Contraction Relaxation Research Articles

Mitochondrial Dysfunction in Cardiac Disease: The Fort Fell

Myocardial cells and the extracellular matrix achieve their functions through the availability of energy. In fact, the mechanical and electrical properties of the heart are heavily dependent on the balance between energy production and consumption. The energy produced is utilized in various forms, including kinetic, dynamic, and thermal energy. Although total energy remains nearly constant, the contribution of each form changes over time. Thermal energy increases, while dynamic and kinetic energy decrease, ultimately becoming insufficient to adequately support cardiac function. As a result, toxic byproducts, unfolded or misfolded proteins, free radicals, and other harmful substances accumulate within the myocardium. This leads to the failure of crucial processes such as myocardial contraction–relaxation coupling, ion exchange, cell growth, and regulation of apoptosis and necrosis. Consequently, both the micro- and macro-architecture of the heart are altered. Energy production and consumption depend on the heart’s metabolic resources and the functional state of the cardiac structure, including cardiomyocytes, non-cardiomyocyte cells, and their metabolic and energetic behavior. Mitochondria, which are intracellular organelles that produce more than 95% of ATP, play a critical role in fulfilling all these requirements. Therefore, it is essential to gain a deeper understanding of their anatomy, function, and homeostatic properties.

Analyzing the Chaotic Dynamics of a Fractional-Order Dadras–Momeni System Using Relaxed Contractions

This paper is inspired by cutting-edge advancements in chaos theory, fractional calculus, and fixed point theory, which together provide a powerful framework for examining the dynamics of complex systems. At the heart of our research is the fractional-order Dadras–Momeni chaotic system, a pivotal model in chaos theory celebrated for its intricate, multi-scroll dynamics. Leveraging the Atangana–Baleanu fractional derivative, we extend fractional computation to chaotic systems, offering deeper insights into their behavior. To fortify the mathematical foundation of our analysis, we employ the relaxed θ rational contractions in the realm of metric spaces, enabling a more precise exploration of the system’s dynamics. A key goal of this work is to simplify the definition of the function class Θ while maintaining the existence and uniqueness of fixed points under θ-relaxed contractions, integrating this framework with the established literature on complete metric spaces. We explore the system’s behavior across six distinct cases by varying δ with a fixed fractional order of ℏ=0.98. In the first case, a single scroll forms, while successive cases lead to increased scrolls—reaching up to four by the sixth case. Phase portraits and time series analyses reveal a progression in complexity and chaos, with denser, intertwined scrolls as δ increases. This behavior highlights the system’s heightened sensitivity to parameter variations, demonstrating how fractional parameters influence the chaotic dynamics. Our results offer meaningful contributions to both the theoretical foundations and practical applications of chaos theory and fractional calculus, advancing the understanding of chaotic systems in new and impacted ways.

Abstract 4134475: Effects of E-cigarette Vaping on Endothelial Function in Diet-Induced Obese Mice

Introduction: Although electronic cigarettes (e-cigs) have been known to increase the risk of vascular complications, little is known about whether e-cig represents an independent risk factor for the development and worsening of obesity and its associated vascular diseases. We hypothesize that a high-fat diet (HFD) enhances e-cig-induced vascular complications. Methods: Male and female eight-week-old C57Bl/6J mice were fed normal chow (NC) or HFD for 15 weeks before being exposed to e-cigs (PG/VG only [PGVG] or PG/VG + 24 mg/ml nicotine [Nic]) or fresh air (FA) for 12 weeks (n=6-8). At the end of the experiments, glucose level and thoracic aortic responses to phenylephrine (PE), acetylcholine (ACh), and sodium nitroprusside (SNP) were assessed via the glucose tolerance test (GTT) and wire myography, respectively. Total RNA from male aortas was extracted and RNA-seq was utilized to identify the transcriptomic changes in our diet-induced obesity mouse model subjected to e-cig vapors (n=4). Results: Compared to NC with FA, HFD alone caused glucose intolerance as shown by the GTT, which was improved only by exposure to nicotine-containing e-cigs (HFD+Nic). Similar improvement in glucose intolerance were found in the NC group with e-cigs (PGVG or Nic). In addition, both NC and HFD-fed male mice exhibited endothelial dysfunction characterized by a decrease in the ACh-dependent (endothelium) relaxation of PE-induced contractions. Importantly, nicotine-containing e-cig exposure (Nic) dramatically reduced the sensitivity of the aorta in the HFD group (HFD+Nic) to both ACh and SNP, while it only affected the sensitivity and maximum relaxation to ACh in the male NC group (NC+Nic). There were no significant differences in the vasoreactivity of female mice exposed to e-cig or HFD. Finally, RNA-seq results suggested that e-cig-treated male mice had altered expression of genes related to endothelial and smooth muscle function and metabolism, particularly fatty acid metabolism, which was also significant with the addition of HFD. Conclusion: Collectively, our results suggest that acute e-cig exposure results in significant vascular dysfunction in male mice, which is worsened in HFD mice. The identification of genes dysregulated in mice exposed to e-cigs provides novel insights into vascular biology and could have a significant impact on our understanding of vascular complications associated with e-cig usage and provide insights into its contributions to obesity and diabetes.

