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PubMedDate not supplied

Intracytoplasmic crystalloid structures in a malignant fibrous histiocytoma: ultrastructural and cytochemical study.

Crystalloid structures were frequently observed in the cytoplasm of the tumor cells of a malignant fibrous histiocytoma arising in the left leg of a 71-year-old female. These structures were located in the cytoplasm of the fibroblastlike and histiocyte-like tumor cells. The structures consisted of an aggregate of dense granules without unit membrane. Neither glycoproteins nor polysaccharides were detected in these structures on sections stained with chromic acid-phosphotungstic acid or periodic acid-thiocarbohydrazide-silver proteinate. On sections from acrylate-embedded specimens, the structures were easily digested by trypsin and protease but were not sensitive to RNase. Although the significance and origin of these structures remain obscure, the results indicate that the crystalloid structures in the present study are mainly composed of proteinaceous substance.

Aged↗
PubMed1989

Histochemical properties of the "crystal ghosts" of calcifying epiphyseal cartilage.

The crystal ghosts represent a crystal associated organic material which is stained by acidic phosphotungstic acid, periodic acid-silver methenamine and periodic acid-thiosemicarbazide-osmium, and is reactive with cations and with colloidal iron at pH 2.0, and unreactive after methylation and saponification. These results suggest that crystal ghosts are, or derive from, proteoglycans of calcifying matrix.

Animals↗
PubMed1988

The ultrastructure of the organic phase associated with the inorganic substance in calcified tissues.

An organic phase is closely associated with the mineral substance is all calcified matrices, where it can be demonstrated as crystal-bound proteins by biochemical methods and as crystal ghosts by electron microscopy. Interest in crystal ghosts derives chiefly from the observation that they have the same shape, arrangement, and orientation as inorganic crystallites, which suggests they may have a role in their formation. Histochemically, crystal ghosts of epiphyseal cartilage react with colloidal iron (pH 2.0), acidic phosphotungstic acid, ruthenium red, and a number of cations including calcium, barium, magnesium, lanthanum, strontium, and terbium chloride. Their reactivity is removed by methylation and only incompletely restored by saponification. Moreover, the crystal ghosts located at the periphery of the calcified areas contain vic-glycol groups, as shown by their reactivity with periodic acid-silver nitrate and periodic acid-thiosemicarbazide-osmium. All these reactions show that the crystal ghosts of epiphyseal cartilage contain acidic, probably sulfate groups and, at least initially, vic-glycol groups. Their reactivity decreases as the calcification process is completed. Although the available data are not sufficient to allow a full understanding of the nature and function of these structures, they seem to play an important role in calcification. The hypothesis is presented that crystal ghosts are preformed in calcifying matrices and are activated by the unmasking of the reactive groups in their polymeric molecule; the unmasked groups then link up with inorganic ions in such a way to form organic-inorganic structures the inorganic ions of which are arranged in an apatitelike configuration and the filamentlike shape of which is the same as that of the polymeric molecule.

Animals↗
PubMed1975

Determinations of nonprotein nitrogen content of cheese whey.

Nonprotein nitrogen in pooled sweet (Cheddar and Dagano) and acid (cottage) wheys was estimated by currently proposed dialysis and chemical precipitation methods. Kjeldahl nitrogen analyses of (a) membrane retentates after water dialysis, and (b) 12% trichloroacetic acid plus .2% phosphotungstic acid filtrates indicated that nonprotein nitrogen values vary significantly with the method of sample preparation. Membrane porosity influence nonprotein nitrogen values for molecular weight cut-offs of 3500, 6000 to 8000 and 12,000 to 14,000. Dialyzable nitrogen values with all membranes were lower than 12% trichloroacetic acid soluble nitrogen for both wheys and higher than the 12% trichloroacetic acid + .2% phosphotungstic acid soluble nitrogen for all but the 3500 molecular weight cut-off membrane. The dialyzable nonprotein nitrogen fraction was heterogeneous but more that 80% was less than 3500 in molecular weight.

Animals↗
PubMed1980

On the mechanism of Mallory's phosphotungstic acid-haematoxylin stain.

The mechanism of Mallory's (1900) phosphotungstic acid-haematoxylin (PTAH) stain is not yet fully understood; staining properties vary with the age of the dye solution. In this study, a 1 year-old solution was employed as described previously. Paper chromatograms revealed blue, red and yellow components of phosphotungstic acid-haematoxylin. Modification of reactive groups as well as consecutive treatment of sections with haematoxylin and phosphotungstic acid indicated hydrogen bond formation by the blue component. Substitution of brazilin for haematoxylin proved that two free phenolic --OH groups per dye residue are essential for binding of the blue phosphotungstic acid-haematoxylin chelate. Uptake of the red fraction was determined by the polyacid moiety of the dye. Van der Waals forces presumably contributed to dye binding, but did not govern the selectivity of the red and blue components of PTAH for various tissue structures.

