Changes In Muscle Tissue Research Articles

Polystyrene nanoplastics exposure alters muscle amino acid composition and nutritional quality of Pacific whiteleg shrimp (Litopenaeus vannamei)

Litopenaeus vannamei were exposed to 80-nm polystyrene nanoplastics (NPs) at different concentrations (0, 0.1, 1, 5, and 10 mg/L) for 28 days to study the effects on muscle nutritional quality. Our results showed that with increasing NPs concentrations, the survival rate, specific gain rate, and protein efficiency ratio decreased but the feed conversion ratio increased. There was no significant difference in moisture, ash, and crude lipid content in the muscle, and a general decrease in crude protein content was observed. However, the total amino acid and semi-essential amino acid contents decreased. The spacing between muscle fibers and the melting morphology of muscle increased. The hardness of muscle flesh texture increased, but springiness, cohesiveness, and chewiness decreased. Regarding antioxidant enzyme activity, the activity of catalase decreased, but the total antioxidant capacity, superoxide dismutase activity, and reduced glutathione first increased and then decreased. The expression level of the growth-related genes retinoid X receptor (RXR), chitin synthase (CHS), and calmodulin A (CaM) first increased then decreased, but calcium/calmodulin-dependent protein kinase I (CaMKI), ecdysteroid receptor (EcR), chitinase 5 (CHT5), cell division cycle 2 (Cdc2), and cyclin-dependent kinase 2 (CDK2) decreased. Our results suggest that exposure to NPs can inhibit growth by inducing oxidative stress, which leads to muscle tissue damage and changes in amino acid composition. These results will provide a theoretical reference for the risk assessment of NPs and the ecological health aquaculture of shrimp.

3D reconstruction of murine mitochondria reveals changes in structure during aging linked to the MICOS complex.

During aging, muscle gradually undergoes sarcopenia, the loss of function associated with loss of mass, strength, endurance, and oxidative capacity. However, the 3D structural alterations of mitochondria associated with aging in skeletal muscle and cardiac tissues are not well described. Although mitochondrial aging is associated with decreased mitochondrial capacity, the genes responsible for the morphological changes in mitochondria during aging are poorly characterized. We measured changes in mitochondrial morphology in aged murine gastrocnemius, soleus, and cardiac tissues using serial block-face scanning electron microscopy and 3D reconstructions. We also used reverse transcriptase-quantitative PCR, transmission electron microscopy quantification, Seahorse analysis, and metabolomics and lipidomics to measure changes in mitochondrial morphology and function after loss of mitochondria contact site and cristae organizing system (MICOS) complex genes, Chchd3, Chchd6, and Mitofilin. We identified significant changes in mitochondrial size in aged murine gastrocnemius, soleus, and cardiac tissues. We found that both age-related loss of the MICOS complex and knockouts of MICOS genes in mice altered mitochondrial morphology. Given the critical role of mitochondria in maintaining cellular metabolism, we characterized the metabolomes and lipidomes of young and aged mouse tissues, which showed profound alterations consistent with changes in membrane integrity, supporting our observations of age-related changes in muscle tissues. We found a relationship between changes in the MICOS complex and aging. Thus, it is important to understand the mechanisms that underlie the tissue-dependent 3D mitochondrial phenotypic changes that occur in aging and the evolutionary conservation of these mechanisms between Drosophila and mammals.

Effect of atorvastatin on muscle tissues of dermatomyositis and antisynthetase syndrome patients with dyslipidemia.

In a recent study, we have shown that atorvastatin is clinically safe for dermatomyositis (DM) and antisynthetase syndrome (ASS) patients with dyslipidemia. Herein, we showed in an unprecedented way, the safety of atorvastatin on the muscular tissues of these patients. Transcriptome analysis was performed on samples of the vastus lateralis muscle obtained at baseline and after 12 weeks of atorvastatin (20 mg/day) intervention in DM or ASS patients with dyslipidemia [6DM and 5ASS received atorvastatin, and 2DM and 3ASS received placebo]. The results were analyzed considering differences in expression fold change before and after treatment. Histological and histochemical analyses were also performed. In both groups, no significant changes were observed in genes related to the mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways. Histological analysis showed a slight variability in the fiber size that was preserved after the intervention. In addition, the mosaic of muscle fibers was preserved in the internal architecture of the fibers and all histological regions. No fiber necrosis or atrophy, focal failures, subsarcolemmal accumulation, lipids, areas of fibrosis, or alterations in mitochondrial activity were observed. All muscle fibers were labeled for MHC I. Atorvastatin did not promote significant changes in the expression of genes related to mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways in the muscle tissues of DM and ASS patients with dyslipidemia. Atorvastatin did not also promote histological and histochemical changes in muscle tissues. Our results reinforce the safety of the administration of atorvastatin to treat dyslipidemia in patients with DM and ASS.

