摘要:

Morphometric methods were used to study the nucleolar ultrastructure during the development of human blood monocytes into macrophages in suspension culture. Nucleolar volume (Vn), surface area (Sn), volume fraction within the nucleus (Vvn), surface-to-volume ratio [(S/V)n] and number of nucleolar profiles per section were measured in 20 healthy adults over a 6-day period, and the results examined using multivariate and univariate analyses of variance. Highly significant increases in Vn Sn and^vn occurred with no significant change in the number of nucleolar profiles per section; (S/V)n decreased during culture; no significant differences were found between male and female subjects. These nucleolar changes would be consistent with an increased protein synthesis during macrophage development. The results provide quantitative data against which changes in nucleolar morphology during macrophage development in disease states may be assessed.

ISSN:1422-6405    

DOI:10.1159/000146631

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Fetal rabbit skin between 10 and 26 days of gestation was observed by light and electron microscopy. The present study indicates that rapid epidermal differentiation, including the epidermal downgrowths as primordia of the hair follicles, is induced by aggregation of mesenchymal cells associated with growing capillaries beneath the epidermis. In addition, the transformation of these mesenchymal cells to vasoformative cells for rapid capillary growth is further evidenced by this study. Glycogen-storing cells in the periderm are most numerous between 15 and 18 days of gestation, but disappear almost completely by 20 days when a capillary network develops beneath the epidermis.This may imply an active involvement of the periderm in glucose uptake from the amniotic fluid during early developmental stages of the skin.

ISSN:1422-6405    

DOI:10.1159/000146632

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

There is considerable controversy in the literature concerning the topography of the parathyroid glands in the calf. In the present study, the position of the parathyroids III (external parathyroids) and of the parathyroids IV (internal parathyroids) was examined in 25 young calves, 10 veal calves and 5 adult oxen. Detailed data for the recognition and the collection of these glands are provided. The parathyroids III are well suited for removal in a fresh state, since they can readily be located. They are situated medial to the carotid bifurcation and ventrolateral to the vagus nerve where the latter gives off the cranial laryngeal nerve. In all young calves and in most veal calves they lie embedded in the subbasilar portion of the thymus, from which they can usually be differentiated easily by their color. However, they should not be confused with lymph nodes and hemal nodes, which are located in the neighborhood. Light-microscopical substantiation is therefore advisable. The parathyroids IV are not suited for collection since they cannot be distinguished macroscopically from the adjacent thyroid gland.

ISSN:1422-6405    

DOI:10.1159/000146633

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

We defined the subsegmental divisions and the ramification patterns of the portal vein in the right and caudate lobes using 25 human liver casts. The ramifications of the portal vein and the subdivisions of the liver were classified based on the major portal veins with the largest diameter and those having a diameter of not less than two thirds of the largest vein in each subsegment. The following results were obtained. (l)The portal trunk showed three ramification patterns and the basic pattern was bifurcation (80%). (2) The anterior portal vein first ramified into several anterior-inferior portal veins (P5) and ran toward the superior direction to bifurcate into 2 major portal veins in the anterior-superior subsegment (Sg). (3)There were three types of ramification patterns of the portal veins in S8: bifurcation (84%), trifurcation and one-pedicle type. (4)There were also three branching types of the largest vein (P5-max) in P5: ramification from the anterior portal vein, Pg-anterior vein supplying the anterior region of S8 and Pg-posterior vein supplying the posterior region of S8. (5)The posterior portal vein showed two ramification patterns of the bifurcation (36%) and nonbifurcation type. (6) The major portal veins in the caudate subsegment ramified at various sites such as the portal trunk, left, right and/or other portal veins.

ISSN:1422-6405    

DOI:10.1159/000146634

出版商:S. Karger AG    

年代:1988

数据来源: Karger