共查询到20条相似文献,搜索用时 206 毫秒
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F. van Leuven 《Molecular and cellular biochemistry》1984,58(1-2):121-128
Summary Human 2macroglobulin combines two unique features: the non-active site directed inhibition of virtually all endoproteases and the selective clearance of 2M-endoprotease complexes by receptor-mediated endocytosis. To study the molecular details of the mechanisms involved, primary amines were found to be worthwhile probes at three specific levels: the inactivation of native 2M, the derivatization by factor XIII and the cellular process of receptor-recycling. In this paper published data are supplemented with recently obtained evidence to discuss and speculate on the possible action or involvement of transglutaminase activities, indicated by the effects of the primary amines. 相似文献
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Shuichi Hashizume Hiroki Murakami Sachiko Hirose Toshikazu Shirai Kazuki Shinohara Hirohisa Omura 《Bioscience, biotechnology, and biochemistry》2013,77(5):1351-1353
The effects of modification of the arginine/lysine ratio of dietary protein on the cholesterol kinetics were studied in male rats. Single amino acids (lysine to soybean protein and arginine to casein) were added to approximate the arginine/lysine ratio in different proteins. After acclimation to these diets for 30 days, rats were administered intravenous [14C]cholesterol and oral [3H]cholesterol. Analysis of the die-away curve of [14C]cholesterol showed an apparent independence of cholesterol kinetics to the dietary manipulations, but there was a moderate reduction of the size of the slowly exchangeable pool and of the biliary concentration of cholesterol when lysine was added to soybean protein. Addition of amino acids neither influenced cholesterol absorption nor the fecal excretion of the radioactivities from labeled cholesterol. The results indicate that manipulating the arginine/lysine ratio of dietary protein by adding single amino acids is not necessarily effective in ameliorating cholesterol metabolism in rats, although the arginine addition caused a significant reduction of serum cholesterol and triglyceride. 相似文献
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X-Linkage of Human α-Galactosidase 总被引:5,自引:0,他引:5
K. H. GRZESCHIK A. M. GRZESCHIK S. BANHOF G. ROMEO M. SINISCALCO H. VAN SOMEREN P. MEERA KHAN A. WESTERVELD D. BOOTSMA 《Nature: New biology》1972,240(97):48-50
A deficiency in α-galactosidase (α-Gal) activity–as measured aspecifically with the use of artificial substrates–is a regular feature in leucocytes and fibroblasts of patients affected by angiokeratoma corporis diffusum or Fabry's disease, a well-known X-linked trait in man1–4. Fibroblast clones derived from mothers of affected males exhibit either normal or deficient activity of α-galactosidase. This demonstrates that the deficiency of α-galactosidase is caused by an X-linked mutation, but does not necessarily prove that the structural locus for this enzyme is itself located on the X-chromosome. 相似文献
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It was a common belief in the first half of this century that human schistosomiasis would not become established in India, despite the regular introduction of the disease by soldiers returning from active campaigns. This was based on the absence of known intermediate hosts for Schistosoma spp, yet in 1952 a focus of human schistosomiasis was discovered in Gimvi village, Ratnagiri District, Maharashtra State. The focus seems to be in recession, but the proposed large irrigation schemes centering upon the Narmada River may exacerbate schistosomiasis in domestic stock, and possibly in humans. Here, Vaughan Southgate and Matesh Agrawal discuss the findings in Gimvi, and the possibilities of human schistosomiasis in India in the future. 相似文献
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Deborah L. Wells 《Anthrozo?s》2019,32(2):169-181
ABSTRACTSince the late 1970s, scientific evidence has accumulated showing that pet ownership can have positive effects on people’s physical and mental wellbeing. This paper reviews the current state of affairs regarding the relationship between companion animals and human health, focusing on both the physical and psychological health outcomes related to human–animal interactions. Although designed to set the general scene on the link between animals and human wellbeing, research specific to older adults is highlighted where relevant. A particular emphasis is placed on disorders prevalent in modern-day society, notably cardiovascular disease and depression. The possible mechanisms by which companion animals might be able to enhance human wellbeing and quality of life are discussed, focusing on routes including, amongst others, the provision of companionship, social lubrication, and improvements to physical fitness. The role of the social bonding hormone, oxytocin, in facilitating attachment to our pets and the implications for human health is also discussed. Inconsistencies in the literature and methodological limitations are highlighted throughout. It is concluded that future human–animal interaction experiments should aim to account for the confounding variables that are inherent in studies of this nature. 相似文献
