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1.
Clin Rehabil ; 35(9): 1317-1328, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33858230

RESUMEN

OBJECTIVE: Compare effectiveness of two differently formatted training programs in educating night-time postural care implementers. DESIGN: Mixed-methods parallel-group double-blind design with random assignment. SETTING: United States academic institution. PARTICIPANTS: Thirty-eight adult caregivers/providers of children with cerebral palsy. INTERVENTIONS: Both 2-hour online programs included content on night-time postural care evidence, risk-factor monitoring, sleep-system types, positioning methods, and assessments. Group A used interactive videos, Group B summary information with web-links. MAIN MEASURES: We measured self-perceived competence via questionnaires (baseline, post-training, post-simulation) containing 4-point rating-scales of knowledge, ability, and confidence and measured positioning ability via a simulation observation instrument comprising 16 positioning-task ratings with space for describing performance. We recorded participant actions/statements using fieldnotes. RESULTS: Thirty-eight completed training (19 per group). Group A (vs B) showed significantly greater self-perceived competence changes post-training (0.46 points (SE 0.17), P = 0.008). Thirty-seven positioned a standardized "client," with groups not differing significantly on total tasks completed correctly (F(1, 92.32) = 1.91, P = 0.17) averaging 11.85 (SE 0.83) and 12.60 (SE 0.84) of 16 tasks correct. Group A's post-positioning/simulation self-ratings were significantly associated with actual ability (r = 0.53, P = 0.019). In both groups ⩾47% of caregivers incorrectly completed the tasks of placing head and neck in neutral and snugging up all [positioning] parts. CONCLUSION: The sleep care positioning training program (interactive video-based format) is effective in building caregivers' self-perceived competence for night-time postural care. While the lesson was well-received by caregivers and considered a "match [to their] learning style," the lesson did not lead to greater improvement in actual ability to position the "client" compared to control training.


Asunto(s)
Cuidadores , Parálisis Cerebral , Adulto , Niño , Humanos , Encuestas y Cuestionarios
2.
PLoS One ; 16(12): e0260676, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34910761

RESUMEN

Major life events, such as the COVID-19 pandemic, affect psychological and physiological health. Social support, or the lack thereof, can modulate these effects. The context of the COVID-19 pandemic offered a unique opportunity to better understand how dogs may provide social support for their owners and buffer heightened symptoms of stress, anxiety and depression and contribute to happiness during a major global crisis. Participants (768 pet dog owners and 767 potential pet dog owners) answered an online survey, including validated depression, anxiety, happiness psychometric scales, attitude to and commitment towards pet, and perceived social support. Potential pet dog owners were defined as individuals who did not own a dog at the time of the survey but would be very or extremely interested in owning one in the future. Dog owners reported having significantly more social support available to them compared to potential dog owners, and their depression scores were also lower, compared to potential dog owners. There were no differences in anxiety and happiness scores between the two groups. Dog owners had a significantly more positive attitude towards and commitment to pets. Taken together, our results suggest that dog ownership may have provided people with a stronger sense of social support, which in turn may have helped buffer some of the negative psychological impacts caused by the COVID-19 pandemic.


Asunto(s)
COVID-19 , Animales , Trastornos de Ansiedad , Perros , Pandemias , Estados Unidos
3.
Arch Rehabil Res Clin Transl ; 2(4): 100087, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33543110

RESUMEN

OBJECTIVES: To identify the sleep-based instruments in postural care intervention research and examine whether the instruments are suitable as postural care outcome measures specifically for children with severe cerebral palsy. DATA SOURCES: Investigators searched the electronic databases from 2 university library systems, including OVID Medline, CINAHL, OT Search, Cochrane Database of Systematic Reviews, and Health and Psychosocial Instruments for articles published between 2000 and October 2019. STUDY SELECTION: The initial search yielded 1928 abstracts. Two independent investigators identified 8 English-language peer-reviewed articles that published postural care intervention study results. DATA EXTRACTION: Investigators screened the 8 articles and found that 6 included sleep as a primary or secondary intervention outcome. The principal investigator then fully reviewed these 6 publications, recorded their sleep-related instruments, and applied Coster's published guidelines (2013) to analyze the sleep-based instruments' suitability as outcome measures. DATA SYNTHESIS: Collectively, the 6 studies used 8 distinct measures, 6 of which (actigraphy, Chailey Sleep Questionnaire, Pediatric Sleep Questionnaire, polysomnography, sleep diary, and Sleep Disturbance Scale for Children) underwent analysis. As stand-alone instruments, none completely met criteria for suitability as outcome measures for those with severe cerebral palsy. CONCLUSIONS: Combined use of the Sleep Disturbance Scale for Children and actigraphy may be favorable for assessing the sleep-related domains relevant to children with severe cerebral palsy. However, rehabilitation professionals should test sensitivity and specificity to understand the instruments' ability for capturing changes in sleep from postural care intervention.

