Morphological changes in rat rectus abdominis muscle induced by diabetes and pregnancy

The urethral muscle of diabetic pregnant rats is affected by long-term mild diabetes and short-term severe diabetes, which plays a crucial role in the pathogenesis of pelvic floor disorders. We hypothesized that muscles outside the pelvis are subject to similar changes. The current study aimed at analyzing the effects of long-term mild and short-term severe diabetes on the structure and ultrastructure of fiber muscles and collagen in rats' rectus abdominis (RA) muscle. Therefore, the RA muscle of virgin, pregnant, long-term mild diabetic, short-term severe diabetic, long-term mild diabetic pregnant and short-term severe diabetic pregnant 3-month-old Wistar rats were collected. The structure was analyzed by picrosirius red staining, immunohistochemistry for fast and slow muscle fibers and transmission electron microscopy. We investigated two levels of STZ- induced diabetes: long-term mild diabetes (blood glucose level: 120-200 mg/dL) and short-term severe diabetes (blood glucose level >300 mg/dL). Long-term mild diabetic pregnant and short-term severe diabetic pregnant rats had decreased fast fibers and increased slow fibers, disrupted areas of sarcomere, intermyofibrillar mitochondria and myelin figures in the RA muscle. Both groups enabled us to analyze the specific influence of pregnancy, separately from diabetes. The current study demonstrated that diabetes and pregnancy induced intramuscular transformation and reorganization of RA muscle with a switch of fiber type adjusting their architecture according to intensity and duration of hyperglycemic insult within pregnancy.

Effects of duodenal-jejunal bypass on structure of diaphragm in western diet obese rats

Abstract Purpose: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . Methods: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. Results: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. Conclusion: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.

Ultrastructural study of the denervated diaphragm in rats / Estudio ultraestructural del diafragma desnervado en ratas

The structural alterations that occur in the muscle fibers of denervated rat diaphragms were studied. Fifteen adult male albino rats (Rattus norvegicus) with a mean weight of 200 g and about 60 days of age were used. Chronically denervated diaphragms were obtained and the animals were sacrificed after 4, 8 and 12 weeks of denervation. The left antimere of the diaphragm was denervated by sectioning of the phrenic nerve and the right antimere served as control. Each antimere was divided into fragments, which were used for analysis transmission electron microscopy. During the initial phase of denervation (4 weeks), ultrastructural muscle modifications appeared in scattered fibers and in foci along these fibers. Muscle fibers with foci of less dense and loosely arranged myofibrils, disorganized Z line, displaced T tubules, and central nucleus exhibiting reentrances and fragmented aspect were observed. After 8 weeks, formation of large aggregates of small elongated mitochondria showing altered cristae, matrix inclusions and increased electron density was noted. At 12 weeks of denervation the alterations were found to be more drastic. Nuclei with internal deposits of myofibrillar or amorphous material were observed. In these fibers, vacuoles harbored enormous myeloid structures in the subsarcolemmal or intermyofibrillar region.

Fueron estudiadas las alteraciones ultra estructurales de las fibras musculares del diafragma denervado de ratas. Fueron utilizadas 15 ratas albinas (Rattus norvegicus), machos, adultas, con peso promedio de 200 g de aproximadamente 60 días de edad. Los diafragmas crónicamente denervados fueron obtenidos después de 4, 8 y 12 semanas de denervación. El antímero izquierdo del diafragma fue denervado por sección del nervio frénico y el antímero derecho fue utilizado como control. Cada antímero fue dividido en fragmentos, que fueron utilizados para el estudio en microscopia electrónica de transmisión. Durante los períodos iniciales de denervación (4 semanas), las modificaciones en la ultraestructura del músculo se disponen en fibras dispersas y en focos a lo largo de las mismas. Se observan fibras musculares con focos de miofibrillas rarefactas y laxamente dispuestas; línea Z desorganizada; túbulos T dislocados; núcleo central con aspecto fragmentado. Después de 8 semanas de denervación, se observa la formación de numeroso agregados de pequeñas mitocondrias alargadas, con alteraciones en las crestas, inclusiones en la matriz y aumento de la electrodensidad. Con 12 semanas de denervación, las alteraciones se muestran más drásticas; se observan núcleos con depósitos internos de material miofibrillar o amorfo. En estas fibras, las vacuolas presentan grandes estructuras mieloides en la región subsarcolemal o intermiofibrillar.

