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Biomedical subjects

A Notario

Publications and source records attributed to A Notario.

At least 19 recordsLinked to original sources
PubMed1993

The role of integrins in granulocyte dysfunction in myelodysplastic syndrome.

The aim of the present study was to evaluate the function of granulocytes in 20 patients affected by myelodysplastic syndrome (MDS) and correlate this with the expression of surface membrane integrins. The granulocytes showed a deficit in chemotaxis (34 +/- 12 vs 84 +/- 10, p < 0.01) in superoxide release (12 +/- 7 vs 30 +/- 10, p < 0.01) and in aggregation 12 +/- 6 vs 36 +/- 9, p < 0.01 using fMLP as stimulus. We also demonstrated with cytofluorimetric and alkaline phosphatase immunoenzymatic analysis (APAAP), decreased expression of CD11b/CD18 receptor detected by OKM1 (p < 0.001) and CD18 detected by MoAb IOT-18 (p < 0.001). PMNs CD11b/CD18 up-regulation and APAAP image analysis studies showed a lower level of expression of CD11b/CD18 in granulocytes from MDS patients compared to controls (p < 0.001). We concluded that granulocyte dysfunction in MDS may be correlated with modification of leukocyte integrins.

Adult↗
PubMed1993

The CD11/CD18 granulocyte adhesion molecules in myelodysplastic syndromes.

We have evaluated the function of granulocytes in 14 patients suffering from myelodysplastic syndrome (MDS). We also evaluated the functional and immunochemical activities of five monoclonal antibodies (MoAbs) reactive with the CD11/CD18 leucocyte adhesion molecules of granulocytes. Granulocytes showed a decrease in chemotaxis (P < 0.001) and in aggregation (P < 0.01) using various agents as a stimulus. Cytofluorimetric and immunoenzymatic assays with alkaline phosphatase (APAAP) analysis showed decreased expression of the CD11b/CD18 receptor detected by OKM1 (P < 0.001). Despite LFA-1 and-CD11a/CD18 was expressed in normal amounts. The studies of upregulation of granulocytes CD11b/CD18 and image analysis of immunochemical preparation (APAAP) demonstrated decreased expression of CD11b/CD18 in granulocytes from MDS compared to controls (P < 0.001). We conclude that granulocyte dysfunction in MDS may be correlated with decreased expression of surface CD11b/CD18 leucocyte adhesion molecules or their structural modification.

Adult↗
PubMed1993

Assay of phagocytic cell functions.

The fundamental role of the immune system is recognition of the self from the non-self; in this way the principal functions of the immune system can be summarized as: resistance against the cells and foreign substances which are potentially damaging the tissues; identification of neoplastic cells to be destroyed. The cells which have this role are essentially lymphocyte, neutrophils and macrophages: extracellular and cellular humoral factors also play their role into the inflammatory process. In fact, we define the normal responses of phagocyte as the capacity of the specific phagocytic cell to respond to various stimuli and to migrate to the location of the damage. This complex cellular defense mechanism comprises several steps that can be summarized as following: opsonization of particles to be ingested, adhesion and aggregation of phagocytes to vascular endothelium, migration of phagocytes through the vessel walls, chemotaxis of phagocytes towards pathogenic agents, recognition of the particles/antigens by the phagocytes which subsequently adhere to their surface, ingestion of the particles with formation of a phagosome. This process is completed with the fusion of the phagosome with cellular granules (lysosomes) and formation of phagolysosomes, degranulation and release of the enzyme laden granules into the phagolysosome, lysis and killing of ingested particles and bacteria. It is clear from this schematic summary, that the response to pathogens can be very complex and each of the processes involved in the above described steps could be deranged leading to various pathological changes. We analyze the most classical and new methods to study the physiopathology of granulocytes, which are important for clinical diagnosis of phagocyte diseases or for phagocytic dysfunction in various syndromes and in neoplastic patients.

Cell Adhesion↗
PubMed1992

Phagocyte activation in coronary artery disease.

