scholarly journals High Seropositivity Rate of Neutralizing Antibodies to Astrovirus VA1 in Human Populations

mSphere ◽  
2021 ◽  
Author(s):  
Andrew B. Janowski ◽  
Macee C. Owen ◽  
Holly Dudley ◽  
Tomás López ◽  
Rafaela Espinosa ◽  
...  

Astroviruses are human pathogens with emerging disease associations, including the recent recognition of their capacity to cause meningoencephalitis. Astrovirus VA1 is the most commonly identified astrovirus genotype from cases of human encephalitis, but it is unknown what percentage of the human population has neutralizing antibodies to VA1.

1982 ◽  
Vol 60 (7) ◽  
pp. 1053-1056
Author(s):  
R. E. M. Lees

The impact of toxins on the health of human populations can only be accurately assessed by epidemiologic methods. The investigation of toxin–disease associations in human populations and the accurate interpretation of data are often very difficult because of the existence of multiple confounding variables and the unrepresentativeness of sample or study populations.Factors influencing the deduction of cause and effect relationship rather than simple association are discussed, as is the need for continued development of epidemiological surveillance techniques.


2020 ◽  
Vol 20 (5) ◽  
pp. 321-332
Author(s):  
Yunbo Liu ◽  
Xu Zhang ◽  
Lin Yang

Adeno-associated virus (AAV) is a promising vector for in vivo gene therapy because of its excellent safety profile and ability to mediate stable gene expression in human subjects. However, there are still numerous challenges that need to be resolved before this gene delivery vehicle is used in clinical applications, such as the inability of AAV to effectively target specific tissues, preexisting neutralizing antibodies in human populations, and a limited AAV packaging capacity. Over the past two decades, much genetic modification work has been performed with the AAV capsid gene, resulting in a large number of variants with modified characteristics, rendering AAV a versatile vector for more efficient gene therapy applications for different genetic diseases.


2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.


2020 ◽  
Vol 26 (5) ◽  
pp. 724-752 ◽  
Author(s):  
Ning Ding ◽  
Siobán D Harlow ◽  
John F Randolph Jr ◽  
Rita Loch-Caruso ◽  
Sung Kyun Park

Abstract BACKGROUND Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are found widespread in drinking water, foods, food packaging materials and other consumer products. Several PFAS have been identified as endocrine-disrupting chemicals based on their ability to interfere with normal reproductive function and hormonal signalling. Experimental models and epidemiologic studies suggest that PFAS exposures target the ovary and represent major risks for women’s health. OBJECTIVE AND RATIONALE This review summarises human population and toxicological studies on the association between PFAS exposure and ovarian function. SEARCH METHODS A comprehensive review was performed by searching PubMed. Search terms included an extensive list of PFAS and health terms ranging from general keywords (e.g. ovarian, reproductive, follicle, oocyte) to specific keywords (including menarche, menstrual cycle, menopause, primary ovarian insufficiency/premature ovarian failure, steroid hormones), based on the authors’ knowledge of the topic and key terms. OUTCOMES Clinical evidence demonstrates the presence of PFAS in follicular fluid and their ability to pass through the blood–follicle barrier. Although some studies found no evidence associating PFAS exposure with disruption in ovarian function, numerous epidemiologic studies, mostly with cross-sectional study designs, have identified associations of higher PFAS exposure with later menarche, irregular menstrual cycles, longer cycle length, earlier age of menopause and reduced levels of oestrogens and androgens. Adverse effects of PFAS on ovarian folliculogenesis and steroidogenesis have been confirmed in experimental models. Based on laboratory research findings, PFAS could diminish ovarian reserve and reduce endogenous hormone synthesis through activating peroxisome proliferator-activated receptors, disrupting gap junction intercellular communication between oocyte and granulosa cells, inducing thyroid hormone deficiency, antagonising ovarian enzyme activities involved in ovarian steroidogenesis or inhibiting kisspeptin signalling in the hypothalamus. WIDER IMPLICATIONS The published literature supports associations between PFAS exposure and adverse reproductive outcomes; however, the evidence remains insufficient to infer a causal relationship between PFAS exposure and ovarian disorders. Thus, more research is warranted. PFAS are of significant concern because these chemicals are ubiquitous and persistent in the environment and in humans. Moreover, susceptible groups, such as foetuses and pregnant women, may be exposed to harmful combinations of chemicals that include PFAS. However, the role environmental exposures play in reproductive disorders has received little attention by the medical community. To better understand the potential risk of PFAS on human ovarian function, additional experimental studies using PFAS doses equivalent to the exposure levels found in the general human population and mixtures of compounds are required. Prospective investigations in human populations are also warranted to ensure the temporality of PFAS exposure and health endpoints and to minimise the possibility of reverse causality.


