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排序方式: 共有644条查询结果,搜索用时 15 毫秒
1.
2.
J. Sherrod DeVerse Keith A. Bailey Greg A. Foster Vaishali Mittal Stuart M. Altman Scott I. Simon Anthony G. Passerini 《Journal of visualized experiments : JoVE》2012,(65)
Atherogenesis is potentiated by metabolic abnormalities that contribute to a heightened state of systemic inflammation resulting in endothelial dysfunction. However, early functional changes in endothelium that signify an individual''s level of risk are not directly assessed clinically to help guide therapeutic strategy. Moreover, the regulation of inflammation by local hemodynamics contributes to the non-random spatial distribution of atherosclerosis, but the mechanisms are difficult to delineate in vivo. We describe a lab-on-a-chip based approach to quantitatively assay metabolic perturbation of inflammatory events in human endothelial cells (EC) and monocytes under precise flow conditions. Standard methods of soft lithography are used to microfabricate vascular mimetic microfluidic chambers (VMMC), which are bound directly to cultured EC monolayers.1 These devices have the advantage of using small volumes of reagents while providing a platform for directly imaging the inflammatory events at the membrane of EC exposed to a well-defined shear field. We have successfully applied these devices to investigate cytokine-,2 lipid-3, 4 and RAGE-induced5 inflammation in human aortic EC (HAEC). Here we document the use of the VMMC to assay monocytic cell (THP-1) rolling and arrest on HAEC monolayers that are conditioned under differential shear characteristics and activated by the inflammatory cytokine TNF-α. Studies such as these are providing mechanistic insight into atherosusceptibility under metabolic risk factors. 相似文献
3.
The current examination was intended to observe the defensive impacts of embelin against paraquat‐incited lung damage in relationship with its antioxidant and anti‐inflammatory action. Oxidative stress marker, like malondialdehyde (MDA), antioxidative enzymes, for example, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH Px), inflammatory cytokines, such as interleukin‐1β (IL‐1β), tumor necrosis factor‐α, and IL‐6, histological examination, and nuclear factor kappa B/mitogen‐activated protein kinase (NF‐κB/MAPK) gene expression were evaluated in lung tissue. Embelin treatment significantly decreased MDA and increased SOD, CAT, and GSH Px. Embelin significantly reduced levels of inflammatory cytokines in paraquat‐administered and paraquat‐intoxicated rats. In addition, embelin suggestively decreased relative protein expression of nuclear NF‐κB p65, p‐NF‐κBp65, p38 MAPK, and p‐p38 MAPKs in paraquat‐intoxicated rats. The outcomes show the impact of embelin inhibitory action on NF‐κB and MAPK and inflammatory cytokines release, and the decrease of lung tissue damage caused by paraquat. 相似文献
4.
Uta Kühne Branka Filjak Hans Kröger 《Biochimica et Biophysica Acta (BBA)/General Subjects》1975,399(1):42-49
An injection of cortisone acetate at a dose of 5 mg/100 g body weight concomitant with dibutryl cyclic AMP prevents the increase in the activity of rat liver cytosol serine aminotransferase (L-serine: pyruvate aminotransferase, EC 2.6.1.51) elicited by the nucleotide with a lag of about 2 h. If the glucocorticoid is given 2 h prior to the nucleotide inducer, the lag disappears. The inhibitory effect of cortisone acetate gradually decays and is no longer detectable 12 h following its administration. Theophylline, insulin and glucose at doses which affect significantly the level of tyrosine aminotransferase, have no effect on the level of serine aminotransferase and on the cortisone inhibition. The inhibitory effect of the glucocorticoid on the dibutyryl cyclic AMP-mediated increase in serine aminotransferase diminishes with the age of animals. Increase in the enzyme activity by a single dose of glucagon can also be inhibited by cortisone acetate and actinomycin D as in the case with dibutyrl cyclic AMP as an inducer. The possibility of the existence of a specific inhibitory factor which is formed in response to cortisone acetate is discussed. 相似文献
5.
Zinc is essential for normal growth, development and brain function although little is known about brain zinc homeostasis. Therefore, in this investigation we have studied65Zn uptake from blood into brain and other tissues and have measured the blood-brain barrier permeability to65Zn in the anaesthetized rat in vivo. Adult male Wistar within the weight range 500–600 g were used.65ZnCl2 and [125I]albumin, the latter serving as a vascular marker, were injected in a bolus of normal saline I.V. Sequential arterial blood samples were taken during experiments that lasted between 5 min and 5 hr. At termination, samples from the liver, spleen, pancreas, lung, heart, muscle, kidney, bone, testis, ileum, blood cells, csf, and whole brain were taken and analysed for radio-isotope activity. Data have been analysed by Graphical Analysis which suggests65Zn uptake from blood by all tissues sampled was unidirectional during this experimental period except brain, where at circulation times<30 min,65Zn fluxes were bidirectional. In addition to the blood space, the brain appears to contain a rapidly exchanging compartment(s) for65Zn of about 4 ml/100g which is not csf. 相似文献
6.