A Study to Compare the Effectiveness of McKenzie Neck Exercise and Contract Relax Stretching in Mechanical Neck Pain

Background: Mechanical neck pain is commonly defined as pain between the superior nuchal line and an imaginary transverse line through the tip of the first thoracic spinous process, extending laterally to the sagittal planes peripheral to the lateral borders of the neck. Neck pain (NP) can be local and/or referred into the head and/or upper limbs. NP is a prevalent musculoskeletal issue worldwide, similar to low back pain (LBP), characterized by episodic occurrences with high recurrence and chronicity rates. It frequently arises insidiously and is multifactorial in origin, with modifiable factors including smoking, poor posture, anxiety, depression, neck strain, and occupational activities. NP is a significant societal burden, particularly prevalent among office workers and computer users. Objective: The objective of this study was to compare the effectiveness of McKenzie neck exercises and contract-relax stretching in alleviating mechanical neck pain. Methods: This quasi-experimental study included 40 participants aged 25 to 50 years from Allied Hospital Faisalabad, selected using purposive sampling. Participants were divided into two groups of 20 each. Group 1 received McKenzie neck exercises, while Group 2 received contract-relax stretching. Both groups underwent treatment three times per week for 6 to 8 weeks. Pain and functional performance were evaluated using the Numeric Pain Rating Scale (NPRS) and Neck Disability Index (NDI). Statistical analysis was conducted using SPSS version 27.0, with the Wilcoxon signed-rank test applied for within-group comparisons and the Mann-Whitney U test for between-group comparisons. Results: In Group 1 (contract-relax stretching), NPRS scores improved from a mean of 2.56 (SD=0.51) to 2.11 (SD=0.47) (Z=-2.828, p<0.05), and NDI scores improved from a mean of 3.78 (SD=0.55) to 0.73 (SD=0.73) (Z=-3.419, p<0.05). In Group 2 (McKenzie neck exercises), NPRS scores improved from a mean of 2.61 (SD=0.50) to 1.72 (SD=0.57) (Z=-2.828, p<0.01), and NDI scores improved from a mean of 3.22 (SD=0.73) to 2.06 (SD=0.94) (Z=-3.391, p<0.05). Between-group comparisons indicated that Group 2 had significantly greater improvements in NPRS (mean rank 15.47 vs. 21.53, p<0.05) and NDI scores (mean rank 13.86 vs. 23.14, p<0.05). Conclusion: Both McKenzie neck exercises and contract-relax stretching effectively reduced pain and improved function in patients with mechanical neck pain. However, McKenzie neck exercises demonstrated significantly greater improvements in pain relief and functional outcomes. Therefore, McKenzie neck exercises may be preferred for managing mechanical neck pain. Keywords: Mechanical Neck Pain, McKenzie Neck Exercise, Contract-Relax Stretching, Numeric Pain Rating Scale, Neck Disability Index

