Artigos de revistas: "Virus – Reproduction (biologie)"

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Kennedy, Anissa, Jacob Herman e Olav Rueppell. "Reproductive activation in honeybee ( Apis mellifera ) workers protects against abiotic and biotic stress". Philosophical Transactions of the Royal Society B: Biological Sciences 376, n.º 1823 (8 de março de 2021): 20190737. http://dx.doi.org/10.1098/rstb.2019.0737.

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Social insect reproductives exhibit exceptional longevity instead of the classic trade-off between somatic maintenance and reproduction. Even normally sterile workers experience a significant increase in life expectancy when they assume a reproductive role. The mechanisms that enable the positive relation between the antagonistic demands of reproduction and somatic maintenance are unclear. To isolate the effect of reproductive activation, honeybee workers were induced to activate their ovaries. These reproductively activated workers were compared to controls for survival and gene expression patterns after exposure to Israeli Acute Paralysis Virus or the oxidative stressor paraquat. Reproductive activation increased survival, indicating better immunity and oxidative stress resistance. After qPCR analysis confirmed our experimental treatments at the physiological level, whole transcriptome analysis revealed that paraquat treatment significantly changed the expression of 1277 genes in the control workers but only two genes in reproductively activated workers, indicating that reproductive activation preemptively protects against oxidative stress. Significant overlap between genes that were upregulated by reproductive activation and in response to paraquat included prominent members of signalling pathways and anti-oxidants known to affect ageing. Thus, while our results confirm a central role of vitellogenin, they also point to other mechanisms to explain the molecular basis of the lack of a cost of reproduction and the exceptional longevity of social insect reproductives. Thus, socially induced reproductive activation preemptively protects honeybee workers against stressors, explaining their longevity. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?'

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Uddin, Mohammed Nizam, Sofi Mahmud Parvez, H. M. Shahadat Ali, Muhammad Samsuddin e A. N. M. Rezaul Karim. "Mathematical modeling on the transmission of COVID-19 and its reproduction numbers in SAARC countries". Journal of Applied and Natural Science 14, n.º 2 (18 de junho de 2022): 469–76. http://dx.doi.org/10.31018/jans.v14i2.3398.

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In the middle of December 2019, a virus known as coronavirus (COVID-19) generated by severe acute respiratory syndrome corona virus 2 (SARC-CoV-2) was first detected in Wuhan, Hubei Province, China. As of the 9th of March, 2022, spread to over 212 countries, causing 429 million confirmed cases and 6 million people to lose their lives worldwide. In developing countries like the South Asian area, alarming dynamic variations in the pattern of confirmed cases and death tolls were displayed. During epidemics, accurate assessment of the characteristics that characterize infectious disease transmission is critical for optimizing control actions, planning, and adapting public health interventions. The reproductive number, or the typical number of secondary cases caused by an infected individual, can be employed to determine transmissibility. Several statistical and mathematical techniques have been presented to calculate across the duration of an epidemic. A technique is provided for calculating epidemic reproduction numbers. It is a MATLAB version of the EpiEstim package's R function estimate R, version 2.2-3. in the South Asian Association for Regional Cooperation (SAARC) countries. The three methodologies supported are 'parametric SI,' 'non-parametric SI,' and 'uncertain SI.' The present study indicated that the highest reproduction number was 12.123 and 11.861 on 5th and 14th March 2020 in India and Sri_Lanka, whereas the lowest reproduction number was the lowest was 0.300 and 0.315 in Sri_Lanka and India. The Maximum and minimum reproductive number of Bangladesh was 3.752 and 0.725. In this study, we have tried to point out the worst, best and current situation of SAARC countries.

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G, Gulothungan, Vickram A S e 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, n.º 5 (31 de outubro de 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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MANDELBROT, LAURENT, e ROGER HENRION. "Human Immunodeficiency Virus and Reproduction". Annals of the New York Academy of Sciences 626, n.º 1 Frontiers in (junho de 1991): 484–501. http://dx.doi.org/10.1111/j.1749-6632.1991.tb37941.x.

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Valansi, Clari, David Moi, Evgenia Leikina, Elena Matveev, Martín Graña, Leonid V. Chernomordik, Héctor Romero, Pablo S. Aguilar e Benjamin Podbilewicz. "Arabidopsis HAP2/GCS1 is a gamete fusion protein homologous to somatic and viral fusogens". Journal of Cell Biology 216, n.º 3 (30 de janeiro de 2017): 571–81. http://dx.doi.org/10.1083/jcb.201610093.

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Cell–cell fusion is inherent to sexual reproduction. Loss of HAPLESS 2/GENERATIVE CELL SPECIFIC 1 (HAP2/GCS1) proteins results in gamete fusion failure in diverse organisms, but their exact role is unclear. In this study, we show that Arabidopsis thaliana HAP2/GCS1 is sufficient to promote mammalian cell–cell fusion. Hemifusion and complete fusion depend on HAP2/GCS1 presence in both fusing cells. Furthermore, expression of HAP2 on the surface of pseudotyped vesicular stomatitis virus results in homotypic virus–cell fusion. We demonstrate that the Caenorhabditis elegans Epithelial Fusion Failure 1 (EFF-1) somatic cell fusogen can replace HAP2/GCS1 in one of the fusing membranes, indicating that HAP2/GCS1 and EFF-1 share a similar fusion mechanism. Structural modeling of the HAP2/GCS1 protein family predicts that they are homologous to EFF-1 and viral class II fusion proteins (e.g., Zika virus). We name this superfamily Fusexins: fusion proteins essential for sexual reproduction and exoplasmic merger of plasma membranes. We suggest a common origin and evolution of sexual reproduction, enveloped virus entry into cells, and somatic cell fusion.

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Rybalko, S., N. Nesterova, S. Diadiun, G. Danylenko, V. Danylenko, S. Guzhova, Y. Maksimov et al. "Therapeutical effect of modified adamantane copolymer compounds: study of molecular mechanisms." Acta Biochimica Polonica 48, n.º 1 (31 de março de 2001): 241–49. http://dx.doi.org/10.18388/abp.2001_5132.

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Copolymers of N-polyvinylpyrrolidone-acrylic acid (AB-1) and adamantane derivatives are known to possess marked antiviral activity in in vitro and in ovo models. Among the constructed preparations of AB-1 modified by adamantane derivatives some, especially AB-4 (modified by deitiforin), were found to show more extended antiviral activity and to inhibit markedly virus reproduction in susceptible permissive cell cultures and chicken embryos. In AB-4 treated cells and allantoic sacs, virus titers (influenza virus, herpes virus, and HIV) and virus antigen concentration were decreased. On the other hand, herpes virus-specific thymidine kinase and of DNA-polymerases isolated from Escherichia coli, Plectonema boryanum, and herpes virus type 1 infected murine brain tissue retained their activity after incubation with AB-4 or AB-2. The compounds investigated, in view of their effect on virus reproduction, are thought to be prospective as antiviral agents.