Protein Banding Pattern Changes in Muscle and Brain Tissues of Fresh Water Fish Labeo rohita (Hamilton) Exposed to Malathion in Gel Electrophoresis

The impact of the organophosphate malathion on the protein electrophoretic patterns of the freshwater fish Labeo rohita (Hamilton) brain and muscle tissues were examined. Over 10 days, fish were given sub-lethal dosages of malathion (2 percent) at 24-, 48-, 72-, and 96-hour intervals. For example, muscle and brain tissue proteins, were run on 7.5% SDS -PAGE to look for alterations in protein structure. Ten protein bands were found to be responsible for controlling skeletal muscle and brain function. At various times after Malathion exposure, the quantity and intensity of protein bands were reduced in the fish. There were also new protein bands found to be antagonistic to pesticides. Standard marker proteins were used to determine protein banding patterns, and Rm values were then determined. Electrophoretogram data from this investigation demonstrated that protein bands in gills and muscles were similar, with very slight differences.

Seasonal effect on fatty acid composition in phospholipid classes and triacylglycerols of male Capoeta umbla

The seasonal changes in muscle tissue, total lipids and fatty acid composition of phospholipids (PL), triacylglycerol (TAG), and phospholipid classes of male Capoeta umbla were investigated in this study. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) were identified as the major phospholipids (PLs) in the muscle tissue (PS). Triacylglycerols showed high contents of MUFA, 14:0, 16:1n-7, 18:1n-9, 18:2n-6, and 18:3n-3; while phospholipids presented high contents of AA, DHA, and 18:0. Myristic acid, 16:1n-7, 18:1n-9, monounsaturated fatty acids (MUFA), linoleic acid (18:2n-6), and linolenic acid (18:3n-3) were shown to be present in larger concentrations in TAG than in PL classes. In PL classes, 16:0, 18:0, arachidonic acid (20:4n-6) (AA), eicosapentaenoic acid (EPA) (20:5n-3), docosahexaenoic acid (DHA) (22:6n-3) and polyunsaturated fatty acid (ΣPUFA) were higher than the TAG fraction. The fatty acid composition of total lipid and lipid classes (TAG and PL) were affected by the seasonal variations and lipid fraction.

HISTOPATHOLOGICAL CHANGES IN THE NUCLEUS AND CONTRACTILE APPARATUS OF CARDIOMYOCYTES IN OVERT ACQUIRED PRIMARY HYPOTHYROIDISM: EXPERIMENTAL STUDY

Hypothyroidism causes a number of histological changes in almost all tissues and cells of the body of a mammal, which is accompanied by numerous clinical and functional disorders. This is due to the multifaceted and multifunctional role of thyroid hormones (thyroxine and triiodothyronine) in the body of mammals. Striated cardiac muscle tissue and its main structural unit (contractile cardiomyocyte) is one of the most frequently involved tissues in the histopathological process in hypothyroidism. In addition, hypothyroidism can be considered as one of the main risk factors for the development of cardiovascular diseases (heart failure, coronary heart disease, cardiac arrhythmias), so the study of histopathological changes in cardiac muscle tissue is of great theoretical and practical importance. To date, there are no studies evaluating histopathological ultrastructural changes in contractile cardiomyocytes in certain forms of hypothyroidism, in particular in overt acquired primary hypothyroidism. The purpose of this study is to investigate the histopathological changes in the nucleus and contractile apparatus of cardiomyocytes in the conditions of experimental modeling of overt acquired primary hypothyroidism. Materials and Methods: male Chinchilla rabbits aged 12-14 months and weighing 3.1-3.5 kg (n=10), were divided into 2 equal groups. 1) The experimental group (n=5), where overt primary hypothyroidism was induced by oral administration of the antithyroid drug thiamazole (10 mg/kg for 4 weeks). 2) The animals of the control group (n=5) received placebo and were in a state of normothyroidism. Transmission electron microscopy (TEM) was used to study ultrastructural changes in contractile cardiomyocytes. Results and Conclusion: Based on the results of electron microscopic study, we detected numerous ultrastructural changes in the nucleus and contractile apparatus of cardiomyocytes: the nucleus (wrinkling, uneven contours of the nucleus and emergence of karyolemma invaginations, chromatin condensation); in the contractile apparatus (thinning of myofibrils, emergence of areas of myofibrils overcontraction with contractures). These ultrastructural changes in cardiomyocytes underlie the disruption of myocardial contractility, as well as an increase in dystrophic and apoptotic changes with the gradual development of heart failure, which is a frequent companion of untreated overt acquired primary hypothyroidism.

