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Biomedical subjects

G Sacchi

Publications and source records attributed to G Sacchi.

At least 73 records · Page 4Linked to original sources
PubMed1984

Attempts at characterizing the allergens of cat saliva and fur.

In the framework of a wide program aimed at identifying various animal allergens, it was deemed interesting to study cat fur and saliva antigens. Cat fur and saliva extracts were prepared. Cat saliva antiserum was raised in rabbits with cat saliva as antigen. Immunochemical techniques such as isoelectric focusing, blotting, CIE, CRIE, fused rocket immunoelectrophoresis, line immunoelectrophoresis were implemented in order to identify the allergens and their isoelectric point, to perform the antigenic and allergenic characterization of the candidate allergen, to define their molecular weights and last, but not least, to carry out the quantitative assay towards a standard. On the whole the results obtained, besides confirming some previous results, pointed out by literature (presence of Cat 1 and albumin in the extracts) do stress the presence of other allergens, and the possibility to implement isoelectric focusing and blotting, which avoids the use of animal antisera, for the allergen detection in biological materials.

Allergens↗
PubMed1983

[Immunotherapy of allergic manifestations].

The Authors, after outlining the epidemiologic role of the allergic disorders, which places them among the pathologies covered by the wide chapter of social diseases, deal with the immunogenetic aspects and the particular conditions of the atopic habitus, atopic condition and atopic disease. The latest trends of antigen non specific immunotherapy, with the relevant possibility of eliciting a non specific suppressive mechanism of the IgE response, are considered. The antigen specific immunotherapy is then discussed under its various aspects: prophylaxis, efficacy, indications, modalities of treatment, unwanted reactions, immunological modifications, possible causes of its failure, medico-legal problems relevant to such therapy. Finally, the latest perspectives in the field of specific immunotherapy are envisaged, such as the use of allergoid vaccines, of liposomes as immunoadjuvants or the stimulation and the induction of suppressive factors of the IgE response.

Allergens↗
PubMed1983

Severe glomerular epithelial cell damage does not prevent passive Heyman nephritis in rats.

Passive Heymann nephritis (PHN) is an experimental model of membranous glomerulopathy in the rat ascribed to in situ formation of immune complexes. Very recently the demonstration that the aminonucleoside of puromycin provides some protection against PHN has highlighted the role of intrinsic properties of the glomerulus in immune complex formation. Adriamycin, a widely employed chemotherapeutic agent, is known to induce a nephrotic syndrome in rats characterized by severe ultrastructural changes of glomerular epithelial cells and by loss of glomerular polyanionic charges. We have studied the effect of pre-treatment with adriamycin on glomerular immune deposits in PHN using immunomorphological and quantitative techniques. In normal rats (group 1) injection of heterologous antibodies to proximal tubular brush border antigen (anti-FxIA), rapidly induces subepithelial immune deposits, as observed by immunofluorescence. Pre-treatment of rats with adriamycin (group 2) 48 hr before injection of anti-FxIA antibodies, when proteinuria is absent, does not alter the immunohistological findings of PHN. Heavily proteinuric rats (group 3) pre-treated with adriamycin 13 days before injection of anti-FxIA did not show any significant difference from groups 1 and 2. Species binding of injected anti-FxIA antibodies, studied by paired label techniques, was similar in normal rats and in proteinuric and non-proteinuric rats treated with adriamycin. The only difference was in the group of proteinuric rats treated with adriamycin, in which at 5 hr binding in the kidney was higher, due to tubular brush border binding as shown by immunofluorescence. This study indicates that local changes of the glomerulus and loss of glomerular histochemical properties do not invariably alter the glomerular deposition of immune complexes.

Animals↗
PubMed1983

Metabolic and morphologic changes induced by serotonin in skeletal muscle of rats after abdominal aorta ligation.

Myopatic changes observed in muscle of rats after abdominal aorta ligation and/or serotonin injection have been regarded as a suitable model to explore the possibility that vasoactive treatments induce muscular damage similar to human myopathies. In the present study, we investigated the effect of serotonin administration to normal and aorta-ligated rats on cAMP-dependent protein-kinase (PK) and hydrolytic enzymes in skeletal muscle.

Animals↗
PubMed1982

Adriamycin-induced nephrotic syndrome in rats: sequence of pathologic events.

Adriamycin has been suspected of causing experimental nephrotoxicity. We report here that adriamycin induces a nephrotic syndrome in rats, proteinuria beginning 4 to 5 days after a single intravenous injection (7.5 mg. per kg. of body weight). The full expression of the syndrome develops 13 to 15 days later. Minimal alterations at light microscopy, negative immunofluorescence, and only some focal "fusion" of foot processes can be observed by electron microscopy in the early phase after injection (28 hours). At 13 days, loss of foot process architecture, and replacement by flattened epithelial cytoplasm, was invariably found. These ultrastructural findings became extensive at 28 days follow-up. Colloidal iron staining of kidney biopsies revealed loss of glomerular polyanions as early as 3 hours and very marked loss at 28 hours after adriamycin injection. Polyanions were totally absent at 13 days and were still undetectable at 28 days. Thus, the loss of polyanionic charges associated with the sialic acid coat precedes the ultrastructural changes and the onset of proteinuria. These changes appeared similar to those reported in rats treated with daunomycin or puromycin animonucleoside. The present study supports in a different animal model the concept that both morphologic changes and proteinuria are the consequence of a common primary event that is the loss of glomerular fixed negative charges.