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Harb, Julien, Nour Debs, Mohamad Rima, Yingliang Wu, Zhijian Cao, Hervé Kovacic, Ziad Fajloun e Jean-Marc Sabatier. "SARS-CoV-2, COVID-19, and Reproduction: Effects on Fertility, Pregnancy, and Neonatal Life". Biomedicines 10, n.º 8 (22 de julho de 2022): 1775. http://dx.doi.org/10.3390/biomedicines10081775.

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Since its discovery in Wuhan, China, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread over the world, having a huge impact on people’s lives and health. The respiratory system is often targeted in people with the coronavirus disease 2019 (COVID-19). The virus can also infect many organs and tissues in the body, including the reproductive system. The consequences of the SARS-CoV-2 infection on fertility and pregnancy in hosts are poorly documented. Available data on other coronaviruses, such as severe acute respiratory syndrome (SARS-CoV) and Middle Eastern Respiratory Syndrome (MERS-CoV) coronaviruses, identified pregnant women as a vulnerable group with increased pregnancy-related complications. COVID-19 was also shown to impact pregnancy, which can be seen in either the mother or the fetus. Pregnant women more likely require COVID-19 intensive care treatment than non-pregnant women, and they are susceptible to giving birth prematurely and having their newborns admitted to the neonatal intensive care unit. Angiotensin converting enzyme 2 (ACE2), a key player of the ubiquitous renin-angiotensin system (RAS), is the principal host cellular receptor for SARS-CoV-2 spike protein. ACE2 is involved in the regulation of both male and female reproductive systems, suggesting that SARS-CoV-2 infection and associated RAS dysfunction could affect reproduction. Herein, we review the current knowledge about COVID-19 consequences on male and female fertility, pregnant women, and their fetuses. Furthermore, we describe the effects of COVID-19 vaccination on reproduction.

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Urnovitz, H. B., e W. H. Murphy. "Human endogenous retroviruses: nature, occurrence, and clinical implications in human disease." Clinical Microbiology Reviews 9, n.º 1 (janeiro de 1996): 72–99. http://dx.doi.org/10.1128/cmr.9.1.72.

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Retroviral diagnostics have become standard in human laboratory medicine. While current emphasis is placed on the human exogenous viruses (human immunodeficiency virus and human T-cell leukemia virus), evidence implicating human endogenous retroviruses (HERVs) in various human disease entities continues to mount. Literature on the occurrence of HERVs in human tissues and cells was analyzed. Substantial evidence documents that retrovirus particles were clearly demonstrable in various tissues and cells in both health and disease and were abundant in the placenta and that their occurrence could be implicated in some of the reproductive diseases. The characteristics of HERVs are summarized, mechanisms of replication and regulation are outlined, and the consistent hormonal responsiveness of HERVs is noted. Clear evidence implicating HERV gene products as participants in glomerulonephritis in some cases of systemic lupus erythematosus is adduced. Data implicating HERVs as etiologic factors in reproductive diseases, in some of the autoimmune diseases, in some forms of rheumatoid arthritis and connective tissue disease, in psoriasis, and in some of the inflammatory neurologic diseases are reviewed. The current major needs are to improve methods for HERV detection, to identify the most appropriate HERV prototypes, and to develop diagnostic reagents so that the putative biologic and pathologic roles of HERVs can be better evaluated.

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Evdokimov, A. A., N. A. Mazurkova, E. G. Malygin, V. F. Zarytova, A. S. Levina, M. N. Repkova, S. N. Zagrebelnyi e N. A. Netesova. "Design of deoxyribozymes for inhibition of influenza a virus reproduction". Molecular Biology 47, n.º 1 (janeiro de 2013): 75–84. http://dx.doi.org/10.1134/s0026893312060040.

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Kabanov, A. V., A. V. Ovcharenko, N. S. Melik-Hubarov, A. I. Bannikov, V. Yu Alakhov, V. I. Kiselev, P. G. Sveshnikov, O. I. Kiselev, A. V. Levashov e E. S. Severin. "Fatty acid acylated antibodies against virus suppress its reproduction in cells". FEBS Letters 250, n.º 2 (3 de julho de 1989): 238–40. http://dx.doi.org/10.1016/0014-5793(89)80729-x.

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Frias-De-Diego, Alba, Jessica M. Gilbertie, Frank Scholle, Sarah Dejarnette e Elisa Crisci. "Effect of BIO-PLYTM, a Platelet-Rich Plasma Derived Biologic on PRRSV-2-Infected Macrophages". Viruses 14, n.º 12 (28 de novembro de 2022): 2666. http://dx.doi.org/10.3390/v14122666.

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Porcine Reproductive and Respiratory Syndrome (PRRS) is the one of the most devastating diseases impacting the swine industry worldwide. Control and prevention methods rely on biosafety measures and vaccination. As an RNA virus with a high rate of mutation, vaccines are only partially effective against circulating and newly emerging strains. To reduce the burden of this disease, research on alternative control methods is needed. Here, we assess the in vitro antiviral effect of a novel platelet-rich plasma-derived biologic termed BIO-PLYTM (for the BIOactive fraction of Platelet-rich plasma LYsate) from both swine and equine origin. Our results show that BIO-PLYTM significantly reduces the amount of PRRSV viral load determined by RT-qPCR and the number of infectious viral particles measured by TCID50 in infected porcine alveolar and parenchymal macrophages. This study also showed limited toxicity of BIO-PLYTM in vitro and aspects of its immunomodulatory capacity evaluating the regulation of reactive oxygen species and cytokines production in infected cells. Finally, this study presents promising data on the effect of BIO-PLYTM on other RNA viruses such as human A influenza viruses and coronavirus.

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Vinogradov, S. V., Y. Suzdaltseva, V. Y. Alakhov e A. V. Kabanov. "Inhibition of Herpes Simplex Virus 1 Reproduction with Hydrophobized Antisense Oligonucleotides". Biochemical and Biophysical Research Communications 203, n.º 2 (setembro de 1994): 959–66. http://dx.doi.org/10.1006/bbrc.1994.2275.

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Basurto-Alcántara, Francisco Javier, Rodolfo Lagunes-Quintanilla, Víctor Roldán-Rodríguez, Uriel Valdez-Espinoza e Ninnet Gómez-Romero. "Genetic characterization of bovine viral diarrhea virus detected in backyard cattle farms in Mexico". Mexican journal of biotechnology 7, n.º 4 (1 de outubro de 2022): 1–13. http://dx.doi.org/10.29267/mxjb.2022.7.4.1.

