Rotenone inhibits embryonic chick myogenesis in a ROS-dependent mechanism.

Skeletal muscle function is highly dependent on the energy supply provided by mitochondria. Besides ATP production, mitochondria have several other roles, such as calcium storage, heat production, cell death signaling, autophagy regulation and redox state modulation. Mitochondrial function is crucial for skeletal muscle fiber formation. Disorders that affect mitochondria have a major impact in muscle development and function. Here we studied the role of mitochondria during chick skeletal myogenesis. We analyzed the intracellular distribution of mitochondria in myoblasts, fibroblasts and myotubes using Mitotracker labeling. Mitochondrial respiration was investigated in chick muscle cells. Our results show that (i) myoblasts and myotubes have more mitochondria than muscle fibroblasts; (ii) mitochondria are organized in long lines within the whole cytoplasm and around the nuclei of myotubes, while in myoblasts they are dispersed in the cytoplasm; (iii) the area of mitochondria in myotubes increases during myogenesis, while in myoblasts and fibroblasts there is a slight decrease; (iv) mitochondrial length increases in the three cell types (myoblasts, fibroblasts and myotubes) during myogenesis; (v) the distance of mitochondria to the nucleus increases in myoblasts and myotubes during myogenesis; (vi) Rotenone inhibits muscle fiber formation, while FCCP increases the size of myotubes; (vii) N-acetyl cysteine (NAC), an inhibitor of ROS formation, rescues the effects of Rotenone on muscle fiber size; and (viii) Rotenone induces the production of ROS in chick myogenic cells. The collection of our results suggests a role of ROS signaling in mitochondrial function during chick myogenesis.

Respiratory muscles's thermographic analysis in asthmatic youth with and without bronchospasm induced by eucapnic voluntary hyperpnea.

OBJECTIVE: To compare the thermographic pattern of regions of interest (ROI) of respiratory muscles in young asthmatics with and without bronchospasm induced by eucapnic voluntary hyperpnea (EVH). MATERIALS AND METHODS: Cross-sectional study carried out with 55 young (55% male and 45% females) aged 12.5 ± 3.3 years, divided in nine nonasthmatics, 22 asthmatics without exercise-induced bronchospasm compatible response (EIB-cr) and 24 asthmatics with EIB-cr. The diagnosis of EIB was given to subjects with a fall in forced expiratory volume in the first second (FEV1) ≥ 10% compared to baseline. Thermographic recordings of respiratory muscles were delimited in ROI of the sternocleidomastoid (SCM), pectoral, and rectus abdominis intention area. Thermal captures and FEV1 were taken before and 5, 10, 15 and 30 min after EVH. RESULTS: Twenty-four (52.1%) of asthmatics had EIB-cr. There was a decrease in temperature at 10 min after EVH test in the SCM, pectoral and rectus abdominis ROIs in all groups (both with p < 0.05). There was a decrease in temperature (% basal) in asthmatic with EIB-cr compared to nonasthmatics in the rectus abdominis area (p < 0.05). CONCLUSION: There was a decrease in temperature in the ROIs of different muscle groups, especially in asthmatics. The greater drop in FEV1 observed in individuals with EIB-cr was initially associated with a decrease in skin temperature, with a difference between the nonasthmatics in the abdominal muscle area. It is likely that this decrease in temperature occurred due to a temporary displacement of blood flow to the most used muscle groups, with a decrease in the region of the skin evaluated in the thermography.

Is rating of perceived exertion a valid method for monitoring exergaming intensity in type-1 diabetics? A cross-sectional randomized trial.

