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Biomedical subjects

W Barcellini

Publications and source records attributed to W Barcellini.

At least 73 records · Page 4Linked to original sources
PubMed1986

In vitro synthesis of IgM rheumatoid factor by lymphocytes from patients with essential mixed cryoglobulinemia.

Peripheral blood mononuclear cells (PBMC) from patients with Essential Mixed Cryoglobulinemia (EMC) were studied for their ability to synthesize polyclonal IgM and rheumatoid factor (RF) IgM in vitro. Our results indicate: that EMC-PBMC produce smaller amounts of polyclonal IgM but higher quantities of IgM-RF than normal PBMC after pokeweed mitogen (PWM) or Staphylococcus aureus activation, so that the IgM-RF to total IgM ratio is significantly greater in EMC than in normal cultures; that enriched EMC-B lymphocytes display a significantly higher spontaneous synthesis of IgM-RF than normal B lymphocytes and that the IgM-RF B cell clones are receptive to T cell regulation. Taken together these findings suggest an expansion of B cell clones committed to IgM RF production and the presence in peripheral blood of differentiated B lymphocytes capable of secreting IgM-RF in EMC.

Adult↗
PubMed1986

Persistent generalized lymphadenopathy in drug addicts: immunological studies.

The persistent generalized lymphadenopathy (PGL) in drug addicts displays the same immunological abnormalities previously found in homosexual and haemophiliac men with PGL: impaired in vivo and in vitro T cell functions, inverted T4/T8 ratio in blood and B cell abnormalities. The peripheral blood B-lymphocytes, in fact, show a reduced in vitro immunoglobulin synthesis after pokeweed mitogen and Staphylococcus aureus activation, with an increased spontaneous IgG secretion. In the lymph node biopsies, the immuno-histological studies reveal an infiltration of OKT8 positive cells in the germinal centers, a depletion of OKT4 positive lymphocytes slighter than in the blood and an explosive follicular hyperplasia with a striking destruction of the dendritic reticulum cell framework. This latter finding, together with the high levels of serum IgG and the presence of preactivated B cells in the blood, seems to be consistent with the presence of an in vivo polyclonal B cell activation. A high incidence of anti-HTLV III antibodies was also found in the PGL drug addicts. The significance of these findings is discussed in this report.

Adult↗
PubMed1985

In vitro immunoglobulin synthesis: T-cell requirement in pokeweed and staphylococcus aureus B-cell activation.

The T-cell requirement for the B-lymphocyte immunoglobulin synthesis induced by Pokeweed mitogen (PWM) and by Staphylococcus aureus Cowan I (SAC) was investigated. We found that the PWM induced B-cell activation was controlled by an absolute Mitomycin-C resistant T-cell helper activity and by a Mitomycin-C sensible T-cell suppressor activity. On the other hand the SAC induced B-cell activation was less thymus dependent and was not influenced by Mitomycin-C treated or irradiated T cells. The different T-cell requirement could be an expression of different responding B-cell subpopulations.

Adult↗
PubMed1984

[Esophageal motor changes in patients with Raynaud's phenomenon and suspected scleroderma. Electromanometric and serologic evaluations].

Esophageal motor dysfunction in patients with collagen disease, although rather frequent, presents difficult etiopathogenetic arrangement. By means of esophageal manometric evaluation and immunopathologic study the Authors observed 44 patients with Raynaud's phenomenon idiopathic or joined with Scleroderma. From collected data the utility of esophageal manometry in early diagnosis is pointed out.

Adult↗
PubMed1984

Anti-ribosomal ribonucleoprotein autoantibodies in systemic lupus erythematosus.

Sera from systemic lupus erythematosus (SLE) patients giving a fluorescent ribosomal pattern on tissue and cell preparations also showed precipitating autoantibodies against purified rat liver ribosomes. Ribosomal antigen is also present in rabbit thymus cellular extract (RTE), since the same sera gave precipitin lines against RTE in identity with ribosomes. Immunofluorescent staining was completely inhibited by serum absorption with ribosomes or with RTE. However ribosomal RNA and RNase or trypsin-treated ribosomes failed to react with these autoantibodies as demonstrated in immunoabsorption and immunodiffusion studies. These data suggest that these sera contain autoantibodies directed against some antigenic site composed of a portion of both RNA and ribosomal protein. Ribosomal autoantibodies were detectable at a low frequency in SLE patients characterized by an active disease and renal involvement.

Antigens↗
PubMed1984

Abnormalities of in vitro immunoglobulin synthesis by peripheral blood lymphocytes from patients with essential mixed cryoglobulinemia.

