摘要:

A technique is described for finding the pineal body of the dog. The posterior half of the skull is cut a little behind the parietofrontal suture, through the occipital condyles. The cerebral hemispheres and cerebellum are carefully sliced, disclosing the pineal at the frontal edge of the colliculi. Two types of cells are present, those with completely round nuclei, and others with vesicular and variably shaped nuclei. In the histological pattern, ependymal cells were observed on the edges, pinealocytes and glial cells within the gland.

ISSN:1422-6405    

DOI:10.1159/000146014

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The present work describes the presence of some photoreceptor nuclei in the embryonic and adult chick retina which are situated outside of the external limiting membrane. We also discuss their possible degenerative character.

ISSN:1422-6405    

DOI:10.1159/000146015

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effects of changes of progesterone concentration on 3H-uridine incorporation and on the volume or number of nuclear ribonucleoprotein particles of the rat endometrial epithelial cells are studied in vivo and in vitro. All progesterone treatments are carried out after estradiol priming and their results are compared with estradiol-treated controls sampled from the same uterus or the same pool of isolated cells. Progesterone induces the same changes, in the parameters studied, administered in vivo or in vitro. Nuclear volume undergoes small but significant increases between 1/2 and 8 h of treatment. The total number of extranucleolar ribonucleoprotein structures as well as the incorporation of 3H-uridine on non-nucleolar areas are also increased by progesterone treatments. However, the numerical density of perichromatin granules does not change during these experiments. The nucleolar volume and the incorporation of 3H-uridine in this structure are increased after an early diminution. These results indicate that progesterone induces small increases in the rate of transcription in the nucleolus and in non-nucleolar genes. The constancy of the density of perichromatin granules suggests that progesterone, in contrast to estradiol, does not affect the ratio transcription/transportation of RNA to the cytplasm.

ISSN:1422-6405    

DOI:10.1159/000146016

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Aminoglutethimide, a corticosteroid inhibitor, administered at a daily dose of 150 mg per kg body weight, showed a dramatic interference with ovarian histology in the rat. The drug caused thinning of the germinal epithelium and disruption of the layers of the follicular cells. It also resulted in the appearance of cytoplasmic vacuoles and distortion of follicle cell nuclei. In the corpus luteum, it caused shrinkage of the lutein cells, resulting in large spaces between the cords of cells. It also arrested immature follicles at various stages of their development. Our results indicate that aminoglutethimide, by modifying ovarian structure in the rat, interferes with the ovulation process.

ISSN:1422-6405    

DOI:10.1159/000146017

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effect of equivalent doses of insulin on the adrenal of both adult and neonatal rats was compared. Glycemia in treated adults dropped to one third of the control, in contrast to the neonatal rat values, which decreased to about one half. After insulin, a large percentage of adult chromaffin cells showed cytoplasmic degranulation and vacuolization. In contrast, a smaller percentage of cytoplasmic changes was seen in the adrenal cells of 4- and 7-day-old rats. In rats of 10 days of age, the percentage of modified cells was similar to the adults. The morphological changes in neonatal medullae were characterized by widening of the perigranular space and enlargement of the endoplasmic reticulum cisternae. No cytoplasmic vacuolization was seen. This response of neonatal rats to insulin may indicate immaturity of the adrenal chromaffin tissue and/or of the centers involved in the mechanism of hypoglycemia-catecholamine release.

ISSN:1422-6405    

DOI:10.1159/000146018

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Developmental features of thoracic intervertrebral discs and their association in the adult with other vertebral structures were investigated in four species. The human anulus fibrosus, nucleus pulposus, and intra-articular ligaments were compared to those of the fetal rhesus monkey, mouse, and kitten. Photomicrographs of transverse sections of intervertebral discs document the presence of intra-articular ligaments in fetuses of these four species. Both transverse and sagittal sections of kittens were used to identify the intercapital ligament as it differentiated from the dorsal part of the intra-articular ligament. Relatively frequent dorsal herniation of the thoracic nucleus pulposus in humans may be due to the vestigial nature of the human intra-articular ligament. Quadrupeds have well-developed intra-articular ligaments, which explains anatomically the paucity of dorsal protrusions of the nucleus pulposus into the vertebral canal in the thoracic region of the cat and mouse when compared to the human. The intra-articular ligament was closely associated with the developing prenatal mammalian intervertebral disc in the four species studied, and this relationship and its surgical importance are described.

ISSN:1422-6405    

DOI:10.1159/000146019

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The initial formation and further development of the intraneural blood vessel network in the tectum opticum of the chick from the 4th to the 14th incubation day have been analyzed and some quantitative data morphometrically recorded. Vessels have been filled by intracardial injection of India ink in vivo. As inferred from our previous investigations on the vasculogenesis of several districts of the central and peripheral nervous system in the chick embryo, also in the developing optic tectum growth and distribution pattern of the vessels seem to unfold step by step under the local influence of earlier occurring morpho-histogenetic processes of the corresponding neural substratum.

ISSN:1422-6405    

DOI:10.1159/000146020

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The constituents of the connective tissues around the capillary of the chick pecten oculi were examined electron microscopically by HCl-collagenase and HCl-elastase methods. The basal lamina like membrane below the endothelial cell of the pecten capillary was digested by collagenases I, II and IV and elastase, and may be a false basal lamina. The basal lamina of cells with pigment granules which surround the capillary was digested by collagenase IV and elastase, and contained type IV collagen. Fibrils between the basal lamina like membrane of the pecten capillary endothelium and the basal lamina of the cells with pigment granules were digested by collagenases I, II and IV, and elastase. Thus, these fibrils are composed of many kinds of collagen. Elastase may be responsible for the breakdown of most collagens as well as elastin.

ISSN:1422-6405    

DOI:10.1159/000146021

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

In most areas of the body, arteries and veins run close together, often sharing a common connective tissue sheath. One exception to this is observed in the brain, where arteries come in from the base and veins collect over the convexity. Classically the larger blood vessels are formed by three coats: intima, media, and adventitia. Leptomeningeal vessels are further reinforced by a monolayer of pial cells. In the guinea pig, however, above the corpus callosum we found a group of blood vessels (an artery and several veins) enclosed in a common leptomeningeal sheath. The artery arises at the confluence of the anterior cerebral arteries; the veins drain into the straight sinus. The epithelial nature of the sheath is evident by the close apposition of cell membranes, the presence of junctional devices, and the existence of a basal lamina. The ultrastructural features of this epithelium are similar to those of the arachnoid-dural membrane. Whether this peculiar vascular complex has any specific function needs to be investigated further.The presence of these vessels apparently ‘isolated’ within a leptomeningeal subcompartment may provide a suitable model to study vascular-extravascular-cerebrospinal fluid substance excha

ISSN:1422-6405    

DOI:10.1159/000146022

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Each neuronal type of the human claustrum is differently pigmented. This has been demonstrated by combining a transparent Golgi technique with the specific staining of lipofuscin deposits. One type of projection cells and four varieties of interneurons have been distinguished. In this study the percentage of these different neuronal types has been evaluated using preparations stained for both Nissl material and pigment deposits.

ISSN:1422-6405    

DOI:10.1159/000146023

出版商:S. Karger AG    

年代:1985

数据来源: Karger