Fibroelastic components of the vesicourethral junction of rats in the aging process / Componentes fibroelásticos de la unión vesicouretral de ratas en el proceso de envejecimiento

The vesicourethral junction comprising the vesical trigone, is relevant in setting and positioning of the urinary bladder, along with the vesical neck, fixed by lateral ligaments of the bladder and tendinous arch of the pelvis fascia. Namely,the puboprostatic ligament (men) and the pubovesical (women). The circular set elastic fibers in this junction are important and valuable in the elasticity and plasticity of the area, allowing quick expansion and withdrawal with the flow of urine, and associated to smooth muscle tissue and nerve control form an important collective to maintain urinary continence. The objective of the present study is to describe the elastic system in the vesicouretral junction in relation to aging and its involvement in the states of urinary continence and incontinence, as well as the study of the vesicouretral junction in various age groups while evaluating with electron transmission microscopy. To carry out the study, 12 Wistar rats were used, divided into groups: neonate (4 animals), adult group (4 animals) and aged group (4 animals). Electron transmission microscopy with use of tanic acid technique associated to glutaraldehyde fixation, satisfactorily showed the extreme structural differences between mature elaunin and oxytalan fibers present between intercelular spaces and bundles of collagen fibers. The phases of elastogenesis in neonate animals and degradation of the elastic system of older animals were also evaluated.

La unión vesico-uretral, componente del trígono vesical, posee una relevante importancia en la fijación y posicionamiento de la vejiga urinaria conjuntamente con el cuello vesical, fijado por los ligamentos laterales de la vejiga y arco tendinoso de la fascia de la pelvis. Principalmente, sus componentes anteriores son: el ligamento puboprostático en los hombres y el ligamento pubovesical en las mujeres. Las fibras elásticas dispuestas circularmente en esta unión, son de valiosa importancia en la elasticidad y plasticidad de la región, permitiendo expansión y retiro rápido con el flujo de la orina, y asociado a musculatura lisa y control nervioso forman un conjunto importante para el mantenimiento de la continencia urinaria. Debido a existencia de puntos no esclarecidos en esta región en relación al sistema elástico y su participación en los estados de continencia/incontinencia urinaria, el presente trabajo tiene por objetivo el estudio de la unión vesico-uretral evaluándola en diferentes grupos etarios, a través de la microscopía electrónica de transmisión. Fueron utilizados 12 ratones Wistar, divididos en grupo de neonatos (4 animales), grupo adulto (4 animales) y grupo de ratones viejos (4 animales). La microscopía electrónica de transmisión, con uso de la técnica del ácido tánico asociado al fijador glutaraldeído, mostró satisfactoriamente las diferencias ultraestructurales entre las fibras elásticas maduras, elaunínicas y oxitalánicas, presentes entre los espacios intercelulares de las células musculares y haces de fibras colágenas, y también fases de elastogénesis en animales neonatos y envejecimiento y degradación del sistema elástico en los animales mayores.

Morfometría de los ramos nerviosos para los músculos interóseos plantares del pie en el hombre / Morphometry of nerve branches for plantar interossei muscles in the foot of man

La inervación del pie ha requerido especial atención por su utilidad en el abordaje clínico y quirúrgico de patologías y síndromes dolorosos como talalgias, fascitis plantar y fibromatosis plantar, entre otras. Estudios realizados, han permitido conocer la importancia funcional de los músculos interóseos plantares. Sin embargo, no se conoce mayores detalles de su inervación. Realizamos un estudio morfométrico en 5 muestras de ramos nerviosos para el primer, segundo y tercer músculo interóseo en cadáveres de individuos adultos, masculinos. Se obtuvieron secciones transversales de cada uno de los nervios después de su origen, a nivel del plano profundo de la región plantar del pie. Realizamos cortes de 4 um de grosor los cuales fueron teñidos con Hematoxilina-Eosina (H.E.). El promedio de fascículos en el ramo para el primer músculo interóseo (R1 IOP) fue 1 (D.E. 0,00); para el segundo músculo interóseo (R2 IOP) fue 2 (D.E. 0,45) y para el tercer músculo interóseo (R3 IOP) fue 2 (D.E. 1,00). El promedio de fibras para el R1 IOP, R2 IOP Y R3 IOP fue: 547 (D.E. 153), 644 (D.E. 258) y 1.161 (D.E. 465) respectivamente. El área promedio del R1 IOP, R2 IOP Y R3 IOP fue: 0,06 mm2 (D. E. 0,02), 0,08 mm2 (D. E. 0,03), 0,14 mm2 (D. E. 0,06), respectivamente. El estudio morfométrico y estereológico de estos ramos nerviosos espera aportar al conocimiento de los profesionales que deben intervenir clínica y quirúrgicamente en la región plantar del pie.

