General Subject 2. Report to ICUMSA on the determination of carry-over alpha-amylase activity in white and refined sugars by a spectrophotometric method

USDA-ARS?s Scientific Manuscript database

A report is given on a new industrial method for the determination of carry-over alpha-amylase activity in raw and refined sugars, as well as a recommendation. In recent years, there has been increased concern over carry-over activity of mostly high temperature (HT) and very high temperature (VHT) s...

Spleen tyrosine kinase mediates high glucose-induced transforming growth factor-{beta}1 up-regulation in proximal tubular epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Won Seok; Chang, Jai Won; Han, Nam Jeong

The role of spleen tyrosine kinase (Syk) in high glucose-induced intracellular signal transduction has yet to be elucidated. We investigated whether Syk is implicated in high glucose-induced transforming growth factor-{beta}1 (TGF-{beta}1) up-regulation in cultured human proximal tubular epithelial cells (HK-2 cell). High glucose increased TGF-{beta}1 gene expression through Syk, extracellular signal-regulated kinase (ERK), AP-1 and NF-{kappa}B. High glucose-induced AP-1 DNA binding activity was decreased by Syk inhibitors and U0126 (an ERK inhibitor). Syk inhibitors suppressed high glucose-induced ERK activation, whereas U0126 had no effect on Syk activation. High glucose-induced NF-{kappa}B DNA binding activity was also decreased by Syk inhibitors. Highmore » glucose increased nuclear translocation of p65 without serine phosphorylation of I{kappa}B{alpha} and without degradation of I{kappa}B{alpha}, but with an increase in tyrosine phosphorylation of I{kappa}B{alpha} that may account for the activation of NF-{kappa}B. Both Syk inhibitors and Syk-siRNA attenuated high glucose-induced I{kappa}B{alpha} tyrosine phosphorylation and p65 nuclear translocation. Depletion of p21-activated kinase 2 (Pak2) by transfection of Pak2-siRNA abolished high glucose-induced Syk activation. In summary, high glucose-induced TGF-{beta}1 gene transcription occurred through Pak2, Syk and subsequent ERK/AP-1 and NF-{kappa}B pathways. This suggests that Syk might be implicated in the diabetic kidney disease.« less

The TF1-ATPase and ATPase activities of assembled alpha 3 beta 3 gamma, alpha 3 beta 3 gamma delta, and alpha 3 beta 3 gamma epsilon complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the alpha 3 beta 3, and alpha 3 beta 3 delta complexes.

PubMed

Paik, S R; Yokoyama, K; Yoshida, M; Ohta, T; Kagawa, Y; Allison, W S

1993-12-01

The ATPase activity of the F1-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 microM where 70% stimulation is observed at 36 degrees C. Half maximal stimulation is observed at about 3 microM dye. At rhodamine 6G concentrations greater than 10 microM, ATPase activity declines with 50% inhibition observed at about 75 microM dye. The ATPase activities of the alpha 3 beta 3 gamma and alpha 3 beta 3 gamma delta complexes assembled from isolated subunits of TF1 expressed in E. coli deleted of the unc operon respond to increasing concentrations of rhodamine 6G nearly identically to the response of TF1. In contrast, the ATPase activities of the alpha 3 beta 3 and alpha 3 beta 3 delta complexes are only inhibited by rhodamine 6G with 50% inhibition observed, respectively, at 35 and 75 microM dye at 36 degrees C. The ATPase activity of TF1 is stimulated up to 4-fold by the neutral detergent, LDAO. In the presence of stimulating concentrations of LDAO, the ATPase activity of TF1 is no longer stimulated by rhodamine 6G, but rather, it is inhibited with 50% inhibition observed at about 30 microM dye at 30 degrees C. One interpretation of these results is that binding of rhodamine 6G to a high-affinity site on TF1 stimulates ATPase activity and unmasks a low-affinity, inhibitory site for the dye which is also exposed by LDAO.

Pharmacological characterization of hydrolysis-resistant analogs of oleoylethanolamide with potent anorexiant properties.

PubMed

Astarita, Giuseppe; Di Giacomo, Barbara; Gaetani, Silvana; Oveisi, Fariba; Compton, Timothy R; Rivara, Silvia; Tarzia, Giorgio; Mor, Marco; Piomelli, Daniele

2006-08-01

Oleoylethanolamide (OEA) is an endogenous lipid mediator that reduces food intake, promotes lipolysis, and decreases body weight gain in rodents by activating peroxisome proliferator-activated receptor-alpha (PPAR-alpha). The biological effects of OEA are terminated by two intracellular lipid hydrolase enzymes, fatty-acid amide hydrolase and N-acylethanolamine-hydrolyzing acid amidase. In the present study, we describe OEA analogs that resist enzymatic hydrolysis, activate PPAR-alpha with high potency in vitro, and persistently reduce feeding when administered in vivo either parenterally or orally. The most potent of these compounds, (Z)-(R)-9-octadecenamide,N-(2-hydroxyethyl,1-methyl) (KDS-5104), stimulates transcriptional activity of PPAR-alpha with a half-maximal effective concentration (EC50) of 100 +/- 21 nM (n = 11). Parenteral administration of KDS-5104 in rats produces persistent dose-dependent prolongation of feeding latency and postmeal interval (half-maximal effective dose, ED50 = 2.4 +/- 1.8 mg kg(-1) i.p.; n = 18), as well as increased and protracted tissue exposure compared with OEA. Oral administration of the compound also results in a significant tissue exposure and reduction of food intake in free-feeding rats. These results suggest that the endogenous high-affinity PPAR-alpha agonist OEA may provide a scaffold for the discovery of novel orally active PPAR-alpha ligands.

[Voluntary alpha-power increasing training impact on the heart rate variability].

PubMed

Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V

2013-01-01

In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock biofeedback training has no such effect. The positive correlation between the alpha-peak frequency and pNN50 in patients with initially low, but negative--those with high baseline alpha frequency explains the multidirectional biofeedback effects on HRV in low and high alpha frequency subjects. The individual alpha-frequency EEG pattern determines the effectiveness of the alpha EEG biofeedback training in changing heart rate variability, which provides a basis for predicting the results and develop individual approaches to the biofeedback technology implementation that can be used in clinical practice for treatment and rehabilitation of psychosomatic syndromes and in educational training.

Dynamics of alpha control: Preparatory suppression of posterior alpha oscillations by frontal modulators revealed with combined EEG and event-related optical signal (EROS)

PubMed Central

Mathewson, Kyle E.; Beck, Diane M.; Ro, Tony; Maclin, Edward L.; Low, Kathy A.; Fabiani, Monica; Gratton, Gabriele

2015-01-01

We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously we proposed that alpha (8-12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top-down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently-recorded electroencephalogram (EEG), while subjects performed a visual target-detection task. The pre-target alpha oscillations measured with EEG and EROS from posterior areas were larger for subsequently undetected targets, supporting alpha's inhibitory role. Using EROS, we localized brain correlates of these awareness-related alpha oscillations measured at the scalp to the cuneus and precuneus. Crucially, EROS alpha suppression correlated with posterior EEG alpha power across subjects. Sorting the EROS data based on EEG alpha power quartiles to investigate alpha modulators revealed that suppression of posterior alpha was preceded by increased activity in regions of the dorsal attention network, and decreased activity in regions of the cingulo-opercular network. Cross-correlations revealed the temporal dynamics of activity within these preparatory networks prior to posterior alpha modulation. The novel combination of EEG and EROS afforded localization of the sources and correlates of alpha oscillations and their temporal relationships, supporting our proposal that top-down control from attention networks modulates both posterior alpha and awareness of visual stimuli. PMID:24702458

Regional Patterns of Elevated Alpha and High-Frequency Electroencephalographic Activity during Nonrapid Eye Movement Sleep in Chronic Insomnia: A Pilot Study

PubMed Central

Riedner, Brady A.; Goldstein, Michael R.; Plante, David T.; Rumble, Meredith E.; Ferrarelli, Fabio; Tononi, Giulio; Benca, Ruth M.

2016-01-01

Study Objectives: To examine nonrapid eye movement (NREM) sleep in insomnia using high-density electroencephalography (EEG). Methods: All-night sleep recordings with 256 channel high-density EEG were analyzed for 8 insomnia subjects (5 females) and 8 sex and age-matched controls without sleep complaints. Spectral analyses were conducted using unpaired t-tests and topographical differences between groups were assessed using statistical non-parametric mapping. Five minute segments of deep NREM sleep were further analyzed using sLORETA cortical source imaging. Results: The initial topographic analysis of all-night NREM sleep EEG revealed that insomnia subjects had more high-frequency EEG activity (> 16 Hz) compared to good sleeping controls and that the difference between groups was widespread across the scalp. In addition, the analysis also showed that there was a more circumscribed difference in theta (4–8 Hz) and alpha (8–12 Hz) power bands between groups. When deep NREM sleep (N3) was examined separately, the high-frequency difference between groups diminished, whereas the higher regional alpha activity in insomnia subjects persisted. Source imaging analysis demonstrated that sensory and sensorimotor cortical areas consistently exhibited elevated levels of alpha activity during deep NREM sleep in insomnia subjects relative to good sleeping controls. Conclusions: These results suggest that even during the deepest stage of sleep, sensory and sensorimotor areas in insomnia subjects may still be relatively active compared to control subjects and to the rest of the sleeping brain. Citation: Riedner BA, Goldstein MR, Plante DT, Rumble ME, Ferrarelli F, Tononi G, Benca RM. Regional patterns of elevated alpha and high-frequency electroencephalographic activity during nonrapid eye movement sleep in chronic insomnia: a pilot study. SLEEP 2016;39(4):801–812. PMID:26943465

High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

PubMed

Lobier, Muriel; Palva, J Matias; Palva, Satu

2018-01-15

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular analysis and functional expression of the human type E neuronal Ca2+ channel alpha 1 subunit.

PubMed

Schneider, T; Wei, X; Olcese, R; Costantin, J L; Neely, A; Palade, P; Perez-Reyes, E; Qin, N; Zhou, J; Crawford, G D

1994-01-01

A human brain alpha 1 Ca2+ channel subunit was cloned and expressed in Xenopus laevis oocytes. The open reading frame, encoding 2,312 amino acids, has high homology to the marine ray doe-1, the rat E-type, and the rabbit brain BII alpha 1 subunits. The amino and carboxy termini of this human.E-type alpha 1 subunit (alpha 1E) are most similar to the rabbit BII-1 splice variant, the remainder being colinear with the BII alpha 1 with the exception of two insertions, one of 43 amino acids in the C-terminus and another of 7 amino acids, found also in the rat alpha 1E, between domains II and III. Two potential Ca2+ binding sites are predicted from its primary structure. The expression of inward Ba2+ currents reveals voltage-dependent activation and inactivation measured by the cut-open oocyte vaseline-gap technique, with kinetics that correspond to that of a high-voltage-activated neuronal Ca2+ channel, and pharmacologic properties that resemble those of some low-voltage-activated neuronal Ca2+ currents. The human alpha 1E currents are insensitive to omega-conotoxin-GVIA (1 microM), omega-agatoxin-IVA (200 nM), a synthetic funnel web spider toxin (FTX, 20 microM), and Bay-K8644 (0.5 microM); they are inhibited 20% by high concentrations of methoxyverapamil and diltiazem, 65% by 0.1% crude funnel web spider venom and 100% by Ni2+ (IC50 = 30 nM). Single-channel records show a complex activity pattern with several apparent conductance states, the largest having a conductance of 14 pS.

In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum (L.) Merr. & Perry (Clove) buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe2+-induced lipid peroxidation in rat pancreas

PubMed Central

Adefegha, Stephen Adeniyi; Oboh, Ganiyu

2012-01-01

Objective To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe2+-induced lipid peroxidation in rat pancreas in vitro. Methods The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined. Results The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (P<0.05) higher than their alpha-amylase inhibitory activity. The free phenolics (31.67 mg/g) and flavonoid (17.28 mg/g) contents were significantly (P<0.05) higher than bound phenolic (23.52 mg/g) and flavonoid (13.70 mg/g) contents. Both extracts also exhibited high antioxidant activities as typified by their high reducing power, 1,1 diphenyl-2- picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS) radical scavenging abilities, as well as inhibition of Fe2+-induced lipid peroxidation in rat pancreas in vitro. Conclusions This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes. PMID:23569846

High-density lipoproteins protect endothelial cells from tumor necrosis factor-alpha-induced apoptosis.

PubMed

Sugano, M; Tsuchida, K; Makino, N

2000-06-16

High-density lipoproteins (HDL) levels have been shown to be inversely correlated with coronary heart disease, but the mechanisms of the direct protective effect of HDL on endothelial cells are not fully understood. The apoptosis of endothelial cells induced by cytokines and/or oxidized low-density lipoproteins, etc. may provide a mechanistic clue to the "response-to-injury" hypothesis of atherogenesis. Here we report that HDL prevent the apoptosis of human umbilical venous endothelial cells (HUVECs) induced by tumor necrosis factor-alpha (TNF-alpha) via an inhibition of CPP32-like protease activity. The incubation of HUVECs with TNF-alpha significantly increased the CPP32-like protease activity, and induced apoptosis. Preincubation of HUVECs with HDL before incubation with TNF-alpha significantly suppressed the increase in the CPP32-like protease activity, preventing apoptosis in a concentration-dependent manner. These results suggest that HDL prevent the suicide pathway leading to apoptosis of endothelial cells by decreasing the CPP32-like protease activity and that HDL thus play a protective role against the "response-to-injury" hypothesis of atherogenesis. Copyright 2000 Academic Press.

In vitro screening of 200 pesticides for agonistic activity via mouse peroxisome proliferator-activated receptor (PPAR){alpha} and PPAR{gamma} and quantitative analysis of in vivo induction pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeuchi, Shinji; Matsuda, Tadashi; Kobayashi, Satoshi

2006-12-15

Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors and key regulators of lipid metabolism and cell differentiation. However, there have been few studies reporting on a variety of environmental chemicals, which may interact with these receptors. In the present study, we characterized mouse PPAR{alpha} and PPAR{gamma} agonistic activities of 200 pesticides (29 organochlorines, 11 diphenyl ethers, 56 organophosphorus pesticides, 12 pyrethroids, 22 carbamates, 11 acid amides, 7 triazines, 8 ureas and 44 others) by in vitro reporter gene assays using CV-1 monkey kidney cells. Three of the 200 pesticides, diclofop-methyl, pyrethrins and imazalil, which have different chemical structures, showed PPAR{alpha}-mediatedmore » transcriptional activities in a dose-dependent manner. On the other hand, none of the 200 pesticides showed PPAR{gamma} agonistic activity at concentrations {<=} 10{sup -5} M. To investigate the in vivo effects of diclofop-methyl, pyrethrins and imazalil, we examined the gene expression of PPAR{alpha}-inducible cytochrome P450 4As (CYP4As) in the liver of female mice intraperitoneally injected with these compounds ({<=} 300 mg/kg). RT-PCR revealed significantly high induction levels of CYP4A10 and CYP4A14 mRNAs in diclofop-methyl- and pyrethrins-treated mice, whereas imazalil induced almost no gene expressions of CYP4As. In particular, diclofop-methyl induced as high levels of CYP4A mRNAs as WY-14643, a potent PPAR{alpha} agonist. Thus, most of the 200 pesticides tested do not activate PPAR{alpha} or PPAR{gamma} in in vitro assays, but only diclofop-methyl and pyrethrins induce PPAR{alpha} agonistic activity in vivo as well as in vitro.« less

Enzyme-polymer composites with high biocatalytic activity and stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jungbae; Kosto, Timothy J.; Manimala, Joseph C.

2004-08-22

We have applied vacuum-spraying and electrospinning to incorporate an enzyme into a polymer matrix, creating a novel and highly active biocatalytic composite. As a unique technical approach, enzymes were co-dissolved in toluene with polymers, and the solvent was then rapidly removed by injecting the mixture into a vacuum chamber or by electrospinning. Subsequent crosslinking of the enzyme with glutaraldehyde resulted in stable entrapped enzyme within the polymeric matrices. For example, an amorphous composite of alpha-chymotrypsin and polyethylene showed no significant loss of enzymatic activity in aqueous buffer for one month. Nanofibers of alpha-chymotrypsin and polystyrene also showed no decrease inmore » activity for more than two weeks. The normalized activity of amorphous composite in organic solvents was 3-13 times higher than that of native alpha-chymotrypsin. The activity of nanofibers was 5-7 times higher than that of amorphous composite in aqueous buffer solution. The composites of alpha-chymotrypsin and polymers demonstrate the feasibility of obtaining a wide variety of active and stable biocatalytic materials with many combinations of enzymes and polymers.« less

The deployment of intersensory selective attention: a high-density electrical mapping study of the effects of theanine.

PubMed

Gomez-Ramirez, Manuel; Higgins, Beth A; Rycroft, Jane A; Owen, Gail N; Mahoney, Jeannette; Shpaner, Marina; Foxe, John J

2007-01-01

: Ingestion of the nonproteinic amino acid theanine (5-N-ethylglutamine) has been shown to increase oscillatory brain activity in the so-called alpha band (8-14 Hz) during resting electroencephalographic recordings in humans. Independently, alpha band activity has been shown to be a key component in selective attentional processes. Here, we set out to assess whether theanine would cause modulation of anticipatory alpha activity during selective attentional deployments to stimuli in different sensory modalities, a paradigm in which robust alpha attention effects have previously been established. : Electrophysiological data from 168 scalp electrode channels were recorded while participants performed a standard intersensory attentional cuing task. : As in previous studies, significantly greater alpha band activity was measured over parieto-occipital scalp for attentional deployments to the auditory modality than to the visual modality. Theanine ingestion resulted in a substantial overall decrease in background alpha levels relative to placebo while subjects were actively performing this demanding attention task. Despite this decrease in background alpha activity, attention-related alpha effects were significantly greater for the theanine condition. : This increase of attention-related anticipatory alpha over the right parieto-occipital scalp suggests that theanine may have a specific effect on the brain's attention circuitry. We conclude that theanine has clear psychoactive properties, and that it represents a potentially interesting, naturally occurring compound for further study, as it relates to the brain's attentional system.

A novel type of thermostable alpha-D-glucosidase from Thermoanaerobacter thermohydrosulfuricus exhibiting maltodextrinohydrolase activity.

PubMed Central

Wimmer, B; Lottspeich, F; Ritter, J; Bronnenmeier, K

1997-01-01

An alpha-glucosidase with the ability to attack polymeric substrates was purified to homogeneity from culture supernatants of Thermoanaerobacter thermohydrosulfuricus DSM 567. The enzyme is apparently a glycoprotein with a molecular mass of 160 kDa. Maximal activity is observed between pH5 and 7 at 75 degrees C. The alpha-glucosidase is active towards p-nitrophenyl-alpha-D-glucoside, maltose, malto-oligosaccharides, starch and pullulan. Highest activity is displayed towards the disaccharide maltose. In addition to glucose, maltohexaose and maltoheptaose can be detected as the initial products of starch hydrolysis. After short incubations of pullulan, glucose is found as the only product. At high substrate concentrations, maltose and malto-oligosaccharide, but not glucose, are used as acceptors for glucosyl-transfer. These findings indicate that the T. thermohydrosulfuricus enzyme represents a novel type of alpha-glucosidase exhibiting maltase, glucohydrolase and 'maltodextrinohydrolase' activity. PMID:9371718

Spontaneous cortical DC-potential shifts: modulation stereotypy; relationships to higher EEG-frequencies.

PubMed

Etlinger, S C; Guttmann, G; Bauer, H

1986-07-01

A description of scalp-recorded, spontaneous, cerebral DC-potential shifts is given independent of other variables (shift stereotypy), in relationship to higher frequencies (theta, alpha 1, alpha 2: 4-13 Hz) and as analyzed pairwise across the median sagittal line (Fz, Cz, Pz) separately according to frequency and condition (relaxation and moderate mental load). Spontaneous DC-shifts are shown to behave unpredictably. Whether measured jointly (up to triads) or as dyad and triad context entropy, the frontal DC-shifts are calculated as being random, whereby their definition as such within the context of the Principle Component Analysis is supported by the analysis of longitudinal registrations. Cross-correlation analysis of the cerebral slow potential's relationship to each of the higher frequencies (theta, alpha 1, alpha 2) reveals it to be highly independent, the highest correlation accounting for merely 11% of the common variance, the average being 9% (R congruent to 0.3). By matching the conjoint activity of the DC-potential between Fz-Cz, Cz-Pz, and Fz-Pz to that of theta, alpha 1, alpha 2 at the same paired sites, the DC-activity is shown to be operating at higher levels of synchronous activity than the higher frequencies, regardless of pairing and/or condition, although the general level of synchronous activity (DC, theta, alpha 1, alpha 2) is remarkably high along the median sagittal line, 75% of the correlation averages of all analysis-pairings being above 0.60.

The effect of prolonged ethanol administration on central alpha 2-adrenoceptors sensitivity.

PubMed

Szmigielski, A; Szmigielska, H; Wejman, I

1989-01-01

The response of an endogenous inhibitor of protein kinases (type II inhibitor) to clonidine was used as an index of sensitivity of central alpha 2-adrenoceptors. Low doses of clonidine (20-50 micrograms/kg) induced an increase in type II inhibitor activity in the nucleus accumbens, hippocampus and in the anterior and posterior hypothalamus by stimulating presynaptic alpha 2-adrenoceptors. Stimulation of postsynaptic alpha 2-adrenoceptors by high doses of clonidine 0.5-1.0 mg/kg resulted in a dose-dependent decrease in type II inhibitor activity. Prolonged treatment with ethanol (5 g/kg/day po for 21 days) greatly reduced the action of high doses of clonidine in all the examined brain areas, suggesting subsensitivity of postsynaptic alpha 2-adrenoceptors lasting for at least 48 h after the last ethanol administration. A single dose of ethanol induced a short lasting subsensitivity of postsynaptic alpha 2-adrenoceptors in the anterior hypothalamus. 12 h after administration of alcohol the response of type II inhibitor to high doses of clonidine in this brain area was the same as in untreated rats.

Constitutively active mutants of the alpha 1B-adrenergic receptor: role of highly conserved polar amino acids in receptor activation.

PubMed Central

Scheer, A; Fanelli, F; Costa, T; De Benedetti, P G; Cotecchia, S

1996-01-01

Site-directed mutagenesis and molecular dynamics simulations of the alpha 1B-adrenergic receptor (AR) were combined to explore the potential molecular changes correlated with the transition from R (inactive state) to R (active state). Using molecular dynamics analysis we compared the structural/dynamic features of constitutively active mutants with those of the wild type and of an inactive alpha 1B-AR to build a theoretical model which defines the essential features of R and R. The results of site-directed mutagenesis were in striking agreement with the predictions of the model supporting the following hypothesis. (i) The equilibrium between R and R depends on the equilibrium between the deprotonated and protonated forms, respectively, of D142 of the DRY motif. In fact, replacement of D142 with alanine confers high constitutive activity to the alpha 1B-AR. (ii) The shift of R143 of the DRY sequence out of a conserved 'polar pocket' formed by N63, D91, N344 and Y348 is a feature common to all the active structures, suggesting that the role of R143 is fundamental for mediating receptor activation. Disruption of these intramolecular interactions by replacing N63 with alanine constitutively activates the alpha 1B-AR. Our findings might provide interesting generalities about the activation process of G protein-coupled receptors. Images PMID:8670860

Purification and characterization of an inhibitor (soluble tumor necrosis factor receptor) for tumor necrosis factor and lymphotoxin obtained from the serum ultrafiltrates of human cancer patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gatanaga, Tetsuya; Whang, Chenduen; Cappuccini, F.

1990-11-01

Serum ultrafiltrates (SUF) from human patients with different types of cancer contain a blocking factor (BF) that inhibits the cytolytic activity of human tumor necrosis factor {alpha} (TNF-{alpha}) in vitro. BF is a protein with a molecular mass of 28kDa on reducing sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE). The active material was purified to homogeneity by a combination of affinity chromatography, PAGE, and high-pressure liquid chromatography. Amino acid sequence analysis revealed that BF is derived from the membrane TNF receptor. Purified BF blocks the lytic activity of recombinant human and mouse TNF-{alpha} and recombinant human lymphotoxin activity of TNF-{alpha} andmore » recombinant human lymphotoxin on murine L929 cells in vitro. However, BF inhibits the lytic activity of TNF-{alpha} more effectively than it does that of lymphotoxin. The BF also inhibits the necrotizing activity of recombinant human TNF-{alpha} when coinjected into established cutaneous Meth A tumors in BALB/c mice. The BF may have an important role in (i) the regulation and control of TNF-{alpha} and lymphotoxin activity in cancer patients, (ii) interaction between the tumor and the host antitumor mechanisms, and (iii) use of systemically administered TNF-{alpha} in clinical trials with human cancer patients.« less

Activation of peroxisome proliferator-activated receptor-alpha protects the heart from ischemia/reperfusion injury.

PubMed

Yue, Tian-li; Bao, Weike; Jucker, Beat M; Gu, Juan-li; Romanic, Anne M; Brown, Peter J; Cui, Jianqi; Thudium, Douglas T; Boyce, Rogely; Burns-Kurtis, Cynthia L; Mirabile, Rosanna C; Aravindhan, Karpagam; Ohlstein, Eliot H

2003-11-11

Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is expressed in the heart and regulates genes involved in myocardial fatty acid oxidation (FAO). The role of PPAR-alpha in acute ischemia/reperfusion myocardial injury remains unclear. The coronary arteries of male mice were ligated for 30 minutes. After reperfusion for 24 hours, ischemic and infarct sizes were determined. A highly selective and potent PPAR-alpha agonist, GW7647, was administered by mouth for 2 days, and the third dose was given 1 hour before ischemia. GW7647 at 1 and 3 mg x kg(-1) x d(-1) reduced infarct size by 28% and 35%, respectively (P<0.01), and myocardial contractile dysfunction was also improved. Cardioprotection by GW7647 was completely abolished in PPAR-alpha-null mice. Ischemia/reperfusion downregulated mRNA expression of cardiac PPAR-alpha and FAO enzyme genes, decreased myocardial FAO enzyme activity and in vivo cardiac fat oxidation, and increased serum levels of free fatty acids. All of these changes were reversed by GW7647. Moreover, GW7647 attenuated ischemia/reperfusion-induced release of multiple proinflammatory cytokines and inhibited neutrophil accumulation and myocardial expression of matrix metalloproteinases-9 and -2. Furthermore, GW7647 inhibited nuclear factor-kappaB activation in the heart, accompanied by enhanced levels of inhibitor-kappaBalpha. Activation of PPAR-alpha protected the heart from reperfusion injury. This cardioprotection might be mediated through metabolic and antiinflammatory mechanisms. This novel effect of the PPAR-alpha agonist could provide an added benefit to patients treated with PPAR-alpha activators for dyslipidemia.

Antithrombin activities in childhood malnutrition.

PubMed Central

Jiménez, R A; Jiménez, E; Ingram, G I; Mora, L A; Atmetlla, F; Carrillo, J M; Vargas, W

1979-01-01

Antithrombin activities in 30 severely malnourished children and 40 normal children were estimated in clotting tests by thrombin neutralisation as anti-Xa and by a heparin antithrombin assay; and by immunodiffusion as alpha 2-globulin and alpha 1-antitrypsin. The patients' mean alpha 2-globulin was severely depressed, and there were less marked depletions in mean values for thrombin neutralisation, anti-Xa, and in the heparin antithrombin assay (which showed the flat curve thought to reflect a thrombotic tendency). The alpha 1-antitrypsin values were normal. The findings support the concept of antithrombin as the summation of alpha 2-globulin and alpha 1-antitrypsin (with alpha 2-macroglobulin); and the low values may be related to the high incidence of thrombosis reported in childhood malnutrition, although it was not seen in these patients. PMID:118190

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danno, Hirosuke; Ishii, Kiyo-aki; Nakagawa, Yoshimi

To elucidate the physiological role of CREBH, the hepatic mRNA and protein levels of CREBH were estimated in various feeding states of wild and obesity mice. In the fast state, the expression of CREBH mRNA and nuclear protein were high and profoundly suppressed by refeeding in the wild-type mice. In ob/ob mice, the refeeding suppression was impaired. The diet studies suggested that CREBH expression was activated by fatty acids. CREBH mRNA levels in the mouse primary hepatocytes were elevated by addition of the palmitate, oleate and eicosapenonate. It was also induced by PPAR{alpha} agonist and repressed by PPAR{alpha} antagonist. Luciferasemore » reporter gene assays indicated that the CREBH promoter activity was induced by fatty acids and co-expression of PPAR{alpha}. Deletion studies identified the PPRE for PPAR{alpha} activation. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) assay confirmed that PPAR{alpha} directly binds to the PPRE. Activation of CREBH at fasting through fatty acids and PPAR{alpha} suggest that CREBH is involved in nutritional regulation.« less

Fourth High Alpha Conference, volume 1

NASA Technical Reports Server (NTRS)

1994-01-01

The goal of the Fourth High Alpha Conference was to focus on the flight validation of high angle-of-attack technologies and provide an in-depth review of the latest high angle-of-attack activities. Areas that were covered include: high angle-of-attack aerodynamics, propulsion and inlet dynamics, thrust vectoring, control laws and handling qualities, tactical utility, and forebody controls.

Discovering an Accessible Enzyme: Salivary [alpha]-Amylase--"Prima Digestio Fit in Ore"--A Didactic Approach for High School Students

ERIC Educational Resources Information Center

Marini, Isabella

2005-01-01

Human salivary [alpha]-amylase is used in this experimental approach to introduce biology high school students to the concept of enzyme activity in a dynamic way. Through a series of five easy, rapid, and inexpensive laboratory experiments students learn what the activity of an enzyme consists of: first in a qualitative then in a semi-quantitative…

Tryptophan W207 in transducin T alpha is the fluorescence sensor of the G protein activation switch and is involved in the effector binding.

PubMed Central

Faurobert, E; Otto-Bruc, A; Chardin, P; Chabre, M

1993-01-01

We have produced a recombinant transducin alpha subunit (rT alpha) in sf9 cells, using a baculovirus system. Deletion of the myristoylation site near the N-terminal increased the solubility and allowed the purification of rT alpha. When reconstituted with excess T beta gamma on retinal membrane, rT alpha displayed functional characteristics of wild-type T alpha vis à vis its coupled receptor, rhodopsin and its effector, cGMP phosphodiesterase (PDE). We further mutated a tryptophan, W207, which is conserved in all G proteins and is suspected to elicit the fluorescence change correlated to their activation upon GDP/GTP exchange or aluminofluoride (AlFx) binding. [W207F]T alpha mutant displayed high affinity receptor binding and underwent a conformational switch upon receptor-catalysed GTP gamma S binding or upon AlFx binding, but this did not elicit any fluorescence change. Thus W207 is the only fluorescence sensor of the switch. Upon the switch the mutant remained unable to activate the PDE. To characterize better its effector-activating interaction we measured the affinity of [W207F]T alpha GDP-AlFx for PDE gamma, the effector subunit that binds most tightly to T alpha. [W207F]T alpha still bound in an activation-dependent way to PDE gamma, but with a 100-fold lower affinity than rT alpha. This suggests that W207 contributes to the G protein effector binding. Images PMID:8223434

EEG alpha synchronization is related to top-down processing in convergent and divergent thinking

PubMed Central

Benedek, Mathias; Bergner, Sabine; Könen, Tanja; Fink, Andreas; Neubauer, Aljoscha C.

2011-01-01

Synchronization of EEG alpha activity has been referred to as being indicative of cortical idling, but according to more recent evidence it has also been associated with active internal processing and creative thinking. The main objective of this study was to investigate to what extent EEG alpha synchronization is related to internal processing demands and to specific cognitive process involved in creative thinking. To this end, EEG was measured during a convergent and a divergent thinking task (i.e., creativity-related task) which once were processed involving low and once involving high internal processing demands. High internal processing demands were established by masking the stimulus (after encoding) and thus preventing further bottom-up processing. Frontal alpha synchronization was observed during convergent and divergent thinking only under exclusive top-down control (high internal processing demands), but not when bottom-up processing was allowed (low internal processing demands). We conclude that frontal alpha synchronization is related to top-down control rather than to specific creativity-related cognitive processes. Frontal alpha synchronization, which has been observed in a variety of different creativity tasks, thus may not reflect a brain state that is specific for creative cognition but can probably be attributed to high internal processing demands which are typically involved in creative thinking. PMID:21925520

Pretreatment by low-dose fibrates protects against acute free fatty acid-induced renal tubule toxicity by counteracting PPAR{alpha} deterioration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, Kyoko; Department of Nephrology Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621; Kamijo, Yuji, E-mail: yujibeat@shinshu-u.ac.jp

2011-05-01

Development of a preventive strategy against tubular damage associated with proteinuria is of great importance. Recently, free fatty acid (FFA) toxicities accompanying proteinuria were found to be a main cause of tubular damage, which was aggravated by insufficiency of peroxisome proliferator-activated receptor alpha (PPAR{alpha}), suggesting the benefit of PPAR{alpha} activation. However, an earlier study using a murine acute tubular injury model, FFA-overload nephropathy, demonstrated that high-dose treatment of PPAR{alpha} agonist (0.5% clofibrate diet) aggravated the tubular damage as a consequence of excess serum accumulation of clofibrate metabolites due to decreased kidney elimination. To induce the renoprotective effects of PPAR{alpha} agonistsmore » without drug accumulation, we tried a pretreatment study using low-dose clofibrate (0.1% clofibrate diet) using the same murine model. Low-dose clofibrate pretreatment prevented acute tubular injuries without accumulation of its metabolites. The tubular protective effects appeared to be associated with the counteraction of PPAR{alpha} deterioration, resulting in the decrease of FFAs influx to the kidney, maintenance of fatty acid oxidation, diminution of intracellular accumulation of undigested FFAs, and attenuation of disease developmental factors including oxidative stress, apoptosis, and NF{kappa}B activation. These effects are common to other fibrates and dependent on PPAR{alpha} function. Interestingly, however, clofibrate pretreatment also exerted PPAR{alpha}-independent tubular toxicities in PPAR{alpha}-null mice with FFA-overload nephropathy. The favorable properties of fibrates are evident when PPAR{alpha}-dependent tubular protective effects outweigh their PPAR{alpha}-independent tubular toxicities. This delicate balance seems to be easily affected by the drug dose. It will be important to establish the appropriate dosage of fibrates for treatment against kidney disease and to develop a novel PPAR{alpha} activator that has a steady serum concentration regardless of kidney dysfunction. - Graphical Abstract: Massive proteinuria introduces free fatty acid toxicity to proximal tubular epithelial cells (PTECs). PPAR{alpha} activationvia clofibrate pretreatment maintains fatty acid catabolism and attenuates oxidative stress, apoptosis, and NF{kappa}B activation, resulting in protection of PTECs. The favorable properties of fibrates are evident when PPAR{alpha}-dependent tubular protective effects outweigh their PPAR{alpha}-independent tubular toxicities. Display Omitted Highlights: > Clofibrate pretreatment protects against acute FFA-induced tubular toxicity. > PPAR{alpha} activation decreases FFA influx and maintains fatty acid catabolism. > PPAR{alpha} activation attenuates oxidative stress, apoptosis, and NF{kappa}B activation. > Protective effects must outweigh PPAR{alpha}-independent tubular toxicities of fibrates.« less

Spatial and temporal relationships of electrocorticographic alpha and gamma activity during auditory processing.

PubMed

Potes, Cristhian; Brunner, Peter; Gunduz, Aysegul; Knight, Robert T; Schalk, Gerwin

2014-08-15

Neuroimaging approaches have implicated multiple brain sites in musical perception, including the posterior part of the superior temporal gyrus and adjacent perisylvian areas. However, the detailed spatial and temporal relationship of neural signals that support auditory processing is largely unknown. In this study, we applied a novel inter-subject analysis approach to electrophysiological signals recorded from the surface of the brain (electrocorticography (ECoG)) in ten human subjects. This approach allowed us to reliably identify those ECoG features that were related to the processing of a complex auditory stimulus (i.e., continuous piece of music) and to investigate their spatial, temporal, and causal relationships. Our results identified stimulus-related modulations in the alpha (8-12 Hz) and high gamma (70-110 Hz) bands at neuroanatomical locations implicated in auditory processing. Specifically, we identified stimulus-related ECoG modulations in the alpha band in areas adjacent to primary auditory cortex, which are known to receive afferent auditory projections from the thalamus (80 of a total of 15,107 tested sites). In contrast, we identified stimulus-related ECoG modulations in the high gamma band not only in areas close to primary auditory cortex but also in other perisylvian areas known to be involved in higher-order auditory processing, and in superior premotor cortex (412/15,107 sites). Across all implicated areas, modulations in the high gamma band preceded those in the alpha band by 280 ms, and activity in the high gamma band causally predicted alpha activity, but not vice versa (Granger causality, p<1e(-8)). Additionally, detailed analyses using Granger causality identified causal relationships of high gamma activity between distinct locations in early auditory pathways within superior temporal gyrus (STG) and posterior STG, between posterior STG and inferior frontal cortex, and between STG and premotor cortex. Evidence suggests that these relationships reflect direct cortico-cortical connections rather than common driving input from subcortical structures such as the thalamus. In summary, our inter-subject analyses defined the spatial and temporal relationships between music-related brain activity in the alpha and high gamma bands. They provide experimental evidence supporting current theories about the putative mechanisms of alpha and gamma activity, i.e., reflections of thalamo-cortical interactions and local cortical neural activity, respectively, and the results are also in agreement with existing functional models of auditory processing. Copyright © 2014 Elsevier Inc. All rights reserved.

High glucose concentrations attenuate hypoxia-inducible factor-1{alpha} expression and signaling in non-tumor cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dehne, Nathalie, E-mail: dehne@biochem.uni-frankfurt.de; Hintereder, Gudrun, E-mail: Gudrun.Hintereder@kgu.de; Bruene, Bernhard, E-mail: bruene@pathobiochemie1.de

2010-04-15

Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1{alpha} expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1{alpha} accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin.more » Transfection of C{sub 2}C{sub 12} cells with a HIF-1{alpha} oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O{sub 2} redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1{alpha} expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1{alpha} accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.« less

State of the art of D&D Instrumentation Technology: Alpha counting in the presence of high background

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickerman, C.E.

1995-08-01

Discrimination of alpha activity in the presence of a high radiation background has been identified as an area of concern to be studied for D&D applications. Upon evaluating the range of alpha detection needs for D&D operations, we have expanded this study to address the operational concern of greatly expediting alpha counting of rough surfaces and rubble. Note that the term, ``rough surfaces`` includes a wide range of practical cases, including contaminated equipment and work surfaces. We have developed provisional applications requirements for instrumentation of this type; and we also have generated the scope of a program of instrument evaluationmore » and testing, with emphasis on practical implementation. In order to obtain the full operational benefit of alpha discrimination in the presence of strong beta-gamma radiation background, the detection system must be capable of some form of remote or semi-remote operation in order to reduce operator exposure. We have identified a highly promising technique, the long-range alpha detector (LRAD), for alpha discrimination in the presence of high radiation background. This technique operates upon the principle of transporting alphaionized air to an ionization detector. A transport time within a few seconds is adequate. Neither the provisional requirements nor the evaluation and testing scope were expressly tailored to force the selection of a LRAD technology, and they could be used as a basis for studies of other promising technologies. However, a technology that remotely detects alpha-ionized air (e. g., LRAD) is a natural fit to the key requirements of rejection of high background at the survey location and operator protection. Also, LRAD appears to be valuable for D&D applications as a means of greatly expediting surface alpha-activity surveys that otherwise would require performing time-consuming scans over surfaces of interest with alpha detector probes, and even more labor-intensive surface wipe surveys.« less

Hydrolases of Hysterothylacium aduncum (Nematoda).

PubMed

Zółtowska, Krystyna; Dmitryjuk, Małgorzata; Rokicki, Jerzy; Lopieńska-Biernat, Elzbieta

2007-01-01

Enzymatic activity is an indicator of an organism's metabolic rate which depends on, i.e., environmental conditions, developmental stage, physiological stage, and sex. The API ZYM test was applied to compare activities of 19 hydrolases of female and male Hysterothylacium aduncum. Sexually mature nematodes were isolated from eelpout individuals caught in the Gulf of Gdańsk. Enzymatic activity of the hydrolases and the protein content was determined in nematode extracts using API ZYM and Bradford's method, respectively. The females and males tested showed a total of 13 enzymes to be active. The males showed additionally the presence of alpha-fucosidase. Acidic and alkaline phosphatases had very high activities in both sexes; short-chain fatty acid esterases, leucine and valine aminopeptidases, alpha-glucosidase, and N-acetylglucosaminidase were highly active. H. aduncum showed no trypsin- and chymotrypsin-specific activities; similarly, no activity of alpha-galactosidase, alpha-mannosidase, and beta-glucuronidase was revealed. Except for lipase (C14), hydrolases were more active in females than in males, which is related to metabolic rate being higher in females due to their reproductive function. Comparison of the results obtained with earlier data produced with API ZYM allowed suggesting that the hydrolase pattern may be more affected by habitat in the host than by the taxonomic affiliation of nematode.

Reactive oxygen species-generating mitochondrial DNA mutation up-regulates hypoxia-inducible factor-1alpha gene transcription via phosphatidylinositol 3-kinase-Akt/protein kinase C/histone deacetylase pathway.

PubMed

Koshikawa, Nobuko; Hayashi, Jun-Ichi; Nakagawara, Akira; Takenaga, Keizo

2009-11-27

Lewis lung carcinoma-derived high metastatic A11 cells constitutively overexpress hypoxia-inducible factor (HIF)-1alpha mRNA compared with low metastatic P29 cells. Because A11 cells exclusively possess a G13997A mutation in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene, we addressed here a causal relationship between the ND6 mutation and the activation of HIF-1alpha transcription, and we investigated the potential mechanism. Using trans-mitochondrial cybrids between A11 and P29 cells, we found that the ND6 mutation was directly involved in HIF-1alpha mRNA overexpression. Stimulation of HIF-1alpha transcription by the ND6 mutation was mediated by overproduction of reactive oxygen species (ROS) and subsequent activation of phosphatidylinositol 3-kinase (PI3K)-Akt and protein kinase C (PKC) signaling pathways. The up-regulation of HIF-1alpha transcription was abolished by mithramycin A, an Sp1 inhibitor, but luciferase reporter and chromatin immunoprecipitation assays indicated that Sp1 was necessary but not sufficient for HIF-1alpha mRNA overexpression in A11 cells. On the other hand, trichostatin A, a histone deacetylase (HDAC) inhibitor, markedly suppressed HIF-1alpha transcription in A11 cells. In accordance with this, HDAC activity was high in A11 cells but low in P29 cells and in A11 cells treated with the ROS scavenger ebselene, the PI3K inhibitor LY294002, and the PKC inhibitor Ro31-8220. These results suggest that the ROS-generating ND6 mutation increases HIF-1alpha transcription via the PI3K-Akt/PKC/HDAC pathway, leading to HIF-1alpha protein accumulation in hypoxic tumor cells.

Effects of tumor necrosis factor-alpha and interferon-gamma on expressions of matrix metalloproteinase-2 and -9 in human bladder cancer cells.

PubMed

Shin, K Y; Moon, H S; Park, H Y; Lee, T Y; Woo, Y N; Kim, H J; Lee, S J; Kong, G

2000-10-31

We have investigated the effects of tumor necrosis factor-alpha (TNF-alpha) and interferon (INF-gamma), the potent Bacillus Calmette-Guerin (BCG)-induced cytokines on the production of MMP-2, MMP-9, TIMP-1, TIMP-2 and MT1-MMP in high grade human bladder cancer cell lines, T-24, J-82 and HT-1376 cell lines. MMP-2 expression and activity were decreased in T-24 cells treated with both cytokines in a dose dependent manner. However, J-82 cells treated with TNF-alpha and INF-gamma revealed dose dependent increases of MMP-9 expression and activity with similar baseline expression and activity of MMP-2. HT-1376 cells after exposure to TNF-alpha only enhanced the expression and activity of MMP-9. These results indicate that TNF-alpha and INF-gamma could regulate the production of MMP-2 or MMP-9 on bladder cancer cells and their patterns of regulation are cell specific. Furthermore, this diverse response of bladder cancer cells to TNF-alpha and INF-gamma suggests that BCG immunotherapy may enhance the invasiveness of bladder cancer in certain conditions with induction of MMPs.

Determination of the volume activity concentration of alpha artificial radionuclides with alpha spectrometer.

PubMed

Liu, B; Zhang, Q; Li, Y

1997-12-01

This paper introduces a method to determine the volume activity concentration of alpha and/or beta artificial radionuclides in the environment and radon/thoron progeny background-compensation based on a Si surface-barrier detector. By measuring the alpha peak counts of 218Po and 214Po in two time intervals, the activity concentration of 218Po, 214Pb and 214Bi aerosol particles were determined; meanwhile, the total beta count of 214Pb and 214Bi aerosols was also calculated from their decay scheme. With the average equilibrium factor of thoron progeny in general environment, the alpha and beta counts of thoron progeny were approximately evaluated by 212Po alpha peak counts. The alpha count of transuranic aerosols was determined by subtracting the trail counts of radon/thoron progeny alpha peaks. The total count of beta artificial radionuclides was determined by subtracting the beta counts of radon/thoron progeny aerosol particles. In our preliminary experiments, if the radon progeny concentration is less than 15 Bq m(-3), the lower limit of detection of transuranics concentration is less than 0.1 Bq m(-3). Even if the radon progeny concentration is as high as 75 Bq m(-3), the lower limit of detection of total beta activity concentration of artificial nuclides aerosols is less than 1 Bq m(-3).

The IL-6/sIL-6R treatment of a malignant melanoma cell line enhances susceptibility to TNF-{alpha}-induced apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagley, Yadav; Yoo, Yung-Choon; Seo, Han Geuk

2007-03-23

Melanoma is an intractable tumor that has shown very impressive and promising response to local administration of high dose recombinant TNF-{alpha} in combination with IFN-{gamma} in clinical studies. In this study, we investigated the effect of IL-6/sIL-6R on TNF-{alpha}-resistant B16/F10.9 melanoma cells. A low dose of TNF-{alpha} or IL-6/sIL-6R had minimal affect on the cell growth. However, the highly active fusion protein of sIL-6R and IL-6 (IL6RIL6), covalently linked by a flexible peptide, sensitized TNF-{alpha}-resistant F10.9 melanoma cells to TNF-{alpha}-induced apoptosis. Stimulation of the cells with IL6RIL6 plus TNF-{alpha} resulted in both the activation of caspase-3 and the reduction ofmore » bcl-2 expression. Flow cytometry analysis showed that IL6RIL6-upregulated TNF-R55 and TNF-R75 expression, suggesting an increase in TNF-{alpha} responsiveness by IL6RIL6 resulting from the induction of TNF receptors. Moreover, exposure of F10.9 cells to neutralizing antibody to TNF-R55 significantly inhibited IL6RIL6/TNF-{alpha}-induced cytotoxicity. These results suggest that the IL6/sIL6R/gp130 system, which sensitizes TNF-{alpha}-resistant melanoma cells to TNF-{alpha}-induced apoptosis, may provide a new target for immunotherapy.« less

Alpha Rhythms in Audition: Cognitive and Clinical Perspectives

PubMed Central

Weisz, Nathan; Hartmann, Thomas; Müller, Nadia; Lorenz, Isabel; Obleser, Jonas

2011-01-01

Like the visual and the sensorimotor systems, the auditory system exhibits pronounced alpha-like resting oscillatory activity. Due to the relatively small spatial extent of auditory cortical areas, this rhythmic activity is less obvious and frequently masked by non-auditory alpha-generators when recording non-invasively using magnetoencephalography (MEG) or electroencephalography (EEG). Following stimulation with sounds, marked desynchronizations can be observed between 6 and 12 Hz, which can be localized to the auditory cortex. However knowledge about the functional relevance of the auditory alpha rhythm has remained scarce so far. Results from the visual and sensorimotor system have fuelled the hypothesis of alpha activity reflecting a state of functional inhibition. The current article pursues several intentions: (1) Firstly we review and present own evidence (MEG, EEG, sEEG) for the existence of an auditory alpha-like rhythm independent of visual or motor generators, something that is occasionally met with skepticism. (2) In a second part we will discuss tinnitus and how this audiological symptom may relate to reduced background alpha. The clinical part will give an introduction into a method which aims to modulate neurophysiological activity hypothesized to underlie this distressing disorder. Using neurofeedback, one is able to directly target relevant oscillatory activity. Preliminary data point to a high potential of this approach for treating tinnitus. (3) Finally, in a cognitive neuroscientific part we will show that auditory alpha is modulated by anticipation/expectations with and without auditory stimulation. We will also introduce ideas and initial evidence that alpha oscillations are involved in the most complex capability of the auditory system, namely speech perception. The evidence presented in this article corroborates findings from other modalities, indicating that alpha-like activity functionally has an universal inhibitory role across sensory modalities. PMID:21687444

Regional Patterns of Elevated Alpha and High-Frequency Electroencephalographic Activity during Nonrapid Eye Movement Sleep in Chronic Insomnia: A Pilot Study.

PubMed

Riedner, Brady A; Goldstein, Michael R; Plante, David T; Rumble, Meredith E; Ferrarelli, Fabio; Tononi, Giulio; Benca, Ruth M

2016-04-01

To examine nonrapid eye movement (NREM) sleep in insomnia using high-density electroencephalography (EEG). All-night sleep recordings with 256 channel high-density EEG were analyzed for 8 insomnia subjects (5 females) and 8 sex and age-matched controls without sleep complaints. Spectral analyses were conducted using unpaired t-tests and topographical differences between groups were assessed using statistical non-parametric mapping. Five minute segments of deep NREM sleep were further analyzed using sLORETA cortical source imaging. The initial topographic analysis of all-night NREM sleep EEG revealed that insomnia subjects had more high-frequency EEG activity (> 16 Hz) compared to good sleeping controls and that the difference between groups was widespread across the scalp. In addition, the analysis also showed that there was a more circumscribed difference in theta (4-8 Hz) and alpha (8-12 Hz) power bands between groups. When deep NREM sleep (N3) was examined separately, the high-frequency difference between groups diminished, whereas the higher regional alpha activity in insomnia subjects persisted. Source imaging analysis demonstrated that sensory and sensorimotor cortical areas consistently exhibited elevated levels of alpha activity during deep NREM sleep in insomnia subjects relative to good sleeping controls. These results suggest that even during the deepest stage of sleep, sensory and sensorimotor areas in insomnia subjects may still be relatively active compared to control subjects and to the rest of the sleeping brain. © 2016 Associated Professional Sleep Societies, LLC.

Substitution of histidine-137 by glutamine abolishes the catalytic activity of the ribosome-inactivating protein alpha-sarcin.

PubMed Central

Lacadena, J; Mancheño, J M; Martinez-Ruiz, A; Martínez del Pozo, A; Gasset, M; Oñaderra, M; Gavilanes, J G

1995-01-01

The alpha-sarcin cytotoxin is an extracellular fungal protein that inhibits protein biosynthesis by specifically cleaving one phosphodiester bond of the 28 S rRNA. The His137 residue of alpha-sarcin is suggested to be involved in the catalytic activity of this protein, based on the observed sequence similarity with some fungal ribonucleases. Replacement of this residue by Gln (H137Q mutant variant of alpha-sarcin) abolishes the ribonuclease activity of the protein. This has been demonstrated for an homogeneous preparation of the H137Q alpha-sarcin by measuring its effect against both intact rabbit ribosomes and the homopolymer poly(A). The conformation of H137Q alpha-sarcin is highly similar to that of the wild-type protein, which has been analysed by CD and fluorescence spectroscopy. Both H137Q and wild-type alpha-sarcin exhibit identical CD spectra in the peptide-bond region, indicating that no changes at the level of the secondary structure are produced upon mutation. Only minor differences are observed in both near-UV CD and fluorescence emission spectra in comparison to those of the wild-type protein. Moreover, H137Q alpha-sarcin interacts with phospholipid vesicles, promoting the same effects as the native cytotoxin. Therefore, we propose that His137 is part of the ribonucleolytic active site of the cytotoxin alpha-sarcin. Images Figure 4 PMID:7626023

Antibacterial activities of peptides from the water-soluble extracts of Italian cheese varieties.

PubMed

Rizzello, C G; Losito, I; Gobbetti, M; Carbonara, T; De Bari, M D; Zambonin, P G

2005-07-01

Water-soluble extracts of 9 Italian cheese varieties that differed mainly for type of cheese milk, starter, technology, and time of ripening were fractionated by reversed-phase fast protein liquid chromatography, and the antimicrobial activity of each fraction was first assayed toward Lactobacillus sakei A15 by well-diffusion assay. Active fractions were further analyzed by HPLC coupled to electrospray ionization-ion trap mass spectrometry, and peptide sequences were identified by comparison with a proteomic database. Parmigiano Reggiano, Fossa, and Gorgonzola water-soluble extracts did not show antibacterial peptides. Fractions of Pecorino Romano, Canestrato Pugliese, Crescenza, and Caprino del Piemonte contained a mixture of peptides with a high degree of homology. Pasta filata cheeses (Caciocavallo and Mozzarella) also had antibacterial peptides. Peptides showed high levels of homology with N-terminal, C-terminal, or whole fragments of well known antimicrobial or multifunctional peptides reported in the literature: alphaS1-casokinin (e.g., sheep alphaS1-casein (CN) f22-30 of Pecorino Romano and cow alphaS1-CN f24-33 of Canestrato Pugliese); isracidin (e.g., sheep alphaS1-CN f10-21 of Pecorino Romano); kappacin and casoplatelin (e.g., cow kappa-CN f106-115 of Canestrato Pugliese and Crescenza); and beta-casomorphin-11 (e.g., goat beta-CN f60-68 of Caprino del Piemonte). As shown by the broth microdilution technique, most of the water-soluble fractions had a large spectrum of inhibition (minimal inhibitory concentration of 20 to 200 microg/mL) toward gram-positive and gram-negative bacterial species, including potentially pathogenic bacteria of clinical interest. Cheeses manufactured from different types of cheese milk (cow, sheep, and goat) have the potential to generate similar peptides with antimicrobial activity.

Alpha chymotrypsin coated clusters of Fe3O4 nanoparticles for biocatalysis in low water media.

PubMed

Mukherjee, Joyeeta; Gupta, Munishwar N

2012-11-08

Enzymes in low water containing non aqueous media are useful for organic synthesis. For example, hydrolases in such media can be used for synthetic purposes. Initial work in this area was carried out with lyophilized powders of enzymes. These were found to have poor activity. Drying (removing bulk water) by precipitation turned out to be a better approach. As enzymes in such media are heterogeneous catalysts, spreading these precipitates over a large surface gave even better results. In this context, nanoparticles with their better surface to volume ratio provide obvious advantage. Magnetic nanoparticles have an added advantage of easy separation after the reaction. Keeping this in view, alpha chymotrypsin solution in water was precipitated over a stirred population of Fe3O4 nanoparticles in n-propanol. This led to alpha chymotrypsin activity coated over clusters of Fe3O4 nanoparticles. These preparations were found to have quite high transesterification activity in low water containing n-octane. Precipitation of alpha chymotrypsin over a stirred suspension of Fe3O4 nanoparticles (3.6 nm diameter) led to the formation of enzyme coated clusters of nanoparticles (ECCNs). These clusters were also magnetic and their hydrodynamic diameter ranged from 1.2- 2.6 microns (as measured by dynamic light scattering). Transmission electron microscopy (TEM), showed that these clusters had highly irregular shapes. Transesterification assay of various clusters in anhydrous n-octane led to optimization of concentration of nanoparticles in suspension during precipitation. Optimized design of enzyme coated magnetic clusters of nanoparticles (ECCN 3) showed the highest initial rate of 465 nmol min-1 mg-1protein which was about 9 times higher as compared to the simple precipitates with an initial rate of 52 nmol min-1 mg-1 protein.Circular Dichroism (CD)(with a spinning cell accessory) showed that secondary structure content of the alpha Chymotrypsin in ECCN 3 [15% α-helix, 37% β-sheet and 48% random coil] was identical to the simple precipitates of alpha chymotrypsin. A strategy for obtaining a high activity preparation of alpha chymotrypsin for application in low water media is described. Such high activity biocatalysts are useful in organic synthesis.

Regulation of hepatic branched-chain alpha-keto acid dehydrogenase complex in rats fed a high-fat diet

USDA-ARS?s Scientific Manuscript database

Objective: Branched-chain alpha-keto acid dehydrogenase complex (BCKDC) regulates branched-chain amino acid (BCAA) metabolism at the level of branched chain alpha-ketoacid (BCKA) catabolism. It has been demonstrated that the activity of hepatic BCKDC is markedly decreased in type 2 diabetic animal...

Neuroelectrical imaging investigation of cortical activity during listening to music in prelingually deaf children with cochlear implants.

PubMed

Marsella, Pasquale; Scorpecci, Alessandro; Vecchiato, Giovanni; Maglione, Anton Giulio; Colosimo, Alfredo; Babiloni, Fabio

2014-05-01

To date, no objective measure of the pleasantness of music perception by children with cochlear implants has been reported. The EEG alpha asymmetries of pre-frontal cortex activation are known to relate to emotional/affective engagement in a perceived stimulus. More specifically, according to the "withdrawal/approach" model, an unbalanced de-synchronization of the alpha activity in the left prefrontal cortex has been associated with a positive affective state/approach toward a stimulus, and an unbalanced de-synchronization of the same activity in the right prefrontal cortex with a negative affective state/withdrawal from a stimulus. In the present study, High-Resolution EEG with Source Reconstruction was used to compare the music-induced alpha asymmetries of the prefrontal cortex in a group of prelingually deaf implanted children and in a control group of normal-hearing children. Six normal-hearing and six age-matched deaf children using a unilateral cochlear implants underwent High-Resolution EEG recordings as they were listening to a musical cartoon. Musical stimuli were delivered in three versions: Normal, Distort (reverse audio flow) and Mute. The EEG alpha rhythm asymmetry was analyzed: Power Spectral Density was calculated for each Region of Interest, together with a right-left imbalance index. A map of cortical activation was then reconstructed on a realistic cortical model. Asymmetries of EEG alpha rhythm in the prefrontal cortices were observed in both groups. In the normal-hearing children, the asymmetries were consistent with the withdrawal/approach model, whereas in cochlear implant users they were not. Moreover, in implanted children a different pattern of alpha asymmetries in extrafrontal cortical areas was noticed as compared to normal-hearing subjects. The peculiar pattern of alpha asymmetries in implanted children's prefrontal cortex in response to musical stimuli suggests an inability by these subjects to discriminate normal from dissonant music and to appreciate the pleasantness of normal music. High-Resolution EEG may prove to be a promising tool for objectively measuring prefrontal cortex alpha asymmetries in child cochlear implant users. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Rotational modulation of hydrogen Lyman alpha flux from 44ii Bootis

NASA Technical Reports Server (NTRS)

Vilhu, O.; Neff, J. E.; Rahunen, T.

1988-01-01

Observations with IUE that cover the entire 6.4 hr orbital cycle of the late-type contact binary 44i Bootis are presented. Intrinsic stellar hydrogen Lyman alpha emission flux was determined from low-resolution IUE spectra, compensating for geocoronal emission and for interstellar absorption. The variation of the stellar Lyman alpha emission flux correlates well with the variation of the C II and C IV emission fluxes, and shows orbital modulation in phase with the visual light curve. The ratio of Lyman alpha to CII flux (15 to 20) is similar to that observed in solar active regions. Hydrogen Lyman alpha emission is thus one of the most important cooling channels in the outer atmosphere of 44i Boo. A high-resolution spectrum of the Lyman alpha line was obtained between orbital phases 0.0 and 0.6. The integrated flux in the observed high-resolution Lyman alpha profile is consistent with the fluxes determined using low-resolution spectra, and the composite profile indicates that both components of this binary have equally active chromospheres and transition regions. The uncertainty in the interstellar hydrogen column density cannot mimic the observed variation in the integrated Lyman alpha flux, because the stellar line is very much broader than the interstellar absorption.

Rotational modulation of hydrogen Lyman alpha flux from 44i Bootis

NASA Technical Reports Server (NTRS)

Vilhu, O.; Neff, J. E.; Rahunen, T.

1989-01-01

Observations with IUE that cover the entire 6.4 hr orbital cycle of the late-type contact binary 44i Bootis are presented. Intrinsic stellar hydrogen Lyman alpha emission flux was determined from low-resolution IUE spectra, compensating for geocoronal emission and for interstellar absorption. The variation of the stellar Lyman alpha emission flux correlates well with the variation of the CII and CIV emission fluxes, and shows orbital modulation in phase with the visual light curve. The ratio of Lyman alpha to CII flux (15 to 20) is similar to that observed in solar active regions. Hydrogen Lyman alpha emission is thus one of the most important cooling channels in the outer atmosphere of 44i Boo. A high-resolution spectrum of the Lyman alpha line was obtained between orbital phases 0.0 and 0.6. The integrated flux in the observed high-resolution Lyman alpha profile is consistent with the fluxes determined using low-resolution spectra, and the composite profile indicates that both components of this binary have equally active chromospheres and transition regions. The uncertainty in the interstellar hydrogen column density cannot mimic the observed variation in the integrated Lyman alpha flux, because the stellar line is very much broader than the interstellar absorption.

Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

PubMed

Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

2008-02-01

People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

Differential activation of G-proteins by mu-opioid receptor agonists.

PubMed

Saidak, Zuzana; Blake-Palmer, Katherine; Hay, Debbie L; Northup, John K; Glass, Michelle

2006-03-01

We investigated the ability of the activated mu-opioid receptor (MOR) to differentiate between myristoylated G(alphai1) and G(alphaoA) type G(alpha) proteins, and the maximal activity of a range of synthetic and endogenous agonists to activate each G(alpha) protein. Membranes from HEK293 cells stably expressing transfected MOR were chaotrope extracted to denature endogenous G-proteins and reconstituted with specific purified G-proteins. The G(alpha) subunits were generated in bacteria and were demonstrated to be recognised equivalently to bovine brain purified G(alpha) protein by CB(1) cannabinoid receptors. The ability of agonists to catalyse the MOR-dependent GDP/[(35)S]GTP(gamma)S exchange was then compared for G(alphai1) and G(alphaoA). Activation of MOR by DAMGO produced a high-affinity saturable interaction for G(alphaoA) (K(m)=20+/-1 nM) but a low-affinity interaction with G(alphai1) (K(m)=116+/-12 nM). DAMGO, met-enkephalin and leucine-enkephalin displayed maximal G(alpha) activation among the agonists evaluated. Endomorphins 1 and 2, methadone and beta-endorphin activated both G(alpha) to more than 75% of the maximal response, whereas fentanyl partially activated both G-proteins. Buprenorphine and morphine demonstrated a statistically significant difference between the maximal activities between G(alphai1) and G(alphaoA). Interestingly, DAMGO, morphine, endomorphins 1 and 2, displayed significant differences in the potencies for the activation of the two G(alpha). Differences in maximal activity and potency, for G(alphai1) versus G(alphaoA), are both indicative of agonist selective activation of G-proteins in response to MOR activation. These findings may provide a starting point for the design of drugs that demonstrate greater selectivity between these two G-proteins and therefore produce a more limited range of effects.

Stress and vascular responses: atheroprotective effect of laminar fluid shear stress in endothelial cells: possible role of mitogen-activated protein kinases.

PubMed

Yoshizumi, Masanori; Abe, Jun-Ichi; Tsuchiya, Koichiro; Berk, Bradford C; Tamaki, Toshiaki

2003-03-01

Atherosclerosis preferentially occurs in areas of turbulent blood flow and low fluid shear stress, whereas laminar blood flow and high shear stress are atheroprotective. Inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), stimulate expression of endothelial cell (EC) genes that may promote atherosclerosis. Recent findings suggest a steady laminar blood flow decreases EC apoptosis and inhibits TNF-mediated EC activation. EC apoptosis or activation is suggested to be involved in plaque erosion, which may lead to platelet aggregation. TNF-alpha regulates gene expression in ECs, in part, by stimulating mitogen-activated protein (MAP) kinases, which phosphorylate transcription factors. We hypothesized that steady laminar flow inhibits cytokine-mediated activation of MAP kinases in ECs. To test this hypothesis, we determined the effects of steady laminar flow (shear stress = 12 dynes/cm(2)) on TNF-alpha-stimulated activity of three MAP kinases in human umbilical vein ECs (HUVEC): extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), and p38. TNF-alpha activated ERK1/2, JNK, and p38 maximally at 15 min in HUVEC. Pre-exposing HUVEC for 10 min to flow inhibited TNF-alpha activation of JNK, but showed no significant effect on ERK1/2 or p38 activation. Incubation of HUVEC with PD98059, a specific ERK1/2 inhibitor, blocked the flow-mediated inhibition of TNF activation of JNK. Transfection studies with dominant-negative constructs of the protein kinase MEK5 suggested an important role for big mitogen-activated protein kinase 1 (BMK1) in flow-mediated regulation of EC activation by TNF-alpha. Understanding the mechanisms by which steady laminar flow regulates JNK activation by cytokines may provide insight into the atheroprotective mechanisms induced by laminar blood flow.

Development of Rapid Radiochemical Method for Gross Alpha and Gross Beta Activity Concentration in Flowback and Produced Waters from Hydraulic Fracturing Operations

EPA Science Inventory

This report summarizes the development and validation of an improved method for the Determination of Gross Alpha and Gross Beta Activity in Flowback and Produced Waters from Hydraulic Fracturing Operations (FPWHFO). Flowback and produced waters are characterized by high concentra...

