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91.
Anca Gafencu Mihaela Stanescu Aurel Mircia Toderici Constantina Heltianu M. Simionescu 《Cell and tissue research》1998,293(1):101-110
In endothelial cells (EC), caveolae or plasmalemmal vesicles (PVs) represent a structurally and biochemically specialized membrane microdomain. Since few data are available on the biochemical composition of PVs of large vessel endothelium, we have designed experiments to isolate this domain and to analyze its chemical components. A highly purified apical membrane fraction was obtained from cultured bovine aortic EC by using cationic colloidal silica (silica-ap), or the EC were surface-radioiodinated and a cell homogenate was prepared. Detergent treatment (Triton X-100; TX) and mechanical disruption of both the silica-ap fraction and cell homogenate followed by ultracentrifugation on a sucrose gradient gave detergent-soluble and detergent-insoluble membranous fractions. The lowest density TX-insoluble fraction appeared morphologically as distinct vesicles (caveolae; 60?nm average diameter; PVs fraction). Biochemical characterization of the PVs fraction (by comparison with the soluble fraction) revealed the presence, at high concentration, of specific caveolar markers, viz., caveolin (both isoforms, the 24-kDa form being conspicuously more abundant) and Ca2+-ATPase. By contrast, angiotensin-converting enzyme and alkaline phosphodiesterase were present almost exclusively in the TX-soluble fraction. The glycoproteins in the PVs fraction were of apparent molecular weights 52, 68, 95, and 114?kDa. Analysis of the fatty acid composition revealed more palmitoleic and stearic acid in the PVs fraction then in the TX-soluble fraction. Thus, in comparison with the plasmalemma proper, the PVs fraction (1) is detergent-insoluble; (2) contains caveolin in two isoforms; (3) contains Ca2+-ATPase at high concentration; (4) contains a set of specific glycoproteins; and (5) is enriched in palmitoleic and stearic acids. 相似文献
92.
Chain elongation is a growth-dependent anaerobic metabolism that combines acetate and ethanol into butyrate, hexanoate, and octanoate. While the model microorganism for chain elongation, Clostridium kluyveri, was isolated from a saturated soil sample in the 1940s, chain elongation has remained unexplored in soil environments. During soil fermentative events, simple carboxylates and alcohols can transiently accumulate up to low mM concentrations, suggesting in situ possibility of microbial chain elongation. Here, we examined the occurrence and microbial ecology of chain elongation in four soil types in microcosms and enrichments amended with chain elongation substrates. All soils showed evidence of chain elongation activity with several days of incubation at high (100 mM) and environmentally relevant (2.5 mM) concentrations of acetate and ethanol. Three soils showed substantial activity in soil microcosms with high substrate concentrations, converting 58% or more of the added carbon as acetate and ethanol to butyrate, butanol, and hexanoate. Semi-batch enrichment yielded hexanoate and octanoate as the most elongated products and microbial communities predominated by C. kluyveri and other Firmicutes genera not known to undergo chain elongation. Collectively, these results strongly suggest a niche for chain elongation in anaerobic soils that should not be overlooked in soil microbial ecology studies.Subject terms: Soil microbiology, Microbial ecology 相似文献
93.
Mut-Popescu D Lupu A Bumbea H Vladareanu AM Barbu D Angelescu S Olteanu N Colita A 《Journal of cellular and molecular medicine》2000,4(3):207-214
Immunophenotyping of B-cell lymphoproliferative disorders is indispensable, especially in disorders with CD19(+) CD5(+) B lymphocytes, where we have to make the distinction between low grade neoplasia, such as chronic lymphocytic leukemia with CD23(+) malignant lymphocytes, and aggressive neoplasia such as mantle cell lymphoma with CD23(-) malignant lymphocytes. We found some cases of CD19(+) CD5(+) lymphoproliferative disorders that do not meet all criteria for diagnosis of chronic lymphocytic leukemia or mantle cell lymphoma. For instance, we found cases with a low or no expression of CD23, asociated with absence of expression of FMC7 and surface immunoglobulins. These cases could be classified as "borderline" CD19(+) CD5(+) B cell lymphoproliferative disorders, with an intermediate neoplasic grade. 相似文献
94.
95.
Daniela Ionita Maria Vardaki Miruna S.Stan Anca Dinischiotu Ioana Demetrescu 《仿生工程学报(英文版)》2017,14(3)
The aim of the present paper is to characterize bioinspired chitosan (CS) + hydroxyapatite (HA) coatings with various components ratio on a zirconium alloy with titanium.The coatings were characterized by FT-IR,SEM,hydrophilic/hydrophobic balance,adherence,roughness,electrochemical stability and in vitro cell response.Electrochemical tests,including potentiodynamic polarization curves and electrochemical impedance spectroscopy,were performed in normal saline physiological solution.Cell viability of MC3T3-E1 osteoblasts,lactate dehydrogenase,nitric oxide,and Reactive Oxygen Species (ROS) levels,as well as actin cytoskeleton morphology,were evaluated as biological in vitro tests.The results on in vitro cell response indicated good cell membrane integrity and viability for all samples,but an increased cell number,a decreased ROS level and a better cytoskeleton organization were noticed for the sample with a higher CS content.The coating with highest CS concentration indicated the best performance based on the experimental data.The highest hydrophilic character,highest resistance to corrosion and best biocompatibility as well recommend this coating for bioapplications in tissue engineering. 相似文献
96.
