ISSN:0003-276X    

DOI:10.1002/ar.1091840102

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

年代:1976

数据来源: WILEY

摘要:

AbstractAt the close of a uterine cycle, the remodelling of the endometrial stroma of the North American opossum involves removal of extracellular material by macrophages. This study provides cytochemical and ultrastructural evidence which indicates that the laden macrophages are eliminated from the endometrium through emigration across the glandular and luminal epithelia. During diestrus or the early postpartum period, the abundant uterine glands relinquish their secretory function to acquire a transient function in the transportation of emigrating stromal cells.During the first three postpartum days endometrial regression in the stroma is marked by sudden appearance of monocytes, macrophages, lymphocytes, and plasma cells. Ultrastructural and cytochemical evidence indicates that the macrophages engulf the extracellular macromolecular material which, in the opossum, consists primarily of ground substance. Macrophages filled with ingested extracellular material aggregate beneath the glandular and luminal epithelia, where they acquire an extracellular coat that resembles the material of the basal lamina elsewhere. A fibroblast‐like cell closely invests the macrophage at the time the extracellular material appears. Simultaneously, the secretory glandular epithelium is being converted to a highly ciliated one. Macrophages, often accompanied by lymphocytes, acquire intraepithelial positions in the glands. From here these stromal cells gain entrance to the glandular lumens. At this time the luminal contents are rich in acid phosphatase activity which most likely reflects the high lysosomal content of the emigrating macrophages. Evidence suggests that these intraluminal macrophages and lymphocytes are swept, by the recently differentiated ciliary lining, toward the glandular orifices and into the uterine cavity. It is hypothesized that this cyclic appearance and transepithelial elimination of macrophages is a cellular mechanism for removing large amounts of extracellular material without disruption of the endometriu

ISSN:0003-276X    

DOI:10.1002/ar.1091840103

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

年代:1976

数据来源: WILEY

摘要:

AbstractDuring the first four days postpartum, heterophils (polymorphonuclear leucocytes) and macrophages occur in the intercellular compartment of the luminal epithelium of the uterine endometrium. Cytochemical and ultrastructural evidence indicates that transepithelial emigration of these stromal cells to the uterine cavity is occurring. This event takes place while the luminal epithelium is proliferating in response to the estrogenic stimulus of the postpartum estrus.Heterophil emigration precedes that of the macrophages and is most conspicuous during days 1 and 2. Although it has been established that collagen fibrils occur in uterine phagocytes (Schwarz and Güldner, 1967) assumed to be macrophages (Parakkal, 1969, 1972), their precise role in collagen degradation remains undefined. It seems likely that the emigrating macrophages, heavily laden with phagolysosomal derivatives and lipid droplets, are hauling the remnants of the intercellular substance out of the endometrium during days 2–4 postpartum. Ultrastructural evidence indicates that the emigrating macrophage punctures the basal lamina and passes through the intercellular compartment of the luminal epithelium by active penetration.Another mode of macrophagic egress operates in the deep stroma of the endometrium and myometrium where lymphatic drainage occurs. Macrophages accumulate in the perilymphatic stroma as well as within lymphatic vessels.Thus macrophagic emigration through the luminal epithelium and lymphatic vessels may provide a cellular mechanism for elimination of the intercellular stromal substance in the regressing uterus. Transepithelial emigration is a mechanism which operates also in the marsupial uterus (Padykula and Taylor, 1976), and thus may be a fundamental mechanism among subprimate mammals that fulfills in part the function that menstruation effects in primat

ISSN:0003-276X    

DOI:10.1002/ar.1091840104

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

年代:1976

数据来源: WILEY

摘要:

AbstractThe principal cell types associated with the humoral immune response (monocyte‐macrophages, lymphocytes, and plasma cells) are numerous in the endometrial stroma of the uterus during the first four postpartum days in two types of mammals, the marsupial North American opossum and the eutherian albino rat. This transient cellular differentiation coincides with the physiologic period of rapid uterine regression which includes massive reduction in the amount of extracellular stromal material. In addition, heterophils and eosinophils, cell types also known to be associated with phagocytic and immunologic activity, appear in the stroma during the first two postpartum days; their presence may, however, be associated more directly with the postpartum estrus that occurs on day 1 postpartum than with endometrial regression. Thus, the five cell types, which are known in pathologic conditions to be components of an inflammatory response to a foreign antigen, are conspicuously present in the normal regressing endometrium. Furthermore, there is ample ultrastructural evidence of frequent macrophagic‐lymphocytic interaction, transformation of lymphocytes, and active secretion by plasma cells during this early postpartum period.An hypothesis has been derived by uniting this new description of endometrial stromal cell differentiation with the existing literature on uterine collagenase activity, an important feature of postpartum regression (reviews by Gross, 1974; Harris and Krane, 1974). It is based on the assumption that during regression the extracellular action of neutral collagenase (and possibly other extracellular proteases) release new antigenic sites in proteins located in the ground substance. In the case of collagenase, these transient antigenic sites would arise at the locus of enzymic cleavage as well as from the subsequent denaturation of the fragments of the collagen molecule. This endogenous antigenic stimulus would be strong and temporary, and would lead to the cellular manifestations of the transient humoral immunologic response which are evident in the regressing stroma of these two mammals. This humoral immune reaction may be one of the regulatory mechanisms involved in the cyclic renewal of the extracellular compartment of the uterine str

