Search Results (140)

Dibutyl phthalate (DBP) is used as a plasticizer to enhance flexibility in several household products, cosmetics, and food-contact materials. Due to its harmful effects, DBP is restricted or banned in children’s products and food items, particularly in Europe. Due to its endocrine disruptor properties and considering its ability to cross the placental barrier, it is imperative to study DBP’s vascular effects in pregnancy, given the vulnerability of this period. Thus, this study investigated the potential effects of DBP on the cardiovascular system using umbilical arteries from healthy pregnant women. Specifically, the impact of DBP on the vascular reactivity after both rapid and 24 h DBP exposure was analyzed, as well as the contractility and the cell viability of vascular smooth muscle cells (VSMC). DBP did not exhibit overt cytotoxic effects on VSMCs, possibly due to its adsorption onto polystyrene surfaces, potentially limiting bioavailability. Interestingly, DBP induced vasorelaxation in a concentration-dependent manner. Although mechanistic insights remain to be fully elucidated, the results suggest the involvement of pathways associated with nitric oxide signaling and calcium handling. Overall, DBP exposure appears to modulate arterial tone regulation, which may have implications for vascular function during pregnancy. Full article

Background: Persistent neuromuscular deficits following anterior cruciate ligament reconstruction (ACLR) are frequently attributed to arthrogenic muscle inhibition (AMI). The type of autologous graft used may influence the trajectory of neuromuscular recovery. Objective: To investigate the influence of graft type—bone–patellar tendon–bone (BPTB), hamstring tendon (HT), and quadriceps tendon (QT)—on the contractile properties of periarticular knee muscles over a 9-month post-operative period. Hypothesis: Each graft type would result in distinct recovery patterns of muscle contractility, as measured by tensiomyography (TMG). Methods: Thirty-one patients undergoing ACLR with BPTB (n = 8), HT (n = 12), or QT (n = 11) autografts were evaluated at 3, 6, and 9 months post-operatively. TMG was used to measure contraction time (Tc) and maximal displacement (Dm) in the rectus femoris, vastus medialis, vastus lateralis, and biceps femoris. Results: Significant within-group improvements in Tc and Dm were observed across all graft types from 3 to 9 months (Tc: p < 0.001 to p = 0.02; Dm: p < 0.001 to p = 0.01). The QT group showed the most pronounced Tc reduction in RF (from 30.16 ± 2.4 ms to 15.44 ± 1.6 ms, p < 0.001) and VM (from 31.05 ± 2.6 ms to 18.65 ± 1.8 ms, p = 0.004). In contrast, HT grafts demonstrated limited Tc recovery in BF between 6 and 9 months compared to BPTB and QT (p < 0.001), indicating a stagnation phase. BPTB exhibited persistent bilateral deficits in both quadriceps and BF at 9 months. Conclusions: Autograft type significantly influences neuromuscular recovery patterns after ACLR. TMG enables objective, muscle-specific monitoring of contractile dynamics and may support future individualized rehabilitation strategies. Full article

Background: Cardiovascular diseases, particularly hypertension, and gastrointestinal disorders represent major public health concerns in Mexico. Although a range of pharmacological treatments exists, their use is associated with adverse effects, highlighting the need for safer therapeutic alternatives. Species of the Ipomoea genus are widely employed in Mexican traditional medicine (MTM) for their purgative, anti-inflammatory, analgesic, and sedative properties. Particularly, Ipomoea purpurea is traditionally used as a diuretic and purgative; its leaves and stems are applied topically for their anti-inflammatory and soothing effects. This study aimed to determine their phytochemical composition and to evaluate the associated vasodilatory activity, modulatory effects on intestinal smooth-muscle motility, and toxicological effects of the methanolic (ME-Ip) and dichloromethane (DE-Ip) extracts obtained from the aerial parts of I. purpurea. Methods: The phytochemical composition of the ME-Ip and DE-Ip extracts of I. purpurea was assessed using UPLC-QTOF-MS and GC-MS, respectively. For both extracts, the vasodilatory activity and effects on intestinal smooth muscle were investigated using ex vivo models incorporating isolated rat aorta and ileum, respectively, whereas acute toxicity was evaluated in vivo. Results: Phytochemical analysis revealed, for the first time, the presence of two glycosylated flavonoids within the Ipomoea genus; likewise, constituents with potential anti-inflammatory activity were detected. The identified compounds in I. purpurea extracts may contribute to the vasodilatory, biphasic, and purgative effects observed in this species. The EC₅₀ values for the vasodilatory effects of the methanolic (ME-Ip) and dichloromethane (DE-Ip) extracts were 0.80 and 0.72 mg/mL, respectively. In the initial phase of the experiments on isolated ileal tissues, both extracts induced a spasmodic (contractile) effect on basal motility, with ME-Ip exhibiting higher potency (EC₅₀ = 27.11 μg/mL) compared to DE-Ip (EC₅₀ = 1765 μg/mL). In contrast, during the final phase of the experiments, both extracts demonstrated a spasmolytic effect, with EC₅₀ values of 0.43 mg/mL for ME-Ip and 0.34 mg/mL for DE-Ip. In addition, both extracts exhibited low levels of acute toxicity. Conclusions: The phytochemical profile and the vasodilatory and biphasic effects of the I. purpurea extracts explain, in part, the use of I. purpurea in MTM. The absence of acute toxic effects constitutes a preliminary step in the toxicological safety assessment of I. purpurea extracts and demonstrates their potential for the development of phytopharmaceutic agents as adjuvants for the treatment of cardiovascular and gastrointestinal disorders. Full article

