Journal articles: 'Viruses – Reproduction'

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Bagirova, A. A., I. M. Guseynova, M. F. Gafar-Zade, and H. M. Kasumov. "Inhibiting Effect of Macrolide Polyene Antibiotics on Reproduction of Viruses." Antibiotics and Chemotherapy 65, no. 1-2 (May 25, 2020): 54–60. http://dx.doi.org/10.37489/0235-2990-2020-65-1-2-54-60.

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The review provides a comparative analysis of the inhibitory effect of macrocyclic polyene antibiotics on the reproductive properties of some viruses of various structures — vesicular stomatitis virus (VSV), human immunodeficiency virus (HIV), enterovirus, influenza virus, etc. The data on the morphological structure of viruses and on the mechanism of penetration of viruses into cells are presented. The article also provides data on the transcription, assembly of viruses, and inhibition of the process of virus replication in cell cultures in vitro using macrolide polyene antibiotics. On the basis of experimental data for the studied viruses, a polyene antibiotics' blocking mechanism of the process of virus penetration through cytoplasmic membranes and their reproduction in the cell is proposed.

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Aralov, Andrey V., Gleb V. Proskurin, Alexey A. Orlov, Liubov I. Kozlovskaya, Alexey A. Chistov, Sergey V. Kutyakov, Galina G. Karganova, Vladimir A. Palyulin, Dmitry I. Osolodkin, and Vladimir A. Korshun. "Perylenyltriazoles inhibit reproduction of enveloped viruses." European Journal of Medicinal Chemistry 138 (September 2017): 293–99. http://dx.doi.org/10.1016/j.ejmech.2017.06.014.

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Gumerov, V. G., I. G. Karimullina, A. K. Galiullin, A. M. Plotnikova, N. I. Xammadov, and M. N. Konnov. "FACTORS AFFECTING REPRODUCTION VIRUSES IN CELL CULTURE." Scientific Notes Kazan Bauman State Academy of Veterinary Medicine 234, no. 2 (June 5, 2018): 83–87. http://dx.doi.org/10.31588/2413-4201-1883-234-2-83-87.

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Koelle, Katia, Oliver Ratmann, David A. Rasmussen, Virginia Pasour, and Jonathan Mattingly. "A dimensionless number for understanding the evolutionary dynamics of antigenically variable RNA viruses." Proceedings of the Royal Society B: Biological Sciences 278, no. 1725 (May 4, 2011): 3723–30. http://dx.doi.org/10.1098/rspb.2011.0435.

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Antigenically variable RNA viruses are significant contributors to the burden of infectious disease worldwide. One reason for their ubiquity is their ability to escape herd immunity through rapid antigenic evolution and thereby to reinfect previously infected hosts. However, the ways in which these viruses evolve antigenically are highly diverse. Some have only limited diversity in the long-run, with every emergence of a new antigenic variant coupled with a replacement of the older variant. Other viruses rapidly accumulate antigenic diversity over time. Others still exhibit dynamics that can be considered evolutionary intermediates between these two extremes. Here, we present a theoretical framework that aims to understand these differences in evolutionary patterns by considering a virus's epidemiological dynamics in a given host population. Our framework, based on a dimensionless number, probabilistically anticipates patterns of viral antigenic diversification and thereby quantifies a virus's evolutionary potential. It is therefore similar in spirit to the basic reproduction number, the well-known dimensionless number which quantifies a pathogen's reproductive potential. We further outline how our theoretical framework can be applied to empirical viral systems, using influenza A/H3N2 as a case study. We end with predictions of our framework and work that remains to be done to further integrate viral evolutionary dynamics with disease ecology.

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Gilmutdinov, Rustam Y., Albert K. Galiullin, Gennady N. Spiridonov, and Pavel V. Sovronov. "Bovine fetal tissue extracts as an alternative to fetal serum for in vitro reproduction of viruses." BIO Web of Conferences 27 (2020): 00044. http://dx.doi.org/10.1051/bioconf/20202700044.

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The authors assessed the possibility of substitution of the serum component with tissue extracts (muscles, liver, kidneys) of bovine fetuses in the culture medium during the cultivation of transplanted LEK and Vero cell lines, as well as the reproduction of infectious rhinotracheitis IR, PI-3 viruses and reovirus on them. The greatest stimulating effect on LEK and Vero cells was obtained from bovine fetuses muscle extract. The effect of this extract on the proliferative activity of LEK and Vero cells is significant and amounts to 27 and 25%, respectively. The power of the effect of liver and kidney extracts is significantly lower and equal, respectively, 15 and 18% for LEK and 14 and 19% for Vero, although it is reliable. The reproductive activity of IR and PI-3 viruses when using tissue extracts was inferior to that when using blood serum. The stimulating effect of blood serum and muscle extract on the reproduction of reovirus was comparable. The effect of fetal muscle extract on the reproduction of IR, PI-3 viruses and reovirus is reliable and amounts to 29, 31 and 33%, respectively. In general, it is close to that of the blood serum of bovine fetuses - 30, 35 and 36%. The power of the influence of the liver and kidney extracts of the bovine fetuses is significantly lower and comparable to that of the blood serum of the cows themselves: 25, 23 and 20%, although it is reliable.

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Krasnopolsky, Vladislav I., Nina V. Zarochentseva, Ksenia V. Krasnopolskaya, Yulia N. Bashankaeva, and Varvara S. Kuzmicheva. "Papillomavirus infection and reproduction." Annals of the Russian academy of medical sciences 75, no. 3 (August 31, 2020): 189–95. http://dx.doi.org/10.15690/vramn1332.

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The purpose of the review a synthesis of research data on the role of human papillomavirus infection in the reproductive health of women and men. Key Points. Human papillomavirus (HPV) is one of the most common sexually transmitted viruses worldwide. According to the World Health Organization, HPV is the main cause of the development of HPV-associated diseases among both women and men. Viruses are subdivided into HPV with low carcinogenic risk, which cause benign warts, and HPV with high carcinogenic risk, which cause cancer. Different types of human papillomaviruses depending on their characteristic tropism, are divided into skin and mucous types. Viral infection in men leads to a decrease in the quality of sperm (for example, asthenozoospermia) due to apoptosis in sperm cells and due to the development of antisperm immunity. A negative viral effect on the fertility of women is manifested in an increase in the frequency of spontaneous miscarriages and a premature rupture of the amniotic membranes during pregnancy. There is evidence that HPV decreases the number of trophoblastic cells and abnormal trophoblastic-endometrial adhesion is also observed. In trophoblastic cells transfected with high-risk HPV, the level of apoptosis increases. HPV vaccination is safe, and the results show not only protection against HPV-associated diseases in women and men, but also a reduction of gestational complications, reduced preterm birth rates and the protection of newborns from infection.

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Batukaev, A. A., D. O. Palaeva, and M. S. Batukaev. "Grapes recovery from viruses during reproduction by biotechnological method." IOP Conference Series: Earth and Environmental Science 954, no. 1 (January 1, 2022): 012010. http://dx.doi.org/10.1088/1755-1315/954/1/012010.