AIMS: The rating of perceived exertion (RPE) provides correlations with physiological measurements of exercise intensity, including metabolic equivalent (MET), oxygen consumption (V˙O2), and heart rate (HR), in real (RS) and virtual (VS) sessions. To use RPE in patients with pathology, we aimed to examine the concurrent validity of RPE in type-1 diabetes mellitus (T1DM) patients while exergaming. METHODS: Ten T1DM patients performed two 30-min crossover sessions of moderate-intensity exercise (washout 72-196 h). The RS group performed running, and the VS group played the Kinect Adventures! video game. METs were measured by a direct gas analyzer during the sessions, and RPE was measured on the 6 - 20 point Borg scale after the sessions. RESULTS: RS and VS showed similar RPE (13.2 ± 2.7 vs. 14.2 ± 2.4) and MET (4.6 ± 1.1 vs. 4.0 ± 0.8) values (p > 0.05). RPE vs. MET correlation-coefficients were large in RS (r = 0.64; R2 = 41; p = 0.04) and were moderate in VS (r = 0.42; R2 = 18; p = 0.22). Additionally, RS secondary values (V˙O2 and HR vs. RPE) showed high coefficients (V˙O2-r = 0.62; average HRr = 0.62; maximal HRr = 0.50, p < 0.05). VS secondary values, on the other hand, showed low-moderate coefficients (V˙O2-r = 0.42; average HRr = 0.23; maximal HRr = 0.21, p > 0.05). CONCLUSION: The current validation showed that RPE may not be a valid and strong method for T1DM patients while exergaming. Healthcare professionals should cautiously use the 6 - 20 point RPE scale in pathological patients, specifically in T1DM while exergaming.

Manganese Exposure Induces Cellular Aggregates and the Accumulation of ß-Catenin in Skin of Zebrafish Embryos.

The effects of manganese (Mn) toxicity in different organs and tissues in humans and other vertebrates have been studied since the beginning of the past century, but most of its cellular effects remain largely unknown. In this study, we studied the effects of Mn in zebrafish, at the cellular level, due to the transparent nature of zebrafish larvae that enables a powerful analysis under the light microscope. The collection of our results shows that environmental concentrations of 0.5 mg/L affect swim bladder inflation; at concentration of 50 and 100 mg/L Mn (1) induces alterations in viability, swim bladder, heart, and size of zebrafish larvae, (2) induces an increase in melanocyte area and the formation of cellular aggregates in the skin, and (3) induces an accumulation of ß-Catenin in mesenchymal cells in the caudal fin of zebrafish larvae. Our data suggest that increased levels of Mn induce cell aggregate formation in the skin and the presence of more melanocytes in the zebrafish caudal fin. Interestingly, the adhesion protein ß-Catenin was activated in mesenchymal cells near the cell aggregates. These results open important new questions on the role of Mn toxicity on cellular organization and ß-Catenin responses in fishes.

BODY COMPOSITION ASSESSED BY DUAL-ENERGY X-RAY ABSORPTIOMETRY ON METABOLIC PROFILE AND CARDIOVASCULAR RISK IN OBESE PATIENTS PRIOR TO BARIATRIC SURGERY.

BACKGROUND: Fat, muscle, and bone are endocrine organs capable of affecting the metabolic profile and cardiovascular risk. Relating these components is important to the establishment of early intervention strategies for overweight patients. AIMS: This study aimed to evaluate the influence of body mass components on the metabolic profile and cardiovascular risk in the preoperative period of bariatric surgery. METHODS: A cross-sectional study was conducted with patients admitted for bariatric surgery at a university hospital in the city of Recife, Brazil, between 2018 and 2019. Body composition was determined using dual-energy x-ray absorptiometry. Cardiovascular risk was assessed using the Framingham risk score. Data were collected on anthropometric, clinical, and lifestyle characteristics. The lipid profile (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), blood glucose, and vitamin D were determined using the standard methods of the hospital laboratory. RESULTS: A total of 60 patients were analyzed, 86.7% of whom had comorbidities, 33.3% had moderate/high cardiovascular risk, and 71.4% had vitamin D insufficiency/deficiency. Lower lean body mass (adjusted PR 3.24; 95%CI 1.19-5.77) was independently associated with the severity of obesity. The body mass index and waist circumference were negatively correlated with lean body mass (r=-0.52; p<0.01)/r=-0.36; p<0.01). Lean body mass was negatively correlated with fat mass (r=-0.26; p<0.05), trunk fat (r=-0.29; p<0.05), fasting glucose (r=-0.26; p<0.05), and bone mineral density (r=-0.26; p<0.05). A total of 84.2% of individuals with less trunk fat tended to have low cardiovascular risk (p=0.05). However, physical inactivity (adjusted PR 2.14; 95%CI 1.19-5.54) and the risk of alcohol dependence (adjusted PR 2.41; 95%CI 1.76-4.15) were the only variables independently associated with cardiovascular risk. CONCLUSION: Obese patients in the preoperative period of bariatric surgery with less trunk fat tended to have low cardiovascular risk. However, the other components of body mass were also not associated with cardiovascular risk.