Whether pattern or amount of daily activity determines neuromuscular properties is the focus of this review. The fast-to-slow conversion of many properties of fast-twitch muscles, by stimulating their nerves electrically with the continuous low-frequency pattern typical of slow motoneurons, argued that muscle properties are determined by their pattern of activity. However, the composition of the motor units (MUs) in almost all muscles is heterogeneous, with the MUs grouped into slow, fast-fatigue-resistant and fast-fatigable types that match corresponding histochemical fiber types. Nonetheless, their contractile forces lie on a continuum, with MUs recruited into activity in order of their size. This ‘size principle’ of MU organization and function applies in normally innervated and reinnervated muscles and, importantly, begs the question of whether it is the amount rather than the pattern of the MU activation that determines their properties. Experimental evidence that uniform daily amounts of ~<0.5, 5%, and 50% ES, converted motoneuron, nerve, and muscle properties to one physiological and histochemical type, argued in favor of the amount of activity determining MU properties. Yet, that the properties were not confined to the expected narrow range argued that factors other than the pattern and/or amount of neuromuscular activity must be considered. These include the progressive increase in the synaptic inputs onto motoneurons. The range of the effects of endurance and intermittent exercise programs on healthy subjects and those suffering nerve injuries and disease is also consistent with the argument that factors other than pattern or amount of neuromuscular activity should be investigated. Full article

Limited data exist on the underlying physiological phenomena of aerobic training; the impulse oscillometry method, allowing the assessment of small airways and lung periphery in addition to standard lung function testing, might be a useful addition to rehabilitation programs. Background/Objectives: This study aimed to determine the immediate effect of a structured low-intensity aerobic training program on small airway function in healthy volunteers to explore potential implications for long-term COPD care. Methods: Thirty-six healthy volunteers were recruited between May 2024 and January 2025; each participant underwent a lung function testing session, followed by low/moderate-intensity aerobic exercise, and, after 15 min, by a second impulse oscillometry assessment. Results: There was a statistically significant reduction in airway resistance following the physical exertion for the whole group (mean difference 0.03 kPa/L/s, 95%CI 0–0.6 kPa/L/s); significantly lower values were recorded for the reactance component X5 (0.02 kPa/L/s, 95%CI 0–0.4 kPa/L/s) for the normal weight subgoup (n = 24). These results, corroborated with literature data, suggest optimization of the distribution of the airflow and possibly alteration of the elastic properties of the thoracic structures following even low-intensity effort. Conclusions: Low-intensity upper body strength and aerobic training seem to have an immediate respiratory beneficial effect on healthy volunteers manifested as a reduction in airway resistance. The underlying mechanism might be related to improved contractility of respiratory muscles, but changes in lung parenchyma elasticity may also be involved, possibly reflecting modifications of ventilation heterogeneity. Impulse oscillometry may be superior to spirometry in monitoring the effects of aerobic training, considering the additional data it provides, and could be used to optimize and personalize rehabilitation protocols. Full article

