摘要:

AbstractProteoglycans (PGs) as well as sulfated glycosaminoglycans (GAGs) are closely associated with cartilage calcification. An inner zone of endoskeletal tesserae of sharks is composed of a unique calcified hyaline cartilage. Initial calcification can be seen in the cartilage close to the inner zone. We have ultrastructurally examined shark,Triakis scyllia, noncalcifying, calcifying, and calcified cartilage using the tannic acid‐ferric chloride (TA‐Fe), the high iron diamine (HID), and the HID‐thiocarbohydrazide‐silver proteinate (HID‐TCH‐SP) methods for localization of sulfated complex carbohydrates. In noncalcifying cartilage, TA‐Fe and HID strongly stained matrix granules which were round, ovoid, elongated, or irregularly shaped and presumably represented PG monomers. The size and staining intensity of the reactive matrix granules progressively decreased in calcifying cartilage toward the calcification front of the calcified cartilage. Similarly, a progressive decrease in the size of the HID‐TCH‐SP stain deposits in the matrix granules was observed in the calcifying cartilage close to the calcification front and was interpreted as a decrease in length of sulfate containing GAG chains. In the calcified cartilage, the highly calcified areas were often localized in the calcification front and contained few or no small HID‐TCH‐SP stain deposits, whereas the weakly calcified regions contained more stain deposits. These results indicate that partial and complete degradation of sulfated GAGs and/or PGs may be a requisite for calcificati

ISSN:0003-276X    

DOI:10.1002/ar.1092080202

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

年代:1984

数据来源: WILEY

摘要:

AbstractPatterns of growth and regeneration in 2‐, 4‐, 8‐, and 17‐week‐old murine dystrophic (129 ReJ dy/dy) extensor digitorum longus muscles have been determined. Necrosis and myofiber loss, hypertrophy, and regeneration result in a reduced population of myofibers whose diameter distribution is more extensive than that found in the extensor digitorum longus muscles of age‐matched normal mice. At the onset of dystrophic symptoms (2 weeks postnatal), the ratio of myosatellite cell nuclei to the total sublaminal nuclear population (myonuclei + myosatellite cells) is similar to that found in 2‐week‐old control muscles. The frequency of finding myosatellite cells decreases with age in both control and dystrophic muscles. Myosatellite cells account for 11%, 6%, 5%, and 3% of the total sublaminal nuclear population in control muscle and 12%, 8%, 6%, and 5% of the total sublaminal nuclear population in dystrophic muscle at 2, 4, 8, and 17 weeks, respectively. No preferential association of myosatellite cells with myofibers of a particular diameter is found in control muscle or in the two youngest dystrophic groups. At 8 and 17 weeks, myosatellite cells are less frequently encountered on small‐diameter, regenerating myofibers of dystrophic muscle, and they are preferentially associated with large diameter, hypertrophied myofibers. The labeling index of myosatellite cells decreases with age in both normal and dystrophic muscle. At all ages the myosatellite cell labeling index is higher in dystrophic muscle (23%, 7%, 5%, and 2% at 2, 4, 8, and 17 weeks, respectively) than in normal muscle (5%,<1% at 2 and 4 weeks, respectively), with no labeled myosatellite cells being found in 8‐ and 17‐week‐old normal muscles. It is suggested that the magnitude of the regenerative response of dystrophic murine muscle decreases with age and that this factor may be responsible for the inability of the regenerative response of dystrophic muscle to keep pace with the rap

ISSN:0003-276X    

DOI:10.1002/ar.1092080203

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe aim of this investigation was to establish the degree of denervation produced by inferior alveolar nerve section and to provide histological evidence for the presence of pulpal nerve fibres supplying the teeth which do not travel with the inferior alveolar nerve. Four adult cats were used. Each stage of the experiment was carried out under general anesthesia. The left inferior alveolar nerve was exposed and sectioned near the mandibular foramen. After 56 hours and 7 days, respectively, the jaw opening reflex to electrical stimulation of each lower canine was tested. Recordings were made from the left canine during electrical stimulation of the ipsilateral inferior alveolar nerve central and peripheral to the site of section as well as from the ipsilateral and contralateral inferior alveolar nerve during electrical stimulation of the left canine. Recordings were also made from the lingual nerve. After the recordings were completed two animals were perfused 56 hours after inferior alveolar nerve section, two more 7 days after section. Ultrathin sections of the apices of the lower canine teeth were examined in the electron microscope and each nerve fibre photographed. Each axon was examined to determine whether it was degenerating or normal.A jaw‐opening reflex could not be elicited by stimulation of the left canine either 2 or 7 days after nerve section, whereas a normal response was evoked by stimulation of the right, control canine. At 2 days small responses could be recorded from the left canine teeth during stimulation of the left inferior alveolar nerve peripheral to the point of section. In one 2‐day animal, responses could be recorded in the lingual nerve during stimulation. No pulpal fibres could be recorded in the inferior alveolar nerve central to the point of section nor from the contralateral inferior alveolar nerve. No pulpal fibres supplying the left canine could be recorded in any of the nerves examined at 7 days.Extensive degeneration was seen histologically even at 2 days. The canine pulp on the operated side contained only 31%, in one animal, and 26% in the other, of the number of axons of normal appearance that were present on the control side. At 7 days the number of remaining normal axons on the operated side were 5% and 13% of the numbers on the control side. All the axons of normal appearance were nonmyelinated.It is possible that the remaining axons represent fibres carried by the lingual nerve or some other alternative pathway that could not be detected electro‐physiologically. Alternatively they may be a collateral innervation from adjacent ti

