Pathocenosis: A Holistic Approach to Disease Ecology

The History of medicine describes the emergence and recognition of infectious diseases, and human attempts to stem them. It also throws light on the role of changing environmental conditions on disease emergence/re-emergence, establishment and, sometimes, disappearance. However, the dynamics of infectious diseases is also influenced by the relationships between the community of interacting infectious agents present at a given time in a given territory, a concept that Mirko Grmek, an historian of medicine, conceptualized with the word “pathocenosis”. The spatial and temporal evolution of diseases, when observed at the appropriate scales, illustrates how a change in the pathocenosis, whether of “natural” or anthropic origin, can lead to the emergence and spread of diseases

Graph-Theoretic Confirmation of Restructuring During Insight

The “flash of insight” sometimes observed in problem solving and in scientific discovery has been thought to be due to a sudden cognitive restructuring of the problem situation Direct confirmation of restructuring has been difficult without an independent procedure for determining cognitive structure Graph structures were derived from judgments of concept relatedness made by subjects who had an insight and by several groups who either did not or could not have the insight The graphs of the solvers differed from the graphs of subjects who tried and failed, those who listened to the solvers, and those who were given the solution When other subjects in a subsequent experiment repeatedly judged similarity of pairs of concepts, there was evidence that those connections critical to the new cognitive order were targeted long before there was the breathtaking cognitive reorganizationYeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Neuroanatomy and cadaver dissection in Italy: History, medicolegal issues, and neurosurgical perspectives.

Despite the significant Italian tradition of important anatomical studies, an outdated law historically influenced by the Catholic church restricts the use of cadavers for teaching and scientific purposes. The object of the present paper was to trace the historical evolution of the Italian anatomical tradition, particularly neuroanatomical studies, in relation to the juridical regulations on the use of cadavers today. Special attention was paid to the opportunities offered to neurosurgery by using cadavers and to the scientific and social issues in neurosurgical training in the twenty-first century. Considering the new Common European Constitution, the authors advocate a political solution from the European community to improve the quality of training in the disciplines with a social impact such as neurosurgery

True versus False Parasite Interactions: A Robust Method to Take Risk Factors into Account and Its Application to Feline Viruses

International audienceBACKGROUND: Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these "false interactions", methods accounting for parasite risk factors must be used. METHODOLOGY/PRINCIPAL FINDINGS: In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed "the corrected chi-square." Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses. CONCLUSIONS/SIGNIFICANCE: This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections

At the intersection of medical geography and disease ecology: Mirko Grmek, Jacques May and the concept of pathocenosis

Environmental historians are not sufficiently aware of the extent to which mid twentieth-century thinkers turned to medical geography—originally a nineteenth-century area of study—in order to think through ideas of ecology, environment, and historical reasoning. This article outlines how the French–Croatian Mirko D. Grmek (Krapina, 1924–Paris, 2000), a major thinker of his generation in the history of medicine, used those ideas in his studies of historical epidemiology. During the 1960s, Grmek attempted to provide, in the context of the Annales School’s research program under the leadership of Fernand Braudel, a new theoretical framework for a world history of disease. Its development was inspired by several sources, most notably the French–American Jacques M. May (Paris 1896–Tunisia, 1975), who was then pioneering an opening up of medical geography and movement towards the concept of disease ecology. The cornerstone of Grmek’s “synthetic approach” to the field was the notion of “pathocenosis”. The diverse uses of this notion in the course of time—from his early agenda focused on a longue durée history of diseases in Western Antiquity to his last, relating to the new epidemiological threat of (re)emerging infectious diseases, specifically HIV/aids—enables us firstly, to note how concepts of ecology sat uneasily alongside those of medical geography; secondly, to assess the reach and limits of his theoretical contribution to historical epidemiology; and thirdly, to understand better the uneven fortunes of his concept of pathocenosis at the end of the twentieth and beginning of the twenty-first centuries.Peer reviewe