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101.
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103.
De Leeuw F Zhang T Wauquier C Huez G Kruys V Gueydan C 《Experimental cell research》2007,313(20):4130-4144
The cold-inducible RNA-binding protein (CIRP) is a nuclear 18-kDa protein consisting of an amino-terminal RNA Recognition Motif (RRM) and a carboxyl-terminal domain containing several RGG motifs. First characterized for its overexpression upon cold shock, CIRP is also induced by stresses such as UV irradiation and hypoxia. Here, we investigated the expression as well as the subcellular localization of CIRP in response to other stress conditions. We demonstrate that oxidative stress leads to the migration of CIRP to stress granules (SGs) without alteration of expression. Stress granules are dynamic cytoplasmic foci at which stalled translation initiation complexes accumulate in cells subjected to environmental stress. Relocalization of CIRP into SGs also occurs upon other cytoplasmic stresses (osmotic pressure or heat shock) as well as in response to stresses of the endoplasmic reticulum. CIRP migration into SGs is independent from TIA-1 which has been previously reported to be a general mediator of SG formation, thereby suggesting the existence of multiple pathways leading to SG formation. Moreover, deletion mutants revealed that both RGG and RRM domains can independently promote CIRP migration into SGs. However, the methylation of arginine residues in the RGG domain is necessary for CIRP to exit the nucleus to be further recruited into SGs. By RNA-tethering experiments, we also show that CIRP down-regulates mRNA translation and that this activity is carried by the carboxyl-terminal RG-enriched domain. Altogether, our findings further reveal the diversity of mechanisms by which CIRP is regulated by environmental stresses and provide new insights into CIRP cytoplasmic function. 相似文献
104.
Victoria M. Dominguez Amanda M. Agnew 《American journal of physical anthropology》2019,168(2):378-382
A major part of histologic studies is the use of high resolution imaging for data collection and analysis. ImageJ, a freely available software from the NIH designed for image analysis, has many features that are not well-known among bone histologists and can be incredibly beneficial in terms of stream-lining data collection and maximizing limited resources. The aims of this technical note are twofold: (a) to describe methods for image annotation and measurement using region of interest overlays in ImageJ, and (b) to present a new code for a semi-automated method of measuring cortical bone areas from high resolution cross-sectional images also using ImageJ. 相似文献
105.
Alex A. Pollen Aparna Bhaduri Madeline G. Andrews Tomasz J. Nowakowski Olivia S. Meyerson Mohammed A. Mostajo-Radji Elizabeth Di Lullo Beatriz Alvarado Melanie Bedolli Max L. Dougherty Ian T. Fiddes Zev N. Kronenberg Joe Shuga Anne A. Leyrat Jay A. West Marina Bershteyn Craig B. Lowe Bryan J. Pavlovic Arnold R. Kriegstein 《Cell》2019,176(4):743-756.e17
106.
Ammar Jabali Anne Hoffrichter Ana Uzquiano Fabio Marsoner Ruven Wilkens Marco Siekmann Bettina Bohl Andrea C Rossetti Sandra Horschitz Philipp Koch Fiona Francis Julia Ladewig 《EMBO reports》2022,23(5)
Malformations of human cortical development (MCD) can cause severe disabilities. The lack of human‐specific models hampers our understanding of the molecular underpinnings of the intricate processes leading to MCD. Here, we use cerebral organoids derived from patients and genome edited‐induced pluripotent stem cells to address pathophysiological changes associated with a complex MCD caused by mutations in the echinoderm microtubule‐associated protein‐like 1 (EML1) gene. EML1‐deficient organoids display ectopic neural rosettes at the basal side of the ventricular zone areas and clusters of heterotopic neurons. Single‐cell RNA sequencing shows an upregulation of basal radial glial (RG) markers and human‐specific extracellular matrix components in the ectopic cell population. Gene ontology and molecular analyses suggest that ectopic progenitor cells originate from perturbed apical RG cell behavior and yes‐associated protein 1 (YAP1)‐triggered expansion. Our data highlight a progenitor origin of EML1 mutation‐induced MCD and provide new mechanistic insight into the human disease pathology. 相似文献
107.
Gonzalez-Gil G Seghezzo L Lettinga G Kleerebezem R 《Biotechnology and bioengineering》2001,73(2):125-134
The kinetic properties of acetate-degrading methanogenic granular sludge of different mean diameters were assessed at different up-flow velocities (V(up)). Using this approach, the influence of internal and external mass transfer could be estimated. First, the apparent Monod constant (K(S)) for each data set was calculated by means of a curve-fitting procedure. The experimental results revealed that variations in the V(up) did not affect the apparent K(S)-value, indicating that external mass-transport resistance normally can be neglected. With regard to the granule size, a clear increase in K(S) was found at increasing granule diameters. The experimental data were further used to validate a dynamic mathematical biofilm model. The biofilm model was able to describe reaction-diffusion kinetics in anaerobic granules, using a single value for the effective diffusion coefficient in the granules. This suggests that biogas formation did not influence the diffusion-rates in the granular biomass. 相似文献
108.