Peripheral blood mononuclear cells from patients with essential mixed cryoglobulinemia (EMC) were studied for their ability to differentiate into cells containing cytoplasmic immunoglobulins (Ig) and to synthetize Ig after in vitro pokeweed mitogen activation. EMC lymphocytes showed a significant defective differentiation and Ig synthesis compared to normal controls. Coculture experiments carried out mixing enriched normal T- and EMC B-cell suspensions, and vice versa, showed that (a) the EMC B-cell-defective Ig synthesis still persisted after removal of suppressor activity by irradiation, both with autologous and with normal allogeneic T suspensions and (b) EMC T cells displayed a less efficient activity in helping Ig production by normal B lymphocytes. A comparable, reduced response was also found after activation with Staphylococcus aureus strain Cowan I. Taken together these results seem to indicate that in essential mixed cryoglobulinemia an impaired T-cell helper activity coexists with a B-lymphocyte impairment. The significance of these abnormalities in the pathogenesis of EMC is discussed.

Adult↗
PubMed1984

Altered expression of B lymphocyte surface immunoglobulins in minimal change nephrotic syndrome and focal glomerulosclerosis.

In 20 patients with nephrotic syndrome (10 minimal change glomerulonephritis, MCN; 10 focal glomerulosclerosis, FGS) the peripheral blood lymphocytes showed a statistically significant increase in IgG-bearing cells (SIgG-C) in comparison with 30 patients with other histological types of primary glomerulonephritis with and without nephrotic syndrome (14 and 16, respectively). In the same MCN and FGS patients the serum IgG levels were slightly decreased. Furthermore, 5 cases of MCN in sustained remission for 1 year after steroid therapy showed normalization of the SIgG-C and the serum IgG levels. The possible significance of these phenomena in the pathogenesis of the hypo-IgG-globulinemia in MCN and FGS is discussed.

Adolescent↗
PubMed1983

Con A suppressor cell assay: a further characterization.

Con A induced suppressor cell assay was further characterized in this study. Significant lower mitogenic responses of autologous fresh cells cocultured with Con A-activated cells were found when compared with the response of cocultures of responders plus control cells preincubated in medium alone. However, Con A-activated cells did not express a real suppression, since no difference was found between responses of fresh responders alone and responses of cocultures with Con A-activated cells. So, Con A activation seemed to block the expression of the enhancement provided by control cells to autologous responders, rather than to induce a real suppressor activity. The induction of the Con A suppressor cell activity required cell proliferation but it was not proportional to the degree of DNA synthesis. Monocyte depleted cell populations exhibited lower Con A suppressor cell activity compared to unfractionated cells, suggesting a cooperative role of monocytes in the Con A induction step. The expression of this activity was not due to a cytotoxicity against the responders and was dependent on the number of activated cells added. Mononuclear cells from active lupus erythematosus (SLE) patients, but not from inactive SLE patients differed from normal controls in showing a significant loss of suppression index.

Adult↗
PubMed1982

Defective suppressor cell activity in essential mixed cryoglobulinemia.

Peripheral blood mononuclear cells from patients with essential mixed cryoglobulinemia were investigated for the ability to induce suppressor cell activity (S.C.A.) following in vitro exposure to Concanavalin A (Con A). The generation of Con A-S.C.A. is significantly impaired in essential mixed cryoglobulinemia compared to the healthy controls. No correlation was found between Con A-S.C.A. and the clinical or laboratory parameters of the disease. This impaired ability to induce Con A-S.C.A. in essential mixed cryoglobulinemia reflects a functional T-cell defect, which may play a role in the pathogenesis of the disease.

Adult↗
PubMedDate not supplied

Immune complexes and IgG-Fc receptors on human platelets in essential mixed cryoglobulinemia.

An enzyme-linked immunosorbent assay (ELISA) using wells coated with normal platelets has been tested in order to quantitate cell-bound immune complexes (ICs) by measuring the uptake of alkaline phosphatase-conjugated antibodies to IgG in the immune complexes. All patients with essential mixed cryoglobulinemia had levels of serum IgG ICs above control values; a poor accordance was found between levels of ICs detected by this method and those obtained using the conglutinin method. The presence of these complexes was correlated with human platelet aggregation: platelets aggregated in vitro when cryoglobulins with higher IgG/IgM ratio were present. This type of ICs could be critical also for platelet activation and aggregation in vivo.

Antigen-Antibody Complex↗
PubMedDate not supplied

In vivo treatment with a monoclonal antibody to interferon-gamma neither affects the survival nor the incidence of lupus-nephritis in the MRL/lpr-lpr mouse.

The effects of the in vitro treatment with a mAb (DB-1) that neutralizes mouse IFN-gamma on the development of the SLE-like syndrome in MRL/lpr-lpr (MRL-lpr) mice were studied. The results show that the i.p. administration of 2.6 mg/week of DB-1 from the 12th to the 20th week of age neither affected the survival nor the incidence and severity of lupus nephritis in MRL-lpr mice. This study argues against the pathogenic relevance of IFN-gamma in this experimental model of human SLE.

Animals↗
PubMedDate not supplied

Age-related changes of beta-endorphin and cholecystokinin in human and rat mononuclear cells.