Background: Moringa oleifera is one of the most famous plants used for medicinal purposes. Its leaf extracts have antimicrobial activity and antioxidant activities, and reduce swelling in ulcers. Objectives: The present article aimed to determine the metabolic profile of Moringa oleifera leaf extracts from two samples originating from India and to evaluate in vitro and ex vivo their biological activities. Methods: The antioxidant properties of Moringa oleifera leaf extracts (methanol, 50% ethanol, and 70% ethanol) were studied in vitro for antimicrobial, anti-inflammatory, and antioxidant activities. The ex vivo contractile effects of the extracts were determined by assaying circularly isolated smooth muscle (SM) strips from a rat’s stomach. Results: The obtained results indicated that one of the samples had amino acid and organic acid content approximately twice that of the second sample. In all the tests, the 50% ethanol extract of both samples showed better antioxidant activity (209 mM TE 100 g⁻¹ for the DPPH method). The 70% ethanolic extract of Sample 1 exhibited the strongest antimicrobial activity, inhibiting Gram-positive Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus. The 50% ethanolic extract of both samples exhibited the highest anti-inflammatory activity, demonstrating a twice better effect than the reference drug diclofenac. Finally, the pre-incubation of SM preparations with both samples significantly enhanced the ACh-induced contractile response, increasing it by 134% and 111%, respectively. Conclusions: The findings suggested potential applications of Moringa oleifera as a suitable candidate for antimicrobial, antioxidant, anti-inflammatory, and antispasmodic supplementation for alternative pharmaceutical and nutraceutical products. Full article

Liquid crystal elastomers (LCE) are a promising material to achieve reversible actuation while being able to perform work, showing great potential as artificial muscles in soft robotics and medical technology. Here, a wet spinning process to prepare liquid crystal elastomer fibers (LCEF) with reversible actuation capability is presented. Furthermore, we demonstrate the ability to process side-chain liquid crystal (LC) 4-Methoxyphenyl 4-(3-butenyloxy)benzoate (MBB) into a fiber, enlarging the material variance available in this field. The wet spinning process is presented and discussed in terms of spinning parameters and their influence on fiber properties, especially LC orientation. Moderate draw ratios of up to 2.3 enable highly oriented mesogens (f = 0.64), enabling the contractile behavior. The generated MBB-based LCEF show low activation temperature (54.52 °C), temperature-dependent mechanical properties, reversible contraction behavior while lifting up to 140 times their own weight and are able to perform work of up to 3.857 J kg⁻¹. Actuation properties are compared with human skeletal muscle, and possible strategies of further enhancing the LCEF performance are discussed. The generated data show promising features of the LCEF for use as artificial muscle fibers in medical applications, e.g., prosthetics and artificial cardiac tissue. Full article

Background/Objectives: Cesarean birth (CB) is linked to nonspecific low back pain (NSLBP). Different properties of the muscular tissue, including contractile, biomechanical, and viscous properties, may reflect its physiological or pathological condition. This study aimed to measure these properties of lumbar paravertebral muscles (LPVMs) and their relationship with post-CB mothers with moderate-severity NSLBP and match their measurements to those of the controls. Methods: Sixty women were included in this case–control research. They were divided into two equal groups: Group (A) representing cases, consisted of 30 females who experienced CB and complained of moderate-severity NSLBP, and Group (B) representing controls, consisted of 30 healthy females who had never experienced pregnancy with no or mild-severity NSLBP. Results: The statistical analysis between the two groups yielded significant differences in the right and left LPVMs’ tone (p = 0.002 and 0.015), relaxation time (p = 0.002 and 0.022), and creep (p = 0.013 and 0.008), respectively. On the other side, there were non-significant differences in the right and left LPVMs’ stiffness (p = 0.055 and 0.367) and elasticity (p = 0.115 and 0.231), respectively. The regression analysis’s final model indicated a strong overall performance (Nagelkerke: 1.00). Conclusions: The LPVMs of post-CB mothers with moderate-severity NSLBP showed remarkable changes in both contractile and viscous properties: muscle tone notably decreased, while viscosity increased. However, biomechanical properties like stiffness and elasticity showed negligible changes. This fitted regression analysis illustrated the holistic strong effect of LPVMs’ properties as risk factors contributing to post-CB NSLBP, emphasizing their consideration in diagnosis and intervention strategies for such cases. Full article

