Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Cytopathology ; 28(6): 524-530, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28913845

RESUMEN

OBJECTIVE: The purpose of this study was to assess the relationship between urinary WT1-positive cells (podocytes and active parietal epithelial cells) and WT1-positive cells in renal biopsy to investigate whether urinary WT1-positive cells are useful for detection of crescent formation. METHODS: Fifty-two patients with kidney disease were investigated (15 cases with crescentic lesions and 37 cases with non-crescentic lesions) for immunoenzyme staining using anti-WT1 antibody for urine cytology and renal biopsy. Numbers of WT1-positive cells in urine and renal biopsy were counted. RESULTS: There was no correlation between urinary WT1-positive cells and WT1-positive cells in renal biopsy. However, the number of urinary WT1-positive cells in patients with crescentic lesions was significantly higher than in patients with non-crescentic lesions. In addition, the best cut-off value to detect patients with crescentic lesions using urinary was 5 cells/10-mL (area under the concentration-time curve=0.735). CONCLUSIONS: The results of our study suggest urinary WT1-positive cells can be used to detect patients with crescent formation using 5 cells/10-mL cutoff value. WT1-positive glomerular podocytes and parietal epithelial cells may be shed into urine in active glomerular disease. This study, investigating the relationship between WT1-positive cells in urine and in the renal biopsy found no correlation; however, the results do suggest that, using a cutoff value of 5 cells/10 mL, WT1 positive urinary cells can be used to detect patients with crescent formation.


Asunto(s)
Biomarcadores/orina , Queratinas/orina , Enfermedades Renales/orina , Podocitos/patología , Proteínas WT1/metabolismo , Adulto , Femenino , Humanos , Enfermedades Renales/diagnóstico , Masculino , Persona de Mediana Edad
2.
Clin Anat ; 16(1): 40-3, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12486738

RESUMEN

We report an anomalous palmar muscle belly of the flexor digitorum superficialis muscle (FDS) in the right hand of an 80-year-old female cadaver. The muscle originated from the center of the volar surface of the flexor retinaculum and inserted onto the palmar aspect of the base of the middle phalanx of the little finger. Its tendon of insertion divided into two bands, a pattern typical of the FDS tendon, between which the tendon of flexor digitorum profundus muscle to the little finger passed. The tendon of the usual antebrachial FDS to the little finger was absent. The anomalous muscle belly was innervated by a branch from the median nerve.


Asunto(s)
Dedos/anomalías , Dedos/anatomía & histología , Músculo Esquelético/anomalías , Anciano , Cadáver , Femenino , Dedos/inervación , Humanos , Nervio Mediano , Tendones/anomalías
3.
Ital J Anat Embryol ; 106(2 Suppl 1): 423-30, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11729985

RESUMEN

Morphogenetic effects of various extracellular matrix proteins on the renal podocyte were investigated using the conditionally immortalized podocyte cell line. Podocytes were plated on glass coverslips and coated with the following matrix proteins: laminin-10/11, laminin-1, fibronectin, collagen type IV, collagen type I. Three hours after plating, podocytes on laminins developed prominent processes, while those on other matrix proteins started to elongate processes after two days. Vinculin-immunolabeling showed that podocytes plated on laminins possessed thin rod-shaped focal contacts, whereas those on fibronectin showed large dot-shaped focal contacts. Inhibition of serine/threonine protein kinases induced podocyte process formation in an extracellular matrix-independent manner. The present study reveals the significance of laminin on podocyte morphogenesis in vitro, and shows that different extracellular matrix proteins trigger different intracellular signals governing podocyte morphogenesis. Taken together with our previous studies, podocyte process formation is thought to be regulated by protein Ser/Thr phosphorylation.


