摘要:

The interaction of cytotrophoblast with maternal endometrium, especially endometrial blood vessels, was examined in macaque gestational stages between 2 and 8 days after the onset of implantation. Serial sectioning of these early implantation sites allowed immunostaining of consecutive sections with a number of different antibodies, facilitating cell identification. In the earliest implantation site, immunostaining showed that antibody to cytokeratin stained cytotrophoblast, syncytial trophoblast, epithelial plaque and endometrial gland cells. However, only those cytotrophoblast cells near the maternal-fetal border and within vessels showed surface staining for neural cell adhesion molecules and only syncytial trophoblast showed SP1 reactivity. Even at this early stage cytotrophoblast filled the lumen of superficial arterioles, whereas dilated venules contained only a few cytotrophoblast cells. In later stages endovascular cytotrophoblast not only plugged many spiral arterioles but also migrated into the walls of these arterioles, and progressed into deeper coils. Displacement of endothelial cells and disruption of vessel walls were illustrated with antibody to factor VIII, TGFoc, and desmin. Clusters of cytotrophoblast cells at the fetal-maternal interface tended to bypass clusters of epithelial plaque cells and larger clusters of maternal fibroblasts, but readily entered all vascular spaces. Consequently the vascular system constituted a major pathway of invasion, although the arterioles were the only component substantially invaded beyond the trophoblastic-shell/endometrial border.

ISSN:1422-6405    

DOI:10.1159/000147800

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The sequential expression of smooth muscle and epithelial markers in the rat bladder has been defined. Smooth muscle differentiation, based on cell morphology and immunohistochemical localization of smooth muscle oc-actin, myosin, vinculin, desmin, vimentin and laminin, begins at 16 days of gestation (birth = 22 days) in the rat bladder. Smooth muscle cell differentiation begins in the periphery of the bladder mesenchyme immediately subadjacent to the serosa and continues toward the urothelium. The cytokeratins 5, 7, 8, 14, 18, and 19 are expressed in the bladder epithelium as a function of developmental age with cytokeratin 7, 8, 18, and 19 being coexpressed at 15 days’ gestation followed by cytokeratin 5 at 17 days’ gestation and cytokeratin 14 in the newborn bladder. An understanding of the ontogeny of both smooth muscle and epithelial differentiation markers in the normal bladder will allow us to study events that occur in the diseased blad

ISSN:1422-6405    

DOI:10.1159/000147801

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The relation of the testis/testosterone with the structure and function of the mammalian parotid gland has so far been poorly investigated. The present study deals with the morphology of the rat parotid gland and its changes after orchiectomy and testosterone substitution. The glands of control and experimental animals (orchiectomized and orchiectomized with testosterone substitution) were analyzed by electron microscopy and stereology. In orchiectomized animals 30-60 days after castration, a significant reduction of the volume of the acini and the duct system as well as a significant increase of the connective tissue volume per cubic millimeter of the gland were noted. The volume and length of the intercalated and the striated ducts per cubic millimeter of parotid tissue are significantly reduced 45-60 days after orchiectomy. Excretory ducts seem to be unaffected by orchiectomy. The structure of the rat parotid acini is also changed by castration, indicating a reduction of acinar-cell activity. In controls, the volume of acinar cells with wide cisternae of rough endoplasmic reticulum is 3 times larger than the volume of acinar cells with regular and narrow cisternae of rough endoplasmic reticulum. After orchiectomy, the volume of acinar cells with wide cisternae of rough endoplasmic reticulum is significantly decreased, while the volume of acinar cells with regular and narrow cisternae of rough endoplasmic reticulum is significantly increased. Exogenously given testosterone can prevent or alleviate the mentioned effects of orchiectomy on the gland. It is concluded that orchiectomy affects the rat parotid gland, demonstrating the existence of an interaction between the testis and the mammalian parotid gland.

ISSN:1422-6405    

DOI:10.1159/000147802

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The effect of distal axonal injury on the soma-dendritic morphology of intrinsic central neurons was examined using adult rat lumbar spinal cord-projecting rubrospinal neurons as a model. The soma-dendritic morphology was revealed using an improved Golgi-aldehyde method. Impregnated neurons were reconstructed in the two-dimensional plane for analysis. Four weeks after axotomy, neurons had reduced soma sizes and remained multipolar in shape. Some dendrites were found to end not far from their cell bodies. In addition, no long dendrite was identified following axotomy. Sholl’s analysis [The Organization of the Cerebral Cortex. London, Methuen, 1956] revealed that axotomized neurons had fewer dendritic branches than control neurons. Total dendritic length was also reduced. Subsequent analyses showed that the average number of dendritic trunks was not altered however the mean number of terminal branches per dendritic trunk was reduced. The dendritic membrane of the normal neurons was usually smooth with occasional short protuberances on the proximal dendrites and spines on the distal dendrites, which did not change after axotomy. In control neurons, we identified an elaborate type of dendritic structures named dendritic appendage aggregates. These aggregates were located preferentially on terminal dendrites and were classified into three categories according to their complexity. The incidence of occurrence for these aggregates decreased following distal axotomy. These phenomena indicate that rat lumbar spinal cord-projecting rubrospinal neurons retract their distal dendrites in response to distal axotomy. The observed anatomic restructuring following axonal injury is likely to be accompanied by an alteration of afferents which normally synapse on distal dendrite

