Granules In Sections Research Articles

The high correlation between counts and area fractions of lipofuscin granules, a biomarker of oxidative stress in muscular dystrophies.

Images of cryostat unstained sections of two skeletal muscles, diaphragm and extensor digitorum longus (EDL), from wild-type normal and dystrophic mdx mice were captured with a fluorescence microscope, binarised and analysed by an automated procedure using ImageJ free software. The numbers, Feret diameters and areas of autofluorescent lipofuscin (LF)-like granules in the sections were determined from the binary images. The mean numbers of counted LF granules per mm3 muscle tissue correlated highly (r ≥ 0.9) with the area fractions of the granules in sections of both normal and mdx muscles. The similar distribution patterns of granule sizes in sections of diaphragm and EDL muscles are consistent with the high correlations.

On the structure of intestine and presence of endocytic cells in the lamina propria of platy and black tetra (Teleostei)

The structure of the intestine in platy ( Xiphophorus maculatus) and black tetra ( Gymnocorymbus ternetzi) and the capability of cells within the intestinal wall to endocytose intraperitoneally injected horse-spleen ferritin, are described. The intestinal epithelial layer has about the same thickness in both species, but the width of the lamina propria and tunica muscularis in black tetra was only about 1/5 of that in platy. Ferritin was taken up by numerous cells within the lamina propria throughout the entire length of the platy intestine. The uptake was demonstrated as large and strongly coloured intracellular Prussian blue granules in sections treated with acid ferrocyanide. There was no such uptake by the lamina propria in black tetras. We suggest that the high numbers of endocytic cells within the intestinal lamina propria of platies provide a local defence against foreign cells and particles. Such a functional role may to some extent compensate for the lack of an HCl-based defence in the digestive system of this stomach-less species.

Immunological homologies between wheat gluten and starch granule proteins

Structural homologies between wheat (Triticum aestivum L.) gluten proteins and proteins present in well-washed starch granules were examined with a panel of mouse monoclonal and mouse and rabbit polyclonal antibodies, using immunoblotting, enzyme-linked immunosorbent assay (ELISA) and immunocytochemical methods. Many antibodies raised against gluten protein fractions cross-reacted with starch granule proteins (SGP), but often weakly. Antibodies with similar gliadin and glutenin subunit specificities had similar SGP specificities: (1) Antibodies to high-mobility (α-, β- or γ-) gliadins cross-reacted weakly with low molecular weight SGP (Mr, 8000, 19000 and 30000) on immunoblots, and very weakly in indirect ELISAs. Some of these antibodies labelled both protein bodies and the periphery of starch granules in sections of immature grain, consistent with low molecular weight SGP, deemed to be ‘surface’ SGP on the basis of extractability studies, indeed being present on the granule surface. (2) Monoclonal antibodies that bound γ- or ω-gliadins and glutenin subunits bound to higher molecular weight SGP, especially a protein of Mr 77000, at concentrations only slightly above those which labelled gluten proteins. As the interior of the starch granule section was labelled, these proteins are likely to be ‘integral’ to the granule. (3) Antibodies binding broadly to all major gluten protein classes also bound most high and low molecular weight SGPs. Some starch proteins of Mr 15000, which have been associated with endosperm softness, appeared to be immunologically distinct.

Antibodies against specific membrane proteins of neurosecretory granules isolated from bovine neural lobes

Membrane proteins from bovine neurosecretory granules isolated by density gradient centrifugation were separated by polyacrylamide gel electrophoresis. A doublet of 120 kDa and 67 kDa bands were identified as specific proteins of the neurosecretory granule membrane. Antibodies against the 120 kDa doublet were raised in rabbits and characterized by western blotting and immunocytochemistry. Analysis of the antiserum by western blotting showed that this recognizes mainly the 120 kDa doublet and some other minor components which seem to be degradation products. The antiserum against the 120 kDa proteins stained, by immunocytochemistry, specifically the supraoptic and paraventricular neurons of the rat hypothalamo-neurohypophysial system. In the neural lobe the immunoreaction was found around blood vessels on structures which appear to be nerve endings and on Herring bodies. Immunoelectron microscopy using protein A-gold showed that the 120 kDa antigens are located on the membrane of neurosecretory granules in sections of rat neural lobes. The presence of the 120 kDa antigens exclusively in the hypothalamo-neurohypophysial system suggests that these proteins are probably not involved in a general secretory mechanism and that they might be a result of the tissue-specific expression of proteins.