Outcomes in Patients With COVID-19 With Acute Encephalopathy and Coma: An International Prospective Study.

BACKGROUND AND OBJECTIVES: To report the prevalence of acute encephalopathy and outcomes in patients with severe coronavirus disease 2019 (COVID-19) and to identify determinants of 90-day outcomes. METHODS: Data from adults with severe COVID-19 and acute encephalopathy were prospectively collected for patients requiring intensive care unit management in 31 university or university-affiliated intensive care units in 6 countries (France, United States, Colombia, Spain, Mexico, and Brazil) between March and September of 2020. Acute encephalopathy was defined, as recently recommended, as subsyndromal delirium or delirium or as a comatose state in case of severely decreased level of consciousness. Logistic multivariable regression was performed to identify factors associated with 90-day outcomes. A Glasgow Outcome Scale-Extended (GOS-E) score of 1-4 was considered a poor outcome (indicating death, vegetative state, or severe disability). RESULTS: Of 4,060 patients admitted with COVID-19, 374 (9.2%) experienced acute encephalopathy at or before the intensive care unit (ICU) admission. A total of 199/345 (57.7%) patients had a poor outcome at 90-day follow-up as evaluated by the GOS-E (29 patients were lost to follow-up). On multivariable analysis, age older than 70 years (odds ratio [OR] 4.01, 95% CI 2.25-7.15), presumed fatal comorbidity (OR 3.98, 95% CI 1.68-9.44), Glasgow coma scale score <9 before/at ICU admission (OR 2.20, 95% CI 1.22-3.98), vasopressor/inotrope support during ICU stay (OR 3.91, 95% CI 1.97-7.76), renal replacement therapy during ICU stay (OR 2.31, 95% CI 1.21-4.50), and CNS ischemic or hemorrhagic complications as acute encephalopathy etiology (OR 3.22, 95% CI 1.41-7.82) were independently associated with higher odds of poor 90-day outcome. Status epilepticus, posterior reversible encephalopathy syndrome, and reversible cerebral vasoconstriction syndrome were associated with lower odds of poor 90-day outcome (OR 0.15, 95% CI 0.03-0.83). DISCUSSION: In this observational study, we found a low prevalence of acute encephalopathy at ICU admission in patients with COVID-19. More than half of patients with COVID-19 presenting with acute encephalopathy had poor outcomes as evaluated by GOS-E. Determinants of poor 90-day outcome were dominated by older age, comorbidities, degree of impairment of consciousness before/at ICU admission, association with other organ failures, and acute encephalopathy etiology. TRIAL REGISTRATION INFORMATION: The study is registered with ClinicalTrials.gov, number NCT04320472.

Original article - Effect of different resistance training intensities on endothelial function in people with type 2 diabetes mellitus: A systematic review.

AIMS: The objective of this systematic review was to analyze the effects of different resistance training (RT) intensities compared with group control (GC) or control conditions (CON) on endothelial function (EF) in people with type 2 diabetes mellitus (T2DM). METHODS: Seven electronic databases were searched Pubmed, Embase, Cochrane, Web of Science, Scopus, PEDro and CINAHL) until February 2021. RESULTS: This systematic review retrieved a total of 2,991 studies of which 29 articles fulfilled the eligibility criteria. Four studies were included in the systematic review compared RT intervention with GC or CON. One study demonstrated an increase in blood flow-mediated dilation (FMD) of the brachial artery immediately after (95% CI: 3.0% to 5.9%; p < 0.05), 60 min after (95% CI: 0.8 % to 4.2%; p < 0.05) and 120 min after (95%CI: 0.7% to 3.1%; p < 0.05) a single high-intensity resistance training session (RPE âˆ¼ 5 "hard"), compared to the control condition. Nevertheless, this increase was not significantly demonstrated in three longitudinal studies (more than 8 weeks). CONCLUSIONS: This systematic review suggest that a single session of high-intensity resistance training improves the EF of people with T2DM. More studies are needed to establish the ideal intensity and effectiveness for this training method.

Blood meal digestion and changes in lipid reserves are associated with the post-ecdysis development of the flight muscle and ovary in young adults of Rhodnius prolixus.

