摘要:

The distribution of type I, III and V collagens in the monkey spleen was examined by indirect immunofluorescent microscopy and immunoelectron microscopy, and compared with that of reticular fibers revealed by a silver impregnation method. Type I collagen was localized on reticular fibers in the white pulps and on coarse reticular fibers in the splenic cords. Type III collagen was localized on the reticular fibers in the white pulps, and on the coarse reticular fibers and a limited number of fine reticular fibers, in the splenic cords. The anti-typeV collagen antibody reacted with annular reticular fibers around the splenic sinuses, as well as with the reticular fibers in the white pulps and with the coarse and fine reticular fibers in the splenic cords. Thus, the distribution pattern of fibers that reacted with the anti-type V collagen antibody was very similar to that of the reticular fibers revealed by the silver impregnation method. Electron-microscopically, the fine reticular fibers in the splenic cords were composed of collagen fibrils, 30–50 nm in diameter, and amorphous substances. They were covered by reticular cell processes. By immunoperoxidase labeling with the anti-type V collagen antibody, electron-dense reaction products were found over the collagen fibrils with a banding pattern. These results indicate that type V collagen is an indispensable component of the reticular fiber

ISSN:1422-6405    

DOI:10.1159/000146395

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The gallbladder of Richardson’s ground squirrel shares many structural similarities with numerous other species, including the mouse, rabbit and man. Dark cells exhibit a condensed cytoplasm but contain all the typical organelles of light cells, although their total complement appears reduced. Edematous cells extruded from the epithelial lining were replaced through mitosis or had their space occupied by adjacent cells. Specializations of the basal plasma membrane and underlying basal lamina form peg-and-socket interdigitations, and desmosomes were observed on the lateral cell boundaries down to the level of the basal lamina. The latter remain intact during active water resorption while the former disappear. Adrenergic nerve fibers were observed intramuscularly and beneath the basal lamina. Random interepithelial migration of leucocytes was also observed. Some of these observations help to elucidate controversial issues whereas others have been previously unreported and may be species-dependen

ISSN:1422-6405    

DOI:10.1159/000146396

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Holtzman rats were subjected to food restriction during gestation or lactation, or both periods (overall stress). At weaning, male pup skulls were measured and female brains and cranial masticatory muscles were weighed and a neuromuscular index was calculated. It was found that gestational protein-calorie malnutrition (PCM) without suckling restoration accounted for about 30% of the growth delay observed under overall stress. That effect disappeared after a normal suckling restoration. Under the same conditions of maternal food restriction in both periods, growth delay in the offspring was greater during lactation than gestation. As in lactation, craniofacial changes during gestational restriction were due to an adjustive response of bone growth to PCM. This response seemed to accrue from an altered relationship between the growth of the brain – less sensitive and highly restorable – and the growth of the masticatory muscles – more sensitive and less restorable. Some degree of delay in orthocephalization would be the skeletal outcome of such adjustive neuromuscular res

ISSN:1422-6405    

DOI:10.1159/000146397

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Vestibular nerves of squirrel monkeys (Saimiri sciureus) embedded in plastics and epoxies were examined with light microscopy (LM) and transmission electron microscopy (TEM) and computerized measures were obtained and analyzed statistically. An average of 12,412 perikarya and 12,005 myelinated nerve fibers was obtained. Approximately 0.7% of the perikarya appeared unmyelinated under LM. About 500 unmyelinated fibers were counted. The cross-sectional area of 1,864 perikarya was 200–650 µm2. The cross-sectional area of 1,346 nerve fibers was 3–11 µm2 for the axoplasm and 11–12 µm2 for the myelin sheath of the same fiber. Myelin thickness was directly proportional to the axoplasm cross-sectional area of the nerve fibers. The cross-sectional area of central axons and peripheral dendrites differed significantly (p < 0.001). The initial segments of peripheral dendrites were usually smaller, but longer than the initial segments of the central axons. Both initial segments increased in diameter after the first node of Ran-vier. Schmidt-Lantermann incisures were more abundant in thick and heavily myelinated fibers than in thin and lightly myelinated fibers. Larger perikarya usually had larger fibers and vice versa, within the first 100–200 µm from the first node of Ranvier. No major ultrastructural differences were found between myelinated and unmyelinated perikarya, except at the hillock region.The Nissl substance was preferentially located in the periphera

ISSN:1422-6405    

DOI:10.1159/000146398

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

A quantitative ultrastructural study of somatotropic cells was carried out in 21-day-old malnourished rats after maternal food restriction during the nursing period. Changes represented mainly by a reduced cytoplasmic mass and diminished secretory material were found. A decrease in growth hormone secretion of malnourished weanling rats is suggested.

ISSN:1422-6405    

DOI:10.1159/000146399

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Frozen sections of vitiliginous skin were treated with the substrates involved in melanogenesis and adrenergic activity to study the effect of changing chemical milieu on the biphasic dendritic melanocytes.The substrates used are tyrosine, DOPA, tyrosine + DOPA, dopamine, adrenalin and cupric ions. It was observed that tyrosine when used alone has a weak melanogenic reaction while DOPA and tyrosine + DOPA show a prominent activity. Adrenalin and dopamine inhibit the neural limb and enhance melanogenesis. Cupric ions on the other hand enhance the neural limb and inhibit melanogenesis. These changes are not evident in the non-dendritic melanocytes. Thus the highly dendritic melanocytes are at a lower state of differentiation. These biphasic cells are more sensitive to changes in the chemical milieu.

ISSN:1422-6405    

DOI:10.1159/000146400

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The antiserum against insoluble elastin from human aorta was applied to immuno-electron microscopy. In the preembedding method, only the outer surface of the amorphous component (elastin) of elastic fibers showed a positive reaction. A major problem encountered with the preembedding method is associated with the penetration of either the primary antiserum or the secondary antibody into the tissue and, in particular, into elastin. On the contrary, a positive reaction was observed inner zones of elastin in the postembedding method. While the postembedding method employed here has limitations with nonspecific binding to the embedding medium, the postembedding method offers a decided advantage over the preembedding method.

ISSN:1422-6405    

DOI:10.1159/000146401

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Ultrastructural characteristics of human blood eosinophils have been analysed by morphometric methods in 18 healthy adults. Data were obtained relating to whole cell, nucleus, mitochondria and specific granules. No significant differences were found between the eosinophils of the 9 male and 9 female subjects. The results provide normal values against which changes in eosinophils in disease states may be assessed.

ISSN:1422-6405    

DOI:10.1159/000146402

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The guinea pig mesentery is a uniform, continuous, thin (18 μm) sheet of connective tissue covered by a single layer of flattened mesothelial cells on both surfaces. Tight and gap junctions provide for cell-to-cell adhesion among mesothelial cells. These cells possess numerous micropinocytotic vesicles; a conspicuous basal lamina separates the mesothelium from the underlying connective tissue. Most of the material found between the two serous coverings consisted of a three-dimensional meshwork of abundant collagenous fibers intermingled with a sparse net of very thin (0.4 μm) elastic fibers. Two distinct populations of collagen fibrils are segregated into different compartments of the mesentery. One population is formed of thick (56 nm) fibrils which associate to form closely packed fibers. The second population, composed of loosely arranged thin (38 nm) fibrils which do not become assembled into fibers, is found underlying the basal lamina that separates the mesothelium from the connective tissue.These observations strongly suggest that the mesentery contains both collagens type I and type III. The guinea pig mesentery contains 6.8 mg of sulfated glycosaminoglycans/g dry weight. Most of these glycosaminoglycans (78%) were identified as dermatan sulfate, whilst the rest (22%) corresponded to heparan sulfate.

ISSN:1422-6405    

DOI:10.1159/000146403

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The temporomandibular joint is a diarthrosis. It has classically been referred to as being a condylar, and functionally as a double condylar joint. We have used the moiré topographical technique to study the morphology of the pars suprameniscalis or meniscotemporalis of the joint. The findings show that this pars suprameniscalis could be classified as a saddle joint. The biomechanical implications are also discussed.

ISSN:1422-6405    

DOI:10.1159/000146404

出版商:S. Karger AG    

年代:1987

数据来源: Karger