Asunto(s)
Diferenciación Celular/fisiología , Células Epiteliales/citología , Células Epiteliales/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Glomérulos Renales/crecimiento & desarrollo , Glomérulos Renales/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Tamaño de la Célula/fisiología , Células Cultivadas , Colágeno/metabolismo , Colágeno/farmacología , Inhibidores Enzimáticos/farmacología , Células Epiteliales/efectos de los fármacos , Proteínas de la Matriz Extracelular/farmacología , Fibronectinas/metabolismo , Fibronectinas/farmacología , Laminina/metabolismo , Laminina/farmacología , Ratones , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Vinculina/metabolismo , Vinculina/farmacología
4.
Acta Psychiatr Scand ; 104(3): 223-6, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11531660

RESUMEN

OBJECTIVE: We assessed the reliability of remote video psychiatric interviews conducted via the internet using narrow and broad bandwidths. METHOD: Televideo psychiatric interviews conducted with 42 in-patients with chronic schizophrenia using two bandwidths (narrow, 128 kilobits/s; broad, 2 megabits/s) were assessed in terms of agreement with face-to-face interviews in a test-retest fashion. As a control, agreement was assessed between face-to-face interviews. Psychiatric symptoms were rated using the Oxford version of the Brief Psychiatric Rating Scale (BPRS), and agreement between interviews was estimated as the intraclass correlation coefficient (ICC). RESULTS: The ICC was significantly lower in the narrow bandwidth than in the broad bandwidth and the control for both positive symptoms score and total score. CONCLUSION: While reliability of televideo psychiatric interviews is insufficient using the present narrow-band internet infrastructure, the next generation of infrastructure (broad-band) may permit reliable diagnostic interviews.


Asunto(s)
Entrevista Psicológica , Trastornos Mentales/diagnóstico , Consulta Remota , Análisis de Varianza , Femenino , Humanos , Internet , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados
5.
J Neuropathol Exp Neurol ; 60(6): 621-7, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11398838

RESUMEN

In order to investigate the mechanism of Bell's palsy, we developed an animal model of facial nerve paralysis induced by the reactivation of herpes simplex virus type 1 (HSV-1). Eight weeks after recovery from facial nerve paralysis caused by inoculation with HSV-1, the mice were treated with auricular skin scratch at the site of the previous inoculation, or with intraperitoneal injection of anti-CD3 monoclonal antibody (mAb), or combination of both procedures. No mice developed facial nerve paralysis when they were treated with either auricular scratch or mAb injection alone. In contrast, 20% of mice developed facial nerve paralysis with the combined treatment. With one exception, no mouse treated with either auricular scratch or mAb injection showed HSV-I DNA in their facial nerve tissue, whereas 4 out of 6 mice receiving both treatments showed HSV-1 DNA on day 10 after treatment. Histopathological findings showed neuronal degeneration in the geniculate ganglion and demyelination of the facial motor nerve in paralyzed mice. These findings suggest that a combination of stimuli, local skin irritation, and general immunosuppression is essential for successfully inducing facial nerve paralysis in mice with latent HSV-1 infection.


Asunto(s)
Parálisis de Bell/virología , Herpes Simple/virología , Simplexvirus/fisiología , Activación Viral , Animales , Anticuerpos Monoclonales/farmacología , ADN Viral/análisis , Modelos Animales de Enfermedad , Oído Externo/lesiones , Femenino , Ganglio Geniculado/patología , Ganglio Geniculado/virología , Herpes Simple/sangre , Herpes Simple/genética , Herpes Simple/patología , Recuento de Linfocitos , Ratones , Ratones Endogámicos BALB C , Simplexvirus/clasificación , Linfocitos T/patología , Latencia del Virus
6.
Am J Otolaryngol ; 22(1): 38-42, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11172213

RESUMEN

Aggressive fibromatosis is characterized by locally aggressive proliferation of fibroblasts and occasionally occurs in the head and neck. Although the etiology of this disease is still controversial, recent studies have shown that high levels of growth factors are found in these lesions. This article reports a case of 51-year-old woman with aggressive fibromatosis in the neck and inguinal region bilaterally. Gastric fiberscopic examination revealed a complication of advanced gastric scirrhous carcinoma. There were remarkably high levels of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) in the serum. Postmortem autopsy examination was performed and scattered gastric carcinoma cells were observed in the fibromatosis lesions. Immunohistological staining showed positive expression of bFGF in the fibromatoses and stomach. We concluded that this was a rare case in which bFGF and PDGF released from gastric carcinoma cells caused aggressive fibromatosis by promoting unregulated proliferation of fibroblasts and collagen production locally.