Rhodnius prolixus is a hemimetabolous, hematophagous insect, and both nymphs and adults feed exclusively on blood. The blood feeding triggers the molting process and, after five nymphal instar stages, the insect reaches the winged adult form. After the final ecdysis, the young adult still has a lot of blood in the midgut and, thus, we have investigated the changes in protein and lipid contents that are observed in the insect organs as digestion continues after molting. Total midgut protein content decreased during the days after the ecdysis, and digestion was finished fifteen days later. Simultaneously, proteins and triacylglycerols present in the fat body were mobilized, and their contents decreased, whereas they increased in both the ovary and the flight muscle. In order to evaluate the activity of de novo lipogenesis of each organ, the fat body, ovary and flight muscle were incubated in the presence of radiolabeled acetate, and the fat body showed the highest efficiency rate (around 47%) to convert the taken up acetate into lipids. The levels of de novo lipid synthesis in the flight muscle and ovary were very low. When 3H-palmitate was injected into the young females, its incorporation by the flight muscle was higher than by the ovary or the fat body. In the flight muscle, the 3H-palmitate was similarly distributed amongst triacylglycerols, phospholipids, diacylglycerols and free fatty acids, while in the ovary and fat body it was mostly found in triacylglycerols and phospholipids. The flight muscle was not fully developed after the molt, and at day two no lipid droplets were observed. At day five, very small lipid droplets were present, and they increased in size up to day fifteen. The diameter of the muscle fibers also increased from day two to fifteen, as well as the internuclear distance, indicating that muscle hypertrophy occurred along these days. The lipid droplets from the fat body showed a different pattern, and their diameter decreased after day two, but started to increase again at day ten. The data presented herein describes the development of the flight muscle after the final ecdysis, and modifications that occur regarding lipid stores. We show that, after molting, substrates that are present in the midgut and fat body are mobilized and directed to the ovary and flight muscle, for the adults of R. prolixus to be ready to feed and reproduce.

Improving quantification of myotube width and nuclear/cytoplasmic ratio in myogenesis research.

BACKGROUND AND OBJECTIVE: The culture of skeletal muscle cells is particularly relevant to basic biomedical research and translational medicine. The incubation of dissociated cells under controlled conditions has helped to dissect several molecular mechanisms associated with muscle cell differentiation, in addition to contributing for the evaluation of drug effects and prospective cell therapies for patients with degenerative muscle pathologies. The formation of mature multinucleated myotubes is a stepwise process involving well defined events of cell proliferation, commitment, migration, and fusion easily identified through optical microscopy methods including immunofluorescence and live cell imaging. The characterization of each step is usually based on muscle cell morphology and nuclei number, as well as the presence and intracellular location of specific cell markers. However, manual quantification of these parameters in large datasets of images is work-intensive and prone to researcher's subjectivity, mostly because of the extremely elongated cell shape of large myotubes and because myotubes are multinucleated. METHODS: Here we provide two semi-automated ImageJ macros aimed to measure the width of myotubes and the nuclear/cytoplasmic localization of molecules in fluorescence images. The width measuring macro automatically determines the best angle, perpendicular to most cells, to draw a profile plot and identify and measure individual myotubes. The nuclear/cytoplasmic ratio macro compares the intensity values along lines, drawn by the user, over cytoplasm and nucleus. RESULTS: We show that the macro measurements are more consistent than manual measurements by comparing with our own results and with the literature. CONCLUSIONS: By relying on semi-automated muscle specific ImageJ macros, we seek to improve measurement accuracy and to alleviate the laborious routine of counting and measuring muscle cell features.

Epithelial-to-mesenchymal transition as a learning paradigm of cell biology.

Epithelial-to-mesenchymal transition (EMT) is a complex biological process that occurs during normal embryogenesis and in certain pathological conditions, particularly in cancer. EMT can be viewed as a cell biology-based process, since it involves all the cellular components, including the plasma membrane, cytoskeleton and extracellular matrix, endoplasmic reticulum, Golgi apparatus, lysosomes, and mitochondria, as well as cellular processes, such as regulation of gene expression and cell cycle, adhesion, migration, signaling, differentiation, and death. Therefore, we propose that EMT could be used to motivate undergraduate medical students to learn and understand cell biology. Here, we describe and discuss the involvement of each cellular component and process during EMT. To investigate the density with which different cell biology concepts are used in EMT research, we apply a bibliometric approach. The most frequent cell biology topics in EMT studies were regulation of gene expression, cell signaling, cell cycle, cell adhesion, cell death, cell differentiation, and cell migration. Finally, we suggest that the study of EMT could be incorporated into undergraduate disciplines to improve cell biology understanding among premedical, medical and biomedical students.

