A highly sensitive nanobody-based immunoassay detecting SARS-CoV-2 nucleocapsid protein using all-recombinant reagents.

Antigen tests have been crucial for managing the COVID-19 pandemic by identifying individuals infected with SARS-CoV-2. This remains true even after immunity has been widely attained through natural infection and vaccination, since it only provides moderate protection against transmission and is highly permeable to the emergence of new virus variants. For this reason, the widespread availability of diagnostic methods is essential for health systems to manage outbreaks effectively.

An ultra-sensitive homologous chemiluminescence immunoassay to tackle penicillin allergy.

Penicillin is one of the most widely used antibiotics to treat bacterial infections in clinical practice. The antibiotic undergoes degradation under physiological conditions to produce reactive compounds that in vivo bind self-proteins. These conjugates might elicit an immune response and trigger allergic reactions challenging to diagnose due to the complex immunogenicity.

Functionalization of Magnetic Beads with Biotinylated Nanobodies for MALDI-TOF/MS-Based Quantitation of Small Analytes.

Over the last two decades, the variable domains from heavy chain-only antibodies in camelids (nanobodies) have emerged as valuable immunoreagents for analytical and diagnostic applications. One prominent use of nanobodies is for the detection of small molecules due to their ease of production, resistance to solvents used in sample extraction, facile genetic manipulation, and small size. These last two properties make it possible to produce biotinylated nanobodies in vivo, which can be loaded in an orientated manner on magnetic beads covered with avidin, creating high-density immunoadsorbenpi twbch ""ts.

Bispecific Single-Domain Antibodies as Highly Standardized Synthetic Calibrators for Immunodiagnosis.

Commonly, serological immunoassays and diagnostic kits include reference standard reagents (calibrators) that contain specific antibodies to be measured, which are used for the quantification of unknown antibodies present in the sample. However, in some cases, such as the diagnosis of allergies or autoimmune diseases, it is often difficult to have sufficient quantities of these reference standards, and there are limitations to their lot-to-lot reproducibility and standardization over time. To overcome this difficulty, this study introduces the use of surrogate recombinant calibrators formulated on the basis of two single-domain antibodies (nanobodies) combined through a short peptide linker to produce a recombinant bispecific construct.

Development of anti-human IgM nanobodies as universal reagents for general immunodiagnostics.

Nanobodies are the smallest antibody fragments which bind to antigens with high affinity and specificity. Due to their outstanding physicochemical stability, simplicity and cost-effective production, nanobodies have become powerful agents in therapeutic and diagnostic applications. In this work, the advantages of nanobodies were exploited to develop generic and standardized anti-human IgM reagents for serology and IgM B-cell analysis.

Noncompetitive Homogeneous Detection of Small Molecules Using Synthetic Nanopeptamer-Based Luminescent Oxygen Channeling.

Our group has previously developed immunoassays for noncompetitive detection of small molecules based on the use of phage borne anti-immunocomplex peptides. Recently, we substituted the phage particles by biotinylated synthetic anti-immunocomplex peptides complexed with streptavidin and named these constructs nanopeptamers. In this work, we report the results of combining AlphaLisa, a commercial luminescent oxygen channeling bead system, with nanopeptamers for the development of a noncompetitive homogeneous assay for the detection of small molecules.

Recombinant streptavidin nanopeptamer anti-immunocomplex assay for noncompetitive detection of small analytes.

Short peptide loops selected from phage libraries can specifically recognize the formation of hapten-antibody immunocomplexes and can thus be used to develop phage anti-immunocomplex assays (PHAIA) for noncompetitive detection of small molecules. In this study, we generated recombinant chimeras by fusing anti-immunocomplex peptides selected from phage libraries to the N- or C-termini of core streptavidin and used them to setup phage-free noncompetitive assays for the herbicide clomazone (MW 240 Da). The best conditions for refolding were optimized by a high throughput screening allowing to obtain tens of mg of purified protein per liter of culture.

Shiga-like toxin B subunit of Escherichia coli as scaffold for high-avidity display of anti-immunocomplex peptides.

Small compounds cannot bind simultaneously to two antibodies, and thus, their immunodetection is limited to competitive formats in which the analyte is indirectly quantitated by measuring the unoccupied antibody binding sites using a competing reporter. This limitation can be circumvented by using phage-borne peptides selected for their ability to specifically react with the analyte-antibody immunocomplex, which allows the detection of these small molecules in a noncompetitive format (PHAIA) with increased sensitivity and a positive readout. In an effort to find substitutes for the phage particles in PHAIA, we explore the use of the B subunit of the Shiga-like toxin of Escherichia coli, also known as verotoxin (VTX), as a scaffold for multivalent display of anti-immunocomplex peptides.

