摘要:

The ACTH influence upon the thymus may be a reliable model for stress involution. In this case, the cortical lymphocytic depletion is accompanied by mast cell accumulation and increased caliber of the blood vessels. The blood-thymus barrier which has an active role in involution shows an enriched transport activity of the endothelial cells, great enlargement of the basement membrane, increased macrophage activity within the perivascular space with elevated values of acid phosphatase activity, and thickening of the fibrillar network. The epithelioreticular cells show plenty of vacuoles in their cytoplasm, the mitochondria undergo swelling processes, and their cristae are diminished. The ultrastructural data show that lymphocyte depletion is carried out by macrophage-mediated lymphocytolisis. But by counting the peripheral blood cells an earlier mechanism is revealed; i.e. migration through the enlarged but more permeable blood-thymus barrier. The epithelioreticular cells do not seem to have an active, direct implication in any of the phenomena.

ISSN:1422-6405    

DOI:10.1159/000145466

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Vasa deferentia of 20 human adult males and 8 children were divided into four portions (proximal, middle, distal and terminal) for histological, histochemical and ultra-structural studies. The epithelium of the adult vas deferens was formed of columnar and basal cells. Three types of columnar cells were observed: (1) principal cells with PAS-positive cytoplasmic granules (lysosomes); (2) dark or pencil cells with a dark cytoplasm and nucleoplasm and cytoplasmic lipid vacuoles, and (3) mitochondrion-rich cells with numerous mitochondria similar to those of principal cells. All these cell types showed stereocilia and irregular convoluted nuclei, some of them containing granular, PAS-positive intranuclear inclusions. Principal cells were the most frequent cell type in the proximal portion but their number gradually decreased along the length of the vas deferens, while the proportion of both pencil cells and mitochondrion-rich cells increased. The muscular coat comprised three muscular layers: (1) inner longitudinal, (2) middle oblique (circular in the distal and terminal portions), and (3) outer longitudinal. The functional significance of regional variations is discussed. The infant vas deferens showed a columnar cell type only. However, cells either with numerous lysosomes or with numerous mitochondria were occasionally found. No regional variations were observed in the infant vas.

ISSN:1422-6405    

DOI:10.1159/000145467

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

By preparing the corrosion cast of the splenic vein and its intrasplenic tree, venous segments have been observed in the spleens of buffalo and dog. The buffalo spleen showed the presence of two venous segments (a dorsal and a ventral) in 85% of cases and three (a dorsal, an intermediate and a ventral) in 15% of cases. The spleen of the dog revealed only two venous segments (a dorsal and a ventral) in all the specimens. The results are compared with descriptions available in the literature.

ISSN:1422-6405    

DOI:10.1159/000145468

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Freeze-fracture replicas of human adrenocortical cells revealed en face fractures (both P and E faces) of the cell surface to be classified into three patterns: (1) the fracture face with no microvillous projections; (2) the fracture face mainly with short microvillous projections which arise horizontally from the edges of the small cavity on the cell surface to form a flower bud-like configuration on the P face; (3) the fracture face mainly with varying-sized, longer microvillous projections which arise almost vertically from the cell surface and show no specific organization. The former two fracture faces were supposed to correspond to the plasma membranes facing the interstitium including pericapillary spaces, since they had no gap junctions and frequently appeared along sinusoidal capillaries. On the other hand, the latter fracture face seemed to be equivalent to the plasma membranes facing intercellular spaces, since it frequently showed gap junctional specialization of intramembranous particles and usually both the P and E fracture faces of plasma membrane on the same surface. En face fractures of these gap junctions were various in shape and size. Tight junctions and their complex form with gap junctions were not encountered. Cell organelles and the nucleus had more numerous intramembranous particles on the P fracture face than on the E fracture face.