Actions of alpha2 adrenoceptor ligands at alpha2A and 5-HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for alpha2A adrenoceptors.

PubMed

Newman-Tancredi, A; Nicolas, J P; Audinot, V; Gavaudan, S; Verrièle, L; Touzard, M; Chaput, C; Richard, N; Millan, M J

1998-08-01

This study examined the activity of chemically diverse alpha2 adrenoceptor ligands at recombinant human (h) and native rat (r) alpha2A adrenoceptors compared with 5-HT1A receptors. First, in competition binding experiments at h alpha2A and h5-HT1A receptors expressed in CHO cells, several compounds, including the antagonists 1-(2-pyrimidinyl)piperazine (1-PP), (+/-)-idazoxan, benalfocin (SKF 86466), yohimbine and RX 821,002, displayed preference for h alpha2A versus h5-HT1A receptors of only 1.4-, 3.6-, 4-, 10- and 11-fold, respectively (based on differences in pKi values). Clonidine, brimonidine (UK 14304), the benzopyrrolidine fluparoxan and the guanidines guanfacine and guanabenz exhibited intermediate selectivity (22- to 31-fold) for h alpha2A receptors. Only the antagonist atipamezole and the agonist dexmedetomidine (DMT) displayed high preference for alpha2 adrenoceptors (1290- and 91-fold, respectively). Second, the compounds were tested for their ability to induce h5-HT1A receptor-mediated G-protein activation, as indicated by the stimulation of [35S]GTPgammaS binding. All except atipamezole and RX 821,002 exhibited agonist activity, with potencies which correlated with their affinity for h5-HT1A receptors. Relative efficacies (Emax values) were 25-35% for guanabenz, guanfacine, WB 4101 and benalfocin, 50-65% for 1-PP, (+/-)-idazoxan and clonidine, and over 70% for fluparoxan, oxymetazoline and yohimbine (relative to 5-HT = 100%). Yohimbine-induced [35S]GTPgammaS binding was inhibited by the selective 5-HT1A receptor antagonist WAY 100,635. In contrast, RX 821,002 was the only ligand which exhibited antagonist activity at h5-HT1A receptors, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Atipamezole, which exhibited negligeable affinity for 5-HT1A receptors, was inactive. Third, the affinities for r alpha2A differed considerably from the affinities for h alpha2A receptors whereas the affinities for r5-HT1A differed much less from the affinities for h5-HT1A receptors. This affected markedly the affinity ratios of certain compounds. For example, (+/-)-idazoxan was only 3.6-fold selective for h alpha2A versus h5-HT1A but 51-fold selective for r alpha2A versus r5-HT1A receptors. Conversely, yohimbine was tenfold selective for h alpha2A versus h5-HT1A adrenoceptors but 4.2-fold selective for r alpha2A versus r5-HT1A receptors. Nevertheless, both atipamezole and DMT were highly selective for both rat and human alpha2A versus rat or human 5-HT1A receptors. In conclusion, these data indicate that: (1) the agonist DMT and the antagonist atipamezole are the ligands of choice to distinguish alpha2-mediated from 5-HT1A-mediated actions, whilst several of the other compounds show only low or modest selectivity for alpha2A over 5-HT1A receptors; (2) caution should be exercised in experimental and clinical interpretation of the actions of traditionally employed alpha2 ligands, such as clonidine, yohimbine and (+/-)-idazoxan, which exhibit marked agonist activity at 5-HT1A receptors.

Evolution and Activity in the Solar Corona: A Comparison of Coronal and Chromospheric Structures Seen in Soft X-Rays, White Light and H-Alpha Emission

NASA Technical Reports Server (NTRS)

Bagenal, Fran

2001-01-01

The work completed under this project, 'Evolution and Activity in the Solar Corona: A Comparison of Coronal and Chromospheric Structures Seen in Soft X-Rays, White Light and H-Alpha Emission', includes the following presentations: (1) Analysis of H-alpha Observations of High-altitude Coronal Condensations; (2) Multi-spectral Imaging of Coronal Activity; (3) Measurement and Modeling of Soft X-ray Loop Arcades; (4) A Study of the Origin and Dynamics of CMEs; and various poster presentations and thesis dissertations.

Variability of Lyman-alpha emission from Jupiter

NASA Technical Reports Server (NTRS)

1979-01-01

The Jovian Lyman-alpha emission line was again observed in 1978 using the high resolution spectrometer on the Copernicus satellite. In intensity of 8.4+3.0 kilo Rayleighs was measured. This value represents a significant increase in intensity over previous (1976) Copernicus observations, but is lower than the recent (1979) values obtained by Voyager I and IUE. The increase in intensity was accompanied by a significant increase in line width, giving strong support to the theory that the emission results from resonant scattering of the solar Ly-alpha line by H atoms in the upper Jovian atmosphere. The strength of Jovian Ly-alpha emission correlates well with the level of solar activity. The solar extreme ultraviolet radiation varies with the solar cycle. This radiation causes the dissociation of H2 and CH4 into H atoms in the Jovian atmosphere. Therefore, in times of high solar activity, the H column density will increase, causing the observed stronger Jovian Ly-alpha emission.

Variability of Lyman-alpha emission from Jupiter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, W.D.; Barker, E.S.

1979-12-01

The Jovian L..cap alpha.. emission line was reobserved in 1978 March using the high-resolution spectrometer of the Copernicus satellite. An intensity of 8.3 +- 2.9 kilorayleighs was measured. This value represents a significant increase in intensity over previous (1976) Copernicus observations, but is lower than the recent (1979) values obtained by Voyager 1 and IUE. The increase in intensity has been accompanied by a significant increase in line width givin strong support to the theory that the emission results from resonant scattering of the solar L..cap alpha.. line by H atoms in the upper Jovian atmosphere. The strength of Jovianmore » L..cap alpha.. emission correlates well with the level of solar activity. The solar extreme ultraviolet radiation varies with the solar cycle. This radiation causes the dissociation of H/sub 2/ and CH/sub 4/ into H atoms in the Jovian atmosphere. Therefore, in times of high solar activity, the H column density will increase, causing the observed stronger Jovian L..cap alpha.. emission.« less

Brain activation during fast driving in a driving simulator: the role of the lateral prefrontal cortex.

PubMed

Jäncke, Lutz; Brunner, Béatrice; Esslen, Michaela

2008-07-16

Little is currently known about the neural underpinnings of the cognitive control of driving behavior in realistic situations and of the driver's speeding behavior in particular. In this study, participants drove in realistic scenarios presented in a high-end driving simulator. Scalp-recorded EEG oscillations in the alpha-band (8-13 Hz) with a 30-electrode montage were recorded while the participants drove under different conditions: (i) excessively fast (Fast), (ii) in a controlled manner at a safe speed (Correct), and (iii) impatiently in the context of testing traffic conditions (Impatient). Intracerebral sources of alpha-band activation were estimated using low resolution electrical tomography. Given that previous studies have shown a strong negative correlation between the Bold response in the frontal cortex and the alpha-band power, we used alpha-band-related activity as an estimation of frontal activation. Statistical analysis revealed more alpha-band-related activity (i.e. less neuronal activation) in the right lateral prefrontal cortex, including the dorsolateral prefrontal cortex, during fast driving. Those participants who speeded most and exhibited greater risk-taking behavior demonstrated stronger alpha-related activity (i.e. less neuronal activation) in the left anterior lateral prefrontal cortex. These findings are discussed in the context of current theories about the role of the lateral prefrontal cortex in controlling risk-taking behavior, task switching, and multitasking.

Sphingosine mediates the immediate negative inotropic effects of tumor necrosis factor-alpha in the adult mammalian cardiac myocyte.

PubMed

Oral, H; Dorn, G W; Mann, D L

1997-02-21

To determine whether activation of the neutral sphingomyelinase pathway was responsible for the immediate (<30 min) negative inotropic effects of tumor necrosis factor-alpha (TNF-alpha), we examined sphingosine levels in diluent and TNF-alpha-stimulated cardiac myocytes. TNF-alpha stimulation of adult feline cardiac myocytes provoked a rapid (<15 min) increase in the hydrolysis of [14C]sphingomyelin in cell-free extracts, as well as an increase in ceramide mass, consistent with cytokine-induced activation of the neutral sphingomyelinase pathway. High performance liquid chromatographic analysis of lipid extracts from TNF-alpha-stimulated cardiac myocytes showed that TNF-alpha stimulation produced a rapid (<30 min) increase in free sphingosine levels. Moreover, exogenous D-sphingosine mimicked the effects of TNF-alpha on intracellular calcium homeostasis, as well as the negative inotropic effects of TNF-alpha in isolated contracting myocytes; time course studies showed that exogenous D-sphingosine produced abnormalities in cell shortening that were maximal at 5 min. Finally, blocking sphingosine production using an inhibitor of ceramidase, n-oleoylethanolamine, completely abrogated the negative inotropic effects of TNF-alpha in isolated contracting cardiac myocytes. Additional studies employing biologically active ceramide analogs and sphingosine 1-phosphate suggested that neither the immediate precursor of sphingosine nor the immediate metabolite of sphingosine, respectively, were likely to be responsible for the immediate negative inotropic effects of TNF-alpha. Thus, these studies suggest that sphingosine mediates the immediate negative inotropic effects of TNF-alpha in isolated cardiac myocytes.

Shifts in Gamma Phase–Amplitude Coupling Frequency from Theta to Alpha Over Posterior Cortex During Visual Tasks

PubMed Central

Voytek, Bradley; Canolty, Ryan T.; Shestyuk, Avgusta; Crone, Nathan E.; Parvizi, Josef; Knight, Robert T.

2010-01-01

The phase of ongoing theta (4–8 Hz) and alpha (8–12 Hz) electrophysiological oscillations is coupled to high gamma (80–150 Hz) amplitude, which suggests that low-frequency oscillations modulate local cortical activity. While this phase–amplitude coupling (PAC) has been demonstrated in a variety of tasks and cortical regions, it has not been shown whether task demands differentially affect the regional distribution of the preferred low-frequency coupling to high gamma. To address this issue we investigated multiple-rhythm theta/alpha to high gamma PAC in two subjects with implanted subdural electrocorticographic grids. We show that high gamma amplitude couples to the theta and alpha troughs and demonstrate that, during visual tasks, alpha/high gamma coupling preferentially increases in visual cortical regions. These results suggest that low-frequency phase to high-frequency amplitude coupling is modulated by behavioral task and may reflect a mechanism for selection between communicating neuronal networks. PMID:21060716

Opposing behavioural alterations in male and female transgenic TGF alpha mice: association with tumour susceptibility.

PubMed Central

Hilakivi-Clarke, L. A.; Arora, P. K.; Clarke, R.; Wright, A.; Lippman, M. E.; Dickson, R. B.

1993-01-01

Psychosocial factors are thought to influence risk and survival from cancer. We have previously studied specific behaviours in transgenic male CD-1 MT42 mice, which overexpress the gene encoding human transforming growth factor alpha (TGF alpha) in multiple tissues, and which develop a high incidence of spontaneous hepatocellular carcinoma. The male TGF alpha mice spent a lengthened time immobile in the swim test, were highly aggressive, had increased plasma levels of 17 beta-estradiol (E2), and reduced natural killer (NK) cell activity. The female transgenic MT42 TGF alpha mice do not develop an increased rate of tumours at any site. We hypothesised that if the alterations in male TGF alpha mice are associated with their development of hepatocellular carcinomas, female TGF alpha should not show these alterations. The data in the present study indicate that female TGF alpha mice display shortened immobility in the swim test, suggesting an improved ability to cope with stress, and appear less aggressive in the resident-intruder test than non-transgenic female CD-1 mice. The female TGF alpha mice also exhibit a 3-fold increase in the plasma levels of E2, and a 3-fold increase in NK cell activity. These findings suggest that the elevated expression of TGF alpha in the transgenic mice is associated with gender-specific behavioural alterations, and the development of spontaneous hepatocellular tumours in the males. Furthermore, TGF alpha alters hormonal and immune parameters similarly in both sexes. It remains to be determined whether the development of hepatocarcinoma in the male TGF alpha animals is associated with an impaired ability to cope with stress and elevated aggressive tendencies and/or whether manipulations leading to an impaired ability to cope with stress will promote tumourigenesis in female TGF alpha mice. PMID:8494695

Organocatalyzed asymmetric alpha-oxidation, alpha-aminoxylation and alpha-amination of carbonyl compounds.

PubMed

Vilaivan, Tirayut; Bhanthumnavin, Worawan

2010-02-11

Organocatalytic asymmetric alpha-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects and synthetic applications of alpha-oxidation, hydroxylation, aminoxylation, amination, hydrazination, hydroxyamination and related alpha-heteroatom functionalization of aldehydes, ketones and related active methylene compounds published during 2005-2009.

Fourth High Alpha Conference, volume 2

NASA Technical Reports Server (NTRS)

1994-01-01

The goal of the Fourth High Alpha Conference, held at the NASA Dryden Flight Research Center on July 12-14, 1994, was to focus on the flight validation of high angle of attack technologies and provide an in-depth review of the latest high angle of attack activities. Areas that were covered include high angle of attack aerodynamics, propulsion and inlet dynamics, thrust vectoring, control laws and handling qualities, and tactical utility.

Basic aminopeptidase activity is an emerging biomarker in collagen-induced rheumatoid arthritis.

PubMed

Mendes, Mariana Trivilin; Murari-do-Nascimento, Stephanie; Torrigo, Isis Rossetti; Alponti, Rafaela Fadoni; Yamasaki, Simone Cristina; Silveira, Paulo Flavio

2011-04-11

The objective of this study was to investigate the catalytic activity of basic aminopeptidase (APB) and its association with periarticular edema and circulating tumor necrosis factor (TNF)-alpha and type II collagen (CII) antibodies (AACII) in a rat model of rheumatoid arthritis (RA) induced by CII (CIA). Edema does not occur in part of CII-treated, even when AACII is higher than in control. TNF-alpha is detectable only in edematous CII-treated. APB in synovial membrane is predominantly a membrane-bound activity also present in soluble form and with higher activity in edematous than in non-edematous CII-treated or control. Synovial fluid and blood plasma have lower APB in non-edematous than in edematous CII-treated or control. In peripheral blood mononuclear cells (PBMCs) the highest levels of APB are found in soluble form in control and in membrane-bound form in non-edematous CII-treated. CII treatment distinguishes two categories of rats: one with arthritic edema, high AACII, detectable TNF-alpha, high soluble and membrane-bound APB in synovial membrane and low APB in the soluble fraction of PBMCs, and another without edema and with high AACII, undetectable TNF-alpha, low APB in the synovial fluid and blood plasma and high APB in the membrane-bound fraction of PBMCs. Data suggest that APB and CIA are strongly related. 2011 Elsevier B.V. All rights reserved.

Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity.

PubMed

Raymond, Wilfred W; Su, Sharon; Makarova, Anastasia; Wilson, Todd M; Carter, Melody C; Metcalfe, Dean D; Caughey, George H

2009-05-01

Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.

Reactivation of the chloroplast CF1-ATPase beta subunit by trace amounts of the CF1 alpha subunit suggests a chaperonin-like activity for CF1 alpha.

PubMed

Avni, A; Avital, S; Gromet-Elhanan, Z

1991-04-25

Incubation of tobacco and lettuce thylakoids with 2 M LiCl in the presence of MgATP removes the beta subunit from their CF1-ATPase (CF1 beta) together with varying amounts of the CF1 alpha subunit (CF1 alpha). These 2 M LiCl extracts, as with the one obtained from spinach thylakoids (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072), could form active hybrid ATPases when reconstituted into inactive beta-less Rhodospirillum rubrum chromatophores. Pure CF1 beta fractions that have been isolated from these extracts could not form such active hybrids by themselves, but could do so when supplemented with trace amounts (less than 5%) of CF1 alpha. A mitochondrial F1-ATPase alpha subunit was recently reported to be a heat-shock protein, having two amino acid sequences that show a highly conserved identity with sequences found in molecular chaperones (Luis, A. M., Alconada, A., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 7713-7716). These sequences are also conserved in CF1 alpha isolated from various plants, but not in F1 beta subunits. The above described reactivation of CF1 beta by trace amounts of CF1 alpha could thus be due to a chaperonin-like function of CF1 alpha, which involves the correct, active folding of isolated pure CF1 beta.

Two forms of alpha-amylase in mantle tissue of Mytilus galloprovincialis: purification and molecular properties of form II.

PubMed

Lombraña, M; Suárez, P; San Juan, F

2005-09-01

alpha-Amylase activity has been shown for the first time in a non-digestive tissue from Mytilus galloprovincialis. alpha-amylase from mussel mantle tissue has been purified by affinity chromatography on insoluble starch, followed by gel-filtration chromatography on Superdex-200. The chromatographic and electrophoretic behaviour of M. galloprovincialis alpha-amylase and stability characteristics suggest two forms of this enzyme: one form forming stable aggregates (form I) and a monomeric form (form II) that is more abundant, active and unstable. Both forms show an inverse quantitative variation. Purified form II was highly unstable and the molecular mass was estimated to be 66 kDa by sodium dodecyl sulphate (SDS)-gel electrophoresis. Maximum activity was noted at pH 6.5 and 35 degrees C.

Use of .sup.3 He.sup.30 + ICRF minority heating to simulate alpha particle heating

DOEpatents

Post, Jr., Douglass E.; Hwang, David Q.; Hovey, Jane

1986-04-22

Neutron activation due to high levels of neutron production in a first heated deuterium-tritium plasma is substantially reduced by using Ion Cyclotron Resonance Frequency (ICRF) heating of energetic .sup.3 He.sup.++ ions in a second deuterium-.sup.3 He.sup.++ plasma which exhibit an energy distribution and density similar to that of alpha particles in fusion reactor experiments to simulate fusion alpha particle heating in the first plasma. The majority of the fast .sup.3 He.sup.++ ions and their slowing down spectrum can be studied using either a modulated hydrogen beam source for producing excited states of He.sup.+ in combination with spectrometers or double charge exchange with a high energy neutral lithium beam and charged particle detectors at the plasma edge. The maintenance problems thus associated with neutron activation are substantially reduced permitting energetic alpha particle behavior to be studied in near term large fusion experiments.

Calcineurin signaling and PGC-1alpha expression are suppressed during muscle atrophy due to diabetes.

PubMed

Roberts-Wilson, Tiffany K; Reddy, Ramesh N; Bailey, James L; Zheng, Bin; Ordas, Ronald; Gooch, Jennifer L; Price, S Russ

2010-08-01

PGC-1alpha is a transcriptional coactivator that controls energy homeostasis through regulation of glucose and oxidative metabolism. Both PGC-1alpha expression and oxidative capacity are decreased in skeletal muscle of patients and animals undergoing atrophy, suggesting that PGC-1alpha participates in the regulation of muscle mass. PGC-1alpha gene expression is controlled by calcium- and cAMP-sensitive pathways. However, the mechanism regulating PGC-1alpha in skeletal muscle during atrophy remains unclear. Therefore, we examined the mechanism responsible for decreased PGC-1alpha expression using a rodent streptozotocin (STZ) model of chronic diabetes and atrophy. After 21days, the levels of PGC-1alpha protein and mRNA were decreased. We examined the activation state of CREB, a potent activator of PGC-1alpha transcription, and found that phospho-CREB was paradoxically high in muscle of STZ-rats, suggesting that the cAMP pathway was not involved in PGC-1alpha regulation. In contrast, expression of calcineurin (Cn), a calcium-dependent phosphatase, was suppressed in the same muscles. PGC-1alpha expression is regulated by two Cn substrates, MEF2 and NFATc. Therefore, we examined MEF2 and NFATc activity in muscles from STZ-rats. Target genes MRF4 and MCIP1.4 mRNAs were both significantly reduced, consistent with reduced Cn signaling. Moreover, levels of MRF4, MCIP1.4, and PGC-1alpha were also decreased in muscles of CnAalpha-/- and CnAbeta-/- mice without diabetes indicating that decreased Cn signaling, rather than changes in other calcium- or cAMP-sensitive pathways, were responsible for decreased PGC-1alpha expression. These findings demonstrate that Cn activity is a major determinant of PGC-1alpha expression in skeletal muscle during diabetes and possibly other conditions associated with loss of muscle mass.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, Rino; Takahashi, Nobuyuki, E-mail: nobu@kais.kyoto-u.ac.jp; Murota, Kaeko

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of fatty acid oxidation-related genes in human intestinal epithelial Caco-2 cells. {yields} PPAR{alpha} activation also increased oxygen consumption rate and CO{sub 2} production and decreased secretion of triglyceride and ApoB from Caco-2 cells. {yields} Orally administration of bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and CO{sub 2} production in small intestinal epithelial cells. {yields} Treatment with bezafibrate decreased postprandial serum concentration of triglyceride after oral injection of olive oil in mice. {yields} It suggested that intestinal lipid metabolism regulated by PPAR{alpha} activation suppresses postprandial lipidemia. -- Abstract: Activation ofmore » peroxisome proliferator-activated receptor (PPAR)-{alpha} which regulates lipid metabolism in peripheral tissues such as the liver and skeletal muscle, decreases circulating lipid levels, thus improving hyperlipidemia under fasting conditions. Recently, postprandial serum lipid levels have been found to correlate more closely to cardiovascular diseases than fasting levels, although fasting hyperlipidemia is considered an important risk of cardiovascular diseases. However, the effect of PPAR{alpha} activation on postprandial lipidemia has not been clarified. In this study, we examined the effects of PPAR{alpha} activation in enterocytes on lipid secretion and postprandial lipidemia. In Caco-2 enterocytes, bezafibrate, a potent PPAR{alpha} agonist, increased mRNA expression levels of fatty acid oxidation-related genes, such as acyl-CoA oxidase, carnitine palmitoyl transferase, and acyl-CoA synthase, and oxygen consumption rate (OCR) and suppressed secretion levels of both triglycerides and apolipoprotein B into the basolateral side. In vivo experiments revealed that feeding high-fat-diet containing bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and production of CO{sub 2} and acid soluble metabolites in enterocytes. Moreover, bezafibrate treatment suppressed postprandial lipidemia after oral administration of olive oil to the mice. These findings indicate that PPAR{alpha} activation suppresses postprandial lipidemia through enhancement of fatty acid oxidation in enterocytes, suggesting that intestinal lipid metabolism regulated by PPAR{alpha} activity is a novel target of PPAR{alpha} agonist for decreasing circulating levels of lipids under postprandial conditions.« less

Inhibition of 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) activity of human lung microsomes by genistein, daidzein, coumestrol and C(18)-, C(19)- and C(21)-hydroxysteroids and ketosteroids.

PubMed

Blomquist, Charles H; Lima, Paul H; Hotchkiss, John R

2005-07-01

Epidemiologic data suggest a relationship between dietary intake of phytochemicals and a lower incidence of some cancers. Modulation of steroid hormone metabolism has been proposed as a basis for this effect. It has been shown that aromatase, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) are inhibited by the isoflavones, genistein and daidzein, and by coumestrol. In general, the extent of inhibition has been expressed in terms of IC50-values, which do not give information as to the pattern of inhibition, i.e., competitive, non-competitive, or mixed. Less is known of the effects of these compounds on 3alpha-HSD. The human lung is known to have a high level of 17beta-HSD and 3alpha-HSD activity. During the course of studies to characterize both activities in normal and inflamed lung and lung tumors we noted that 3alpha-HSD activity with 5alpha-DHT of microsomes from normal, adult lung was particularly susceptible to inhibition by coumestrol. To clarify the pattern of inhibition, the inhibition constants Ki and K'i were evaluated from plots of 1/v versus [I] and [S]/v versus [I]. Genistein, daidzein and coumestrol gave mixed inhibition patterns versus both 5alpha-DHT and NADH. In contrast, 5alpha-androstane-3,17-dione and 5alpha-pregnane-3,20-dione were competitive with 5alpha-DHT. NAD inhibited competitively with NADH. Our findings demonstrate that phytochemicals have the potential to inhibit 5alpha-DHT metabolism and thereby affect the androgen status of the human lung. The observation of a mixed inhibition pattern suggests these compounds bind to more than one form of the enzyme within the catalytic pathway.

Residual radioactivity of treated green diamonds.

PubMed

Cassette, Philippe; Notari, Franck; Lépy, Marie-Christine; Caplan, Candice; Pierre, Sylvie; Hainschwang, Thomas; Fritsch, Emmanuel

2017-08-01

Treated green diamonds can show residual radioactivity, generally due to immersion in radium salts. We report various activity measurements on two radioactive diamonds. The activity was characterized by alpha and gamma ray spectrometry, and the radon emanation was measured by alpha counting of a frozen source. Even when no residual radium contamination can be identified, measurable alpha and high-energy beta emissions could be detected. The potential health impact of radioactive diamonds and their status with regard to the regulatory policy for radioactive products are discussed. Copyright © 2017. Published by Elsevier Ltd.

Is there "neural efficiency" during the processing of visuo-spatial information in male humans? An EEG study.

PubMed

Capotosto, Paolo; Perrucci, M Gianni; Brunetti, Marcella; Del Gratta, Cosimo; Doppelmayr, Michael; Grabner, Roland H; Klimesch, Wolfgang; Neubauer, Aljoscha; Neuper, Christa; Pfurtscheller, Gert; Romani, Gian Luca; Babiloni, Claudio

2009-12-28

More intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10 Hz) event-related desynchronization (ERD; Doppelmayr et al., 2005). The opposite is true ("neural efficiency") during the retrieval of the encoded information, as revealed by both lower alpha ERD and/or lower theta (about 5 Hz) event-related synchronization (ERS; Grabner et al., 2004). To reconcile these contrasting results, here we evaluated the working hypothesis that more intelligent male subjects are characterized by a high cortical activity during the encoding phase. This deep encoding would explain the relatively low cortical activity for the retrieval of the encoded information. To test this hypothesis, electroencephalographic (EEG) data were recorded in 22 healthy young male volunteers during visuo-spatial information processing (encoding) and short-term retrieval of the encoded information. Cortical activity was indexed by theta ERS and alpha ERD. It was found that the higher the subjects' total IQ, the stronger the frontal theta ERS during the encoding task. Furthermore, the higher the subjects' total IQ, the lower the frontal high-frequency alpha ERD (about 10-12 Hz) during the retrieval task. This was not true for parietal counterpart of these EEG rhythms. These results reconcile previous contrasting evidence confirming that more intelligent persons do not ever show event-related cortical responses compatible with "neural efficiency" hypothesis. Rather, their cortical activity would depend on flexible and task-adapting features of frontal activation.

Production of interferon-alpha in high cell density cultures of recombinant Escherichia coli and its single step purification from refolded inclusion body proteins.

PubMed

Babu, K R; Swaminathan, S; Marten, S; Khanna, N; Rinas, U

2000-06-01

Escherichia coli TG1 transformed with a temperature-regulated interferon-alpha expression vector was grown to high cell density in defined medium containing glucose as the sole carbon and energy source, utilizing a simple fed-batch process. Feeding was carried out to achieve an exponential increase in biomass at growth rates which minimized acetate production. Thermal induction of such high cell density cultures resulted in the production of approximately 4 g interferon-alpha/l culture broth. Interferon-alpha was produced exclusively in the form of insoluble inclusion bodies and was solubilized under denaturing conditions, refolded in the presence of arginine and purified to near homogeneity, utilizing single-step ion-exchange chromatography on Q-Sepharose. The yield of purified interferon-alpha was approximately 300 mg/l with respect to the original high cell density culture broth (overall yield of approximately 7.5% active interferon-alpha). The purified recombinant interferon-alpha was found by different criteria to be predominantly monomeric and possessed a specific bioactivity of approximately 2.5 x 10(8) IU/mg based on viral cytopathic assay.

Prefrontal brain asymmetry and aggression in imprisoned violent offenders.

PubMed

Keune, Philipp M; van der Heiden, Linda; Várkuti, Bálint; Konicar, Lilian; Veit, Ralf; Birbaumer, Niels

2012-05-02

Anterior brain asymmetry, assessed through the alpha and beta band in resting-state electroencephalogram (EEG) is associated with approach-related behavioral dispositions, particularly with aggression in the general population. To date, the association between frontal asymmetry and aggression has not been examined in highly aggressive groups. We examined the topographic characteristics of alpha and beta activity, the relation of both asymmetry metrics to trait aggression, and whether alpha asymmetry was extreme in anterior regions according to clinical standards in a group of imprisoned violent offenders. As expected, these individuals were characterized by stronger right than left-hemispheric alpha activity, which was putatively extreme in anterior regions in one third of the cases. We also report that in line with observations made in the general population, aggression was associated with stronger right-frontal alpha activity in these violent individuals. This suggests that frontal alpha asymmetry, as a correlate of trait aggression, might be utilizable as an outcome measure in studies which assess the effects of anti-aggressiveness training in violent offenders. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Quantitative digital image analysis of chromogenic assays for high throughput screening of alpha-amylase mutant libraries.

PubMed

Shankar, Manoharan; Priyadharshini, Ramachandran; Gunasekaran, Paramasamy

2009-08-01

An image analysis-based method for high throughput screening of an alpha-amylase mutant library using chromogenic assays was developed. Assays were performed in microplates and high resolution images of the assay plates were read using the Virtual Microplate Reader (VMR) script to quantify the concentration of the chromogen. This method is fast and sensitive in quantifying 0.025-0.3 mg starch/ml as well as 0.05-0.75 mg glucose/ml. It was also an effective screening method for improved alpha-amylase activity with a coefficient of variance of 18%.

Detection of alpha radiation in a beta radiation field

DOEpatents

Mohagheghi, Amir H.; Reese, Robert P.

2001-01-01

An apparatus and method for detecting alpha particles in the presence of high activities of beta particles utilizing an alpha spectrometer. The apparatus of the present invention utilizes a magnetic field applied around the sample in an alpha spectrometer to deflect the beta particles from the sample prior to reaching the detector, thus permitting detection of low concentrations of alpha particles. In the method of the invention, the strength of magnetic field required to adequately deflect the beta particles and permit alpha particle detection is given by an algorithm that controls the field strength as a function of sample beta energy and the distance of the sample to the detector.

Fluorescence-Assisted Gamma Spectrometry for Surface Contamination Analysis

NASA Astrophysics Data System (ADS)

Ihantola, Sakari; Sand, Johan; Perajarvi, Kari; Toivonen, Juha; Toivonen, Harri

2013-02-01

A fluorescence-based alpha-gamma coincidence spectrometry approach has been developed for the analysis of alpha-emitting radionuclides. The thermalization of alpha particles in air produces UV light, which in turn can be detected over long distances. The simultaneous detection of UV and gamma photons allows detailed gamma analyses of a single spot of interest even in highly active surroundings. Alpha particles can also be detected indirectly from samples inside sealed plastic bags, which minimizes the risk of cross-contamination. The position-sensitive alpha-UV-gamma coincidence technique reveals the presence of alpha emitters and identifies the nuclides ten times faster than conventional gamma spectrometry.

High concentration of antioxidants N-acetylcysteine and mitoquinone-Q induces intercellular adhesion molecule 1 and oxidative stress by increasing intracellular glutathione.

PubMed

Mukherjee, Tapan K; Mishra, Anurag K; Mukhopadhyay, Srirupa; Hoidal, John R

2007-02-01

In endothelial cells, the intracellular level of glutathione is depleted during offering protection against proinflammatory cytokine TNF-alpha-induced oxidative stress. Administration of anti-inflammatory drugs, i.e., N-acetylcysteine (NAC) or mitoquinone-Q (mito-Q) in low concentrations in the human pulmonary aortic endothelial cells offered protection against depletion of reduced glutathione and oxidative stress mediated by TNF-alpha. However, this study addressed that administration of NAC or mito-Q in high concentrations resulted in a biphasic response by initiating an enhanced generation of both reduced glutathione and oxidized glutathione and enhanced production of reactive oxygen species, along with carbonylation and glutathionylation of the cellular proteins. This study further addressed that IkappaB kinase (IKK), a phosphorylation-dependent regulator of NF-kappaB, plays an important regulatory role in the TNF-alpha-mediated induction of the inflammatory cell surface molecule ICAM-1. Of the two catalytic subunits of IKK (IKKalpha and IKKbeta), low concentrations of NAC and mito-Q activated IKKalpha activity, thereby inhibiting the downstream NF-kappaB and ICAM-1 induction by TNF-alpha. High concentrations of NAC and mito-Q instead caused glutathionylation of IKKalpha, thereby inhibiting its activity that in turn enhanced the downstream NF-kappaB activation and ICAM-1 expression by TNF-alpha. Thus, establishing IKKalpha as an anti-inflammatory molecule in endothelial cells is another focus of this study. This is the first report that describes a stressful situation in the endothelial cells created by excess of antioxidative and anti-inflammatory agents NAC and mito-Q, resulting in the generation of reactive oxygen species, carbonylation and glutathionylation of cellular proteins, inhibition of IKKalpha activity, and up-regulation of ICAM-1expression.

Alpha chymotrypsin coated clusters of Fe3O4 nanoparticles for biocatalysis in low water media

PubMed Central

2012-01-01

Background Enzymes in low water containing non aqueous media are useful for organic synthesis. For example, hydrolases in such media can be used for synthetic purposes. Initial work in this area was carried out with lyophilized powders of enzymes. These were found to have poor activity. Drying (removing bulk water) by precipitation turned out to be a better approach. As enzymes in such media are heterogeneous catalysts, spreading these precipitates over a large surface gave even better results. In this context, nanoparticles with their better surface to volume ratio provide obvious advantage. Magnetic nanoparticles have an added advantage of easy separation after the reaction. Keeping this in view, alpha chymotrypsin solution in water was precipitated over a stirred population of Fe3O4 nanoparticles in n-propanol. This led to alpha chymotrypsin activity coated over clusters of Fe3O4 nanoparticles. These preparations were found to have quite high transesterification activity in low water containing n-octane. Results Precipitation of alpha chymotrypsin over a stirred suspension of Fe3O4 nanoparticles (3.6 nm diameter) led to the formation of enzyme coated clusters of nanoparticles (ECCNs). These clusters were also magnetic and their hydrodynamic diameter ranged from 1.2- 2.6 microns (as measured by dynamic light scattering). Transmission electron microscopy (TEM), showed that these clusters had highly irregular shapes. Transesterification assay of various clusters in anhydrous n-octane led to optimization of concentration of nanoparticles in suspension during precipitation. Optimized design of enzyme coated magnetic clusters of nanoparticles (ECCN 3) showed the highest initial rate of 465 nmol min-1 mg-1protein which was about 9 times higher as compared to the simple precipitates with an initial rate of 52 nmol min-1 mg-1 protein. Circular Dichroism (CD)(with a spinning cell accessory) showed that secondary structure content of the alpha Chymotrypsin in ECCN 3 [15% α-helix, 37% β-sheet and 48% random coil] was identical to the simple precipitates of alpha chymotrypsin. Conclusion A strategy for obtaining a high activity preparation of alpha chymotrypsin for application in low water media is described. Such high activity biocatalysts are useful in organic synthesis. PMID:23137100

Magnetic Field Configuration of Active Region NOAA 6555 at the Time of a Long Duration Flare on 23 March 1991: An Exception to Standard Flare Reconnection Model

NASA Technical Reports Server (NTRS)

Choudhary, Debi Prasad; Gary, Allen G.

1998-01-01

The high-resolution H(sub alpha) images observed during the decay phase of a long duration flare on 23 March 1991 are used to study the three-dimensional magnetic field configuration of the active region NOAA 6555. Whereas, all the large flares in NOAA 6555 occurred at the location of high magnetic shear and flux emergence, this long duration flare was observed in the region of low magnetic shear at the photosphere. The H(sub alpha) loop activity started soon after the maximum phase of the flare. There were few long loop at the initial phase of the activity. Some of these were sheared in the chromosphere at an angle of about 45 deg with the east-west axis. Gradually, increasing number of shorter loops, oriented along the east-west axis, started appearing. The chromospheric Dopplergrams show blue-shifts at the end points of the loops. By using different magnetic field models, we have extrapolated the photospheric magnetograms to the chromospheric heights. The magnetic field lines computed by using the potential field model correspond to most of the observed H(sub alpha) loops. The height of the H(sub alpha) loops were derived by comparing them with the computed field lines. From the temporal evolution of the H(sub alpha) loop activity, we derive the negative rate of appearance of H(sub alpha) features as a function of height. It is found that the field lines oriented along one of the neutral lines was sheared and low lying. The higher field lines were mostly potential. The paper also outlines a possible scenario for describing the post-flare stage of the observed long duration flare.

Tumor necrosis factor-inducing activities of Cryptococcus neoformans components.

PubMed Central

Delfino, D; Cianci, L; Migliardo, M; Mancuso, G; Cusumano, V; Corradini, C; Teti, G

1996-01-01

Cryptococcus neoformans-induced tumor necrosis factor alpha (TNF-alpha) production may lead to increased human immunodeficiency virus replication in patients with AIDS. In order to identify cryptococcal components that are predominantly responsible for stimulating TNF production, various concentrations of glucuronoxylomannan (GXM), galactoxylomannan (GalXM), mannoproteins (MP), and alpha(1-3) [corrected] glucan were added to whole-blood cultures. All of the cryptococcal components tested, as well as whole heat-killed cryptococci, were capable of inducing TNF-alpha release in a dose-dependent manner. MP were significantly more potent than any of the other cryptococcal components tested or heat-killed cryptococci in stimulating TNF-alpha production (P < 0.05). GXM, in contrast, was significantly less potent in this activity than either GalXM or MP (P < 0.05). As little as 0.5 microg of MP per ml was sufficient to produce moderate but significant elevations of TNF-alpha release. Maximal MP-induced TNF-alpha levels were similar to those induced by Salmonella enteritidis lipopolysaccharide, our positive control. Further experiments using isolated leukocytes suggested that monocytes were the cell population mainly responsible for TNF-alpha production, although the participation of other cell types could not be excluded. The presence of complement-sufficient plasma was a necessary requirement for TNF-alpha induction by GXM, GalXM, and low doses of MP. High MP concentrations (100 microg/ml) were also capable of stimulating TNF-alpha production in the absence of plasma. These data indicate that soluble products released by C. neoformans are capable of inducing TNF-alpha secretion in human leukocytes. This may be clinically relevant, since high concentrations of such products are frequently found in the body fluids of AIDS patients infected with C. neoformans. PMID:8945566

Functional properties of an isolated. cap alpha beta. heterodimeric human placenta insulin-like growth factor 1 receptor complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feltz, S.M.; Swanson, M.L.; Wemmie, J.A.

1988-05-03

Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment of pH 7.6, resulted in the formation of a functional ..cap alpha beta.. heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state. The membrane-bound ..cap alpha beta.. heterodimeric complex displayed similar curvilinear /sup 125/I-IGF-1 equilibrium binding compared to the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric complex. /sup 125/I-IGF-1 binding to both the isolated ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta..more » heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of ..cap alpha beta.. heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric state. These data demonstrate that (i) a combination of alkaline pH and DTT treatment of human placenta membranes results in the formation of an ..cap alpha beta.. heterodimeric IGF-1 receptor complex, (ii) unlike the insulin receptor, high-affinity homogeneous IGF-1 binding occurs in both the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes, and (iii) IGF-1-dependent autophosphorylation of the ..cap alpha beta.. heterodimeric IGF-1 receptor complex correlates wit an IGF-1 dependent covalent reassociation into an ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state.« less

Effect of alpha-tocopherol supplementation on renal oxidative stress and Na+/K+ -adenosine triphosphatase in ethanol treated Wistar rats.

PubMed

Mailankot, Maneesh; Jayalekshmi, H; Chakrabarti, Amit; Alang, Neha; Vasudevan, D M

2009-07-01

Ethanol intoxication resulted in high extent of lipid peroxidation, and reduction in antioxidant defenses (decreased GSH, GSH/GSSG ratio, and catalase, SOD and GPx activities) and (Na+/K+)-ATPase activity in kidney. Alpha-tocopherol treatment effectively protected kidney from ethanol induced oxidative challenge and improved renal (Na+/K+)-ATPase activity. Ethanol induced oxidative stress in the kidney and decreased (Na+/K+)-ATPase activity could be reversed by treatment with ascorbic acid.

Increased alpha 2-macroglobulin in diabetes: a hyperglycemia related phenomenon associated with reduced antithrombin III activity.

PubMed

Ceriello, A; Giugliano, D; Quatraro, A; Stante, A; Dello Russo, P; Torella, R

1989-01-01

Increased alpha 2-macroglobulin (alpha 2M) activity and concentration, and decreased antithrombin III (ATIII) plasma concentration are reported in diabetic subjects. In diabetes an inverse correlation between ATIII activity and blood glucose, HbA1, alpha 2M activity and alpha 2M concentration, and a direct correlation between both alpha 2M activity and alpha 2M concentration with blood glucose and HbA1 are found. Moreover, a direct correlation between alpha 2M activity and alpha 2M concentration fails. In both diabetic and normal subjects induced hyperglycemia increases alpha 2M activity and alpha 2M concentration reduces ATIII activity, while ATIII concentration is not affected. These data which show that hyperglycemia may increase alpha 2M molecule levels while altering only the biological function of ATIII, provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may condition the levels of some risk factors for the development of diabetic complications such as alpha 2M.

DNA-binding activity of TNF-{alpha} inducing protein from Helicobacter pylori

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuzuhara, T.; Suganuma, M.; Oka, K.

2007-11-03

Tumor necrosis factor-{alpha} (TNF-{alpha}) inducing protein (Tip{alpha}) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-{alpha} and chemokine genes and activation of nuclear factor-{kappa}B. Since Tip{alpha} enters gastric cancer cells, the Tip{alpha} binding molecules in the cells should be investigated. The direct DNA-binding activity of Tip{alpha} was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tip{alpha} and DNA, revealed that the affinity of Tip{alpha} for (dGdC)10 is 2400 times stronger than that of del-Tip{alpha}, an inactive Tip{alpha}. This suggestsmore » a strong correlation between DNA-binding activity and carcinogenic activity of Tip{alpha}. And the DNA-binding activity of Tip{alpha} was first demonstrated with a molecule secreted from H. pylori.« less

Antioxidants from the bark of Burkea africana, an African medicinal plant.

PubMed

Mathisen, Elin; Diallo, Drissa; Andersen, Øyvind M; Malterud, Karl Egil

2002-03-01

The bark of the tree Burkea africana is used medicinally in large areas of sub-Saharan Africa. The constituents responsible for its putative activity are not well known. We have investigated the bark of B. africana for antioxidant and radical scavenging activity. A hydroethanol bark extract showed high activity, and most of this activity was located in semipolar fractions of the extract. From chromatographic purification and spectroscopical structure studies, we conclude that the active constituents are proanthocyanidins. Two major components appear to be fisetinidol-(4alpha- --> 8)-catechin 3-gallate and bis-fisetinidol-(4alpha- --> 6, 4alpha- --> 8)-catechin 3-gallate. The latter compound is a new natural product. Smaller amounts of monomeric flavan-3-ols (catechin, epicatechin and fisetinidol) were also found. Copyright 2002 John Wiley & Sons, Ltd.

Alpha-lactalbumin unfolding is not sufficient to cause apoptosis, but is required for the conversion to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

PubMed

Svensson, Malin; Fast, Jonas; Mossberg, Ann-Kristin; Düringer, Caroline; Gustafsson, Lotta; Hallgren, Oskar; Brooks, Charles L; Berliner, Lawrence; Linse, Sara; Svanborg, Catharina

2003-12-01

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex of human alpha-lactalbumin and oleic acid (C18:1:9 cis) that kills tumor cells by an apoptosis-like mechanism. Previous studies have shown that a conformational change is required to form HAMLET from alpha-lactalbumin, and that a partially unfolded conformation is maintained in the HAMLET complex. This study examined if unfolding of alpha-lactalbumin is sufficient to induce cell death. We used the bovine alpha-lactalbumin Ca(2+) site mutant D87A, which is unable to bind Ca(2+), and thus remains partially unfolded regardless of solvent conditions. The D87A mutant protein was found to be inactive in the apoptosis assay, but could readily be converted to a HAMLET-like complex in the presence of oleic acid. BAMLET (bovine alpha-lactalbumin made lethal to tumor cells) and D87A-BAMLET complexes were both able to kill tumor cells. This activity was independent of the Ca(2+)site, as HAMLET maintained a high affinity for Ca(2+) but D87A-BAMLET was active with no Ca(2+) bound. We conclude that partial unfolding of alpha-lactalbumin is necessary but not sufficient to trigger cell death, and that the activity of HAMLET is defined both by the protein and the lipid cofactor. Furthermore, a functional Ca(2+)-binding site is not required for conversion of alpha-lactalbumin to the active complex or to cause cell death. This suggests that the lipid cofactor stabilizes the altered fold without interfering with the Ca(2+)site.

Increase in posterior alpha activity during rehearsal predicts successful long-term memory formation of word sequences.

PubMed

Meeuwissen, Esther B; Takashima, Atsuko; Fernández, Guillén; Jensen, Ole

2011-12-01

It is becoming increasingly clear that demanding cognitive tasks rely on an extended network engaging task-relevant areas and, importantly, disengaging task-irrelevant areas. Given that alpha activity (8-12 Hz) has been shown to reflect the disengagement of task-irrelevant regions in attention and working memory tasks, we here ask if alpha activity plays a related role for long-term memory formation. Subjects were instructed to encode and maintain the order of word sequences while the ongoing brain activity was recorded using magnetoencephalography (MEG). In each trial, three words were presented followed by a 3.4 s rehearsal interval. Considering the good temporal resolution of MEG this allowed us to investigate the word presentation and rehearsal interval separately. The sequences were grouped in trials where word order either could be tested immediately (working memory trials; WM) or later (LTM trials) according to instructions. Subjects were tested on their ability to retrieve the order of the three words. The data revealed that alpha power in parieto-occipital regions was lower during word presentation compared to rehearsal. Our key finding was that parieto-occipital alpha power during the rehearsal period was markedly stronger for successfully than unsuccessfully encoded LTM sequences. This subsequent memory effect demonstrates that high posterior alpha activity creates an optimal brain state for successful LTM formation possibly by actively reducing parieto-occipital activity that might interfere with sequence encoding. Copyright © 2010 Wiley Periodicals, Inc.

Radiological Assessment for the Removal of Legacy BPA Power Lines that Cross the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millsap, William J.; Brush, Daniel J.

This paper discusses some radiological field monitoring and assessment methods used to assess the components of an old electrical power transmission line that ran across the Hanford Site between the production reactors area (100 Area) and the chemical processing area (200 Area). This task was complicated by the presence of radon daughters -- both beta and alpha emitters -- residing on the surfaces, particularly on the surfaces of weathered metals and metals that had been electrically-charged. In many cases, these activities were high compared to the DOE Surface Contamination Guidelines, which were used as guides for the assessment. These methodsmore » included the use of the Toulmin model of argument, represented using Toulmin diagrams, to represent the combined force of several strands of evidences, rather than a single measurement of activity, to demonstrate beyond a reasonable doubt that no or very little Hanford activity was present and mixed with the natural activity. A number of forms of evidence were used: the overall chance of Hanford contamination; measurements of removable activity, beta and alpha; 1-minute scaler counts of total surface activity, beta and alpha, using "background makers"; the beta activity to alpha activity ratios; measured contamination on nearby components; NaI gamma spectral measurements to compare uncontaminated and potentially-contaminated spectra, as well as measurements for the sentinel radionuclides, Am- 241 and Cs-137 on conducting wire; comparative statistical analyses; and in-situ measurements of alpha spectra on conducting wire showing that the alpha activity was natural Po-210, as well as to compare uncontaminated and potentially-contaminated spectra.« less

Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi

2011-04-22

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a humanmore » adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected effects of PPAR{alpha} activation are very valuable for managing diabetic conditions accompanied by obesity, because PPAR{gamma} agonists, usually used as antidiabetic drugs, induce excessive lipid accumulation in adipocytes in addition to improvement of insulin resistance.« less

The Effect of Fucoidan from the Brown Alga Fucus evanescence on the Activity of α-N-Acetylgalactosaminidase of Human Colon Carcinoma Cells.

PubMed

Bakunina, Irina; Chadova, Oksana; Malyarenko, Olesya; Ermakova, Svetlana

2018-05-10

α- N -acetylgalactosaminidase (EC 3.2.1.49) (alpha-NaGalase) catalyzes the hydrolysis of N -acetamido-2-deoxy-α-d-galactoside residues from non-reducing ends of various complex carbohydrates and glycoconjugates. It is known that human cancer cells express an alpha-NaGalase, which accumulates in the blood plasma of patients. The enzyme deglycosylates the Gc protein-derived macrophage activating factor (GcMAF) and inhibits macrophage activity acting as an immunosuppressor. The high specific activity 0.033 ± 0.002 μmol mg −1 min −1 of the enzyme was found in human colon carcinoma cells DLD-1. The alpha-NaGalase of DLD-1 cells was isolated and biochemical characterized. The enzyme exhibits maximum activity at pH 5.2 and temperature 55 °C. The K m is 2.15 mM, V max ⁻0.021 μmol min −1 mL −1 , k cat ⁻1.55 min −1 and k cat / K m ⁻0.72 min −1 mM −1 at 37 °C, pH 5.2. The effects of fucoidan from the brown alga Fucus evanescence on the activity of alpha-NaGalase in human colon carcinoma DLD-1 cells and on the biosynthesis of this enzyme were investigated. It was shown that fucoidan did not inhibit free alpha-NaGalase, however, it reduced the expression of the enzyme in the DLD-1 cells at IC 50 73 ± 4 μg mL −1 .

Detailed correlation of type III radio bursts with H alpha activity. I - Active region of 22 May 1970.

NASA Technical Reports Server (NTRS)

Kuiper, T. B. H.; Pasachoff, J. M.

1973-01-01

Comparison of observations of type III impulsive radio bursts made at the Clark Lake Radio Observatory with high-spatial-resolution cinematographic observations taken at the Big Bear Solar Observatory. Use of the log-periodic radio interferometer makes it possible to localize the radio emission uniquely. This study concentrates on the particularly active region close to the limb on May 22, 1970. Sixteen of the 17 groups were associated with some H alpha activity, 11 of them with the start of such activity.

Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.

PubMed

Denmark, Scott E; Chung, Won-Jin

2008-06-20

A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

Tumor necrosis factor (cachectin) is an endogenous pyrogen and induces production of interleukin 1.

PubMed

Dinarello, C A; Cannon, J G; Wolff, S M; Bernheim, H A; Beutler, B; Cerami, A; Figari, I S; Palladino, M A; O'Connor, J V

1986-06-01

Recombinant human tumor necrosis factor (rTNF alpha) injected intravenously into rabbits produces a rapid-onset, monophasic fever indistinguishable from the fever produced by rIL-1. On a weight basis (1 microgram/kg) rTNF alpha and rIL-1 produce the same amount of fever and induce comparable levels of PGE2 in rabbit hypothalamic cells in vitro; like IL-1, TNF fever is blocked by drugs that inhibit cyclooxygenase. At higher doses (10 micrograms/kg) rTNF alpha produces biphasic fevers. The first fever reaches peak elevation 45-55 min after bolus injection and likely represents a direct action on the thermoregulatory center. During the second fever peak (3 h later), a circulating endogenous pyrogen can be shown present using passive transfer of plasma into fresh rabbits. This likely represents the in vivo induction of IL-1. In vitro, rTNF alpha induces the release of IL-1 activity from human mononuclear cells with maximal production observed at 50-100 ng/ml of rTNF alpha. In addition, rTNF alpha and rIFN-gamma have a synergistic effect on IL-1 production. The biological activity of rTNF alpha could be distinguished from IL-1 in three ways: the monophasic pyrogenic activity of rIL-1 was destroyed at 70 degrees C, whereas rTNF alpha remained active; anti-IL-1 neutralized IL-1 but did recognize rTNF alpha or natural cachectin nor neutralize its cytotoxic effect; and unlike IL-1, rTNF alpha was not active in the mitogen-stimulated T cell proliferation assay. The possibility that endotoxin was responsible for rTNF alpha fever and/or the induction of IL-1 was ruled-out in several studies: rTNF alpha produced fever in the endotoxin-resistant C3H/HeJ mice; the IL-1-inducing property of rTNF alpha was destroyed either by heat (70 degrees C) or trypsinization, and was unaffected by polymyxin B; pyrogenic tolerance to daily injections of rTNF alpha did not occur; levels of endotoxin, as determined in the Limulus amebocyte lysate, were below the minimum rabbit pyrogen dose; and these levels of endotoxin were confirmed by gas chromatography/mass spectrometry analysis for the presence of beta-hydroxymyristic acid. Although rTNF alpha is not active in T cell proliferation assays, it may mimic IL-1 in a T cell assay, since high concentrations of rTNF alpha induced IL-1 from epithelial or macrophagic cells in the thymocyte preparations. These studies show that TNF (cachectin) is another endogenous pyrogen which, like IL-1 and IFN-alpha, directly stimulate hypothalamic PGE2 synthesis. In addition, rTNF alpha is an endogenous inducer of IL-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization and identification of a chymotryptic hydrolysate of alpha-lactalbumin stimulating cholecystokinin release in STC-1 cells.

PubMed

Catiau, Lucie; Delval-Dubois, Véronique; Guillochon, Didier; Nedjar-Arroume, Naïma

2011-11-01

Alpha-lactalbumin hydrolysate is of significant interest, due to its potential application as a source of bioactive peptides in nutraceutical and pharmaceutical domains. This study was focused on the cholecystokinin (CCK) family compounds which are small peptides involved in the satiety control. The action of chymotryptic hydrolysate of alpha-lactalbumin on cholecystokinin release from intestinal endocrine STC-1 cells was investigated. We demonstrated for the first time that a chymotryptic hydrolysate of alpha-lactalbumin was able to highly stimulate CCK-releasing activity from STC-1 cells. The peptidic hydrolysate was characterized by LC/MS and MS/MS, thus highlighting the presence of 11 fractions containing 21 peptides, each potentially having the desired activity.

The relationship between physical activity and 2-hydroxyestrone, 16alpha-hydroxyestrone, and the 2/16 ratio in premenopausal women (United States).

PubMed

Bentz, Ann T; Schneider, Carole M; Westerlind, Kim C

2005-05-01

Estrogen is metabolized in the body through two mutually exclusive pathways yielding metabolites with different biological activities: the low estrogenic 2-hydroxyestrone (2-OHE1) and the highly estrogenic 16alpha-hydroxyestrone (16alpha-OHE1). The ratio of these metabolites (2/16) may be predictive of risk for developing breast cancer. Early evidence has demonstrated that exercise may alter estrogen metabolism to favor the weak estrogen, 2-OHE1. Seventy-seven eumenorrheic females completed physical activity logs for two weeks prior to providing a luteal phase urine sample. Concentrations of 2-OHE1 and 16alpha-OHE1 were measured and the 2/16 ratio computed. Hierarchical regression, controlling for age and body mass index (BMI), was used to determine relationships between estrogen metabolites and daily physical activity. Regression analyses indicated significant positive relationships between physical activity and 2-OHE1 and the 2/16 ratio (p < 0.05) that appears to be independent of BMI. 16alpha-OHE1 was not significantly related to physical activity. These results indicate that physical activity may modulate estrogen metabolism to favor the weak estrogen, 2-OHE1, thus producing a higher 2/16 ratio. This alteration in estrogen metabolism may represent one of the mechanisms by which increased physical activity reduces breast cancer risk.

Molecular cloning of alpha-amylases from cotton boll weevil, Anthonomus grandis and structural relations to plant inhibitors: an approach to insect resistance.

PubMed

Oliveira-Neto, Osmundo B; Batista, João A N; Rigden, Daniel J; Franco, Octávio L; Falcão, Rosana; Fragoso, Rodrigo R; Mello, Luciane V; dos Santos, Roseane C; Grossi-de-Sá, Maria F

2003-01-01

Anthonomus grandis, the cotton boll weevil, causes severe cotton crop losses in North and South America. Here we demonstrate the presence of starch in the cotton pollen grains and young ovules that are the main A. grandis food source. We further demonstrate the presence of alpha-amylase activity, an essential enzyme of carbohydrate metabolism for many crop pests, in A. grandis midgut. Two alpha-amylase cDNAs from A. grandis larvae were isolated using RT-PCR followed by 5' and 3' RACE techniques. These encode proteins with predicted molecular masses of 50.8 and 52.7kDa, respectively, which share 58% amino acid identity. Expression of both genes is induced upon feeding and concentrated in the midgut of adult insects. Several alpha-amylase inhibitors from plants were assayed against A. grandis alpha-amylases but, unexpectedly, only the BIII inhibitor from rye kernels proved highly effective, with inhibitors generally active against other insect amylases lacking effect. Structural modeling of Amylag1 and Amylag2 showed that different factors seem to be responsible for the lack of effect of 0.19 and alpha-AI1 inhibitors on A. grandis alpha-amylase activity. This work suggests that genetic engineering of cotton to express alpha-amylase inhibitors may offer a novel route to A. grandis resistance.

Continuous extraovular administration of prostaglandin F2alpha for midtrimester abortion.

PubMed

Lauersen, N H; Wilson, K H

1974-09-15

Midtrimester abortion was successfully induced in 74 of 76 patients by a continuous extraovular administration of (PGF2alpha) prostaglandin F2alpha via a constant-infusion pump. 2 patients in the 13th-14th weeks of gestation failed to abort despite good uterine activity. The mean abortion time for successful inductions was 16.21 hours. Parous patients aborted somewhat faster than nulliparous patients, but the difference was not statistically significant. All patients were monitored throughout the abortion procedure, and uterine activity was calculated and analyzed. Uterine activity developed within 15 minutes of PGF2alpha instillation and showed the characteristic uterine response to PGs with a sharp rise in intrauterine tonus. The gastrointestinal side effects in this series were much less than those reported for intraamniotic instillation of PG, and there was good patient tolerance of the procedure. The main complication of extraovular administration of PGF2alpha for midtrimester abortion was endometritis, which occurred in 7 patients. The patients who developed endometritis had, as a group, longer abortion times (mean=28 hours). 3 patients with severe preeclampsia and intrauterine death in the third trimester also had successfully induced labor with extraovular administration of PGF2alpha. The method of PGF2alpha administration in the series was found to have a high success rate, good patient tolerance, and fewer side effects than when abortion was induced by intraamniotic instillation of PGF2alpha.

Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

NASA Technical Reports Server (NTRS)

Weiler, E. J.

1978-01-01

Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

PubMed Central

McGlade, C J; Ellis, C; Reedijk, M; Anderson, D; Mbamalu, G; Reith, A D; Panayotou, G; End, P; Bernstein, A; Kazlauskas, A

1992-01-01

The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors. Images PMID:1372092

Effect of thyroid status on the development of the different molecular forms of Na+,K+-ATPase in rat brain.

PubMed

Atterwill, C K; Reid, J; Athayde, C M

1985-05-01

The effect of thyroid status on the postnatal development of the two molecular forms of Na+,K+-ATPase, distinguished kinetically on the basis of their ouabain sensitivity, was examined in rat brain. Hypothyroidism induced by PTU from day 1 postnatally significantly reduced the Na+,K+-ATPase activity in cerebellum (22-30 days) but not forebrain, whereas hyperthyroidism (T4 treatment from day 1) had no effect. The hypothyroidism-induced reduction in cerebellum was reflected by a 20-45% reduction in the activity of the alpha(+) form of Na+,K+-ATPase (high ouabain affinity) against control brains compared to a 60-70% reduction in the activity of the alpha form (low ouabain affinity). These results show that neonatally induced hypothyroidism leads to a selectively greater impairment of the ontogenesis of the activity of cerebellar alpha form of Na+,K+-ATPase. This may possibly reflect a retarded development of a selective cerebellar cell population containing predominantly the alpha form of the enzyme.

Whey protein rich in alpha-lactalbumin increases the ratio of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects.

PubMed

Markus, C Rob; Olivier, Berend; de Haan, Edward H F

2002-06-01

Cognitive performance often declines under chronic stress exposure. The negative effect of chronic stress on performance may be mediated by reduced brain serotonin function. The uptake of the serotonin precursor tryptophan into the brain depends on nutrients that influence the availability of tryptophan by changing the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp-LNAA ratio). In addition, a diet-induced increase in tryptophan may increase brain serotonergic activity levels and improve cognitive performance, particularly in high stress-vulnerable subjects. We tested whether alpha-lactalbumin, a whey protein with a high tryptophan content, would increase the plasma Trp-LNAA ratio and improve cognitive performance in high stress- vulnerable subjects. Twenty-three high stress-vulnerable subjects and 29 low stress-vulnerable subjects participated in a double-blind, placebo-controlled, crossover study. All subjects conducted a memory-scanning task after the intake of a diet enriched with either alpha-lactalbumin (alpha-lactalbumin diet) or sodium caseinate (control diet). Blood samples were taken to measure the effect of dietary manipulation on the plasma Trp-LNAA ratio. A significantly greater increase in the plasma Trp-LNAA ratio after consumption of the alpha-lactalbumin diet than after the control diet (P = 0.0001) was observed; memory scanning improved significantly only in the high stress-vulnerable subjects (P = 0.019). Because an increase in the plasma Trp-LNAA ratio is considered to be an indirect indication of increased brain serotonin function, the results suggest that dietary protein rich in alpha-lactalbumin improves cognitive performance in stress-vulnerable subjects via increased brain tryptophan and serotonin activities.

Altered expression and activation of signal transducers and activators of transcription (STATs) in hepatitis C virus infection: in vivo and in vitro studies.

PubMed

Larrea, E; Aldabe, R; Molano, E; Fernandez-Rodriguez, C M; Ametzazurra, A; Civeira, M P; Prieto, J

2006-08-01

Signal transducers and activators of transcription (STATs) play a critical role in antiviral defence. STAT3 is also important in cell protection against inflammatory damage. STAT proteins are activated by interferons and by hepatoprotective cytokines of the interleukin 6 superfamily, including cardiotrophin 1. We analysed the status of STATs in hepatitis C virus (HCV) infected livers and the relationship between expression and activation of STATs and HCV replication in Huh7 cells transfected with HCV genomic replicon. STAT3alpha expression was reduced in HCV infected livers showing an inverse correlation with serum alanine aminotransferase. In patients with HCV infection, nuclear staining for phosphorylated STAT3 was faint in parenchymal cells (although conspicuous in infiltrating leucocytes), in contrast with strong nuclear staining in hepatocytes from control livers. Expression and activation of STAT1 (a factor activated by both interferon (IFN)-alpha and IFN-gamma) were increased in HCV infected livers, particularly in those with high inflammatory activity. Conversely, phosphorylated STAT2 (a factor selectively activated by IFN-alpha) was undetectable in livers with HCV infection, a finding that was associated with marked downregulation of the two functional subunits of the IFN-alpha receptor. HCV replication in Huh7 cells caused STAT3alpha downregulation and blocked STAT3 phosphorylation by either IFN-alpha or cardiotrophin 1. HCV replication in Huh7 cells also inhibited STAT1 and STAT2 activation by IFN-alpha while there was no impairment of STAT1 phosphorylation by the proinflammatory cytokine IFN-gamma. STAT3 is downregulated in HCV infected livers and in Huh7 cells bearing the full length HCV replicon. HCV replication is associated with impaired Jak-STAT signalling by antiviral and cytoprotective cytokines. These effects may favour viral replication while facilitating the progression of liver disease.

Heritable major histocompatibility complex class II-associated differences in production of tumor necrosis factor. alpha. : Relevance to genetic predisposition to systemic lupus erythematosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, C.O.; Fronek, Z.; Koo, M.

1990-02-01

The authors report on the production of tumor necrosis factor (TNF)-{alpha} and TNF-{beta} by mitogen-activated peripheral blood lymphocytes or enriched monocyte subpopulations from human leukocyte antigen (HLA)-typed healthy subjects. The results indicate that HLA-DR2- and DQw1-positive donors frequently exhibit low production of TNF-{alpha}, whereas DR3- and DR4-positive subjects show high levels of TNF-{alpha} production. No correlation between TNF-{alpha} levels and HLA-A, -B, and -C genotype was found. The relevance of this quantitative polymorphism to the genetic predisposition to lupus nephritis in systemic lupus erythematosus (SLE) patients was investigated. DR2, DQw1-positive SLE patients show low levels of TNF-{alpha} inducibility; this genotypemore » is also associated with an increased incidence of lupus nephritis. DR3-positive SLE patients, on the other hand, are not predisposed to nephritis, and these patients have high TNF-{alpha} production. DR4 haplotype is associated with high TNF-{alpha} inducibility and is negatively correlated with lupus nephritis. These data may help explain the strong association between HLA-DR2, DQw1 in SLE patients and their susceptibility to nephritis.« less

Alpha-particle spectrometer experiment

NASA Technical Reports Server (NTRS)

Gorenstein, P.; Bjorkholm, P.

1972-01-01

Mapping the radon emanation of the moon was studied to find potential areas of high activity by detection of radon isotopes and their daughter products. It was felt that based on observation of regions overflown by Apollo spacecraft and within the field of view of the alpha-particle spectrometer, a radon map could be constructed, identifying and locating lunar areas of outgassing. The basic theory of radon migration from natural concentrations of uranium and thorium is discussed in terms of radon decay and the production of alpha particles. The preliminary analysis of the results indicates no significant alpha emission.

