ISSN:0003-276X    

DOI:10.1002/ar.1091990313

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

年代:1981

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091990314

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

年代:1981

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091990315

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

年代:1981

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091990316

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

年代:1981

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091990317

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

年代:1981

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091990318

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe formation and maturation of collagen secretion granules in periodontal ligament (PDL) fibroblasts of young male Balb‐C mice were studied by electron microscopy and cytochemistry. The Golgi apparatus was composed of several dictyosomes, each consisting of a stack of five smooth‐walled cisternae. Each cisterna was connected at both ends to a dilated saccule. The cisternae, with their associated pairs of saccules, underwent progressive maturational changes from the immature to mature face of each dictyosome. The most immature saccules (type 1) were large, spherical, and filled with loosely arranged short filamentous structures. These saccules were continuous with the first and second Golgi cisternae (counting from the immature side). Golgi saccules type 2 were ellipsoidal, associated with the third and fourth cisternae, and contained parallel, elongate filaments. The most mature saccules, type 3, were more rectangular and connected by a short fifth cisterna. They contained aggregated filamentous material in the form of eight segment‐long‐spacing (SLS)‐like crystallites, one in the center and seven at the periphery, to form a basic secretory unit. As type 3 saccules matured, the interconnecting cisterna progressively shortened until the two saccules were nearly juxtaposed. At this time the shortened fifth cisterna split to give rise to two independent presecretory granules. By progressive condensation, presecretory granules matured into secretion granules that contained a densely packed SLS‐ like aggregate, within which individual crystallites were no longer discernable. Maturation of cisternae and saccules involved removal of membrane, apparently by the formation and detachment of coated vesicles. The staining reaction with silver methenamine and phosphotungstic acid increased over the procollagen as the saccules matured, indicating addition of carbohydrate moieties and possible crosslinkages. It is concluded that the formation and maturation of collagen secretion granules in PDL fibroblasts involves the packaging and further modification of eight SLS‐like crystallites, which are secreted as

ISSN:0003-276X    

DOI:10.1002/ar.1091990302

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

年代:1981

数据来源: WILEY

摘要:

AbstractA comparison of the anatomy, fiber type profiles, and contractile properties of the wrist flexor muscles was undertaken in the cat. Isometric contractile characteristics were measured for each muscle. Three muscle fiber types, FG, FOG, and SO, were differentiated by staining cross sections of each muscle for ATPase, NADH diaphorase, SDH, and α‐GPD activities. The wrist flexor muscles ranged from less than 1% to 49% SO fiber content; with two of the five heads of the flexor digitorium profundus (FDP) having 1% or less SO fibers (FDP1—1.07%, FDP5—0.81%) and the humeral head of the flexor carpi ulnaris muscle (FCUh) having the greatest content of SO fibers. The mean contraction time (CT) plus one‐half relaxation time for an isometric twitch was correlated with the percentage of SO fibers and ranged from 40.5 to 111.8 ms. Except for the FCU (37 ms), the CT was less than 25 ms for the wrist flexor muscles. The uniarticular wrist flexor muscles, the flexor carpi radialis (FCR), and the FCU had the highest percentage of SO fibers and were more fatigue‐resistant that the multiarticular muscles. Considerable differences exist in muscle structure, fiber type proportions, and contractile properties between the FCR and FCU, which may be related to functional differences between the two sides of the wrist that may exist during the placement of the foot during

ISSN:0003-276X    

DOI:10.1002/ar.1091990303

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

年代:1981

数据来源: WILEY

摘要:

AbstractPatterns of activity of six dehydrogenase enzymes were studied histochemically in 42 free muscle grafts in the rat. Within hours, the surviving peripheral muscle fibers can be distinguished from the central ischemic muscle fibers. The surviving muscle fibers retain their characteristic pattern of staining throughout the post‐transplantation period. The central ischemic muscle fibers stain abnormally and by five or six days they lose their enzymatic activity. The zone of regeneration, between the surviving and the ischemic muscle fibers, initially shows little dehydrogenase activity, but as the regenerating muscle fibers mature, they develop first a homogeneous staining pattern and, later, differences in staining intensity among different types of muscle fiber

ISSN:0003-276X    

DOI:10.1002/ar.1091990304

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe establishment of the undifferentiated gonad was studied inXenopus laevisandRana pipiensusing high resolution techniques. It was found that the cells of the so‐called “mesonephric blastema” had no structural resemblance to the cells of the gonadal medulla in both species. Furthermore, there was no morphological evidence that would suggest a migration of the former cells towards the incipient gonad at the time of its appearance. However, the basal lamina of the coelomic epithelium was interrupted in the region of the genital crest, and there was a definite ultrastructural similarity between the cells of this epithelium and those that first form the medulla. These observations suggest that, in amphibians, the cells of the gonadal medulla come from a cellular line arising from the coelomic epithelium and not from the “mesonephric blastema,” as has been

ISSN:0003-276X    

DOI:10.1002/ar.1091990305

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

年代:1981

数据来源: WILEY