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Biomedical subjects

M Candela

Publications and source records attributed to M Candela.

47 records · Page 3Linked to original sources
PubMedDate not supplied

Human monoclonal recombinant Fabs specific for HCV antigens obtained by repertoire cloning in phage display combinatorial vectors.

Molecular cloning of the antibody repertoire in phage display combinatorial vectors is a powerful method enabling the dissection of the immunoresponse against a given pathogen. In this paper we describe the construction of a combinatorial library displayed on phage surface, containing the antibody repertoire of a patient with high serological response against hepatitis C virus (HCV) antigens. Following selection of the library against solid-phase-bound antigen, sixteen human antibody Fab fragments able to bind to HCV-specific antigens were generated and studied for binding characteristics. The majority of them appeared to have specificity for the HCV c33 peptide. All the clones reacting with the c33 peptide shared the same heavy-chain CDR3 sequence. This is the first report of molecular cloning in a combinatorial phage display vector of the antibody repertoire of an anti-HCV-positive patient.

Amino Acid Sequence↗
PubMedDate not supplied

Probing the natural antibody repertoire by combinatorial cloning of IgM and IgD isotypes in phage display vectors.

It is well known that immunoglobulins with no identifiable immunogenic origin, called natural antibodies, are present in the sera of healthy individuals and their role as a defence against important pathogens has been proposed. Unfortunately, the studies are hampered by the fact that these immunoglobulins seem to have low affinity and to be polyreactive, and are commonly available in polyclonal preparations. Lately, new technologies for the production of monoclonal antibodies became available, and in particular the cloning of genes coding for antibody fragments in combinatorial phage display vectors provided a handy tool for the selection of human monoclonal antibodies. In this work, we describe the successful development of a technology for the molecular cloning of combinatorial phage display libraries containing genes coding exclusively for antibody fragment of the IgM or IgD phenotype. These libraries can be useful for molecular cloning of monoclonal antibodies of the IgM and IgD phenotype and can help elucidate the role played by natural antibodies in defence against infectious agents.

Antibodies, Monoclonal↗
PubMedDate not supplied

Coagulative modifications in patients with systemic sclerosis treated with iloprost or nifedipine.

This study compared iloprost and nifedipine to ascertain whether they could improve parameters of endothelial and platelet functions in the treatment of Raynaud's phenomenon secondary to systemic sclerosis. Thirteen patients affected by systemic sclerosis were treated with intravenous infusion of iloprost, and 7 patients were treated with oral nifedipine. Blood samples were taken at baseline and after 6 and 12 months of therapy to assess main serological indexes of endothelial damage, thrombin activation, fibrinolysis, as well as natural inhibitors of coagulation. After 12 months of therapy, the patients treated with iloprost had a significant decrease in thrombomodulin levels (p = 0.02) and a significant increase in tissue-plasminogen activator levels (p = 0.007), in comparison with the patients taking nifedipine (p = 0.007). Moreover, patients treated with nifedipine showed increased levels of thrombin-antithrombin complex after 12 months of therapy in comparison with baseline values (p = 0.03) and in comparison with the values of the patients treated with iloprost over the same period (p = 0.05). These preliminary results thus seem to indicate that iloprost plays an important, if at least partial, role in the protection and restoration of endothelial integrity in patients with systemic sclerosis.

Blood Coagulation↗
PubMedDate not supplied

Are behaviour and motor performances of rheumatoid arthritis patients influenced by subclinical cognitive impairments? A clinical and neuroimaging study.

OBJECTIVE: To determine whether some behavioural manifestations and poor motor performances in patients affected by rheumatoid arthritis (RA) are due to subclinical cognitive defects. METHODS: We performed a psychometric assessment of 30 patients affected by RA exploring several cognitive domains such as memory, visual-spatial integration, motor planning, mental flexibility, relating performances with morphological and functional neuroimaging (MRI and SPECT). We also related the cognitive data with the Ritchie and Lee indexes and other clinical parameters. RESULTS: We found an impairment in visual-spatial tasks in 71% of patients with a high correlation to activity and disease severity as expressed by the Ritchie and Lee indexes (p < 0.005; p < 0.01). Furthermore, we detected in 38% of patients some difficulties in mental flexibility related to the Lee Index (p < 0.05). These poor performances are related to hypoperfusion of the frontal and parietal lobes as detected by brain SPECT; this finding is more evident in patients with brain white matter alterations on MRI. CONCLUSIONS: Our data allow us to hypothesize that manual dexterity could be due to a disconnection between subcortical white matter and parietal-frontal lobes because of microangiopathy; furthermore, a chronic reduction in sensorial stimuli by impaired joints could lead to produce an alteration in motor planning cognitive processes.

Adult↗
PubMedDate not supplied

Antibodies against terminal galactosyl (alpha 1-3) galactose epitopes in systemic sclerosis (scleroderma).

Sera from 224 patients with systemic sclerosis (scleroderma) were analyzed for circulating antibodies against an antigenic determinant characterized by two molecules of galactose in alpha 1-3 linkage. About 45% of the patients were found to have values above the normal range. The mean antibody level was significantly higher than that found in normal subjects (p less than 0.001) or in patients with primary Raynaud's phenomenon who were included as controls. The mean level of anti-Gal antibodies correlated with the degree of skin and internal organ involvement, as well as with the presence of progression or inflammation. Furthermore, when patients with early onset disease were analyzed, high levels of anti-Gal antibodies were present in the subgroups characterized by evidence of progression or inflammation, whereas patients with stable disease did not differ from the controls. We conclude that humoral immunity against Gal alpha 1-3 Gal is an early feature of scleroderma, may be important for its pathogenesis, and may provide a more sensitive tool to detect disease activity.

