摘要:

By preparing a new experimental model for the carpal tunnel syndrome, the authors evaluated the differences of the human and rabbit carpal tunnels using a comparative anatomical study. A nearly identical situation -regarding the osseous and connective tissue formations in the carpal channel – was found. Therefore, the carpal tunnel of the rabbit is recommended for a model of chronic nerve compression, which is now planned by the author

ISSN:1422-6405    

DOI:10.1159/000146971

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

A quantitative approach to the nuclear ultrastructure of cerebellar granule cells is described here. The study was made using conventional electron microscopy from cerebellar cortices of adult rats by means of a semiautomatic image analyzer. The basic observation is that the nuclei of mature granule cells constitute a homogeneous population in terms of morphometric and stereologic data; in fact, the volume density of condensed chromatin within the nuclei remains practically constant in all nuclear sections. These results seem to indicate the existence of a cell-specific nuclear morphometric phenotype which might be considered as an effective criterion for the typification of this cellular lineage.

ISSN:1422-6405    

DOI:10.1159/000146972

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The muscular system, the connective tissue and the bones are the components of a biomechanical pelvis-lower extremity model. The occasional electrical events in the muscles were not taken into account, as they can only be measured by physiological methods. In this publication, the connective tissue of the lower extremities is examined. The connective tissue system of the thigh and leg was prepared; after removal of the muscles the so-called ‘hollow’ lower extremity could be studied. A topographical documentation followed, and the structure and directions of the fibers were observed with polarized light. The connective tissue systems of the lower extremities and bones form a biomechanical effective and functional system, the bone-fascia-tendon system. The components of the connective tissue in such a system are the fascia lata, the crural fascia, the iliotibial tract, the femoral and crural intermuscular septa, and the membrana interossea. The iliotibial tract is not the sole part of this system having a tension band effect, other components – above all the lateral femoral intermuscular septum – also reduce the forces acting on the bones. Therefore, the tensile strength of the iliotibial tract has to be considered lower as supposed. The iliotibial tract is not a part of the fascia lata; it is an independent, vertically tightened tendon of the ‘pelvic deltoid muscle’ (gluteus maximus, tensor fasciae latae). The iliotibial tract passes over the greater trochanter like on a roller bearing. It is not attached directly to the greater trochanter and to the lateral femoral condyle, so that previous models have to be modified. The iliotibial tract glides in a fascia bag which is composed of oblique and horizontal fibers of the broad fascia. The iliotibial tract, as tendon of the pelvic deltoid muscle, continues in a lateral location into the leg where it is fixed to the lateral malleolus. The present report provides a new description of the structure of the connective tissue system of the lower extremities. The model reported complies with the laws of similarity mechanics by describing exactly the geometric, physical and functional conditions. This representation could facilitate the construction of a computer-aided, efficient, biomechanical model of the pelvis-lower extremity region considering also the complex functional circumstances, in contrast to previous models. In order to construct such a model the data obtained by the examination of the connective tissue of the lower extremities have to be given into a data bank, which, however, has to

ISSN:1422-6405    

DOI:10.1159/000146973

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The proximal portions of axons of large anterior-horn cells were investigated in the lumbar cords of 10 normal human autopsy cases. Light-microscopically, 81 myelinated axons were observed to be connected with the cell body. Of the 81 axons, 78 emanated from the cell body and 3 others originated in the proximal part of primary dendri-tes. As for normal-looking neurons (n = 77), the length of the axon hillock plus initial segment was 64.0 ± 12.3 µm (average ± SEM) ranging from 47.5 to 110.0 µm, while the diameter of the thinnest portion of the initial segment was 2.40 ± 0.30 µm (average ± SEM), ranging from 1.32 to 3.92 µm. Electron-microscopically, the predominant organelles of the axon hillock were mitochondria, neurofilaments which merged into the axon and occasional granular endoplasmic reticulum. A few synaptic boutons were found on the surface of the axon hillock. The cell membrane of the initial segment consisted of a layer of electron-dense material (undercoating). The cytoplasm contained many neurofilaments, running parallel to the longitudinal axis of the initial segment. Among the neurofilaments, lysosomes, smooth endoplasmic reticulum, dense bodies and vesicular profiles as well as mitochondria were seen. At the beginning of the myelin sheath, the axoplasm contained mitochondria, many neurofilaments and occasional ly