Ecological and toxicological features of the effect of stable cesium on striated muscle tissue (myocardium and skeletal muscles) of mammals

Recently, the risks of radiation danger have significantly increased. This is connected with the start of a full-scale war against Ukraine and the seizure of the Zaporizhzhya NPP by the Russian Federation, which has the second most powerful arsenal of nuclear weapons in the world. The majority of studies devoted to the effect of radioactive radiation on the human body and animals absolutely do not take into account the ecotoxic effect of the carrier and a chemical element. At the same time, the body does not distinguish between radioactive and non-radioactive isotopes of chemical elements and interacts with them during exchange processes. The aim of the work was to study the influence of stable cesium on the microscopic structure of striated muscle tissue, both skeletal and cardiac ones. The results of our research revealed that intensive accumulation of cesium for 24 days occurred in all the examined organs and tissues. In fact, the most intensive accumulative process appeared to be in the heart by 214.9 times and by 695.3 times with skeletal muscles, with a simultaneous decrease in potassium content by 19.2% and 29.1%, respectively, compared to intact rats. We can talk about the presence of two mechanisms of action of cesium on tissues, including striated muscles: as an antagonist of potassium, which concerns the transport system of the latter and as a toxic element that initiates peroxide processes with subsequent modification of membranes and their potassium channels. Functional disturbances in the work of potassium channels of excitable tissues in the repolarization phase occur in the conditions of an increase in intracellular cesium in striated muscles. These disorders can proceed according to the type of acquired "potassium" channelopathies, which in the myocardium can manifest in the form of rhythm disorders, prolonged QT syndrome, etc. This leads to the appearance of significant violations of the histological structure of the examined tissues. Cesium has pronounced damaging effects on both skeletal and cardiac striated muscle tissue, with morphological changes in skeletal and cardiac striated muscle tissue being generally similar. Dystrophic changes in the nuclei and cytoplasm of cardiomyocytes and striated muscles, signs of impaired blood circulation in the microcirculatory channel with the formation of vascular wall edema, destruction of endothelial cells, various types of hemorrhages and lymphohistiocytic infiltration of the stroma of fibers are the consequences of the toxic effect of cesium on tissues. Thus, the results of changes in the histological structure of striated muscles under the action of cesium chloride obtained by us indicate a fairly high cytocidal activity of stable cesium.

The effect of C60 fullerene on the mechanokinetics of muscle gastrocnemius contraction in chronically alcoholized rats

The C60 fullerene effect (oral administration at a dose of 1 mg kg−1) on the selected biomechanical parameters of muscle gastrocnemius contraction, biochemical indicators of blood and muscle tissue as well as histological changes in rat muscle tissue after chronic alcoholization for 3, 6 and 9 months was studied in detail. Water-soluble C60 fullerenes were shown to reduce the pathological processes development in the muscle apparatus by an average of (35–40)%. In particular, they reduced the time occurrence of fatigue processes in muscle during the long-term development of alcoholic myopathy and inhibited oxidative processes in muscle, thereby preventing its degradation. These findings open up the possibility of using C60 fullerenes as potent antioxidants for the correction of the pathological conditions of the muscle system arising from alcohol intoxication.

