摘要:

To investigate the development of the retinal layers, the eyes of mice with trisomy 19 have been examined by light microscopy between the 2nd and 15th postnatal day. The diameter of the eye, thickness of the entire retina and both relative thickness and nuclear density of each of the retinal layers have been measured and compared to those of chromosomally balanced control animals. Malformations of the eye, alterations of cell morphology or disturbed lamination can not be observed. Retinal differentiation of trisomy 19 mice is delayed by approximately two days. The development of all cellular constituents i. e. of both neuroectodermal and mesenchymal origin is retarded accordingly. The eyes of trisomy 19 mice are of reduced size. The relative thickness of each retinal layer follows a normal growth pattern; there is no indication for a selective impairment of the development of one particular layer. With the exception of the ganglion cell layer, nuclear densities of each retinal layer do not differ from those of control mice. The comparison of nuclear densities in the ganglion cell layer suggests that in trisomy 19 mice fewer postmitotic cells differentiate into mature retinal cells.

ISSN:1422-6405    

DOI:10.1159/000146486

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Anterior pituitary glands were homografted into the anterior chamber of the eye in female rats. The pituitary grafts survived and were well vascularized three weeks after the transplantation.The prolactin cells were morphologically active as shown by their well-developed Golgi complexes and granular endoplasmic reticulum and the exocytosis of secretory granules. The injection of dopamine into the common carotid artery of the graft-bearing rat rapidly suppressed the granule extrusion and then gradually induced a remarkable morphological atrophy in the prolactin cells.

ISSN:1422-6405    

DOI:10.1159/000146487

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Due to the translucency of the skin and underlying soft tissues, the external examination of near-term mouse fetuses can be extended to parts of the skeletal, visceral and vascular systems which are not taken into account in the protocols of teratogenicity tests. The importance of such visualization for improving the accuracy of such tests is discussed.

ISSN:1422-6405    

DOI:10.1159/000146488

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The length, total and cortical widths at midshaft, and robusticity of femora were measured in growing and mature male Holtzman rats. Analysis of covariance revealed significant differences in the regression coefficients (slopes) between young rats (1–4 months) and adult rats (5–16 months), indicating that, for a given increment in femoral length, young rats have a smaller increment in total femoral width than do adult rats. In addition, the results indicated that femoral expansion occurs in adult male Holtzman rats (5–16 months of age) without cortical thinning or loss of bone

ISSN:1422-6405    

DOI:10.1159/000146489

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

A case of asymptomatic congenital occlusion of the ostium of the coronary sinus is described. The myocardial venous drainage was maintained via a persistent left superior vena cava as well via ectatic, widened atrial veins of the dorsal wall of the left atrium. The study shows that complete ostial occlusion of the coronary sinus does not reduce cardiac venous drainage. The view of the literature allows a comparison with the comprehensive classification of coronary sinus anomalies.

ISSN:1422-6405    

DOI:10.1159/000146490

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Growth and remodelling of the first cervical vertebra were studied in the rat by means of biometry, vital staining (alizarin red S and oxytetracycline) and histology. The measurements showed a change in the ratio of the dorso-ventral to the transversal diameter in the lumen after obliteration of the dorsal synchondrosis.The pattern of labelling between the three segments of the vertebrae joined by synchondroses in the young animals indicated that expansion of the vertebral lumen took the form of a displacement of all three parts making up the bony ring. After closure of the dorsal synchondrosis the two ventral ones were still active and the lumen size increased more in the dorso-ventral direction than transversally. Alizarin red S and oxytetracycline tended to persist in the ventral part of the vertebra, while the staining almost disappeared from the dorso-lateral segment. Resting lines were found laterally to the ventral synchondroses in haematoxylin and eosin stained sections, but not in the ventral segment between the cartilages.The growth of the rat atlas is the result of an early rapid cartilage-mediated expansion of the vertebral lumen in conjunction with the growth of the spinal cord and at a later age mainly of a displacement of the ventral vertebral segment leading to the final form of the vertebra and its lumen.

ISSN:1422-6405    

DOI:10.1159/000146491

出版商:S. Karger AG    

年代:1988

数据来源: Karger