Variations in Postmenopausal Body Composition: A Cross-Sectional Comparison between Physical Activity Practitioners and Sedentary Individuals.

Physical activity is broadly recognized for promoting weight reduction and bestowing numerous health benefits. Nonetheless, robust evidence concerning the impact of physical activity on postmenopausal women, undergoing physiological shifts, remains scant. This study aimed to elucidate the relationship between physical activity and body composition among postmenopausal women. Employing a cross-sectional and retrospective design, 702 women were examined. Data on physical activity and body composition were amassed through anthropometric assessments and Dual-Energy X-ray Absorptiometry (DEXA). A significant proportion of women exhibited anthropometric alterations indicative of overweight/obesity, alongside elevated values in Waist Circumference (WC), Waist-to-Hip Ratio, Waist-to-Height, and bone mass, signifying a heightened risk for disease onset. While a majority engaged in some form of physical activity, this did not yield notable reductions in the assessed metrics. Noteworthy changes were only discerned in BMI and bone mass among pre-menopausal women; whereas among postmenopausal women, in addition to disparities in bone mass, those inactive were 1.18 times more prone to a very high disease risk, as gauged by WC.

Body composition assessed by dual-energy x-ray absorptiometry on metabolic profile and cardiovascular risk in obese patients prior to bariatric surgery / Composição corporal avaliada pela absortometria radiológica de dupla energia sobre o perfil metabólico e o risco cardiovascular em obesos antes da cirurgia bariátrica

ABSTRACT BACKGROUND: Fat, muscle, and bone are endocrine organs capable of affecting the metabolic profile and cardiovascular risk. Relating these components is important to the establishment of early intervention strategies for overweight patients. AIMS: This study aimed to evaluate the influence of body mass components on the metabolic profile and cardiovascular risk in the preoperative period of bariatric surgery. METHODS: A cross-sectional study was conducted with patients admitted for bariatric surgery at a university hospital in the city of Recife, Brazil, between 2018 and 2019. Body composition was determined using dual-energy x-ray absorptiometry. Cardiovascular risk was assessed using the Framingham risk score. Data were collected on anthropometric, clinical, and lifestyle characteristics. The lipid profile (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), blood glucose, and vitamin D were determined using the standard methods of the hospital laboratory. RESULTS: A total of 60 patients were analyzed, 86.7% of whom had comorbidities, 33.3% had moderate/high cardiovascular risk, and 71.4% had vitamin D insufficiency/deficiency. Lower lean body mass (adjusted PR 3.24; 95%CI 1.19-5.77) was independently associated with the severity of obesity. The body mass index and waist circumference were negatively correlated with lean body mass (r=-0.52; p<0.01)/r=-0.36; p<0.01). Lean body mass was negatively correlated with fat mass (r=-0.26; p<0.05), trunk fat (r=-0.29; p<0.05), fasting glucose (r=-0.26; p<0.05), and bone mineral density (r=-0.26; p<0.05). A total of 84.2% of individuals with less trunk fat tended to have low cardiovascular risk (p=0.05). However, physical inactivity (adjusted PR 2.14; 95%CI 1.19-5.54) and the risk of alcohol dependence (adjusted PR 2.41; 95%CI 1.76-4.15) were the only variables independently associated with cardiovascular risk. CONCLUSION: Obese patients in the preoperative period of bariatric surgery with less trunk fat tended to have low cardiovascular risk. However, the other components of body mass were also not associated with cardiovascular risk.

