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Biomedical subjects

M Marini

Publications and source records attributed to M Marini.

At least 19 recordsLinked to original sources
PubMed1992

Scintigraphic evaluation of disease activity in rheumatoid arthritis: a comparison of technetium-99m human non-specific immunoglobulins, leucocytes and albumin nanocolloids.

Technetium-99m-labelled, non-specific, polyclonal, human immunoglobulin G (99mTc-hIG) has been used to quantify synovial inflammation in rheumatoid arthritis. A comparison was carried out between the scintigraphic results obtained with this tracer, 99mTc-hexamethylpropylene amine oxime-labelled white blood cells (99mTc-WBC) and 99mTc-albumin nanocolloids (99mTc-NC). Twenty patients affected by rheumatoid arthritis and suffering from clinically active synovitis were studied with 99mTc-hIG. The number and sites of the involved joints had been previously assessed on the basis of the presence of pain and/or swelling. A radiological examination had already been carried out on all the joints. Two days after the 99mTc-hIG scan, 10 patients (group 1) underwent 99mTc-WBC scintigraphy and the other 10 (group 2) underwent a 99mTc-NC scan. The results show that the results of 99mTc-hIG and 99mTc-NC scans are in agreement with clinical examinations in the majority of cases. However, a certain number of positive joint scans corresponding to negative clinical examinations was found. The numerical distribution of these results according to the radiological stages seems to show that 99mTc-hIG is more useful than 99mTc-NC in the initial phases of the disease. The 99mTc-WBC scan was negative in a consistent percentage of the joints previously assessed as clinically and 99mTc-hIG scan positive.

Arthritis, Rheumatoid↗
PubMed1992

Soluble enkephalin-degrading enzymes released by lymphomic and erythroleukaemic cell lines.

The possible existence of soluble proteolytic enzymes released by cells of lymphomic (U937 and 1301) and erythroleukaemic (K562) lines was studied measuring the hydrolysis of 3H-leucine enkephalin in the presence of cell-free supernatants obtained from these lines. Results indicate that leu-enkephalin is rapidly degraded in the presence of these supernatants, and that enkephalin disappearance is paralleled by the formation of peptides that can be interpreted as its hydrolysis fragments. To characterize the factors involved in leu-enkephalin degradation, cell supernatants were analyzed by ion exchange and by steric exclusion chromatography. Data obtained indicate the presence of three groups of proteins active in leu-enkephalin degradation: aminopeptidases, dypeptidylaminopeptidases and dypeptidylcarboxypeptidases. In all three lines, these enzymes are represented by a considerable number of distinct activities. The sizable number of soluble enzymes identified and the significant total activity observed suggest a possible role in the regulatory degradation of informational peptides, as proposed by several groups for the membrane-bound proteolytic enzymes of immunocompetent cells.

Amino Acid Sequence↗
PubMed1992

Evaluation of the performance of the copper T380A IUD up to ten years. Is this IUD a reversible but potentially permanent method?

The clinical experience of a cohort of 340 women using a TCu380A IUD for up to 10 years at the Family Planning Clinic of the State University of Campinas, Brazil was evaluated by life-table analysis. Removals for medical reasons were more frequent during the first year of use, while from the third year on, removals for personal reasons were more frequent. Expulsions were concentrated in the first two years of use, and none were detected after the fourth. Gross pregnancy rate accumulated to 2.0, 2.8 and 5.3 and continuation rate was 64.2, 43.4 and 27.8 per 100 women at three, six and ten years of use, respectively. The effectiveness of the device did not decrease significantly after the eighth year of use and it could be considered a reversible but potentially permanent method.

Adolescent↗
PubMed1992

Expression of the potent inflammatory cytokines, granulocyte-macrophage-colony-stimulating factor and interleukin-6 and interleukin-8, in bronchial epithelial cells of patients with asthma.

We have previously demonstrated that cultured human bronchial epithelial cells produce cytokines with potent proinflammatory properties on exposure to several stimuli in vitro, and we have hypothesized that these epithelial cell-derived factors may contribute to the pathogenesis of some inflammatory diseases of the bronchial mucosa, particularly asthma, by promoting the infiltration of granulocytes and T cells and their local activation. We provide, in this study, direct evidence of an increased expression of granulocyte-macrophage-colony-stimulating factor, interleukin-6, and interleukin-8 genes and proteins in bronchial epithelium from patients with symptomatic asthma. The up regulation of the production of these cytokines in bronchial epithelial cells of patients with asthma could be abolished in vitro by corticosteroids (hydrocortisone, 10(-7) mol/L), but the up regulation also spontaneously disappeared during a period of 6 days after the removal of the cells from the diseased tissue.

