keyword
MENU ▼
Read by QxMD icon Read
search

Heart muscle contraction

keyword
https://www.readbyqxmd.com/read/29212831/impaired-pulmonary-arterial-vasoconstriction-and-nitric-oxide-mediated-relaxation-underlie-severe-pulmonary-hypertension-in-sugen-hypoxia-rat-model
#1
Helen Christou, Hannes Hudalla, Zoe Michael, Evgenia Filatava, Jun Li, Minglin Zhu, Jose Possomato-Vieira, Carlos Dias-Junior, Stella Kourembanas, Raouf A Khalil
Pulmonary vasoreactivity could determine the responsiveness to vasodilators and in turn the prognosis of pulmonary hypertension (PH). We hypothesized that pulmonary vasoreactivity is impaired, and examined the underlying mechanisms, in the sugen-hypoxia rat model of severe PH. Male Sprague-Dawley rats were injected with sugen (20 mg/kg sc) and exposed to hypoxia (9% O2) for 3 weeks followed by 4 weeks in normoxia (Su/Hx), or treated with sugen alone (Su) or hypoxia alone (Hx) or neither (Nx). After hemodynamic measurements, the heart was assessed for right ventricular hypertrophy (Fulton's Index), the pulmonary artery, aorta and mesenteric arteries were isolated for vascular function studies, and contractile markers were measured in pulmonary artery using quantitative PCR...
December 6, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/29201608/toward-bioelectronic-medicine-neuromodulation-of-small-peripheral-nerves-using-flexible-neural-clip
#2
Sanghoon Lee, Wendy Yen Xian Peh, Jiahui Wang, Fengyuan Yang, John S Ho, Nitish V Thakor, Shih-Cheng Yen, Chengkuo Lee
Neural modulation technology and the capability to affect organ function have spawned the new field of bioelectronic medicine. Therapeutic interventions depend on wireless bioelectronic neural interfaces that can conformally and easily attach to small (few hundred micrometers) nerves located deep in the body without neural damage. Besides size, factors like flexibility and compliance to attach and adapt to visceral nerves associated moving organs are of paramount importance and have not been previously addressed...
November 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://www.readbyqxmd.com/read/29199785/acute-effect-of-moderate-intensity-concentric-and-eccentric-exercise-on-cardiac-effort-perceived-exertion-and-interleukin-6-level-in-physically-inactive-males
#3
Mayank Agarwal, Shraddha Singh, Priyanka Sharma, Rahul Saini
BACKGROUND: Muscle-derived interleukin-6 (IL-6) not only enhances glucose and fat metabolism but also has an anti-inflammatory effect that can prevent the development of cardiovascular disease (CVD) and metabolic syndrome. Dynamic resistance exercise comprises a muscle shortening and a lengthening phase known as concentric and eccentric contraction respectively. We compared an acute bout of concentric exercise (CE) with eccentric exercise (EE) for the serum IL-6 concentration, myocardial oxygen consumption (MVO2) and rating of perceived exertion (RPE)...
December 1, 2017: Journal of Sports Medicine and Physical Fitness
https://www.readbyqxmd.com/read/29197461/ineffective-and-prolonged-apical-contraction-is-associated-with-chest-pain-and-ischaemia-in-apical-hypertrophic-cardiomyopathy
#4
Edward Stephenson, Pierre Monney, Francesca Pugliese, James Malcolmson, Steffen E Petersen, Charles Knight, Peter Mills, Andrew Wragg, Constantinos O'Mahony, Neha Sekhri, Saidi A Mohiddin
OBJECTIVES: To investigate the hypothesis that persistence of apical contraction into diastole is linked to reduced myocardial perfusion and chest pain. BACKGROUND: Apical hypertrophic cardiomyopathy (HCM) is defined by left ventricular (LV) hypertrophy predominantly of the apex. Hyperdynamic contractility resulting in obliteration of the apical cavity is often present. Apical HCM can lead to drug-refractory chest pain. METHODS: We retrospectively studied 126 subjects; 76 with apical HCM and 50 controls (31 with asymmetrical septal hypertrophy (ASH) and 19 with non-cardiac chest pain and culprit free angiograms and structurally normal hearts)...
