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A Tato

Publications and source records attributed to A Tato.

35 records · Page 2Linked to original sources
PubMed1996

Effect of rHuEpo therapy in dialysis patients on endogenous erythropoietin synthesis after renal transplantation.

UNLABELLED: We have undertaken a prospective study to examine the effect of recombinant human erythropoietin (rHuEpo) therapy during dialysis on Epo levels after renal transplantation and to evaluate the impact of this therapy on the immediate graft function. Between December 1991 and December 1993, 91 renal transplant recipients were studied. There were 34 females and 57 males and the mean age was 38 years. Forty-two patients were treated during dialysis with rHuEpo due to anemia and 49 patients did not receive it. Endogenous Epo (eEpo), hemoglobin concentration, hematocrit level and serum creatinine were determined on days 0, 2, 4, 8, 15, 30, 60 and 180 after transplantation. Ferritin level was determined pretransplant and on day 60. RESULTS: Patients not treated with rHuEpo during dialysis experienced a transient increase in endogenous Epo after renal transplant that was not observed in treated patients (26 +/- 3.3 vs. 9 +/- 1.5 mU/ml, p < 0.001). The eEpo peak was similar in patients with early or delayed graft function (23 +/- 4.3 vs. 32 +/- 5.4 mU/ml, NS). The recovery of the anemia after a successful renal transplant took place in patients treated as well as those not treated with rHuEpo without significant differences. In the treated group, the pretransplant hematocrit level was similar in patients with early or delayed graft function (31 +/- 3.5% vs. 32 +/- 4.8%), but in the untreated group, the hematocrit level was lower in patients with early renal function (28.5 +/- 4% vs. 32 +/- 3%, p < 0.05). However, these patients also had a significantly shorter warm ischemia time (53 +/- 13.8 vs. 64 +/- 14.5 min). Fifty-two percent of the rHuEpo-treated patients and 36% of the untreated patients had delayed graft function. In conclusion, different courses of eEpo levels after renal transplant were observed depending on whether or not patients had been treated with rHuEpo during dialysis. Untreated patients experienced a transient increase which was not observed in the treated group. Immediate or delayed graft function did not modify eEpo levels. No association was found between rHuEpo therapy during dialysis and delayed graft function.

Adolescent↗
PubMed1995

Differential reactivity of structural components of eosinophil leucocyte granules as revealed by ethanolic phosphotungstic acid.

After glutaraldehyde fixation and ethanolic phosphotungstic acid (E-PTA) treatment before embedding, thin sections of rat bone marrow and large intestine showed a characteristic pattern of electron opacity in eosinophil leucocyte granules. In both mature eosinophils and precursor cells, the matrix appeared highly contrasted while the crystalline core revealed no electron density. Additional treatment of sections with uranyl acetate did not modify the contrasting pattern of eosinophil granules. The absence of electron dense reaction in the crystalline core after E-PTA treatment seems to originate from removal of core components. The selective reactivity of the matrix toward E-PTA could be a valuable ultrastructural marker for studies on the differentiation of specific granules along the maturation of eosinophil leucocytes.

Animals↗
PubMed1991

Alkaline hydrolysis/methylation-acetylation: a new technique for ultrastructural DNA cytochemistry.

A new technique for the visualization of DNA-containing structures in electron microscopy is described. Samples of glutaraldehyde-fixed bone marrow from rats were subjected to alkaline hydrolysis to remove RNA and the phosphate of phosphoproteins, followed by a combined blockage of protein carboxyl and amino groups through methylation-acetylation. After uranyl acetate staining of epoxy-embedded ultrathin sections, chromatin from all cell types showed a highly selective and intense electron opacity. Staining methods for DNA were also positive in semithin sections. This simple procedure could be very useful in ultrastructural cytochemistry of DNA and chromatin.

Acetylation↗
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↗
PubMed1990

Observations on the contrasting reaction of some electron dense stains applied on epoxy-embedded tissue sections.