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ABSTRACTIn 2016, the Gerontological Society of America (GSA) developed a research focus on the benefits and potential risks associated with pets among older adults. With the goal of developing a roadmap for human–animal interaction (HAI) research in older people residing in both the community and institutions, GSA convened a workshop of international experts and policy-makers in the fields of aging and HAI. The status of current knowledge was shared on the success factors for healthy aging and the potential challenges (GSA, 2016). Participants considered what roles pets might play in the lives of older adults and their potential to mitigate loneliness, social isolation, and depression, and to enhance mobility and cognitive function. Existing research was shared to provide insights into the ways in which pets can impact older adults and their caregivers and to identify where further research is needed. This paper introduces a series of papers from that meeting, with some additional papers from meeting attendees to expand on the topics covered and provide key perspectives and gaps in information needed, as a foundation for those considering research into this topic. Although HAI/Animal-Assistant Intervention (AAI) research is in its infancy, there is some evidence that pet ownership or animal interaction can have major benefits for many older adults. At the same time, there are some risks to both the pet and the older adult that need to be addressed. Innovative approaches to both AAIs and the ways to overcome challenges are presented in this themed issue of Anthrozoös. Our hope is that the findings from these reviews and reports will stimulate additional work in this area. 相似文献
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《Anthrozo?s》2013,26(4):194-202
ABSTRACTA sample of 514 adults completed a postal questionnaire measuring both their empathy with humans (using the Mehrabian and Epstein (1972) Questionnaire for the Measurement of Emotional Empathy) and their empathy with non-human animals (using the Animal Empathy Scale, developed for this study). There was a significant, but modest correlation between the two scales (Kendall's tau=0.26, p<0.001), indicating that although the two types of empathy measure are in some way linked, they are unlikely to tap a single, unitary construct. This conclusion is reinforced by the finding that human- and animal-oriented empathy exhibit different levels of association with different potential sources of variation. Animal-oriented empathy was related to the current ownership of pets (U=19825.5, p<0.0001) and to the ownership of pets during childhood (U= 10271.0, p<0.01), while human-oriented empathy was related to currently having a child or children at home (U= 21020.5, p<0.05). 相似文献
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Marga Vicedo 《Journal of the history of biology》2018,51(2):191-221
This paper explores ethologist Niko Tinbergen’s path from animal to human studies in the 1960s and 1970s and his views about human nature. It argues, first, that the confluence of several factors explains why Tinbergen decided to cross the animal/human divide in the mid 1960s: his concern about what he called “the human predicament,” his relations with British child psychiatrist John Bowlby, the success of ethological explanations of human behavior, and his professional and personal situation. It also argues that Tinbergen transferred his general adaptationist view of animal behavior to the realm of human biology; here, his concern about disadaptation led him to a view of human behavior that was strongly determined by the species’ evolutionary past, a position that I call evolutionary determinism. These ideas can be seen in the work he carried out with his wife, Elisabeth Tinbergen, on autism. The paper concludes that Tinbergen’s vision of human nature constitutes another version of what anthropologist Clifford Geertz called in 1966 the “stratigraphic” conception of the human: a view of human nature as a composite of levels in which a universal ancestral biological core is superimposed by psychological and cultural layers that represent accidental variation at best and pathological deviation at worst. 相似文献
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Masaaki Yoshdcawa Takashi Yoshimura Hideo Chiba 《Bioscience, biotechnology, and biochemistry》2013,77(12):3185-3187
A bacterium that assimilates 2,3-dichloro-1-propanol was isolated from soil by enrichment culture. The strain was identified as Pseudomonas sp. by the taxonomic studies. The strain converted 2,3-dichloro-1-propanol to 3-chloro-1,2-propanediol, releasing chloride ion. The conversion was stereospecific because the residual 2,3-dichloro-1-propanol and formed 3-chloro-1,2-propanediol gave optical rotation. The resting cells converted various halohydrins to the dehalogenated alcohols, and cell-free extracts had strong epoxyhydrolase activity. These results indicated that the strain assimilated 2,3-dichloro-1-propanol via 3-chloro-1,2-propanediol, glycidol, and glycerol. The possibility to manufacture optically active 2,3-dichloro-1-propanol is discussed. 相似文献
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Pablo D. Becker Nicolas Legrand Caroline M. M. van Geelen Miriam Noerder Nicholas D. Huntington Annick Lim Etsuko Yasuda Sean A. Diehl Ferenc A. Scheeren Michael Ott Kees Weijer Heiner Wedemeyer James P. Di Santo Tim Beaumont Carlos A. Guzman Hergen Spits 《PloS one》2010,5(10)
Background
Passive transfer of antibodies not only provides immediate short-term protection against disease, but also can be exploited as a therapeutic tool. However, the ‘humanization’ of murine monoclonal antibodies (mAbs) is a time-consuming and expensive process that has the inherent drawback of potentially altering antigenic specificity and/or affinity. The immortalization of human B cells represents an alternative for obtaining human mAbs, but relies on the availability of biological samples from vaccinated individuals or convalescent patients. In this work we describe a novel approach to generate fully human mAbs by combining a humanized mouse model with a new B cell immortalization technique.Methodology/Principal Findings
After transplantation with CD34+CD38− human hematopoietic progenitor cells, BALB/c Rag2−/−IL-2Rγc−/− mice acquire a human immune system and harbor B cells with a diverse IgM repertoire. “Human Immune System” mice were then immunized with two commercial vaccine antigens, tetanus toxoid and hepatitis B surface antigen. Sorted human CD19+CD27+ B cells were retrovirally transduced with the human B cell lymphoma (BCL)-6 and BCL-XL genes, and subsequently cultured in the presence of CD40-ligand and IL-21. This procedure allows generating stable B cell receptor-positive B cells that secrete immunoglobulins. We recovered stable B cell clones that produced IgM specific for tetanus toxoid and the hepatitis B surface antigen, respectively.Conclusion/Significance
This work provides the proof-of-concept for the usefulness of this novel method based on the immunization of humanized mice for the rapid generation of human mAbs against a wide range of antigens. 相似文献15.
Roberta d’Emmanuele di Villa Bianca Emma Mitidieri Davide Esposito Erminia Donnarumm Annapina Russo Ferdinando Fusco Angela Ianaro Vincenzo Mirone Giuseppe Cirino Giulia Russo Raffaella Sorrentino 《PloS one》2015,10(9)
Urothelium, the epithelial lining the inner surface of human bladder, plays a key role in bladder physiology and pathology. It responds to chemical, mechanical and thermal stimuli by releasing several factors and mediators. Recently it has been shown that hydrogen sulfide contributes to human bladder homeostasis. Hydrogen sulfide is mainly produced in human bladder by the action of cystathionine-β-synthase. Here, we demonstrate that human cystathionine-β-synthase activity is regulated in a cGMP/PKG-dependent manner through phosphorylation at serine 227. Incubation of human urothelium or T24 cell line with 8-Bromo-cyclic-guanosine monophosphate (8-Br-cGMP) but not dibutyryl-cyclic-adenosine monophosphate (d-cAMP) causes an increase in hydrogen sulfide production. This result is congruous with the finding that PKG is robustly expressed but PKA only weakly present in human urothelium as well as in T24 cells. The cGMP/PKG-dependent phosphorylation elicited by 8-Br-cGMP is selectively reverted by KT5823, a specific PKG inhibitor. Moreover, the silencing of cystathionine-β-synthase in T24 cells leads to a marked decrease in hydrogen sulfide production either in basal condition or following 8-Br-cGMP challenge. In order to identify the phosphorylation site, recombinant mutant proteins of cystathionine-β-synthase in which Ser32, Ser227 or Ser525 was mutated in Ala were generated. The Ser227Ala mutant cystathionine-β-synthase shows a notable reduction in basal biosynthesis of hydrogen sulfide becoming unresponsive to the 8-Br-cGMP challenge. A specific antibody that recognizes the phosphorylated form of cystathionine-β-synthase has been produced and validated by using T24 cells and human urothelium. In conclusion, human cystathionine-β-synthase can be phosphorylated in a PKG-dependent manner at Ser227 leading to an increased catalytic activity. 相似文献
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Albrecht U 《Genome biology》2004,5(11):246-5
Recent research on mouse models has taken us closer to deciphering the molecular clock mechanism that defines an individual's 'body time'. How feasible will it be to create a molecular timetable that allows determination of individual body time from tissue harvested at a single time point? 相似文献
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Xenotropic murine leukemia virus-related virus (XMRV) has been proposed to be associated with prostate cancer and chronic fatigue syndrome (CFS). This proposition has been controversial because many investigators have failed to replicate the reported associations. Here, we explore whether XMRV is an authentic human pathogen in the light of recent findings that indicate otherwise. 相似文献