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Infection by bovine viral diarrhea virus (BVDV) in cattle remains a source of significant economic losses for livestock producers. This virus is classified within the Pestivirus genus, including three main species: Pestivirus A (BVDV-1), Pestivirus B (BVDV-2), and Pestivirus H (HoBi-like pestivirus). Here, we performed a molecular epidemiological investigation aiming to evaluate the genetic diversity of BVDV in cattle from backyard farms in a municipality in Mexico named Tepalcingo, Morelos, with records of reproductive disorders. RT-PCR was conducted in 111 serum samples from affected cattle. Viral RNA was detected in 47.74% of the samples analyzed. Sequencing and phylogenetic analysis based on 5'UTR showed that the circulating subgenotype was BVDV-1a in all positive samples. These findings reveal the prevalence of BVDV in the surveyed population; thus suggesting a possible association with the previous records of reproductive manifestation in the herd. However, further studies are needed to confirm BVDV as the causative agent. Additionally, our results represent a helpful tool for designing control and prevention strategies accurate to the current regional epidemiological situation. Moreover, obtained information from this type of epidemiological study will assist the implementation of biosafety measures on backyard farms with limited economic resources.

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Hula, N. M., A. A. Chumak, A. G. Berdyshev, G. V. Kosiakova, T. M. Goridko, O. F. Meged’, V. S. Asmolkova et al. "N-stearoylethanolamine - a new inhibitor of the hepatitis C virus reproduction". Biopolymers and Cell 37, n.º 3 (30 de junho de 2021): 167–76. http://dx.doi.org/10.7124/bc.000a54.

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Asfaw Wodajo, Firaol, e Temesgen Tibebu Mekonnen. "Mathematical model analysis and numerical simulation of intervention strategies to reduce transmission and re-activation of hepatitis B disease". F1000Research 11 (12 de agosto de 2022): 931. http://dx.doi.org/10.12688/f1000research.124234.1.

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Background: Because of its asymptomatic nature, the Hepatitis B Virus (HBV) has become the most lethal and silent killer. In this research, we offer HBV virus transmission characteristics in the form of a mathematical model. We suggested and examined a seven-compartment compartmental nonlinear deterministic mathematical model for transmission dynamics with immigration and HBV reactivation after recovery, as well as control measures for Hepatitis B virus disease transmission. By considering the following facts and cases, this work will provide new knowledge. First, re-infection of HBV after liver transplantation, chemotherapy, and other therapies is one of the most essential aspects in HBV transmission, although reactivation of HBV was not taken into account in some compartmental models of HBV transmission. Furthermore, the exposure rate, immigration rate, and level of infectiousness of the chronic infective class were not given enough weight in the numerical assessment of the force of HBV infection. These facts influenced the development of our model. Methods: We demonstrated that the solution of the dynamical system under consideration is positive and bounded. The effective reproductive number that represents the epidemic indicator is generated from the biggest eigenvalue of the netgeneration matrix, and the model is examined qualitatively using differential equation stability theory. For disease-free and endemic equilibria, both local and global asymptotic stability criteria are determined. Results: A full explanation of the parameters and their numerical findings is presented and debated well based on the numerical simulation. Conclusions: According to the findings of this study, vaccination and treatment interventions play a critical role in reducing HBV transmission and reproduction. It has also been demonstrated that HBV reactivation contributes significantly to an increase in theinfective population, which boosts virus transmission, and that a combination of vaccination and treatment will be the most effective strategy for controlling HBV infection and reinfection after recovery.

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Belavilas-Trovas, Alexandros, Spyros Tastsoglou, Shengzhang Dong, Mary Kefi, Mihra Tavadia, Kostas D. Mathiopoulos e George Dimopoulos. "Long non-coding RNAs regulate Aedes aegypti vector competence for Zika virus and reproduction". PLOS Pathogens 19, n.º 6 (15 de junho de 2023): e1011440. http://dx.doi.org/10.1371/journal.ppat.1011440.

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Long non-coding RNAs (lncRNAs) play critical regulatory roles in various cellular and metabolic processes in mosquitoes and all other organisms studied thus far. In particular, their involvement in essential processes such as reproduction makes them potential targets for the development of novel pest control approaches. However, their function in mosquito biology remains largely unexplored. To elucidate the role of lncRNAs in mosquitoes’ reproduction and vector competence for arboviruses, we have implemented a computational and experimental pipeline to mine, screen, and characterize lncRNAs related to these two biological processes. Through analysis of publicly available Zika virus (ZIKV) infection-regulated Aedes aegypti transcriptomes, at least six lncRNAs were identified as being significantly upregulated in response to infection in various mosquito tissues. The roles of these ZIKV-regulated lncRNAs (designated Zinc1, Zinc2, Zinc3, Zinc9, Zinc10 and Zinc22), were further investigated by dsRNA-mediated silencing studies. Our results show that silencing of Zinc1, Zinc2, and Zinc22 renders mosquitoes significantly less permissive to ZIKV infection, while silencing of Zinc22 also reduces fecundity, indicating a potential role for Zinc22 in trade-offs between vector competence and reproduction. We also found that silencing of Zinc9 significantly increases fecundity but has no effect on ZIKV infection, suggesting that Zinc9 may be a negative regulator of oviposition. Our work demonstrates that some lncRNAs play host factor roles by facilitating viral infection in mosquitoes. We also show that lncRNAs can influence both mosquito reproduction and permissiveness to virus infection, two biological systems with important roles in mosquito vectorial capacity.

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Zhang, Tongqian, Xinzhu Meng e Tonghua Zhang. "Global Dynamics of a Virus Dynamical Model with Cell-to-Cell Transmission and Cure Rate". Computational and Mathematical Methods in Medicine 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/758362.

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The cure effect of a virus model with both cell-to-cell transmission and cell-to-virus transmission is studied. By the method of next generation matrix, the basic reproduction number is obtained. The locally asymptotic stability of the virus-free equilibrium and the endemic equilibrium is considered by investigating the characteristic equation of the model. The globally asymptotic stability of the virus-free equilibrium is proved by constructing suitable Lyapunov function, and the sufficient condition for the globally asymptotic stability of the endemic equilibrium is obtained by constructing suitable Lyapunov function and using LaSalle invariance principal.

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Shved, A. D. "Polymicleothle inhibitors of virus reproduction (alkylated nucleic acids, antisensc RNAs and ribozyme)". Biopolymers and Cell 14, n.º 4 (20 de julho de 1998): 332–42. http://dx.doi.org/10.7124/bc.0004dd.