Recent studies suggest that granulocytes (PMNs) play a role in the pathogenesis of acute and chronic myocardial ischemia and extension of myocardial injury. Granulocytes can release a variety of molecules mediating tissue injury which act synergistically with other molecules and cells. The aim of our investigation was to evaluate the granulocyte function in patients affected by coronary artery disease (CAD) and during coronary angioplasty (PTCA). We studied 20 patients suffering from CAD. The PMN's aggregating activity was greater in the coronary sinus than in the aorta (P < 0.01). The increase in aggregating activity was evident in patients who were smokers: their cells release significantly lower quantities of leukotriene C4 (P < 0.025). In the 20 patients who underwent coronary angioplasty we analyzed superoxide release after stimulation with phorbol-myristate-acetate (PMA). The results showed a greater decrease of PMN's superoxide production in the coronary sinus than in the aorta (P < 0.05). In all patients affected by CAD we evaluated the PMN's expression of CD11b/CD18 membrane integrins. In these patients the increase in expression of CD11b/CD18 was statistically significant in comparison with the controls (P < 0.01). This increase in expression correlates with a higher aggregation (r = 0.87, P < 0.001). The potential role of leukocytes, oxygen radicals, leukotrienes and granulocyte enzymes in the pathophysiology of myocardial injury due to regional ischemia and reperfusion is an area of intense investigation. This paper presents studies carried out in vivo which have been instrumental in demonstrating the role of granulocytes as mediators of myocardial ischemia.

Angioplasty, Balloon, Coronary↗
PubMed1992

Sex hormones and bone metabolism in postmenopausal rheumatoid arthritis treated with two different glucocorticoids.

To investigate the effect of low doses of 2 different glucocorticoids on bone mass, sex hormone status and bone metabolic indices, a study was undertaken in 16 postmenopausal women with rheumatoid arthritis (RA) receiving < 15 mg/day of deflazacort and in 16 patients with RA matched for age, years postmenopause and disease duration, receiving < 10 mg/day of prednisone. Sixteen healthy postmenopausal women and 16 nonsteroid treated patients with RA were also studied as control groups. Vertebral bone density (vBMD) was lower (mean +/- SD: 0.65 +/- 0.07 vs 0.73 +/- 0.09 g/cm2; p < 0.02) in prednisone treated patients than in deflazacort treated patients, whose vBMD values were similar to those of nonsteroid treated RA. No significant difference was found as for radial bone mineral content. Circulating levels of estradiol, dehydroepiandrosterone sulfate, androstenedione and progesterone were low in all patient groups with RA when compared with healthy controls. The prednisone treated patients showed significantly lower values of all sex hormones with respect to deflazacort treated patients. Osteocalcin values were also lower (3.0 +/- 1.4 vs 3.9 +/- 1.6 ng/ml; p < 0.05) in prednisone treated patients with respect to deflazacort treated group. Glucocorticoid treated patients showed a direct correlation (r2 = 0.39) between vBMD and plasma estradiol levels, while no correlation was found with osteocalcin values. In conclusion, our postmenopausal patients with RA treated with low dose prednisone had reduced levels of sex hormones and osteocalcin and reduced vertebral bone mass. Comparable doses of deflazacort showed only a mild inhibitory effect on sex hormones and osteocalcin, and did not show any detectable effect on bone mass.

Adult↗
PubMed1990

Peptide opioids and morphine effects on inflammatory process.

Morphine was found to inhibit human granulocyte aggregation and ATP, thromboxane B2 (TxB2), and leukotriene B4 (LTB4) secretion during cell aggregation. None of the opioid peptides tested [(D-Ala2, D-Leu5)-enkephalin (DADL), (D-Ala2, N-Me-Phe4, Gly-ol5)-enkephalin (DAGO) or dynorphin 1-9 (Dyn 1-9)] was capable of mimicking morphine effects, while Dyn 1-9 per se induced TxB2 and LTB4 secretion from granulocytes. Morphine inhibition of both cell aggregation and ATP, but not of arachidonic acid metabolism product secretion, was prevented by naloxone. The naloxone-sensitive impairment by morphine of CD11b-CD18 complex surface expression observed could play a role in opioid inhibition of granulocyte activation.

Adenosine Triphosphate↗
PubMed1989

Definition of CD 11a, b, c, and CD 18 glycoproteins on chemotactically deficient granulocyte membranes in patients affected by myeloid disorders.