Adrenal Cortex Hormones↗
PubMed1992

Role of hydrolysis in the association of leu-enkephalin to peripheral blood mononucleate cells.

The possible hydrolysis of labelled leucine enkephalin in the presence of peripheral blood mononucleate cells and its association with the same cells have been investigated. Results obtained indicate that under experimental conditions leu-enkephalin is rapidly hydrolysed in the presence of model cells. Under the same conditions, the radioactive label is partially associated with the cells. The presence of protease inhibitors reduces both enkephalin degradation and association of the radioactive label with the cells. The hypothesis that the associated species is intact leu-enkephalin is not supported by the relative kinetics of enkephalin hydrolysis and of association of the radioactive label with the cells, nor by the statistically significant correlation between these data, nor again by the effect of proteolysis inhibitors. The same data agree with the hypothesis that the radioactive label associated with the cells is represented by one, or several, of the fragments formed by enkephalin hydrolysis, not by the intact molecule. However, results obtained in the presence of hydrolysis-stable DADL indicate association with the cells of the intact peptide. Moreover, antigen stimulation has opposite effects on the two peptides: with leu-enkephalin, hydrolysis and association are increased, with DADL association is decreased by stimulation. The sum of these data seems to suggest the co-existence in PBMC of two phenomena, i.e. internalization of one, or several, of the fragments formed by the enzyme degradation of enkephalin and binding to membrane receptors of the intact pentapeptide.

Cells, Cultured↗
PubMed1992

Hydrolysis and association of leucine enkephalin to lymphomic and erythroleukaemic cell lines--II.

The relationship between the hydrolysis of labelled leucine enkephalin and the association of its radioactive label to the cells of lymphomic and erythroleukaemic cell lines have been studied using intact cells and resealed membranes obtained from these cells as models. Hydrolysis by cell enzymes and its effect on association have been analysed using protease inhibitors and non-hydrolysable enkephalin analogues. Results obtained confirm that hydrolysis of the pentapeptide is a prerequisite for association of the radiolabel to cells. The same results provide evidence of marked differences between enkephalin hydrolysis by whole cells and hydrolysis measured in the presence of resealed membranes, suggesting the existence in intact cells of proteolytic enzymes other than those bound to the membranes. The lack of reversibility of association and the intracellular localization of the radioactive label suggest that the association measured is prevailingly caused by internalization of a hydrolysis fragment, and not by binding to receptors. In order to determine the nature of the active fragment, association was measured in the presence of all four labelled N-terminal hydrolysis fragments of leu-enkephalin under conditions of nearly-total inhibition of proteolytic enzymes. Under these conditions, the label carried by Tyr, but not that carried by the other N-terminal fragments, was associated with cells. Free Tyr, furthermore, inhibits the association to cells of both labelled Tyr and leu-enkephalin. Data summarized above are consistent with the hypothesis that the radioactive label is taken up by the cells as Tyr, freed from the parent peptide by cell-related enzymes. The same data tend to exclude that a relevant fraction of the intact pentapeptide is bound to membrane receptors or that the radioactive label is carried into the cell by a N-terminal fragment other than Tyr.

Chromatography, Thin Layer↗
PubMed1992

Hydrolysis and association of leucine enkephalin to lymphomic and erythroleukaemic cell lines--III. Soluble enzymes.

The possible existence of soluble proteolytic enzymes released by cells of lymphomic (U937 and 1301) and erythroleukaemic (K562) lines was studied measuring the hydrolysis of 3H-leucine enkephalin in the presence of cell-free supernatants. Results obtained indicate that in the presence of these supernatants leu-enkephalin rapidly disappears and that enkephalin disappearance is paralleled by the formation of peptides that can be interpreted as its hydrolysis fragments. Chromatographic analyses of cell supernatants indicate the presence of three groups of proteins active in leu-enkephalin degradation: aminopeptidases, dipeptidylaminopeptidases and dipeptidylcarboxypeptidases. In all three lines, soluble enzymes are represented by a sizeable number (from 13 to 25) of distinct activities. The number of enzymes identified and their considerable total activity suggest a possible role in the regulatory degradation of informational peptides, as proposed by several groups for the membrane-bound proteolytic enzymes of immunocompetent cells.

Chromatography, Ion Exchange↗
PubMed1992

Protective effect of nedocromil sodium on the IL1-induced release of GM-CSF from cultured human bronchial epithelial cells.