Thermal Profiles for Focal Pulsed Electric Field Ablation

BackgroundPulsed electrical field (PEF) ablation may cause tissue heating. These changes are reportedly small, but each PEF system and waveform will have a different behavior, and data are lacking. ObjectivesThis study sought to compare the temperature profile of focal point, monopolar biphasic PEF ablation versus radiofrequency (RF). MethodsAblation lesions were performed on perfused thigh muscle of swine. PEF lesions were performed with 3 compatible ablation catheters at the highest (25 amp) energy, and 1 catheter (Tacticath SE) was also used at the 22- and 19-amp levels. Temperature changes in the tissue were measured using fluoroptic temperature probes inserted at the muscle surface, as well as 3 mm and 7 mm below the surface. Temperatures were recorded continuously at baseline, during delivery, and after ablation. Muscle temperatures were compared with those of RF lesions performed with 1 catheter (Tacticath SE) at 30 W for 30 seconds. ResultsPEF ablation with 3energy settings produced small temperature changes. Maximum average temperature rise for PEF for the maximum (25-amp) energy setting (32 lesions) was 7.6 °C, 2.8 °C, and 0.9 °C at the surface, 3-mm depth, and 7-mm depth, respectively. The temperature rise was dose dependent, with lower energy settings yielding less temperature rise. RF ablations (10 lesions) produced temperature increases of 16.6 °C, 39.8 °C, and 9.5 °C at the surface, 3-mm depth, and 7-mm depth, respectively. ConclusionsPEF caused detectable temperature changes in muscle tissue, which never exceeded 2.8 °C at the 3-mm depth versus baseline. By contrast, RF produced substantial temperature rises. These data support that focal monopolar biphasic energy delivered by this PEF technology retains a favorable thermal safety profile.

Assessment of longitudinal changes in body composition of children with lymphoma and rhabdomyosarcoma.

Studies examining changes in skeletal muscle and adipose tissue during treatment for cancer in children, adolescents, and young adults and their effect on the risk of chemotherapy toxicity (chemotoxicity) are limited. Among 78 patients with lymphoma (79.5%) and rhabdomyosarcoma (20.5%), changes were measured in skeletal muscle (skeletal muscle index [SMI]; skeletal muscle density [SMD]) and adipose tissue (height-adjusted total adipose tissue [hTAT]) between baseline and first subsequent computed tomography scans at the third lumbar vertebral level by using commercially available software. Body mass index (BMI; operationalized as a percentile [BMI%ile]) and body surface area (BSA) were examined at each time point. The association of changes in body composition with chemotoxicities was examined by using linear regression. The median age at cancer diagnosis of this cohort (62.8% male; 55.1% non-Hispanic White) was 12.7 years (2.5-21.1 years). The median time between scans was 48days (range, 8-207 days). By adjusting for demographics and disease characteristics, this study found that patients undergo a significant decline in SMD (β ± standard error [SE]=-4.1±1.4; p<.01). No significant changes in SMI (β ± SE=-0.5±1.0; p=.7), hTAT (β ± SE=5.5±3.9; p=.2), BMI% (β ± SE=4.1±4.8; p=.3), or BSA (β ± SE=-0.02±0.01; p=.3) were observed. Decline in SMD (per Hounsfield unit) was associated with a greater proportion of chemotherapy cycles with grade ≥3 nonhematologic toxicity (β ± SE=1.09±0.51; p=.04). This study shows that children, adolescents, and young adults with lymphoma and rhabdomyosarcoma undergo a decline in SMD early during treatment, which is associated with a risk of chemotoxicities. Future studies should focus on interventions designed at preventing the loss of muscle during treatment. We show that among children, adolescents, and young adults with lymphoma and rhabdomyosarcoma receiving chemotherapy, skeletal muscle density declines early during treatment. Additionally, a decline in skeletal muscle density is associated with a greater risk of nonhematologic chemotoxicities.

Intervention effect of Qufeng Gutong Cataplasm on myofascial pain syndrome in rats and its mechanism

