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Biomedical subjects

M Cutolo

Publications and source records attributed to M Cutolo.

At least 127 records · Page 7Linked to original sources

Monoreactive and polyreactive rheumatoid factors produced by in vitro Epstein-Barr virus-transformed peripheral blood and synovial B lymphocytes from rheumatoid arthritis patients.

The CD5 membrane molecule, initially identified as an exclusive T-cell marker, also defines a phenotypically and functionally distinct B-lymphocyte population. In normal individuals, CD5+ B cells are committed to secrete 'natural' polyreactive (auto)antibodies, that is antibodies, mainly IgM, endowed with multiple antigen-binding capabilities, including rheumatoid factor (RF) activity. At variance with this, in rheumatoid arthritis (RA) as well as in other autoimmune conditions, monoreactive autoantibodies binding with high affinity and specificity to a given self antigen have been isolated and the cells from which they originate differently related to the CD5+ B-lymphocyte subset. Here, we studied the proportions of CD5+ B cells and the characteristics, in terms of polyreactivity and monoreactivity, of RF produced by B lymphocytes in RA patients with classified disease activity. Our results suggest that patients with a more severe disease activity have higher proportions of CD5+ B cells and higher frequencies of B lymphocytes committed to secrete RF, with the characteristics of polyreactive antibodies. On the other hand, we did not find a significant difference between the proportions of peripheral B cells producing monoreactive RF in patients with high- versus patients with low-activity RA. However, in two highly active RA patients, we found that synovial fluid, compared with peripheral blood, was significantly enriched for (IgG and IgA) monoreactive RF-producing B cells.

Adult↗

Sex hormone status of male patients with rheumatoid arthritis: evidence of low serum concentrations of testosterone at baseline and after human chorionic gonadotropin stimulation.

Serum concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, 17 beta-estradiol, testosterone, androstenedione, dehydrotestosterone, dehydroepiandrosterone sulfate, and cortisol were examined in 14 men with rheumatoid arthritis (RA) and in age-matched osteoarthritis controls. Hypophyseal, adrenal, and testicular responses to stimulation with luteinizing hormone-releasing hormone, adrenocorticotropin, and human chorionic gonadotropin, respectively, were evaluated in 8 RA patients and in 8 age-matched healthy volunteers. Basal serum testosterone concentrations were significantly lower in male RA patients than in the osteoarthritis control subjects (P less than 0.01). After human chorionic gonadotropin stimulation, serum concentrations of testosterone were also lower in the RA patients than in normal healthy controls (P less than 0.05). These findings suggest that diminished testicular steroid biosynthesis might contribute to the serum testosterone deficiency observed in male RA patients.

Adult↗

Adhesion of human dermal reticular fibroblasts on complementary fragments of fibronectin: aging in vivo or in vitro.

Attachment, spreading, and microfilament reorganization have been evaluated in human dermal reticular fibroblasts isolated from the inner, upper aspect of the arm of a newborn male (RET5 cells) and a 78-year-old male (RET8 cells). Substrata were tested using a set of complementary fragments from individual polypeptide chains of human plasma fibronectin (pFN) or cellular FNs (cFN). With both cell classes, fragments containing the C-terminal heparin-binding (HepII) domain only elicited linear bundles of microfilaments in spreading cells but no stress fibers; fragments containing the RGDS-dependent cell-binding (CellI) domain elicited only partial spreading with condensations of F-actin at ruffling membranes and at other regions along the plasma membrane. The minimum sequence required to obtain responses identical to those on intact pFN (broad spreading with extensive stress fiber formation) was found in fragment 155 (F155) from the beta chain of pFN; F155 contains both HepII and CellI domains. In contrast, the analogous fragment from the alpha chain of pFN (F145) was notably less effective for generating stress fibers. This evidence along with the better attachment, spreading, and microfilament bundle formation on the HepII fragment from the beta chain than the analogous fragment from the alpha chain indicates that the extra type III homology unit permits more effective interaction of beta chain fragments with cell-surface heparan sulfate proteoglycan and possibly integrin (binding efficiency to the substratum was similar for fragments from both chains). Therefore, alternatively spliced sequences that neighbor binding domains can play significant roles in the interaction of the domain with cell-surface receptors of dermal fibroblasts. Comparison of RET5 responses with those of RET8 cells has identified changes in adhesive mechanisms as cells undergo "aging" processes. Attachment and microfilament bundle formation were far more effective for RET5 cells than for RET8 cells on any of the HepII fragments. Conversely, RET8 cells were far more sensitive to an RGDS-containing peptide in their medium on CellI fragments than RET5 cells. These results together indicate that in vivo aging leads to greater dependence upon cell-surface integrin binding and less dependence upon heparan sulfate proteoglycan binding for responses on FN matrices. When RET5 cells entered senescence (in vitro aging), they also became much more sensitive to peptide A. On several fragments and on intact pFN, RET8 cells generated very thick stress fibers that were observed only on one fragment with RET5 cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