4.
Pathobiology ; 76(5): 227-34, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19816082

RESUMEN

BACKGROUND: Nepsilon-(carboxymethyl)-lysine (CML) is an advanced glycation end product (AGE), the accumulation of which has been implicated in the etiology of diabetes complications. Skeletal muscle in diabetes demonstrates altered function, and increased accumulation of CML has been found in several fast-twitch muscles of diabetic animals. OBJECTIVE: This study aims to explore the accumulation of CML in soleus (a slow muscle) in diabetic animals, with and without insulin therapy. METHODS: Twenty-one rats were randomly divided into control and diabetes groups (DNI: diabetes without insulin; DI: diabetes with insulin; C: control). Diabetes was induced by intravenous administration of streptozotocin. At the end of the 12-week experimental period the soleus muscle was excised and snap frozen in liquid nitrogen. Muscle cross-sections were immunolabeled for CML. The number of CML-labeled muscle fibers was quantified; fibers were also evaluated for fiber types and cross-sectional areas. RESULTS: The percentage of myofibers immunolabeling for CML was highest in the DNI group (13.8 +/- 2.5%), lower in the DI group (5.4 +/- 1.1%) and lowest in the C group (2.1 +/- 0.6%). Statistical analysis revealed that AGE accumulation was significantly greater in the DNI group than in both C and DI groups (p = 0.0002). There was no significant difference between C and DI groups. In the DNI animals, AGE-positive myofibers showed a higher percentage of fast fiber types than did the AGE-negative fibers (49.5 +/- 6.9 vs. 13.7 +/- 1.5%, p = 0.002). No differences existed in cross-sectional areas between AGE-positive and AGE-negative fibers within any group. CONCLUSION: The greatest accumulation of AGE was in the soleus of the DNI group, and was significantly less in the DI group. These findings may be linked to disordered glucose metabolism, increased oxidative stress and/or fiber type transformation in these muscles.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Lisina/análogos & derivados , Fibras Musculares de Contracción Lenta/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Animales , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Procesamiento de Imagen Asistido por Computador , Lisina/metabolismo , Masculino , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Rápida/metabolismo , Fibras Musculares de Contracción Rápida/patología , Fibras Musculares de Contracción Lenta/metabolismo , Fibras Musculares de Contracción Lenta/patología , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Ratas , Ratas Sprague-Dawley
5.
Am J Phys Med Rehabil ; 98(4): 266-274, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30286018

RESUMEN

OBJECTIVE: The aim of this study was to evaluate adaptations in soleus and tibialis anterior muscles in a rat model 4 wks after hemorrhagic stroke. DESIGN: Young adult Sprague Dawley rats were randomly assigned to two groups: stroke and control, with eight soleus and eight tibialis anterior muscles per group. Hemorrhagic stroke was induced in the right caudoputamen of the stroke rats. Control rats had no intervention. Neurologic status was evaluated in both groups before stroke and 4 wks after stroke. Muscles were harvested after poststroke neurologic testing. Muscle fiber types and cross-sectional areas were determined in soleus and tibialis anterior using immunohistochemical labeling for myosin heavy chain. RESULTS: No generalized fiber atrophy was found in any of the muscles. Fiber types shifted from faster to slower in the tibialis anterior of the stroke group, but no fiber type shifts occurred in the soleus muscles of stroke animals. CONCLUSIONS: Because slower myosin heavy chain fiber types are associated with weaker contractile force and slower contractile speed, this faster to slower fiber type shift in tibialis anterior muscles may contribute to weaker and slower muscle contraction in this muscle after stroke. This finding may indicate potential therapeutic benefit from treatments known to influence fiber type plasticity.


