Search results for "Infectious"
showing 10 items of 2953 documents
Phenotypic plasticity in haptoral structures of Ligophorus cephali (Monogenea: Dactylogyridae) on the flathead mullet (Mugil cephalus): A Geometric M…
2015
Abstract Evaluating phenotypic plasticity in attachment organs of parasites can provide information on the capacity to colonise new hosts and illuminate evolutionary processes driving host specificity. We analysed the variability in shape and size of the dorsal and ventral anchors of Ligophorus cephali from Mugil cephalus by means of geometric morphometrics and multivariate statistics. We also assessed the morphological integration between anchors and between the roots and points in order to gain insight into their functional morphology. Dorsal and ventral anchors showed a similar gradient of overall shape variation, but the amount of localised changes was much higher in the former. Statist…
Differentiation of Trichuris species using a morphometric approach
2019
Trichuris trichiura is a nematode considered as the whipworm present in humans and primates. The systematics of the genus Trichuris is complex. Morphological studies of Trichuris isolated from primates and humans conclude that the species infecting these hosts is the same. Furthermore, numerous molecular studies have been carried out so far to discriminate parasite species from humans and Non-Human Primates using molecular techniques, but these studies were not performed in combination with a parallel morphological study. The hypothesised existence of more species of Trichuris in primates opens the possibility to revise the zoonotic potential and host specificity of T. trichiura and other p…
The overlapping burden of the three leading causes of disability and death in sub-Saharan African children
2022
Publisher Copyright: © 2022, The Author(s). Despite substantial declines since 2000, lower respiratory infections (LRIs), diarrhoeal diseases, and malaria remain among the leading causes of nonfatal and fatal disease burden for children under 5 years of age (under 5), primarily in sub-Saharan Africa (SSA). The spatial burden of each of these diseases has been estimated subnationally across SSA, yet no prior analyses have examined the pattern of their combined burden. Here we synthesise subnational estimates of the burden of LRIs, diarrhoea, and malaria in children under-5 from 2000 to 2017 for 43 sub-Saharan countries. Some units faced a relatively equal burden from each of the three diseas…
Accuracy of SCORTEN to predict the prognosis of Stevens‐Johnson syndrome/toxic epidermal necrolysis: a systematic review and meta‐analysis
2019
BACKGROUND The SCORTEN score is a specific predictor of the probability of death for patients diagnosed with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). OBJECTIVES To evaluate the overall accuracy of SCORTEN and the influence of several moderators such as age, sex, geographical region and age of the study. METHODS A systematic search was performed on MEDLINE, The Cochrane Library, EMBASE, SCOPUS and Web of Knowledge, with no restriction on language (last update 5 February 2019 for all databases). Original studies on the use of SCORTEN were eligible. The standardized mortality ratio (SMR), defined as the quotient between the number of deaths observed and the number expec…
Adoptive CD8 T Cell Control of Pathogens Cannot Be Improved by Combining Protective Epitope Specificities
2008
Adoptive transfer of CD8 T cells has the potential to cure infectious or malignant diseases that are refractory to conventional chemotherapy. A practically important but still unanswered question is whether mixtures of protective CD8 T cells with different epitope specificities mediate more efficient effector cell functions than do the monospecific individual CD8 T cell populations. In this study, we have addressed this issue for models of viral and bacterial infection. CD8 T cell-mediated cytotoxicity in vitro and protection in vivo were assessed to test whether CD8 T cell lines cooperate in target cell lysis and control of infection, respectively. Our data clearly show that mixtures of cy…
In vivo impact of cytomegalovirus evasion of CD8 T-cell immunity: Facts and thoughts based on murine models
2010
Cytomegaloviruses (CMVs) co-exist with their respective host species and have evolved to avoid their elimination by the hosts' immune effector mechanisms and to persist in a non-replicative state, known as viral latency. There is evidence to suggest that latency is nevertheless a highly dynamic condition during which episodes of viral gene desilencing, which can be viewed as incomplete reactivations, cause intermittent antigenic activity that stimulates CD8 memory-effector T cells and drives their clonal expansion. These T cells are supposed to terminate reactivation before completion of the productive viral cycle. In this view, CMVs do not "evade" their respective host's immune response bu…
Correlation between mutation rate and genome size in riboviruses: mutation rate of bacteriophage Qβ.
2013
Abstract Genome sizes and mutation rates covary across all domains of life. In unicellular organisms and DNA viruses, they show an inverse relationship known as Drake’s rule. However, it is still unclear whether a similar relationship exists between genome sizes and mutation rates in RNA genomes. Coronaviruses, the RNA viruses with the largest genomes (∼30 kb), encode a proofreading 3′ exonuclease that allows them to increase replication fidelity. However, it is unknown whether, conversely, the RNA viruses with the smallest genomes tend to show particularly high mutation rates. To test this, we measured the mutation rate of bacteriophage Qβ, a 4.2-kb levivirus. Amber reversion-based Luria–D…
Variability in the mutation rates of RNA viruses
2014
ABSTRACT: It is well established that RNA viruses show extremely high mutation rates, but less attention has been paid to the fact that their mutation rates also vary strongly, from 10-6 to 10-4 substitutions per nucleotide per cell infection. The causes explaining this variability are still poorly understood, but candidate factors are the viral genome size and polarity, host-specific gene expression patterns, or the intracellular environment. Differences between animal and plant viruses, or between arthropod-borne and directly transmitted viruses have also been postulated. Finally, RNA viruses may be able to regulate the rate at which new mutations spread in the population by modifying f…
Variation in RNA virus mutation rates across host cells.
2014
It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10−6 to 10−4 substitutions per nucleotide per round of copying (s/n/r) and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV), which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly…
Die Lepra in Riga, ihre Ausbreitung und Bekämpfung: Vortrag, gehalten am 22. April 1911 in der Gesellschaft für kommunale Sozialpolitik in Riga
1911
"Als Manuskript gedruckt für die Mitglieder der Gesellschaft für kommunale Sozialpolitik in Riga."