摘要:

It is.well established that the spinal cord of embryonic vertebrates induces sclerotomal somitic mesoderm to chondrify. We have investigated whether the spinal cord retains this inductive ability for the duration of the life of the avian embryo. Somites were isolated from embryos of H.H. stages 16 to 18 and either cultured alone in a medium which would not allow spontaneous chondrogenesis or cultured in direct contact with the spinal cord from embryos ranging in age between H.H. stages 33 and 44 (7½-18 days of incubation). Somites cultured alone did not chondrify. Somites cultured in contact with either the ventral surface of the spinal cord or with the ependyma of the spinal cord chondrified in virtually 100% of all culturesirrespective of the age of the donor embryo providing the spinal cord. The somites which were cultured in contact with the dorsal surface of the spinal cord did not undergo chondrogenesis. We conclude that the ventral spinal cord and the ependyma retain inductive ability through embryonic life and discuss the possible reasons for this

ISSN:1422-6405    

DOI:10.1159/000145111

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The carbohydrate content of the specific granules of atrial muscle cells has been confirmed by ultracytochemical and ultrastructural findings. The carbohydrate proteins of the granules seem to consist mainly of proteoglycans, probably with a great content of dermatan sulfate. Therefore, in mammals only the atrial muscle cells seem to retain postnatally the capability of embryonic heart muscle cells to synthesize proteoglycans. Secreted into the blood of the atria and atrial coronary vessels, they may bind lipoproteins of the blood serum, especially the atherogenic low-density lipoproteins. On the other hand, the antithrombotic effect of proteoglycans could be able to prevent a raised coagulability of the blood in the heart cavities caused by the beat of the heart cusps.

ISSN:1422-6405    

DOI:10.1159/000145112

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The morphology of musculus levator veli palatini in the 15-week fetus was analyzed using 30-µm subserial sections. The sample included 26 specimens, of which 9 each were sectioned coronally and sagittally while 8 were sectioned in the transverse plane. At this stage of development m. levator veli palatini takes a general attachment to the precursor of the petrous part of the temporal bone, and, in some cases, auxilary attachments to the auditory tube complex were also observed. At its origin, the muscle is located anterior to the tube. It then runs medially, passing beneath the auditory tube prior to entering the velum. As it nears the region of the lateral pharyngeal wall, a small fascicle trails posteriorly and inferiorly to the main muscle mass and occasionally runs into the upper margin of m. constrictor pharyngis superior. The levator muscle is more localized within the velum at this stage of development than it has been reported to be in the adult, being confined here to the central third of the soft palate. Most of the fibers of the muscle appear to form a sling within the central 20% of the velum, although some were seen to take attachment to loose connective tissue and the palatine raphe. Upon its entry into the velum, m. levator veli palatini is intersected vertically by bundles of both mm.palatoglossus and palatopharyngeus

ISSN:1422-6405    

DOI:10.1159/000145113

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Metabolic processes in the uterus damaged in different parts of its innervation were studied. The specificity of neurodystrophic processes in the uterus depends on the nature of the injury to its innervation. Combination of different methods of modern morphological analysis made it possible to reveal hypoplastic processes in all the layers of the uterus.

ISSN:1422-6405    

DOI:10.1159/000145114

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000145115

出版商:S. Karger AG    

年代:1979

数据来源: Karger