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排序方式: 共有1363条查询结果,搜索用时 15 毫秒
1.
In vivo Kinetic Biodistribution of Nano‐Sized Outer Membrane Vesicles Derived from Bacteria 下载免费PDF全文
Su Chul Jang Sae Rom Kim Yae Jin Yoon Kyong‐Su Park Ji Hyun Kim Jaewook Lee Oh Youn Kim Eun‐Jeong Choi Dae‐Kyum Kim Dong‐Sic Choi Yoon‐Keun Kim Jaesung Park Dolores Di Vizio Yong Song Gho 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(4):456-461
Evaluation of kinetic distribution and behaviors of nanoparticles in vivo provides crucial clues into their roles in living organisms. Extracellular vesicles are evolutionary conserved nanoparticles, known to play important biological functions in intercellular, inter‐species, and inter‐kingdom communication. In this study, the first kinetic analysis of the biodistribution of outer membrane vesicles (OMVs)—bacterial extracellular vesicles—with immune‐modulatory functions is performed. OMVs, injected intraperitoneally, spread to the whole mouse body and accumulate in the liver, lung, spleen, and kidney within 3 h of administration. As an early systemic inflammation response, increased levels of TNF‐α and IL‐6 are observed in serum and bronchoalveolar lavage fluid. In addition, the number of leukocytes and platelets in the blood is decreased. OMVs and cytokine concentrations, as well as body temperature are gradually decreased 6 h after OMV injection, in concomitance with the formation of eye exudates, and of an increase in ICAM‐1 levels in the lung. Following OMV elimination, most of the inflammatory signs are reverted, 12 h post‐injection. However, leukocytes in bronchoalveolar lavage fluid are increased as a late reaction. Taken together, these results suggest that OMVs are effective mediators of long distance communication in vivo. 相似文献
2.
Dr. Alejandra A. Carriles Alberto Mills Dr. María-José Muñoz-Alonso Dr. Dolores Gutiérrez Dr. Juan M. Domínguez Prof. Dr. Juan A. Hermoso Prof. Dr. Federico Gago 《Chembiochem : a European journal of chemical biology》2021,22(2):374-391
Spontaneous mutations in the EEF1A2 gene cause epilepsy and severe neurological disabilities in children. The crystal structure of eEF1A2 protein purified from rabbit skeletal muscle reveals a post-translationally modified dimer that provides information about the sites of interaction with numerous binding partners, including itself, and maps these mutations onto the dimer and tetramer interfaces. The spatial locations of the side chain carboxylates of Glu301 and Glu374, to which phosphatidylethanolamine is uniquely attached via an amide bond, define the anchoring points of eEF1A2 to cellular membranes and interorganellar membrane contact sites. Additional bioinformatic and molecular modeling results provide novel structural insight into the demonstrated binding of eEF1A2 to SH3 domains, the common MAPK docking groove, filamentous actin, and phosphatidylinositol-4 kinase IIIβ. In this new light, the role of eEF1A2 as an ancient, multifaceted, and articulated G protein at the crossroads of autophagy, oncogenesis and viral replication appears very distant from the “canonical” one of delivering aminoacyl-tRNAs to the ribosome that has dominated the scene and much of the thinking for many decades. 相似文献
3.
Daniela M. Nevskaia Maria Luisa Rojas Cervantes Antonio Guerrero Ruíz Juan de Dios Lpez Gonzlez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,63(3):249-256
Adsorption of Triton X-100 on various silica substrates has been investigated. A number of solids, including a natural quartz, this quartz washed with HCl acid and subsequently heated at 1273 K; two aerosils and one Kieselgel silicas were studied. These solids exhibit surface areas in the range of 5 to 430 m2 g?1. All the Triton adsorption isotherms display an S-shape at the adsorption temperatures studied (298 and 308 K). It has been found that the pretreatments of natural quartz (by water washing, impurities removed by acid and/or high temperature calcination) affect considerably the amounts of TX-100 adsorbed. Measurements of surface composition have been made by X-ray photoelectron spectroscopy (XPS) with particular emphasis on the presence of impurities and on the number of OH groups at the surface of the samples. The nature of the surface hydroxyl has also been studied by infrared spectroscopy. Furthermore, the specific number of hydroxyl groups on the surface of the silica samples has been determined by thermogravimetric analysis. Finally an attempt to correlate solid surface characteristics with adsorption isotherms has been developed. 相似文献
4.