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Elaiw, A. M., R. M. Abukwaik e E. O. Alzahrani. "Global Stability of HIV Infection of CD4+T Cells and Macrophages with CTL Immune Response and Distributed Delays". Computational and Mathematical Methods in Medicine 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/653204.

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We study the global stability of a human immunodeficiency virus (HIV) infection model with Cytotoxic T Lymphocytes (CTL) immune response. The model describes the interaction of the HIV with two classes of target cells, CD4+T cells and macrophages. Two types of distributed time delays are incorporated into the model to describe the time needed for infection of target cell and virus replication. Using the method of Lyapunov functional, we have established that the global stability of the model is determined by two threshold numbers, the basic reproduction numberR0and the immune response reproduction numberR0∗. We have proven that, ifR0≤1, then the uninfected steady state is globally asymptotically stable (GAS), ifR0*≤1<R0, then the infected steady state without CTL immune response is GAS, and, ifR0*>1, then the infected steady state with CTL immune response is GAS.

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Zhou, Ao, e Shujun Zhang. "Regulation of cell signaling and porcine reproductive and respiratory syndrome virus". Cellular Signalling 24, n.º 5 (maio de 2012): 973–80. http://dx.doi.org/10.1016/j.cellsig.2012.01.004.

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Abiodun, Oluwakemi E., Olukayode Adebimpe, James Ndako, Olajumoke Oludoun, Benedicta Aladeitan e Michael Adeniyi. "Qualitative analysis of HIV and AIDS disease transmission: impact of awareness, testing and effective follow up". F1000Research 11 (7 de outubro de 2022): 1145. http://dx.doi.org/10.12688/f1000research.123693.1.

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Background: Since the early 1980s, human immunodeficiency virus (HIV) and its accompanying acquired immunodeficiency syndrome (AIDS) have spread worldwide, becoming one of the world's major global health issues. From the beginning of the epidemic until 2020, about 79.3 million people became infected, with 36.3 million deaths due to AIDS illnesses. This huge figure is a result of those unaware of their status due to stigmatization and invariably spreading the virus unknowingly. Methods: Qualitative analysis through a mathematical model that will address HIV unaware individuals and the effect of an increasing defaulter on the dynamics of HIV/AIDS was investigated. The impact of treatment and the effect of inefficient follow-up on the transmission of HIV/AIDS were examined. The threshold for the effective reduction of the unaware status of HIV through testing, in response to awareness, and the significance of effective non-defaulting in treatment commonly called defaulters loss to follow-up as these individuals contribute immensely to the spread of the virus due to their increase in CD4+ count was determined in this study. Stability analysis of equilibrium points is performed using the basic reproduction number $R_0$, an epidemiological threshold that determines disease eradication or persistence in viral populations. We tested the most sensitive parameters in the basic reproduction numbers. The model of consideration in this study is based on the assumption that information (awareness) and non-stigmatization can stimulate change in the behaviours of infected individuals, and can lead to an increase in testing and adherence to treatment. This will in turn reduce the basic reproduction number, and consequently, the spread of the virus. Results: The results portray that the early identification and treatment are inadequate for the illness to be eradicated. Conclusions: Other control techniques, such as treatment adherence and effective condom usage, should be investigated in order to lessen the disease's burden.

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Mateusen, B., A. Van Soom, D. G. D. Maes, H. Favoreel e H. J. Nauwynck. "Receptor-Determined Susceptibility of Preimplantation Embryos to Pseudorabies Virus and Porcine Reproductive and Respiratory Syndrome Virus". Biology of Reproduction 76, n.º 3 (1 de março de 2007): 415–23. http://dx.doi.org/10.1095/biolreprod.106.056697.

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Doan, Danny N. P., e Terje Dokland. "Structure of the Nucleocapsid Protein of Porcine Reproductive and Respiratory Syndrome Virus". Structure 11, n.º 11 (novembro de 2003): 1445–51. http://dx.doi.org/10.1016/j.str.2003.09.018.

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Teklu, Shewafera Wondimagegnhu. "Analysis of HBV and COVID-19 Coinfection Model with Intervention Strategies". Computational and Mathematical Methods in Medicine 2023 (29 de setembro de 2023): 1–17. http://dx.doi.org/10.1155/2023/6908757.

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Coinfection of hepatitis B virus (HBV) and COVID-19 is a common public health problem throughout some nations in the world. In this study, a mathematical model for hepatitis B virus (HBV) and COVID-19 coinfection is constructed to investigate the effect of protection and treatment mechanisms on its spread in the community. Necessary conditions of the proposed model nonnegativity and boundedness of solutions are analyzed. We calculated the model reproduction numbers and carried out the local stabilities of disease-free equilibrium points whenever the associated reproduction number is less than unity. Using the well-known Castillo-Chavez criteria, the disease-free equilibrium points are shown to be globally asymptotically stable whenever the associated reproduction number is less than unity. Sensitivity analysis proved that the most influential parameters are transmission rates. Moreover, we carried out numerical simulation and shown results: some parameters have high spreading effect on the disease transmission, single infections have great impact on the coinfection transmission, and using protections and treatments simultaneously is the most effective strategy to minimize and also to eradicate the HBV and COVID-19 coinfection spreading in the community. It is concluded that to control the transmission of both diseases in a population, efforts must be geared towards preventing incident infection with either or both diseases.

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Danane, Jaouad, e Karam Allali. "Mathematical Analysis and Clinical Implications of an HIV Model with Adaptive Immunity". Computational and Mathematical Methods in Medicine 2019 (16 de novembro de 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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Hernández-Sánchez, Brenda, Ericka Santacruz-Juárez, David Moore e Carmen Sánchez. "Bioactive compounds from fungi with antiviral activities: Mechanism of action and biosynthetic pathways". Mexican journal of biotechnology 6, n.º 1 (11 de janeiro de 2021): 165–89. http://dx.doi.org/10.29267/mxjb.2021.6.1.165.

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Viral infections have affected human health, causing critical pandemics and mortality worldwide. Viruses can also cause enormous economic problems for society globally. Bioactive compounds isolated from fungi (both edible and nonedible) have shown potential activity against viruses. In this review, we describe the fungal natural compounds that have exhibited capability to inhibit some human pathogenic viruses, such as human immunodeficiency virus, dengue virus, herpes simplex virus, bovine herpes virus, influenza virus, respiratory syndrome virus, hepatitis virus among others. We focused on the biosynthetic pathways of fungal bioactive compounds and addressed the current knowledge about their antiviral mechanisms of action and specific targets. Fungal bioactive compounds are able to inhibit viral reproduction, blocking viral penetration, replication or translation as well as integrase or protease action. Fungal compounds able to inhibit protease such as. ganodermatriol, ergosterol, terpenoids, ganoderic acid GS-2, ganoderiol, sterigmatocystin, emericellin, cordycepin, ergosterol peroxide, myristic acid among others, may have a significant value to society at present, as they may have the potential to treat severe viral respiratory infections. Fungi represent a potential natural source of bioactive molecules that can be exploited for treating viral infections, which represent one of the main causes of disease worldwide. However, extensive investigations on clinical trials are required for the introduction of new antiviral agents into the market.