Innervation of the foot has required special attention in view of its use in clinical and surgical treatment of painful diseases and syndromes such as talalgia, plantar fasciitis and plantar fibromatosis are among those mentioned. Studies realized have made possible the functional significance of plantar interossei muscles. However, there is no information regarding greater detail of their innervation. A morphometric study was carried out in 5 nerve branches for the first, second and third plantar interossei muscles in cadavers of adult male individuals. Cross sections were obtained of each one of the nerves after their origin, at the deep level of the plantar region of the foot. Cuts of 4 um thick were realized which were stained with Hematoxylin-Eosin (H.E.). Average fascicles in the branch for the first interosseous muscle(R1 IOP) was 1 (D.E. 0,00); for the second interosseous muscle(R2 IOP) was 2 (D.E. 0.45); and for the third interosseous muscle(R3 IOP) was 2 (D.E. 1.00). The average of fibers for thel R1 IOP, R2 IOP was:547 (D.E. 153), 644 (D.E. 258) and 1.161 (D.E. 465) respectively. The average area ofR1 IOP, R2 IOP Y R3 IOP was: 0.06 mm2 (D. E. 0.02), 0.08 mm2 (D. E. 0.03), 0.14 mm2 (D. E. 0.06), respectively. The morphometric and stereological study of these nerve branches is expected to contribute to the information available to professionals who must clinically and surgically treat the plantar region of the foot.

Esophageal anatomy of the llama (Lama glama) / Anatomía del esófago de la llama (Lama glama)

This study describes gross, microscopic and muscle fiber anatomy of the esophagus of the llama, Lama glama. The esophagus was studied grossly in twenty-five adult llamas and a subset of ten with normal esophageal physiology was used for the microanatomic studies. Esophageal length was 122 +/- 7 cm with two-thirds of the length in the neck and the remainder in the thorax, consistent with the long neck of the llama. Esophageal diameter increased steadily from 2.5 +/- 0.3 cm in the cranial cervical region to 3.9 +/- 0.8 cm in the caudal thoracic region. The mucosal epithelium was keratinized stratified squamous and there were abundant submucosal glands throughout the esophagus. The entire muscularis of the esophagus was striated muscle in two general layers but also with a somewhat random orientation of fibers. The tunica muscularis steadily increased in thickness from 3.43 +/- 0.30 mm in the cranial cervical region to 4.39 +/- 0.39 mm in the middle thoracic region. In the llama Type 2 muscle fibers predominated in the esophageal musculature, with the percentage of Type 1 fibers increasing from 1 percent cranially to 33 percent in the caudal thoracic region of the esophagus. This study of the normal llama esophagus enhances our knowledge of this species and provides the basis for future study of pathological conditions of the esophagus.

Este estudio describe la anatomía morfológica, microscópica, y tipo de fibra muscular del esófago de la llama, Lama glama. Estudiamos la anatomía morfológica del esófago, con fisiología normal, en 25 llamas adultas y, adicionalmente, en 10 de ellas la anatomía microscópica. La longitud del esófago fue 122 +/- 7 cm con dos tercios en el cuello y un tercio en el tórax. El diámetro del esófago aumentó de 2,5 +/- 0,3 cm en la región craneal del cuello y a 3,9 +/- 0,8 cm en la región caudal del tórax. El epitelio de la mucosa eera escamoso estratificado queratinizado y la submucosa contenía abundantes glándulas a lo largo de todo el esófago. La muscular entera del esófago se compuso de músculo esquelético en más o menos dos capas, pero con algunas fibras orientadas al azar. La muscular aumentó de 3,43 +/- 0,30 mm en la región craneal del cuello a 4,39 +/- 0,39 mm en la región media del tórax. Fibras musculares Tipo 2 predominaron en la muscular. El porcentaje de fibras Tipo 1 aumentó de 1 por ciento al inicio del esófago a 33 por ciento en la región caudal torácica. Este estudio del esófago normal de la llama ofrece más información sobre la anatomía de la llama y proporciona una base para futuros estudios de patologías esofágicas.