Kotchoubey B Busch S Strehl U Birbaumer N 《Applied psychophysiology and biofeedback》1999,24(4):213-233
The goal of the study was to explore parallel changes in EEG spectral frequencies during biofeedback of slow cortical potentials (SCPs) in epilepsy patients. Thirty-four patients with intractable focal epilepsy participated in 35 sessions of SCP self-regulation training. The spectral analysis was carried out for the EEG recorded at the same electrode site (Cz) that was used for SCP feedback. The most prominent effect was the increase in the 2 power (6.0–7.9 Hz) and the relative power decrement in all other frequency bands (particularly 1, 2, and 2) in transfer trials (i.e., where patients controlled their SCPs without continuous feedback) compared with feedback trials. In the second half of the training course (i.e., sessions 21–35) larger power values in the , , and bands were found when patients were required to produce positive versus negative SCP shifts. Both across-subject and across-session (within-subject) correlations between spectral EEG parameters, on the one hand, and SCP data, on the other hand, were low and inconsistent, contrary to high and stable correlations between different spectral variables. This fact, as well as the lack of considerable task-dependent effects during the first part of training, indicates that learned SCP shifts did not directly lead to the specific dynamics of the EEG power spectra. Rather, these dynamics were related to nonspecific changes in patients' brain state. 相似文献
109.
Nitric oxide (NO) has been implicated in both the pathogenesis of and protection from NMDA receptor-mediated neuronal injury. This apparent paradox has been attributed to alternate redox states of nitrogen monoxide, whereby, depending on the redox milieu, nitrogen monoxide can be neuroprotective via nitrosation chemistry or react with superoxide to form secondary toxic species. In our murine mixed cortical cell culture system, the NONOate-type NO donors diethylamine/NO complex sodium (Dea/NO), (Z)-[N-(3-ammoniopropyl)-N-(n-propyl)amino]diazen-1-ium++ +-1,2-diolate (Papa/NO), and spermine/NO complex sodium (Sper/NO), as well as the S-nitrosothiols S-nitroso-L-glutathione (GSNO) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) (NO+ equivalents), decreased NMDA-induced neuronal injury in a concentration-dependent manner. 8-Bromo-cyclic GMP did not mimic the inhibitory effects of the donors, suggesting that the neuroprotection was not the result of NO-stimulated neuronal cyclic GMP production. Furthermore, neuronal injury induced by exposure of cultures to H2O2 was not altered by the presence of Dea/NO, indicating the absence of a direct antioxidant effect. NONOates did, however, reduce NMDA-stimulated uptake of 45Ca2+, whereas high potassium-induced 45Ca2+ accumulation, a measurement of entry via voltage-gated calcium channels, was unaffected. The parallel reduction of 45Ca2+ accumulation and NMDA neurotoxicity by NONOates mimicked that seen with an NMDA receptor antagonist. Electrochemical measurements of NO via an NO-sensitive electrode demonstrated that neuroprotective concentrations of all donors produced appreciable amounts of NO over the 5-min time frame. Determination of the formation of NO+ equivalents, as assessed by N-nitrosation of 2,3-diaminonaphthylene, revealed little or no observable N-nitrosation by Sper/NO, GSNO, and SNAP with significant N-nitrosation observed by Papa/NO and Dea/NO. However, addition of ascorbate (400 microM) effectively prevented the nitrosation of 2,3-diaminonaphthylene produced by Dea/NO and Papa/NO without altering their neuroprotective properties or their effects on 45Ca2+ accumulation. Present results indicate that the intrinsic NO/NO+ characteristics of NO donor compounds may not be a good predictor of their ability to inhibit NMDA receptor-mediated neurotoxicity at the cellular level. 相似文献
110.
To investigate the effect of granular structure on resistance to toxic chemicals in UASB (Upflow Anaerobic Sludge Blanket) reactors, normal and broken granules were examined for their ability to degrade acetate with and without the addition of toluene or trichloroethylene as a toxic chemical. Without a toxic chemical, both normal and broken granules degraded the acetate at the same volumetric degradation rate (3.21 mM h–1). However, when 500 l l–1 of toluene or trichloroethylene was added, the acetate-degradation rate of the broken granules was about a third of the rate with normal granules. Therefore, the layered structure of the UASB granules seems to give microbial populations the ability to resist toxic chemicals. 相似文献