A monoclonal antibody-based copro-ELISA kit for canine echinococcosis to support the PAHO effort for hydatid disease control in South America.

Cystic echinococcosis is still a major concern in South America. While some regions show advances in the control of the disease, others have among the highest incidence in the world. To reverse this situation the Pan American Health Organization (PAHO) has launched a regional project on cystic echinococcosis control and surveillance.

[Evaluation of management of infarction in the Franche Comté province by the use of the Franche Comté Cardiology Registry, May 2005-May 2006].

Rationale: The management of acute infarction often necessitates a network of organisation between different centres, thus making it the object of an evaluation of professional practices (EPP). We report the experience in the Franche Comté province of an EPP at a regional level in the management of infarction.

Methods: All of the patients admitted to 10 of the 11 centres in the region were included in a prospective survey.

Compliance with guidelines and 1-year mortality in patients with acute myocardial infarction: a prospective study.

Aims: In patients with acute myocardial infarction (MI), mortality can be predicted by risk scoring systems, but the impact of therapy recommended by guidelines is poorly documented. The aim of this study was to determine, taking into account the patient's condition at admission, to what extent the degree of guideline compliance influences the 1-year survival of patients admitted for acute MI.

Methods And Results: A 6-month registry was carried out in a geographically limited area, prospectively including all patients with acute MI.

[Pulmonary arterial hypertension and primary biliary cirrhosis].

The authors report a case of the association of primary biliary cirrhosis and pulmonary hypertension presenting with syncopal complete atrioventricular block. The clinical, aetiopathological and therapeutic aspects of this pathology are reviewed with special emphasis on the value of early diagnosis of the pulmonary hypertension in cases of unusual dyspnoea in patients with primary biliary cirrhosis especially those of an age when they could benefit from liver-heart-lung transplantation.

[Acute respiratory distress syndrome in the initial phase of myocardial infarction in adults].

Four patients developed an acute respiratory distress syndrome characterised by clinical and radiological signs of pulmonary oedema, a protein-rich oedema, severe hypoxemia refractory to oxygen therapy, contrasting with normal left ventricular filling pressures and indicating increased permeability of the alveolo-capillary membrane, 24 to 72 hours after the onset of acute myocardial infarction. After having excluded the usual causes of the acute respiratory distress syndrome, the authors suggest that acute myocardial infarction, especially when extensive, may cause a lesion of the alveolo-capillary membrane by an unknown mechanism. Treatment consisted in mechanical ventilation with positive expiratory pressures in 3 cases and with continuous positive pressure during spontaneous respiration in the third patient and in relay with controlled ventilation in the other two.

[Annulo-aortic ectasia].

On the basis of a literature review and the study of 18 cases, the authors examine annuloaortic ectasia, which involves dilatation of the fibrous ring of the heart at the aortic orifice, marked by aortic regurgitation and dystrophic aneurysm of the ascending aorta. The authors noted a predominantly muscular disorder (14 males, 4 females) often detected from an assessment of aortic regurgitation without clinical, radiologic or specific electrical features. The value of echocardiography and Doppler echocardiography is clearly apparent from the diagnosis of the disease, monitoring of progress, selection of patients for invasive pre-operative explorations and post-operative surveillance.

[Course and prognosis of primary hypertrophic cardiomyopathies].

33 patients with hypertrophic cardiomyopathy were followed for a mean duration of 48 months. 29 of them were reviewed; 6 had died, including 4 with a familial form belonging to two different families. No cases of sudden death were observed.

[Course and prognosis of primary hypertrophic cardiomyopathies].

33 patients with hypertrophic cardiomyopathy were followed for a mean duration of 48 months. 29 of them were reviewed; 6 had died, including 4 with a familial form belonging to two different families. No cases of sudden death were observed.

[Coronary lesions in myocardial infarction].

The authors analyse the coronary lesions in 285 patients with primary myocardial infarction (164 anterior, 121 inferior infarcts) undergoing coronary angiography an average of 4 months after infarction. The statistical study of the analytical table of the lesions according to severity and site, demonstrated a significant difference in each group (p less than 0,001): --there was a very clear dominance of occlusion of the LAD artery in anterior infarction but severe narrowing (greater than or equal to 70%) was observed mainly on the right coronary and left circumflex arteries; --in inferior infarction, the incidence of occlusion was higher on the right coronary artery and severe narrowing was divided between the LAD and left circumflex arteries. Controlateral, double or triple vessel disease was present in 74% of anterior and 85% of inferior infarcts.

[Two-dimensional echocardiography of ventricular aneurysm. Study of 38 cases with angiographic correlation].

This is a study of the data supplied by cross-sectional echocardiography in the diagnosis of post-infarction aneurysm. It involves 38 confirmed cases of myocardial infarction. The clinical, electrical, radiological and echocardiographic data (in M mode) were specified.