摘要:

Mast cells, which had until recently been believed to be not present in the mammalian brain, were studied in the brains of 29 mammalian species. Although there was considerable intraspecific and interspecific variation, mast cells were most numerous within the leptomeninges (especially in those overlying the cerebrum and the dorsal thalamus -most rodents, most carnivores, chimpanzees, squirrel monkeys and elephant), the cerebral cortex (most rodents, tiger, fox, chimpanzee, tarsier, and elephant) and in many nuclei of the dorsal thalamus (most rodents, tiger, lion, and fox). In some mammals, mast cells were also numerous in the stroma of the telencephalic choroid plexuses (chimpanzee, squirrel monkey), the putamen and the claustrum (chimpanzee), the subfornical organ (pack rat, tiger, chimpanzee), the olfactory peduncles (hooded rat, albino rat), the stroma of the diencephalic choroid plexus (lion, chimpanzee, squirrel monkey), the pineal organ (chimpanzee, squirrel monkey), some nuclei of the hypothalamus (tiger), the infundibulum (hooded rat, tiger, fox), the area postrema (pack rat, chinchilla, lion, spider monkey, chimpanzee, fox) and some nuclei and tracts of the metencephalon and the myelencephalon (tiger). Neither the sex of the animal nor electrolytic lesions made in the brains of some of the animals at various times prior to sacrifice appeared to effect the number and the distribution of mast cells. Age-related changes in mast cell number and distribution were detected in the albino rat.

ISSN:1422-6405    

DOI:10.1159/000144540

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

A study was made concerning the effects of sialoadenectomy and parotin hormone administration upon sponge-induced granulation tissue of young adult rats. The effects of sialoadenectomy alone and sialoadenectomy plus a single subcutaneous injection of parotin hormone, in two different doses (0.15 and 0.30 mg), on the development of 15-day-old granulation tissue were observed. The action of parotin hormone administration without sialoadenectomy was also investigated. The results have shown that sialoadenectomy produces a retardation effect upon the development of the tissue. This effect was partially inhibited by 0.15 mg and totally eliminated by the administration of 0.30 mg of the hormone. When administered in rats which were not síaloadenectomized, the dose of 0.30 mg caused increased fibroplasia and vascularization of granulation tissue, while a dose of 0.15 mg did not cause any significant difference when compared to the control tissue

ISSN:1422-6405    

DOI:10.1159/000144541

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Glucose evoked significant hyperglycemia in the frog, Rana tigrina, 0.5 h after the injection and it took a longer time to regain normoglycemia than mammals, thus exhibiting a low glucose tolerance. The islet tissue of injected animals showed degranulation and atrophy of /?-cells only, the α-cells remained almost normal. This damage suggests that the β-cells of this frog are functionally like those of mammals and other vertebrates, and secrete insulin. A single dose of glucose was found incapable of producing permanent diabetes, and β-cells damage was repairable at later stages. Excess of glucose in the blood seems to stimulate secretion of insulin by the β-ce

ISSN:1422-6405    

DOI:10.1159/000144542

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The early growth and development of the symphyseal joint and pertinent adjacent regions of the mandible in the hamster, Mesocricetus auratus, are described. The joint is patent throughout life and in adults contains a large fibrocartilage which mediates mandibular movements. Evidence is presented to show that this cartilage is formed by the fusion of Meckel’s cartilage with two secondary cartilages that appear within the joint space. Evidence is also presented which suggests that cells of the symphyseal cartilage have the capacity to produce bon

ISSN:1422-6405    

DOI:10.1159/000144543

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The effect of carbon tetrachloride on the liver of Heteropneustes fossilis has been studied. It results in centrolobular necrosis and cirrhosis. The hepatocyte nuclei are enlarged and balloon-shaped cells are visible at a few places. There is an increase at this stage in the DNA content of the hepatocyte nucleus. The cytoplasm is heavily laden with glycogen. Fatty infiltration starts and the fat content in the cytoplasm of the liver cells is increased. After 5 h of injection, the nuclei undergo lysis followed by ruptures in the cell membrane. The DNA content is greatly reduced. There is a marked depletion in the glycogen content. The bile canaliculi are filled with the extruded cell contents. The fatty infiltration increases at this stage.

