The use of the Picrosirius-polarization method for the study of the biopathology of collagen.
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Adult↗
Biomedical subjects
L C Junqueira
Publications and source records attributed to L C Junqueira.
A simple and sensitive method for the quantitative estimation of collagen.
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Animals↗
Do Schwann cells produce collagen type III?
The fact that collagen from both normal nerve endoneurium and Schwann cell tumours present characteristics of collagen type III, suggests that Schwann cells produce this type of collagen.
Animals↗
The collagen of the vertebrate peripheral nervous system.
Nerves and ganglia from a variety of fish, amphibian, reptilian and mammalian species were studied by optical and electron microscopy. Observations using the Picrosirius-polarization method strongly suggest that two different types of collagen fibers are present in the connective tissues of nerves and ganglia. Electron microscopy of nerves and ganglia showed the presence of two different collagen fibril populations, distinguishable on the basis of diameter, located in different compartments of these structures. Thicker fibrils are present in nerve and ganglionic epineurium. Thinner fibrils are present in the endoneurium, surrounding nerve fibers and ganglionic cells, and between the concentric layers of perineurial cells. These results were consistently observed in all species studied and very probably represent a general phenomenon in vertebrates.
Amphibians↗
Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections.
Sirius Red, a strong anionic dye, stains collagen by reacting, via its sulphonic acid groups, with basic groups present in the collagen molecule. The elongated dye molecules are attached to the collagen fibre in such a way that their long axes are parallel. This parallel relationship between dye and collagen results in an enhanced birefringency. Examination of tissue sections from 15 species of vertebrates suggests that staining with Sirius Red, when combined with enhancement of birefringency, may be considered specific for collagen. An improved and modified method of staining with Sirius Red is presented.
Animals↗
Differential staining of collagens type I, II and III by Sirius Red and polarization microscopy.
Organs of fish, amphibian, reptile, bird and mammals when stained by Sirius Red and studied with polarization microscopy present different colors in regions where collagens I, II and III have been described. Collagen type I presented a yellow, orange or red color while collagen type III appeared green. Collagen type II, present in cartilage and chondrosarcoma showed a variable color according to the tissue and the species. Its color and morphology however always permitted its clear distinction from collagens type I and type III.
Animals↗
Carotenoid and pterin pigment localization in fish chromatophores.
The classical sulfuric acid method for the histochemical detection of carotenoids has been adapted to give a reliable cytological localization of these compounds in fish chromatophores. This procedure consists mainly in fixing skin fragments in glutaraldehyde and dehydrating in a 50% solution of glycerin followed by exposure to air. It is essential that the preparation permit direct contact of the sulfuric acid with the pigment cells. Under these conditions, carotenoid containing cells stain green or blue. When associated with the extraction of the carotenoids by acetone, the procedure permits the distinction between pterin and carotenoid in fish chromatophores.
Acetone↗
Gross, microscopic and ultrastructural study of the intestinal tube of Xenodon merremii Wagler, 1824 (Ophidia).
The small and large intestines of Xenodon merremii have a similar structure. They are separated by a sphincter of thickened circular muscle. The mucosa of the proximal part of the small intestine is raised into a honeycomb pattern, but distally there are only longitudinal folds. The lining epithelium throughout is of a simple columnar type, with absorptive, goblet, argentaffin and argyrophil cells, but no Paneth cells, villi or crypts of Lieberkühn are present.
Animals↗
Fine structure of the esophagus lining epithelials cells of the snake Xenodon merremii Wagler, 1824 (Ophidia).
The authors studied the ultrastructure of the esophagus lining epithelial cells of the snake Xenodon merremii. The initial shows ciliated wedge shaped cells and goblet cells which are gradually displaced by columnar ones in the posterior third of the organ. Other cellular types, such as basal, argentaffin and argyrophil cells can be found throughout the esophagus mucosa.
Animals↗