This paper aims to investigate the intervention effect of Qufeng Gutong Cataplasm(QFGT) on myofascial pain syndrome(MPS) in rats and to preliminarily explain its mechanism from the perspective of improving muscle inflammation and pain. Male SD rats were divided into 6 groups, namely normal group, model group, positive control drug(Huoxue Zhitong Ointment, HXZT) group, and low, medium, and high-dose QFGT groups(75, 150, and 300 mg·d~(-1)). The rat model of MPS was established by striking combined with centrifugation for 8 weeks, during which QFGT and HXZT were used for corresponding intervention. Standard VonFrey fiber was used to evaluate the mechanical pain threshold, and acetone was used to detect the cold pain threshold. The electrophysiological activity of muscle at trigger point was detected, and the electromuscular analysis of trigger point was performed. CatWalk gait analyzer was used to detect pain-induced gait adaptation changes. The hematoxylin-eosin(HE) staining was used to observe the pathological changes in muscle and skin tissues at the trigger point of rats. Immunohistochemistry was used to detect the expression of capsaicin receptor transient receptor potential vanilloid 1(TRPV1) in muscle tissues and interleukin(IL)-33 in skin tissues at the trigger point. The protein expression levels of TRPV1, protein kinase B(Akt), phosphorylated protein kinase B(p-Akt), IL-1β, and tumor necrosis factor-α(TNF-α) in muscle tissues at the trigger point were detected by Western blot. The results showed that as compared with the model group, the mechanical pain threshold and cold pain threshold of rats in other groups were increased after treatment with QFGT. The spontaneous electromyography(EMG) activity was observed in the model group, but QFGT alleviated the EMG activity in a dose-dependent manner. Gait analysis showed that standing duration, average intensity, swing speed, maximum contact point, maximum contact area, paw print length, paw print width, and paw print area were significantly improved in all QFGT groups. Pathological results showed that the disorder of muscle arrangement at the trigger point was decreased, muscle fiber adhesion and atrophy were reduced, and inflammatory cell infiltration was alleviated after treatment with QFGT. In addition, QFGT and HXZT both inhibited the protein expression of TRPV1, PI3K, Akt, p-Akt, IL-1β, and TNF-α in the muscle tissues of rats with MPS. However, there was no significant difference in the pathological structure and expression of IL-33 in the treated skin as compared with the normal group. The related results have proved that QFGT can inhibit the release of inflammatory factors by inhibiting the TRPV1/PI3K/Akt signaling pathway in the muscle trigger point of rats with MPS and finally attenuate the atrophy and adhesion of local muscles and inflammatory infiltration, thereby relieving the muscle pain of rats with MPS, and local administration has no skin irritation.

Rapid and visual evaluation the internal corruption of meat tissue by a designed near-infrared fluorescence probe with a broad pH response range

Rapid and visual evaluation the internal corruption of meat tissue is closely related to public health. The pH change caused by glycolysis and amino acid decomposition is an important indicator of meat freshness. Herein, we designed a pH-responsive NIR fluorescent probe (Probe-OH) based on protonation/deprotonation for monitoring the internal corruption of meat tissue. Probe-OH was synthesized by a stable hemicyanine skeleton with phenolic hydroxyl group, which exhibited excellent performances such as high selectivity, high sensitivity, fast response time (60 s), a broad pH-responsive range of 4.0–10.0, and superior spatio-temporal sampling ability. In addition, we conducted a paper chip platform to measure pH value in different meat samples (pork and chicken), which is convenient to evaluate pH value of meat by observing the color changes of paper strips. Furthermore, in combination with the NIR advantages of fluorescence imaging, Probe-OH was successfully applied to assess the freshness of pork and chicken breasts, and the structural changes of muscle tissue can be clearly observed under confocal microscope. The results of Z-axis scanning showed that Probe-OH could penetrate into the interior to monitor the internal corruption of meat tissue, the fluorescence intensity changes with scanning height in the meat tissue section, and reaches its maximum at 50 μm. To the best of our knowledge, there have been no reports of fluorescence probe being used to image the inside of meat tissue section so far. It is expected that we can provide a new rapid, sensitive, near-infrared fluorescence method for assessment of the freshness in the internal organization of meat.

Shared gene expression signatures between visceral adipose and skeletal muscle tissues are associated with cardiometabolic traits in children with obesity

Obesity in children is related to the development of cardiometabolic complications later in life, where molecular changes of visceral adipose tissue (VAT) and skeletal muscle tissue (SMT) have been proven to be fundamental. The aim of this study is to unveil the gene expression architecture of both tissues in a cohort of Spanish boys with obesity, using a clustering method known as weighted gene co-expression network analysis. For this purpose, we have followed a multi-objective analytic pipeline consisting of three main approaches; identification of gene co-expression clusters associated with childhood obesity, individually in VAT and SMT (intra-tissue, approach I); identification of gene co-expression clusters associated with obesity-metabolic alterations, individually in VAT and SMT (intra-tissue, approach II); and identification of gene co-expression clusters associated with obesity-metabolic alterations simultaneously in VAT and SMT (inter-tissue, approach III). In both tissues, we identified independent and inter-tissue gene co-expression signatures associated with obesity and cardiovascular risk, some of which exceeded multiple-test correction filters. In these signatures, we could identify some central hub genes (e.g., NDUFB8, GUCY1B1, KCNMA1, NPR2, PPP3CC) participating in relevant metabolic pathways exceeding multiple-testing correction filters. We identified the central hub genes PIK3R2, PPP3C and PTPN5 associated with MAPK signaling and insulin resistance terms. This is the first time that these genes have been associated with childhood obesity in both tissues. Therefore, they could be potential novel molecular targets for drugs and health interventions, opening new lines of research on the personalized care in this pathology. This work generates interesting hypotheses about the transcriptomics alterations underlying metabolic health alterations in obesity in the pediatric population.