ISSN:1422-6405    

DOI:10.1159/000144544

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The postnatal development of bone marrow adipose cells was studied by sequential examination of marrow tissue obtained from the tibia and femur of 1- to 8-week-old rabbits. The bone marrow adipocyte begins to develop 2 weeks after birth. Its cellular origin differs from the ‘fibroblast-like’ cell that is the progenitor of the extra-medullary adipocyte. The marrow pre-adipocyte is associated with the sinus endothelium and adventitial cells, but is not associated with collagen and does not contain abundant organized rough endoplasmic reticulum. Unlike the extramedullary adipocyte, the course of differentiation of the medullary adipocyte is not characterized by the appearance of glycogen; furthermore, during the coalescence of lipid droplets to form larger fat globules, cytoplasmic organelles, such as mitochondria and ribosomes, are trapped within the lipid substance to form intralipid vacuoles containing degraded cytoplasmic organelles. The possible significance of these morphologic differences between the developing bone marrow adipocyte and that of its extramedullary counterpart is discus

ISSN:1422-6405    

DOI:10.1159/000144545

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

An attempt is made to separate in the submucous plexus and mucous membrane of the chronically isolated intestine of the cat the fibers originating from the myenteric plexus and those originating from the submucous plexus by secondary degeneration after the extirpation of the myenteric plexus. A considerable part of the nerve processes in the submucous plexus originate from the cells of the myenteric ganglia and establish direct synaptic relationships between the ganglion cells, or are very close to the blood vessels. The numerous intact synapses between the different nerve elements in the submucous plexus point to local reflex connexions within the plexus itself. The degeneration of sub-epithelial nerve elements, containing always clear and dense-core (1,000–1,200 Å in diameter) vesicles besides the numerous intact nerve elements, might indicate the presence of real sensory nerve processes in this layer. The terminal fibers remaining intact after removal of the myenteric plexus contain numerous medium-sized dense-core vesicles in potassium permanganate-fixed material. This suggests that there are cells containing 5-hydroxytryptamine in the submucous plex

ISSN:1422-6405    

DOI:10.1159/000144546

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

A number of nuclei and fibre systems of the parakeet di-mesencephalon, as visible in transverse series stained with the methods of Häggqvist and of Klüver and Barrera, have been described. In the preparations used, in which both neurones and myelinated fibres are visible, a relatively great number of elements can be distinguished, because of differences in cell and fibre content. Probably these elements are more sharply circumscribed than in the pigeon and therefore more readily visible. A few of them have been described for the first time, but they require experimental substantiation. Typical features of some nuclei and fibre systems of the parakeet have been pointed out. Attributing a certain type to the di-mesencephalon of the parakeet proved to be unfeasible, because of a deficient knowledge both about the elements studied and to their aspect in a sufficient number of other avian species. The pictures produced may be helpful in recognizing nuclei and fibre systems in other birds in which they are less distinc

ISSN:1422-6405    

DOI:10.1159/000144547

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

In various respiratory areas of the mucosa of the nasal conchae of the zebu (Bos indicus) there is a quantitative variation of goblet cells. The glands are tubular or tubulo-alveolar, having morphologically serous and mucous cells. The excretory ducts are formed by non-secreting cells. The goblet cells and glands elaborate a glycoprotein. The carbohydrate portion is probably an association of neutral mucopolysaccharides, sulphated acid mucopolysaccharides and sialic acid and its proteic portion contains α-amino radicals. Tryptophan- and tyrosine-rich proteins are demonstrated only in the glandular secretion

ISSN:1422-6405    

DOI:10.1159/000144548

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The ligamenta flava have been investigated in Cercopithecus pygerythrus (vervet monkey) and C. mitis (blue monkey) at various levels of the vertebral column. It has been shown that in the cervical, thoracic and lumbar regions the topography of these ligaments differs. The cervical ligamenta flava do not extend over the intervertebral joints, while in the thoracic and lumbar regions they reinforce and fuse with the capsule. The ligamenta flava from T4 to SI replace the interspinous ligaments by extending into the interspinous space. The ligamenta flava consist mostly of interwoven layers of elastic and collagen fibres. The area of attachment has four zones whose histological details are described. These findings are discussed in relation to the function of the vertebral column and to the role of ligamenta flava in providing flexibility of the column and mechanical adaptation to absorb sudden stresses.

ISSN:1422-6405    

DOI:10.1159/000144549

出版商:S. Karger AG    

年代:1976

数据来源: Karger