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

The enzymatic and kinetic analyses were used to demonstrate that 5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)methylamino-25,27-dihexyloxy-26,28-dihydroxythiacalix[4]arene С-1087 effectively inhibited the Са2+,Mg2+-АТРase activity of the rat myometrium cells plasma membrane (І0.5 = 9.4 ± 0.6 µM) with no effect on the relative activity of other membrane ATPases. With the use of confocal microscopy and Ca2+-sensitive fluorescent probe fluo-4, it was shown that the application of thiacalix[4]arene С-1087 to the immobilized uterus myocytes increased the cytosolic concentration of Ca2+. Tenzometric studies of rat uterus smooth muscles with the subsequent mechanokinetic analysis revealed that thiacalix[4]arene С-1087 considerably decreased the maximal velocity of the relaxation of both spontaneous contractile response and contraction induced by hyperpotassium solution. Keywords: contraction-relaxation mechanokinetics, cytosolic Ca(2+), myometrium, plasma membrane Са(2+)‚Mg(2+)-АТРase, smooth muscle cell, thiacalix[4]arene

TRAINING ON THE APPLICATION OF KINESIOTAPING COMBINED WITH CONTRACT RELAX AS A PREVENTIVE AND REHABILITATIVE MEASURE FOR SPORTS INJURIES

The problems experienced by PPLP/D Papua athletes is sports injuries which limit athletes in running an optimal training program. The dense and heavy training program causes a tendency for sports injuries to occur. The purpose of this community service is to upgrade knowledge and skills on how to install kinesiotaping and contract relax as an effort to preventive and rehabilitative sports injuries. The method used is training with the flow of delivering material and demonstration. Population in this community service are PPLP/D Papua athletes with a total of 98 athletes. The sample used was 60 athletes from 12 sports. The results obtained are an increase in PPLP/D athletes' knowledge about kinesiotaping and contract relax, the dominant pretest results of the very low category 53 athletes (88.3%) become the dominant category of very high 19 athletes (31.7%), high category 18 athletes (30%), and medium category 18 athletes (30%). The results of the t test analysis (paired sample test) found the sig value (2-tailed) = 0.001 <0.05. Based on the results obtained, it can be concluded that the training provided has a positive impact on PPLP/D Papua athletes in terms of increasing knowledge about the application of kinesiotaping and contract relax as preventive and rehabilitative sports injuries.

Effect of 8-Weeks PNF Stretching on Muscle Strength and Neuromuscular Activity of the Hamstring Muscles

Background: Hamstring injuries are common in sports that involve rapid, forceful lengthening of the hamstring muscles, such as sprinting, jumping, and kicking. This type of injury is more likely to occur in team sports such as football and handball. Objectives: The purpose of this study was to investigate chronic effects of proprioceptive neuromuscular facilitation (PNF) stretching on muscle strength and neuromuscular activity of the hamstring muscle. Methods: Six male team sports players (age: 24.38 ± 1.94 years; height: 180.73 ± 6.05 cm; body-mass: 80.23 ± 10.42 kg) were recruited for this study. Participants completed a 2-month rehabilitation program that included three sessions per week of contract-relax (CR) PNF stretching. Neuromuscular activity and strength were evaluated by electromyography (EMG) and force sensor before and after 8 weeks of CR-PNF stretching. Results: The neuromuscular activity of the medial and lateral hamstring muscles was significantly different between pre-and post-training for the apex and area of muscle (P < 0.01). Similarly, there was a large difference between pre- and post-training for hamstring muscle strength (medial and lateral) in the contract and relax positions (P < 0.001). Conclusions: Eight weeks of contract-relax proprioceptive neuromuscular facilitation (PNF) stretching is effective in increasing neuromuscular activity and muscle strength in the hamstring muscles.

Differences in Nordic Hamstring Exercise and Contract Relax Stretching on Increasing Flexibility in Students with Hamstring Tightness at Muhammadiyah University of Sidoarjo

This study aims to determine the differences between Nordic Hamstring Exercise and Contract Relax Stretching on increasing flexibility in students with Hamstring Tightness at Muhammadiyah University of Sidoarjo, with male and female respondents aged 19-24 years experiencing hamstring tightness. Methods: This study was conducted by comparing the increased flexibility of the group given Nordic Hamstring Exercise with the Contract Relax Stretching group, hamstring flexibility was measured by measuring the hip joint range of motion during the passive straight leg raise (SLR) or active knee extension (AKE) test. Results: The results of this study were paired sample T-test in both groups, where in group 1 the mean value of the pre-test was changed from 42.69±6.957 to 20.77±7.316 at the time of post-test, p value = 0.001 ( p<0.05). Meanwhile, in group 2, the mean value of the pre-test was changed from 43.85±10.637 to 32.31±0.919 at the post-test, the value of p=0.001 (p<0.05) it can be concluded that there is a change in the flexibility of the hamstring muscles in students after being given Nordic Hamstring Exercise and Contract Relax Stretching. The results of the Independent T-test showed a p value = 0.004 <0.05, which means that there are differences in the effectiveness of the two groups to increase the flexibility of the hamstring muscles in students.