Benzopyrans↗
PubMed1978

Nature of the phosphotungstic acid-chromic acid (PACP) stain for plasma membranes of plants and mammalian sperm.

The selective staining of plasma membranes of plants and porcine spermatozoa given by a mixture consisting of 1% phosphotungstic acid in 10% chromic acid (PACP) applied following periodic acid destaining of glutaraldehyde-osmium tetroxide-fixed electron microscope sections is reduced or eliminated by prior extraction of the tissues with lipid solvents, including ethanol. The ethanol-soluble fraction of sperm contains constituents which restore the PACP-staining reaction when added to ethanol-extracted and lyophilized sperm. Analysis of the ethanol extracts by thin layer chromatography revealed two major components which reacted with both phosphotungstic acid (PTA) and alpha-naphthol detection reagents. These PTA-positive constituents were concentrated in plasma membranes of sperm; components with similar mobilities were found in fractions of plasma membranes from plants. Addition of the PTA-positive constituents from either sperm or plants to extracted and lyophilized sperm restored the PACP staining. The findings are interpreted to mean that one or more low molecular weight constituents (saccharides or glycolipids), rather than glycoproteins, concentrated in plaslma membranes are responsible for the unique PACP staining in both plants and porcine sperm.

Animals↗
PubMed1991

Differential staining of mucin granules from epoxy resin sections by a phosphotungstic acid-methyl green procedure.

After treatment of epoxy resin semithin sections from glutaraldehyde fixed rat large intestine with 5% aqueous phosphotungstic acid (PTA), staining with unpurified 0.2% solutions of methyl green at 60 C for 5 min produces a color differentiation between mucin granules of goblet cells. Some mucin granules and the glycocalyx appear deep green while the remaining granules, luminal mucin and collagen fibers are pink. The known contamination of unpurified methyl green with crystal violet seems to be responsible for the pink staining reaction of the latter structures, which also present an orange-red fluorescence under green exciting light. Electron microscopic observations show selective contrast of mucin granules which appear with a different amount of PTA deposits. This procedure is useful to reveal the heterogeneity of mucin granules in light and electron microscopy.

Animals↗
PubMed1981

The axonal reticulum in the neurons of the superior cervical ganglion of the rat as a direct extension of the Golgi apparatus.

Adrenergic neurons from the superior cervical ganglion of the rat have been studied with the chromaffin reaction and the zinc iodide-osmium tetroxide method. Phosphotungstic acid staining at a low pH and a combined acid phosphatase reaction and phosphotungstic acid staining have also been performed on glycolmethacrylate-embedded tissue. The results indicate that phosphotungstic acid-positive elements lacking acid phosphatase activity are present at the inner side of the Golgi apparatus. These elements give rise directly to reticular differentiations, carrying catecholamines, or to tubular extensions, representing the origin of the axonal reticulum. On these tubules, reticular differentiations can again be formed at any level. In the cell body, the differentiations are mainly found close to the neurolemma. In the axons, they are especially abundant at the axon terminals. Large granules may be associated with the reticular differentiations and small and large granules may detach from them. It is concluded that the whole catecholamine-producing and/or -storing system in sympathetic neurons can be considered as a direct extension of the Golgi apparatus, set up for local catecholamine synthesis. The relative importance of small and large granules along this system may reflect th functional status of the nerve cell.

Acid Phosphatase↗
PubMed1987

Electron microscopy procedure influences detection of rotaviruses.

Technical parameters of electron microscope staining procedures (type of stain, pH of stain, and time of staining) influence particle integrity for three groups of rotaviruses. Simian rotavirus SA11 (group A), Chinese adult diarrhea rotavirus and porcine rotavirus-like agent (group B), and porcine pararotavirus (group C) were tested. All rotavirus strains were quite stable in uranyl acetate and phosphotungstic acid at pH 4.5 and relatively stable in ammonium molybdate. However, staining with phosphotungstic acid at higher pH values with increased staining time yielded a reduction in the number of particles and particles that were broken or degraded to single-shelled particles or core particles. The different staining procedures were also tested in immunoelectron microscopy experiments. Antibody molecules bound to rotavirus particles were observed clearly only with phosphotungstic acid staining and not with uranyl acetate. 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. These technical points may be critical for rotavirus detection and are important for studies pertaining to the epidemiology and clinical importance of the non-group A rotaviruses.

Animals↗
PubMed1978

[Comparative studies on the determination of uric acid with the continuous flow machine, the manual reduction method and the enzymatic color test].