January 15, 2018: International Journal of Cardiology
https://www.readbyqxmd.com/read/29190094/active-glucocorticoids-have-a-range-of-important-adverse-developmental-and-physiological-effects-on-developing-zebrafish-embryos
#5
Raffael Alois Willi, Susanne Faltermann, Timm Hettich, Karl Fent
Glucocorticoids in aquatic systems originating from natural excretion and medical use may pose a risk to fish. Here, we analyzed physiological and transcriptional effects of clobetasol propionate (CLO), cortisol and cortisone in zebrafish embryos as single compounds and binary mixtures. CLO and cortisol, but not cortisone showed a concentration-dependent decrease in muscle contraction, increase in heart beating, and accelerated hatching. CLO also induced immobilization and edema at high concentrations. Transcription analysis covering up to 26 genes showed that mostly genes related to glucose metabolism, immune system and development were differentially expressed at 91 ng/L and higher...
November 30, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29186814/alternative-splicing-of-l-type-cav1-2-calcium-channels-implications-in-cardiovascular-diseases
#6
REVIEW
(no author information available yet)
L-type Cav1.2 calcium channels are the major pathway for Ca2+ influx to initiate the contraction of smooth and cardiac muscles. Alteration of Cav1.2 channel function has been implicated in multiple cardiovascular diseases, such as hypertension and cardiac hypertrophy. Alternative splicing is a post-transcriptional mechanism that expands Cav1.2 channel structures to modify function, pharmacological and biophysical property such as calcium/voltage-dependent inactivation (C/VDI), or to influence its post-translational modulation by interacting proteins such as Galectin-1...
November 24, 2017: Genes
https://www.readbyqxmd.com/read/29180358/nonclinical-cardiovascular-studies-of-prucalopride-a-highly-selective-5-hydroxytryptamine-4-receptor-agonist
#7
Kelly Conlon, Joris H De Maeyer, Chris Bruce, Jan A J Schuurkes, Lee Christie, James McRedmond, Katayoun Derakhchan, Paul R Wade
Patients with chronic constipation benefit from treatment with 5-hydroxytryptamine 4 (5-HT4) receptor agonists. However, the first-generation 5-HT4 receptor agonists cisapride and tegaserod were withdrawn from the market owing to rare cardiovascular adverse events, which were not 5-HT4-receptor-related, but due to the lack of selectivity of these drugs. Here we report the nonclinical cardiovascular profile of the selective 5-HT4 receptor agonist prucalopride. To assess its non-5-HT4 receptor-mediated effects on cardiovascular electrophysiological parameters, in vitro studies were performed in human ether-a-go-go-related gene-transfected cells, guinea pig ventricular myocytes and papillary muscle preparations, rabbit and dog Purkinje fibers, and the Langendorff rabbit heart...
November 27, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/29170180/muscle-fasciculation-detected-by-ecg
#8
Jonathan S Zipursky, Donald A Redelmeier
A 79-year-old man presented to hospital with scald burns to the perineum after a syncopal episode while in a hot bathtub. Admission ECG was misdiagnosed as possible ventricular fibrillation with high-frequency irregular waveforms in lead V2 at a rate exceeding 1000 cycles per minute, corresponding to intervening skeletal muscle contractions unrelated to the heart. Follow-up ECG showed full resolution of the irregular waveforms. Muscle fasciculations are a benign cause of ECG artefact and can easily be mistaken for serious cardiac arrhythmias...
November 23, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/29154423/the-contractile-adaption-to-preload-depends-on-the-amount-of-afterload
#9
Hanna Schotola, Samuel T Sossalla, André Renner, Jan Gummert, Bernhard C Danner, Peter Schott, Karl Toischer
AIMS: The Frank-Starling mechanism (rapid response (RR)) and the secondary slow response (SR) are known to contribute to increases contractile performance. The contractility of the heart muscle is influenced by pre-load and after-load. Because of the effect of pre-load vs. after-load on these mechanisms in not completely understood, we studied the effect in isolated muscle strips. METHODS AND RESULTS: Progressive stretch lead to an increase in shortening/force development under isotonic (only pre-load) and isometric conditions (pre- and after-load)...
