Environmental alteration and allergophytes

Summary The plant recolonization of wasted biotopes was studied in the Karst region in order to evaluate the incidence of allergophytes. The frequency of allergenic species is higher in habitats with low human disturbance, such as wall, ruins, dumps, roadsides and slopes, colonized by ruderal and semi-ruderal plant associations.     

Global alteration of freshwaters: influences on human and environmental well-being

Human and environmental well-being—including disease resistance or avoidance, good nutrition, and species-appropriate population dynamics—are congruent with sustained healthy conditions. Unfortunately, hydrological alterations designed to benefit human societies often have unintended—and sometimes severe—consequences for the environment and the biodiversity it supports, and hence affecting billions of people. Improving this situation necessitates new water-resource developments, better water-use efficiency, and a reduction of contamination. Overall, the influences of existing and future freshwater (FW) regimes on human and environmental well-being are varied and wide-ranging. Furthermore, the scale is daunting: >1 billion people currently live in basins likely to require river management interventions for climate change alone. Global declines in FW biodiversity, in the nutritional value, and abundance of harvestable FW and riparian products, as well as deterioration in habitat quality for many species, require solutions; as do ongoing increases in the spread of FW-related diseases and non-native species. Modifications to FWs are now manifested in population declines and non-sustainable demographics for many aquatic species, as well as in deterioration of human health. In response, scientists, policy-makers, and water users are beginning to conceptualize FWs in terms of a global water system (GWS) to better understand and manage anthropogenic impacts. This involves identifying the ecological and policy implications of changes to the GWS, establishing international programs to understand and resolve major social and environmental issues arising from those changes, and developing broad-based mitigation or restoration techniques (e.g., environmental flow methodologies). Achieving these goals is paramount for maintaining human health as well as for the FW ecosystems upon which we depend.     

Ethics and infectious disease

Bioethics apparently suffers from a misdistribution of research resources analogous to the '10/90' divide in medical research. Though infectious disease should be recognized as a topic of primary importance for bioethics, the general topic of infectious disease has received relatively little attention from the discipline of bioethics in comparison with things like abortion, euthanasia, genetics, cloning, stem cell research, and so on. The fact that the historical and potential future consequences of infectious diseases are almost unrivalled is one reason that the topic of infectious disease warrants more attention from bioethicists. The 'Black Death' eliminated one third of the European population during the 14th Century; the 1989 flu killed between 20 and 100 million people; and, in the 20th Century smallpox killed perhaps three times more people than all the wars of that period. In the contemporary world, epidemics (AIDS, multi-drug resistant turberculosis, and newly emerging infectious diseases such as SARS) continue to have dramatic consequences. A second reason why the topic of infectious disease deserves further attention is that it raises difficult ethical questions of its own. While infected individuals can threaten the health of other individuals and society as a whole, for example, public health care measures such as surveillance, isolation, and quarantine can require the infringement of widely accepted basic human rights and liberties. An important and difficult ethical question asks how to strike a balance between the utilitarian aim of promoting public health, on the one hand, and libertarian aims of protecting privacy and freedom of movement, on the other, in contexts involving diseases that are--to varying degrees--contagious, deadly, or otherwise dangerous. Third, since their burden is most heavily shouldered by the poor (in developing countries), infectious diseases involve issues of justice--which should be a central concern of ethics. I conclude by providing sociological and historical explanations of why the topic of infectious disease has not already received more attention from bioethicists.     

Microbial pathogenesis: mechanisms of infectious disease

The FASEB Summer Research Conference on Microbial Pathogenesis: Mechanisms of Infectious Disease was held in Colorado, USA in July 2007. The central theme was the interplay between pathogenic microbes and their mammalian hosts. Here, we review the presented research that highlights this theme, including studies of both short-term and long-term interactions between microbes and their hosts.     