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Ferguson, Neil M., Christl A. Donnelly e Roy M. Anderson. "Transmission dynamics and epidemiology of dengue: insights from age–stratified sero–prevalence surveys". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, n.º 1384 (29 de abril de 1999): 757–68. http://dx.doi.org/10.1098/rstb.1999.0428.

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The relationship between infection with the four major serotypes of dengue virus and the occurrence of different forms of disease is complex and not fully understood. Interpreting longitudinal records of the incidence of serious disease to gain insight into the transmission dynamics and epidemiology of the virus is therefore complicated. Since age reflects duration of exposure, age–stratified, strain–specific serological surveys carried out at one point in time, or over a short time interval, can potentially provide a rich source of information on longitudinal patterns. This paper describes the development and application (to data collected in Thailand) of statistically rigorous methods designed to estimate time–varying, strain–specific forces of infection, and thus basic reproduction numbers, from cross–sectional serological data. The analyses provide support for the hypothesis that antibody– dependent enhancement of transmission influences observed epidemiological pattern. Age–stratified serological data also reveal evidence of a propensity for the annual incidence of infection to oscillate over time with a frequency of several years. The latter observation is consistent with the predictions of simple mathematical models of the transmission dynamics of the virus. The estimates of the basic reproduction numbers obtained are similar in magnitude for each dengue serotype, being in the range of four to six. Such values are higher than those obtained from earlier analyses, and the implications of this for dengue control are discussed.

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Forsberg, Roald. "Divergence Time of Porcine Reproductive and Respiratory Syndrome Virus Subtypes". Molecular Biology and Evolution 22, n.º 11 (6 de julho de 2005): 2131–34. http://dx.doi.org/10.1093/molbev/msi208.

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Slesarchuk, Nikita A., Evgeny V. Khvatov, Alexey A. Chistov, Gleb V. Proskurin, Timofei D. Nikitin, Anastasiya I. Lazarevich, Angelina A. Ulanovskaya et al. "Simplistic perylene-related compounds as inhibitors of tick-borne encephalitis virus reproduction". Bioorganic & Medicinal Chemistry Letters 30, n.º 10 (maio de 2020): 127100. http://dx.doi.org/10.1016/j.bmcl.2020.127100.

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Shtro, Anna A., Vladimir V. Zarubaev, Olga A. Luzina, Dmitry N. Sokolov, Oleg I. Kiselev e Nariman F. Salakhutdinov. "Novel derivatives of usnic acid effectively inhibiting reproduction of influenza A virus". Bioorganic & Medicinal Chemistry 22, n.º 24 (dezembro de 2014): 6826–36. http://dx.doi.org/10.1016/j.bmc.2014.10.033.

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Salinas, Dino G., M. Leonor Bustamante e Mauricio O. Gallardo. "Modelling quarantine effects on SARS-CoV-2 epidemiological dynamics in Chilean communes and their relationship with the Social Priority Index". PeerJ 11 (10 de março de 2023): e14892. http://dx.doi.org/10.7717/peerj.14892.

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Background An epidemiological model (susceptible, un-quarantined infected, quarantined infected, confirmed infected (SUQC)) was previously developed and applied to incorporate quarantine measures and calculate COVID-19 contagion dynamics and pandemic control in some Chinese regions. Here, we generalized this model to incorporate the disease recovery rate and applied our model to records of the total number of confirmed cases of people infected with the SARS-CoV-2 virus in some Chilean communes. Methods In each commune, two consecutive stages were considered: a stage without quarantine and an immediately subsequent quarantine stage imposed by the Ministry of Health. To adjust the model, typical epidemiological parameters were determined, such as the confirmation rate and the quarantine rate. The latter allowed us to calculate the reproduction number. Results The mathematical model adequately reproduced the data, indicating a higher quarantine rate when quarantine was imposed by the health authority, with a corresponding decrease in the reproduction number of the virus down to values that prevent or decrease its exponential spread. In general, during this second stage, the communes with the lowest social priority indices had the highest quarantine rates, and therefore, the lowest effective viral reproduction numbers. This study provides useful evidence to address the health inequity of pandemics. The mathematical model applied here can be used in other regions or easily modified for other cases of infectious disease control by quarantine.

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Andronova, V. L., e G. A. Galegov. "Comparative study of reproduction of sindbis virus sensitive and resistant to adamantane derivatives". Bulletin of Experimental Biology and Medicine 129, n.º 1 (janeiro de 2000): 74–77. http://dx.doi.org/10.1007/bf02433874.

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Schmidt, Jenna K., Katherine D. Mean, Riley C. Puntney, Eric S. Alexander, Ruth Sullivan, Heather A. Simmons, Xiankun Zeng, Andrea M. Weiler, Thomas C. Friedrich e Thaddeus G. Golos. "Zika virus in rhesus macaque semen and reproductive tract tissues: a pilot study of acute infection†". Biology of Reproduction 103, n.º 5 (6 de agosto de 2020): 1030–42. http://dx.doi.org/10.1093/biolre/ioaa137.

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Abstract Although sexual transmission of Zika virus (ZIKV) is well-documented, the viral reservoir(s) in the male reproductive tract remains uncertain in humans and immune-intact animal models. We evaluated the presence of ZIKV in a rhesus macaque pilot study to determine persistence in semen, assess the impact of infection on sperm functional characteristics, and define the viral reservoir in the male reproductive tract. Five adult male rhesus monkeys were inoculated with 105 PFU of Asian-lineage ZIKV isolate PRVABC59, and two males were inoculated with the same dose of African-lineage ZIKV DAKAR41524. Viremia and viral RNA (vRNA) shedding in semen were monitored, and a cohort of animals were necropsied for tissue collection to assess tissue vRNA burden and histopathology. All animals exhibited viremia for limited periods (1–11 days); duration of shedding did not differ significantly between viral isolates. There were sporadic low levels of vRNA in the semen from some, but not all animals. Viral RNA levels in reproductive tract tissues were also modest and present in the epididymis in three of five cases, one case in the vas deferens, but not detected in testis, seminal vesicles or prostate. ZIKV infection did not impact semen motility parameters as assessed by computer-assisted sperm analysis. Despite some evidence of prolonged ZIKV RNA shedding in human semen and high tropism of ZIKV for male reproductive tract tissues in mice deficient in Type 1 interferon signaling, in the rhesus macaques assessed in this pilot study, we did not consistently find ZIKV RNA in the male reproductive tract.