Muscular partitioning in the semitendinosus muscle of the pig / Compartimientos musculares del músculo semitendinoso del cerdo

Neuromuscular compartments are subvolumens supplied by a primary nerve branch with homogeneous fiber characteristics. This muscular organization is important for understanding the muscle function in relation to postural and dynamic implications and also is relevant for appraising meat quality. Current researches associate fiber muscle characteristics with perimortem processes that regulate muscle transformation into meat. It is known that pig muscle has four heavy chain myosin isoforms: I, IIa, IIx and IIb. Castrated male pigs were slaughtered at 100 kg live weight. Semitendinosus muscle samples of each subvolumen determined previously (R1, R2, R3, R4) were frozen in liquid nitrogen and reacted for myofibrillar ATPase and NADH-TR for determining fiber types and oxidative capacity respectively. It were identified I, IIA and IIX/IIB fiber types. The frequency distribution of the I, IIA, and IIX/IIB fiber types were significantly greater in R1- R4, R4 and R3 respectively. The CSA of all fiber types was significantly larger in R1 than other compartments, notwithstanding CSA did not vary significantly among fiber types; oxidative capacity was significantly greater in R4. These results show a heterogeneousness of the muscle which would explain probably the disagreements documented between characteristics of fiber and meat quality traits.

Los compartimientos neuromusculares son subvolúmenes abastecidos por un ramo nervioso primario, los cuales poseen características fibrilares homogéneas. Esta organización muscular es importante para entender la función muscular en relación tanto en la estática y dinámica como en la apreciación de la calidad de la carne. Actuales investigaciones asocian características fibrilares con procesos perimorten que regulan la transformación del músculo en carne. Es conocido que en el músculo del cerdo están presentes cuatro cadenas pesadas de miosina: I, IIa, IIx y IIb. Cerdos machos castrados fueron faenados a los 100K kg de peso vivo. Muestras musculares de cada subvolumen del músculo semitendinoso, previamente determinados (R1, R2, R3, R4), fueron congeladas en nitrógeno líquido y tratadas con las reacciones de ATPasa miofribrilar y NADH-TR para determinar los tipos fibrilares y la capacidad oxidativa, respectivamente. Fueron identificadas los tipos fibrilares I, IIA y IIX/IIB. La frecuencia de distribución de los tipos fibrilares I, IIA, y IIX/IIB fueron significativamente mayores en R1- R4, R4 y R3, respectivamente. La CSA de todos los tipos fibrilares fueron significativamente mayores en R1 que en los otros compartimientos, sin embargo CSA no varía en forma significativa entre los tipos fibrilares; la capacidad oxidativa fue significativamente mayor en R4. Estos resultados evidencian una heterogeneidad muscular la cual podría probablemente explicar los desacuerdos documentados entre las características de las fibras y su relación con la evaluación de la calidad de la carne.

Muscle fibre types and connective tissue morphometry in frontal muscle of Norfolk rabbits (Oryctolagus cuniculus) / Morfometría de los tipos de fibra muscular y del tejido conectivo en músculo frontal de conejos Norfolk (Oryctolagus cuniculus)

The frontal muscle is formed by a complex of contractile elements which compose the set of facial muscles responsible for the expression of emotions. In view of its functional characteristics the frontal muscle consists of a mixture of high (type I) and low oxidative (type II) muscle fibres. The objective of the present study was to determine the area, diameter, and relative volume occupied by each fibre type in frontal muscles of Norfolk rabbits using nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) histochemistry combined with morphometry. In addition, the connective tissue area (endomysium) and the number of blood vessels per fibre were evaluated. Female rabbits ranging in age from 6 to 8 months and weighing 2.8 to 3.1 kg were used. Four quadrants of samples from 12 animals were analysed. Type IIB fibres occupied the largest area compared to the other fibre types. The fibre diameter and relative volume were similar among the different fibre types identified by NADH-TR staining. No significant difference in the number of vessels per fibre was observed between the different fibre types. The endomysial area occupied the smallest area among the parameters analyzed. These findings demonstrated the intense activity of this muscle in the facial architecture of the animal. However, the low oxidative type II fibres predomination indicates more prone to muscle fatigue. The present findings may contribute to the study of myopathies involving this muscle.

