摘要:

AbstractThe fine structure of spermatozoa of two species of monkey,Macaca mulattaandMacaca nemestrina, and man was studied following fixation of seminal fluids in buffered picric acid‐formaldehyde (PAF). The various components of the sperm have been studied mostly in light of the behavior of this cell at the time of conjugation with the ovum.The possible equivalence between acrosome and lysosomes has been discrussed considering the origin, enzymatic activity, and mechanism of action of these two classes of organelles. The fine morphology of the post‐acrosomal cap has been found to be comparable to that of a septate desmosome. We have introduced the hypothesis that the cap plays a role in establishing and maintaining adhesion between the spermatozoon and the ovum at the time of gamete conjugation. The formation of the scrolls of the nuclear membrance in the posterior region of the nucleus has been put into relation with the modifications of volume and shape of the spermatid nucleus. The function of the scrolls could be to increase the surface through which nucleocytoplasmic exchanges take place. The possibility that the presence of a voluminous cytoplasmic droplet in human spermatozoa is a sign of cellular immaturity has also been discus

ISSN:0003-276X    

DOI:10.1002/ar.1091690202

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe study of the fine structural organization of the various components of the neck of mature spermatozoa of rabbit, monkey and man has demonstrated that the striated columns of the connecting piece implant on the proximal centriole, that the distal centriole does not disappear but persists albeit in a modified form and that the central tubules of the axoneme of the flagellum terminate at the lower vault of the proximal centriole. Of the two centrioles, the most plausible candidate for the role of basal body of the flagellum and center of the sperm motility appears to be the proximal centriole. This hypothesis is supported directly by the apparent continuity of this centriole with all the contractile elements of the flagellum, and indirectly by the consideration that the distal centriole cannot be a basal body in that its lumen is traversed throughout by a central pair of tubules. The orientation of the proximal centriole at an angle to the flagellum, a unique situation since basal bodies are normally oriented on the same axes of cilia and flagella, has been tentatively accounted for by the particular type of motility of the spermatozoon.

ISSN:0003-276X    

DOI:10.1002/ar.1091690203

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

年代:1971

数据来源: WILEY

摘要:

AbstractThere is wide support for the concept that there are two types of secretory cells in adrenal medulla of various species. One cell is filled with electron dense bodies believed to contain norepinephrine; the other cell's lesser stained bodies contain epinephrine. This differential density may be seen by fixation in osmium tetroxide after glutaraldehyde.The two cell types have not been clearly shown in human tissues. Such a failure may be related to fixation. In consideration of this, fresh human adrenal was fixed in cold 1% glutaraldehyde, then 1% osmium tetroxide — a procedure known to give satisfactory differentiation in other species. A parallel study with rat tissue was then done.Electron microscopy revealed two types of cells in rats, while in man an obvious cell difference was not found. There is, however, a clear difference in human chromaffin granule density, which implies that the human cells have random numbers of both light and dark granules. The morphologic difference of the cell types in man may be less distinct than in the rat. Another possibility is that in cells with predominantly dark granules, there are co‐mingled lighter granules with the coexistence of cells of opposite dominance. Both hormones then would occur in the same cell in varying proportions according to functional demand. It seems highly unlikely that two distinct cell types would have been overlooked with wide sampling, however, in a study of three adrenal glands, one cannot rule out their existe

ISSN:0003-276X    

DOI:10.1002/ar.1091690204

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

年代:1971

数据来源: WILEY

摘要:

AbstractRat lungs were fixed by perfusion of fixatives through pulmonary vessels which resulted in good fixation of bronchioles. This technique allows the preservation of a hitherto not described extracellular lining of the bronchiolar surface, which by conventional fixation (immersion or instillation of the fixatives into the airways) is washed out. The cilia appear to be embedded in an extra‐cellular, amorphous material. This material is often lined at its surface by a strongly osmiophilic layer. Tubular myelin figures can also be identified. Comparison with recent physiological and biochemical work, which establishes the presence of surface‐active material in the airways, strengthens the conclusion that this layer is related to bronchiolar “surfactant” fixed in situ. A mixed origin of this material from the Clara cells and from the alveolar surface lining layer is su

ISSN:0003-276X    

DOI:10.1002/ar.1091690205

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe epithelium in the region of the vaginal introitus in the rat (“introital epithelium”) was examined in sexually mature animals in different stages of the estrous cycle. It was found to be stratified squamous in type and invariably cornified, irrespective of the state of the vaginal epithelium above it. Thus, it failed to undergo the estrous cyclic changes seen in the rest of the vaginal epithelium. The introital epithelium extends for a distance of 1.5 to 5 mm above the vaginal orif

ISSN:0003-276X    

DOI:10.1002/ar.1091690206

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

年代:1971

数据来源: WILEY

摘要:

AbstractInTadarida, the endodermal cells that form the yolk sac originally delaminate from the inner cell mass and proliferate to form a complete lining of the trophoblastic vesicle, creating a bilaminar omphalopleure. These cells remain squamous until the splanchnic mesoderm migrates in between the two layers of the omphalopleure, at which time they begin to hypertrophy. The current study is an analysis of the cytological changes that accompany this hypertrophy as well as additional changes that occur throughout the remainder of the gestation period. Among the early changes are: (1) the formation of numerous microvilli along the apical surface of the cells, (2) the appearance of coated vesicles, also along the apical plasma membrane, (3) the establishment of a system of absorption tubules in the apical cytoplasm, (4) an increase in mitochondria, and (5) the appearance of glycogen within the channels of the membranous organelle.A wave of hematopoietic activity follows the migration of splanchnic mesoderm around the trophoblastic vesicle, and at this time the erythroblasts and embryonic erythrocytes can be seen in a close relationship with the endodermal cells.Subsequent changes include the enlargement of the membranous organelle and the appearance of a paracrystalline membranous structure. In addition, the endodermal cells store large quantities of lipid and glycogen that are substantially depleted just before birth.

ISSN:0003-276X    

DOI:10.1002/ar.1091690207

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

年代:1971

数据来源: WILEY

摘要:

AbstractIn the molossid bat,Tadarida brasiliensis cynocephala, there is a prominent diffuse endotheliodichorial placenta over the parietal area of the uterus prior to mid‐gestation. During the neural groove stage the syncytium rapidly increases in quantity, and cells from the cytotrophoblast have been observed being contributed to the syncytium. The transitional cells become swollen and the plasma membranes between the syncytium and the transitional cell fuse, become porous, and rupture. The contents of the transitional cell then “flow” into the syncytial

ISSN:0003-276X    

DOI:10.1002/ar.1091690208

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

年代:1971

数据来源: WILEY

摘要:

AbstractGroups of five rabbits were killed at 0, 2, 4, 7, 10, 24, 48, 98, 168 and 240 hours after mating. The glycogen content of the lower half of the Fallopian tube was greater than in the upper half at each interval. Uterine and Fallopian tube levels of glycogen decreased during the interval from mating to ovulation. Both cervical and vaginal glycogen declined significantly within 24 hours after mating. Decidual uterine areas contained 1.5 and 5.0 times more glycogen on days 7 and 10, respectively, than interdecidual areas. Castrate rabbit Fallopian tube, uterus, cervix and vagina responded with glycogen synthesis to estradiol, but not to progesterone administration.

ISSN:0003-276X    

DOI:10.1002/ar.1091690209

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

年代:1971

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091690210

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

年代:1971

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091690201

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

年代:1971

数据来源: WILEY