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Abstract Grape regenerant plants obtained from apical meristems were assessed for the presence of the viruses using PCR and enzyme-linked immunosorbent assay (ELISA). The vast majority of the samples studied for the presence of the most common viruses (Grapevine Leafroll-Associated Virus – 1 (GLRaV-1); Grapevine yellow mosaic virus; Grapevine vein banding; virus; Grapevine Leafroll Virus; Grapevine stemm pitting) by ELISA showed negative results. Testing of regenerant plants of the Augustine variety clones showed that only one plant out of 80 plants showed a positive reaction to the presence of this virus. Analysis of 80 plants of the Moldova variety clones revealed a positive reaction to the yellow mosaic virus (Grapevine yellow mosaic virus) in 1 plant as well as in the original donor plant (Moldova variety). The rest of the regenerated plants (79 pcs.) were absolutely healthy. PCR analysis showed that the spectrum of fragments of the original genotypes of Moldova varieties (lanes 1–4) and Augustin (lanes 5–8) contained DNA fragments of 450 bps, corresponding to Candidatus Phytoplasma vitis Flavescence doree. In Bart variety (lanes 9–11), no pathogen was detected. Analysis of the spectrum of fragments of grape regenerant plants obtained from apical meristems (lanes 1–4) and Augustine (lanes 5–8) showed the absence of the pathogen Candidatus Phytoplasma vitis Flavescence doree.

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Horas, Elena, Loukas Theodosiou, and Lutz Becks. "Why Are Algal Viruses Not Always Successful?" Viruses 10, no. 9 (September 5, 2018): 474. http://dx.doi.org/10.3390/v10090474.

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Algal viruses are considered to be key players in structuring microbial communities and biogeochemical cycles due to their abundance and diversity within aquatic systems. Their high reproduction rates and short generation times make them extremely successful, often with immediate and strong effects for their hosts and thus in biological and abiotic environments. There are, however, conditions that decrease their reproduction rates and make them unsuccessful with no or little immediate effects. Here, we review the factors that lower viral success and divide them into intrinsic—when they are related to the life cycle traits of the virus—and extrinsic factors—when they are external to the virus and related to their environment. Identifying whether and how algal viruses adapt to disadvantageous conditions will allow us to better understand their role in aquatic systems. We propose important research directions such as experimental evolution or the resurrection of extinct viruses to disentangle the conditions that make them unsuccessful and the effects these have on their surroundings.

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Glebova, T. I., N. G. Klivleyeva, G. V. Lukmanova, N. T. Saktaganov, and N. S. Ongarbayeva. "Sensitivity of infl uenza virus strains isolated from various regions of Kazakhstan in 2018–2019 to antiviral drugs." Clinical Medicine (Russian Journal) 99, no. 4 (September 20, 2021): 276–81. http://dx.doi.org/10.30629/0023-2149-2021-99-4-276-281.

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The purpose of the study was to examine susceptibility of the Kazakhstan strains of infl uenza A/H1N1 and type B viruses, isolated from various regions of Kazakhstan in 2018–2019, to antiviral drugs. Materials and methods. The susceptibility analysis of 20 strains of infl uenza A/H1N1 and B viruses was carried out with chemotherapeutic agents including Remantadine, Tamifl u, Arbidol, and Ingavirin. Viruses were cultured in the allantoic cavity of developing 10-day-old chicken embryos for 48 hours at 36 °C. The hemagglutinating activity was determined according to the conventional method on 96-well plates using 0.75% chicken red blood cell suspension; the infectivity was calculated by the Reed-Muench method. The sensitivity of virus strains to diff erent concentrations of antiviral drugs was evaluated by the level of reproductive suppression of 100 lg EID50/0.2 ml of virus in chicken embryos. Statistical analysis was performed with the use of Microsoft Offi ce Excel 2010 software. Results. A study of sensitivity to chemotherapeutic agents demonstrated heterogeneity of Kazakhstan 2018–2019 infl uenza A and B viruses population on this feature. The sensitivity to Tamifl u was found in all Kazakhstan strains of infl uenza A/H1N1 virus and three type B strains (inhibitory concentration was 0.44–25.38 μg/mL). The reproduction of most viruses was eff ectively inhibited by tamifl u at a concentration of 0.68–3.23 μg/mL. The inhibitory concentration for the three strains of A/H1N1 virus was 7.23–25.38 μg/mL. Remantadin inhibited the reproduction of viruses at higher doses (12.60–25.55 μg/mL). All viruses under study were resistant to Arbidol and Ingavirin. One type B infl uenza virus was found to be weakly sensitive to Ingavirin. Conclusion. The heterogeneity of the infl uenza virus population in their sensitivity to antiviral drugs indicates the need for constant epidemiological surveillance in order to identify drug-resistant variants.

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Ewald, Paul W., and Holly A. Swain Ewald. "The scope of viral causation of human cancers: interpreting virus density from an evolutionary perspective." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1773 (April 8, 2019): 20180304. http://dx.doi.org/10.1098/rstb.2018.0304.

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Most known oncogenic viruses of humans use DNA as their genomic material. Research over the past quarter century has revealed that their oncogenicity results largely from direct interference with barriers to oncogenesis. In contrast to viruses that have been accepted causes of particular cancers, candidate viral causes tend to have fewer viral than cellular genomes in the tumours. These low viral loads have caused researchers to conclude that the associated viruses are not primary causes of the associated cancers. Consideration of differential survival, reproduction and infiltration of cells in a tumour suggest, however, that viral loads could be low even when viruses are primary causes of cancer. Resolution of this issue has important implications for human health because medical research tends to be effective at preventing and controlling infectious diseases. Mathematical models may clarify the problem and help guide future research by assessing whether low viral loads are likely outcomes of the differential survival, reproduction, and infiltration of cells in a tumour and, more generally, the extent to which viruses contribute to cancer. This article is part of the theme issue ‘Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses’.

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Leon, Cristina, Vladimir Popov, and Vitaly Volpert. "Viruses competition in the genotype space." ITM Web of Conferences 31 (2020): 02002. http://dx.doi.org/10.1051/itmconf/20203102002.

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This paper is devoted to the study of persistence and evolution of two viruses taking into account virus mutation, reproduction, and genotype dependent mortality, either natural or determined by an antiviral treatment. The model describes the virus density distribution u(x; t) for the first virus and v(y; t) for the second one as functions of genotypes x and y considered as continuous variables and of time t. The model consists of a system of reaction-diffusion equations with integral terms characterizing virus competition for host cells. The analysis of the model shows the conditions of the existence of virus strains.

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Glebova, T. I., N. G. Klivleyeva, G. V. Lukmanova, N. T. Saktaganov, and A. M. Baimukhametova. "2018–2019 antiviral drug sensitivity of the influenza virus strains isolated from various regions of Kazakhstan." Russian Journal of Infection and Immunity 11, no. 6 (June 28, 2021): 1159–66. http://dx.doi.org/10.15789/2220-7619-ads-1497.