Asunto(s)
Adaptación Fisiológica , Miembro Posterior/fisiopatología , Hemorragias Intracraneales/fisiopatología , Fibras Musculares Esqueléticas/fisiología , Accidente Cerebrovascular/fisiopatología , Animales , Modelos Animales de Enfermedad , Hemorragias Intracraneales/etiología , Masculino , Contracción Muscular , Músculo Esquelético , Cadenas Pesadas de Miosina , Ratas , Ratas Sprague-Dawley , Accidente Cerebrovascular/etiología
6.
J Gerontol A Biol Sci Med Sci ; 62(11): 1204-10, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18000139

RESUMEN

One mechanism that may influence the quality of skeletal muscle proteins, and explain the age-related decline in contractility, is protein damage. Advanced glycation end-products (AGE) in vivo are useful biomarkers of damage. In this study, comparison of extensor digitorum longus (EDL) muscles from young (8 months), old (33 months), and very old (36 months) Fischer 344 Brown Norway F1 (F344BNF1) hybrid rats shows that muscles from the very old rats have a significantly higher percentage of myofibers that immunolabel intracellularly for AGE-antibody 6D12 compared to the younger age group. The AGE-modified proteins, determined in the semimembranosus muscles from young (9 months) and old (27 months) F344 rats, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry include creatine kinase, carbonic anhydrase III, beta-enolase, actin, and voltage-dependent anion-selective channel 1. Moreover, there is a significant increase in AGE modification of beta-enolase with age. These results identify a common subset of proteins that contain AGE and suggest that metabolic proteins are targets for glycation with aging.


Asunto(s)
Envejecimiento/fisiología , Productos Finales de Glicación Avanzada/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Análisis de Varianza , Animales , Biomarcadores/metabolismo , Western Blotting , Electroforesis/métodos , Masculino , Ratas , Ratas Endogámicas F344 , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
7.
J Appl Physiol (1985) ; 99(2): 472-8, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15831797

RESUMEN

The purpose of this study was to characterize the contractile properties of individual skinned muscle fibers from insulin-treated streptozotocin-induced diabetic rats after an endurance exercise training program. We hypothesized that single-fiber contractile function would decrease in the diabetic sedentary rats and that endurance exercise would preserve the function. In the study, 28 rats were assigned to either a nondiabetic sedentary, a nondiabetic exercise, a diabetic sedentary, or a diabetic exercise group. Rats in the diabetic groups received subcutaneous intermediate-lasting insulin daily. The exercise-trained rats ran on a treadmill at a moderate intensity for 60 min, five times per week. After 12 wk, the extensor digitorum longus and soleus muscles were dissected. Single-fiber diameter, Ca(2+)-activated peak force, specific tension, activation threshold, and pCa(50) as well as the myosin heavy chain isoform expression (MHC) were determined. We found that in MHC type II fibers from extensor digitorum longus muscle, diameters were significantly smaller from diabetic sedentary rats compared with nondiabetic sedentary rats (P < 0.001). Among the nondiabetic rats, fiber diameters were smaller with exercise (P = 0.038). The absolute force-generating capacity of single fibers was lower in muscles from diabetic rats. There was greater specific tension (force normalized to cross-sectional area) by fibers from the rats that followed an endurance exercise program compared with sedentary. From the results, we conclude that alterations in the properties of contractile proteins are not implicated in the decrease in strength associated with diabetes and that endurance-exercise training does not prevent or increase muscle weakness in diabetic rats.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/fisiopatología , Insulina/uso terapéutico , Contracción Isométrica , Fibras Musculares Esqueléticas , Músculo Esquelético/fisiopatología , Condicionamiento Físico Animal/métodos , Resistencia Física , Adaptación Fisiológica/fisiología , Animales , Células Cultivadas , Diabetes Mellitus Experimental/inducido químicamente , Ratas , Ratas Sprague-Dawley , Estreptozocina , Estrés Mecánico
8.
Anat Rec A Discov Mol Cell Evol Biol ; 286(1): 866-73, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16086433

