摘要:

AbstractMature male rats were rendered cryptorchid and followed for up to nine weeks during which serial blood specimens were obtained for multiple hormonal analyses; serial testicular samples were obtained as well. In contrast with control animals, cryptorchid rats showed transient rises in FSH which returned to normal at the end of the study; estrogen levels were high in the final weeks. Plasma testosterone levels were unchanged and LH levels changed little. Light and electron microscopic studies of testicular biopsy specimens showed prompt disruption of spermatogenesis which became more extensive with time. Sertoli cells underwent multiple changes including increased lipid storage and phagocytosis of spermatozoa. Comparisons are made between the sequence of hormonal changes and that of histological changes. In addition, questions are raised concerning the ways in which Sertoli cells are affected by experimental cryptorchidism.

ISSN:0003-276X    

DOI:10.1002/ar.1091890102

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

年代:1977

数据来源: WILEY

摘要:

AbstractPulp development was studied with light and electron microscopy in apical portions of cat primary and permanent incisors at various stages of development in order to qualitatively assess hypothesized differences during maturation. Primary and permanent tooth pulps passed through similar stages up to when the primary teeth began to resorb. At that point permanent tooth pulps continued to develop in complexity relative to myelinated axons and developed thin epineurial sheaths. Although the stages were similar in several regards, the time needed by the permanent tooth pulps to reach each stage was considerably greater than for the primary tooth pulps. It is of interest that the young permanent teeth had only a small portion of their final complement of nerves in spite of their relatively complete development.Individual axons, especially myelinated axons, appeared more immature in younger primary and permanent teeth. This suggests a less mature sensory capability for erupting primary teeth as compared to fully developed primary teeth as well as for erupting and young permanent teeth compared to old permanent teeth.

ISSN:0003-276X    

DOI:10.1002/ar.1091890103

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

年代:1977

数据来源: WILEY

摘要:

AbstractWithin 45 minutes after mating in the rabbit, numerous heterophil leukocytes adhere to the endothelium of venules in the vagina. Initial association appears to occur via small protuberances from the leukocyte which fit into small indentions in the endothelial cell. Following adherence, leukocytes flatten and pass between endothelial cells. A regular intercellular space separates the leukocyte from the endothelial cells. Leukocytes subsequently migrate through the connective tissue to the epithelium. By three hours postcoitus, the region beneath the basement lamina of the vaginal epithelium is crowded with numerous juxtaposed leukocytes. Leukocytes subsequently migrate between epithelial cells into the vaginal lumen where they actively engulf spermatozoa. Spermatozoa appear to be ingested head first. Numerous small filaments are observed in the leukocyte cytoplasm in the region adjacent to the sperm head. Degranulation of azurophyl granules follows sperm uptake. The leu kocyte response can be elicited either by spermatozoa (from the epididymis) or by semen (from vasectomized bucks), but is not elicited by ovulation (with human chorionic gonadotropin). It is suggested that the response may be initiated because the vagina does not distinguish between semen, spermatozoa and bacterial infection.

ISSN:0003-276X    

DOI:10.1002/ar.1091890104

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

年代:1977

数据来源: WILEY

摘要:

AbstractTwenty‐four hours after mating in the rabbit, numerous spermatozoa are observed attached to the surface of the vaginal epithelium. Spermatozoa appear to be attached by their heads to microvilli of the simple columnar cells which compose the vaginal epithelium. Spermatozoa are taken up by the epithelial cells, and they are found within the cells in various stages of de generation up to seven days after mating. Epithelial cells frequently appear to be filled with numerous vacuoles containing sperm components in various stages of degeneration. It is suggested that some property of the surface of sperm heads may render them particularly susceptible to phagocytosis. Phagocytosis of spermatozoa may not have long‐term harmful effects for the epithelium since these epithelial cells presumably have a high rate of turno

ISSN:0003-276X    

DOI:10.1002/ar.1091890105

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

年代:1977

数据来源: WILEY

摘要:

AbstractNerve endings were observed between collagen fiber bundles in the alveolar compartment of the periodontal ligament. In close relation to these endings, cells were observed with a rounded cell body from which cytoplasmic extensions protruded, each forming part of a sheath around the terminal region of a small nerve fiber. The nuclei of these cells occupied an eccentric position in the cytoplasm and were characterized by a typical kidney shape. In the cell's center a prominent Golgi complex was present. In the peripheral cytoplasm ladder‐like structures with a periodicity of 160 nm were occasionally observed. The cell bodies were surrounded by a basal lamina, while the cytoplasmic extensions investing the nerve endings were surrounded by an envelope consisting of alternating electron dense and electron translucent layers containing material that stained with PAS and Alcian Blue. Where these envelopes bordered on the connective tissue, areas of filamentous material with a periodicity of 100–150 nm were occasionally found. The end organs may be considered to form part of a receptor sys