Background: This paper aims to complement the latest contribution in the literature that provides estimates of physiological parameters of a dynamic model for the elbow time profile during walking while linking them to a neurodegenerative disorder (Parkinsons’s disease) characterized by motor symptoms. An upper limb model is here proposed in which an active contractile element is included within a model, viewing the arm as a double pendulum system and muscles as represented by a Kelvin–Voight system. All model parameters characterizing both the shoulder and the elbow of each subject are estimated via a gradient-like identifier whose exponential convergence properties are determined by a non-anticipative Lyapunov function, ensuring robustness features. Methods: Joint angle data from different walking subjects (healthy subjects and patients with Parkinson’s disease) have been recorded using an IMU sensor system and compared with the joint angles obtained by means of the proposed model, which was adapted to each subject using available anthropometric knowledge and relying on the estimated parameters. Results: Experiments show that the reconstruction of shoulder and elbow time profiles can be definitely achieved through the proposed procedure with the estimated stiffness parameters turning out to constitute objective and quantitative indices of muscle stiffness (as a pivotal symptom of the pathology), which are able to track changes due to the therapy. Conclusions: The same dynamic model is actually able to capture the main features of the upper limb movement of both (healthy and pathological) walking subjects, with its parameters, in turn, characterizing the nature and progress of the pathology. Full article

Large skeletal muscle injuries such as volumetric muscle loss (VML) disrupt native tissue structures, including biophysical and biochemical signaling cues that promote the regeneration of functional skeletal muscle. Various biofabrication strategies have been developed to create engineered skeletal muscle constructs that mimic native matrix and cellular microenvironments to enhance muscle regeneration; however, there remains a need to create scalable engineered tissues that provide mechanical stability as well as structural and spatiotemporal signaling cues to promote cell-mediated regeneration of contractile skeletal muscle. We describe a novel strategy for bioprinting multifunctional myoblast-loaded fibrin microthreads (myothreads) that recapitulate the cellular microniches to drive myogenesis and aligned myotube formation. We characterized myoblast alignment, myotube formation, and tensile properties of myothreads as a function of cell-loading density and culture time. We showed that increasing myoblast loading densities enhances myotube formation. Additionally, alignment analyses indicate that the bioprinting process confers myoblast alignment in the constructs. Finally, tensile characterizations suggest that myothreads possess the structural stability to serve as a potential platform for developing scalable muscle scaffolds. We anticipate that our myothread biofabrication approach will enable us to strategically investigate biophysical and biochemical signaling cues and cellular mechanisms that enhance functional skeletal muscle regeneration for the treatment of VML. Full article

Tensiomyography (TMG) is a non-invasive tool used to assess contractile properties. This systematic review aimed to accomplish the following: (1) Analyze quadriceps TMG parameters in professional football players during the season and compare them with reference values. (2) Assess the differences in TMG parameters between quadriceps muscles. A PRISMA-guided search in PubMed, Web of Science, and Sport Discus (up to March 2024) identified 139 studies. Twelve in-season professional soccer players (20–29 years old) and quadriceps tensiomyography parameters were included (muscle displacement, delay time, and contraction time). All the studies were assessed using the Newcastle–Ottawa scale, scoring 7/9 to 8/9, indicating good quality. The findings of this study were that of the nine parameters analyzed, three variables were found to differ significantly. The weighted mean values were as follows: rectus femoris (contraction time 30.11 ms, muscle displacement 8.88 mL, delay time, 24.68 ms), vastus medialis (contraction time 25.29 ms, muscle displacement 7.45 mL, delay time, 21.27 ms), and vastus lateralis (contraction time 23.21 ms, muscle displacement 5.31 mL, delay time, 21.89 Â ms). Furthermore, significant differences were observed in muscle displacement between the rectus femoris and vastus medialis, and between the rectus femoris and vastus lateralis. The TMG can serve as a valuable device for assessing neuromuscular function in soccer players. Full article

Pediatric dilated cardiomyopathy (DCM) is a rare heart muscle disorder leading to the enlargement of all chambers and systolic dysfunction. We identified a novel de novo variant, c.88A>G (p.Lys30Glu, K30E), in the TPM1 gene encoding the major cardiac muscle tropomyosin (Tpm) isoform, Tpm1.1. The variant was found in a proband with DCM and left ventricular non-compaction who progressed to terminal heart failure at the age of 3 years and 8 months. To study the properties of the mutant protein, we produced recombinant K30E Tpm and used various biochemical and biophysical methods to compare its properties with those of WT Tpm. The K30E substitution decreased the thermal stability of Tpm and its complex with actin and significantly reduced the sliding velocity of the regulated thin filaments over a surface covered by ovine cardiac myosin in an in vitro motility assay across the entire physiological range of Ca²⁺ concentration. Our molecular dynamics simulations suggest that the charge reversal of the 30th residue of Tpm alters the actin monomer to which it is bound. We hypothesize that this rearrangement of the actin–Tpm interaction may hinder the transition of a myosin head attached to a nearby actin from a weakly to a strongly bound, force-generating state, thereby reducing myocardial contractility. The impaired myosin interaction with regulated actin filaments and the decreased thermal stability of the actin–Tpm complex at a near physiological temperature likely contribute to the pathogenicity of the variant and its causative role in progressive DCM. Full article