Epon sections from glutaraldehyde-fixed rat bone marrow were treated with aqueous solutions of the following electron contrasting agents: uranyl acetate, ruthenium red, potassium permanganate, potassium dichromate, stannous chloride, palladium (II) chloride, sodium molybdate, phosphomolybdic acid, molybdenum heteropolyblue, phosphotungstic acid, iron(II)-phenanthroline, aluminium-hematoxylin, mercurochrome, cuprolinic blue, and sirius light turquoise blue. At the ultrastructural level, a high degree of electron opacity was always observed in mast cell granules and the crystalline inclusion (internum) of eosinophil granules. The chromatin revealed a somewhat lower and variable contrasting reaction, while the matrix (externum) of eosinophil granules appeared with scarce or no contrast. This pattern of electron opacity showed no correlation with the type of agent used; therefore, it can be assumed that binding processes based on the own chemical reactivity of the compounds are rather of secondary importance. The differential epoxy resin embedding of cell structures and the variable access of aqueous reagents through the non-polar plastic could be the predominant factors which account for these contrasting reactions.

Animals↗
PubMed1989

Tungsten and molybdenum heteropolyacids as staining and contrasting agents: reactivity with epoxyresin-embedded cell and tissue structures.

In this work, we carry out a further approach to the knowledge of the reaction mechanism of phosphotungstic and phosphomolybdic acids (PTA and PMA), as well as some derivatives, with cell structures from epoxyresin-embedded materials. Applied on thin sections from glutaraldehyde-fixed tissues, PTA and PMA induced a strong electron contrasting reaction in spermatid acrosomes, goblet cell mucin, callose and plant cell walls, endexine, intine and starch granules. In light microscopy, the localization of heteropolyacids on these structures was achieved by treatments of semithin sections with suitable reducing agents (titanous sulfate, stannous chloride, sodium borohydride, or p-phenylenediamine) to form the mixed-valence heteropolyblues, or with Schiffs's reagent. The use of PTA-dye complexes (pyronin-PTA and Mallory's PTA-hematoxylin) also showed the same staining pattern. Taking into account the chemical characteristics of the PTA- and PMA-reactive tissue elements, the present results indicate that heteropolyacids selectively enter into the highest hydrophilic structures from non-polar epoxy-embedded sections; after brief washing, they appear predominantly retained in tissue structures containing a great amount of carbohydrate components.

Animals↗
PubMed1987

Metachromatic staining and electron dense reaction of glycosaminoglycans by means of cuprolinic blue.

The cationic phthalocyanin-like dye Cuprolinic Blue, unlike phthalocyanin dyes such as Alcian Blue or Astra Blue, can definitely exhibit a clear metachromatic reaction with appropriate substrates. The application of Cuprolinic Blue to epoxy-embedded semithin sections revealed that mast cell cytoplasmic granules, goblet cell mucin and cartilage matrix stained in violet shades (metachromatic), whereas nuclear chromatin presented a bright blue coloration (orthochromatic). The metachromatic structures showed a high degree of contrast when ultrathin sections treated with Cuprolinic Blue were examined by electron microscopy. Cytophotometric measurements of stained components from the large intestine showed different absorption maxima: at 580 nm for mucin and at 640 nm for nuclei. The spectroscopical analysis revealed a clear-cut metachromatic shift when the dye was in the presence of chondroitin-4-sulphate. The addition of aluminium metal to Cuprolinic Blue solutions resulted in a striking spectral change; under such conditions the dye showed absorption maximum at 530 nm.

Animals↗
PubMed1986

Increased acidophilia of eosinophil granules after EDTA treatment.

The acidophilic reaction of eosinophil leucocyte granules from human, pig and horse blood smears was investigated by using May-Grünwald-Giemsa staining after previous treatment with EDTA and sodium citrate solutions. The same peak at 530 nm, but absorption values considerably higher than those of controls, were found in eosinophil granules after application of chelating agents, indicating that removal of metal cations could unmask basic groups in these structures.

Animals↗
PubMed1986

Electronmicroscopical contrast by palladium chloride.

Thin sections of glutaraldehyde-fixed, epoxy resin-embedded bone marrow from rats were treated with 2% palladium chloride in 2% concentrated HCl. This procedure was found to induce high electron density in chromatin from all cell types and in cytoplasmic granules of neutrophils and eosinophils. In the latter, the crystalline body showed more contrast than the matrix.