Catalposide is a natural agonistic ligand of peroxisome proliferator-activated receptor-{alpha}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ji Hae; Jun, Hee-jin; Hoang, Minh-Hien

2012-06-15

Highlights: Black-Right-Pointing-Pointer Catalposide is a novel ligand for PPAR{alpha}. Black-Right-Pointing-Pointer Cell stimulated with catalposide improved fatty acid uptake, regulated target genes in fatty acid {beta}-oxidation and synthesis. Black-Right-Pointing-Pointer Catalposdie reduces hepatic triacylglycerides. Black-Right-Pointing-Pointer Theses demonstrate catalposide could ameliorate hyperlipidemia and hepatic steatosis. -- Abstract: Peroxisome proliferator-activated receptor-alpha (PPAR{alpha}) is a nuclear receptor that regulates the expression of genes related to cellular lipid uptake and oxidation. Thus, PPAR{alpha} agonists may be important in the treatment of hypertriglyceridemia and hepatic steatosis. In this study, we demonstrated that catalposide is a novel natural PPAR{alpha} agonist, identified from reporter gene assay-based activity screening withmore » approximately 900 natural plant and seaweed extracts. Results of time-resolved fluorescence resonance energy transfer analyses suggested that the compound interacted directly with the ligand-binding domain of PPAR{alpha}. Cultured hepatocytes stimulated with catalposide exhibited significantly reduced cellular triglyceride concentrations, by 21%, while cellular uptake of fatty acids was increased, by 70% (P < 0.05). Quantitative PCR analysis revealed that the increase in cellular fatty acid uptake was due to upregulation of fatty acid transporter protein-4 (+19% vs. the control) in cells stimulated with catalposide. Additionally, expression of genes related to fatty acid oxidation and high-density lipoprotein metabolism were upregulated, while that of genes related to fatty acid synthesis were suppressed. In conclusion, catalposide is hypolipidemic by activation of PPAR{alpha} via a ligand-mediated mechanism that modulates the expression of in lipid metabolism genes in hepatocytes.« less

Enzymatic breakdown of raffinose oligosaccharides in pea seeds.

PubMed

Blöchl, Andreas; Peterbauer, Thomas; Hofmann, Julia; Richter, Andreas

2008-06-01

Both alkaline and acidic alpha-galactosidases (alpha-D: -galactoside galactohydrolases, E.C.3.2.1.22) isolated from various plant species have been described, although little is known about their co-occurrence and functions in germinating seeds. Here, we report on the isolation of two cDNAs, encoding for alpha-galactosidases from maturing and germinating seeds of Pisum sativum. One was identified as a member of the acidic alpha-galactosidase of the family 27 glycosyl hydrolase cluster and the other as a member of the family of alkaline alpha-galactosidases, which are highly homologous to seed imbibition proteins (SIPs). PsGAL1 transcripts, encoding for the ACIDIC alpha-GALACTOSIDASE, were predominately expressed during seed maturation and acidic enzyme activities were already present in dry seeds, showing little changes during seed germination. Compartmentation studies revealed that acidic alpha-galactosidases were located in protein storage vacuoles (PSVs). PsAGA1, encoding for the ALKALINE alpha-GALACTOSIDASE, was only expressed after radicle protrusion, when about 50% of RFOs have already been broken down. RFO breakdown was markedly decreased when the translation of the alkaline enzyme was inhibited, providing evidence that PsAGA1 indeed functioned in RFO degradation. Based on these data, we present an integrated model of RFO breakdown by two sequentially active alpha-galactosidases in pea seeds.

Alpha-crystallin-type heat shock proteins: socializing minichaperones in the context of a multichaperone network.

PubMed

Narberhaus, Franz

2002-03-01

Alpha-crystallins were originally recognized as proteins contributing to the transparency of the mammalian eye lens. Subsequently, they have been found in many, but not all, members of the Archaea, Bacteria, and Eucarya. Most members of the diverse alpha-crystallin family have four common structural and functional features: (i) a small monomeric molecular mass between 12 and 43 kDa; (ii) the formation of large oligomeric complexes; (iii) the presence of a moderately conserved central region, the so-called alpha-crystallin domain; and (iv) molecular chaperone activity. Since alpha-crystallins are induced by a temperature upshift in many organisms, they are often referred to as small heat shock proteins (sHsps) or, more accurately, alpha-Hsps. Alpha-crystallins are integrated into a highly flexible and synergistic multichaperone network evolved to secure protein quality control in the cell. Their chaperone activity is limited to the binding of unfolding intermediates in order to protect them from irreversible aggregation. Productive release and refolding of captured proteins into the native state requires close cooperation with other cellular chaperones. In addition, alpha-Hsps seem to play an important role in membrane stabilization. The review compiles information on the abundance, sequence conservation, regulation, structure, and function of alpha-Hsps with an emphasis on the microbial members of this chaperone family.

A simple electroelution method for rapid protein purification: isolation and antibody production of alpha toxin from Clostridium septicum.

PubMed

Vázquez-Iglesias, Lorena; Estefanell-Ucha, Borja; Barcia-Castro, Leticia; Páez de la Cadena, María; Álvarez-Chaver, Paula; Ayude-Vázquez, Daniel; Rodríguez-Berrocal, Francisco Javier

2017-01-01

Clostridium septicum produces a number of diseases in human and farm animals which, in most of the cases, are fatal without clinical intervention. Alpha toxin is an important agent and the unique lethal virulent factor produced by Clostridium septicum. This toxin is haemolytic, highly lethal and necrotizing activities but is being used as an antigen to develop animal vaccines. The aim of this study was to isolate the alpha toxin of Clostridium septicum and produce highly specific antibodies against it. In this work, we have developed a simple and efficient method for alpha toxin purification, based on electroelution that can be used as a time-saving method for purifying proteins. This technique avoids contamination by other proteins that could appear during other protein purification techniques such chromatography. The highly purified toxin was used to produce polyclonal antibodies. The specificity of the antibodies was tested by western blot and these antibodies can be applied to the quantitative determination of alpha toxin by slot blot.

A simple electroelution method for rapid protein purification: isolation and antibody production of alpha toxin from Clostridium septicum

PubMed Central

Estefanell-Ucha, Borja; Barcia-Castro, Leticia; Páez de la Cadena, María; Álvarez-Chaver, Paula; Ayude-Vázquez, Daniel; Rodríguez-Berrocal, Francisco Javier

2017-01-01

Clostridium septicum produces a number of diseases in human and farm animals which, in most of the cases, are fatal without clinical intervention. Alpha toxin is an important agent and the unique lethal virulent factor produced by Clostridium septicum. This toxin is haemolytic, highly lethal and necrotizing activities but is being used as an antigen to develop animal vaccines. The aim of this study was to isolate the alpha toxin of Clostridium septicum and produce highly specific antibodies against it. In this work, we have developed a simple and efficient method for alpha toxin purification, based on electroelution that can be used as a time-saving method for purifying proteins. This technique avoids contamination by other proteins that could appear during other protein purification techniques such chromatography. The highly purified toxin was used to produce polyclonal antibodies. The specificity of the antibodies was tested by western blot and these antibodies can be applied to the quantitative determination of alpha toxin by slot blot. PMID:28652930

The role of fluid intelligence and learning in analogical reasoning: How to become neurally efficient?

PubMed

Dix, Annika; Wartenburger, Isabell; van der Meer, Elke

2016-10-01

This study on analogical reasoning evaluates the impact of fluid intelligence on adaptive changes in neural efficiency over the course of an experiment and specifies the underlying cognitive processes. Grade 10 students (N=80) solved unfamiliar geometric analogy tasks of varying difficulty. Neural efficiency was measured by the event-related desynchronization (ERD) in the alpha band, an indicator of cortical activity. Neural efficiency was defined as a low amount of cortical activity accompanying high performance during problem-solving. Students solved the tasks faster and more accurately the higher their FI was. Moreover, while high FI led to greater cortical activity in the first half of the experiment, high FI was associated with a neurally more efficient processing (i.e., better performance but same amount of cortical activity) in the second half of the experiment. Performance in difficult tasks improved over the course of the experiment for all students while neural efficiency increased for students with higher but decreased for students with lower fluid intelligence. Based on analyses of the alpha sub-bands, we argue that high fluid intelligence was associated with a stronger investment of attentional resource in the integration of information and the encoding of relations in this unfamiliar task in the first half of the experiment (lower-2 alpha band). Students with lower fluid intelligence seem to adapt their applied strategies over the course of the experiment (i.e., focusing on task-relevant information; lower-1 alpha band). Thus, the initially lower cortical activity and its increase in students with lower fluid intelligence might reflect the overcoming of mental overload that was present in the first half of the experiment. Copyright © 2016 Elsevier Inc. All rights reserved.

Age-related changes in neocortical high-voltage spindles and alpha EEG power during quiet waking in rats.

PubMed

Moyanova, Slavianka G; Kirov, Roumen K; Kortenska, Lidia V

2002-04-01

Age-related changes in neocortical high-voltage spindle (HVS) and in electroencephalographic (EEG) alpha power were examined in young (3.0 to 4.6 months), middle-aged (10.2 to 13.8 months), and old (21.5 to 24.0 months) male Wistar rats during quiet waking. Whereas the duration of quiet waking stage did not change as a function of age, a significant increase in HVS amount and EEG alpha peak power was observed in the middle-aged rats with only a tendency for a further enhancement in the old animals. An additional analysis showed that the elevation of alpha power is associated with age rather than with HVS activity.

Thermally induced disintegration of the oligomeric structure of alphaB-crystallin mutant F28S is associated with diminished chaperone activity.

PubMed

Kelley, Patrick B; Abraham, Edathara C

2003-10-01

alphaB-crystallin, a member of the small heat-shock protein (hsp) family of proteins, is able to function as a molecular chaperone by protecting other proteins from stress-induced aggregation by recognizing and binding to partially unfolded species of damaged proteins. The present work has investigated the role of phenylalanine-28 (F28) of the 22RLFDQFF28 region of alphaB-crystallin in maintaining chaperone function and oligomeric structure under physiological condition and under thermal stress. Bovine alphaB-crystallin was cloned for the first time and the cDNA sequence revealed greater than 90% homology to that of human, rat and mouse alphaB-crystallins. F28 was mutated to a serine followed by expression of the mutant F28S and the wild-type alphaB (alphaB-wt) in E. coli and subsequent purification of the protein by size-exclusion chromatography. Secondary and tertiary structure analyses showed some structural changes in the mutant. Chaperone activity and oligomeric size of the mutant was unchanged at 37 degrees C whereas at 58 degrees C the chaperone activity was significantly decreased and the oligomeric size ranged from low molecular weight to high molecular weight showing disintegration of the oligomeric structure. The data support the idea that the participation of large oligomeric structure rather than smaller units is required to have optimal chaperone activity and the hydrophobic F28 residue is needed for maintaining the native oligomeric structure under thermal stress.

In vitro characterization of high purity factor IX concentrates for the treatment of hemophilia B.

PubMed

Limentani, S A; Gowell, K P; Deitcher, S R

1995-04-01

This study employed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and immunoblotting to assess the purity of seven high purity factor IX concentrates: Aimafix (Aima), AlphaNine-SD (Alpha Therapeutic), Factor IX VHP (Biotransfusion), Immunine (Immuno), Mononine (Armour Pharmaceutical), Nanotiv (Kabi Pharmacia), and 9MC (Blood Products Laboratory). The mean specific activity of these products ranged from 68 U factor IX/mg (Aimafix) to 246 U factor IX/mg (Mononine). SDS-PAGE analysis showed that the highest purity product, Mononine, had a single contaminating band under non-reducing conditions. Two additional bands were detected when this product was analyzed under reducing conditions. All other products had multiple contaminating bands that were more apparent under reducing than non-reducing conditions. The immunoblot for factor IX showed a dominant factor IX band for all products. In addition, visible light chain of factor IX was detected for AlphaNine-SD, Factor IX VHP, Immunine, Mononine, Nanotiv, and 9MC, suggesting that the factor IX in these products had undergone partial activation to factor IXa. Another contaminating band was visible at 49,500 for all of the products except 9MC. In addition to this band, high molecular weight contaminants were apparent for some products, most notably AlphaNine-SD. The identity of these bands is unknown. Immunoblotting failed to demonstrate factor VII as a contaminant of any of the high purity products, although factor VIIa could be detected in some lots of Immunine, Nanotiv, and 9MC by a clot-based assay. Factor X contaminated Aimafix, AlphaNine-SD, Factor IX VHP, Immunine, Nanotiv, and 9MC, but activation products of factor X were not detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Roles of Ca(v) channels and AHNAK1 in T cells: the beauty and the beast.

PubMed

Matza, Didi; Flavell, Richard A

2009-09-01

T lymphocytes require Ca2+ entry though the plasma membrane for their activation and function. Recently, several routes for Ca2+ entry through the T-cell plasma membrane after activation have been described. These include calcium release-activated channels (CRAC), transient receptor potential (TRP) channels, and inositol-1,4,5-trisphosphate receptors (IP3Rs). Herein we review the emergence of a fourth new route for Ca2+ entry, composed of Ca(v) channels (also known as L-type voltage-gated calcium channels) and the scaffold protein AHNAK1 (AHNAK/desmoyokin). Both helper (CD4+) and killer (CD8+) T cells express high levels of Ca(v)1 alpha1 subunits (alpha1S, alpha1C, alpha1D, and alpha1F) and AHNAK1 after their differentiation and require these molecules for Ca2+ entry during an immune response. In this article, we describe the observations and open questions that ultimately suggest the involvement of multiple consecutive routes for Ca2+ entry into lymphocytes, one of which may be mediated by Ca(v) channels and AHNAK1.

[T and B lymphocytes and serum alpha 1-antitrypsin activity in children with bronchial asthma treated with broncho-vaxom].

PubMed

Wartenberg, J; Lewandowska, J; Pilarek, M; Piltz, D

The aim of this study was to evaluate an effect of Broncho-Vaxom treatment on T and B lymphocytes and serum alpha 1AT in children treated at "Zuch" sanatorium in Szczawno-spa. The trial involved 46 school aged children suffering from infectious or infectious-atopic asthma. The post-Broncho-Vaxom treatment values for T lymphocytes were significantly higher in infectious, and significantly lower for B lymphocytes in infectious-atopic asthma. Serum alpha 1AT activity in children suffering from infectious asthma decreased significantly after the treatment. A correlation between the efficacy of the treatment and the lymphocyte percentage was observed. In children with very effective clinical results of Broncho-Vaxom treatment, the significant increase in T lymphocyte, and decrease in B lymphocyte populations was observed. Changes in T and B lymphocyte percentage were analysed in respect to alpha 1AT pre-treatment activity. In children with high alpha 1AT value, T lymphocytes after the treatment increased significantly in infectious, and B lymphocytes decreased significantly in infectious-atopic group.

Antisense oligodeoxynucleotide inhibition of a swelling-activated cation channel in osteoblast-like osteosarcoma cells

NASA Technical Reports Server (NTRS)

Duncan, R. L.; Kizer, N.; Barry, E. L.; Friedman, P. A.; Hruska, K. A.

1996-01-01

By patch-clamp analysis, we have shown that chronic, intermittent mechanical strain (CMS) increases the activity of stretch-activated cation channels of osteoblast-like UMR-106.01 cells. CMS also produces a swelling-activated whole-cell conductance (Gm) regulated by varying strain levels. We questioned whether the swelling-activated conductance was produced by stretch-activated cation channel activity. We have identified a gene involved in the increase in conductance by using antisense oligodeoxynucleotides (ODN) derived from the alpha 1-subunit genes of calcium channels found in UMR-106.01 cells (alpha1S, alpha1C, and alpha1D). We demonstrate that alpha 1C antisense ODNs abolish the increase in Gm in response to hypotonic swelling following CMS. Antisense ODNs to alpha1S and alpha1D, sense ODNs to alpha1C, and sham permeabilization had no effect on the conductance increase. In addition, during cell-attached patch-clamp studies, antisense ODNs to alpha1c completely blocked the swelling-activated and stretch-activated nonselective cation channel response to strain. Antisense ODNs to alpha1S treatment produced no effect on either swelling-activated or stretch-activated cation channel activity. There were differences in the stretch-activated and swelling-activated cation channel activity, but whether they represent different channels could not be determined from our data. Our data indicate that the alpha1C gene product is involved in the Gm and the activation of the swelling-activated cation channels induced by CMS. The possibility that swelling-activated cation channel genes are members of the calcium channel superfamily exists, but if alpha1c is not the swelling-activated cation channel itself, then its expression is required for induction of swelling-activated cation channel activity by CMS.

Inhibition of cholesterol absorption associated with a PPAR alpha-dependent increase in ABC binding cassette transporter A1 in mice.

PubMed

Knight, Brian L; Patel, Dilip D; Humphreys, Sandy M; Wiggins, David; Gibbons, Geoffrey F

2003-11-01

Dietary supplementation with the peroxisome proliferator-activated receptor alpha (PPAR alpha) ligand WY 14,643 gave rise to a 4- to 5-fold increase in the expression of mRNA for the ATP binding cassette transporter A1 (ABCA1) in the intestine of normal mice. There was no effect in the intestine of PPAR alpha-null mice. Consumption of a high-cholesterol diet also increased intestinal ABCA1 expression. The effects of WY 14,643 and the high-cholesterol diet were not additive. WY 14,643 feeding reduced intestinal absorption of cholesterol in the normal mice, irrespective of the dietary cholesterol concentration, and this resulted in lower diet-derived cholesterol and cholesteryl ester concentrations in plasma and liver. At each concentration of dietary cholesterol, there was a similar significant inverse correlation between intestinal ABCA1 mRNA content and the amount of cholesterol absorbed. The fibrate-induced changes in the intestines of the normal mice were accompanied by an increased concentration of the mRNA encoding the sterol-regulatory element binding protein-1c gene (SREBP-1c), a known target gene for the oxysterol receptor liver X receptor alpha (LXR alpha). There was a correlation between intestinal ABCA1 mRNA and SREBP-1c mRNA contents, but not between SREBP-1c mRNA content and cholesterol absorption. These results suggest that PPAR alpha influences cholesterol absorption through modulating ABCA1 activity in the intestine by a mechanism involving LXR alpha.

Using the virtual brain to reveal the role of oscillations and plasticity in shaping brain's dynamical landscape.

PubMed

Roy, Dipanjan; Sigala, Rodrigo; Breakspear, Michael; McIntosh, Anthony Randal; Jirsa, Viktor K; Deco, Gustavo; Ritter, Petra

2014-12-01

Spontaneous brain activity, that is, activity in the absence of controlled stimulus input or an explicit active task, is topologically organized in multiple functional networks (FNs) maintaining a high degree of coherence. These "resting state networks" are constrained by the underlying anatomical connectivity between brain areas. They are also influenced by the history of task-related activation. The precise rules that link plastic changes and ongoing dynamics of resting-state functional connectivity (rs-FC) remain unclear. Using the framework of the open source neuroinformatics platform "The Virtual Brain," we identify potential computational mechanisms that alter the dynamical landscape, leading to reconfigurations of FNs. Using a spiking neuron model, we first demonstrate that network activity in the absence of plasticity is characterized by irregular oscillations between low-amplitude asynchronous states and high-amplitude synchronous states. We then demonstrate the capability of spike-timing-dependent plasticity (STDP) combined with intrinsic alpha (8-12 Hz) oscillations to efficiently influence learning. Further, we show how alpha-state-dependent STDP alters the local area dynamics from an irregular to a highly periodic alpha-like state. This is an important finding, as the cortical input from the thalamus is at the rate of alpha. We demonstrate how resulting rhythmic cortical output in this frequency range acts as a neuronal tuner and, hence, leads to synchronization or de-synchronization between brain areas. Finally, we demonstrate that locally restricted structural connectivity changes influence local as well as global dynamics and lead to altered rs-FC.

Activation of orphan nuclear constitutive androstane receptor requires subnuclear targeting by peroxisome proliferator-activated receptor gamma coactivator-1 alpha. A possible link between xenobiotic response and nutritional state.

PubMed

Shiraki, Takuma; Sakai, Noriko; Kanaya, Eiko; Jingami, Hisato

2003-03-28

In contrast to the classical nuclear receptors, the constitutive androstane receptor (CAR) is transcriptionally active in the absence of ligand. In the course of searching for the mediator of CAR activation, we found that ligand-independent activation of CAR was achieved in cooperation with the peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha). PGC-1 beta, a PGC-1 alpha homologue, also activated CAR to less of an extent than PGC-1 alpha. Coexpression of the ligand-binding domain of a heterodimerization partner, retinoid X receptor alpha, enhanced the PGC-1 alpha-mediated activation of CAR, although it had a weak effect on the basal activity of CAR in the absence of PGC-1 alpha. Both the N-terminal region, with the LXXLL motif, and the C-terminal region, with a serine/arginine-rich domain (RS domain), in PGC-1 alpha were required for full activation of CAR. Pull-down experiments using recombinant proteins revealed that CAR directly interacted with both the LXXLL motif and the RS domain. Furthermore, we demonstrated that the RS domain of PGC-1 alpha was required for CAR localization at nuclear speckles. These results indicate that PGC-1 alpha mediates the ligand-independent activation of CAR by means of subnuclear targeting through the RS domain of PGC-1 alpha.

Detecting potential teratogenic alkaloids from blue cohosh rhizomes using an in vitro rat embryo culture.

PubMed

Kennelly, E J; Flynn, T J; Mazzola, E P; Roach, J A; McCloud, T G; Danford, D E; Betz, J M

1999-10-01

The novel alkaloid thalictroidine (1), as well as the known alkaloids taspine (2), magnoflorine (3), anagyrine (4), baptifoline (5), 5,6-dehydro-alpha-isolupanine (6), alpha-isolupanine (7), lupanine (8), N-methylcytisine (9), and sparteine (10), were identified from an extract of Caulophyllum thalictroides rhizomes. N-Methylcytisine exhibited teratogenic activity in the rat embryo culture (REC), an in vitro method to detect potential teratogens. The structure of 1 was elucidated using various spectroscopic methods, primarily by NMR techniques. Thalictroidine, anagyrine, and alpha-isolupanine were not teratogenic in the REC at tested concentrations. Taspine (2) showed high embryotoxicity, but no teratogenic activity, in the REC.

MAPPING THE CLUMPY STRUCTURES WITHIN SUBMILLIMETER GALAXIES USING LASER-GUIDE STAR ADAPTIVE OPTICS SPECTROSCOPY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menendez-Delmestre, Karin; Goncalves, Thiago S.; Blain, Andrew W.

2013-04-20

We present the first integral-field spectroscopic observations of high-redshift submillimeter-selected galaxies (SMGs) using Laser-Guide Star Adaptive Optics. We target H{alpha} emission of three SMGs at redshifts z {approx} 1.4-2.4 with the OH-Suppressing Infrared Imaging Spectrograph on Keck. The spatially resolved spectroscopy of these galaxies reveals unresolved broad-H{alpha} line regions (FWHM >1000 km s{sup -1}) likely associated with an active galactic nucleus (AGN) and regions of diffuse star formation traced by narrow-line H{alpha} emission (FWHM {approx}< 500 km s{sup -1}) dominated by multiple H{alpha}-bright stellar clumps, each contributing 1%-30% of the total clump-integrated H{alpha} emission. We find that these SMGs hostmore » high star formation rate surface densities, similar to local extreme sources, such as circumnuclear starbursts and luminous infrared galaxies. However, in contrast to these local environments, SMGs appear to be undergoing such intense activity on significantly larger spatial scales as revealed by extended H{alpha} emission over 4-16 kpc. H{alpha} kinematics show no evidence of ordered global motion as would be found in a disk, but rather large velocity offsets ({approx}few Multiplication-Sign 100 km s{sup -1}) between the distinct stellar clumps. Together with the asymmetric distribution of the stellar clumps around the AGN in these objects, it is unlikely that we are unveiling a clumpy disk structure as has been suggested in other high-redshift populations of star-forming galaxies. The SMG clumps in this sample may correspond to remnants of originally independent gas-rich systems that are in the process of merging, hence triggering the ultraluminous SMG phase.« less

Memory impairment, oxidative damage and apoptosis induced by space radiation: ameliorative potential of alpha-lipoic acid.

PubMed

Manda, Kailash; Ueno, Megumi; Anzai, Kazunori

2008-03-05

Exposure to high-energy particle radiation (HZE) may cause oxidative stress and cognitive impairment in the same manner that seen in aged mice. This phenomenon has raised the concerns about the safety of an extended manned mission into deep space where a significant portion of the radiation burden would come from HZE particle radiation. The present study aimed at investigating the role of alpha-lipoic acid against space radiation-induced oxidative stress and antioxidant status in cerebellum and its correlation with cognitive dysfunction. We observed spontaneous motor activities and spatial memory task of mice using pyroelectric infrared sensor and programmed video tracking system, respectively. Whole body irradiation of mice with high-LET (56)Fe beams (500 MeV/nucleon, 1.5 Gy) substantially impaired the reference memory at 30 day post-irradiation; however, no significant effect was observed on motor activities of mice. Acute intraperitoneal treatment of mice with alpha-lipoic acid prior to irradiation significantly attenuated such memory dysfunction. Radiation-induced apoptotic damage in cerebellum was examined using a neuronal-specific terminal deoxynucleotidyl transferase-mediated nick end-labeling method (NeuroTACS). Radiation-induced apoptotic and necrotic cell death of granule cells and Purkinje cells were inhibited significantly by alpha-lipoic acid pretreatment. Alpha-lipoic acid pretreatment exerted a very high magnitude of protection against radiation-induced augmentation of DNA damage (comet tail movement and serum 8-OHdG), lipid proxidation products (MDA+HAE) and protein carbonyls in mice cerebellum. Further, radiation-induced decline of non-protein sulfhydryl (NP-SH) contents of cerebellum and plasma ferric reducing power (FRAP) was also inhibited by alpha-lipoic acid pre-treatment. Results clearly indicate that alpha-lipoic acid is a potent neuroprotective antioxidant. Moreover, present finding also support the idea suggesting the cerebellar involvement in cognition.

Differences in genotoxic activity of alpha-Ni3S2 on human lymphocytes from nickel-hypersensitized and nickel-unsensitized donors.

PubMed

Arrouijal, F Z; Marzin, D; Hildebrand, H F; Pestel, J; Haguenoer, J M

1992-05-01

The genotoxic activity of alpha-Ni3S2 was assessed on human lymphocytes from nickel-hypersensitized (SSL) and nickel-unsensitized (USL) subjects. Three genotoxicity tests were performed: the sister chromatid exchange (SCE) test, the metaphase analysis test and the micronucleus test. (i) The SCE test (3-100 micrograms/ml) showed a weak but statistically significant increase in the number of SCE in both lymphocyte types with respect to controls, USL presenting a slightly higher SCE incidence but only at one concentration. (ii) The metaphase analysis test demonstrated a high dose-dependent clastogenic activity of alpha-Ni3S2 in both lymphocyte types. The frequency of chromosomal anomalies was significantly higher in USL than in SSL for all concentrations applied. (iii) The micronucleus test confirmed the dose-dependent clastogenic activity of alpha-Ni3S2 and the differences already observed between USL and SSL, i.e. the number of cells with micronuclei was statistically higher in USL. Finally, the incorporation study with alpha-63Ni3S2 showed a higher uptake of its solubilized fraction by USL. This allows an explanation of the different genotoxic action of nickel on the two cell types. In this study we demonstrated that hypersensitivity has an influence on the incorporation of alpha-Ni3S2 and subsequently on the different induction of chromosomal aberrations in human lymphocytes.

Analysis of the two-peptide bacteriocins lactococcin G and enterocin 1071 by site-directed mutagenesis.

PubMed

Oppegård, Camilla; Fimland, Gunnar; Thorbaek, Lisbeth; Nissen-Meyer, Jon

2007-05-01

The two peptides (Lcn-alpha and Lcn-beta) of the two-peptide bacteriocin lactococcin G (Lcn) were changed by stepwise site-directed mutagenesis into the corresponding peptides (Ent-alpha and Ent-beta) of the two-peptide bacteriocin enterocin 1071 (Ent), and the potencies and specificities of the various hybrid constructs were determined. Both Lcn and, to a lesser extent, Ent were active against all the tested lactococcal strains, but only Ent was active against the tested enterococcal strains. The two bacteriocins thus differed in their relative potencies to various target cells, despite their sequence similarities. The hybrid combination Lcn-alpha+Ent-beta had low potency against all strains tested, indicating that these two peptides do not interact optimally. The reciprocal hybrid combination (i.e., Ent-alpha+Lcn-beta), in contrast, was highly potent, indicating that these two peptides may form a functional antimicrobial unit. In fact, this hybrid combination (Ent-alpha+Lcn-beta) was more potent against lactococcal strains than wild-type Ent was (i.e., Ent-alpha+Ent-beta), but it was inactive against enterococcal strains (in contrast to Ent but similar to Lcn). The observation that Ent-alpha is more active against lactococci in combination with Lcn-beta and more active against enterococci in combination with Ent-beta suggests that the beta peptide is an important determinant of target cell specificity. Especially the N-terminal residues of the beta peptide seem to be important for specificity, since Ent-alpha combined with an Ent-beta variant with Ent-to-Lcn mutations at positions 1 to 4, 7, 9, and 10 was >150-fold less active against enterococcal strains but one to four times more active against lactococcal strains than Ent-alpha+Ent-beta. Moreover, Ent-to-Lcn single-residue mutations in the region spanning residues 1 to 7 in Ent-beta had a more detrimental effect on the activity against enterococci than on that against lactococcal strains. Of the single-residue mutations made in the N-terminal region of the alpha peptide, the Ent-to-Lcn mutations N8Q and P12R in Ent-alpha influenced specificity, as follows: the N8Q mutation had no effect on activity against tested enterococcal strains but increased the activity 2- to 4-fold against the tested lactococcal strains, and the P12R mutation reduced the activity >150-fold and only approximately 2-fold against enterococcal and lactococcal strains, respectively. Changing residues in the C-terminal half/part of the Lcn peptides (residues 20 to 39 and 25 to 35 in Lcn-alpha and Lcn-beta, respectively) to those found in the corresponding Ent peptides did not have a marked effect on the activity, but there was an approximately 10-fold or greater reduction in the activity upon also introducing Lcn-to-Ent mutations in the mid-region (residues 8 to 19 and 9 to 24 in Lcn-alpha and Lcn-beta, respectively). Interestingly, the Lcn-to-Ent F19L+G20A mutation in an Lcn-Ent-beta hybrid peptide was more detrimental when the altered peptide was combined with Lcn-alpha (>10-fold reduction) than when it was combined with Ent-alpha ( approximately 2-fold reduction), suggesting that residues 19 and 20 (which are part of a GXXXG motif) in the beta peptide may be involved in a specific interaction with the cognate alpha peptide. It is also noteworthy that the K2P and A7P mutations in Lcn-beta reduced the activity only approximately 2-fold, suggesting that the first seven residues in the beta peptides do not form an alpha-helix.

HIV turns plasmacytoid dendritic cells (pDC) into TRAIL-expressing killer pDC and down-regulates HIV coreceptors by Toll-like receptor 7-induced IFN-alpha.

PubMed

Hardy, Andrew W; Graham, David R; Shearer, Gene M; Herbeuval, Jean-Philippe

2007-10-30

Plasmacytoid dendritic cells (pDC) are key players in viral immunity and produce IFN-alpha after HIV-1 exposure, which in turn regulates TNF-related apoptosis-inducing ligand (TRAIL) expression by CD4(+) T cells. We show here that infectious and noninfectious HIV-1 virions induce activation of pDC into TRAIL-expressing IFN-producing killer pDC (IKpDC). IKpDC expressed high levels of activation markers (HLA-DR, CD80, CD83, and CD86) and the migration marker CCR7. Surprisingly, CXCR4 and CCR5 were down-regulated on IKpDC. We also show that HIV-1-induced IKpDC depended on Toll-like receptor 7 (TLR7) activation. HIV-1 or TLR7 agonistexposed IKpDC induced apoptosis of the CD4(+) T cell line SupT1 via the TRAIL pathway. Furthermore, IFN-alpha produced after HIV-induced TLR7 stimulation was responsible for TRAIL expression and the down-regulation of both CXCR4 and CCR5 by IKpDC. In contrast, activation and migration markers were not regulated by IFN-alpha. Finally, IFN-alpha increased the survival of IKpDC. We characterized a subset of pDC with a killer activity that is activated by endosomal-associated viral RNA and not by infection.

Pharmacological characterisation of strychnine and brucine analogues at glycine and alpha7 nicotinic acetylcholine receptors.

PubMed

Jensen, Anders A; Gharagozloo, Parviz; Birdsall, Nigel J M; Zlotos, Darius P

2006-06-06

Strychnine and brucine from the plant Strychnos nux vomica have been shown to have interesting pharmacological effects on several neurotransmitter receptors, including some members of the superfamily of ligand-gated ion channels. In this study, we have characterised the pharmacological properties of tertiary and quaternary analogues as well as bisquaternary dimers of strychnine and brucine at human alpha1 and alpha1beta glycine receptors and at a chimera consisting of the amino-terminal domain of the alpha7 nicotinic receptor (containing the orthosteric ligand binding site) and the ion channel domain of the 5-HT3A serotonin receptor. Although the majority of the analogues displayed significantly increased Ki values at the glycine receptors compared to strychnine and brucine, a few retained the high antagonist potencies of the parent compounds. However, mirroring the pharmacological profiles of strychnine and brucine, none of the analogues displayed significant selectivity between the alpha1 and alpha1beta subtypes. The structure-activity relationships for the compounds at the alpha7/5-HT3 chimera were significantly different from those at the glycine receptors. Most strikingly, quaternization of strychnine and brucine with substituents possessing different steric and electronic properties completely eliminated the activity at the glycine receptors, whereas binding affinity to the alpha7/5-HT3 chimera was retained for the majority of the quaternary analogues. This study provides an insight into the structure-activity relationships for strychnine and brucine analogues at these ligand-gated ion channels.

The liver glucose-6-phosphatase of intact microsomes is inhibited and displays sigmoid kinetics in the presence of alpha-ketoglutarate-magnesium and oxaloacetate-magnesium chelates.

PubMed

Mithieux, G; Vega, F V; Riou, J P

1990-11-25

We have recently shown that the Ca.EGTA and Mg.EDTA complexes, but not free Ca2+ or Mg2+, inhibit the liver glucose-6-phosphatase (Mithieux, G., Vega, F. V., Beylot, M., and Riou, J. P. (1990) J. Biol. Chem. 265, 7257-7259). In this work, we report that, when complexed with Mg2+, two endogenous dicarboxylic keto acids (alpha-ketoglutarate (alpha-KG) and oxaloacetate (OAA] inhibit the glucose-6-phosphatase activity at low concentrations of substrate. This phenomenon is specific for complexes of Mg2+ with alpha-KG and OAA since 1) the complexes of Mg2+ with a number of other di- or tricarboxylic acids having high structural analogy with alpha-KG and OAA (oxalate, malate, succinate, citrate, aspartate, and glutamate) do not inhibit the glucose-6-phosphatase activity and 2) the Ca.alpha-KG and Ca.OAA chelates do not inhibit the glucose-6-phosphatase activity. In the presence of Mg.alpha-KG or Mg.OAA chelates, the enzyme displays sigmoid kinetics; the Hanes plots deviate from linearity, indicating the positive cooperative dependence of the velocity upon the substrate concentration. Hill coefficients (equal to 1 in the absence of the chelates) of 1.23 and 1.33 have been determined in the presence of Mg.alpha-KG and Mg.OAA complexes, respectively. The disruption of microsomal integrity by detergents abolishes the effect of Mg.alpha-KG and Mg.OAA, suggesting that the magnesium chelates inhibit the translocase component of the glucose-6-phosphatase system.

Ovine cardiac Na,K-ATPase: isolation by means of selective solubilization in Lubrol and the effect of 1 alpha,2 alpha-epoxyscillirosidin on this enzyme.

PubMed

Venter, P A; Naudé, R J; Oelofsen, W; Swan, G E

1997-01-01

The inhibition of cardiac Na,K-ATPase by 1 alpha,2 alpha-epoxyscillirosidin is the principal cause of poisoning of cattle by the tulip, Homeria pallida. The ultimate goals of this study were to study the interaction between 1 alpha,2 alpha-epoxyscillirosidin and ovine Na,K-ATPase by means of inhibition and displacement binding studies. Ovine cardiac Na,K-ATPase was isolated in membrane-bound form by means of deoxycholate treatment, high-speed ultracentrifugation, NaI treatment and selective solubilization in Lubrol. The inhibition of ovine cardiac and commercial porcine cerebral cortex Na,K-ATPase by 1 alpha,2 alpha-epoxyscilirosidin and ouabain was studied using a discontinuous Na,K-ATPase assay. The binding of 1 alpha,2 alpha-epoxyscillirosidin, ouabain and digoxin to the above enzymes was compared using a displacement binding assay with [3H] oubain. The Lubrol-solubilized ovine cardiac Na,K-ATPase showed a specific activity of 0.3 U/mg with no ouabain insensitive activity. I50 values of 2.1 x 10(-8) and 2.7 x 10(-8) were obtained for the inhibition of this enzyme by 1 alpha,2 alpha-epoxyscillirosidin and ouabain, respectively. 1 alpha,2 alpha-Epoxyscillirosidin has a much higher KD value (1.5 x 10(-7) M), however, than ouabain (9.5 x 10(-9) M) and digoxin (1.7 x 10(-8) M) in displacement binding studies with [3H]ouabain. 1 alpha,2 alpha-Epoxyscillirosidin is a potent inhibitor of ovine cardiac Na,K-ATPase and is a slightly stronger inhibitor of the enzyme than ouabain. The anomalous result for the displacement of 1 alpha,2 alpha-epoxyscillirosidin from its receptor is either a result of different affinities that K+ has for the enzyme ouabain and enzyme-1 alpha,2 alpha-epoxyscillirosidin complexes or because of different complex stabilities of these complexes.

Fatty acid homeostasis and induction of lipid regulatory genes in skeletal muscles of peroxisome proliferator-activated receptor (PPAR) alpha knock-out mice. Evidence for compensatory regulation by PPAR delta.

PubMed

Muoio, Deborah M; MacLean, Paul S; Lang, David B; Li, Shi; Houmard, Joseph A; Way, James M; Winegar, Deborah A; Corton, J Christopher; Dohm, G Lynis; Kraus, William E

2002-07-19

Ablation of peroxisome proliferator activated receptor (PPAR) alpha, a lipid-activated transcription factor that regulates expression of beta-oxidative genes, results in profound metabolic abnormalities in liver and heart. In the present study we used PPAR alpha knockout (KO) mice to determine whether this transcription factor is essential for regulating fuel metabolism in skeletal muscle. When animals were challenged with exhaustive exercise or starvation, KO mice exhibited lower serum levels of glucose, lactate, and ketones and higher nonesterified fatty acids than wild type (WT) littermates. During exercise, KO mice exhausted earlier than WT and exhibited greater rates of glycogen depletion in liver but not skeletal muscle. Fatty acid oxidative capacity was similar between muscles of WT and KO when animals were fed and only 28% lower in KO muscles when animals were starved. Exercise-induced regulation and starvation-induced regulation of pyruvate-dehydrogenase kinase 4 and uncoupling protein 3, two classical and robustly responsive PPAR alpha target genes, were similar between WT and KO in skeletal muscle but markedly different between genotypes in heart. Real time quantitative PCR analyses showed that unlike in liver and heart, in mouse skeletal muscle PPAR delta is severalfold more abundant than either PPAR alpha or PPAR gamma. In both human and rodent myocytes, the highly selective PPAR delta agonist GW742 increased fatty acid oxidation about 2-fold and induced expression of several lipid regulatory genes, including pyruvate-dehydrogenase kinase 4 and uncoupling protein 3, responses that were similar to those elicited by the PPAR alpha agonist GW647. These results show redundancy in the functions of PPARs alpha and delta as transcriptional regulators of fatty acid homeostasis and suggest that in skeletal muscle high levels of the delta-subtype can compensate for deficiency of PPAR alpha.

Evidence of Neurotoxicity of Ecstasy: Sustained Effects on Electroencephalographic Activity in Polydrug Users

PubMed Central

Adamaszek, Michael; Khaw, Alexander V.; Buck, Ulrike; Andresen, Burghard; Thomasius, Rainer

2010-01-01

Objective According to previous EEG reports of indicative disturbances in Alpha and Beta activities, a systematic search for distinct EEG abnormalities in a broader population of Ecstasy users may especially corroborate the presumed specific neurotoxicity of Ecstasy in humans. Methods 105 poly-drug consumers with former Ecstasy use and 41 persons with comparable drug history without Ecstasy use, and 11 drug naives were investigated for EEG features. Conventional EEG derivations of 19 electrodes according to the 10-20-system were conducted. Besides standard EEG bands, quantitative EEG analyses of 1-Hz-subdivided power ranges of Alpha, Theta and Beta bands have been considered. Results Ecstasy users with medium and high cumulative Ecstasy doses revealed an increase in Theta and lower Alpha activities, significant increases in Beta activities, and a reduction of background activity. Ecstasy users with low cumulative Ecstasy doses showed a significant Alpha activity at 11 Hz. Interestingly, the spectral power of low frequencies in medium and high Ecstasy users was already significantly increased in the early phase of EEG recording. Statistical analyses suggested the main effect of Ecstasy to EEG results. Conclusions Our data from a major sample of Ecstasy users support previous data revealing alterations of EEG frequency spectrum due rather to neurotoxic effects of Ecstasy on serotonergic systems in more detail. Accordingly, our data may be in line with the observation of attentional and memory impairments in Ecstasy users with moderate to high misuse. Despite the methodological problem of polydrug use also in our approach, our EEG results may be indicative of the neuropathophysiological background of the reported memory and attentional deficits in Ecstasy abusers. Overall, our findings may suggest the usefulness of EEG in diagnostic approaches in assessing neurotoxic sequela of this common drug abuse. PMID:21124854

The thalidomide analogue CC-3052 inhibits HIV-1 and tumour necrosis factor-alpha (TNF-alpha) expression in acutely and chronically infected cells in vitro.

PubMed

La Maestra, L; Zaninoni, A; Marriott, J B; Lazzarin, A; Dalgleish, A G; Barcellini, W

2000-01-01

We investigated the in vitro effect of the water-soluble, highly stable thalidomide analogue CC-3052 on HIV-1 expression and TNF-alpha production in latently infected promonocytic U1 cells, acutely infected T cells and monocyte-derived human macrophages (MDM), and in mitogen-stimulated ex vivo cultures from patients with primary acute HIV-1 infection. HIV-1 expression was assessed by Northern blot analysis of RNAs, and ELISA for p24 antigen release and reverse transcriptase (RT) activity. TNF-alpha expression was evaluated by RT-polymerase chain reaction (PCR)-ELISA for mRNA and ELISA for protein secretion. We demonstrated that CC-3052 is able to inhibit HIV-1 expression, as evaluated by mRNA, p24 release and RT activity, in phorbol myristate acetate (PMA)- and cytokine-stimulated U1 cells. Furthermore, CC-3052 inhibited HIV-1 expression, as evaluated by p24 and RT activity, in acutely infected MDM and T cells. As far as TNF-alpha is concerned, CC-3052 significantly reduced TNF-alpha mRNA and protein secretion in PMA-stimulated U937 and U1 cells, and in PMA-stimulated uninfected and acutely infected MDM. Consistently, the addition of CC-3052 reduced TNF-alpha production in phytohaemagglutinin (PHA) and lipopolysaccharide (LPS)-stimulated whole blood cultures from patients during the primary acute phase of HIV-1 infection. Since TNF-alpha is among the most potent enhancers of HIV-1 expression, the effect of CC-3052 on TNF-alpha may account for its inhibitory activity on HIV-1 expression. Given the well documented immunopathological role of TNF-alpha and its correlation with viral load, advanced disease and poor prognosis, CC-3052 could be an interesting drug for the design of therapeutic strategies in association with anti-retroviral agents.

Phosphorylation of a conserved serine in the deoxyribonucleic acid binding domain of nuclear receptors alters intracellular localization.

PubMed

Sun, Kai; Montana, Vedrana; Chellappa, Karthikeyani; Brelivet, Yann; Moras, Dino; Maeda, Yutaka; Parpura, Vladimir; Paschal, Bryce M; Sladek, Frances M

2007-06-01

Nuclear receptors (NRs) are a superfamily of transcription factors whose genomic functions are known to be activated by lipophilic ligands, but little is known about how to deactivate them or how to turn on their nongenomic functions. One obvious mechanism is to alter the nuclear localization of the receptors. Here, we show that protein kinase C (PKC) phosphorylates a highly conserved serine (Ser) between the two zinc fingers of the DNA binding domain of orphan receptor hepatocyte nuclear factor 4alpha (HNF4alpha). This Ser (S78) is adjacent to several positively charged residues (Arg or Lys), which we show here are involved in nuclear localization of HNF4alpha and are conserved in nearly all other NRs, along with the Ser/threonine (Thr). A phosphomimetic mutant of HNF4alpha (S78D) reduced DNA binding, transactivation ability, and protein stability. It also impaired nuclear localization, an effect that was greatly enhanced in the MODY1 mutant Q268X. Treatment of the hepatocellular carcinoma cell line HepG2 with PKC activator phorbol 12-myristate 13-acetate also resulted in increased cytoplasmic localization of HNF4alpha as well as decreased endogenous HNF4alpha protein levels in a proteasome-dependent fashion. We also show that PKC phosphorylates the DNA binding domain of other NRs (retinoic acid receptor alpha, retinoid X receptor alpha, and thyroid hormone receptor beta) and that phosphomimetic mutants of the same Ser/Thr result in cytoplasmic localization of retinoid X receptor alpha and peroxisome proliferator-activated receptor alpha. Thus, phosphorylation of this conserved Ser between the two zinc fingers may be a common mechanism for regulating the function of NRs.

Decoding and Reconstructing the Focus of Spatial Attention from the Topography of Alpha-band Oscillations.

PubMed

Samaha, Jason; Sprague, Thomas C; Postle, Bradley R

2016-08-01

Many aspects of perception and cognition are supported by activity in neural populations that are tuned to different stimulus features (e.g., orientation, spatial location, color). Goal-directed behavior, such as sustained attention, requires a mechanism for the selective prioritization of contextually appropriate representations. A candidate mechanism of sustained spatial attention is neural activity in the alpha band (8-13 Hz), whose power in the human EEG covaries with the focus of covert attention. Here, we applied an inverted encoding model to assess whether spatially selective neural responses could be recovered from the topography of alpha-band oscillations during spatial attention. Participants were cued to covertly attend to one of six spatial locations arranged concentrically around fixation while EEG was recorded. A linear classifier applied to EEG data during sustained attention demonstrated successful classification of the attended location from the topography of alpha power, although not from other frequency bands. We next sought to reconstruct the focus of spatial attention over time by applying inverted encoding models to the topography of alpha power and phase. Alpha power, but not phase, allowed for robust reconstructions of the specific attended location beginning around 450 msec postcue, an onset earlier than previous reports. These results demonstrate that posterior alpha-band oscillations can be used to track activity in feature-selective neural populations with high temporal precision during the deployment of covert spatial attention.

Deglycosylation of serum vitamin D3-binding protein by alpha-N-acetylgalactosaminidase detected in the plasma of patients with systemic lupus erythematosus.

PubMed

Yamamoto, N; Naraparaju, V R; Moore, M; Brent, L H

1997-03-01

A serum glycoprotein, Gc protein (vitamin D3-binding protein), can be converted by beta-galactosidase of B cells and sialidase of T cells to a potent macrophage-activating factor (MAF), a protein with N-acetylgalactosamine as the remaining sugar moiety. Thus, Gc protein is the precursor for MAF. Treatment of Gc protein with immobilized beta-galactosidase and sialidase generates a remarkably high titered macrophage-activating factor (GcMAF). When peripheral blood monocytes/ macrophages (designated macrophages) of 33 systemic lupus erythematosus patients were incubated with GcMAF (100 pg/ml), the macrophages of all patients were activated as determined by superoxide generation. However, the precursor activity of patient plasma Gc protein was lost or reduced in these patients. Loss of the precursor activity was the result of deglycosylation of plasma Gc protein by alpha-N-acetylgalactosaminidase activity found in the patient plasma. Levels of plasma alpha-N-acetylgalactosaminidase activity in individual patients had an inverse correlation with the MAF precursor activity of their plasma Gc protein. Deglycosylated Gc protein cannot be converted to macro-phage-activating factor. The resulting defect in macro-phage activation may lead to an inability to clear pathogenic immune complexes. Thus, elevated plasma alpha-N-acetylgalactosaminidase activity resulting in the loss of MAF precursor activity and reduced macro-phage activity may play a role in the pathogenesis of systemic lupus erythematosus.

Pressure effects on enzyme reactions in mainly organic media: alpha-chymotrypsin in reversed micelles of Aerosol OT in octane.

PubMed

Mozhaev, V V; Bec, N; Balny, C

1994-08-01

Biocatalytic transformations in reversed micelles formed by anionic surfactant Aerosol OT in octane have been studied at high pressures by an example of alpha-chymotrypsin-catalyzed hydrolysis of N-carbobenzoxy-L-tyrosine p-nitrophenyl ester and N-succinyl-L-phenylalanine p-nitroanilide. For the first time it has been found that the enzyme retains high activity in these water-in-oil microemulsions up to a pressure of 2 kbar. The value of the activation volume (delta V*) for the enzyme reactions shows a dependence on the water content in the system. When the size of the micellar aqueous inner cavity (as evaluated at 1 atm) approaches the molecular size of alpha-chymotrypsin, delta V* becomes significantly different from the value in aqueous solution and in the micelles with a larger size. Possibilities of regulating the enzyme activity by pressure in systems with a low content of water are discussed.

Regulation by magnesium of potato tuber mitochondrial respiratory activities.

PubMed

Vicente, Joaquim A F; Madeira, Vítor M C; Vercesi, Anibal E

2004-12-01

Dehydrogenase activities of potato tuber mitochondria and corresponding phosphorylation rates were measured for the dependence on external and mitochondrial matrix Mg2+. Magnesium stimulated state 3 and state 4 respiration, with significantly different concentrations of matrix Mg2+ required for optimal activities of the several substrates. Maximal stimulation of respiration with all substrates was obtained at 2-mM external Mg2+. However, respiration of malate, citrate, and alpha-ketoglutarate requires at least 4-mM Mg2+ inside mitochondria for maximization of dehydrogenase activities. The phosphorylation system, requires a low level of internal Mg2+ (0.25 mM) to reach high activity, as judged by succinate-dependent respiration. However, mitochondria respiring on citrate or alpha-ketoglutarate only sustain high levels of phosphorylation with at least 4-mM matrix Mg2+. Respiration of succinate is active without external and matrix Mg2+, although stimulated by the cation. Respiration of alpha-ketoglutarate was strictly dependent on external Mg2+ required for substrate transport into mitochondria, and internal Mg2+ is required for dehydrogenase activity. Respiration of citrate and malate also depend on internal Mg2+ but, unlike alpha-ketoglutarate, some activity still remains without external Mg2+. All the substrates revealed insensitive to external and internal mitochondrial Ca2+, except the exogenous NADH dehydrogenase, which requires either external Ca2+ or Mg2+ for detectable activity. Calcium is more efficient than Mg2+, both having cumulative stimulation. Unlike Ca2+, Mn2+ could substitute for Mg2+, before and after addition of A23, showing its ability to regulate phosphorylation and succinate dehydrogenase activities, with almost the same efficiency as Mg2+.

Temporal expression of the human alcohol dehydrogenase gene family during liver development correlates with differential promoter activation by hepatocyte nuclear factor 1, CCAAT/enhancer-binding protein alpha, liver activator protein, and D-element-binding protein.

PubMed Central

van Ooij, C; Snyder, R C; Paeper, B W; Duester, G

1992-01-01

The human class I alcohol dehydrogenase (ADH) gene family consists of ADH1, ADH2, and ADH3, which are sequentially activated in early fetal, late fetal, and postnatal liver, respectively. Analysis of ADH promoters revealed differential activation by several factors previously shown to control liver transcription. In cotransfection assays, the ADH1 promoter, but not the ADH2 or ADH3 promoter, was shown to respond to hepatocyte nuclear factor 1 (HNF-1), which has previously been shown to regulate transcription in early liver development. The ADH2 promoter, but not the ADH1 or ADH3 promoter, was shown to respond to CCAAT/enhancer-binding protein alpha (C/EBP alpha), a transcription factor particularly active during late fetal liver and early postnatal liver development. The ADH1, ADH2, and ADH3 promoters all responded to the liver transcription factors liver activator protein (LAP) and D-element-binding protein (DBP), which are most active in postnatal liver. For all three promoters, the activation by LAP or DBP was higher than that seen by HNF-1 or C/EBP alpha, and a significant synergism between C/EBP alpha and LAP was noticed for the ADH2 and ADH3 promoters when both factors were simultaneously cotransfected. A hierarchy of ADH promoter responsiveness to C/EBP alpha and LAP homo- and heterodimers is suggested. In all three ADH genes, LAP bound to the same four sites previously reported for C/EBP alpha (i.e., -160, -120, -40, and -20 bp), but DBP bound strongly only to the site located at -40 bp relative to the transcriptional start. Mutational analysis of ADH2 indicated that the -40 bp element accounts for most of the promoter regulation by the bZIP factors analyzed. These studies suggest that HNF-1 and C/EBP alpha help establish ADH gene family transcription in fetal liver and that LAP and DBP help maintain high-level ADH gene family transcription in postnatal liver. Images PMID:1620113

Z-DNA binding protein from chicken blood nuclei

NASA Technical Reports Server (NTRS)

Herbert, A. G.; Spitzner, J. R.; Lowenhaupt, K.; Rich, A.

1993-01-01

A protein (Z alpha) that appears to be highly specific for the left-handed Z-DNA conformer has been identified in chicken blood nuclear extracts. Z alpha activity is measured in a band-shift assay by using a radioactive probe consisting of a (dC-dG)35 oligomer that has 50% of the deoxycytosines replaced with 5-bromodeoxycytosine. In the presence of 10 mM Mg2+, the probe converts to the Z-DNA conformation and is bound by Z alpha. The binding of Z alpha to the radioactive probe is specifically blocked by competition with linear poly(dC-dG) stabilized in the Z-DNA form by chemical bromination but not by B-form poly(dC-dG) or boiled salmon-sperm DNA. In addition, the binding activity of Z alpha is competitively blocked by supercoiled plasmids containing a Z-DNA insert but not by either the linearized plasmid or by an equivalent amount of the parental supercoiled plasmid without the Z-DNA-forming insert. Z alpha can be crosslinked to the 32P-labeled brominated probe with UV light, allowing us to estimate that the minimal molecular mass of Z alpha is 39 kDa.

Alpha absolute power measurement in panic disorder with agoraphobia patients.

PubMed

de Carvalho, Marcele Regine; Velasques, Bruna Brandão; Freire, Rafael C; Cagy, Maurício; Marques, Juliana Bittencourt; Teixeira, Silmar; Rangé, Bernard P; Piedade, Roberto; Ribeiro, Pedro; Nardi, Antonio Egidio; Akiskal, Hagop Souren

2013-10-01

Panic attacks are thought to be a result from a dysfunctional coordination of cortical and brainstem sensory information leading to heightened amygdala activity with subsequent neuroendocrine, autonomic and behavioral activation. Prefrontal areas may be responsible for inhibitory top-down control processes and alpha synchronization seems to reflect this modulation. The objective of this study was to measure frontal absolute alpha-power with qEEG in 24 subjects with panic disorder and agoraphobia (PDA) compared to 21 healthy controls. qEEG data were acquired while participants watched a computer simulation, consisting of moments classified as "high anxiety"(HAM) and "low anxiety" (LAM). qEEG data were also acquired during two rest conditions, before and after the computer simulation display. We observed a higher absolute alpha-power in controls when compared to the PDA patients while watching the computer simulation. The main finding was an interaction between the moment and group factors on frontal cortex. Our findings suggest that the decreased alpha-power in the frontal cortex for the PDA group may reflect a state of high excitability. Our results suggest a possible deficiency in top-down control processes of anxiety reflected by a low absolute alpha-power in the PDA group while watching the computer simulation and they highlight that prefrontal regions and frontal region nearby the temporal area are recruited during the exposure to anxiogenic stimuli. © 2013 Elsevier B.V. All rights reserved.

Arylesterase activities in the plasma of rats, rabbits and humans on low- and high-cholesterol diets.

PubMed

Beynen, A C; Weinans, G J; Katan, M B

1984-01-01

Arylesterase activities were measured with beta-naphthylpropionate and/or alpha-naphthylacetate as substrate in the plasma of rats, rabbits and humans on low- and high-cholesterol diets. The plasma esterase activities measured with alpha-naphthylacetate were similar in rats, rabbits and humans. With beta-naphthylpropionate as a substrate, rabbits were found to have a markedly higher esterase activity than rats and humans. Basal plasma esterase activity was significantly higher in an inbred rat strain which is hyporesponsive to dietary cholesterol than in a hyperresponsive strain. In rats, but not in humans and rabbits, plasma esterase activity was significantly increased by a high-cholesterol diet. In individual humans and random-bred rabbits and rats there was no association between initial plasma total esterase activity and the subsequent plasma cholesterol response to cholesterol feeding. We suggest that arylesterases are associated with cholesterol metabolism and with the response to dietary cholesterol in rats; evidence for such a role in rabbits and humans is, however, inconclusive.

alpha-Adrenoceptor and opioid receptor modulation of clonidine-induced antinociception.

PubMed Central

Sierralta, F.; Naquira, D.; Pinardi, G.; Miranda, H. F.

1996-01-01

1. The antinociceptive action of clonidine (Clon) and the interactions with alpha 1, alpha 2 adrenoceptor and opioid receptor antagonists was evaluated in mice by use of chemical algesiometric test (acetic acid writhing test). 2. Clon produced a dose-dependent antinociceptive action and the ED50 for intracerebroventricular (i.c.v.) was lower than for intraperitoneal (i.p.) administration (1 ng kg-1 vs 300 ng kg-1). The parallelism of the dose-response curves indicates activation of a common receptor subtype. 3. Systemic administration of prazosin and terazosin displayed antinociceptive activity. Pretreatment with prazosin produced a dual action: i.c.v. Clon effect did not change, and i.p. Clon effect was enhanced. Yohimbine i.c.v. or i.p. did not induce antinonciception, but antagonized Clon-induced activity. These results suggest that alpha 1- and alpha 2-adrenoceptors, either located at the pre- and/or post-synaptic level, are involved in the control of spinal antinociception. 4. Naloxone (NX) and naltrexone (NTX) induced antinociceptive effects at low doses (microgram kg-1 range) and a lower antinociceptive effect at higher doses (mg kg-1 range). Low doses of NX or NTX antagonized Clon antinociception, possibly in relation to a preferential mu opioid receptor antagonism. In contrast, high doses of NX or NTX increased the antinociceptive activity of Clon, which could be due to an enhanced inhibition of the release of substance P. 5. The results obtained in the present work suggest the involvement of alpha 1-, alpha 2-adrenoceptor and opioid receptors in the modulation of the antinociceptive activity of clonidine, which seems to be exerted either at spinal and/or supraspinal level. PMID:8894177

alpha-Adrenoceptor and opioid receptor modulation of clonidine-induced antinociception.

PubMed

Sierralta, F; Naquira, D; Pinardi, G; Miranda, H F

1996-10-01

1. The antinociceptive action of clonidine (Clon) and the interactions with alpha 1, alpha 2 adrenoceptor and opioid receptor antagonists was evaluated in mice by use of chemical algesiometric test (acetic acid writhing test). 2. Clon produced a dose-dependent antinociceptive action and the ED50 for intracerebroventricular (i.c.v.) was lower than for intraperitoneal (i.p.) administration (1 ng kg-1 vs 300 ng kg-1). The parallelism of the dose-response curves indicates activation of a common receptor subtype. 3. Systemic administration of prazosin and terazosin displayed antinociceptive activity. Pretreatment with prazosin produced a dual action: i.c.v. Clon effect did not change, and i.p. Clon effect was enhanced. Yohimbine i.c.v. or i.p. did not induce antinonciception, but antagonized Clon-induced activity. These results suggest that alpha 1- and alpha 2-adrenoceptors, either located at the pre- and/or post-synaptic level, are involved in the control of spinal antinociception. 4. Naloxone (NX) and naltrexone (NTX) induced antinociceptive effects at low doses (microgram kg-1 range) and a lower antinociceptive effect at higher doses (mg kg-1 range). Low doses of NX or NTX antagonized Clon antinociception, possibly in relation to a preferential mu opioid receptor antagonism. In contrast, high doses of NX or NTX increased the antinociceptive activity of Clon, which could be due to an enhanced inhibition of the release of substance P. 5. The results obtained in the present work suggest the involvement of alpha 1-, alpha 2-adrenoceptor and opioid receptors in the modulation of the antinociceptive activity of clonidine, which seems to be exerted either at spinal and/or supraspinal level.

Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves.

PubMed

Valgaeren, Bonnie R; Pardon, Bart; Goossens, Evy; Verherstraeten, Stefanie; Roelandt, Sophie; Timbermont, Leen; Van Der Vekens, Nicky; Stuyvaert, Sabrina; Gille, Linde; Van Driessche, Laura; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip; Deprez, Piet

2015-07-10

Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin.

Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves

PubMed Central

Valgaeren, Bonnie R.; Pardon, Bart; Goossens, Evy; Verherstraeten, Stefanie; Roelandt, Sophie; Timbermont, Leen; Van Der Vekens, Nicky; Stuyvaert, Sabrina; Gille, Linde; Van Driessche, Laura; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip; Deprez, Piet

2015-01-01

Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin. PMID:26184311

Evaluation of the alpha-amylase activity as an indicator of pasteurization efficiency and microbiological quality of liquid whole eggs.

PubMed

Silva, Guilherme Resende da; Menezes, Liliane Denize Miranda; Lanza, Isabela Pereira; Oliveira, Daniela Duarte de; Silva, Carla Aparecida; Klein, Roger Wilker Tavares; Assis, Débora Cristina Sampaio de; Cançado, Silvana de Vasconcelos

2017-09-01

In order to evaluate the efficiency of the pasteurization process in liquid whole eggs, an UV/visible spectrophotometric method was developed and validated for the assessment of alpha-amylase activity. Samples were collected from 30 lots of raw eggs (n = 30) and divided into three groups: one was reserved for analysis of the raw eggs, the second group was pasteurized at 61.1°C for 3.5 minutes (n = 30), and the third group was pasteurized at 64.4°C for 2.5 minutes (n = 30). In addition to assessing alpha-amylase activity, the microbiological quality of the samples was also evaluated by counting total and thermotolerant coliforms, mesophilic aerobic microorganisms, Staphylococcus spp., and Salmonella spp. The validated spectrophotometric method demonstrated linearity, with a coefficient of determination (R2) greater than 0.99, limits of detection (LOD) and quantification (LOQ) of 0.48 mg kg-1 and 1.16 mg kg-1, respectively, and acceptable precision and accuracy with relative standard deviation (RSD) values of less than 10% and recovery rates between 98.81% and 105.40%. The results for alpha-amylase activity in the raw egg samples showed high enzyme activity due to near-complete hydrolysis of the starch, while in the eggs pasteurized at 61.1°C, partial inactivation of the enzyme was observed. In the samples of whole eggs pasteurized at 64.4°C, starch hydrolysis did not occur due to enzyme inactivation. The results of the microbiological analyses showed a decrease (P < 0.0001) in the counts for all the studied microorganisms and in the frequency of Salmonella spp. in the pasteurized egg samples according to the two binomials under investigation, compared to the raw egg samples, which showed high rates of contamination (P < 0.0001). After pasteurization, only one sample (3.33%) was positive for Salmonella spp., indicating failure in the pasteurization process, which was confirmed by the alpha-amylase test. It was concluded that the validated methodology for testing alpha-amylase activity is adequate for assessing the efficiency of the pasteurization process, and that the time-temperature binomial used in this study is suitable to produce pasteurized eggs with high microbiological quality. © 2017 Poultry Science Association Inc.

Allosteric regulation of tryptophan synthase channeling: the internal aldimine probed by trans-3-indole-3'-acrylate binding.

PubMed

Casino, Patricia; Niks, Dimitri; Ngo, Huu; Pan, Peng; Brzovic, Peter; Blumenstein, Lars; Barends, Thomas Reinier; Schlichting, Ilme; Dunn, Michael F

2007-07-03

Substrate channeling in the tryptophan synthase bienzyme complex from Salmonella typhimurium is regulated by allosteric interactions triggered by binding of ligand to the alpha-site and covalent reaction at the beta-site. These interactions switch the enzyme between low-activity forms with open conformations and high-activity forms with closed conformations. Previously, allosteric interactions have been demonstrated between the alpha-site and the external aldimine, alpha-aminoacrylate, and quinonoid forms of the beta-site. Here we employ the chromophoric l-Trp analogue, trans-3-indole-3'-acrylate (IA), and noncleavable alpha-site ligands (ASLs) to probe the allosteric properties of the internal aldimine, E(Ain). The ASLs studied are alpha-d,l-glycerol phosphate (GP) and d-glyceraldehyde 3-phosphate (G3P), and examples of two new classes of high-affinity alpha-site ligands, N-(4'-trifluoromethoxybenzoyl)-2-aminoethyl phosphate (F6) and N-(4'-trifluoromethoxybenzenesulfonyl)-2-aminoethyl phosphate (F9), that were previously shown to bind to the alpha-site by optical spectroscopy and X-ray crystal structures [Ngo, H., Harris, R., Kimmich, N., Casino, P., Niks, D., Blumenstein, L., Barends, T. R., Kulik, V., Weyand, M., Schlichting, I., and Dunn, M. F. (2007) Synthesis and characterization of allosteric probes of substrate channeling in the tryptophan synthase bienzyme complex, Biochemistry 46, 7713-7727]. The binding of IA to the beta-site is stimulated by the binding of GP, G3P, F6, or F9 to the alpha-site. The binding of ASLs was found to increase the affinity of the beta-site of E(Ain) for IA by 4-5-fold, demonstrating for the first time that the beta-subunit of the E(Ain) species undergoes a switching between low- and high-affinity states in response to the binding of ASLs.