Isotopic turnover of carbon δ13C and nitrogen δ15N in the muscle tissue of tambaqui Colossoma macropomum juveniles fed diets containing different levels of digestible protein

The technique that uses natural stable isotopes rises as a safe alternative to evaluate the deposition of potential food constituents’ elements. Diets with distinct isotopic signatures can be used to measure turnover rates in all animal tissues, improving knowledge of metabolic processes in fish nutrition. The aim of the study was to evaluate the growth and turnover of stable isotopes of carbon and nitrogen in the muscle tissue of tambaqui juveniles fed diets containing different levels of digestible protein. A total of 1750 tambaquis were used (weight 6.53 ± 0.43 g and length 7.58 ± 0.18 cm) and distributed in 35 tanks (450 L), with a density of 50 fish per tank. Seven isoenergetic (3378.4 cal g−1) experimental diets were formulated with digestible protein (DP) levels of 14%, 17%, 20%, 23%, 26%, 29% and 32%. During 120 days of experiment, the animals grew over time in all treatments (P < 0.05); and in the evaluated periods, the protein levels of 29% and 32% stood out from the first biometric evaluations, at 30 days, with similar weight averages (P > 0.05) and higher than the averages in the other treatments (P < 0.05). The speed of isotopic changes in muscle tissue was influenced by the characteristics of the diets, and the rates of carbon and nitrogen turnover were more accelerated the higher the protein level. The trial period of 120 days was sufficient for the fish to reflect the isotopic composition of the diets in all treatments (P < 0.05). However, the isotopic contribution of the diet to the tissue as a function of time was different, with indices that reached about 96–97% in 49–63 days of feeding for the diets of 29% and 32% DP and indices of 81–82% for diets of 14% and 17% DP in the same period. The isotopic data analyzed by exponential equations and exploratory analysis showed the formation of three groups with homogeneous characteristics in response to the effects of protein levels: a grouping of diets with 14%, 17% and 20% DP (P > 0.05); another with intermediate levels (23% and 26%); and a third with the highest levels (29% and 32%). Thus, the diet containing 29% of digestible protein proved to be the most attractive for the productive performance of tambaqui juveniles in the growth phase studied.

Global warming and nanoplastic toxicity; small temperature increases can make gill and liver toxicity more dramatic, which affects fillet quality caused by polystyrene nanoplastics in the adult zebrafish model

Increasing nanoplastics (NPs) pollution may lead to unknown environmental risks when considered together with climate change, which has the potential to become an increasingly important environmental issue in the coming decades. In this context, the present study aimed to evaluate the stressor modelling of polystyrene nanoplastic (PS-NPs) combined with temperature increase in zebrafish. For this purpose, changes in gill, liver and muscle tissues of zebrafish exposed to PS-NPs (25 ppm) and/or different temperatures (28, 29 and 30 °C) for 96 h under static conditions were evaluated. The results obtained emphasize that exposure to PS-NPs stressors under controlled conditions with temperature increase induces DNA damage through stress-induced responses accompanied by degeneration, necrosis and hyperaemia in zebrafish liver and adhesion of lamellae, desquamation and inflammation in lamellar epithelium in gills. Metabolomic analyses also supported changes indicating protein and lipid oxidation, especially PS-NPs-mediated. These findings will contribute to the literature as key data on the effects of PS-NPs presence on protein/lipid oxidation and fillet quality in muscle tissues.

Ultrasound Measures of Muscle Morphology in Multiple Sclerosis and its Relation to Patient Characteristics, Muscle Performance and Functional Mobility