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Influenza is a serious public health problem. The ability of influenza virus to change upon replication is the most serious issue for practical medicine and virology, which can fundamentally alter virus biological properties, such as infectivity and virulence. The high mutational variability of influenza viruses can contribute to rapidly emerging drug resistance. Therefore, the study of antiviral drug sensitivity among influenza viruses is necessary to justify proper drug use for treatment and prevention of influenza infection. The aim of the study was to examine antiviral drug susceptibility of influenza A/H1N1 and B virus strains isolated from various regions of Kazakhstan in the years 2018–2019. Materials and methods. The susceptibility analysis of 20 strains of influenza A/H1N1 and B viruses was carried out by using chemotherapeutic agents including Remantadine, Tamiflu, Arbidol, and Ingavirin. Viruses were cultured in the allantoic cavity of developing 10-day-old chicken embryos for 48 hours at 36оC. The hemagglutinating activity was determined according to the standard method on 96-well plates using 0.75% chicken red blood cell suspension; the infectivity was calculated by the Reed–Muench method. The susceptibility of virus strains to different concentrations of antiviral drugs was evaluated by the level of virus reproductive suppression of 100 lg EID50/0.2 ml in chicken embryos. Statistical analysis was performed using Microsoft Office Excel 2010 software. Results. A study of susceptibility to chemotherapeutic agents demonstrated heterogeneity of influenza A and B virus population isolated in Kazakhstan during the 2018–2019 period. The susceptibility to tamiflu was found in all Kazakhstan strains of influenza A/H1N1 virus and three type B strains (inhibitory concentration was 0.44–25.38 μg/mL). The reproduction of most viruses was effectively inhibited by Tamiflu at a concentration of 0.68–3.23 μg/mL. The inhibitory concentration for three strains of A/H1N1 virus was 7.23–25.38 μg/mL. Remantadine inhibited reproduction of viruses at higher doses (12.60–25.55 μg /mL). All investigated viruses were resistant to Arbidol and Ingavirin. A single type B influenza virus strain was found to be weakly susceptible to Ingavirin. Conclusion. The heterogeneity of influenza virus population in susceptibility to antiviral drugs suggest a need for constant epidemiological surveillance in order to identify drug-resistant variants.

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Larionova, N. V., I. V. Kiseleva, and L. G. Rudenko. "Evolution of influenza viruses based on sensitivity to temperature of replication." Journal of microbiology epidemiology immunobiology, no. 6 (December 16, 2019): 47–55. http://dx.doi.org/10.36233/0372-9311-2019-6-47-55.

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Introduction. The assessment of the ability of influenza viruses to replication at temperature conditions beyond optimal values approaches us to understanding the laws of their evolutionary variability. The temperature range for the reproduction of epidemic viruses is also an important indicator for choosing a rational strategy for producing attenuated reassortants for a live influenza vaccine.The purpose of the study is a retrospective analysis of the biological properties of influenza viruses from various pandemic and epidemic cycles based on their ability to replicate at temperatures beyond optimal values.Materials and methods. We studied 234 strains of human influenza A and B viruses that caused epidemics in the 20th – 21st centuries. The infectious activity of viruses at different incubation temperatures was determined in developing chicken embryos. The temperature sensitivity and cold resistance of viruses replication were estimated as a difference of infectious titers at the optimum and raised or lowered incubation temperatures.Results. Data from a retrospective study indicate that the range of sensitivity to replication temperature during the natural drift of influenza A and B pathogens is subject to regular variability that has a cyclic character.Discussion. To assess the evolution and epidemic potential of influenza viruses, it is important not only to register a change in their antigenic properties but also to take into account the temperature sensitivity of the reproduction. Both of these properties contribute to the manifestation of the virulence of the virus. Prolonged circulation of temperature-sensitive viruses can be a prerequisite for the appearance of a radically new drift variant and even shift.Conclusion. The analysis of the variability of the biological properties of influenza viruses approaches to the comprehension of possible ways of their evolution, that contributes to the development of rational methods for preventing the spread of viruses and the incidence caused by them.

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Durnova, Anna Olegovna, Renata Anvarovna Kadyrova, Darya Mikhaylovna Danilenko, Maksim Igorevich Dyukov, Vera Aleksandrovna Martyntseva, Tatyana Dmitriyevna Smirnova, Mikhail Yuryevich Yeropkin, and Oleg Ivanovich Kiselev. "Influenza A virus reproduction in humanendometrial cells." Journal of obstetrics and woman disease 62, no. 2 (May 15, 2013): 23–28. http://dx.doi.org/10.17816/jowd62223-28.

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Study of replication of influenza A viruses (IAV) of A(H3N2) and A(H1N1)pdm subtypes in human endometrial cells was performed. It was shown that endometrial infection with IAV strongly depends on the multiplicity of infection and causes substantial changes in functional activities of these cells. Moreover endometrial cells of proliferative phase (day 8) were more sensitive to IAV infection than cells from secretory phase of menstrual cycle on day 19th.

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Dietrich, Muriel, Teresa Kearney, Ernest C. J. Seamark, Janusz T. Paweska, and Wanda Markotter. "Synchronized shift of oral, faecal and urinary microbiotas in bats and natural infection dynamics during seasonal reproduction." Royal Society Open Science 5, no. 5 (May 2018): 180041. http://dx.doi.org/10.1098/rsos.180041.

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Seasonal reproduction is a period of extreme physiological and behavioural changes, yet we know little about how it may affect host microbial communities (i.e. microbiota) and pathogen transmission. Here, we investigated shifts of the bacterial microbiota in saliva, urine and faeces during the seasonal reproduction of bats in South Africa, and test for an interaction in shedding patterns of both bacterial ( Leptospira ) and viral (adeno- and herpesviruses) agents. Based on a comparative approach in two cave-dwelling bat species and high-throughput sequencing of the 16S rRNA gene, we demonstrated a clear signature in microbiota changes over the reproduction season, consistent across the multiple body habitats investigated, and associated with the sex, age and reproductive condition of bats. We observed in parallel highly dynamic shedding patterns for both bacteria and viruses, but did not find a significant association between viral shedding and bacterial microbiota composition. Indeed, only Leptospira shedding was associated with alterations in both the diversity and composition of the urinary microbiota. These results illustrate how seasonal reproduction in bats substantially affects microbiota composition and infection dynamics, and have broad implications for the understanding of disease ecology in important reservoir hosts, such as bats.

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Zhang, Chunming, Tianliang Feng, Yun Zhao, and Guifeng Jiang. "A New Model for Capturing the Spread of Computer Viruses on Complex-Networks." Discrete Dynamics in Nature and Society 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/956893.

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Based on complex network, this paper proposes a novel computer virus propagation model which is motivated by the traditional SEIRQ model. A systematic analysis of this new model shows that the virus-free equilibrium is globally asymptotically stable when its basic reproduction is less than one, and the viral equilibrium is globally attractive when the basic reproduction is greater than one. Some numerical simulations are finally given to illustrate the main results, implying that these results are applicable to depict the dynamics of virus propagation.

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Nikolayeva, Y. V., E. A. Ulashchik, E. V. Chekerda, A. V. Galochkina, N. A. Slesarchuk, A. A. Chistov, T. D. Nikitin, et al. "5-(Perylen-3-ylethynyl)uracil Derivatives Inhibit Reproduction of Respiratory Viruses." Russian Journal of Bioorganic Chemistry 46, no. 3 (May 2020): 315–20. http://dx.doi.org/10.1134/s1068162020030139.

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Gilling-Smith, Carole, Serena Emiliani, Paula Almeida, Corinne Liesnard, and Yvon Englert. "Laboratory safety during assisted reproduction in patients with blood-borne viruses." Human Reproduction 20, no. 6 (April 7, 2005): 1433–38. http://dx.doi.org/10.1093/humrep/deh828.

