Disease relevance of PHOSPHOTUNGSTIC ACID

• Using both conventional and high-voltage electron microscopy, we performed two- and three-dimensional analyses of synapses selectively stained with ethanolic phosphotungstic acid in the hippocampus of rats subjected to 15 min of ischemia followed by various periods of reperfusion [1].
• Ethanolic phosphotungstic acid does not stain blebs, suggesting the absence of basic protein in their contents [2].
• All rotavirus strains were quite stable in uranyl acetate and phosphotungstic acid at pH 4.5 and relatively stable in ammonium molybdate [3].
• This second neoplasm contained areas of papillary ependymoma that displayed phosphotungstic acid hematoxylin-positive glial fibers and immunoreactivity for glial fibrillary acidic and S-100 proteins [4].
• Electron microscopic examination of poliovirus in CsCl-solutions without conventional staining with phosphotungstic acid or uranyl acetate revealed the existence of cores inside poliovirus particles [5].

High impact information on PHOSPHOTUNGSTIC ACID

• Cerebrum and cerebellum contain numerous asymmetric synapses characterized by the presence of a postsynaptic thickening prominently stained by phosphotungstic acid and other electron-dense stains suitable for electron microscopy [6].
• We show that this stacking is produced by the phosphotungstic acid used for staining, independent of the presence of tubulin in the sample [7].
• After staining with sodium tungstate, the lipids form a network of multilayered lamellae with a periodicity of approximately 55 A. Phosphotungstic acid produces stacks of flattened vesicles with a period of approximately 115 A as well as broader multilamellar structures having a 55 A repeat [7].
• Membranes were characterized by phosphotungstic acid (PTA)-chromic acid staining [8].
• The entire core of the A granules was markedly positive after ultrathin sections of glutaraldehyde-fixed, glycol methacrylate (GMA)-embedded medullae were stained with phosphotungstic acid (PTA) at low pH (0.3) [9].

Chemical compound and disease context of PHOSPHOTUNGSTIC ACID

• Among the treatments tested, a partial dehydration with 70% ethanol containing 2% phosphotungstic acid (PTA) well preserved the ultrastructure of the pituitary tissue without spoiling the antigenicity of LHbeta and other representative markers for the Golgi apparatus [10].
• When a staining technique using phosphotungstic acid (PTA) in 10% (w/v) chromic acid was applied to cells of Escherichia coli, the periplasmic space was seen as a dark 15-nm-thick layer of uniform appearance and constant width [11].

Biological context of PHOSPHOTUNGSTIC ACID

• The PTA and PAS stains were abolished by acetylation, restored by saponification, unchanged by methylation, and greatly diminished by sulfation [9].
• The kinetochores of isolated HeLa cell chromosomes attached to an electron microscope specimen grid, fixed in formaldehyde, and stained with alcoholic phosphotungstic acid are visible as dark, preferentially stained structures distinct from the chromatin with which they are associated [12].
• The rates of appearance of trichloroacetic acid/phosphotungstic acid-insoluble products were greater than expected for cell death and leakage [13].
• The kinetochore was also seen as a band extending the length of the chromosome in whole mount preparations of chromosomes stained with ethanolic phosphotungstic acid [14].
• The pathology was reviewed blind and in addition to H & E sections, staining with Luxol Fast Blue, phosphotungstic acid haematoxylin and E-M studies were performed to identify parietal cell differentiation [15].

Anatomical context of PHOSPHOTUNGSTIC ACID

• In both cell types, the cell coat, lysosomes, and multivesticular bodies reacted to PTA [9].
• In the A cells, PTA stained a large part of the Golgi complex, whereas in the N cells the Golgi complex was mostly unstained [9].
• Protein particles staining densely with phosphotungstic acid become apparent in nuclei of spermatids after [3H]arginine incorporation becomes significant [16].
• Staining the sections with potassium permanganate, phosphotungstic acid, or uranyl acetate, or immersing them in glutaraldehyde, increased the contrast of cell organelles [17].
• From quantitative electron-microscope observations on the binding of permanganate to regions of erythrocytes and reticulocytes of known chemical composition, it is concluded that KMnO4, like phosphotungstic acid (PTA), binds preferentially to sites on proteins [18].

Associations of PHOSPHOTUNGSTIC ACID with other chemical compounds

• When the isolation medium contains magnesium ions (1 mM), sucrose (0-4 M) and Tris buffer (0.01 M, pH 7-5) called SMTOG (see text), the ultrastructure in thin sections through the condensed chromatin bodies, after staining with either uranyl-lead or phosphotungstic acid (PTA), is similar to that found in the intact cell [19].
• It seems that the direct HDL cholesterol assay reacts with apolipoprotein (apo) B-containing lipoproteins in the fraction with a density of >1.063; these apo B-containing lipoproteins are suggested to be coprecipitated with the phosphotungstic acid method [20].
• Structure analysis of crystalline areas in either sodium phosphotungstic acid or a sodium phosphotungstic acid/glucose mixture has been performed with electron microscopy and image processing [21].
• Thereby determined HDL-C values were in good agreement with those obtained by precipitation with phosphotungstic acid/MgCl2 or by a combination of ultracentrifugation and precipitation (0.956 < r < 0.994) [22].
• The presence of capsule was determined by transmission electron microscopy with glutaraldehyde-osmium, ruthenium red, alcian blue, and phosphotungstic acid staining procedures [23].

Gene context of PHOSPHOTUNGSTIC ACID

• Rare rhabdomyoblasts were present and stained positively for desmin, muscle-specific actin, and phosphotungstic acid hematoxylin [24].
• Staining with ethanolic phosphotungstic acid or digestion of specimens with proteinase K showed that these loose fibrillar structures also consisted of proteins [25].
• Because we have previously shown HDL cholesterol isolated by phosphotungstic acid precipitation to be lower than that by ultracentrifugation, the positive bias found in this study was expected [20].
• Ultrastructural homogeneity was not matched by the results of histochemical and immunohistochemical analysis: while all Type II cells stained positive to phosphotungstic acid hematoxylin, only 50% expressed glial fibrillary acidic protein [26].
• Sodium phosphotungstic acid (NaPTA) precipitation of protease-resistant PrP isoforms (PrP(res)) prior to Western blotting was found to approach the sensitivity of the Tga/20 bioassay and was superior to conventional Western blot and histopathological methods, wherein infectivity was commonly found when both of the latter were negative [27].

Analytical, diagnostic and therapeutic context of PHOSPHOTUNGSTIC ACID

• Tissues were analysed by sodium phosphotungstic acid precipitation of PrP(Sc) and western blotting using high sensitivity enhanced chemiluminescence [28].
• The identity and homogeneity of the isolated membranes was established, by comparison with membranes in intact nodules, using phosphotungstic acid and silver staining of thin sections and particle densitites on faces of freeze-fracture replicas of the membranes [29].
• We describe the quantitative densitometric determination of phosphatidylcholine (PC) and sphingomyelin (SP) in human serum after precipitation with phosphotungstic acid/MgCl2 and use of thin-layer chromatography [30].
• A 62-year-old woman receiving chemotherapy with etoposide showed discrepant uric acid values as measured by a direct phosphotungstic acid (PTA) method (150 mg/L) compared with a uricase technique (40 mg/L) [31].
• We therefore recommend that uranyl acetate and phosphotungstic acid at pH 4.5 be used for negative staining of rotaviruses; phosphotungstic acid at pH 4.5 is optimal for immunoelectron microscopy [3].

References