摘要:

The profiles of the neurosecretory granules were measured in the supraoptic nucleus and in axons, swellings and endings in the neurohypophysis. This was performed after the secretion of vasopressin had been fully suppressed by water load for 1.5, 2.5 and 24 h, after the secretion had been stimulated by water deprival for 72 h and in normal rats with water ad libitum. A finite-difference algorithm was used for unfolding the size distribution of neurosecretory granules from the observed profiles, and showed a clear grouping of the neurosecretory granules into 3 size groups: small, medium-sized and large granules. Estimates of the relative volumes of the granules from these 3 groups were combined with previous results. In the supraoptic nucleus, water deprival increased the total volumes of the small and medium-sized granules, and water load decreased the volumes of the medium-sized and especially the large granules. However, in the neurohypophysis, water deprival decreased and water load increased the volume densities of the small and medium-sized, but did not influence that of the large granules. The results indicate that the medium-sized granules are vasopressinergic and the large oxytocinergic. Moreover, the results are consistent with the hypothesis that the small contain another peptide.

ISSN:1422-6405    

DOI:10.1159/000146557

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Promethazine HCl (Phenergan) was added to the drinking water (2.4–9.6 mg/kg/day) of castrated adult male Holtzman rats. One group of castrates and a group of normal rats received no drug and served as controls. Treatment was started at castration and continued for 4 months. After controlling for body weight, analyses of covariance and Student-Newman-Keuls tests revealed that promethazine did not prevent the development of femoral osteoporosis in the castrate rats. However, control rats (normal and untreated castrates) had significantly wider femora and thicker cortices at midshaft than did promethazine-treated animals. The results indicated that promethazine HCl had no effect on the development of femoral osteoporosis and retarded normal femoral expansion in the adult castrate male rat

ISSN:1422-6405    

DOI:10.1159/000146558

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

We investigated the ultrastructural localization of calcium in progenitor predentine and preodontoblasts of developing rat molar tooth germs using the potassium pyroantimonate technique. At the precalcification stage, antimonate reaction product was sparsely, randomly distributed in the preodontoblasts and in the progenitor predentine but no significant reaction could be noticed associated with matrix vesicles. At the matrix vesicle calcification stage, large amounts of antimonate reaction product tended to be localized in the region adjacent to the distal, outer surface membrane of preodontoblasts in which moderate antimonate reaction activity could be observed in mitochondria. Strong antimonate reaction was detected preferentially on the outer surface membrane of some matrix vesicles at this stage. At the subsequent collagen calcification stage definite antimonate reaction was no longer seen within mitochondria of the late preodontoblasts, instead precipitate was mainly distributed in Golgi area, secretory granules and lateral intercellular spaces. It is suggested that although matrix vesicles contain few calcium capable of reacting to antimonate immediately after their biogenesis, subsequently, large amounts of calcium are accumulated associated with the outer surface membrane of matrix vesicles in the extracellular matrix.

ISSN:1422-6405    

DOI:10.1159/000146559

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The spatial arrangement of the muscular, elastic and collagenous fibers was examined in 20 splenic veins of adult humans. Histologic and panorganographic sections were stained by the following methods: azan, resorcin-fuchsin (Weigert) Verhoeff-van Gieson’s stain and Masson’s trichrome. Unstained sections were examined under polarized light. The results show that the muscular and collagenous fibers of the splenic vein exhibit an elongated spiral arrangement with no polarization. The elastic fibers form a threedimensional network disposed predominantly in a longitudinal direction. Hemodynamics are discussed based on the spatial structure of the muscular, elastic and collagenous elements of the vein wall and its relationship with the circulatory functions of the spl

ISSN:1422-6405    

DOI:10.1159/000146560

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The cranial base and whole mandible of 7-day-old mice were cultured for 1 or 2 weeks in a novel organ culture system that provided an articulating movement for the temporomandibular joints. The mandibles were articulating either in a closed or in an open position to simulate the in vivo mouth-breathing pattern. The reactions of the condylar processes were followed macroscopically and microscopically after osteoid or von Kossa staining. After 1 week of culture, small differences were found in the shape of the condylar processes between the two groups. After 2 weeks, significantly increased growth was observed superiorly in those condyles which had been working in a closed position and posteriorly in the condyles which had been working in an open position. Histologic analysis revealed that after 1 week calcification had proceeded faster in the posterior aspect of the condyles in the mandibles which had been working in a closed position as compared to the mandibles which had been working in an open position, and the difference was even more marked after 2 weeks. In the latter condyles calcification had proceeded markedly in the anterosuperior aspect. Osteoid staining showed that perichondrial mesenchymal cells had differentiated into osteoblasts in the posterior aspect of the condyles in those mandibles which had been working in a closed position. This led to a ceasing of expansive growth in the posterior aspect and thus to a more upwardly directed condylar growth. In mandibles which had been working in the open position to simulate the mouth-breathing pattern in vivo, chondrogenesis and thus expansive growth continued in the posterior aspect, leading to a more posteriorly directed condylar growth. We tried to simulate in a novel organ culture system the in vivo functional pattern where the mandible is lowered anteriorly as, for instance, in association with mouth-breathing.This led to a more posteriorly directed condylar growth as compared to control mandibles which had been functioning in a more closed position.The histologic findings after osteoid staining support the assumption that the differentiation of the mesenchymal cells in the anterior and posterior aspect of the condyle either into osteogenic or chondrogenic cells, depending on the position of the condyle in the fossa, has a role in the adaptive mechanism. The differentiation seems to be regulated by maturation of the cartilage which further is regulated by articulating function.