MP Romero A García-Perga?eda JM Guerrero C Osuna 《Canadian Metallurgical Quarterly》1998,12(13):1401-1408
Melatonin has been suggested as a physiological antagonist of calmodulin. In this work, we have characterized melatonin binding sites in Xenopus laevis oocyte membranes. Binding of [125I]melatonin by X. laevis oocyte membranes fulfills all criteria for binding to a receptor site. Binding was dependent on time, temperature, and membrane concentration and was stable, reversible, saturable, and specific. The binding site was also pharmacologically characterized. Stoichiometric studies showed a high-affinity binding site with a Kd of 1.18 nM. These data are in close agreement with data obtained from kinetic studies (Kd=0.12 nM). In competition studies, we observed a low-affinity binding site (Kd=63.41 microM). Moreover, the binding site was characterized as calmodulin. Thus, binding was dependent on calcium and blocked by anti-CaM antibodies in a concentration-dependent manner. Calmodulin inhibitor chlorpromazine also inhibited binding of the tracer. From these results, it is suggested that membrane-bound calmodulin acts as a melatonin binding site in Xenopus laevis oocytes, where it might couple cellular activities to rhythmic circulating levels of melatonin. This hypothesis correlates with the previous findings describing melatonin as a physiological antagonist of calmodulin. 相似文献
5.
María Pinto Dora Sales Anne-Vinciane Doucet Andrés Fernández-Ramos David Guerrero 《Scientometrics》2007,72(2):345-370
The purpose of the study proposed in this paper is to evaluate the Spanish public university websites dedicated to the European
Higher Education Area (EHEA). To do so, the quality of these resources has been analysed in the light of data provided by
a series of indicators grouped in seven criteria, most of which were used to determine what information is made available
and in what way. The criteria used in our analysis are: visibility, authority, updatedness, accesibility, correctness and
completeness, quality assessment and navigability.
All in all, the results allow us to carry out an overall diagnosis of the situation and also provide us with information about
the situation at each university, thus revealing their main strengths, namely authority and navegability, and also their chief
shortcomings: updatedness, accessibility and quality assessment. In this way it is possible to detect the best practices in
each of the aspects evaluated so that they can serve as an example and guide for universities with greater deficiencies and
thus help them to improve their EHEA websites. 相似文献
6.
Malik Mary L.; Beutler Larry E.; Alimohamed Shabia; Gallagher-Thompson Dolores; Thompson Larry 《Canadian Metallurgical Quarterly》2003,71(1):150
The definition of an empirically supported treatment (EST) arguably embodies 2 untested assumptions: (a) that different manualized renditions of the same therapy are functionally equivalent and (b) that therapies can be reliably applied independently of therapist, setting, and format. These assumptions were tested as applied to cognitive therapy (CT), using process data from a large multisite study (N=235) that included 3 cognitive and 6 alternative therapies. Although the non-CTs were more variable than the CTs on 2 of 4 dimensions studied (directiveness and emotional arousal), there was considerable variation among the 3 CTs, even when implemented in the current context of rigorous training, manualization, and adherence checks. Results are discussed as related to the assumptions underlying EST criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
JC Hernández Guerrero J Portilla Robertson C Ledezma Montes S Ponce-Bravo A Miranda Gómez EM Arias Rivera 《Canadian Metallurgical Quarterly》1996,44(1-4):25-30
Several forms of cell perturbation have been associated with ethanol ingestion. Fetal alcohol syndrome (FAS) as well as diminished maxillofacial development and inhibition of cell regeneration in vitro and in vivo have been described. Epidermal growth factor (EGF) stimulates maxillofacial growth, DNA synthesis, and it is a potent mitogen for a number of various cell types. EGF exerts its effects on cells through binding to a specific cell surface receptor which leads to activation of a thyrosine kinase in the intracellular part of the receptor. The inhibitory effect of alcohol on EGF in the mouse dental follicle was studied in the offspring of alcoholic mothers using immunocytochemistry. Adult female mice were given 22% alcohol in their drinking water and fed a pelleted diet before and during pregnancy. Maternal blood alcohol levels were 262 +/- 1.3 mg/100 ml on gestation day 12.5. The offspring of the alcoholic and control mice were sacrificed on postnatal day 1.5, their mandibles were dissected, weighed and processed by routine immunocytochemistry with the following results. 1) Significant differences were found in mandible weight p < 0.01 after parturition. 2) The tooth germs in the offspring of ethanol treated mice were morphometrically smaller than those of control littermates. 3) Immunoexpression of EGF in the mandibular first molar of the control group was strong and homogeneous while in the experimental group the expression was light and heterogeneous. It is concluded that maternal alcoholism reduces EGF in the offspring. 相似文献
8.
