摘要:

This report describes the prenatal development and closure of the secondary palate in the Mongolian gerbil. Palatal shelves can be regularly observed on day 16, at which time they are directed vertically. On day 17, the shelves show an overall increase in size and length but remain vertically directed. During day 18, palatal shelves are usually in a state of transition from the vertical to the horizontal position. The process of palatal closure (fusion) occurs on the 19th day and is complete by day 20. The process of palatal formation and closure in the gerbil more closely resembles that of the rat and rabbit than that of the mouse.

ISSN:1422-6405    

DOI:10.1159/000144765

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The extensor digitorum longus muscle of the rat was denervated and transplanted onto the vastus lateralis muscle of the same limb 1 or 2 weeks after denervation. The morphological changes appearing after transplantation were examined by light and electron microscopy. Only three to four superficial layers of muscle fibres remained unchanged after transplantation. The other parts of the transplanted muscle degenerated nearly entirely during the first 10 days. The myofibrils were removed by macrophages, thus within the tubes of basal lamina no contractile material could be observed. In a second period, regeneration of myofilaments took place. 6 weeks after transplantation, newly formed muscle could be observed, capable of normal function. The diameter of the fibres, however, was smaller and the connective tissue between the fibres markedly increased as compared to the normal muscle of the other side. The importance of the findings for muscle transplantation, especially the relationship between satellite cells and myoblasts, is discussed.

ISSN:1422-6405    

DOI:10.1159/000144766

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Age-related changes in the number of cartilage cells within the proximal growth plate of the humerus were determined in normal ICR male mice. The rates of reduction in the number of proliferative and hypertrophic chondrocytes were calculated and compared during the animals’ first 6 months of life. It was found that during the period of highest growth activity, between weanling and sexual maturation, the rate of cell production is hardly decreased, thus maintaining the thickness of the cartilaginous growth plate and thereby enabling an extensive bone growth. A close correlation was found between the following skeletal activities: decrease in longitudinal bone growth, narrowing of the epiphyseal growth plate and a decrease in the proliferative activity of young chondrocyte

ISSN:1422-6405    

DOI:10.1159/000144767

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000144768

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000144769

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000144754

出版商:S. Karger AG    

年代:1977

数据来源: Karger