction. The most common etiology of spontaneous myocardial infarction is an acute coronary syndrome caused by rupture or erosion of an atherosclerotic plaque. However, the differential diagnosis in the patient described below also included infarction due to embolization or coronary spasm. It can be challenging to discriminate between the different causes of myocardial infarction based on interpretation of symptoms, physical examination, laboratory tests, and electrocardiography alone...
July 12, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28691201/combined-myocardial-deformation-to-predict-cardiac-resynchronization-therapy-response-in-non-ischemic-cardiomyopathy
#5
Ning Yang, Zhao-Guang Liang, Zhao-Jun Wang, Hui Liu, Chao Chi, Yan-Feng Tian, Shu-Han Qi, Bi-Yu Wang, Wei Han
BACKGROUND: 20-30% of patients do not benefit from CRT when the established selection criteria were applied. We hypothesized that a combined assessment of mechanical dyssynchrony, myocardial deformation and diastolic function would identify patients who would benefit most from CRT. METHOD: In 36 CRT patients, clinical evaluation and echocardiography were performed before and after CRT. Patients were classified into 3 subgroups according to their amount of response: echocardiographic responders, clinical responders, and nonresponders...
July 10, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28673810/repeated-mechanical-thrombectomy-in-the-same-intracranial-artery-segment
#6
Herbert Tejada Meza, Maria Rosario Barrena Caballo, Santiago Guelbenzu Morte, Roberto Martínez García, Javier Marta Moreno
We report a patient with an important scenario that may arise in the management of an acute ischemic stroke: the need for a repeated mechanical thrombectomy in the same intracranial artery segment. The patient had a history of atrial fibrillation and a mechanical mitral valve replacement. In her first stroke, she had an occlusion of the proximal segment of the right middle cerebral artery; 58 days later, she presented with an occlusion in the same segment of that cerebral artery. In both instances, the thrombus was extracted by a stent retriever with good clinical and radiographic results...
June 30, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28671806/valvular-heart-disease-in-adults-management-of-prosthetic-heart-valves
#7
John F Trujillo, Steven M Hollenberg
Patients undergoing cardiac valve replacement may receive mechanical or bioprosthetic valves. Mechanical valves require lifelong anticoagulation but are durable and the need for a second surgery is up to eightfold times less than with bioprosthetic valves. Bioprosthetic valves do not require lifelong anticoagulation and thus are associated with fewer bleeding complications but they are less durable and associated with higher morbidity and mortality rates, particularly in younger patients. Anticoagulation with mechanical valves is achieved using warfarin; use of direct-acting oral anticoagulants is not indicated...
June 2017: FP Essentials
https://www.readbyqxmd.com/read/28666659/myxoma-knocking-on-the-mitral-door-a-singular-mechanism-of-mitral-regurgitation
#8
EDITORIAL
Miriam Blanco, Gregorio Laguna, Yolanda Carrascal
No abstract text is available yet for this article.
May 22, 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28659550/significant-prognostic-value-of-acute-preload-stress-echocardiography-using-leg-positive-pressure-maneuver-for-patients-with-symptomatic-severe-aortic-stenosis-awaiting-aortic-valve-intervention
#9
Hiroki Matsuzoe, Kensuke Matsumoto, Hidekazu Tanaka, Yutaka Hatani, Keiko Hatazawa, Hiroyuki Shimoura, Junichi Ooka, Hiroyuki Sano, Keiko Ryo-Koriyama, Toshiro Shinke, Hirotsugu Yamada, Yutaka Okita, Ken-Ichi Hirata
BACKGROUND: Although aortic valve intervention is recommended for virtually all symptomatic patients with aortic stenosis (AS), how urgently the intervention should be performed remains controversial. The aim of this study was thus to determine whether the preload reserve in response to leg-positive pressure (LPP) maneuver could serve for decision-making for AS patients awaiting aortic valve intervention.Methods and Results:Sixty-eight patients with symptomatic AS, who were referred for aortic valve intervention, were recruited...
June 28, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28659282/experience-dependent-plasticity-in-accessory-olfactory-bulb-interneurons-following-male-male-social-interaction
#10
Hillary L Cansler, Marina A Maksimova, Julian P Meeks
Chemosensory information processing in the mouse accessory olfactory system (AOS) guides the expression of social behavior. After salient chemosensory encounters, the accessory olfactory bulb (AOB) experiences changes in the balance of excitation and inhibition at reciprocal synapses between mitral cells (MCs) and local interneurons. The mechanisms underlying these changes remain controversial. Moreover, it remains unclear whether MC-interneuron plasticity is unique to specific behaviors, such as mating, or whether it is a more general feature of the AOB circuit...
