首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The article describes how the medical school in Montpellier, organized in 1498, responded to the development of the Jussiaean classification of plants. Though overshadowed by Paris in the eighteenth century as a center of medical and botanical training, botany as taught at Montpellier provided the impetus for the conversion of traditional herbalism into a biology-based medicine by the nineteenth century. In addition, the plant affinities and analogies underlying natural classification led to the conception of a viable theory of evolution, as Darwin acknowledged. The opposition to these advances, evident in the nineteenth century, remains alive today.  相似文献   

2.
Diffusion theory explains in physical terms how materials move through a medium, e.g. water or a biological fluid. There are strong and widely acknowledged grounds for doubting the applicability of this theory in biology, although it continues to be accepted almost uncritically and taught as a basis of both biology and medicine. Our principal aim is to explore how this situation arose and has been allowed to continue seemingly unchallenged for more than 150 years. The main shortcomings of diffusion theory will be briefly reviewed to show that the entrenchment of this theory in the corpus of biological knowledge needs to be explained, especially as there are equally valid historical grounds for presuming that bulk fluid movement powered by the energy of cell metabolism plays a prominent note in the transport of molecules in the living body. First, the theory's evolution, notably from its origins in connection with the mechanistic materialist philosophy of mid nineteenth century physiology, is discussed. Following this, the entrenchment of the theory in twentieth century biology is analyzed in relation to three situations: the mechanism of oxygen transport between air and mammalian tissues; the structure and function of cell membranes; and the nature of the intermediary metabolism, with its implicit presumptions about the intracellular organization and the movement of molecules within it. In our final section, we consider several historically based alternatives to diffusion theory, all of which have their precursors in nineteenth and twentieth century philosophy of science. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

3.
For roughly forty years, from 1870 to 1910, Americans recognized and feared gases emanating from sewers, believing that they were responsible for causing an array of diseases. Fears of sewer gas arose from deeper anxieties toward contact with decomposing organic matter and the vapors emitted from such refuse. These anxieties were exacerbated by the construction of sewers across the country during the mid-to-late-nineteenth century, which concentrated waste emanations and connected homes to one another. The result was the birth of sewer gas and the attribution of sickness and death to it, as well as the development of a host of plumbing devices and, especially, bathroom fixtures, to combat sewer gas. The rise of the germ theory, laboratory science, and belief in disease specificity, however, transformed the threat of sewer gas, eventually replacing it (and the larger fear of miasmas) with the threat of germs. The germ theory framework, by 1910, proved more suitable than the sewer gas framework in explaining disease causation; it is this suitability that often shapes the relationship between science and society.  相似文献   

4.
This article explores one of a citation classics in medical literature—Koch's postulates. It analyses their creation in the nineteenth century and their popularity in the twentieth century. As a genre of historiography, references to the postulates are anecdotes. In referring to a historical event that never happened, such references serve to remind their audiences of a tradition of experimental medicine that supposedly originated with Robert Koch.  相似文献   

5.
Historians of modern medicine often divide their subject into two parts, separated by the bacteriological revolution of the late nineteenth century, when medicine supposedly became 'scientific' for the first time. The history of medical geography--to say nothing of other subjects--calls this common view into question. At least in the United States, students of medical geography, arguably the pre-eminent medical science in an age dominated by miasmatic theories of disease, readily adapted to the discovery of germs. And although bacteriology quickly eclipsed medical geography in the world of medicine, place remained an important consideration in treating asthma (and allergies generally) throughout the post-bacteriological period.  相似文献   

6.
The concept of chordates arose from the alliance between embryology and evolution in the second half of the nineteenth century, as a result of a theoretical elaboration on Kowalevsky’s discoveries about some fundamental similarities between the ontogeny of the lancelet, a putative primitive fish, and that of ascidians, then classified as molluscs. Carrying out his embryological studies in the light of Darwin’s theory and von Baer’s account of the germ layers, Kowalevsky was influenced by the German tradition of idealistic morphology that was concerned with transformations driven by laws of form, rather than with a gradual evolution occurring by means of variation, selection and adaptation. In agreement with this tradition, Kowalevsky interpreted the vertebrate-like structures of the ascidian larva according to von Kölliker’s model of heterogeneous generation. Then, he asserted the homology of the germ layers and their derivatives in different types of animals and suggested a common descent of annelids and vertebrates, in agreement with Saint-Hilaire’s hypothesis of the unity of composition of body plans, but in contrast with Haeckel’s idea of the Chordonia (chordates). In The Descent of Man Darwin quoted Kowalevsky’s discoveries, but accepted Haeckel’s interpretation of the ascidian embryology within the frame of a monophyletic tree of life that was produced by the fundamental biogenetic law. Joining embryology to evolution in the light of idealistic morphology, the biogenetic law turned out to be instrumental in bringing forth different evolutionary hypotheses: it was used by Haeckel and Darwin to link vertebrates to invertebrates by means of the concept of chordates, and by Kowalevsky to corroborate the annelid theory of the origin of vertebrates. Yet, there was still another interpretation of Kowalevsky’s discoveries. As an adherent to empiricism and to Cuvier’s theory of types, von Baer asserted that these discoveries did not prove convincingly a dorsal position of the nervous system in the ascidian tadpole larva; hence, they could not support a homology between different animal types suggesting a kinship between ascidians and vertebrates.  相似文献   

