ISSN:0003-276X    

DOI:10.1002/ar.1092150302

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe antigenic phenotype of mouse lymph node follicular dendritic cells (FDCs) was studied by immunocytochemical techniques. Indirect fluorescence was used in conjunction with monoclonal antibodies to localize FDC surface antigens on FDC‐enriched cell preparations and in cryostat sections. Lymph nodes from rats and mice were also labeled directly for Ia antigens with fluorescein‐ or peroxidase‐conjugated Ia‐specific monoclonal antibodies (i.e., MRC Ox4 and 10‐2.16, respectively). Lymphoid tissue was also prepared for electron microscopy to allow clear distinction between Ia antigens of B lymphocytes and FDCs in situ. In these experiments, gold‐labeled antigen was used to clearly identify FDCs and their processes among the Ia‐positive cells of lymph node follicles. The labeling observed by light and electron microscopy showed that FDCs expressed Ia in situ and in vitro. Additional surface determinants shown to be expressed by FDCs included H2‐K, common leukocyte antigen, and the receptor for the Fc portion of IgG1and IgG2b. Neither macrophage antigens, such as Mac‐1, Mac‐2, Mac‐3, and F4/80, nor the lymphocyte markers Ly‐1, Ly‐2, and Thy‐1 were expressed by FDCs. Thus, the antigenic phenotype of FDCs, along with their distinctive dendritic morphology, their nonphagocytic and nonadherent nature, and their ability to trap and retain immune complexes on their plasma membrane, identifies them

ISSN:0003-276X    

DOI:10.1002/ar.1092150303

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe arterial terminals in the red pulp of the perfused rat spleen were studied by scanning electron microscopy. The arterial terminals were tubular or funnel‐shaped and ended openly in the splenic cord. No continuity was observed between the arteries and the sinuses. The endothelial cells of the arterial terminals extended their processes at the fringe of the terminal ends, and these endothelial processes were connected to the processes of the reticular cells of the splenic cord. In addition, large pores, measuring 0.5–8 μm in size, were found in the wall of the terminals adjacent to their

ISSN:0003-276X    

DOI:10.1002/ar.1092150304

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

年代:1986

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1092150305

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe distribution of bone calcium between morphologically identifiable cortical and trabecular bone obtained by dissection and quantitated by neutron activation analysis (NAA) is described. The skeleton of a female beagle dog was dissected into approximately 400 pieces and assayed for49Ca produced in the University of California, Irvine TRIGA reactor. For each of the skeletal sections, we give the initial weight of the alcohol‐fixed tissue, which includes cortical bone, trabecular bone, marrow, and cartilage, and a final tissue weight after the marrow and trabecular bone have been dissected away; total section and cortical section calcium weights are reported. The level of detail is represented, for example, by the vertebrae, which were divided into three parts (body, spine, and transverse processes) and by the long bones, which were divided into 10–12 parts such that characterization of the epiphysis, metaphysis, and diaphysis was accomplished. The nedian percentage cortical calcium values for cervical, thoracic, and lumbar vertebrae were 82%, 56%, and 66%, respectively; however, variation within these groups and among individual vertebral sections was about a factor of 2. For long bones, the median percentage cortical calcium varied from 90–100% in the midshaft to below 50% in the proximal and distal sections. The final calculated cortical tissue‐to‐calcium mass ratio (TCR) varied from about 4.5 for midshafts of the long bones to about 9 for thoracic vertebral bodies and indicated that the mineral fraction of cortical bone is not constant throughout the skeleton. The ratio of cortical to trabecular calcium in the skeleton was

ISSN:0003-276X    

DOI:10.1002/ar.1092150306

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

年代:1986

数据来源: WILEY

摘要:

AbstractFrom light and electron microscopic studies on perirenal fat from human donors 27, 39, and 47 years old, unequivocal evidence is found for the presence of islands of multilocular adipocytes. After glyoxylic acid condensation for visualisation of biogenic amines, catecholaminergic nerve plexuses were demonstrated around the arteries of supply to these islands and within the intercellular spaces between their constituent adipocytes. Transmission electron microscopy revealed the cytology of these adipocytes to be similar to that of brown adipocytes in rodents. These findings are viewed in the light of a possible energetic potential for brown adipose tissue in the human adult.