Cultured human bronchial epithelial cells constitutively produce granulocyte-macrophage colony-stimulating factor (GM-CSF). The synthesis and release of GM-CSF is upregulated in bronchial epithelium of patients with symptomatic asthma and this may contribute to the local activation of inflammatory cells in their bronchial mucosa. The cause of this upregulation of GM-CSF expression is unknown, but an increased release of interleukin-1 (IL1) from other airway resident cells might be involved, as an increase in GM-CSF production can be induced in vitro in normal bronchial epithelial cells by IL1 and the airway secretions of asthmatics contain high amounts of this cytokine. In the present study, we have evaluated the effect of the anti-inflammatory and antiasthmatic drug, nedocromil sodium, on the spontaneous and IL1-induced expression of GM-CSF in cultured bronchial epithelial cells. This compound, at the concentration of 10(-5) M, reduced the IL1-induced increase in GM-CSF release from epithelial cells by more than 40%, but it did not affect the constitutive production of GM-CSF.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

Increased expression of endothelin in bronchial epithelial cells of asthmatic patients and effect of corticosteroids.

We have previously demonstrated that human bronchial smooth muscle cells possess specific binding sites for the potent bronchoconstrictive peptide endothelin 1 and that primary cultures of human bronchial epithelial cells constitutively produce an endothelin-like material that binds to smooth muscle cell receptors with a kinetic ability analogous to that shown by the authentic peptide. To evaluate the potential role of airway epithelium-derived endothelin in the pathogenesis of asthma, we have examined here the expression of endothelin in the bronchial epithelial cells of 6 patients with symptomatic asthma and reversible airflow obstruction. The epithelial cells of 5 normal volunteers and 5 patients with chronic bronchitis and airflow obstruction unaffected by bronchodilators were tested as controls. The bronchial epithelial cells of all the asthmatic patients expressed preproendothelin 1 mRNA, as assessed by in situ hybridization, and released high amounts of mature and biologically active endothelin during a 48-h period of incubation (radioimmunoassay). By contrast, the epithelial cells from normal donors did not contain preproendothelin 1 transcripts, and the endothelin-like material in their supernatants was invariably below the detection limit of the assay. Only a few cells from 2 patients with chronic bronchitis expressed preproendothelin mRNA and endothelin immunoreactivity. When hydrocortisone (10(-6)M) was added to the culture medium of asthmatic bronchial epithelial cells for 48 h, the release of immunoreactive endothelin significantly decreased (p < 0.025), but the numbers of cells expressing preproendothelin 1 mRNA did not change to the same extent.

Adrenal Cortex Hormones↗
PubMed1992

Cytokine mRNA profile and cell activation in bronchoalveolar lavage fluid from nonatopic patients with symptomatic asthma.

Recent studies have indicated that airway inflammation in atopic asthma is characterized by T-cell activation and local eosinophilia, but it is unknown whether this also applies to nonatopic asthma. In this study, the cytokine mRNA profile and activation status of inflammatory cells in bronchoalveolar lavage fluid (BALF) of eight nonallergic patients with symptomatic asthma and eight nonallergic healthy controls were compared using the message amplification phenotyping (MAPPing) with the polymerase chain reaction (PCR) procedure and immunocytochemical evaluation. Asthmatics had an increasing number of inflammatory cells in BALF, including activated eosinophils (EG2-positive) (p less than 0.001) and activated T cells (CD25-positive) (p less than 0.001). Activated T cells from five of the eight asthmatic patients and from one control subject expressed high levels of interleukin 5 (IL-5) and granulocyte-macrophage colony-stimulating factor (GM-CSF). All the asthmatic patients had increased numbers of monocytes in their BALF (p less than 0.002) and those cells invariably showed increased expression of interleukin 1 beta (IL1 beta) transcripts. In five patients they also expressed appreciable levels of IL-6 and GM-CSF mRNA. IL-5 and GM-CSF can induce local activation of eosinophils, and IL-1 beta and IL-6 are known to promote T-cell activation and proliferation. Thus, there is an increased production of cytokines with inflammatory properties in the airways of patients with nonatopic symptomatic asthma, which may contribute to the persistence of inflammation, and monocytes and activated T cells are important sources of these cytokines.

Adult↗
PubMed1992

Acid phosphatase activity in the supramedullary neurons of Coris julis (L.).