ISSN:0003-276X    

DOI:10.1002/ar.1092080204

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

年代:1984

数据来源: WILEY

摘要:

AbstractMultinucleated cells were observed to account for more than 17% of all cells in the periodontal ligament (PDL) of 20‐month‐old mice. The number of nuclei contained in sections of these cells ranged from 2 to 17, with over 50% of the multinucleated cells containing four or more nuclei within the plane of section. The multinucleated cells contained several cytoplasmic features resembling those previously described by the authors as characteristic of PDL fibroblasts. The multinucleated cells did not resemble osteoclasts or foreign body giant cells. It is suggested that fibroblasts develop a tendency to fuse and form multinucleated cells in the aged PDL. Similar cells were not observed in the PDL of young (5‐week‐old) mice or in the tail tendon at

ISSN:0003-276X    

DOI:10.1002/ar.1092080205

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

年代:1984

数据来源: WILEY

摘要:

AbstractMouse and guinea pig epididymal tissues have been investigated by light and electron microscopic autoradiography after long intervals ranging from 24 h to 5 days postinjection (p.i.) of the glycoprotein precursors, L‐fucose‐6‐3H of D‐glucosamine‐1‐3H. Using modified fixations to enhance glcoprotein preservation in situ, we found intense labelling of luminal contents in at least some of the epididymal segments after all the intervals investigated. At 24 h p.i., the label in guinea pig was associated with spermatozoa during remodelling of the acrosome in segment II, and at 3 days p.i., radioactivity was trapped within sperm head associations (“rouleaux”) in segment IV of the epididymis. At this time, similar rouleau labelling extended from segment IV to segment VIII. In mouse, the luminal contents of the cauda epididymis were still intensely labelled at 5 days p.i.; analysis of the electron microscopic autoradiograms showed that relative grain concentration over the spermatozoa was twice that of the epididymal plasma. This concentration was especially elevated in the region of the sperm head. These findings taken together were interpreted as the binding of secreted epididymal glycoproteins to spermatozoa during sperm transit through the epididymis.In contrast to luminal contents, the labelling of the epididymal epithelium was generally lower, except on the clear cells which showed more pronounced labelling than the neighboring principal cells in mouse cauda epididymis at 5 days p.i. This label probably originated from the resorption of lumina

ISSN:0003-276X    

DOI:10.1002/ar.1092080206

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

年代:1984

数据来源: WILEY

摘要:

AbstractSterological methods at the light and electron microscopic levels were used to examine the morphological changes in the beagle prostate associated with inceasing age and with the occurrence of spontaneous benign hyperplasia. Analyses of semithin sections of tissue embedded in plastic revealed that proliferation of prostatic glandular and stromal components, increase in epithelial cell numbers, and increase in epithelial cell size all contributed to the dramatic increase in prostate weight seen in aging dogs. Analyses at the electron microscopic level revealed that the volume densities of rough endoplasmic reticulum and secretion granules were significantly lower in epithelial cells of the immature prostate than in the prostate of mature dogs (greater than 1.5 years of age). In contrast, no significant difference were seen in the volume densities of rough endoplasmic reticulum, free ribosomes, secretion granules, smooth endoplsmic reticulum, or mitochondria in randomly selected prostatic epithelial cells of dogs 1.5 to 9 years of age, whether or not the prostates were hyperplastic.