Abstract P1028: Elucidating Differential Mechanisms That Underlie Phenotypic Variability In Two Independent Dcm Models

Mutations in components of the cardiac thin filament cause disease via complex, multi-faceted myocellular mechanisms, ultimately presenting as heterogeneous, symptomatic cardiomyopathies. The heterogeneity of both the myocellular mechanism(s) involved and the clinical outcome(s) represents a challenge in ongoing efforts to link genotype to phenotype. Two DCM-associated thin filament mutations (D230N-Tm and R173W-cTnT) with similar clinical phenotypes, were selected explore the molecular basis of disease trajectory. In patient populations, D230N-Tm exhibits an earlier time of onset compared to R173W-cTnT, with children (<1yr) presenting with an often-fatal DCM. We hypothesize that the difference in time of onset can be explained by distinct myocellular mechanisms. We utilized transgenic mice expressing D230N-Tm and R173W-cTnT and defined the progression of pathogenic remodeling across 3 independent timepoints via 2D-echo. At 2 months the %FS of D230N-Tm was significantly reduced (21.79 ± 1.19) compared to NTg littermates (33.45±1.45). R173W-cTnT, however, exhibited no reduction in %FS until 4 months (22.53±0.78), thus phenocopying the patient population. Using these timepoints to guide our myocellular mechanics, contractility measurements were then utilized to assess the myocellular mechanics associated with the mutations. At 2 months D230N-Tm exhibited a decrease in the rate of contraction (4.53±0.24μm/sec) and rate of relaxation (2.88±0.23) compared to NTg. R173W-cTnT did not diverge from NTg until 4 months, exhibiting a later onset of impaired contractility. By 4 months, both mutations displayed the opposite, an increase in rate of contraction and relaxation (rate of contraction, D230N-Tm 4.49±0.18 and R173W-cTnT 5.83±0.27; and rate of relaxation, D230N-Tm 3.14±0.19 and R173W-cTnT 3.70±0.24). Our results suggest that the accelerated time course for the development of D230N-Tm – linked DCM is caused by differential myocellular mechanism(s) that induce the early reduction in contractility and relaxation observed. Ongoing studies aim to further identify possible myocellular mechanism(s) by which these mutations exhibit different myocellular mechanics.

Preadaptivity of Non-Contractive Thermogenesis in the Evolution of Warm-Bloodedness in Vertebrates

Most of the heat that is released in the vertebrate body is produced in the muscles during contractive (during movement or trembling) and non-contractive (without muscle activity) thermogenesis. Contractive thermogenesis is characteristic for all vertebrates, but it is not able to constantly maintain a high body temperature in animals. The main idea discussed in this article, and based on a large number of publications in recent years: the main biochemical base of warm-bloodedness in vertebrates is part of the cycle of contraction–relaxation of striated skeletal muscles, in which the act of muscle contraction somehow falls out, and the energy that should have been used for it is dissipated in the form of heat. This non-contractive thermogenesis, which is able to support the regional and general endothermy in vertebrates, can be considered the real biochemical basis of warm-bloodedness. Thus, the presence of skeletal muscles in all vertebrates and the common biochemical foundations of the contraction–relaxation cycle represent a single preadaptive property of the manifestation of non-contractive thermogenesis in all vertebrates, starting with fish, which is the basis for the evolution of warm-bloodedness. Therefore, it is understandable and unsurprising modern data that the first terrestrial vertebrates were most likely animals with high levels of both metabolism and body temperature.