Differential expression of the ED sequence-containing form of cellular fibronectin in embryonic and adult human tissues.

Monoclonal mouse hybridoma antibodies were obtained for secreted cellular fibronectin (cFn) from A8387 fibrosarcoma cells. One of them, 52-DH1 (DH), reacted exclusively with cFns but not with plasma Fns (pFns) in immunoblotting and solid-phase EIA. The DH antibody also recognized thermolysin cFn fragments and beta-galactosidase-Fn fusion protein which contained the ED sequence specific to at least some forms of cFns. On the other hand, the DH antibody failed to recognize a fusion protein that was otherwise identical but lacked the ED sequence. Thus, the antigenic determinant for the DH antibody was located to the ED sequence. The DH antibody was then used to study the expression of ED sequence containing cFn (EcFn). For comparisons, another monoclonal antibody, 52BF12 (BF), recognizing equally well both pFns and cFns, was used. Immunoblotting of pFn fragments indicated that this antibody had the antigenic determinant at or close to the cell-binding site of Fn. EcFn was revealed by the DH antibody in embryonic and adult fibroblasts and in a variety of other cultured normal and malignant human cells. In embryonic tissues EcFn was abundant in developing basement membranes, as shown in foetal kidney and muscle, while in adult tissues it was confined only to endothelia of larger blood vessels. Furthermore, in embryonic tissues the capillaries showed bright EcFn-positivity not found any more in adult tissues. Human plasma contained a small quantity of EcFn, which may hence have an endothelial origin. EcFn was also prominent in the stroma of malignant tumours as well as in reactive benign conditions, such as granulation tissue and decidual cells. The results suggest that EcFn is a form of the protein which may have a particular role in developing and reactive tissues in embryos and adults.

Adult↗

Plasma and tissue levels of some lanthanide elements in malignant and non-malignant human tissues.

Lanthanum (La) levels in plasma, in erythrocyte hemolysate and in tissue from healthy subjects and patients with laryngeal carcinoma were determined by neutron activation analysis. Plasma lanthanum levels were significantly higher in laryngeal carcinomas than in either healthy controls or in subjects suffering from localized inflammation (e.g. epicondylitis of the elbow) (p less than 0.001). The mean La concentration in malignant tissue samples was 57.5 +/- 7.2 ng g-1; the corresponding level in normal adjacent tissue from the same organ was 94.6 +/- 12.0 ng g-1. This 61% decrease in the concentration of La in malignant tissues was highly significant (p less than 0.001). In patients with laryngeal carcinoma we did not observe any detectable level of lanthanum in erythrocyte hemolysate; the mean La erythrocyte hemolysate level in healthy controls and in patients suffering from localized inflammatory condition was 14.3 and 33.2 ng ml-1, respectively. Further studies are in progress to evaluate whether or not this element can serve as a marker for diagnosis or prognosis in cancer.

Adult↗

Sex hormone status in women suffering from rheumatoid arthritis.