RESUMEN

Fiber type shifts in aging skeletal muscle have been studied with myofibrillar ATPase histochemistry and gel electrophoresis, but less commonly with immunohistochemistry. Immunohistochemical study of myosin heavy chains (MHCs) in single myofibers yields additional information about aged skeletal muscle. Furthermore, many studies of aging rodent skeletal muscle have been performed on fast-MHC-predominant muscle and in several different strains. The aim of this study was to evaluate immunohistochemically MHC characteristics in the slow-MHC-predominant soleus muscle in the Fischer Brown Norway F1 hybrid aging rat (FBN). Three age groups of FBN rats were studied: 12 months, 30 months, and 36 months. Soleus muscles were excised, quick-frozen, and stained immunohistochemically for slow, fast, developmental, and neonatal MHC isoforms. Cross-sections were evaluated for the number and cross-sectional areas of fibers expressing each isoform. Single myofibers in soleus muscles of the aged rats showed significantly greater amounts of coexpression of slow and fast MHC than did younger animals. This change began by 30 months of age, but did not reach statistical significance until 36 months of age. The soleus from 36-month-old rats also expressed greater amounts of developmental MHC than did the other groups. These developmental MHC-positive myofibers also coexpressed either slow or slow and fast MHC. The age-related increase in MHC coexpression of slow with fast isoforms may indicate a fiber type shift suggestive of denervation that outpaces reinnervation. The developmental MHC-positive fibers provide evidence of ongoing myofiber remodeling in the oldest rats in the midst of the fiber degeneration of aging.


Asunto(s)
Envejecimiento , Fibras Musculares Esqueléticas/química , Músculo Esquelético/química , Cadenas Pesadas de Miosina/análisis , Animales , Inmunohistoquímica , Masculino , Desnervación Muscular , Fibras Musculares Esqueléticas/fisiología , Músculo Esquelético/fisiología , Cadenas Pesadas de Miosina/fisiología , Isoformas de Proteínas/análisis , Isoformas de Proteínas/fisiología , Ratas , Ratas Endogámicas BN , Ratas Endogámicas F344 , Regeneración/fisiología
9.
Acta Histochem ; 107(3): 221-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16054675

RESUMEN

This study evaluated mature and immature myosin heavy chain (MHC) isoform immunolocalisation in soleus muscle of diabetic rats with documented motor neuropathy. Sprague Dawley rats were assigned to one of three groups: control (C), diabetic with insulin (DI), or diabetic without insulin (DNI). Twelve weeks after diabetes induction, soleus muscles were excised and quick-frozen. Cross-sections were labelled immunohistochemically for slow, fast, developmental and neonatal MHC isoforms to determine fiber-type composition. Fiber cross-sectional areas were determined morphometrically. Results revealed that DNI and DI muscles contained greater percentages of myofibers positive for fast MHC compared with controls. DNI animals also showed a lower percentage of myofibers positive for slow MHC compared to the DI group. The number of fibers immunolabelled for developmental MHC isoforms was greater in DNI animals than in the other groups. The differences in slow and fast MHC-labelling appear to indicate a condition of altered neuromuscular activity affecting the diabetic muscles. The increase in developmental MHC-labelling in the DNI muscles could indicate myofiber regeneration or reinnervation that would be more pronounced in the DNI animals in context of their more severe neuropathy. Insulin appeared to influence muscle fiber cross-sectional area and possibly fiber-type grouping frequency; the potential mechanism for these effects was not elucidated.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Neuropatías Diabéticas/metabolismo , Músculo Esquelético/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Animales , Diabetes Mellitus Experimental/patología , Neuropatías Diabéticas/patología , Modelos Animales de Enfermedad , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Masculino , Fibras Musculares de Contracción Rápida/metabolismo , Fibras Musculares de Contracción Rápida/patología , Fibras Musculares de Contracción Lenta/metabolismo , Fibras Musculares de Contracción Lenta/patología , Músculo Esquelético/patología , Isoformas de Proteínas , Ratas , Ratas Sprague-Dawley , Coloración y Etiquetado
10.
Brain Stimul ; 8(6): 1074-84, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26198365

RESUMEN

BACKGROUND: Preceding low-frequency repetitive transcranial magnetic stimulation (rTMS) with a bout of high-frequency rTMS called priming potentiates the after-effects of the former in healthy adults. The utility of primed rTMS in stroke remains under-explored despite its theoretical benefits in enhancing cortical excitability and motor function. OBJECTIVE: To ascertain the efficacy of priming in chronic stroke by comparing changes in cortical excitability and paretic hand function following three types of primed low-frequency rTMS treatments. METHODS: Eleven individuals with chronic stroke participated in this repeated-measures study receiving three treatments to the contralesional primary motor cortex in randomized order: 6 Hz primed 1 Hz rTMS, 1 Hz primed 1 Hz rTMS, and sham 6 Hz primed active 1 Hz rTMS. Within- and between-treatment differences from baseline in cortical excitability and paretic hand function from baseline were analyzed using mixed effects linear models. RESULTS: 6 Hz primed 1 Hz rTMS produced significant within-treatment differences from baseline in ipsilesional cortical silent period (CSP) duration and short-interval intracortical inhibition. Compared to 1 Hz priming and sham 6 Hz priming of 1 Hz rTMS, active 6 Hz priming generated significantly greater decreases in ipsilesional CSP duration. These heightened effects were not observed for intracortical facilitation or interhemispheric inhibition excitability measures. CONCLUSION: Our findings demonstrate the efficacy of 6 Hz primed 1 Hz rTMS in probing homeostatic plasticity mechanisms in the stroke brain as best demonstrated by differences CSP duration and SICI from baseline. Though 6 Hz priming did not universally enhance cortical excitability across measures, our findings pose important implications in non-invasive brain stimulation application in stroke rehabilitation.


