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Biomedical subjects

A Stacchini

Publications and source records attributed to A Stacchini.

At least 73 records · Page 4Linked to original sources
PubMed1982

Sodium, and potassium dependent adenosinetriphosphatase from Cavia cobaya kidney: interaction with very low cardiotonic steroid concentrations.

We noticed that very low cardiotonic steroid concentrations activate the Na, K-ATPase in a variety of different preparations. In the present research the effect of three cardioactive steroids on the enzymatic activity was tested. The glycosides activated the Na,K-ATPase, while the aglycone strophantidine does not. Ouabain binding studies on various preparations showed the presence of two binding site classes with different affinities. Purification procedures shift the apparent Kd values, while K+ increase them. Accordingly, the activatory and inhibitory effects may be explained by the cardiotonic steroid binding on different sites of the Na,K-ATPase molecule.

Animals↗
PubMed1982

Na,K-ATPase from Xenopus laevis kidney and epidermis: ouabain interaction studies.

A satisfactory purification from Xenopus laevis epidermis is presented. Ki and Kd values for the ouabain-enzyme interaction have been evaluated. Both parameters appear very low, as compared with those demonstrated in other anurans. Very low digitalis-like compound level was demonstrated in Xenopus; on the contrary in Bufo, in which these substances play a defensive role, it is very high. Our results strengthen the hypothesis of a physiological action of such compounds in regulating enzyme-driven Na+/K+ exchanges.

Animals↗
PubMed1982

Artificial sphincters as surgical treatment for experimental massive resection of small intestine.

A modification of the technique of Schiller, DiDio, and Anderson was adopted by extending removal of the longitudinal layer of the muscular coat to the entire perimeter of a segment of the small intestine in dogs, resulting in the construction of artificial sphincters, to assist animals undergoing enterectomy. The creation of one or two artificial sphincters prolonged the survival of dogs undergoing massive resection of the small intestine (87.5 percent of the total length).

Animals↗
PubMedDate not supplied

A basis for estimation of consumption: literature values for selected food volatiles. Part I.

This paper is a compilation of quantitative data available on volatile compounds reported so far in 18 food items including some legume, cereals, grapes and cheeses as well as crab, lobster, cocoa and chocolate. No publications reporting quantitative data were found for five of these 18 food products, i.e. sultana grape, broad beans, cassava, oat and rye. About 440 volatile compounds have been assayed globally in the other 13 food products and more than 50% of them were found in grape or in grape juice. Levels of these volatile compounds in the selected foods were generally in the ppb range and less often in the low ppm range. Very high levels were found for some carboxylic acids in cheeses and cocoa and for some alcohols and acids as well as for ethyl acetate in grape juice.

Diet↗
PubMedDate not supplied

A basis for estimation of consumption: literature values for selected food volatiles. Part II.

In this paper we present a compilation of quantitative literature data on volatile compounds in 15 food items including some brandies, meats, oils as well as vegetables, vinegar and potatoes. Levels of the volatile compounds identified (approximately 900) in this group of food items are generally in the ppm range. Carboxylic acids were present in much higher levels in plum brandy, vinegar, lamb and mutton (heated), whereas alcohols, esters and carbonyls aldehydes are particularly abundant in brandy.

Alcohols↗
PubMedDate not supplied

Effect of unbalanced diets on the long-term metabolism of a toxicant. 1. Lead in rats: preliminary note.

The aim of this study was the evaluation of the effect of dietary imbalances on absorption and distribution of lead in the female Sprague-Dawley rat. In this note preliminary results on the relationship between blood concentrations of lead and unbalanced diets are presented. Hyperproteic, hyperglycidic, hyperlipidic and balanced diets were prepared, and most of them included 15 mg/kg lead. Blood samples were collected at day 0, 21, 36, and 95 of the diets and analyzed by anodic stripping voltammetry (ASV). Lead uptake as a function of feed consumption was found to decrease in the order: balanced, hyperproteic and hyperglycidic, hyperlipidic diet. On the other hand lead blood levels were as follows (decreasing order): hyperlipidic, hyperproteic, hyperglycidic, balanced. Further research is being carried out on the influences of dietary imbalances on whole-body distribution of lead.

Absorption↗
PubMedDate not supplied

A basis for estimation of consumption: literature values for selected food volatiles. Part III.