ISSN:0003-276X    

DOI:10.1002/ar.1091840105

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

年代:1976

数据来源: WILEY

摘要:

AbstractIn placentas from viable rat fetuses which surgically had been retained beyond term in lactating animals for as long as four days, the fine structue of much of the interhemal membrane was quite like that of full‐term placentas. Moreover, contrary to what has been reported previously (Jollie, 1964a), in retained placentas which were autopsied at term there were few changes in the four cytoplasmic layers of the membrane which could be interpreted as degenerative. With prolongation of the placenta beyond normal delivery the number of pericytes which were associated with the allantoic endothelium increased; the basal lamina separating the endothelium from trophoblast III progressively became more focally split; and the apposed plasma membranes between this latter layer and trophoblast II appeared to dissociate. Trophoblast II became regionally divided in its cytoplasmic organization, its more superficial zone becoming highly infolded and/or vacuolar. As a consequence, the intertrophoblastic space between layers I and II became more extensive and complex. Within this space, a flocculent material appeared; and there was ultrastructural evidence of massive pinocytosis from the space by trophoblast II. With increased prolongation of gestation, a variety of lysosome‐like inclusions appeared within this layer of the membr

ISSN:0003-276X    

DOI:10.1002/ar.1091840106

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

年代:1976

数据来源: WILEY

摘要:

AbstractThe cat's tentorium cerebelli is an osseous structure which overlies much of the brain stem. None of the current brain atlases list the coordinates of this bony projection. With a stiff wire and a stereotaxic apparatus, the location of its free edge and dorsal surface was mapped in 1.0 mm steps in the skulls of 16 cats. In the midline the dorsal surface meets the calvaria at a point 7 mm posterior and 15 mm superior to the atlas zero (intra‐aural plane + 10 mm horizontal). From this junction it slopes inferiorly and anteriorly between the cerebrum and cerebellum along a 50° slope to terminate along a curved line. In the midline this free edge is located 0.5 mm anterior, and 6.5 mm superior to the atlas zero. It recedes laterally along a curved line to a point 6 mm lateral, 6 mm superior and 3 mm posterior to the atlas zero. The free edge then curves forward and descends to pass through an imaginary line 3 mm anterior and 4.5 mm inferior to the atlas zero. Statistical comparisons between measurements made in male and female cats revealed no significant differenc

ISSN:0003-276X    

DOI:10.1002/ar.1091840107

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

年代:1976

数据来源: WILEY

摘要:

AbstractUrinary bladders from the desert tortoises,Testudo graecaandGeochelone carbonariawere removed at specific times during the year and studied by electron microscopy. Three epithelial cell types were found in both species in all bladders examined: (1) granular cells, (2) mitochondria‐rich cells, and (3) basal cells. Cells analogous to these three types have also been observed in amphibian bladders (from to adBufo marinusand bullfrog,Rana catesbiana) and reptilian bladders (fromPseudemys scriptaandClemmys caspica). Both tortoises have an incomplete layer of basal cells so that the granular and mitochondria‐rich cells extend from the lumen to the basement membrane: some thing not observed in bladders from bullfrog or turtles. A flask‐shaped light cell was observed in theGeochelone carbonariabladder obtained in April. No counterpart of this cell was seen in the same species sacrificed in January, or in any of theTestudo graecabladders, although a similar cell has been described in the turtle,Pseudemys scripta(Rosen, Expt. Molec. Path.,12: 286–296, 1970). This study was undertaken to characterize the cell types present in tortoise bladder and to compare them with cell types in the bladder of the turtle, bullfrog a

ISSN:0003-276X    

DOI:10.1002/ar.1091840108

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

年代:1976

数据来源: WILEY

摘要:

AbstractIn autoradiographs of the retina from two‐week old chicks injected with tritiated thymidine during the first week after hatching, the labelled cells were found mainly in the extreme periphery of the retina and the ciliary epithelium of the pars plana. The pattern of labelling in the extreme periphery resembles that observed (Fujita and Horii, 1963) in retinae exposed to tritiated thymidine during embryonic development. The mechanisms underlying the histogenesis of retinal cells during growth at the extreme periphery in young stages may be the same as those which operate during embryonic developmen

ISSN:0003-276X    

DOI:10.1002/ar.1091840109

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

年代:1976

数据来源: WILEY

摘要:

AbstractThe parotid gland of the olive baboon,Papio anubis, was examined by electron microscopy. The acini are all serous in nature, and consist of pyramidal cells with abundant secretory granules of varying size. These granules consist of a dense matrix in which a denser spherule or lenticular body is present. Granules linked by a short isthmus are observed in the apical cytoplasm, and granules in the process of discharging their contents to the acinar lumen may be connected to the luminal plasma membrane by a neck‐like protrusion. Intercalated duct cells contain granules reminiscent of those found in the rat submandibular acinar cells. The striated ducts consist of tall cells interloked in a complex fashion near their bases, with numerous vertically‐oriented mitochondria lodged in their basal crenulations. Small vesicles whose contents vary in density are present in the apical cytoplasm as are large deposits of lipofuscin. The striated duct cells display a proclivity for ballooning into the duct lumen. Excretory ducts consist of simple to pseudostratified columnar epithelium, and lack basal striations or apical bl

ISSN:0003-276X    

DOI:10.1002/ar.1091840110

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

年代:1976

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091840101

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

年代:1976

数据来源: WILEY