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The German medical bacteriologist Robert Koch is commonly considered one of the founding fathers of medical bacteriology. His investigations into the aetiology of tuberculosis uncovered the pathogen of this condition, the tubercle bacillus today known as Mycobacterium tuberculosis, in 1882. This work can be seen as a cornerstone of contemporary medical bacteriology, its technologies and methods. It has often been asked how such successful research connected to the tuberculin episode of 1890/91, when Koch produced a medicine for that disease, which spectacularly failed when applied in practice. The analysis concentrates on the path of mostly experimental investigations which Koch followed between 1882 and 1890. From Koch's laboratory notes it becomes clear that tuberculin therapy did in fact work in Koch's laboratory, even though it failed to do so almost anywhere else. The clue to this contradictory picture lies in the peculiar nature of Koch's understanding of tuberculosis as a disease e.g. his reliance an animal experiments, which essentially differed from what many of his contemporaries held as essentials of that condition.  相似文献   

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Current historiography has considered eugenics to be an emanation from state structures or a movement which sought to appeal to the state in order to implement eugenic reform. This paper examines the limitations of that view and argues that it is necessary to expand our horizons to consider particularly working-class eugenics movements that were based on the dissemination of knowledge about sex and which did not aspire to positions of political power. The paper argues that anarchism, with its contradictory practice afforded by the convulsive social situation of the Civil War in Spain, allows us to assess critically the parameters of the social action of eugenics, its many alliances, and its struggle for existence in changing political circumstances not of its own making.  相似文献   

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M. Kazemi  G. Gumpert  M. I. Marks 《CMAJ》1974,110(11):1253-1255,1257
A study was done of 117 children with nontyphoidal salmonellosis from the clinic and inpatient populations of The Montreal Children''s Hospital. Uncomplicated gastroenteritis was the most common clinical presentation and the mean duration of illness was 8.7 days. Eleven (24%) of 45 patients tested had bacteremia; retrospective analysis of these patients did not reveal major differences in clinical presentation, laboratory findings, underlying disease or complications when compared with the patients from whom blood cultures were not taken. There were no complications in any of the patients and no deaths. Prolonged stool carriage beyond eight weeks was not a problem except in infants under the age of 3 months, of whom 27% were carriers eight weeks after the onset of illness. Antibiotic therapy was not effective in treating the acute illness and seemed to prolong carriage in young infants.  相似文献   

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Molecular phylogenies constitute an important new way of tracking the progress of viral epidemics. The phylogenetic analysis of viral sequence data provides information on the origin, spread and maintenance of infections and can be used to reconstruct contact networks of infected individuals. Analysis of the branching structure of phylogenetic trees also allows inferences to be made about the rate of transmission and the distinction between endemic and epidemic infections, and provides estimates of the numbers of infected individuals.  相似文献   

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Starting from an assessment of how far Robert Koch's bacteriology had developed in the late 1880s this paper attempts to analyse different aspects of the process that led to the foundation of the Berlin Institute for Infectious Diseases in 1891. With the development of his supposed cure against tuberculosis, tuberculin, Koch attempted to give his research a new direction, earn a fortune with the profits and become more independent of Prussian government officials who, up to that point, had had a major influence on his career. In the period following the presentation of the cure in autumn 1890, however, it became clear that tuberculin's value in treatment was at most dubious. Thus, the failure of tuberculin meant that Koch had to drop his own plans and accommodate those of the Prussian Ministry of Culture. As a result he assumed directorship of the newly founded Institute for Infectious Diseases in Berlin. Even though this was definitely a prestigious position it reaffirmed Koch's dependency on Prussian government officials and was by no means the kind of institution he had aimed for at the outset.  相似文献   

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This essay draws a new picture of the science of bacteria in its 'golden age', circa 1880-1900: the organization of its knowledge and practice, its germ theory of disease, the difference between its two major research traditions, and, above all, its place in life science in this period that bristled with theories and debates over inheritance, variation, selection, evolution and that witnessed the transition from natural history to laboratory biology. Pasteur and Koch's science acquired this biological dimension not despite being outside academic biology, nor despite the limitations of its applied, medical matrix, but rather because of that framework. The very practices of vaccine development constituted, at the same time, a new biological model of bacterial species and variation, which aligned them with other living things. Finally, the new picture reveals unsuspected continuity to later microbiology and molecular biology. In illuminating the self-perceptions of these sciences in relation to the past, it situates and opens a critical perspective on writings by bacteriologists such as Ludwik Fleck, Fran?ois Jacob and René Dubos, which have widely informed how we understand science.  相似文献   