Raquel Cano Laura Torres-Benito Rocío Tejero Anca I. Biea Rocío Ruiz William J. Betz Lucía Tabares 《Molecular neurobiology》2013,47(1):209-219
Virtually all functions of the nervous system rely upon synapses, the sites of communication between neurons and between neurons and other cells. Synapses are complex structures, each one comprising hundreds of different types of molecules working in concert. They are organized by adhesive and scaffolding molecules that align presynaptic vesicular release sites, namely, active zones, with postsynaptic neurotransmitter receptors, thereby allowing rapid and reliable intercellular communication. Most synapses are relatively small, and acting alone exerts little effect on their postsynaptic partners. Some, however, are much larger and stronger, reliably driving the postsynaptic cell to its action potential threshold, acting essentially as electrical relays of excitation. These large synapses are among the best understood, and two of these are the subject of this review, namely, the vertebrate neuromuscular junction and the calyx of Held synapse in the mammalian auditory pathway of the brain stem. Both synapses undergo through a complex and well-coordinated maturation process, during which time the molecular elements and the biophysical properties of the secretory machinery are continuously adjusted to the synapse size and to the functional requirements. We here review the morphological and functional changes occurring during postnatal maturation, noting particular similarities and differences between these two large synapses. 相似文献
97.
Ionică Loredana N. Gaiță Laura Bînă Anca M. Soșdean Raluca Lighezan Rodica Sima Alexandra Malița Daniel Crețu Octavian M. Burlacu Ovidiu Muntean Danina M. Sturza Adrian 《Molecular and cellular biochemistry》2021,476(11):4019-4029
Molecular and Cellular Biochemistry - In the past decade, monoamine oxidase (MAO) with 2 isoforms, MAO-A and B, has emerged as an important source of mitochondrial reactive oxygen species (ROS) in... 相似文献
98.
Monica Neagu Daniela Calina Anca Oana Docea Carolina Constantin Tommaso Filippini Marco Vinceti Nikolaos Drakoulis Konstantinos Poulas Taxiarchis Konstantinos Nikolouzakis Demetrios A. Spandidos Aristidis Tsatsakis 《Journal of cellular and molecular medicine》2021,25(10):4523-4533
The outbreak of the coronavirus disease 2019 (COVID-19) has gathered 1 year of scientific/clinical information. This informational asset should be thoroughly and wisely used in the coming year colliding in a global task force to control this infection. Epidemiology of this infection shows that the available estimates of SARS-CoV-2 infection prevalence largely depended on the availability of molecular testing and the extent of tested population. Within molecular diagnosis, the viability and infectiousness of the virus in the tested samples should be further investigated. Moreover, SARS-CoV-2 has a genetic normal evolution that is a dynamic process. The immune system participates to the counterattack of the viral infection by pathogen elimination, cellular homoeostasis, tissue repair and generation of memory cells that would be reactivated upon a second encounter with the same virus. In all these stages, we still have knowledge to be gathered regarding antibody persistence, protective effects and immunological memory. Moreover, information regarding the intense pro-inflammatory action in severe cases still lacks and this is important in stratifying patients for difficult to treat cases. Without being exhaustive, the review will cover these important issues to be acknowledged to further advance in the battle against the current pandemia. 相似文献
99.
Zack Blumenfeld Anca Velisar Mandy Miller Koop Bruce C. Hill Lauren A. Shreve Emma J. Quinn Camilla Kilbane Hong Yu Jaimie M. Henderson Helen Bront?-Stewart 《PloS one》2015,10(3)
High frequency subthalamic nucleus (STN) deep brain stimulation (DBS) improves the cardinal motor signs of Parkinson’s disease (PD) and attenuates STN alpha/beta band neural synchrony in a voltage-dependent manner. While there is a growing interest in the behavioral effects of lower frequency (60 Hz) DBS, little is known about its effect on STN neural synchrony. Here we demonstrate for the first time that during intra-operative 60 Hz STN DBS, one or more bands of resting state neural synchrony were amplified in the STN in PD. We recorded intra-operative STN resting state local field potentials (LFPs) from twenty-eight STNs in seventeen PD subjects after placement of the DBS lead (model 3389, Medtronic, Inc.) before and during three randomized neurostimulation sets (130 Hz/1.35V, 130 Hz/2V, 60 Hz/2V). During 130 Hz/2V DBS, baseline (no DBS) STN alpha (8 – 12 Hz) and beta (13 – 35 Hz) band power decreased (N=14, P < 0.001 for both), whereas during 60 Hz/2V DBS, alpha band and peak frequency power increased (P = 0.012, P = 0.007, respectively). The effect of 60 Hz/2V DBS opposed that of power-equivalent (130 Hz/1.35V) DBS (alpha: P < 0.001, beta: P = 0.006). These results show that intra-operative 60 Hz STN DBS amplified whereas 130 Hz STN DBS attenuated resting state neural synchrony in PD; the effects were frequency-specific. We demonstrate that neurostimulation may be useful as a tool to selectively modulate resting state resonant bands of neural synchrony and to investigate its influence on motor and non-motor behaviors in PD and other neuropsychiatric diseases. 相似文献
100.