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Edogbanya, Helen O., Anselm O. Oyem, John O. Dominic e Jessica M. Gyegwe. "Dynamics of Hepatitis B Virus Disease with Infectious Latent and Vertical Transmission". WSEAS TRANSACTIONS ON BIOLOGY AND BIOMEDICINE 21 (16 de abril de 2024): 178–91. http://dx.doi.org/10.37394/23208.2024.21.19.

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Hepatitis B has become a major health threat because it is a life-threatening liver disease with an estimated 0.25 billion people suffering from this infectious disease worldwide. This paper presents a SLITR (Susceptible-Latent-Infectious-Treatment-Recovery) mathematical model that combines both vaccination and treatment as a means of controlling the hepatitis B virus (HBV). The nonlinear ordinary differential equations for the HBV transmission capacities were resolved and the basic reproduction number R0 computed using the next generation matrix method and simulated numerically using the Runge-Kutta fourth order scheme implemented using MatLab. The stability points for disease-free equilibrium state (DFE), endemic equilibrium state (EE), and basic reproduction number R0 were obtained and the results show that the disease-free equilibrium was both locally and globally asymptotically stable (R0<1) . Similarly, treatment or vaccine administered was effective in alleviating the spread of HBV disease, and when both control strategies are combined, the diseases are quickly controlled and eventually eradicated.

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Kim, Keun Il, Ming Yan, Oxana Malakhova, Jiann-Kae Luo, Mei-Feng Shen, Weiguo Zou, Juan Carlos de la Torre e Dong-Er Zhang. "Ube1L and Protein ISGylation Are Not Essential for Alpha/Beta Interferon Signaling". Molecular and Cellular Biology 26, n.º 2 (15 de janeiro de 2006): 472–79. http://dx.doi.org/10.1128/mcb.26.2.472-479.2006.

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ABSTRACT The expression of ubiquitin-like modifier ISG15 and its conjugation to target proteins are highly induced by interferon (IFN) stimulation and during viral and bacterial infections. However, the biological significance of this modification has not been clearly understood. To investigate the function of protein modification by ISG15, we generated a mouse model deficient in UBE1L, an ISG15-activating enzyme. Ube1L−/− mice did not produce ISG15 conjugates but expressed free ISG15 normally. ISGylation has been implicated in the reproduction and innate immunity. However, Ube1L−/− mice were fertile and exhibited normal antiviral responses against vesicular stomatitis virus and lymphocytic choriomeningitis virus infection. Our results indicate that UBE1L and protein ISGylation are not critical for IFN-α/β signaling via JAK/STAT activation. Moreover, using Ube1L/Ubp43 double-deficient mice, we showed that lack of UBP43, but not the increase of protein ISGylation, is related to the increased IFN signaling in Ubp43-deficient mice.

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Li, Zhiming, Zhidong Teng, Xiaomei Feng, Yingke Li e Huiguo Zhang. "Dynamical Analysis of an SEIT Epidemic Model with Application to Ebola Virus Transmission in Guinea". Computational and Mathematical Methods in Medicine 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/582625.

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In order to investigate the transmission mechanism of the infectious individual with Ebola virus, we establish an SEIT (susceptible, exposed in the latent period, infectious, and treated/recovery) epidemic model. The basic reproduction number is defined. The mathematical analysis on the existence and stability of the disease-free equilibrium and endemic equilibrium is given. As the applications of the model, we use the recognized infectious and death cases in Guinea to estimate parameters of the model by the least square method. With suitable parameter values, we obtain the estimated value of the basic reproduction number and analyze the sensitivity and uncertainty property by partial rank correlation coefficients.

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Lebkowski, J. S., M. M. McNally, T. B. Okarma e L. B. Lerch. "Adeno-associated virus: a vector system for efficient introduction and integration of DNA into a variety of mammalian cell types". Molecular and Cellular Biology 8, n.º 10 (outubro de 1988): 3988–96. http://dx.doi.org/10.1128/mcb.8.10.3988-3996.1988.

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Adeno-associated virus (AAV) is a single-stranded DNA parvovirus that is dependent on adenovirus or herpesvirus for reproductive functions. We describe the construction of recombinant AAV vectors containing the chloramphenicol acetyltransferase gene or the neomycin phosphotransferase gene. These vectors carried their respective genes into a wide variety of cell types, including primary skin fibroblasts and hematopoietic cells. Infection efficiencies varied with cell type and ranged up to 3.0%. Coinfection of two different recombinant viruses was also used to introduce two different sequences simultaneously into a given cell. Finally, methods for obtaining recombinant AAV vectors with minimal contamination of wild-type virus are described. These various attributes of AAV vectors make them a viable DNA transduction system.

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Zhou, Feng, Aojie Wang, Lu Chen, Xingang Wang, Dandan Cui, Hongtao Chang e Chuanqing Wang. "Isolation and phylogenetic analysis of Getah virus from a commercial modified live vaccine against porcine reproductive and respiratory syndrome virus". Molecular and Cellular Probes 53 (outubro de 2020): 101650. http://dx.doi.org/10.1016/j.mcp.2020.101650.

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Li, Guo-Li, Ying-Qian Han, Bing-Qian Su, Hai-Shen Yu, Shuang Zhang, Guo-Yu Yang, Jiang Wang, Fang Liu, Sheng-Li Ming e Bei-Bei Chu. "Porcine reproductive and respiratory syndrome virus 2 hijacks CMA-mediated lipolysis through upregulation of small GTPase RAB18". PLOS Pathogens 20, n.º 4 (12 de abril de 2024): e1012123. http://dx.doi.org/10.1371/journal.ppat.1012123.