Zinc is essential for normal development and function of the CNS although much is to be learned about brain Zn homeostasis. In these experiments adult male Wistar rats within the weight range 500–600 g were used. Ventriculo-cisternal perfusion was performed to allow the measurement of65Zn fluxes between blood and csf across the choroid plexuses. Blood-brain or blood-cerebrospinal fluid barrier permeability to65Zn has been determined by graphical analysis in experiments that lasted between 5 and 180 minutes. Cerebral capillary permeability to65Zn was found to be low with a Kin of about 5×10–4ml/min/g. Choroid plexus permeability to65Zn was about 12 fold greater, although Zn influx to brain via this route was <5% that across cerebral capillaries. The autoradiographic distribution of65Zn in brain showed regional variation with lowest levels in white matter and high levels in the dentate gyrus and hippocampus. 相似文献
7.
When grown with nitrate as terminal electron acceptor both the soluble (periplasm, cytoplasm) and the membrane fraction of Spirillum strain 5175 exhibited high nitrite reductase activity. The nitrite reductase obtained from the soluble fraction was purified 76-fold to electrophoretical homogeneity. The enzyme reduced nitrite to ammonia with a specific activity of 723 mol NO
inf2
sup-
× (mg protein × min)-1. The molecular mass was 58±1 kDa by SDS-PAGE compared to 59±2 kDa determined by size exclusion chromatography under nondenaturing conditions. The enzyme (as isolated) contained 5.97±0.15 heme c molecules/Mr 58 kDa. The absorption spectrum was typical for c-type cytochrome with maxima at 280, 408, 532 and 610 nm (oxidized) and at 420, 523 and 553 nm (dithionite-reduced). The enzyme (as isolated) exhibited a complex set of high-spin and lowspin ferric heme resonances with g-values at 9.82, 3,85, 3.31, 2.95, 2.30 and 1.49 in agreement with data reported for electron paramagnetic resonance spectra of nitrite reductases from Desulfovibrio desulfuricans, Wolinella succinogenes and Escherichia coli.Abbreviations DNRA
dissimilatory nitrate reduction to ammonia
- EPR
electron paramagnetic resonance
- PAGE
polyacrylamide gel electrophoresis
- NaPi
sodium phosphate
- SDS
sodium dodecylsulfate 相似文献
8.
Using the whole-cell configuration of the patch-clamp technique, we studied the conditions necessary for the activation of
Cl−-currents in retinal pigment epithelial (RPE) cells from rats with retinal dystrophy (RCS) and nondystrophic control rats.
In RPE cells from both rat strains, intracellular application of 10 μm inositol-1,4,5-triphosphate (IP3) via the patch pipette led to a sustained activation of voltage-dependent Cl− currents, blockable by 1 mm 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS). IP3 activated Cl− currents in the presence of a high concentration of the calcium chelator BAPTA (10 mm) in the pipette solution, but failed to do so when extracellular calcium was removed. Intracellular application of 10−5
m Ca2+ via the patch pipette also led to a transient activation of Cl− currents. When the cells were preincubated in a bath solution containing thapsigargin (1 μm) for 5 min before breaking into the whole-cell configuration, IP3 failed to activate voltage-dependent currents. Thus, IP3
led to release of Ca2+ from cytosolic calcium stores. This in turn activated an influx of extracellular calcium into the submembranal space by a
mechanism as yet unknown, leading to an activation of calcium-dependent chloride currents. In RPE cells from RCS rats, which
show an increased membrane conductance for calcium compared to normal rats, we observed an accelerated speed of Cl−-current activation induced by IP3 which could be reduced by nifedipine (1 μm). Thus, the increased membrane conductance to calcium in RPE cells from RCS rats changes the response of the cell to the
second messenger IP3.
Received: 17 July 1995/Revised: 31 January 1996 相似文献
9.
Patrick J. Cummings Sharon S. Rowland Nancy E. Hooper Richard S. Schwalbe 《Microbiology and immunology》1996,40(11):883-886
Murine monoclonal antibodies were produced against Mycobacterium tuberculosis (Mtb) using standard hybridoma procedures. By a whole cell enzyme-linked immunosorbent assay (ELISA), one monoclonal antibody (mAb), HB28, demonstrated high level specific reactivity to Mtb. Western blot analysis demonstrated reactivity to a single 65 kDa Mtb protein in the cell wall extract and culture filtrate. HB28 mAb appears to be recognizing a 65 kDa Mtb protein that is over-expressed by Mtb but not other species under certain culture conditions. Differential expression and detection of this protein by HB28 mAb may have potential for diagnostic applications. 相似文献
10.
J. De Kok C. Van Der Schoot M. Veldhuizen H. Th. Wolterbeek 《Biological trace element research》1993,38(1):13-26
The in vitro uptake of zinc by erythrocytes was measured under near-physiological conditions, using65Zn as a radioactive tracer. Because of the presence of serum albumin—a strong zinc ligand—a low concentration of medium free
zinc was maintained. Under these conditions a high-affinity carrier for zinc transport over the cell membrane was identified.
With human erythrocytes, a Michaelis constant (K
m
) of 0.2 nM with respect to free medium zinc was measured and aV
max
of 4.5 nmoles Zn transported per h/g dry wt. TheK
m
for medium Zn increases when the size of the internal erythrocytic Zn pool is augmented, whereasV
max
remains virtually unchanged. A model to explain this phenomenon is proposed. It is suggested that this phenomenon could underlie
observations, confirmed here, that the in vitro uptake of Zn by animal erythrocytes depends on the Zn status of the animal. 相似文献