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Antiviral Drugs as Tools for Nanomedicine
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
During the 20th Century, transmittable agents that can cause tumors in chickens and rabbits were identified as rous sarcoma virus (RSV). RSV was the first RNA tumour virus, and shope papillomavirus was the first DNA tumor virus studied for its oncogenic efficiency. In recent years, focus has been given to viruses that can cause human cancers. The role of viruses in human cancer led to identification and characterisation of various oncogenes and tumour-suppressor genes. With the help of these studies, a few generalised principles were deduced as:In the virally associated cancers, long latent periods follow initial infection, indicating that the viruses are not sufficient to cause cancer on their own. During this long latent period, these viruses must be able to survive in the host.The virus-induced cancers do not constitute a natural part of the viral life cycle. However, virally associated cancer cells are like dead-end streets, which are not of any advantage to the virus.The viral properties responsible for the induction of tumors often play critical roles in the life cycle of the virus.
Salmonids (Salmonidae)
Published in John A Plumb, Health Maintenance Of Cultured Fishes, 1994
Death of A. salmonicida-infected trout is generally attributed to a massive septicemia that interferes with the host’s blood supply and results in massive tissue necrosis. Skin lesions are characterized by loss of scales, necrosis of epithelium and muscle, capillary dilation, and hemorrhage at the periphery of the lesion.31 Klontz et al.32 experimentally infected rainbow trout with A. salmonicida and found that the most consistent pathological aberration was an enlarged spleen that appeared 16 h after injection and persisted throughout the infection. Sinusoids of the spleen became congested and engorged with erythrocytes. Bacteria could be isolated at 8 h postinjection, but not during the ensuing 48 h. Following this latent period a systemic infection developed. At the site of injection extensive inflammation and severe muscle necrosis developed.
Analysis of a reaction–diffusion SVIR model with a fixed latent period and non-local infections
Published in Applicable Analysis, 2022
Jianguo Gao, Chao Zhang, Jinliang Wang
In fact, the above works have been done under the assumption that the environment is well-mixed uniformly and without considering the mobility of host populations. In the real world, due to the variance such as temperature and availability of resources, etc., host population habitats are always spatially heterogeneous. Spatial environmental heterogeneity is also central factors that affect the spatial spreading of a disease [9]. A recent study on reaction–diffusion SVIR epidemic model in a spatial heterogeneous environment (see, e.g. [10]) reveal that the spatial heterogeneity can enhance the spread risk of the disease. It is found in [10] that the prevalence of infected individuals becomes higher when a larger diffusion rate is adopted. It is well-known from the recent studies (see, e.g. [11]) that spatial movement of a human in the latent period will result in non-local infection. The reason lies in the fact that an individual infected by the disease in one place may not stay at the same space in the domain due to the movement of human during the incubation period. Thus, it is reasonable to consider the transmission of an infectious disease that has a latency within a population.
The application of phage reactivation capacity to sens bacterial viability and activity after photocatalytic treatment
Published in Environmental Technology, 2021
Myriam Ben Said, Marwa Ben Saad, Faouzi Achouri, Latifa Bousselmi, Ahmed Ghrabi
The relative increase of free phage titre or the phage amplification rate compared to the initially inoculated phage titre (Pi) was observed when we can still perceive a bacterial culture in the usual media (Figure 2). Conversely, when the post-treated bacteria lose their ability to form a colony in used media, a decrease of free phage titre (inferior to Pi) was observed. This decrease was associated probably with the interaction of phage-injured cells not yet resuscitated after treatment. This category of bacteria can allow the attachment of the specific phage with the probability of release of the new, mature and infectious virus after an extension of contact time phage-stressed host cells. Indeed, according to [11], VBNC bacteria were capable to support phage replication. In addition, the interaction phage-host cells under stress conditions have revealed the flexibility of phage’s replication cycle related to the physiological state of bacterial host cells [14,21]. In addition, Wang et al. [7] were suggested that the timing of phage-induced host cell lysis may be subject to a host quantity- and host quality-dependent selection. The latter study concludes that a phage will evolve a shorter latent period when either host density is high or host quality is good (Pop). The latent period is defined by the timing of phage induced host cell lysis, which typically is under the control of a phage protein complex known as a holin. Holins restrain the activity of cell-wall-digesting endolysins [22].
Detection of the change in characteristics of self-grooming by the neural network in the latent period of the Rat Kainate Epilepsy model
Published in SICE Journal of Control, Measurement, and System Integration, 2022
Hirofumi Arai, Masaya Shigemoto, Kiyohisa Natsume
In the latent period, the KA group facilitated self-grooming bouts. The number of bouts was significantly increased in the latent period compared to that before injection (Figure 1; **p = 0.002, Wilcoxon signed-rank test [WSRT] with Bonferroni correction [BC]). The number of self-grooming bouts in the KA group was significantly larger than that in the control group during the latent period (Figure 1; **p = 0.002, Wilcoxon rank test [WRT] with BC). The duration of grooming was significantly longer than before injection in the KA group (Figure 2; **p = 0.009, WSRT with BC). The duration of the latent period of the KA group was significantly longer than that of the control group (Figure 2; *p = 0.01, WRT with BC).