7.
The etiology of skull lesions known as porotic hyperostosis has long been a matter for speculation. The most widely accepted theory at present suggests that an anemia, either acquired or genetic, is responsible for lesion development. However, acceptance of this theory is not universal and the nature of the relationship between orbital and vault lesions remains a controversial issue. This paper provides a much broader field of supportive evidence on which to base the anemia theory. This involves a synthesis of information from the clinical and anthropological literature as well as new data from two skeletal collections: Poundbury Camp, a Romano-British series, and the Hodgson collection, a 19th century East Asian series. A comparison is made between clinical and anthropological data at the macroscopic, microscopic, radiographic, and demographic levels of analysis. This approach reveals the similarities in expression between clinically diagnosed anemias and porotic hyperostosis.  相似文献   

8.
9.
Niche construction theory (NCT) has been represented as a new and comprehensive theory of evolution, one that breaks the constraints imposed by the dominant and largely gene-selectionist standard evolutionary model that is presently mischaracterized as “Darwinian.” I will argue that NCT is not so much a new theory, as it is a fruitful readmission of a venerable physiological perspective on adaptation, selection and evolution. This perspective is closer in spirit and philosophy to the original (and richer) Darwinian idea developed by Darwin himself, and that animated much of the rich late nineteenth century debate about evolution, heredity, adaptation and development, a debate that was largely eclipsed by the early twentieth century emergence of the Neodarwinian synthesis. I will argue that a full realization of the promise of NCT turns on a full understanding of another intellectual revolution of the nineteenth century, Claude Bernard’s conception of homeostasis, a profound statement of the nature of life that has, through the twentieth century, come to be widely misunderstood and trivialized.  相似文献   

10.
Early nineteenth century systematists sought to describe what they called the Natural System or the Natural Classification. In the nineteenth century, there was no agreement about the basis of observed patterns of similarity between organisms. What did these systematists think they were doing, when they named taxa, proposed relationships between taxa, and arranged taxa into representational schemes? In this paper I explicate Charles Frederic Girard’s (1822–1895) theory and method of systematics. A student of Louis Agassiz, and subsequently (1850–1858) a collaborator with Spencer Baird, Girard claimed that natural classificatory methods do not presuppose either a special creationist or an evolutionary theory of the natural world. The natural system, in Girard’s view, comprises three distinct ways in which organisms can be related to each other. Girard analyzed these relationships, and justified his classificatory methodology, by appeal to his embryological and physiological work. Girard offers an explicit theoretical answer to the question, what characters are evidence for natural classificatory hypotheses? I show that the challenge of simultaneously depicting the three distinct types of relationship led Girard to add a third dimension to his classificatory diagrams.  相似文献   

11.
12.
Medicine's inability to humanely respond to the concerns of its patients has often been attributed to its Cartesian dualism of mind and body. More recently, this inability has been ascribed to medicine's penchant for isolating biological disease as its sole proper concern to the exclusion of experienced illness. This dualism of disease and illness is claimed to be an outgrowth of the Cartesian dualism but the differences and similiarities between these two forms of dualism is not clear. This paper seeks to clarify their relationship through an examination of their historical origins.Disease is currently identified and characterized by a process of clinico-pathological correlation. By this means clinical impressions are corrected in light of autopsy findings. Our current mode of clinico-pathological correlation originated in Paris in the early nineteenth century with the work of Xavier Bichat and others. The theory of knowledge implicit within this clinico-pathological approach to the body is described and compared to that of Descartes. Though medicine does pursue certain Cartesian goals for knowledge, such as knowledge of the patient that does not rely upon his candor, it ultimately espouses neither a Cartesian theory of knowledge nor a Cartesian theory of the body. With pathological inquiry modeled after the autopsy as the final word in the identification and characterization of disease, the patient's capacity for self-knowledge and interpretation — not an entity called mind — is isolated away from his body. This approach to the body means that objective evidence of disease is valued to the exclusion of subjective evidence.If the shortcomings of modern biomedicine are to be effectively addressed, not only must the interdependence of disease and illness be acknowledged. The very canons of medical evidence must be revised. Subjective evidence must be rehabilitated and rejuvenated with better methods of subjective clinical investigation. Host factors relevant to the healing and knowing of sickness must be elucidated so that medicine may rediscover the sentience of its patients. Department of Psychiatry and Behavioral Sciences University of Washington Seattle, WA 98195, U.S.A.  相似文献   