November 2017: ESC Heart Failure
https://www.readbyqxmd.com/read/29146505/muscarinic-receptor-oligomerization
#10
REVIEW
Sara Marsango, Richard J Ward, Elisa Alvarez-Curto, Graeme Milligan
G protein coupled receptors (GPCRs) have been classically described as monomeric entities that function by binding in a 1:1 stoichiometric ratio to both ligand and downstream signalling proteins. However, in recent years, a growing numbers of studies have supported the hypothesis that these receptors can interact to form dimers and higher order oligomers although the molecular basis for these interactions, the overall quaternary arrangements and the functional importance of the GPCR oligomerization remain topics of intense speculation...
November 13, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/29144742/successful-identification-of-cardiac-troponin-calcium-sensitizers-using-a-combination-of-virtual-screening-and-roc-analysis-of-known-troponin-c-binders
#11
Melanie L Aprahamian, Svetlana B Tikunova, Morgan V Price, Andres F Cuesta, Jonathan P Davis, Steffen Lindert
Calcium-dependent cardiac muscle contraction is regulated by the protein complex troponin. Calcium binds to the N-terminal domain of troponin C (cNTnC) which initiates the process of contraction. Heart failure is a consequence of a disruption of this process. With the prevalence of this condition, a strong need exists to find novel compounds to increase the calcium sensitivity of cNTnC. Desirable are small chemical molecules that bind to the interface between cTnC and the cTnI switch peptide and exhibit calcium sensitizing properties by possibly stabilizing cTnC in an open conformation...
November 16, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/29143336/inter-filament-cooperativity-is-crucial-for-regulating-muscle-contraction
#12
Wanjian Tang, Christopher M Yengo
Understanding how muscle contraction is regulated has important implications for the treatment of heart disease, diabetes, and obesity. This article is protected by copyright. All rights reserved.
November 16, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29135658/muscle-strength-influences-pressor-responses-to-static-handgrip-in-men-and-women
#13
Karambir Notay, Jordan B Lee, Anthony V Incognito, Jeremy D Seed, Adam A Arthurs, Philip J Millar
PURPOSE: Whether differences in absolute muscle strength impact blood pressure (BP) responses to relative intensity static exercise remains controversial but could contribute to known sex-based differences and influence the interpretation of cross-sectional data. METHODS: One hundred thirty-two healthy participants (66 men and 66 women, age: 22±3yrs) underwent continuous seated measurements of BP (Finometer) and heart rate (electrocardiography) during baseline rest and two minutes of static handgrip (30% maximal voluntary contraction [MVC])...
November 10, 2017: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/29135437/an-adaptation-of-astronomical-image-processing-enables-characterization-and-functional-3d-mapping-of-individual-sites-of-excitation-contraction-coupling-in-rat-cardiac-muscle
#14
Qinghai Tian, Lars Kaestner, Laura Schröder, Jia Guo, Peter Lipp
In beating cardiomyocytes, synchronized localized Ca(2+) transients from thousands of active excitation-contraction coupling sites (ECC couplons) comprising plasma and sarcoplasmic reticulum membrane calcium channels are important determinants of the heart's performance. Nevertheless, our knowledge about their properties is limited by the lack of appropriate experimental and analysis strategies. We designed CaCLEAN to untangle fundamental characteristics of ECC couplons by combining the astronomer's CLEAN algorithm with known properties of calcium diffusion...
November 14, 2017: ELife
https://www.readbyqxmd.com/read/29127860/human-embryonic-stem-cell-derived-cardiovascular-progenitor-cells-efficiently-colonize-in-bfgf-tethered-natural-matrix-to-construct-contracting-humanized-rat-hearts
#15
Sarah Rajabi, Sara Pahlavan, Mohammad Kazemi Ashtiani, Hassan Ansari, Saeed Abbasalizadeh, Forough Azam Sayahpour, Fahimeh Varzideh, Sawa Kostin, Nasser Aghdami, Thomas Braun, Hossein Baharvand
Bioengineering of whole hearts using human embryonic stem cells (hESCs)-derived cardiovascular progenitor cells (CPCs) and natural matrices is a promising approach to overcome organ donor shortage threatening millions of patients awaiting for heart transplantation. Here, we developed a novel strategy for generation of heart constructs by repopulating engineered decellularized rat hearts using hESCs-derived CPCs. Careful expansion of CPCs in a scalable stirred-suspension bioreactor combined with step-wise seeding (60 million cells in 3 steps of 20 million per 1...
