Adaptations in skeletal muscle capillarity following changes in oxygen supply and changes in oxygen demands

Summary The effects of changes in oxygen supply and oxygen demands on fiber cross-sectional areas, capillary dersities and capillary to fiber ratios were determined in three skeletal muscles of rat. The muscles examined were the vastus lateralis, soleus, and diaphragm. Reduced oxygen supply was produced by subjecting rats to ambient hypoxia, and increased oxygen demands were produced by subjecting rats to low ambient temperatures or treatment with thyroxin. Capillaries were visualized by injecting fluorescent dyes into the circulation. Muscles were quick frozen at resting lengths to preserve normal fiber geometry and were subsequently sectioned on a cryostat. All of the muscles sampled from animals in the experimental groups had elevated capillary densities. However, capillary to fiber ratios were not increased significantly in any muscle, for any experimental condition. Thus, all of the observed differences in capillarity were due to changes in the intrinsic rate of muscle fiber growth. Further, the relations of capillary density and capillary to fiber ratio to fiber area were the same as those obtained during normal maturation, suggesting that capillary growth is closely linked to the intrinsic rate of fiber growth.     

Gastrointestinal motility of patients with Roux-en-Y reconstruction

The electromyographic activity of the gastrointestinal tract was studied in 28 patients undergoing gastric, biliary, and pancreatic operations with reconstruction of the gastrointestinal tract with a Roux-en-Y limb. The Roux-en-Y limb was constructed 1 to 5 years before the study in 8 patients (chronic Roux-en-Y) and at the operation in which the electrodes were implanted in 20 patients (recent Roux-en-Y). All four phases of the migrating motor complex (MMC) were identified in the gastrointestinal tract, including in the Roux-en-Y limb. The duration of the MMC was 82.4 ± 22.3 min in the patients with chronic Roux-en-Y and 89.0 ± 25.1 min in the patients with recent Roux-en-Y. Food ingestion converted the MMC to the fed pattern in the entire gastrointestinal tract, including the Roux-en-Y limb in 16 (76.2%) of 21 recordings of the patients with chronic Roux-en-Y and in 27 (84.4%) of 32 recordings of the patients with recent Roux-en-Y. The duration of the fed pattern was 170 ± 34 min in the patients with chronic Roux-en-Y and 154 ± 26 min in the patients with recent Roux-en-Y. The findings of this study indicate that the electromyographic activity of the Roux-en-Y limb is normal during both fasting and fed states, even many years after the construction of the Roux-en-Y.

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Resumen Se estudió la motilidad electromiográphica del tracto gastrointestinal de 28 pacientes sometidos a operaciones gástricas, biliares y pancreáticas con reconstrucción de tipo Roux-en-Y. El asa de Roux-en-Y fue construida 1–5 años antes del estudio en un grupo de ocho pacientes (Roux-en-Y crónica) y en otro grupo de 20 lose electrodos fueron implantados durante la operación (Roux-en-Y reciente). Se identificaron las cuatro fases del complejo motormigratorio en el tracto gastrointestinal, incluso en el asa de Roux-en-Y. La duración del CMM fue 82.4 ± 22.3 min en los pacientes con Roux-en-Y crónica y 89.0 ± 25.1 min en los pacientes con Roux-en-Y reciente. Con la ingesta de alimento se substituyó el CMM por el patrón postalimentación en la totalidad del tracto gastrointestinal incluso en el asa de Roux-en-Y, en 16 de los 21 registros (76.2%) de los pacientes con Roux-en-Y crónica y en 27 de los 32 registros (84.4%) de los pacientes con Roux-en-Y reciente. La duración del patrón postalimentacón fue 170 ± 34 min en los pacientes con Roux-en-Y crónica y 154 ± 26 min en los pacientes con Roux-en-Y reciente. Los hallazgos en este estudio indican que la actividad electromiográphica del asa de Roux-en-Y es normal durante las fases de ayuno o de alimentación, aún transcurridos muchos años de la confección del Roux-en-Y.