13.
Darwin was a teleologist   总被引:3,自引:0,他引:3  
It is often claimed that one of Darwin's chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin's closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin's version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth century about Darwin's attitude to teleology is argued to be a result of Darwin's teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin's explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations.I would like to thank John Beatty, David Hull and one of this journal's readers for constructive comments on an earlier draft of this paper.  相似文献   

14.
Despite the practical knowledge throughout the nineteenth century that citrus fruit cured scurvy, and that rickets and beriberi were diseases caused by poor diet, it was not until 1901 that animal feeding experiments led one investigator to propose the existence of ‘accessory food factors,’ a lack of which was determined to be the cause of some illnesses (Hopkins, 1949. In Joseph Needham and E. Baldwin (eds.), Hopkins and Biochemistry, 18611947: Papers Concerning Sir Frederick Gowland Hopkins, O.M., P.R.S., with a Selection of His Addresses and a Bibliography of His Publications. Cambridge: W. Heffer and Sons Ltd). The discovery of vitamins has long been considered as a delayed discovery. This delay has been attributed to the power of the germ theory in physiology at the time. While the germ theory and theories of auto-intoxication certainly played a role in delaying the discovery of vitamins, I argue further that it is important to consider the difference made to physiology by understanding the vitamins’ catalytic function. The profound difference made to physiology by the vitamins’ catalytic function suggests that a vitamin concept had previously been systematically inaccessible to researchers working within the conceptual framework of Bernardian physiology.  相似文献   

15.
Place names and evidence from the literature show the Pine Marten (Martes martes) to have been well distributed in Cumbria until late in the nineteenth century, with a core area in the central fells. The habitat available to these martens is assessed and the species' status and the reasons for its decline reviewed. Despite the modern emphasis on the absolute importance of woodland to the Pine Marten, it is argued that historical Cumbrian populations survived successfully for many generations in highly fragmented habitats.  相似文献   

16.
In the past years, several methodologies were developed for potency ranking of genotoxic carcinogens and germ cell mutagens. In this paper, we analyzed six sub-classes of covalent deoxyribonucleic acid (DNA) binding antineoplastic drugs comprising a total of 37 chemicals and, in addition, four alkyl-epoxides, using four approaches for the ranking of genotoxic agents on a potency scale: the EPA/IARC genetic activity profile (GAP) database, the ICPEMC agent score system, and the analysis of qualitative and quantitative structure-activity and activity-activity relationships (SARs, AARs) between types of DNA modifications and genotoxic endpoints. Considerations of SARs and AARs focused entirely on in vivo data for mutagenicity in male germ cells (mouse, Drosophila), carcinogenicity (TD50s) and acute toxicity (LD50s) in rodents, whereas the former two approaches combined the entire database on in vivo and in vitro mutagenicity tests. The analysis shows that the understanding and prediction of rank positions of individual genotoxic agents requires information on their mechanism of action. Based on SARs and AARs, the covalent DNA binding antineoplastic drugs can be divided into three categories. Category 1 comprises mono-functional alkylating agents that primarily react with N7 and N3 moieties of purines in DNA. Efficient DNA repair is the major protective mechanism for their low and often not measurable genotoxic effects in repair-competent germ cells, and the need of high exposure doses for tumor induction in rodents. Due to cell type related differences in the efficiency of DNA repair, a strong target cell specificity in various species regarding the potency of these agents for adverse effects is found. Three of the four evaluation systems rank category 1 agents lower than those of the other two categories. Category 2 type mutagens produce O-alkyl adducts in DNA in addition to N-alkyl adducts. In general, certain O-alkyl DNA adducts appear to be slowly repaired, or even not at all, which make this kind of agents potent carcinogens and germ cell mutagens. Especially the inefficient repair of O-alkyl—pyrimidines causes the high mutational response of cells to these agents. Agents of this category give high potency scores in all four expert systems. The major determinant for the high rank positions on any scale of genotoxic of category 3 agents is their ability to induce primarily structural chromosomal changes. These agents are able to cross-link DNA. Their high intrinsic genotoxic potency appears to be related to the number of DNA cross-links per target dose unit they can induce. A confounding factor among category 3 agents is that often the genotoxic endpoints occur closed to or toxic levels, and that the width of the mutagenic dose range, i.e., the dose area between the lowest observed effect level and the LD50, is smaller (usually no more than 1 logarithmic unit) than for chemicals of the other two categories. For all three categories of genotoxic agents, strong correlations are observed between their carcinogenic potency, acute toxicity and germ cell specificity.  相似文献   

