Lactate dehydrogenase as a marker of Plasmodium infection in malaria vector Anopheles

Lactate dehydrogenase (Ldh) electrophoresis showed the presence of #Plasmodium yoelii yoelii in #Anopheles stephensi and #An. gambiae. The Ldh appeared as an additional band (pLdh) whose activity was more intense with 3-acetyl pyridine adenine dinucleotide as coenzyme than with beta nicotinamide adenine dinucleotide. Several allelic forms occurred both in the vector and the host. The isoelectric point of Ldh, similar in the vector and host, differed from those of Ldh from mosquito and mouse. The presence of pLdh was detected from the 2nd to the 28th day of infection. The pLdh appeared to be proportional to the number of sporozoites present in infected salivary glands. However, pLdh was not found in salivary glands or midguts, but it was detected in the rest of the corresponding mosquito. The origin and use of pLdh as a marker of #Plasmodium in its vector is discussed. (Résumé d'auteur

Magnetic Beads Based Immunoaffinity Capillary Electrophoresis of Total Serum IgE with Laser-Induced Fluorescence Detection

A magnetic beads based immunoaffinity capillary electrophoresis method for total Immunoglobulin E quantification in serum has been developed. The method combines speed, automation ability, and minimal sample consumption. Only 1 μL of serum is required while the whole immunoaffinity capillary electrophoresis method is performed in less than 50 min. The concomitant use of online immunocapture, transient isotachophoresis, and laserinduced fluorescence detection provides a sensitivity in the low picomolar range and a highly linear fluorescence response over 4 orders of magnitude (IgE concentration ranging from 2.4 to 2400 ng/mL). After validation with a reference material, the method has been successfully applied to the quantification of total IgEs in patient sera. The results compared well with classical ImmunoCap data

Allergies respiratoires, pollens et polluants

National audienceFor 30 years, an increased incidence of respiratory allergy and asthma has been observed, particularly in children and young people living in urban areas of developed countries. A genetic origin is unlikely due to the rapidity of this increase and environmental factors (diet, lifestyle, exposure to xenobiotics...) should be involved. Epidemiological studies have shown that atmospheric pollutants may play a role. They could have an effect on the respiratory tract by inducing irritation, inflammation, airway hyperresponsiveness or enhancing respiratory allergies (adjuvant effect) or they could have an effect on the aeroallergens, in particular the pollens. Experimental studies have shown that pollen exposure to pollutants induce enhanced deformation or fracture of the external envelope linking to an enhanced liberation of intracytoplasmic allergenic granules and induce also a qualitative and quantitative modification of allergens. However, few experimental studies have shown that pollutant-exposed pollens are more allergenic that "clean" pollens. One important point to consider is the enhanced granule liberation by exposed pollens. Due to the small size of the granules, the allergen bioavailability may increase, leading to higher incidence of respiratory allergies.Depuis 30 ans, une incidence accrue des allergies respiratoires est observée, notamment chez les enfants et les adolescents vivant dans les zones urbaines des pays industrialisés. Il est admis que cette augmentation est trop rapide pour être liée à des facteurs génétiques et que d'autres facteurs, notamment environnementaux (alimentation, mode de vie, contact avec des xénobiotiques...) sont impliqués. Les études épidémiologiques montrent que les polluants de l'air en particulier semblent jouer un rôle important dans l'incidence des allergies. Ils peuvent agir soit par action au niveau du système respiratoire, en provoquant une irritation, une inflammation, une augmentation de l'hyperréactivité bronchique non spécifique ou en potentialisant une réponse allergique pré-existante (effet adjuvant), soit par action au niveau des aéroallergènes, dont les pollens représentent la majeure partie. Les principaux effets observés expérimentalement sont une augmentation des déformations et fractures de l'enveloppe externe conduisant à une libération accrue de granules intracytoplasmiques, eux-mêmes allergisants et une modification quantitative et qualitative des allergènes. Peu de travaux ont toutefois clairement mis en évidence une augmentation du potentiel allergisant des pollens après exposition aux polluants. Une piste à explorer reste la libération plus importante des granules intrapolliniques qui, de part leur petite taille, pourraient augmenter la biodisponibilité des allergènes et donc la fréquence et la gravité des allergies respiratoires

Immuno-analyses pour l'agriculture et l'alimentation

Collection : "techniques et pratiques"National audienc

Immuno-analyses pour l'agriculture et l'alimentation

Collection : "techniques et pratiques"National audienc

Biochemical features of grain legume allergens in humans and animals

International audienc

Allergenicity of pulses in humans

National audienc

Allergenicity of pulses in humans

International audienc