June 28, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28654069/optimized-protocol-for-the-extraction-of-proteins-from-the-human-mitral-valve
#11
Cristina Banfi, Anna Guarino, Maura Brioschi, Stefania Ghilardi, Valeria Mastrullo, Elena Tremoli, Gianluca Polvani
Analysis of the cellular proteome can help to elucidate the molecular mechanisms underlying diseases due to the development of technologies that permit the large-scale identification and quantification of the proteins present in complex biological systems.The knowledge gained from a proteomic approach can potentially lead to a better understanding of the pathogenic mechanisms underlying diseases, allowing for the identification of novel diagnostic and prognostic disease markers, and, hopefully, of therapeutic targets...
June 14, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28647732/perioperative-strokes-following-surgical-correction-of-mitral-valves-a-systematic-review-and-meta-analysis
#12
Reshmi Udesh, Piruthiviraj Natarajan, Vinodh Jeevanantham, Thomas G Gleason, Vinay Badhwar, Parthasarathy D Thirumala
OBJECTIVE: The primary aim of this meta-analysis was to quantify the impact of perioperative strokes on stroke-related mortality after open mitral valve (MV) procedures were performed. METHODS: An electronic search of the PubMed, Embase, and the Web of Science databases was performed to retrieve articles published up to December 2015, relevant to patients undergoing MV procedures. Data were extracted from the final list of 25 studies to calculate a summary OR for 30-day stroke-related mortality...
June 24, 2017: European Neurology
https://www.readbyqxmd.com/read/28645798/left-atrial-mechanics-and-integrated-calibrated-backscatter-in-anthracycline-treated-long-term-survivors-of-childhood-cancers
#13
Vivian Wing-Yi Li, Clare Tik-Man Lai, Anthony Pak-Yin Liu, Daniel Ka-Leung Cheuk, Yiu-Fai Cheung
We tested the hypothesis that left atrial (LA) mechanics and myocardial calibrated integrated backscatter (cIB) are altered in anthracycline-treated long-term survivors of childhood cancers. Forty-nine survivors and 25 controls were studied. Survivors had significantly smaller maximal (p = 0.009) and minimal (p = 0.017) LA volumes and lower peak negative LA strains (p = 0.011). For left ventricular (LV) indices, survivors had significantly lower shortening fraction (p < 0.001), ejection fraction (p < 0...
June 20, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28637704/the-structure-function-remodeling-in-rabbit-hearts-of-myocardial-infarction
#14
Haotian Wu, Li Li, Pei Niu, Xu Huang, Jinyi Liu, Fengshun Zhang, Wenzeng Shen, Wenchang Tan, Yiling Wu, Yunlong Huo
Animal models are of importance to investigate basic mechanisms for ischemic heart failure (HF). The objective of the study was to create a rabbit model through multiple coronary artery ligations to investigate the postoperative structure-function remodeling of the left ventricle (LV) and coronary arterial trees. Here, we hypothesize that the interplay of the degenerated coronary vasculature and increased ventricle wall stress relevant to cardiac fibrosis in vicinity of myocardial infarction (MI) precipitates the incidence and progression of ischemic HF Echocardiographic measurements showed an approximately monotonic drop of fractional shortening and ejection fraction from 40% and 73% down to 28% and 58% as well as persistent enlargement of LV cavity and slight mitral regurgitation at postoperative 12 weeks...
June 2017: Physiological Reports
https://www.readbyqxmd.com/read/28634695/assessment-of-early-diastolic-intraventricular-pressure-gradient-in-the-left-ventricle-among-patients-with-repaired-tetralogy-of-fallot
#15
Maki Kobayashi, Ken Takahashi, Mariko Yamada, Kana Yazaki, Kotoko Matsui, Noboru Tanaka, Sachie Shigemitsu, Katsumi Akimoto, Masahiko Kishiro, Keisuke Nakanishi, Shiori Kawasaki, Masaki Nii, Keiichi Itatani, Toshiaki Shimizu
Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV...