We studied the sex hormone status of 21 seropositive (IgM-RF) women with rheumatoid arthritis (RA), who were subdivided according to their premenopausal and postmenopausal status. Age matched women with secondary osteoarthritis were used as controls. The hormones evaluated were luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), 17-beta-estradiol (E2), progesterone (Pg), testosterone (T), delta 4-androstenedione (A), dehydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHEAS) and cortisol (C). Normal concentrations of all the hormones considered were found in premenopausal women with RA. Statistically higher concentrations of T (p less than 0.05), A (p less than 0.05) and DHEAS (p less than 0.01) were observed in postmenopausal women with RA when compared to controls, whereas no differences were found for all other hormones studied. Although the significance of observed relative hyperandrogenism in postmenopausal women with RA is not clear, our data seem to indicate that sex hormone levels are altered in patients with RA.

Adolescent↗

Different fibronectin concentrations in plasma samples drawn from the affected and unaffected arms of a pagetic patient.

Plasma fibronectin concentrations in blood drawn from both arms of a pagetic patient affected only at the humerus, ulna and radius of the right arm were studied. Significantly higher levels were observed in the affected arm compared to the nonpagetic arm. Results suggest that in vivo synthesis of soluble fibronectin is associated with increased bone turnover and demonstrate the value of bilateral blood sample collection when localized bone disease is present.

Aged↗

Characterization of synovial fluid fibronectin from patients with rheumatic inflammatory diseases and healthy subjects.

Synovial fluid fibronectin from normal subjects and from patients who have rheumatic inflammatory diseases has been studied and compared with plasma fibronectin. The average fibronectin concentration in synovial fluids from normal subjects was 172 +/- 69 micrograms/ml; it was 721 +/- 315 and 556 +/- 349 micrograms/ml in synovial fluids from patients with rheumatoid arthritis and osteoarthritis, respectively. This is the first report on fibronectin concentrations in normal synovial fluids. Synovial fluid fibronectin from healthy subjects and patients with rheumatoid arthritis or osteoarthritis showed a molecular weight identical to that of plasma fibronectin. All normal and pathologic synovial fluid fibronectins showed a remarkably lower electrophoretic mobility compared with that of plasma fibronectin, when separated according to net molecular charge on agarose gel. Peptides from thermolysin digests of fibronectin from plasma and synovial fluid, when compared on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, showed distinct differences. These data demonstrate that synovial fluid fibronectin represents a molecular form which is structurally different from that of plasma fibronectin. This suggests that synovial fluid fibronectin is locally synthesized, possibly by a cell type which differs from that responsible for the production of the plasmatic fibronectin pool.

Aged↗

Plasma fibronectin in psoriatic arthritis subgroups.

Plasma from 38 patients suffering from one of the five broad clinical subgroups of Psoriatic Arthritis (PA) were studied for soluble plasma Fibronectin (pFn). The mean total concentration of pFn was 453.03 micrograms/ml +/- 142.83 SD, with a significant statistical difference (p less than 0.01) versus a healthy control group matched with respect to sex and age. In order to evaluate the biological role that pFn might play in this pathological condition, observed concentrations were correlated with the degree and duration of the psoriasis and arthritis. In addition, pFn was correlated to some biohumoral parameters that are modified during inflammatory processes (ESR, CRP, sCu, sFe, Hb) and to uric acid levels. Tissue typing (HLA) was done where possible. From our observations, we suggest that pFn most likely is not an acute phase protein and rather than having specificity for a particularly disease, might, in widespread and severe cases be, a general and useful marker of the connective-tissue organizing and repairing response, following its injury.

Arthritis↗

Serum copper and caeruloplasmin are higher in seropositive than seronegative rheumatoid arthritis.

Increased serum copper (sCu) and alpha 2 caeruloplasmin (alpha 2 sCP) concentrations have been reported in patients with rheumatoid arthritis and other inflammatory conditions. Close parallel changes of sCu and alpha 2 sCP in rheumatoid arthritis have recently been observed by us in 30 subjects. The 'IgM rheumatoid factor positive (IgM-RF)' patients showed higher sCu and alpha 2 sCP concentrations when compared with 'IgM-RF negative'. Moreover a significant correlation was found between sCu alpha 2 sCP and other humoral indexes altered in rheumatoid arthritis. Therefore it seems useful, as further index of inflammation, to test both sCu and alpha 2 sCP.

Adult↗