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Biomedical subjects

P Pizzolato

Publications and source records attributed to P Pizzolato.

At least 37 records · Page 2Linked to original sources
PubMed1976

Formalin pigment (acid hematin) and related pigments.

Black to brown amorphous to microcrystalline granules are encountered in histologic sections prepared from tissues fixed in formalin having a low pH. This pigment is produced by acid acting upon hemoglobin and is known as formalin pigment or acid hematin. A similar pigment is also observed in sites of bleeding ulcers in areas of acid production such as the stomach. These pigments exhibit many physical and histochemical properties similiar to pigments produced by some animal parasites as in malaria, schistosoma and pulmonary mites. These parasites disintegrate erythrocytes in an unknown manner, and liberate an acid hematin-like pigment which is phagocytized by the reticuloendothelial system. Since formalin pigment can be considered as an artifact, confusion with other pigments can be avoided by the use of neutral buffered formalin for the fixation of tissues.

Animals↗
PubMed1975

Indirect sulphonation of mucopolysaccharides and glycogen in tissue sections with the use of bisulphite or dithionite after periodic acid oxidation.

Tissue mucopolysaccharides and glycogen can be indirectly sulphated after being oxidized by periodic acid and treated with sodium bisulphite or dithionite in aqueous solution. The sulphated sites are darkly stained by Roluidine Blue and realted dyes at pH less than 1.0. The background is very pale or colourless. The stained sections resist extraction with 1% hydrochloric acid for 48 hr, but can be extracted by 5% ammonium hydroxide in ethanol in 1 hr. Other oxidizing agents cannot be substituted for periodic acid.

Dithionite↗
PubMed1975

Hematoxylin substitutes. A study of phenocyanin TC and the use of afterchrome mordanting in histology.

A practical, simple synthesis of the obsolete mordant dye, phenocyanin, was devised, proceding from gallocyanin and resorcinol with acid and heat. The dye gave promise of good performance in metachrome iron mixtures, but because of excessive precipitation, the practice of afterchroming was taken from textile dyeing usage, and proved very successful. Of a number of metallic salts tried, Fe II proved to be the best, then Cu II and Fe III. The stain acts as a cationic dye on nucleic acids and other acidic tissue components: acid mucins, cartilage, mast cells, corpora amylacea, etc. The afterchroming process renders the stain much more resistant to various extraction agents and even moderately resistant to acid alcohol. Color values are quite comparable to those obtained with hematoxylin-eosin when an eosin counterstain is used. Nuclei basophilic cytoplasm, Nissl granules, and bacteria color dark blue; cartilage, mast cells, and some acid mucins, deep violet. Staining with the 1% solution was essentially unaltered from neutrality down to 1.2 N HCl, pH 0.68, and dilution of the dye to 0.05% in 1% conc. HCl (pH 1.2) still gave excellent nuclear, RNA, and mast-cell staining. At 0.02% and pH 1.2, nuclear staining was distinctly weakened; mast cell granules were still dark violet.

Benzopyrans↗
PubMed1975

Hematoxylin substitutes: fluorone black and methyl fluorone black (9-phenyl- and 9-methyl-2,3,7-trihydroxy-6-fluorone) as metachrome iron alum mordant dyes.

The phenyl and methyl trihydroxyfluorones, hitherto used histologically only in the rather difficult and unreliable Turchini technics for discriminating deoxyribonucleic from ribonucleic acid, find a new use as iron mordant metachrome dyes which act as nuclear stains. Nuclear staining is unaffected by acid extraction of nucleic acids, as with hematoxylin lakes. The two dyes, named by Liebermann and Lindenbaum 9-phenyl-2, 3, 7-trihydroxy-6-fluorone, have also acquired (illustrating with the phenyl homolog) longer chemical names of the form 2,6,7-trihydroxy-9-phenylisoxanthene-3-one (Eastman). Aldrich and Pfalz-Bauer adhere to the Liebermann-Lindenbaum nomenclature. The trivial name fluorone black is proposed for the phenyl homolog and methyl fluorone black for the methyl homolog. The iron lake of fluorone black appears to be a useful substitute for iron hematoxylin, methyl flurone black less useful. Neither dye has the diverse capability of hematoxylin.

Aluminum↗
PubMed1975

The staining of Brunner's gland and other neutral mucins by carmine, hematoxylin and orcein in alkaline solutions.

Brunner's glands and other neutral mucins may be stained red, brownish red, and violet, respectively, by carmine, hematoxylin, and orcein from appropriate alkaline solutions. Carmine and hematoxylin in concentrations of 0.2-1% are dissolved in 60-70% alcohol containing 1% potassium carbonate; orcein is used in a 0.2% alcoholic solution of sodium hydroxide. Staining times are 15 to 30 minutes. The stained sections are rinsed in 95% or absolute alcohol prior to xylene and mounting. The staining of these mucins is blocked by mild bromine oxidation. By using alcian blue 0.1% in 3% acetic acid for 5 minutes prior to the above stains, mucins may be characterized in the same preparation as acid, neutral or mixed.

Alkalies↗
PubMed1975

Histochemical factors influencing the sulfation of the mucosubstances of the Brunner's glands of the human duodenum.

The mucopolysaccharides of the human Brunner's glands were sulfated by sulfuric acid diluted with acetic anhydride or nitrobenzene (1:50) in 5 min. They were recognized by toluidine blue at a pH of less than 1 by exhibiting a red-violet or violet-red metachromasia. The sulfated radicals were removed by methanol or butanol with HCl, H2SO4, Na or NaOH, aqueous Ba(OH)2 at 60 degrees C, or by acetic anhydride, acetyl chloride, benzoyl chloride, or bromine water at 25 degrees C. The carbohydrates were altered so that sulfation was prevented by prior treatment with aqueous Ba(OH)2, or by acetic anhydride with pyridine at 60 degrees C and by acetyl chloride and by bromine water at 25 degrees C. Periodic acid Schiff staining was prevented by sulfation with a nitrobenzene: H2SO4 mixture but not by an acetic anhydride: H2SO4 combination in 1 h suggesting an additional sulfate radical at hydroxyl sites 1 or 2. Brunner's glands contain a large amount of a neutral mucopolysaccharide and can be used as a model for testing a large number of chemical and blockage reactions. In nearly all instances, Brunner's glands reacted more like pyloric glands than duodenal goblet cells.

Acetates↗