El músculo frontal está formado por un complejo de elementos contráctiles que componen el conjunto de músculos faciales responsables de la expresión de emociones. A la vista de las características funcionales, el músculo frontal está constituido de una mezcla de fibras musculares de alto (tipo I) y bajo nivel de oxidación (tipo II). El objetivo del presente estudio fue determinar área, diámetro y volumen relativo ocupado por cada tipo de fibra en los músculos frontales de conejos Norfolk utilizando histoquímica para nicotinamide adenina dinucleotide tetrazolium reductasa (NADH-TR), combinado con su morfología. Además, fueron evaluados la zona de tejido conectivo (endomisio) y el número de vasos sanguíneos por fibras. Fueron utilizados conejos hembras, de edades comprendidas entre los 6 a 8 meses y con un peso de 2,8 a 3,1 kg. Se analizaron cuatro cuadrantes de las muestras de 12 animales. Las fibras tipo IIB ocuparon la mayor superficie, en comparación con los otros tipos de fibras. Los diámetros y volúmenes relativos de las fibras fueron similares entre los diferentes tipos identificados por NADH-TR. No se observaron diferencias significativas en el número de vasos por fibra, entre los diferentes tipos de fibras. El área ocupada por el endomisio fue la superficie más pequeña entre los parámetros analizados. Estos resultados demostraron la intensa actividad de este músculo en la arquitectura facial del animal. Sin embargo, el predominio de las fibras tipo II, de baja oxidación, indica más propensión a la fatiga muscular. El presente hallazgo pueden contribuir al estudio de las miopatías con la participación de este músculo.

Spontaneous stage differentiation of mouse-virulent Toxoplasma gondii RH parasites in skeletal muscle cells: an ultrastructural evaluation

Although the predilection for Toxoplasma gondii to form cysts in the nervous system and skeletal and heart muscles has been described for more than fifty years, skeletal muscle cells (SkMCs) have not been explored as a host cell type to study the Toxoplasma-host cell interaction and investigate the intracellular development of the parasite. Morphological aspects of the initial events in the Toxoplasma-SkMC interaction were analysed and suggest that there are different processes of protozoan adhesion and invasion and of the subsequent fate of the parasite inside the parasitophorous vacuole (PV). Using scanning electron microscopy,Toxoplasma tachyzoites from the mouse-virulent RH strain were found to be attached to SkMCs by the anterior or posterior region of the body, with or without expansion of the SkMC membrane. This suggests that different types of parasite internalization occurred. Asynchronous multiplication and differentiation of T. gondii were observed. Importantly, intracellular parasites were seen to display high amounts of amylopectin granules in their cytoplasm, indicating that tachyzoites of the RH strain were able to differentiate spontaneously into bradyzoites in SkMCs. This stage conversion occurred in approximately 3 percent of the PVs. This is particularly intriguing as tachyzoites of virulent Toxoplasma strains are not thought to be prone to cyst formation. We discuss whether biological differences in host cells are crucial to Toxoplasma stage conversion and suggest that important questions concerning the host cell type and its relevance in Toxoplasma differentiation are still unanswered.

Aspectos ultra-estruturais da fibra muscular cardíaca de rats albinas durante o ciclo gravídico-puerperal / Ultrastructural aspects of cardiac muscle fibers of albino rats during pregnancy and puerperal cycle

