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https://www.readbyqxmd.com/read/28102317/time-resolved-neutron-scattering-provides-new-insight-into-protein-substrate-processing-by-a-aaa-unfoldase
#1
Ziad Ibrahim, Anne Martel, Martine Moulin, Henry S Kim, Michael Härtlein, Bruno Franzetti, Frank Gabel
We present a combination of small-angle neutron scattering, deuterium labelling and contrast variation, temperature activation and fluorescence spectroscopy as a novel approach to obtain time-resolved, structural data individually from macromolecular complexes and their substrates during active biochemical reactions. The approach allowed us to monitor the mechanical unfolding of a green fluorescent protein model substrate by the archaeal AAA+ PAN unfoldase on the sub-minute time scale. Concomitant with the unfolding of its substrate, the PAN complex underwent an energy-dependent transition from a relaxed to a contracted conformation, followed by a slower expansion to its initial state at the end of the reaction...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101344/evaluation-of-pharmacological-relaxation-effect-of-the-natural-product-naringin-on-in-vitro-cultured-airway-smooth-muscle-cells-and-in-vivo-ovalbumin-induced-asthma-balb-c-mice
#2
Yue Wang, Yun Lu, Mingzhi Luo, Xiaohao Shi, Yan Pan, Huilong Zeng, Linhong Deng
Asthma has become a common chronic respiratory disease worldwide and its prevalence is predicted to continue increasing in the next decade, particularly in developing countries. A key component in asthma therapy is to alleviate the excessive bronchial airway narrowing ultimately due to airway smooth muscle contraction, which is often facilitated by a smooth muscle relaxant, such as the β2-adrenergic agonists. Recently, bitter taste receptor (TAS2R) agonists, including saccharin and chloroquine, have been found to potently relax the airway smooth muscle cells (ASMCs) via intracellular Ca(2+) signaling...
December 2016: Biomedical Reports
https://www.readbyqxmd.com/read/28101178/endothelium-dependent-vasodilation-effects-of-panax-notoginseng-and-its-main-components-are-mediated-by-nitric-oxide-and-cyclooxygenase-pathways
#3
Yanyan Wang, Yu Ren, Leilei Xing, Xiangdong Dai, Sheng Liu, Bin Yu, Yi Wang
Panax notoginseng, a traditional Chinese herbal medicine, has been used for the treatment of cardiovascular diseases. The main bioactive components of this species are Panax notoginseng saponins (PNS). The present study aimed to investigate the effects of PNS and five of its main components (ginsenosides Rg1, Re, Rb1 and Rd, and notoginsenoside R1) on rat aorta rings pre-contracted with norepinephrine (NE) and to determine the underlying mechanism of action. Isolated aorta rings (with or without intact endothelium) from adult male Wistar rats were stimulated with NE to induce vasoconstriction, and subsequently treated with different concentrations of PNS and its five main components (Rg1, Re, Rb1, R1 and Rd) separately...
December 2016: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28100216/antispasmodic-bronchodilator-vasorelaxant-and-cardiosuppressant-effects-of-buxus-papillosa
#4
Arif-Ullah Khan, Shamsher Ali, Anwarul-Hassan Gilani, Manzoor Ahmed, Muhammad Iqbal Choudhary
BACKGROUND: The present research was carried out to investigate pharmacological properties of Buxus papillosa C.K. Schneid. (Buxaceae). METHODS: Buxus papillosa extracts of leaves (BpL), stem (BpS), roots (BpR) and BpL fractions: hexane (BpL-H), aqueous (BpL-A) also plant constituent, cyclomicrobuxine effect were studied in jejunum, atria, aorta and tracheal preparations from rabbit and guine-peg. RESULTS: Ca(++) antagonistic effect of BpS, BpR, BpL-H, BpL-A and cyclomicrobuxine were conclusively suggested, when spontaneous contractions of rabbit jejunal preparation was relaxed along with subsequent relaxation of potassium chloride (80 mM) induced contractions...
January 18, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28097712/force-generation-by-titin-folding
#5
Zsolt Mártonfalvi, Pasquale Bianco, Katalin Naftz, György G Ferenczy, Miklós Kellermayer
Titin is a giant protein that provides elasticity to muscle. As the sarcomere is stretched, titin extends hierarchically according to the mechanics of its segments. Whether titin's globular domains unfold during this process and how such unfolded domains might contribute to muscle contractility are strongly debated. To explore the force-dependent folding mechanisms, here we manipulated skeletal-muscle titin molecules with high-resolution optical tweezers. In force-clamp mode, after quenching the force (<10 pN), extension fluctuated without resolvable discrete events...