N Benito A Nú?ez M de Górgolas J Esteban T Calabuig MC Rivas ML Fernández Guerrero 《Canadian Metallurgical Quarterly》1997,157(14):1577-1580
BACKGROUND: Fever is commonly observed in patients with human immunodeficiency virus (HIV) disease and frequently eludes diagnosis. The role of bone marrow biopsy in the diagnosis of fever of unknown origin in patients infected with HIV remains controversial. PATIENTS AND METHODS: One hundred twenty-three consecutive patients with 137 episodes of fever lasting 10 or more days without diagnosis after 1 week of hospitalization were evaluated by bone marrow biopsy. RESULTS: Overall, a specific diagnosis was achieved in 52 episodes by means of culture and histopathological examination (diagnostic yield, 37.9%). Three types of disease were found: mycobacterial infections (n = 36, 69% of documented episodes), including 18 patients with disseminated tuberculosis and 14 with Mycobacterium avium-intracellulare complex infections; non-Hodgkin lymphomas (n = 12, 23%); and visceral leishmaniasis (n = 4, 8%). Although bone marrow cultures were more sensitive than microscopic examination with special stains for the diagnosis of mycobacterial infections, the pathological examination of bone marrow led to a more rapid diagnosis of disease. In addition, the histopathological examination of bone marrow alone led to the diagnosis of a specific condition in 43 episodes (31.3% of all episodes). CONCLUSIONS: Bone marrow biopsy is a useful procedure for the diagnosis of fever in patients with advanced HIV disease, particularly in areas where tuberculosis and leishmaniasis are prevalent. Involvement of the marrow may be the first indication of the existence of extranodal non-Hodgkin lymphoma. For Mycobacterium avium-intracellulare complex infection, blood cultures were more sensitive than bone marrow biopsy. 相似文献
9.
Astaxanthin Extraction From Shrimp Waste by Lactic Fermentation and Enzymatic Hydrolysis of the Carotenoprotein Complex 总被引:1,自引:0,他引:1
ABSTRACT: Natural carotenoids are an alternative to synthetic orange-red pigments. They are present in crustaceans as a protein-pigment complex. In order to extract this highly unstable pigment, crustacean waste must be stabilized; lactic fermentation is a simple and environmentally friendly method to achieve this goal. Shrimp wastes were inoculated with Lactobacillus bacterial cultures. Carotenoids were then extracted with an organic solvent system. Protein-pigment splitting was carried out using a mixture of 4 commercial enzymes; and the protein was separated from the pigment by ultrafiltration. Electrophoretograms showed that the pigment was attached to a 265-kDa protein. Splitting the protein-pigment complex allows studies on pigment absorption, stability and application. 相似文献
10.
Jarrett Robin B.; Basco Monica R.; Risser Richard; Ramanan Janaki; Marwill Maria; Kraft Dolores; Rush A. John 《Canadian Metallurgical Quarterly》1998,66(6):1036
Two pilot studies evaluated the rate of relapse or recurrence (i.e., major depressive disorder) after cognitive therapy (CT). Two sequential cohorts included outpatients who responded to acute phase CT (A-CT) and who agreed to monthly, treatment-free follow-up. In Study 1, the Kaplan-Meier technique estimated relapse and recurrence rates of 40% at 6 months, 45% at 8 months, 50% at 12 months, 67% at 18 months, and 74% at 24 months. In Study 2, responders to A-CT received 8 months (10 sessions) of continuation phase CT (C-CT). In Study 2, relapse or recurrence was 20% at 6 and 8 months, 27% at 12 months, and 36% at 18 and 24 months after A-CT. An exploratory log-rank test showed that relapse or recurrence-free survival was greater in Study 2 than in Study 1. If replicated, this result suggests that C-CT can reduce depressive relapse or recurrence. Alternative explanations are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献