Asunto(s)
Adenocarcinoma Escirroso/complicaciones , Adenocarcinoma Escirroso/diagnóstico , Fibromatosis Agresiva/etiología , Neoplasias de Cabeza y Cuello/etiología , Neoplasias Gástricas/complicaciones , Neoplasias Gástricas/diagnóstico , Adenocarcinoma Escirroso/metabolismo , Colágeno/metabolismo , Resultado Fatal , Femenino , Tecnología de Fibra Óptica/métodos , Factor 2 de Crecimiento de Fibroblastos/sangre , Fibroblastos/metabolismo , Fibromatosis Agresiva/diagnóstico , Neoplasias de Cabeza y Cuello/diagnóstico , Humanos , Inmunohistoquímica , Imagen por Resonancia Magnética , Persona de Mediana Edad , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Neoplasias Gástricas/metabolismo , Tomografía Computarizada por Rayos X
7.
Artículo en Inglés | MEDLINE | ID: mdl-11209854

RESUMEN

Anhydrous potassium pelargonate (KC9) undergoes four thermal transitions from room temperature to 450 degrees C. A normal mode analysis was made for the molecule in phase I at room temperature and the molecule was considered to have an all-trains conformation. With increasing temperature, partial melting of the alkyl chains occurred in phase II and complete melting was observed in phase III, as confirmed by vibrational spectra. In addition, orientational disorder of the carboxylate groups was suggested in phase II. This transition behavior of potassium pelargonate was compared with the behavior of nonane and pelargonic acid.


Asunto(s)
Ácidos Grasos/química , Calor , Modelos Moleculares , Conformación Molecular , Potasio , Espectrofotometría Infrarroja , Espectrometría Raman , Termodinámica , Vibración
8.
J Neurocytol ; 30(8): 685-93, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12118156

RESUMEN

This study presents the first direct evidence for herpes simplex virus type 1 (HSV-1) infection in the neurons of the vestibular ganglion. Although many investigators have reported electron microscopic evidence of HSV-1 infection in sensory ganglia, HSV-1 infection in the vestibular ganglion has not been described. Vestibular ganglion neurons have a unique structure, with a loose myelin sheath instead of the satellite cell sheath that is seen in other ganglia. This loose myelin is slightly different from compact myelin which is known as too tight for HSV-1 to penetrate. The role of loose myelin in terms of HSV-1 infection is completely unknown. Therefore, in an attempt to evaluate the role of loose myelin in HSV-1 infection, we looked for HSV-1 particles, or any effects mediated by HSV-1, in the vestibular ganglion as compared with the geniculate ganglion. At the light microscopic level, some neurons with vacuolar changes were observed, mainly in the distal portion of the vestibular ganglion where the communicating branch from the geniculate ganglion enters. At the electron microscopic level, vacuoles, dilated rough endoplasmic reticulum and Golgi vesicles occupied by virus were observed in both ganglia neurons. In contrast, viral infections in Schwann and satellite cells were observed only in the geniculate ganglion, but not in the vestibular ganglion. These results suggest that loose myelin is an important barrier to HSV-1 infection, and it must play an important role in the prevention of viral spread from infected neurons to other cells.


Asunto(s)
Ganglio Geniculado/virología , Herpes Simple/patología , Herpesvirus Humano 1/patogenicidad , Vaina de Mielina/virología , Neuronas/virología , Nervio Vestibular/virología , Animales , Retículo Endoplásmico Rugoso/patología , Retículo Endoplásmico Rugoso/ultraestructura , Retículo Endoplásmico Rugoso/virología , Femenino , Técnica del Anticuerpo Fluorescente , Ganglio Geniculado/patología , Ganglio Geniculado/ultraestructura , Aparato de Golgi/patología , Aparato de Golgi/ultraestructura , Aparato de Golgi/virología , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica , Vaina de Mielina/patología , Vaina de Mielina/ultraestructura , Neuronas/patología , Neuronas/ultraestructura , Células Satélites Perineuronales/patología , Células Satélites Perineuronales/ultraestructura , Células Satélites Perineuronales/virología , Células de Schwann/patología , Células de Schwann/ultraestructura , Células de Schwann/virología , Nervio Vestibular/patología , Nervio Vestibular/ultraestructura
9.
Kaibogaku Zasshi ; 74(4): 429-39, 1999 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-10496088