Asunto(s)
Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Estimulación Magnética Transcraneal/métodos , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Estudios Cruzados , Método Doble Ciego , Potenciales Evocados Motores/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiología , Accidente Cerebrovascular/fisiopatología , Resultado del Tratamiento
11.
J Appl Physiol (1985) ; 96(2): 498-506, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14514706

RESUMEN

The purpose of this study was to determine whether increased muscle activity could reverse myosin structural alterations that occur in aged rat muscle and whether those alterations could be induced in young rat muscle by decreased activity. Semimembranosus muscle activity was increased by electrical stimulation (200-ms trains, 154 Hz, 5 V) through a nerve cuff on the tibial branch of the ischiatic nerve. The protocol consisted of 5 sets of 6-10 maximal isometric contractions performed twice per week for 4 or 8-10 wk. Decreased muscle activity was induced by denervation of the semimembranosus muscle for 2 or 4 wk. Semimembranosus fibers were then studied for Ca(2+)-activated force generation. Fibers were also spin labeled on the myosin catalytic domain and studied using electron paramagnetic resonance (EPR) spectroscopy to assess myosin structural distribution. Increased muscle activity for 4 and 8-10 wk in approximately 32-mo-old rats resulted in -16 and +4% changes in specific tension, respectively (P < 0.01). EPR spectra showed that the fraction of myosin heads in the strong-binding structural state during contraction was reduced at 4 wk (0.241 +/- 0.020 vs. 0.269 +/- 0.018, P = 0.046) but returned to normal by 8-10 wk (P = 0.67). Decreased muscle activity for 2 and 4 wk in approximately 9-mo-old rats resulted in 23 and 34% reductions, respectively, in specific tension; EPR spectra showed 16 and 35% decreases in strong-binding myosin (P < 0.01). These data support the hypothesis that changes in muscle activity affect muscle strength, at least in part through alterations in myosin structure and function.


Asunto(s)
Envejecimiento/fisiología , Fibras Musculares Esqueléticas/fisiología , Músculo Esquelético/fisiología , Miosinas/fisiología , Animales , Desnervación , Estimulación Eléctrica , Espectroscopía de Resonancia por Spin del Electrón , Masculino , Contracción Muscular/fisiología , Músculo Esquelético/citología , Músculo Esquelético/inervación , Ratas , Ratas Endogámicas BN , Ratas Endogámicas F344
12.
Am J Phys Med Rehabil ; 91(11): 965-76, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22760110

RESUMEN

OBJECTIVE: The aim of this study was to determine the contribution of spontaneous post-stroke physical activity to skeletal muscle plasticity after stroke. DESIGN: A randomized controlled study was conducted of 24 young adult male Sprague-Dawley rats assigned to three experimental groups: (1) STR-hemorrhagic stroke in the right caudoputamen; (2) SHAM-procedural control; and (3) CONT-no intervention (n = 8/group). Neurologic testing was performed before and 2 wks after stroke. Spontaneous physical activity was monitored five nights per week for 1 wk preoperatively and 2 wks postoperatively. Two weeks after stroke induction, bilateral soleus and tibialis anterior muscles were harvested. Myofiber cross-sectional areas were determined, and fiber typing was performed with immunohistochemistry. RESULTS: STR animals demonstrated neurologic deficit in the contralesional hindlimb 2 wks after stroke. Quantity of spontaneous physical activity did not differ between groups within each of the week-long study intervals. No significant difference was found in fiber types or cross-sectional areas in the soleus muscle of STR vs. CONT groups. However, the tibialis anterior muscle of the contralesional hindlimbs of the STR animals showed atrophy in 2x and 1 + 2x myofibers, as well as type 1 hypertrophy. CONCLUSIONS: Skeletal muscle adaptation occurs by 2 wks post-stroke in this model. It is muscle specific and appears to be influenced by factors other than spontaneous post-stroke physical activity.


