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1.
Paul W. Ewald 《Ecological Research》2011,26(6):1017-1026
Assessments of future threats posed by infection have focused largely on zoonotic, acute disease, under the rubric “emerging
diseases.” Evolutionary and epidemiological studies indicate, however, that particular aspects of infrastructure, such as
protected water supplies, vector-proof housing, and health care facilities, protect against the emergence of zoonotic, acute
infectious diseases. While attention in the global health community has focused on emerging diseases, there has been a concurrent,
growing recognition that important chronic diseases, such as cancer, are often caused by infectious agents that are already
widespread in human populations. For economically prosperous countries, the immediacy of this threat contrasts with their
infrastructural protection from severe acute infectious disease. This reasoning leads to the conclusion that chronic infectious
diseases pose a more significant threat to economically prosperous countries than zoonotic, acute infectious diseases. Research
efforts directed at threats posed by infection may therefore be more effective overall if increased efforts are directed toward
understanding and preventing infectious causes of chronic diseases across the spectrum of economic prosperity, as well as
toward specific infrastructural improvements in less prosperous countries to protect against virulent, acute infectious diseases. 相似文献
2.
Is the Social–Ecological Framework Useful in Understanding Infectious Diseases? The Case of HIV/AIDS
The extraordinary complexity of emerging infectious diseases calls for new paradigms and approaches to understand the casual
mechanisms underlying pathogen emergence and to improve disease prevention. An attempt was made to foster interdisciplinary
collaboration and stimulate transdisciplinary approaches to improve emerging infectious disease research during and subsequent
to a meeting held in March 2005 as part of the US NIH Roadmap initiative “Research Teams of the Future.” The meeting drew
on models and theories associated with the idea of humans and nature as interactive, complex systems. Of the three diseases
chosen as case studies to represent the wide range of social and ecological emergence factors involved (dengue, leptospirosis,
and HIV/AIDS), HIV/AIDS proved especially difficult. This Profile examines the meeting themes with a particular focus on the
deliberations of a working group focused on HIV/AIDS. Attention is given to the challenges of bridging different disciplines
and perspectives in applying a social-ecological framework to analyze HIV/AIDS and the benefits of reductionistic vs. holistic
strategies in responding to the global HIV/AIDS pandemic. The issues raised point to opportunities to significantly deepen
understanding of HIV/AIDS as a transdisciplinary problem.
Disclaimer: The author is Director of the Research Program at the East–West Center and was chair of the HIV/AIDS mini-symposium.
This Profile is based on the important contributions and efforts of all the members of the HIV/AIDS working group. All omissions
or misrepresentations are the author’s. 相似文献
3.
Ridley RM 《Molecular biotechnology》2003,24(3):243-256
T. H. Huxley was “Darwin’s bulldog,” and took the offensive in championing the cause of evolution against skeptical scientists
and outraged theologians. As such, he took part in one of the great “paradigm shifts” of biology, at the end of the nineteenth
century. Huxley was a rigorous scientist and wrote important articles on scientific method, as well as publishing extensively
on a wide range of subjects in natural history. In the second half of the twentieth century, the “prion hypothesis” was put
forward to explain the pathogenesis of a curious group of diseases known as the transmissible spongiform encephalopathies.
This also involved a “paradigm shift” because the prion hypothesis postulated that biologically relevant information could
be enciphered in protein conformation (rather than encoded in nucleic acid base sequences), and could be transmitted from
one molecule to another, thereby causing infectious disease. This article examines a few of Huxley’s remarks to speculate
on how he might have responded to the scientific debate about prion disease had he lived a century later. 相似文献
4.
Stephen Lyng 《Journal of bioethical inquiry》2010,7(1):53-69
The utilization of alternative medical therapies and practitioners has increased dramatically in the U.S. in the last two
to three decades. This trend seems paradoxical when one considers the rapid advances taking place in biomedical knowledge
and technology during this same time period. Observers both inside and outside of the medical profession have attempted to
explain the rising popularity of alternative medicine by proposing that it signals a growing sense of dissatisfaction and
disenchantment with professional biomedical practices on the part of the lay public. This paper challenges this thesis and
offers an alternative explanation, arguing that the rise of alternative medicine is a consequence of the success and expanding
influence of biomedicine rather than its failure and declining authority. The argument presented draws primarily on Ulrich
Beck’s “risk society” perspective and theory of “reflexive modernization,” with specific attention to his analysis of the
“reflexive scientization” process. The application of this perspective allows us to understand the emergence and development
of alternative medicine as an unanticipated consequence of the process of reflexive biomedicalization in the late modern era. 相似文献
5.
