摘要:

The human pyloric glands are simple or branched tubular glands which spiral through the connective tissue of the lamina propria. They are comprised of three cell types: the pyloric gland (mucous) cell, the parietal cell, and endocrine cells. The mucous cell is the most common cell type in the human pyloric glands and is characterized by an abundance of secretory granules. The secretory granules are usually round in shape and vary considerably in diameter. They are membrane-bound and comprise a heterogeneous population. The larger granules contain a light staining amorphous material and often possess an area of increased electron density near the limiting membrane of the granule giving them a mottled appearance. A smaller, more electron-dense secretory granule also is found both in relation to the Golgi complex and cell apex.The morphological observations indicate that the mechanism of mucin production by the mucous cells of the human pyloric glands may be similar to that reported in other mucin-secreting cells.

ISSN:1422-6405    

DOI:10.1159/000144828

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The melanocytes, the intermediate cells of Billingham and Medawar and the Langerhans’ cells of the epidermis of the white guinea pig were found to be positive to Biel-schowsky’s silver and Gomori’s acetylcholinesterase reactions. The melanocytes were full of Nissl substance. On these evidences, supported by other morphological and histochemical characteristics, the dendritic cells of the epidermis were considered to be nervous struc

ISSN:1422-6405    

DOI:10.1159/000144829

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The hypothesis that patterns of sexual dimorphism in transverse dimensions of the metacarpal only reflect sex differences in body size was investigated in a sample of 324 Mexican school children 6.00–10.99 years of age. Several patterns of sexual dimorphism in second metacarpal dimensions are seen with regard to stature and weight. Sex differences in medullary diameter and percent cortical area are not related to sexual dimorphism in body size, while sex differences in cortical thickness are related to, but not fully explained by, differences in body size. Dimorphism in metacarpal diaphyseal diameter is related to differences in body size, but, at a constant body size and age, boys still have significantly larger diaphyseal diameters than girls. Finally, sexual dimorphism in cortical area is closely associated with sex differences in body siz

ISSN:1422-6405    

DOI:10.1159/000144830

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The brains and retinas of laboratory animals fixed by perfusion occasionally contain isolated round fat emboli, which increase in number if the two organs are covered with oil during the autopsy. These emboli, in contrast to emboli induced by intravenous injection of oil, are present in smaller numbers, occur without adjacent aggregation of erythrocytes and do not cause widening of the occluded vascular channel. The fat emboli in the normal brain are attributed to connective tissue fat aggregating on the exposed cerebral surface and flowing through openings cut in the leptomeninges and the vascular walls during removal of the brain. Their formation could not be entirely prevented by covering the brain with running water or by submerging the forepart of the animal’s body in water during the autopsy. Nevertheless, such a procedure is recommended to avoid introduction of extraneous fat when in a given experiment the question of fat embolism arises. Fat emboli demonstrable in the flattened retina of the cat and the mulatta monkey are ascribed to aspiration of retrobulbar connective tissue fat; they can be prevented by placing a ligature around the optic nerve prior to removal of the ey

ISSN:1422-6405    

DOI:10.1159/000144831

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

An invariant feature of the olfactory bulb in placental and marsupial mammals is the arrangement of the perikarya of mitral cells in a monolayer. Contrasting with this is the arrangement found in the olfactory bulbs of the monotremes, platypus and echidna, where the large perikarya are not only absent from the position of a monolayer (usually forming the external boundary of the internal plexiform layer) but occupy a region which would characterize them as tufted cells. In other classes of amniote vertebrates, reptiles and birds, the placement of large perikarya in the olfactory bulb ranges from a compact layer to a broad band. Such an overview among several vertebrate classes suggests that a monolayer of mitral cells may be a specialized subset of the tufted-mitral cell population. The accessory olfactory formation among mammals also exhibits variation in the compactness of the large perikarya: a broadband in most but a compact layer in a few others such as the chinchilla and the capybara. Such specialized alignment of perikarya (and, consequently, of their dendritic and axonal elements) may enable more refined signal processing than does random alignment of these elements. Such speculations can be tested using appropriate phylogenetic sampling, and monotremes provide particularly advantageous test cases.