Comparison between contract-relax stretching and McKenzie neck exercise on decreasing pain of upper trapezius muscle in peeling onions workers

Background: Upper trapezius muscle pain is caused by overuse of the neck, hand, and shoulder muscles with the same movement resulting in decreased oxygen supply to the muscles. The treatments that can be given are contract-relax stretching and Mckenzie neck exercise. Contract relax stretching aims to reduce pain with stretching techniques. McKenzie's neck exercise aims to relax muscles, reduce spasms and return the alignment of the neck to a normal position.
 Methods: This type of research is a pre-experimental study with two pretest and post-test design groups. This design uses two groups to compare the causal relationship between the independent and dependent variables. The research population was peeling onion workers at CV. Anita Jaya Sukses had upper trapezius muscle pain. The sample of this study is a member of the people that meets the inclusion and exclusion criteria with a total of 18 selections. The sampling technique used purposive sampling. The research instrument used is the numeric rating scale (NRS).
 Results: The Independent Sample T-Test showed that giving contract-relax stretching and McKenzie neck exercise had a significant value of 0.005 (p< 0.05), so H1 was accepted.
 Conclusion: There is a difference in the effect between contract-relax stretching and McKenzie neck exercise on reducing upper trapezius muscle pain in onion peel workers' CV. Anita Jaya Sukses and McKenzie's neck exercise has proven more effective.

An In Vitro and In Silico Characterization of Salvia sclarea L. Methanolic Extracts as Spasmolytic Agents.

The use of medicinal plant species and their products is widespread in the field of gastrointestinal and respiratory diseases. This study aimed to evaluate the traditional use of Salvia sclarea L., clary sage, finding the possible mechanisms of its spasmolytic and bronchodilator actions in in vitro conditions supported by molecular docking analysis, along with the antimicrobial effects. Four dry extracts were prepared from the aerial parts of S. sclarea, using absolute or 80% (v/v) methanol by the method of a single-stage maceration or an ultrasound-assisted extraction. Characterization of the bioactive compounds by high-performance liquid chromatography indicated the presence of significant amounts of polyphenolics, with rosmarinic acid as the prevalent one. The spontaneous ileal contractions were best inhibited by the extract prepared with 80% methanol and maceration. The same extract was superior in the carbachol- and KCl-induced tracheal smooth muscle contractions, being the strongest bronchodilator agent. The most powerful relaxation of KCl-induced ileal contractions was achieved with the extract made of absolute methanol by maceration, while the 80% methanolic extract made with the ultrasound method generated the best spasmolytic effects in the acetylcholine-induced ileal contractions. Docking analysis suggested that apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited the highest binding affinity to voltage-gated calcium channels. Gram (+) bacteria were more susceptible to the effects of the extracts, particularly Staphylococcus aureus, in contrast to Gram (-) bacteria and Candida albicans. This is the first study to point out the influence of S. sclarea methanolic extracts on the gastrointestinal and respiratory spasm reduction, paving the way for their potential place in complementary medicine.

Immediate and Long-Term Effectiveness of Proprioceptive Neuromuscular Facilitation and Static Stretching on Joint Range of Motion, Flexibility, and Electromyographic Activity of Knee Muscles in Older Adults.

Introduction and Objective: Previously, various stretching techniques were compared to study their effects on the different physiological parameters of hamstring muscles in the elderly population. There is no research that compares the immediate and long-term effects of proprioceptive neuromuscular facilitation-contract-relax (PNF-CR) and static stretching (SS) techniques on knee range of motion (ROM), hamstring flexibility, and knee flexor muscle EMG activity in the elderly. This study intends to compare the same. Methods: A total of 30 males aged 55-75 years were randomly assigned into the PNF-CR group (n = 10), SS group (n = 10), and control group (n = 10). The PNF-CR group received four trials of the contract-relax technique, the SS group received passive stretching of an 80 s duration by the therapist, and the control group received no intervention. A total of 12 sessions were given during the four-week period. Knee range of motion, electromyographic activity of the biceps femoris, and the sit-and-reach test were taken for the dominant side thrice: pre-intervention, immediately after stretching, and after the training period. Results: A statistically significant difference was observed in the maximum voluntary isometric contraction (MVIC) of biceps femoris between the PNF and the control groups (p = 0.01) after four weeks of intervention. The knee ROM and hamstring flexibility for the PNF group showed significant improvement immediately post-test (p = 0.01) and after four weeks of training (p = 0.07 and p = 0.001). SS showed significant results for both ROM and flexibility after four weeks of intervention (p = 0.001), and significant immediate post-test improvements were seen for ROM only (p = 0.007). Conclusions: PNF stretching has an immediate, as well as long-term, effect on knee ROM and hamstring flexibility, whereas it has only a long-term effect on muscle electromyographic activity. SS has an immediate, as well as long-term, effect on knee ROM and only a long-term effect on hamstring flexibility, without any immediate or long-term effects on muscle electromyographic activity.

