76 research outputs found
DEEP LEARNING BASED SKIN LESIONS DIAGNOSIS
Melanoma is one of the most virulent lesions of humanās skin. The visual diagnosis accuracy of melanoma directly depends on the doctorās qualification and specialization. State-of-the-art solutions in the field of image processing and machine learning allows to create intelligent systems based on artificial convolutional neural network exceeding humanās rates in the field of object classification, including the case of malignant skin lesions. This paper presents an algorithm for the early melanoma diagnosis based on artificial deep convolutional neural networks. The algorithm proposed allows to reach the classification accuracy of melanoma at least 91%
Orthopoxvirus Infections: Epidemiology, Clinical Picture, and Diagnostics (Scientific Review)
Lack of immunity among the population against pathogenic orthopoxviruses and an increased number of these infections human cases testify to the need of development of the rapid high-sensitive methods for species-specific orthopoxvirus diagnostics. The review presents current epidemiological situation on human orthopoxvirus infections. Addressed are clinical aspects of the disease, caused by small pox virus (SPV), Monkeypox virus, cowpox virus, and vaccinia virus. Represented is a historical survey of the conventional methods for diagnostics of these particular viruses. Reconsidered are the benefits of researches into the sphere of state-of-the-art molecular-diagnostic techniques taking into view both genus-specific and species-specific detection of agents, causing orthopoxvirus infections in humans. Demonstrated is the urgency of new-generation typing in view of occurrence of a novel SPV-like virus emerged as a result of natural evolution of existing zoonotic orthopoxviruses or SPV application as a biological terroristic agent
A comparative study of replicative properties of antitumor recombinant vaccinia viruses on human glioblastoma cell culture U87 and monkey kidney cell culture CV-1
In the world of today, virotherapy is one of the rapidlyĀ developing areas in the treatment of cancer, and itsĀ advantage is selective destruction of cancer cellsĀ with minimizing the destructive effect on normalĀ cells of the body. A promising basis for the creationĀ of oncolytic drugs is orthopoxviruses, which have aĀ number of advantages over other viral vectors, andĀ one of these advantages is a large capacity of theĀ genome, which allows genes encoding proteins withĀ antitumor properties to be cloned into their genome.Ā In this study, we compared the replicative propertiesĀ of ten variants of vaccinia virus (the strain LIVP ofĀ VACV) using human glioblastoma cell culture; some ofĀ these viruses have additional genes, such as the geneĀ encoding granulocyte-macrophage colony stimulatingĀ factor, gene encoding apoptosis-inducing proteinĀ TRAIL and gene encoding green fluorescent protein.Ā Furthermore, the virus with five virulence genes deletedĀ (genes encoding hemagglutinin, Ī³-interferonbindingĀ protein, thymidine kinase, complementbindingĀ protein and Bcl2-like inhibitor of apoptosis),Ā which has significantly lower reactogenicity andĀ neurovirulence compared to the original strain LIVPĀ of VACV, was studied. These data suggest that variantsĀ of vaccinia virus with a defective gene encodingĀ thymidine kinase most actively replicate in glioblastomaĀ cell culture
WILL RUSSIAN QUALITY MARK BE RECOGNIZED AND IN DEMAND?
Nowadays the market is saturated with goods and services, people are always faced with the problem of selecting the best. The problem of choice became particularly acute when there was a separation of spheres of production. In the result, there was a need to delegate the right to choose an expert in this field. In the history of Russia, like in other countries, at the time of formation of a saturated market, there was a need to identify the manufacturer of high-quality goods and services. The easiest and most affordable way to identify honest manufacturers, whose products have passed the conformity assessment procedures, is the use of heraldic symbol in the goods description. The paper provides a brief history of quality marks in Russia. The article presents the rules developed by the non-profit organization "Roskachestvo" for the selection and evaluation of products, and the registration procedure of the right to use quality mark. The authors analyze factors promoting and impeding the introduction if the quality mark into the daily practice of marking the best domestic products
Obtainingvaccinia virus with increased production of extracellular enveloped virions and directing GM-CSF synthesis as a promising basis for development of antitumor drug
The problems of oncological disease treatment are considered relevant and timely issues of the current research programs. Since monotherapy is increasingly clear to be less effective than combination therapy, the novel studies seek for advancement of current treatments and development of new ones employing oncolytic immunotherapy being among the most rapidly evolving approaches. Modern genetic engineering techniques enable new applications of oncolytic viruses in the frames of combined cancer therapy. These applications are feasible, due to the abilities of oncolytic viruses to destruct tumor cells, like as by changing susceptibility of cancer cells to anti-tumor drug, and upon the whole body, thus overcoming the mechanisms conferring immunoresistance of tumor cells. In the present work, we have developed a recombinant vaccinia virus which is a promising platform for designing the antitumor drugs. The following modifications of viral genome were made by means of genetic engineering: gene encoding granulocyte-macrophage colony-stimulating factor was inserted into the region of viral thymidine kinase gene; viral A34R gene encoding a membrane glycoprotein, was replaced by A34R gene with two nucleotide substitutions resulting into D110N and K151E mutations which cause increased proportion of extracellular enveloped virions during the virus reproduction. Some properties of the recombinant virus were studied in vitro. The virus was shown to produce granulocyte-macrophage colony stimulating factor, and high numbers of extracellular enveloped virions. The genome modifications had no effect upon viral replication
Genome stability of the vaccine strain VACā6