Adolescent↗
PubMedDate not supplied

[Diet and autoimmunity].

New data emphasize the importance of nutritional factors in autoimmune diseases. Dietary alterations can be linked to autoimmune disorders as a specific pathogenetic mechanism and also for the malnutrition conditions frequently documented in these patients. The precise function of different nutrients is not completely known as they can be primary pathogenetic agents or causes of acute reacerbations or, finally, simply accompanying phenomena. It is also difficult to modify the intake of a single dietary component and to clarify its metabolic importance for the complexity of metabolic events in the human body and for the possible appearance of cascade-mechanisms. In lipid metabolism the multiple interactions between fatty acids, prostaglandins and leukotrienes are linked to alterations in inflammatory parameters. The exact role of modifications of proteins or of a single amino acid on immune function, also for the possible interference in protein restricted diet of the caloric component, is still unknown. Trace elements and vitamins are certainly important for the control of inflammation and of susceptibility in infections, albeit their role is not clear. More studies are necessary to clarify the link between dietary component and autoimmune diseases. However, study in experimental models and in human Systemic Lupus Erythematosus and Rheumatoid Arthritis demonstrated that a good nutritional homeostasis can contribute to decrease the severity of these disorders and to modify the clinical course with a physiological treatment that is free of side effects.

Animals↗
PubMedDate not supplied

[Prognostic evaluation of the cardiopathy in Duchenne's muscular dystrophy].

As it has now been ascertained that there is cardiac damage during the course of Duchenne muscular dystrophy (DMD), the authors have aimed at evaluating the relationship existing between the development of heart damage with respect to the advancement of age, and, at finding a sure prognostic index of the illness, easily acquired by using non-invasive techniques. Whilst the parameters which show the behaviour of the pumping function of the left ventricle (EF, Delta D%) did not demonstrate a clear correlation regarding their alteration in relation to age, the relationship PEP/LVET showed an accuracy of 92% predicting the terms of survival of patients suffering from DMD.

Adolescent↗
PubMedDate not supplied

Fish-oil fatty acid supplementation in mixed cryoglobulinemia: a preliminary report.

OBJECTIVE: Since fish oils seem to play a potential role in the treatment of inflammatory disorders by inhibiting arachidonic acid metabolism, the purpose of this study was to determine their therapeutic efficacy in mixed cryoglobulinemia (MC), an inflammatory condition caused by the deposition of immune complexes in vessel walls. METHODS: In an 8-week double-blind randomized trial, ten MC patients received a daily dietary supplement of 3 gm of eicosapentaenoic acid (EPA) and 2 gm of docosahexenoic acid (DHA), while 10 other MC patients received placebo (olive oil). The severity of purpura, arthralgias, paresthesias, asthenia and Raynaud's phenomenon were monitored daily, and serological assays were performed at the beginning of the study, at the end of the treatment period, and after 4 weeks of wash-out. RESULTS: No significant differences were found between the two groups with regard to the clinical symptoms, although the percentage of patients who reported a clinical improvement was higher in the group treated with fish oils. As for the serological parameters, no variation was found in the placebo group, while in the group receiving fish oils a significant decrease in cryocrit and rheumatoid factor levels was observed, which in the case of rheumatoid factor persisted at the end of the wash-out period. CONCLUSIONS: Under the experimental conditions employed in this study, we could not demonstrate a significant improvement in clinical symptoms in patients with mixed cryoglobulinemia treated with fish oils. However, since our results indicated some improvement in the serological parameters potentially involved in the pathogenesis of the disorder, further studies are warranted to establish the optimal dose and duration of fish oil supplementation in the treatment of MC.

Adult↗
PubMedDate not supplied

Humoral immune response and natural killer activity in patients with mixed cryoglobulinemia.

OBJECTIVE: Based on serological and molecular evidence of hepatitis C virus (HCV) infection in a significant proportion of patients with mixed cryoglobulinemia (MC), a direct association between HCV and MC has been suggested. The goal of the present study was to investigate the role played by HCV and by the immune response to the virus in the pathogenesis of mixed cryoglobulinemia. METHODS: A competitive reverse transcription polymerase chain reaction was employed to evaluate the concentrations of specific HCV RNA sequences in different clinical specimens (plasma, sera, cryoprecipitates, bone marrow and peripheral blood cells). Using recombinant and synthetic peptides covering the HCV core, envelope 1 (E1) and nonstructural regions 4 (NS4) and 5 (NS5), the humoral immune response in a group of MC patients was assessed with an enzyme-linked immunosorbent assay. Natural killer (NK) cell activity was estimated using a 4 hr 51 Cr release assay. RESULTS: Quantitation of the RNA molecules in the biological samples confirmed an increased virion concentration in cryoprecipitates from 13/15 patients with mixed cryoglobulinemia. Analysis of the humoral immune response against the synthetic peptides suggested a distinct response to HCV antigens in MC patients when compared to patients with HCV infection but without serological evidence of cryoglobulinemia. Unstimulated NK cell functioning was below the normal range in all patients tested. However, peripheral blood mononuclear cells showed no enhancement of NK activity by the interferon inducer polyinosinic acid:polycytidilic acid. Enhancement by interferon-alpha was normal, suggesting an impairment in interferon production. CONCLUSION: The quantitative data are in line with the hypothesis of a direct or indirect role of HCV in mixed cryoglobulinemia. The abnormal immune response could be involved in the onset and persistence of HCV infection, and possibly in the appearance of cryoglobulinemia.

Antibody Formation↗