Biomedical subjects

B Cosso

Publications and source records attributed to B Cosso.

6 recordsLinked to original sources

PubMed1990

Interleukin-1 release by alveolar macrophages in asthmatic patients and healthy subjects.

A thymocyte proliferative response assay was used to compare spontaneous and lipopolysaccharide (LPS)-induced interleukin-1 (IL-1) release by alveolar macrophage (AM) in asthmatic patients and normal subjects. Twelve asthmatic patients and seven nonsmoking healthy subjects underwent a bronchoalveolar lavage (BAL). All asthmatic patients had a reversible airway obstruction and 7/12 were allergic. BAL AM were separated by adherence on tissue culture plates in medium RPMI-1640 supplemented with antibiotics and fetal calf serum, and were incubated with or without 10 micrograms/ml LPS for 20 h. Free-cell supernatants were tested by C3H/HeJ mice thymocyte proliferative assay. Unstimulated AM supernatant IL-1 activity was significantly higher in asthmatic patients (mean +/- SEM: 47.8 +/- 11.9 units/10(6) AM) in comparison with healthy subjects (4.8 +/- 2.3 units/10(6) AM; p less than 0.05, Mann-Whitney U test) but did not significantly differ between allergic (42.2 +/- 15.5 units/10(6) AM) and intrinsic asthmatic patients (55.8 +/- 20.7 units/10(6) AM). For healthy subjects, IL-1 activity was significantly higher in LPS-stimulated AM supernatants (85 +/- 20 units/10(6) AM, p less than 0.05; Mann-Whitney U test) in comparison with unstimulated ones; for asthmatic patients, unstimulated and LPS-stimulated AM supernatant IL-1 activity did not significantly differ. This finding is in accordance with previous work suggesting that AM from asthmatic patients have a weak suppressive activity upon lymphocyte proliferation and emphasize the enhanced AM releasability in asthma.

Adolescent↗

PubMed1987

Identification of class II HLA alloantibodies in placenta-eluted gamma globulins used for treating rheumatoid arthritis.

Placenta-eluted gamma globulins (PEGG) have been recently and successfully used in the treatment of patients with rheumatoid arthritis. PEGG, eluted at acid pH from large pools of human placentas, contained 99% IgG material. Sephacryl S300 gel filtration revealed a main fraction (76%) of native IgG accompanied by 10% aggregates and 14% digested fragments (as identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoelectrophoresis with specific antisera). Previous in vitro data had suggested that alloantibodies to class II HLA antigens were present in this preparation. This study confirms that PEGG and F(ab')2 fragments were able to inhibit stimulating cells in mixed lymphocyte reactions. Additional findings showed that: IgG from PEGG were cytotoxic for the non-T cell population; IgG or F(ab')2 from PEGG bound only to class II HLA-bearing cells; F(ab')2 from PEGG were able to block the complement-mediated cytotoxicity of anti-HLA-DR and anti-DQw1 alloantibodies. These data confirm the presence of class II HLA alloantibodies in PEGG. These antibodies may account for the clinical improvement reported in patients with rheumatoid arthritis. Our findings are similar to recent data showing that the injection of anti-Ia antibodies in experimental animal models decreases the autoimmune process.

Arthritis, Rheumatoid↗

PubMed1987

[Complement activation in extracorporeal circulation. Comparison of nylon versus polyester bubble oxygenators].

Complement activation during cardiopulmonary bypass is well known and may influence postoperative morbidity. As nylon can particularly induce complement activation, its influence was assessed by measuring total haemolytic complement and B, C3 and C4 factors, during cardiopulmonary bypass with bubble oxygenators for coronary surgery, comparing "nylon" circuits (20 patients, Bentley BOS 10) versus "polyester" circuits (19 patients, Shiley S 100 A). Complement activation began with induction of anaesthesia and surgical procedures, B, C3 and C4 levels falling significantly (respectively 15, 17 and 20% from baseline values). The alternative pathway was activated before the classical pathway. Complement activation continued during cardiopulmonary bypass, with no more consumption of complement factors (slight variations of about 0 to 3% of the levels found after anaesthetic induction and surgical procedures). No statistically significant difference appeared between the two groups. This suggested that nylon did not significantly increase complement activation during cardiopulmonary bypass. The bubble oxygenator material cannot therefore be considered as a criterion for choosing the type of equipment.

