Biological structures and morphogenesis最新文献_第6页

The irradiated epidermis inhibits newt limb regeneration by preventing blastema growth. A histological study. 照射过的表皮通过阻止胚泡生长抑制蝾螈肢体再生。组织学研究。

Biological structures and morphogenesis Pub Date : 1988-01-01

E Lheureux, F Carey

{"title":"The irradiated epidermis inhibits newt limb regeneration by preventing blastema growth. A histological study.","authors":"E Lheureux, F Carey","doi":"","DOIUrl":"","url":null,"abstract":"It has been established that X-ray irradiation localized to a forelimb or entire irradiation of premetamorphic Pleurodeles larvae prevented limb regeneration. Transplantation of non-irradiated skin, dermis or muscle to limb stumps of locally irradiated newts was sufficient to allow a blastema to develop. Transplantation of the same tissues to limb stumps of entirely irradiated newts yielded different results with the different graft types. Skin graft allowed a normal blastema to be established but dermis or muscle grafts did not. In order to define more precisely the role played by the epidermis in the establishment of a blastema, and in the growth of a regenerate, different combinations of limb tissues, either irradiated or not, were carried out at the level of amputated limb stumps. At four different times (8-10 days; 13-15 days; 20-23 days; 30 days or more) after amputation the stumps were examined in histological longitudinal sections to study the first events of regeneration, that is dedifferentiation and growth. Dedifferentiation occurred in both normal and irradiated tissues of mesodermal origin. The healthy mesenchymal cells began dividing and formed a growing blastema only when associated with a non-irradiated epidermis. Healthy mesenchymal cells covered with an irradiated epidermis exhibited a few mitoses after dedifferentiation, but the mitotic figures became rarer and rarer until the animals died. The lack of dense accumulation of blastemal cells in such limb stumps suggested that the healthy epidermis allows the mesenchymal cells to divide actively to constitute a growing blastema. Hence, X-ray irradiation seems to be responsible for the loss of such an epidermal mitogenic influence on the underlying mesenchymal cells.","PeriodicalId":77037,"journal":{"name":"Biological structures and morphogenesis","volume":"1 2","pages":"49-57"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14176845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Immunolocalization of matricial components during the early stages of chick embryonic liver development. 鸡胚肝发育早期材料成分的免疫定位。

Biological structures and morphogenesis Pub Date : 1988-01-01

C M Barioz, P Sengel, J A Grimaud

{"title":"Immunolocalization of matricial components during the early stages of chick embryonic liver development.","authors":"C M Barioz, P Sengel, J A Grimaud","doi":"","DOIUrl":"","url":null,"abstract":"In the chick embryo, the first liver primordium is observed at the end of the second day of incubation. At 3 and 4 days, ultrastructural analysis of the primitive vascular spaces showed that the endothelial limiting plate was constituted by one or several cell layers. At the vascular pole of the hepatoblasts, mesenchymal cells and connective matrix, present as fibrillar and non fibrillar components, were closely associated. At 5 days, some vascular spaces were limited by a simple endothelial layer. The limiting plate was fenestrated and the connective matrix was reduced to rare collagen fibrils and fibers. Collagen types I, III, IV, procollagen type III, fibronectin and laminin were visualized in the perivascular spaces using immunoperoxidase labeling methods. These components were also detected in the endoplasmic reticulum of hepatoblastic, endothelial and mesenchymal cells. All these appeared to be involved in connective matrix synthesis. Comparing 4 and 5 days, we demonstrated that the number of cells showing intracellular labelling of matricial components dropped dramatically at 5 days, indicating a possible decrease of connective matrix synthesis. Quantification of parenchymal and vascular surfaces was carried out using a semi-automatic image analyzer on consecutive parasagittal sections chosen in the axial part of the embryonic liver. These measurements were performed in order to quantitate the vascular distribution pattern during early development of the liver. These combined immunomorphological studies and morphometrical analyses suggest that during embryogenesis of the liver the synthesis of connective matrix precedes and possibly initiates the vascular differentiation.","PeriodicalId":77037,"journal":{"name":"Biological structures and morphogenesis","volume":"1 1","pages":"3-14"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14526317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Origin of the iris sphincter muscle in chick embryo. 鸡胚虹膜括约肌的起源。

Biological structures and morphogenesis Pub Date : 1988-01-01

L Sisto Daneo, G Corvetti, G Filogamo

引用次数: 0

Topography and microscopical configuration of the corpus striatum of the dog. 狗纹状体的地形和显微结构。

Biological structures and morphogenesis Pub Date : 1988-01-01

I Salazar, P Ruiz Pesini, P Fernandez Alvarez, J Gonzalez Soriano

引用次数: 0