摘要:

Twelve female Wistar rats received 1.5 mg/kg of colchicine (CLC) intravenously. Control animals were similarly injected with isotonic saline solution. The animals were killed 5 h, 24 h, 3 days and 7 days after injection. Ninety minutes prior to sacrifice, all animals received an intraperitoneal injection of 3H-proline. Autoradiograms of maxillary incisors showed that CLC increased the retention of the labeled precursor in the odontoblasts. It was also shown that the odontoblasts in the different sectors of the rat incisor present different sensitivities to the CLC action.

ISSN:1422-6405    

DOI:10.1159/000146613

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

A new tool for the study of biological form change is applied in a comparison of craniofacial growth in normal children and those affected with Apert syndrome. Using finite-element scaling analysis, the magnitude of size change during postnatal growth in the Apert sample was determined to be generally less than normal, and the magnitude of shape change was generally greater than normal. No consistent, statistically significant, alteration from normal growth was defined in the Apert sample, however. There appears to be no consistent effect on general cell and tissue proliferation in Apert syndrome. Rather, specific subpopulations of cells and tissues may be affected differentially over time.

ISSN:1422-6405    

DOI:10.1159/000146614

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The morphological analysis of nerves in axillary lymph nodes of the rat revealed the presence of two types of axon possessing either a more or a less electron-lucent matrix. The more electron-lucent axons enter the node finely myelinated, do not contain synaptic vesicles and quickly divide to form branches approaching the basement membranes of blood vessels, as well as cellular elements.They may be interpreted as sensory axons. The less electron-lucent axons are unmyelinated, and contain three distinct populations of synaptic vesicles.These may all be present in one axonal varicosity, so that the existence of cotransmitters is highly probable.

ISSN:1422-6405    

DOI:10.1159/000146615

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Biopsies from 74 cases of vitiligo were examined to study the reactions of marginal melanocytes. In 35 cases, the melanocytes at the edge of the patch appeared highly dendritic and large with marked arborisation of the dendrites between the surrounding epidermal cells. These cells showed low pigmentation but a high enzyme activity which extended along the dendrites. The enzymes include tyrosinase/dopa oxidase, dopamine oxidase and noradrenaline activity, indicating that these cells have a biphasic melanogenic/adrenergic differentiation.This similarity between the dendritic melanocytes and the amelanotic melanoma cell line HT-18 is of interest.

ISSN:1422-6405    

DOI:10.1159/000146616

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The localization of insulin-like growth factor I (IGF-I, also called somatomedin C) production in porcine epiphysial growth plates of the distal humerus was studied by immunohistochemistry. Counterstaining with Alcian blue-van Gieson demonstrated two cell types (blue and red cells) in the germinal (reserve) proliferating and hypertrophic zones; only those chondrocytes of the proliferative and hypertrophic zones that stained red were also immunoreactive to the antibody to IGF-I. The results indicate that there exists a functional heterogeneity among the chondrocytes of both the proliferative and hypertrophic zones of growth cartilage and that IGF-I is locally produced in only the red cells of these zones. Because the red cells of the germinal zone were not immunoreactive, the results suggest that the red cells of the germinal zone and the red cells of the proliferative and hypertrophic zones are also functionally distinct.

ISSN:1422-6405    

DOI:10.1159/000146617

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The present investigation of fiber arrangement in the collateral ligaments of the knee was carried out in cats and man in various positions of flexion and extension, without compression load. In all knee joint positions, the fibers of the collateral ligaments are twisted except for the fibers in the meniscal part of the medial collateral ligament which have a parallel arrangement. Furthermore, most of the fibers in the collateral ligaments are taut in all positions of the knee joint in both cat and man. By means of planar models representing different fiber arrangements, the kinematic behavior of the collateral ligaments was analyzed. It appears that a crossed (twisted) arrangement of the fibers is most effective in rotatory movements, whereas a parallel orientation is most effective in translation. Our data further indicate that, in measuring the changes in lengths of ligaments during joint motion, one cannot neglect the internal arrangement of fibers and the geometry of the articular surfaces and menisci.

ISSN:1422-6405    

DOI:10.1159/000146618

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The fine structure of the parathyroid glands of golden hamsters exposed to 2, 5 or 10 g environment for 5 h was studied. In the centrifuged hamsters, many secretory granules are located in a peripheral position just beneath the plasma membrane of chief cells, and the Golgi complexes and cisternae of the granular endoplasmic reticulum are significantly increased compared with those of control animals. There are no significant differences between the control and centrifuged animals with regard to secretory granules, large secretory granules, lysosomes, vacuolar bodies and lipid droplets. These findings suggest that the secretory activity of the parathyroid gland may be stimulated in response to hypergravity environment.

ISSN:1422-6405    

DOI:10.1159/000146619

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The microvascular pattern of the feline renal medulla was studied by scanning electron microscopy using corrosion casts. At the corticömeduUary junction, numerous efferent arterioles were observed giving rise to peritubular capillary plexuses and arteriole rectae. Considerable differences in vessel diameters were seen. Arteriolae rectae coursed around interlobar veins before returning to the corticömeduUary area, as venulae rectae. Diffuse capillary papillary plexuses were seen protruding into the renal pelvi

ISSN:1422-6405    

DOI:10.1159/000146620

出版商:S. Karger AG    

年代:1988

数据来源: Karger