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Delattre, Hadrien, Kalesh Sasidharan, and Orkun S. Soyer. "Inhibiting the reproduction of SARS-CoV-2 through perturbations in human lung cell metabolic network." Life Science Alliance 4, no. 1 (November 24, 2020): e202000869. http://dx.doi.org/10.26508/lsa.202000869.

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Viruses rely on their host for reproduction. Here, we made use of genomic and structural information to create a biomass function capturing the amino and nucleic acid requirements of SARS-CoV-2. Incorporating this biomass function into a stoichiometric metabolic model of the human lung cell and applying metabolic flux balance analysis, we identified host-based metabolic perturbations inhibiting SARS-CoV-2 reproduction. Our results highlight reactions in the central metabolism, as well as amino acid and nucleotide biosynthesis pathways. By incorporating host cellular maintenance into the model based on available protein expression data from human lung cells, we find that only few of these metabolic perturbations are able to selectively inhibit virus reproduction. Some of the catalysing enzymes of such reactions have demonstrated interactions with existing drugs, which can be used for experimental testing of the presented predictions using gene knockouts and RNA interference techniques. In summary, the developed computational approach offers a platform for rapid, experimentally testable generation of drug predictions against existing and emerging viruses based on their biomass requirements.

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Marion, Jean-Yves. "From Turing machines to computer viruses." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1971 (July 28, 2012): 3319–39. http://dx.doi.org/10.1098/rsta.2011.0332.

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Self-replication is one of the fundamental aspects of computing where a program or a system may duplicate, evolve and mutate. Our point of view is that Kleene's (second) recursion theorem is essential to understand self-replication mechanisms. An interesting example of self-replication codes is given by computer viruses. This was initially explained in the seminal works of Cohen and of Adleman in the 1980s. In fact, the different variants of recursion theorems provide and explain constructions of self-replicating codes and, as a result, of various classes of malware. None of the results are new from the point of view of computability theory. We now propose a self-modifying register machine as a model of computation in which we can effectively deal with the self-reproduction and in which new offsprings can be activated as independent organisms.

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Zhu, Qingyi, Pingfan Xiang, Xuhang Luo, and Chenquan Gan. "Dynamical Behavior of Hybrid Propagation of Computer Viruses." Security and Communication Networks 2022 (February 9, 2022): 1–15. http://dx.doi.org/10.1155/2022/2576685.

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Considering the horizontal and vertical propagation of computer viruses over the Internet, this article proposes a hybrid susceptible-latent-breaking-recovered-susceptible (SLBRS) model. Through mathematical analysis of the model, two equilibria (virus-free and virose equilibria) and their global stabilities are both proved depending on the basic reproduction number R 0 , which is affected by the vertical propagation of infected computers. Moreover, the feasibility of the obtained results is verified by numerical simulations. Finally, the dependence of R 0 on system parameters and the parameters affecting the stability level of infected computers are both analyzed.

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Nakayama, Masataka, and Shigeru Kyuwa. "Basic reproduction numbers of three strains of mouse hepatitis viruses in mice." Microbiology and Immunology 66, no. 4 (January 18, 2022): 166–72. http://dx.doi.org/10.1111/1348-0421.12961.

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Pfeiffer, I., J. Litter, Zs Pénzes, and J. Kucsera. "Effects of double-stranded RNA viruses on the reproduction of Phaffia Rhodozyma." Acta Biologica Hungarica 52, no. 2-3 (May 2001): 299–306. http://dx.doi.org/10.1556/abiol.52.2001.2-3.14.

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Gold, Eran, Yossi Mizrachi, Amir Shalev, Jacob Farhi, Eran Horowitz, Amir Ravhon, Sarit Alush, David Levran, Arie Raziel, and Ariel Weissman. "Screening for blood born viruses in assisted reproduction: is annual testing necessary?" Archives of Gynecology and Obstetrics 299, no. 6 (March 14, 2019): 1709–13. http://dx.doi.org/10.1007/s00404-019-05112-0.

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G, Gulothungan, Vickram A S, and Kuldeep Dhama. "Angiotensin Converting Enzyme 2 (ACE2) - A macromolecule and its impact on human reproduction during COVID-19 pandemic." Journal of Experimental Biology and Agricultural Sciences 10, no. 5 (October 31, 2022): 960–77. http://dx.doi.org/10.18006/2022.10(5).960.977.

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Coronavirus disease 2019 (COVID 19) is caused by severe acute respiratory syndrome novel coronavirus 2 (SARS-nCoV-2). It has been declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Since then, several researchers have worked/ are working on this virus by a multifactorial approach to finding out the mechanism of entry, transmission route, post-infection replication process, survival, and post-recovery utilities. As we know, SARS, MERS, and Zika viruses have affected human reproductive potentials, consequently, COVID 19 also can affect both men's and women's reproductive potential through ACE2 macromolecule. This study aimed to summarize the role of ACE2- macromolecule in COVID 19 entry and further processes in the reproductive path of both men and women. Research articles were searched in NCBI-NLM, Google Scholar, and Scopus databases. We searched based on the phrase “COVID 19”, “ACE2”, “ACE2 in testes”, “ACE2 in the female reproductive tract”, “ACE2 during pregnancy”, “ACE2 during early embryo”, “COVID 19 and impact in human reproduction” and selected the articles for summarizing this article. Most recent articles and the mechanism of COVID 19 were selected for our understanding. The results of the study revealed that COVID 19 impacts the reproductive potential of both men and women. Testes are the most vulnerable organ prone to infection in men, and vaginal fluid and the uterus could be the choice of infection in the female. Till now, COVID 19 has not been directly detected in semen samples and vaginal fluid. Results of the study can be concluded that ACE2 plays a major role in COVID 19 infection, ACE2 expression could be more in the testes, ovary, uterus, and vagina. COVID 19 could impact more on human reproduction and lead to a loss of fertility status for a while. All antiviral treatments could pose a negative impact on human reproduction. Further research should be carried out on the already existing theoretical hypothesis of SARS-Co-V-2 on human reproduction.

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Cao, Hui, Si Wang, Dongxue Yan, Hongwu Tan, and Hemiao Xu. "The Dynamical Analysis of Computer Viruses Model with Age Structure and Delay." Discrete Dynamics in Nature and Society 2021 (April 27, 2021): 1–13. http://dx.doi.org/10.1155/2021/5538438.

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This paper deals with the dynamical behaviors for a computer viruses model with age structure, where the loss of the acquired immunity and delay are incorporated. Through some rigorous analyses, an explicit formula for the basic reproduction number of the model is calculated, and some results about stability and instability of equilibria for the model are established. These findings show that the age structure and delay can produce Hopf bifurcation for the computer viruses model. The numerical examples are executed to validate the theoretical results.

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Chen, Shanshan, Kaihua Wang, Mengfeng Sun, and Xinchu Fu. "Spread of competing viruses on heterogeneous networks." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375, no. 2096 (May 15, 2017): 20160284. http://dx.doi.org/10.1098/rsta.2016.0284.