Objetivo. No presente estudo avalianos, por intermédio da microscopia eletrônica de transmissão, a morfologia dos cardiomiócitos do ventrículo esquerdo de ratas albinas no decorrer do ciclo gravídico-puerperal. Métodos. Obtida a prenhez, 77 ratas foram divididas ao acaso em dois grupos denominados, respectivamente, de: gestação (G) e puerpério (P). Os animais pertencentes ao grupo gestação foram ainda subdivididos em quatro subgrupos, de acordo com a idade gestacional; 1§ (G-A), 7§ (G-B), 14§ (G-C) e 21§ (G-D) dias de prenhez. O grupo definido como puerpério foi também subdividido em três subgrupos; 7§ (P-A), 14§ (P-B) e 21§ (P-C) dias de puerpério. Findo o período estabelecido para cada subgrupo, os animais foram sacrificados, sendo coletados fragmentos do terço médio do ventrículo esquerdo, os quais após processamento apropriado, permitiram observação adequada à microscopia eletrônica de transmissão. Resultados. Os resultados hipertrofia gradativos dos cardiomiócitos no decorrer da prenhez (aumento das miofibrilas, que ao final da gestação apresentaram-se entremeadas de numerosas mitocôndrias). As paredes dos capilares sangüíneos, progressivamente, tornaram-se mais delgadas, com aumento das vesículas de pinocitose no interior das células endoteliais. Revelou ainda, acentuadas dobras do sarcolema em nível dos túbulos T (túneis capilares). No grupo puerpério, notamos gradativa regressão nessas alterações, com retorno às características pré-gestacionais. Os achados demonstram a ocorrência de hipertrofia no decorrer da gestação. Conclusão. Durante a prenhez há hipertrofia em cardiomiócito do ventrículo esquerdo com regressão durante o puerpério.

Centronuclear myopathy: histopathological aspects in ten patients with childhood onset

Centronuclear myopathy is a rare congenital myopathy. According to the period of onset os sings and symptoms and the degree of muscular involvement there clinical forms are distinguished: severe neonatal; childhood onset; and adult onset. We describe herein the muscle biopsy findings of ten patients with the childhood onset form of the disease including three cases with ultrastructural study. The biopsies disclosed increased nuclear centralization that varied from 25 to 90 percent of the fibers, type 1 predominance, great variability in fiber diameters, involvement in the internal fiber's architecture, and focal areas of myofilament disorganization. The main histopathologic different diagnoses included type I fiber predominance, congenital fiber type disproportion, and myotonic dystrophy. The histologic abnormalities in centronuclear myopathy may be due to an arrest of maturation on the fetal myotubular stage. The cause of this arrest remains elusive.

Description of nodal fibers in the cranial vein cava walls of the bovine (bos indicus)

Muchas investigaciones han estudiado la presencia de fibras musculares estriadas cardíacas, con características de fibras nodales en las paredes de la vena cava y del seno coronario de mamíferos. Sin embargo no hay un consenso sobre la localización exacta de estas fibras. El objetivo de este trabajo fue identificar estas fibras en la vena cava craneal de bovino. Para este propósito, utilizando 10 corazones bovinos con los vasos de la base, fijados en formol 10 por ciento. Después de la fijación, el segmento intrapericárdico fue aislado e incluido en paraplástico. Se obtuvieron cortes transversales y longitudinales los que fueron sometidos a coloración con tricrómicos de Masson y Mallory, orceína clorhídrica de Unna-Taenzer y Calleja. Los resultados microscópicos revelaron que estas fibras nodales están localizadas en las paredes ventral e izquierda de la vena cava craneal a nivel de la desembocadura en el atrio derecho. Concluimos que estas fibras presentes en las paredes de la vena craneal, transmiten el estímulo eléctrico originado en el nodo sinoatrial para toda musculatura atrial, hasta las paredes venosas, causando la constricción del ostio venoso impidiendo el reflujo venoso durante la sístole atrial

Microscopic observations on the great saphenous vein at the upper third level of the thigh and at the level of discharge into the femoral vein

For the microscopical study of the great saphenous vein wall, the venous segments from six male necropsiedcadavers: were obtained three young individuals between 16 and 35 years old and three aged individuals between 50 and 83 years old. The tunica media of the great saphenous vein at the upper third level of the thigh belonging to both young and aged individuals is made up of two layers: an internal formed by fascicles of smooth longitudinal muscular fibers and the external layer made up by fascicles of smooth circular muscular fibers. At the level of the discharge in the femoral, the tunica media of the great saphenous vein wall of both, young and aged individuals, is made up of one layer, whose fascicles of smooth muscular fibers are circularly orientated in relation to the vascular axis. The tunica adventitia of the great saphenous vein wall at the upper third level of the young individuals thigh, presents elastic fibers whereas it the aged individuals it is made up of fascicles of smooth longitudinal fibers; at the level of the femoral vein disdarge in both young and aged individuals, the tunica adventitia presents a fiber elastic constitution. The young and aged individuals' parietal venous valve is elastic fiber in nature. The young individuals' ostial valve is also elastic and that of aged individuals is muscular fiber in nature.