RESUMO RACIONAL: O tecido adiposo, músculos e ossos representam órgãos endócrinos, capazes de interferir no perfil metabólico e risco cardiovascular. Relacionar esses componentes será importante para estratégias de intervenção precoce, em obesos. OBJETIVOS: Avaliar a influência dos compartimentos da massa corporal, sobre o perfil metabólico e risco cardiovascular, no pré-operatório de cirurgia bariátrica. MÉTODOS: Estudo transversal, com pacientes admitidos para cirurgia bariátrica, em hospital universitário. A composição corporal foi avaliada pela absortometria radiológica de dupla energia e o risco cardiovascular pelo escore de risco de Framingham. Foram analisadas variáveis antropométricas, clínicas e de estilo de vida. Foi avaliado perfil lipídico (colesterol total, HDL-c, LDL-c, triglicerídeos), glicemia e vitamina D, utilizando a metodologia padrão. RESULTADOS: Foram analisados 60 pacientes, 86,7% apresentavam comorbidades, 33,3% risco cardiovascular moderado/elevado e 71,4% insuficiência/deficiência de vitamina D. Menor massa corporal magra associou-se à gravidade da obesidade. O índice de massa corpórea e a circunferência da cintura correlacionaram-se negativamente com a massa corporal magra (r=-0,52; p<0,01)/r=-0,36; p<0,01). A massa corporal magra correlacionou-se negativamente com a massa gorda (r=-0,26; p<0,05), gordura troncular (r=-0,29; p<0,05), glicemia de jejum (r=-0,26; p<0,05) e densidade mineral óssea (r=-0,26; p<0,05). Ao todo, 84,2% dos indivíduos com menos gordura troncular apresentaram tendência a baixo risco cardiovascular (p=0,05). Contudo, inatividade física (razão de prevalência ajustada 2,14; IC95% 1,19-5,54) e risco de dependência alcoólica foram as únicas variáveis independentemente associadas ao risco cardiovascular. CONCLUSÕES: Os pacientes obesos em pré-operatório de cirurgia bariátrica com menos gordura troncular, apresentaram tendência a baixo risco cadiovascular. Contudo, o risco cardiovascular também não foi associado aos demais componentes da massa corporal.

Simvastatin and Muscle: Zebrafish and Chicken Show that the Benefits are not Worth the Damage.

Simvastatin is one of the most common medicines prescribed to treat human hypercholesterolemia. Simvastatin acts through the inhibition of cholesterol synthesis. Unfortunately, simvastatin causes unwanted side effects on muscles, such as soreness, tiredness, or weakness. Therefore, to understand the mechanism of action of simvastatin, it is important to study its physiological and structural impacts on muscle in varied animal models. Here we report on the effects of simvastatin on two biological models: zebrafish embryos and chicken muscle culture. In the last years, our group and others showed that simvastatin treatment in zebrafish embryos reduces fish movements and induces major structural alterations in skeletal muscles. We also showed that simvastatin and membrane cholesterol depletion induce major changes in proliferation and differentiation of muscle cells in chick muscle cultures. Here, we review and discuss these observations considering reported data on the use of simvastatin as a potential therapy for Duchenne muscular dystrophy.

What does desmin do: A bibliometric assessment of the functions of the muscle intermediate filament.

Intermediate filaments were first described in muscle in 1968, and desmin was biochemically identified about 10 years afterwards. Its importance grew after the identification of desminopathies and desmin mutations that cause mostly cardiopathies. Since its characterization until recently, different functions have been attributed to desmin. Here, we use bibliometric tools to evaluate the articles published about desmin and to assess its several putative functions. We identified the most productive authors and the relationships between research groups. We studied the more frequent words among 9734 articles (September 2021) containing "desmin" on the title and abstract, to identify the major research focus. We generated an interactive spreadsheet with the 934 papers that contain "desmin" only on the title that can be used to search and quantify terms in the abstract. We further selected the articles that contained the terms "function" or "role" from the spreadsheet, which we then classified according to type of function, organelle, or tissue involved. Based on the bibliographic analysis, we assess comparatively the putative functions, and we propose an alternative explanation for the desmin function.

The perinuclear region concentrates disordered proteins with predicted phase separation distributed in a 3D network of cytoskeletal filaments and organelles.

Membraneless organelles have emerged during the evolution of eukaryotic cells as intracellular domains in which multiple proteins organize into complex structures to perform specialized functions without the need of a lipid bilayer compartment. Here we describe the perinuclear space of eukaryotic cells as a highly organized network of cytoskeletal filaments that facilitates assembly of biomolecular condensates. Using bioinformatic analyses, we show that the perinuclear proteome is enriched in intrinsic disorder with several proteins predicted to undergo liquid-liquid phase separation. We also analyze immunofluorescence and transmission electron microscopy images showing the association between the nucleus and other organelles, such as mitochondria and lysosomes, or the labeling of specific proteins within the perinuclear region of cells. Altogether our data support the existence of a perinuclear dense sub-micron region formed by a well-organized three-dimensional network of structural and signaling proteins, including several proteins containing intrinsically disordered regions with phase behavior. This network of filamentous cytoskeletal proteins extends a few micrometers from the nucleus, contributes to local crowding, and organizes the movement of molecular complexes within the perinuclear space. Our findings take a key step towards understanding how membraneless regions within eukaryotic cells can serve as hubs for biomolecular condensates assembly, in particular the perinuclear space. Finally, evaluation of the disease context of the perinuclear proteins revealed that alterations in their expression can lead to several pathological conditions, and neurological disorders and cancer are among the most frequent.

