Transmission-blocking activity induced by malaria vaccine candidates Pfs25/Pvs25 is a direct and predictable function of antibody titer

<p>Abstract</p> <p>Background</p> <p>Mosquito stage malaria vaccines are designed to induce an immune response in the human host that will block the parasite's growth in the mosquito and consequently block transmission of the parasite. A mosquito membrane-feeding assay (MFA) is used to test transmission-blocking activity (TBA), but in this technique cannot accommodate many samples. A clear understanding of the relationship between antibody levels and TBA may allow ELISA determinations to be used to predict TBA and assist in planning vaccine development.</p> <p>Methods</p> <p>Rabbit anti-Pfs25 sera and monkey anti-Pvs25 sera were generated and the antibody titers were determined by a standardized ELISA. The biological activity of the same sera was tested by MFA using <it>Plasmodium </it>gametocytes (cultured <it>Plasmodium falciparum </it>or <it>Plasmodium vivax </it>from malaria patients) and <it>Anopheles </it>mosquitoes.</p> <p>Results</p> <p>Anti-Pfs25 and anti-Pvs25 sera showed that ELISA antibody units correlate with the percent reduction in the oocyst density per mosquito (Spearman Rank correlations: 0.934 and 0.616, respectively), and fit a hyperbolic curve when percent reduction in oocyst density is plotted against antibody units of the tested sample. Antibody levels also correlated with the number of mosquitoes that failed to become infected, and this proportion can be calculated from the reduction in oocyst numbers and the distribution of oocysts per infected mosquito in control group.</p> <p>Conclusion</p> <p>ELISA data may be used as a surrogate for the MFA to evaluate transmission-blocking vaccine efficacy. This will facilitate the evaluation of transmission-blocking vaccines and implementation of this malaria control strategy.</p

Meiosis at Microsporogenesis in Siberian Fir (Abies sibirica Ledeb.) in Natural Populations and in an Arboretum

Meiosis in Siberian fir is characterized by asynchrony (prophase I and tetrads in the same microsporangium simultaneously). Up to 4 nucleoli (in natural stands) and 5 (in an arboretum) are observed at prophase I. The shortest meiotic stages are telophase 1 and 2. Each of them is observed in 0.2% (in an arboretum) and 0.05% (in natural stands) of cells. In natural stands meiosis elapses quickly (within 2 days). In an arboretum it can continue for more than two weeks. Mainly meiosis is regular. Meiotic irregularities are, though, also encountered at different stages (fragments, bridges, etc.). In trees growing in an arboretum the total number of irregular cells can reach 17.9%. In natural populations only 11.7-13.3% of cells are irregular. The spectrum of meiotic irregularities in an arboretum is wider than in natural stands.Research materia

Additional possibilities of bioregulation products in correction of ENT-associated halitosis (bad smelling breath)

Chronic tonsillitis is a very common disease, often occurs in patients with somatic pathology, such as enterocolitis against the background of lactase deficiency, diabetes, kidney disease. Chronic tonsillitis is accompanied by halitosis, and with comorbidities, this symptom may become dominant. With exacerbation of chronic tonsillitis, patients are forced to increase the drug load, which is due to concomitant somatic diseases. To prevent polypragmasy, doctors more often began to turn to modern means of bioregulatory therapy, providing detoxification and anti-inflammatory effects. Of the diseases of the internal organs, giving an unpleasant smell from the mouth, in the first place is diabetes. Treatment of diabetes, especially in the newly ill, takes a lot of time and effort, and a more rapid deposition of plaque and the formation of tartar in violation of microcirculation and deterioration of tissue supply, including in the oral cavity and pharynx, contributes to halitosis. The appearance of an unpleasant odor in diseases of the kidneys, liver, endocrine system, intestines in exhaled air, due to metabolites in the blood, is persistent and does not respond well to correction. In this regard, the search for detoxification drugs is relevant. Having studied the pharmacodynamic capabilities of the drug Engystol we paid attention to its ability to improve the condition of patients with viral infections, allergic reactions, restore metabolic processes in tissues, maintain general homeostasis. Unlike many drugs that have a toxic effect on the liver, this bioregulatory drug is safe