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In this paper, we propose a model where two strains compete with each other at the expense of common susceptible individuals on heterogeneous networks by using pair-wise approximation closed by the probability-generating function (PGF). All of the strains obey the susceptible–infected–recovered (SIR) mechanism. From a special perspective, we first study the dynamical behaviour of an SIR model closed by the PGF, and obtain the basic reproduction number via two methods. Then we build a model to study the spreading dynamics of competing viruses and discuss the conditions for the local stability of equilibria, which is different from the condition obtained by using the heterogeneous mean-field approach. Finally, we perform numerical simulations on Barabási–Albert networks to complement our theoretical research, and show some dynamical properties of the model with competing viruses. This article is part of the themed issue ‘Mathematical methods in medicine: neuroscience, cardiology and pathology’.

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Kalinina, O. S. "ТАКСОНОМІЧНА ХАРАКТЕРИСТИКА ДНК-ГЕНОМНИХ ВІРУСІВ ХРЕБЕТНИХ ТВАРИН І ЛЮДИНИ." Scientific Messenger of LNU of Veterinary Medicine and Biotechnology 18, no. 2(66) (September 8, 2016): 83–88. http://dx.doi.org/10.15421/nvlvet6618.

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Presented modern taxonomy and nomenclature of the DNA-genomic of viruses of vertebrates animals and humans in accordance with the information ICTV release 2015 (ratification 2016). Described the basic criteria for the classification of viruses: characteristics of the viral genome, the mechanism of replication and virions morphology. Viruses of vertebrates (1120 species) consist of 4 orders, 34 families (12 – DNA-genomic, 22 – RNA-genomic), 11 subfamilies and 219 genera. DNA-genomic viruses of vertebrates (546 species) classified in 1 orders, 12 families, 5 subfamilies and 113 genera. The order Herpesvirales has united family Herpesviridae and Alloherpesviridae. Family Poxviridae, Iridoviridae and Parvoviridae, except of viruses of vertebrates, contain viruses of insects. Described the taxa of viruses:family, subfamily, genera, species. Characterized the basic taxonomic features of DNA-genomic viruses of vertebrates: the shape, size and structure of virions – the presence of outer membrane lipoprotein, capsid symmetry type, the structure of the viral DN and the number of proteins. The attention is focused on the features of reproduction of viruses. The replication of majority DNA-genomic viruses of vertebrates occur in the nucleus of cells, except for members of families Poxviridae and Asfarviridae, which are replicate in the cytoplasm. Yield virions is done due to destruction of cells or budding through the cell membrane (sometimes in combination with exocytosis) depending on the structural organization of the virus.

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Larionova, N. V., I. V. Kiseleva, E. A. Bazhenova, E. P. Grigorieva, and L. G. Rudenko. "The influence of seasonal influenza viruses biological features on the effectiveness of development strains for live influenza vaccine." Journal of microbiology, epidemiology and immunobiology, no. 5 (November 21, 2019): 24–34. http://dx.doi.org/10.36233/0372-9311-2019-5-24-34.

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Aim. Evaluation of the efficiency of the method of reassortant strains for live influenza vaccine development and ways to optimize it, taking into account the differences in the current epidemic influenza viruses by key biological characteristics.Materials and methods. Influenza viruses — candidates for seasonal LAIVs, MDVs for Russian LAIVs A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69. The vaccine strains development in developing chicken embryos included reassortment, selective passages at low temperature in the presence of hyperimmune serum to the MDV, several stages of reassortants cloning, their virological and molecular genetic characteristics. Epidemic influenza viruses and LAIVs strains were evaluated by their ability to reproduction at temperatures beyond optimal values, by sensitivity to serum inhibitors.Results. The assessment of phenotypic properties used in reassortment epidemic viruses is carried out. Presented the data on the efficiency of development reassortant strains for LAIV depending on the biological properties of circulating epidemic influenza viruses: their temperature-resistant, cold-sensitive phenotype, inhibitor resistance, and receptor specificity.Conclusion. Based on the assessment of the influence of the biological characteristics of the epidemic viruses, the rational methodological techniques for the most effective development of reassortants for LAIV are selected.

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DeLong, John P., Zeina Al-Ameeli, Garry Duncan, James L. Van Etten, and David D. Dunigan. "Predators catalyze an increase in chloroviruses by foraging on the symbiotic hosts of zoochlorellae." Proceedings of the National Academy of Sciences 113, no. 48 (November 7, 2016): 13780–84. http://dx.doi.org/10.1073/pnas.1613843113.

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Virus population growth depends on contacts between viruses and their hosts. It is often unclear how sufficient contacts are made between viruses and their specific hosts to generate spikes in viral abundance. Here, we show that copepods, acting as predators, can bring aquatic viruses and their algal hosts into contact. Specifically, predation of the protistParamecium bursariaby copepods resulted in a >100-fold increase in the number of chloroviruses in 1 d. Copepod predation can be seen as an ecological “catalyst” by increasing contacts between chloroviruses and their hosts, zoochlorellae (endosymbiotic algae that live within paramecia), thereby facilitating viral population growth. When feeding, copepods passedP. bursariathrough their digestive tract only partially digested, releasing endosymbiotic algae that still supported viral reproduction and resulting in a virus population spike. A simple predator–prey model parameterized for copepods consuming protists generates cycle periods for viruses consistent with those observed in natural ponds. Food webs are replete with similar symbiotic organisms, and we suspect the predator catalyst mechanism is capable of generating blooms for other endosymbiont-targeting viruses.

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Antipova, A. Yu, and I. N. Lavrentieva. "VIRUSES OF THE PARVOVIRIDAE FAMILY: MOLECULAR GENETICAL ASPECTS OF REPRODUCTION AND MEDICAL IMPORTANCE." Russian Journal of Infection and Immunity 7, no. 1 (January 1, 2017): 7–20. http://dx.doi.org/10.15789/2220-7619-2017-1-7-20.

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Babaeva, F. E., A. V. Lipatova, D. V. Kochetkov, P. M. Chumakov, and S. K. Kravchenko. "The study of oncolytic viruses reproduction in organ cultures of human lymphoid tumors." Oncohematology 14, no. 4 (December 22, 2019): 84–89. http://dx.doi.org/10.17650/1818-8346-2019-14-4-84-89.

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Heider, H., S. Markushin, C. Schroeder, and Y. Ghendon. "The influence of norakin� on the reproduction of influenza A and B viruses." Archives of Virology 86, no. 3-4 (September 1985): 283–90. http://dx.doi.org/10.1007/bf01309832.

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Plotnikova, E. M., I. A. Nesterova, Z. G. Churina, A. S. Saifullin, I. G. Karimullina, and F. Kh Kalimullin. "STUDY OF THE EFFECT OF BIOLOGICALLY ACTIVE SUBSTANCES ON THE REPRO-DUCTION OF THE TRANSPLANTED CELL CULTURE LINE." Scientific Notes Kazan Bauman State Academy of Veterinary Medicine 246, no. 2 (June 1, 2021): 157–60. http://dx.doi.org/10.31588/2413-4201-1883-246-2-157-160.

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The present study was carried out with take into account the high biological activity of bi-opolymers, in particular chitin and chitosan for animal cell cultures in vivo and in vitro. The aim of the study was investigating the effect of apiphytoextract on the growth and reproduction of trans-planted Taurus-1 cell lines after their recriopreservation for long-term storage in the liquid nitrogen. The use of apiphytoextract as part of the culture medium in the cultivation of hydrated cell lines allowed the use of the method of cell recriopreservation for reproduction of viruses, which are used for vaccine production.