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Résumé L'activité électromyographique de l'intestin grêle a été étudiée chez 28 patients ayant eu des interventions portant sur le l'estomac, les voies biliaires ou le pancréas et comportant une reconstruction avec une anse en Y. Chez huit de ces patients, l'intervention initiale pendant laquelle cette anse en Y avait été mopntée, datait de 1 à 5 ans (anse en Y dite chronique). Chez les 20 autres patients, les électrodes pour mesurer l'activité électrique ont été placées pendant l'intervention initiale (anse en Y dite récente). Les quatre phases du complexe moteur migrateur (CMM) ont été identifiées sur l'intestin et sur l'anse en Y. La durée du CMM a été de 82.4 ± 22.3 min chez les patients ayant une anse en Y chronique, et de 89.0 ± 25.1 min chez les patients ayant une anse en Y récente. Pendant l'alimentation, la courbe d'activité dite d'alimentation a remplacé les CMM dans le tube intestinal en entier, y compris l'anse en Y chez 16 des 21 enregistrements (76.2%) des patients ayant une anse en Y chronique et chez 27 des 32 (84.4%) enregistrements des patients ayant une anse en Y récente. La durée des courbes dites d'alimentation a été de 170 ± 34 min chez les patients avec une anse en Y chronique et de 154 ± 26 min chez les patients avec une anse en Y récente. Les résultats de cette étude indiquent que l'activité électromyographique des anses en Y est normale pendant le jeûne et pendant l'alimentation, et ce même plusieurs années après la confection d'une anse en Y.

     

Perceived exertion during isometric quadriceps contraction. A comparison between men and women

BACKGROUND: 1) To examine the validity and accuracy of the CR-10 scale for evaluating perceived exertion, and 2) to assess gender differences in perceived exertion across different levels of contraction intensity. METHODS: Experimental design: cross-sectional, comparative design. Setting: Human Performance and Fatigue Laboratory, Eastern Washington University. Subjects: 30 healthy, college age volunteers (15 males, 15 females). Measures: All subjects were assessed for isometric torque and perceived exertion of the quadriceps femoris muscles, via the CR-10 scale. One low anchor was applied under resting conditions with the knee flexed to 60 degrees, and a high anchor was applied during a maximal voluntary muscle contraction (MVC). Subjects performed five-second isometric contractions equivalent to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their MVC, in a random order, and were assessed for perceived exertion by visually observing the CR-10 scale. One sample "t"-tests and 95% confidence intervals were calculated for perceived exertion at each relative torque level. A single factor ANOVA with repeated measures was performed across al levels of exercise intensity. Linearity for perceived exertion was assessed via regression analysis. RESULTS: Perceived exertion at each exercise intensity were as follows: 10%: 1.87+/-1.14, 20%: 2.43+/-1.19, 30%: 3.5+/-1.36, 40%: 3.97+/-1.52, 50%: 4.73+/-1.28, 60%: 5.53+/-1.28, 70%: 6.73+/-1.62, 80%: 7.57+/-1.72, and 90%: 8.6+/-1.52. The increase in perceived exertion across the intensity spectrum was found to fit both linear and quadratic trends. There were no gender differences in perceived exertion across all levels of exercise intensity. CONCLUSIONS: The findings demonstrate that the CR-10 scale closely approximates perceived exertion of the quadriceps femoris muscles during sub-maximal, static contractions, and is not gender specific.     

Influence of selant fibrin on the wound healing of the pigs vocal folds

Fibrin sealants or fibrin glue are products made from human plasma proteins, which mimic the final pathway of the coagulation cascade. Its application to stimulate the healing process has been a topic of debate in the literature. The use of fibrin sealants in phonosurgery has been empirical; there have been no studies that investigate the action of fibrin sealant in Reinke's space.AimTo evaluate the effect of fibrin glue in healing of the vocal folds of pigs after surgical manipulation.Materials and MethodsThis was a prospective and experimental study. Six animals had both vocal folds incised. Sealant was applied in one of them; the other served as a control. After three months, the animals were sacrificed and a collagen count was carried out.ResultsThe side on which glue was applied had an average of 27.8% against 20.4% of the side without glue.ConclusionThe collagen concentration in the samples where the fibrin sealant was applied was significantly higher compared to samples without glue. Thus, the presence of a fibrin sealant stimulates fibrogenesis in this tissue.     

Pseudoxanthoma elasticum: report of two cases

Pseudoxanthoma elasticum is a rare inherited multisystem disorder that is characterized by a pathological mineralization of the elastic connective tissue, which involves predominantly the skin, eyes and cardiovascular system. Its cause lies on mutations in the ABCC6 gene, which lead to reduction or absence of the transmembrane transport ADP dependent protein (MRP6), causing an accumulation of extracellular material and subsequent deposition of calcium and other minerals in the elastic tissue. The authors report two cases of pseudoxanthoma elasticum, emphasizing its major clinical features and the importance of early diagnosis of the disorder, aiming for adequate therapeutic management of associated complications.