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Biomedical subjects

A Corvetta

Publications and source records attributed to A Corvetta.

At least 19 recordsLinked to original sources
PubMed1992

Juvenile rheumatoid arthritis patients manifest immune reactivity to the mycobacterial 65-kDa heat shock protein, to its 180-188 peptide, and to a partially homologous peptide of the proteoglycan link protein.

Immune reactivity to the 65-kDa mycobacterial heat shock protein (hsp65) has been associated with arthritis in rats and humans. In this report we evaluated patients with juvenile rheumatoid arthritis for such immunity. A high proportion of affected children showed both antibody and T lymphocyte responses to hsp65 and to two related peptides: the nonapeptide 180-188 sequence of hsp65 and a partially homologous peptide of the cartilage proteoglycan link protein. The titer of circulating antibodies was generally higher in patients with clinically active disease. In contrast to the juvenile rheumatoid arthritis patients, patients with adult rheumatoid arthritis tended to have lower responses of their peripheral blood T lymphocytes to the whole hsp65 molecule. Moreover, the adult rheumatoid arthritis patients did not respond to the peptides. Thus, there appear to be immunological differences between juvenile and adult forms of rheumatoid arthritis related to hsp65 reactivity.

Adolescent↗
PubMed1992

Complement deficiency and antibody profile in survivors of meningococcal meningitis due to common serogroups in Italy.

A collaborative survey was carried out in Italy on a group of 59 subjects with a past history of meningococcal meningitis. The aim was to evaluate the prevalence of complement deficiencies, the serogroup of meningococci responsible for the disease and other possible immune abnormalities associated with the infection. Complement analysis allowed the detection of 10 cases (17%) with deficiencies of the terminal components, and in particular six cases of C8 beta, three of C7 and one of C6 defect. Half of the subjects with complement deficiencies had recurrences of meningitis and developed the infection at an older age in comparison with the control group with normal complement activity. The meningococcal C strain was the most diffuse (68%) and infected all the complement-deficient subjects. Evaluation of the antibody response to meningococcal capsular polysaccharides (PS) showed that only 42.5% of the individuals with group C had antibodies as opposed to 83% and 100% of the patients with meningitis due to group A and B, respectively. In all 59 subjects serum Ig as well as IgG subclasses were present, at normal levels for the age. Vaccination of seven out of the 24 subjects without detectable anti-meningococcal PS antibodies with the sole PS A+C induced a normal response in six of them, including a subject with complement defect. In the subject who did not respond to the antigen, the antibodies against the ubiquitous pneumococcal PS type 14 were also lacking, whereas anti-tetanus toxoid (TT) antibodies were normally present. From these data we may conclude the following: (1) the high prevalence (17%) of late complement components defect among survivors of meningococcal meningitis is also confirmed in the Italian population; (2) the serogroup C, responsible for the infections in all the cases with late complement components defect, is highly recirculating in Italy and apparently less immunogenic; (3) specific vaccination with meningococcal PS is a valid prophylaxis in subjects with lack of specific antibodies as well as in subjects with complement defect.

Adolescent↗
PubMed1992

MHC gene products and anticardiolipin antibodies in systemic lupus erythematosus results of a multicenter study. SLE Study Group.

Anticardiolipin antibodies (aCL) and HLA-DR antigens were determined in 314 central European patients with systemic lupus erythematosus (SLE). Both HLA-DR4 and DR7 were increased in aCL-positive patients, and aCL were significantly associated with DRw53. The association between DRw53 and aCL was also apparent in those 17 patients with SLE and the anticardiolipin syndrome. There was no association between aCL and HLA-DQ or C4 alleles in SLE.

Antibodies, Anticardiolipin↗
PubMed1991

5-Methylcytosine content of DNA in blood, synovial mononuclear cells and synovial tissue from patients affected by autoimmune rheumatic diseases.