Partial agonist clonidine mediates alpha(2)-AR subtypes specific regulation of cAMP accumulation in adenylyl cyclase II transfected DDT1-MF2 cells.

PubMed

Limon-Boulez, I; Bouet-Alard, R; Gettys, T W; Lanier, S M; Maltier, J P; Legrand, C

2001-02-01

alpha2-Adrenergic receptor (alpha(2)-AR) activation in the pregnant rat myometrium at midterm potentiates beta(2)-AR stimulation of adenylyl cyclase (AC) via Gbetagamma regulation of the type II isoform of adenylyl cyclase. However, at term, alpha(2)-AR activation inhibits beta(2)-AR stimulation of AC. This phenomenon is associated with changes in alpha(2)-AR subtype expression (midterm alpha(2A/D)-AR > alpha(2B)-AR; term alpha(2B) >or =alpha(2A/D)-AR), without any change in ACII mRNA, suggesting that alpha(2A/D)- and alpha(2B)-AR differentially regulate beta(2)-cAMP production. To address this issue, we have stably expressed the same density of alpha(2A/D)- or alpha(2B)-AR with AC II in DDT1-MF2 cells. Clonidine (partial agonist) increased beta(2)-AR-stimulated cAMP production in alpha(2A/D)-AR-ACII transfectants but inhibited it in alpha(2B)-AR-ACII transfectants. In contrast, epinephrine (full agonist) enhanced beta(2)-stimulated ACII in both alpha(2A)- and alpha(2B)-ACII clonal cell lines. 4-Azidoanilido-[alpha-(32)P]GTP-labeling of activated G proteins indicated that, in alpha(2B)-AR transfectants, clonidine activated only Gi(2), whereas epinephrine, the full agonist, effectively coupled to Gi(2) and Gi(3). Thus, partial and full agonists selectively activate G proteins that lead to drug specific effects on effectors. Moreover, these data indicate that Gi(3) activation is required for potentiation of beta(2)-AR stimulation of AC by alpha(2A/D) and alpha(2B)-AR in DDT1-MF2 cells. This may reflect an issue of the amount of Gbetagamma released upon receptor activation and/or betagamma composition of Gi(3) versus Gi(2).

Peroxisome proliferator-activated receptor {alpha}-independent peroxisome proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Xiuguo; Tanaka, Naoki; Nakajima, Takero

2006-08-11

Hepatic peroxisome proliferation, increases in the numerical and volume density of peroxisomes, is believed to be closely related to peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) activation; however, it remains unknown whether peroxisome proliferation depends absolutely on this activation. To verify occurrence of PPAR{alpha}-independent peroxisome proliferation, fenofibrate treatment was used, which was expected to significantly enhance PPAR{alpha} dependence in the assay system. Surprisingly, a novel type of PPAR{alpha}-independent peroxisome proliferation and enlargement was uncovered in PPAR{alpha}-null mice. The increased expression of dynamin-like protein 1, but not peroxisome biogenesis factor 11{alpha}, might be associated with the PPAR{alpha}-independent peroxisome proliferation at least in part.

Improve the catalytic activity of {alpha}-Fe{sub 2}O{sub 3} particles in decomposition of ammonium perchlorate by coating amorphous carbon on their surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Yifu; Liu Xinghai, E-mail: liuxh@whu.edu.c; Nie Jiaorong

2011-02-15

Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value of the designed synthetic system, respectively. The sphere-like {alpha}-Fe{sub 2}O{sub 3} particles with diameter about 25 nm on average were encapsulated into carbon shells to fabricate a novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C) through the coating experiments. The catalytic performance of the products on the thermal decomposition of ammonium perchlorate (AP) was investigated by thermal gravimetric analyzer (TG) and differential thermal analysis (DTA). The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3},more » sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which show that {alpha}-Fe{sub 2}O{sub 3}-C core-shell composites have higher catalytic activity than that of {alpha}-Fe{sub 2}O{sub 3}. -- Graphical abstract: The catalytic performance of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C on the thermal decomposition of ammonium perchlorate (AP). Display Omitted Research highlights: {yields} Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value. {yields} A novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C core-shell structured composite) has been successfully synthesized using sphere-like {alpha}-Fe{sub 2}O{sub 3} particles as the cores and glucose as the source of carbon. {yields} The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which shows that these materials have high catalytic activity.« less

Glutathione regulation of redox-sensitive signals in tumor necrosis factor-{alpha}-induced vascular endothelial dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsou, T.-C.; Yeh, S.C.; Tsai, F.-Y.

2007-06-01

We investigated the regulatory role of glutathione in tumor necrosis factor-alpha (TNF-{alpha})-induced vascular endothelial dysfunction as evaluated by using vascular endothelial adhesion molecule expression and monocyte-endothelial monolayer binding. Since TNF-{alpha} induces various biological effects on vascular cells, TNF-{alpha} dosage could be a determinant factor directing vascular cells into different biological fates. Based on the adhesion molecule expression patterns responding to different TNF-{alpha} concentrations, we adopted the lower TNF-{alpha} (0.2 ng/ml) to rule out the possible involvement of other TNF-{alpha}-induced biological effects. Inhibition of glutathione synthesis by L-buthionine-(S,R)-sulfoximine (BSO) resulted in down-regulations of the TNF-{alpha}-induced adhesion molecule expression and monocyte-endothelial monolayermore » binding. BSO attenuated the TNF-{alpha}-induced nuclear factor-kappaB (NF-{kappa}B) activation, however, with no detectable effect on AP-1 and its related mitogen-activated protein kinases (MAPKs). Deletion of an AP-1 binding site in intercellular adhesion molecule-1 (ICAM-1) promoter totally abolished its constitutive promoter activity and its responsiveness to TNF-{alpha}. Inhibition of ERK, JNK, or NF-{kappa}B attenuates TNF-{alpha}-induced ICAM-1 promoter activation and monocyte-endothelial monolayer binding. Our study indicates that TNF-{alpha} induces adhesion molecule expression and monocyte-endothelial monolayer binding mainly via activation of NF-{kappa}B in a glutathione-sensitive manner. We also demonstrated that intracellular glutathione does not modulate the activation of MAPKs and/or their downstream AP-1 induced by lower TNF-{alpha}. Although AP-1 activation by the lower TNF-{alpha} was not detected in our systems, we could not rule out the possible involvement of transiently activated MAPKs/AP-1 in the regulation of TNF-{alpha}-induced adhesion molecule expression.« less

Tumor cell alpha-N-acetylgalactosaminidase activity and its involvement in GcMAF-related macrophage activation.

PubMed

Mohamad, Saharuddin B; Nagasawa, Hideko; Uto, Yoshihiro; Hori, Hitoshi

2002-05-01

Alpha-N-acetyl galactosaminidase (alpha-NaGalase) has been reported to accumulate in serum of cancer patients and be responsible for deglycosylation of Gc protein, which is a precursor of GcMAF-mediated macrophage activation cascade, finally leading to immunosuppression in advanced cancer patients. We studied the biochemical characterization of alpha-NaGalase from several human tumor cell lines. We also examined its effect on the potency of GcMAF to activate mouse peritoneal macrophage to produce superoxide in GcMAF-mediated macrophage activation cascade. The specific activity of alpha-NaGalases from human colon tumor cell line HCT116, human hepatoma cell line HepG2, and normal human liver cells (Chang liver cell line) were evaluated using two types of substrates; GalNAc-alpha-PNP (exo-type substrate) and Gal-beta-GalNAc-alpha-PNP (endo-type substrate). Tumor-derived alpha-NaGalase having higher activity than normal alpha-NaGalase, had higher substrate specificity to the exo-type substrate than to the endo-type substrate, and still maintained its activity at pH 7. GcMAF enhance superoxide production in mouse macrophage, and pre-treatment of GcMAF with tumor cell lysate reduce the activity. We conclude that tumor-derived alpha-NaGalase is different in biochemical characterization compared to normal alpha-NaGalase from normal Chang liver cells. In addition, tumor cell-derived alpha-NaGalase decreases the potency of GcMAF on macrophage activation.

Doppler line profiles measurement of the Jovian Lyman Alpha emission with OAO-C

NASA Technical Reports Server (NTRS)

Barker, E. S.; Cochran, W. D.; Smith, H. J.

1982-01-01

Observation of Jupiter made with the high resolution ultraviolet spectrometer of the Orbiting Astronomical Observatory copernicus in April and May, 1980, yield a Jovian Lyman alpha emission intensity of 7 + or 2.5 RR. This indicates a decrease by about a factor of two since the Voyager ultraviolet spectrometer measurements, nearly a year earlier. An unusually high column abundance of hydrogen atoms above the methane homopause at the Voyager epoch is indicated. Since the auroral charged particle bombardment of molecular hydrogen is expected to contribute significantly to the global population of the hydrogen atoms, it is suggested that at the time of the Voyager Jupiter encounter unusually high auroral activity existed, perhaps d to the high concentration of the Io plasma torus. The temporal variation of the Saturn lyman alpha emission, when contrasted with the Jovian data, reveals that the auroral processes are not nearly as important in determining the Saturn Lyman alpha intensity in the nonauroral region.

Lewis base activation of Lewis acids: catalytic, enantioselective vinylogous aldol addition reactions.

PubMed

Denmark, Scott E; Heemstra, John R

2007-07-20

The generality of Lewis base catalyzed, Lewis acid mediated, enantioselective vinylogous aldol addition reactions has been investigated. The combination of silicon tetrachloride and chiral phosphoramides is a competent catalyst for highly selective additions of a variety of alpha,beta-unsaturated ketone-, 1,3-diketone-, and alpha,beta-unsaturated amide-derived dienolates to aldehydes. These reactions provided high levels of gamma-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded high enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although alpha,beta-unsaturated ketone-derived dienolate did not react with aliphatic aldehydes, alpha,beta-unsaturated amide-derived dienolates underwent addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivities achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride-chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.

TNF-{alpha} promotes cell survival through stimulation of K{sup +} channel and NF{kappa}B activity in corneal epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Ling; Reinach, Peter; Lu, Luo

2005-11-15

Tumor necrosis factor (TNF-{alpha}) in various cell types induces either cell death or mitogenesis through different signaling pathways. In the present study, we determined in human corneal epithelial cells how TNF-{alpha} also promotes cell survival. Human corneal epithelial (HCE) cells were cultured in DMEM/F-12 medium containing 10% FBS. TNF-{alpha} stimulation induced activation of a voltage-gated K{sup +} channel detected by measuring single channel activity using patch clamp techniques. The effect of TNF-{alpha} on downstream events included NF{kappa}B nuclear translocation and increases in DNA binding activities, but did not elicit ERK, JNK, or p38 limb signaling activation. TNF-{alpha} induced increases inmore » p21 expression resulting in partial cell cycle attenuation in the G{sub 1} phase. Cell cycle progression was also mapped by flow cytometer analysis. Blockade of TNF-{alpha}-induced K{sup +} channel activity effectively prevented NF{kappa}B nuclear translocation and binding to DNA, diminishing the cell-survival protective effect of TNF-{alpha}. In conclusion, TNF-{alpha} promotes survival of HCE cells through sequential stimulation of K{sup +} channel and NF{kappa}B activities. This response to TNF-{alpha} is dependent on stimulating K{sup +} channel activity because following suppression of K{sup +} channel activity TNF-{alpha} failed to activate NF{kappa}B nuclear translocation and binding to nuclear DNA.« less

A crystalline protein-proteinase inhibitor from pinto bean seeds.

PubMed

Wang, D

1975-06-26

A crystalline protein-proteinase inhibitor has been isolated from seeds of Pinto bean (Phaseolus vulgaris cultvar. Pinto). It has an average molecular weight of 19 000 as estimated by gel filtration. This crystalline inhibitor is highly active against both bovine pancreatic trypsin and alpha-chymotrypsin. Complexes of both trypsin-inhibitor and alpha-chymotrypsin-inhibitor have been isolated. The inhibitor which was derived from the dissociated trypsin-inhibitor complex was only 62% as effective as the original compound against either enzyme. In contrast, the inhibitor obtained from alpha-chymotrypsin-inhibitor complex retained its full original inhibitory activity for trypsin, but only 25% of its original activity against alpha-chymotrypsin. The dissociated inhibitor from alpha-chymotrypsin-inhibitor compex, despite its full inhibitory activity, had been modified to such an extent that it could no longer form any precipitable complex with trypsin. The crystalline protein-proteinase inhibitor is not homogeneous and has been resolved into two distinct inhibitors in terms of their physical and chemical properties. These two inhibitors are designated as Pinto bean proteinase inhibitor I and II and their respective minimum molecular weights are 9100 and 10 000. They differ most strikingly in their amino acid composition in that inhibitor II is void of both valine and methionine.

Skeletal muscle adaptation to fatty acid depends on coordinated actions of the PPARs and PGC1 alpha: implications for metabolic disease.

PubMed

Muoio, Deborah M; Koves, Timothy R

2007-10-01

Dyslipidemia and intramuscular accumulation of fatty acid metabolites are increasingly recognized as core features of obesity and type 2 diabetes. Emerging evidence suggests that normal physiological adaptations to a heavy lipid load depend on the coordinated actions of broad transcriptional regulators such as the peroxisome proliferator activated receptors (PPARs) and PPAR gamma coactivator 1 alpha (PGC1 alpha). The application of transcriptomics and targeted metabolic profiling tools based on mass spectrometry has led to our finding that lipid-induced insulin resistance is a condition in which upregulation of PPAR-targeted genes and high rates of beta-oxidation are not supported by a commensurate upregulation of tricarboxylic acid (TCA) cycle activity. In contrast, exercise training enhances mitochondrial performance, favoring tighter coupling between beta-oxidation and the TCA cycle, and concomitantly restores insulin sensitivity in animals fed a chronic high-fat diet. The exercise-activated transcriptional coactivator, PGC1 alpha, plays a key role in coordinating metabolic flux through these 2 intersecting metabolic pathways, and its suppression by overfeeding may contribute to diet-induced mitochondrial dysfunction. Our emerging model predicts that muscle insulin resistance arises from a mitochondrial disconnect between beta-oxidation and TCA cycle activity. Understanding of this "disconnect" and its molecular basis may lead to new therapeutic approaches to combatting metabolic disease.

Study of the Many Fluorescent Lines and the Absorption Variability in GX 301-2 with XMM-Newton

NASA Technical Reports Server (NTRS)

Fuerst, F.; Suchy, S.; Kreykenbohm, I.; Barragan, L.; Wilms, J.; Pottschmidt, K.; Caballero, I.; Kretschmar, P.; Ferrigno, C.; Rothschild, R. E.

2011-01-01

We present an in-depth study of the High Mass X-ray Binary (HMXB) GX 301-2 during its pre-periastron flare using data from the XMM-Newton satellite. The energy spectrum shows a power law continuum absorbed by a large equivalent hydrogen column on the order of 10(exp 24)/ sq cm and a prominent Fe K-alpha fluorescent emission line. Besides the Fe K-alpha line, evidence for Fe K-Beta, Ni K-alpha, Ni K-Beta, S K-alpha, Ar K-alpha, Ca K-alpha, and Cr K-alpha fluorescent lines is found. The observed line strengths are consistent with fluorescence in a cold absorber. This is the first time that Cr K-alpha is seen in emission in the X-ray spectrum of a HMXB. In addition to the modulation by the strong pulse period of approx 685 sec the source is highly variable and shows different states of activity. We perform time-resolved as well as pulse-to-pulse resolved spectroscopy to investigate differences between these states of activity. We find that fluorescent line fluxes are strongly variable and generally follow the overall flux. The N-H value is variable by a factor of 2, but not correlated to continuum normalization. We find an interval of low flux in the light curve in which the pulsations cease almost completely, without any indication of an increasing absorption column. We investigate this dip in detail and argue that it is most likely that during the dip the accretion ceased and the afterglow of the fluorescent iron accounted for the main portion of the X-ray flux. A similar dip was found earlier in RXTE data, and we compare our findings to these results.

Deglycosylation of serum vitamin D3-binding protein leads to immunosuppression in cancer patients.

PubMed

Yamamoto, N; Naraparaju, V R; Asbell, S O

1996-06-15

Serum vitamin D3-binding protein (Gc protein) can be converted by beta-galactosidase of B cells and sialidase of T cells to a potent macrophage activating factor, a protein with N-acetylgalactosamine as the remaining sugar moiety. Thus, Gc protein is the precursor of the macrophage activating factor (MAF). Treatment of Gc protein with immobilized beta-galactosidase and sialidase generates an extremely high titered MAF, Gc-MAF. When peripheral blood monocytes/macrophages of 52 patients bearing various types of cancer were incubated with 100 pg/ml of GcMAF, the monocytes/macrophages of all patients were efficiently activated. However, the MAF precursor activity of patient plasma Gc protein was found to be severely reduced in about 25% of this patient population. About 45% of the patients had moderately reduced MAF precursor activities. Loss of the precursor activity was found to be due to deglycosylation of plasma Gc protein by alpha-N-acetylgalactosaminidase detected in the patient's bloodstream. The source of the enzyme appeared to be cancerous cells. Radiation therapy decreased plasma alpha-N-acetylgalactosaminidase activity with concomitant increase of precursor activity. This implies that radiation therapy decreases the number of cancerous cells capable of secreting alpha-N-acetylgalactosaminidase. Both alpha-N-acetylgalactosaminidase activity and MAF precursor activity of Gc protein in patient bloodstream can serve as diagnostic and prognostic indices.

Cloning and Molecular Characterization of an Alpha-Glucosidase (MalH) from the Halophilic Archaeon Haloquadratum walsbyi.

PubMed

Cuebas-Irizarry, Mara F; Irizarry-Caro, Ricardo A; López-Morales, Carol; Badillo-Rivera, Keyla M; Rodríguez-Minguela, Carlos M; Montalvo-Rodríguez, Rafael

2017-11-21

We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi . A 2349 bp region ( Hqrw_2071 ) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and alpha-xylosidases of Halorubrum . Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

IL-2 activation of STAT5 enhances production of IL-10 from human cytotoxic regulatory T cells, HOZOT.

PubMed

Tsuji-Takayama, Kazue; Suzuki, Motoyuki; Yamamoto, Mayuko; Harashima, Akira; Okochi, Ayumi; Otani, Takeshi; Inoue, Toshiya; Sugimoto, Akira; Motoda, Ryuichi; Yamasaki, Fumiyuki; Nakamura, Shuji; Kibata, Masayoshi

2008-02-01

Interleukin (IL)-10 is an immunosuppressive cytokine produced by many cell types, including T cells. We previously reported that a novel type of regulatory T (Treg) cells, termed HOZOT, which possesses a FOXP3+CD4+CD8+CD25+ phenotype and dual suppressor/cytotoxic activities, produced high levels of IL-10. In this study, we examined the mechanisms of high IL-10 production by HOZOT, focusing on Janus activating kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway. We prepared five different types of T cells, including HOZOT from human umbilical cord blood. Cytokine productions of IL-10, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) were compared among these T cells after anti-CD3/CD28 antibody stimulation in the presence or absence of IL-2. Specific inhibitors for JAK/STAT, nuclear factor-kappaB (NF-kappaB), and nuclear factor for activated T cell (NFAT) were used to analyze signal transduction mechanisms. IL-10 production by HOZOTs was greatly enhanced by the addition of IL-2. Little or no enhancement of IFN-gamma and TNF-alpha production was observed under the same conditions. The enhancing effect of IL-2 was specific for both HOZOT and IL-10-secreting Treg cells. T helper type 2 cells, whose IL-10 production mechanisms involve GATA-3, failed to show IL-2-mediated enhancement of IL-10. Similar enhancing effects of IL-15 and IFN-alpha suggested a major role of JAK/STAT activation pathway for high IL-10 production. Further inhibitor experiments demonstrated that STAT5 rather than STAT3 was critically involved in this mechanism. Our results demonstrated that IL-2 selectively enhanced production of IL-10 in HOZOT primarily through activation of STAT5, which synergistically acts with NF-kappaB/NFAT activation, implying a novel regulatory mechanism of IL-10 production in Treg cells.

Isoenzymes of protein kinase C in rat mammary tissue: changes in properties and relative amounts during pregnancy and lactation.

PubMed

Connor, K; Clegg, R A

1993-05-01

Protein kinase isoenzymes belonging to the protein kinase C (PK-C) family present in rat mammary tissue have been resolved from one another by chromatography on hydroxyapatite, and characterized. PK-C alpha is the predominant isoenzyme and is present at a constant level of activity throughout mammary-gland development and differentiation. In contrast, marked changes in the relative abundance of other mammary PK-C isoenzymes accompany the transition from pregnancy to lactation. The sensitivity of mammary PK-C alpha to Ca2+ is greater in tissue from pregnant than from lactating rats. This isoenzyme has other atypical properties consistent with its being more highly phosphorylated than PK-C alpha in rat brain and spleen. One of the protein kinase isoenzymes resolved from mammary tissue recognizes the peptide substrate used to assay AMP-activated kinase and may thus interfere in the determination of this activity. Another is fully active in the absence of Ca2+ and is more than 80% active in the absence of added lipid effectors. A 'housekeeping' role is proposed for PK-C alpha in mammary tissue, whereas the less abundant PK-C isoenzymes may be involved in mammary cell proliferation and differentiation.

Effect of oral contraceptive use on the erythrocytic glutathione reductase and aspartate aminotransferase activities in women with or without clinical signs of vitamin deficiency.

PubMed

Tovar, A; Bourges, H; Canto, T; Torres, N; Lopez-castro, B R

1985-07-01

The effect of the chronic use of combined oral contraceptives (OCs) on the "activity coefficients" (alpha = coenzyme-stimulated activity/basal activity) of erythrocytic glutathione reductase and aspartate aminotransferase was studied in 2 groups of 90 female volunteers each; 1 of the groups, from the state of Yucatan in southeast Mexico, presented clinical lesions of vitamin deficiency, while the other group, from Mexico City, did not have any clinical evidence of vitamin deficiency. One half of the women (45) in each group were chronic OC users and the other half were not. The results were analyzed comparing OC users with non-users in each location. For both glutathione reductase and aspartate aminotransferase, the Mexico City OC users had significantly higher (p 0.001) alpha values than nonusers, while in the Yucatan women, the alpha values were similarly high independent of OC use.

Activation of the alpha-globin gene expression correlates with dramatic upregulation of nearby non-globin genes and changes in local and large-scale chromatin spatial structure.

PubMed

Ulianov, Sergey V; Galitsyna, Aleksandra A; Flyamer, Ilya M; Golov, Arkadiy K; Khrameeva, Ekaterina E; Imakaev, Maxim V; Abdennur, Nezar A; Gelfand, Mikhail S; Gavrilov, Alexey A; Razin, Sergey V

2017-07-11

In homeotherms, the alpha-globin gene clusters are located within permanently open genome regions enriched in housekeeping genes. Terminal erythroid differentiation results in dramatic upregulation of alpha-globin genes making their expression comparable to the rRNA transcriptional output. Little is known about the influence of the erythroid-specific alpha-globin gene transcription outburst on adjacent, widely expressed genes and large-scale chromatin organization. Here, we have analyzed the total transcription output, the overall chromatin contact profile, and CTCF binding within the 2.7 Mb segment of chicken chromosome 14 harboring the alpha-globin gene cluster in cultured lymphoid cells and cultured erythroid cells before and after induction of terminal erythroid differentiation. We found that, similarly to mammalian genome, the chicken genomes is organized in TADs and compartments. Full activation of the alpha-globin gene transcription in differentiated erythroid cells is correlated with upregulation of several adjacent housekeeping genes and the emergence of abundant intergenic transcription. An extended chromosome region encompassing the alpha-globin cluster becomes significantly decompacted in differentiated erythroid cells, and depleted in CTCF binding and CTCF-anchored chromatin loops, while the sub-TAD harboring alpha-globin gene cluster and the upstream major regulatory element (MRE) becomes highly enriched with chromatin interactions as compared to lymphoid and proliferating erythroid cells. The alpha-globin gene domain and the neighboring loci reside within the A-like chromatin compartment in both lymphoid and erythroid cells and become further segregated from the upstream gene desert upon terminal erythroid differentiation. Our findings demonstrate that the effects of tissue-specific transcription activation are not restricted to the host genomic locus but affect the overall chromatin structure and transcriptional output of the encompassing topologically associating domain.

Inhibitory spectrum of alpha 2-plasmin inhibitor.

PubMed Central

Saito, H; Goldsmith, G H; Moroi, M; Aoki, N

1979-01-01

alpha 2-Plasmin inhibitor (alpha 2PI) has been recently characterized as a fast-reacting inhibitor of plasmin in human plasma and appears to play an important role in the regulation of fibrinolysis in vivo. We have studied the effect of purified alpha 2PI upon various proteases participating in human blood coagulation and kinin generation. At physiological concentration (50 microgram/ml), alpha 2PI inhibited the clot-promoting and prekallikrein-activating activity of Hageman factor fragments, the amidolytic, kininogenase, and clot-promoting activities of plasma kallikrein, and the clot-promoting properties of activated plasma thromboplastin antecedent (PTA, Factor XIa) and thrombin. alpha 2PI had minimal inhibitory effect on surface-bound activated PTA and activated Stuart factor (Factor Xa). alpha 2PI did not inhibit the activity of activated Christmas factor (Factor IXa) or urinary kallikrein. Heparin (1.5-2.0 units/ml) did not enhance the inhibitory function of alpha 2PI. These results suggest that, like other plasma protease inhibitors, alpha 2PI possesses a broad in vitro spectrum of inhibitory properties. PMID:156364

Structure and kinetic investigation of Streptococcus pyogenes family GH38 alpha-mannosidase.

PubMed

Suits, Michael D L; Zhu, Yanping; Taylor, Edward J; Walton, Julia; Zechel, David L; Gilbert, Harry J; Davies, Gideon J

2010-02-03

The enzymatic hydrolysis of alpha-mannosides is catalyzed by glycoside hydrolases (GH), termed alpha-mannosidases. These enzymes are found in different GH sequence-based families. Considerable research has probed the role of higher eukaryotic "GH38" alpha-mannosides that play a key role in the modification and diversification of hybrid N-glycans; processes with strong cellular links to cancer and autoimmune disease. The most extensively studied of these enzymes is the Drosophila GH38 alpha-mannosidase II, which has been shown to be a retaining alpha-mannosidase that targets both alpha-1,3 and alpha-1,6 mannosyl linkages, an activity that enables the enzyme to process GlcNAc(Man)(5)(GlcNAc)(2) hybrid N-glycans to GlcNAc(Man)(3)(GlcNAc)(2). Far less well understood is the observation that many bacterial species, predominantly but not exclusively pathogens and symbionts, also possess putative GH38 alpha-mannosidases whose activity and specificity is unknown. Here we show that the Streptococcus pyogenes (M1 GAS SF370) GH38 enzyme (Spy1604; hereafter SpGH38) is an alpha-mannosidase with specificity for alpha-1,3 mannosidic linkages. The 3D X-ray structure of SpGH38, obtained in native form at 1.9 A resolution and in complex with the inhibitor swainsonine (K(i) 18 microM) at 2.6 A, reveals a canonical GH38 five-domain structure in which the catalytic "-1" subsite shows high similarity with the Drosophila enzyme, including the catalytic Zn(2+) ion. In contrast, the "leaving group" subsites of SpGH38 display considerable differences to the higher eukaryotic GH38s; features that contribute to their apparent specificity. Although the in vivo function of this streptococcal GH38 alpha-mannosidase remains unknown, it is shown to be an alpha-mannosidase active on N-glycans. SpGH38 lies on an operon that also contains the GH84 hexosaminidase (Spy1600) and an additional putative glycosidase. The activity of SpGH38, together with its genomic context, strongly hints at a function in the degradation of host N- or possibly O-glycans. The absence of any classical signal peptide further suggests that SpGH38 may be intracellular, perhaps functioning in the subsequent degradation of extracellular host glycans following their initial digestion by secreted glycosidases.

Effects of alpha lipoic acid on acrylamide-induced hepatotoxicity in rats.

PubMed

Al-Qahtani, F A; Arafah, M; Sharma, B; Siddiqi, N J

2017-07-31

Acrylamide (ACR) is a neurotoxicant, reproductive toxicant, and carcinogen in animal species.  It is used in many industries and has been found to form naturally in foods cooked at high temperatures. Alpha-lipoic acid (ALA) is a naturally occurring antioxidant whose therapeutic effect has been related to its antioxidant activity.  This study was carried out to study the protective effect of alpha lipoic acid on acrylamide induced perturbations in rat liver.  Four groups of rats were studied viz., control rats, acrylamide treated rats, alpha lipoic acid treated rats, and alpha lipoic acid plus acrylamide treated rats. ACR and ALA treatment alone and together caused a signifi-cant increase in hepatic reduced glutathione content while a decrease in hepatic ascorbic content was observed when compared to control group.  ALA pretreatment of acrylamide exposed rats caused no a signifi-cant alteration in superoxide dismutase activity but resulted in a tendency towards restoration of glutathione peroxidase and catalase activity to near normal levels.  Gel electrophoresis showed fragmentation of DNA in the treated groups.  The dose of ALA used in the present study afforded partial restoration of oxidative indices altered by ACR in rat liver.

Increased alpha band activity indexes inhibitory competition across a border during figure assignment.

PubMed

Sanguinetti, Joseph L; Trujillo, Logan T; Schnyer, David M; Allen, John J B; Peterson, Mary A

2016-09-01

Figure-ground assignment is thought to entail inhibitory competition between potential objects on opposite sides of a shared border; the winner is perceived as the figure, and the loser as the shapeless ground. Computational models and response time measures support this understanding but to date no online measure of inhibitory competition during figure-ground assignment has been reported. The current study assays electroencephalogram (EEG) alpha power as a measure of inhibitory competition during figure-ground assignment. Activity in the EEG alpha band has been linked to functional inhibition in the brain, and it has been proposed that increased alpha power reflects increased inhibition. In 2 experiments participants viewed silhouettes designed so that the insides would be perceived as figures. Real-world silhouettes depicted namable objects. Novel silhouettes depicted novel objects on the insides of their borders, but varied in the amount of hypothesized cross-border competition for figural status: In "Low-Competition" silhouettes, the borders suggested novel objects on the outside as well as on the inside. In "High-Competition" silhouettes the borders suggested portions of real-world objects on the outside; these compete with the figural properties favoring the inside as figure. Participants accurately categorized both types of novel silhouettes as "novel" objects and were unaware of the real world objects suggested on the outside of the High-Competition silhouettes. In both experiments, we observed more alpha power while participants viewed High- rather than Low-Competition novel silhouettes. These are the first results to show via an online index of neural activity that figure assignment entails inhibitory competition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibitors of sterol synthesis. Chemical syntheses and spectral properties of 26-oxygenated derivatives of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells.

PubMed

Siddiqui, A U; Wilson, W K; Ruecker, K E; Pinkerton, F D; Schroepfer, G J

1992-11-01

26-Oxygenated derivatives of delta 8(14)-15-ketosterols have been synthesized from (25R)-3 beta,26-diacetoxy-5 alpha-cholest-8(14)-en-15-one (IX) as part of a program to prepare potential metabolites and analogs of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I), a potent regulator of cholesterol metabolism. Partial hydrolysis of IX gave a mixture, from which the 3 beta,26-diol II and the 26-acetate (XI) and 3 beta-acetate (X) monoesters were isolated. Mitsunobu reaction of XI followed by hydrolysis gave (25R)-3 alpha,26-dihydroxy-5 alpha-cholest-8(14)-en-15-one (VI). Oxidation of XI with pyridinium chlorochromate followed by hydrolysis of the acetate gave (25R)-26-hydroxy-5 alpha-cholest-8(14)-ene-3,15-dione (VII). Oxidation of X with Jones reagent followed by hydrolysis of the acetate gave (25R)-3 beta-hydroxy-15-keto-5 alpha-cholest-8(14)-en-26-oic acid (IVa). Jones oxidation of II gave (25R)-3,15-diketo-5 alpha-cholest-8(14)-en-26-oic acid (VII). 1H and 13C nuclear magnetic resonance assignments and analyses of mass spectral fragmentation data are presented for each of the new compounds and their derivatives. The 3,15-diketone VII was found to be highly active in lowering the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells, with a potency comparable to that of I. In contrast, 3 alpha,26-diol VI was less potent than I or VII. The two carboxylic acid analogs IVa and VIII were considerably less potent than VI in lowering the levels of HMG-CoA reductase activity.

A serum response factor-dependent transcriptional regulatory program identifies distinct smooth muscle cell sublineages.

PubMed Central

Kim, S; Ip, H S; Lu, M M; Clendenin, C; Parmacek, M S

1997-01-01

The SM22alpha promoter has been used as a model system to define the molecular mechanisms that regulate smooth muscle cell (SMC) specific gene expression during mammalian development. The SM22alpha gene is expressed exclusively in vascular and visceral SMCs during postnatal development and is transiently expressed in the heart and somites during embryogenesis. Analysis of the SM22alpha promoter in transgenic mice revealed that 280 bp of 5' flanking sequence is sufficient to restrict expression of the lacZ reporter gene to arterial SMCs and the myotomal component of the somites. DNase I footprint and electrophoretic mobility shift analyses revealed that the SM22alpha promoter contains six nuclear protein binding sites (designated smooth muscle elements [SMEs] -1 to -6, respectively), two of which bind serum response factor (SRF) (SME-1 and SME-4). Mutational analyses demonstrated that a two-nucleotide substitution that selectively eliminates SRF binding to SME-4 decreases SM22alpha promoter activity in arterial SMCs by approximately 90%. Moreover, mutations that abolish binding of SRF to SME-1 and SME-4 or mutations that eliminate each SME-3 binding activity totally abolished SM22alpha promoter activity in the arterial SMCs and somites of transgenic mice. Finally, we have shown that a multimerized copy of SME-4 (bp -190 to -110) when linked to the minimal SM22alpha promoter (bp -90 to +41) is necessary and sufficient to direct high-level transcription in an SMC lineage-restricted fashion. Taken together, these data demonstrate that distinct transcriptional regulatory programs control SM22alpha gene expression in arterial versus visceral SMCs. Moreover, these data are consistent with a model in which combinatorial interactions between SRF and other transcription factors that bind to SME-4 (and that bind directly to SRF) activate transcription of the SM22alpha gene in arterial SMCs. PMID:9121477

Autism, Attention, and Alpha Oscillations: An Electrophysiological Study of Attentional Capture.

PubMed

Keehn, Brandon; Westerfield, Marissa; Müller, Ralph-Axel; Townsend, Jeanne

2017-09-01

Autism spectrum disorder (ASD) is associated with deficits in adaptively orienting attention to behaviorally-relevant information. Neural oscillatory activity plays a key role in brain function and provides a high-resolution temporal marker of attention dynamics. Alpha band (8-12 Hz) activity is associated with both selecting task-relevant stimuli and filtering task-irrelevant information. The present study used electroencephalography (EEG) to examine alpha-band oscillatory activity associated with attentional capture in nineteen children with ASD and twenty-one age- and IQ-matched typically developing (TD) children. Participants completed a rapid serial visual presentation paradigm designed to investigate responses to behaviorally-relevant targets and contingent attention capture by task-irrelevant distractors, which either did or did not share a behaviorally-relevant feature. Participants also completed six minutes of eyes-open resting EEG. In contrast to their TD peers, children with ASD did not evidence posterior alpha desynchronization to behaviorally-relevant targets. Additionally, reduced target-related desynchronization and poorer target detection were associated with increased ASD symptomatology. TD children also showed behavioral and electrophysiological evidence of contingent attention capture, whereas children with ASD showed no behavioral facilitation or alpha desynchronization to distractors that shared a task-relevant feature. Lastly, children with ASD had significantly decreased resting alpha power, and for all participants increased resting alpha levels were associated with greater task-related alpha desynchronization. These results suggest that in ASD under-responsivity and impairments in orienting to salient events within their environment are reflected by atypical EEG oscillatory neurodynamics, which may signify atypical arousal levels and/or an excitatory/inhibitory imbalance.

Characterization of toxin III of the scorpion Leiurus quinquestriatus quinquestriatus: a new type of alpha-toxin highly toxic both to mammals and insects.

PubMed

Kopeyan, C; Mansuelle, P; Martin-Eauclaire, M F; Rochat, H; Miranda, F

1993-01-01

The primary structure of toxin III of Leiurus quinquestriatus quinquestriatus (Lqq III) was elucidated by automatic Edman degradation of the reduced and S-carboxymethylated protein and derived tryptic peptides. Like other scorpion toxins that are active on sodium channels, Lqq III, consisting of 64 amino acids, is a 7 kDa single-chain polypeptide crosslinked by four disulfide bridges. It belongs to the alpha-toxin group, as judged by competition experiments with 125I AaH II for binding to rat brain synaptosomes (K0.5 = 7 x 10(-7) M). Lqq III is the first alpha-toxin to be characterized that is highly toxic to mice [LD50 = 50 micrograms (7.1 nmol)/kg body wt], by subcutaneous injection, insects Blatella germanica [LD50 = 60 ng (8.5 pmol)/g body wt.] and Musca domestica [LD50 = 120 ng (17 pmol)/g body wt]. When tested via the intracerebroventricular route, the toxicity for mice [55 micrograms (8 nmol)/kg] was of the same order as that found by subcutaneous injection, indicating that Lqq III has a higher affinity for peripheral sodium channels that for those of the central nervous system. There are three differences between the sequences of Lqq III and Lqh alpha IT, an alpha-toxin isolated from the venom of Leiurus quinquestriatus hebraeus. These substitutions are found at positions 20, 24, and 64 (Ser-->Ala,Asp-->Glu and His-->Arg, respectively). Surprisingly Lqh alpha IT is only weakly active in mice [LD50 = 5 mg (0.7 mumol)/kg], while in insects its toxicity is similar to that of Lqq III [140 ng (20 pmol)/g body wt blowfly larvae]. These observations are relevant to the definition of scorpion toxin structure-activity relationships.

An experimental study on amelioration of dyslipidemia-induced atherosclesis by Clematichinenoside through regulating Peroxisome proliferator-activated receptor-α mediated apolipoprotein A-I, A-II and C-III.

PubMed

Liu, Chao; Guo, Qianqian; Lu, Mengchen; Li, Yunman

2015-08-15

Prevention or amelioration the prevalence of atherosclerosis has been an effective strategy in the management of cardiovascular diseases. The aim of the study was to scrutinize the effect of Clematichinenoside (AR) on dyslipidemia-induced atherosclerosis and explore its capability on expression of Peroxisome proliferator-activated receptor-α (PPAR-alpha), apolipoprotein A-I (APOA1) and A-II (APOA2), and suppression of apolipoprotein C-III (APOC3) genes and proteins. In the present study, we investigated atherosclerosis effect of AR using a combination of high-fat diet and balloon injury model in rabbits. The levels of biochemical indicators were evaluated in plasma, liver and HepG2 cells using immunoassay technology. In order to expose the underlying mechanism, we evaluated the regulation of PPAR-alpha, APOA1, APOA2 and APOC3 expressions by AR, and we further evaluated the interactions between them after transfection with shRNA (shPPAR-alpha) and, the action of PPAR-alpha in HepG2 cells. We could find that AR markedly promoted the PPAR-alpha transfer from cytoplasm to nucleus which resulted in the alteration of APOA1, APOA2 and APOC3 expressions in HepG2 cells. Moreover, AR significantly reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) levels, and elevated high-density lipoprotein cholesterol (HDL-C) level, which play an important role in dyslipidemia-induced atherosclerosis. In conclusion, AR ameliorated atherosclerosis via the regulation of hepatic lipid metabolism, and AR also contributed to the activation of PPAR-alpha, APOA1, APOA2 and APOC3. Therefore, AR could be a potential therapeutic agent in the treatment of atherosclerosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Regulation of the oncodevelopmental expression of type 1 chain ABH and Lewis(b) blood group antigens in human colon by alpha-2-L-fucosylation.

PubMed Central

Orntoft, T F; Greenwell, P; Clausen, H; Watkins, W M

1991-01-01

Blood group antigen expression in the distal human colon is related to the development of the organ and is modified by malignant transformation. To elucidate the biochemical basis for these changes, we have (a) analysed the activity of glycosyltransferases coded for by the H, Se, Le, X, and A genes, in tissue biopsy specimens from normal and malignant proximal and distal human colon; (b) characterised the glycosphingolipids expressed in the various regions of normal and malignant colon by immunostaining of high performance thin layer chromatography plates; and (c) located the antigens on tissue sections from the same subjects by immunohistochemistry. In both secretors and non-secretors we found a significantly higher activity of alpha-2-L-fucosyltransferases in carcinomatous rectal tissue than in tissue from normal subjects, whereas the other transferase activities studied showed no significant differences. The acceptor substrate specificity suggested that both the Se and the H gene dependent alpha-2-L-fucosyltransferases are increased in carcinomas. In non-malignant tissue the only enzyme which showed appreciably higher activity in caecum than in rectum was alpha-2-L-fucosyltransferase. Immunochemistry and immunohistochemistry showed alpha-2-L-fucosylated structures in normal caecum from secretors and in tumour tissue from both secretors and non-secretors. We conclude that the alpha-2-L-fucosyltransferases control the expression of ABH, and Lewis(b) structures in normal and malignant colon. Images Figure 4 PMID:1826491

rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

PubMed Central

Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

2013-01-01

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

Effect of TNF{alpha} on activities of different promoters of human apolipoprotein A-I gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orlov, Sergey V., E-mail: serge@iem.sp.ru; Department of Embryology, St. Petersburg State University, 199034 St. Petersburg; Mogilenko, Denis A.

2010-07-23

Research highlights: {yields} TNF{alpha} stimulates the distal alternative promoter of human apoA-I gene. {yields} TNF{alpha} acts by weakening of promoter competition within apoA-I gene (promoter switching). {yields} MEK1/2 and nuclear receptors PPAR{alpha} and LXRs take part in apoA-I promoter switching. -- Abstract: Human apolipoprotein A-I (ApoA-I) is a major structural and functional protein component of high-density lipoproteins. The expression of the apolipoprotein A-I gene (apoA-I) in hepatocytes is repressed by pro-inflammatory cytokines such as IL-1{beta} and TNF{alpha}. Recently, two novel additional (alternative) promoters for human apoA-I gene have been identified. Nothing is known about the role of alternative promoters inmore » TNF{alpha}-mediated downregulation of apoA-I gene. In this article we report for the first time about the different effects of TNF{alpha} on two alternative promoters of human apoA-I gene. Stimulation of HepG2 cells by TNF{alpha} leads to activation of the distal alternative apoA-I promoter and downregulation of the proximal alternative and the canonical apoA-I promoters. This effect is mediated by weakening of the promoter competition within human apoA-I 5'-regulatory region (apoA-I promoter switching) in the cells treated by TNF{alpha}. The MEK1/2-ERK1/2 cascade and nuclear receptors PPAR{alpha} and LXRs are important for TNF{alpha}-mediated apoA-I promoter switching.« less

Salacia oblonga root improves postprandial hyperlipidemia and hepatic steatosis in Zucker diabetic fatty rats: Activation of PPAR-{alpha}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsun-Wei Huang, Tom; Peng Gang; Qian Li, George

Salacia oblonga (SO) root is an Ayurvedic medicine with anti-diabetic and anti-obese properties. Peroxisome proliferator-activated receptor (PPAR)-{alpha}, a nuclear receptor, plays an important role in maintaining the homeostasis of lipid metabolism. Here, we demonstrate that chronic oral administration of the water extract from the root of SO to Zucker diabetic fatty (ZDF) rats, a genetic model of type 2 diabetes and obesity, lowered plasma triglyceride and total cholesterol (TC) levels, increased plasma high-density lipoprotein levels and reduced the liver contents of triglyceride, non-esterified fatty acids (NEFA) and the ratio of fatty droplets to total tissue. By contrast, the extract hadmore » no effect on plasma triglyceride and TC levels in fasted ZDF rats. After olive oil administration to ZDF the extract also inhibited the increase in plasma triglyceride levels. These results suggest that SO extract improves postprandial hyperlipidemia and hepatic steatosis in ZDF rats. Additionally, SO treatment enhanced hepatic expression of PPAR-{alpha} mRNA and protein, and carnitine palmitoyltransferase-1 and acyl-CoA oxidase mRNAs in ZDF rats. In vitro, SO extract and its main component mangiferin activated PPAR-{alpha} luciferase activity in human embryonic kidney 293 cells and lipoprotein lipase mRNA expression and enzyme activity in THP-1 differentiated macrophages; these effects were completely suppressed by a selective PPAR-{alpha} antagonist MK-886. The findings from both in vivo and in vitro suggest that SO extract functions as a PPAR-{alpha} activator, providing a potential mechanism for improvement of postprandial hyperlipidemia and hepatic steatosis in diabetes and obesity.« less

Alpha reactivity to first names differs in subjects with high and low dream recall frequency

PubMed Central

Ruby, Perrine; Blochet, Camille; Eichenlaub, Jean-Baptiste; Bertrand, Olivier; Morlet, Dominique; Bidet-Caulet, Aurélie

2013-01-01

Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG). We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names) during wakefulness and sleep (intensity, 50 dB above the subject's hearing level). Subjects were selected as High-recallers (HR, DRF = 4.42 ± 0.25 SEM, dream recalls per week) and Low-recallers (LR, DRF = 0.25 ± 0.02) using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects' quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000–1200 ms) during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs. 14 ± 4 min). As a whole our results support the hypothesis of neurophysiological trait differences in high and low-recallers. PMID:23966960

Identification of a novel cyclosporin-sensitive element in the human tumor necrosis factor alpha gene promoter

PubMed Central

1993-01-01

Tumor necrosis factor alpha (TNF-alpha), a cytokine with pleiotropic biological effects, is produced by a variety of cell types in response to induction by diverse stimuli. In this paper, TNF-alpha mRNA is shown to be highly induced in a murine T cell clone by stimulation with T cell receptor (TCR) ligands or by calcium ionophores alone. Induction is rapid, does not require de novo protein synthesis, and is completely blocked by the immunosuppressant cyclosporin A (CsA). We have identified a human TNF-alpha promoter element, kappa 3, which plays a key role in the calcium-mediated inducibility and CsA sensitivity of the gene. In electrophoretic mobility shift assays, an oligonucleotide containing kappa 3 forms two DNA protein complexes with proteins that are present in extracts from unstimulated T cells. These complexes appear in nuclear extracts only after T cell stimulation. Induction of the inducible nuclear complexes is rapid, independent of protein synthesis, and blocked by CsA, and thus, exactly parallels the induction of TNF-alpha mRNA by TCR ligands or by calcium ionophore. Our studies indicate that the kappa 3 binding factor resembles the preexisting component of nuclear factor of activated T cells. Thus, the TNF-alpha gene is an immediate early gene in activated T cells and provides a new model system in which to study CsA-sensitive gene induction in activated T cells. PMID:8376940

Effect of conformational mobility and hydrogen-bonding interactions on the selectivity of some guanidinoaryl-substituted mechanism-based inhibitors of trypsin-like serine proteases.

PubMed

Rai, R; Katzenellenbogen, J A

1992-11-13

Previously, we have reported that some guanidino-substituted alpha- and beta-aryl enol lactones I and II behaved as selective, mechanism-based inhibitors of some trypsin-like proteases (Rai, R.; Katzenellenbogen, J.A. J. Med. Chem., submitted). In this study, we describe the synthesis and kinetic evaluation of some related, guanidino-substituted enol lactones having greater conformational mobility and affording additional hydrogen-bonding sites at the active site. The alpha-aryl-substituted lactones 1 and 2, which have greater conformational mobility in the guanidinoaryl linkage than I, selectively inhibited the trypsin-like enzymes, and they were relatively poor inactivators of alpha-chymotrypsin and human neutrophil elastase (HNE). The iodo enol lactone 2 permanently inactivated trypsin, urokinase, tissue plasminogen activator, and plasmin, showing exceptionally high specificity in its interaction with trypsin and urokinase. The selectivity pattern exhibited by the closely related, conformationally less mobile alpha-aryl-substituted iodo lactone Ib, which was previously shown to be a selective suicide substrate of urokinase and plasmin, provides an interesting comparison. The alpha-benzamido-substituted lactones 3 and 4, which afford an additional site for active-site hydrogen bonding, were found to be very potent alternate substrate inhibitors of trypsin and urokinase. In addition, the iodo lactone 4 permanently inactivated alpha-chymotrypsin. The importance of secondary interactions in increasing the specificities in the case of alpha-chymotrypsin is discussed.

The activity of hydrolases of larval stages of Anisakis simplex (Nematoda).

PubMed

Lopieńska-Biernat, Elzbieta; Zółtowska, Krystyna; Rokicki, Jerzy

2004-01-01

Activity of hydrolases during the third and fourth larval stage of Anisakis simplex was identified by applying the API ZYM test method. In A. simplex larvae the activity of phosphatases was high, particularly that of acid phosphatase (40 nmol/mg(-1)). Among esterases lack of activity of lipase (C14) is worth noticing while the activity of esterases (C4) and (C8) was high. The activity of those later two enzymes was higher in L3 larvae than in L4 larvae. The highest activity in the subclass of glucosidases was recorded for beta-fucosidase and N-acetyl-beta-glucosaminidase. A higher activity in L3 larvae than in L4 larvae was recorded for: beta-glucuronidase and N-acetyl-beta-glucosaminidase (2-fold) and beta-fucosidase (3-fold). Differently the activity of beta-galactosidase and beta-glucosidase was higher in L4 larvae than in L3 larvae. The tests did not show activity of alpha-galactosidase, beta-glucosidase and alpha-mannosidase on both larval forms.

Brain-computer interface design using alpha wave

NASA Astrophysics Data System (ADS)

Zhao, Hai-bin; Wang, Hong; Liu, Chong; Li, Chun-sheng

2010-01-01

A brain-computer interface (BCI) is a novel communication system that translates brain activity into commands for a computer or other electronic devices. BCI system based on non-invasive scalp electroencephalogram (EEG) has become a hot research area in recent years. BCI technology can help improve the quality of life and restore function for people with severe motor disabilities. In this study, we design a real-time asynchronous BCI system using Alpha wave. The basic theory of this BCI system is alpha wave-block phenomenon. Alpha wave is the most prominent wave in the whole realm of brain activity. This system includes data acquisition, feature selection and classification. The subject can use this system easily and freely choose anyone of four commands with only short-time training. The results of the experiment show that this BCI system has high classification accuracy, and has potential application for clinical engineering and is valuable for further research.

Purification and properties of an alpha-amylase protein-inhibitor from Arachis hypogaea seeds.

PubMed

Irshad, M; Sharma, C B

1981-06-15

A protein showing highly specific inhibitory activity towards hog pancreatic and human salivary alpha-amylases (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1), but not towards plant and bacterial alpha-amylases, has been purified 197-fold from an aqueous extract of peanut cotyledons using heat treatment, (NH4)2SO4 precipitation and ion-exchange chromatography on DEAE- and CM-cellulose. The purified inhibitor was homogeneous by polyacrylamide gel electrophoresis. Its molecular weight, as determined by Sephadex G-100 gel-filtration, and its electrophoretic mobility at pH 8 relative to bromophenol blue, were 25 000 and 0.14, respectively. The inhibitory activity was relatively resistant to thermal treatment and markedly increased when the inhibitor was preincubated with the enzyme before the addition of starch. Further, the inhibition was found to be pH-dependent and non-competitive in nature.

Resolution of the diadenosine 5',5"'-P1,P4-tetraphosphate binding subunit from a multiprotein form of HeLa cell DNA polymerase alpha.

PubMed Central

Baril, E; Bonin, P; Burstein, D; Mara, K; Zamecnik, P

1983-01-01

A diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) binding subunit has been resolved from a high molecular weight (640,000) multiprotein form of DNA polymerase alpha [deoxynucleoside triphosphate:DNA nucleotidyltransferase (DNA-directed), EC 2.7.7.7] from HeLa cells [DNA polymerase alpha 2 of Lamothe, P., Baril, B., Chi, A., Lee, L. & Baril, E. (1981) Proc. Natl. Acad. Sci. USA 78, 4723-4727]. The Ap4A binding activity copurifies with the DNA polymerizing activity during the course of purification. Hydrophobic chromatography on butylagarose resolves the Ap4A binding activity from the DNA polymerase. The Ap4A binding activity is protein in nature since the binding of Ap4A is abolished by treatment of the isolated binding activity with proteinase K but is insensitive to treatment with DNase or RNase. The molecular weight of the Ap4A binding protein, as determined by polyacrylamide gel electrophoresis under nondenaturing conditions or by NaDodSO4/polyacrylamide gel electrophoresis after photoaffinity labeling of the protein with [32P]Ap4A is 92,000 or 47,000. The binding activity of this protein is highly specific for Ap4A. Images PMID:6576366

Alpha-Driven MHD and MHD-Induced Alpha Loss in TFTR DT Experiments

NASA Astrophysics Data System (ADS)

Chang, Zuoyang

1996-11-01

Theoretical calculation and numerical simulation indicate that there can be interesting interactions between alpha particles and MHD activity which can adversely affect the performance of a tokamak reactor (e.g., ITER). These interactions include alpha-driven MHD, like the toroidicity-induced-Alfven-eigenmode (TAE) and MHD induced alpha particle losses or redistribution. Both phenomena have been observed in recent TFTR DT experiments. Weak alpha-driven TAE activity was observed in a NBI-heated DT experiment characterized by high q0 ( >= 2) and low core magnetic shear. The TAE mode appears at ~30-100 ms after the neutral beam turning off approximately as predicted by theory. The mode has an amplitude measured by magnetic coils at the edge tildeB_p ~1 mG, frequency ~150-190 kHz and toroidal mode number ~2-3. It lasts only ~ 30-70 ms and has been seen only in DT discharges with fusion power level about 1.5-2.0 MW. Numerical calculation using NOVA-K code shows that this type of plasma has a big TAE gap. The calculated TAE frequency and mode number are close to the observation. (2) KBM-induced alpha particle loss^1. In some high-β, high fusion power DT experiments, enhanced alpha particle losses were observed to be correlated to the high frequency MHD modes with f ~100-200 kHz (the TAE frequency would be two-times higher) and n ~5-10. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Alpha loss increases by 30-100% during the modes. Particle orbit simulations show the added loss results from wave-particle resonance. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes (KBM) driven primarily by strong local pressure gradients. ----------------- ^1Z. Chang, et al, Phys. Rev. Lett. 76 (1996) 1071. In collaberation with R. Nazikian, G.-Y. Fu, S. Batha, R. Budny, L. Chen, D. Darrow, E. Fredrickson, R. Majeski, D. Mansfield, K. McGuire, G. Rewoldt, G. Taylor, R. White, K.-L. Wong and S. Zweben, Princeton Plasma Physics Lab. Department of Physics, University of California, Irvine, CA 92717 ^*Work supported by the U.S. Department of Energy DoE Contract No. DE-AC02-76CH03073.

Proactive vs. reactive car driving: EEG evidence for different driving strategies of older drivers

PubMed Central

Wascher, Edmund; Getzmann, Stephan

2018-01-01

Aging is associated with a large heterogeneity in the extent of age-related changes in sensory, motor, and cognitive functions. All these functions can influence the performance in complex tasks like car driving. The present study aims to identify potential differences in underlying cognitive processes that may explain inter-individual variability in driving performance. Younger and older participants performed a one-hour monotonous driving task in a driving simulator under varying crosswind conditions, while behavioral and electrophysiological data were recorded. Overall, younger and older drivers showed comparable driving performance (lane keeping). However, there was a large difference in driving lane variability within the older group. Dividing the older group in two subgroups with low vs. high driving lane variability revealed differences between the two groups in electrophysiological correlates of mental workload, consumption of mental resources, and activation and sustaining of attention: Older drivers with high driving lane variability showed higher frontal Alpha and Theta activity than older drivers with low driving lane variability and—with increasing crosswind—a more pronounced decrease in Beta activity. These results suggest differences in driving strategies of older and younger drivers, with the older drivers using either a rather proactive and alert driving strategy (indicated by low driving lane variability and lower Alpha and Beta activity), or a rather reactive strategy (indicated by high driving lane variability and higher Alpha activity). PMID:29352314

Mycophenolic acid induces ATP-binding cassette transporter A1 (ABCA1) expression through the PPAR{gamma}-LXR{alpha}-ABCA1 pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yanni; Lai, Fangfang; Xu, Yang

2011-11-04

Highlights: Black-Right-Pointing-Pointer Using an ABCA1p-LUC HepG2 cell line, we found that MPA upregulated ABCA1 expression. Black-Right-Pointing-Pointer MPA induced ABCA1 and LXR{alpha} protein expression in HepG2 cells. Black-Right-Pointing-Pointer PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. Black-Right-Pointing-Pointer The effect of MPA upregulating ABCA1 was due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 pathway. -- Abstract: ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I and plays an important role in atherosclerosis. In a previous study, we developed a high-throughput screening method using an ABCA1p-LUC HepG2 cell line to find upregulators of ABCA1.more » Using this method in the present study, we found that mycophenolic acid (MPA) upregulated ABCA1 expression (EC50 = 0.09 {mu}M). MPA upregulation of ABCA1 expression was confirmed by real-time quantitative reverse transcription-PCR and Western blot analysis in HepG2 cells. Previous work has indicated that MPA is a potent agonist of peroxisome proliferator-activated receptor gamma (PPAR{gamma}; EC50 = 5.2-9.3 {mu}M). Liver X receptor {alpha} (LXR{alpha}) is a target gene of PPAR{gamma} and may directly regulate ABCA1 expression. Western blot analysis showed that MPA induced LXR{alpha} protein expression in HepG2 cells. Addition of PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. These data suggest that MPA increased ABCA1 expression mainly through activation of PPAR{gamma}. Thus, the effects of MPA on upregulation of ABCA1 expression were due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 signaling pathway. This is the first report that the antiatherosclerosis activity of MPA is due to this mechanism.« less

Comparison of alpha-amylase, alpha-glucosidase and lipase inhibition activity of the phenolic substances in two black legumes of different genera

USDA-ARS?s Scientific Manuscript database

Antioxidant-rich plant foods can inhibit starch and lipid digestions that are relevant to diabetes management and also may be extracted and concentrated for use as natural food preservatives against lipid oxidation and enzymatic breakdown of starch. Two high-antioxidant black legumes black soybean...

Structural modification of serum vitamin D3-binding protein and immunosuppression in AIDS patients.

PubMed

Yamamoto, N; Naraparaju, V R; Srinivasula, S M

1995-11-01

A serum glycoprotein, vitamin D3-binding protein (Gc protein), can be converted by beta-galactosidase of stimulated B lymphocytes and sialidase of T lymphocytes to a potent macrophage-activating factor (MAF), a protein with N-acetylgalactosamine as the remaining sugar moiety. Thus, Gc protein is a precursor for MAF. Treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generates an extremely high-titered MAF (GcMAF). When peripheral blood monocytes/macrophages of 46 HIV-infected patients were treated with GcMAF (100 pg/ml), the monocytes/macrophages of all patients were efficiently activated. However, the MAF precursor activity of plasma Gc protein was low in 16 (35%) of of these patients. Loss of the MAF precursor activity appeared to be due to deglycosylation of plasma Gc protein by alpha-N-acetylgalactosaminidase found in the patient blood stream. Levels of plasma alpha-N-acetylgalactosaminidase activity in individual patients had an inverse correlation with the MAF precursor activity of their plasma Gc protein. Thus, precursor activity of Gc protein and alpha-N-acetylgalactosaminidase activity in patient blood can serve as diagnostic and prognostic indices.

Modelling and Dosimetry for Alpha-Particle Therapy

PubMed Central

Sgouros, George; Hobbs, Robert F.; Song, Hong

2015-01-01

As a consequence of the high potency and short range of alpha-particles, radiopharmaceutical therapy with alpha-particle emitting radionuclides is a promising treatment approach that is under active pre-clinical and clinical investigation. To understand and predict the biological effects of alpha-particle radiopharmaceuticals, dosimetry is required at the micro or multi-cellular scale level. At such a scale, highly non-uniform irradiation of the target volume may be expected and the utility of a single absorbed dose value to predict biological effects comes into question. It is not currently possible to measure the pharmacokinetic input required for micro scale dosimetry in humans. Accordingly, pre-clinical studies are required to provide the pharmacokinetic data for dosimetry calculations. The translation of animal data to the human requires a pharmacokinetic model that links macro- and micro-scale pharmacokinetics thereby enabling the extrapolation of micro-scale kinetics from macroscopic measurements. These considerations along with a discussion of the appropriate physical quantity and related units for alpha-particle radiopharmaceutical therapy are examined in this review. PMID:22201712

Alpha: A real-time decentralized operating system for mission-oriented system integration and operation

NASA Technical Reports Server (NTRS)

Jensen, E. Douglas

1988-01-01

Alpha is a new kind of operating system that is unique in two highly significant ways. First, it is decentralized transparently providing reliable resource management across physically dispersed nodes, so that distributed applications programming can be done largely as though it were centralized. And second, it provides comprehensive, high technology support for real-time system integration and operation, an application area which consists predominately of aperiodic activities having critical time constraints such as deadlines. Alpha is extremely adaptable so that it can be easily optimized for a wide range of problem-specific functionality, performance, and cost. Alpha is the first systems effort of the Archons Project, and the prototype was created at Carnegie-Mellon University directly on modified Sun multiprocessor workstation hardware. It has been demonstrated with a real-time C(sup 2) application. Continuing research is leading to a series of enhanced follow-ons to Alpha; these are portable but initially hosted on Concurrent's MASSCOMP line of multiprocessor products.

Radiation-induced cognitive dysfunction and cerebellar oxidative stress in mice: protective effect of alpha-lipoic acid.

PubMed

Manda, Kailash; Ueno, Megumi; Moritake, Takashi; Anzai, Kazunori

2007-02-12

Reactive oxygen species are implicated in neurodegeneration and cognitive disorders due to higher vulnerability of neuronal tissues. The cerebellum is recently reported to be involved in cognitive function. Therefore, present study aimed at investigating the role alpha-lipoic acid against radiation-induced oxidative stress and antioxidant status in cerebellum and its correlation with cognitive dysfunction. We observed spontaneous motor activities and spatial memory task of mice using pyroelectric infrared sensor and programmed video tracking system, respectively. Whole body X-irradiation (6 Gy) of mice substantially impaired the reference memory and motor activities of mice. However, acute intraperitoneal treatment of mice with alpha-lipoic acid prior to irradiation significantly attenuated such cognitive dysfunction. Alpha-lipoic acid pretreatment exerted a very high magnitude of protection against radiation-induced augmentation of protein carbonyls and thiobarbituric acid reactive substance (TBARS) in mice cerebellum. Further, radiation-induced deficit of total, nonprotein and protein-bound sulfhydryl (T-SH, NP-SH, PB-SH) contents of cerebellum and plasma ferric reducing power (FRAP) was also inhibited by alpha-lipoic acid pre-treatment. Moreover, alpha-lipoic acid treated mice showed an intact cytoarchitecture of cerebellum, higher counts of intact Purkinje cells and granular cells in comparison to untreated irradiated mice. Results clearly indicate that alpha-lipoic acid is potent neuroprotective antioxidant.

Characterization of the primary interaction between the mating pheromone, alpha-factor, and its receptor in Saccharomyces cerevisiae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raths, S.K.

1987-01-01

Alpha-factor is a peptide of thirteen amino acids which is required for mating between the haploid mating types, a and ..cap alpha.., in Saccharomyces cerevisiae. An analogue of alpha-factor, DHP/sup 8/ DHP/sup 11/ Nle/sup 12/ tridecapeptide, was catalytically reduced in the presence of /sup 3/H gas for production of a radiolabeled pheromone suitable for use in binding studies. Incorporation of tritium resulted in /sup 3/H-alpha-factor with high specific activity, purity, biological activity and long shelf-life. Binding studies revealed that alpha-factor interacts with its receptor via a simple, reversible process which obeys the law of mass action. Association and dissociation kineticsmore » indicate values of 2.92 x 10/sup 6/ M/sup /minus/1/ min/sup -1/ for k/sub 1/ and between 4 and 7 x 10/sup /minus/2/ min/sup /minus/1/ for k/sub /minus/1/. Saturation binding studies reveal an equilibrium dissociation constant equal to 2.32 x 10/sup /minus/8/ M which approximate the kinetically-derived K/sub D/ of 2.12 x 10/sup /minus/8/ M. Scatchard and Hill analyses as well as dissociation behavior in the presence of excess unlabeled ligand indicate alpha-factor interacts with a homogeneous population of binding sites which do not interact and exhibit one affinity for the alpha-factor pheromone.« less

Copernicus Measurement of the Jovian Lyman-alpha emission and its aeronomical significance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atreya, S.K.; Festou, M.C.; Donahue, T.M.