This work describes the acid phosphatase activity in supramedullary neurons of Coris julis, analyzed by a cytochemical method. The presence of both acid phosphatase-positive and -negative membrane bound granules indicates that only a part of the numerous electrodense granules in the supramedullary neurons can be interpreted as lysosomes. The great number of lysosomes in these large neurons of young animals is indicative of the rapid turnover of cell structures, which may be correlated with the high rate of synthesis. The electrodense granules showing no acid phosphatase activity are postulated to be vesicles containing gastrin/CCK-like peptide or precursors of this neuromediator.

Acid Phosphatase↗
PubMed1992

[Technical principles of solid tridimensional modeling with computerized tomography for the study of maxillofacial diseases].

3DCT allows the solid modeling of body structures from contiguous slices. The 3D images are free to rotate on the x, y, and z axes. It is possible to evidentiate structures with various densities by means of threshold operators, which allow a 3D model of both soft tissues and bones to be obtained. Shading operations allow image quality to be improved by varying the elementary units to surface units ratio. Implemented 3D rendering reduces the spatial edges by means of anti-aliasing functions. The 3D images allow the study of the complexity of maxillofacial bony structures, and they are especially useful in both surgical planning and in postoperative follow-up. We studied 58 patients with maxillofacial diseases (34 traumatic, 14 malformations, 4 dysplastic, and 6 neoplastic). In most cases (96.5%), we obtained high-quality images, which allowed both the site and the extension of the lesions to be evaluated, together with their relationships to adjacent structures. In 65% of traumatic cases, the 4 basic views thoroughly demonstrated lesion spread, while in the extant 35% of cases cutting operations and rotatory translations were necessary. In all malformation cases a clear visualization of somatic asymmetries was obtained. In both dysplastic and neoplastic cases, the best lesion evidence was obtained in superficial lesions with cortical bone involvement. This technique was always easy and quick to perform, with no need for supplemental dose exposure to the patient.

Bone Diseases↗
PubMed1991

[Test with ovine corticotropin-releasing hormone (oCRH): clinical application and reference values in the young adult and the postmenopausal women].

CRH (corticotropin-releasing hormone) is a hypothalamic polypeptide that stimulates ACTH secretion by the anterior pituitary and, subsequently, cortisol secretion by the adrenal cortex. CRH test administration is indicated in the differential diagnosis of Cushing syndrome and in the assessment of corticotropic function in different pituitary conditions. Both human CRH (hCRH) and ovine CRH (oCRH) can be used by i.v. injection. Intrinsic ACTH-releasing activities of the two molecular forms are similar. Nevertheless, and contrary to hCRH, oCRH does not interact with the human CRH specific binding protein (CRH-BP) and the use of this ovine form could be useful in testing pituitary function while avoiding possible changes in peptide activity due to protein binding. The present study was conducted in 3 distinct groups of human volunteers to evaluated the ACTH and cortisol responses to i.v. oCRH (1 micrograms per kg body weight) at noon (oCRH test). 24 healthy, nonobese subjects, not under medication, participated in the study. The first group consisted of 8 young men, the second of 8 women of childbearing age and the third of 8 menopausal women. Tolerance to the oCRH test was excellent in all 3 groups. A significant increase in plasma ACTH and cortisol was observed in all the subjects, with peak occurrence for ACTH between 15 and 60 minutes after oCRH and between 20 and 120 minutes for cortisol. The responses were not sex-related among the young subjects, but the menopausal women displayed a higher cortisol increase than the other 2 groups.

Adrenocorticotropic Hormone↗
PubMed1991

Age-related expansion of functionally inefficient cells with markers of natural killer activity in Down's syndrome.

Peripheral blood lymphocyte subsets of two groups of patients affected by Down's syndrome (DS), ie, 28 children and nine adults of relatively advanced age (greater than 34 years), were investigated and compared with those of age- and sex-matched healthy controls (13 children and 20 adults). Particular attention was devoted to cells with markers of natural killer (NK) activity. Double- and triple-color cytofluorimetric analysis was used to better characterize the phenotypic features of the different subsets. Apart from a reduced number of T lymphocytes (CD3+) in DS children and of B lymphocytes (CD19+) in both DS groups, the major alteration we found was a marked age-related increase of the percentage of cells bearing markers associated with NK activity, such as CD16, CD56, and CD57. These DS cells were apparently severely defective as far as their function was concerned, because NK activity was significantly reduced in comparison with age-matched controls, but still capable of responding to cytokines such as interleukin-2, interferon-beta, and interferon-gamma, and to the modulation of lytic activity exerted by the anti-CD16 monoclonal antibody. On the whole, our data stress the importance of studying DS subjects of different ages to fully appreciate the immunologic derangement characteristic of this syndrome.

Adolescent↗