Multiple sclerosis (MS) is an inflammatory disease impacting the central nervous system affecting approximately 2.5 million people worldwide. Morphological changes in muscle tissue, such as muscle size and quality, may result from weakness due to decreased mobility. This study aimed to investigate asymmetries in lower limb muscle morphology via sonography in people with MS and to quantify relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. Twenty-nine Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Expanded Disability Status Scale: 3.6 ± 1.4) underwent measurement of ultrasound-measured rectus femoris (RF) muscle morphology (thickness and echo intensity), muscle performance (knee extension strength and power), and functional mobility (Timed 25-Foot Walk, 5-Times Sit-to-Stand). The more-involved limb was identified with weaker knee extension strength. Differences between more and less-involved limb were quantified using a t-test for all muscle morphology and performance outcomes. Relationships between muscle morphology, patient characteristics, performance, and functional mobility were quantified using bivariate and multivariate analysis. The more-involved limb had significantly less RF thickness (p<0.001) than the less-involved limb, but echo intensity was not different between limbs (p=0.147). The more-involved RF thickness was significantly associated with age, muscle strength, power, and gait speed, while echo intensity was associated with only muscle strength and power. Normalized RF thickness has a positive association with knee extension torque at 60 deg/sec and 180 deg/sec (p=0.003,p=0.003) and gait speed (p=0.024), whereas the corrected echo intensity values had negative associations at 60 deg/sec and 180 deg/sec (p=0.013,p=0.006). Asymmetrical differences between RF thickness measured by ultrasound are consistent with muscle strength and power asymmetries. Deficiencies in the morphology of the RF were associated with patient characteristics, knee extension muscle performance, and functional mobility. Ultrasound is an important clinical assessment tool used to identify muscle morphology asymmetries in MS. Multiple sclerosis (MS) is an inflammatory disease impacting the central nervous system affecting approximately 2.5 million people worldwide. Morphological changes in muscle tissue, such as muscle size and quality, may result from weakness due to decreased mobility. This study aimed to investigate asymmetries in lower limb muscle morphology via sonography in people with MS and to quantify relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. Twenty-nine Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Expanded Disability Status Scale: 3.6 ± 1.4) underwent measurement of ultrasound-measured rectus femoris (RF) muscle morphology (thickness and echo intensity), muscle performance (knee extension strength and power), and functional mobility (Timed 25-Foot Walk, 5-Times Sit-to-Stand). The more-involved limb was identified with weaker knee extension strength. Differences between more and less-involved limb were quantified using a t-test for all muscle morphology and performance outcomes. Relationships between muscle morphology, patient characteristics, performance, and functional mobility were quantified using bivariate and multivariate analysis. The more-involved limb had significantly less RF thickness (p<0.001) than the less-involved limb, but echo intensity was not different between limbs (p=0.147). The more-involved RF thickness was significantly associated with age, muscle strength, power, and gait speed, while echo intensity was associated with only muscle strength and power. Normalized RF thickness has a positive association with knee extension torque at 60 deg/sec and 180 deg/sec (p=0.003,p=0.003) and gait speed (p=0.024), whereas the corrected echo intensity values had negative associations at 60 deg/sec and 180 deg/sec (p=0.013,p=0.006). Asymmetrical differences between RF thickness measured by ultrasound are consistent with muscle strength and power asymmetries. Deficiencies in the morphology of the RF were associated with patient characteristics, knee extension muscle performance, and functional mobility. Ultrasound is an important clinical assessment tool used to identify muscle morphology asymmetries in MS.

Shear wave ultrasound elastography of the biceps brachii can be used as a precise proxy for passive elbow torque in individuals with hemiparetic stroke.

Muscle tissue is prone to changes in composition and architecture following stroke. Changes in muscle tissue of the extremities are thought to increase resistance to muscle elongation or joint torque under passive conditions. These effects likely compound neuromuscular impairments, exacerbating movement function. Unfortunately, conventional rehabilitation is devoid of precise measures and relies on subjective assessments of passive joint torques. Shear wave ultrasound elastography, a tool to measure muscle mechanical properties, may be readily available for use in the rehabilitation setting as a precise measure, albeit at the muscle-tissue level. To support this postulation, we evaluated the criterion validity of shear wave ultrasound elastography of the biceps brachii; we investigated its relationship with a laboratory-based criterion measure for quantifying elbow joint torque in individuals with moderate to severe chronic stroke. Additionally, we evaluated construct validity, with the specific sub-type of hypothesis testing of known groups, by testing the difference between arms. Measurements were performed under passive conditions at seven positions spanning the arc of elbow joint flexion-extension in both arms of nine individuals with hemiparetic stroke. Surface electromyography was utilized for threshold-based confirmation of muscle quiescence. A moderate relationship between the shear wave velocity and elbow joint torque was identified, and both metrics were greater in the paretic arm. Data supports the progression toward a clinical application of shear wave ultrasound elastography in evaluating altered muscle mechanical properties in stroke, while acknowledging that undetectable muscle activation or hypertonicity may contribute to the measurement. Shear wave ultrasound elastography may augment the conventional method of manually testing joint mobility by providing a high-resolution precise value. Tissue-level measurement may also assist in identifying new therapeutic targets for patient-specific impairment-based interventions.