1982-11-01

Observations of Jupiter made with the high-resolution ultraviolet spectrometer of the Orbiting Astronomical Observatory Copernicus in 1980 April and May yield the intensity of the Jovian Lyman-alpha emission to be 7 +- 2.5 kR. These measurements indicate that the Lyman-alpha intensity has decreased by about a factor of 2 from the time of the Voyager ultraviolet spectrometer measurements, nearly a year earlier. The Copernicus measurements, when combined with all other previous measurements of the Jovian Lyman-alpha emission, point to an unusually high column abundance of hydrogen atoms above the methane homopause at the Voyager epoch. Since the auroral charged particlemore » bombardment of moelcular hydrogen is expected to contribute significantly to the global population of the hydrogen atoms, it is suggested that at the time of the Voyager Jupiter encounter, unusually high auroral activity existed, and it was perhaps linked to the high concentration of the Io plasma torus. It should be pointed out that the temporal variation of the Saturn Lyman-alpha emission, when contrasted with the Jovian data, reveals that the auroral processes are not nearly as important in determining the Saturn Lyman-alpha intensity in the nonauroral region. The latest Copernicus observations also suggest an increase in the Jovian homopause value of the eddy mixing coefficient by about a factor of 5--10 since the Voyager epoch.« less

Characterization of adrenergic receptors of the cat iris and nictitating membrane.

PubMed

Koss, M C; Hey, J A; Gherezghiher, T

1990-01-01

Graded pupillary dilations and nictitating membrane (NM) contractions were elicited in anesthetized cats by electrical stimulation of the preganglionic sympathetic nerve or by i.a. administration of norepinephrine (NE) or phenylephrine into the carotid artery. Pupil and NM responses were measured simultaneously from the same side. Alpha-adrenoceptor antagonists were administered intravenously. All of the alpha 1-adrenoceptor blockers tested produced a dose-related reduction of NM responses to both neural and agonist activation; the potency rank order was prazosin greater than WB-4101 greater than phentolamine greater than phenoxybenzamine (PBZ). In contrast, responses of the iris dilator were antagonized only by WB-4101 and PBZ. The iris was almost totally refractory to doses of prazosin and phentolamine that blocked NM responses by more than 75% of control. Neither alpha 2- nor beta-adrenoceptor antagonism produced significant inhibition of neural or agonist activation of either organ (with the exception of high doses of yohimbine on the NM). These results suggest that the postjunctional adrenoceptors of the NM are exclusively of the alpha 1-adrenoceptor subtype. In contrast, those of the iris dilator muscle cannot be easily classified pharmacologically as either alpha 1 or alpha 2-adrenoceptors.

Determination of carotenoids in foods by high-performance liquid chromatography.

PubMed

Abdel-Kader, Z M

1991-01-01

The mean values of alpha and beta-carotene of 10 fruits and vegetables from supermarkets in Cairo and Alexandria have been determined using HPLC method, and the average vitamin A activities (in retinol equivalents) calculated. Carrots, spinach and sweet potatoes were the best sources of provitamin A activity. Beta-carotene was the more prevalent carotenoid compared with alpha-carotene. An analysis of variance including all foods investigated demonstrated that there were no significant differences among either locations or times of analysis. There was no difference between the analysed values of vitamin A activity and the USDA Handbook No. 8 values.

Two novel, putatively cell wall-associated and glycosylphosphatidylinositol-anchored alpha-glucanotransferase enzymes of Aspergillus niger.

PubMed

van der Kaaij, R M; Yuan, X-L; Franken, A; Ram, A F J; Punt, P J; van der Maarel, M J E C; Dijkhuizen, L

2007-07-01

In the genome sequence of Aspergillus niger CBS 513.88, three genes were identified with high similarity to fungal alpha-amylases. The protein sequences derived from these genes were different in two ways from all described fungal alpha-amylases: they were predicted to be glycosylphosphatidylinositol anchored, and some highly conserved amino acids of enzymes in the alpha-amylase family were absent. We expressed two of these enzymes in a suitable A. niger strain and characterized the purified proteins. Both enzymes showed transglycosylation activity on donor substrates with alpha-(1,4)-glycosidic bonds and at least five anhydroglucose units. The enzymes, designated AgtA and AgtB, produced new alpha-(1,4)-glycosidic bonds and therefore belong to the group of the 4-alpha-glucanotransferases (EC 2.4.1.25). Their reaction products reached a degree of polymerization of at least 30. Maltose and larger maltooligosaccharides were the most efficient acceptor substrates, although AgtA also used small nigerooligosaccharides containing alpha-(1,3)-glycosidic bonds as acceptor substrate. An agtA knockout of A. niger showed an increased susceptibility towards the cell wall-disrupting compound calcofluor white, indicating a cell wall integrity defect in this strain. Homologues of AgtA and AgtB are present in other fungal species with alpha-glucans in their cell walls, but not in yeast species lacking cell wall alpha-glucan. Possible roles for these enzymes in the synthesis and/or maintenance of the fungal cell wall are discussed.

Metabolism of. cap alpha. -C/sup 14/-histidine in the intact rat. II. Radioactive excretion products in urine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, G.; Wu, P.H.L.; Heck, W.W.

1956-09-01

The normal metabolic pathways in the intact rat was investigated via the radioactive urinary excretion products following administration of a physiological dose of a radioactive compound such as ..cap alpha..-C/sup 14/-DL-histidine. The major metabolites, except one, excreted in the urine 5 hours after administration of ..cap alpha..-C/sup 14/-DL-histidine were isolated and identified. Glutamic acid and urocanic acids had simlar and low activities, whereas carboxyl-labeled imidazoacetic acid was found to be the principal metabolite with a high level of activity. It was concluded that the main end-product of the catabolism of DL-histidine is imidazoleacetic acid probably formed through imidazolepyruvic acid.

Pertussis toxin-catalyzed ADP-ribosylation of a G protein in mouse oocytes, eggs, and preimplantation embryos: Developmental changes and possible functional roles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, J.; Schultz, R.M.

1990-06-01

G proteins, which in many somatic cells serve as mediators of signal transduction, were identified in preimplantation mouse embryos by their capacity to undergo pertussis toxin-catalyzed ADP-ribosylation. Two pertussis toxin (PT) substrates with Mr = 38,000 and 39,000 (alpha 38 and alpha 39) are present in approximately equal amounts. Relative to the amount in freshly isolated germinal vesicle (GV)-intact oocytes, the amount of PT-catalyzed ADP-ribosylation of alpha 38-39 falls during oocyte maturation, rises between the one- and two-cell stages, falls by the eight-cell and morula stages, and increases again by the blastocyst stage. The decrease in PT-catalyzed ADP-ribosylation of alphamore » 38-39 that occurs during oocyte maturation, however, does not require germinal vesicle breakdown (GVBD), since inhibiting GVBD with 3-isobutyl-1-methyl xanthine (IBMX) does not prevent the decrease in the extent of PT-catalyzed ADP-ribosylation. A biologically active phorbol diester (12-O-tetradecanoyl phorbol 13-acetate), but not an inactive one (4 alpha-phorbol 12,13-didecanoate, 4 alpha-PDD), totally inhibits the increase in PT-catalyzed ADP-ribosylation of alpha 38-39 that occurs between the one- and two-cell stage; TPA inhibits cleavage, but not transcriptional activation, which occurs in the two-cell embryo. In contrast, cytochalasin D, genistein, or aphidicolin, each of which inhibits cleavage of one-cell embryos, or alpha-amanitin or H8, each of which inhibits transcriptional activation but not cleavage of one-cell embryos, have little or inhibitory effects on the increase in PT-catalyzed ADP-ribosylation of alpha 38-39. Results of immunoblotting experiments using an antibody that is highly specific for alpha il-3 reveal the presence of a cross-reactive species of Mr = 38,000 (alpha 38) in the GV-intact oocyte, metaphase II-arrested egg, and one-, two-cell embryos.« less

Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiba, Takuya, E-mail: takuya@nagasaki-u.ac.jp; Tsuchiya, Tomoshi; Komatsu, Toshimitsu

2010-10-15

Research highlights: {yields} We identified four sequence motifs lying upstream of putative pro-longevity genes. {yields} One of these motifs binds to HNF-4{alpha}. {yields} HNF-4{alpha}/PGC-1{alpha} could up-regulate the transcription of a reporter gene linked to this motif. {yields} The reporter system described here could be used to screen candidate anti-aging molecules. -- Abstract: Suppression of the growth hormone/insulin-like growth factor-I pathway in Ames dwarf (DF) mice, and caloric restriction (CR) in normal mice extends lifespan and delays the onset of age-related disorders. In combination, these interventions have an additive effect on lifespan in Ames DF mice. Therefore, common signaling pathways regulatedmore » by DF and CR could have additive effects on longevity. In this study, we tried to identity the signaling mechanism and develop a system to assess pro-longevity status in cells and mice. We previously identified genes up-regulated in the liver of DF and CR mice by DNA microarray analysis. Motif analysis of the upstream sequences of those genes revealed four major consensus sequence motifs, which have been named dwarfism and calorie restriction-responsive elements (DFCR-REs). One of the synthesized sequences bound to hepatocyte nuclear factor-4{alpha} (HNF-4{alpha}), an important transcription factor involved in liver metabolism. Furthermore, using this sequence information, we developed a highly sensitive bioassay to identify chemicals mimicking the anti-aging effects of CR. When the reporter construct, containing an element upstream of a secreted alkaline phosphatase (SEAP) gene, was co-transfected with HNF-4{alpha} and its regulator peroxisome proliferator-activated receptor (PPAR) {gamma} coactivator-1{alpha} (PGC-1{alpha}), SEAP activity was increased compared with untransfected controls. Moreover, transient transgenic mice established using this construct showed increased SEAP activity in CR mice compared with ad libitum-fed mice. These data suggest that because of its rapidity, ease of use, and specificity, our bioassay will be more useful than the systems currently employed to screen for CR mimetics, which mimic the beneficial effects of CR. Our system will be particularly useful for high-throughput screening of natural and synthetic candidate molecules.« less

Urokinase plasminogen activator mRNA is induced by IL-1alpha and TNF-alpha in in vitro acantholysis.

PubMed

Feliciani, Claudio; Toto, Paola; Wang, Binghe; Sauder, Daniel N; Amerio, Pierluigi; Tulli, Antonio

2003-08-01

The role of urokinase type plasminogen activator (uPA) has been well documented in the pathogenesis of pemphigus vulgaris (PV). Activation of plasminogen into active serine protease plasmin initiates extracellular proteolysis leading to acantholysis but the mechanisms underlying this process are not clearly understood. We have previously shown that keratinocyte derived cytokines IL-1alpha and TNF-alpha are involved in PV-induced acantholysis. In the present study we sought to examine whether keratinocyte-derived IL-1alpha and TNF-alpha are correlated with uPA induction in keratinocytes during acantholysis. Normal human keratinocytes were incubated with diluted PV serum. mRNAs for IL-1alpha, TNF-alpha and uPA were examined with RT-PCR at various time points and acantholysis was measured. IL-1alpha, TNF-alpha and uPA mRNAs were all induced in keratinocytes following PV serum stimulation; IL-1alpha/TNF-alpha mRNAs' expression was earlier than the expression of uPA mRNA. To further examine the role of IL-1alpha, TNF-alpha and uPA in acantholysis, we performed antibody blocking studies. Anti-IL-1alpha, anti-TNF-alpha and anti-uPA antibodies suppressed acantholysis by 76%, 80% and 90%, respectively. In addition, anti-IL-1alpha and anti-TNF-alpha antibodies inhibited uPA mRNA induction, whereas anti-uPA antibodies did not alter IL-1alpha/TNF-alpha mRNAs' expression. Our results confirm the role of uPA in acantholysis and suggest an involvement of IL-1alpha/TNF-alpha in uPA induction.

Activation of bean (Phaseolus vulgaris) [alpha]-amylase inhibitor requires proteolytic processing of the proprotein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pueyo, J.J.; Hunt, D.C.; Chrispeels, M.J.

Seeds of the common bean (Phaseolus vulgaris) contain a plant defense protein that inhibits the [alpha]-amylases of mammals and insects. This [alpha]-amylase inhibitor ([alpha]Al) is synthesized as a proprotein on the endoplasmic reticulum and is proteolytically processed after arrival in the protein storage vacuoles to polypeptides of relative molecular weight (M[sub r]) 15,000 to 18,000. The authors report two types of evidence that proteolytic processing is linked to activation of the inhibitory activity. First, by surveying seed extracts of wild accessions of P. vulgaris and other species in the genus Phaseolus, they found that antibodies to [alpha]Al recognize large (M[submore » r] 30,000-35,000) polypeptides as well as typical [alpha]Al processing products (M[sub r] 15,000-18,000). [alpha]Al activity was found in all extracts that had the typical [alpha]Al processed polypeptides, but was absent from seed extracts that lacked such polypeptides. Second, they made a mutant [alpha]Al in which asparagine-77 is changed to aspartic acid-77. This mutation slows down the proteolytic processing of pro-[alpha]Al when the gene is expressed in tobacco. When pro-[alpha]Al was separated from mature [alpha]Al by gel filtration, pro-[alpha]Al was found not to have [alpha]-amylase inhibitory activity. The authors interpret these results to mean that formation of the active inhibitor is causally related to proteolytic processing of the proprotein. They suggest that the polypeptide cleavage removes a conformation constraint on the precursor to produce the biochemically active molecule. 43 refs., 5 figs., 1 tab.« less

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in hepatocellular carcinoma.

PubMed

Liu, Rui; Zhang, Haiyang; Zhang, Yan; Li, Shuang; Wang, Xinyi; Wang, Xia; Wang, Cheng; Liu, Bin; Zen, Ke; Zhang, Chen-Yu; Zhang, Chunni; Ba, Yi

2017-04-01

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha plays a crucial role in regulating the biosynthesis of mitochondria, which is closely linked to the energy metabolism in various tumors. This study investigated the regulatory role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha in the pathogenesis of hepatocellular carcinoma. In this study, the changes of peroxisome proliferator-activated receptor gamma coactivator-1 alpha messenger RNA levels between normal human liver and hepatocellular carcinoma tissue were examined by quantitative reverse transcription polymerase chain reaction. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by RNA interference in the human liver cell line L02, while overexpression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha complementary DNA in the human hepatocarcinoma cell line HepG2. Cellular morphological changes were observed via optical and electron microscopy. Cellular apoptosis was determined by Hoechst 33258 staining. In addition, the expression levels of 21,400 genes in tissues and cells were detected by microarray. It was shown that peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression was significantly downregulated in hepatocellular carcinoma compared with normal liver tissues. After knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression in L02 cells, cells reverted to immature and dedifferentiated morphology exhibiting cancerous tendency. Apoptosis occurred in the HepG2 cells after transfection by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha. Microarray analysis showed consistent results. The results suggest that peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in the formation and development of hepatocellular carcinoma and that peroxisome proliferator-activated receptor gamma coactivator-1 alpha may be a potential therapeutic target for hepatocellular carcinoma.

Lifestyle determinants of 5alpha-reductase metabolites in older African-American, white, and Asian-American men.

PubMed

Wu, A H; Whittemore, A S; Kolonel, L N; Stanczyk, F Z; John, E M; Gallagher, R P; West, D W

2001-05-01

Men with higher endogenous 5alpha-reductase activity may have higher prostate cancer risk. This hypothesis raises two questions: (a) Could racial differences in 5alpha-reductase activity explain the observed racial differences in prostate cancer risk? and (b) Could a man reduce his activity level by modifying his lifestyle? To address these questions, we measured two hormonal indices of 5alpha-reductase activity [serum levels of androstane-3alpha-17beta-diol glucuronide (3alpha-diol G) and androsterone glucuronide (AG)] in healthy, older African-American, white, and Asian-American men, who are at high, intermediate, and low prostate cancer risk, respectively. We also examined associations between these metabolite levels and such lifestyle characteristics as body size and physical activity as well as select aspects of medical history and family history of prostate cancer. Men included in this cross-sectional analysis (n = 1054) had served as control subjects in a population-based case-control study of prostate cancer we conducted in California, Hawaii, and Vancouver, Canada and provided information on certain personal attributes and donated blood between March 1990 and March 1992. In this study, concentrations of 3alpha-diol G declined significantly with age and increased significantly with body mass index. Mean levels of 3alpha-diol G, adjusted for age and body mass index, were 6.1 ng/ml in African-Americans, 6.9 ng/ml in whites and 4.8 ng/ml in Asian-Americans. These differences were statistically significant (African-Americans versus whites: P < 0.01; whites versus Asian-Americans: P < 0.001). Concentrations of AG decreased significantly with age, but only in whites, and were unrelated to any of the reported personal attributes. Mean levels of AG, adjusted for age, were 44.1 ng/ml in African-Americans, 44.9 ng/ml in whites, and 37.5 ng/ml in Asian-Americans (Asian-Americans versus whites, P < 0.001). In conclusion, older African-American and white men have similar levels of these two indices of 5alpha-reductase activity, and these levels are higher than those of older Asian-American men. This difference may be related to the lower prostate cancer risk in Asian-Americans.

The chicken skeletal alpha-actin gene promoter region exhibits partial dyad symmetry and a capacity to drive bidirectional transcription.

PubMed Central

Grichnik, J M; French, B A; Schwartz, R J

1988-01-01

The chicken skeletal alpha-actin gene promoter region (-202 to -12) provides myogenic transcriptional specificity. This promoter contains partial dyad symmetry about an axis at nucleotide -108 and in transfection experiments is capable of directing transcription in a bidirectional manner. At least three different transcription initiation start sites, oriented toward upstream sequences, were mapped 25 to 30 base pairs from TATA-like regions. The opposing transcriptional activity was potentiated upon the deletion of sequences proximal to the alpha-actin transcription start site. Thus, sequences which serve to position RNA polymerase for alpha-actin transcription may allow, in their absence, the selection of alternative and reverse-oriented start sites. Nuclear runoff transcription assays of embryonic muscle indicated that divergent transcription may occur in vivo but with rapid turnover of nuclear transcripts. Divergent transcriptional activity enabled us to define the 3' regulatory boundary of the skeletal alpha-actin promoter which retains a high level of myogenic transcriptional activity. The 3' regulatory border was detected when serial 3' deletions bisected the element (-91 CCAAA TATGG -82) which reduced transcriptional activity by 80%. Previously we showed that disruption of its upstream counterpart (-127 CCAAAGAAGG -136) resulted in about a 90% decrease in activity. These element pairs, which we describe as CCAAT box-associated repeats, are conserved in all sequenced vertebrate sarcomeric actin genes and may act in a cooperative manner to facilitate transcription in myogenic cells. Images PMID:3211124

Hepatocyte nuclear factor 4alpha contributes to thyroid hormone homeostasis by cooperatively regulating the type 1 iodothyronine deiodinase gene with GATA4 and Kruppel-like transcription factor 9.

PubMed

Ohguchi, Hiroto; Tanaka, Toshiya; Uchida, Aoi; Magoori, Kenta; Kudo, Hiromi; Kim, Insook; Daigo, Kenji; Sakakibara, Iori; Okamura, Masashi; Harigae, Hideo; Sasaki, Takeshi; Osborne, Timothy F; Gonzalez, Frank J; Hamakubo, Takao; Kodama, Tatsuhiko; Sakai, Juro

2008-06-01

Type 1 iodothyronine deiodinase (Dio1), a selenoenzyme catalyzing the bioactivation of thyroid hormone, is highly expressed in the liver. Dio1 mRNA and enzyme activity levels are markedly reduced in the livers of hepatocyte nuclear factor 4alpha (HNF4alpha)-null mice, thus accounting for its liver-specific expression. Consistent with this deficiency, serum T4 and rT3 concentrations are elevated in these mice compared with those in HNF4alpha-floxed control littermates; however, serum T3 levels are unchanged. Promoter analysis of the mouse Dio1 gene demonstrated that HNF4alpha plays a key role in the transactivation of the mouse Dio1 gene. Deletion and substitution mutation analyses demonstrated that a proximal HNF4alpha site (direct repeat 1 [TGGACAAAGGTGC]; HNF4alpha-RE) is crucial for transactivation of the mouse Dio1 gene by HNF4alpha. Mouse Dio1 is also stimulated by thyroid hormone signaling, but a direct role for thyroid hormone receptor action has not been reported. We also showed that thyroid hormone-inducible Krüppel-like factor 9 (KLF9) stimulates the mouse Dio1 promoter very efficiently through two CACCC sequences that are located on either side of HNF4alpha-RE. Furthermore, KLF9 functions together with HNF4alpha and GATA4 to synergistically activate the mouse Dio1 promoter, suggesting that Dio1 is regulated by thyroid hormone in the mouse through an indirect mechanism requiring prior KLF9 induction. In addition, we showed that physical interactions between the C-terminal zinc finger domain (Cf) of GATA4 and activation function 2 of HNF4alpha and between the basic domain adjacent to Cf of GATA4 and a C-terminal domain of KLF9 are both required for this synergistic response. Taken together, these results suggest that HNF4alpha regulates thyroid hormone homeostasis through transcriptional regulation of the mouse Dio1 gene with GATA4 and KLF9.

Role of the C-terminal extensions of alpha-crystallins. Swapping the C-terminal extension of alpha-crystallin to alphaB-crystallin results in enhanced chaperone activity.

PubMed

Pasta, Saloni Yatin; Raman, Bakthisaran; Ramakrishna, Tangirala; Rao, Ch Mohan

2002-11-29

Several small heat shock proteins contain a well conserved alpha-crystallin domain, flanked by an N-terminal domain and a C-terminal extension, both of which vary in length and sequence. The structural and functional role of the C-terminal extension of small heat shock proteins, particularly of alphaA- and alphaB-crystallins, is not well understood. We have swapped the C-terminal extensions between alphaA- and alphaB-crystallins and generated two novel chimeric proteins, alphaABc and alphaBAc. We have investigated the domain-swapped chimeras for structural and functional alterations. We have used thermal and non-thermal models of protein aggregation and found that the chimeric alphaB with the C-terminal extension of alphaA-crystallin, alphaBAc, exhibits dramatically enhanced chaperone-like activity. Interestingly, however, the chimeric alphaA with the C-terminal extension of alphaB-crystallin, alphaABc, has almost lost its activity. Pyrene solubilization and bis-1-anilino-8-naphthalenesulfonate binding studies show that alphaBAc exhibits more solvent-exposed hydrophobic pockets than alphaA, alphaB, or alphaABc. Significant tertiary structural changes are revealed by tryptophan fluorescence and near-UV CD studies upon swapping the C-terminal extensions. The far-UV CD spectrum of alphaBAc differs from that of alphaB-crystallin whereas that of alphaABc overlaps with that of alphaA-crystallin. Gel filtration chromatography shows alteration in the size of the proteins upon swapping the C-terminal extensions. Our study demonstrates that the unstructured C-terminal extensions play a crucial role in the structure and chaperone activity, in addition to generally believed electrostatic "solubilizer" function.

Functional characterization of recombinant prefoldin complexes from a hyperthermophilic archaeon, Thermococcus sp. strain KS-1.

PubMed

Iizuka, Ryo; Sugano, Yuri; Ide, Naoki; Ohtaki, Akashi; Yoshida, Takao; Fujiwara, Shinsuke; Imanaka, Tadayuki; Yohda, Masafumi

2008-03-28

Prefoldin is a heterohexameric molecular chaperone complex that is found in the eukaryotic cytosol and also in archaea. It captures a nonnative protein and subsequently delivers it to a group II chaperonin for proper folding. Archaeal prefoldin is a heterocomplex containing two alpha subunits and four beta subunits with the structure of a double beta-barrel assembly, with six long coiled coils protruding from it like a jellyfish with six tentacles. We have studied the protein folding mechanism of group II chaperonin using those of Thermococcus sp. strain KS-1 (T. KS-1) because they exhibit high protein folding activity in vitro. We have also demonstrated functional cooperation between T. KS-1 chaperonins and prefoldin from Pyrococcus horikoshii OT3. Recent genome analysis has shown that Thermococcus kodakaraensis KOD1 contains two pairs of prefoldin subunit genes, correlating with the existence of two different chaperonin subunits. In this study, we characterized four different recombinant prefoldin complexes composed of two pairs of prefoldin subunits (alpha1, alpha2, beta1, and beta2) from T. KS-1. All of them (alpha1-beta1, alpha2-beta1, alpha1-beta2, and alpha2-beta2) exist as alpha(2)beta(4) heterohexamers and can protect several proteins from forming aggregates with different activities. We have also compared the collaborative activity between the prefoldin complexes and the cognate chaperonins. Prefoldin complexes containing the beta1 subunit interacted with the chaperonins more strongly than those with the beta2 subunit. The results suggest that Thermococcus spp. express different prefoldins for different substrates or conditions as chaperonins.

CP-25, a Novel Anti-inflammatory and Immunomodulatory Drug, Inhibits the Functions of Activated Human B Cells through Regulating BAFF and TNF-alpha Signaling and Comparative Efficacy with Biological Agents.

PubMed

Zhang, Feng; Shu, Jin-Ling; Li, Ying; Wu, Yu-Jing; Zhang, Xian-Zheng; Han, Le; Tang, Xiao-Yu; Wang, Chen; Wang, Qing-Tong; Chen, Jing-Yu; Chang, Yan; Wu, Hua-Xun; Zhang, Ling-Ling; Wei, Wei

2017-01-01

Paeoniflorin-6'- O -benzene sulfonate (code: CP-25) was the chemistry structural modifications of Paeoniflorin (Pae). CP-25 inhibited B cells proliferation stimulated by B cell activating factor belonging to the TNF family (BAFF) or Tumor necrosis factor alpha (TNF-alpha). CP-25, Rituximab and Etanercept reduced the percentage and numbers of CD19 + B cells, CD19 + CD20 + B cells, CD19 + CD27 + B cells and CD19 + CD20 + CD27 + B cells induced by BAFF or TNF-alpha. There was significant difference between CP-25 and Rituximab or CP-25 and Etanercept. CP-25 down-regulated the high expression of BAFFR, BCMA, and TACI stimulated by BAFF or TNF-alpha. The effects of Rituximab and Etanercept on BAFFR or BCMA were stronger than that of CP-25. CP-25, Rituximab and Etanercept down-regulated significantly the expression of TNFR1 and TNFR2 on B cell stimulated by BAFF or TNF-alpha. CP-25, Rituximab and Etanercept down-regulated the expression of MKK3, P-p38, P-p65, TRAF2, and p52 in B cells stimulated by BAFF and the expression of TRAF2 and P-p65 in B cells stimulated by TNF-alpha. These results suggest that CP-25 regulated moderately activated B cells function by regulating the classical and alternative NF-κB signaling pathway mediated by BAFF and TNF-alpha-TRAF2-NF-κB signaling pathway. This study suggests that CP-25 may be a promising anti-inflammatory immune and soft regulation drug.

Alpha-emitting isotopes and chromium in a coastal California aquifer

USGS Publications Warehouse

Densmore, Jill N.; Izbicki, John A.; Murtaugh, Joseph M.; Swarzenski, Peter W.; Bullen, Thomas D.

2014-01-01

The unadjusted 72-h gross alpha activities in water from two wells completed in marine and alluvial deposits in a coastal southern California aquifer 40 km north of San Diego were 15 and 25 picoCuries per liter (pCi/L). Although activities were below the Maximum Contaminant Level (MCL) of 15 pCi/L, when adjusted for uranium activity; there is concern that new wells in the area may exceed MCLs, or that future regulations may limit water use from the wells. Coupled well-bore flow and depth-dependent water-quality data collected from the wells in 2011 (with analyses for isotopes within the uranium, actinium, and thorium decay-chains) show gross alpha activity in marine deposits is associated with decay of naturally-occurring 238U and its daughter 234U. Radon activities in marine deposits were as high as 2230 pCi/L. In contrast, gross alpha activities in overlying alluvium within the Piedra de Lumbre watershed, eroded from the nearby San Onofre Hills, were associated with decay of 232Th, including its daughter 224Ra. Radon activities in alluvium from Piedra de Lumbre of 450 pCi/L were lower than in marine deposits. Chromium VI concentrations in marine deposits were less than the California MCL of 10 μg/L (effective July 1, 2014) but δ53Cr compositions were near zero and within reported ranges for anthropogenic chromium. Alluvial deposits from the nearby Las Flores watershed, which drains a larger area having diverse geology, has low alpha activities and chromium as a result of geologic and geochemical conditions and may be more promising for future water-supply development.

Alpha4 containing nicotinic receptors are positioned to mediate postsynaptic effects on serotonin neurons in the rat dorsal raphe nucleus

PubMed Central

Commons, Kathryn G.

2008-01-01

Nicotinic acetylcholine receptors containing the alpha4 and beta2 subunits constitute the most abundant high-affinity binding site of nicotine in the brain and are critical for the addictive qualities of nicotine. Serotonin neurotransmission is thought to be an important contributor to nicotine addiction. Therefore in this study it was examined how alpha4-containing receptors are positioned to modulate the function of serotonin neurons using ultrastructural analysis of immunolabeling for the alpha4 receptor subunit in the dorsal raphe nucleus (DR), a primary source of forebrain serotonin in the rat. Of 150 profiles labeled for the alpha4 subunit, 140 or 93% consisted of either soma or dendrites, these were often small-caliber (distal) dendrites <1.5 um in diameter (63/150 or 42%). The majority (107/150 or 71%) of profiles containing labeling for alpha4 were dually labeled for the synthetic enzyme for serotonin, tryptophan hydroxylase (TPH). Within dendrites immunogold labeling for alpha4 was present on the plasma membrane or near postsynaptic densities. However, labeling for alpha4 was commonly localized to the cytoplasmic compartment often associated with smooth endoplasmic reticulum, plausibly representing receptors in transit to or from the plasma membrane. Previous studies have suggested that nicotine presynaptically regulates activity onto serotonin neurons, however alpha4 immunolabeling was detected in only 10 axons in the DR or 7% of profiles sampled. This finding suggest that alpha4 containing receptors are minor contributors to presynaptic regulation of synaptic activity onto serotonin neurons, but rather alpha4 containing receptors are positioned to influence serotonin neurons directly at postsynaptic sites. PMID:18403129

Changes in alpha-L-arabinofuranosidase activity in peel and pulp of banana (Musa sp.) fruits during ripening and softening.

PubMed

Zhuang, Jun-Ping; Su, Jing; Li, Xue-Ping; Chen, Wei-Xin

2007-04-01

Arabinose is one of the most dynamic cell wall glycosyl residues released during fruit ripening, alpha-L-arabinofuranosidase (alpha-Arab) are major glycosidases that may remove arabinose units from fruit cell wall polysaccharides. To find out whether alpha-Arab plays important roles in banana fruit softening, the enzyme activities in peel and pulp, fruit firmness, respiration rate and ethylene release rate were assayed during banana softening. The results showed that alpha-Arab activities in banana pulp and peel increased slightly at the beginning of storage and reached their maxima when the fruit firmness decreased drastically, alpha-Arab activity increased by more than ten folds in both pulp and peel during ripening and alpha-Arab activities were higher in pulp than in peel. Treatment of banana fruits with ethylene absorbent postponed the time of reaching of its maxima of respiration and ethylene, enhanced the firmness of pup and decreased alpha-Arab activity in the peel and pulp. These results suggest that alpha-Arab induced the decrease of fruit firmness and played an important role in banana fruit softening, and its activity was regulated by ethylene.

The TWIST1 oncogene is a direct target of hypoxia-inducible factor-2alpha.

PubMed

Gort, E H; van Haaften, G; Verlaan, I; Groot, A J; Plasterk, R H A; Shvarts, A; Suijkerbuijk, K P M; van Laar, T; van der Wall, E; Raman, V; van Diest, P J; Tijsterman, M; Vooijs, M

2008-03-06

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that play a crucial role in oxygen homeostasis. Intratumoral hypoxia and genetic alterations lead to HIF activity, which is a hallmark of solid cancer and is associated with poor clinical outcome. HIF activity is regulated by an evolutionary conserved mechanism involving oxygen-dependent HIFalpha protein degradation. To identify novel components of the HIF pathway, we performed a genome-wide RNA interference screen in Caenorhabditis elegans, to suppress HIF-dependent phenotypes, like egg-laying defects and hypoxia survival. In addition to hif-1 (HIFalpha) and aha-1 (HIFbeta), we identified hlh-8, gska-3 and spe-8. The hlh-8 gene is homologous to the human oncogene TWIST1. We show that TWIST1 expression in human cancer cells is enhanced by hypoxia in a HIF-2alpha-dependent manner. Furthermore, intronic hypoxia response elements of TWIST1 are regulated by HIF-2alpha, but not HIF-1alpha. These results identify TWIST1 as a direct target gene of HIF-2alpha, which may provide insight into the acquired metastatic capacity of hypoxic tumors.

Characterization of a new multigene family encoding isomaltases in the yeast Saccharomyces cerevisiae, the IMA family.

PubMed

Teste, Marie-Ange; François, Jean Marie; Parrou, Jean-Luc

2010-08-27

It has been known for a long time that the yeast Saccharomyces cerevisiae can assimilate alpha-methylglucopyranoside and isomaltose. We here report the identification of 5 genes (YGR287c, YIL172c, YJL216c, YJL221c and YOL157c), which, similar to the SUCx, MALx, or HXTx multigene families, are located in the subtelomeric regions of different chromosomes. They share high nucleotide sequence identities between themselves (66-100%) and with the MALx2 genes (63-74%). Comparison of their amino acid sequences underlined a substitution of threonine by valine in region II, one of the four highly conserved regions of the alpha-glucosidase family. This change was previously shown to be sufficient to discriminate alpha-1,4- to alpha-1,6-glucosidase activity in YGR287c (Yamamoto, K., Nakayama, A., Yamamoto, Y., and Tabata, S. (2004) Eur. J. Biochem. 271, 3414-3420). We showed that each of these five genes encodes a protein with alpha-glucosidase activity on isomaltose, and we therefore renamed these genes IMA1 to IMA5 for IsoMAltase. Our results also illustrated that sequence polymorphisms among this family led to interesting variability of gene expression patterns and of catalytic efficiencies on different substrates, which altogether should account for the absence of functional redundancy for growth on isomaltose. Indeed, deletion studies revealed that IMA1/YGR287c encodes the major isomaltase and that growth on isomaltose required the presence of AGT1, which encodes an alpha-glucoside transporter. Expressions of IMA1 and IMA5/YJL216c were strongly induced by maltose, isomaltose, and alpha-methylglucopyranoside, in accordance with their regulation by the Malx3p-transcription system. The physiological relevance of this IMAx multigene family in S. cerevisiae is discussed.

[Trofosides A and B and other cytostatic steroid-derived compounds from the Far East starfish Trofodiscus über].

PubMed

Levina, E V; Kalinovskiĭ, A I; Andriiashchenko, P V; Menzorova, N I; Dmitrenok, P S

2007-01-01

Three new polar steroids identified as trofoside A, (20R,24S)-24-O-(3-O-methyl-beta-D-xylopyranosyl)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, its 22(23)-dehydro derivative (trofoside B), and 15-sulfoxy-(20R,24S)-5alpha-cholestane-3beta,6beta,8,15alpha,24-pentaol sodium salt, were isolated from Trofodiscus uber starfish extracts collected in the Sea of Okhotsk. Two known compounds, trofoside A aglycone, (20R,24S)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, and triseramide, (20R,24R,25S,22E)-24-methyl-3beta,6alpha,8,15beta-tetrahydroxy-5alpha-cholest-22-en-27-oic acid (2-sulfoethyl)amide sodium salt, were also found. The structures of the isolated polyoxysteroids were established from their spectra. Minimal concentrations causing degradation of unfertilized egg-cells of the sea-urchin Strongylocentrotus intermedius (C(min)) and terminating the cell division at the stage of the first division (C(min) embr.), as well as the concentrations causing 50% immobilization of sperm cells (ImC50) and inhibiting their ability to fertilize egg-cells by 50% (IC50) were determined for the isolated compounds. Of three compounds highly toxic in embryos and sea-urchin sperm cells, the polyol with a sulfo group in the steroid core was the most active; two glycosides with monosaccharide chains located at C3 and C24 atoms were less toxic. Note that all the compounds with the spermiotoxic activities differently affected the embryo development. The positions of monosaccharide residues in the core considerably influence the compound activity. For example, both mono- and double chained glycosides with the monosaccharide fragment at C3 and C24 atoms are active against sea-urchin sperm cells and embryos, whereas the C24 glycosylated trofoside A does not affect embryos and displays a poor spermiotoxicity.

Specific high-affinity binding sites for a synthetic gliadin heptapeptide of human peripheral blood lymphocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Payan, D.G.; Horvath, K.; Graf, L.

1987-03-23

The synthetic peptide containing residues 43-49 of ..cap alpha..-gliadin, the major protein component of gluten, has previously been shown to inhibit the production of lymphokine activities by mononuclear leukocytes. The authors demonstrate using radiolabeled ..cap alpha..-gliadin(43-49) that human peripheral blood lymphocytes express approximately 20,000-25,000 surface receptors for this peptide, with a dissociation constant (K/sub D/) of 20 nM. In addition, binding is inhibited by naloxone and an enkephalin analog, thus confirming the functional correlate which demonstrates inhibition by these agents of ..cap alpha..-gliadin(43-49) functional effects. Furthermore, B-lymphocytes bind specifically a greater amount of (/sup 125/I)..cap alpha..-gliadin(43-49) than T-lymphocytes. The lymphocytemore » ..cap alpha..-gliadin(43-49) receptor may play an important role in mediating the immunological response to ..cap alpha..-gliadin. 16 references, 4 figures.« less

[ALPHA-fitness test battery: health-related field-based fitness tests assessment in children and adolescents].

PubMed

Ruiz, J R; España Romero, V; Castro Piñero, J; Artero, E G; Ortega, F B; Cuenca García, M; Jiménez Pavón, D; Chillón, P; Girela Rejón, Ma J; Mora, J; Gutiérrez, A; Suni, J; Sjöstrom, M; Castillo, M J

2011-01-01

Hereby we summarize the work developed by the ALPHA (Assessing Levels of Physical Activity) Study and describe the tests included in the ALPHA health-related fitness test battery for children and adolescents. The evidence-based ALPHA-Fitness test battery include the following tests: 1) the 20 m shuttle run test to assess cardiorespiratory fitness; 2) the handgrip strength and 3) standing broad jump to assess musculoskeletal fitness, and 4) body mass index, 5) waist circumference; and 6) skinfold thickness (triceps and subscapular) to assess body composition. Furthermore, we include two versions: 1) the high priority ALPHA health-related fitness test battery, which comprises all the evidence-based fitness tests except the measurement of the skinfold thickness; and 2) the extended ALPHA health-related fitness tests battery for children and adolescents, which includes all the evidence-based fitness tests plus the 4 x 10 m shuttle run test to assess motor fitness.

Cannabinoid ester constituents from high-potency Cannabis sativa.

PubMed

Ahmed, Safwat A; Ross, Samir A; Slade, Desmond; Radwan, Mohamed M; Zulfiqar, Fazila; Matsumoto, Rae R; Xu, Yan-Tong; Viard, Eddy; Speth, Robert C; Karamyan, Vardan T; ElSohly, M A

2008-04-01

Eleven new cannabinoid esters, together with three known cannabinoid acids and Delta9-tetrahydrocannabinol ( Delta9-THC ), were isolated from a high-potency variety of Cannabis sativa. The structures were determined by extensive spectroscopic analyses to be beta-fenchyl Delta9-tetrahydrocannabinolate ( 1), epi-bornyl Delta9-tetrahydrocannabinolate ( 2), alpha-terpenyl Delta9-tetrahydrocannabinolate ( 3), 4-terpenyl Delta 9-tetrahydrocannabinolate ( 4), alpha-cadinyl Delta9-tetrahydrocannabinolate ( 5), gamma-eudesmyl Delta9-tetrahydrocannabinolate ( 6), gamma-eudesmyl cannabigerolate ( 7), 4-terpenyl cannabinolate ( 8), bornyl Delta9-tetrahydrocannabinolate ( 9), alpha-fenchyl Delta9-tetrahydrocannabinolate ( 10), alpha-cadinyl cannabigerolate ( 11), Delta9-tetrahydrocannabinol ( Delta9-THC ), Delta9-tetrahydrocannabinolic acid A ( Delta9-THCA ), cannabinolic acid A ( CBNA), and cannabigerolic acid ( CBGA). Compound 8 showed moderate antimicrobial activity against Candida albicans ATCC 90028 with an IC 50 value of 8.5 microg/mL. The isolated acids and the ester-containing fractions showed low affinity to the CB-1 receptor. [corrected

Treatment of solid tumors by interstitial release of recoiling short-lived alpha emitters

NASA Astrophysics Data System (ADS)

Arazi, L.; Cooks, T.; Schmidt, M.; Keisari, Y.; Kelson, I.

2007-08-01

A new method utilizing alpha particles to treat solid tumors is presented. Tumors are treated with interstitial radioactive sources which continually release short-lived alpha emitting atoms from their surface. The atoms disperse inside the tumor, delivering a high dose through their alpha decays. We implement this scheme using thin wire sources impregnated with 224Ra, which release by recoil 220Rn, 216Po and 212Pb atoms. This work aims to demonstrate the feasibility of our method by measuring the activity patterns of the released radionuclides in experimental tumors. Sources carrying 224Ra activities in the range 10-130 kBq were used in experiments on murine squamous cell carcinoma tumors. These included gamma spectroscopy of the dissected tumors and major organs, Fuji-plate autoradiography of histological tumor sections and tissue damage detection by Hematoxylin-Eosin staining. The measurements focused on 212Pb and 212Bi. The 220Rn/216Po distribution was treated theoretically using a simple diffusion model. A simplified scheme was used to convert measured 212Pb activities to absorbed dose estimates. Both physical and histological measurements confirmed the formation of a 5-7 mm diameter necrotic region receiving a therapeutic alpha-particle dose around the source. The necrotic regions shape closely corresponded to the measured activity patterns. 212Pb was found to leave the tumor through the blood at a rate which decreased with tumor mass. Our results suggest that the proposed method, termed DART (diffusing alpha-emitters radiation therapy), may potentially be useful for the treatment of human patients.

Alpha-amylase Inhibition and Antioxidant Activity of Marine Green Algae and its Possible Role in Diabetes Management.

PubMed

Unnikrishnan, P S; Suthindhiran, K; Jayasri, M A

2015-10-01

In the continuing search for safe and efficient antidiabetic drug, marine algae become important source which provide several compounds of immense therapeutic potential. Alpha-amylase, alpha-glucosidase inhibitors, and antioxidant compounds are known to manage diabetes and have received much attention recently. In the present study, four green algae (Chaetomorpha aerea, Enteromorpha intestinalis, Chlorodesmis, and Cladophora rupestris) were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro. The phytochemical constituents of all the extracts were qualitatively determined. Antidiabetic activity was evaluated by inhibitory potential of extracts against alpha-amylase and alpha-glucosidase by spectrophotometric assays. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide (H2O2), and nitric oxide scavenging assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to determine the major compound responsible for its antidiabetic action. Among the various extracts screened, chloroform extract of C. aerea (IC50 - 408.9 μg/ml) and methanol extract of Chlorodesmis (IC50 - 147.6 μg/ml) showed effective inhibition against alpha-amylase. The extracts were also evaluated for alpha-glucosidase inhibition, and no observed activity was found. Methanol extract of C. rupestris showed notable free radical scavenging activity (IC50 - 666.3 μg/ml), followed by H2O2 (34%) and nitric oxide (49%). Further, chemical profiling by GC-MS revealed the presence of major bioactive compounds. Phenol, 2,4-bis (1,1-dimethylethyl) and z, z-6,28-heptatriactontadien-2-one were predominantly found in the methanol extract of C. rupestris and chloroform extract of C. aerea. Our results demonstrate that the selected algae exhibit notable alpha-amylase inhibition and antioxidant activity. Therefore, characterization of active compounds and its in vivo assays will be noteworthy. Four green algae were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro C. aerea and Chlorodesmis showed significant inhibition against alpha-amylase, and C. rupestris showed notable free radical scavenging activityNo observed activity was found against alpha-glucosidaseGC-MS analysis of the active extracts reveals the presence of major compounds which gives an insight on the antidiabetic and antioxidant activity of these algae. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, BHT: Butylated hydroxytoluene, GC-MS: Gas chromatography-mass spectrometry.

Alpha-amylase Inhibition and Antioxidant Activity of Marine Green Algae and its Possible Role in Diabetes Management

PubMed Central

Unnikrishnan, P. S.; Suthindhiran, K.; Jayasri, M. A.

2015-01-01

Aim: In the continuing search for safe and efficient antidiabetic drug, marine algae become important source which provide several compounds of immense therapeutic potential. Alpha-amylase, alpha-glucosidase inhibitors, and antioxidant compounds are known to manage diabetes and have received much attention recently. In the present study, four green algae (Chaetomorpha aerea, Enteromorpha intestinalis, Chlorodesmis, and Cladophora rupestris) were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro. Materials and Methods: The phytochemical constituents of all the extracts were qualitatively determined. Antidiabetic activity was evaluated by inhibitory potential of extracts against alpha-amylase and alpha-glucosidase by spectrophotometric assays. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide (H2O2), and nitric oxide scavenging assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to determine the major compound responsible for its antidiabetic action. Results: Among the various extracts screened, chloroform extract of C. aerea (IC50 − 408.9 μg/ml) and methanol extract of Chlorodesmis (IC50 − 147.6 μg/ml) showed effective inhibition against alpha-amylase. The extracts were also evaluated for alpha-glucosidase inhibition, and no observed activity was found. Methanol extract of C. rupestris showed notable free radical scavenging activity (IC50 – 666.3 μg/ml), followed by H2O2 (34%) and nitric oxide (49%). Further, chemical profiling by GC-MS revealed the presence of major bioactive compounds. Phenol, 2,4-bis (1,1-dimethylethyl) and z, z-6,28-heptatriactontadien-2-one were predominantly found in the methanol extract of C. rupestris and chloroform extract of C. aerea. Conclusion: Our results demonstrate that the selected algae exhibit notable alpha-amylase inhibition and antioxidant activity. Therefore, characterization of active compounds and its in vivo assays will be noteworthy. SUMMARY Four green algae were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro C. aerea and Chlorodesmis showed significant inhibition against alpha-amylase, and C. rupestris showed notable free radical scavenging activityNo observed activity was found against alpha-glucosidaseGC-MS analysis of the active extracts reveals the presence of major compounds which gives an insight on the antidiabetic and antioxidant activity of these algae. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, BHT: Butylated hydroxytoluene, GC-MS: Gas chromatography-mass spectrometry. PMID:27013787

Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

PubMed

Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

2014-01-01

The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

210Po in Nevada groundwater and its relation to gross alpha radioactivity

USGS Publications Warehouse

Seiler, R.L.

2011-01-01

Polonium-210 (210Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. 210Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high 210Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous 210Po is unsupported by 210Pb, indicating that the 210Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are 234/238U, 222Rn, and 210Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with 210Po activity. The only applicable drinking water standard for 210Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. 210Po was not volatile in a Nevada well, but volatile 210Po has been reported in a Florida well. Additional information on the volatility of 210Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had 210Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10−4 (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of 210Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded.

210Po in nevada groundwater and its relation to gross alpha radioactivity.

PubMed

Seiler, Ralph L

2011-01-01

Polonium-210 ((210) Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. (210) Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high (210) Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous (210) Po is unsupported by (210) Pb, indicating that the (210) Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are (234/238) U, (222) Rn, and (210) Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with (210) Po activity. The only applicable drinking water standard for (210) Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. (210) Po was not volatile in a Nevada well, but volatile (210) Po has been reported in a Florida well. Additional information on the volatility of (210) Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had (210) Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10(-4) (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of (210) Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded. Journal compilation © 2010 National Ground Water Association. No claim to original US government works.

Confined trapped alpha behaviour in TFTR deuterium-tritium plasmas

NASA Astrophysics Data System (ADS)

Medley, S. S.; Budny, R. V.; Duong, H. H.; Fisher, R. K.; Petrov, M. P.; Gorelenkov, N. N.; Redi, M. H.; Roquemore, A. L.; White, R. B.

1998-09-01

Confined trapped alpha energy spectra and differential radial density profiles in TFTR D-T plasmas were obtained with the pellet charge exchange (PCX) diagnostic, which measures high energy (Eα = 0.5-3.5 MeV) trapped alphas (v||/v = -0.048) at a single time slice (Δt approx 1 ms) with a spatial resolution of Δr approx 5 cm. Tritons produced in D-D plasmas and RF driven ion tails (H, 3He or T) were also observed and energetic tritium ion tail measurements are discussed. PCX alpha and triton energy spectra extending up to their birth energies were measured in the core of MHD quiescent discharges where the expected classical slowing down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with TRANSP predictions, indicating that the PCX measurements are consistent with classical thermalization of the fusion generated alphas and tritons. From calculations, these results set an upper limit on possible anomalous radial diffusion for trapped alphas of Dα <= 0.01 m2·s-1. Outside the core, where the trapped alphas are influenced by stochastic ripple diffusion effects, the PCX measurements are consistent with the functional dependence of the Goldston-White-Boozer stochastic ripple threshold on the alpha energy and the q profile. In the presence of strong sawtooth activity, the PCX diagnostic observes significant redistribution of the alpha signal radial profile wherein alphas are depleted in the core and redistributed to well outside the q = 1 radius, but apparently not beyond the energy dependent stochastic ripple loss boundary. The helical electric field produced during the sawtooth crash plays an essential role in modelling the sawtooth redistribution data. In sawtooth free discharge scenarios with reversed shear operation, the PCX diagnostic also observes radial profiles of the alpha signal that are significantly broader than those for supershots. ORBIT modelling of reversed shear and monotonic shear discharges is in agreement with the q dependent alpha profiles observed. Redistribution of trapped alpha particles in the presence of core localized toroidal Alfvén eigenmode (TAE) activity was observed and modelling of the PCX measurements based on a synergism involving the α-TAE resonance and the effect of stochastic ripple diffusion is in progress.

Succinate links TCA cycle dysfunction to oncogenesis by inhibiting HIF-alpha prolyl hydroxylase.

PubMed

Selak, Mary A; Armour, Sean M; MacKenzie, Elaine D; Boulahbel, Houda; Watson, David G; Mansfield, Kyle D; Pan, Yi; Simon, M Celeste; Thompson, Craig B; Gottlieb, Eyal

2005-01-01

Several mitochondrial proteins are tumor suppressors. These include succinate dehydrogenase (SDH) and fumarate hydratase, both enzymes of the tricarboxylic acid (TCA) cycle. However, to date, the mechanisms by which defects in the TCA cycle contribute to tumor formation have not been elucidated. Here we describe a mitochondrion-to-cytosol signaling pathway that links mitochondrial dysfunction to oncogenic events: succinate, which accumulates as a result of SDH inhibition, inhibits HIF-alpha prolyl hydroxylases in the cytosol, leading to stabilization and activation of HIF-1alpha. These results suggest a mechanistic link between SDH mutations and HIF-1alpha induction, providing an explanation for the highly vascular tumors that develop in the absence of VHL mutations.

Synthesis of peptide .alpha.-thioesters

DOEpatents

Camarero, Julio A [Livermore, CA; Mitchell, Alexander R [Livermore, CA; De Yoreo, James J [Clayton, CA

2008-08-19

Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

Simulated Microgravity Reduces TNF-Alpha Activity, Suppresses Glucose Uptake and Enhances Arginine Flux in Pancreatic Islets of Langerhans

NASA Technical Reports Server (NTRS)

Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.; Paloski, W. H. (Technical Monitor)

2000-01-01

The present studies were designed to determine effects of microgravity upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF - alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-117,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS 3) static culture, 4) static culture plus LPS TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). A decrease in insulin concentration was demonstrated in the LPS stimulated HARV culture (p<0.05). We observed a greater glucose concentration and increased disappearance of arginine in islets cultured in HARVs. While nitrogenous compound analysis indicated a ubiquitous reliance upon glutamine in all experimental groups, arginine was converted to ornithine at a two-fold greater rate in the islets cultured in the HARV microgravity paradigm (p<0.05). These studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV paradigm. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

Structural and functional comparison of two human liver dihydrodiol dehydrogenases associated with 3 alpha-hydroxysteroid dehydrogenase activity.

PubMed Central

Deyashiki, Y; Taniguchi, H; Amano, T; Nakayama, T; Hara, A; Sawada, H

1992-01-01

Two monomeric dihydrodiol dehydrogenases with pI values of 5.4 and 7.6 were co-purified with androsterone dehydrogenase activity to homogeneity from human liver. The two enzymes differed from each other on peptide mapping and in their heat-stabilities; with respect to the latter the dihydrodiol dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase activities of the respective enzymes were similarly inactivated. The pI 5.4 enzyme was equally active towards trans- and cis-benzene dihydrodiols, and towards (S)- and (R)-forms of indan-1-ol and 1,2,3,4-tetrahydronaphth-1-ol and oxidized the 3 alpha-hydroxy group of C19-, C21- and C24-steroids, whereas the pI 7.6 enzyme showed high specificity for trans-benzene dihydrodiol, (S)-forms of the alicyclic alcohols and C19- and C21-steroids. Although the two enzymes reduced various xenobiotic carbonyl compounds and the 3-oxo group of C19- and C21-steroids, and were A-specific in the hydrogen transfer from NADPH, only the pI 5.4 enzyme showed reductase activity towards 7 alpha-hydroxy-5 beta-cholestan-3-one and dehydrolithocholic acid. The affinity of the two enzymes for the steroidal substrates was higher than that for the xenobiotic substrates. The two enzymes also showed different susceptibilities to the inhibition by anti-inflammatory drugs and bile acids. Whereas the pI-5.4 enzyme was highly sensitive to anti-inflammatory steroids, showing mixed-type inhibitions with respect to indan-1-ol and androsterone, the pI 7.6 enzyme was inhibited more potently by non-steroidal anti-inflammatory drugs and bile acids than by the steroidal drugs, and the inhibitions were all competitive. These structural and functional differences suggest that the two enzymes are 3 alpha-hydroxysteroid dehydrogenase isoenzymes. Images Fig. 2. PMID:1554355

Dynamic Neural State Identification in Deep Brain Local Field Potentials of Neuropathic Pain.

PubMed

Luo, Huichun; Huang, Yongzhi; Du, Xueying; Zhang, Yunpeng; Green, Alexander L; Aziz, Tipu Z; Wang, Shouyan

2018-01-01

In neuropathic pain, the neurophysiological and neuropathological function of the ventro-posterolateral nucleus of the thalamus (VPL) and the periventricular gray/periaqueductal gray area (PVAG) involves multiple frequency oscillations. Moreover, oscillations related to pain perception and modulation change dynamically over time. Fluctuations in these neural oscillations reflect the dynamic neural states of the nucleus. In this study, an approach to classifying the synchronization level was developed to dynamically identify the neural states. An oscillation extraction model based on windowed wavelet packet transform was designed to characterize the activity level of oscillations. The wavelet packet coefficients sparsely represented the activity level of theta and alpha oscillations in local field potentials (LFPs). Then, a state discrimination model was designed to calculate an adaptive threshold to determine the activity level of oscillations. Finally, the neural state was represented by the activity levels of both theta and alpha oscillations. The relationship between neural states and pain relief was further evaluated. The performance of the state identification approach achieved sensitivity and specificity beyond 80% in simulation signals. Neural states of the PVAG and VPL were dynamically identified from LFPs of neuropathic pain patients. The occurrence of neural states based on theta and alpha oscillations were correlated to the degree of pain relief by deep brain stimulation. In the PVAG LFPs, the occurrence of the state with high activity levels of theta oscillations independent of alpha and the state with low-level alpha and high-level theta oscillations were significantly correlated with pain relief by deep brain stimulation. This study provides a reliable approach to identifying the dynamic neural states in LFPs with a low signal-to-noise ratio by using sparse representation based on wavelet packet transform. Furthermore, it may advance closed-loop deep brain stimulation based on neural states integrating multiple neural oscillations.

Dynamic Neural State Identification in Deep Brain Local Field Potentials of Neuropathic Pain

PubMed Central

Luo, Huichun; Huang, Yongzhi; Du, Xueying; Zhang, Yunpeng; Green, Alexander L.; Aziz, Tipu Z.; Wang, Shouyan

2018-01-01

In neuropathic pain, the neurophysiological and neuropathological function of the ventro-posterolateral nucleus of the thalamus (VPL) and the periventricular gray/periaqueductal gray area (PVAG) involves multiple frequency oscillations. Moreover, oscillations related to pain perception and modulation change dynamically over time. Fluctuations in these neural oscillations reflect the dynamic neural states of the nucleus. In this study, an approach to classifying the synchronization level was developed to dynamically identify the neural states. An oscillation extraction model based on windowed wavelet packet transform was designed to characterize the activity level of oscillations. The wavelet packet coefficients sparsely represented the activity level of theta and alpha oscillations in local field potentials (LFPs). Then, a state discrimination model was designed to calculate an adaptive threshold to determine the activity level of oscillations. Finally, the neural state was represented by the activity levels of both theta and alpha oscillations. The relationship between neural states and pain relief was further evaluated. The performance of the state identification approach achieved sensitivity and specificity beyond 80% in simulation signals. Neural states of the PVAG and VPL were dynamically identified from LFPs of neuropathic pain patients. The occurrence of neural states based on theta and alpha oscillations were correlated to the degree of pain relief by deep brain stimulation. In the PVAG LFPs, the occurrence of the state with high activity levels of theta oscillations independent of alpha and the state with low-level alpha and high-level theta oscillations were significantly correlated with pain relief by deep brain stimulation. This study provides a reliable approach to identifying the dynamic neural states in LFPs with a low signal-to-noise ratio by using sparse representation based on wavelet packet transform. Furthermore, it may advance closed-loop deep brain stimulation based on neural states integrating multiple neural oscillations. PMID:29695951

The morphology of flare phenomena, magnetic fields, and electric currents in active regions. II - NOAA active region 5747 (1989 October)

NASA Technical Reports Server (NTRS)

Leka, K. D.; Canfield, Richard C.; Mcclymont, A. N.; De La Beaujardiere, J.-F.; Fan, Yuhong; Tang, F.

1993-01-01

The paper describes October 1989 observations in NOAA Active Region 5747 of the morphology of energetic electron precipitation and high-pressure coronal flare plasmas of three flares and their relation to the vector magnetic field and vertical electric currents. The H-alpha spectroheliograms were coaligned with the vector magnetograms using continuum images of sunspots, enabling positional accuracy of a few arcsec. It was found that, during the gradual phase, the regions of the H-alpha flare that show the effects of enhanced pressure in the overlying corona often encompass extrema of the vertical current density, consistent with earlier work showing a close relationship between H-alpha emission and line-of-sight currents. The data are also consistent with the overall morphology and evolution described by erupting-filament models such as those of Kopp and Pneuman (1976) and Sturrock (1989).

Toxicity of trichlorotoluene isomers: a 28-day feeding study in the rat.

PubMed

Chu, I; Shen, S Y; Villeneuve, D C; Secours, V E; Valli, V E

1984-03-01

Groups of 10 male and 10 female rats were fed alpha,alpha,alpha-, alpha,2,6- or 2,3,6- trichlorotoluene (TCT) in their diet at 0, 0.5, 5.0, 50 or 500 ppm for 28 days. Growth rate and food consumption were not affected by treatment. No deaths occurred. Significant increases in liver weights were observed in male rats fed 5.0 and 500 ppm 2,3,6-TCT. Mild serum biochemical changes occurred in male rats. These included increased SDH activities in the groups fed 5.0 and 50 ppm alpha, alpha, alpha-TCT, and 5.0 ppm 2,3,6-TCT. Alpha, alpha, alpha-TCT at 500 ppm caused elevated LDH activities in male rats. Hepatic microsomal aminopyrine N-demethylase activities were increased in male rats fed 500 ppm alpha,2,6-TCT. Hematological parameters were not affected by treatment. Mild histological changes were seen in the liver, kidney and thyroid of treated rats. Data presented here suggest that alpha, alpha, alpha-, alpha,2,6- and 2,3,6-TCT possess a low order of oral toxicity in the rat.

Reduced prefrontal MEG alpha-band power in mild traumatic brain injury with associated posttraumatic stress disorder symptoms.

PubMed

Popescu, Mihai; Hughes, John D; Popescu, Elena-Anda; Riedy, Gerard; DeGraba, Thomas J

2016-09-01

To determine if changes in cortical alpha-band power in patients with mild traumatic brain injury (mTBI) are associated with the severity of their post-traumatic stress disorder (PTSD) symptoms, and if injury severity and level of exposure to psychologically traumatic events are predictors of these electrophysiological changes. Resting-state magnetoencephalographic recordings were analyzed in 32 patients with mTBI. Alpha-band power was estimated for each patient in 68 cortical regions and was compared between groups of patients with low versus high PTSD symptoms severity. Participants with high PTSD symptom severity showed reduced alpha-band power bilaterally in the superior and middle frontal gyri and frontal poles, and in the left inferior frontal gyrus. Alpha-band power in bilateral middle frontal gyri and frontal poles was negatively correlated with scores reflecting symptoms of emotional numbing. Loss of consciousness (LOC) associated with mTBI and level of exposure to psychologically traumatic events were predictors of decreased prefrontal alpha-band power in some of these regions. Altered prefrontal alpha-band activity, shown to be partly explained by mTBI-related LOC, is associated with PTSD symptoms severity. Our findings will guide future studies addressing the electrophysiological mechanisms underlying a higher incidence of PTSD in patients with mTBI. Published by Elsevier Ireland Ltd.

Characterization of alpha-ketobutyrate metabolism in rat tissues: effects of dietary protein and fasting.

PubMed

Steele, R D; Weber, H; Patterson, J I

1984-04-01

The oxidative decarboxylation of alpha-ketobutyrate was studied in rat tissue preparations. Decarboxylation was confined to the mitochondrial fraction and required coenzyme A, NAD, TPP and FAD for optimal activity in solubilized preparations. The pH optimum for this reaction in liver was 7.8, somewhat higher than that reported for other alpha-keto acid dehydrogenases. An apparent Km of 0.63 mM for alpha-ketobutyrate was determined for the rat liver system. Competition by other alpha-keto acids at 10 mM concentrations inhibited enzyme activity up to 75%. Tissue distribution of alpha-ketobutyrate dehydrogenase activity relative to liver activity was (in percent): liver, 100; heart, 127; brain, 63; kidney, 57; skeletal muscle, 38; and small intestine, 7. Total liver alpha-ketobutyrate dehydrogenase was decreased by 40% after a 24-hour fast. Similar results were found for kidney and heart activity. alpha-Aminobutyrate-pyruvate aminotransferase activity in liver or kidney was not affected by fasting; however, it was induced in liver by 50% after feeding a 40% casein diet for 10 days compared to rats fed a 20% casein diet. Increasing the dietary casein content from 6 through 40% of the diet resulted in about a fivefold increase in liver alpha-ketobutyrate dehydrogenase activity. The substantial extrahepatic capacity for alpha-ketobutyrate metabolism makes it unlikely that a loss of liver function results in an inability to metabolize alpha-ketobutyrate. Whether alpha-ketobutyrate is decarboxylated by a specific enzyme or by an already characterized complex such as pyruvate dehydrogenase or the branched-chain keto acid dehydrogenase remains to be established.

The influence of phase transitions in phosphatidylethanolamine models on the activity of violaxanthin de-epoxidase.

PubMed

Vieler, Astrid; Scheidt, Holger A; Schmidt, Peter; Montag, Cindy; Nowoisky, Janine F; Lohr, Martin; Wilhelm, Christian; Huster, Daniel; Goss, Reimund

2008-04-01

In the present study, the influence of the phospholipid phase state on the activity of the xanthophyll cycle enzyme violaxanthin de-epoxidase (VDE) was analyzed using different phosphatidylethanolamine species as model lipids. By using (31)P NMR spectroscopy, differential scanning calorimetry and temperature dependent enzyme assays, VDE activity could directly be related to the lipid structures the protein is associated with. Our results show that the gel (L beta) to liquid-crystalline (L alpha) phase transition in these single lipid component systems strongly enhances both the solubilization of the xanthophyll cycle pigment violaxanthin in the membrane and the activity of the VDE. This phase transition has a significantly stronger impact on VDE activity than the transition from the L alpha to the inverted hexagonal (HII) phase. Especially at higher temperatures we found increased VDE reaction rates in the presence of the L alpha phase compared to those in the presence of HII phase forming lipids. Our data furthermore imply that the HII phase is better suited to maintain high VDE activities at lower temperatures.

Cloning and expression pattern of a gene encoding an alpha-xylosidase active against xyloglucan oligosaccharides from Arabidopsis.

PubMed

Sampedro, J; Sieiro, C; Revilla, G; González-Villa, T; Zarra, I

2001-06-01

An alpha-xylosidase active against xyloglucan oligosaccharides was purified from cabbage (Brassica oleracea var. capitata) leaves. Two peptide sequences were obtained from this protein, the N-terminal and an internal one, and these were used to identify an Arabidopsis gene coding for an alpha-xylosidase that we propose to call AtXYL1. It has been mapped to a region of chromosome I between markers at 100.44 and 107.48 cM. AtXYL1 comprised three exons and encoded a peptide that was 915 amino acids long, with a potential signal peptide of 22 amino acids and eight possible N-glycosylation sites. The protein encoded by AtXYL1 showed the signature regions of family 31 glycosyl hydrolases, which comprises not only alpha-xylosidases, but also alpha-glucosidases. The alpha-xylosidase activity is present in apoplastic extractions from Arabidopsis seedlings, as suggested by the deduced signal peptide. The first eight leaves from Arabidopsis plants were harvested to analyze alpha-xylosidase activity and AtXYL1 expression levels. Both increased from older to younger leaves, where xyloglucan turnover is expected to be higher. When this gene was introduced in a suitable expression vector and used to transform Saccharomyces cerevisiae, significantly higher alpha-xylosidase activity was detected in the yeast cells. alpha-Glucosidase activity was also increased in the transformed cells, although to a lesser extent. These results show that AtXYL1 encodes for an apoplastic alpha-xylosidase active against xyloglucan oligosaccharides that probably also has activity against p-nitrophenyl-alpha-D-glucoside.