ISSN:0003-276X    

DOI:10.1002/ar.1092080207

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to determine the effect of ethanol consumption on compensatory ovarian hypertrophy (COH) which occurs follwoing unilateral ovariectomy. Holtzman rats, 40 days old, were either unilaterally ovariectomized or sham‐ovariectomized. The rats were then placed into subgroups which would receive either an ad libitum chow and water diet, a liquid diet, or a liquid diet containing 5% ethanol. The animals were maintained on their respective diets for 11 days. The rats were killed at 51 days of age, and the ovaries and uteri were removed, weighed, and prepared for histological investigation. The results showed that uteri from ethanol‐fed animals failed to develop epithelial glands and exhibited a condensed stroma in comparison to uteri from animals fed ad libitum or pair‐fed to ethanol‐fed rats. Also, rats that were fed ad libitum had a COH of 82 ± 16% and rats that were pair‐fed a liquid diet had 114 ± 28% COH; rats that were fed the liquid diet containing ethanol did not experience compensatory ovarian hypertrophy (−3 ± 10%). Histologically, the ovaries of rats fed ad libitum showed large numbers of corpora lutea and only a few mature ova. The histology of ovaries from pair‐fed animals was similar to those from animals fed ad libitum. In contrast, the ovaries from the animals fed the ethanol diet had nearly twice as many mature ova but only one‐fourth as many corpora lutea as the number seen in ovaries from the other groups. The data show that ethanol consumption inhibits COH by suppressing ovulation and the subsequen

ISSN:0003-276X    

DOI:10.1002/ar.1092080208

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe activation of physiologically inactive medullary bone osteococlasts by paratathyroid hormone (PTH) was examined using light and electron microscopy and histomorphometric methods. Medullary bone osteoclasts are functionally inactive during the avian egg‐laying cycle when an egg shell is not being calcified in the shell gland. Japanese quail hens were given 0.5 IU/g PTH and the medullary bone osteoclasts were examined up to 90 min later. Administration of PTH results in rapid changes in osteoclast morphology and ultrastructure. Within 10 min ectoplasmic regions containing condensed‐appearing material are evident in areas of the cell adjacent to bone surfaces. In tannic acid‐fixed specimens, these ectoplasmic regions contain bundles of filaments extending perpendicularly from the osteoclast plasma membrane into the cytoplasm. It is in these areas that ruffled border development is initiated. Even at 10 min after PTH administration, mineral crystals are seen between the developing cell surface invaginations and folds. By 15 min after PTH administration, ruffled borders have appeared next to bone surfaces. The rapid development of ruffled borders on medullary bone osteoclasts after PTH is confirmed by electron microscope histormorphometry. By 30 min after PTH administation, ruffled borders are well developed and large endocytic vaculoles are beginning to appear in the osteoclast cytoplasm. Light microscope histomorphometric measurements indicate that osteoclasts are also increasing in size and speeading along bone surfaces with time after PTH administration. This study provides a morphologic and ultrastructural desciption of osteoclast activation by PTH. The results indicate that osteoclasts may effect rapid changes in bone resorption and mineral metabolism due to exogenous PTH in

ISSN:0003-276X    

DOI:10.1002/ar.1092080209

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

年代:1984

数据来源: WILEY

摘要:

AbstractInsulin, glucagon, somatostain, and pancreatic polypeptide (PP) were localized in the pancreas of the common garter snake,Thamnophis sirtalis, by light and transmission electeron microscopic (TEM) immunocytochemistry. Colloidal gold‐protein A was used for TEM localization and the peroxidase containing A cells and the insulin‐positive B cells were the most numerous cell types. The somatostatin‐containing D cells made up about 15% of the endocrine cells. PP‐positive F cells were a minor cell type. The only topographic arrangement of the cells within the endocrine‐rich areas that was apparent was the peripheral localization of the D and F cells. Cells of a specific cell type were sometimes grouped together. At the elctron microscopic (EM) level, the gold particles (indicating the pesence of hormone) were localized nearly exclusively over the secretory grnules of the ractive cells. The α‐granules were the largest found and were predominantly electron dense with a moderately electron‐dense periphery. PP‐containing granules were the smallest. The somatostatin‐reactive δ‐granules were round and moderately electron opaque. The β‐granules were heterogeneous in appearance. The morphognomy of the secretory granules of the major endocrine cell types is qualitatively similar to that of mammals. Wheter or not the quantitative and/or associative differences contribute to the marked metabolic differences between reptiles and mammals,

ISSN:0003-276X    

DOI:10.1002/ar.1092080210

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

年代:1984

数据来源: WILEY

摘要:

AbstractWe have described an extramedullary myelopoietic tissue located in the wall of the yolk sac. This myelopoietic site is absent at hatch and it produces only granulocytic and monocytic cells during the regression of the yolk sac from 2 to 7 weeks of age. The granulocytic and monocytic cells are located in two distinct zones. The monocytic cells migrate close to the lumen of the yolk sac where they may fuse and form giant cells. There are no mature granulocytes present. Cell migration has not been observed. Therefore, the fate and function of the young granulocytic cells are unknown. In this extramedullary myelopoietic tissue, the absence of erythrocyte and thrombocyte formation may indirectly suggest that these cells develop together in sinuses that are lacking in the wall of the yolk sac.

ISSN:0003-276X    

DOI:10.1002/ar.1092080211

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

年代:1984

数据来源: WILEY