Clinical failure after Dresden repair of mid-substance Achilles tendon rupture: human cadaveric testing

The purpose of this study was to describe the angle of clinical failure during cyclical mobilization exercises in the Achilles tendon of human cadaveric specimens that were repaired using the Dresden technique and FiberWire(A (R)) No. 2. The secondary aim was to identify the secure limit of mobilization, the type of failure, and the type of apposition. The lower limbs of eight males (mean age: 60.3 +/- 6.3 years) were repaired with the Dresden technique following complete, percutaneous mid-substance Achilles tendon rupture. A basal tension of 10 N at 30A degrees of plantarflexion was placed on each specimen. The angle of the ankle during clinical failure (tendon ends separation > 5 mm) was then tested via cyclical exercises (i.e. 100 cycles between 30A degrees and 15A degrees of plantarflexion; 100 cycles between 15A degrees of plantarflexion and 0A degrees; 100 cycles between 0A degrees and 15A degrees of dorsiflexion; and 100 cycles between 15A degrees of dorsiflexion and full dorsiflexion). Clinical failure was determined using the Laplacian edge detection filter, and the angle of clinical failure was obtained using a rotatory potentiometer aligned in relation to the intermalleolar axis of each foot specimen. The type of failure (knot, tendon, or suture) and apposition (termino-terminal or non-termino-terminal) were determined. Descriptive statistics were used to obtain the mean; standard deviation; 95 % confidence interval; 1st, 25th, 50th, 75th, and 100th percentiles; and the standard error of the mean for angle data. Proportions were used to describe the type of failure and apposition. The main results were a mean angle of clinical failure equal to 12.5A degrees of plantarflexion, a limit of mobilization equal to 14.0A degrees of plantarflexion, tendon failure type, and non-termino-terminal apposition in all specimens. While the mean angle of clinical failure in human cadaveric models was 12.5A degrees of plantarflexion, after 14.0A degrees of plantarflexion, the percutaneous Dresden technique was found insecure for cyclical mobilization exercises, with a 5 % range of error. These findings are clinically relevant as they provide mechanical limits for diminishing the risk of Achilles lengthening during immediate rehabilitation

Effect of a 12-week endurance training program on force transfer and membrane integrity proteins in lean, obese, and type 2 diabetic subjects.

The mechanisms accounting for the loss of muscle function with obesity and type 2 diabetes are likely the result of a combination of neural and muscular factors. One muscular factor that is important, yet has received little attention, is the protein machinery involved in longitudinal and lateral force transmission. The purpose of this study was to compare the levels of force transfer and membrane integrity proteins before and after a 12-week endurance training program in lean, obese, and obese type 2 diabetic adults. Nineteen sedentary subjects (male = 8 and female = 11) were divided into three groups: Lean (n = 7; 50.3 ± 4.1 y; 69.1 ± 7.2 kg); Obese (n = 6; 49.8 ± 4.1 y; 92.9 ± 19.5 kg); and Obese with type 2 diabetes (n = 6; 51.5 ± 7.9 years; 88.9 ± 15.1 kg). Participants trained 150 min/week between 55% and 75% of VO2max for 12 weeks. Skeletal muscle biopsies were taken before and after the training intervention. Baseline dystrophin and muscle LIM protein levels were higher (~50% p < .01) in lean compared to obese and type 2 diabetic adults, while the protein levels of the remaining force transfer and membrane integrity proteins were similar between groups. After training, obese individuals decreased (-53%; p < .01) the levels of the muscle ankyrin repeat protein and lean individuals decreased dystrophin levels (-45%; p = .01), while the levels of the remaining force transfer and membrane integrity proteins were not affected by training. These results suggest that there are modest changes to force transfer and membrane integrity proteins in middle-aged individuals as a result of 12 weeks of lifestyle and training interventions

Effect of a 12-week endurance training program on force transfer and membrane integrity proteins in lean, obese, and type 2 diabetic subjects.

The mechanisms accounting for the loss of muscle function with obesity and type 2 diabetes are likely the result of a combination of neural and muscular factors. One muscular factor that is important, yet has received little attention, is the protein machinery involved in longitudinal and lateral force transmission. The purpose of this study was to compare the levels of force transfer and membrane integrity proteins before and after a 12-week endurance training program in lean, obese, and obese type 2 diabetic adults. Nineteen sedentary subjects (male = 8 and female = 11) were divided into three groups: Lean (n = 7; 50.3 ± 4.1 y; 69.1 ± 7.2 kg); Obese (n = 6; 49.8 ± 4.1 y; 92.9 ± 19.5 kg); and Obese with type 2 diabetes (n = 6; 51.5 ± 7.9 years; 88.9 ± 15.1 kg). Participants trained 150 min/week between 55% and 75% of VO2max for 12 weeks. Skeletal muscle biopsies were taken before and after the training intervention. Baseline dystrophin and muscle LIM protein levels were higher (~50% p < .01) in lean compared to obese and type 2 diabetic adults, while the protein levels of the remaining force transfer and membrane integrity proteins were similar between groups. After training, obese individuals decreased (-53%; p < .01) the levels of the muscle ankyrin repeat protein and lean individuals decreased dystrophin levels (-45%; p = .01), while the levels of the remaining force transfer and membrane integrity proteins were not affected by training. These results suggest that there are modest changes to force transfer and membrane integrity proteins in middle-aged individuals as a result of 12 weeks of lifestyle and training interventions

Activation of protein synthesis, regeneration, and MAPK signaling pathways following repeated bouts of eccentric cycling.

The aim of this study was to examine the activation of skeletal muscle signaling pathways related to protein synthesis and the gene expression of regeneration/degradation markers following repeated bouts of eccentric cycling. Nine untrained men (25.4 ± 1.9 yr) performed two 30-min eccentric cycling bouts (ECC1, ECC2) at 85% of maximal concentric workload, separated by 2 wk. Muscle biopsies were taken from the vastus lateralis before and 2 h after each bout. Indirect markers of muscle damage were assessed before and 24-48 h after exercise. Changes in the Akt/mammalian target of rapamycin (mTOR)/rbosomal protein S6 kinase 1 (S6K1)/ribosomal protein S6 (rpS6) and MAPK signaling pathways were measured by Western blot and changes in mRNA expression of IL-6 and IL-1β, and myogenic regulatory factors (MRFs) were measured by real-time PCR. ECC1 induced greater increases in indirect markers of muscle damage compared with ECC2. Phosphorylation of S6K1 and rpS6 increased after both exercise bouts ( < 0.05), whereas phosphorylation of mTOR increased after ECC2 only ( = 0.03). Atrogin-1 mRNA expression decreased after ECC1 and ECC2 ( < 0.05) without changes in muscle RING-finger protein-1 mRNA. Basal mRNA levels of myoblast determination protein-1 (MyoD), MRF4, and myogenin were higher 2 wk after ECC1 ( < 0.05). MRF4 mRNA increased after ECC1 and ECC2 ( < 0.05), whereas MyoD mRNA expression increased only after ECC1 ( = 0.03). Phosphorylation of JNK and p38 MAPK increased after both exercise bouts ( < 0.05), similar to IL-6 and IL-1β mRNA expression. All together, these results suggest that differential regulation of the mTOR pathway and MRF expression could mediate the repeated bout effect observed between an initial and secondary bout of eccentric exercise

Severe COVID‐19 correlates with lower mitochondrial cristae density in PBMCs and greater sitting time in humans

Abstract An interaction between mitochondrial dynamics, physical activity levels, and COVID‐19 severity has been previously hypothesized. However, this has not been tested. We aimed to compare mitochondrial morphology and cristae density of PBMCs between subjects with non‐severe COVID‐19, subjects with severe COVID‐19, and healthy controls. Additionally, we compared the level of moderate‐vigorous physical activity (MVPA) and sitting time between groups. Blood samples were taken to obtain PBMCs. Mitochondrial dynamics were assessed by electron microscopy images and western blot of protein that regulate mitochondrial dynamics. The International Physical Activity Questionnaire (IPAQ; short version) was used to estimate the level of MVPA and the sitting time The patients who develop severe COVID‐19 (COVID‐19++) not present alterations of mitochondrial size neither mitochondrial density in comparison to non‐severe patients COVID‐19 (COVID‐19) and control subjects (CTRL). However, compared to CTRL, COVID‐19 and COVID‐19++ groups have lower mitochondrial cristae length, a higher proportion of abnormal mitochondrial cristae. The COVID‐19++ group has lower number (trend) and length of mitochondrial cristae in comparison to COVID‐19 group. COVID‐19, but not COVID‐19++ group had lower Opa 1, Mfn 2 and SDHB (Complex II) proteins than CTRL group. Besides, COVID‐19++ group has a higher time sitting. Our results show that low mitochondrial cristae density, potentially due to physical inactivity, is associated with COVID‐19 severity

Effect of laterotrusive occlusal scheme on chewing duration, external intercostal muscular activity, heart rate, and oxygen saturation

Objective: To evaluate the effect of the laterotrusive occlusal scheme on chewing duration, external intercostal (EIC) electromyographic (EMG) activity, heart rate (HR), and oxygen saturation (OS) during different tasks in the upright seated position. Methods: Fifty young participants, 25 with canine guidance and 25 with group function, were included. Chewing duration, bilateral EIC EMG activity, HR, and OS were recorded during the following tasks: 1) chewing until swallowing threshold; 2) laterotrusive teeth grinding. Results: Chewing duration, bilateral EIC EMG activity, HR, and OS showed no significant differences between the two laterotrusive occlusal schemes during the tasks studied. Conclusion: These results suggest that chewing duration, EIC muscle activity, HR, and OS were not significantly influenced by the laterotrusive occlusal scheme. Therefore, when a modification of the laterotrusive occlusal scheme is needed during oral rehabilitation or orthodontic treatment, canine guidance or group function should not significantly change EMG activity of EIC muscles

Una visión global del proceso de análisis de políticas para la conducción del desarrollo agrícola y rural

58 páginas. Series Publicación miscelánea No. 405.Este documento presenta una perspectiva de la que se considera esencial en la función y tareas del planificador, el análisis del políticas para el asesoramiento permanente en la toma de decisiones para conducir el proceso de desarrollo agrícola y rural