摘要:

AbstractIn this study, specimens of both sexes of a Western Australian wallaby (Setonix brachyurus) had surgical or electrolytic lesions made in the habenular complex unilaterally. Thirty‐five‐micron sections, cut coronally and parasagitally, were stained by the Nauta‐Gygax ('54) or the Fink‐Heimer ('67) technique to demonstrate degenerating fibers. Degeneration was seen in the habenular commissure and bilaterally in the habenula and fasciculus retroflexus, but was most extensive ipsilaterally. Habenular fibers destined for the tegmentum and central gray passed caudally into the midbrain in a continuous fan‐like array which extended from the central gray dorsally to the interpeduncular nucleus ventrally. In their posterior course some fibers crossed the midline with the decussating cerebellar fibers. The majority of fibers, with those in the fasciculus retroflexus which passed ventral to the decussation of the superior cerebellar peduncle, turned dorsally. They passed mostly just lateral to the midline nuclei and into the central gray where degeneration was seen throughout the entire extent. Terminal degeneration was seen in the interpeduncular nucleus primarily in the dorsal and posterior parts, in the ventral tegmental nucleus and throughout the central gray, but was more densely clustered in the region of the dorsal tegmenta

ISSN:0002-9106    

DOI:10.1002/aja.1001420102

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

年代:1975

数据来源: WILEY

摘要:

AbstractDeveloping lymph nodes from 30 human embryos and fetuses with crown‐rump lengths (CRL) of 18 mm (5.6 wk) to 245 mm (26 wk) were examined by light microscopy. The nodes were embedded in araldite, and the sections examined were approximately 1 μ in thickness. The development of nodes was divided into three stages: 1. the lymphatic plexus and connective tissue invagination (30 mm to 67 mm CRL); 2. the early fetal lymph node (43 mm to 95 mm CRL); and 3. the late fetal lymph node (CRL greater than 75 mm). The lymphatic plexus was formed by connective tissue invaginations and bridges which divided a lymph sac into a meshwork of channels and spaces. Connective tissue invaginations were endothelially‐lined and were surrounded by lymphatic space. Reticular cells, macrophages, and blood vessels were found in these invaginations. Early fetal lymph nodes were formed from invaginations when the cellular density and lymphocyte content increased. The lymphatic space surrounding the early node was the developing subcapsular sinus. With further development the early node became packed with lymphocytes, increasing the cellular density and size of the node. The connective tissue surrounding the subcapsular sinus condensed to form the capsule. Afferent lymphatic vessels pierced the capsule. Capillaries, veins, postcapillary venules, and occasional arteries were found in early and late n

ISSN:0002-9106    

DOI:10.1002/aja.1001420103

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe object of the present study was to establish a model for the study of parotid gland regeneration. Adult female Sprague‐Dawley rats were placed for 11 days on a protein‐free diet with daily intraperitoneal doses of aqueous DL‐ethionine equivalent to 0.5 mg/gm body weight, and returned to a normal diet on day 12. At varying intervals, both during and after intoxication, animals were sacrificed and the parotid glands prepared for study with the transmission electron microscope.Ultrastructural observations indicated that damage was essentially limited to the acinar cells, in which the protein synthetic apparatus was the focus of injury. The rough endoplasmic reticulum displayed atypical configurations, loss of attached ribosomes and membrane fragmentation. In the Golgi region, an atypical structure, a “crystalloid” arose during intoxication. Because of the morphology and apparent formation of the “crystalloid” it was assumed to be an abnormal secretion product. Resumption of a normal diet resulted in the rapid restitution of the normal cytoarchitecture. During the first week of recovery, there was prominent mitotic activity in mature acinar cells.It was concluded that the primary effect of ethionine upon the parotid gland is interference with the function of the protein‐synthetic apparatus, leading to morphologic alteration of the acinar cells. The mitotic activity observed during recovery indicated that in the adult rat, acinar cells retain the potential fo

ISSN:0002-9106    

DOI:10.1002/aja.1001420104

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe endometrium of 40 cycling bitches was studied using cytological, cytochemical, and morphometric techniques. Two principal phases of growth and differentiation can be discerned. Phase one begins at the end of anestrus as serum estrogen levels begin to rise and is completed just prior to estrus. It is characterized by growth of the crypts and differentiation of the glandular epithelial cells into well‐developed, mucus‐secreting cells. Growth, initially rapid, gradually slows. The second growth phase does not begin until the middle of estrus as serum progestin levels rise and lasts nearly a week. Both hypertrophy and hyperplasia of the glandular epithelium and growth of the basal glands characterize this stage. The gland cells develop many well‐defined characteristics of absorptive and secretory cells. Another phase of growth occurs in pregnant animals at the onset of implantation. During the third week of metestrus in non‐pregnant bitches, the uterus begins to involute. Acid phosphatase and the number of lysosomes increase dramatically in the epithelial cells particularly in the basal glands. Cells lining the lumen and crypts accumulate numerous large lipid droplets.The data are discussed in relation to the clear separation of two distinct uterine functions: (1) sperm transport and maintenance and (2) production and secretion of nutritive uterine milk. Extended periods of follicular development, breeding, and preimplantation in the bitch probably impose this sep