November 1, 2017: Biomaterials
https://www.readbyqxmd.com/read/29123488/wearing-compression-tights-on-the-thigh-during-prolonged-running-attenuated-exercise-induced-increase-in-muscle-damage-marker-in-blood
#16
Sahiro Mizuno, Mari Arai, Fumihiko Todoko, Eri Yamada, Kazushige Goto
Purpose: To examine the effects of wearing a lower-body compression garment with different body coverage areas during prolonged running on exercise performance and muscle damage. Methods: Thirty male subjects were randomly assigned to one of three groups: (1) wearing a compression tights with 15 mmHg to thigh [n = 10, CT group], (2) wearing a compression socks with 15 mmHg to calf [n = 10, CS group], and (3) wearing a lower-body garment with < 5 mmHg to thigh and calf [n = 10, CON group]. The exercise consisted of 120 min of uphill running at 55% of [Formula: see text]O2max...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29121035/ischemic-conditioning-of-human-heart-muscle-depends-on-opioid-receptor-system
#17
Marcin Kunecki, Tomasz Oleksy, Jolanta Biernat, Paweł Kukla, Katarzyna Szwajkos, Piotr Podolec, Marek Deja, Krzysztof Gołba, Wojciech Płazak
BACKGROUND: Despite progress in the invasive treatment of ischemic heart disease, the ability to limit ischemia-reperfusion (I/R) injury remains largely unrealized. Ischemic pre-conditioning (IPC) and post-conditioning (POC) induce the protective mechanisms of resistance against I/R injury. Stimulation of opioid receptors mimic the protective effect of IPC or POC in an animal models. We tested the hypothesis, that IPC and POC provide cardioprotection in opioid-dependent mechanism in human myocardium...
2017: Folia Medica Cracoviensia
https://www.readbyqxmd.com/read/29120706/administration-of-cloprostenol-and-oxytocin-before-electroejaculation-in-goat-bucks-reduces-the-needed-amount-of-electrical-stimulation-without-affecting-seminal-quality
#18
Rodolfo Ungerfeld, Daniela Casuriaga, Julia Giriboni, Aline Freitas-de-Melo, Patricia Silveira, Felipe Zandonadi Brandão
Electroejaculation (EE) is a widely used semen collection technique; but, it is stressful and painful for the animals. Considering these concerns, it may be important to develop practices to decrease the negative implications of EE on animals. Oxytocin and prostaglandin-F2alpha (PGF2α) stimulate the contractions of the muscles of the male genital tract. Therefore, the aim of this study was to analyze the effectiveness of the administration of oxytocin and/or a PGF2α analogue (cloprostenol) to bucks in relation to their stress response and sperm parameters before semen collection by EE was performed...
October 28, 2017: Theriogenology
https://www.readbyqxmd.com/read/29117189/cardiac-cycle-synchronized-electrical-muscle-stimulator-for-lower-limb-training-with-the-potential-to-reduce-the-heart-s-pumping-workload
#19
Ken-Ichiro Sasaki, Hiroo Matsuse, Ryuji Akimoto, Shiro Kamiya, Toshio Moritani, Motoki Sasaki, Yuta Ishizaki, Masanori Ohtsuka, Takaharu Nakayoshi, Takafumi Ueno, Naoto Shiba, Yoshihiro Fukumoto
BACKGROUND: The lower limb muscle may play an important role in decreasing the heart's pumping workload. Aging and inactivity cause atrophy and weakness of the muscle, leading to a loss of the heart-assisting role. An electrical lower limb muscle stimulator can prevent atrophy and weakness more effectively than conventional resistance training; however, it has been reported to increase the heart's pumping workload in some situations. Therefore, more effective tools should be developed...
2017: PloS One
https://www.readbyqxmd.com/read/29100827/sex-differences-in-neuromuscular-fatigability-in-response-to-load-carriage-in-the-field-in-british-army-recruits
#20
Thomas J O'Leary, Samantha C Saunders, Stephen J McGuire, Rachel M Izard
OBJECTIVES: Women are resistant to neuromuscular fatigue compared to men in response to a range of exercise tasks. The sex differences in the neuromuscular responses to load carriage have yet to be investigated. DESIGN: Prospective cohort study. METHODS: Twenty-three male and 19 female British Army recruits completed a 9.7km loaded march within 90min, with the weight carried dependent on military trade (16±2kg for men and 15±1kg for women)...
October 23, 2017: Journal of Science and Medicine in Sport
keyword
keyword
35691
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"