January 18, 2017: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/28097042/the-relaxant-activity-of-safranal-in-isolated-rat-aortas-is-mediated-predominantly-via-an-endothelium-independent-mechanism-vasodilatory-mechanism-of-safranal
#6
Bibi Marjan Razavi, Mojtaba Alipoor Amanloo, Mohsen Imenshahidi, Hossein Hosseinzadeh
OBJECTIVES: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. METHODS: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using 10(-6)-M phenylephrine (PE) or 80-mM KCl...
December 2016: Journal of Pharmacopuncture
https://www.readbyqxmd.com/read/28096047/cellular-basis-of-angiotensin-1-7-induced-augmentation-of-left-ventricular-functional-performance-in-heart-failure
#7
Xiaowei Zhang, Heng-Jie Cheng, Peng Zhou, Dalane W Kitzman, Carlos M Ferrario, Wei-Min Li, Che Ping Cheng
BACKGROUND: Angiotensin-(1-7) [Ang-(1-7)] exhibits cardiovascular effects opposite those of angiotensin II (Ang II), thus providing protection against heart disease. However, how Ang-(1-7) imparts cardioprotection is unclear, and its direct cardiac effects are controversial. Whether heart failure (HF) alters cardiac contractile responses to Ang-(1-7) remains undetermined. We tested the hypothesis that in HF, Ang-(1-7) may produce positive modulation on [Ca(2+)]i regulation, enhancing left ventricular (LV) and myocyte contraction and relaxation via Ang-(1-7) Mas receptor coupled with nitric oxide (NO)/bradykinin (BK)-mediated mechanism...
January 10, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28094639/chronic-heart-failure-part-1-pathophysiology-signs-and-symptoms
#8
Rebecca Brake, Ian David Jones
Chronic heart failure is a common and complex clinical syndrome that results from impaired cardiac relaxation or contraction. Patients with chronic heart failure may experience multiple debilitating symptoms, such as fatigue, pain, and peripheral oedema. However, breathlessness may be considered the most debilitating symptom. This is the first of two articles on chronic heart failure, and outlines the pathophysiology of the condition, its causes, assessment, and signs and symptoms. Part 2 will discuss the treatment and management of the condition, including pharmacological strategies, device implantation, lifestyle modification, cardiac rehabilitation and palliative care...
January 4, 2017: Nursing Standard
https://www.readbyqxmd.com/read/28091624/paracrine-cross-talk-between-skeletal-muscle-and-macrophages-in-exercise-by-pgc-1%C3%AE-controlled-bnp
#9
Regula Furrer, Petra S Eisele, Alexander Schmidt, Markus Beer, Christoph Handschin
Activation of resident and infiltrating immune cells is a central event in training adaptation and other contexts of skeletal muscle repair and regeneration. A precise orchestration of inflammatory events in muscle fibers and immune cells is required after recurrent contraction-relaxation cycles. However, the mechanistic aspects of this important regulation remain largely unknown. We now demonstrate that besides a dominant role in controlling cellular metabolism, the peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) also has a profound effect on cytokine expression in muscle tissue...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28090637/diltiazem-prevents-stress-induced-contractile-deficits-in-cardiomyocytes-but-does-not-reverse-the-cardiomyopathy-phenotype-in-mybpc3-knock-in-mice
#10
Frederik Flenner, Birgit Geertz, Silke Reischmann-Düsener, Florian Weinberger, Thomas Eschenhagen, Lucie Carrier, Felix W Friedrich
Left ventricular hypertrophy, diastolic dysfunction and fibrosis are main features of hypertrophic cardiomyopathy (HCM). Guidelines recommend β-adrenoceptor or Ca(2+) channel antagonists as pharmacological treatment. The Ca(2+) channel blocker diltiazem recently showed promising beneficial effects in pre-clinical HCM, particularly in patients carrying MYBPC3 mutations. In the present study we evaluated whether diltiazem could ameliorate or reverse the disease phenotype in cells and in vivo in Mybpc3-targeted knock-in (KI) mouse model of HCM...