ISSN:1422-6405    

DOI:10.1159/000146561

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The mechanical papillae of the horse and cow were studied by scanning electron microscopy in order to determine their morphostructural characteristics and the differences between the two species.The horse has only thin, small and interlaced filiform papillae, while the cow shows robust and more ordered filiform papillae. Furthermore, the cow tongue presents conical and lenticular papillae surrounded by a papillary groove. A characteristic distribution of stratified scales and channeled tracts is observed in conical and lenticular papillae but not in the filiform papillae. The morphostructural features of each papilla are analyzed and compared in each species and their possible significance is discussed.

ISSN:1422-6405    

DOI:10.1159/000146562

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

This study of the Black bear (Ursus amerícanus) was undertaken to provide basic information related to structural modifications in the renal microvasculature that might provide insight into the drastic alteration in renal urinary output that occurs during winter sleep. Vascular casts, as well as light microscopy and scanning electron microscopy, were used to study the vascular components of the juxtaglomerular complex and related vessels. Histologically, arterial cushions were readily identified at the origin of the afferent arterioles. In the area of the juxtaglomerular complex, the wall of the afferent arteriole appeared to be highly modified. The smooth muscle cells at this site demonstrated a change in morphology and orientation, and the diameter of the arteriole was altered. The pattern of the vascular casts at the origin of the afferent arteriole varied from that portion at the glomerulus, suggesting a modification of the vascular wall near the renal corpuscle. Although the morphology of the renal microvasculature of the Black bear is similar to that of other mammals in some aspects, it is dissimilar to that of other carnivores and of the human kidney in that there are structural modifications of the afferent arteriole that may contribute to a reduction of blood flow to the nephron during winter sleep

ISSN:1422-6405    

DOI:10.1159/000146563

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In the epithelium lining the nasopalatine duct of the infant mouse, a transitional zone between the stratified squamous epithelium and the ciliated columnar one can be observed. The epithelium lining the transitional zone shows gradations ranging from the stratified squamous through the stratified cuboidal to the ciliated stratified low-columnar type, and gradually transforms into the stratified squamous epithelium with advancing ages. In the adult mouse, the nasopalatine duct is lined with the stratified squamous epithelium throughout up to the vicinity of the nasal cavity, and changes abruptly into the ciliated columnar epithelium lining the nasal cavity. It is suggested that the epithelium lining the transitional zone is identical with the ‘intermediate epithelium’ in the mouse nasopharynx and epiglot

ISSN:1422-6405    

DOI:10.1159/000146564

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

145 women showing clinical and radiological signs of involutional osteoporosis of the spine were biopsed at the ilium for histomorphometric analysis of bone mass including trabecular bone volume and parameters reflecting the spatial distribution of bony elements (mean trabecular plate thickness, density and separation). Results were compared with an age-matched population of 22 healthy females. Postmenopausal osteoporotics (i.e. younger than 75 years) were characterized by a significant reduction in trabecular bone volume, plate density and thickness, while senile osteoporotics (i.e. older than 75 years) did not exhibit any difference with controls. 51% of the osteoporotic patients had a trabecular bone volume higher than the spontaneous vertebral crush threshold defined by Meunier. Osteoporotic patients with trabecular bone volume under the vertebral crush threshold had a significant decrease in all trabecular parameters. On the opposite, patients with trabecular bone volume above the vertebral crush threshold had only a significant decrease in the number of trabeculae. A negative correlation was found between age and plate density in both osteoporotic patients and controls. Alinear correlation was found between trabecular bone volume and plate density, but thickness and density of trabecular plates were not correlated. This study confirms that involutional osteoporosis is not only a decreased bone mass disorder. A modified spatial distribution of trabeculae or a«mechanically less resistant bone matrix could be additional factors

ISSN:1422-6405    

DOI:10.1159/000146565

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Several works have concerned themselves with the anatomy of the supraventricular crest, for example, analyzing its role in the physiology of the right ventricle; nevertheless, its structure and arterial supply have been less studied. We have studied the morphogenesis of the architecture and the arterial supply of the supraventricular crest, in 25 embryos and human fetuses of 13–71 mm crown-rump length. The muscular organization of the crest (proper muscular bundles and parietal bundles of the right ventricle) and the development of the supraventricular crest’s artery as well as its trajectory and its distribution during the fetal period were exami

ISSN:1422-6405    

DOI:10.1159/000146566

出版商:S. Karger AG    

年代:1988

数据来源: Karger