The percentage of 5-methylcytosine (m5Cyt) has been determined in peripheral blood, synovial mononuclear cells and synovial tissue from patients affected by various rheumatic autoimmune diseases. The determination was performed by reversed-phase high-performance liquid chromatography. Fifteen controls were compared to twenty-one patients affected by rheumatoid arthritis and to nine patients affected by systemic lupus erythematosus. The mean percentage of m5Cyt in normal individuals was significantly higher than in the rheumatoid arthritis and systemic lupus erythematosus patients. In addition, patients with active disease showed lower values than patients in remission. This finding is in agreement with the hypothesis that DNA hypomethylation may play a role in the pathogenesis of the autoimmune diseases, resulting in altered oncogene expression. Therapy with cyclosporin A led to a decrease in the percentage of m5Cyt in three rheumatoid arthritis patients, but a rebound was observed when the cyclosporin A was suspended. The percentage of m5Cyt in the DNA of synovial tissue from four rheumatoid arthritis patients and five patients with osteoarthritis was similar; this observation confirms that, in addition to disease-specific and disease activity-specific variations, the percentage of m5Cyt may also show tissue-specific variations.

5-Methylcytosine↗
PubMed1991

Low number of complement C3b/C4b receptors (CR1) on erythrocytes from patients with essential mixed cryoglobulinemia, systemic lupus erythematosus and rheumatoid arthritis: relationship with disease activity, anticardiolipin antibodies, complement activation and therapy.

Our aim was to assess whether the amount of complement C3b/C4b receptors (CR1) on erythrocytes shows a correlation to disease activity in various connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and essential mixed cryoglobulinemia (EMC). Using an anti-CR1 monoclonal antibody, 26 patients with SLE, 34 with RA and 22 patients with EMC were investigated for erythrocyte CR1 expression. The control group consisted of 30 healthy individuals. The mean number of CR1/erythrocyte in the control group was 568 +/- 197 (range 174-1060), significantly higher than studied (EMC:379 +/- 248; p = 0.0005;SLE 147 +/- 56, p less than 0.0001; RA 298 +/- 177, p less than 0.0001). In patients with RA and in SLE, but not in patients with EMC, the number of CR1 numbers and anticardiolipin antibody (aCl) titers (r2 = 0.493; p = 0.034). A statistically significant correlation between CR1 numbers and CH50 values was found in patients with SLE, while in 3 patients with RA 4 months of therapy with cyclosporine A led to a further 30% reduction in CR1 number. Our conclusions are that (a) the decreased expression of erythrocyte CR1 is apparently a common feature of patients with various connective tissue diseases; (b) several acquired factors such as disease activity, complement activation, aCl and drugs may contribute to the loss of CR1 from erythrocytes; (c) in patients with RA and SLE, but not in patients with EMC, CR1 enumeration on erythrocytes may serve as a variable for clinical monitoring.

Adult↗
PubMed1991

[Magnetic resonance of the rheumatoid hand].

The purpose of this study was to evaluate MRI diagnostic accuracy in rheumatoid arthritis (RA), to compare MRI and radiological findings and to correlate these findings with the clinical and serological profile of the disease. The hands of 24 patients (20 females, 4 males) affected with typical RA (ARA criteria) were studied using a tomograph Magnetom 1.0 T Siemens. Two patients affected with RA refractory to conventional second-line drugs who received a bolus of methylprednisolone (1 g) were studied before and after such treatment. The hands of healthy volunteers were examined as controls. Besides MRI study all patients underwent: (1) radiological examination of the hands performed with a standard technique and (2) clinical and serological investigation aimed at characterizing diseases activity and extent. The radiographic and MRI findings were evaluated by two different observers who found 15 pathological elementary lesions and assigned a MRI and a radiological score to each patient. MRI exhibited significantly higher accuracy than radiography in evaluating rheumatoid soft-tissue changes and in detecting minimal skeletal lesions, while severe skeletal lesions were better detected by radiology. No correlation was found between pathological MRI findings, radiological results and clinical or serological data. A significant drop in soft-tissue effusion was observed after methylprednisolone pulse in two patients. This study confirms MRI potential in the study of rheumatoid joint lesions and in the early detection of minimal soft-tissue changes. Its use appears to be suitable for accurate monitoring of RA patients under specific therapy.

Adult↗
PubMed1990

Cyclosporin effect on sodium and potassium transport across erythrocytes in rheumatoid arthritis.