June 20, 2017: Heart and Vessels
https://www.readbyqxmd.com/read/28626989/electrical-isolation-of-the-left-atrial-appendage-by-maze-like-catheter-substrate-modification-a-reproducible-strategy-for-pulmonary-vein-isolation-non-responders
#16
Stefano Bordignon, Laura Perrotta, Daniela Dugo, Fabrizio Bologna, Takahiko Nagase, Alexander Fuernkranz, Kr Julian Chun, Boris Schmidt
INTRODUCTION: The ablation strategy for atrial fibrillation (AF) despite pulmonary vein isolation (PVI) is controversial. Left atrial appendage isolation (LAAI) may contribute to improve outcome. We describe an ablation approach ("Maze-like"-LAAI) that (1) modifies the underlying LA substrate by linear ablation (2) eliminates the LAA as a putative AF trigger site and (3) incorporates an unambiguous procedural endpoint. The role of LAA closure (LAAC) after LAAI was investigated. METHODS: Patients with atrial tachyarrhythmias non-responsive to PVI underwent a LAAI ablation procedure...
June 19, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28626146/mitral-valve-structure-in-addition-to-myocardial-viability-determines-the-outcome-of-functional-mitral-regurgitation-after-coronary-artery-bypass-grafting
#17
Shohei Yoshida, Satsuki Fukushima, Shigeru Miyagawa, Teruya Nakamura, Yasushi Yoshikawa, Hiroki Hata, Shunsuke Saito, Daisuke Yoshioka, Keitaro Domae, Noriyuki Kashiyama, Kouji Yamamoto, Ayumi Shintani, Satoshi Nakatani, Koichi Toda, Yoshiki Sawa
BACKGROUND: Coronary artery bypass grafting (CABG) reduces functional mitral regurgitation (MR) associated with ischemic heart disease, although the predictive factors or mechanisms of reversibility of functional MR after CABG are not fully understood.We investigated whether mitral valve structure is associated with the outcome of functional MR after CABG.Methods and Results:From a consecutive series of 98 patients with mild-moderate functional MR preoperatively who underwent isolated CABG, we enrolled 66 patients who were followed up for >1 year postoperatively using echocardiography...
June 16, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28621665/neural-mechanisms-of-social-learning-in-the-female-mouse
#18
Yuan Gao, Carl Budlong, Emily Durlacher, Ian G Davison
Social interactions are often powerful drivers of learning. In female mice, mating creates a long-lasting sensory memory for the pheromones of the stud male that alters neuroendocrine responses to his chemosignals for many weeks. The cellular and synaptic correlates of pheromonal learning, however, remain unclear. We examined local circuit changes in the accessory olfactory bulb (AOB) using targeted ex vivo recordings of mating-activated neurons tagged with a fluorescent reporter. Imprinting led to striking plasticity in the intrinsic membrane excitability of projection neurons (mitral cells, MCs) that dramatically curtailed their responsiveness, suggesting a novel cellular substrate for pheromonal learning...
June 16, 2017: ELife
https://www.readbyqxmd.com/read/28600094/cardiac-resynchronization-therapy-for-heart-failure
#19
REVIEW
Amole Ojo, Sohaib Tariq, Prakash Harikrishnan, Sei Iwai, Jason T Jacobson
Cardiac resynchronization therapy (CRT) has emerged as a valued nonpharmacologic therapy in patients with heart failure, reduced ejection fraction (EF), and ventricular dyssynchrony manifest as left bundle branch block. The mechanisms of benefit include remodeling of the left ventricle leading to decreased dimensions and increased EF, as well as a decrease in the severity of mitral regurgitation. This article reviews the rationale, effects, and indications for CRT, and discusses the patient characteristics that predict response and considerations for nonresponders...
July 2017: Interventional cardiology clinics
https://www.readbyqxmd.com/read/28597998/a-novel-mechanical-mitral-valve-replacement-using-sapien-xt
#20
Megan Koehle, Justin A Strote, Mark Guadagnoli, J Bradley Oldemeyer
PATIENT PRESENTATION: We report the case of a 66 year old female who presented to our institution fourteen years after receiving a St. Jude Mechanical Mitral Valve Replacement. She presented in refractory NYHA class IV congestive heart failure with comorbidities of acute renal failure, liver failure, and mental status changes. She was found to have immobility of one of the mitral valve disks with resultant severe mitral stenosis with a mean pressure gradient of 12 mmHg. EVALUATION AND MANAGEMENT: The patient was found to have an STS predicted mortality of 39% with redo surgical MVR, and evaluation by the valve team led to a recommendation of a hybrid surgical and transcatheter procedure...
June 9, 2017: Catheterization and Cardiovascular Interventions
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