Anti-inflammatory effect of intravenous immunoglobulin in comparison with dexamethasone in vitro: implication for treatment of Kawasaki disease.

PubMed

Makata, Haruyuki; Ichiyama, Takashi; Uchi, Ryutaro; Takekawa, Tsuyoshi; Matsubara, Tomoyo; Furukawa, Susumu

2006-08-01

High-dose intravenous immunoglobulin (IVIG) is a well-established standard therapy for Kawasaki disease (KD) that reduces the risk of developing coronary artery aneurysms. On the other hand, some reports have recommended an alternative therapy with steroids for KD patients. In this study we investigated the anti-inflammatory effect of IVIG in comparison with dexamethasone at clinical doses in vitro. High-dose IVIG inhibited tumor necrosis factor-alpha (TNF-alpha)-induced activation of nuclear factor-kappaB (NF-kappaB) to a greater degree than dexamethasone in human monocytic U937 cells and human coronary arterial endothelial cells (HCAEC), but not in human T lymphocytic Jurkat cells. IVIG was more potent than dexamethasone in reducing the expression of CD16 (FcgammaRIII) in human monocytic THP-1 cells stimulated with lipopolysaccharide and in Jurkat cells stimulated with dimethyl sulfoxide. In HCAEC exposed to TNF-alpha, IVIG and dexamethasone inhibited interleukin-6 production to a similar degree, whereas the expression of E-selectin was inhibited more strongly by IVIG. Our results show that high-dose IVIG inhibits the activation of monocytes/macrophages and coronary arterial endothelial cells more strongly than that of T cells, whereas dexamethasone inhibits the activation of all three cell types. These findings suggest that IVIG or dexamethasone therapy should be chosen to match the types of cells that are activated during acute KD.

Gallium-67 activity in bronchoalveolar lavage fluid in sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trauth, H.A.; Heimes, K.; Schubotz, R.

1986-01-01

Roentgenograms and gallium-67 scans and gallium-67 counts of BAL fluid samples, together with differential cell counts, have proved to be useful in assessing activity and lung involvement in sarcoidosis. In active pulmonary sarcoidosis gallium-67 scans are usually positive. Quantitation of gallium-67 uptake in lung scans, however, may be difficult. Because gallium-67 uptake and cell counts in BAL fluid may be correlated, we set out to investigate gallium-67 activity in BAL fluid recovered from patient of different groups. Sixteen patients with recently diagnosed and untreated sarcoidosis, nine patients with healthy lungs, and five patients with CFA were studied. Gallium-67 uptake ofmore » the lung, gallium-67 activity in the lavage fluid, SACE and LACE levels, and alpha 1-AT activity were measured. Significantly more gallium-67 activity was found in BAL fluid from sarcoidosis patients than in that from CFA patients (alpha = .001) or patients with healthy lungs (alpha = .001). Gallium-67 activity in BAL fluid could be well correlated with the number of lymphocytes in BAL fluid, but poorly with the number of macrophages. Subjects with increased levels of SACE or serum alpha 1-AT showed higher lavage gallium-67 activity than did normals, but no correlation could be established. High gallium-67 activity in lavage fluid may be correlated with acute sarcoidosis or physiological deterioration; low activity denotes change for the better. The results show that gallium-67 counts in BAL fluid reflects the intensity of gallium-67 uptake and thus of activity of pulmonary sarcoidosis.« less

Galloylated polyphenols efficiently reduce alpha-tocopherol radicals in a phospholipid model system composed of sodium dodecyl sulfate (SDS) micelles.

PubMed

Pazos, Manuel; Torres, Josep Lluís; Andersen, Mogens L; Skibsted, Leif H; Medina, Isabel

2009-06-10

The ability of several polyphenolic fractions from grape ( Vitis vinifera ) pomace, pine ( Pinus pinaster ) bark, and witch hazel ( Hammamelis virginiana ) bark to repair alpha-tocopherol (alpha-TOH) through reduction of the alpha-tocopheroxyl radical was investigated in a homogeneous hexane system and a phospholipid-like system based on SDS micelles. These natural polyphenols were compared with pure related phenolics (epicatechin, gallic acid, epigallocatechin gallate, quercetin, and rutin) and ascorbic acid, which is a substance with a well-recognized capacity for regenerating alpha-TOH. alpha-Tocopheroxyl radicals were monitored and quantified by electron spin resonance (ESR) spectroscopy in the absence and presence of phenolics. Polyphenols from grape and pine bark were essentially catechin monomers and proanthocyanidins differing in the content of galloyl residues; those from pine bark had a negligible degree of galloylation. Polyphenolic fractions from witch hazel bark were composed of approximately 80% hydrolyzable tannins rich in galloyl moieties, together with a smaller amount of catechin monomers and proanthocyanidins. In the homogeneous hexane system, polyphenols from grape and pine bark exhibited similar activities, reducing the alpha-tocopheroxyl radicals by over 27-40%, whereas phenols from witch hazel were more highly effective, reducing 80% of alpha-TOH. In contrast, pine bark polyphenols were found to be significantly less active than the grape fractions in SDS micelles, reducing 30 and 70% of alpha-tocopheroxyl radicals, respectively. Polyphenolic fractions from witch hazel were also able to reduce the highest amount of alpha-TOH in SDS-micelles. The reducing capacity on alpha-tocopheroxyl radical of polyphenolic fractions was found to be pH-dependent and more effective at higher pH in the range of pH studied (5.8-7.8). These results stress the potential role of polyphenols, in particular those rich in galloyl groups, to maintain intact endogenous alpha-TOH in biological membranes through reduction of alpha-tocopheroxyl radicals.

alpha-Adrenergic-mediated activation of human reconstituted fibrinogen receptor (integrin alphaIIbbeta3) in Chinese hamster ovary cells.

PubMed

Butta, Nora; Larrucea, Susana; Gonzalez-Manchon, Consuelo; Alonso, Sonia; Parrilla, Roberto

2004-12-01

This work reports the functional studies of CHO cells coexpressing alpha-adrenergic (alphaAR) and human fibrinogen (Fg) receptors (integrin alphaIIbbeta3). Stimulation of these cells with alpha-agonists produced a transient rise in the free cytosolic calcium (Ca(++)) accompanied by enhanced binding to soluble Fg, and these effects were prevented by specific alphaAR antagonists. The alpha-adrenergic-induced activation of alphaIIbbeta3 in CHO-alphaIIbbeta3-alphaAR increased the rate of adhesion and extension of cells onto Fg coated plates, and also induced a soluble Fg- and alphaIIbbeta3-dependent formation of cell aggregates, whereas no effects were observed by the stimulation of CHO-alphaIIbbeta3 cells. alpha-Adrenergic antagonists, the ligand mimetic peptide RGDS, pertussis toxin (PTX), or EDTA, they all prevented the alpha-adrenergic stimulation of adhesion and aggregation. However, inhibition of PKC prevented the alpha-adrenergic stimulation of cell adherence, whereas blocking the intracellular Ca(++) mobilization impeded the stimulation of cell aggregation. The alpha-adrenergic activation was associated with phosphorylation of a protein of approximately 100 kDa and proteins of the MAPK family. The former was selectively phosphorylated by alpha-adrenergic stimulation whereas the latter were phosphorylated by the binding of cells to Fg and markedly intensified by alpha-adrenergic stimulation.

TNF{alpha} acting on TNFR1 promotes breast cancer growth via p42/P44 MAPK, JNK, Akt and NF-{kappa}B-dependent pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivas, Martin A.; Carnevale, Romina P.; Proietti, Cecilia J.

2008-02-01

Tumor necrosis factor {alpha} (TNF{alpha}) enhances proliferation of chemically-induced mammary tumors and of T47D human cell line through not fully understood pathways. Here, we explored the intracellular signaling pathways triggered by TNF{alpha}, the participation of TNF{alpha} receptor (TNFR) 1 and TNFR2 and the molecular mechanism leading to breast cancer growth. We demonstrate that TNF{alpha} induced proliferation of C4HD murine mammary tumor cells and of T47D cells through the activation of p42/p44 MAPK, JNK, PI3-K/Akt pathways and nuclear factor-kappaB (NF-{kappa}B) transcriptional activation. A TNF{alpha}-specific mutein selectively binding to TNFR1 induced p42/p44 MAPK, JNK, Akt activation, NF-{kappa}B transcriptional activation and cell proliferation,more » just like wild-type TNF{alpha}, while a mutein selective for TNFR2 induced only p42/p44 MAPK activation. Interestingly, blockage of TNFR1 or TNFR2 with specific antibodies was enough to impair TNF{alpha} signaling and biological effect. Moreover, in vivo TNF{alpha} administration supported C4HD tumor growth. We also demonstrated, for the first time, that injection of a selective inhibitor of NF-{kappa}B activity, Bay 11-7082, resulted in regression of TNF{alpha}-promoted tumor. Bay 11-7082 blocked TNF{alpha} capacity to induce cell proliferation and up-regulation of cyclin D1 and of Bcl-x{sub L}in vivo and in vitro. Our results reveal evidence for TNF{alpha} as a breast tumor promoter, and provide novel data for a future therapeutic approach using TNF{alpha} antagonists and NF-{kappa}B pharmacological inhibitors in established breast cancer treatment.« less

Preparation and catalytic activities of LaFeO3 and Fe2O3 for HMX thermal decomposition.

PubMed

Wei, Zhi-Xian; Xu, Yan-Qing; Liu, Hai-Yan; Hu, Chang-Wen

2009-06-15

Perovskite-type LaFeO(3) and alpha-Fe(2)O(3) with high specific surface areas were directly prepared with appropriate stearic acid-nitrates ratios by a novel stearic acid solution combustion method. The obtained powders were characterized by XRD, FT-IR and XPS techniques. The catalytic activities of perovskite-type LaFeO(3) and alpha-Fe(2)O(3) for the thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were investigated by TG and TG-EGA techniques. The experimental results show that the catalytic activity of perovskite-type LaFeO(3) was much higher than that of alpha-Fe(2)O(3) because of higher concentration of surface-adsorbed oxygen (O(ad)) and hydroxyl of LaFeO(3). The study points out a potential way to develop new and more active perovskite-type catalysts for the HMX thermal decomposition.

Lyman alpha radiation in external galaxies

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Mckee, Christopher F.

1990-01-01

The Ly alpha line of atomic hydrogen is often a luminous component of the radiation emitted by distant galaxies. Except for those galaxies which have a substantial central source of non-stellar ionizing radiation, most of the Ly alpha radiation emitted by galaxies is generated within regions of the interstellar medium which are photoionized by starlight. Conversely, much of the energy radiated by photoionized regions is carried by the Ly alpha line. Only hot, massive stars are capable of ionizing hydrogen in the interstellar medium which surrounds them, and because such stars are necessarily short-lived, Ly alpha emission traces regions of active star formation. Researchers argue that the strength of the Ly alpha emission observed from external galaxies may be used to estimate quantitatively the dust content of the emitting region, while the Ly alpha line profile is sensitive to the presence of shock waves. Interstellar dust particles and shock waves are intimately associated with the process of star formation in two senses. First, both dust particles and shock waves owe their existence to stellar activity; second, they may both serve as agents which facilitate the formation of stars, shocks by triggering gravitational instabilities in the interstellar gas that they compress, and dust by shielding star-forming molecular clouds from the ionizing and dissociative effects of external UV radiation. By using Ly alpha observations as a probe of the dust content in diffuse gas at high redshift, we might hope to learn about the earliest epochs of star formation.

Effects of the pesticide amitraz and its metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas: involvement of alpha2D-adrenergic receptors.

PubMed

Abu-Basha, E A; Yibchok-Anun, S; Hopper, D L; Hsu, W H

1999-11-01

The study purpose was to investigate the direct effect of amitraz, a formamidine insecticide/acaricide, and its active metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas. Amitraz and BTS 27271 (0.01, 0.1, 1, and 10 micromol/L) inhibited insulin secretion in a concentration-dependent manner. Amitraz increased glucagon secretion at 10 micromol/L, whereas BTS 27271 increased glucagon secretion at 1 and 10 micromol/L. Amitraz- and BTS 27271-induced decreases in insulin secretion and increases in glucagon secretion were not abolished during the 10-minute washout period. During the arginine treatment, both amitraz and BTS 27271 groups (0.1, 1, and 10 micromol/L) had lower insulin secretion and higher glucagon secretion than the control group. Idazoxan, an alpha2A/2D-adrenergic receptor (AR) antagonist, prevented the inhibitory effect of amitraz on insulin secretion in a concentration-dependent manner, but prazosin, an alpha1- and alpha2B/2C-AR antagonist, failed to antagonize the effect of amitraz. These results demonstrate that (1) amitraz and BTS 27271 inhibit insulin and stimulate glucagon secretion from the perfused rat pancreas, (2) amitraz inhibits insulin secretion by activation of alpha2D-ARs, since rats have alpha2D- but not alpha2A-ARs, and (3) amitraz and BTS 27271 may have a high binding affinity to the alpha2D-ARs of pancreatic islets.

Peroxisome proliferator-activated receptor-alpha regulates fatty acid utilization in primary human skeletal muscle cells.

PubMed

Muoio, Deborah M; Way, James M; Tanner, Charles J; Winegar, Deborah A; Kliewer, Steven A; Houmard, Joseph A; Kraus, William E; Dohm, G Lynis

2002-04-01

In humans, skeletal muscle is a major site of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) expression, but its function in this tissue is unclear. We investigated the role of hPPAR-alpha in regulating muscle lipid utilization by studying the effects of a highly selective PPAR-alpha agonist, GW7647, on [(14)C]oleate metabolism and gene expression in primary human skeletal muscle cells. Robust induction of PPAR-alpha protein expression occurred during muscle cell differentiation and corresponded with differentiation-dependent increases in oleate oxidation. In mature myotubes, 48-h treatment with 10-1,000 nmol/l GW7647 increased oleate oxidation dose-dependently, up to threefold. Additionally, GW7647 decreased oleate esterification into myotube triacylglycerol (TAG), up to 45%. This effect was not abolished by etomoxir, a potent inhibitor of beta-oxidation, indicating that PPAR-alpha-mediated TAG depletion does not depend on reciprocal changes in fatty acid catabolism. Consistent with its metabolic actions, GW7647 induced mRNA expression of mitochondrial enzymes that promote fatty acid catabolism; carnitine palmityltransferase 1 and malonyl-CoA decarboxylase increased approximately 2-fold, whereas pyruvate dehydrogenase kinase 4 increased 45-fold. Expression of several genes that regulate glycerolipid synthesis was not changed by GW7647 treatment, implicating involvement of other targets to explain the TAG-depleting effect of the compound. These results demonstrate a role for hPPAR-alpha in regulating muscle lipid homeostasis.

Multi-frequency localization of aberrant brain activity in autism spectrum disorder.

PubMed

Xiang, Jing; Korostenskaja, Milena; Molloy, Cynthia; deGrauw, Xinyao; Leiken, Kimberly; Gilman, Carley; Meinzen-Derr, Jareen; Fujiwara, Hisako; Rose, Douglas F; Mitchell, Terry; Murray, Donna S

2016-01-01

The abnormality of intrinsic brain activity in autism spectrum disorders (ASDs) is still inconclusive. Contradictory results have been found pointing towards hyper-activity or hypo-activity in various brain regions. The present research aims to investigate the spatial and spectral signatures of aberrant brain activity in an unprecedented frequency range of 1-2884 Hz at source levels in ASD using newly developed methods. Seven ASD subjects and age- and gender-matched controls were studied using a high-sampling rate magnetoencephalography (MEG) system. Brain activity in delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz), low gamma (30-55 Hz), high gamma (65-90 Hz), ripples (90-200 Hz), high-frequency oscillations (HFOs, 200-1000 Hz), and very high-frequency oscillations (VHFOs, 1000-2884 Hz) was volumetrically localized and measured using wavelet and beamforming. In comparison to controls, ASD subjects had significantly higher odds of alpha activity (8-12 Hz) in the sensorimotor cortex (mu rhythm), and generally high-frequency activity (90-2884 Hz) in the frontal cortex. The source power of HFOs (200-1000 Hz) in the frontal cortex in ASD was significantly elevated as compared with controls. The results suggest that ASD has significantly altered intrinsic brain activity in both low- and high-frequency ranges. Increased intrinsic high-frequency activity in the frontal cortex may play a key role in ASD. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Alternative splicing produces transcripts coding for alpha and beta chains of a hetero-dimeric phosphagen kinase.

PubMed

Ellington, W Ross; Yamashita, Daisuke; Suzuki, Tomohiko

2004-06-09

Glycocyamine kinase (GK) catalyzes the reversible phosphorylation of glycocyamine (guanidinoacetate), a reaction central to cellular energy homeostasis in certain animals. GK is a member of the phosphagen kinase enzyme family and appears to have evolved from creatine kinase (CK) early in the evolution of multi-cellular animals. Prior work has shown that GK from the polychaete Neanthes (Nereis) diversicolor exits as a hetero-dimer in vivo and that the two polypeptide chains (termed alpha and beta) are coded for by unique transcripts. In the present study, we demonstrate that the GK from a congener Nereis virens is also hetero-dimeric and is coded for by alpha and beta transcripts, which are virtually identical to the corresponding forms in N. diversicolor. The GK gene from N. diversicolor was amplified by PCR. Sequencing of the PCR products showed that the alpha and beta chains are the result of alternative splicing of the GK primary mRNA transcript. These results also strongly suggest that this gene underwent an early tandem exon duplication event. Full-length cDNAs for N. virens GKalpha and GKbeta were individually ligated into expression vectors and the resulting constructs used to transform Escherichia coli expression hosts. Regardless of expression conditions, minimal GK activity was observed in both GKalpha and GKbeta constructs. Inclusion bodies for both were harvested, unfolded in urea and alpha chains, beta chains and mixtures of alpha and beta chains were refolded by sequential dialysis. Only modest amounts of GK activity were observed when alpha and beta were refolded individually. In contrast, when refolded the alpha and beta mixture yielded highly active hetero-dimers, as validated by size exclusion chromatography, electrophoresis and mass spectrometry, with a specific activity comparable to that of natural GK. The above evidence suggests that there is a preference for hetero-dimer formation in the GKs from these two polychaetes. The evolution of the alternate splicing and an additional exon in these GKs, producing alpha and beta transcripts, can be viewed as a possible compensation for a mutation(s) in the original gene, which most likely coded for a homo-dimeric protein.

Mitochondria mediate tumor necrosis factor-alpha/NF-kappaB signaling in skeletal muscle myotubes

NASA Technical Reports Server (NTRS)

Li, Y. P.; Atkins, C. M.; Sweatt, J. D.; Reid, M. B.; Hamilton, S. L. (Principal Investigator)

1999-01-01

Tumor necrosis factor-alpha (TNF-alpha) is implicated in muscle atrophy and weakness associated with a variety of chronic diseases. Recently, we reported that TNF-alpha directly induces muscle protein degradation in differentiated skeletal muscle myotubes, where it rapidly activates nuclear factor kappaB (NF-kappaB). We also have found that protein loss induced by TNF-alpha is NF-kappaB dependent. In the present study, we analyzed the signaling pathway by which TNF-alpha activates NF-kappaB in myotubes differentiated from C2C12 and rat primary myoblasts. We found that activation of NF-kappaB by TNF-alpha was blocked by rotenone or amytal, inhibitors of complex I of the mitochondrial respiratory chain. On the other hand, antimycin A, an inhibitor of complex III, enhanced TNF-alpha activation of NK-kappaB. These results suggest a key role of mitochondria-derived reactive oxygen species (ROS) in mediating NF-kappaB activation in muscle. In addition, we found that TNF-alpha stimulated protein kinase C (PKC) activity. However, other signal transduction mediators including ceramide, Ca2+, phospholipase A2 (PLA2), and nitric oxide (NO) do not appear to be involved in the activation of NF-kappaB.

Evaluation of the alpha-1 and alpha-2 adrenoceptor-mediated effects of a series of dimethoxy-substituted tolazoline derivatives in the cardiovascular system of the pithed rat.

PubMed

Ruffolo, R R; Messick, K

1985-01-01

The alpha-1 and alpha-2 adrenoceptor-mediated effects of a series of dimethoxy-substituted tolazoline derivatives were investigated in the cardiovascular system of the pithed rat. The 2,5- and 3,5-dimethoxy-substituted tolazoline derivatives produced vasopressor responses that were inhibited by the alpha-1 adrenoceptor antagonist, prazosin (0.1 mg/kg i.v.), and were not affected by the alpha-2 adrenoceptor antagonist, yohimbine (1 mg/kg i.v.), suggesting that these derivatives selectively activate postsynaptic vascular alpha-1 adrenoceptors. The 2,5- and 3,5-dimethoxy-substituted derivatives of tolazoline did not produce an alpha-2 adrenoceptor-mediated inhibition of neurogenic tachycardia in cord-stimulated pithed rats and were therefore presumed to be devoid of alpha-2 adrenoceptor agonist activity. In contrast, 2,3-dimethoxytolazoline produced a vasopressor effect that was inhibited by yohimbine but not by prazosin, suggesting selective activation of postsynaptic vascular alpha-2 adrenoceptors. Consistent with this observation is the fact that 2,3-dimethoxytolazoline elicited a dose-dependent, alpha-2 adrenoceptor-mediated inhibition of neurogenic tachycardia in cord-stimulated pithed rat. 3,4-Dimethoxytolazoline was a weak alpha-1 adrenoceptor agonist in the vasculature of the pithed rat and was devoid of agonist activity at alpha-2 adrenoceptors. However, 3,4-dimethoxytolazoline was found to be an alpha-2 adrenoceptor antagonist of similar potency as yohimbine. The results of the present study indicate that dimethoxy-substituted derivatives of tolazoline possess different activities and selectivities at alpha-1 and alpha-2 adrenoceptors depending upon the positions of substitution.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced variability of auditory alpha activity in chronic tinnitus.

PubMed

Schlee, Winfried; Schecklmann, Martin; Lehner, Astrid; Kreuzer, Peter M; Vielsmeier, Veronika; Poeppl, Timm B; Langguth, Berthold

2014-01-01

Subjective tinnitus is characterized by the conscious perception of a phantom sound which is usually more prominent under silence. Resting state recordings without any auditory stimulation demonstrated a decrease of cortical alpha activity in temporal areas of subjects with an ongoing tinnitus perception. This is often interpreted as an indicator for enhanced excitability of the auditory cortex in tinnitus. In this study we want to further investigate this effect by analysing the moment-to-moment variability of the alpha activity in temporal areas. Magnetoencephalographic resting state recordings of 21 tinnitus subjects and 21 healthy controls were analysed with respect to the mean and the variability of spectral power in the alpha frequency band over temporal areas. A significant decrease of auditory alpha activity was detected for the low alpha frequency band (8-10 Hz) but not for the upper alpha band (10-12 Hz). Furthermore, we found a significant decrease of alpha variability for the tinnitus group. This result was significant for the lower alpha frequency range and not significant for the upper alpha frequencies. Tinnitus subjects with a longer history of tinnitus showed less variability of their auditory alpha activity which might be an indicator for reduced adaptability of the auditory cortex in chronic tinnitus.

Activation of p115-RhoGEF Requires Direct Association of G[alpha subscript 13] and the Dbl Homology Domain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Zhe; Guo, Liang; Hadas, Jana

2012-09-05

RGS-containing RhoGEFs (RGS-RhoGEFs) represent a direct link between the G{sub 12} class of heterotrimeric G proteins and the monomeric GTPases. In addition to the canonical Dbl homology (DH) and pleckstrin homology domains that carry out the guanine nucleotide exchange factor (GEF) activity toward RhoA, these RhoGEFs also possess RGS homology (RH) domains that interact with activated {alpha} subunits of G{sub 12} and G{sub 13}. Although the GEF activity of p115-RhoGEF (p115), an RGS-RhoGEF, can be stimulated by G{alpha}{sub 13}, the exact mechanism of the stimulation has remained unclear. Using combined studies with small angle x-ray scattering, biochemistry, and mutagenesis, wemore » identify an additional binding site for activated G{alpha}{sub 13} in the DH domain of p115. Small angle x-ray scattering reveals that the helical domain of G{alpha}{sub 13} docks onto the DH domain, opposite to the surface of DH that binds RhoA. Mutation of a single tryptophan residue in the {alpha}3b helix of DH reduces binding to activated G{alpha}{sub 13} and ablates the stimulation of p115 by G{alpha}{sub 13}. Complementary mutations at the predicted DH-binding site in the {alpha}B-{alpha}C loop of the helical domain of G{alpha}{sub 13} also affect stimulation of p115 by G{alpha}{sub 13}. Although the GAP activity of p115 is not required for stimulation by G{alpha}{sub 13}, two hydrophobic motifs in RH outside of the consensus RGS box are critical for this process. Therefore, the binding of G{alpha}{sub 13} to the RH domain facilitates direct association of G{alpha}{sub 13} to the DH domain to regulate its exchange activity. This study provides new insight into the mechanism of regulation of the RGS-RhoGEF and broadens our understanding of G protein signaling.« less

[The changes of alpha 2-plasmin inhibitor, and notably urokinase activities in blood measured by synthetic chromogenic substrates S-2444 after urokinase administration].

PubMed

Itoh, Y; Tsuji, K; Tanaka, N; Yamada, M; Nakanishi, M; Ishihara, M; Kobayashi, M

1983-01-01

Thrombolytic therapy with Urokinase (UK) has often been successful but it is very difficult to determine the effective dosage of UK. It is reported that after UK administration, plasmin fibrinolytic activity was immediately inhibited by alpha 2-Plasmin inhibitor (alpha 2-PI). In this study, we used UK on patients with myoma to prevent the occurrence of thrombosis after operation and the initial decrease in alpha 2-PI activities following UK administration was investigated to determine the minimum effective dosage of UK required to suppress alpha 2-PI. An attempt was also made to measure UK activity in blood by means of chromogenic substrate S-2444, and in some cases by administering 60,000 I.U. UK, alpha 1-Antitrypsin (alpha 1-AT), alpha 2-Macroglobulin (alpha 2-M), Antithrombin III (AT III) and Plasminogen (Plg) were measured at the same time. The results were as follows: 1) By the drip infusion method. In all doses, alpha 2-PI and UK activity showed no remarkable change. 2) By the one shot method. a) A decrease in alpha 2-PI was observed following both 48,000 and 60,000 I.U. UK administration. It was noted that in the case of 48,000 I.U. UK, alpha 2-PI showed the lowest level, 60% of the pre-administration level. b) UK activity showed a gradual increase in the case of 60,000 I.U. UK only and large changes in the other cases. c) alpha 1-AT, alpha 2-M, AT III and Plg produced no remarkable changes. This indicated that the effective dosage of UK for suppressing alpha 2-PI was at least 48,000 I.U. UK with the one shot method, and alpha 2-PI is a reliable indicator of the effectiveness of UK therapy.

Crystal Structures of Human Choline Kinase Isoforms in Complex with Hemicholinium-3 Single Amino Acid near the Active Site Influences Inhibitor Sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Bum Soo; Allali-Hassani, Abdellah; Tempel, Wolfram

2010-07-06

Human choline kinase (ChoK) catalyzes the first reaction in phosphatidylcholine biosynthesis and exists as ChoK{alpha} ({alpha}1 and {alpha}2) and ChoK{beta} isoforms. Recent studies suggest that ChoK is implicated in tumorigenesis and emerging as an attractive target for anticancer chemotherapy. To extend our understanding of the molecular mechanism of ChoK inhibition, we have determined the high resolution x-ray structures of the ChoK{alpha}1 and ChoK{beta} isoforms in complex with hemicholinium-3 (HC-3), a known inhibitor of ChoK. In both structures, HC-3 bound at the conserved hydrophobic groove on the C-terminal lobe. One of the HC-3 oxazinium rings complexed with ChoK{alpha}1 occupied the choline-bindingmore » pocket, providing a structural explanation for its inhibitory action. Interestingly, the HC-3 molecule co-crystallized with ChoK{beta} was phosphorylated in the choline binding site. This phosphorylation, albeit occurring at a very slow rate, was confirmed experimentally by mass spectroscopy and radioactive assays. Detailed kinetic studies revealed that HC-3 is a much more potent inhibitor for ChoK{alpha} isoforms ({alpha}1 and {alpha}2) compared with ChoK{beta}. Mutational studies based on the structures of both inhibitor-bound ChoK complexes demonstrated that Leu-401 of ChoK{alpha}2 (equivalent to Leu-419 of ChoK{alpha}1), or the corresponding residue Phe-352 of ChoK{beta}, which is one of the hydrophobic residues neighboring the active site, influences the plasticity of the HC-3-binding groove, thereby playing a key role in HC-3 sensitivity and phosphorylation.« less

Adsorption behavior of alpha -cypermethrin on cork and activated carbon.

PubMed

Domingues, Valentina F; Priolo, Giuseppe; Alves, Arminda C; Cabral, Miguel F; Delerue-Matos, Cristina

2007-08-01

Studies were undertaken to determine the adsorption behavior of alpha -cypermethrin [R)-alpha -cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-alpha-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carried out using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyze alpha -cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface area and pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations thereby indicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC. Kinetics adsorption studies allowed the determination of the equilibrium time - 24 hours for both cork (1-2 mm and 3-4 mm) and GAC. For the studied alpha -cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parameters for equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1-2 mm have the maximum amount of adsorbed alpha-cypermethrin (q(m)) (303 microg/g); followed by GAC (186 microg/g) and cork 3-4 mm (136 microg/g). The standard deviation (SD) values, demonstrate that Freundlich model better describes the alpha -cypermethrin adsorption phenomena on GAC, while alpha -cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorption results obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removing alpha -cypermethrin from water.

Reversible conformational transition gives rise to 'zig-zag' temperature dependence of the rate constant of irreversible thermoinactivation of enzymes.

PubMed

Levitsky VYu; Melik-Nubarov, N S; Siksnis, V A; Grinberg VYa; Burova, T V; Levashov, A V; Mozhaev, V V

1994-01-15

We have obtained unusual 'zig-zag' temperature dependencies of the rate constant of irreversible thermoinactivation (k(in)) of enzymes (alpha-chymotrypsin, covalently modified alpha-chymotrypsin, and ribonuclease) in a plot of log k(in) versus reciprocal temperature (Arrhenius plot). These dependencies are characterized by the presence of both ascending and descending linear portions which have positive and negative values of the effective activation energy (Ea), respectively. A kinetic scheme has been suggested that fits best for a description of these zig-zag dependencies. A key element of this scheme is the temperature-dependent reversible conformational transition of enzyme from the 'low-temperature' native state to a 'high-temperature' denatured form; the latter form is significantly more stable against irreversible thermoinactivation than the native enzyme. A possible explanation for a difference in thermal stabilities is that low-temperature and high-temperature forms are inactivated according to different mechanisms. Existence of the suggested conformational transition was proved by the methods of fluorescence spectroscopy and differential scanning calorimetry. The values of delta H and delta S for this transition, determined from calorimetric experiments, are highly positive; this fact underlies a conclusion that this heat-induced transition is caused by an unfolding of the protein molecule. Surprisingly, in the unfolded high-temperature conformation, alpha-chymotrypsin has a pronounced proteolytic activity, although this activity is much smaller than that of the native enzyme.

A kinetic model to explain the maximum in alpha-amylase activity measurements in the presence of small carbohydrates.

PubMed

Baks, Tim; Janssen, Anja E M; Boom, Remko M

2006-06-20

The effect of the presence of several small carbohydrates on the measurement of the alpha-amylase activity was determined over a broad concentration range. At low carbohydrate concentrations, a distinct maximum in the alpha-amylase activity versus concentration curves was observed in several cases. At higher concentrations, all carbohydrates show a decreasing alpha-amylase activity at increasing carbohydrate concentrations. A general kinetic model has been developed that can be used to describe and explain these phenomena. This model is based on the formation of a carbohydrate-enzyme complex that remains active. It is assumed that this complex is formed when a carbohydrate binds to alpha-amylase without blocking the catalytic site and its surrounding subsites. Furthermore, the kinetic model incorporates substrate inhibition and substrate competition. Depending on the carbohydrate type and concentration, the measured alpha-amylase activity can be 75% lower than the actual alpha-amylase activity. The model that has been developed can be used to correct for these effects in order to obtain the actual amount of active enzyme. 2006 Wiley Periodicals, Inc.

High level activity of the mouse CCAAT/enhancer binding protein (C/EBP alpha) gene promoter involves autoregulation and several ubiquitous transcription factors.

PubMed Central

Legraverend, C; Antonson, P; Flodby, P; Xanthopoulos, K G

1993-01-01

The promoter region of the mouse CCAAT-Enhancer Binding Protein (C/EBP alpha) gene is capable of directing high levels of expression of reporter constructs in various cell lines, albeit even in cells that do not express their endogenous C/EBP alpha gene. To understand the molecular mechanisms underlying this ubiquitous expression, we have characterized the promoter region of the mouse C/EBP alpha gene by a variety of in vitro and in vivo methods. We show that three sites related in sequence to USF, BTE and C/EBP binding sites and present in promoter region -350/+3, are recognized by proteins from rat liver nuclear extracts. The sequence of the C/EBP alpha promoter that includes the USF binding site is also capable of forming stable complexes with purified Myc+Max heterodimers and mutation of this site drastically reduces transcription of C/EBP alpha promoter luciferase constructs both in liver and non liver cell lines. In addition, we identify three novel protein-binding sites two of which display similarity to NF-1 and a NF kappa B binding sites. The region located between nucleotides -197 and -178 forms several heat-stable complexes with liver nuclear proteins in vitro which are recognized mainly by antibodies specific for C/EBP alpha. Furthermore, transient expression of C/EBP alpha and to a lesser extent C/EBP beta expression vectors, results in transactivation of a cotransfected C/EBP alpha promoter-luciferase reporter construct. These experiments support the notion that the C/EBP alpha gene is regulated by C/EBP alpha but other C/EBP-related proteins may also be involved. Images PMID:8493090

Experience-dependent modulation of alpha and beta during action observation and motor imagery.

PubMed

Di Nota, Paula M; Chartrand, Julie M; Levkov, Gabriella R; Montefusco-Siegmund, Rodrigo; DeSouza, Joseph F X

2017-03-06

EEG studies investigating the neural networks that facilitate action observation (AO) and kinaesthetic motor imagery (KMI) have shown reduced, or desynchronized, power in the alpha (8-12 Hz) and beta (13-30 Hz) frequency bands relative to rest, reflecting efficient activation of task-relevant areas. Functional modulation of these networks through expertise in dance has been established using fMRI, with greater activation among experts during AO. While there is evidence for experience-dependent plasticity of alpha power during AO of dance, the influence of familiarity on beta power during AO, and alpha and beta activity during KMI, remain unclear. The purpose of the present study was to measure the impact of familiarity on confidence ratings and EEG activity during (1) AO of a brief ballet sequence, (2) KMI of this same sequence, and (3) KMI of non-dance movements among ballet dancers, dancers from other genres, and non-dancers. Ballet dancers highly familiar with the genre of the experimental stimulus demonstrated higher individual alpha peak frequency (iAPF), greater alpha desynchronization, and greater task-related beta power during AO, as well as faster iAPF during KMI of non-dance movements. While no between-group differences in alpha or beta power were observed during KMI of dance or non-dance movements, all participants showed significant desynchronization relative to baseline, and further desynchronization during dance KMI relative to non-dance KMI indicative of greater cognitive load. These findings confirm and extend evidence for experience-dependent plasticity of alpha and beta activity during AO of dance and KMI. We also provide novel evidence for modulation of iAPF that is faster when tuned to the specific motor repertoire of the observer. By considering the multiple functional roles of these frequency bands during the same task (AO), we have disentangled the compounded contribution of familiarity and expertise to alpha desynchronization for mediating task engagement among familiar ballet dancers and reflecting task difficulty among unfamiliar non-dance subjects, respectively. That KMI of a complex dance sequence relative to everyday, non-dance movements recruits greater cognitive resources suggests it may be a more powerful tool in driving neural plasticity of action networks, especially among the elderly and those with movement disorders.

Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy.

PubMed

Bemmerer, D; Confortola, F; Costantini, H; Formicola, A; Gyürky, Gy; Bonetti, R; Broggini, C; Corvisiero, P; Elekes, Z; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Imbriani, G; Junker, M; Laubenstein, M; Lemut, A; Limata, B; Lozza, V; Marta, M; Menegazzo, R; Prati, P; Roca, V; Rolfs, C; Alvarez, C Rossi; Somorjai, E; Straniero, O; Strieder, F; Terrasi, F; Trautvetter, H P

2006-09-22

The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity, and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148, and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S factor to solar energies.

Clasp/SJ Observation of Time Variations of Lyman-Alpha Emissions in a Solar Active Region

NASA Technical Reports Server (NTRS)

Ishikawa, S.; Kubo, M.; Katsukawa, Y.; Kano, R.; Narukage, N.; Ishikawa, R.; Bando, T.; Winebarger, A.; Kobayashi, K.; Trujillo Bueno, J.;

3D cultured immortalized human hepatocytes useful to develop drugs for blood-borne HCV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aly, Hussein Hassan; Shimotohno, Kunitada; Hijikata, Makoto

2009-02-06

Due to the high polymorphism of natural hepatitis C virus (HCV) variants, existing recombinant HCV replication models have failed to be effective in developing effective anti-HCV agents. In the current study, we describe an in vitro system that supports the infection and replication of natural HCV from patient blood using an immortalized primary human hepatocyte cell line cultured in a three-dimensional (3D) culture system. Comparison of the gene expression profile of cells cultured in the 3D system to those cultured in the existing 2D system demonstrated an up-regulation of several genes activated by peroxisome proliferator-activated receptor alpha (PPAR{alpha}) signaling. Furthermore,more » using PPAR{alpha} agonists and antagonists, we also analyzed the effect of PPAR{alpha} signaling on the modulation of HCV replication using this system. The 3D in vitro system described in this study provides significant insight into the search for novel anti-HCV strategies that are specific to various strains of HCV.« less

The effects of left and right monocular viewing on hemispheric activation.

PubMed

Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

2018-03-01

Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

Functional coupling of rat myometrial alpha 1-adrenergic receptors to Gh alpha/tissue transglutaminase 2 during pregnancy.

PubMed

Dupuis, Morgan; Lévy, Arlette; Mhaouty-Kodja, Sakina

2004-04-30

Gh alpha protein, which exhibits both transglutaminase and GTPase activities, represents a new class of GTP-binding proteins. In the present study, we characterized Gh alpha in rat uterine smooth muscle (myometrium) and followed its expression during pregnancy by reverse transcription-PCR and Western blot. We also measured transglutaminase and GTP binding functions and used a smooth muscle cell line to evaluate the role of Gh alpha in cell proliferation. The results show that pregnancy is associated with an up-regulation of Gh alpha expression at both the mRNA and protein level. Gh alpha induced during pregnancy is preferentially localized to the plasma membrane. This was found associated with an increased ability of plasma membrane preparations to catalyze Ca(2+)-dependent incorporation of [(3)H]putrescine into casein in vitro. In the cytosol, significant changes in the level of immunodetected Gh alpha and transglutaminase activity were seen only at term. Activation of alpha1-adrenergic receptors (alpha1-AR) enhanced photoaffinity labeling of plasma membrane Gh alpha. Moreover, the level of alpha1-AR-coupled Gh alpha increased progressively with pregnancy, which parallels the active period of myometrial cell proliferation. Overexpression of wild type Gh alpha in smooth muscle cell line DDT1-MF2 increased alpha1-AR-induced [(3)H]thymidine incorporation. A similar response was obtained in cells expressing the transglutaminase inactive mutant (C277S) of Gh alpha. Together, these findings underscore the role of Gh alpha as signal transducer of alpha1-AR-induced smooth muscle cell proliferation. In this context, pregnant rat myometrium provides an interesting physiological model to study the mechanisms underlying the regulation of the GTPase function of Gh alpha

Peroxisome proliferator-activated receptor {alpha} agonist-induced down-regulation of hepatic glucocorticoid receptor expression in SD rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Xiang; Li Ming; Sun Weiping

2008-04-18

It was reported that glucocorticoid production was inhibited by fenofibrate through suppression of type-1 11{beta}-hydroxysteroid dehydrogenase gene expression in liver. The inhibition might be a negative-feedback regulation of glucocorticoid receptor (GR) activity by peroxisome proliferator-activated receptor alpha (PPAR{alpha}), which is quickly induced by glucocorticoid in the liver. However, it is not clear if GR expression is changed by fenofibrate-induced PPAR{alpha} activation. In this study, we tested this possibility in the liver of Sprague-Dawley rats. GR expression was reduced by fenofibrate in a time- and does-dependent manner. The inhibition was observed in liver, but not in fat and muscle. The corticosteronemore » level in the blood was increased significantly by fenofibrate. These effects of fenofibrate were abolished by PPAR{alpha} inhibitor MK886, suggesting that fenofibrate activated through PPAR{alpha}. In conclusion, inhibition of GR expression may represent a new molecular mechanism for the negative feedback regulation of GR activity by PPAR{alpha}.« less

Regulation of NT-PGC-1alpha subcellular localization and function by protein kinase A-dependent modulation of nuclear export by CRM1.

PubMed

Chang, Ji Suk; Huypens, Peter; Zhang, Yubin; Black, Chelsea; Kralli, Anastasia; Gettys, Thomas W

2010-06-04

Peroxisome proliferator-activated receptor gamma co-activator-1alpha (PGC-1alpha) plays a central role in the regulation of cellular energy metabolism and metabolic adaptation to environmental and nutritional stimuli. We recently described a novel, biologically active splice variant of PGC-1alpha (NT-PGC-1alpha, amino acids 1-270) that retains the ability to interact with and transactivate nuclear hormone receptors through its N-terminal transactivation domain. Whereas PGC-1alpha is an unstable nuclear protein sensitive to ubiquitin-mediated targeting to the proteasome, NT-PGC-1alpha is relatively stable and predominantly cytoplasmic, suggesting that its ability to interact with and activate nuclear receptors and transcription factors is dependent upon regulated access to the nucleus. We provide evidence that NT-PGC-1alpha interacts with the nuclear exportin, CRM1, through a specific leucine-rich domain (nuclear export sequence) that regulates its export to the cytoplasm. The nuclear export of NT-PGC-1alpha is inhibited by protein kinase A-dependent phosphorylation of Ser-194, Ser-241, and Thr-256 on NT-PGC-1alpha, which effectively increases its nuclear concentration. Using site-directed mutagenesis to prevent or mimic phosphorylation at these sites, we show that the transcriptional activity of NT-PGC-1alpha is regulated in part through regulation of its subcellular localization. These findings suggest that the function of NT-PGC-1alpha as a transcriptional co-activator is regulated by protein kinase A-dependent inhibition of CRM1-mediated export from the nucleus.

Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Xia, E-mail: zhongxia1977@126.com; Li, Xiaonan; Liu, Fuli

2012-08-24

Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibitedmore » TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.« less

Identification of an antagonist that selectively blocks the activity of prostamides (prostaglandin-ethanolamides) in the feline iris.

PubMed

Woodward, D F; Krauss, A H; Wang, J W; Protzman, C E; Nieves, A L; Liang, Y; Donde, Y; Burk, R M; Landsverk, K; Struble, C

2007-02-01

The prostamides (prostaglandin-ethanolamides) and prostaglandin (PG) glyceryl esters are biosynthesized by COX-2 from the respective endocannabinoids anandamide and 2-arachidonyl glycerol. Agonist studies suggest that their pharmacologies are unique and unrelated to prostanoid receptors. This concept was further investigated using antagonists. The isolated feline iris was used as a key preparation, where prostanoid FP receptors and prostamide activity co-exist. Activity at human recombinant FP and other prostanoid receptors was determined using stable transfectants. In the feline iris, AGN 204396 produced a rightward shift of the dose-response curves for prostamide F2alpha and the prostamide F2alpha analog bimatoprost but did not block the effects of PGF2alpha and synthetic FP receptor agonists. Studies on human recombinant prostanoid receptors confirmed that AGN 204396 did not behave as a prostanoid FP receptor antagonist. AGN 204396 exhibited no antagonism at DP and EP1-4, but was a highly effective TP receptor antagonist. Contrary to expectation, the FP receptor antagonist AL-8810 efficaciously contracted the cat iris. AGN 204396 did not affect AL-8810 induced contractions, demonstrating that AL-8810 and AGN 204396 are pharmacologically distinct. Unlike AL-8810, the ethylamide derivate of AL-8810 was not an agonist. Al-8810 did not block prostamide F2alpha activity. Finally, AGN 204396 did not block PGE2-glyceryl ester activity. The ability of AGN 204396 to selectively block prostamide responses suggests the existence of prostamide sensitive receptors as entities distinct from receptors recognizing PGF2alpha and PGE2-glyceryl ester.

Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

PubMed

Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

1994-05-13

Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

Alpha-synuclein levels in blood plasma decline with healthy aging.

PubMed

Koehler, Niklas K U; Stransky, Elke; Meyer, Mirjam; Gaertner, Susanne; Shing, Mona; Schnaidt, Martina; Celej, Maria S; Jovin, Thomas M; Leyhe, Thomas; Laske, Christoph; Batra, Anil; Buchkremer, Gerhard; Fallgatter, Andreas J; Wernet, Dorothee; Richartz-Salzburger, Elke

2015-01-01

There is unequivocal evidence that alpha-synuclein plays a pivotal pathophysiological role in neurodegenerative diseases, and in particular in synucleinopathies. These disorders present with a variable extent of cognitive impairment and alpha-synuclein is being explored as a biomarker in CSF, blood serum and plasma. Considering key events of aging that include proteostasis, alpha-synuclein may not only be useful as a marker for differential diagnosis but also for aging per se. To explore this hypothesis, we developed a highly specific ELISA to measure alpha-synuclein. In healthy males plasma alpha-synuclein levels correlated strongly with age, revealing much lower concentrations in older (avg. 58.1 years) compared to younger (avg. 27.6 years) individuals. This difference between the age groups was enhanced after acidification of the plasmas (p<0.0001), possibly reflecting a decrease of alpha-synuclein-antibody complexes or chaperone activity in older individuals. Our results support the concept that alpha-synuclein homeostasis may be impaired early on, possibly due to disturbance of the proteostasis network, a key component of healthy aging. Thus, alpha-synuclein may be a novel biomarker of aging, a factor that should be considered when analyzing its presence in biological specimens.

Hyperglycemia-conditioned increase in alpha-2-macroglobulin in healthy normal subjects: a phenomenon correlated with deficient antithrombin III activity.

PubMed

Ceriello, A; Quatraro, A; Dello Russo, P; Marchi, E; Barbanti, M; Giugliano, D

1989-01-01

Induced hyperglycemia in normal subjects increases alpha 2-macroglobulin (alpha 2M) activity and alpha 2M concentration and reduces antithrombin III (ATIII) activity, while it does not affect ATIII plasma concentration. Hyperglycemia-determined variations in ATIII activity and alpha 2M molecules are correlated in an inverse and parallel fashion. A compensatory role for the increase in alpha 2M in the regulation of the coagulation system may be hypothesized. Moreover, these data provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may influence the levels of some risk factors for the development of complications in diabetes.

Structural elucidation of novel phosphocholine-containing glycosylinositol-phosphoceramides in filamentous fungi and their induction of cell death of cultured rice cells.

PubMed Central

Aoki, Kazuhiro; Uchiyama, Ryosuke; Itonori, Saki; Sugita, Mutsumi; Che, Fang-Sik; Isogai, Akira; Hada, Noriyasu; Hada, Junko; Takeda, Tadahiro; Kumagai, Hidehiko; Yamamoto, Kenji

2004-01-01

Novel ZGLs (zwitterionic glycosphingolipids) have been found in and extracted from the mycelia of filamentous fungi ( Acremonium sp.) isolated from soil. Five ZGLs (ZGL1-ZGL5) were structurally elucidated by sugar compositional analysis, methylation analysis, periodate oxidation, matrix-assisted laser-desorption ionization-time-of-flight MS, (1)H-NMR spectroscopy and fast-atom bombardment MS. Their chemical structures were as follows: GlcN(alpha1-2)Ins1-P-1Cer (ZGL1), Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL2), Man(alpha1-6)Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL3), PC-->6Man(alpha1-6)GlcN(alpha1-2)Ins1- P -1Cer (ZGL4), and PC-->6Man(alpha1-6)Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL5) (where Cer is ceramide and PC is phosphocholine). In addition, one acidic glycosphingolipid, which was the precursor of ZGLs, was also characterized as inositol-phosphoceramide. The core structure of the ZGLs, GlcN(alpha1-2)Ins1- P, is rather different from those found in other fungi, such as Man(alpha1-2)Ins1- P and Man(alpha1-6)Ins1- P. Interestingly, the terminal mannose residue of ZGL4 and ZGL5 was modified further with a PC group. The presence of PC-containing glycosylinositol-phosphoceramides has not been reported previously in any organism. The ceramide constituents of both ZGLs and acidic glycosphingolipid were essentially the same, and consisted of a 4-hydroxyoctadecasphinganine (phytosphingosine) as the sole sphingoid base and 2-hydroxytetracosanoic acid (>90%) as the major fatty acid. ZGLs were found to cause cell death in suspensions of cultured rice cells. The cell death-inducing activity of ZGLs is probably due to the characteristic glycan moiety of Man(alpha1-6)GlcN, and PC-containing ZGLs had high activity. This study is the first to demonstrate that fungal glycosylinositol-phosphoceramides induce cell death in cultured rice cells. PMID:14583095

High-voltage electroencephalogram spindles in rats, aging and 5-HT2 antagonism.

PubMed

Moyanova, S; Kortenska, L; Kirov, R

1998-03-09

We examined the effects of serotonin-2 (5-hydroxytryptamine-2, 5-HT2) receptor antagonists on the so-called high-voltage spindles (HVS, electroencephalographic patterns, characterized by large amplitude rhythmic waves mainly in the alpha band), recorded from the frontal cortex of young, middle-aged and old freely-moving rats during waking immobility. The study was based on the assumption that the effects of 5-HT2 receptor antagonists on the HVS activity depend on the age of rats, because there is evidence for an age-related decrease in the 5-HT2 binding sites density. Four parameters of the electroencephalogram (EEG) were used to characterize the HVS activity: the square root-transformed EEG peak power in the alpha band, the frequency corresponding to this peak (both measured from the EEG power spectra using the fast Fourier transform), the HVS mean duration, and the HVS incidence (both measured from the EEG records). The EEG parameters were analyzed after i.p. administration of three 5-HT2 receptor antagonists: ketanserin, ritanserin and cyproheptadine. In young rats, the three drugs increased the alpha power, but did not change the alpha peak-corresponding frequency. Ketanserin and ritanserin did not change the HVS mean duration and HVS incidence, while cyproheptadine increased both these parameters in young rats. In middle-aged and old untreated rats, the HVS activity was significantly increased. The three 5-HT2 antagonists did not change the HVS activity in aged rats, which could be due to age-related suppression of the 5-HT2 receptor functions. Copyright 1998 Elsevier Science B.V.

Pioglitazone inhibits LOX-1 expression in human coronary artery endothelial cells by reducing intracellular superoxide radical generation.

PubMed

Mehta, Jawahar L; Hu, Bo; Chen, Jiawei; Li, Dayuan

2003-12-01

LOX-1, a novel lectin-like receptor for oxidized LDL (ox-LDL), is expressed in response to ox-LDL, angiotensin II (Ang II), tumor necrosis factor (TNF)-alpha, and other stress stimuli. It is highly expressed in atherosclerotic tissues. Peroxisome proliferator-activated receptor (PPAR)-gamma ligands, such as pioglitazone, exert antiatherosclerotic effects. This study examined the regulation of LOX-1 expression in human coronary artery endothelial cells (HCAECs) by pioglitazone. Fourth generation HCAECs were treated with ox-LDL, Ang II, or TNF-alpha with or without pioglitazone pretreatment. All 3 stimuli upregulated LOX-1 expression (mRNA and protein). Pioglitazone, in a concentration-dependent manner, reduced LOX-1 expression (P<0.01 versus ox-LDL, Ang II, or TNF-alpha alone). Ox-LDL, Ang II, and TNF-alpha each enhanced intracellular superoxide radical generation, and pioglitazone pretreatment reduced superoxide generation (P<0.01 versus ox-LDL, Ang II, or TNF-alpha). Furthermore, all 3 stimuli upregulated the expression of the transcription factors nuclear factor-kappaB and activator protein-1 (determined by electrophoretic mobility shift assay), and pioglitazone pretreatment reduced this expression (P<0.01 versus ox-LDL, Ang II, or TNF-alpha). To determine the biological significance of pioglitazone-mediated downregulation of LOX-1, we studied monocyte adhesion to ox-LDL-treated HCAECs. Pioglitazone reduced the adhesion of monocytes to activated HCAECs in a fashion similar to that produced by antisense to LOX-1 mRNA. These observations suggest that the PPAR-gamma ligand pioglitazone reduces intracellular superoxide radical generation and subsequently reduces the expression of transcription factors, expression of the LOX-1 gene, and monocyte adhesion to activated endothelium. The salutary effect of PPAR-gamma ligands in atherogenesis may involve the inhibition of LOX-1 and the adhesion of monocytes to endothelium.

How active was solar cycle 22?

NASA Technical Reports Server (NTRS)

Hoegy, W. R.; Pesnell, W. D.; Woods, T. N.; Rottman, G. J.

1993-01-01

Solar EUV observations from the Langmuir probe on Pioneer Venus Orbiter suggest that at EUV wavelengths solar cycle 22 was more active than solar cycle 21. The Langmuir probe, acting as a photodiode, measured the integrated solar EUV flux over a 13 1/2 year period from January 1979 to June 1992, the longest continuous solar EUV measurement. The Ipe EUV flux correlated very well with the SME measurement of L-alpha during the lifetime of SME and with the UARS SOLSTICE L-alpha from October 1991 to June 1992 when the Ipe measurement ceased. Starting with the peak of solar cycle 21, there was good general agreement of Ipe EUV with the 10.7 cm, Ca K, and He 10830 solar indices, until the onset of solar cycle 22. From 1989 to the start of 1992, the 10.7 cm flux exhibited a broad maximum consisting of two peaks of nearly equal magnitude, whereas Ipe EUV exhibited a strong increase during this time period making the second peak significantly higher than the first. The only solar index that exhibits the same increase in solar activity as Ipe EUV and L-alpha during the cycle 22 peak is the total magnetic flux. The case for high activity during this peak is also supported by the presence of very high solar flare intensity.

Involvement of the Clock Gene Rev-erb alpha in the Regulation of Glucagon Secretion in Pancreatic Alpha-Cells

PubMed Central

Vieira, Elaine; Marroquí, Laura; Figueroa, Ana Lucia C.; Merino, Beatriz; Fernandez-Ruiz, Rebeca; Nadal, Angel; Burris, Thomas P.; Gomis, Ramon; Quesada, Ivan

2013-01-01

Disruption of pancreatic clock genes impairs pancreatic beta-cell function, leading to the onset of diabetes. Despite the importance of pancreatic alpha-cells in the regulation of glucose homeostasis and in diabetes pathophysiology, nothing is known about the role of clock genes in these cells. Here, we identify the clock gene Rev-erb alpha as a new intracellular regulator of glucagon secretion. Rev-erb alpha down-regulation by siRNA (60–70% inhibition) in alphaTC1-9 cells inhibited low-glucose induced glucagon secretion (p<0.05) and led to a decrease in key genes of the exocytotic machinery. The Rev-erb alpha agonist GSK4112 increased glucagon secretion (1.6 fold) and intracellular calcium signals in alphaTC1-9 cells and mouse primary alpha-cells, whereas the Rev-erb alpha antagonist SR8278 produced the opposite effect. At 0.5 mM glucose, alphaTC1-9 cells exhibited intrinsic circadian Rev-erb alpha expression oscillations that were inhibited by 11 mM glucose. In mouse primary alpha-cells, glucose induced similar effects (p<0.001). High glucose inhibited key genes controlled by AMPK such as Nampt, Sirt1 and PGC-1 alpha in alphaTC1-9 cells (p<0.05). AMPK activation by metformin completely reversed the inhibitory effect of glucose on Nampt-Sirt1-PGC-1 alpha and Rev-erb alpha. Nampt inhibition decreased Sirt1, PGC-1 alpha and Rev-erb alpha mRNA expression (p<0.01) and glucagon release (p<0.05). These findings identify Rev-erb alpha as a new intracellular regulator of glucagon secretion via AMPK/Nampt/Sirt1 pathway. PMID:23936124

Alpha Centauri at a Crossroads

NASA Astrophysics Data System (ADS)

Ayres, Thomas

2014-09-01

Nearby Alpha Centauri (G2V+K1V) contains the two best characterized solar-like dwarf stars, which also have the best studied X-ray activity cycles, extending back to the 1970's. Objective is to continue tracking the evolving multi-decadal high-energy narrative of Alpha Cen with semiannual HRC-I pointings in Cycles 16-18, as the system reaches a coronal crossroads: solar twin A rising toward cycle maximum, K-type companion B sinking into a minimum. HST/STIS UV spectra will support and leverage the X-ray measurements by probing subcoronal dynamics, with connection to the corona through the FUV Fe XII forbidden line. Only Chandra can resolve the AB X-ray sources as the Alpha Cen orbit also reaches a crossroads in 2016.

Apolipoprotein CIII-induced THP-1 cell adhesion to endothelial cells involves pertussis toxin-sensitive G protein- and protein kinase C alpha-mediated nuclear factor-kappaB activation.

PubMed

Kawakami, Akio; Aikawa, Masanori; Nitta, Noriko; Yoshida, Masayuki; Libby, Peter; Sacks, Frank M

2007-01-01

Plasma apolipoprotein CIII (apoCIII) independently predicts risk for coronary heart disease (CHD). We recently reported that apoCIII directly enhances adhesion of human monocytes to endothelial cells (ECs), and identified the activation of PKC alpha as a necessary upstream event of enhanced monocyte adhesion. This study tested the hypothesis that apoCIII activates PKC alpha in human monocytic THP-1 cells, leading to NF-kappaB activation. Among inhibitors specific to PKC activators, phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609 limited apoCIII-induced PKC alpha activation and THP-1 cell adhesion. ApoCIII increased PC-PLC activity in THP-1 cells, resulting in PKC alpha activation. Pertussis toxin (PTX) inhibited apoCIII-induced PC-PLC activation and subsequent PKC alpha activation, implicating PTX-sensitive G protein pathway. ApoCIII further activated nuclear factor-kappaB (NF-kappaB) through PKC alpha in THP-1 cells and augmented beta1-integrin expression. The NF-kappaB inhibitor peptide SN50 partially inhibited apoCIII-induced beta1-integrin expression and THP-1 cell adhesion. ApoCIII-rich VLDL had similar effects to apoCIII alone. PTX-sensitive G protein pathway participates critically in PKC alpha stimulation in THP-1 cells exposed to apoCIII, activating NF-kappaB, and increasing beta1-integrin. This action causes monocytic cells to adhere to endothelial cells. Furthermore, because leukocyte NF-kappaB activation contributes to inflammatory aspects of atherogenesis, apoCIII may stimulate diverse inflammatory responses through monocyte activation.

Cancer-preventive activities of tocopherols and tocotrienols.

PubMed

Ju, Jihyeung; Picinich, Sonia C; Yang, Zhihong; Zhao, Yang; Suh, Nanjoo; Kong, Ah-Ng; Yang, Chung S

2010-04-01

The cancer-preventive activity of vitamin E has been studied. Whereas some epidemiological studies have suggested a protective effect of vitamin E against cancer formation, many large-scale intervention studies with alpha-tocopherol (usually large doses) have not demonstrated a cancer-preventive effect. Studies on alpha-tocopherol in animal models also have not demonstrated robust cancer prevention effects. One possible explanation for the lack of demonstrable cancer-preventive effects is that high doses of alpha-tocopherol decrease the blood and tissue levels of delta-tocopherols. It has been suggested that gamma-tocopherol, due to its strong anti-inflammatory and other activities, may be the more effective form of vitamin E in cancer prevention. Our recent results have demonstrated that a gamma-tocopherol-rich mixture of tocopherols inhibits colon, prostate, mammary and lung tumorigenesis in animal models, suggesting that this mixture may have a high potential for applications in the prevention of human cancer. In this review, we discuss biochemical properties of tocopherols, results of possible cancer-preventive effects in humans and animal models and possible mechanisms involved in the inhibition of carcinogenesis. Based on this information, we propose that a gamma-tocopherol-rich mixture of tocopherols is a very promising cancer-preventive agent and warrants extensive future research.

Cortical processes of speech illusions in the general population.

PubMed

Schepers, E; Bodar, L; van Os, J; Lousberg, R

2016-10-18

There is evidence that experimentally elicited auditory illusions in the general population index risk for psychotic symptoms. As little is known about underlying cortical mechanisms of auditory illusions, an experiment was conducted to analyze processing of auditory illusions in a general population sample. In a follow-up design with two measurement moments (baseline and 6 months), participants (n = 83) underwent the White Noise task under simultaneous recording with a 14-lead EEG. An auditory illusion was defined as hearing any speech in a sound fragment containing white noise. A total number of 256 speech illusions (SI) were observed over the two measurements, with a high degree of stability of SI over time. There were 7 main effects of speech illusion on the EEG alpha band-the most significant indicating a decrease in activity at T3 (t = -4.05). Other EEG frequency bands (slow beta, fast beta, gamma, delta, theta) showed no significant associations with SI. SIs are characterized by reduced alpha activity in non-clinical populations. Given the association of SIs with psychosis, follow-up research is required to examine the possibility of reduced alpha activity mediating SIs in high risk and symptomatic populations.

Structural and functional characterization of a novel homodimeric three-finger neurotoxin from the venom of Ophiophagus hannah (king cobra).

PubMed

Roy, Amrita; Zhou, Xingding; Chong, Ming Zhi; D'hoedt, Dieter; Foo, Chun Shin; Rajagopalan, Nandhakishore; Nirthanan, Selvanayagam; Bertrand, Daniel; Sivaraman, J; Kini, R Manjunatha

2010-03-12

Snake venoms are a mixture of pharmacologically active proteins and polypeptides that have led to the development of molecular probes and therapeutic agents. Here, we describe the structural and functional characterization of a novel neurotoxin, haditoxin, from the venom of Ophiophagus hannah (King cobra). Haditoxin exhibited novel pharmacology with antagonism toward muscle (alphabetagammadelta) and neuronal (alpha(7), alpha(3)beta(2), and alpha(4)beta(2)) nicotinic acetylcholine receptors (nAChRs) with highest affinity for alpha(7)-nAChRs. The high resolution (1.5 A) crystal structure revealed haditoxin to be a homodimer, like kappa-neurotoxins, which target neuronal alpha(3)beta(2)- and alpha(4)beta(2)-nAChRs. Interestingly however, the monomeric subunits of haditoxin were composed of a three-finger protein fold typical of curaremimetic short-chain alpha-neurotoxins. Biochemical studies confirmed that it existed as a non-covalent dimer species in solution. Its structural similarity to short-chain alpha-neurotoxins and kappa-neurotoxins notwithstanding, haditoxin exhibited unique blockade of alpha(7)-nAChRs (IC(50) 180 nm), which is recognized by neither short-chain alpha-neurotoxins nor kappa-neurotoxins. This is the first report of a dimeric short-chain alpha-neurotoxin interacting with neuronal alpha(7)-nAChRs as well as the first homodimeric three-finger toxin to interact with muscle nAChRs.

Resting-State Alpha in Autism Spectrum Disorder and Alpha Associations with Thalamic Volume

ERIC Educational Resources Information Center

Edgar, J. Christopher; Heiken, Kory; Chen, Yu-Han; Herrington, John D.; Chow, Vivian; Liu, Song; Bloy, Luke; Huang, Mingxiong; Pandey, Juhi; Cannon, Katelyn M.; Qasmieh, Saba; Levy, Susan E.; Schultz, Robert T.; Roberts, Timothy P. L.

2015-01-01

Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism spectrum disorder (ASD). The present study obtained estimates of resting-state (RS) alpha activity in children with ASD and examined associations between alpha activity, age, and clinical symptoms. Given that the thalamus modulates cortical RS alpha…

Hepatocyte nuclear factor-4alpha is a central transactivator of the mouse Ntcp gene.