Bone Marrow↗
PubMed1986

Oxidized p-phenylenediamine: observations on the staining reaction in epoxy embedded tissues.

p-Phenylenediamine (PPD) is easily oxidized to brown compounds which stain acidic substrates. On account of the spontaneous oxidation process, the colour of PPD increases and becomes ochre-brown in a few days, showing an absorption peak at lambda = 510 nm with shoulder at about 440 to 460 nm. Studies on the application of oxidized PPD as a stain for semi-thin sections revealed that some tissue components could be clearly visualized. After glutaraldehyde fixation, semi-thin and thin sections of animal tissues were treated with 0.5% aqueous PPD solutions which were aged for variable times at room temperature. Microvilli, goblet cell mucin, mast cell granules, cartilage matrix, collagen, elastin, keratohyalin granules, acrosomes, cytoplasmic granules of Drosophila hydei salivary glands and chromatin showed positive staining reactions after treatment of semi-thin sections with oxidized PPD (7-10 days aged) for 20-30 minutes. Microspectrophotometric studies revealed an absorption peak at lambda = 520-530 nm and a shoulder at lambda = 440-460 nm in goblet cell mucin stained by oxidized PPD. In the presence of anionic macromolecules, the main peak of oxidized PPD solutions showed a strong hyperchromism. Thin sections stained by oxidized PPD did not appear contrasted, but the treatment with 0.125% gold chloride (AuCl3) induced massive gold deposits in structures stained by oxidized PPD. Hyperchromic shifts were also produced in oxidized PPD solutions after the addition of small amounts of AuCl3. This procedure can be used as a simple and rapid staining method for epoxy sections, giving selective contrast for some tissue components.

Animals↗
PubMed1984

Ruthenium red staining of polyanion containing structures in sections from epoxy-resin embedded tissues.

Staining by ruthenium red (0.5 mg/ml in borate buffer at pH = 9.2) has been used for light and electron microscopic visualization of polyanion containing structures in sections from glutaraldehyde-fixed, epoxy-embedded tissues. This staining technique can be applied in a simple and rapid way, showing the reactive cell components with suitable resolution and contrast. Preliminary spectrophotometric studies show the correspondence in absorption characteristics of the dye which is bound to polyanions in situ or in vitro.

Animals↗
PubMed1984

Blue molybdenum oxides: a stain for light and electron microscopy.

Blue molybdenum oxides (molybdenum blues) have been prepared from aqueous phosphomolybdic acid solutions and applied to thin and semi-thin sections of glutaraldehyde-fixed, epoxy-embedded tissues. A light blue colour and high electron opacity were found in mast cell granules, the secretion content of goblet cells, and cytoplasmic granules in Drosophila salivary glands. The possibility that binding of blue molybdenum oxides to polyhydroxylic components accounts for the staining and contrasting reactions in some cell structures is briefly discussed.

Animals↗
PubMedDate not supplied

Oxidized p-phenylenediamine staining of epoxy resin sections.

Semithin and thin sections of glutaraldehyde-fixed, epoxy resin-embedded animal tissues were treated with solutions of oxidized p-phenylenediamine (PPD). This method is suitable to reveal the general morphology of tissues in light microscopy, showing a high staining degree in some polyanion containing components. Posttreatments of thin sections with gold chloride solutions give considerable electron opacity in PPD positive structures.

Animals↗
PubMedDate not supplied

Electron microscopical morphology of cytoplasmic granules from horse eosinophil leucocytes.

The structure of specific granules from horse eosinophil leukocytes is still largely unknown. In this work, electron microscopical studies of horse eosinophils reveal that the large cytoplasmic granules contain an external membrane, a matrix of less density, and a dense (non crystalline) core. Round vacuolar inclusions of matrix materials were often observed within the cores. Horse eosinophil granules showed a considerable heterogeneity, and three morphological types could be identified according to structural features of the core and matrix.

Animals↗
PubMedDate not supplied

Subcutaneous nodules following treatment with aluminium-containing allergen extracts.

We describe two patients who developed multiple itching nodules following immunization with vaccines adsorbed on aluminium hydroxide. Both patients had been treated with vaccines for extrinsic asthma and rhinitis for 4 and 10 years respectively. The lesions were persistent and lasted for several years. Histopathological findings were those of a foreign body reaction. Aluminium was most probably involved in the pathogenesis of these lesions because its presence could be demonstrated in macrophages using energy-dispersive X-ray microanalysis. Although some symptomatic relief was achieved with topical corticosteroids and oral antihistamines, treatment was unsuccessful.

Adult↗