January 15, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28089077/the-changing-pattern-of-uterine-contractions-before-and-after-fresh-embryo-transfer-and-its-relation-to-clinical-outcome
#11
Cathy Hoi Sze Chung, Alice Wai Yee Wong, Carol Pui Shan Chan, Sotirios H Saravelos, Grace Wing Shan Kong, Lai Ping Cheung, Jacqueline Pui Wah Chung, Tin Chiu Li
In this prospective cohort study of 286 women undergoing fresh embryo transfer after IVF, uterine contraction frequency and direction were measured before (-5 min), 5 min after (+5 min) and 60 min after (+60 min) embryo transfer. Mean ± SD uterine contraction frequency at -5 min was 1.8 ± 1.1 contractions per min, increasing significantly (P < 0.05) to 2.0 ± 1.1 at +5 min, and returning back to baseline 1.8 ± 1.1 at +60 min. At -5 min, the proportion of women the with retrograde, antegrade, indeterminate direction and absent contractions were 33%, 44%, 17% and 6%; at +5 min, 40%, 42%, 13% and 5%, and at +60 min, 42%, 38%, 14% and 6%...
December 23, 2016: Reproductive Biomedicine Online
https://www.readbyqxmd.com/read/28088386/trypsin-induces-biphasic-muscle-contraction-and-relaxation-via-transient-receptor-potential-vanilloid-1-and-neurokinin-receptors-1-2-in-porcine-esophageal-body
#12
Bai Xiaopeng, Yoshimasa Tanaka, Eikichi Ihara, Katsuya Hirano, Kayoko Nakano, Mayumi Hirano, Yoshinao Oda, Kazuhiko Nakamura
Duodenal reflux of fluids containing trypsin relates to refractory gastroesophageal reflux disease (GERD). Esophageal peristalsis and clearance are important factors in GERD pathogenesis. However, the function of trypsin in esophageal body contractility is not fully understood. In this study, effects of trypsin on circular smooth muscle (CSM) and longitudinal smooth muscle (LSM) of the porcine esophageal body were examined. Trypsin elicited a concentration dependent biphasic response, a major contraction and a subsequent relaxation only in CSM...
January 11, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28075307/chronic-heart-failure-part-2-treatment-and-management
#13
Rebecca Brake, Ian David Jones
Chronic heart failure is a common and complex clinical syndrome that results from impaired cardiac relaxation or contraction. There have been considerable advances in the management of chronic heart failure; however, the mortality rate remains high. Patients with chronic heart failure may experience multiple debilitating symptoms, such as fatigue, pain, and peripheral oedema. However, breathlessness may be considered the most debilitating symptom. The management of chronic heart failure aims to improve the patient's quality of life by reducing symptoms and supporting the patient to manage their condition...
January 11, 2017: Nursing Standard
https://www.readbyqxmd.com/read/28069694/myocardial-tissue-engineering-with-cells-derived-from-human-induced-pluripotent-stem-cells-and-a-native-like-high-resolution-3-dimensionally-printed-scaffold
#14
Ling Gao, Molly Kupfer, Jangwook Jung, Libang Yang, Patrick Zhang, Yong Sie, Quyen Tran, Visar Ajeti, Brian Freeman, Vladimir Fast, Paul Campagnola, Brenda Ogle, Jianyi Zhang
RATIONALE: Conventional three-dimensional (3D) printing techniques cannot produce structures of the size at which individual cells interact. OBJECTIVE: Here, we used multiphoton-excited, 3-dimensional printing (MPE-3DP) to generate a native-like, extracellular matrix (ECM) scaffold with submicron resolution, and then seeded the scaffold with cardiomyocytes (CMs), smooth-muscle cells (SMCs), and endothelial cells (ECs) that had been differentiated from human induced-pluripotent stem cells (iPSCs) to generate a human, iPSC-derived cardiac muscle patch (hCMP), which was subsequently evaluated in a murine model of myocardial infarction (MI)...
January 9, 2017: Circulation Research
https://www.readbyqxmd.com/read/28059795/evidence-of-a-cardiovascular-function-for-microtubule-associated-protein-tau
#15
Ashenafi H Betrie, Scott Ayton, Ashley I Bush, James A Angus, Peng Lei, Christine E Wright
Aggregation of tau protein into intracellular deposits is a pathognomonic feature of tauopathies such as Alzheimer's disease (AD) and lowering tau is a prominent therapeutic strategy under development. However, the physiological function of tau protein is not well known, particularly in the periphery. Lowering tau protein risks disrupting its physiological role leading to unwanted effects. In this study, the presence of tau protein in cardiac tissue is confirmed and the functional role in the cardiovascular system and the consequences of its loss were explored...
