摘要:

Using confocal fluorescence microscopy with a monoclonal antibody, we have localized the receptor for urokinase plasminogen activator (uPAR) in MDA-MB-231 human breast cancer cells migrating into a reconstituted basement membrane. Patchy and polarized uPAR immunoreactivity was found at the cell membrane, and strong staining was found both in the ruffled border or leading edge of the cells and at pseudopodia penetrating into the membrane. Intracellular uPAR staining was localized in the paranuclear region and in rounded granule-like structures: some of these were identified as lysosomes by double staining for uPAR and the lysosomal enzyme cathepsin D. Urokinase plasminogen activator (uPA) activity has previously been shown to play a role in migration of cells into basement membranes, and it has been proposed that uPAR also is involved in this process. uPA is known to be internalized and degraded after complex formation with the inhibitor PAI-1. Lysosomal uPAR immunoreactivity may result from concomitant internalization of the receptor.

ISSN:1052-0295    

DOI:10.3109/10520299409106263

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Although there are many histological techniques for assessing myelin sheaths and axons in paraffin embedded or frozen sections of the peripheral nervous system, modern approaches usually use plastic embedded material. Although plastic embedding is superior for small cutaneous branches, this method has limited value for histological assessment of nerve trunks. We report three methods which together yield a comprehensive approach for thorough and detailed investigation of human nerve trunks. The rapid osmication method permitted assessment of myelinated nerve fibers from frozen sections at operation, thus providing the surgeon with guidance on the extent of nerve resection. The modification presented here resulted in permanent slides, allowing comparison of results with those of the other two procedures. The new osmium-hematoxylin technique could be performed on paraffin embedded nerves. Paraffin, unlike plastic, permitted the study of the whole cross sectional area of the nerve in single sections. Moreover, the sharp image of the myelin permitted computerized morphometry. The significantly modified axonal silver impregnation technique was performed on frozen sections mounted on glass slides, as opposed to the time-consuming impregnation of free-floating sections. The latter technique had a high success rate and permitted semiquantitative assessment of axons in nerve trunks. These methods can be performed in any routine histology laboratory and resulted in greater accuracy compared to conventional methods.

ISSN:1052-0295    

DOI:10.3109/10520299409106264

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

A horizontal toggle clamp mounted on a rigid base plate makes nuclear extrusion and polytene chromosome squashing simple and reproducible. The base plate has a stage with shallow flat grooves to align the tissue sample directly below the clamp's swivel foot and hold the microscope slide in place during squashing. Appropriate pressure to obtain either extruded nuclei or squash preparations of polytene chromosomes is established empirically by adjusting the clamp's spindle assembly up or down.

ISSN:1052-0295    

DOI:10.3109/10520299409106265

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

We developed staining techniques that permit identification and histomorphometric analysis of microcracks in the human femoral head 1) from thick, ground bone sections (100μm) by prestaining with the Villanueva mineralized bone stain (MIBS), and 2) from plastic embedded, undecalcified thin bone sections (5–15μm) by staining in gallocyanin chrome alum-Villanueva blood stain methods. Both methods represent a significant improvement in the stainability of the microcracks, cellular and tissue elements, and the simultaneous assessment of osteoid seams and tetracycline markers by histomorphometry. Shrinkage and other artifacts were minimized, which helped to clarify some of the uncertainties arising from artifacts resulting from some bone staining methods. Histomorphometric analyses of microcracks were conducted on thick, ground sections of subchondral and trabecular bone. Microcracks were more prevalent in the subchondral bone and osteochondral junction than in the more distant trabeculae. We have consistently localized microcrack areas in bone tissues prepared in these ways.