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Information on the epidemiology, clinic and diagnostics of bartonellosis is updated. The importance of bartonellosis lies in the fact that its main risk group embraces patients with immunodeficiencies of different origin, the number of such patients constantly growing. The diagnostics of bartonellosis is insufficiently developed and the research on Bartonella organisms, except for the trunch (Volynia) fever causative agent, is insufficient in our country.  相似文献   

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Current historiography has considered eugenics to be an emanation from state structures or a movement which sought to appeal to the state in order to implement eugenic reform. This paper examines the limitations of that view and argues that it is necessary to expand our horizons to consider particularly working-class eugenics movements that were based on the dissemination of knowledge about sex and which did not aspire to positions of political power. The paper argues that anarchism, with its contradictory practice afforded by the convulsive social situation of the Civil War in Spain, allows us to assess critically the parameters of the social action of eugenics, its many alliances, and its struggle for existence in changing political circumstances not of its own making.  相似文献   

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The coinfection of a host by several parasite strains is known to affect selective pressures on parasite strategies of host exploitation. I present a general model of coinfections that ties together kin selection models of virulence evolution and epidemiological models of multiple infections. I derive an analytical expression for the invasion fitness of a rare mutant in a population with an arbitrary distribution of the multiplicity of infection (MOI) across hosts. When a single mutation affects parasite strategies in all MOI classes, I show that the evolutionarily stable level of virulence depends on a demographic average of within‐host relatedness across all host classes. This generalization of previous kin selection results requires that within‐host parasite densities do not vary between hosts. When host exploitation strategies are allowed to vary across classes, I show that the strategy of host exploitation in a focal MOI class depends on the relative magnitudes of parasite reproductive values in the focal class and in the next. Thus, in contrast to previous findings, lower within‐host relatedness in competitive parasite interactions can potentially correspond to either higher or lower levels of virulence.  相似文献   

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Novel functions of melatonin continue to be uncovered. Those summarized in this report include actions at the level of the peripheral reproductive organs and include functions as an antioxidant to protect the maturing oocyte in the vesicular follicle and during ovulation, melatonin actions on the developing fetus particularly in relation to organizing the circadian system, its potential utility in combating the consequences of pre-eclampsia, reducing intrauterine growth restriction, suppressing endometriotic growths and improving the outcomes of in vitro fertilization/embryo transfer. The inhibitory effects of melatonin on many cancer types have been known for decades. Until recently, however, melatonin had not been tested as a protective agent against exocrine pancreatic tumors. This cancer type is highly aggressive and 5 year survival rate in individuals with pancreatic cancer is very low. Recent studies with melatonin indicate it may have utility in the treatment of these otherwise almost untreatable pancreatic cancers. The discovery of melatonin in plants has also opened a vast new field of research which is rapidly being exploited although the specific functions(s) of melatonin in plant organs remains enigmatic. Finally, the described application of melatonin's use as a chemical reductant in industry could well serve as a stimulus to further define the utility of this versatile molecule in new industrial applications.  相似文献   

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Actinoporus elongatus is a widely distributed, tropical, intertidal anemone from the Indo-Pacific and Caribbean regions. Its recorded occurrences are disjunct and its feeding and reproductive ecology have not previously been described in detail. A population of this sand-dwelling species was studied for one year at Shelly Bay, Queensland, Australia. Individuals were found to be randomly distributed within the study site at a density of 42 anemones per hectare. No immigration, juvenile recruitment or mortality was observed. Histological analysis indicated a protracted period of gamete maturity during the summer months, and that the sex ratio was 1:1. A. elongatus is an opportunistic feeder with two distinct feeding methods — actinopharyngeal eversion and a newly described trapdoor response. Ciliary currents on the tentacular crown and oral disk were used mainly for cleaning and sand removal.Department of Zoology, James Cook University of North QueenslandDepartment of Marine Biology, James Cook University of North QueenslandDepartment of Marine Biology, James Cook University of North Queensland  相似文献   

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