December 3, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28050326/use-of-botulinum-neurotoxin-in-ophthalmology
#16
REVIEW
Emel Başar, Ceyhun Arıcı
Botulinum neurotoxin (BoNT) is the first biological toxin used in the treatment of ophthalmic diseases and to decrease skin wrinkles as an aesthetic agent. When used appropriately, it weakens the force of muscular contraction and/or inhibits glandular secretion. The most common areas for botulinum toxin treatment are the upper face, including the glabella, forehead, brows, and lateral canthal lines, or crow's feet. By relaxing the muscles causing wrinkles, non-permanent results may be achieved with its use...
December 2016: Turkish Journal of Ophthalmology
https://www.readbyqxmd.com/read/28049727/allosteric-transmission-along-a-loosely-structured-backbone-allows-a-cardiac-troponin-c-mutant-to-function-with-only-one-ca2-ion
#17
Mayra de A Marques, Jose Renato Pinto, Adolfo H Moraes, Anwar Iqbal, Mariana T Q de Magalhães, Jamila Monteiro, Murilo M Pedrote, Martha M Sorenson, Jerson L Silva, Guilherme A P de Oliveira
Hypertrophic cardiomyopathy (HCM) is one of the most common cardiomyopathies, and a major cause of sudden death in young athletes. The Ca2+ sensor of the sarcomere, cardiac troponin C (cTnC), plays an important role in regulating muscle contraction. Although several cardiomyopathy-causing mutations have been identified in cTnC, limited information about their structural defects has been mapped to the HCM phenotype. Here, we use high-resolution electron-spray ionization mass spectrometry (ESI-MS), Carr-Purcell-Meiboom-Gill relaxation dispersion (CPMG-RD) and affinity measurements of cTnC for the thin filament in reconstituted papillary muscles to provide evidence of an allosteric mechanism in mutant cTnC that may play a role to the HCM phenotype...
January 3, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28049099/the-effect-of-glyphosate-based-herbicide-roundup-and-its-co-formulant-poea-on-the-motoric-activity-of-rat-intestine-in-vitro-study
#18
Magdalena Chłopecka, Marta Mendel, Natalia Dziekan, Wojciech Karlik
The study was aimed at evaluating the effect of Roundup, polyoxyethylene tallow amine (POEA) and mixture of glyphosate and POEA in different levels on the motoric activity of jejunum strips. The incubation in the Roundup solutions caused a significant, mostly miorelaxant, reversible reaction of smooth muscle; only in the highest tested dose which is equivalent to the agricultural concentration (1% corresponding to 1.7g glyphosate/L) there was an irreversible disturbance of the spontaneous contractility and reactivity...
December 26, 2016: Environmental Toxicology and Pharmacology
https://www.readbyqxmd.com/read/28046050/postsystolic-shortening-is-associated-with-altered-right-ventricular-function-in-children-after-tetralogy-of-fallot-surgical-repair
#19
Radosław Pietrzak, Bożena Werner
: The aim of the study was to determine whether segmental interactions, as expressed by postsystolic shortening (PSS), affects RV mechanics and are connected with impaired systolic and diastolic function in rTOF children. PATIENTS AND METHODS: 55 rTOF adolescent (study group), and 34 healthy volunteers (control group) were examined using classical Doppler flow (Doppler), Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE). PSS was found to occur when time to peak (TTP) was longer than pulmonary valve closure time (PVCT)...
2017: PloS One
https://www.readbyqxmd.com/read/28041845/inverse-bayesian-inference-as-a-key-of-consciousness-featuring-a-macroscopic-quantum-logical-structure
#20
Yukio-Pegio Gunji, Shuji Shinohara, Taichi Haruna, Vasileios Basios
To overcome the dualism between mind and matter and to implement consciousness in science, a physical entity has to be embedded with a measurement process. Although quantum mechanics has been regarded as a candidate for implementing consciousness, nature at its macroscopic level is inconsistent with quantum mechanics. We propose a measurement-oriented inference system comprising Bayesian and inverse Bayesian inferences. While Bayesian inference contracts probability space, the newly defined inverse one relaxes the space...
December 29, 2016: Bio Systems
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