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RAB GTPases (RABs) control intracellular membrane trafficking with high precision. In the present study, we carried out a short hairpin RNA (shRNA) screen focused on a library of 62 RABs during infection with porcine reproductive and respiratory syndrome virus 2 (PRRSV-2), a member of the family Arteriviridae. We found that 13 RABs negatively affect the yield of PRRSV-2 progeny virus, whereas 29 RABs have a positive impact on the yield of PRRSV-2 progeny virus. Further analysis revealed that PRRSV-2 infection transcriptionally regulated RAB18 through RIG-I/MAVS-mediated canonical NF-κB activation. Disrupting RAB18 expression led to the accumulation of lipid droplets (LDs), impaired LDs catabolism, and flawed viral replication and assembly. We also discovered that PRRSV-2 co-opts chaperone-mediated autophagy (CMA) for lipolysis via RAB18, as indicated by the enhanced associations between RAB18 and perlipin 2 (PLIN2), CMA-specific lysosomal associated membrane protein 2A (LAMP2A), and heat shock protein family A (Hsp70) member 8 (HSPA8/HSC70) during PRRSV-2 infection. Knockdown of HSPA8 and LAMP2A impacted on the yield of PRRSV-2 progeny virus, implying that the virus utilizes RAB18 to promote CMA-mediated lipolysis. Importantly, we determined that the C-terminal domain (CTD) of HSPA8 could bind to the switch II domain of RAB18, and the CTD of PLIN2 was capable of associating with HSPA8, suggesting that HSPA8 facilitates the interaction between RAB18 and PLIN2 in the CMA process. In summary, our findings elucidate how PRRSV-2 hijacks CMA-mediated lipid metabolism through innate immune activation to enhance the yield of progeny virus, offering novel insights for the development of anti-PRRSV-2 treatments.

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Ramyasoma, Hewawasam Patuwatha Badathuruge Kalindu Dulanja, Yasanthi Illika Nilmini Silva Gunawardene, Menaka Hapugoda e Ranil Samantha Dassanayake. "Assessment of Developmental and Reproductive Fitness of Dengue-Resistant Transgenic Aedes aegypti and Improvement of Fitness Using Antibiotics". BioMed Research International 2021 (2 de março de 2021): 1–10. http://dx.doi.org/10.1155/2021/6649038.

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Background. Genetic modification offers opportunities to introduce artificially created molecular defence mechanisms to vector mosquitoes to counter diseases causing pathogens such as the dengue virus, malaria parasite, and Zika virus. RNA interference is such a molecular defence mechanism that could be used for this purpose to block the transmission of pathogens among human and animal populations. In our previous study, we engineered a dengue-resistant transgenic Ae. aegypti using RNAi to turn off the expression of dengue virus serotype genomes to reduce virus transmission, requiring assessment of the fitness of this mosquito with respect to its wild counterpart in the laboratory and semifield conditions. Method. Developmental and reproductive fitness parameters of TM and WM have assessed under the Arthropod Containment Level 2 conditions, and the antibiotic treatment assays were conducted using co-trimoxazole, amoxicillin, and doxycycline to assess the developmental and reproductive fitness parameters. Results. A significant reduction of developmental and reproductive fitness parameters was observed in transgenic mosquito compared to wild mosquitoes. However, it was seen in laboratory-scale studies that the fitness of this mosquito has improved significantly in the presence of antibiotics such as co-trimoxazole, amoxicillin, and doxycycline in their feed. Conclusion. Our data indicate that the transgenic mosquito produced had a reduction of the fitness parameters and it may lead to a subsequent reduction of transgenic vector density over the generations in field applications. However, antibiotics of co-trimoxazole, amoxicillin, and doxycycline have shown the improvement of fitness parameters indicating the usefulness in field release of transgenic mosquitoes.

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Oludoun, Olajumoke, Olukayode Adebimpe, James Ndako, Michael Adeniyi, Oluwakemi Abiodun e Babatunde Gbadamosi. "The impact of testing and treatment on the dynamics of Hepatitis B virus". F1000Research 10 (17 de setembro de 2021): 936. http://dx.doi.org/10.12688/f1000research.72865.1.

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Despite the intervention of WHO on vaccination for reducing the spread of Hepatitis B Virus (HBV), there are records of the high prevalence of HBV in some regions. In this paper, a mathematical model was formulated to analyze the acquisition and transmission process of the virus with the view of identifying the possible way of reducing the menace and mitigating the risk of the virus. The models' positivity and boundedness were demonstrated using well-known theorems. Equating the differential equations to zero demonstrates the equilibria of the solutions i.e., the disease-free and endemic equilibrium. The next Generation Matrix method was used to compute the basic reproduction number for the models. Local and global stabilities of the models were shown via linearization and Lyapunov function methods respectively. The importance of testing and treatment on the dynamics of HBV were fully discussed in this paper. It was discovered that testing at the acute stage of the virus and chronic unaware state helps in better management of the virus.

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Zhao, Xiting, Liwei Jiang, Ke Liu, Mengdan Ma, Yingyuan Zhou, Ying Tian e Mingjun Li. "Tomato aspermy virus elimination improves medicinal quality of chrysanthemum". Archives of Biological Sciences 70, n.º 3 (2018): 497–502. http://dx.doi.org/10.2298/abs171226010z.

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Chrysanthemum morifolium cv. ?Huaihuang?, a medicinal chrysanthemum of China, undergoes long-term asexual reproduction and virus infection that change its quality characteristics. Our previous studies have shown that tomato aspermy virus (TAV) is the main virus infecting ?Huaihuang?. Many studies indicate that plant virus elimination can improve plant growth, but only a few studies have focused on the effects of detoxification on the medicinal components of medicinal plants. In this paper, the content of medicinal components, including chlorogenic acid, luteoloside and 3,5-O-dicaffeoylquinic acid, was compared between the TAV-free and TAV-infected (control) chrysanthemum. In addition, the reason why TAV elimination improves the medicinal components of chrysanthemum is explored. Our results suggest that TAV elimination significantly improves plant growth, enhances the enzyme activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase and 4-coumarate:CoA ligase, and increases the levels of CmHCT and CmCHS expression, thereby greatly improving the medicinal quality of chrysanthemum.

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Chen, Jiaping, Xiaodong Xu, Hu Tao, Yuanyuan Wang e Hongying Chen. "Chemical shift assignments of nsp7α from porcine reproductive and respiratory syndrome virus". Biomolecular NMR Assignments 10, n.º 2 (9 de setembro de 2016): 391–94. http://dx.doi.org/10.1007/s12104-016-9706-7.

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Ren, Shanhui, Chan Ding e Yingjie Sun. "Morphology Remodeling and Selective Autophagy of Intracellular Organelles during Viral Infections". International Journal of Molecular Sciences 21, n.º 10 (23 de maio de 2020): 3689. http://dx.doi.org/10.3390/ijms21103689.

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Viruses have evolved different strategies to hijack subcellular organelles during their life cycle to produce robust infectious progeny. Successful viral reproduction requires the precise assembly of progeny virions from viral genomes, structural proteins, and membrane components. Such spatial and temporal separation of assembly reactions depends on accurate coordination among intracellular compartmentalization in multiple organelles. Here, we overview the rearrangement and morphology remodeling of virus-triggered intracellular organelles. Focus is given to the quality control of intracellular organelles, the hijacking of the modified organelle membranes by viruses, morphology remodeling for viral replication, and degradation of intracellular organelles by virus-triggered selective autophagy. Understanding the functional reprogram and morphological remodeling in the virus-organelle interplay can provide new insights into the development of broad-spectrum antiviral strategies.