?Copper? granules in the barnacle Balanus balanoides

Balanus balanoides (L.) collected from an area with high heavy-metal run-off contained two different types of granule within the parenchyma cells of the prosoma. X-ray microprobe analysis shows one to be the familiar “zinc” granule made up of concentric layers and giving major peaks for phosphorus and zinc, and the other to be homogeneous and giving peaks for sulphur and copper. This latter granule is designated the “copper” granule. Whilst “zinc” granules are known to be composed of inorganic phosphate, various tests on “copper” granules in sections and in a granule-rich pellet have shown that the copper is probably complexed with organic matter. The tests also demonstrated the relatively, insoluble (inert) nature of these granules. Although “zinc” and “copper” granules were present together in the prosoma, atomic absorption analyses of whole bodies (prosoma+thorax) have shown the level of zinc (50.28 μg/mg dry weight) to be much higher than that of copper (3.75 μg/mg dry weight).

Trans-epidermal elimination of immune deposits in the skin. An immunohistochemical study on immune deposits using horseradish peroxidase as antigen.

ABSTRACTUsing horseradish peroxidase (HRP) as antigen, reversed passive Arthus reactions were carried out on the skin of rabbits, in which HRP‐anti HRP immune deposits were observed as brownish granules in sections treated with diaminobenzidine and peroxide. Some immune deposits, presumably insoluble immune complexes, were found to be taken up by neutrophilic leukocytes in the subepidermal papillary layer, then pushed up into the epidermal layer and subsequently eliminated from the epidermal surface as small crusts.In the course of this trans‐epidermal elimination, intra‐epidermal and subcorneal micro‐abscesses were observed. Most of the neutrophilic leukocytes in the micro‐abscesses were shown to contain peroxidase‐positive granules. The trans‐epidermal elimination of immune deposits might represent a way of biological clearance of immune deposits occurring in the sub‐epidermal papillary layer or within the epidermis.

Lipofuscin granules in normal, benign and malignant human prostatic tissue.

Confirmation and extension of the identification and variation of the frequency of lipofuscin granules in sections of specimens of normal, benign and malignant human prostatic tissue by fluorescent microscopy was obtained. However, the suggestion of the possible relationship between the presence of these granules and alterations in the metabolic processes within the prostate occuring in consequence of senescence and/or disease-specific factors is perhaps somewhat questionable as cellular and structural variations ranging from the benign to the most anaplastic were frequently observed in the same microscopic section.

Ultrastructure and size of rat anterior pituitary secretory granules.

The ultrastructure of the cells of male and female rat anterior pituitary glands was studied by negative staining and by sectioning for electron microscopy. Negative staining showed that pituitary granules are flexible, colloid-filled sacs that usually absorb the stain and are flattened by its drying. Six morphologically distinct cell types were identified and measurements of sections of their granules were made. The granules from each cell type showed variation both in ordinary sections and in middle diameters of serial sections. Up to 4-fold differences in diameter and 25-fold differences in volume of granules were observed within individual cells. The mean values obtained by the 2 types of measurements were not significantly different. Other evidence showed that the level of sectioning had little effect on the apparent size of granules in sections and that the variation in granule size is real and not an artifact of sectioning. This finding was confirmed by measurements made on granules in individual t...

Isolation and biological properties of secretory granules from rat anterior pituitary glands.

A method is described for the isolation of secretory granules from rat anterior pituitary glands. The method consists of differential and isopycnic gradient centrifugations, followed by filtration of the zones containing granules on Nuclepore filters to remove mitochondria. Highly purified granules were obtained as indicated by electron microscopy. Major parts of the thyrotropin (TSH) and adrenocorticotropin (ACTH) were recovered in a single fraction of granules as were follicle-stimulating (FSH) and luteinizing (LH) hormones. The somatotropin (STH) and prolactin (LTH) were recovered in separate granule fractions. The major parts of the six different hormones were associated with their respective granule fractions as shown by bioassays specific for each of the hormones. The diameters of granules in sections of intact rat pituitary glands and in isolated pellets were measured, and the means and ranges were in close agreement. These results contribute to the identification of the cell types which produce the different pituitary hormones.