摘要:

AbstractIn this continuing series of studies of implantation in the rhesus monkey, eight specimens, ranging in gestation age from 9.5 days to 16.5 days after ovulation, were examined with a focus on localized modifications in the endometrium as a response to implantation. Additionally, evidence of continuing changes in early pregnancy was provided by three specimens at the end of the first month of gestation (days 24, 28, and 35). The responses of the endometrium to pregnancy start with a localized accumulation of stromal eosinophils, which is rapidly followed by epithelial plaque formation in the basal cells of the luminal epithelium and gland necks. Plaque cells hypertrophy, develop marginal dense granules, and accumulate glycogen. They form a pad underlying the margins but not the central zone of the implantation site. However, some degenerating plaque cells are found as early as day 15; and little more than a region of leukocytic infiltration remains of the plaque by day 35. Shortly after the plaque response is initiated there is a striking subepithelial edema surrounding the plaque, and the venular capillaries enlarge by engorgement and by endothelial hyperplasia. The endothelial cells subsequently hypertrophy, resulting in a largely columnar endothelium. There is a localized decidual cell response, consisting of an increase in rough endoplasmic reticulum and in filaments, but only a moderate amount of hypertrophy of these cells. Endometrial granular cells become more conspicuous in the area as they accumulate glycogen. Patches of large pale cells appear in the lumen and walls of arterioles subjacent to the implantation site, but the cytology of these cells provided insufficient clues to their origin (cytotrophoblast?). Although the endometrial responses described are impressive and diverse, their advantages to the organism are not obvious. The hypertrophy of the anastomotic capillary bed that accompanies plaque formation may well provide an extensive vascular network available to the developing trophoblastic lacunae. The role of endometrial granular cells, decidual cells, and even plaque cells may be more related to their largely unexplored secretory activity than to their physical contribution to the formation of the basal plate.

ISSN:0002-9106    

DOI:10.1002/aja.1001730302

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe intraperitoneal injection of bacterial toxin and complete Freund's adjuvant in mice produced the classical inflammatory response. However, when allowed to continue, this process led to the formation of granulation tissue of the mesothelial surface. The initial lesion of the reaction was characterized by the deposition of a copious amount of fibrin filaments which were involved in the adhesion and aggregation of peritoneal cells into discrete cellular mounds on the peritoneal mesothelial surface. By 1 week postinjection, fibrin was markedly diminished and appeared as electron‐dense precipitates upon which collagen fibrils were deposited. By 2 weeks, the amount of collagen was greatly increased; and the granular components of fibrin were markedly diminished. Coincident with the deposition of collagen fibrils, there was also a neovascularization of the cellular aggregates. This process occurred when the blood and lymphatic vessels within the submesothelial connective tissue branched and invaded the newly aggregated cellular mounds. By 1 month, the cellular aggregates had taken on the appearance of granulation tissue with foci of closely packed macrophages, fibroblasts, and a network of newly formed blood and lymphatic capillaries. This intraperitoneal stimulation provides anin vivosystem in which the various cellular and extracellular events of inflammation leading to the formation of granulation tissue can be monitore

ISSN:0002-9106    

DOI:10.1002/aja.1001730303

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

年代:1985

数据来源: WILEY

摘要:

AbstractSensory endings of chorda tympani and lingual (trigeminal) nerve fibers were identified by selective denervation and localized within specific regions of fungiform pipillae in the hamster. The chorda tympani was resected from the middle ear and the peripheral fibers were allowed to degenerate for 1, 3, or 8 days prior to perfusion‐fixation and electron‐microscopic examination of the anterior tongue. Taste buds were virtually devoid of intact nerves by 3 days following chorda tympani denervation. Remnants of the fibers were restricted to taste buds. Lingual fibers, on the other hand, persist in normal numbers after chorda tympani resection and populate perigemmal areas of connective tissue and extragemmal areas located apically in the squamous, nontaste epithelium surrounding the taste bud. This study provides evidence of a segregation of chorda tympani fibers in the taste bud and lingual nerve fibers in the apical fungiform papilla. The lingual nerve‐epithelial arrangement and superficial location, near the least cornified area of the tongue, may be well suited for relatively sensitive somatosensation, possibly mechanoreception. Thus, the apical fungiform papilla appears to be a site where both taste and tactile oral stimuli interact with rece