117例医院真菌感染分析及预防

目的 了解佛山市南海人民医院真菌感染的分布,探讨有效预防和控制真菌感染的措施。方法 对该院117例真菌感染病例作回顾性分析。结果 3583例送检标本中真菌检出率为3．27％（117／3583）,医院内真菌感染率为2．95％（106／3583）。分离出真菌以白色念珠菌为主（70／117．59．8％）、热带念珠菌次之（17／117,14．5％）、霉菌居第3位（9／117．7．69％）。药敏显示：5-氟胞嘧啶、两性霉素B和制霉素敏感率较高,分别为92．4％、93．3％和92．5％,咪康唑、酮康唑和益康唑敏感率较低．为52．0％、49．0％和36．0％。结论 医院内真菌感染占真菌感染绝大部分,感染真菌以白色念珠菌为主。感染部位以呼吸道为主;临床规范、合理使用广谱抗生素,加强消毒护理工作。是预防控制真菌感染发生的最有效措施。     

Seasonal infectious disease epidemiology

Seasonal change in the incidence of infectious diseases is a common phenomenon in both temperate and tropical climates. However, the mechanisms responsible for seasonal disease incidence, and the epidemiological consequences of seasonality, are poorly understood with rare exception. Standard epidemiological theory and concepts such as the basic reproductive number R0 no longer apply, and the implications for interventions that themselves may be periodic, such as pulse vaccination, have not been formally examined. This paper examines the causes and consequences of seasonality, and in so doing derives several new results concerning vaccination strategy and the interpretation of disease outbreak data. It begins with a brief review of published scientific studies in support of different causes of seasonality in infectious diseases of humans, identifying four principal mechanisms and their association with different routes of transmission. It then describes the consequences of seasonality for R0, disease outbreaks, endemic dynamics and persistence. Finally, a mathematical analysis of routine and pulse vaccination programmes for seasonal infections is presented. The synthesis of seasonal infectious disease epidemiology attempted by this paper highlights the need for further empirical and theoretical work.     

Glycosaminoglycans in infectious disease

Glycosaminoglycans (GAGs) are complex carbohydrates that are ubiquitously present on the cell surface and in the extracellular matrix. Interactions between GAGs and pathogens represent the first line of contact between pathogen and host cell and are crucial to a pathogen's invasive potential. Their complexity and structural diversity allow GAGs to control a wide array of biological interactions influencing many physiological and pathological processes, including adhesion, cell‐to‐cell communication, biochemical cascades, and the immune response. In recent years, increasing evidence indicates an extraordinary role for GAGs in the pathogenesis of viruses, bacteria and parasites. Herein, we examine the interface between GAGs and different pathogens, and address the divergent biological functions of GAGs in infectious disease. We consider approaches to use this understanding to design novel therapeutic strategies addressing new challenges in the treatment of infectious diseases.     

Bacterial DNA topology and infectious disease

The Gram-negative bacterium Escherichia coli and its close relative Salmonella enterica have made important contributions historically to our understanding of how bacteria control DNA supercoiling and of how supercoiling influences gene expression and vice versa. Now they are contributing again by providing examples where changes in DNA supercoiling affect the expression of virulence traits that are important for infectious disease. Available examples encompass both the earliest stages of pathogen–host interactions and the more intimate relationships in which the bacteria invade and proliferate within host cells. A key insight concerns the link between the physiological state of the bacterium and the activity of DNA gyrase, with downstream effects on the expression of genes with promoters that sense changes in DNA supercoiling. Thus the expression of virulence traits by a pathogen can be interpreted partly as a response to its own changing physiology. Knowledge of the molecular connections between physiology, DNA topology and gene expression offers new opportunities to fight infection.     

DNA vaccines: successes and limitations in cancer and infectious disease

Vaccination with plasmid DNA is an active area of investigation that is being applied to diseases including cancer and microbial pathogens associated with infectious diseases. Since its discovery, great progress has been made with the administration of DNA vaccines to initiate specific and effective immune responses against targeted illnesses. However, many obstacles still face its use in prophylactic and therapeutic vaccination scenarios. The nature of these difficulties alongside the successes and future of plasmid DNA will be discussed.