RESUMEN

Microtubular cytoskeletons play a crucial role in the morphogenesis of process-bearing cells, such as the neuron and the renal glomerular podocyte. Microtubules are bundled and stabilized by various microtubule-associated proteins, providing a mechanical basis to maintain the deviated morphology of cell processes. To support the process morphology, microtubules are also associated with other cytoskeletal elements such as actin and intermediate filaments. The microtubular polarity is uniformly plus-end-distal in neuronal axons, whereas in dendrites as well as in podocytes, the polarity is revealed to be non-uniform (i.e., both plus-end-distal and minus-end-distal microtubules are present in cell processes). Recently, this non-uniformity is reported to be established by a microtubule-dependent motor protein. Motor proteins are capable to drive the intracellular transport of cytoskeletal elements in addition to that of membrane vesicles. It is still an open question whether cytoskeletal elements are transported along cell processes as subunits or as polymers.


Asunto(s)
Diferenciación Celular , Glomérulos Renales/citología , Microtúbulos/fisiología , Neuronas/citología , Animales , Transporte Axonal , Polaridad Celular , Proteínas del Citoesqueleto/metabolismo , Proteínas del Citoesqueleto/fisiología , Dendritas , Células Epiteliales/ultraestructura , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Proteínas Asociadas a Microtúbulos/fisiología , Morfogénesis
10.
Exp Neurol ; 155(2): 274-83, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10072303

RESUMEN

Exogenous basic fibroblast growth factor (bFGF) has been shown to prevent death of injured cholinergic neurons and stimulate neurite outgrowth from the proximal stump of the transected sciatic nerve. The present study was designed to examine the role of endogenous bFGF, rather than exogenous bFGF in the regenerative process of the transected facial nerve of guinea pig, by using the so-called silicone tubulization model which enabled us to bridge the transected facial nerve with a silicone tube and to inject into the tube bFGF-neutralizing antibody, normal IgG, saline, or platelet factor 4 (an antagonist for bFGF receptor). Under light microscopy, treatment with bFGF-neutralizing antibody caused significant decreases in vascular number, vascular area, and regenerating axons in the middle point of regeneration chambers at the third week after facial nerve transection, even though electron microscopy revealed that the bFGF-neutralizing antibody increased the number of thin axons with caliber smaller than 1 micrometer. Treatment with platelet factor 4 exhibited similar but more conspicuous effects on facial nerve regeneration. These findings suggest that endogenous bFGF not only facilitates angiogenesis within the transected facial nerve but also acts as a neurotrophic agent during facial nerve regeneration; it appears that endogenous bFGF contributes to the enlargement of axon caliber and increases the number of relatively large caliber axons.


Asunto(s)
Anticuerpos Bloqueadores/farmacología , Nervio Facial/efectos de los fármacos , Factor 2 de Crecimiento de Fibroblastos/antagonistas & inhibidores , Regeneración Nerviosa/efectos de los fármacos , Factor Plaquetario 4/farmacología , Animales , Nervio Facial/irrigación sanguínea , Nervio Facial/ultraestructura , Factor 2 de Crecimiento de Fibroblastos/inmunología , Cobayas , Inmunohistoquímica , Masculino , Microscopía Electrónica , Neovascularización Fisiológica/efectos de los fármacos , Fibras Nerviosas/efectos de los fármacos , Fibras Nerviosas/fisiología , Fibras Nerviosas/ultraestructura , Flujo Sanguíneo Regional/efectos de los fármacos , Fijación del Tejido
11.
Kaibogaku Zasshi ; 73(6): 603-13, 1998 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-9990197

RESUMEN

Sensory ganglion neurons in higher vertebrates are unique in that they are pseudounipolar with a single stem process that divides at some distance from the cell body into central and peripheral processes. In the early stages of development, these neurons are bipolar but later they became pseudounipolar. This developmental process of sensory ganglion neurons with satellite cells was examined by scanning electron microscopy following removal of connective tissue. This pseudo-unipolarization began earlier but proceeded at a slower rate in chick than in rat embryos. This difference may due to the difference found in the extent and intimacy of satellite cell investments in these two animals, which was due to the fact that sensory neurons undergo pseudo-unipolarization only in the presence of satellite cells in vitro. The neuronal perikaryal projections were observed by scanning electron microscopy after removal of connective tissue and satellite cells. Morphometric analysis reveal that perikaryal projections were more numerous on the surface of mature pseudounipolar neurons than on the surface of premature bipolar neurons, and that the number of projections increased as the neuronal cell bodies grew larger. This may support the hypothesis that perikaryal projections are structural devices for increasing the neuron-satellite interface and for improving the efficiency of metabolic exchange between these two cell types. These results suggest that satellite cells play an important role in neuronal maturation.