ISSN:0003-276X    

DOI:10.1002/ar.1092150307

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

年代:1986

数据来源: WILEY

摘要:

AbstractIn this study the three‐dimensional organization of pinocytotic vesicles in mouse endothelia from permeable (choroid plexus, area postrema, and skeletal muscle) and blood‐brain barrier (bbb) (cerebral gray and white matter) microvessels was examined. Reconstructions of 75 segments of endothelial cells from microvessels were done with very thin (<23 nm) serial sections and tracings. A total of 2,013 vesicles from five tissues were reconstructed for this study. Vesicles were classified as to whether they were attached to other vesicles (fused), connected to golgi or endoplasmic peticulum (tubule‐connected), open to vessel lumen or ablumen (surface‐connected) or isolated in the cytoplasm (free).The densities of tubule‐connected vesicles and free vesicles were the same in all four types of vessels. It seems unlikely, therefore, that these vesicles are related to vascular permeability. Vesicular clusters and surface‐connected vesicles were found in much higher densities in area postrema, choroid plexus, and skeletal muscle vessels than in bbb vessels. Single‐vesicle transendothelial channels were found in attenuated endothelia of area postrema and choroid plexus. These results support the hypothesis that endothelial vesicles play a role in vascular permeability, possibility by transient fusion of vesicle clusters to the plasmalemma, to form transendothe

ISSN:0003-276X    

DOI:10.1002/ar.1092150308

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

年代:1986

数据来源: WILEY

摘要:

AbstractEndocervix and corresponding endometrium of women of reproductive age were studied histochemically with 13 fluorescein isothiocyanate‐labeled lectins to delineate the differences between the epithelial cells in two anatomical sites. Lectin fromMaclura pomifera(MPA),Ulex europaeus(UEA‐I),Glycine max(SBA), andVicia villosa(VVA) bound only to endocervical epithelium and were the only four lectins that distinguished endocervical from endometrial epithelium. These differences were independent of menstrual cyclic changes and blood group antigen secretion. These data show that lectins can be used to histochemically distinguish endocervical from endometrial gla

ISSN:0003-276X    

DOI:10.1002/ar.1092150309

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe terminal portion of the bowel of the lethal spotted mutant mouse (ls/ls) lacks an enteric nervous system due to the failure of neural crest precursors to colonize this region during embryonic life. As a result, the mouse develops congenital megacolon. We have postulated that the defect occurs because the microenvironment of the aganglionic segment is segmentally abnormal and does not permit the migration and/or survival of the enteric neural or glial precursors in the affected zone. We have examined the terminal segment of adult ls/ls and control mice by light and electron microscopy to determine if the defect is associated with identifiable structural abnormalities that persist to maturity. A striking abnormality is an overgrowth of the muscularis mucosa in the adult ls/ls mouse, particularly in the outer longitudinal layer. Electron microscopy also reveals an extensive thickening of the basal lamina around smooth muscle cells. In addition, nerves that are derived from fibers that are extrinsic to this area are abnormal. Large bundles of nerve fibers, some of which contain myelinated axons, large‐caliber unmyelinated axons, and abundant collagen, are prominent in the intermuscular region of the aganglionic segments and often reach into the submucosa. The supporting cells of the unmyelinated and myelinated nerves in the aganglionic segment have voluminous perineural cytoplasm typical of immature Schwann cells. They also exhibit intermediate filaments in their cytoplasm. Otherwise they have the typical morphology of peripheral Schwann cells, rather than enteric glia, including individual ensheathment of axons and a surrounding basal lamina. We suggest that the extracellular matrix and/or cells of mesenchymal origin of the terminal bowel of the ls/ls mouse may prevent the ingrowth of the normal precursors of the glia as well as neurons of the enteric nervous system, but may permit or even encourage the ingrowth of abnormal numbers of extrinsic axon

ISSN:0003-276X    

DOI:10.1002/ar.1092150310

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe embryonic development of somatotrophs and mammotrophs in the adenohypophysis in dwarf (dw) mutant mice was studied by means of ultrastructural immunocytochemistry. Embryos at 16–18 days of gestation were removed from litters consisting entirely of dwarf homozygotes obtained from homozygous matings of adult dwarfs in which reproductivity was induced by means of hormone supplementation and renal capsule implants of normal pituitaries. Litters from normal (−/+) matings served as controls. Pituitaries from adult normal and dwarf mice also were removed and processed with the embryonic material. Thin sections were exposed to anti‐growth‐hormone serum (anti‐GH) or to antiprolactin serum (anti‐PRL) and processed immunocytochemically with the colloidal gold procedure. In the normal pituitaries, a strong positive reaction to anti‐GH occurred in the adult and in embryos as early as 16 days, whereas the reaction to anti‐PRL was strong in the adults but relatively weak in the embryos. In dwarf embryonic and adult pituitaries, ambiguous cells showing combinations of features characteristic of somatotrophs and mammotrophs were present. However, neither these cells nor other granulated cells reacted to anti‐GH or to anti‐PRL, except for a questionable reaction to the latter at 18 days and in the adult. Thus, the dwarf pituitary shows functional as well as morphological abnormalities as early as 1

ISSN:0003-276X    

DOI:10.1002/ar.1092150311

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

年代:1986

数据来源: WILEY