Quantitative data on volatile compounds have been reported in 16 food items. No publications reporting quantitative data were found for two of these 16 food products, i.e. avocado and jackfruit. About 550 volatile compounds have been assayed globally in the other 14 food products. Mango and raspberry were the products with the greatest number of volatile compounds; the most representative substances were benzaldehyde, ethyl acetate, limonene, and 2-phenylethanol.

Flavoring Agents↗
PubMedDate not supplied

Monoclonal antibody panels for acute leukemia and myelodysplastic syndrome diagnosis. Results of a co-operative quality control group.

The need for standardization criteria and result reproducibility in immunophenotyping hematological diseases has increased along with their clinical importance. Our group "Policentric Study Group on Immunological Markers", is composed of 40 laboratories. Its aim, over recent years, has been to find a standardized way of immunophenotypic analysis applicable to various hematological diseases. The objective of this study is to contribute to the debate concerning standardization of monoclonal antibody panels and immunophenotypic analysis procedures in acute leukemia (AL) and myelodysplastic syndrome (MDS), with the following targets: to improve interlaboratory reproducibility of the immunophenotyping data, and interpretative results; to study, with improved feasibility, correlation between immunophenotype and clinical or biological findings on a large number of AL and MDS cases; to verify the utility of the proposed monoclonal antibody panels for proper AL and MDS classification, and to detect minimal residual disease. In the field of AL and MDS our experience is based on about 1800 and 700 cases respectively analyzed over the last five years. Starting from these experiences and data of the literature we have elaborated the proposed panels of monoclonal antibodies and the methods of analysis. We have suggested a standardized immunophenotypic approach to study AL and MDS. In particular our work has focused on the gating strategy. This aims at drawing a gate of analysis having high purity and recovery, and on the choice of monoclonal antibody combinations for multiparametric analysis, particularly the normal antigen expression on each step of lineage differentiation or their clinically relevant aberrant expressions. A standardized criteria has become a necessary starting point in any kind of analytical process. In the field of acute leukemias and myelodysplastic syndromes the work of this polycentric group has focused on the pre-analytical and analytical steps to be taken in cytometric evaluation of hematological malignancies. The results obtained may contribute to reaching intra and inter-laboratory reproducibility.

Acute Disease↗
PubMedDate not supplied

Expression of the CD31 antigen in normal B-cells and non Hodgkin's lymphomas.

The role cell adhesion molecules play in the biological and clinical behaviour of non Hodgkin's lymphomas (NHL) has been reported in several studies. This study reports the findings on B-cells taken from various healthy control tissues and compared them to B-cells from 83 malignant B-lymphomas, that had been classified according to the WHO classification. Flow cytometry was used to investigate the surface expression of CD31, an adhesion molecule involved in B-cell development and vascular adhesion mechanisms. Quantification of the fluorescence signals showed specific patterns of CD31 expression on normal B-cell subpopulations and different NHL groups. Our results demonstrate that CD31 expression is modulated during the differentiation process in normal B-cells, high in pre-B-I cells, low in pre-B-II precursors, intermediate in the mature B-cell subpopulations or, depending on the functional state absent in activated follicular centre cells, present in pre- and post- germinal centre cells. When the CD31 expression is evaluated as fluorescence intensity in NHL, it reveals a heterogeneous pattern related to histogenetic derivation (high in small lymphocytic lymphoma, low in follicular lymphoma, intermediate in marginal zone and large cell lymphomas). These observations suggest that CD31 might well play a critical role in the ontogeny and physiology of B-lymphocytes. Therefore, on the basis of these observations we propose the CD31 molecule as an interesting additional useful parameter to be used for the differential diagnosis of NHL and hypothese that it has a pathophysiologic role in NHL evolution.

Antibodies, Monoclonal↗
PubMedDate not supplied

Differential effect of transforming growth factor beta 1 on the proliferation of human lymphoid and myeloid leukemia cells.

