摘要:

AbstractThe degree of mineralization of deeply embedded intraosseous fibers has been the subject of speculation. However, there were few available descriptive morphological studies addressing this question. The present study demonstrated that morphological differences were evident between intraoseous fibers of different levels of the interdental septum. It also revealed that the degree of mineralization of intraosseous fibers was often different at the wall of the tooth socket in comparsion to that at deeper levels of interdental bone. Except in the superior crestal third, intraosseous fibers became less mineralized as they passed from the wall of the tooth socket to the midline of the interdental septum. They were surrounded by sheaths throughout their distribution. It was concluded that there might be significant differences in the morphology of intraossoeus fibers of the mouse in comparision to the morphology of intrasseous fibers of the dog, which have previously been described in detail.

ISSN:0003-276X    

DOI:10.1002/ar.1092060102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThis study compares the acinar cell regnerative response in submandibular gland (SMG) autografts that were cultured before grafting to the rat tongue with the acinar cell regenerative response in direct SMG autografts to the tongue. In addition, the effects of isoproterenol on direct SMG autografts were studied. A portion of the left SMG was excised from each rat and cut into fragments which were autografted either immediately into the middle one‐third of the rat's tongue; or were cultured for 1, 4, or 7 days and then autografted to the donor's tongue. After 8 weeks the rats were killed and the tongues were removed and processed for light microscopic study. The histologic preparations showed evidence of cytodifferentiation into acinar cells in four of the previously cultured SMG autografts. Some of the direct SMG autografts did not contain acinar cells, whereas other direct. SMG autografts contained numerous acinar cells and even straited ducts. In the SMG autografts that were cultured for 1 day before autografting and in the direct SMG autografts, that contained ductlike structures that were apparently connected to the epithelial surface of the tongue. Lastly, isoproterenol appeared to accelerate the regenerative responses in some of the direct SMG autografts, and the drug caused acinar cell hypertrophy in two of the direct SMG autograft

ISSN:0003-276X    

DOI:10.1002/ar.1092060103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of estradiol on the granular ducts in submandibular glands of female albino rats were studied. Twenty‐five‐milligram pellets of 17 β‐estradiol were implanted subcutaneously in the experimental animals, and their glands, as well as controls, were examined after 2, 4, 7, and 10 wk using light and electron microscopy. During the course of the experiment an increasing proportion of the granules in the granules ducts appeared more lightly stained in the experimental animals. In the estradiol‐treated rats the granular ducts increased in relative cross‐sectional area at a faster rate than in the controls, which exhibited maturation changes. In addition, the average number of granules per granular duct cell decreased significantly in the treated animals. Our results indicate that estradiol caused a change in the cytology of the granular ducts suggesting an alteration in protein synthesis. These results might occur through a change in structural proteins or in other hormones and growth factors which are known to influence the submandib

ISSN:0003-276X    

DOI:10.1002/ar.1092060104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractAn emphysemalike condition can be induced in animal lungs by the instillation of a single dose of elastase. Autoradiogrphy was used to determine the location of3H‐methylated porcine pancreatic elastase in hamster lungs at four time points. Six hours after instillation of radiolabeled enzyme the distribution of silver grains was very patchy, but in heavily labeled areas grains were concentrated over macrophages, connective tissue areas and over some fibroblasts. By 24 hr the labeling of connective tissue areas was no longer evident and almost all silver grains were associated with macrophages or with the edema fluid that filled many alveoli at this time. By 4 days only macrophages exhibited concentrations of silver grains. The labeling of macrophages was still evident at 7 days.Elastase inactivated by N‐acetyl‐(L‐alanyl)3‐L‐alanine chloromethyl ketone showed a different distribution 6 hr after instillation. Silver grains were concentrated over macrophages and alveolar type II cells but showed no affinity for connective tissue areas or fibroblasts. By 24 hr almost all grains were located over heavily labeled

ISSN:0003-276X    

DOI:10.1002/ar.1092060105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractClonal pituitary cells (2B8) derived from embryonic Rathke's pouch epithelium of Wister‐Imamichi rats established by Ishikawa et al. (1977) were used in this study. Late‐passage 2B8 cells were found to contain small secretory granules which contained immunoreactive prolactin as demonstrated by electron microscopic immunocytochemistry. When 2B8 cells were incubated in the presence of various agents that are known to stimulate or inhibit prolactin secretion, the volume density of the secretory granules in the cytoplasm was shown to be alte

ISSN:0003-276X    

DOI:10.1002/ar.1092060106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe noradrenergic sympathetic innervation of the penis of control and 4‐month streptozotocin‐diabetic rats was examined with the glyoxylic acid histofluorescence method. Noradrenergic varicosities were found in the corpora cavernosa in a dense subtunical plexus and in the perisinusoidal and trabecular regions of the erectile tissue, in the corpus spongiosum in perisinusoidal tissue, around large arteries and veins, and around small tortuous arterioles and small draining veins of the corpora cavernosa and spongiosum. Noradrenergic varicosities were diminished in number and fluorescent intensity in all regions of the penis of diabetic rats compared with controls. The subtunical plexus was absent, perisinusoidal and trabecular varicosiities were sparse, and only occasional intermittent, discontinuous, dull fluorescent fibers or plexuses were found around the vessels. Quantitation with highperformance liquid chromatography revealed a significant reduction of norepinephrine in the penis of diabetic rats compared with controls. The present study suggests that long‐term streptozotocin diabetes in the rat is accompained by sympathetic autonomic neuropathy of the penis that seems to parallel changes in the noradrenergic content of penile corpora of men with diabetes and erectile impotence. The streptozotocin‐diabetic rat merits further study to explore the relationship between noradrenergic innervation of the penis and erectile