Calumenin, a Ca2+ Binding Protein, Is Required for Dauer Formation in Caenorhabditis elegans.

Caenorhabditis elegans can adapt and survive in dynamically changing environments by the smart and delicate switching of molecular plasticity. C. elegans dauer diapause is a form of phenotypic and developmental plasticity that induces reversible developmental arrest upon environmental cues. An ER (endoplasmic reticulum)-resident Ca2+ binding protein, calumenin has been reported to function in a variety of malignant diseases in vertebrates and in the process of muscle contraction-relaxation. In C. elegans, CALU-1 is known to function in Ca2+-regulated behaviors (pharyngeal pumping and defecation) and cuticle formation. The cuticles of dauer larvae are morphologically distinct from those of larvae that develop in favorable conditions. The structure of the dauer cuticle is thicker and more highly reinforced than that of other larval stages to protect dauer larvae from various environmental insults. Since the calu-1(tm1783) mutant exhibited abnormal cuticle structures such as highly deformed annuli and alae, we investigated whether CALU-1 is involved in dauer formation or not. Ascaroside pheromone (ascr#2) and crude daumone were used under starvation conditions to analyze the rate of dauer formation in the calu-1(tm1783) mutant. Surprisingly, the dauer ratio of the calu-1(tm1783) mutant was extremely low compared to that of the wild type. In fact, the calu-1(tm1783) mutants were mostly unable to enter diapause. We also found that calu-1 is expressed in body-wall muscle and AIA interneurons at the dauer stage. Taken together, our results suggest that CALU-1 is required for normal entry into diapause in C. elegans.

Ethnobotanical Survey and Pharmacological Screening of Medicinal Plants Used as Antihypertensive in Sefrou Province (Middle-North of Morocco): Benefits and Challenges

Herbal medicine was used since the old time in the treatment of different types of diseases in Sefrou province, Morocco. However, few studies have been carried out to identify local medicinal flora and to scientifically document the knowledge of the traditional use of these medicinal plants by the population. This study aims to investigate the medicinal plants in Sefrou province, record their usage in folk medicine by the population and evaluate the hypotensive effect of selected plants using in vitro vascular activity. For that, an ethnobotanical survey was conducted among the Arabs and Amazighs population of Sefrou province from January 2017 to December 2018. The survey was conducted through oral interviews with a structured questionnaire. It covered those who knew and/or used plants for medicinal purposes, retailers, and wholesalers, and also included ecological repartition as well as the mode of administration. Then we selected some plants to evaluate the antihypertensive activity based on the in vitro bioassay. A total of 134 medicinal plants belonging to 52 families were identified; 61% are wild species, 49 (36%) are cultivated and 4 (3%) are cultivated as well as spontaneous. Medicinal plants used in Sefrou folk medicine have been investigated for their antihypertensive activity. They were selected based on their usage as cardiotonic, diuretics, and other uses related to the symptoms of hypertension. Most of the plants tested in this study were found to be more sensitive to relaxing contractions induced by noradrenaline. Out of 32 species examined, 14 (44%) showed more than 50% inhibition in isolated rat aortic rings, the vasorelaxant activity of these plants used for the screening was mostly inhibited by pre-treatment with N-ω-nitro-L-arginine (L-NOArg). The plants inventoried are alleged to be active against 104 therapeutic indications. Nine common symptoms are widely treated in indigenous pharmacopeia: gastrointestinal (19 plants), renal (27 plants), broncho-pulmonary system (7 plants), skin (13 species), diabetes (12 plants), cardiovascular (13 plants), eye, ear, nose, teeth, and throat diseases (5 plants); gynecological disorders (6 plants); rheumatism and gnawing pain (11 plants). 14% (19 species) of the plant inventoried are traded on a large scale and scope and more than 90 percent of the medicinal plants purchased from Sefrou go to big cities for export. The expansion of unregulated trade and commercial use of medicinal and aromatic plants poses a major threat to biodiversity in the region. Overall, people in Sefrou hold rich knowledge of herbal medicine. The vasorelaxant activity proved for the documented plants will provide a basis for other preclinical and clinical investigations.