Due to cessation of mass smallpox vaccination in 1980, the collective immunity of humans against orthopoxvirus infections has virtually been lost. Therefore, the risk of spreading zoonotic human orthopoxvirus infections caused by monkeypox and cowpox viruses has increased in the world. First-generation smallpox vaccines based on Vaccinia virus (VAC) are reactogenic and therefore not suitable for mass vaccination under current conditions. This necessitates the development of modern safe live vaccines based on VAC using genetic engineering. We created the VACĪ6 strain by transient dominant selection. In the VACĪ6 genome, five virulence genes were intentionally deleted, and one gene was inactivated by inserting a synthetic DNA fragment. The virus was passaged 71 times in CV-1 cells to obtain the VACĪ6 strain from the VAC LIVP clonal variant. Such a long passage history might have led to additional off-target mutations in VACĪ6 compared to the original LIVP variant. To prevent this, we performed a genome-wide sequencing of VAC LIVP, VACĪ6, and five intermediate viral strains to assess possible off-target mutations. A comparative analysis of complete viral genomes showed that, in addition to target mutations, only two nucleotide substitutions occurred spontaneously when obtaining VACĪ4 from the VACĪ3 strain; the mutations persisting in the VACĪ5 and VACĪ6 genomes. Both nucleotide substitutions are located in intergenic regions (positions 1431 and 189738 relative to LIVP), which indicates an extremely rare occurrence of off-target mutations when using transient dominant selection to obtain recombinant VAC variants with multiple insertions/deletions. To assess the genome stability of the resulting attenuated vaccine strain, 15 consecutive cycles of cultivation of the industrial VACĪ6 strain were performed in 4647 cells certified for vaccine production in accordance with the āGuidelines for Clinical Trials of Medicinal Productsā. PCR and sequencing analysis of six DNA fragments corresponding to the regions of disrupted genes in VACĪ6 showed that all viral DNA sequences remained unchanged after 15 passages in 4647 cells
Mutations in the <i>A34R</i> gene increase the immunogenicity of vaccinia virus
Vaccination is the most simple and reliable approach of protection to virus infections. The most effective agents are live vaccines, usually low-virulence organisms for humans and closely related to pathogenic viruses or attenuated as a result of mutations/deletions in the genome of pathogenic virus. Smallpox vaccination with live vaccinia virus (VACV) closely related to smallpox virus played a key role in the success of the global smallpox eradication program carried out under the World Health Organization auspices. As a result of the WHO decision as of 1980 to stop smallpox vaccination, humankind has lost immunity not only to smallpox, but also to other zoonotic, orthopoxviruscaused human infections. This new situation allows orthopoxviruses to circulate in the human population and, as a consequence, to alter several established concepts of the ecology and range of sensitive hosts for various orthopoxvirus species. Classic VACV-based live vaccine for vaccination against orthopoxvirus infections is out of the question, because it can cause severe side effects. Therefore, the development of new safe vaccines against orthopoxviral infections of humans and animals is an important problem. VACV attenuation by modern approaches carried out by targeted inactivation of certain virus genes and usually leads to a decrease in the effectiveness of VACV in vivo propagation. As a result, it can cause a diminishing of the immune response after administration of attenuated virus to patients at standard doses. The gene for thymidine kinase is frequently used for insertion/inactivation of foreign genes and it causes virus attenuation. In this research, the effect of the introduction of two point mutations into the A34R gene of attenuated strain LIVP-GFP (Š¢Šā), which increase the yield of extracellular enveloped virions (EEV), on the pathogenicity and immunogenicity of VACV LIVP-GFP-A34R administered intranasally to laboratory mice were studied. It was shown that increase in EEV production by recombinant strain VACV LIVP-GFP-A34R does not change the attenuated phenotype characteristic of the parental strain LIVP-GFP, but causes a significantly larger production of VACV-specific antibodies
Route-coupled pathogenicity and immunogenicity of vaccinia virus variant inoculated mice
Vaccinia virus had played a key role in the global smallpox eradication. However, in case of mass vaccination with various Vaccinia virus strains severe side effects were revealed sometimes ending up with lethal outcomes, especially in immunocompromised humans. Hence, in 1980 the World Health Organization recommended to cancel smallpox vaccination after declaring about smallpox eradication. Over the last 40 years, human population virtually lost immunity not only against smallpox, but also against other zoonotic orthopoxvirus infections, such as monkeypox, cowpox, buffalopox, and camelpox. All of them pose a represent increasing threat to human health and heighten a risk of emerging highly contagious viruses due to natural evolution of previous zoonotic orthopoxviruses. In order to prevent development of small outbreaks into spreading epidemics and, thus, to decrease a risk of emergence due to natural evolution of highly pathogenic for humans orthopoxviruses, efforts should be applied to develop safe new generation live vaccines based on Vaccinia virus with target virulence genes inactivation. These strains should be examined in laboratory animal models inoculated via different routes. Currently, Vaccinia virus often becomes attenuated to create live recombinant vaccines due to inserting target DNA sequences into the virus virulence genes resulting in their inactivation. Vaccinia virus strain LIVP used in the Russian Federation as smallpox vaccine as well as derivative attenuated variant LIVP-GFP created by using genetic engineering methods with inactivating its thymidine kinase gene were examined. Such viruses were intracerebrally inoculated into suckling mice at doses of 101 or 102 PFU/animal for neurovirulence assessment. Adult mice were infected intranasally, subcutaneously or intradermally at doses of 107 or 108 PFU/animal and clinical manifestations were analyzed for 14 days. On the 28th day after the onset, blood serum samples were collected from individual mice to measure virus specific antibody level by using ELISA. It was shown that recombinant Vaccinia virus strain LIVP-GFP displayed markedly lowered neurovirulence and pathogenicity for mice as compared to parental LIVP. Finally, intradermal route turned out to demonstrate the most safe and effective profile for immunization with both examined Vaccinia virus strains
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