S. V. Tillib 《Molecular Biology》2011,45(1):66-73
This short review provides an introduction to the rapidly developing field of generation and utilization of “camel nanoantibodies”
(or “nanobodies”). The term “nanoantibody” or “nanobody” was given to single-domain variable fragments of special type of
antibodies that naturally exist (in addition to classical types of antibodies) in blood of Camelidae family animals and in
some chondrichthyan fishes. The existence of very efficient technology of nanobody generation and some very useful characteristic
features promise a big potential for their use in immunobiotechnology and medicine. 相似文献
6.
E. I. Korenberg 《Biology Bulletin》2010,37(7):753-757
Consideration is given to basic concepts of natural focality that remain debatable (natural focus, epizootic and epidemic
processes) and to the most relevant problems that largely determine the pathways of further research in this field, such as
application of molecular biological methods to the study of natural foci, modes and forms of pathogen existence at the reservation
phase, ways of emergence of “new” diseases with natural focality, and current strategy in disease prevention. 相似文献
7.
Stonington S 《Culture, medicine and psychiatry》2011,35(2):113-133
In this article, I describe a new form of clinical subjectivity in Thailand, emerging out of public debate over medical care
at the end of life. Following the controversial high-tech death of the famous Buddhist monk Buddhadasa, many began to denounce
modern death as falling prey to social ills in Thai society, such as consumerism, technology-worship, and the desire to escape
the realities of existence. As a result, governmental and non-governmental organizations have begun to focus on the end-of-life
as a locus for transforming Thai society. Moving beyond the classic outward focus of the medical gaze, they have begun teaching
clinicians and patients to gaze inward instead, to use the suffering inherent in medicine and illness to face the nature of
existence and attain inner wisdom. In this article, I describe the emergence of this new gaze and its major conceptual components,
including a novel idea of what it means to be ‘human,’ as well as a series of technologies used to craft this humanity: confession,
“facing suffering,” and untying “knots” in the heart. I also describe how this new subjectivity has begun to change the long-stable
Buddhist concept of death as taking place at a moment in time, giving way for a new concept of “end-of-life,” an elongated
interval to be experienced, studied, and used for inner wisdom. 相似文献
8.
Guilloud-Bataille M Bouzigon E Annesi-Maesano I Bousquet J Charpin D Gormand F Hochez J Just J Lemainque A Le Moual N Matran R Neukirch F Oryszczyn MP Paty E Pin I Vervloet D Kauffmann F Lathrop M Demenais F Dizier MH 《Human genetics》2008,122(6):605-614
Asthma, allergic rhinitis (AR) and atopic dermatitis also called eczema are allergic co-morbidites, which are likely to depend
on pleiotropic genetic effects as well as on specific genetic factors. After a previous genome-wide linkage screen conducted
for asthma and AR in a sample of 295 French EGEA families ascertained through asthmatic subjects, the aim here was to search
for genetic factors involved in eczema and more particularly the ones shared by the three allergic diseases using the same
EGEA data. In this sake, eczema and phenotypes of “allergic disease” accounting for the joint information on the presence/absence
of the three diseases were examined by linkage analyses using the maximum likelihood binomial method. A fine mapping was carried
out in regions detected for potential linkage, followed by association studies using the family-based association test (FBAT).
Evidence for linkage to 11p14 region was shown for “allergic disease” and eczema. Linkage was also indicated between eczema
and 5q13 and between “allergic disease” and both 5p15 and 17q21 regions. Fine mapping supported the evidence of linkage to
11p14 and FBAT analyses showed the association between “allergic disease” and a marker located at the linkage peak on 11p14.
Further investigations in this region will allow identifying genetic factor(s) which could have pleiotropic effect in the
three allergic diseases. 相似文献
9.
Heterogeneity in the number of potentially infectious contacts and connectivity correlations (“like attaches to like” i.e.,
assortatively mixed or “opposites attract” i.e., disassortatively mixed) have important implications for the value of the
basic reproduction ratio R
0 and final epidemic size. In this paper, we present a contact-network-based derivation of a simple differential equation model
that accounts for preferential mixing based on the number of contacts. We show that results based on this model are in good
qualitative agreement with results obtained from preferential mixing models used in the context of sexually transmitted diseases
(STDs). This simple model can accommodate any mixing pattern ranging from completely disassortative to completely assortative
and allows the derivation of a series of analytical results. 相似文献
10.