17.
As a result of their intrinsic beauty and relative abundance in some Mesozoic deposits, ammonites have always attracted the attention of scholars and curious people, with written testimonies that can be traced back to Pliny's Naturalis Historiae of 75 ad. The mysterious and evocative charm enclosed behind these extinct cephalopod has made its influence felt on legends, myths, necromancy, medicine, religion and literature, attracting the literary interest of authors such as Goethe, Scott, Schiller and Salgari. Of particular interest is the evolution of scientific thought and interpretations that, over time, have groped to find a place for these ‘difficult fossils’, suspended between the organic world and the stone. In the present work, I briefly discuss the history of the study of ammonites in the Italian peninsula, during the period between the sixteenth and the late nineteenth centuries. Initially interpreted as petrified snakes, and believed for a long time to be ‘giant’ ancestors of living and extinct foraminifera, only in the nineteenth century, ammonites were definitively interpreted as extinct cephalopods, with the recognition of their crucial importance for biostratigraphy.  相似文献   

18.
Edler FC 《Parassitologia》2005,47(3-4):271-278
In the mid nineteenth century, laboratory research in embryology, development, ecology and pathogeny of helminths unexpectedly resulted in a change in the explication of the etiology of some human pathology that was traditionally attributed to environmental factors. The new postulates of the parasitology of helminths put in question the traditional explications as well as the recognized authorities in the fields of clinical medicine, hygiene, and of medical geography, affecting not only the traditional circles where the innovations were discussed, but also the institutions that controlled and validated medical knowledge. From the beginning of the decade of the 1860s, a group of Brazilian medical doctors, initially led by Otto Wucherer, took part in this scientific movement that had an important impact on the area of the domestic and international academic medicine. The causality of known diseases, such as intertropical hypoemia, hematochyluria and elephantiasis, became the focus of intense debate between 1866 and 1892. By the end of this period, the field of helminthic parasitology had available well-established methodological and conceptual criteria and the role of Ankylostomum duodenale and of Wuchereria bancrofti in the production of those diseases was fully accepted.  相似文献   

19.
Hall K 《Bioethics》1997,11(3-4):241-245
The ethics of treating the seriously and critically ill have not been static throughout the ages. Twentieth century medicine has inherited from the nineteenth century a science which places an inappropriate weight on diagnosis over prognosis and management, combined with a seventeenth century duty to prolong life. However other earlier ethical traditions, both Hippocratic and Christian, respected both the limitations of medicine and emphasised the importance of prognosis. This paper outlines some of the historical precedents for the treatment of the critically ill, and also how the current paradigm limits clinical practice and causes ethical tensions. An understanding that other paradigms have been ethically acceptable in the past allows wider consideration and acceptance of alternatives for the future. However future alternatives will also have to address the role of technology, given its importance in this area of medicine.  相似文献   

20.
Functional and mechanistic diversity of distal transcription enhancers   总被引:1,自引:0,他引:1  
Bulger M  Groudine M 《Cell》2011,144(3):327-339
Biological differences among metazoans and between cell types in a given organism arise in large part due to differences in gene expression patterns. Gene-distal enhancers are key contributors to these expression patterns, exhibiting both sequence diversity and cell type specificity. Studies of long-range interactions indicate that enhancers are often important determinants of nuclear organization, contributing to a general model for enhancer function that involves direct enhancer-promoter contact. However, mechanisms for enhancer function are emerging that do not fit solely within such a model, suggesting that enhancers as a class of DNA regulatory element may be functionally and mechanistically diverse.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号