ISSN:1052-0295    

DOI:10.3109/10520299409106266

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Common methods for preparing samples for immuno electron microscopy involve glutaraldehyde fixation (GA) followed by chemical dehydration (CD) or cryofixation (CF) succeeded by physical dehydration, i.e., freeze drying (FD) or freeze substitution (FS). The effects of these techniques have been evaluated with regard to the sizes of epoxy resin embedded rat somatotrophic secretory granules as well as the immuno labeling densities over these granules. The measurements were performed by computerized image analysis using electron microscopy in transmission (TEM) and scanning transmission (STEM) modes, which allowed us to define the immuno labeling in detail. The embedded secretory granules showed the same diameters after GA (2 hr) with CD and GA (15 min) with CF and FS, but were smaller after CF-FS, and smallest after GA (15 min) with CF and FD. The highest labeling density appeared after GA (15 min) and physical dehydration, in particular after freeze substitution. Based on our STEM pictures a new factor for evaluating and interpreting immuno labeling of granules is introduced the“accessible immuno gold labeling surface.”It defines the fraction of the epoxy resin surface that is labeled and varies with the preparation methods. By using this factor, an order of labeling densities/μm2over the accessible areas could be established for the different techniques: GA-CF-FS>CF-FS>GA-CF-FD>GA-CD. The high labeling after GA-CF-FS may be due to the combination of a large accessible area and accurate preservation of the antigenicity of the hormones in the granules.

ISSN:1052-0295    

DOI:10.3109/10520299409106267

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

A rapid method for fixation and embedding of plant materials, especially pterido-phytes, is suggested. Addition of tannic acid following osmication improved the visualization of membranes. Staining enblocwith uranyl acetate between osmication and tannic acid is suggested for tissues infected with fungi and bacteria.

ISSN:1052-0295    

DOI:10.3109/10520299409106268

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Phagocytosis has been used to characterize on a functional basis leukocytes adhered to the aortic endothelium of the rat. After intravenous administration of particles, phagocytosis was observed microscopically in esterase-positive leukocytes adhered to the endothelium in whole mounts of aorta. PolybeadRblue and red, 0.5 and 1μmparticle size, were inadequate because they were insufficiently colored to be identified individually at 400. FluoresbritetmYG 0.25 and 0.50μmat doses of 0.2 and 2±0.3 m1/100 g, respectively, produced endothelial lesions. The same occurred with Monastral blue BR(MbB) at 0.3 ml/100 g, red iron at 2±16 mg/100 g and India ink at different concentrations depending on the supplier. At lower particle doses, lesions were not found. Deferoxamine mesylate 1.5 mg/100 g intravenous and allopurinol 5 mg/100 g intraperitoneal administered before the particles diminished the number and intensity of lesions. In none of the cases studied was the percentage of phagocytic cells greater than 50%. Clearance curves of MbB and Fluoresbritetmindicated rapid disappearance of particles from the blood. Results indicate that administration of particulate suspensions is not a good method for characterizing the phagocytic leukocytes adhering to the aortic endothelium because low doses produce rapid clearance of particles, thus impeding sufficient leukocyte loading, and higher doses produce endothelial lesions that often impair reliable counting of the adhering leukocytes.

ISSN:1052-0295    

DOI:10.3109/10520299409106269

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

PC10 is a monoclonal antibody to proliferating cell nuclear antigen, a nuclear protein associated with the cell cycle. We have evaluated the effects of tissue fixation on PC10 immunoreactivity in sections of paraffin embedded rat tissues. Immunoreactivity was well preserved in tissues after fixation with alcohol-based solutions for 3–24 hr. Fewer PC10-positive cells were detectable in samples fixed with formaldehydecontaining solutions compared with samples fixed with alcohol for the same time. Loss of PC10 immunoreactivity in formaldehyde fixed tissues was progressive, and quantifiable as early as after 3 hr fixation. Consequently, alcohol-based fixatives are strongly recommended for any immunocytochemical prospective study using PC10 antibody. In contrast, loss of PC10-immunoreactivity is always predictable, but difficult to quantitate, using formaldehyde fixed specimens. This aspect should be considered when using PC10 antibody in retrospective studies with routinely-processed archival material.

ISSN:1052-0295    

DOI:10.3109/10520299409106270

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

ISSN:1052-0295    

DOI:10.3109/10520299409106271

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

ISSN:1052-0295    

DOI:10.3109/10520299409106272

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor