摘要:

Using morphometric techniques, we analyzed the effects of Δ9-tetrahydrocannabinol (THC) on the ultrastructure of rat preovulatory follicles. Rats were injected intraperitonally once daily with vehicle alone, or with vehicle plus THC on diestrus (D), metestrus (M) and diestrus (D), or on estrus (E), M and D. All animals were killed on proestrus. Nuclear, mitochondrial, lipid droplet and lysosomal volume density in the membrana granulosa were analyzed. There was no change in nuclear volume, but there were significantTHC-induced decreases in mitochondrial and lipid droplet volumes in the peripheral region of the granulosa. There were increases in dense-body volume in all regions of the granulosa from rats given THC either on D alone, or M and D. Dense-body volume returned to control levels in rats injected on E, M and D. It appears that THC can affect follicular ultrastructure and the effects change with the number of injections

ISSN:1422-6405    

DOI:10.1159/000146527

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The chick chorioallantoic membrane (CAM) is a common model for studying biological processes, but descriptions of the CAM circulatory system and especially experimental preparations of the CAM in shell-less eggs are both scant and controversial. We studied the CAM structure and the three-dimensional spatial configuration of the CAM vessels using five methods: in vivo stereoscopic observations, whole-mount preparations, histological sections, corrosion cast microinjection techniques and the reconstruction of a three-dimensional wax model. Our findings show that the CAM consists of a superficial two-dimensional layer composed of a network of a very dense capillary mesh, floating over and enclosing a deeper three-dimensional space in which medium and larger free-floating vessels are seen to supply and drain the superficial layer. It is interesting to note that no tips or sprouts of blood vessels were observed during the development of the CAM vessels. In a shell-less egg preparation, the capillaries were found in the mesoderm layer of the CAM and not in or superficial to the ectoderm as is the case in the CAM of the intact egg which adheres to the shell membrane.

ISSN:1422-6405    

DOI:10.1159/000146528

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The segmental nature of the arterial tree of the human spleen was analyzed in 181 subjects of both sexes, who had died of various accidental causes. Based on the observation of the pattern of the terminal and polar splenic branches, selective arteriographs and corrosion casts, and taking account of the ideas reported in the literature, we proposed that the spleen is divided in arterial segments and subsegments. Segments are the territories corresponding to both the primary branches of the splenic artery (primary segments) and the polar arteries (polar segments). In 92.82% of the cases there are two primary segments and in 7.18% three primary segments. Associated to these, in 29.28% there is a superior polar segment, in 44.75% an inferior polar segment, and in 10.49% both superior and inferior polar segments are present. Thus, the number of segments varies from two to five. Occasionally, two or three inferior polar segments can be present. Subsegments are the territories corresponding to the extrasplenic subdivisions of the primary branches and the polar arteries. According to the number of arterial subdivisions, the subsegments can be of second, third, fourth, fifth or sixth order. The last branches of the splenic artery (penetrating arteries) are all sub-segmentary in nature and supply hilar or polar subsegments. Anastomoses between extrasplenic branches of the splenic artery were observed in 19.89% of the cases. Sometimes, thin anastomotic bridges could be observed between arterial splenic compartments.

ISSN:1422-6405    

DOI:10.1159/000146529

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In order to clarify the vascularization of the pectoralis major muscle by the pectoral branch of the thoracoacromial artery, morphometric investigations and selective injection studies of the vessel were performed. A comparison with the anatomical orientation points clinically used for locating the vessel and its course confirms that the origin of the artery is at a constant spot at half the sternoacromial distance; the main vessel axis, however, deviates considerably from the clinically used acromioxiphoid axis in lateral direction.The lumen of the thoracoacromial artery has a range of more than 150% of the smallest vessel. Atherosclerotic alterations are not the reason for this variety but only an additional handicap for the vessel capacity. Two types of muscle-perforating arteries were found, and the cutaneous area of blood supply was defined.

ISSN:1422-6405    

DOI:10.1159/000146530

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Since opinions about the presence of a band structure or a ligament in the lateral part of the temporomandibular joint capsule are divergent in the literature, the capsule of 16 post-mortem human specimens was examined both anatomically and histologically. A distinguishable ligamentous formation in the lateral part of the capsule was observed only in three specimens. In one of these, the distinguishable formation had morphological characteristics of tendineous tissue.This study indicates caution with too generalised opinions about temporomandibular morphology.