ISSN:1422-6405    

DOI:10.1159/000147803

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A quantitative light-microscopic analysis of the ventral and dorsal roots at the C8 and L4 segments of the spinal cord was made in the opossum, Monodelphis domestica, to evaluate the number of myelinated fibers and their class distribution, and will serve as a baseline to a study of myelinogenesis in that species. In male opossums, the C8 ventral root comprises an average of 595 myelinated fibers (70.3% a:29.7%y), and the dorsal root 1,124 fibers (29.4% type I: 41.2% type 11:29.4% type III). The L4 ventral root has an average of 831 fibers (57.9% a:42.1%y), and the dorsal root 2,079 fibers (17.4% type 1:44.7 type II: 37.9% type III). The females have less fibers but their size and class proportions are comparable to those of the males. These data are discussed in relation to peripheral innervation and are compared to those reported for the rat and the cat.

ISSN:1422-6405    

DOI:10.1159/000147804

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The effect of altered masticatory muscle function on bone mass at different sites in the rat mandible was studied using aluminium as a reference substance in computer-assisted image analysis. Forty-two growing male rats were divided into three groups, of which one group was killed at the beginning of the experiment to provide baseline values. Of the remaining two, one received a hard diet (control group) and the other a soft diet. After 28 days the rats were killed and the mandibles were excised. Lateral radiographs were taken of the mandible halves together with an aluminium stepwedge and then analysed by an image analysis system. Radiographic bone mass was measured in the transverse plane as ‘aluminium-equivalent thickness’ in millimetres. Standardized areas were chosen to investigate regions with different functional demands. Significant differences were found between the groups in the alveolar bone of the molars and the incisor, as well as in the condylar costa and the condylar process. Significant differences were also found in some areas related to muscle insertion, such as the anterior lower border of the ramus, whereas no statistically significant differences could be found in others, such as the posterior lower border of the angular process. In conclusion, altered masticatory function influences the amount of bone mass in certain parts of the mandible, where changes in applied bending forces have possibly altered the bone str

ISSN:1422-6405    

DOI:10.1159/000147805

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The skeletal maturation of the upper limb distal segment was studied in 239 Spanish boys and girls between birth and 14 years of age. The atlas of Greulich and Pyle, offering standards of skeletal development of white North American children, was used as reference. The results obtained show firstly that in absolute terms, the ossification process is earlier in girls than in boys. This difference is maximum between 5 and 11 years of age. The boys show a delay of around 3 months with respect to their North American opposites. The girls, in contrast, show a better fit to the corresponding (female) standard of the atlas. In general, the highest agreement between bone age and chronologic age is for the ossification centers of the distal epiphysis of the ulna and radius and for those of the metacarpal bones. At the level of the carpus, individual analysis of the ossification centers shows that the capitate and hamate bones in the girls evolve most in accord with chronologic age. At the other extreme, and in both sexes, the ossification centers of the trapezium and trapezoid bones are statistically furthest from chronologic age.

ISSN:1422-6405    

DOI:10.1159/000147806

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Variations of the arterial and venous pubic anastomoses (APA, VPA) were studied. Forty-four percent of the APA were replaced by an obturator artery arising from the inferior epigastric and 25% by an obturator artery arising from the external iliac. Seven percent of the VPA were replaced by a single obturator vein, 37% by the superior companion of a double obturator vein, and 2% by a double obturator vein. Black South African subjects exhibit a higher incidence of variations of the pubic anastomoses than North American, European and Japanese populations.

ISSN:1422-6405    

DOI:10.1159/000147807

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

While dissecting 88 lower limbs, a distal division of the sartorius muscle was detected in one of the specimens. The larger posteromedial portion was found to take a normal course to the so-called superficial pes anserinus. The thinner anterolateral portion attached to the medial meniscus anteromedially. The smaller anterolateral part approached the medial meniscus anteromedially, pushing the synovial membrane into the joint. Its meniscal attachment ensures that the medial meniscus is stabilized in its primary position during bending and external rotation in the knee joint, thus preventing its herniation or injury during sudden extension. The accessory part of the sartorius muscle thus acts as a protector of the medial meniscus.

ISSN:1422-6405    

DOI:10.1159/000147808

出版商:S. Karger AG    

年代:1996

数据来源: Karger