Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microtomy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed1986

The effect of sympathomimetic drugs on bone capillaries.

Mineral transport to bone is dependent on an adequate blood supply. Thus, the role of vasoactive agents merits orthopaedic interest. This paper outlines the morphology of osteons and capillaries in cortical bone and discusses the possible morphological effects of systemic phenylephrine on mice tibiae. The frequency of dilated capillaries on histological serial sections did not significantly change. Hence, a postcapillary mechanism is likely to explain previous EM findings: i.e., an adrenaline-induced increase of the lumen diameter and perivascular cell edema.

Animals↗
PubMed1995

Immunocytochemical localization of peroxisomal proteins in human liver and kidney.

The sample preparation and immunocytochemical methods for investigating the presence and subcellular localization of peroxisomal proteins (catalase, the three beta-oxidation enzymes, alanine : glyoxylate aminotransferase and a peroxisomal membrane protein) in human liver biopsies are described. We present a protocol for immunolabelling on ultrathin and semithin sections from the same tissue block, with protein A-colloidal gold as a reporter system. For this purpose, the tissue is embedded in Unicryl, a hydrophilic acrylic resin that is cured by ultraviolet illumination at 2 degrees C. The limitations and possibilities of the methods are discussed together with methodological problems. Cryostat sections of prefixed material should be used for the visualization by light microscopy of cytoplasmic catalase. It is emphasized that immunolabelling for catalase in formalin-fixed archival liver samples and in liver autopsy tissue (in the latter also for the peroxisomal beta-oxidation enzymes) permits visualization of peroxisomes; this can be helpful in diagnosing an index case retrospectively.

Catalase↗
PubMed1992

Initial reaction kinetics of succinate dehydrogenase in mouse liver studied with a real-time image analyser system.

The initial reaction kinetics of succinate dehydrogenase in situ were investigated in sections of mouse unfixed liver using an ARGUS-100 image analyser system. The sections were incubated on substrate-containing agarose gel films. Images of a section, illuminated with monochromatic light (584 nm), were captured with the image analyser in real time at intervals of 10 s during the incubation. The absorbances of selected hepatocytes in the successive images were determined as a function of time. In every cell, the absorbance increased nonlinearly after the first minute of incubation. The initial velocity of the dehydrogenase was calculated from the linear activities during the first 20 s of incubation. Hanes plots of the initial velocities and succinate concentration yielded the following mean kinetic constants. For periportal hepatocytes, the apparent Km = 1.2 +/- 0.8 mM and Vmax = 29 +/- 2 mumol hydrogen equivalents formed/cm3 hepatocyte cytoplasm per min. For pericentral hepatocytes, Km = 1.4 +/- 1.0 mM and Vmax = 21 +/- 2 mumol hydrogen equivalents/cm3 per min. The Km values are very similar to those determined previously from biochemical assays. These results, and the observed dependence of the initial velocity on the enzyme concentration, suggest that the technique reported here is valid for the histochemical assay of succinate dehydrogenase.

Animals↗
PubMed1985

Rapid and sensitive detection of oestrogen receptors in cells and tissue sections by autoradiography with 125I-oestradiol.

The presence of receptors for steroid hormones in individual cells and tissue sections was assessed within 4-24 h using dry mount autoradiography with radio-iodinated oestradiol. Low affinity and nonspecific binding of steroids were significantly reduced by washing the cells or sections with diluted antiserum to oestradiol. For cells of the MCF-7 cell line variations in grain density were observed, indicating that cells of the MCF-7 cell line are heterogeneous with respect to their cellular receptor concentrations of oestrogen receptors. Receptor-negative cells, such as peritoneal macrophages, did not retain oestradiol label. In tissue sections of rat and calf uterus, predominant labelling was observed on the endometrial gland cells and stroma. Oestradiol receptor binding in the uterus cytosol for both radio-iodinated and tritiated oestradiol showed the same qualitative characteristics as determined by sucrose gradient sedimentation profiles and a comparable amount of binding sites was found for both labels. The relative binding affinity of 125I-oestradiol compared to [3H]oestradiol is about 70-80%. The dry mount autoradiographic technique as presented can be used for rapid screening of heterogeneity in oestrogen receptor distribution in cells and tissue sections, since this technique reveals differences in receptor concentrations on the single cell level.