ISSN:1422-6405    

DOI:10.1159/000144832

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

A histochemical and electron-microscopic study has been done on the parafollicular (C) cells of the thyroid in the gerbil. Histochemical tests revealed the characteristic presence of α-glycerophosphoric dehydrogenase and the presence of phenolic groups and indoleamines. Acid phosphatase levels were similar to those observed in the apical cytoplasm of the follicular cells. Electron microscopy revealed characteristic presence of noncisternal rough endoplasmic reticulum, well-developed Golgi apparatus, numerous prosecretory granules and a few electron-dense mature secretory granules. Most characteristic of these cells was the presence of numerous large, electron-lucent vesicles which often were packed in the cytoplasmic processes that were located subjacent to the follicular cells and close to the blood capillaries. Significance of these histochemical and ultrastructural findings is emphasized particularly in regard to the presence of monoamines and their possible role in the release of calcitonin and thyroxin

ISSN:1422-6405    

DOI:10.1159/000144833

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The results show that irradiation affects both the size of the gonads and the number of germ cells they contain. At stage 64, gonads from irradiated animals were smaller than those from unirradiated ones. The reduced length and thickness of gonads of the test animals were probably due to cell killing. The variation in size of gonads of different test animals and the difference between the left and right ovary of a single individual are indicative of the degree of radiation sensitivity.

ISSN:1422-6405    

DOI:10.1159/000144834

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

A histotopographic study of the nasal septum mucosa in rats was made using semi-serial sections stained with PAS-hematoxylin, reconstructed in form of maps representing the structure in a sagittal plane. The stratified squamous, respiratory and olfactory epithelia and Masera’s organ cover 14.8, 43.6, 41.6 and 1.8%, respectively, of the septal surface (117.1 mm2). In the vestibular region, only ducts of PAS-negative glands of the respiratory region are found, and below the septum there is the infraseptal gland with PAS-negative acini. In the respiratory region, PAS-negative acinous glands form two groups: the superior and the inferior one occupying 10.5 and 1.5%, respectively, of the septal area. PAS-positive acinous glands are in the inferior half of the respiratory region and in a small anteroinferior portion of the olfactory region. Besides goblet cells broadly distributed, the respiratory epithelium presents scattered intraepithelial PAS-positive glands which are concentrated in the anterior portion and close to the nasopharyngeal duct. In the olfactory region prevail Bowman’s PAS-positive glands which are also present in the mucosa of Masera’s organ, but are not seen in the olfactory mucosa of Jacobson’s organ. In the latter, PAS-positive glands are found in the respiratory mucosa. Globular leukocytes, cells of connective tissue origin, are constantly infiltrating the superior regions of the respiratory and olfactory epithelia, being more numerous in fema

ISSN:1422-6405    

DOI:10.1159/000144835

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Internal surface structures of the auricular and ventricular chambers were studied with scanning electron microscopy. We observed vascular connections between the ventricular chamber and the coronary vessels, including cords and papillary muscles covering the lining of the endocardium. The endothelial cells covering the inner surface of the endocardium appeared to be functionally active with many microvilli similar to pinocytic microprojections of other endothelial cells. The pinocytic microprojections ranged between approximately 100 and 300 Å in diameter. The epicardium contained mainly bundles of collagenous fibers

ISSN:1422-6405    

DOI:10.1159/000144836

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Pulp tissue, enamel and incisal and basal dentine of the mandibular incisor were taken from one litter of rats and transplanted subcutaneously or intracerebrally to sex-matched, 5-day-old animals of the subsequent litter of the same parents. As sham-operations the mere transplantation instrument was inserted into the transplantation sites. With some exceptions, the host animals were killed 4, 32, 128–138 and 210 days after the operation and the transplantation sites were examined either grossly or microscopically or both. The pulp tissue transplantation had resulted in formation of osseous tissue observed 128 days post-operatively. Bone was found in association with many of the basal dentine transplants 128–210 days after their insertion whereas no such tissue was observed with the transplanted enamel of incisal dentine. The sham-operation seemed to have elicited intracerebral bone formation in two animals. The osteoinductive activity of the transplanted tissues seemed reduced by their mineral phase. Further, in contrast to deminerahzed hard tissues, the non-demineralized inductive agents do not seem to possess bone morphogenetic propert

ISSN:1422-6405    

DOI:10.1159/000144837

出版商:S. Karger AG    

年代:1977

数据来源: Karger