Corpos de inclusäo citoplasmática: estudo em diversas doenças e revisäo da literatura / Cytoplasmic inclusion bodies: a study in several diseases and a review of the literature

Estudamos 16 casos entre 1400 biópsias musculares que apresentavam vacúolos marginados, cujo aspecto histológico sugeria corpos de inclusao citoplasmáticos. Procuramos correlacionar os dados clínicos, laboratoriais e histopatológicos, a fim de determinar a especificidade dos corpos de inclusao citoplasmáticos para determinadas doenças. A creatinaquinase mostrou-se elevada em 1O casos. A eletromiografia foi anormal em todos os casos. A histoquímica muscular em 5 casos revelou uma miopatia, em 7 padrao misto, em dois desinervaçao e em 2 casos miopatia inflamatória. A microscopia eletrônica demonstrou a presença de filamentos em 8 casos (nucleares, dispersos no citoplasma ou na regiao subsarcolemal). Os pacientes foram classificados conforme a história clínica, hereditariedade, dados laboratoriais, eletrofisiológicos, histoquímicos e microscopia eletrônica. Encontramos miosite com corpos de inclusao citoplasmática (4 casos), atrofia muscular espinhal juvenil (6 casos), miopatias distais (3 casos), distrofia de cinturas pélvica e escapular (2 casos) e polineuropatia periférica (1 caso). Apresentamos revisao sobre a patogenia, formaçao e possível etiologia dos vacúolos marginados e sua relaçao com as diversas entidades em que foram detectados, sugerindo que nao sao específicos para uma única doença.

Estudo morfológico e histoquímico em nível ultra-estrutural da corda tendínea de coraçöes de rato albino / Morphological and histochemical study in structural pattern of chordae tendinae of hearts from albino rat

Fragmentos de cordas tendíneas dos complexos valores mitral e tricúspide de ratos albinos foram observados ao microscópio eletrônico de transmissäo com o objetivo de estudar os componentes da matriz extracelulair. Foram utilizados dois tipos de fixador, um contendo ácido tânico para demonstrar a presença de fibras dos sistemas colágeno e elástico, e outro contendo vermelho de rutênio para a visualizaçäo de proteuglicans. Alguns fragmentos foram tratados previamente pela colagenase ou pela tripisina antes de serem fixados pelo glutaraldeído com vermelho de rutênio. Foi observado que as cordas tendíneas de rato säo revestidas por um endotélio contínuo que repousa sobre uma camada de conjuntivo contendo fibroblastos e esparsas fibras de colágeno, compondo a zona esponjosa. Tal camada circunda uma zona central (zaza fibrosa) constituída de grossos feixes de colágeno onde se encontram vários fibroblastos. Tanto na zona esponjosa como na fibrosa foram detectadas inúmeras fibras com padräo ultra-estrutural de fibras elaunínicas, os quais, juntamente com o colágeno, desempenham funçöes de resistência mecânica ao transmitirem as forças de traçäo exercidas pelo músculo papilar às bordas das válvulas. Adicionalmente, foram observadas as relaçöes morfológicas entre proteoglicans, fibrilas de colágeno e microfibrilas elaunínicas, tendo sido enfatizada a importância do equilíbrio de funçöes entre os diversos componentes da matriz extracelular concorrendo para o perfeito funcionamento deste complexo morfofuncional na fisiologia da corda tendínea.

Cambios en la (Ca2+)i inducida por el dantrolene en fibras musculares de sujetos susceptibles a hipertermia maligna