Asunto(s)
Ganglios Sensoriales/embriología , Oligodendroglía/fisiología , Animales , Tipificación del Cuerpo , Embrión de Pollo , Ganglios Sensoriales/ultraestructura , Microscopía Electrónica de Rastreo , Morfogénesis , Oligodendroglía/ultraestructura , Ratas
12.
Pathol Int ; 47(8): 578-80, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9293541

RESUMEN

An 85-year-old man was found to have a calcified mass protruding from the joint space of the right temporomandibular joint (TMJ). Microscopically, the removed mass consisted of chondromyxoid tissue with atypical chondrocytes, resembling a cartilaginous tumor. However, the chondromyxoid tissue contained abundant deposits of rod-shaped to rhomboid crystals which proved to be calcium pyrophosphate dihydrate (CPPD) crystals. The review of the literature revealed that tophaceous pseudogout was the most common variant of CPPD deposition disease involving the TMJ.


Asunto(s)
Condrocalcinosis/patología , Articulación Temporomandibular/patología , Anciano , Anciano de 80 o más Años , Pirofosfato de Calcio/metabolismo , Humanos , Masculino
13.
J Gastroenterol ; 30(4): 551-4, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7550872

RESUMEN

Endothelial nitric oxide (NO) synthase, a unique NO synthase (NOS) isoform that is expressed constitutively by the vascular endothelium both in vivo and in vitro, is believed to be essential to systemic and/or local vascular integrity. NOS expression by endothelial cells may indicate vascular activation. We successfully established a simple method for the culture of microvascular endothelial cells from a small amount of tissue and investigated ulcerative colitis (UC), in which condition vascular factors have not been studied extensively. We cultured endothelial cells from the mesenteries of surgical patients with UC and assayed NOS activity by reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry. Strong NOS activity was demonstrated in the cells from all UC patients (5/5), whereas no activity was detected in the cells from human umbilical veins and the mesenteries of colon cancer patients (0/10 and 0/5, respectively). This strong NOS activity was not diminished by incubation with a high concentration of glucocorticoid, suggesting that it was constitutive. These results indicate a close relationship of vascular activation (high NOS activity) with the pathogenesis of UC.


Asunto(s)
Colitis Ulcerosa/enzimología , Endotelio Vascular/enzimología , Óxido Nítrico Sintasa/metabolismo , Adulto , Células Cultivadas , Colitis Ulcerosa/fisiopatología , Femenino , Histocitoquímica , Humanos , Masculino , NADPH Deshidrogenasa/metabolismo , Vasodilatación/fisiología
14.
Exp Anim ; 44(2): 79-86, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7601229

RESUMEN

To reveal the developmental process of the chondrocranial base of the musk shrew, Suncus murinus (Insectivora), light microscopic observation of serial sections and macroscopic observation with whole-mount differential staining of bone and cartilage were performed on day-17 to -22 embryos. The following unusual findings were obtained: (1) The sphenoethmoidal commissure formed a part of the posterior edge of the tectum nasi, implying that the posterior portion of the paries nasi in the mammalian nasal capsule shares a common origin with the neurocranium. (2) The processus alaris arose independently from the hypophysial cartilage and also contributed to formation of the carotid foramen. (3) The hypophysial cartilage consisted of one medial and a pair of lateral cartilage nodules. The homology of the pair of cartilages with polar cartilages in lower vertebrates is discussed.


Asunto(s)
Cartílago/embriología , Musarañas/embriología , Cráneo/embriología , Animales , Embrión de Mamíferos/anatomía & histología , Femenino , Masculino , Factores de Tiempo
15.
J Anat ; 185 ( Pt 2): 433-7, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7961150

RESUMEN

The occipital squama of the Japanese musk shrew, Suncus murinus, consists only of membrane bone which arises from the periosteal bony band of the supraoccipital cartilage. No cartilaginous tectum posterius, generally forming the dorsal border to the foramen magnum, was found in the developing chondrocranium. Also additional intramembranous ossification centres were occasionally observed, and could be interpreted as being the primordium of the interparietal bone. These observations indicate that the membrane bone is homologous not with the interparietal bone but with the tectum posterius, i.e. the membranous supraoccipital bone. This is an instance of interchangeability between cartilage and membrane bone in a mammal.


