摘要:

In this work, the author carried out mesoscopic and microscopic studies of the human carotid sheath in order to verify its existence, constitution, mode of attachment and the real appearance of its initial portion near the first portion of the internal jugular vein; the surrounding connective tissue formations which attach this vessel to the carotid sheath were studied as well. In 40 anatomical specimens of both sides, microscopic examination revealed that the carotid sheath is always present; it constitutes a complete cover around the neurovascular complex and presents subdivisions which envelop the internal jugular vein, the internal carotid artery and the glossopharyngeal, vagus, external branches of the accessory and internal carotid nerves. Mesoscopic inspection showed that fascicles of conjunctive fibers connect the wall of the first portion of the internal jugular vein with the internal face of the carotid sheath; and that fibrous prolongations superiorly fix the carotid sheath to the border of the jugular foramen and carotid canal. Microscopically, the carotid sheath has a fibroelastic constitution and its walls are of variable thickness.

ISSN:1422-6405    

DOI:10.1159/000145207

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The seminal coUiculus is completely absent in the donkey. It is fibroglandular in the males of camel, ox, buffalo and pig. Prostatic acini are richly found in its depth. They are lined by cubical or low columnar epithelium, are separated from each other by trabeculae of connective tissue and smooth muscle, and separated from the deeper prostate gland by the striated muscle of the urethra. A rare type of seminal coUiculus was once encountered in the ox. This type is muscular with autonomic ganglia and complete absence of glandular acini. It seems that the seminal coUiculus shares the prostate in its glandular functions and prevents oozing of semen from the seminal ducts.

ISSN:1422-6405    

DOI:10.1159/000145208

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The prostate of the nine-banded armadillo is a compound tubulo-alveolar, bilobed gland situated on the ventral surface of the seminal vesicles. The two lobes, which may be connected by a narrow isthmus of tissue, are encapsulated by a thin layer of connective tissue and are located peripheral to the urethral musculature. The acini within the gland are separated by a fibromuscular stroma and contain an amorphous secretory product. The mucosa, characterized by a simple columnar epithelium, is thrown into folds which frequently branch. Numerous secretory ducts arise from the gland and course caudally parallel to the vasa deferentia and ducts of the seminal vesicles to a tubercle on the wall of the urethra. Several secretory ducts open into the vasa deferentia near the latter’s termination at the urethra, while other prostatic ducts empty directly into the urethra. The columnar cells of the mucosa resemble protein secretory cells with a spherical nucleus in the basal portion of the cell and numerous secretory granules located in the apical region of the cell. The rough endoplasmic reticulum is a complex network of stacks of interconnecting cisternae and tubules which is often connected to the nuclear envelope. The Golgi apparatus is extensive and is located in the supranuclear region of the cell. The secretory ^granules appear in various sizes and densities and seem to be released by exocytosi

ISSN:1422-6405    

DOI:10.1159/000145209

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Testoviron is a potent neural inducer, acting on the epiblast of the chick embryo during the period of competence (Hamburger-Hamilton stages 3 and 4). Under the influence of Testoviron, the epiblast differentiates in the neural direction. The structure that develops is typically neural in appearance with a ‘dorsoventraΓ and a mediolateral pattern. The notochord is not formed; consequently, there is no lengthening and therefore no craniocaudal pattern. Hence, Testoviron is an ‘inducer’ and not an ‘evocator’ even though it differs from the ‘primary organizer’ in that it does not organize the neural groove in the axial direction as does the dorsal lip of the blastopore of the amphibians or as with Hensen’s node in birds. Therefore, it would be very interesting to ascertain whether there is a biochemical difference in the constitution between Hensen’s node and the notochord of the bird. The inducing action is localized in a small region around the testoviron implant. The steroids might be of major importance in the early morphogenetic processes. We feel steroids deserve more attention than they are receiving a

ISSN:1422-6405    

DOI:10.1159/000145210

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Female baboons maintained under laboratory conditions were subjected to a series of 10 weekly injections (4 mg/kg body weight) of the synthetic glucocorticoid, triamcinolone hexacetonide. In response to the treatment, serum immunoreactive parathyroid hormone (PTH) levels were raised, though blood calcium levels remained within normal physiological limits. Light and electron-microscopic studies were made on the parathyroid glands at the end of the experimental period. The baboon parathyroid glands were composed of ‘light’ and ‘dark’ forms of the chief cells in varying ratios from gland to gland even within a single animal. Glucocorticoid-induced parathyroid hyperactivity as measured by circulating PTH levels was not accompanied by cellular hypertrophy, though there was an increase in the relative number of ‘light’ cells. At the ultrastructural level, after treatment, many of the ‘light’ cells were found to contain more free ribosomes, larger profiles of granular endoplasmic reticulum and had better developed mitochondria. Interdigitations between adjacent chief cells were more complex in treated glands. Apart from these features, chief cells of treated glands were basically similar to those of untreated controls. Our study showed that functional parathyroid hyperactivity in baboons is not necessarily accompanied by significant ultrastructural changes