This study examined the erector spinae contractile properties, trunk isokinetic strength, and differences in acute muscle fatigue response after exercise in young females with and without non-specific chronic low back pain (NSCLBP). This study evaluated participants using tensiomyography and isokinetic trunk strength tests. An independent t-test compared the control group and the NSCLBP group, while a two-way mixed ANOVA analyzed differences in the erector spinae’s acute muscle fatigue response before and after exercise within and between groups. The results of the tensiomyography indicated that the NSCLBP group exhibited significantly lower Dm and Vc (p < 0.05) compared to the control group, while Tc showed no significant difference between groups. Significant differences in all variables were observed between the groups in the isokinetic trunk strength test (p < 0.05). Furthermore, the two-way mixed ANOVA revealed significant group main effects in Dm and Vc of the erector spinae (p < 0.05). This study found that non-specific chronic low back pain is linked to a decrease in Dm, Vc, and trunk isokinetic strength in both extensor and flexor muscles. It suggests that future research should further investigate the acute muscle fatigue response in individuals with and without NSCLBP. Full article

Background: Hyalocytes are the main vitreal cell types with critical functions in health and vitreoretinal diseases. Our aim was to develop cultures of human hyalocytes and verify the retention of their initial cellular features after 3 and 6 days of culturing (3 d and 6 d) by analyzing and comparing a few morphological and functional parameters. Methods: Vitreous samples (n = 22) were collected and vitreous cells and bead-enriched hyalocytes were developed and compared (3 d vs. 6 d cultures). Vitreous and conditioned media were tested for collagen, vascular endothelial growth factor (VEGF), transforming growth factor β1 (TGFβ1), nerve growth factor (NGF), matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and alpha-smooth muscle actin (αSMA) expression (ELISA, array/IP/WB, RT-PCR). Cells were observed at light and fluorescent microscopy (phenotypical properties) and tested for their 3D collagen gel contraction abilities. Results: An increased expression of collagens, vimentin, fibronectin, and the MMP9/TIMP1 ratio were observed in vitreous tissues. In 3 d cultures, collagens and MMP9 were upregulated while the related tissue-enzymes were deregulated. Vitreous samples also showed high levels of TGFβ1, VEGF, and NGF, and this protein signature was retained at 3 d while decreased at 6 d. The original phenotype (low αSMA) was retained at 3 d from seeding while an increased αSMA expression was observed at 6 d; NGF/trkA^NGFR was expressed in cultured hyalocytes and partially drives the collagen retraction. Conclusions: The vitreous print comparison between untouched and cultured hyalocytes allowed us, on one side, to select 3 d cultures and, on the other, to highlight the neuroprotective/contractile NGF in vitro hyalocytes effects. The possibility of scoring reactive hyalocytes would represent an interesting aspect of screening the vitreoretinal interface severity. Full article

This study aimed to evaluate changes in muscle contractile properties during a training microcycle in semi-professional female football players and explore their relationship with training load variables. Nineteen players (age: 23.9 ± 3.9 years; body mass: 60.6 ± 6.9 kg; height: 164.5 ± 6.7 cm) underwent myotonometric assessments of the biceps femoris (BF) and rectus femoris (RF) before and after the following training sessions: MD1 (i.e., 1 day after the match), MD3, MD4, and MD5. Training loads were quantified for each session, revealing significant variations, with MD4 exhibiting the highest values for high-speed running distance, number of sprints, and accelerations. Notably, MD3 showed the highest perceived exertion (RPE), while MD5 recorded the lowest total distance run. Myotonometric assessments indicated significant differences in stiffness of the RF in MD3 and BF in MD5, as well as RF tone in MD5. The findings underscore a notable relationship between training load and myotometric variables, particularly in muscle stiffness and tone. These results emphasize the need for further research to clarify how training loads affect muscle properties in female athletes. Full article