Asunto(s)
Hueso Occipital/embriología , Musarañas/embriología , Animales , Cartílago/anatomía & histología , Microscopía , Hueso Occipital/anatomía & histología , Cráneo/anatomía & histología
16.
Brain Res ; 627(1): 177-80, 1993 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-8293300

RESUMEN

The extrafusal and intrafusal muscle fibers in the masseter muscle are innervated by motoneurons in the trigeminal motor nucleus (Mo 5). In the present study, we found that the number of trigeminal motor neurons in the male mouse was significantly larger than that in the female. However, we could not detect any significant difference between male and female mice in the number of sensory neurons in the trigeminal mesencephalic nucleus (Me 5). This is the first report on sexual dimorphism in masticatory motoneurons of mammals.


Asunto(s)
Músculo Masetero/inervación , Neuronas Motoras/fisiología , Caracteres Sexuales , Núcleos del Trigémino/citología , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos ICR
17.
Anat Rec ; 236(4): 602-10, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8379585

RESUMEN

Using digital image analysis and several anatomical methods, morphometric analysis of nonspanning fibers which had tapering profiles at their intrafascicular termination sites and represented overlapping arrangements within the fiber fascicles was performed in the rat rectus abdominis. Special emphasis was focused on dimensional relationships occurring between overlapping portions and tapering segments and sarcomere lengths in non- and overlapping portions. Nonspanning fibers were found to overlap each other for more than 40% of their length. In length, their overlapping portions generally corresponded to their tapering segments, which were also greater than 40% of the fiber length. In addition, despite the presence of overlapping linkages, nonspanning fibers maintained a fairly uniform length irrespective of their overlapping and nonoverlapping portions. Overlapping linkages in fibers without tapering profiles have a larger cross-sectional area in the overlapping portion than in the non-overlapping one, resulting in a phenomenon which will cause different sarcomere lengths between the two portions during fiber stretching. The present results suggest that tapering profiles in the overlapping portion ensure uniform sarcomere lengths within nonspanning fibers, thereby providing mechanical stability in each fiber.


Asunto(s)
Músculos Abdominales/ultraestructura , Uniones Intercelulares/ultraestructura , Sarcómeros/ultraestructura , Músculos Abdominales/fisiología , Animales , Procesamiento de Imagen Asistido por Computador , Uniones Intercelulares/fisiología , Masculino , Microscopía Electrónica , Ratas , Ratas Wistar , Sarcómeros/fisiología
18.
Anat Rec ; 234(4): 500-12, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1456453

RESUMEN

The rectus abdominis muscle is architecturally compartmentalized by tendinous intersections and is supplied by multiple thoracic nerves. In this study, the rectus abdominis of the rat has been qualitatively and quantitatively examined with regard to muscle dimensions, fiber organization, fiber-type composition, and innervation. The muscle exhibits architectural heterogeneity and different patterns of innervation among its thoracic, epigastric, and hypogastric parts. The epigastric part, adherent to the rectus sheath via tendinous intersections, represents relatively simple design. It is formed by serially arranged compartments with shorter fibers, compared with the other parts. These compartments are segmentally supplied by thoracic nerves. The hypogastric part is more complex, forms an interdigitation of muscular slips, and has segmental distribution of thoracic nerves in mediolateral direction. The thoracic part much differs from the other parts. It has smaller cross-sectional areas, compartments composed of abundant nonspanning fibers with intrafascicular termination, and non-segmental distribution of thoracic nerves. In addition to these craniocaudal specializations among the three parts, the muscle exhibits mediolateral differences in fiber-type composition. Slow-twitch oxidative fibers are more densely distributed in the medial half region than the lateral, whereas fast-twitch glycolytic fibers follow an inverse pattern. The mediolateral differences in fiber-type composition as well as the craniocaudal specializations in architectural design and innervation imply regionally differentiated recruitments of the muscle in various behaviors.


Asunto(s)
Músculos Abdominales/anatomía & histología , Músculos Abdominales/inervación , Animales , Masculino , Ratas , Ratas Wistar
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA