Search results for " antibodies"
showing 10 items of 383 documents
SARS-CoV-2 antibodies, serum inflammatory biomarkers and clinical severity of hospitalized COVID-19 patients
2020
Background The involvement of SARS-CoV-2 antibodies in mediating immunopathogenetic events in COVID-19 patients has been suggested. By using several experimental approaches, we investigated the potential association between SARS-CoV-2 IgGs recognizing the spike (S) protein receptor-binding domain (RBD), neutralizing antibodies (NtAb) targeting S, and COVID-19 severity. Patients and methods This unicenter, retrospective, observational study included 51 hospitalized patients (24 at the intensive care unit; ICU). A total of 93 sera from these patients collected at different time points from the onset of symptoms were analyzed. SARS-CoV-2 RBD IgGs were quantitated by ELISA and NtAb50 titers wer…
CD38-Specific Biparatopic Heavy Chain Antibodies Display Potent Complement-Dependent Cytotoxicity Against Multiple Myeloma Cells
2018
CD38 is overexpressed by multiple myeloma cells and has emerged as a target for therapeutic antibodies. Nanobodies are soluble single domain antibody fragments derived from the VHH variable domain of heavy chain antibodies naturally occurring in camelids. We previously identified distinct llama nanobodies that recognize three non-overlapping epitopes of the extracellular domain of CD38. Here, we fused these VHH domains to the hinge, CH2, and CH3 domains of human IgG1, yielding highly soluble chimeric llama/human heavy chain antibodies (hcAbs). We analyzed the capacity of these hcAbs to mediate complement-dependent cytotoxicity (CDC) to CD38-expressing human multiple myeloma and Burkitt lymp…
Development of a sensitive and specific enzyme-linked immunosorbent assay for the determination of fludioxonil residues in fruit juices
2014
Fludioxonil is a fungicide with a singular mode of action that is widely employed in the treatment of fruit crops. A competitive enzyme-linked immunosorbent assay (cELISA) has been developed and validated for the determination of residues of this fungicide in fruit juices. A collection of monoclonal antibodies (mAbs) against the fungicide fludioxonil has been produced and characterized using direct and indirect cELISAs. The high affinity achieved (IC50lower than 0.5 μg L-1) considerably improved that obtained with previous polyclonal antibodies. The proposed cELISA was applied to the analysis of fludioxonil residues in apple juice and red grape must samples with a limit of quantification of…
Antibodies to hepatitis B virus x-protein in sera of patients with acute and chronic acitve hepatitis
1989
Sera of patients with acute (AH) and chronic active hepatitis (CAH) were tested for anti-hepatitis B virus (HBV) x-protein (HBx) by immunoblotting, using recombinant MS2- and beta gal-HBx fusion proteins as substrate. Antibodies against HBx were detected in 5 out of 17 patients with AH at an early stage of infection, and in 13 out of 35 patients with CAH. Positive sera from AH patients showed a relatively weak anti-HBx reactivity when compared to sera from CAH patients. In follow up studies we tested serial serum samples from patients positive for anti-HBx. Patients with AH were observed for 3 to 6 weeks and CAH patients for up to 51 months. In general anti-HBx reactivities appeared to be s…
Characteristics of patients with hepatitis C virus-related chronic liver diseases just before the era of oral direct-acting antiviral therapy in Italy
2018
Background In 2017, oral direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection became available free of charge for all HCV-RNA-positive patients, irrespective of their fibrosis stage. Aim The aim of this study was to evaluate the characteristics of HCV-related chronic liver disease (CLD) in Italy just before the introduction of DAA therapy. Patients and methods Patients with CLD were enrolled in two national surveys conducted in 2001 and in 2014. The two surveys prospectively enrolled patients aged older than 18 years referring to Italian liver units throughout the country using a similar clinical approach and analytical methods. Results Out of the 12 564 patie…
A novel pyruvate kinase (PK-S) from boar spermatozoa is localized at the fibrous sheath and the acrosome
2007
Boar spermatozoa contain a novel pyruvate kinase (PK-S) that is tightly bound at the acrosome of the sperm head and at the fibrous sheath in the principal piece of the flagellum, while the midpiece contains a soluble pyruvate kinase (PK). PK-S could not be solubilized by detergents, but by trypsin with no loss of activity. Purified PK-S as well as PK-S still bound to cell structures and soluble sperm PK have all kinetics similar to those of rabbit muscle PK-M1. The PK-S subunit had a relative molecular mass of 64 ± 1 × 103(n= 3), i.e. slightly higher than that of PK-M1, and carried an N-terminal extension (NH2-TSEAM-COOH) that is lacking in native PK-M1. Evidence is provided that PK-S is en…
Low prevalence of anti-HCV antibody among Italian children
1994
The seroprevalence of anti-HCV antibody was studied among 2,749 children and teenagers (1,438 males and 1,311 females) living in Italy. Anti-HCV antibody testing was positive by both EIA and RIBA in ten (0.36%) subjects. The positivity rate increased with age, ranging from 0 among children less than 6 years of age to 0.8% among those aged 17-19 years chi 2 linear regression = 0.038). Anti-HCV prevalence ranged from 0.2% in northeastern regions and in Apulia to 0.6% in Sicily and Sardinia (p0.005), and no difference was seen between males (0.35%, C.I. 95%: 0.04-0.66) and females (0.38%, C.I. 95%: 0.04-0.66) (Fisher's exact test = 0.565). From these data it appears that in Italy HCV infection…
Characterization of cell wall proteins from yeast and mycelial cells of Candida albicans by labelling with biotin: Comparison with other techniques
1992
Candida albicans ATCC 26555 blastoconidia and blastoconidia bearing germ tubes were metabolically labelled by incubating the cells with 14C-labelled protein hydrolysate and were subsequently tagged with biotin. Double-labelled (radioactive and biotinylated) cell wall proteins and glycoproteins were extracted from intact cells of both growth forms by treatment with 2-mercaptoethanol (beta ME) and with beta-glucanases (Zymolyase) after treatment with beta ME. The beta ME- and Zymolyase-extracts were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotted (immunoblotted) to nitrocellulose paper. Polyacrylamide gels were stained with Coomassie blue and process…
Aids in sicily: Prevalence of antibodies to human immunodeficiency virus (HIV) in low and high risk groups
1987
A seroepidemiological survey, carried out to evaluate the prevalence of antibodies to HIV in patients with ARC and in healthy individuals at risk for AIDS, showed the infection to be widespread in the groups at risk, namely in drug abusers and hemophiliacs. However, remarkable difference existed between the prevalence of antibodies to HIV in drug abusers of the city of Palermo and those of other Sicilian provinces. Spread of the virus among Sicilian thalassemics, however, was very low and quite similar in all geographic areas. Antibodies were found very rarely (0.06%) in unpaid voluntary blood donors. The spread of the virus is still confined in high risk groups, and the major part of the s…
The burden of HBV infection in HCV patients in Italy and the risk of reactivation under DAA therapy
2019
Background: There is increasing awareness of HBV reactivation in HCV-RNA-positive/HBV-coinfected patients with chronic liver disease (CLD) treated with oral direct-acting antivirals (DAAs). Aim: To provide figures on the prevalence of HBV markers in HCV-RNA-positive subjects in Italy, where these findings are lacking. Methods: All subjects aged ≥18 years with CLD consecutively referring to Italian liver units located throughout country were prospectively enrolled in two national surveys in 2001 and 2014. Results: The total number of HCV-RNA-positive cases was 6984; 356 (5.1%) subjects vaccinated against HBV were excluded. A total of 6628 cases were evaluated. The prevalence rates of HBsAg, …