ISSN:1422-6405    

DOI:10.1159/000146531

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The pattern of the superficial arteries in the palma manus can be characterized in the following manner. In 58% of the cases the arteria ulnaris runs in an arch from the ulna to the radius and gives off a varying number of arteries to the fingers. There is no connection with any other artery. In 42% of the cases there are arterial connections, of which 32.1% are present in the form of an ‘arcus’ of a rather large diameter, formed through connection of the arteria ulnaris with the ramus palmaris superficialis of the arteria radialis or with the arteria metacarpalis dorsalis I. Likewise, in 9.9% there is a connection between the arteries but this, which we call an ‘anastomosis’, is of a more delicate

ISSN:1422-6405    

DOI:10.1159/000146532

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Morphological features of the coronary microvasculature were examined in ten Black bears (Ursus americanus). Tissue samples were collected for scanning electron microscopy from five animals, and vascular casts of the coronary vessels were prepared from five. Each portion of the microvasculature examined had specific morphological characteristics which may contribute to the control of blood flow. All indications from the present study suggest that the structure of the coronary microvasculature in the Black bear is similar to that of mammalian species previously examined.

ISSN:1422-6405    

DOI:10.1159/000146533

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Various morphological features of the Schwann cells of myelinated fibres in the lizard thoracic spinal roots were studied, and, when possible, quantified using morphometric methods. About 0.8% of the Schwann cells are binucleate and some display clusters of microvilli along the irtternodes.The percentages of the cytoplasmic area of the Schwann cell occupied by the following cytoplasmic components were determined: mitochondria, Golgi apparatus, granular endoplasmic reticulum, smooth endoplasmic reticulum, multivesicular bodies, dense bodies, autophagic vacuoles, peroxisome-like bodies, lipofuscin granules and lipid droplets. Linear relationships were found between the sectional areas of the mitochondria and granular endoplasmic reticulum of the Schwann cell and both the length of the profile of the Schwann cell plasma membrane and the size of the related axon. The results obtained are compatible both with the hypothesis that the mitochondria and granular endoplasmic reticulum of the Schwann cell are involved in the production and storage of proteins for the plasma membrane of this cell, and with the hypothesis that these organelles are involved in the production and storage of protein metabolites which are subsequently transferred to the related axons.

ISSN:1422-6405    

DOI:10.1159/000146534

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

There are marked sex differences in the Harderian gland of the C3H/He mouse strain, the females having a larger number of mast cells than the males as one of the major differences. Mast cell counts of the Harderian gland were made on male mice subjected to combinations of adrenalectomy, gonadectomy and administration of sex steroid hormones. Castration alone caused a significant increase in the count resulting in about three times the number found in intact males. Castration plus adrenalectomy increased the count over 6-fold, to levels close to those found in female mice. Administration of testosterone or estrone to the mice which had been castrated and adrenalectomized prevented the increase, while progesterone treatment had no effect on the count. Although the number of mast cells in the male Harderian gland was necessarily small compared to either the female gland or that of castrated and adrenalectomized males, no obvious dimorphism could be found microscopically.

ISSN:1422-6405    

DOI:10.1159/000146535

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The normal secondary tympanic membrane in human fetuses was examined by transmission electron microscopy. The membranes in 5- to 9-month-old fetuses consist of the following three layers: (1) an outer squamous epithelial layer facing the middle ear, which is not formed until 4 months old; (2) a middle fibrous layer containing collagen, elastin, fibroblasts and fibrocytes, and (3) an inner layer of flat cells facing the scala tympani. Following the maturation of the fetus the epithelium is getting thinner and fibroblasts are reduced in number, but fibrocytes are increased and collagen and elastin grow gradually in density. The ultrastructure of the secondary tympanic membrane at 8 month is mature in type and shows the same characteristics as in the adult.This membrane has an important and complicated physiological function. The epithelium of the outer layer, with tight junctions and multiple desmosomes, provides a barrier to keep harmful substances out. The stability of the membrane provides protection against rupture, while the elasticity plays a role in the physiology of hearing as well.

ISSN:1422-6405    

DOI:10.1159/000146536

出版商:S. Karger AG    

年代:1988

数据来源: Karger