PubMed

Geier, Andreas; Martin, Ina V; Dietrich, Christoph G; Balasubramaniyan, Natarajan; Strauch, Sonja; Suchy, Frederick J; Gartung, Carsten; Trautwein, Christian; Ananthanarayanan, Meenakshisundaram

2008-08-01

Sodium taurocholate cotransporting polypeptide (Ntcp) is the major uptake system for conjugated bile acids. Deletions of hepatocyte nuclear factor (HNF)-1alpha and retinoid X receptor-alpha:retinoic acid receptor-alpha binding sites in the mouse 5'-flanking region corresponding to putatively central regulatory elements of rat Ntcp do not significantly reduce promoter activity. We hypothesized that HNF-4alpha, which is increasingly recognized as a central regulator of hepatocyte function, may directly transactivate mouse (mNtcp). A 1.1-kb 5'-upstream region including the mouse Ntcp promoter was cloned and compared with the rat promoter. In contrast to a moderate 3.5-fold activation of mNtcp by HNF-1alpha, HNF-4alpha cotransfection led to a robust 20-fold activation. Deletion analysis of mouse and rat Ntcp promoters mapped a conserved HNF-4alpha consensus site at -345/-326 and -335/-316 bp, respectively. p-475bpmNtcpLUC is not transactivated by HNF-1alpha but shows a 50-fold enhanced activity upon cotransfection with HNF-4alpha. Gel mobility shift assays demonstrated a complex of the HNF-4alpha-element formed with liver nuclear extracts that was blocked by an HNF-4alpha specific antibody. HNF-4alpha binding was confirmed by chromatin immunoprecipitation. Using Hepa 1-6 cells, HNF-4alpha-knockdown resulted in a significant 95% reduction in NTCP mRNA. In conclusion, mouse Ntcp is regulated by HNF-4alpha via a conserved distal cis-element independently of HNF-1alpha.

6-Mercaptopurine, an activator of Nur77, enhances transcriptional activity of HIF-1alpha resulting in new vessel formation.

PubMed

Yoo, Y-G; Na, T-Y; Yang, W-K; Kim, H-J; Lee, I-K; Kong, G; Chung, J-H; Lee, M-O

2007-05-31

Hypoxia-inducible factor-1alpha (HIF-1alpha) plays a central role in oxygen homeostasis. Previously, we reported that the orphan nuclear receptor Nur77 functions in stabilizing HIF-1alpha. Here, we demonstrate that 6-mercaptopurine (6-MP), an activator of the NR4A family members, enhances transcriptional activity of HIF-1. 6-MP enhanced the protein-level of HIF-1alpha as well as vascular endothelial growth factor (VEGF) in a dose- and time-dependent manner. The induction of HIF-1alpha was abolished by the transfection of either a dominant-negative Nur77 mutant or si-Nur77, indicating a critical role of Nur77 in the 6-MP action. The HIF-1alpha protein level remained up to 60 min in the presence of 6-MP when de novo protein synthesis was blocked by cycloheximide, suggesting that 6-MP induces stabilization of the HIF-1alpha protein. The fact that 6-MP decreased the association of HIF-1alpha with von Hippel-Lindau protein and the acetylation of HIF-1alpha, may explain how 6-MP induced stability of HIF-1alpha. Further, 6-MP induced the transactivation function of HIF-1alpha by recruiting co-activator cyclic-AMP-response-element-binding protein. Finally, 6-MP enhanced the expression of HIF-1alpha and VEGF, and the formation of capillary tubes in human umbilical vascular endothelial cells. Together, our results provide a new insight for 6-MP action in the stabilization of HIF-1alpha and imply a potential application of 6-MP in hypoxia-associated human vascular diseases.

Identification of potential target genes of ROR-alpha in THP1 and HUVEC cell lines.

PubMed

Gulec, Cagri; Coban, Neslihan; Ozsait-Selcuk, Bilge; Sirma-Ekmekci, Sema; Yildirim, Ozlem; Erginel-Unaltuna, Nihan

2017-04-01

ROR-alpha is a nuclear receptor, activity of which can be modulated by natural or synthetic ligands. Due to its possible involvement in, and potential therapeutic target for atherosclerosis, we aimed to identify ROR-alpha target genes in monocytic and endothelial cell lines. We performed chromatin immunoprecipitation (ChIP) followed by tiling array (ChIP-on-chip) for ROR-alpha in monocytic cell line THP1 and endothelial cell line HUVEC. Following bioinformatic analysis of the array data, we tested four candidate genes in terms of dependence of their expression level on ligand-mediated ROR-alpha activity, and two of them in terms of promoter occupancy by ROR-alpha. Bioinformatic analyses of ChIP-on-chip data suggested that ROR-alpha binds to genomic regions near the transcription start site (TSS) of more than 3000 genes in THP1 and HUVEC. Potential ROR-alpha target genes in both cell types seem to be involved mainly in membrane receptor activity, signal transduction and ion transport. While SPP1 and IKBKA were shown to be direct target genes of ROR-alpha in THP1 monocytes, inflammation related gene HMOX1 and heat shock protein gene HSPA8 were shown to be potential target genes of ROR-alpha. Our results suggest that ROR-alpha may regulate signaling receptor activity, and transmembrane transport activity through its potential target genes. ROR-alpha seems also to play role in cellular sensitivity to environmental substances like arsenite and chloroprene. Although, the expression analyses have shown that synthetic ROR-alpha ligands can modulate some of potential ROR-alpha target genes, functional significance of ligand-dependent modulation of gene expression needs to be confirmed with further analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

Combinations of ERK and p38 MAPK inhibitors ablate tumor necrosis factor-alpha (TNF-alpha ) mRNA induction. Evidence for selective destabilization of TNF-alpha transcripts.

PubMed

Rutault, K; Hazzalin, C A; Mahadevan, L C

2001-03-02

Tumor necrosis factor-alpha (TNF-alpha) is a potent proinflammatory cytokine whose synthesis and secretion are implicated in diverse pathologies. Hence, inhibition of TNF-alpha transcription or translation and neutralization of its protein product represent major pharmaceutical strategies to control inflammation. We have studied the role of ERK and p38 mitogen-activated protein (MAP) kinase in controlling TNF-alpha mRNA levels in differentiated THP-1 cells and in freshly purified human monocytes. We show here that it is possible to produce virtually complete inhibition of lipopolysaccharide-stimulated TNF-alpha mRNA accumulation by using a combination of ERK and p38 MAP kinase inhibitors. Furthermore, substantial inhibition is achievable using combinations of 1 microm of each inhibitor, whereas inhibitors used individually are incapable of producing complete inhibition even at high concentrations. Finally, addressing mechanisms involved, we show that inhibition of p38 MAP kinase selectively destabilizes TNF-alpha transcripts but does not affect degradation of c-jun transcripts. These results impinge on the controversy in the literature surrounding the mode of action of MAP kinase inhibitors on TNF-alpha mRNA and suggest the use of combinations of MAP kinase inhibitors as an effective anti-inflammatory strategy.

Leptin interferes with the effects of the antiestrogen ICI 182,780 in MCF-7 breast cancer cells.

PubMed

Garofalo, Cecilia; Sisci, Diego; Surmacz, Eva

2004-10-01

Obesity is a risk factor for breast cancer development in postmenopausal women and correlates with shorter disease-free and overall survival in breast cancer patients, regardless of menopausal status. Adipose tissue is a major source of leptin, a cytokine regulating energy balance and controlling different processes in peripheral tissues, including breast cancer cell growth. Here, we investigated whether leptin can counteract antitumorigenic activities of the antiestrogen ICI 182,780 in breast cancer cells. Mitogenic response to leptin and the effects of leptin on ICI 182,780-dependent growth inhibition were studied in MCF-7 estrogen receptor alpha-positive breast cancer cells. The expression of leptin receptor and the activation of signaling pathways were studied by Western immunoblotting. The interference of leptin with ICI 182,780-induced estrogen receptor alpha degradation was probed by Western immunoblotting, fluorescence microscopy, and pulse-chase experiments. Leptin effects on estrogen receptor alpha-dependent transcription in the presence and absence of ICI 182,780 were studied by luciferase reporter assays and chromatin immunoprecipitation. MCF-7 cells were found to express the leptin receptor and respond to leptin with cell growth and activation the signal transducers and activators of transcription 3, extracellular signal-regulated kinase-1/2, and Akt/GSK3/pRb pathways. The exposure of cells to 10 nmol/L ICI 182,780 blocked cell proliferation, induced rapid estrogen receptor alpha degradation, inhibited nuclear estrogen receptor alpha expression, and reduced estrogen receptor alpha-dependent transcription from estrogen response element-containing promoters. All of these effects of ICI 182,780 were significantly attenuated by simultaneous treatment of cells with 100 ng/mL leptin. Leptin interferes with the effects of ICI 182,780 on estrogen receptor alpha in breast cancer cells. Thus, high leptin levels in obese breast cancer patients might contribute to the development of antiestrogen resistance.

Function of the two Xenopus smad4s in early frog development.

PubMed

Chang, Chenbei; Brivanlou, Ali H; Harland, Richard M

2006-10-13

Signals from the transforming growth factor beta family members are transmitted in the cell through specific receptor-activated Smads and a common partner Smad4. Two Smad4 genes (alpha and beta/10, or smad4 and smad4.2) have been isolated from Xenopus, and conflicting data are reported for Smad4beta/10 actions in mesodermal and neural induction. To further understand the functions of the Smad4s in early frog development, we analyzed their activities in detail. We report that Smad10 is a mutant form of Smad4beta that harbors a missense mutation of a conserved arginine to histidine in the MH1 domain. The mutation results in enhanced association of Smad10 with the nuclear transcription corepressor Ski and leads to its neural inducing activity through inhibition of bone morphogenetic protein (BMP) signaling. In contrast to Smad10, both Smad4alpha and Smad4beta enhanced BMP signals in ectodermal explants. Using antisense morpholino oligonucleotides (MOs) to knockdown endogenous Smad4 protein levels, we discovered that Smad4beta was required for both activin- and BMP-mediated mesodermal induction in animal caps, whereas Smad4alpha affected only the BMP signals. Neither Smad4 was involved directly in neural induction. Expression of Smad4beta-MO in early frog embryos resulted in reduction of mesodermal markers and defects in axial structures, which were rescued by either Smad4alpha or Smad4beta. Smad4alpha-MO induced only minor deficiency at late stages. As Smad4beta, but not Smad4alpha, is expressed at high levels maternally and during early gastrulation, our data suggest that although Smad4alpha and Smad4beta may have similar activities, they are differentially utilized during frog embryogenesis, with only Smad4beta being essential for mesoderm induction.

Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

PubMed Central

May, Felicity EB

2014-01-01

The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel drugs might have utility in the management of advanced breast cancer, and biomarkers for stratification of patients likely to benefit, are discussed. Finally, the potential side effects of the novel drugs on metabolism, osteoporosis, osteo-metastasis, and cachexia are considered. PMID:24904222

Activity of Tumor Necrosis Factor-alpha (TNF-alpha) and its soluble type I receptor (p55TNF-R) in some drug-induced cutaneous reactions.

PubMed

Chodorowska, Grazyna; Czelej, Dorota; Niewiedzioł, Marta

2003-01-01

Plasma concentration of TNF-alpha and its type I receptor (p55TNF-R) was examined in 126 patients with drug-induced skin reactions using immunoenzymatic ELISA method. Patients were subdivided into 6 groups: maculopapular eruptions (ME), erythema multiforme (EM), erythema multiforme coexisting with erythema nodosum (EMN), hyperergic vasculitis (HV), Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN). In the acute clinical stage highly significant (p<0.001) or significant (p<0.01) elevation of mean plasma concentrations of the cytokine and its receptor was found in all examined groups in comparison with the control. Clearing of clinical symptoms was connected with considerable decrease (p<0.001, p<0.01) of mean plasma levels of the both proteins in comparison with the before treatment values. TNF-alpha concentrations still remained significantly more elevated than those observed in the control. The results indicate that plasma activity of TNF-alpha and its p55 receptor change with the clinical course of the examined drug-induced skin reactions, which suggests the partake of both proteins in the pathogenesis of these diseases.

Cloning, sequencing, and expression of the gene encoding amylopullulanase from Pyrococcus furiosus and biochemical characterization of the recombinant enzyme.

PubMed Central

Dong, G; Vieille, C; Zeikus, J G

1997-01-01

The gene encoding the Pyrococcus furiosus hyperthermophilic amylopullulanase (APU) was cloned, sequenced, and expressed in Escherichia coli. The gene encoded a single 827-residue polypeptide with a 26-residue signal peptide. The protein sequence had very low homology (17 to 21% identity) with other APUs and enzymes of the alpha-amylase family. In particular, none of the consensus regions present in the alpha-amylase family could be identified. P. furiosus APU showed similarity to three proteins, including the P. furiosus intracellular alpha-amylase and Dictyoglomus thermophilum alpha-amylase A. The mature protein had a molecular weight of 89,000. The recombinant P. furiosus APU remained folded after denaturation at temperatures of < or = 70 degrees C and showed an apparent molecular weight of 50,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Denaturating temperatures of above 100 degrees C were required for complete unfolding. The enzyme was extremely thermostable, with an optimal activity at 105 degrees C and pH 5.5. Ca2+ increased the enzyme activity, thermostability, and substrate affinity. The enzyme was highly resistant to chemical denaturing reagents, and its activity increased up to twofold in the presence of surfactants. PMID:9293009

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity

PubMed Central

1984-01-01

The processing of asparagine-linked oligosaccharides on the alpha- chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N- acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin. PMID:6420419

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity.

PubMed

Hickman, S; Theodorakis, J L; Greco, J M; Brown, P H

1984-02-01

The processing of asparagine-linked oligosaccharides on the alpha-chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N-acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin.

Determination of 7alpha-OH cholesterol by LC-MS/MS: Application in assessing the activity of CYP7A1 in cholestatic minipigs

USDA-ARS?s Scientific Manuscript database

An LC-MS/MS method was developed and validated to determine 7alpha-OH cholesterol in liver microsome. This method was convenient and fast with high specificity and sensitivity. Briefly, a gradient elution was performed on a Synergi polar-C18 column (50 x 4.6mm i.d., 3microm). The mobile phase (cons...

A novel method for determination of alpha1,6fucosyltransferase activity using a reducing oligosaccharide from egg yolk as a specific acceptor.

PubMed

Yazawa, S; Kochibe, N; Nishimura, T; Shima, C; Takai, I; Adachi, M; Asao, T; Hada, T; Enoki, Y; Juneja, L R

1998-09-01

A new method for determination of alpha1,6fucosyltransferase activity has been described. Recently, the disialyl-biantennary undecasaccharide was prepared in high yield from egg yolk [(1996), Carbohydr Lett 2: 137-42]. By treatment of this oligosaccharide with neuraminidase and beta-galactosidase, we readily obtained an asialo-agalacto-biantennary heptasaccharide (GlcNAcbeta 1,2Manalpha1,6[GlcNAcbeta1,2Manalpha1,3]Manbeta1 ,4GlcNAcbeta1,4GlcNAc). Using this asialo-agalacto-oligosaccharide as an acceptor, fucosyltransferases from human plasma and extracts of various human hepatoma cell lines were assayed in the presence of GDP-[3H]fucose. The reaction mixture was applied to a column of GlcNAc-binding, Psathyrella velutina lectin coupled gel. All the fucosylated acceptor were bound to the column which was eluted with 50 mM GlcNAc. Structural analyses revealed that only the innermost GlcNAc residue of the acceptor was fucosylated through an alpha1,6-linkage, and the oligosaccharide prepared could be used as a specific acceptor for alpha1,6fucosyltransferase. The present method was used to screen plasma alpha1,6fucosyltransferase in several patient groups, and significantly elevated activities were found in samples from patients with liver diseases, including chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma.

C/EBP beta regulation of the tumor necrosis factor alpha gene.

PubMed Central

Pope, R M; Leutz, A; Ness, S A

1994-01-01

Activated macrophages contribute to chronic inflammation by the secretion of cytokines and proteinases. Tumor necrosis factor alpha (TNF alpha) is particularly important in this process because of its ability to regulate other inflammatory mediators in an autocrine and paracrine fashion. The mechanism(s) responsible for the cell type-specific regulation of TNF alpha is not known. We present data to show that the expression of TNF alpha is regulated by the transcription factor C/EBP beta (NF-IL6). C/EBP beta activated the TNF alpha gene promoter in cotransfection assays and bound to it at a site which failed to bind the closely related protein C/EBP alpha. Finally, a dominant-negative version of C/EBP beta blocked TNF alpha promoter activation in myeloid cells. Our results implicate C/EBP beta as an important regulator of TNF alpha by myelomonocytic cells. Images PMID:7929820

Anticipatory Attentional Suppression of Visual Features Indexed by Oscillatory Alpha-Band Power Increases: A High-Density Electrical Mapping Study

PubMed Central

Snyder, Adam C.; Foxe, John J.

2010-01-01

Retinotopically specific increases in alpha-band (~10 Hz) oscillatory power have been strongly implicated in the suppression of processing for irrelevant parts of the visual field during the deployment of visuospatial attention. Here, we asked whether this alpha suppression mechanism also plays a role in the nonspatial anticipatory biasing of feature-based attention. Visual word cues informed subjects what the task-relevant feature of an upcoming visual stimulus (S2) was, while high-density electroencephalographic recordings were acquired. We examined anticipatory oscillatory activity in the Cue-to-S2 interval (~2 s). Subjects were cued on a trial-by-trial basis to attend to either the color or direction of motion of an upcoming dot field array, and to respond when they detected that a subset of the dots differed from the majority along the target feature dimension. We used the features of color and motion, expressly because they have well known, spatially separated cortical processing areas, to distinguish shifts in alpha power over areas processing each feature. Alpha power from dorsal regions increased when motion was the irrelevant feature (i.e., color was cued), and alpha power from ventral regions increased when color was irrelevant. Thus, alpha-suppression mechanisms appear to operate during feature-based selection in much the same manner as has been shown for space-based attention. PMID:20237273

Multiple Binding Modes between HNF4[alpha] and the LXXLL Motifs of PGC-1[alpha] Lead to Full Activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rha, Geun Bae; Wu, Guangteng; Shoelson, Steven E.

2010-04-15

Hepatocyte nuclear factor 4{alpha} (HNF4{alpha}) is a novel nuclear receptor that participates in a hierarchical network of transcription factors regulating the development and physiology of such vital organs as the liver, pancreas, and kidney. Among the various transcriptional coregulators with which HNF4{alpha} interacts, peroxisome proliferation-activated receptor {gamma} (PPAR{gamma}) coactivator 1{alpha} (PGC-1{alpha}) represents a novel coactivator whose activation is unusually robust and whose binding mode appears to be distinct from that of canonical coactivators such as NCoA/SRC/p160 family members. To elucidate the potentially unique molecular mechanism of PGC-1{alpha} recruitment, we have determined the crystal structure of HNF4{alpha} in complex with amore » fragment of PGC-1{alpha} containing all three of its LXXLL motifs. Despite the presence of all three LXXLL motifs available for interactions, only one is bound at the canonical binding site, with no additional contacts observed between the two proteins. However, a close inspection of the electron density map indicates that the bound LXXLL motif is not a selected one but an averaged structure of more than one LXXLL motif. Further biochemical and functional studies show that the individual LXXLL motifs can bind but drive only minimal transactivation. Only when more than one LXXLL motif is involved can significant transcriptional activity be measured, and full activation requires all three LXXLL motifs. These findings led us to propose a model wherein each LXXLL motif has an additive effect, and the multiple binding modes by HNF4{alpha} toward the LXXLL motifs of PGC-1{alpha} could account for the apparent robust activation by providing a flexible mechanism for combinatorial recruitment of additional coactivators and mediators.« less

Comprehensive analysis of all triple helical repeats in beta-spectrins reveals patterns of selective evolutionary conservation.

PubMed

Baines, Anthony J

2003-01-01

The spectrin superfamily (spectrin, alpha-actinin, utrophin and dystrophin) has in common a triple helical repeating unit of ~106 amino acid residues. In spectrin, alpha and beta chains contain multiple copies of this repeat. beta-spectrin chains contain the majority of binding activities in spectrin and are essential for animal life. Canonical beta-spectrins have 17 repeats; beta-heavy spectrins have 30. Here, the repeats of five human beta-spectrins, plus beta-spectrins from several other vertebrates and invertebrates, have been analysed. Repeats 1, 2, 14 and 17 in canonical beta are highly conserved between invertebrates and vertebrates, and repeat 8 in some isoforms. This is consistent with conservation of critical functions, since repeats 1, 2 and 17 bind alpha-spectrin. Repeats 1 of beta-spectrins are not always detected by SMART or Pfam tools. A profile hidden Markov model of beta-spectrin repeat 1 detects alpha-actinins, but not utrophin or dystrophin. Novel examples of repeat 1 were detected in the spectraplakins MACF1, BPAG1 and plectin close to the actin-binding domain. Ankyrin binds to the C-terminal portion of repeat 14; the high conservation of this entire repeat may point to additional, undiscovered ligand-binding activities. This analysis indicates that the basic triple helical repeat pattern was adapted early in the evolution of the spectrin superfamily to encompass essential binding activities, which characterise individual repeats in proteins extant today.

Anticonvulsant properties of alpha, gamma, and alpha, gamma-substituted gamma-butyrolactones.

PubMed

Klunk, W E; Covey, D F; Ferrendelli, J A

1982-09-01

Derivatives of gamma-butyrolactone (GBL) substituted on the alpha- and/or gamma-positions were synthesized and tested for their effects on behavior in mice, on the electroencephalographs and blood pressure of paralyzed-ventilated guinea pigs, and on electrical activity of incubated hippocampal slices. Several compounds, including alpha-ethyl-alpha-methyl GBL (alpha-EMGBL), alpha, alpha-dimethyl GBL, alpha, gamma-diethyl-alpha, gamma-dimethyl GBL, and gamma-ethyl-gamma-methyl GBL, prevented seizures induced by pentylenetetrazol, beta-ethyl-beta-methyl-gamma-butyrolactone (beta-EMGBL), picrotoxin, or all three compounds in mice and guinea pigs but had no effect on seizures induced by maximal electroshock or bicuculline. Neither gamma-hydroxybutyrate (GHB) nor alpha-isopropylidine GBL had any anticonvulsant activity. The anticonvulsant alpha-substituted compounds had a potent hypotensive effect and antagonized the hypertensive effect of beta-EMGBL, alpha-EMGBL was tested in incubated hippocampal slices and was found to depress basal activity and antagonize excitation induced by beta-EMGBL. These results demonstrate that alpha-alkyl-substituted GBL and, to a lesser extent, gamma-substituted derivatives are anticonvulsant agents and that their effects are strikingly different from those of GHB or beta-alkyl-substituted GBLs, which are epileptogenic. Possibly beta- and alpha-substituted GBLs act at the same site as agonists and antagonists, respectively.

Monocarboxylate and alpha-ketoglutarate carriers from bovine heart mitochondria. Purification by affinity chromatography on immobilized 2-cyano-4-hydroxycinnamate.

PubMed

Bolli, R; Nałecz, K A; Azzi, A

1989-10-25

2-Cyano-4-hydroxycinnamate was covalently linked, through a diazo bond, to Sepharose 4B, which had been elongated with a hydrophobic spacer. A Triton X-100 extract from bovine heart mitochondria was pre-purified by hydroxylapatite chromatography and passed through the 2-cyano-4-hydroxycinnamate affinity resin in the presence of 0.7% deoxycholate. At pH 6 and in the presence of 0.2 M sodium chloride, a single polypeptide with an Mr of 34,000 was eluted. Subsequently, at pH 8 and in the presence of 2-cyano-4-hydroxycinnamate, another single protein with an Mr of 31,500 was released. Both proteins were reconstituted into phospholipid vesicles and their transport activities were measured. High, delta pH-dependent, 2-cyanocinnamate-sensitive pyruvate uptake was measured in vesicles containing only the 34-kDa protein. alpha-Ketobutyrate and other alpha-ketomonocarboxylic acids were competitive inhibitors of the pyruvate uptake, whereas di- and tricarboxylates had only small effects. alpha-Ketoglutarate-alpha-ketoglutarate exchange could only be measured in vesicles containing the 31.5-kDa protein. The molecular weight of this protein and its functional properties were similar to those of the alpha-ketoglutarate carrier isolated by a different method (Bisaccia, Indiveri, C., and Palmieri, F. (1985) Biochim. Biophys. Acta 810, 362-369). 2-Cyano-4-hydroxycinnamate inhibited the alpha-ketoglutarate exchange in a noncompetitive manner with an apparent Ki of 0.7 mM. It is concluded that by the described affinity chromatography procedure, two mitochondrial carriers transporting alpha-ketoacids, i.e. the monocarboxylate and the alpha-ketoglutarate carrier, could be purified in a functionally active state.

Regulation of valine and. alpha. -ketoisocaproate metabolism in rat kidney mitochondria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, R.H.; Harper, A.E.

1988-10-01

Activities of branched-chain amino acid (BCAA) aminotransferase (BCAT) and {alpha}-keto acid dehydrogenase (BCKD) were assayed in mitochondria isolated from kidneys of rats. Rates of transamination of valine and oxidation of keto acids {alpha}-ketoisocaproate (KIC) or {alpha}-ketoisovalerate (KIV) were estimated using radioactive tracers of the appropriate substrate from amounts of {sup 14}C-labeled products formed. Because of the high mitochondrial BCAT activity, an amino acceptor for BCAT, {alpha}-ketoglutarate ({alpha}-KG) or KIC, was added to the assay medium when valine was the substrate. Rates of valine transamination and subsequent oxidation of the KIV formed were determined with 0.5 mM {alpha}-KG as the aminomore » acceptor; these rates were 5- to 50-fold those without added {alpha}-KG. Rates of CO{sub 2} evolution from valine also increased when KIC was present; however, with KIC concentrations above 0.2 mM, rates of CO{sub 2} evolution from valine declined although rates of transamination continued to rise. When 0.05 mM KIC was added to the assay medium, oxidation of KIC was suppressed by inclusion of valine or glutamate in the medium. When valine was present KIC was not oxidized preferentially, presumably because it was also serving as an amino acceptor for BCAT. These results indicate that as the supply of amino acceptor, {alpha}-KG or KIC, is increased in mitochondria not only is the rate of valine transamination stimulated but also the rate of oxidation of the KIV formed from valine. Thus the rate of oxidation of BCAA can be controlled by factors that influence the rate and direction of BCAA transamination and, thereby, the supply of substrate for BCKD.« less

Characterization of histamine-releasing activity: role of cytokines and IgE heterogeneity.

PubMed

Liao, T N; Hsieh, K H

1992-07-01

Histamine-releasing factors (HRFs) are a group of cytokines that cause histamine release (HR) from basophils and mast cells. The concept of the priming effect of cytokines and the heterogeneity of IgE involved in the HRF-induced HR have been emphasized in recent years. In this study, we performed a series of experiments to elucidate the above-mentioned hypotheses. The stock HRF were obtained by stimulating mononuclear cells (MNC) with phytohemagglutinin (PHA). Maximal activity was observed 36 hr after culture. By gel filtration, HRF was eluted with a peak activity ranging from 12 to 18 KD. A large portion (75%) of HRF activity could be neutralized by a combination of antibodies against interleukin 1 (IL-1), IL-3, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha). The stimulation of basophils with 100 ng/ml each of IL-3, IL-6, IL-7, GM-CSF, or TNF-alpha alone caused 10% HR; however, when the cells were pretreated with 10 ng/ml of either IL-3, IL-6, IL-7, IL-8, TNF-alpha, or GM-CSF and then stimulated with anti-IgE, a marked increase in HR was regularly observed. The combination of 100 ng/ml each of IL-1, IL-3, IL-8, GM-CSF, and TNF-alpha could induce only about 20% HR; furthermore, such combinations did not have an additive or synergistic priming effect on anti-IgE-induced HR compared to the effect of single cytokines. Stripping of surface-bound IgE with lactic acid markedly reduced the capacity of basophils to release histamine in response to MNC-HRF and anti-IgE. Passive sensitization of IgE-stripped basophils with high-HRF responders' serum could restore their responsiveness to both MNC-HRF and anti-IgE, but passive sensitization with low-HRF responders' serum could restore responsiveness to anti-IgE only. Moreover, passage of MNC-HRF through high-, but not low-HRF, responders' IgE-Sepharose columns significantly reduced the HR activity of MNC-HRF. Finally, although the eluant could induce only 10% HR, the majority of its HR activity could be restored by the addition of effluent but not by the mixture of IL-1, IL-3, IL-8, GM-CSF, and TNF-alpha, suggesting the presence of a complex interaction among those cytokines. In summary, MNC-HRF contained at least two types of HRF activity; one was IgE dependent and the other was IgE independent.(ABSTRACT TRUNCATED AT 400 WORDS)

Peroxisome proliferator-activated receptor {alpha} agonists modulate Th1 and Th2 chemokine secretion in normal thyrocytes and Graves' disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonelli, Alessandro, E-mail: a.antonelli@med.unipi.it; Ferrari, Silvia Martina, E-mail: sm.ferrari@int.med.unipi.it; Frascerra, Silvia, E-mail: lafrasce@gmail.com

2011-07-01

Until now, no data are present about the effect of peroxisome proliferator-activated receptor (PPAR){alpha} activation on the prototype Th1 [chemokine (C-X-C motif) ligand (CXCL)10] (CXCL10) and Th2 [chemokine (C-C motif) ligand 2] (CCL2) chemokines secretion in thyroid cells. The role of PPAR{alpha} and PPAR{gamma} activation on CXCL10 and CCL2 secretion was tested in Graves' disease (GD) and control primary thyrocytes stimulated with interferon (IFN){gamma} and tumor necrosis factor (TNF){alpha}. IFN{gamma} stimulated both CXCL10 and CCL2 secretion in primary GD and control thyrocytes. TNF{alpha} alone stimulated CCL2 secretion, while had no effect on CXCL10. The combination of IFN{gamma} and TNF{alpha} hadmore » a synergistic effect both on CXCL10 and CCL2 chemokines in GD thyrocytes at levels comparable to those of controls. PPAR{alpha} activators inhibited the secretion of both chemokines (stimulated with IFN{gamma} and TNF{alpha}) at a level higher (for CXCL10, about 60-72%) than PPAR{gamma} agonists (about 25-35%), which were confirmed to inhibit CXCL10, but not CCL2. Our data show that CCL2 is modulated by IFN{gamma} and TNF{alpha} in GD and normal thyrocytes. Furthermore we first show that PPAR{alpha} activators inhibit the secretion of CXCL10 and CCL2 in thyrocytes, suggesting that PPAR{alpha} may be involved in the modulation of the immune response in the thyroid.« less

Integrin-mediated transforming growth factor-beta activation regulates homeostasis of the pulmonary epithelial-mesenchymal trophic unit.

PubMed

Araya, Jun; Cambier, Stephanie; Morris, Alanna; Finkbeiner, Walter; Nishimura, Stephen L

2006-08-01

Trophic interactions between pulmonary epithelial and mesenchymal cell types, known as the epithelial-mesenchymal trophic unit (EMTU), are crucial in lung development and lung disease. Transforming growth factor (TGF)-beta is a key factor in mediating these interactions, but it is expressed in a latent form that requires activation to be functional. Using intact fetal tracheal tissue and primary cultures of fetal tracheal epithelial cells and fibroblasts, we demonstrate that a subset of integrins, alpha(v)beta(6) and alpha(v)beta(8), are responsible for almost all of the TGF-beta activation in the EMTU. Both alpha(v)beta(8) and alpha(v)beta(6) contribute to fetal tracheal epithelial activation of TGF-beta, whereas only alpha(v)beta(8) contributes to fetal tracheal fibroblast activation of TGF-beta. Interestingly, fetal tracheal epithelial alpha(v)beta(8)-mediated TGF-beta activation can be enhanced by phorbol esters, likely because of the increased activity of MT1-MMP, an essential co-factor in alpha(v)beta(8)-mediated activation of TGF-beta. Autocrine alpha(v)beta(8)-mediated TGF-beta activation by fetal tracheal fibroblasts results in suppression of both transcription and secretion of hepatocyte growth factor, which is sufficient to affect phosphorylation of the airway epithelial hepatocyte growth factor receptor, c-Met, as well as airway epithelial proliferation in a co-culture model of the EMTU. These findings elucidate the function and complex regulation of integrin-mediated activation of TGF-beta within the EMTU.

One-step production of immobilized alpha-amylase in recombinant Escherichia coli.

PubMed

Rasiah, Indira A; Rehm, Bernd H A

2009-04-01

Industrial enzymes are often immobilized via chemical cross-linking onto solid supports to enhance stability and facilitate repeated use in bioreactors. For starch-degrading enzymes, immobilization usually places constraints on enzymatic conversion due to the limited diffusion of the macromolecular substrate through available supports. This study describes the one-step immobilization of a highly thermostable alpha-amylase (BLA) from Bacillus licheniformis and its functional display on the surface of polyester beads inside engineered Escherichia coli. An optimized BLA variant (Termamyl) was N-terminally fused to the polyester granule-forming enzyme PhaC of Cupriavidus necator. The fusion protein lacking the signal sequence mediated formation of stable polyester beads exhibiting alpha-amylase activity. The alpha-amylase beads were assessed with respect to alpha-amylase activity, which was demonstrated qualitatively and quantitatively. The immobilized alpha-amylase showed Michaelis-Menten enzyme kinetics exerting a V(max) of about 506 mU/mg of bead protein with a K(m) of about 5 microM, consistent with that of free alpha-amylase. The stability of the enzyme at 85 degrees C and the capacity for repeated usage in a starch liquefaction process were also demonstrated. In addition, structural integrity and functionality of the beads at extremes of pH and temperature, demonstrating their suitability for industrial use, were confirmed by electron microscopy and protein/enzyme analysis. This study proposes a novel, cost-effective method for the production of immobilized alpha-amylase in a single step by using the polyester granules forming protein PhaC as a fusion partner in engineered E. coli.

Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha as a Novel Target for Bipolar Disorder and Other Neuropsychiatric Disorders.

PubMed

Nierenberg, Andrew A; Ghaznavi, Sharmin A; Sande Mathias, Isadora; Ellard, Kristen K; Janos, Jessica A; Sylvia, Louisa G

2018-05-01

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha) is a protein that regulates metabolism and inflammation by activating nuclear receptors, especially the family of peroxisome proliferator-activated receptors (PPARs). PGC-1 alpha and PPARs also regulate mitochondrial biogenesis, cellular energy production, thermogenesis, and lipid metabolism. Brain energy metabolism may also be regulated in part by the interaction between PGC-1 alpha and PPARs. Because neurodegenerative diseases (Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis) and bipolar disorder have been associated with dysregulated mitochondrial and brain energy metabolism, PGC-1 alpha may represent a potential drug target for these conditions. The purpose of this article is to review the physiology of PGC-1 alpha, PPARs, and the role of PPAR agonists to target PGC-1 alpha to treat neurodegenerative diseases and bipolar disorder. We also review clinical trials of repurposed antidiabetic thiazolidines and anti-triglyceride fibrates (PPAR agonists) for neurodegenerative diseases and bipolar disorder. PGC-1 alpha and PPARs are innovative potential targets for bipolar disorder and warrant future clinical trials. Copyright © 2018. Published by Elsevier Inc.

Macrophage-induced angiogenesis is mediated by tumour necrosis factor-alpha.

PubMed

Leibovich, S J; Polverini, P J; Shepard, H M; Wiseman, D M; Shively, V; Nuseir, N

Macrophages are important in the induction of new blood vessel growth during wound repair, inflammation and tumour growth. We show here that tumour necrosis factor-alpha (TNF-alpha), a secretory product of activated macrophages that is believed to mediate tumour cytotoxicity, is a potent inducer of new blood vessel growth (angiogenesis). In vivo, TNF-alpha induces capillary blood vessel formation in the rat cornea and the developing chick chorioallantoic membrane at very low doses. In vitro, TNF-alpha stimulates chemotaxis of bovine adrenal capillary endothelial cells and induces cultures of these cells grown on type-1 collagen gels to form capillary-tube-like structures. The angiogenic activity produced by activated murine peritoneal macrophages is completely neutralized by a polyclonal antibody to TNF-alpha, suggesting immunological features are common to TNF-alpha and the protein responsible for macrophage-derived angiogenic activity. In inflammation and wound repair, TNF-alpha could augment repair by stimulating new blood vessel growth; in tumours, TNF-alpha might both stimulate tumour development by promoting vessel growth and participate in tumour destruction by direct cytotoxicity.

Demonstration of 3 alpha(17 beta)-hydroxysteroid dehydrogenase distinct from 3 alpha-hydroxysteroid dehydrogenase in hamster liver.

PubMed Central

Ohmura, M; Hara, A; Nakagawa, M; Sawada, H

1990-01-01

NAD(+)-linked and NADP(+)-linked 3 alpha-hydroxysteroid dehydrogenases were purified to homogeneity from hamster liver cytosol. The two monomeric enzymes, although having similar molecular masses of 38,000, differed from each other in pI values, activation energy and heat stability. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with protease. The NADP(+)-linked enzyme catalysed the oxidoreduction of various 3 alpha-hydroxysteroids, whereas the NAD(+)-linked enzyme oxidized the 3 alpha-hydroxy group of pregnanes and some bile acids, and the 17 beta-hydroxy group of testosterone and androstanes. The thermal stabilities of the 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the NAD(+)-linked enzyme were identical, and the two enzyme activities were inhibited by mixing 17 beta- and 3 alpha-hydroxysteroid substrates, respectively. Medroxyprogesterone acetate, hexoestrol and 3 beta-hydroxysteroids competitively inhibited 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the enzyme. These results show that hamster liver contains a 3 alpha(17 beta)-hydroxysteroid dehydrogenase structurally and functionally distinct from 3 alpha-hydroxysteroid dehydrogenase. Images Fig. 1. Fig. 2. PMID:2317205

Mechanism of alpha-lipoic acid in attenuating kanamycin-induced ototoxicity☆

PubMed Central

Wang, Aimei; Hou, Ning; Bao, Dongyan; Liu, Shuangyue; Xu, Tao

2012-01-01

In view of the theory that alpha-lipoic acid effectively prevents cochlear cells from injury caused by various factors such as cisplatin and noise, this study examined whether alpha-lipoic acid can prevent kanamycin-induced ototoxicity. To this end, healthy BALB/c mice were injected subcutaneously with alpha-lipoic acid and kanamycin for 14 days. Auditory brainstem response test showed that increased auditory brainstem response threshold shifts caused by kanamycin were significantly inhibited. Immunohistochemical staining and western blot analysis showed that the expression of phosphorylated p38 mitogen-activated protein kinase and phosphorylated c-Jun N-terminal kinase in mouse cochlea was significantly decreased. The experimental findings suggest that phosphorylated p38 and phosphorylated c-Jun N-terminal kinase mediated kanamycin-induced ototoxic injury in BALB/c mice. Alpha-lipoic acid effectively attenuated kanamycin ototoxicity by inhibiting the kanamycin-induced high expression of phosphorylated p38 and phosphorylated c-Jun N-terminal kinase. PMID:25317129

Neural network communication facilitates verbal working memory.

PubMed

Kustermann, Thomas; Rockstroh, Brigitte; Miller, Gregory A; Popov, Tzvetan

2018-05-28

Oscillatory brain activity in the theta, alpha, and gamma frequency ranges has been associated with working memory (WM). In addition to alpha and theta activity associated with WM retention, and gamma band activity with item encoding, activity in the alpha band is related to the deployment of attention resources and information. The present study sought to specify distinct roles of neuromagnetic 4-7 Hz theta, 9-13 Hz alpha, and 50-70 Hz gamma power modulation and communication in fronto-parietal networks during cued, hemifield-specific item presentation in a modified Sternberg verbal WM task in 14 student volunteers. Lateralized posterior alpha and gamma power during encoding suggest a preparatory role of alpha oscillations. Bilateral alpha power increases during maintenance reflect information retention for the non-lateralized probe response. Lateralized alpha power increase during encoding was apparently driven by a monotonic increase in fronto-parietal 6 Hz phase, suggesting a mechanism facilitating WM encoding and successful performance. Copyright © 2018 Elsevier B.V. All rights reserved.

Structural integration in hypoxia-inducible factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Dalei; Potluri, Nalini; Lu, Jingping

The hypoxia-inducible factors (HIFs) coordinate cellular adaptations to low oxygen stress by regulating transcriptional programs in erythropoiesis, angiogenesis and metabolism. These programs promote the growth and progression of many tumours, making HIFs attractive anticancer targets. Transcriptionally active HIFs consist of HIF-alpha and ARNT (also called HIF-1 beta) subunits. Here we describe crystal structures for each of mouse HIF-2 alpha-ARNT and HIF-1 alpha-ARNT heterodimers in states that include bound small molecules and their hypoxia response element. A highly integrated quaternary architecture is shared by HIF-2 alpha-ARNT and HIF-1 alpha-ARNT, wherein ARNT spirals around the outside of each HIF-alpha subunit. Five distinctmore » pockets are observed that permit small-molecule binding, including PAS domain encapsulated sites and an interfacial cavity formed through subunit heterodimerization. The DNA-reading head rotates, extends and cooperates with a distal PAS domain to bind hypoxia response elements. HIF-alpha mutations linked to human cancers map to sensitive sites that establish DNA binding and the stability of PAS domains and pockets.« less

Cloning and purification of alpha-neurotoxins from king cobra (Ophiophagus hannah).

PubMed

He, Ying-Ying; Lee, Wei-Hui; Zhang, Yun

2004-09-01

Thirteen complete and three partial cDNA sequences were cloned from the constructed king cobra (Ophiophagus hannah) venom gland cDNA library. Phylogenetic analysis of nucleotide sequences of king cobra with those from other snake venoms revealed that obtained cDNAs are highly homologous to snake venom alpha-neurotoxins. Alignment of deduced mature peptide sequences of the obtained clones with those of other reported alpha-neurotoxins from the king cobra venom indicates that our obtained 16 clones belong to long-chain neurotoxins (seven), short-chain neurotoxins (seven), weak toxin (one) and variant (one), respectively. Up to now, two out of 16 newly cloned king cobra alpha-neurotoxins have identical amino acid sequences with CM-11 and Oh-6A/6B, which have been characterized from the same venom. Furthermore, five long-chain alpha-neurotoxins and two short-chain alpha-neurotoxins were purified from crude venom and their N-terminal amino acid sequences were determined. The cDNAs encoding the putative precursors of the purified native peptide were also determined based on the N-terminal amino acid sequencing. The purified alpha-neurotoxins showed different lethal activities on mice.

Cortisol and alpha-amylase as stress response indicators during pre-hospital emergency medicine training with repetitive high-fidelity simulation and scenarios with standardized patients.

PubMed

Valentin, Bernd; Grottke, Oliver; Skorning, Max; Bergrath, Sebastian; Fischermann, Harold; Rörtgen, Daniel; Mennig, Marie-Therese; Fitzner, Christina; Müller, Michael P; Kirschbaum, Clemens; Rossaint, Rolf; Beckers, Stefan K

2015-04-08

In emergency medicine, the benefits of high-fidelity simulation (SIM) are widely accepted and standardized patients (SP) are known to mimic real patients accurately. However, only limited data are available concerning physicians' stress markers within these training environments. The aim of this pilot study was to investigate repetitive stress among healthcare professionals in simulated pre-hospital emergency scenarios using either SIM or SPs. Teams with one emergency medical services (EMS) physician and two paramedics completed three SIM scenarios and two SP scenarios consecutively. To evaluate stress, salivary cortisol and alpha-amylase were measured in saliva samples taken before, during and after the scenarios. A total of 14 EMS physicians (29% female; mean age: 36.8 ± 5.0 years; mean duration of EMS-experience: 9.1 ± 5.8 years) and 27 paramedics (11% female; age: 30.9 ± 6.9 years; EMS experience: 8.1 ± 6.0 years) completed the study. Alpha-amylase and cortisol levels did not differ significantly between the two professions. Cortisol values showed a gradual and statistically significant reduction over time but little change was observed in response to each scenario. In contrast, alpha-amylase activity increased significantly in response to every SIM and SP scenario, but there was no clear trend towards an overall increase or decrease over time. Increases in salivary alpha-amylase activity suggest that both SIM and SP training produce stress among emergency healthcare professionals. Corresponding increases in salivary cortisol levels were not observed. Among physicians in the emergency setting, it appears that alpha-amylase provides a more sensitive measure of stress levels than cortisol.

Regulation of hypoxia-inducible factor-1alpha by nitric oxide through mitochondria-dependent and -independent pathways.

PubMed Central

Mateo, Jesús; García-Lecea, Marta; Cadenas, Susana; Hernández, Carlos; Moncada, Salvador

2003-01-01

Nitric oxide (NO) has been reported both to promote and to inhibit the activity of the transcription factor hypoxia-inducible factor-1 (HIF-1). In order to avoid the pitfalls associated with the use of NO donors, we have developed a human cell line (Tet-iNOS 293) that expresses the inducible NO synthase (iNOS) under the control of a tetracycline-inducible promoter. Using this system to generate finely controlled amounts of NO, we have demonstrated that the stability of the alpha-subunit of HIF-1 is regulated by NO through two separate mechanisms, only one of which is dependent on a functional respiratory chain. HIF-1alpha is unstable in cells maintained at 21% O(2), but is progressively stabilized as the O(2) concentration decreases, resulting in augmented HIF-1 DNA-binding activity. High concentrations of NO (>1 microM) stabilize HIF-1alpha at all O(2) concentrations tested. This effect does not involve the respiratory chain, since it is preserved in cells lacking functional mitochondria (rho(0)-cells) and is not reproduced by other inhibitors of the cytochrome c oxidase. By contrast, lower concentrations of NO (<400 nM) cause a rapid decrease in HIF-1alpha stabilized by exposure of the cells to 3% O(2). This effect of NO is dependent on the inhibition of mitochondrial respiration, since it is mimicked by other inhibitors of mitochondrial respiration, including those not acting at cytochrome c oxidase. We suggest that, although stabilization of HIF-1alpha by high concentrations of NO might have implications in pathophysiological processes, the inhibitory effect of lower NO concentrations is likely to be of physiological relevance. PMID:14531732

The Transliminal Brain at Rest: Baseline EEG, Unusual Experiences, and Access to Unconscious Mental Activity

PubMed Central

Fleck, Jessica I.; Green, Deborah L.; Stevenson, Jennifer L.; Payne, Lisa; Bowden, Edward M.; Jung-Beeman, Mark; Kounios, John

2008-01-01

Transliminality reflects individual differences in the threshold at which unconscious processes or external stimuli enter into consciousness. Individuals high in transliminality possess characteristics such as magical ideation, belief in the paranormal, and creative personality traits, and also report the occurrence of manic/mystic experiences. The goal of the present research was to determine if resting brain activity differs for individuals high versus low in transliminality. We compared baseline EEG recordings (eyes-closed) between individuals high versus low in transliminality, assessed using The Revised Transliminality Scale of Lange et al. (2000). Identifying reliable differences at rest between high- and low-transliminality individuals would support a predisposition for transliminality-related traits. Individuals high in transliminality exhibited lower alpha, beta, and gamma power than individuals low in transliminality over left posterior association cortex and lower high alpha, low beta, and gamma power over the right superior temporal region. In contrast, when compared to individuals low in transliminality, individuals high in transliminality exhibited greater gamma power over the frontal-midline region. These results are consistent with prior research reporting reductions in left temporal/parietal activity, as well as the desynchronization of right temporal activity in schizotypy and related schizophrenia spectrum disorders. Further, differences between high- and low-transliminality groups extend existing theories linking altered hemispheric asymmetries in brain activity to a predisposition toward schizophrenia, paranormal beliefs, and unusual experiences. PMID:18814870

Top-down controlled alpha band activity in somatosensory areas determines behavioral performance in a discrimination task.

PubMed

Haegens, Saskia; Händel, Barbara F; Jensen, Ole

2011-04-06

The brain receives a rich flow of information which must be processed according to behavioral relevance. How is the state of the sensory system adjusted to up- or downregulate processing according to anticipation? We used magnetoencephalography to investigate whether prestimulus alpha band activity (8-14 Hz) reflects allocation of attentional resources in the human somatosensory system. Subjects performed a tactile discrimination task where a visual cue directed attention to their right or left hand. The strength of attentional modulation was controlled by varying the reliability of the cue in three experimental blocks (100%, 75%, or 50% valid cueing). While somatosensory prestimulus alpha power lateralized strongly with a fully predictive cue (100%), lateralization was decreased with lower cue reliability (75%) and virtually absent if the cue had no predictive value at all (50%). Importantly, alpha lateralization influenced the subjects' behavioral performance positively: both accuracy and speed of response improved with the degree of alpha lateralization. This study demonstrates that prestimulus alpha lateralization in the somatosensory system behaves similarly to posterior alpha activity observed in visual attention tasks. Our findings extend the notion that alpha band activity is involved in shaping the functional architecture of the working brain by determining both the engagement and disengagement of specific regions: the degree of anticipation modulates the alpha activity in sensory regions in a graded manner. Thus, the alpha activity is under top-down control and seems to play an important role for setting the state of sensory regions to optimize processing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin, E-mail: Jqin710@vip.sina.com

Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-addedmore » active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.« less

A defective retroviral vector encoding human interferon-alpha2 can transduce human leukemic cell lines.

PubMed

Austruy, E; Bagnis, C; Carbuccia, N; Maroc, C; Birg, F; Dubreuil, P; Mannoni, P; Chabannon, C

1998-01-01

Using the LXSN backbone, a defective retroviral vector (LISN) was constructed that encodes the human interferon (IFN)-alpha2 (hIFN-alpha2) gene and the neomycin resistance gene; the hIFN-alpha2 gene was cloned from human placental genomic DNA. High titers of the LISN retrovirus were produced by the amphotropic packaging cell line GP+envAM12. LISN is able to infect three human hematopoietic and leukemic cell lines: K562, LAMA-84, and TF-1. G418-resistant cells were detected in a similar proportion after infection with either the LISN retroviral vector or the LnLSN retroviral vector (encoding the nlsLacZ gene instead of hIFN-alpha2), suggesting that hIFN-alpha2 does not inhibit (or only partially inhibits) the production of retroviral particles by the packaging cell line and the infection of human cells. LISN-infected cells express and secrete hIFN-alpha2 as demonstrated by Northern blot analysis of poly(A)+ RNA, detection of the intracellular protein by fluorescence-activated cell sorter analysis, and detection of secreted hIFN-alpha in cell supernatants using an enzyme-linked immunosorbent assay. Retrovirally produced hIFN-alpha2 is biologically active, as demonstrated by the partial inhibition of the growth of K562 and TF-1, the modulation of the expression of cell surface antigens, the induction of the (2'-5') oligoadenylate synthetase, and, for LAMA-84, the down-modulation of the BCR-ABL protein. We conclude that the infection of human leukemic cell lines with a retroviral vector encoding hIFN-alpha2 is feasible and induces the expected biological effects. This experimental model will be useful in investigating the possibility of transducing normal and leukemic cells and hematopoietic progenitors and in determining the consequences of the autocrine production of hIFN-alpha2 on the behavior of these cells.

FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

PubMed

Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

2009-12-01

FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast cell-mediated allergic reactions.

EEG Topographic Mapping of Visual and Kinesthetic Imagery in Swimmers.

PubMed

Wilson, V E; Dikman, Z; Bird, E I; Williams, J M; Harmison, R; Shaw-Thornton, L; Schwartz, G E

2016-03-01

This study investigated differences in QEEG measures between kinesthetic and visual imagery of a 100-m swim in 36 elite competitive swimmers. Background information and post-trial checks controlled for the modality of imagery, swimming skill level, preferred imagery style, intensity of image and task equality. Measures of EEG relative magnitude in theta, low (7-9 Hz) and high alpha (8-10 Hz), and low and high beta were taken from 19 scalp sites during baseline, visual, and kinesthetic imagery. QEEG magnitudes in the low alpha band during the visual and kinesthetic conditions were attenuated from baseline in low band alpha but no changes were seen in any other bands. Swimmers produced more low alpha EEG magnitude during visual versus kinesthetic imagery. This was interpreted as the swimmers having a greater efficiency at producing visual imagery. Participants who reported a strong intensity versus a weaker feeling of the image (kinesthetic) had less low alpha magnitude, i.e., there was use of more cortical resources, but not for the visual condition. These data suggest that low band (7-9 Hz) alpha distinguishes imagery modalities from baseline, visual imagery requires less cortical resources than kinesthetic imagery, and that intense feelings of swimming requires more brain activity than less intense feelings.

Curcumin inhibits interferon-{alpha} induced NF-{kappa}B and COX-2 in human A549 non-small cell lung cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jeeyun; Im, Young-Hyuck; Jung, Hae Hyun

2005-08-26

The A549 cells, non-small cell lung cancer cell line from human, were resistant to interferon (IFN)-{alpha} treatment. The IFN-{alpha}-treated A549 cells showed increase in protein expression levels of NF-{kappa}B and COX-2. IFN-{alpha} induced NF-{kappa}B binding activity within 30 min and this increased binding activity was markedly suppressed with inclusion of curcumin. Curcumin also inhibited IFN-{alpha}-induced COX-2 expression in A549 cells. Within 10 min, IFN-{alpha} rapidly induced the binding activity of a {gamma}-{sup 32}P-labeled consensus GAS oligonucleotide probe, which was profoundly reversed by curcumin. Taken together, IFN-{alpha}-induced activations of NF-{kappa}B and COX-2 were inhibited by the addition of curcumin in A549more » cells.« less

Radon daughter plate-out measurements at SNOLAB for polyethylene and copper

NASA Astrophysics Data System (ADS)

Stein, Matthew; Bauer, Dan; Bunker, Ray; Calkins, Rob; Cooley, Jodi; Loer, Ben; Scorza, Silvia

2018-02-01

Polyethylene and copper samples were exposed to the underground air at SNOLAB for approximately three months while several environmental factors were monitored. Predictions of the radon-daughter plate-out rate are compared to the resulting surface activities, obtained from high-sensitivity measurements of alpha emissivity using the XIA UltraLo-1800 spectrometer at Southern Methodist University. From these measurements, we determine an average 210Pb plate-out rate of 249 and 423 atoms/day/cm2 for polyethylene and copper, respectively, when exposed to radon activity concentration of 135 Bq/m3 at SNOLAB. A time-dependent model of alpha activity is discussed for these materials placed in similar environmental conditions.

Radon daughter plate-out measurements at SNOLAB for polyethylene and copper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, Matthew; Bauer, Dan; Bunker, Ray

2018-02-01

Polyethylene and copper samples were exposed to the underground air at SNOLAB for approximately three months while several environmental factors were monitored. Predictions of the radon-daughter plate-out rate are compared to the resulting surface activities, obtained from high-sensitivity measurements of alpha emissivity using the XIA UltraLo-1800 spectrometer at SMU. From these measurements, we determine an averagemore » $$^{210}$$Pb plate-out rate of 249 and 423~atoms/day/cm$$^{2}$$ for polyethylene and copper, respectively, when exposed to radon activity of 135 Bq/m$$^{3}$$ at SNOLAB. A time-dependent model of alpha activity is discussed for these materials placed in similar environmental conditions.« less

Brain-computer interface for alertness estimation and improving

NASA Astrophysics Data System (ADS)

Hramov, Alexander; Maksimenko, Vladimir; Hramova, Marina

2018-02-01

Using wavelet analysis of the signals of electrical brain activity (EEG), we study the processes of neural activity, associated with perception of visual stimuli. We demonstrate that the brain can process visual stimuli in two scenarios: (i) perception is characterized by destruction of the alpha-waves and increase in the high-frequency (beta) activity, (ii) the beta-rhythm is not well pronounced, while the alpha-wave energy remains unchanged. The special experiments show that the motivation factor initiates the first scenario, explained by the increasing alertness. Based on the obtained results we build the brain-computer interface and demonstrate how the degree of the alertness can be estimated and controlled in real experiment.

Syntheses and biological activities of 13-substituted avermectin aglycons.

PubMed

Mrozik, H; Linn, B O; Eskola, P; Lusi, A; Matzuk, A; Preiser, F A; Ostlind, D A; Schaeffer, J M; Fisher, M H

1989-02-01

The reactions of sulfonate esters of the allylic/homoallylic 13-alcohol of 5-O-(tert-butyldimethylsilyl)-22,23-dihydroavermectin B1a aglycon (1a) were investigated. Nucleophilic substitution gave 13 beta-chloro and 13 beta-iodo derivatives, while solvolytic reaction conditions yielded 13 alpha-methoxy, 13 alpha-fluoro, and 13 alpha-chloro products. A mixture of 13 alpha- and 13 beta-fluorides was obtained upon reaction with DAST. The 13 beta-iodide gave, upon elimination with lutidine, the 8(9),10(11),12(13),14(15)-tetraene. The 13 beta-alcohol and the rearranged 15-ol 13(14)-ene and 15-amino 13(14)-ene derivatives were obtained by substitution via the allylic carbonium ion. MEM ethers 11 and 12 of the two epimeric 13-ols were prepared by alkylation with MEM chloride. In contrast, methylation of 1a with MeI and Ag2O in CH2Cl2 occurred exclusively at the tertiary 7-hydroxy group and not at the secondary 13 alpha-ol. Oxidation of the allylic alcohol 1a proceeded under Swern conditions but not with MnO2 to the 13-oxo aglycon, which was reduced by NaBH4 exclusively to the natural 13 alpha-ol, while reductive amination with NaCNBH3-NH4OAc gave the 13 alpha-amine. The methoxime derivative was obtained in the form of the two geometric isomers. Anthelmintic activities against the sheep nematode Trichostrongylus colubriformis, miticidal activities against the two-spotted spider mite (Tetranychus urticae), and insecticidal activities against the southern armyworm (Spodoptera eridania) as well as the binding constants to a free living nematode (Caenorhabditis elegans) derived receptor assay were obtained and compared to avermectin B1a, 22,23-dihydroavermectin B1a, and the 13-deoxy-22,23-dihydroavermectin B1 aglycon related to the milbemycins. None of the newly prepared derivatives exceeded the potency of the three reference compounds. Lipophilic 13-substituents such as halogen, alkoxy, and methoxime retained high biological activities in all assays, while the more polar substituents hydroxy and amino had weaker activities. Rearranged 15-substituted 13(14)-ene derivatives were completely inactive. The 13-oxo and the 12,13-dehydro analogues were only weakly active in vivo despite having good binding affinity to the receptor, possibly due to instability or poor absorption.

An additional bolus of rapid-acting insulin to normalise postprandial cardiovascular risk factors following a high-carbohydrate high-fat meal in patients with type 1 diabetes: A randomised controlled trial.

PubMed

Campbell, Matthew D; Walker, Mark; Ajjan, Ramzi A; Birch, Karen M; Gonzalez, Javier T; West, Daniel J

2017-07-01

To evaluate an additional rapid-acting insulin bolus on postprandial lipaemia, inflammation and pro-coagulation following high-carbohydrate high-fat feeding in people with type 1 diabetes. A total of 10 males with type 1 diabetes [HbA 1c 52.5 ± 5.9 mmol/mol (7.0% ± 0.5%)] underwent three conditions: (1) a low-fat (LF) meal with normal bolus insulin, (2), a high-fat (HF) meal with normal bolus insulin and (3) a high-fat meal with normal bolus insulin with an additional 30% insulin bolus administered 3-h post-meal (HFA). Meals had identical carbohydrate and protein content and bolus insulin dose determined by carbohydrate-counting. Blood was sampled periodically for 6-h post-meal and analysed for triglyceride, non-esterified-fatty acids, apolipoprotein B48, glucagon, tumour necrosis factor alpha, fibrinogen, human tissue factor activity and plasminogen activator inhibitor-1. Continuous glucose monitoring captured interstitial glucose responses. Triglyceride concentrations following LF remained similar to baseline, whereas triglyceride levels following HF were significantly greater throughout the 6-h observation period. The additional insulin bolus (HFA) normalised triglyceride similarly to low fat 3-6 h following the meal. HF was associated with late postprandial elevations in tumour necrosis factor alpha, whereas LF and HFA was not. Fibrinogen, plasminogen activator inhibitor-1 and tissue factor pathway levels were similar between conditions. Additional bolus insulin 3 h following a high-carbohydrate high-fat meal prevents late rises in postprandial triglycerides and tumour necrosis factor alpha, thus improving cardiovascular risk profile.

Activity and subcellular compartmentalization of peroxisome proliferator-activated receptor alpha are altered by the centrosome-associated protein CAP350.

PubMed

Patel, Hansa; Truant, Ray; Rachubinski, Richard A; Capone, John P

2005-01-01

Peroxisome proliferator-activated nuclear hormone receptors (PPAR) are ligand-activated transcription factors that play pivotal roles in governing metabolic homeostasis and cell growth. PPARs are primarily in the nucleus but, under certain circumstances, can be found in the cytoplasm. We show here that PPAR(alpha) interacts with the centrosome-associated protein CAP350. CAP350 also interacts with PPAR(delta), PPAR(gamma) and liver-X-receptor alpha, but not with the 9-cis retinoic acid receptor, RXR(alpha). Immunofluorescence analysis indicated that PPAR(alpha) is diffusely distributed in the nucleus and excluded from the cytoplasm. However, in the presence of coexpressed CAP350, PPAR(alpha) colocalizes with CAP350 to discrete nuclear foci and to the centrosome, perinuclear region and intermediate filaments. In contrast, the subcellular distribution of RXR(alpha) or of thyroid hormone receptor alpha was not altered by coexpression of CAP350. An amino-terminal fragment of CAP350 was localized exclusively to nuclear foci and was sufficient to recruit PPAR(alpha) to these sites. Mutation of the single putative nuclear hormone receptor interacting signature motif LXXLL present in this fragment had no effect on its subnuclear localization but abrogated recruitment of PPAR(alpha) to nuclear foci. Surprisingly, mutation of the LXXLL motif in this CAP350 subfragment did not prevent its binding to PPAR(alpha) in vitro, suggesting that this motif serves some function other than PPAR(alpha) binding in recruiting PPAR(alpha) to nuclear spots. CAP350 inhibited PPAR(alpha)-mediated transactivation in an LXXLL-dependent manner, suggesting that CAP350 represses PPAR(alpha) function. Our findings implicate CAP350 in a dynamic process that recruits PPAR(alpha) to discrete nuclear and cytoplasmic compartments and suggest that altered intracellular compartmentalization represents a regulatory process that modulates PPAR function.

Impaired coactivator activity of the Gly{sub 482} variant of peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) on mitochondrial transcription factor A (Tfam) promoter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Yon-Sik; Hong, Jung-Man; Lim, Sunny

2006-06-09

Mitochondrial dysfunction may cause diabetes or insulin resistance. Peroxisome proliferation-activated receptor-{gamma} (PPAR-{gamma}) coactivator-1 {alpha} (PGC-1{alpha}) increases mitochondrial transcription factor A (Tfam) resulting in mitochondrial DNA content increase. An association between a single nucleotide polymorphism (SNP), G1444A(Gly482Ser), of PGC-1{alpha} coding region and insulin resistance has been reported in some ethnic groups. In this study, we investigated whether a change of glycine to serine at codon 482 of PGC-1{alpha} affected the Tfam promoter activity. The cDNA of PGC-1{alpha} variant bearing either glycine or serine at 482 codon was transfected into Chang human hepatocyte cells. The PGC-1{alpha} protein bearing glycine had impaired coactivatormore » activity on Tfam promoter-mediated luciferase. We analyzed the PGC-1{alpha} genotype G1444A and mitochondrial DNA (mtDNA) copy number from 229 Korean leukocyte genomic DNAs. Subjects with Gly/Gly had a 20% lower amount of peripheral blood mtDNA than did subjects with Gly/Ser and Ser/Ser (p < 0.05). No correlation was observed between diabetic parameters and PGC-1{alpha} genotypes in Koreans. These results suggest that PGC-1{alpha} variants with Gly/Gly at 482nd amino acid may impair the Tfam transcription, a regulatory function of mitochondrial biogenesis, resulting in dysfunctional mtDNA replication.« less

Phosphorylation regulates the water channel activity of the seed-specific aquaporin alpha-TIP.