ISSN:1422-6405    

DOI:10.1159/000145469

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The autonomic abdominal and pelvic nerve plexuses of the human female fetus, were studied by an in toto acetylcholinesterase method in order to obtain data on innervation of the ovaries, uterus, ureter and umbilical cord. The results of this study indicate that in the human fetus there is no anatomical evidence for the concept of a distinct regional nervous supply towards the organs of the abdomen and the pelvis. The ureteric nerve plexus contains small ganglia and the input for this plexus is found along the entire ureter. In the umbilical cord nerve plexuses were found along the blood vessels and urachus up to 30 mm from the umbilicus. The innervation of the skin does not continue in the superficial layer of the umbilical cord.

ISSN:1422-6405    

DOI:10.1159/000145470

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The authors performed an electromyographic study on behavior of the rectus abdominis and the external and internal oblique muscles on 20 young healthy male volunteers during the performance of many movements of the trunk in the standing and supine positions. Concentric needle electrodes were used in connection with a model Te-4, Teca electromyograph of direct recording on paper.

ISSN:1422-6405    

DOI:10.1159/000145471

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The fine structure of the striated muscle fibers of the cremaster of the guinea pig was studied using the cholinesterase technique and light and electron microscopy. Under light microscopy, isolated single muscle fibers showed two types of nerve endings: the first one presented elliptic or oval areas having digit-like structures inside, some of the borders of which were heavily stained. These fibers had only one end-plate. The second type presented elongated clear areas with most of the density located on the borders. Several nerve endings were apparent in these fibers. By electron microscopy, the former had large and numerous sarcolemmal foldings and these characteristics were also observed in unstained fibers. In the latter, the foldings were scanty or absent. At the ultrastructural level, the fibers having only one end-plate presented a regular array of fibrils with an abundant sarcoplasmic reticulum (‘Fibrillenstruktur’ type) in contrast to the multi-innervated fiber with an irregular distribution pattern of fibrils and a scarce sarcoplasmic reticulum (‘Felderstruktur’ type). The striated muscle fiber layer of the cremaster probably contains both fast and slow fibers. The possible functional role for the slow striated muscle fibers is di

ISSN:1422-6405    

DOI:10.1159/000145472

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The superior sagittal sinus and confluens sinuum of 27 fetuses and newborns ranging from postmenstrual intervals of 26–54 weeks were studied by scanning electron microscopy and histology. 26-week specimens showed oval depressions in the final portions of tributary veins to the sinus. Histologically there were arachnoid tissue clusters within the dural wall. The walls of the depressions were more irregular by the 30th week. Arachnoid villi were apparent by the 35th week and granulations were observed after the 39th week. The granulations increased in complexity as development proceede

ISSN:1422-6405    

DOI:10.1159/000145473

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The paper deals with the alterations in the size and functions of the endocrine glands in relation to the reproductive and the seasonal sexual activity of the male hedgehog. Results show that the seasonal variations in body weight, testis, adrenal and the thyroid follow the general pattern of most of the hibernating mammals. Histometric measurements of the seminiferous tubule, Leydig’s cells, thyroid follicles and the thyroid follicular epithelial cells also present an interrelationship in the seasonal cyclical activity with each other. This indicates that in Hemiechinus hormones fluctuate during the summer and winter months of the year or one can say that they are regulated seasonally thereby affecting the seasonal pattern of breeding. It has also been proposed that the cyclic activity of the endocrine glands is partly correlated with the hibernation of the animal and partly with the increased metabolic activity of the body incidental to the events of the annual cycl

ISSN:1422-6405    

DOI:10.1159/000145474

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Globule leucocytes are described in the tracheal epithelium of young and adult rats. They do not appear in newborn rats up to 4 weeks. Globule leucocytes migrate through the epithelium to be found free in the tracheal lumen. They seem to be retarded a certain time in the apical part of the epithelium. The inclusions of the globule leucocytes are divided into four types. The different steps in the formation and transformation process of these inclusions are suggested. The electron-dense content of the inclusions is digested by pepsin, indicating that they contain protein. This result is not conflicting with the opinion that the globule leucocytes should contain immunoglobulins.

ISSN:1422-6405    

DOI:10.1159/000145475

出版商:S. Karger AG    

年代:1981

数据来源: Karger