Asunto(s)
Hemorragia Cerebral/fisiopatología , Actividad Motora , Músculo Esquelético/fisiopatología , Accidente Cerebrovascular/fisiopatología , Animales , Modelos Animales de Enfermedad , Masculino , Atrofia Muscular , Ratas , Ratas Sprague-Dawley
13.
Pathobiology ; 73(5): 244-51, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17314495

RESUMEN

BACKGROUND: Advanced glycation end products (AGEs) are implicated in the etiology of diabetic complications in the kidney, nerve and eye. Skeletal muscle contractile parameters have also been found to be altered in diabetes. Glycation has not been extensively studied in skeletal muscle, but AGE-modified proteins may influence contractility. OBJECTIVE AND METHODS: The aim of this study was to use immunohistochemistry to identify distribution patterns of the AGE Nepsilon-(carboxymethyl)-lysine in plantaris muscle of diabetic rats. RESULTS: Results revealed the presence of Nepsilon-(carboxymethyl)-lysine intracellularly and also at sites along the myofiber periphery. The number of myofibers immunolabeling for AGE in animals with diabetes was more than 4-fold greater than in control animals. Additionally, there was a greater proportion of slow + fast myosin heavy chain coexpression in the AGE-positive cells from diabetic animals than in AGE-positive fibers from control animals. No significant difference was present between cross-sectional areas of AGE-positive fibers and AGE-negative fibers within the respective experimental groups. CONCLUSIONS: AGE accumulation is greater in skeletal muscle in vivo from diabetic animals than in control animals. This AGE accumulation appears to be associated with fiber-type transformation rather than with myofiber size. Further study is needed to determine the identity of these AGE-modified proteins and to determine how they influence skeletal muscle function in diabetes.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Músculo Esquelético/metabolismo , Animales , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley
14.
Am J Phys Med Rehabil ; 84(10): 770-9, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16205433

RESUMEN

OBJECTIVE: This study evaluated the effect of endurance exercise on myosin heavy chain (MHC) isoform expression in soleus muscle of diabetic rats with peripheral neuropathy. DESIGN: Male Sprague Dawley rats were randomly divided into four groups: control sedentary, diabetic sedentary, control exercise, and diabetic exercise. The exercised animals performed treadmill running five times per week. After 12 wks, electrophysiologic testing documented peripheral neuropathy in the diabetic rats. The soleus muscles were then excised and quick-frozen. Cross-sections were immunohistochemically stained for slow, fast, developmental, and neonatal MHCs. Fiber-type composition and fiber cross-sectional areas were then determined. RESULTS: The diabetic groups showed a significantly greater percentage of fast MHC than did the control groups, regardless of exercise status (diabetic sedentary, 22.6%; diabetic exercise, 25.2%; control sedentary, 13.5%; control exercise, 13.1%). The diabetics also showed a significantly lower percentage of slow-only MHC than controls (diabetic sedentary, 77.1%; diabetic exercise, 74.3%; control sedentary, 86.2%; control exercise, 86.1%). No differences in muscle fiber cross-sectional area existed between the groups. The exercised animals showed greater expression of developmental MHC than did the sedentary animals (diabetic sedentary, 1.6%; diabetic exercise, 3.8%; control sedentary, 0.8%; control exercise, 2.0%). CONCLUSION: The altered slow and fast MHC expression in the diabetic muscle is similar to MHC expression in several other conditions, including decreased neuromuscular activity and denervation. Mechanisms of this MHC expression shift are unknown. Chronic endurance training does not alter adult MHC expression in the diabetic animals. The developmental MHC expression is likely a manifestation of uphill treadmill running due to eccentric contractions in the soleus resulting in myofiber injury and regeneration.


Asunto(s)
Músculo Esquelético/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Enfermedades del Sistema Nervioso Periférico/diagnóstico , Condicionamiento Físico Animal , Resistencia Física/fisiología , Análisis de Varianza , Animales , Biopsia con Aguja , Diabetes Mellitus Experimental , Neuropatías Diabéticas/diagnóstico , Neuropatías Diabéticas/metabolismo , Modelos Animales de Enfermedad , Inmunohistoquímica , Masculino , Músculo Esquelético/patología , Cadenas Pesadas de Miosina/análisis , Enfermedades del Sistema Nervioso Periférico/metabolismo , Probabilidad , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Sensibilidad y Especificidad , Estreptozocina
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