The manual and automatised determination of uric acid by means of phosphotungstic acid as well as the enzymatic test are compared: 1. When the manual reduction method is performed in the deproteinisation losses of uric acid develop (too low pH-value, absorption). For the precipitation of protein the pH-value 3 must not be undercut. Use uranyl acetate (no trichloro-acetic acid). 2. By dialysing of serum the automatized method avoid errors in precipitation. On the other hand, the simultaneous determination of non-uric acid chromogens is valid as for the manual method. Therefore, the automatically established values are higher. 3. Normal regions for the automatized phosphotungstic acid method are: males 4.8--8.2, females 3.5--7.5 mg uric acid/100 ml serum. 4. Comparisons of the quality of the manual and automatized reduction method for the enzymatic colour test are performed: In the precision the methods tested achieve comparable results (VK 2.1--3.5). The investigations of the correctness by means of control sera achieved acceptable results. The enzymatic colour test gives, since scarcely influenced by pharmaca and nearly specifically, the most reliable results. When using reduction methods analytic and preanalytic sources of error (e.g. pharmaca) must vastly be excluded. The automatised reduction method gives the advantage that there do no more appear any losses of uric acid. There is another normal region for the methods tested.

Automation↗
PubMed1976

Alpha-methyldopa interference with the phosphotungstate uric acid test.

The effect of alpha-methyldopa on the phosphotungstate method of uric acid analysis was tested using a group of 17 hypertensive patients being treated with only this drug for their elevated blood pressure. The uric acid values of these patients tested by the phosphotungstate method showed no significant difference from the uricase test values, when compared to a control population of 32 normotensive patients tested in the same manner. The proposed interference was further tested by in vitro studies. Both uricase and phosphotungstate analysis of uric acid was performed on serum containing various dilutions of alpha-methyldopa. The concentration of alpha-methyldopa required to clinically affect the uric acid level, whereby a false positive result occurred, was 60 mug/ml. The mean plasma aplha-methyldopa concentration in the study group, however, was found to be only 2.03 mug/ml. The postulated interference of therapeutic levels of alpha-methyldopa on the phosphotungstate uric acid method was invalid.

Adult↗
PubMed1976

Phosphotungstic acid-iron-haematoxylin staining method for osteoid, boundary bone and bone components in paraffin sections.

A new staining technique which stains osteoid and bone tissue differentially and also demonstrates boundary bone, pathological osteoid and the changes in ageing, pathological and dead bone matrix in decalcified paraffin or low-viscosity-nitrocellulose bone sections was developed. This phosphotungstic acid-iron-haematoxylin (PTAIH) method is based on pretreating the sections with phosphotungstic acid followed by an iron alum mordant and staining in haematoxylin with subsequent timed differentiation, at certain stages of which the features listed above appear. Van Gieson's picrofuchsin is then used as a counterstain. After standard differentiation osteoid appears red in sharp contrast with the black bone, young and woven bone, old and lamellar bone, and allows one to demonstrate changes in stainability of diseased osteoid and bone matrix, and dead bone. With the differentiation done individually and interrupted at certain stages it is possible to distinguish between various bone components depending on the amount and quality of their in vivo mineralisation. Comparison with controls showed that in this respect the method is more sensitive than the curremt staining techniques of undecalcified bone sections since it demonstrates not only unmineralised and fully mineralised tissues but also shows the poorly calcified, demineralised and ill-calcified bone components. The advantages of the method compared with those using undecalcified sections are its simplicity, suitability for fixed and decalcified material in any unspecialised histological laboratory and the fact that osteoid and other bone components can be studied in sections of unlimited size and in undisturbed relationship to their surrounding soft tissues.

Aging↗
PubMed1980

Theophylline interference with the phosphotungstate uric acid test.

The effect of theophylline on serum uric acid measurements was studied. Serum uric acid levels were measured by the phosphotungstate method in eight healthy adults, three of whom received a single u.3-mg/kg oral theophylline dose (as aminophylline elixir) while fasting, and in 15 fasting nonuremic patients (age 14 to 51 years) on chronic oral aminophylline therapy. Uric acid levels also were measured in vitro for serum with known amounts of theophylline (0-49 microgram/ml). Serum theophylline levels were measured by high-pressure liquid chromatography for the patients receiving chronic theophylline therapy and spectrophotometrically for the subjects receiving a single oral dose. In the 15 chronic theophylline patients, actual total serum uric acid levels were not significantly different (p greater than 0.05) from those expected had they been a normal population (i.e., healthy, not receiving theophylline). Likewise, in vitro studies showed no difference in uric acid levels of serum exposed to various concentrations of theophylline. A positive correlation (r greater than or equal to 0.816) between serum theophylline and uric acid levels was found in two of the three single-dose studies, suggesting a pharmacological interaction. Therapeutic serum theophylline levels do not interfere with the measurement of serum uric acid levels by the phosphotungstate method.

Adolescent↗