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Danane, Jaouad, and Karam Allali. "Mathematical Analysis and Clinical Implications of an HIV Model with Adaptive Immunity." Computational and Mathematical Methods in Medicine 2019 (November 16, 2019): 1–19. http://dx.doi.org/10.1155/2019/7673212.

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In this paper, a mathematical model describing the human immunodeficiency virus (HIV) pathogenesis with adaptive immune response is presented and studied. The mathematical model includes six nonlinear differential equations describing the interaction between the uninfected cells, the exposed cells, the actively infected cells, the free viruses, and the adaptive immune response. The considered adaptive immunity will be represented by cytotoxic T-lymphocytes cells (CTLs) and antibodies. First, the global stability of the disease-free steady state and the endemic steady states is established depending on the basic reproduction number R0, the CTL immune response reproduction number R1z, the antibody immune response reproduction number R1w, the antibody immune competition reproduction number R2w, and the CTL immune response competition reproduction number R3z. On the other hand, different numerical simulations are performed in order to confirm numerically the stability for each steady state. Moreover, a comparison with some clinical data is conducted and analyzed. Finally, a sensitivity analysis for R0 is performed in order to check the impact of different input parameters.

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LIU, HUIJUAN, FEI XU, and JIA-FANG ZHANG. "ANALYSIS OF AN AGE-STRUCTURED HIV-1 INFECTION MODEL WITH LOGISTIC TARGET CELL GROWTH." Journal of Biological Systems 28, no. 04 (November 11, 2020): 927–44. http://dx.doi.org/10.1142/s0218339020500229.

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In this work, we construct an age-structured HIV-1 infection model to investigate the interplay between [Formula: see text] cells and viruses. In our model, we assume that the variations in the death rate of productively infected [Formula: see text] cells and the production rate of virus in infected cells are all age-dependent, and the target cells follow logistic growth. We perform mathematical analysis and prove the persistence of the semi-flow of the system. We calculate the basic reproduction number and prove the local and global stability of the steady states. We show that if the basic reproduction number is less than one, the disease-free equilibrium is globally asymptotically stable, and if the basic reproduction number is greater than one, the infected steady state is locally asymptotically stable.

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Teulon, D. A. J., and M. A. W. Stufkens. "Biosecurity and aphids in New Zealand." New Zealand Plant Protection 55 (August 1, 2002): 12–17. http://dx.doi.org/10.30843/nzpp.2002.55.3906.

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About 110 introduced aphid species (Hemiptera Aphididae) have been recorded in New Zealand Only 12 indigenous species have been recorded On average there has been about one new aphid incursion into New Zealand per year over the last 130 years although this rate has declined dramatically in recent years The origins of introduced aphids appear to include most parts of the globe Many introduced aphids damage economically important plants through their feeding and transmitting plant viruses Less quantifiable environmental impacts include injury to native plants and the displacement of native aphids on their host plants Aspects of aphid biology such as small size parthenogenetic reproduction high reproductive rates short generation time rapid dispersal and eruptive population dynamics pose particularly difficult challenges for aphid biosecurity in New Zealand

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Kazmirchuk, V. E. "Viralpneumonitis: a long-standingdisease." Likarska sprava, no. 1-2 (May 25, 2021): 14–18. http://dx.doi.org/10.31640/jvd.1-2.2021(3).

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The work reveals the main differences between pneumonitis and pneumonia. Features of mucosal immunity of the lungs, the dominant role of surfactant in the protection and reproduction of viruses in the lungs, etiology and pathogenesis of viral pneumonitis. Features of diagnosis, the main clinical symptoms and principles of treatment of pneumonitis (pulmonitis), in contrast to pneumonia.

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Nazaryan, R. S., Yu V. Fomenko, N. A. Scheblykina, T. A. Kolesova, N. V. Golik, and E. V. Sukhostavets. "Herpesviruses. Part 2." Ukraïnsʹkij žurnal medicini, bìologìï ta sportu 6, no. 2 (April 28, 2021): 211–20. http://dx.doi.org/10.26693/jmbs06.02.211.

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The clinical manifestations of herpes infection depend on the pathogenic properties of the pathogen and on the state of immunity of the infected organism. Herpesviruses type 1-3 are predominantly neurotropic and cause diseases of the nervous system. The reproduction of the virus is carried out in the neurons of the nerve ganglia and epithelial cells, as they have a common ectodermal origin. Herpesviruses type 4, 5 and 8 are predominantly lymphotropic and cause diseases of the immune system. In a latent and persistent state, viruses are found in lymphocytes, monocytes, polymorphonuclear leukocytes, as they exhibit tropism for cells of mesenchymal origin. When the infection is reactivated, the virus is reproduced in cells of ectodermal origin, which leads to characteristic organ lesions. Type 6 and 7 viruses are both neurotropic and lymphotropic. They are capable to infect T-lymphocytes, B-lymphocytes, epithelial cells, endothelial cells, hepatocytes, fibroblasts, glial cells, stem cells, monocytes, macrophages, leukocytes, etc. They are able to promote the reactivation of other viruses, forming mixed forms, which leads to an aggravation of the clinical picture of the disease. Therapy of herpesvirus infections should be scientifically grounded, consistent, gradual, complex and include: specific antiviral treatment; immunotherapy; antibacterial therapy; detoxification therapy; symptomatic treatment and therapeutic measures aimed to eliminate various complications. Antiviral drugs for the treatment of herpes infection are divided into 4 groups: nucleoside analogs; drugs that cause the destruction of viruses located extracellularly; drugs that are active against intracellular viruses; drugs with a double effect. Modern therapy of herpesvirus infections is capable to suppress the reproductive activity of the reactivated virus, modulate the body's immune response, prevent and eliminate various complications of herpes infections, but is unable to affect the latent form of viruses. In the complex therapy of herpes infection, along with the specific treatment methods aimed to destroy the virus and to enhance the body's immunity, it is necessary to apply the entire range of therapeutic measures that help eliminate the accompanying symptoms and complications of diseases caused by herpesviruses

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Eldon, Bjarki. "Evolutionary Genomics of High Fecundity." Annual Review of Genetics 54, no. 1 (November 23, 2020): 213–36. http://dx.doi.org/10.1146/annurev-genet-021920-095932.

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Natural highly fecund populations abound. These range from viruses to gadids. Many highly fecund populations are economically important. Highly fecund populations provide an important contrast to the low-fecundity organisms that have traditionally been applied in evolutionary studies. A key question regarding high fecundity is whether large numbers of offspring are produced on a regular basis, by few individuals each time, in a sweepstakes mode of reproduction. Such reproduction characteristics are not incorporated into the classical Wright–Fisher model, the standard reference model of population genetics, or similar types of models, in which each individual can produce only small numbers of offspring relative to the population size. The expected genomic footprints of population genetic models of sweepstakes reproduction are very different from those of the Wright–Fisher model. A key, immediate issue involves identifying the footprints of sweepstakes reproduction in genomic data. Whole-genome sequencing data can be used to distinguish the patterns made by sweepstakes reproduction from the patterns made by population growth in a population evolving according to the Wright–Fisher model (or similar models). If the hypothesis of sweepstakes reproduction cannot be rejected, then models of sweepstakes reproduction and associated multiple-merger coalescents will become at least as relevant as the Wright–Fisher model (or similar models) and the Kingman coalescent, the cornerstones of mathematical population genetics, in further discussions of evolutionary genomics of highly fecund populations.