Animals↗
PubMed1982

[Characterization and standardization of allergen extracts].

The allergenic extracts employed in the diagnostic or therapeutic fields are prepared from the different raw materials employing different extraction fluids: it has been shown that the solute contains, besides the allergens, many other substances. The analytical techniques, of which some of the most useful are described, should be implemented for the characterization and standardization of the extracts. The results obtainable, when using these techniques, for the extract characterization, are presented. Subsequently, the most important allergens identified and purified are briefly reviewed. The use of the analytical techniques described allows verifying the changes occurring in the allergenic extracts during storage. The implementation of the same allows the evaluation of the possibility, in subsequent times, of preparing, therefore standardizing, replicated allergenic extracts, similar to the former insofar as the allergenic and antigenic characteristics are concerned.

Allergens↗
PubMed1979

[Histochemical and ultrastructural studies of the innervation of the lymph-vessel and blood-vessel wall. 1. Adrenergic innervation].

The adrenergic innervation of the lymph vascular wall was studied by means of the Falck fluorescence histochemical tecnique and electron microscopy with Tranzer and Richards' histochemical tecnique. The lymph vessels wall, compared with that of blood vessels, shows very few adrenergic nerve fibers located in the adventitia outside the smooth muscle cells. The possible role of the nervous system in the motor control of the lymph vessels is discussed.

Adrenergic Fibers↗
PubMed1979

[Histochemical and ultrastructural studies of the innervation of the lymph-vessel and blood-vessel wall. II. Cholinergic innervation].

Using the Acetylcholinesterase (AChE) tecnique applied to light and electron microscopy, was observed that the lymph vascular wall shows very few and inconstant AChE-positive fibers. The cholinergic fibers run prevalently longitudinal in the perivascular connective tissue, only brief segments show a loose network. The results are discussed and compared with blood vessels innervation.

Animals↗
PubMed1979

Modification of arginyl residues in ferredoxin-NADP+ reductase from spinach leaves.

Reaction of spinach leaves ferredoxin-NADP+ reductase (NADPH:ferredoxin oxidoreductase, EC 1.6.7.1) with alpha-dicarbonyl compounds results in a biphasic loss of activity. The rapid phase yields modified enzyme with about 30% of the original activity, but no change in the Km for NADPH. Only partial protection against inactivation is provided by NADP+, NADPH and their analogs, whereas ferredoxin affords complete protection. The reductase inactivated to 30% of original activity shows a loss of about two arginyl residues, whereas only one residue is lost in the NADP+-protected enzymes. The data suggest that the integrity of at least two arginyl residues are requested for maximal activity of ferredoxin-NADP+ reductase: one residue being located near the NADP+-binding site, the other presumably situated in the ferredoxin-binding domain.

Aldehydes↗
PubMed1979

Plaque assay with protein A-coated erythrocytes for the evaluation of human immunoglobulin-secreting cells induced by pokeweed mitogen.

Cells secreting IgM, IgG and IgA were evaluated in cultures of human peripheral blood lymphocytes stimulated in vitro with pokeweed mitogen by a haemolytic plaque assay using protein A-coated erythrocytes in the presence of class-specific antisera. Kinetic study revealed that immunoglobulin-secreting cells appeared after 3 days of culture and peaked between days 5 and 7. IgM-secreting cells predominated throughout the culture period. This plaque assay is a useful and sensitive in vitro test for the evaluation of polyclonal B-cell activation in humans and may provide a good approach to the study of disturbances in the synthesis of the various classes of immunoglobulins.

Adult↗
PubMed1978

[Syphilis serology: "ELISA", a third generation test].

The characteristics and the working modalities of ELISA (Enzyme Linked Immunosorbent Assay) are outlined at the onset. Subsequently, the Authors refer the data relevant to the use of ELISA in the syphilis serodiagnosis, by describing the operative phases for the working out of the test with the enzyme peroxidase, and reporting the results of the clinical investigation performed on primary and secondary syphilis in progress, on treated primary and secondary syphilis (examinations performed 1 to 10 years after the end of therapy), on healthy blood donors, and on samples of false biological positivities. On the basis of the analysis of the results, the Authors feel that ELISA for its characteristics of sensitivity, easiness in carrying out, rapidity and reproducibility, might find a rational indication in the modern serodiagnosis of the syphilis.

Blood Donors↗