La hipertermia maligna (HM), es miopatía hereditaria, la cual se desencadena cuando los individuos susceptibles son expuestos a la acción de relajantes musculares despolarizantes y/o potentes anestésicos volátiles halogenados. Hemos estudiado el efecto del dantrolene sódico sobre la concentración intracelular de calcio libre (Ca2+)i, en, biopsias de músculo intercostal externo obtenidas de: A) Seis pacientes susceptibles a HM, antes y después de la administración oral 2,5 mg/kg1, durante tres días e intravenosa 1,0 mg/kg1, dos horas antes de la segunda biopsia de dantrolene sódico. Seis pacientes susceptibles a HM antes y despuésde la administración únicamente intravenosa, de dantrolene sódico, a una dosis de 1 mg/kg1, dos horas antes de la segunda biopsia y C) Ocho pacientes susceptibles aHM, después de la administración intravenosa de dantrolene sódico 2 mg/kg1, dos horas antes de la realización de la segunda biopsia. La (Ca2+)i libre, fue medida mediante microelectrodos selectivos a calcio. El promedio de la (Ca2+)i, en fibras musculares provenientes de sujetos susceptibles a HM, antes del tratamiento con dantrolene, fue en el grupo A, de 0,42+0,02M (n=41) en el grupo C. La Administración de dantrolene, redujo ese valor a 0,29+0,02M (n=30), 0,25+0,02M (n=31) y 0.11+0,01 (n=26) en los grupos A,B y C respectivamente.No hubo diferencias significativas en el potencial de membrana en reposos después del dantrolene. Estos resultados representan una demostración de que el dantrolene sódico puede reducir (Ca2+)i libre de reposo, en el músculo esquelético, de pacientes susceptibles a la HM, de una manera dosis dependiente

Alteraçöes ultra-estruturais da fibra muscular cardíaca do rato albino submetido a nutriçäo parenteral total / Ultrastructural alterations of the cardiac muscular fiber in albino rat submitted to total parenteral nutrition

A nutriçao parenteral consiste na administraçao de nutrientes por via endovenosa, sendo de grande utilidade quando a via digestiva é inviável para a alimentaçao; trata-se de um procedimento, contudo, que pode acarretar inúmeras complicaçoes. O objetivo deste trabalho é analisar as alteraçoes ultra-estruturais da fibra muscular cardíaca do rato albino submetido à nutriçao parenteral total, sem lipídeos na sua composiçao. Utilizamos para a presente pesquisa oito ratos (Rattus norvegicus, var. albinus, Rodentia, Mammalia) pesando entre 150 e 165 gramas. Quatro animais constituíram o grupo Experimento, isto é, foram submetidos à nutriçao por via endovenosa durante o período de 10 dias, e quatro, o grupo Controle, que permaneceram em regime de alimentaçao normal, porém tendo sido submetidos ao mesmo procedimento técnico que os animais do outro grupo e permanecendo com o cateter na veia jugular durante todo o experimento. Ao término do 10( dia de experimento os animais de ambos os grupos foram pesados, anestesiados por éter sulfúrico e submetidos à toracotomia. Exposto o coraçao foi colhido sangue, por punçao cardíaca, para dosagem de albumina e glicose; fragmentos do ventrículo esquerdo foram, entao, retirados e submetidos a processamento para observaçao ao microscópio eletrônico. Com a finalidade de constatarmos a presença de estresse nos animais elegemos o método de detecçao de lipídeos localizados no córtex das glândulas supra-renais. Assim, fragmentos da glândula supra-renal esquerda de cada animal de ambos os grupos foram processados para demonstraçao de lipídeos pelo método do Sudan IV. Durante os 10 dias de experimento, fezes e urina dos animais de ambos os grupos foram colhidos para determinaçao do nitrogênio e do balanço nitrogenado. A análise dos resultados demonstrou que as calorias e o nitrogênio recebidos pelos animais bem como a excreçao nitrogenada e o ganho de peso nao apresentaram diferenças significantes nos vários dias do experimento (p < O,05). No estudo comparativo da quantidade de calorias recebidas pelos animais de ambos os grupos ficou bastante evidente que aqueles que receberam nutriçao por via oral tiveram ingesta calórica menor, porém ganharam mais peso (p < O,05). Em relaçao ao nitrogênio, os nutridos por via oral receberam maior quantidade que os nutridos por via endovenosa, porém o excretaram mais, sendo o balanço nitrogenado positivo em todos os dias do experimento (p < O,05). Ao término dos 10 dias do experimento, o nível de albumina sérica mostrou-se inferior nos animais do grupo Experimento (p < O,05) e o de glicose no sangue, maior (p < O,05). A detecçao de lipídeos pelo método Sudan IV na córtex das glândulas supra-renais dos animais de ambos os grupos demonstrou que no córtex das glândulas dos ratos submetidos à nutriçao parenteral os lipídeos encontram-se diminuídos em relaçao ao córtex das glândulas dos animais nutridos por via oral.