Moving, fast and slow: behavioural insights into bradykinesia in Parkinson's disease.

The debilitating symptoms of Parkinson's disease, including the hallmark slowness of movement, termed bradykinesia, were described more than 100 years ago. Despite significant advances in elucidating the genetic, molecular and neurobiological changes in Parkinson's disease, it remains conceptually unclear exactly why patients with Parkinson's disease move slowly. To address this, we summarize behavioural observations of movement slowness in Parkinson's disease and discuss these findings in a behavioural framework of optimal control. In this framework, agents optimize the time it takes to gather and harvest rewards by adapting their movement vigour according to the reward that is at stake and the effort that needs to be expended. Thus, slow movements can be favourable when the reward is deemed unappealing or the movement very costly. While reduced reward sensitivity, which makes patients less inclined to work for reward, has been reported in Parkinson's disease, this appears to be related mainly to motivational deficits (apathy) rather than bradykinesia. Increased effort sensitivity has been proposed to underlie movement slowness in Parkinson's disease. However, careful behavioural observations of bradykinesia are inconsistent with abnormal computations of effort costs due to accuracy constraints or movement energetic expenditure. These inconsistencies can be resolved when considering that a general disability to switch between stable and dynamic movement states can contribute to an abnormal composite effort cost related to movement in Parkinson's disease. This can account for paradoxical observations such as the abnormally slow relaxation of isometric contractions or difficulties in halting a movement in Parkinson's disease, both of which increase movement energy expenditure. A sound understanding of the abnormal behavioural computations mediating motor impairment in Parkinson's disease will be vital for linking them to their underlying neural dynamics in distributed brain networks and for grounding future experimental studies in well-defined behavioural frameworks.

Tracking the structural dynamics of SERCA regulation in real time.

Calcium (Ca2+) signaling in eukaryotic cells is integral to biological processes such as neuronal activity, transcription, and muscle contraction-relaxation. Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) proteins play a vital role in this intricate signaling network by returning Ca2+ to the sarco/endoplasmic reticulum (SR/ER), thereby resetting the signal and restoring SR/ER Ca2+ levels. SERCA activity is optimised for different tissues and developmental stages by expression of different isoforms and by regulatory factors such as regulatory peptides, Ca2+ concentration and internal regulatory domains. Mutations are known to cause Brody's (SERCA1) and Darier's (SERCA2) diseases, and dysregulation of SERCA2a is associated with heart failure. To investigate the kinetic and structural effects of SERCA regulation, we performed time-resolved x-ray solution scattering (TR-XSS) experiments on two SERCA isoforms. In our TR-XSS setup the reaction is initiated by laser-induced ATP release, and the resulting structural dynamics are then monitored in real time using synchrotron x-ray pulses. We investigated the effect of Ca2+ concentration on SERCA1a in native membranes and identified three distinct structural states that developed slower under high-Ca2+ conditions and showed structural differences compared to the low-Ca2+ condition. The SERCA2b isoform has a unique regulatory domain consisting of an 11th transmembrane helix and a luminal extension loop that increases its Ca2+ affinity and lowers the maximal turnover rate. We collected TR-XSS datasets for SERCA2b with and without this regulatory region and observed differences in the reaction-cycle kinetics that indicate a loss of control of transitions between states. In summary, we have developed a synchrotron-based x-ray technique and determined the kinetic and structural basis of regulation of P-type ATPase transport across biological membranes.