We studied neutrophil chemotaxis and surface membrane glycoproteins in 12 patients suffering from myeloid disorders with abnormal karyotype using in vitro techniques in all 12. Chromosome studies were also carried out virtually simultaneously. We chose to study only patients showing a deficit of chemotaxis (p less than 0.001). Ten of these patients revealed a clonal chromosome abnormality in most of the leukemic cells. The monoclonal antibody technique using MoAb 60.1, 60.3, 60.5, OKM1, LFA-1 and 9E8 demonstrated normal leukocyte membrane glycoproteins CD 11a, b, c and CD 18 and therefore excludes that an abnormality of these is involved in the pathogenesis of altered leukocyte chemotaxis. No correlation between chemotactic deficit and any specific clonal chromosome abnormality was found.

Anemia, Refractory, with Excess of Blasts↗
PubMed1989

[Granulocyte disease caused by glycoprotein complex deficiency correlated with leukocyte adhesion].

This report summarizes the clinical and laboratory findings from a group of our patients and literature reviews from several families who have a genetic deficiency in three related leukocyte membrane surface antigens known as CR3,LFA-1, and p150,95. Each surface antigen has an identical beta-chain noncovalenty linked to one of three distinct alpha-chain types. Patients affected by this autosomal recessive disease have now been identified by several investigators. The patients have an increased susceptibility to bacterial infections that is similar to patients who have other types of neutrophil functional deficiencies or neutropenia. Laboratory tests have indicated that isolated neutrophils from these patients have two major types of functional deficiencies that probably contribute to their reduced ability to overcome bacterial infections. This review focuses exclusively on the phagocytic and cytotoxic abnormalities of neutrophils from these patients.

Antibodies, Monoclonal↗
PubMed1988

The influence of thyroid hormones on colony growth of peripheral CFU-GM from normal and leukemic subjects.

In order to clarify the alterations of granuloblastic cells in chronic and acute myeloid leukemia, the colony growth behavior of cultured CFU-GM from the peripheral blood of normal and leukemic subjects was examined in basal conditions and after adding to the medium T3 or T4 and/or thioproline and/or flurbiprofen. These drugs had in previous investigations proved their ability to modify cellular receptors and the uptake of thyroid hormones. The study was carried out in semisolid (double agar layer) and liquid medium, utilizing the techniques described previously. Both thyroid hormones enhanced the colony growth from normal peripheral blood CFU-GM and the response was more evident with T4 than T3. The effect on leukemic CFU-GM (from CML and AML) was less clear, probably due to the presence in leukemic cells of a defect of cellular uptake and to the utilization of T3 and T4. Indeed, on addition to the culture medium of thioproline, which modifies membrane permeability, and of fluorbiprofen, which inhibits PGE synthesis, the colony number and growth from leukemic CFU increased considerably in accordance with the results of our previous studies on these substances showing that they are able to modify cellular receptors for thyroid and several other hormones.

Cells, Cultured↗
PubMed1984

Drugs affecting the hormonal receptors of normal and leukaemic peripheral leucocytes.

The authors investigated the behaviour of steroid hormone uptake in leukaemic cells (CML, CLL, AML, ALL), in basal conditions and after incubation with drugs which modify the cellular concentration of cAMP, PGE and PGF. The results demonstrated the presence in leukaemic cells of an alteration in the incorporation of steroid hormones. This alteration was scarcely modified by incubation with theophylline, which increases cellular concentration of cAMP. On the other hand, it was moderately counteracted by thioproline and was evidently inhibited by flurbiprofen, which also reduced cellular concentrations of prostaglandins, particularly PGE2, with the exception of PGF2 which showed a poor response. Differences were observed in the behavior of hormonal uptake of CML, in contrast to that of AML, CLL and ALL peripheral leucocytes.

Estradiol↗
PubMed1983

[Plasmapheresis and survival of patients with myeloma and secondary renal insufficiency].

The mortality rate due to renal insufficiency in patients with myelomas was studied and the results obtained compared with figures on patients given plasmapheresis to correct the insufficiency. The results of the comparison confirm the value of the immediate use of plasmapheresis on patients with myelomas. In a large percentage of cases, the technique either completely cured or significantly improved renal dysfunction, thus normalizing the blood and urine situation and improving the patients' chances of survival.

Blood Proteins↗