ISSN:0003-276X    

DOI:10.1002/ar.1091890106

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

年代:1977

数据来源: WILEY

摘要:

AbstractSelective cooling of the brain during heat stress has been shown by others to be a method of temperature regulation for mammals having carotid retia. This study describes the macroscopic anatomy of the cranial circulation of elk, deer and pronghorn as it might pertain to the functioning of carotid retia and orbital retia as heat exchangers. Emphasis has been placed on describing the source of venous blood bathing these retia, for blood flow from these sources to the ophthalmic plexus and cavernous sinus will establish a temperature difference between arterial and venous blood, and influence the magnitude of this gradient. The pronghorn possesses a carotid rete with greater density and smaller calibre vessels overall and a more highly vascular orbital rete compared to the elk and the deer. These anatomical differences may indicate differences in efficiency of heat exchange in the retia. It is suggested that the orbital rete is anatomically in a position to moderate extremes of temperature by cooling arterial blood flowing to neural tissue of the eye and olfactory bulbs.

ISSN:0003-276X    

DOI:10.1002/ar.1091890107

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

年代:1977

数据来源: WILEY

摘要:

AbstractNonjunctional and nonsynaptic membranes of hair cells in the chinchilla organ of Corti were examined using the freeze‐fracture technique. Cy‐toplasmic leaflets of theapicalmembranes of hair cells have particles, 6–12 nm in diameter, but many more particles are found on apical membranes of outer hair cells than on inner hair cells. Cytoplasmic leaflets of thelateralmembranes of outer hair cells are covered with large particles, but the corresponding regions of the inner hair cell membrane have fewer particles and these are small or medium‐sized. Two types of particle aggregate also distinguish this region of the inner hair cell. The first consists of patches of particles closely spaced in rec tilinear arrays. The second consists of parallel strands of widely spaced large particles similar in size, but not in distribution, to the large particles on the lateral membranes of the outer hair cells. The basal membrane of outer hair cells is distinguished from that of inner hair cells by plaques consisting of cross‐hatched in‐cisures in the external membrane leaflet. While the significance of these anatomical features is not yet apparent, they give the hair cell plasmalemma a richness of regional specialization found in few other cells and suggest that there are important functional differences between inner and outer

ISSN:0003-276X    

DOI:10.1002/ar.1091890108

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

年代:1977

数据来源: WILEY

摘要:

AbstractLight and electron microscopic histochemistry was carried out on the serous secretory granules of the parotid acinar and sublingual demilunar cells of the Mongolian gerbil. These are bipartite in structure with a central dense core and a rim of lower density. Light microscopic techniques included staining of sections with Alcian blue and PAS reaction before and after sialidase digestion. PA‐methenamine silver, dialyzed iron, colloidal thorium and ruthenium red reactions for mucosubstance were compared on control and pronase digested materials. The results obtained have been interpreted to indicate that the peripheral rim of the granules contained mainly sialomucin whereas the central dense core was rich in protein. Freeze‐etched replicas and frozen thin sections of the gerbil salivary glands revealed the bipartite substructure of the granules to be a consistent structure regardless of specimen preparation procedures.The secretory granules in the serous acinar cells of the monkey submandibular gland which also have a central dense spherule and a rim of lower dense matrix were tested in the same way with the PA‐methenamine silver method. A positive reaction was limited to the rim of lower density matrix, indicating that this granular matrix is rich in carbohydrates in contrast to an unstained dense central spherule which is digested with pronase. Morphological and cytochemical similarities of the granule content between species are com

ISSN:0003-276X    

DOI:10.1002/ar.1091890109

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

年代:1977

数据来源: WILEY

摘要:

AbstractInflammatory exudate (SE) cells were collected from subcutaneous coverslips in mice and transferred into lethally irradiated (1,000 r) recipients. Eight days after transplantation59Fe incorporation in the spleen and bone marrow was significantly greater than in controls treated with the suspending medium only. One hundred percent of mitoses were of the T6T6 karyotype in the marrow and spleen when SE cells were obtained from CBA/T6T6 donors. The repopulating potential of SE cells, however, lagged significantly, behind that of bone marrow cells and the failure to observe consistently macroscopic spleen colonies calls into question whether the observed regeneration was due to pluripo‐tent stem cells. Radioautographic studies with3H‐TdR showed that the majority of SE cells had recently been generated, but long‐lived, noncycling cells of lymphoid and monocytoid morphology were also present in the ex

ISSN:0003-276X    

DOI:10.1002/ar.1091890110

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

年代:1977

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091890101

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

年代:1977

数据来源: WILEY