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Yang, Hyun Mo. "Comparison between chikungunya and dengue viruses transmission based on a mathematical model." International Journal of Biomathematics 10, no. 06 (April 4, 2017): 1750087. http://dx.doi.org/10.1142/s1793524517500875.

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Chikungunya and dengue viruses are transmitted by mosquitoes of genus Aedes. Based on a mathematical model dealing with arboviruses transmission that encompasses human and mosquito populations, the risks of dengue and chikungunya infections are compared. By the fact that chikungunya virus attains high viral load earlier than dengue virus in both humans and mosquitoes, the potential risk of chikungunya could be higher than the dengue infection. The risk of arboviruses infections is assessed by the reproduction number [Formula: see text], which is obtained by the next generation matrix method and Routh–Hurwitz criteria.

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Fediakina, I. T., M. V. Konopleva, E. S. Proshina, E. V. Linnik, and N. I. Nikitina. "ANTIVIRAL EFFECT OF «KAGOCEL» SUBSTANCE IN VITRO ON INFLUENZA VIRUSES H1N1, H1N1PDM09 AND H3N2." Problems of Virology, Russian journal 64, no. 3 (June 20, 2019): 125–31. http://dx.doi.org/10.18821/0507-4088-2019-64-3-125-131.

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Introduction. Active circulation of pandemic influenza and new variants of influenza H3N2 strains requires monitoring of antiviral efficacy of drugs permitted for influenza therapy in the Russian Federation. Purpose. Assessment of antiviral efficacy of «Kagocel» substance against influenza viruses H1N1, H1N1pdm09 and H3N2 in vitro. Material and methods. Cytotoxic effect of «Kagocel» substance on MDCK cells had been determined by stained with MTS. Antiviral efficacy of «Kagocel» substance against influenza infection has been studied in vitro in the culture of MDCK cells infected with influenza virus strains: A/Puerto Rico/8/34 (H1N1), А/California/7/2009 (H1N1)pdm09, А/Hong Kong/1/68 (H3N2) and А/Hong Kong/4801/2014 (H3N2). The antiviral activity of «Kagocel» substance was tested by its effect on the infectious titer of the influenza viruses and on its impact on the expression level of viral antigens in the enzyme immunoassay test system. Results. «Kagocel» substance had low toxicity for MDCK cells. «Kagocel» inhibited the infection titer of influenza virus strains A/Puerto Rico/8/34 (H1N1), А/California/7/2009 (H1N1)pdm09, А/Hong Kong/1/68 (H3N2) and А/ Hong Kong /4801/2014 (H3N2) in the MDCK cell culture with equal efficacy. Study of the impact of «Kagocel» substance on the expression level of viral antigens by ELISA also revealed its antiviral efficacy for all tested strains. Dose dependence was observed from concentration of substance and from infective dose of virus. Discussion. Effective suppression of the reproduction of influenza virus strains A(H1N1), A(Н1N1)pdm09 and A(H3N2) in the different sublines of MDCK cells with «Kagocel» was shown by the different methods. These results give the possibility to suggest that along with the ability to induce interferons, «Kagocel» can impact on the reproduction of influenza virus, but the further research is needed. Conclusion. «Kagocel» substance effectively inhibits the reproduction of influenza virus strains A(H1N1), A(Н1N1)pdm09 and A(H3N2) in vitro. At the same time, the selectivity index is quite high.

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Nifong, Rachel L., and James F. Gillooly. "Temperature effects on virion volume and genome length in dsDNA viruses." Biology Letters 12, no. 3 (March 2016): 20160023. http://dx.doi.org/10.1098/rsbl.2016.0023.

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Heterogeneity in rates of survival, growth and reproduction among viruses is related to virus particle (i.e. virion) size, but we have little understanding of the factors that govern the four to five orders of magnitude in virus size variation. Here, we analyse variation in virion size in 67 double-stranded DNA viruses (i.e. dsDNA) that span all major biomes, and infect organisms ranging from single-celled prokaryotes to multicellular eukaryotes. We find that two metrics of virion size (i.e. virion volume and genome length) decrease by about 55-fold as the temperature of occurrence increases from 0 to 40°C. We also find that gene overlap increases exponentially with temperature, such that smaller viruses have proportionally greater gene overlap at higher temperatures. These results indicate dsDNA virus size increases with environmental temperature in much the same way as the cell or genome size of many host species.

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Chadsuthi, Sudarat, and Surapa Wichapeng. "The Modelling of Hand, Foot, and Mouth Disease in Contaminated Environments in Bangkok, Thailand." Computational and Mathematical Methods in Medicine 2018 (June 3, 2018): 1–8. http://dx.doi.org/10.1155/2018/5168931.

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Hand, foot, and mouth disease (HFMD) has spread widely in a continuing endemic in Thailand. There are no specific vaccines or antiviral treatments available that specifically target HFMD. Indirect transmission via free-living viruses from the environment may influence HFMD infections because the virus can survive for long periods in the environment. In this study, a new mathematical model is proposed to investigate the effect of indirect transmission from contaminated environments and the impact of asymptomatic individuals. By fitting our model to reported data on hospitalized individuals of HFMD endemic in Bangkok, Thailand, 2016, the basic reproduction number was estimated as 1.441, which suggests that the disease will remain under current conditions. Numerical simulations show that the direct transmission from asymptomatic individuals and indirect transmission via free-living viruses are important factors which contribute to new HFMD infections. Sensitivity analysis indicates that the basic reproduction number is sensitive to the transmission rate of asymptomatic and symptomatic subgroups and indirect transmission. Our findings suggest that cleaning the environment frequently and healthcare precautions which include the reduction of direct transmission rates should be promoted as effective control strategies for preventing the HFMD spread.

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Sarbasov, A. B., B. L. Manin, R. V. Yashin, I. N. Shumilova, and V. I. Diev. "TESTING SHEEP AND GOAT POX VIRUSES FOR THEIR REPRODUCTION IN PRIMARY AND SUBCULTURED CELLS." Veterinary Science Today, no. 2 (June 28, 2019): 35–40. http://dx.doi.org/10.29326/2304-196x-2019-2-29-35-40.

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Results of tests of sheep and goat poxviruses for their reproduction in primary and subcultured cell cultures derived from lamb and goat kid kidneys and testicles are presented. Monolayer cultures were subcultured by 5 passages in plastic vials and infected with sheep and goat poxviruses. It was shown that production ARRIAH strain of sheep pox virus and ARRIAH 2003 strain of goat pox virus successfully propagated both in primary lamb and goat kid kidney and testicle cell cultures and lamb and goat kid kidney and testicle cell subcultures. Activity of sheep and goat poxviruses passaged 5 times was 5.5–6.0 lg TCID50/cm3. Taking into account that modern cell cultivation conditions allow primary trypsinized cell populations subcultivation up to 25–30th passage, subcultures together with continuous cell lines can be used for large-scale sheep and goat poxvirus production and research purposes.