Complement Activation↗

PubMed1985

Human placenta-eluted gammaglobulins in immunomodulating treatment of rheumatoid arthritis.

Thirty-one patients with severe rheumatoid arthritis were treated with intravenous perfusion of human placenta-eluted gammaglobulins. These gammaglobulins, which are IgG eluted from placental tissue, have strong immunomodulating properties in vitro. Several clinical trials were tested to find the optimal useful dosage. A 50 percent improvement was considered a good result and was obtained in 60 percent of patients with rheumatoid arthritis. The best results were obtained in patients receiving 1,500 mg daily seven days each month. Six subjects had a long remission of their disease after the end of treatment. The side effects were usually minor. In all patients, an immunostimulation of lymphocyte function was shown, even when they had no improvement. A control group of patients underwent perfusion with IgG from placental blood without any clinical or immunologic effect. It is suggested that the in vivo effects of placenta-eluted gammaglobulins might be mediated by polyspecific anti-HLA-DR antibodies.

Adult↗

PubMed1984

Decreased suppressor cell activity of alveolar macrophages in bronchial asthma.

In 8 allergic asthmatic patients and 12 healthy volunteers, we investigated the effects of alveolar macrophages (AM) on lymphoproliferative responses to polyclonal T-cell mitogens of autologous peripheral blood mononuclear cells (PBMC). The AM were obtained by bronchoalveolar lavage. Peripheral blood mononuclear cells (PBMC) and mitomycin-treated autologous bronchoalveolar cells (BAC) were cocultured at various AM-to-PBMC ratios, and were stimulated or not by phytohemagglutinin and concanavalin A. Half of AM expressed HLA-DR antigens in both the asthmatic and the control group. The BAC from normal subjects were able to modify the lymphoproliferative responses of autologous PBMC to cell mitogens. A dose-dependent effect was observed related to the number of BAC added to PBMC--suppressive at high ratios but enhancing at low ratios. In allergic bronchial asthma, there was a decreased suppressor cell activity of BAC. Among BAC the adherent cells were responsible for this effect. This abnormality could be a part of more general decreased functional activity of AM in allergic bronchial asthma.

Adolescent↗

PubMedDate not supplied

[Treatment of rheumatoid polyarthritis with IgG eluted from the placenta. Results of an open study on 31 patients].

Thirty-one patients presenting classical or defined, severe and active rheumatoid polyarthritis (RP) unresolved by most of the usual basic treatments (due to inefficacy or safety problems) were treated with human placental IgG preparations (HPIgG) in an open study. Various therapeutic protocols were tested to determine the most efficacious dosage. Favorable results were noted in 62% of cases. Improvement was generally rapid, often occurring after the first week of treatment. Rheumatoid nodules subsided by more than 50% and were resolved in two of nine cases. A decrease in dosage of analgesics or anti-inflammatories was possible in seven of 31 cases. Remission of RP of duration exceeding six months after withdrawal of HPIgG treatment was noted in six of 18 favorable results (33.3%). Best results were seen with intravenous administration of 1,500 mg per day seven days per month. No clinical or immunological effects were seen in a control group treated with venous globulins (1,500 mg/day for seven days). Safety was very satisfactory: four withdrawals from treatment due to proteinuria (3 cases) or phlebitis (1 case); these adverse reactions subsided rapidly. Immunostimulation of lymphocyte function was seen in all patients treated with HPIgG. The mode of action of HPIgG is currently under study. HPIgG may act as polyspecific antibodies against class II HLA antigens thus opening up the possibility of a new type of therapeutic immunomodulation in man.

Adult↗