BACKGROUND: Transforming Growth Factor beta (TGF beta) exerts different effects on the hemopoietic system which range from the growth stimulation of more mature myeloid progenitors to the growth inhibition of more immature and multilineage hemopoietic precursors. TGF beta is also an inhibitor of the proliferation and functional activities of normal T and B lymphocytes. The aim of this study was to evaluate its effect on the growth of a human leukemic cells of lymphoid and myeloid origin. METHODS: We tested its activity on the doubling time, the DNA synthesis rate and the clonal growth of a panel of lymphoid and myeloid leukemic cell lines. RESULTS: Among the myeloid cell lines, the proliferation in liquid cultures as well as the clonal growth of KG1, HL60 and U937 were suppressed by TGF beta 1 at doses ranging from 0.025 to 2.5 ng/ml; the degree of inhibition was, however, variable. BV 137, a Ph1-positive cell line derived from a very undifferentiated stem cell, was also highly responsive to TGF beta 1 inhibition. Among the six lymphoid neoplastic cell lines, only Nalm 6, a pre-B leukemic cell line, was consistently and reproducibly inhibited by the same doses of TGF beta 1. Conversely, two Burkitt lymphoma cell lines, Raji and Daudi, and three T-cell leukemias (Molt 4, Jurkat and PF 382) were insensitive to TGF beta inhibition.

Cell Differentiation↗
PubMedDate not supplied

Modulation by retinoic acid of the growth of bone marrow cell progenitors from patients with myelodysplastic syndrome.

The in vitro effect of increasing concentrations of retinoic acid on the growth of day 7 and day 14 CFU-GM and of pre-CFU-GM from patients with myelodysplastic syndromes has been studied. Unlike in normal cells, where retinoic acid enhances the in vitro growth of myeloid progenitors, there was an overall inhibition of bone marrow progenitors from patients with myelodysplastic syndromes at concentrations of 10(-7) to 10(-6) M retinoic acid, with the exception of day 14 CFU-GM whose growth may be enhanced by 10(-7) M retinoic acid.

Bone Marrow↗
PubMedDate not supplied

Expression of the hybrid P210 bcr/abl protein in Philadelphia chromosome positive B-lymphoid cell lines.

An altered c-abl protein (P210) bearing increased tyrosine kinase activity represents the product of the hybrid bcr/c-abl gene arising as a consequence of the Philadelphia (Ph1) chromosome translocation, the consistent cytogenetic abnormality of chronic myelogenous leukemia (CML). Although the chronic phase of this disease is substantially characterized by a marked proliferation of myeloid cells, the Ph1 translocation occurs in an early multipotent stem cell, giving rise to both myeloid and lymphoid cell lineages. Here we show that P210 bcr/abl protein expression varies greatly in different Ph1 chromosome positive B-lymphoid cell lines obtained from Epstein-Barr virus-transformed lymphocytes of a CML patient in the chronic phase. In addition Ph1 positive and Ph1 negative lymphoid cell lines obtained from the same patient were tested for a number of biological properties including the immunophenotype, the capacity to grow in soft agar and possible tumorigenicity in nude mice. No differences were found.

Animals↗
PubMedDate not supplied

[Angiographic anatomy of the cecal artery].

After studying the angiographic anatomy of the cecal artery in 80 post--mortem examinations we have demonstrated the following: -The common cecal trunk (76,2% of the cases) had its origin from the right colic artery in 12 (15%) and from the ileal artery in 49 (61,2%) observations. -The anterior and posterior cecal arteries had a separate origin in 19 observations (23,7%). In 7 of these observations (8,7%) the anterior cecal artery had its origin from the right colic artery and, the posterior cecal artery originated directly from the ileal artery. In 11 observations (13,8%) both cecal arteries, originated directly from the ileal artery and, in one case (1,2%) the anterior cecal artery originated from the right colic artery and the posterior cecal artery from the ileocolic artery.

Adolescent↗
PubMedDate not supplied

[Radiologic results of an artificial pylorus performed primarily in patients with Billroth II gastric resection].

The authors describe the radiological results after primary execution of an "artificial pylorus". In 18 patients were done a troncular vagotomy, hemigastrectomy (Billroth II) and Braum jejunal anastomosis. In twelve of this patients an "artificial pylorus" were done on the efferent loop, 10 cm distant of the gastroenterostomy and before the jejunal Braun anastomosis. The technique, previously described, was a 3 cm circumferencial ressection of the longitudinal muscular layer and circular layer plicature. The cut edges were approached. A significant delay in gastrojejunal emptying was observed in patients with an "artificial pylorus" caused by the effective presence of a sphincter-like mechanism.

Adult↗