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Fang, Jianyu, Haiyan Wang, Juan Bai, Qiaoya Zhang, Yufeng Li, Fei Liu e Ping Jiang. "Monkey Viperin Restricts Porcine Reproductive and Respiratory Syndrome Virus Replication". PLOS ONE 11, n.º 5 (27 de maio de 2016): e0156513. http://dx.doi.org/10.1371/journal.pone.0156513.

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Al-Maqrashi, Kifah, Fatma Al-Musalhi, Ibrahim ELmojtaba e Nasser Al-Salti. "Investigating the Role of Mobility between Rural Areas and Forests on the Spread of Zika". BIOMATH 11, n.º 2 (22 de dezembro de 2022): 2212149. http://dx.doi.org/10.55630/j.biomath.2022.12.149.

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A mathematical model of Zika virus transmission, incorporating human movement between rural areas and nearby forests, is presented to investigate the role of human movement in the spread of Zika virus infections in human and mosquito populations. Proportions of both susceptible and infected humans living in rural areas are assumed to move to nearby forest areas. Direct, indirect, and vertical transmission routes are incorporated for all populations. A mathematical analysis of the proposed model is presented. The analysis starts with normalizing the proposed model. The positivity and boundedness of solutions to the normalized model are then addressed. The basic reproduction number is calculated using the next-generation matrix method and its relation to the three routes of disease transmission has been presented. The sensitivity analysis of the basic reproduction number to all model parameters is investigated. The analysis also includes the existence and stability of disease-free and endemic equilibrium points. Bifurcation analysis is also carried out. Finally, numerical solutions to the normalized model are obtained to confirm the theoretical results and demonstrate human movement's role in disease transmission in human and mosquito populations.

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Endashaw, Engida Endriyas, Dawit Melese Gebru e Haileyesus Tessema Alemneh. "Coinfection Dynamics of HBV-HIV/AIDS with Mother-to-Child Transmission and Medical Interventions". Computational and Mathematical Methods in Medicine 2022 (21 de dezembro de 2022): 1–21. http://dx.doi.org/10.1155/2022/4563577.

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In this study, we analyzed the effect of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) on the transmission dynamics of their coinfection to make a recommendation based on reasons to public health sector, policy makers, and programme implementers. We proved that the solutions of the sub and full models are positive and bounded. The effective reproduction numbers of the models are derived using the next generation matrix method. The disease-free and endemic equilibria of the submodels and the coinfection model are computed, and the stability of those equilibria is analyzed using Routh-Hurwitz criteria after computing the associated effective reproduction numbers. We performed a sensitivity analysis to show the influence of different parameters on the effective reproduction number of HBV-HIV/AIDS coinfection model, and we identified the most sensitive parameters are τ 2 and α 1 , which are the rate of MTCT of HIV and treatment rate for HBV infected class, respectively. The numerical simulation of the model is done using MATLAB and the findings from the simulations are discussed. From the results of numerical simulations, we observed that an increase in the rates of MTCT of HBV and HIV exacerbated HBV-HIV/AIDS coinfection, while a decrease in the rates of MTCT of these infections would decline the number of cases, minimize the spread, and help to eliminate HBV-HIV/AIDS coinfection from the society gradually.

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Wang, Haiyan, Juan Bai, Baochao Fan, Yufeng Li, Qiaoya Zhang e Ping Jiang. "The Interferon-Induced Mx2 Inhibits Porcine Reproductive and Respiratory Syndrome Virus Replication". Journal of Interferon & Cytokine Research 36, n.º 2 (fevereiro de 2016): 129–39. http://dx.doi.org/10.1089/jir.2015.0077.

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Dejucq, Nathalie, e Bernard Jégou. "Viruses in the Mammalian Male Genital Tract and Their Effects on the Reproductive System". Microbiology and Molecular Biology Reviews 65, n.º 2 (1 de junho de 2001): 208–31. http://dx.doi.org/10.1128/mmbr.65.2.208-231.2001.

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SUMMARY This review describes the various viruses identified in the semen and reproductive tracts of mammals (including humans), their distribution in tissues and fluids, their possible cell targets, and the functional consequences of their infectivity on the reproductive and endocrine systems. The consequences of these viral infections on the reproductive tract and semen can be extremely serious in terms of organ integrity, development of pathological and cancerous processes, and transmission of diseases. Furthermore, of essential importance is the fact that viral infection of the testicular cells may result not only in changes in testicular function, a serious risk for the fertility and general health of the individual (such as a fall in testosteronemia leading to cachexia), but also in the possible transmission of virus-induced mutations to subsequent generations. In addition to providing an exhaustive account of the data available in these domains, this review focuses attention on the fact that the interface between endocrinology and virology has so far been poorly explored, particularly when major health, social and economical problems are posed. Our conclusions highlight the research strategies that need to be developed. Progress in all these domains is essential for the development of new treatment strategies to eradicate viruses and to correct the virus-induced dysfunction of the endocrine system.

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Paff, Matthew L., Scott L. Nuismer, Andrew Ellington, Ian J. Molineux e James J. Bull. "Virus wars: using one virus to block the spread of another". PeerJ 4 (29 de junho de 2016): e2166. http://dx.doi.org/10.7717/peerj.2166.

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The failure of traditional interventions to block and cure HIV infections has led to novel proposals that involve treating infections with therapeutic viruses–infectious viruses that specifically inhibit HIV propagation in the host. Early efforts in evaluating these proposals have been limited chiefly to mathematical models of dynamics, for lack of suitable empirical systems. Here we propose, develop and analyze an empirical system of a therapeutic virus that protects a host cell population against a lethal virus. The empirical system usesE. colibacteria as the host cell population, an RNA phage as the lethal virus and a filamentous phage as the therapeutic virus. Basic dynamic properties are established for each virus alone and then together. Observed dynamics broadly agree with those predicted by a computer simulation model, although some differences are noted. Two cases of dynamics are contrasted, differing in whether the therapeutic virus is introduced before the lethal virus or after the lethal virus. The therapeutic virus increases in both cases but by different mechanisms. With the therapeutic virus introduced first, it spreads infectiously without any appreciable change in host dynamics. With the therapeutic virus introduced second, host abundance is depressed at the time therapy is applied; following an initial period of therapeutic virus spread by infection, the subsequent rise of protection is through reproduction by hosts already protected. This latter outcome is due to inheritance of the therapeutic virus state when the protected cell divides. Overall, the work establishes the feasibility and robustness to details of a viral interference using a therapeutic virus.

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