11.
Yi-ming Shao 《中国病毒学》2007,22(6):421-425
By the end of 2005, the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls
for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. “Prevention
First” is the cornerstone of the country’s health policy. On 2003 World AIDS Day, Premier Jiabao Wen announced a new national
AIDS control policy, “Four Frees and One Care”. This policy clearly shows that the Chinese government has once again taken
full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006, the
central government put scientific and technology innovation as a national priority and set the target to build an innovative
China by year 2020. Since then, the government has been increasing investment in science and technology with major emphasis
on both infectious diseases control and new drug research and development. For the first time, development of 100 new drugs
and control of major infectious diseases (AIDS, HBV, TB and other emerging infectious diseases) have been selected as national
key scientific projects. China’s best minds in related fields will be pooled to work together in order to remove the technical
barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology, immunology,
pathogenesis, HAART, as well as HIVDR strains will certainly provide urgently needed scientific information for China’s AIDS
control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.
相似文献
12.
In eukaryotic cells, degradation of most intracellular proteins is realized by proteasomes. The substrates for proteolysis
are selected by the fact that the gate to the proteolytic chamber of the proteasome is usually closed, and only proteins carrying
a special “label” can get into it. A polyubiquitin chain plays the role of the “label”: degradation affects proteins conjugated
with a ubiquitin (Ub) chain that consists at minimum of four molecules. Upon entering the proteasome channel, the polypeptide
chain of the protein unfolds and stretches along it, being hydrolyzed to short peptides. Ubiquitin per se does not get into the proteasome, but, after destruction of the “labeled” molecule, it is released and labels another molecule.
This process has been named “Ub-dependent protein degradation”. In this review we systematize current data on the Ub-proteasome
system, describe in detail proteasome structure, the ubiquitination system, and the classical ATP/Ub-dependent mechanism of
protein degradation, as well as try to focus readers’ attention on the existence of alternative mechanisms of proteasomal
degradation and processing of proteins. Data on damages of the proteasome system that lead to the development of different
diseases are given separately. 相似文献
13.
This article is a review of scientific publications, in which issues of pathogenetics of multifactorial diseases (MFDs) are
considered from the viewpoint of evolution and ontogeny. Concepts explaining significance of evolutionary processes in the
formation of genetic architecture of human chronic diseases (“thrifty” genomes and phenotypes, “drifty genes,” decanalization)
are analyzed. The roles of natural selection and genetic drift in the formation of hereditary diversity of genes for susceptibility
to MFDs are considered. The modern concept of “disease ontogeny” (somatic mosaicism, loss of heterozygosity, paradominant
inheritance, epigenetic variability) is discussed. It is demonstrated that the evolutionary and ontogenetic approaches to
analysis of genimuc and other “-omic” data are essential for understanding the biology of diseases. 相似文献
14.
15.
I. Opatowski 《Bulletin of mathematical biology》1945,7(4):161-180
A mathematical theory applicable to the biological effects of radiations as chain processes is developed. The theory may be
interpreted substantially as a “hit theory” involving the concepts of “sensitive volume” or “target area”. The variability
of the sensitivity of the organism to the radiation and its capacity of recovery between single hits is taken into account.
It is shown that in a continuous irradiation of a biological aggregate in which the effect of each single hit cannot be observed,
recovery and variation of sensitivity are formally equivalent to each other so that a discrimination between these two phenomena
is possible only by discontinuous irradiation or by using different radiation intensities. Methods for the calculation of
the “number of hits” and for the determination of the kinetics of the processes from “survival curves” or similar experimental
data are given. The relation between the recovery and the Bunsen-Roscoe law is discussed. The case in which the injury of
the organism is dependent on the destruction of more than one “sensitive volume” is also considered. 相似文献
16.
N. V. Joshi 《Journal of genetics》1992,71(3):105-119
Competition between seeds within a fruit for parental resources is described using one-locus-two-allele models. While a “normal”
allele leads to an equitable distribution of resources between seeds (a situation which also corresponds to the parental optimum),
the “selfish” allele is assumed to cause the seed carrying it to usurp a higher proportion of the resources. The outcome of
competition between “selfish” alleles is also assumed to lead to an asymmetric distribution of resources, the “winner” being
chosen randomly. Conditions for the spread of an initially rare selfish allele and the optimal resource allocation corresponding
to the evolutionarily stable strategy, derived for species with n-seeded fruits, are in accordance with expectations based
on Hamilton’s inclusive fitness criteria. Competition between seeds is seen to be most intense when there are only two seeds,
and decreases with increasing number of seeds, suggesting that two-seeded fruits would be rarer than one-seeded or many-seeded
ones. Available data from a large number of plant species are consistent with this prediction of the model.