Postmortem Interval Estimation Using Protein Chip Technology Combined with Multivariate Analysis Methods.

To estimate postmortem interval (PMI) by analyzing the protein changes in skeletal muscle tissues with the protein chip technology combined with multivariate analysis methods. Rats were sacrificed for cervical dislocation and placed at 16 ℃. Water-soluble proteins in skeletal muscles were extracted at 10 time points (0 d, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 d, 8 d and 9 d) after death. Protein expression profile data with relative molecular mass of 14 000-230 000 were obtained. Principal component analysis (PCA) and orthogonal partial least squares (OPLS) were used for data analysis. Fisher discriminant model and back propagation (BP) neural network model were constructed to classify and preliminarily estimate the PMI. In addition, the protein expression profiles data of human skeletal muscles at different time points after death were collected, and the relationship between them and PMI was analyzed by heat map and cluster analysis. The protein peak of rat skeletal muscle changed with PMI. The result of PCA combined with OPLS discriminant analysis showed statistical significance in groups with different time points (P<0.05) except 6 d, 7 d and 8 d after death. By Fisher discriminant analysis, the accuracy of internal cross-validation was 71.4% and the accuracy of external validation was 66.7%. The BP neural network model classification and preliminary estimation results showed the accuracy of internal cross-validation was 98.2%, and the accuracy of external validation was 95.8%. There was a significant difference in protein expression between 4 d and 25 h after death by the cluster analysis of the human skeletal muscle samples. The protein chip technology can quickly, accurately and repeatedly obtain water-soluble protein expression profiles in rats' and human skeletal muscles with the relative molecular mass of 14 000-230 000 at different time points postmortem. The establishment of multiple PMI estimation models based on multivariate analysis can provide a new idea and method for PMI estimation.

Clinical significance of indicators of energy metabolism in muscles involved in dystonic hyperkinesis in patients with idiopathic muscular dystonia

Introduction. Dystonia is a syndrome with location of pathological mechanisms in the central nervous system. The clinical manifestation of the syndrome is dystonic hyperkinesis with the formation of increased muscle tone, which may be associated with changes in cellular metabolism. Aim is to evaluate the indicators of energy metabolism in the muscles involved in dystonic hyperkinesis and compare with the severity of dystonia in patients with idiopathic muscular dystonia.&#x0D; Materials and methods. There were examined eighty four patients diagnosed with idiopathic muscular dystonia, including 17 men (20.2%) and 67 women (79.8%). In 38 cases there was cervical muscular dystonia, 36 and 10 cases showed segmental and generalized forms of dystonia with predominance of cervical dystonia syndrome, respectively. The average age of patients was 46 ± 11 among men and 52 ± 11 among women. The control group included 10 conditionally healthy individuals with an average age of 53.0 ± 13.4 years. The severity of cervical dystonia was assessed by the TWSTRS and Tsui scales. All participants of the study underwent biopsy sampling from the trapezius muscle, followed by determination of the level of ATP (adenosine triphosphoric acid), lactate and 2,3 DPH (2,3-diphosphoglyceric acid).&#x0D; Results. The results of the study revealed changes in the bioenergetics of muscle tissue in the form of a decrease in ATP and 2,3-DPH and an increase in lactate levels that did not correlate with the severity of dystonia on the TWSTRS and Tsui scales.&#x0D; Conclusion. Thus, bioenergetic changes in muscle tissue are not associated with the severity of dystonia and probably reflect general changes in the organization of intracellular energy metabolism in muscles in a hypertonic state.

Histomorphometry of muscle fibers in breast fillets of broilers with wooden breast myopathy

Wooden breast myopathy (WB) strongly affects the poultry industry mainly in terms of consumers rejection and economical loses, due to morphological changes in broiler muscle tissue and consequently low meat quality. The aim of this study is to evaluate the histomorphometry of muscle fibers of breast fillets of broilers with severity levels of WB myopathy. The histological evaluation considered 30 samples of the pectoralis major muscle and the level of WB myopathy (ten normal fillets, ten moderate fillets, and ten severe fillets). Fillets with a severe level of WB present low average fiber number, high average fiber diameter, low percentage of fibers with diameter of less than 20 µm, low percentage of fibers with diameter between 20 and 40 µm, and high percentage of fibers with diameter between 40 and 70 µm. Fiber cross-sectional area is greater in fillets affected by moderate and severe WB. Thus, fillets with a severe level of WB damage the muscle fiber structure and contribute more severely to the degenerative processes of breast meat.