The aim of the present work was to evaluate the action of cyclosporin (CsA) both in vivo and in vitro on the active sodium transport across the erythrocyte membrane of rheumatoid arthritis (RA) patients. The in vivo study was performed on 20 patients affected by refractory RA and treated with CsA (5 mg/kg/die) or with azathioprine (2 mg/kg/die) before and after 7 days' therapy. The control group was formed of 25 healthy subjects. RA patients before treatment showed increased intra-erythrocyte Na+ concentration and decreased Na+, K+ ATPase activity in comparison with normal subjects. A rise in the activity of the sodium pump and a reduction in the intra-erythrocyte Na+ concentration were observed after cyclosporin treatment, but not after azathioprine. The in vitro study was performed on intact RBCs and on erythrocyte membranes from 15 healthy subjects and from 12 patients affected by classical RA, in the presence or absence of CsA (0.5-1-2 micrograms/ml). CsA (0.5 micrograms/ml) increased the Na+, K+ ATPase activity in intact RBCs and in erythrocyte membranes from both groups of subjects. Intracellular Na+ was decreased only in erythrocytes from RA patients after addition of 0.5 micrograms/ml CsA. A direct action of CsA on the membrane hydrophobic environment of the Na+, K+ ATPase is hypothesized on the basis of the present results.

Adult↗
PubMed1987

Decreased NA+, K+-ATPase activity in erythrocyte membrane from rheumatoid arthritis patients.

The activity of the plasma membrane Na+/K+-ATPase and cellular sodium (Nai) and potassium (Ki) content were analysed in RBCs from 15 rheumatoid arthritis (RA) and 30 reference subjects (11 healthy controls, 12 osteoarthritis and 7 gouty patients). Na+/K+-ATPase activity was determined by measuring the inorganic phosphate (Pi) released by incubation in a reaction medium in the presence and absence of K ions or ouabain. Nai and Ki were measured with an ion-selective electrode analyser on the hemolysates, after washing the RBCs in 110 mM MgCl2. The Na/K-ATPase activity was significantly lower in RA patients than in both healthy controls and patients with osteoarthritis or gout. A slight but significant increase in Nai was observed in rheumatoid subjects. It is hypothesized that the decrease in the Na+/K+-ATPase activity in RA may be the result of a defective expression of membrane proteins, which is probably related to the altered cell sensitivity observed.

Adult↗
PubMed1987

Multicenter double-blind randomized clinical trial of imidazole salicylate versus ibuprofen in patients with osteoarthrosis.

Imidazole salicylate (750 mg t.i.d.) was compared with ibuprofen (400 mg t.i.d.) in a 30-day multicenter double-blind clinical trial in patients with osteoarthrosis. Both drugs were effective in relieving joint pain and in reducing the duration of morning stiffness. A statistically significant reduction of the severity of these symptoms was observed already one week after the start of treatment, lasting until the end of the study. No significant differences in efficacy were demonstrated between the two drugs throughout the trial. The systemic tolerability, assessed by changes in tests of hematological, liver and kidney function, was excellent with both treatments. The incidence of side effects (mostly gastrointestinal complaints) was fairly low in both groups, and lower in the group treated with imidazole salicylate.

Adult↗
PubMed1985

Immune deposits in normal skin of patients with systemic lupus erythematosus: relationship to the serum capacity to solubilize immune complexes.

Immunofluorescent deposits at the dermal-epidermal junction (DEJ) of the skin (lupus band test or LBT) were evaluated in 134 patients with various connective tissue diseases. LBT was found positive in 23 of 32 (71.8%) patients with systemic lupus erythematosus (SLE), in 3 of 53 (5.6%) patients with rheumatoid arthritis (RA), and in 1 of 5 cases of mixed connective tissue disease (MCTD). No deposits were found in patients with systemic sclerosis and with vasculitis. In patients with SLE a positive LBT showed a direct correlation with serum Clq binding activity (ClqBA) and with hypocomplementemia. The mean ClqBA was 13.49 +/- 12.85 and 2.38 +/- 2.27% in SLE patients with positive and negative band test, respectively (P less than 0.005). Likewise depressed mean serum levels of C3 and C4 were detected in patients with skin deposits (P less than 0.005). Sera from SLE patients showed an overall decreased capacity to solubilize preformed immune complexes when compared to normal sera. Furthermore 10 band-positive patients were less able to solubilize immune complexes than sera from LBT-negative lupus patients (45 +/- 16 and 62 +/- 11%, respectively; P less than 0.01). Also the capacity to inhibit the precipitation of immune complexes was decreased in SLE patients with negative LBT (P less than 0.05). In conclusion our data suggest that in SLE patients a decreased complement-mediated solubilization of immune complexes is involved in the persistence of high levels of circulating immune aggregates and, considered its correlation with positive LBT, may be responsible for the deposits of immunoglobulins at the dermal-epidermal junction of the skin.

Adolescent↗