Based on a talk given at the Haldane Centenary Symposium held on 6 November 1992 at Ahmedabad as part of the 58th Annual Meeting
of the Indian Academy of Sciences. 相似文献
17.
Willson SJ 《Bulletin of mathematical biology》2007,69(8):2561-2590
Suppose G is a phylogenetic network given as a rooted acyclic directed graph. Let X be a subset of the vertex set containing the root, all leaves, and all vertices of outdegree 1. A vertex is “regular” if
it has a unique parent, and “hybrid” if it has two parents. Consider the case where each gene is binary. Assume an idealized
system of inheritance in which no homoplasies occur at regular vertices, but homoplasies can occur at hybrid vertices. Under
our model, the distances between taxa are shown to be described using a system of numbers called “originating weights” and
“homoplasy weights.” Assume that the distances are known between all members of X. Sufficient conditions are given such that the graph G and all the originating and homoplasy weights can be reconstructed from the given distances. 相似文献
18.
Many of the most virulent emerging infectious diseases in humans, e.g., AIDS and Ebola, are zoonotic, having shifted from
wildlife populations. Critical questions for predicting disease emergence are: (1) what determines when and where a disease
will first cross from one species to another, and (2) which factors facilitate emergence after a successful host shift. In
wild primates, infectious diseases most often are shared between species that are closely related and inhabit the same geographic
region. Therefore, humans may be most vulnerable to diseases from the great apes, which include chimpanzees and gorillas,
because these species represent our closest relatives. Geographic overlap may provide the opportunity for cross-species transmission,
but successful infection and establishment will be determined by the biology of both the host and pathogen. We extrapolate
the evolutionary relationship between pathogen sharing and divergence time between primate species to generate “hotspot” maps,
highlighting regions where the risk of disease transfer between wild primates and from wild primates to humans is greatest.
We find that central Africa and Amazonia are hotspots for cross-species transmission events between wild primates, due to
a high diversity of closely related primate species. Hotspots of host shifts to humans will be most likely in the forests
of central and west Africa, where humans come into frequent contact with their wild primate relatives. These areas also are
likely to sustain a novel epidemic due to their rapidly growing human populations, close proximity to apes, and population
centers with high density and contact rates among individuals. 相似文献
19.
It is a common medical folk-practice for parents to encourage their children to contract certain infectious diseases while
they are young. This folk-practice is controversial, in part, because it contradicts the long-term public health goal of minimizing
disease incidence. We study an epidemiological model of infectious disease in an age-structured population where virulence
is age-dependent and show that, in some cases, the optimal behavior will increase disease transmission. This provides a rigorous justification of the concept of “endemic stability,” and demonstrates that
folk-practices may have been historically justified. 相似文献
20.
Natural enemies can be a powerful force when structuring natural communities, and in facilitating or preventing species coexistence
depending on the nature of the trophic interaction. In particular, “keystone” predators can promote species coexistence, provided
they preferentially attack the competitively dominant species. However, it is not clear whether parasites can play a similar
structuring role; parasites typically form chronic associations with their victims, reducing their fitness (i.e., fecundity)
rather than survival, and allowing infected hosts to remain viable competitors within the community. Therefore the density-dependent
suppression of the host is likely to be more subtle than that due to predation. Using a series of simple population-dynamic
models we show that specialist parasites can facilitate species coexistence, although possibly less so than predators. These
results contrast with those typically found with models of generalist parasites, which can reduce the likelihood of species
coexistence through apparent competition. In addition, we show that the likelihood of parasite-facilitated species coexistence
depends greatly on the specific type of parasite. In particular, macroparasites (e.g., parasitic helminths) may be less likely
to facilitate species coexistence than microparasites (e.g., viruses or bacteria) due to their typically highly aggregated
distribution amongst their hosts. Furthermore, species coexistence is more likely if the parasite is relatively benign to
its host. Parasitism by apparently “harmless” specialist parasites may provide an important but overlooked factor in the maintenance
of species diversity, facilitating species invasions into new communities and the emergence of novel infectious diseases. 相似文献