Animals↗
PubMed1978

Thickness measurements of skeletal muscle sections using the light microscope.

A new device is described for improving the accuracy of measuring the thickness of cryostat sections by the focusing technique in the light microscope. The necessity of such measurements is demonstrated by the great variation (range 2.55 micrometer--11.93 micrometer) in the thickness of serial cross-sections of frozen muscle biopsies from 12 healthy men. The final dehydration of the sections was found to reduce the thickenss of fresh sections by 47%. However, dehydration caused the cross-sectional area to be reduced by only 2.8%.

Adenosine Triphosphatases↗
PubMedDate not supplied

A rapid immunogold-silver staining for detection of bromodeoxyuridine in large numbers of plastic sections, using microwave irradiation.

A rapid and convenient method for the large scale, immunogold-silver staining (IGSS) of bromodeoxyuridine (BrdU) incorporated by S phase cells, by means of a monoclonal antibody (anti-BrdU) is described. Nineteen slides at a time can be incubated with the antibodies and the protein A-gold (PAG) in staining jars. The antibody and protein A-gold solutions could be used at least five times to incubate new batches of slides. The incubation times with these solutions were shortened by means of microwave irradiation. In this way 200 slides carrying at least 800 sections could be easily processed under the same conditions in one day, using 1.25 ml neat antibody solutions of anti-BrdU and rabbit anti-mouse. For light microscopy both plastic embedding systems: methylmethacrylate (MMA) and glycolmethacrylate (GMA) can be stained with this technique. The MMA sections, of which the plastic has to be removed before the IGSS, has the advantage of a stronger labelling intensity. The GMA plastic, which contains a cross-linking agent cannot be removed and consequently for GMA sections it is necessary to incubate the sections with a proteolytic enzyme (trypsin) before the IGSS, to reexpose the antigenic binding sides. However, the GMA sections can be allowed to air dry during the IGSS without negative effects on the morphology. This makes it possible to perform the antibody and the PAG-incubating steps on one day and to finish the IGSS the next day. In this way twice as many GMA slides can be incubated with the same antibody and PAG solutions than with MMA slides.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Use of poly(vinylpyrrolidone) and poly(vinyl alcohol) for cryoultramicrotomy.

Specimens infused with or suspended in a mixture of 10-30% poly(vinylpyrrolidone) and 2.07-1.61 M sucrose can often be more easily frozen-sectioned than those infused with sucrose alone. The pH of such a mixture can be efficiently adjusted to neutrality by using Na2CO3. Use of poly(vinylpyrrolidone) causes little or no increase in the background level of immunolabelling. Adsorption staining of ultrathin frozen sections with a mixture of uranyl acetate and poly(vinyl alcohol), i.e. a simple thin-embedding of the sections in such a mixture, produces positive staining effects that are often enough to delineate structures of many organelles. When OsO4-treated frozen sections are stained with uranyl acetate and further adsorption-stained with a mixture of lead citrate and poly(vinyl alcohol), the overall staining effects are similar to those observed in double-stained conventional sections.

Animals↗
PubMed1980

Immunochemistry on ultrathin frozen sections.

Ultrathin frozen sections can be cut smoothly from many fixed and appropriately treated specimens. To use such sections for immunochemical localization of intracellular antigens, fixation conditions must be selected to optimize at least three variables, namely, preservation of ultrastructure, preservation of antigenicity and retention of accessibility of the antigen to the antibody. Furthermore, staining of the sections must be such that both the immunolabels and structures are clearly recognized. Our efforts to attain these goals are described in relation to their historical background. Although there are still problems to be solved and improvements to be made, we now consider that cryoultramicrotomy has reached the stage of being useful in studying many questions which will not be easily approached otherwise.

Animals↗