2011 ◽  
Vol 93 (2) ◽  
pp. 105-114 ◽  
Author(s):  
LEEYOUNG PARK

SummaryIn order to estimate the effective population size (Ne) of the current human population, two new approaches, which were derived from previous methods, were used in this study. One is based on the deviation from linkage equilibrium (LE) between completely unlinked loci in different chromosomes and another is based on the deviation from the Hardy–Weinberg Equilibrium (HWE). When random mating in a population is assumed, genetic drifts in population naturally induce linkage disequilibrium (LD) between chromosomes and the deviation from HWE. The latter provides information on the Ne of the current population, and the former provides the same when the Ne is constant. If Ne fluctuates, recent Ne changes are reflected in the estimates based on LE, and the comparison between two estimates can provide information regarding recent changes of Ne. Using HapMap Phase III data, the estimates were varied from 622 to 10 437, depending on populations and estimates. The Ne appeared to fluctuate as it provided different estimates for each of the two methods. These Ne estimates were found to agree approximately with the overall increment observed in recent human populations.


Author(s):  
Dorothy N. Gamble

This entry describes how the viability of long-term human social systems is inextricably linked to human behavior, environmental resources, the health of the biosphere, and human relationships with all living species. New ways of thinking and acting in our engagement with the biosphere are explored, with attention to new ways of measuring well-being to understand the global relationships among human settlements, food security, human population growth, and especially alternative economic efforts based on prosperity rather than on growth. The challenge of social work is to engage in socioecological activities that will prevent and slow additional damage to the biosphere while at the same time helping human populations to develop the cultural adaptation and resilience required to confront increasing weather disasters; displacement resulting from rising seas; drought conditions that severely affect food supplies; the loss of biodiversity, soils, forests, fisheries, and clean air; and other challenges to human social organizations.


2019 ◽  
Vol 37 (2) ◽  
pp. 442-454 ◽  
Author(s):  
Diego Forni ◽  
Rachele Cagliani ◽  
Mario Clerici ◽  
Uberto Pozzoli ◽  
Manuela Sironi

Abstract JC polyomavirus (JCPyV) is one of the most prevalent human viruses. Findings based on the geographic distribution of viral subtypes suggested that JCPyV codiverged with human populations. This view was however challenged by data reporting a much more recent origin and expansion of JCPyV. We collected information on ∼1,100 worldwide strains and we show that their geographic distribution roughly corresponds to major human migratory routes. Bayesian phylogeographic analysis inferred a Subsaharan origin for JCPyV, although with low posterior probability. High confidence inference at internal nodes provided strong support for a long-standing association between the virus and human populations. In line with these data, pairwise FST values for JCPyV and human mtDNA sampled from the same areas showed a positive and significant correlation. Likewise, very strong relationships were found when node ages in the JCPyV phylogeny were correlated with human population genetic distances (nuclear-marker based FST). Reconciliation analysis detected a significant cophylogenetic signal for the human population and JCPyV trees. Notably, JCPyV also traced some relatively recent migration events such as the expansion of people from the Philippines/Taiwan area into Remote Oceania, the gene flow between North-Eastern Siberian and Ainus, and the Koryak contribution to Circum-Arctic Americans. Finally, different molecular dating approaches dated the origin of JCPyV in a time frame that precedes human out-of-Africa migration. Thus, JCPyV infected early human populations and accompanied our species during worldwide dispersal. JCPyV typing can provide reliable geographic information and the virus most likely adapted to the genetic background of human populations.


