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61.
Activities of angiotensin-converting enzyme (ACE), other proteinases, and eosinophil chemotactic factor (ECF-G) are known to be elevated in hepatic hypersensitivity granulomas of thymus intact (nu/+) mice after Schistosoma mansoni infection. The enzyme activities also increase, but to a lesser degree in hepatic granulomas of athymic nude (nu/nu) mice, and ECF-G is not detectable. In this study isolated hepatic granulomas from nu/+ mice were grafted into the skin of uninfected nu/nu mice, and changes in those cellular functions were determined to examine whether the newly formed granulomas by recipient nu/nu cells acquire the functional activities as well as the histological appearance of nu/+ granulomas. ACE and ECF-G rapidly disappeared from grafted sites during the first 5 days, corresponding to loss of nu/+ cells from the graft. Reduction in activities of arylsulfatases, lysozyme, and acid phosphatase also occurred, but to a lesser extent. Recovery of ACE and ECF-G activities to the levels seen in nu/+ hepatic granulomas was observed by 14 days after grafting when nu/nu cells had accumulated in the grafts and formed new granulomas. Other enzymes increased to approximately half the levels seen in grafted donor granulomas. Circulating eosinophilia also increased. The findings indicate that nu/nu cells that accumulated in the skin grafts not only morphologically mimicked nu/+ type granulomas but also demonstrated nu/+ levels of cellular function. Analysis of skin granulomas developing in nu/+ mice after grafting of nu/+ hepatic granulomas showed the similar histology and enzymatic changes, whereas the skin sites inoculated with purified schistosome eggs alone caused neither significant histological changes nor elevation of ACE activity.  相似文献   
62.
Animal experimentation contributes significantly to the progression of science. Nonhuman primates play a particularly important role in biomedical research not only because of their anatomical, physiological, biochemical, and behavioral similarities with humans but also because of their close phylogenetic affinities. In order to investigate the use of New World primates (NWP) in biomedical research over the last four decades (1966–2005), we performed a quantitative study of the literature listed in bibliographic databases from the Health Sciences. The survey was performed for each genus of NWP that has been bred in the National Center of Primates in Brazil. The number of articles published was determined for each genus and sorted according to the country from which the studies originated and the general scientific field. The data obtained suggests that Brazil is a leader in generating knowledge with NWP models for translational medicine. Am. J. Primatol. 72:1055–1061, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
63.
To explore the ways in which biomedical culture responds to the new curricular addition of communication skills training, we observed activities related to the communication skills training of a class of 70 first-year medical students in an Israeli medical school during 2002–3. In addition, focus groups were conducted with medical students (n = 210) during 1998–2001. A gap was found between the rhetoric of “patient-centered communication” and “empathy” and the traditional concerns of medical authority, efficiency, and scientism. Communication skills and empathy training were appropriated into medical socialization by being reconstructed as clinical competence. Findings are further discussed in the context of medical professionalism, Israeli culture, service acting and service roles, and organizational learning.  相似文献   
64.
Chitin and Chitosan: Functional Biopolymers from Marine Crustaceans   总被引:3,自引:0,他引:3  
Chitin and chitosan, typical marine polysaccharides as well as abundant biomass resources, are attracting a great deal of attention because of their distinctive biological and physicochemical characteristics. To fully explore the high potential of these specialty biopolymers, basic and application researches are being made extensively. This review deals with the fundamental aspects of chitin and chitosan such as the preparation of chitin and chitosan, crystallography, extent of N-acetylation, and some properties. Recent progress of their chemistry is then discussed, focusing on elemental modification reactions including acylation, alkylation, Schiff base formation and reductive alkylation, carboxyalkylation, phthaloylation, silylation, tosylation, quaternary salt formation, and sulfation and thiolation.  相似文献   
65.
Abstract

One of the most interesting questions in bioelectromagnetic and compatibility studies is differences between results of experiments performed in different labs in “identical” conditions, especially in bioelectromagnetics studies. A reason of these differences may be due to differences in investigated objects, particularly in in vivo experiments. However, the author, as engineer, would like to focus the readers' attention on the technical aspects of exposure systems namely: presence and role of mutual interaction between the object under test and the exposure system, interaction between exposure objects, the role of polarization and the similarity of real-life exposure to those applied in experiments, etc. All these factors may change the results of experiments and lead to false conclusions.  相似文献   
66.
磁性纳米材料,由于其独特的磁学性能、小尺寸效应,被广泛应用于生物医学领域.本文总结了磁性纳米材料的化学设计与合成、表面功能化方法,及其在核磁共振成像、磁控治疗、磁热疗和生物分离等生物医学领域的应用进展.  相似文献   
67.
生物医学动物实验中的实验设计和统计分析   总被引:1,自引:0,他引:1  
实验设计和统计分析在动物实验研究的启动、实施和结果评价中起着关键的作用。我们对实验设计的因素、原则及实验设计类型进行了综述,阐明了统计分析在整个研究所有环节中的重要意义,并提出在生物医学动物实验中容易忽视的统计学分析的问题。  相似文献   
68.
Benedict Rumbold 《Bioethics》2017,31(7):543-551
In this article I seek to establish what, if anything, might be morally troubling about morally enhancing oneself through biomedical means. Building on arguments by Harris, while simultaneously acknowledging several valid counter‐arguments that have been put forth by his critics, I argue that taking BMEs necessarily incurs at least one moral cost in the restrictions they impose on our freedom. This does not necessarily entail that the use of BMEs cannot be overall justified, nor that, in certain cases, their costs may not be forestalled. It does show, however, that their use is not morally neutral. There is a cost to such technologies and, as such, the onus will always be on their defenders to show that these costs can compensated for.  相似文献   
69.
Patient-specific simulations of heart (dys)function aimed at personalizing cardiac therapy are hampered by the absence of in vivo imaging technology for clinically acquiring myocardial fiber orientations. The objective of this project was to develop a methodology to estimate cardiac fiber orientations from in vivo images of patient heart geometries. An accurate representation of ventricular geometry and fiber orientations was reconstructed, respectively, from high-resolution ex vivo structural magnetic resonance (MR) and diffusion tensor (DT) MR images of a normal human heart, referred to as the atlas. Ventricular geometry of a patient heart was extracted, via semiautomatic segmentation, from an in vivo computed tomography (CT) image. Using image transformation algorithms, the atlas ventricular geometry was deformed to match that of the patient. Finally, the deformation field was applied to the atlas fiber orientations to obtain an estimate of patient fiber orientations. The accuracy of the fiber estimates was assessed using six normal and three failing canine hearts. The mean absolute difference between inclination angles of acquired and estimated fiber orientations was 15.4 °. Computational simulations of ventricular activation maps and pseudo-ECGs in sinus rhythm and ventricular tachycardia indicated that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.The new insights obtained from the project will pave the way for the development of patient-specific models of the heart that can aid physicians in personalized diagnosis and decisions regarding electrophysiological interventions.  相似文献   
70.
《Trends in biotechnology》2020,38(3):264-279
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