The relation between biomedical knowledge and clinicalknowledge is discussed by comparing their respectivestructures. The knowledge of a disease as a biologicalphenomenon is constructed by the interaction of factsand theories from the main biomedical disciplines:epidemiology, diagnostics, clinical trial, therapydevelopment and pathogenesis. Although these facts andtheories are based on probabilities andextrapolations, the interaction provides a reliableand coherent structure, comparable to a Kuhnianparadigma. In the structure of clinical knowledge,i.e. knowledge of the patient with the disease, notonly biomedical knowledge contributes to the structurebut also (...) economic and social relations, ethics andpersonal experience. However, the interaction betweeneach of the participating ``knowledges'' in clinicalknowledge is not based on mutual dependency andaccumulation of different arguments from each, as inbiomedical knowledge, but on competition and partialexclusion. Therefore, the structure of biomedicalknowledge is different from that of clinicalknowledge. This difference is used as the basis for adiscussion in which the place of technology,evidence-based medicine and the gap between scientificand clinical knowledge are evaluated. (shrink)

An analysis is presented of published methods that have been used by experimenters to justify the reliability of the theory of invasion of microorganisms into cultured cells. The results show that, to demonstrate this invasion, many experimenters used two or more methods that were based on independent technical and theoretical principles, and by doing so improved the reliability of the theory. Subsequently I compare this strategy of 'multiple derivability' with other strategies, discussed in the literature in relation to the mesosome, (...) a bacterial organelle that had been detected with the electron microsope, but which appeared later to be an artifact. I propose that different strategies have been applied in this problem, and multiple derivability may have been the decisive one. Finally I discuss the idea that multiple derivability may help to anchor theories in a larger network of theories. (shrink)

Somatic cell count is a diagnostic test of milk for mastitis in cows. Its specificity and sensitivity are less than 1.0, making test results uncertain. I discuss epistemological problems of the test such as underdetermination, undercalibration and underdiscrimination, in the solution of which biomedical and economic factors may play a role. Diagnostics of the SCC should be considered as an epistemological network, functioning in a network in which farmers, veterinarians, epidemiologists and milk industry shift their position following biomedical, technological and (...) economic changes, which is described as an actor-network to understand how human and non-human agents in mastitis may be associated. (shrink)

This paper analyzes the investigation of the distribution of the protein tenascin-C in canine mammary tumors. The method involved immunohistochemistry of tissue slices, performed by the application of an antibody to tenascin-C that specifically can be made visible for microscopic inspection. The first phase of the project is the making of the protocol, the second the deduction of a pattern of tenascin-C distribution in tumors and the third the writing of a paper. Each of the phases is analyzed separately, using (...) the concept of resistance and accommodation. My purpose is to show that in each phase of the process of producing knowledge, the scientist meets resistances which force him to accommodate by changing his conceptual, technical and methodological approaches. In reverse, the details of the non-human agent have to be accommodated to the wishes and expectations of the scientist. Through this interaction a situation of stability of knowledge is reached at the end of each phase.In the protocol phase, resistance is found in the antibody and tissue slices. In the phase of pattern deduction the resistance is in the pathological diagnosis of the tumors and the expectations and hypothesis with which the scientist had entered the project; in the criteria to be used for assigning the slices to a tenascin-C pattern; and in the responses of colleagues and supervisor. In the paper-writing phase the interaction is between the scientist and the scientific community which should take on board the knowledge from the research project.When stabilization of knowledge is obtained in one of the phases, the agents of resistance turn into allies in the next phase, giving support to accommodating the resistances in this later phase. Second, the stabilization of knowledge of the protocol is further enhanced when stabilization of the pattern is achieved; in addition, knowledge of the pattern is more definite when it has become stabilized and closed knowledge within the science community. (shrink)