2018 ◽  
Vol 92 (11) ◽  
Author(s):  
M. Justin Iampietro ◽  
Rafael A. Larocca ◽  
Nicholas M. Provine ◽  
Peter Abbink ◽  
Zi Han Kang ◽  
...  

ABSTRACT Adenovirus (Ad) vectors are being investigated as vaccine candidates, but baseline antivector immunity exists in human populations to both human Ad (HuAd) and chimpanzee Ad (ChAd) vectors. In this study, we investigated the immunogenicity and cross-reactivity of a panel of recently described rhesus adenoviral (RhAd) vectors. RhAd vectors elicited T cells with low exhaustion markers and robust anamnestic potential. Moreover, RhAd vector immunogenicity was unaffected by high levels of preexisting anti-HuAd immunity. Both HuAd/RhAd and RhAd/RhAd prime-boost vaccine regimens were highly immunogenic, despite a degree of cross-reactive neutralizing antibodies (NAbs) between phylogenetically related RhAd vectors. We observed extensive vector-specific cross-reactive CD4 T cell responses and more limited CD8 T cell responses between RhAd and HuAd vectors, but the impact of vector-specific cellular responses was far less than that of vector-specific NAbs. These data suggest the potential utility of RhAd vectors and define novel heterologous prime-boost strategies for vaccine development. IMPORTANCE To date, most adenoviral vectors developed for vaccination have been HuAds from species B, C, D, and E, and human populations display moderate to high levels of preexisting immunity. There is a clinical need for new adenoviral vectors that are not hindered by preexisting immunity. Moreover, the development of RhAd vector vaccines expands our ability to vaccinate against multiple pathogens in a population that may have received other HuAd or ChAd vectors. We evaluated the immunogenicity and cross-reactivity of RhAd vectors, which belong to the poorly described adenovirus species G. These vectors induced robust cellular and humoral immune responses and were not hampered by preexisting anti-HuAd vector immunity. Such properties make RhAd vectors attractive as potential vaccine vectors.


2017 ◽  
Vol 372 (1735) ◽  
pp. 20160415 ◽  
Author(s):  
V. P. Weinberger ◽  
C. Quiñinao ◽  
P. A. Marquet

Biodiversity is sustained by and is essential to the services that ecosystems provide. Different species would use these services in different ways, or adaptive strategies, which are sustained in time by continuous innovations. Using this framework, we postulate a model for a biological species ( Homo sapiens ) in a finite world where innovations, aimed at increasing the flux of ecosystem services (a measure of habitat quality), increase with population size, and have positive effects on the generation of new innovations (positive feedback) as well as costs in terms of negatively affecting the provision of ecosystem services. We applied this model to human populations, where technological innovations are driven by cumulative cultural evolution. Our model shows that depending on the net impact of a technology on the provision of ecosystem services ( θ ), and the strength of technological feedback ( ξ ), different regimes can result. Among them, the human population can fill the entire planet while maximizing their well-being, but not exhaust ecosystem services. However, this outcome requires positive or green technologies that increase the provision of ecosystem services with few negative externalities or environmental costs, and that have a strong positive feedback in generating new technologies of the same kind. If the feedback is small, then the technological stock can collapse together with the human population. Scenarios where technological innovations generate net negative impacts may be associated with a limited technological stock as well as a limited human population at equilibrium and the potential for collapse. The only way to fill the planet with humans under this scenario of negative technologies is by reducing the technological stock to a minimum. Otherwise, the only feasible equilibrium is associated with population collapse. Our model points out that technological innovations per se may not help humans to grow and dominate the planet. Instead, different possibilities unfold for our future depending on their impact on the environment and on further innovation. This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.


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