Beta-endorphin (BE) and cholecystokinin (CCK) were measured in fresh PBMC isolated from human subjects and rats. The BE and CCK PBMC contents increased significantly with age both in human and rat models. Moreover, polyclonal stimulation induced a significant decrease of BE but not CCK contents in mononuclear cells from human aged subjects. The time course of changes in BE and CCK concentrations observed in fresh and cultured cells from subjects of different ages did not directly correlate to the time course of age-associated impairment of lectin-induced lymphocyte proliferative response and interleukin-2 synthesis. In fact, the lymphocyte functional defects were significantly observed only in the 71-99 year age group, whereas the neuropeptide changes were already evident in the 31-50 age group. Since BE has been shown to participate in the modulation of the immune system, the age-related modifications of PBMC BE could play a role in the immunodepression observed during aging.

Adult↗
PubMedDate not supplied

Toxicological and immune findings in workers exposed to pentachlorophenol (PCP).

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial and domestic applications. Data available on the effects of technical-grade PCP on the immune system are insufficient and equivocal; some data indicate inhibitory effects, whereas others suggest stimulating effects. This study was performed to evaluate toxicological and immune findings in 32 subjects who had prolonged exposure to PCP in a wood factory and in 37 controls. PCP concentrations were determined in plasma and urine of all subjects. Lymphocyte subsets of CD3-, CD4-, and CD8-positive cells were evaluated, and the proliferative response of peripheral blood mononuclear cells (PBM) to mitogens was assessed. The results suggested the absence of major laboratory and clinical signs of PCP-dependent immune deficiency. A weak effect of long-term exposure to PCP on the functional immune response could not be ruled out because of the finding of a decreased response to 5% PHA in the high-exposure group. A weak effect against hepatocyte membrane was evidenced by the finding of raised serum concentration of glycocholic, taurodeoxycholic, and glycochenodeoxycholic acids in subjects directly exposed to PCP for more than 10 y.

Adolescent↗
PubMedDate not supplied

Immunomodulatory effects of occupational exposure to mancozeb.

The effects of occupational exposure to ethylene-bis-dithiocarbamate of manganese and zinc on the immune system were evaluated in a group of mancozeb-exposed manufacturers and controls. The immune system tests revealed the following: (a) lymphocyte proliferative responses triggered by different activators and mitogen-induced IL-2 production were higher in exposed subjects than in controls; (b) production of monocyte/macrophage-derived IL-1 and polyclonal IgG and IgM, by beta-lymphocytes, did not differ between exposed subjects and controls; (c) percentages and absolute numbers of total T-cells, T-helper cells, T-suppressor/cytotoxic cells, activated T-cells, total beta-cells, and natural killer cells were similar in exposed subjects and controls; (d) serum immunoglobulin classes and complement fractions were within the range of normality; and (e) rheumatoid factor and non-organ-specific serum autoantibodies were absent in exposed and control subjects. An increase in T-cell functional response was found in the exposed group, suggesting a slight immunomodulator effect of mancozeb in conditions of low-level, prolonged occupational exposure.

Air Pollutants, Occupational↗
PubMedDate not supplied

Antiphospholipid antibodies cross-reacting with erythrocyte membranes. A case report.

We describe a patient with primary antiphospholipid syndrome (PAPS) and haemolytic anemia with cryoagglutinins, in whom antibodies eluted from red blood cells (RBC) displayed anti-cardiolipin (CL) binding activity. This activity was confined to the IgG isotype and was directed to the negatively-charged phospholipids only. In addition, the patient's IgG fraction displayed a higher binding to RBC in comparison to normal control IgG and this reactivity was inhibited after absorption of the anti-CL activity with CL-micelles. These findings further sustain the association between antiphospholipid antibodies (APA) and Coombs' positivity with or without haemolytic anemia and suggest that APA could be at least in part responsible for anti-RBC activity.

Aged↗
PubMedDate not supplied

Relationship between anti-phospholipid and anti-endothelial cell antibodies: further characterization of the reactivity on resting and cytokine-activated endothelial cells.

Sera positive for autoimmune anti-phospholipid antibodies were studied by a cell surface radioimmunoassay for their cross-reactivity with resting or activated human endothelial cells. The endothelial cell activation by interleukin 1 beta, gamma-interferon, lipopolysaccharide or phorbol-12 myristate-13 acetate did not affect the cross-reactivity. Comparable findings were also found by testing anti-cardiolipin affinity purified preparations. Taken together these data indicate that endothelial cell activation is not sufficient per se to modulate the expression of antigenic determinants recognizable by the anti-phospholipid antibodies. However, anti-cardiolipin affinity purified preparations displayed enhanced cell binding after cell membrane perturbation by paraformaldehyde fixation, suggesting that an alteration in endothelial cell integrity might further trigger the reaction of circulating anti-phospholipid antibodies with vessel walls in vivo.

Antibodies↗