Activation of YAP regulates muscle fiber size in a PKC-dependent mechanism during chick in vitro myogenesis.

The formation of skeletal muscle fibers is an intricate process controlled by a multitude of signaling pathways, including Wnt, Shh, and FGF. However, the role of the Hippo pathway during vertebrate myofiber formation has conflicting reports, which we decided to address in chick muscle cultures. We found that the transcriptional regulator Yes-associated protein (YAP) was highly concentrated within the nuclei of myoblasts. As cells differentiate into myotubes, YAP localization shifted to the cell cytoplasm in more mature myotubes. Treatment of cultures with XMU-MP-1 (XMU), a MST1/2 inhibitor, stimulated the nuclear localization of YAP in myoblasts and in myotubes, upregulated myogenin, and promoted myoblast fusion, ultimately resulting in the formation of large and fully striated multinucleated myotubes. The XMU-induced phenotype was blocked by the protein kinase C (PKC) inhibitor calphostin, which raises the possibility that the Hippo pathway controls the growth of skeletal muscle fibers through a PKC-dependent mechanism.

Acute Effects of Parallel Back Squat Performed in Different Set Configurations on Neuromuscular Performance.

We compared the acute effects of parallel back squat performed from different resistance training configurations on neuromuscular performance. Twenty-eight young adults underwent 4 experimental conditions: inter-repetition rest, traditional, traditional to failure, and rest-pause in the parallel back squat in a randomized, counterbalanced, and cross-over design. The neuromuscular performance was assessed through peak torque of knee extensors and flexors at two angular velocities (90 and 120 º/s) in three moments (before, post, and post-30 min). The peak torque of the knee extensors and flexors at 90 and 120 º/s decreased immediately after training for traditional, traditional to failure, and rest-pause (-8.1% to -17.7%, P<0.001). A greater reduction in the extensor peak torque was found at 120 º/s (P<0.05) in the rest-pause (-17.7%) when compared to traditional (-10.8%). The peak torque returned to baseline values only at post-30 min for the traditional configuration for the knee flexion action at 120 º/s. The peak torque remained similar for the muscular actions and angular velocities for the inter-repetition rest (P>0.05). Our results suggest the inter-repetition rest configuration seems to be a more appropriate strategy for maintaining the lower limb neuromuscular performance after a resistance training session.

Do estimated metabolic equivalent and energy expenditure verify the physical effort of type-1 diabetics in resting and exercise situations? A randomized crossover trial / O equivalente metabólico estimado e o gasto energético verificam o esforço físico de diabéticos tipo 1 em repouso e exercícios? Um ensaio cruzado randomizado / ¿El equivalente metabólico y el gasto energético estimados verifican el esfuerzo físico de los diabéticos tipo 1 en situaciones de reposo y ejercicio? Un ensayo cruzado aleatorio

ABSTRACT To compare measured and estimated metabolic equivalent (MET) and energy expenditure (EE) in different situations with Type-1 diabetes (T1DM) patients. Ten T1DM patients performed three 30-minute sessions (resting, running-RS, and exergame-VS) at moderate intensity. MET and EE were measured by direct gas analyzer and estimated using the formula applying heart rate and V̇02peak. MET values (measured vs. estimated) were statistically different during RS (4.58±1.11 vs.7.59±1.36) and VS (3.98± 0.84 vs. 5.77±0.84) (p<0.001). EE values were similar: RS (147±43 vs. 246±157) and VS (129±33 vs. 184±20) (p<0.001). The error between the methods: 0.41, 1.51, and 1.07 METs and 20.1, 51.5, and 32.5 Kcals for resting, RS, and VS. Estimation could be used in resting and with caution for RS and VS.