ISSN:0002-9106    

DOI:10.1002/aja.1001730304

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe endocytic activity taking place at the apex of Sertoli cells was analyzed by using various tracers to demonstrate fluid‐phase and adsorptive endocytosis. Native ferritin and protein‐gold complexes, used to demonstrate fluid‐phase endocytosis, were internalized by Sertoli cells at all stages of the cycle of the seminiferous epithelium. At 5 min after injection, the tracers were found in the large spherical or C‐shaped vesicles seen in the apical processes; at 15 and 30 min, the tracers accumulated in light multivesicular bodies, and at 60 min in dense multivesicular bodies and lysosomes. At later time intervals, an increasing number of lysosomes contained the tracers. Following injection of cationic ferritin or concanavalin A‐ferritin, these tracers, used to demonstrate adsorptive endocytosis, were found to be found to the plasma membrane of Sertoli‐cell apical processes but were not collected by the large cytoplasmic apical vesicles, multivesicular bodies, or lysosomes. As an exception, a few special multivesicular bodies seen in the large apical processes which encapsulate the heads of late spermatids at stage VII of the cycle contained these tracers. During stage VIII of the cycle, the residual bodies which detach from the mature spermatids are phagocytosed by Sertoli cells. Such residual bodies do not contain their own hydrolytic lysosomal enzymes. However, it was observed that the lysosomes which form as a result of the fluid‐phase endocytic activity of the Sertoli cells fuse with the phagocytosed residual bodies and by means of their hydrolytic enzymes contribute to the rapid disintegration of these bodies. Thus, during stage VIII of the cycle, the Sertoli cells integrate two distinct processes, i.e., fluid‐phase endocytosis a

ISSN:0002-9106    

DOI:10.1002/aja.1001730305

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

年代:1985

数据来源: WILEY

摘要:

AbstractThis wide‐ranging, omnivorous lizard of Australia has a very complex adductor muscle mass, with fibers differing in length by a factor of three and in insertion angle by 90°. Stimulated muscles produce maximal moment with the mouth nearly fully open. The opening mechanism appears to involve only simple rotation and no translation of the mandible. EMGs indicate that the entire mass is activated equivalently in crushing and there are no temporal subdivisions, for instance, matching activity to angle of opening. During crushing of hard objects, the chin is brought into contact with the ground so that the subvertebral muscles may aid buccal closure. The lizards also activate the muscles in a pulsatile staircase effect leading to an unfused tetanus that generates forces several times the twitch level. Application in parallel of a maximum number of sarcomeres to the crushing bite appears to be the major design characteristic. Hence, this species offers an ideal case for analysis of the effects of different sarcomere placements on the simple movement generated. For the primary adductor muscles, the angles of fiber insertion relative to the lines connecting each insertion with the jaw joint are equivalent; this relation persists as the mouth opens. Also, fiber lenghts are proportional to the distance between jaw joint and site of insertion so that each sarcomere contributes equally to the movement generated. Complex tendons provide additional space for muscle placement. Some of these also extend beyond the bony attachment sites, producing tendinous “coronoid processes.” The fibers of laterally and ventrally placed muscles are short relative to the length of the entire muscle, insert at relatively short moment arms, and undergo short excursion during opening; however, there are many such fibers. Also, muscles with a low incident angle are crossed; they apparently protect the jaw joint from horizontal (disarticulating)

ISSN:0002-9106    

DOI:10.1002/aja.1001730306

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

年代:1985

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001730301

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

年代:1985

数据来源: WILEY