Search results for " viruses"

Killer toxin-secreting double-stranded RNA mycoviruses in the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii.

1994

Killer toxin-secreting strains of the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii were shown to contain linear double-stranded RNAs (dsRNAs) that persist within the cytoplasm of the infected host cell as encapsidated virus-like particles. In both yeasts, L- and M-dsRNAs were associated with 85-kDa major capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was shown to be encapsidated by a 35-kDa coat protein. Although Northern (RNA) blot hybridizations indicated that L-dsRNA from Z. bailii is a LA species,…

[Norovirus infections: an overview]

2010

National audience; Noroviruses belong to the Caliciviridae family. They are a major cause of sporadic cases and outbreaks of gastroenteritis in all age groups, and are responsible for a considerable disease burden in industrialized countries. Noroviruses are single-stranded RNA viruses, and show great genetic diversity making their detection difficult. Noroviruses can be divided into 5 genogroups, which themselves are subdivided into genotypes. Besides chance mutations that occur during viral replication, the great heterogeneity observed among noroviruses is also due to intra and inter-genotypic recombination events between strains. Some of these new variants or new recombinants are frequen…

Bleomycin: Action on growth of oncogenic RNA viruses and on cell transformation

1975

Bleomycin (BLM) inhibits cell proliferation of noninfected chick embryo fibroblasts by blocking their DNA synthesis selectively. Chick embryo fibroblasts have beentransformed by Schmidt-Ruppin D strain of Rous Sarcoma Virus. Transformation has been determined by a focus assay. Foci formation is strongly reduced by BLM. Virus replication is inhibited by BLM in growing and confluent monolayer cells. This result might be explained by the observation that this drug reduces proliferation of growing and of confluent monolayer cells very sensitively. During the first 24 hours after infection the BLM inhibitory effect is more pronounced than in the case of BLM-application during the period 24--48 h…

Identification of Replicator Mutator models

2006

The complexity of biology literally calls for quantitative tools in order to support and validate biologists intuition and traditional qualitative descriptions. In this paper, the Replicator-Mutator models for Evolutionary Dynamics are validated/invalidated in a worst-case deterministic setting. These models analyze the DNA and RNA evolution or describe the population dynamics of viruses and bacteria. We identify the Fitness and the Replication Probability parameters of a genetic sequences, subject to a set of stringent constraints to have physical meaning and to guarantee positiveness. The conditional central estimate is determined in order to validate/invalidate the model. The effectivene…

The Application of CRISPR/Cas9 Technology for Cancer Immunotherapy: Current Status and Problems

2022

Cancer is one of the main causes of disease-related deaths in the world. Although cancer treatment strategies have been improved in recent years, the survival time of cancer patients is still far from satisfied. Cancer immunotherapy, such as Oncolytic virotherapy, Immune checkpoints inhibition, Chimeric antigen receptor T (CAR-T) cell therapy, Chimeric antigen receptor natural killer (CAR-NK) cell therapy and macrophages genomic modification, has emerged as an effective therapeutic strategy for different kinds of cancer. However, many patients do not respond to the cancer immunotherapy which warrants further investigation to optimize this strategy. The clustered regularly interspaced short …

Classification of current anticancer immunotherapies.

2014

© 2014. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Viruses are ancient parasites that have influenced the evolution of contemporary and archaic forms of life

2010

Data from: Virus epidemics can lead to a population-wide spread of intragenomic parasites in a previously parasite-free asexual population

2014

In a recent issue of Molecular Ecology the role of intragenomic parasites in maintaining sexual reproduction was both experimentally evaluated by Kraaijeveld et al. and discussed by Crespi and Schwander. The prevalence of sex is difficult to explain, due to its costs when compared with asexual reproduction. Yet, as reviewed by Crespi and Schwander, sex can be favorable in the presence of proliferating transposons. Transposons are similar to mutations, in that their integration to non-neutral loci is likely to have deleterious effects, and sexual recombination provides a potential mechanism to confine their accumulation.

SARS-CoV-2 vs. Hepatitis Virus Infection Risk in the Hemodialysis Population: What Should We Expect?

2021

Since the dramatic rise of the coronavirus infection disease 2019 (COVID-19) pandemic, patients receiving dialysis have emerged as especially susceptible to this infection because of their impaired immunologic state, chronic inflammation and the high incidence of comorbidities. Although several strategies have thus been implemented to minimize the risk of transmission and acquisition in this population worldwide, the reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence varies across studies but is higher than in the general population. On the contrary, the screening for hepatitis viruses (HBV and HCV) has seen significant improvements in recent years, with va…

Studies on a measles virus variant inducing persistent infections in cultured cells

1976

Attempts were made to characterized by a plaque assay two variants of the Edmonston strain of measles virus and to obtain plaque purified virus populations. The UP non-cytocidal variant, in all the examined cell systems, mainly produced small but also large plaques; the DP cytocidal variant always large plaques. Three clones, UP-SP4, UP-LP4 and DP-LP4, were derived by plaque purfication respectively of the UP small plaque, UP large plaque and DP large plaque forming particles. The virus populations of the clones could be distinguished by some other biological and physical characters: cytopathic effect in roller tube cultures, growth potential in HeLa cells, thermal stability at 45 degrees C…