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Kontarov, N. A., S. A. Grishunina, N. V. Balaev, N. V. Yuminova, and V. V. Zverev. "THE STUDY OF VIRUSES REPRODUCTION IN CELL CULTURES BY THE METHOD OF MATHEMATICAL MODELING." Russian Journal of Infection and Immunity 3, no. 4 (July 9, 2014): 376. http://dx.doi.org/10.15789/2220-7619-2013-4-376-378.

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Kazakova, O. B., N. I. Medvedeva, I. P. Baikova, G. A. Tolstikov, T. V. Lopatina, M. S. Yunusov, and L. Zaprutko. "Synthesis of triterpenoid acylates: Effective reproduction inhibitors of influenza A (H1N1) and papilloma viruses." Russian Journal of Bioorganic Chemistry 36, no. 6 (November 2010): 771–78. http://dx.doi.org/10.1134/s1068162010060142.

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Holder, K. Kichler, and J. J. Bull. "Profiles of Adaptation in Two Similar Viruses." Genetics 159, no. 4 (December 1, 2001): 1393–404. http://dx.doi.org/10.1093/genetics/159.4.1393.

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AbstractThe related bacteriophages ϕX174 and G4 were adapted to the inhibitory temperature of 44° and monitored for nucleotide changes throughout the genome. Phage were evolved by serial transfer at low multiplicity of infection on rapidly dividing bacteria to select genotypes with the fastest rates of reproduction. Both phage showed overall greater fitness effects per substitution during the early stages of adaptation. The fitness of ϕX174 improved from −0.7 to 5.6 doublings of phage concentration per generation. Five missense mutations were observed. The earliest two mutations accounted for 85% of the ultimate fitness gain. In contrast, G4 required adaptation to the intermediate temperature of 41.5° before it could be maintained at 44°. Its fitness at 44° increased from −2.7 to 3.2, nearly the same net gain as in ϕX174, but with three times the opportunity for adaptation. Seventeen mutations were observed in G4: 14 missense, 2 silent, and 1 intergenic. The first 3 missense substitutions accounted for over half the ultimate fitness increase. Although the expected pattern of periodic selective sweeps was the most common one for both phage, some mutations were lost after becoming frequent, and long-term polymorphism was observed. This study provides the greatest detail yet in combining fitness profiles with the underlying pattern of genetic changes, and the results support recent theories on the range of fitness effects of substitutions fixed during adaptation.

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Мацкевич, О. В. "MICROCLONAL REPRODUCTION OF HAZELNUTS." Bulletin of Uman National University of Horticulture 1 (August 2022): 106–15. http://dx.doi.org/10.31395/2310-0478-2022-1-106-115.

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For the rapid introduction of large quantities of high-quality hazelnut planting material, it is important to use various modifications of microclonal propagation: classic on gel media, bioreactors with periodic flooding (TiS) and photoautotrophic methods. At the first stage of classical methods there are three main problems: phenol formation; endogenous contamination; selection of trophic and hormonal determinants of in vitro ontogenesis. In cases of infection of mother plants with viruses, viroids, it is mandatory to use meristem explants with a size of not more than 0.3 mm, followed by diagnosis of the effectiveness of recovery. To prevent self-intoxication with phenol-like oxidation products, a set of measures is used to prepare explant donors and modify nutrient media. The most common artificial nutrient media are Driver and Buzzard (DKW) and Nas and Read (NRM). Hazelnuts are sensitive to excess nitrogen and calcium and copper deficiency in artificial nutrient media. On media with a high N content, regenerants have shortened and thickened shoots, often with signs of hypehydration. Inhibition of calcium uptake by nitrogen leads to necrotization of shoot tips and root tips. The incorporation of iron ions into the metabolism of a plant depends on their valence and the form of chelating agents. During the multiplication and induction of rhizogenesis in aseptic conditions, mainly synthetic cytokinin benzylaminopurine and auxin indolylbutyric acid are used. The effectiveness of hormones increases with the use of combinations within groups, in particular cytokinins are benzylaminopurine and kinetin. At the stage of multiplication there is a predominance of cytokinins over auxins, and at the stage of rhizogenesis the number of auxins in the environment is greater than the number of cytokinins. Of the organic components, vitamins B1, B6, C, PP, amino acids and inositol are added to the environment. Ex vitro acclimatization of plants is carried out on peat-pearlite substrates in closed soil or modules of photoautrophic microclonal propagation with increased light intensity and high carbon dioxide content. The photoautotrophic method combines animation, rhizogenesis and acclimatization at the same time. The effectiveness of adaptation to factor-nestatic conditions increases with mycorrhizae by fungi of the genera Glomus, Trichoderma, Tuber in the transfer of plants from aseptic conditions.

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Kalinina, O. S. "Таксономічна характеристика РНК-геномних вірусів хребетних тварин і людини." Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 19, no. 78 (April 7, 2017): 30–35. http://dx.doi.org/10.15421/nvlvet7807.

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The article presents a modern taxonomy and nomenclature of viruses of vertebrates animals and human based on information ICTV release 2016 (ratification 2017). Described the basic criteria for the classification of viruses: characteristics of the viral genome, the mechanism of replication and virions structure. Viruses of vertebrates (1269 species) consist of 5 orders, 38 families, including 12 – DNA-genomic and 26 – RNA-genomic, 12 subfamilies and 233 genera. RNA-genomic viruses of vertebrates (679 species) classified of 4 orders, 26 families, 6 subfamilies and 119 genera. The order Mononegavirales has united family Paramyxoviridae, Pneumoviridae, Rhabdoviridae, Filoviridae, Bornaviridae, Nyamiviridae and Sunviridae, order Nidovirales – family Coronaviridae and Arteriviridae, order Bunyavirales –family Hantaviridae, Nairoviridae, Peribunyaviridae and Phenuiviridae, order Picornavirales – family Picornaviridae. Family Rhabdoviridae, Nodaviridae, Peribunyaviridae, Phenuiviridae, Reoviridae and Birnaviridae, except viruses of vertebrates, contain viruses of insects, and family Rhabdoviridae, Phenuiviridae and Reoviridae – viruses of plants. There is а one of «floating» genus Deltavirus, which is not included of families. The family Reoviridae includes the Eriocheir sinensis reovirus, and the family Birnaviridae – Tellina virus. Described the taxa of viruses: family, subfamily, genera, species. Named typical species genera of viruses. Characterized the basic taxonomic features of RNA-genomic vertebrates viruses of animals and human: the shape, size and structure of virions – the presence of outer membrane lipoprotein, capsid symmetry type (spiral, icosahedral), the structure of the viral RNA (the number of threads, conformation, fragmentation, polarity). The attention to virus reproduction features. Replication of most RNA-genomic viruses occurs in cells of the cytoplasm, except for the representatives of the families Bornaviridae, Nyamiviridae, Orthomyxoviridae, Retroviridae and «floating» genus Deltavirus, which are replicated in the nucleus. Output of the progeny virions in simply organized viruses is due to cell destruction, and in most of the complexly organized viruses – plasma membrane buds, as well as through the membranes of the Golgi complex or the endoplasmic net in combination with exocytosis (Peribunyaviridae, Hantaviridae, Nairoviridae, Phenuiviridae, Flaviviridae, Coronaviridae, Arteriviridae).

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Journal articles on the topic 'Viruses – Reproduction'

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