RESUMO Comparar o equivalente metabólico (MET) medido e estimado e o gasto energético (EE) em diferentes situações em pacientes com diabetes tipo 1 (DM1). Dez DM1 realizaram três sessões de 30 minutos (Repouso, Corrida-RS e Exergame-VS) em intensidade moderada. MET e EE foram medidos por um analisador direto de gases e estimados pela fórmula usando frequência cardíaca e V̇02pico. Valores MET (medidos vs. estimados) foram estatisticamente diferentes durante o RS (4,58±1,11 vs. 7,59±1,36) e o VS (3,98±0,84 vs. 5,77±0,84) (p<0,001). Semelhante em EE: RS (147±43 vs. 246±157) e VS (129±33 vs. 184±20) (p<0,001). O erro entre os métodos: 0,41, 1,51 e 1,07 MET e 20,1, 51,5 e 32,5 Kcal para Repouso, RS e VS. A estimativa pode ser usada em repouso e com cuidado durante RS e VS.

RESUMEN Comparar el equivalente metabólico (MET)y gasto energético (EE) medido y estimado en diferentes situaciones en diabeticos tipo-1 (T1DM). Diez T1DM realizaron tres sesiones de 30 minutos (Descanso, Running-RS y Exergame-VS) en intensidad moderada. El MET y EE se midieron con un analizador de gases y se calcularon con fórmula utilizando la frecuencia cardíaca y VO2pico. Valores MET (medidos frente a estimados) eran estadísticamente diferentes durante RS (4,58±1,11 vs 7,59±1,36) y VS (3,98±0,84 vs 5,77±0,84) (p<0,001). Similar en EE: RS (147±43 vs 246±157) y VS (129±33 vs 184±20) (p<0,001). El error entre los métodos: 0.41, 1.51 y 1.07 MET y 20.1, 51.5 y 32.5 Kcal para Reposo, RS y VS. La estimación podría usarse en reposo y con cuidado durante RS y VS.

Relationships between take-off speed and performance in F-44 and F-46 paralympic discus throwers / Relações entre a velocidade de decolagem e desempenho em lançadores de disco paraolímpicos da classe F-44 e F-46 / Relaciones entre la velocidad de despegue y el rendimiento en los lanzadores de discos paralímpicos de las clases F-44 y F-46

ABSTRACT This study aimed to analyze discus throwing in Paralympic athletes from two functional classes (FCs). Seven athletes from two classes F-44 (N=4) and F-46 (N=3) performed three throws each during a regional competition and were evaluated through 3D kinemetry. The assessed athletes presented a similar throwing technique, with a preparation movement opposite to the throw preceding the shot. Class F-44 showed a weak correlation between take-off speed and range (r= 0.15; p>0.05). F-46 showed a strong correlation between take-off speed and range (r=0.77; p=0.014). We conclude that athletes from the assessed FCs present important differences in terms of performance.

RESUMO O presente estudo teve como objetivo a análise do lançamento de disco em atletas paralímpicos de duas classes funcionais (CFs). Sete atletas de duas classes F-44 (N=4) e F-46 (N=3) executaram 3 lançamentos cada durante uma competição regional, e foram avaliados por meio de cinemetria 3D. Os atletas avaliados apresentaram uma técnica de lançamento semelhante, com movimento de preparação em direção oposta ao lançamento que antecedia o arremate. Na classe F-44 houve uma fraca correlação entre a velocidade de decolagem e o alcance do disco (r= 0,15; p>0,05). Na F-46 houve forte correlação entre a velocidade de decolagem e o alcance (r= 0,77; p=0,014). Conclui-se que atletas das CFs avaliadas apresentam diferenças importantes em termos de desempenho.

RESUMEN El presente estudio tuvo como objetivo analizar el lanzamiento de disco en atletas paralímpicos de dos clases funcionales (FC). Siete atletas de dos clases F-44 (N = 4) y F-46 (N = 3) realizaron 3 lanzamientos cada uno durante una competencia regional, y fueron evaluados usando cinemetría 3D. Los deportistas evaluados presentaron una técnica de lanzamiento similar, con un movimiento de preparación en sentido contrario al lanzamiento que precedió al tiro. En la clase F-44 hubo una correlación débil entre la velocidad de despegue y el alcance del disco (r = 0,15; p> 0,05). En el F-46 hubo una fuerte correlación entre la velocidad de despegue y el alcance (r = 0,77; p = 0,014). Se concluye que los deportistas de los CF evaluados presentan importantes diferencias en cuanto a rendimiento.