ISSN:1422-6405    

DOI:10.1159/000145211

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Coronary arteries and arterioles in the left and right normal rat ventricle were examined histochemically to determine their metabolic activities. Aerobic metabolic capacity was determined by assessing the reactivities of the enzymes succinate dehydrogenase, cytochrome oxidase and myosin ATPase. Glucose-6-phosphate dehydrogenase was examined to determine the activity of the hexose-monophosphate-shunt, while lactate dehydrogenase and glycogen reactivity were determined as an evaluation of the anaerobic metabolic capacity. The amounts of deoxyribonucleic and ribonucleic acid were assessed as an indication of protein synthesis. Reactivities of the enzymes succinate dehydrogenase, cytochrome oxidase and myosin ATPase are greater in arteriolar smooth muscle than in arteries. This suggests that arterioles have a higher capacity for aerobic metabolism than do arteries. The greater reactivity for lactate dehydrogenase and glycogen in arterial smooth muscle than in arterioles suggests that arteries are more adapted for anaerobic metabolism. Glucose-6-phosphate dehydrogenase shows substantially greater activity in arteries and in some larger arterioles than in most smaller coronary arterioles, which implies that the coronary arteries and larger arterioles possess a higher capacity for nucleic acid and protein synthesis. Deoxyribonucleic and ribonucleic acids show low reactivity in both arteries and arterioles from the ventricular myocardium, which conforms to the view that under normal conditions, the coronary vasculature is stable with little cell proliferation.

ISSN:1422-6405    

DOI:10.1159/000145212

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

We investigated by means of coronarography and dissection the arterial vascularization of the human heart in relation to the type of coronary ramification in 200 human hearts taken at random from males and females between 20 and 85 years of age. Examination of the selective coronarography findings was subsequently performed by means of careful dissection of the injected arteries and their branches in order to compare the results obtained with coronarographic findings in living human beings.

ISSN:1422-6405    

DOI:10.1159/000145213

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Tibiae of young rats were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to study the origin and structure of matrix vesicles in periosteal bone. SEM studies have shown that periosteal osteoblasts have elongated processes with globular structures of 0.1 µm in diameter attached to the cell surface and processes. Similar structures were found to cover the inner surface of osteoblastic lacunae. The SEM studies have further shown that in the periosteal surface (forming bone) the above-described globules once mineralized, aggregated to form larger, nonhomogeneous mineralized spherules in which, by proper treatment with NaOCl, hydroxyapatite crystals could be exposed. Endosteal osteoblasts had fewer processes, devoid of the globular structures. Similarly, osteocytic and osteoclastic processes, although elongated and numerous, were not covered by the globular structures. In the matrix, collagen fibers of forming bone were randomly orientated, while in the deeper areas of bone they formed bundles with a longitudinal orientation. TEM studies have shown that the structures found on the osteoblastic surface and in the matrix are membrane-bound matrix vesicles which seem to be formed by budding from cell processes.Preformed membrane-bound vesicles were also observed by TEM inside sections of osteoblastic processes. These vesicles resembled the extracellular matrix vesicles in size and shape, thus giving the impression that at least some of the matrix vesicles are preformed cellular structures. While comparing SEM with TEM, it can be concluded that in bone, as in cartilage, matrix vesicles which probably serve as the initial locus of calcification, are formed directly by osteoblasts

ISSN:1422-6405    

DOI:10.1159/000145214

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Volumetric determinations were made by means of linear measurements and permanent stone models of 98 fresh eyes from 84 Dutch rabbits ranging from 15 to 540 days of age. The relationship of eye volume to age was evaluated. At 15 days of age, the eye volume is about 20% of adult size, at 100 days of age about two thirds of adult size, at 180 days of age about 85% of adult size, which is reached at about 300 days of age.

ISSN:1422-6405    

DOI:10.1159/000145215

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

1,1,3-tricyano-2-amino-l-propene (malononitrile dimer), administered intraperitoneally to mice, induced histological changes in the thyroid gland 6 h after drug administration. The histology of the thyroid gland is normal up to 16 h after drug treatment. Pathological conditions characteristic of hyperthyroidism are observed after 16 h of the drug treatment. By 48 h, the thyroid again appeared normal. The antithyroid action of the drug is attributed to the initial acute inhibition of the organic binding of iodine causing supression in the formation of thyroxine, which is later compensated.

ISSN:1422-6405    

DOI:10.1159/000145216

出版商:S. Karger AG    

年代:1980

数据来源: Karger