BEDA PENGARUH ANTARA PEMBERIAN CONTRACT RELAX DENGAN HOLD RELAX TERHADAP PENINGKATAN FLEKSIBILITAS OTOT HAMSTRING PADA ATLET SMAN 18 MAKASSAR

Background: Flexibility is the ability of a tissue or muscle to experience maximum lengthening so that the body can move with the full range of motion of the joints, without the onset of pain. Decreased hamstring flexibility can be caused by several factors, such as shortening of the hamstring muscles, acute or chronic injury to the hamstring muscles, decreased hip joint, excessive activity, and improper training patterns.Methods: This study was a quasi-experimental study using a two-group pre-test and post-test design. The aim was to determine the different effects of the Contract Relax intervention compared to the Hold Relax on increasing the flexibility of the Hamstring muscles. This research was conducted at SMA N 18 Makassar, with the sample being students who fit the inclusion criteria. The number of samples was 20 people who were randomly divided into 2 groups, namely the treatment group I who were given Contract Relax as many as 10 people and the treatment group II who were given Hold Relax as many as 10 people.Results: Based on the analysis of the paired sample t-test in the treatment group I obtained a p value <0.05 with pre and post test results of 0.00 for the Sit and Reach value which means that Contract Relax can result in a significant increase in Hamstring muscle flexibility. While the treatment group II also obtained a p value <0.05 with pre and post test results of 0.00 for the Sit and Reach value which means that holding Relax can result in a significant increase in Hamstring muscle flexibility. Then based on the Independent sample t-test, a p value <0.05 was obtained for the Sit and Reach value, which means that Hold Relax is significantly more effective than Contract Relax for increasing hamstring muscle flexibility.Conclusion : Hold Relax is better than Contract Relax in increasing the flexibility of the Hamstring musclesKeywords: Contract Relax, Hold Relax, Hamstring Flexibility

The Roots of Neorautanenia mitis (A. Rich) Verdcourt: Further Evidence of Its Antidiarrhoeal Activity.

Despite the current management options and therapeutics used in the treatment of diarrhoea, in Africa and Asia, diarrhoea remains a major concern, especially in children under the age of 5 years. Traditional knowledge of medicinal plants used in the management of diarrhoea symptoms can be explored for their efficacy. In Nigeria, the TMPs (Traditional Medicine Practitioners) have, over the years, employed medicinal plants in the management of diarrhoea symptoms. In our current and previous studies, we aimed at validating the effectiveness of Neorautanenia mitis in the management of diarrhoea as claimed by the TMPs. Out of the 20 compounds isolated from N. mitis, the compounds neodulin, pachyrrhizine, neotenone and dolineone were the most abundant, and in this study, neodulin showed a pronounced relaxation of the rhythmic contraction of the isolated rabbit jejunum in an organ bath in a concentration-dependent manner, with a complete relaxation at 60 µg/mL. Neotenone and dolineone showed a dose-dependent inhibition of defecation of 65.07%, and 50.01%, respectively, at 20 mg/kg in a castor-oil-induced diarrhoea model. This is a strong indication that compounds from N. mitis possess antidiarrhoeal properties, thereby giving credence to its traditional usage in diarrhoea therapy, and therefore validating its antidiarrhoeal activity and its being worthy of further investigation.

Effect of 8-Weeks PNF Stretching on Muscle Strength and Neuromuscular Activity of the Hamstring Muscles

Background: Hamstring injuries are common in sports that involve rapid, forceful lengthening of the hamstring muscles, such as sprinting, jumping, and kicking. This type of injury is more likely to occur in team sports such as football and handball. Objectives: The purpose of this study was to investigate chronic effects of proprioceptive neuromuscular facilitation (PNF) stretching on muscle strength and neuromuscular activity of the hamstring muscle. Methods: Six male team sports players (age: 24.38 ± 1.94 years; height: 180.73 ± 6.05 cm; body-mass: 80.23 ± 10.42 kg) were recruited for this study. Participants completed a 2-month rehabilitation program that included three sessions per week of contract-relax (CR) PNF stretching. Neuromuscular activity and strength were evaluated by electromyography (EMG) and force sensor before and after 8 weeks of CR-PNF stretching. Results: The neuromuscular activity of the medial and lateral hamstring muscles was significantly different between pre-and post-training for the apex and area of muscle (P < 0.01). Similarly, there was a large difference between pre- and post-training for hamstring muscle strength (medial and lateral) in the contract and relax positions (P < 0.001). Conclusions: Eight weeks of contract-relax proprioceptive neuromuscular facilitation (PNF) stretching is effective in increasing neuromuscular activity and muscle strength in the hamstring muscles.