ISSN:0002-9106    

DOI:10.1002/aja.1001420105

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

年代:1975

数据来源: WILEY

摘要:

AbstractRegeneration of olfactory epithelium was studied at the ultrastructural level in two different strains of mice (C57B1/6J and SWR/J) following destructive changes induced by nasal irrigation with a 1% aqueous solution of zinc sulfate (ZnSO4).Three epithelial conditions were seen during the first four to 14 days following treatment: a “surface alteration” state characterized by changes at the apical ends of olfactory and columnar supporting cells, a “squamous‐metaplastic” state, and a “simple‐squamous” state. In the latter two conditions, thought to represent regenerative states, cells contained inclusions similar to secretion granules in Bowman's glands. This observation supports earlier suggestions that new epithelial cells originate from these glands. Later regenerative changes consist of differentiation of new sensory cells and columnar supporting cells in an initially disorganized epithelium. This epithelium then changes to a normal, pseudostratified organization.Regeneration of the epithelium begins earlier and proceeds more rapidly in the SWR/J strain than in C57B1/6J mice. Possibly, a genetle difference exists between strains. After 72 days the epithelium in both strains

ISSN:0002-9106    

DOI:10.1002/aja.1001420106

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe migration of blood cells across the wall of splenic sinusoids has been studied by means of serial sections in rats inoculated with murine erythroblastosis virus (MEV). The sinusoidal walls of the normal spleen have no permanent openings. In the normal spleen, mature red blood cells and blood cells in the latest stages of maturation can be seen in diapedesis. The predominant form of transmural migration is intercellular. In MEV‐inoculated animals, in which there is a vigorous erythroblastic proliferation, large numbers of erythroblasts are in transmural passage. Serial sections show that these cells migrate through the cytoplasm of the endothelial lining cells. On the basis of these observations, it is suggested that the transcellular mode of migration may be related to the delivery of newly formed red blood cells into the circulation while the intercellular mode may be part of the mechanism by which the spleen controls the removal of red cells from the circulatio

ISSN:0002-9106    

DOI:10.1002/aja.1001420107

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

年代:1975

数据来源: WILEY

摘要:

AbstractIntrapulmonary airways were studied in rhesus (Macaca mulatta), stumptail (Macaca arctoides), and bonnet (Macaca radiata) monkeys by correlated scanning and transmission electron microscopy. Lobar, segmental, and subsegmental bronchi in all three macaques were lined by pseudostratified columnar epithelium composed primarily of ciliated cells, mucous cells, and basal cells. Neuronal processes and cells containing dense‐core vesicles were also observed. Terminal bronchioles in rhesus and stumptail monkeys were short and only developed to a single generation. Terminal bronchioles were moderately longer in bonnet monkeys and were occasionally developed to two generations. Terminal bronchioles in bonnet and stumptail monkeys were lined by ciliated pseudostratified columnar epithelium which included nonciliated bronchiolar epithelial (Clara) cells. The arrangement of epithelium in terminal bronchioles differed slightly in rhesus monkeys. All three species had long respiratory bronchioles. They were lined by simple, nonciliated cuboidal and squamous epithelium which usually did not contain secretory droplets. Capillaries were often observed immediately below the luminal epithelium. Cuboidal cells containing dense‐core vesicles were a rare component of the epithelium of respiratory bronchioles in stumptail monkeys. Alveolar ducts were lined by an epithelium composed of type I and type II cells. The results of this study indicate that there is general similarity in the mucosal structure of bronchi and respiratory bronchioles between macaques and man but that there are differences in the number of generations and epithelial lining of terminal bronchio

ISSN:0002-9106    

DOI:10.1002/aja.1001420108

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

年代:1975

数据来源: WILEY

摘要:

AbstractCytoplasmic inclusions have been found in both normal and stimulated rat periosteal cells. These inclusions are bounded by a pentilaminar membrane similar to a tight junction and contain a core of granular material. The origin and function of this inclusion are unknown.

ISSN:0002-9106    

DOI:10.1002/aja.1001420109

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

年代:1975

数据来源: WILEY

摘要:

AbstractA combined autoradiographic and immunohistochemical technique is introduced which is suitable to simultaneously localize hypophyseal sites of nuclear (3H)‐estradiol uptake and anti‐hCG‐characterized “gonadotropes”. Most, but not all, “gonadotropes” show significant nuclear concentration of radioactivity. A large percentage of non‐“gonadotropes” also show nucl

ISSN:0002-9106    

DOI:10.1002/aja.1001420110

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

年代:1975

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001420101

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

年代:1975

数据来源: WILEY