ISSN:1422-6405    

DOI:10.1159/000146974

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The plane between longitudinal and circular muscle of human colon, as revealed on examination with light and electron microscopes, has no clear-cut border. Some groups of smooth muscle cells, obliquely oriented and with features similar to both circular and longitudinal ones – the connecting muscle bundles – run from one muscle layer to another. Other groups of smooth muscle cells, possessing their own specific ultrastructural features – the myenteric muscle sheaths - make up envelopes of variable thickness around some myenteric ganglia and nerve strands, partially or completely embedding them in one or other muscle layer. Non-neuronal, non-muscular cells (interstitial cells of Cajal, covering cells, fibroblast-like and macrophage-like cells) complicate the texture of the myenteric muscle sheaths, creating an intricate, interconnected cellular network inside them, widespread among nerve bundles and smooth muscle cells; however, only interstitial cells have cell-to-cell junctions also with the smooth muscle cells and nerve endings. These data document the existence in this colonic area of two different types of muscle cell arrangements, one of which, the myenteric muscle sheath, only contains putative pacemaker

ISSN:1422-6405    

DOI:10.1159/000146975

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The ventral sebaceous gland of the Djungarian hamster is a macroscopically visible organ situated in the midventral area of the abdominal wall. It consists of densely packed acini arranged in lobules with common excretory ducts. The rich vascular network of the gland is characterized by fenestrated capillaries. Fenestrated endothelium has not yet been reported as a characteristic and regular finding within sebaceous glands. Results are discussed with regard to proliferation rate of sebocytes and the demand of fluid and nutrient supply.

ISSN:1422-6405    

DOI:10.1159/000146976

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

It has been found previously under the light microscope that there was a circadian variation in mast cell number in the pinna of mice. The mast cell number was increased at 18.00 h and decreased at 06.00 h. In the current study, 5 mice of each group were synchronized for 4 weeks with a standard lighting regimen (light: 06.00–20.00 h; dark: 20.00–06.00 h). Both pinnas of every mouse of each group were removed at 06.00, 12.00, 18.00 and 24.00 h, respectively. Under the electron microscope, it was observed that more degranulated mast cells were found at 06.00 h and more intact mast cells were visible at 18.00 h. It appeared that the mast cell numbers decreased and increased under the light microscope, were due to mast cell degradation and re granulation. This finding suggests that a functional circadian variation exists in the mast cell under physiological conditi

ISSN:1422-6405    

DOI:10.1159/000146977

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The relations between the saccus lacrimalis and different portions of the musculus orbicularis oculi were studied in orbital regions of human fetuses sectioned into numbered series. No insertions of the pars lacrimalis or Horner’s muscle on the saccus were found. These muscular fibres pass along the dorsal wall of the saccus and are separated from it by the reflex tendon of the ligamentum palpebrale mediale. The only muscular fibres that insert on the saccus are those that approach the anterior face of the saccus and the fornix. The fibres that insert on the anterior face proceed from the deep bundles of the pars preseptalis of the lower eyelids, and those that insert on the fornix derive from the deep bundles of the pars preseptalis of the upper eyeli

ISSN:1422-6405    

DOI:10.1159/000146978

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The bovine ejaculatory duct is lined by a pseudostratified columnar epithelium. Two cell types are present: small basal cells and columnar principal cells in different functional states. The basal cells are able to accumulate lipid material. The principal cells are observed in a less active state and in a state of either increased endocytosis and fluid uptake or active spermiophagy. Endocytotically active cells are characterized by an apical brush border and a system of micro vesicles, multivesicular bodies and lysosomal dense bodies. Cells involved in phagocytosis of spermatozoa are mostly provided with a smooth apical border, an expanded Golgi apparatus, many phagocytic vacuoles and condensing phagolysosomes.

ISSN:1422-6405    

DOI:10.1159/000146979

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The synthesis of prostaglandins (PGs) in the mucosa of the esophagus is studied in 20 albinotic adult guinea pigs and rats using the radioimmunoassay method. Both species investigated synthesize five PGs. The PG synthesis activity in the guinea pig’s esophagus is higher than that in the rat’s. PGE2 and PGF2α might be involved in the regulation of lower esophagus sphincter pres

ISSN:1422-6405    

DOI:10.1159/000146980

出版商:S. Karger AG    

年代:1990

数据来源: Karger