ISSN:0003-276X    

DOI:10.1002/ar.1092060107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe frontal region of the embryonic chick was studied to determine whether epithelial influences are necessary for frontal bone development. The frontal bone is a membrane bone, of neural crest and head mesodermal origin, which develops within mesenchyme sandwiched between two epithelia, neural ectoderm and epidermis. Rudiments were treated enzymatically to separate epithelial and mesenchymal tissues. Frontal mesenchyme then was grown as chorioallantoic membrane grafts either in the presence or absence of neural ectoderm and/or epidermis. The results indicate that neural ectoderm, though required during early stages of development to induce frontal bone development (Schowing, 1968), is not required during later stages (HH 22–30, the stages tested in this study) for osteogenesis. Epidermis, however, was shown to be required for frontal bone development during the stages tested. Frontal mesenchyme formed bone when epidermis was present on the outer aspect of the mesenchyme, and did not form bone when the epidermis had been removed prior to grafting, whether or not neural ectoderm was present. This dependence upon epidermis continues beyond the onset of meningeal differentiation. Once the outer ectomeninx‐dermis is distinguishable from the inner endomeninx, osteogenic capabilities are confined to the ectomeninx‐dermis layer. Furthermore, the ectomeninx‐dermis layer attached to epidermis is able to form membrane bone in the absence of the endomeninx and neural ectoderm. The endomeninx, though normally nonchondrogenic, was shown to be capable of forming cartilage when the neural ectoderm is removed. Neural ectoderm, therefore, may have an inhibitory effect on chondrogenesis in the end

ISSN:0003-276X    

DOI:10.1002/ar.1092060108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe goal of this study is to determine the average numbers of afferent axons and postganglionic autonomic (sympathetic) efferent axons supplying the cat knee joint through the medial and posterior articular nerves. Interestingly, both nerves are composed primarily of unmyelinated axons. Only 20% of the axons in the medial articular nerve are myelinated, with the overwhelming majority, 80%, being unmyelinated. The posterior articular nerve has 78% unmyelinated and 22% myelinated axons. Neither nerve contains ventral root efferent axons. The sympathetic chain, in both nerves, contributes no myelinated and only 50% of the unmyelinated axons. The medial and posterior articular nerves are therefore predominantly afferent, since all myelinated and the remaining 50% of the unmyelinated axons arise from the dorsal root ganglion cell. The ratio of afferent unmyelinated to myelinated axons is 2:1. The roles of these afferent unmyelinated axons must now be considered in regard to joint kinesthetics and pain.

ISSN:0003-276X    

DOI:10.1002/ar.1092060109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe surface morphology of normal and regenerated nerve roots was studied using correlated scanning and transmission electron microscopic methods. Nerve roots of the cauda equina were either cut and rejoined or crossed from a segment above to a segment below. Good regeneration was observed in both experimental procedures. The regenerated nerve root sheath had alterations in surface structure created by extensive growth of collagen. Despite this collagen formation, regenerated axons crossed the anastomotic site with relative ease. Surface features of the regenerated axons were similar in appearance to those of the normal axon. Schwann cells were easily recognized, as were the collagen fibers of the endoneurium, although the endoneurium was more prominent and occupied more of the interaxonal space. Macrophages were identified as round structures with a laminated surface or as a honeycomb structure. Internal features of the regenerating axons were more difficult to identify, but mitochondria and a fibrous network were observed. These studies have demonstrated the application of scanning electron microscopic methods to visualize surface structures and cells in regenerated nerve roots.

ISSN:0003-276X    

DOI:10.1002/ar.1092060110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe morphological characteristics of olfactory receptor neurons and their relations to the sustentacular cells and to the sheath cells of Schwann in the olfactory mucosa of the salamander (Ambystoma maculatum et tigrinum) were studied using a modification of the rapid Golgi technique. The bipolar receptor neurons had a fusiform‐shaped cell body whose apical pole gave rise to a surface‐reachig dendrite and a basal pole which gave rise to an axon. The length and width of the dendrite, although variable, were positively correlated with the relative depth at which the cell body was located in the sensory epithelium. Beyond the initial segment, the axon had a sinuos course prior to its entrance into the lamina propria. Within the lamina propria, the axons were associated with the sheath cells of Schwann to for the olfactory nerve fascicles. The processes of adjacent sheath cells formed an elaborate network of continous cavities through which the axons coursed.Two morphologically distinct varieties of sustentacular cells, designated types I and II, were found in the sensory epithelium. Both types had a columnar profile cnsisting of an elongated cell body, a central stalk, and a basilar expansion of the stalk found at the junction of the epithelium with the lamina propria. The central stalk of type I sustentacular cells was unbranched, whereas that of type II cells gave rise to riblike processes from which cytoplasmic veils extended to envelop the cell bodies of receptor neurons. The basilar expansions were found in close apposition to the wall of capillaries or to acinar cells of Bowman's glands located in the most superficial region of the lamina propria. The morphological relationships and possible interdependencies among receptor neurons, the types of sustentacular cells, and the sheath cells are discus

ISSN:0003-276X    

DOI:10.1002/ar.1092060111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY