Role of exosomes in malignancies.

BACKGROUND: Extracellular vesicles are closed structured surrounded by a lipid membrane that are secreted by almost all types of cells; their function is information delivery during cell-to-cell communication. They are most commonly divided into three categories - exosomes, microvesicles and apoptotic bodies. Exosomes are small vesicles with the size of 30-100 nm, and they are found in almost all body fluids, including peripheral blood, urine, breast milk, saliva and others. They are able to deliver their content to target cells and change their behavior. Cancer cells are able to secrete more exosomes and also contain different proteins and RNA species than the exosomes from healthy cells. Due to their specific composition that is connected to the cell of origin, exosomes could be used as bio-markers of various diseases in the future. PURPOSE: The aim of this work is to summarize current knowledge about exosomes and their role in various processes connected to resistance in tumors. This work was supported by grant of the Ministry of Health of the Czech Republic AZV 17-29343A. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

[Reactivity and immunologic activity of polyvalent split influenza vaccine in children]. / Studium reaktogennosti a imunogenní aktivity chripkové polyvalentní stepené vakcíny u detí.

In a group of 144 children (six months to 15 years) three doses vaccine were administered. The latter contains the main strains of the influenza type A and strain type B. From the clinical evaluation ensued that this vaccine in children is areactogenic even after repeated doses. The morbidity was followed up for 18 months and during this period in the immunized communities no case of influenza was recorded. The antibody levels were assessed by the haemagglutination-inhibition test (HIT) and the enzyme test (NIT) The assessed HI titres were high after the second and third dose, in particular as regard subtype H3N2 and H1N1. The titres against subtype H2N2 and type B were markedly lower. Antibodies against neuraminidase were highest against subtype N1 and type B, lowest against N2. The dynamics of the formation of antineuraminidase antibodies was similar as that of haemagglutination-inhibition antibodies. Based on these results the vaccine is evaluated as very satisfactory and after approval by the Ministry of Health and Social Affairs this vaccine will be used for a field trial in 1-2 thousand children where above all the protective effect of the vaccine will be investigated. This vaccine is intended for children, with the aim to induce complex immunity against influenza.

[Use of the Sevac Immunoskintest kit in children]. / Pouzití soupravy Imunoskintest Sevac u detí.

The Immunoskintest SEVAC is a kit of antigens for skin tests to evaluate the state of cellular immunity. By means of this kit 591 children from birth to 15 years were examined: the children suffered from acute diseases of the CNS, respiratory diseases incl. relapsing ones, a malignant tumour, haematological disease, and there were children who were Mantoux II negative and healthy children from children's homes. The value of the index of the skin test was referred to the child's age and sex; the lowest values were recorded in children with immunosuppressive therapy and the highest values of the skin test were found in healthy children and those with acute disease; boys had higher values than girls. In none of the children undesirable side-reaction were recorded after administration of the antigens.