PubMed

Maurel, C; Kado, R T; Guern, J; Chrispeels, M J

1995-07-03

The vacuolar membrane protein alpha-TIP is a seed-specific protein of the Major Intrinsic Protein family. Expression of alpha-TIP in Xenopus oocytes conferred a 4- to 8-fold increase in the osmotic water permeability (Pf) of the oocyte plasma membrane, showing that alpha-TIP forms water channels and is thus a new aquaporin. alpha-TIP has three putative phosphorylation sites on the cytoplasmic side of the membrane (Ser7, Ser23 and Ser99), one of which (Ser7) has been shown to be phosphorylated. We present several lines of evidence that the activity of this aquaporin is regulated by phosphorylation. First, mutation of the putative phosphorylation sites in alpha-TIP (Ser7Ala, Ser23Ala and Ser99Ala) reduced the apparent water transport activity of alpha-TIP in oocytes, suggesting that phosphorylation of alpha-TIP occurs in the oocytes and participates in the control of water channel activity. Second, exposure of oocytes to the cAMP agonists 8-bromoadenosine 3',5'-cyclic monophosphate, forskolin and 3-isobutyl-1-methylxanthine, which stimulate endogenous protein kinase A (PKA), increased the water transport activity of alpha-TIP by 80-100% after 60 min. That the protein can be phosphorylated by PKA was demonstrated by phosphorylating alpha-TIP in isolated oocyte membranes with the bovine PKA catalytic subunit. Third, the integrity of the three sites at positions 7, 23 and 99 was necessary for the cAMP-dependent increase in the Pf of oocytes expressing alpha-TIP, as well as for in vitro phosphorylation of alpha-TIP. These findings demonstrate that the alpha-TIP water channel can be modulated via phosphorylation of Ser7, Ser23 and Ser99.(ABSTRACT TRUNCATED AT 250 WORDS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gulec, Cagri, E-mail: cagri.gulec@gmail.com; Coban, Neslihan, E-mail: neslic@istanbul.edu.tr; Ozsait-Selcuk, Bilge, E-mail: ozsaitb@istanbul.edu.tr

ROR-alpha is a nuclear receptor, activity of which can be modulated by natural or synthetic ligands. Due to its possible involvement in, and potential therapeutic target for atherosclerosis, we aimed to identify ROR-alpha target genes in monocytic and endothelial cell lines. We performed chromatin immunoprecipitation (ChIP) followed by tiling array (ChIP-on-chip) for ROR-alpha in monocytic cell line THP1 and endothelial cell line HUVEC. Following bioinformatic analysis of the array data, we tested four candidate genes in terms of dependence of their expression level on ligand-mediated ROR-alpha activity, and two of them in terms of promoter occupancy by ROR-alpha. Bioinformatic analysesmore » of ChIP-on-chip data suggested that ROR-alpha binds to genomic regions near the transcription start site (TSS) of more than 3000 genes in THP1 and HUVEC. Potential ROR-alpha target genes in both cell types seem to be involved mainly in membrane receptor activity, signal transduction and ion transport. While SPP1 and IKBKA were shown to be direct target genes of ROR-alpha in THP1 monocytes, inflammation related gene HMOX1 and heat shock protein gene HSPA8 were shown to be potential target genes of ROR-alpha. Our results suggest that ROR-alpha may regulate signaling receptor activity, and transmembrane transport activity through its potential target genes. ROR-alpha seems also to play role in cellular sensitivity to environmental substances like arsenite and chloroprene. Although, the expression analyses have shown that synthetic ROR-alpha ligands can modulate some of potential ROR-alpha target genes, functional significance of ligand-dependent modulation of gene expression needs to be confirmed with further analyses.« less

Structural basis of nucleic-acid recognition and double-strand unwinding by the essential neuronal protein Pur-alpha

PubMed Central

Weber, Janine; Bao, Han; Hartlmüller, Christoph; Wang, Zhiqin; Windhager, Almut; Janowski, Robert; Madl, Tobias; Jin, Peng; Niessing, Dierk

2016-01-01

The neuronal DNA-/RNA-binding protein Pur-alpha is a transcription regulator and core factor for mRNA localization. Pur-alpha-deficient mice die after birth with pleiotropic neuronal defects. Here, we report the crystal structure of the DNA-/RNA-binding domain of Pur-alpha in complex with ssDNA. It reveals base-specific recognition and offers a molecular explanation for the effect of point mutations in the 5q31.3 microdeletion syndrome. Consistent with the crystal structure, biochemical and NMR data indicate that Pur-alpha binds DNA and RNA in the same way, suggesting binding modes for tri- and hexanucleotide-repeat RNAs in two neurodegenerative RNAopathies. Additionally, structure-based in vitro experiments resolved the molecular mechanism of Pur-alpha's unwindase activity. Complementing in vivo analyses in Drosophila demonstrated the importance of a highly conserved phenylalanine for Pur-alpha's unwinding and neuroprotective function. By uncovering the molecular mechanisms of nucleic-acid binding, this study contributes to understanding the cellular role of Pur-alpha and its implications in neurodegenerative diseases. DOI: http://dx.doi.org/10.7554/eLife.11297.001 PMID:26744780

Reward bias and lateralization in gambling behavior: behavioral activation system and alpha band analysis.

PubMed

Balconi, Michela; Finocchiaro, Roberta; Canavesio, Ylenia; Messina, Rossella

2014-11-30

The present research explored the main factors that can influence subjects' choices in the case of decisions. In order to elucidate the individual differences that influence the decisional processes, making their strategies more or less advantageous, we tested the effect of a reward sensitivity in the behavioral activation system (BAS-Reward) constructed on the ability to distinguish between high- and low-risk decisions. Secondly, the lateralization effect, related to increased activation of the left (BAS-related) hemisphere, was explored. Thirty-one subjects were tested using the Iowa Gambling Task, and the BAS-Reward measure was applied to distinguish between high-BAS and low-BAS groups. Behavioral responses (gain/loss options) and alpha-band modulation were considered. It was found that high-BAS group increased their tendency to opt in favor of the immediate reward (loss strategy) rather than the long-term option (win strategy). Secondly, high-BAS subjects showed an increased left-hemisphere activation in response to losing (with immediate reward) choices in comparison with low-BAS subjects. A "reward bias" effect was supposed to explain both the bad strategy and the unbalanced hemispheric activation for high-BAS and more risk-taking subjects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Regulation of tumour necrosis factor production by adrenal hormones in vivo: insights into the antiinflammatory activity of rolipram.

PubMed Central

Pettipher, E. R.; Labasi, J. M.; Salter, E. D.; Stam, E. J.; Cheng, J. B.; Griffiths, R. J.

1996-01-01

1. The role of adrenal hormones in the regulation of the systemic and local production of tumour necrosis factor (TNF alpha) was examined in male Balb/c mice. 2. Intraperitoneal injection of 0.3 mg E. coli lipopolysaccharide (LPS, 0111:B4) led to high levels of circulating TNF alpha without stimulating TNF alpha production in the peritoneal cavity. Systemic production of TNF alpha in response to LPS was increased in adrenalectomized animals and in normal animals treated with the beta-adrenoceptor antagonist, propranolol. The glucocorticoid antagonist, RU 486, did not modify systemic TNF alpha production. These results indicate that systemic TNF alpha production is regulated by adrenaline but not by corticosterone. 3. When mice were primed with thioglycollate, TNF alpha was produced in the peritoneal cavity in response to low dose LPS (1 micrograms). The levels of TNF alpha in the peritoneal cavity were not enhanced by adrenalectomy or by treatment with either propranolol or RU 486, indicating local production of TNF alpha in the peritoneal cavity is not regulated by adrenaline or corticosterone. 4. The phosphodiesterase type IV (PDE-IV) inhibitor, rolipram, inhibited both the systemic production of TNF alpha in response to high dose endotoxin (ED50 = 1.3 mg kg-1) and the local production of TNF alpha in the peritoneal cavity in response to low dose endotoxin (ED50 = 9.1 mg kg-1). In adrenalectomized mice there was a slight reduction in the ability of rolipram to inhibit the systemic production of TNF alpha (ED50 = 3.3 mg kg-1) while the ability of rolipram to inhibit the local production of TNF alpha in the peritoneal cavity was virtually abolished (24% inhibition at 30 mg kg-1). The glucocorticoid antagonist, RU 486, also reduced the ability of rolipram to inhibit local TNF alpha production while propranolol was without effect. 5. Systemic treatment with rolipram increased the plasma concentrations of corticosterone in normal mice but not in adrenalectomized mice indicating that rolipram can cause adrenal stimulation in vivo. 6. In summary, these data indicate that systemic production of TNF alpha in response to high dose endotoxin is controlled differently from the local production of TNF alpha in response to low dose endotoxin. The systemic production of TNF alpha is regulated by catecholamines, but not by corticosterone, while the local production of TNF alpha in the peritoneal cavity is not regulated by basal levels of either catecholamines or corticosterone. 7. These data also show that the ability of rolipram to inhibit the local production of TNF alpha is dependent on the release of corticosterone from the adrenal glands. PMID:8730750

Regulation of tumour necrosis factor production by adrenal hormones in vivo: insights into the antiinflammatory activity of rolipram.

PubMed

Pettipher, E R; Labasi, J M; Salter, E D; Stam, E J; Cheng, J B; Griffiths, R J

1996-04-01

1. The role of adrenal hormones in the regulation of the systemic and local production of tumour necrosis factor (TNF alpha) was examined in male Balb/c mice. 2. Intraperitoneal injection of 0.3 mg E. coli lipopolysaccharide (LPS, 0111:B4) led to high levels of circulating TNF alpha without stimulating TNF alpha production in the peritoneal cavity. Systemic production of TNF alpha in response to LPS was increased in adrenalectomized animals and in normal animals treated with the beta-adrenoceptor antagonist, propranolol. The glucocorticoid antagonist, RU 486, did not modify systemic TNF alpha production. These results indicate that systemic TNF alpha production is regulated by adrenaline but not by corticosterone. 3. When mice were primed with thioglycollate, TNF alpha was produced in the peritoneal cavity in response to low dose LPS (1 micrograms). The levels of TNF alpha in the peritoneal cavity were not enhanced by adrenalectomy or by treatment with either propranolol or RU 486, indicating local production of TNF alpha in the peritoneal cavity is not regulated by adrenaline or corticosterone. 4. The phosphodiesterase type IV (PDE-IV) inhibitor, rolipram, inhibited both the systemic production of TNF alpha in response to high dose endotoxin (ED50 = 1.3 mg kg-1) and the local production of TNF alpha in the peritoneal cavity in response to low dose endotoxin (ED50 = 9.1 mg kg-1). In adrenalectomized mice there was a slight reduction in the ability of rolipram to inhibit the systemic production of TNF alpha (ED50 = 3.3 mg kg-1) while the ability of rolipram to inhibit the local production of TNF alpha in the peritoneal cavity was virtually abolished (24% inhibition at 30 mg kg-1). The glucocorticoid antagonist, RU 486, also reduced the ability of rolipram to inhibit local TNF alpha production while propranolol was without effect. 5. Systemic treatment with rolipram increased the plasma concentrations of corticosterone in normal mice but not in adrenalectomized mice indicating that rolipram can cause adrenal stimulation in vivo. 6. In summary, these data indicate that systemic production of TNF alpha in response to high dose endotoxin is controlled differently from the local production of TNF alpha in response to low dose endotoxin. The systemic production of TNF alpha is regulated by catecholamines, but not by corticosterone, while the local production of TNF alpha in the peritoneal cavity is not regulated by basal levels of either catecholamines or corticosterone. 7. These data also show that the ability of rolipram to inhibit the local production of TNF alpha is dependent on the release of corticosterone from the adrenal glands.

Intracellular signaling required for CCL25-stimulated T cell adhesion mediated by the integrin alpha4beta1.

PubMed

Parmo-Cabañas, Marisa; García-Bernal, David; García-Verdugo, Rosa; Kremer, Leonor; Márquez, Gabriel; Teixidó, Joaquin

2007-08-01

The alpha4beta1 integrin is expressed on thymocytes and mediates cell attachment to its ligands CS-1/fibronectin (CS-1/FN) and VCAM-1 in the thymus. The chemokine CCL25 is highly expressed in the thymus, where it binds to its receptor CCR9 on thymocytes promoting migration and activation. We show here that alpha4beta1 and CCR9 are coexpressed mainly on double- and single-positive thymocytes and that CCL25 strongly stimulates CD4(+)CD8(+) and CD4(+)CD8(-) adhesion to CS-1/FN and VCAM-1. CCL25 rapidly activated the GTPases Rac and Rap1 on thymocytes, and this activation was required for stimulation of adhesion, as detected using the CCR9(+)/alpha4beta1(+) human T cell line Molt-4. To study the role on CCL25-stimulated adhesion of the Rac downstream effector Wiskott-Aldrich syndrome protein family verproline-homologous protein 2 (WAVE2) as well as of Rap1-GTP-interacting proteins, regulator of adhesion and cell polarization enriched in lymphoid tissues (RAPL) and Rap1-GTP-interacting adapter molecule (RIAM), we knocked down their expression and tested transfectant attachment to alpha4beta1 ligands. We found that WAVE2 and RAPL but not RIAM were required for efficient triggering by CCL25 of T cell adhesion to CS-1/FN and VCAM-1. Although Rac and Rap1 activation was required during early steps of T cell adhesion stimulated by CCL25, WAVE2 was needed for the development of actin-dependent T cell spreading subsequent to adhesion strengthening but not during initial alpha4beta1-ligand interactions. These results suggest that regulation by CCL25 of adhesion of thymocyte subpopulations mediated by alpha4beta1 could contribute to control their trafficking in the thymus during maturation, and identify Rac-WAVE2 and Rap1-RAPL as pathways whose activation is required in inside-out signaling, leading to stimulated adhesion.

Discovery and observation of BY Draconis variables

NASA Astrophysics Data System (ADS)

Bopp, B. W.; Noah, P. V.; Klimke, A.; Africano, J.

1981-10-01

The discovery of BY Draconis variables was efficiently accomplished by a spectroscopic survey of dK-M stars for weak H-alpha emissions, using 1-2 A resolution. The four BY Dra variables discovered are all spectroscopic binaries with P values lower than about 10 d, in light of which, it is noted that the onset of high surface activity and appearance of H-alpha emission occur sharply at v(equator) of approximately 5 km/sec. At v(equator) of about 3 km/sec, dK-M stars have low levels of surface activity. It is found that while there is a range of Ca II emission strength, and only the strongest emitters of this line are BY Dra and/or flare stars, the H-alpha feature changes abruptly to an emission feature signaling the onset of flaring and/or the BY Dra syndrome. An increase of the rotation rate above v(equator) 5 km/sec does not appear to increase the level of surface activity.

Characterization and localization of progesterone 5 alpha-reductase from cell cultures of foxglove (Digitalis lanata EHRH).

PubMed Central

Wendroth, S; Seitz, H U

1990-01-01

Progesterone 5 alpha-reductase, which catalyses the reduction of progesterone to 5 alpha-pregnane-3,20-dione, was isolated and characterized from cell cultures of Digitalis lanata (foxglove). Optimum enzyme activity was observed at pH 7.0, and the enzyme had an apparent Km value of 30 microM for its substrate progesterone. The enzyme needs NADPH as reductant, which could not be replaced by NADH. For NADPH, the apparent Km value is 130 microM. The optimum temperature was 40 degrees C; at temperatures below 45 degrees C, the product 5 alpha-pregnane-3,20-dione was reduced by a second reaction to 5 alpha-pregnan-3 beta-ol-20-one. Progesterone 5 alpha-reductase activity was not dependent on bivalent cations. In the presence of EDTA, 0.1 mM-Mn2+ had no influence on enzyme activity, whereas 0.1 mM-Ca2+, -Co2+ and -Zn2+ decreased progesterone 5 alpha-reductase activity. Only 0.1 mM-Mg2+ was slightly stimulatory. EDTA and thiol reagents such as dithiothreitol stimulate progesterone 5 alpha-reductase activity. By means of linear sucrose gradient fractionation of the cellular membranes, progesterone 5 alpha-reductase was found to be located in the endoplasmic reticulum. PMID:2106876

Effect of certain plant extracts on alpha-amylase activity.

PubMed

Prashanth, D; Padmaja, R; Samiulla, D S

2001-02-01

Ethanolic extracts of Punica granatum, Mangifera indica, Boerhaavia diffusa, Embelia ribes, Phyllanthus maderaspatensis, and Withania somnifera, were tested for their effect on alpha-amylase activity (in vitro). P. granatum and M. indica were found to exhibit interesting alpha-amylase inhibitory activity.

Regulation of neurosteroid allopregnanolone biosynthesis in the rat spinal cord by glycine and the alkaloidal analogs strychnine and gelsemine.

PubMed

Venard, C; Boujedaini, N; Belon, P; Mensah-Nyagan, A G; Patte-Mensah, C

2008-04-22

The neurosteroid allopregnanolone (3alpha,5alpha-THP) is well characterized as a potentially therapeutic molecule which exerts important neurobiological actions including neuroprotective, antidepressant, anxiolytic, anesthetic and analgesic effects. We have recently observed that neurons and glial cells of the rat spinal cord (SC) contain various key steroidogenic enzymes such as 5alpha-reductase and 3alpha-hydroxysteroid oxido-reductase which are crucial for 3alpha,5alpha-THP biosynthesis. Furthermore, we demonstrated that the rat SC actively produces 3alpha,5alpha-THP. As the key factors regulating neurosteroid production by nerve cells are unknown and because glycine is one of the pivotal inhibitory neurotransmitters in the SC, we investigated glycine effects on 3alpha,5alpha-THP biosynthesis in the rat SC. Glycine markedly stimulated [(3)H]-progesterone conversion into [(3)H]3alpha,5alpha-THP by SC slices. The alkaloid strychnine, well-known as a glycine receptor (Gly-R) antagonist, blocked glycine stimulatory effect on 3alpha,5alpha-THP formation. Gelsemine, another alkaloid containing the same functional groups as strychnine, increased 3alpha,5alpha-THP synthesis. The stimulatory effects of glycine and gelsemine on 3alpha,5alpha-THP production were additive when the two drugs were combined. These results demonstrate that glycine and gelsemine, acting via Gly-R, upregulate 3alpha,5alpha-THP biosynthesis in the SC. The data also revealed a structure-activity relationship of the analogs strychnine and gelsemine on neurosteroidogenesis. Possibilities are opened for glycinergic agents and gelsemine utilization to stimulate selectively 3alpha,5alpha-THP biosynthetic pathways in diseases evoked by a decreased neurosteroidogenic activity of nerve cells.

Influence of temperature on flavour compound production from citrate by Lactobacillus rhamnosus ATCC 7469.

PubMed

De Figueroa, R M; Oliver, G; Benito de Cárdenas, I L

2001-03-01

The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was found to be temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C]citrate rate were observed at 37 degreesC. At this temperature, maximum citrate lyase activity and specific diacetyl and acetoin production (Y(DA%)) were observed. The high levels of alpha-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L-lactate dehydrogenase found at 37 degreesC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45 degreesC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increased with increasing culture temperature from 22 degreesC to 37 degreesC. Thus there are greater quantities of pyruvate available for the production of alpha-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.

Redifferentiation of human hepatoma cells (SMMC-7721) induced by two new highly oxygenated bisabolane-type sesquiterpenes.

PubMed

Miao, Ruidong; Wei, Juan; Zhang, Qi; Sajja, Venkateswara; Yang, Jinbo; Wang, Qin

2008-12-01

Bisabolane-type sesquiterpenes are a class of biologically active compounds that has antitumour,antifungal, antibacterial,antioxidant and antivenom properties.We investigated the effect of two new highly oxygenated bisabolane-type sesquiterpenes (HOBS)isolated from Cremanthodium discoideum (C.discoideum) on tumour cells. Our results showed that HOBS induced morphological differentiation and reduced microvilli formation on the cell surface in SMMC-7721 cells.Flow cytometry analysis demonstrated that HOBS could induce cell-cycle arrest in the G1 phase. Moreover,HOBS was able to increase tyrosine-alpha ketoglutarate transaminase activity,decrease alpha- foetoprotein level and gamma-glutamyl transferase activity. In addition,we found that HOBS inhibited the anchorage- independent growth of SMMC-7721 cells in a dose-dependent manner.Taken together,all the above observations indicate that HOBS might be able to normalize malignant SMMC-7721 cells by inhibiting cell proliferation and inducing redifferentiation.

Activation of PKC isoform beta(I) at the blood-brain barrier rapidly decreases P-glycoprotein activity and enhances drug delivery to the brain.

PubMed

Rigor, Robert R; Hawkins, Brian T; Miller, David S

2010-07-01

P-glycoprotein is an ATP (adenosine triphosphate)-driven drug efflux transporter that is highly expressed at the blood-brain barrier (BBB) and is a major obstacle to the pharmacotherapy of central nervous system diseases, including brain tumors, neuro-AIDS, and epilepsy. Previous studies have shown that P-glycoprotein transport activity in rat brain capillaries is rapidly reduced by the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha) acting through protein kinase C (PKC)-dependent signaling. In this study, we used isolated rat brain capillaries to show that the TNF-alpha-induced reduction of P-glycoprotein activity was prevented by a PKCbeta(I/II) inhibitor, LY333531, and mimicked by a PKCbeta(I/II) activator, 12-deoxyphorbol-13-phenylacetate-20-acetate (dPPA). Western blotting of brain capillary extracts with phospho-specific antibodies showed that dPPA activated PKCbeta(I), but not PKCbeta(II). Moreover, in intact rats, intracarotid infusion of dPPA potently increased brain accumulation of the P-glycoprotein substrate, [(3)H]-verapamil without compromising tight junction integrity. Thus, PKCbeta(I) activation selectively reduced P-glycoprotein activity both in vitro and in vivo. Targeting PKCbeta(I) at the BBB may prove to be an effective strategy for enhancing the delivery of small molecule therapeutics to the brain.

[(35)S]-GTPgammaS autoradiography reveals alpha(2) adrenoceptor-mediated G-protein activation in amygdala and lateral septum.

PubMed

Newman-Tancredi, A; Chaput, C; Touzard, M; Millan, M J

2000-04-03

alpha(2)-adrenoceptor-mediated G-protein activation was examined by [(35)S]-GTPgammaS autoradiography. In alpha(2)-adrenoceptor-rich regions (amygdala, lateral septum), noradrenaline stimulated [(35)S]-GTPgammaS binding. These actions were abolished by the selective alpha(2) antagonist, atipamezole. Conversely, in caudate nucleus, which expresses few alpha(2) receptors, noradrenaline-induced stimulation was not inhibited by atipamezole, suggesting that it is not mediated by alpha(2)-adrenoceptors.

Effect of pregnant mare's serum gonadotrophin on the activities of delta 4-5 alpha-reductase, aromatase, and other enzymes in the ovaries of immature rats.

PubMed

Suzuki, K; Kawakura, K; Tamaoki, B I

1978-05-01

After incubation of progesterone, 17 alpha-hydroxyprogesterone, androstenedione, and testostrone with an ovarian preparation (supernatant fluid at 10,000 x g) of immature rats (21-23 days of age) in the presence of NADPH, 3 alpha- and 3 beta-hydroxy-5 alpha-reduced steroids were obtained as the major metabolites. Among the enzyme activities relevant to the metabolism, delta 4-5 alpha-reductase and 3 beta-hydroxysteroid dehydrogenase were intracellularly localized to the microsomal fraction (10,000--105,000 x g), and 3 alpha-hydroxysteroid dehydrogenase was detected exclusively in the cytosol fraction (supernatant fluid at 105,000 x g). Within 2 days after a single injection of pregnant mare's serum gonadotrophin (10 IU/rat) to 21-day-old female rats, the following occurred: 1) an enhancement of 17 alpha-hydroxylase and C-17-C-20 lyase activities; 2) a suppression of delta 4-5 alpha-reductase activity; and 3) an increase in aromatizing activity. From the above-mentioned results, it was concluded that the increased secretion of estrogen from ovaries of immature rats stimulated by pregnant mare's serum gonadotrophin administration was caused by a modification of the ovarian enzyme activities relevant to estrogen production.

Isoform-specific changes in the Na,K-ATPase of rat soleus muscle during acute hindlinb suspension

NASA Astrophysics Data System (ADS)

Krivoi, Igor; Heiny, Judith; Bouzinova, Elena; Matchkov, Vladimir; Kravtsova, Violetta; Petrov, Aleksey; Zefirov, Andrey; Vasiliev, Alexander

The largest pool of Na,K-ATPase (NKA) in a vertebrate's body is contained in the skeletal muscles where the alpha1 and alpha2 isoforms of NKA alpha subunit are expressed. The NKA is critically important for excitability, electrogenesis and contractility of skeletal muscle. Skeletal muscle use strongly regulates the content of NKA, and increased muscle activity differently regulates the alpha1 and alpha2 isoforms. However, whether skeletal muscle disuse affects NKA content and activity has not been investigated. This study examines for the first time the consequences of acute hindlinb suspension (HS) on the alpha1 and alpha2 NKA isozymes in rat soleus muscle. We subjected rats to HS for 6-12 hours and analyzed its effect on the resting membrane potential (RMP) in different sarcolemma regions of m.soleus fibers; the electrogenic transport activity, protein content and mRNA expression of the alpha1 and alpha2 NKA; the extracellular level of acetylcholine, and the plasma membrane localization of the alpha2 isozyme using confocal microscopy with cytochemistry. Our results show that 6 h HS specifically decreases the electrogenic activity of the NKA alpha2 isozyme and depolarizes m.soleus fibers. These effects are irreversible in the extrajunctional membrane region up to 12 h HS. The decreased alpha2 NKA activity is due to a decrease in enzyme activity rather than by altered protein content, mRNA expression, or localization in the sarcolemma. In addition, HS does not alter the alpha2 NKA electrogenic transport due to decreased extracellular acetylcholine level. However, adaptive mechanism(s) operate at the junctional membrane to restore alpha2 NKA electrogenic activities and the RMP after 12 h of HS. This mechanism operates specifically at the synaptic membrane region, presumably via increase in both alpha2 isozyme mRNA expression and protein content. This basic information on a protein as vital as the NKA is expected to advance our understanding of the cellular and molecular mechanisms responsible for microgravity-induced muscle atrophy. Supported by RFBR #13-04-00973; St. Petersburg State University research grants #1.50.1621.2013 and #1.38.231.2014; grant #MK-108.2014.4., the Novo Nordisk Foundation and N.I.H grant #1 R01 AR063710.

Different responses of spontaneous and stimulus-related alpha activity to ambient luminance changes.

PubMed

Benedetto, Alessandro; Lozano-Soldevilla, Diego; VanRullen, Rufin

2017-12-04

Alpha oscillations are particularly important in determining our percepts and have been implicated in fundamental brain functions. Oscillatory activity can be spontaneous or stimulus-related. Furthermore, stimulus-related responses can be phase- or non-phase-locked to the stimulus. Non-phase-locked (induced) activity can be identified as the average amplitude changes in response to a stimulation, while phase-locked activity can be measured via reverse-correlation techniques (echo function). However, the mechanisms and the functional roles of these oscillations are far from clear. Here, we investigated the effect of ambient luminance changes, known to dramatically modulate neural oscillations, on spontaneous and stimulus-related alpha. We investigated the effect of ambient luminance on EEG alpha during spontaneous human brain activity at rest (experiment 1) and during visual stimulation (experiment 2). Results show that spontaneous alpha amplitude increased by decreasing ambient luminance, while alpha frequency remained unaffected. In the second experiment, we found that under low-luminance viewing, the stimulus-related alpha amplitude was lower, and its frequency was slightly faster. These effects were evident in the phase-locked part of the alpha response (echo function), but weaker or absent in the induced (non-phase-locked) alpha responses. Finally, we explored the possible behavioural correlates of these modulations in a monocular critical flicker frequency task (experiment 3), finding that dark adaptation in the left eye decreased the temporal threshold of the right eye. Overall, we found that ambient luminance changes impact differently on spontaneous and stimulus-related alpha expression. We suggest that stimulus-related alpha activity is crucial in determining human temporal segmentation abilities. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Three dimensional structural studies of alpha-N-acetylgalactosaminidase (alpha-NAGA) in alpha-NAGA deficiency (Kanzaki disease): different gene mutations cause peculiar structural changes in alpha-NAGAs resulting in different substrate specificities and clinical phenotypes.

PubMed

Kanekura, Takuro; Sakuraba, Hitoshi; Matsuzawa, Fumiko; Aikawa, Seiichi; Doi, Hirofumi; Hirabayashi, Yoshio; Yoshii, Noriko; Fukushige, Tomoko; Kanzaki, Tamotsu

2005-01-01

Kanzaki disease (OMIM#104170) is attributable to a deficiency in alpha-N-acetylgalactosaminidase (alpha-NAGA; E.C.3.2.1.49), which hydrolyzes GalNAcalpha1-O-Ser/Thr. Missense mutations, R329W or R329Q were identified in two Japanese Kanzaki patients. Although they are on the same codon, the clinical manifestation was more severe in R329W because an amino acid substitution led to protein instability resulting in structural change, which is greater in R329W than in R329Q. To examine whether the different clinical phenotypes are attributable to the two mutations. Plasma alpha-NAGA activity and urinary excreted glycopeptides were measured and three-dimensional models of human alpha-NAGA and its complexes with GalNAcalpha1-O-Ser and GalNAcalpha1-O-Thr were constructed by homology modeling. Residual enzyme activity was significantly higher in the R329Q- than the R329W mutant (0.022+/-0.005 versus 0.005+/-0.001 nmol/h/ml: p<0.05); the urinary ratios of GalNAcalpha1-O-Ser:GalNAcalpha1-O-Thr were 2:10 and 8:10, respectively. GalNAcalpha1-O-Ser/Thr fit tightly in a narrow space of the active site pocket of alpha-NAGA. GalNAcalpha1-O-Thr requires a larger space to associate with alpha-NAGA because of the side chain (CH3) of the threonine residue. Our findings suggest that the association of alpha-NAGA with its substrates is strongly affected by the amino acid substitution at R329 and that the association with GalNAcalpha1-O-Thr is more highly susceptible to structural changes. The residual mutant enzyme in R329W could not associate with GalNAcalpha1-O-Thr and GalNAcalpha1-O-Ser. However, the residual mutant enzyme in R329Q catalyzed GalNAcalpha1-O-Ser to some extent. Therefore, the urinary ratio of GalNAcalpha1-O-Ser:GalNAcalpha1-O-Thr was lower and the clinical phenotype was milder in the R329Q mutation. Structural analysis revealed biochemical and phenotypic differences in these Kanzaki patients with the R329Q and R329W mutation.

Amygdala, Anxiety and Alpha(1) Adrenoceptors: Investigations Utilizing a Rodent Model of Traumatic Stress

DTIC Science & Technology

2006-08-23

Hypothalamic-pituitary-adrenocortical (HPA) Lateral hypothalamus (LH) Long-term depression (LTD) Long-term potentiation (LTP) Medial geniculate ...Aghajanian,GK. Activation of lateral geniculate neurons by norepinephrine: mediation by an alpha-adrenergic receptor. Brain Res. 1980;182: 345- 359...expressed in moderate to high levels, whereas 1B and 1D receptors are expressed at low levels. Conversely, in the lateral nucleus, 1B and 1D receptors are

Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate.

PubMed

Corradi, Lara S; Góes, Rejane M; Carvalho, Hernandes F; Taboga, Sebastião R

2004-06-01

Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5 alpha-reductase (5 alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5 alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5 alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.

Inhibitory properties of the antibothropic complex from the South American opossum (Didelphis marsupialis) serum.

PubMed

Neves-Ferreira, A G; Perales, J; Ovadia, M; Moussatché, H; Domont, G B

1997-06-01

The South American opossum Didelphis marsupialis is known to be highly resistant to snake envenomation. In this paper it is shown that the opossum serum inhibits haemorrhage induced by both Crotalinae and Viperinae venoms. Tested against Bothrops jararaca (jararaca) venom, the antibothropic complex (ABC) isolated from the opossum serum was at least six times more antihaemorrhagic than the commercial antivenom. ABC showed no proteolytic activity by itself and was not hydrolysed by the venom. It inhibited the hydrolysis of casein by B. jararaca venom, but did not inhibit its hydrolytic activities upon N alpha-benzoyl-L-arginine ethyl ester (BAEE) and N alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA). The inhibitor did not interfere with trypsin and bacterial collagenase activities on BAPNA and N-(3-[2-furyl]acryloyl)-Leu-Gly-Pro-Ala (FALGPA), respectively. It reduced chymotrypsin hydrolysis of N-acetyl-L-tyrosine ethyl ester (ATEE) because ABC is also a substrate for this enzyme. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, B. jararaca venom preferentially degraded fibrinogen A alpha-chain and fibrin alpha-chain. Tested on extracellular matrix proteins, the venom hydrolysed collagen IV, gelatins I and V, laminin and fibronectin, besides depolimerizing collagen I alpha-chain dimers. Fibrillar collagen V was not digested. These hydrolyses were inhibited by ABC and by EDTA. Our results show that the antibothropic complex is a venom metalloproteinase inhibitor, which could, at least partially, account for its antihaemorrhagic activity. Electrophoretic evidence indicated non-covalent complex formation between the antihaemorrhagic factor and component(s) of B. jararaca venom.

Cortical Alpha Activity in Schizoaffective Patients

PubMed Central

Moeini, Mahdi; Khaleghi, Ali; Mohammadi, Mohammad Reza; Zarafshan, Hadi; Fazio, Rachel L.; Majidi, Hamid

2017-01-01

Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT) receptor function in schizoaffective disorder (SA), a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA. Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders–Fourth Edition (DSM–IV) criteria for SA, and in 39 healthy controls. Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75) = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75) = 5.67, P = 0.025]. Conclusion: A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations. PMID:28496495

Cortical Alpha Activity in Schizoaffective Patients.

PubMed

Moeini, Mahdi; Khaleghi, Ali; Mohammadi, Mohammad Reza; Zarafshan, Hadi; Fazio, Rachel L; Majidi, Hamid

2017-01-01

Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT) receptor function in schizoaffective disorder (SA), a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA. Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) criteria for SA, and in 39 healthy controls. Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75) = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75) = 5.67, P = 0.025]. Conclusion : A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations.

Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

PubMed Central

Pickard, Gary E.; So, Kwok-Fai; Pu, Mingliang

2015-01-01

Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

Different patterns of 5{alpha}-reductase expression, cellular distribution, and testosterone metabolism in human follicular dermal papilla cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shicheng; Yamauchi, Hitoshi

Androgens regulate hair growth, and 5{alpha}-reductase (5{alpha}R) plays a pivotal role in the action of androgens on target organs. To clarify the molecular mechanisms responsible for controlling hair growth, the present study presents evidence that the human follicular dermal papilla cells (DPCs) from either beard (bDPCs) or scalp hair (sDPCs) possess endogenous 5{alpha}R activity. Real-time RT-PCR revealed that the highest level of 5{alpha}R1 mRNA was found in bDPCs, followed by sDPCs, and a low but detectable level of 5{alpha}R1 mRNA was observed in fibroblasts. Minimally detectable levels of 5{alpha}R2 mRNA were found in all three cell types. A weak bandmore » at 26 kDa corresponding to the human 5{alpha}R1 protein was detected by Western blot in both DPCs, but not in fibroblasts. Immuonofluorescence analysis confirmed that 5{alpha}R1 was localized to the cytoplasm rather than in the nuclei in both DPCs Furthermore, a 5{alpha}R assay using [{sup 14}C]testosterone labeling in intact cells revealed that testosterone was transformed primarily into androstenedione, and in small amounts, into DHT. Our results demonstrate that the 5{alpha}R activities of either bDPCs or sDPCs are stronger than that of dermal fibroblasts, despite the fact that the major steroidogenic activity is attributed to 17{beta}-HSD rather than 5{alpha}R among the three cell types. The 5{alpha}R1 inhibitor MK386 exhibited a more potent inhibitory effect on 5{alpha}R activity than finasteride (5{alpha}R2 inhibitor) in bDPCs.« less

Role of microsomal retinol/sterol dehydrogenase-like short-chain dehydrogenases/reductases in the oxidation and epimerization of 3alpha-hydroxysteroids in human tissues.

PubMed

Belyaeva, Olga V; Chetyrkin, Sergei V; Clark, Amy L; Kostereva, Natalia V; SantaCruz, Karen S; Chronwall, Bibie M; Kedishvili, Natalia Y

2007-05-01

Allopregnanolone (ALLO) and androsterone (ADT) are naturally occurring 3alpha-hydroxysteroids that act as positive allosteric regulators of gamma-aminobutyric acid type A receptors. In addition, ADT activates nuclear farnesoid X receptor and ALLO activates pregnane X receptor. At least with respect to gamma-aminobutyric acid type A receptors, the biological activity of ALLO and ADT depends on the 3alpha-hydroxyl group and is lost upon its conversion to either 3-ketosteroid or 3beta-hydroxyl epimer. Such strict structure-activity relationships suggest that the oxidation or epimerization of 3alpha-hydroxysteroids may serve as physiologically relevant mechanisms for the control of the local concentrations of bioactive 3alpha-hydroxysteroids. The exact enzymes responsible for the oxidation and epimerization of 3alpha-hydroxysteroids in vivo have not yet been identified, but our previous studies showed that microsomal nicotinamide adenine dinucleotide-dependent short-chain dehydrogenases/reductases (SDRs) with dual retinol/sterol dehydrogenase substrate specificity (RoDH-like group of SDRs) can oxidize and epimerize 3alpha-hydroxysteroids in vitro. Here, we present the first evidence that microsomal nicotinamide adenine dinucleotide-dependent 3alpha-hydroxysteroid dehydrogenase/epimerase activities are widely distributed in human tissues with the highest activity levels found in liver and testis and lower levels in lung, spleen, brain, kidney, and ovary. We demonstrate that RoDH-like SDRs contribute to the oxidation and epimerization of ALLO and ADT in living cells, and show that RoDH enzymes are expressed in tissues that have microsomal 3alpha-hydroxysteroid dehydrogenase/epimerase activities. Together, these results provide further support for the role of RoDH-like SDRs in human metabolism of 3alpha-hydroxysteroids and offer a new insight into the enzymology of ALLO and ADT inactivation.

Effect of two active compounds obtained from the essential oil of Cordia verbenacea on the acute inflammatory responses elicited by LPS in the rat paw.

PubMed

Medeiros, R; Passos, G F; Vitor, C E; Koepp, J; Mazzuco, T L; Pianowski, L F; Campos, M M; Calixto, J B

2007-07-01

alpha-Humulene and trans-caryophyllene are sesquiterpene compounds identified in the essential oil of Cordia verbenacea which display topical and systemic anti-inflammatory effects in different experimental models. However, the molecular mechanisms through which they exert their anti-inflammatory activity still remain unclear. Here, we evaluate the effects of alpha-humulene and trans-caryophyllene on the acute inflammatory responses elicited by LPS. The biological activities of alpha-humulene and trans-caryophyllene were investigated in a model of acute inflammation in rat paw, induced by LPS and characterized by paw oedema, neutrophil recruitment, cytokine production, activation of MAP kinases and NF-kappaB and up-regulated expression of kinin B(1) receptors. Treatment with either alpha-humulene or trans-caryophyllene effectively reduced neutrophil migration and activation of NF-kappaB induced by LPS in the rat paw. However, only alpha-humulene significantly reduced the increase in TNF-alpha and IL-1beta levels, paw oedema and the up-regulation of B(1) receptors following treatment with LPS. Both compounds failed to interfere with the activation of the MAP kinases, ERK, p38 and JNK. Both alpha-humulene and trans-caryophyllene inhibit the LPS-induced NF-kappaB activation and neutrophil migration, although only alpha-humulene had the ability to prevent the production of pro-inflammatory cytokines TNF-alpha and IL-1beta and the in vivo up-regulation of kinin B(1) receptors. These data provide additional molecular and functional insights into the beneficial effects of the sesquiterpenes alpha-humulene and trans-caryophyllene isolated from the essential oil of Cordia verbenacea as agents for the management of inflammatory diseases.

Tumor necrosis factor alpha mediates resistance to Trypanosoma cruzi infection in mice by inducing nitric oxide production in infected gamma interferon-activated macrophages.

PubMed Central

Silva, J S; Vespa, G N; Cardoso, M A; Aliberti, J C; Cunha, F Q

1995-01-01

Cell invasion by Trypanosoma cruzi and its intracellular replication are essential for continuation of the parasite life cycle and for production of Chagas' disease. T. cruzi is able to replicate in nucleated cells and can be killed by activated macrophages. Gamma interferon (IFN-gamma) is one of the major stimuli for the activation of macrophages and has been shown to be a key activation factor for the killing of intracellular parasites through a mechanism dependent upon nitric oxide (NO) biosynthesis. We show that although the addition of exogenous tumor necrosis factor alpha (TNF-alpha) does not potentiate the trypanocidal activity of IFN-gamma in vitro, treatment of resistant C57BI/6 mice with an anti-TNF-alpha monoclonal antibody increased parasitemia and mortality. In addition, the anti-TNF-alpha-treated animals had decreased NO production, both in vivo and in vitro, suggesting an important role for TNF-alpha in controlling infection. In order to better understand the role of TNF-alpha in the macrophage-mediating killing of parasites, cultures of T. cruzi-infected macrophages were treated with an anti-TNF-alpha monoclonal antibody. IFN-gamma-activated macrophages failed to kill intracellular parasites following treatment with 100 micrograms of anti-TNF-alpha. In these cultures, the number of parasites released at various time points after infection was significantly increased while NO production was significantly reduced. We conclude that IFN-gamma-activated macrophages produce TNF-alpha after infection by T. cruzi and suggest that this cytokine plays a role in amplifying NO production and parasite killing. PMID:7591147

Signatures of solar wind latitudinal structure in interplanetary Lyman-alpha emissions - Mariner 10 observations

NASA Technical Reports Server (NTRS)

Kumar, S.; Broadfoot, A. L.

1979-01-01

A detailed analysis is conducted which shows that signatures in the interplanetary Lyman-alpha emissions observed in three different data sets from Mariner 10 (corresponding to different locations of the spacecraft) provide firm evidence that the intensity departures are correlated with a decrease in solar wind flux with increasing latitude. It is suggested that observations of the interplanetary emission can be used to monitor average solar wind activity at high latitudes. The asymmetry in the solar radiation field as a source of observed departures in L-alpha data is considered and attention is given to the interstellar hydrogen and helium density.

Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

PubMed

Saher, G; Hildt, E

1999-09-24

Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

Design and operation of the pellet charge exchange diagnostic for measurement of energetic confined alphas and tritons on TFTR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medley, S.S.; Duong, H.H.; Fisher, R.K.

1996-05-01

Radially-resolved energy and density distributions of the energetic confined alpha particles in D-T experiments on TFTR are being measured by active neutral particle analysis using low-Z impurity pellet injection. When injected into a high temperature plasma, an impurity pellet (e.g. Lithium or Boron) rapidly ablates forming an elongated cloud which is aligned with the magnetic field and moves with the pellet. This ablation cloud provides a dense target with which the alpha particles produced in D-T fusion reactions can charge exchange. A small fraction of the alpha particles incident on the pellet ablation cloud will be converted to helium neutralsmore » whose energy is essentially unchanged by the charge transfer process. By measuring the resultant helium neutrals escaping from the plasma using a mass and energy resolving charge exchange analyzer, this technique offers a direct measurement of the energy distribution of the incident high-energy alpha particles. Other energetic ion species can be detected as well, such as tritons generated in D-D plasmas and H or He{sup 3} RF-driven minority ion tails. The diagnostic technique and its application on TFTR are described in detail.« less

Shikonins, phytocompounds from Lithospermum erythrorhizon, inhibit the transcriptional activation of human tumor necrosis factor alpha promoter in vivo.

PubMed

Staniforth, Vanisree; Wang, Sheng-Yang; Shyur, Lie-Fen; Yang, Ning-Sun

2004-02-13

Tumor necrosis factor alpha (TNF-alpha) contributes to the pathogenesis of both acute and chronic inflammatory diseases and has been a target for the development of new anti-inflammatory drugs. Shikonins, the naphthoquinone pigments present in the root tissues of Lithospermum erythrorhizon Sieb. et Zucc. (Boraginaceae), have been reported to exert anti-inflammatory effects both in vitro and in vivo. In this study, we evaluated the effects of shikonin and its derivatives on the transcriptional activation of human TNF-alpha promoter in a gene gun-transfected mouse skin system by using a luciferase reporter gene assay. The crude plant extract of L. erythrorhizon as well as derived individual compounds shikonin, isobutyryl shikonin, acetyl shikonin, dimethylacryl shikonin and isovaleryl shikonin showed significant dose-dependent inhibition of TNF-alpha promoter activation. Among the tested compounds, shikonin and isobutyryl shikonin exhibited the highest inhibition of TNF-alpha promoter activation and also showed significant suppression of transgenic human TNF-alpha mRNA expression and protein production. We demonstrated that shikonin-inhibitory response was retained in the core TNF-alpha promoter region containing the TATA box and a 48-bp downstream sequence relative to the transcription start site. Further our results indicated that shikonin suppressed the basal transcription and activator-regulated transcription of TNF-alpha by inhibiting the binding of transcription factor IID protein complex (TATA box-binding protein) to TATA box. These in vivo results suggest that shikonins inhibit the transcriptional activation of the human TNF-alpha promoter through interference with the basal transcription machinery. Thus, shikonins may have clinical potential as anti-inflammatory therapeutics.

Both alpha(1A)- and alpha(1B)-adrenergic receptors crosstalk to down regulate beta(1)-ARs in mouse heart: coupling to differential PTX-sensitive pathways.

PubMed

Rorabaugh, Boyd R; Gaivin, Robert J; Papay, Robert S; Shi, Ting; Simpson, Paul C; Perez, Dianne M

2005-11-01

Adrenergic receptors (ARs) play an important role in the regulation of cardiac function. Cardiac inotropy is primarily regulated by beta(1)-ARs. However, alpha(1)-ARs may play an important role in inotropy during heart failure. Previous work has suggested that the alpha(1B)-AR modulates beta(1)-AR function in the heart. The potential role of the alpha(1A)-AR has not been previously studied. We used transgenic mice that express constitutively active mutant (CAM) forms of the alpha(1A)-AR or alpha(1B)-AR regulated by their endogenous promoters. Expression of the CAM alpha(1A)-AR or CAM alpha(1B)-AR had no effect on basal cardiac function (developed pressure, +dP/dT, -dP/dT, heart rate, flow rate). However, both alpha(1)-AR subtypes significantly decreased isoproterenol-stimulated +dP/dT. Pertussis toxin had no effect on +dP/dT in CAM alpha(1A)-AR hearts but restored +dP/dT to non-transgenic values in CAM alpha(1B)-AR hearts. Radioligand binding indicated a selective decrease in the density of beta(1)-ARs in both CAM mice. However, G-proteins, cAMP, or the percentage of high and low affinity states were unchanged in either transgenic compared with control. These data demonstrate that CAM alpha(1A)- and alpha(1B)-ARs both down regulate beta(1)-AR-mediated inotropy in the mouse heart. However, alpha(1)-AR subtypes are coupled to different beta-AR mediated signaling pathways with the alpha(1B)-AR being pertussis toxin sensitive.

Fusing Multiple Sensor Modalities for Complex Physiological State Monitoring

DTIC Science & Technology

2012-12-01

sleep-alpha variants (drowsiness alpha activity and REM -alpha bursts) over frontal, central, parietal and occipital regions. Note the higher spectral...contribution of the slowest components (7.8–8.6 Hz) during REM alpha bursts as compared with drowsiness-alpha activity (13...occipital regions of the brain during the drowsiness state as compared to REM sleep and other states, as seen in figure 1 (13). Furthermore, using EEG

Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souza, Sandra C.; Chau, Mary D.L.; Yang, Qing

2011-07-08

Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract:more » Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) by 1.4-fold. Treatment of human adipocytes with fatty acids and tumor necrosis factor {alpha} (TNF{alpha}) induced insulin resistance and down-regulation of mitochondrial genes, which was restored by ANP treatment. These results show that ANP regulates lipid catabolism and enhances energy dissipation through AMPK activation in human adipocytes.« less

Molecular cloning of rock bream (Oplegnathus fasciatus) tumor necrosis factor-alpha and its effect on the respiratory burst activity of phagocytes.

PubMed

Kim, Min Sun; Hwang, Yoon Jung; Yoon, Ki Joon; Zenke, Kosuke; Nam, Yoon Kwon; Kim, Sung Koo; Kim, Ki Hong

2009-11-01

Rock bream (Oplegnathus fasciatus) tumor necrosis factor-alpha (rbTNF-alpha) gene was cloned, recombinantly produced, and the effect of the recombinant rbTNF-alpha on the respiratory burst activity of rock bream phagocytes was analyzed. Structurally, genomic DNA of rbTNF-alpha was comprised with four exons and three introns, and deduced amino acid sequence of its cDNA possessed the TNF family signature, a transmembrane domain, a protease cleavage site, and two cysteine residues, which are the typical characteristics of TNF-alpha gene in mammals and fish. The chemiluminescent (CL) response of rock bream phagocytes was significantly enhanced by pre-incubation with recombinant rbTNF-alpha, when opsonized zymosan was used as a stimulant of the respiratory burst. However, CL enhancing effect of the recombinant rbTNF-alpha was very weak when the respiratory burst activity of phagocytes was triggered with phorbol-12-myristate-13-acetate (PMA) instead of zymosan. These results suggest that rock bream TNF-alpha might have an ability to prime the respiratory burst activity of phagocytes against receptor-mediated phagocytosis inducing stimulants, such as zymosan, but have little ability against stimulants not accompanying receptor-mediated phagocytosis.

Electroencephalograph (EEG) study on self-contemplating image formation

NASA Astrophysics Data System (ADS)

Meng, Qinglei; Hong, Elliot; Choa, Fow-Sen

2016-05-01

Electroencephalography (EEG) is one of the most widely used electrophysiological monitoring methods and plays a significant role in studies of human brain electrical activities. Default mode network (DMN), is a functional connection of brain regions that are activated while subjects are not in task positive state or not focused on the outside world. In this study, EEG was used for human brain signals recording while all subjects were asked to sit down quietly on a chair with eyes closed and thinking about some parts of their own body, such as left and right hands, left and right ears, lips, nose, and the images of faces that they were familiar with as well as doing some simple mathematical calculation. The time is marker when the image is formed in the subject's mind. By analyzing brain activity maps 300ms right before the time marked instant for each of the 4 wave bands, Delta, Theta, Alpha and Beta waves. We found that for most EEG datasets during this 300ms, Delta wave activity would mostly locate at the frontal lobe or the visual cortex, and the change and movement of activities are slow. Theta wave activity tended to rotate along the edge of cortex either clockwise or counterclockwise. Beta wave behaved like inquiry types of oscillations between any two regions spread over the cortex. Alpha wave activity looks like a mix of the Theta and Beta activities but more close to Theta activity. From the observation we feel that Beta and high Alpha are playing utility role for information inquiry. Theta and low Alpha are likely playing the role of binding and imagination formation in DMN operations.

Cardiac Alpha1-Adrenergic Receptors: Novel Aspects of Expression, Signaling Mechanisms, Physiologic Function, and Clinical Importance

PubMed Central

O’Connell, Timothy D.; Jensen, Brian C.; Baker, Anthony J.

2014-01-01

Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate “inside-out” signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure. PMID:24368739

Opposite effects of lateralised transcranial alpha versus gamma stimulation on auditory spatial attention.

PubMed

Wöstmann, Malte; Vosskuhl, Johannes; Obleser, Jonas; Herrmann, Christoph S

2018-04-06

Spatial attention relatively increases the power of neural 10-Hz alpha oscillations in the hemisphere ipsilateral to attention, and decreases alpha power in the contralateral hemisphere. For gamma oscillations (>40 Hz), the opposite effect has been observed. The functional roles of lateralised oscillations for attention are currently unclear. If lateralised oscillations are functionally relevant for attention, transcranial stimulation of alpha versus gamma oscillations in one hemisphere should differentially modulate the accuracy of spatial attention to the ipsi-versus contralateral side. 20 human participants performed a dichotic listening task under continuous transcranial alternating current stimulation (tACS, vs sham) at alpha (10 Hz) or gamma (47 Hz) frequency. On each trial, participants attended to four spoken numbers on the left or right ear, while ignoring numbers on the other ear. In order to stimulate a left temporo-parietal cortex region, which is known to show marked modulations of alpha power during auditory spatial attention, tACS (1 mA peak-to-peak amplitude) was applied at electrode positions TP7 and FC5 over the left hemisphere. As predicted, unihemispheric alpha-tACS relatively decreased the recall of targets contralateral to stimulation, but increased recall of ipsilateral targets. Importantly, this spatial pattern of results was reversed for gamma-tACS. Results provide a proof of concept that transcranially stimulated oscillations can enhance spatial attention and facilitate attentional selection of speech. Furthermore, opposite effects of alpha versus gamma stimulation support the view that states of high alpha are incommensurate with active neural processing as reflected by states of high gamma. Copyright © 2018 Elsevier Inc. All rights reserved.

Double gene deletion reveals the lack of cooperation between PPAR{alpha} and PPAR{beta} in skeletal muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bedu, E.; Desplanches, D.; Pequignot, J.

2007-06-15

The peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of most of the pathways linked to lipid metabolism. PPAR{alpha} and PPAR{beta} isotypes are known to regulate muscle fatty acid oxidation and a reciprocal compensation of their function has been proposed. Herein, we investigated muscle contractile and metabolic phenotypes in PPAR{alpha}-/-, PPAR{beta}-/-, and double PPAR{alpha}-/- {beta}-/- mice. Heart and soleus muscle analyses show that the deletion of PPAR{alpha} induces a decrease of the HAD activity ({beta}-oxidation) while soleus contractile phenotype remains unchanged. A PPAR{beta} deletion alone has no effect. However, these mild phenotypes are not due to a reciprocal compensationmore » of PPAR{beta} and PPAR{alpha} functions since double gene deletion PPAR{alpha}-PPAR{beta} mostly reproduces the null PPAR{alpha}-mediated reduced {beta}-oxidation, in addition to a shift from fast to slow fibers. In conclusion, PPAR{beta} is not required for maintaining skeletal muscle metabolic activity and does not compensate the lack of PPAR{alpha} in PPAR{alpha} null mice.« less

Chemical composition, larvicidal action, and adult repellency of Thymus magnus against Aedes albopictus.

PubMed

Park, Young-Uk; Koo, Hyun-Na; Kim, Gil-Hah

2012-09-01

Thymus magnus, an endemic species, is found in the Republic of Korea. The volatile compounds extracted by SPME from T. magnus were investigated for their chemical composition and electrophysiological response against the Asian tiger mosquito, Aedes albopictus. The volatile compounds of T. magnus as determined by gas chromatography mass spectrometry were gamma-terpinene (33.0%), thymol (29.9%), beta-bisabolene (8.9%), p-cymene (8.3%), alpha-terpinene (5.0%), myrcene (4.7%), beta-caryophyllene (4.0%), alpha-thujene (2.7%), camphene (1.3%), carvacrol (1.2%), and alpha-pinene (1.1%). Among these candidates, thymol exhibited complete (100%) repellent activity against female Ae. albopictus, an effect that was confirmed through evaluating the electrophysiological response on the antenna of Ae. albopictus. The effectiveness of a binary 1:2 mixture of thymol and vanillin (0.05:0.1 microl per cm2) was found to be significantly more effective than thymol alone for a period of 120 min. In addition, thymol, alpha-terpinene, and carvacrol showed high larvicidal activity against on the third-stage larvae with LC50 values of 0.9 microl per 100 ml.

Androgenic correlates of genetic variation in the gene encoding 5alpha-reductase type 1.

PubMed

Ellis, Justine A; Panagiotopoulos, Sianna; Akdeniz, Aysel; Jerums, George; Harrap, Stephen B

2005-01-01

Androgens determine male secondary sexual characteristics and influence a variety of metabolic pathways. Circulating levels of androgens are highly heritable; however, the genes involved are largely unknown. The 5alpha-reductase enzymes types 1 and 2 responsible for converting testosterone to the more potent androgen dihydrotestosterone are encoded by the SRD5A1 and SRD5A2 genes, respectively. We performed indirect genetic association studies of SRD5A1 and SRD5A2 and the dihydrotestosterone/testosterone ratio that reflects the activity of 5alpha-reductase in 57 males with type 2 diabetes. We found evidence of significant association between a single nucleotide polymorphism in SRD5A1 and the dihydrotestosterone/testosterone ratio (median 0.10, interquartile range 0.08 vs. median 0.06, interquartile range 0.04, P = 0.009). The polymorphism was not associated with any diabetic phenotypes. These results suggest that functional genetic variants might exist in or around SRD5A1 that affect the activity of the 5alpha-reductase enzyme type 1 and influence androgen levels.

Creativity as a distinct trainable mental state: An EEG study of musical improvisation.

PubMed

Lopata, Joel A; Nowicki, Elizabeth A; Joanisse, Marc F

2017-05-01

Alpha-band EEG was used to index how creative mental states relate to the creation of artistic works in skilled musicians. We contrasted differences in frontal upper alpha-band activity between tasks with high and low creativity demands by recording EEGs while skilled musicians listened to, played back, and improvised jazz melodies. Neural responses were compared for skilled musicians with training in musical improvisation versus those who had no formal improvisation training. Consistent with our hypotheses, individuals showed increased frontal upper alpha-band activity during more creative tasks (i.e., improvisation) compared to during less creative tasks (i.e., rote playback). Moreover, this effect was greatest for musicians with formal improvisation training. The strength of this effect also appeared to modulate the quality of these improvisations, as evidenced by significant correlations between upper alpha EEG power and objective post-hoc ratings of individuals' performances. These findings support a conceptualization of creativity as a distinct mental state and suggest spontaneous processing capacity is better nurtured through formal institutional training than informal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expression of {beta}{sub 1} integrins in human endometrial stromal and decidual cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiokawa, Shigetatsu; Yoshimura, Yasunori; Nakamura, Yukio

The present study was undertaken to investigate the expression of {beta}{sub 1} integrins in human endometrium and decidua using flow cytometry, immunohistochemistry, and immunoprecipitation. Fluorescence-activated flow cytometry demonstrated the greater expression of the {beta}{sub 1}, {alpha}{sub 1}, {alpha}{sub 2}, and {alpha}{sub 5} subunits of the {beta}{sub 1} integrin family in cultured stromal cells from the midsecretory phase, than in those of the early proliferative phase. The addition of estradiol (E{sub 2}) and progesterone (P) to cultured stromal cells in the early proliferative phase increased the expression of {beta}{sub 1} integrins in vitro. Flow cytometry also demonstrated the expression of themore » {beta}{sub 1}, {alpha}{sub 1}, {alpha}{sub 2}, {alpha}{sub 3}, {alpha}{sub 5}, and {alpha}{sub 6} subunits of {beta}{sub 1} integrin family in cultured decidual cells, and the enriched-fraction of prolactin (PRL)-producing decidual cells isolated by Percoll gradients showed high levels of {beta}{sub 1} integrins expression. Immunohistochemistry confirmed the {beta}{sub 1} integrin cell surface phenotypes in cultured decidual cells observed by flow cytometry. In summary, the present study demonstrated that endometrial stromal and decidual cells expressed {beta}{sub 1} integrin subunits at their surfaces. The expression exhibited a variability throughout the menstrual cycles, being predominantly detected in the secretory phase, and was maintained highly in the decidua. Thus, {beta}{sub 1} integrins in human endometrium and decidua may be important in mediating the organization of extracellular matrix proteins derived from embryos during the early stage of implantation. 43 refs., 7 figs., 2 tabs.« less

Mutant alpha-synuclein overexpression mediates early proinflammatory activity.

PubMed

Su, Xiaomin; Federoff, Howard J; Maguire-Zeiss, Kathleen A

2009-10-01

Microglia provide immune surveillance for the brain through both the removal of cellular debris and protection against infection by microorganisms and "foreign" molecules. Upon activation, microglia display an altered morphology and increased expression of proinflammatory molecules. Increased numbers of activated microglia have been identified in a number of neurodegenerative diseases including Parkinson's disease (PD). What remains to be determined is whether activated microglia result from ongoing cell death or are involved in disease initiation and progression. To address this question we utilized a transgenic mouse model that expresses a mutated form of a key protein involved in Parkinson's disease, alpha-synuclein. Herein, we report an increase in activated microglia and proinflammatory molecules in 1-month-old transgenic mice well before cell death occurs in this model. Frank microglial activation is resolved by 6 months of age while a subset of proinflammatory molecules remain elevated for 12 months. Both tyrosine hydroxylase mRNA expression and alpha-synuclein protein are decreased in the striatum of older animals evidence of dystrophic neuritic projections. To determine whether mutated alpha-synuclein could directly activate microglia primary microglia-enriched cell cultures were treated with exogenous mutated alpha-synuclein. The data reveal an increase in activated microglia and proinflammatory molecules due to direct interaction with mutated alpha-synuclein. Together, these data demonstrate that mutated alpha-synuclein mediates a proinflammatory response in microglia and this activity may participate in PD pathogenesis.

[Effect of Psidium guajava leaf extract on alpha-glucosidase activity in small intestine of diabetic mouse].

PubMed

Wang, Bo; Liu, Heng-Chuan; Hong, Jun-Rong; Li, Hong-Gu; Huang, Cheng-Yu

2007-03-01

To investigate the inhibition effect of Psidium guajava linn (PGL), a leaf water-soluble extract, on the activities of alpha-glucosidases. The PGL water-soluble extract (PGL WE) was obtained by the procedure of distilled water immersion, filtration, extracted fluid concentration and dry of Psidium guajava leaf. The diabetes of Kunming mice was induced by intraperitoneal injection of Streptozotocin (STZ). The small intestinal mucosa of diabetic mice was scraped to make the homogenate for the preparation of alpha-glucosidases. In vitro, the homogenates were incubated with sucrose and maltose. The formed glucose represented the activities of alpha-glucosidases. The Lineweaver-Burk plot was applied to determine the type of alpha-glucosidase activity inhibited. The water-soluble extract from PGL significantly inhibited, in the dose-dependent manner, the activities of alpha-glucosidase from small intestinal mucosa of diabetic mice. The PGL extract inhibition concentration (IC50) to sucrase or maltase was 1.0 g/L or 3.0 g/L respectively. The mixed inhibition type was showed to be the competitive and non-competitive inhibition. The GPL water-soluble extract possesses the potential effect of inhibition on the alpha-glucosidase activity from the small intestinal mucosa of diabetic mouse.

[EEG alpha indices in dependence on the menstrual cycle phase and salivary progesterone].

PubMed

Bazanova, O M; Kondratenko, A V; Kuz'minova, O I; Muravleva, K B; Petrova, S E

2014-01-01

The effects of the neurohumoral status on the EEG alpha - activity indices were studied in a within-subject design with 78 women aged 18-27 years during 1-2 menstrual cycle. Psychometric and EEG indices of alpha waves basal body temperature, saliva progesterone and cortisol level were monitored every 2-3 days. Menstrual and follicular recording sessions occurred before the ovulatory temperature rise, luteal recording session--after increasing progesterone level more than 20% respect to previous day and premenstrual sessions after decreasing progesterone level more that 20% respect to previous day. The design consisted of rest and task periods EEG, EMG and ECG recordings. Half the subjects began during their menstrual phase and half began during their luteal phase. All 5 phases were compared for differences between psychometric features EEG alpha activity, EMG and ECG baseline resting levels, as well as for reactivity to cognitive task. The results showed menstrual phase differences in all psychometric and alpha EEG indices. The cognitive fluency, alpha peak frequency, alpha band width, power in alpha-2 frequency range are maximal at luteal, alpha visual activation and reactivity to cognitive task performance--at follicular phase. The hypothesis that the EEG alpha activity depends on the hormonal status supported by the positive association salivary progesterone level with the alpha peak frequency, power in the alpha-2 band and negative--with the power of the alpha-1 band. According these results, we conclude that psycho-physiological recording sessions with women might be provided with a glance to phase of menstrual cycle.

Role of hypoxia-inducible factor-{alpha} in hepatitis-B-virus X protein-mediated MDR1 activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Hyo-Kyung; Han, Chang Yeob; Cheon, Eun-Pa

2007-06-01

The transition from chemotherapy-responsive cancer cells to chemotherapy-resistant cancer cells is mainly accompanied by the increased expression of multi-drug resistance 1 (MDR1). We found that hepatitis-B-virus X protein (HBx) increases the transcriptional activity and protein level of MDR1 in a hepatoma cell line, H4IIE. In addition, HBx overexpression made H4IIE cells more resistant to verapamil-uptake. HBx stabilized hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) and induced the nuclear translocation of C/EBP{beta}. Reporter gene analyses showed that HBx increased the reporter activity in the cells transfected with the reporter containing MDR1 gene promoter. Moreover, the luciferase reporter gene activity was significantly inhibited by HIF-1{alpha} siRNAmore » but not by overexpression of C/EBP dominant negative mutant. These results imply that HBx increases the MDR1 transporter activity through the transcriptional activation of the MDR1 gene with HIF-1{alpha} activation, and suggest HIF-1{alpha} for the therapeutic target of HBV-mediated chemoresistance.« less

Coevolving residues of (beta/alpha)(8)-barrel proteins play roles in stabilizing active site architecture and coordinating protein dynamics.

PubMed

Shen, Hongbo; Xu, Feng; Hu, Hairong; Wang, Feifei; Wu, Qi; Huang, Qiang; Wang, Honghai

2008-12-01

Indole-3-glycerol phosphate synthase (IGPS) is a representative of (beta/alpha)(8)-barrel proteins-the most common enzyme fold in nature. To better understand how the constituent amino-acids work together to define the structure and to facilitate the function, we investigated the evolutionary and dynamical coupling of IGPS residues by combining statistical coupling analysis (SCA) and molecular dynamics (MD) simulations. The coevolving residues identified by the SCA were found to form a network which encloses the active site completely. The MD simulations showed that these coevolving residues are involved in the correlated and anti-correlated motions. The correlated residues are within van der Waals contact and appear to maintain the active site architecture; the anti-correlated residues are mainly distributed on opposite sides of the catalytic cavity and coordinate the motions likely required for the substrate entry and product release. Our findings might have broad implications for proteins with the highly conserved (betaalpha)(8)-barrel in assessing the roles of amino-acids that are moderately conserved and not directly involved in the active site of the (beta/alpha)(8)-barrel. The results of this study could also provide useful information for further exploring the specific residue motions for the catalysis and protein design based on the (beta/alpha)(8)-barrel scaffold.

Neuronal oscillations reveal the processes underlying intentional compared to incidental learning in children and young adults.

PubMed

Köster, Moritz; Haese, André; Czernochowski, Daniela

2017-01-01

This EEG study investigated the neuronal processes during intentional compared to incidental learning in young adults and two groups of children aged 10 and 7 years. Theta (3-8 Hz) and alpha (10-16 Hz) neuronal oscillations were analyzed to compare encoding processes during an intentional and an incidental encoding task. In all three age groups, both encoding conditions were associated with an increase in event-related theta activity. Encoding-related alpha suppression increased with age. Memory performance was higher in the intentional compared to the incidental task in all age groups. Furthermore, intentional learning was associated with an improved encoding of perceptual features, which were relevant for the retrieval phase. Theta activity increased from incidental to intentional encoding. Specifically, frontal theta increased in all age groups, while parietal theta increased only in adults and older children. In younger children, parietal theta was similarly high in both encoding phases. While alpha suppression may reflect semantic processes during encoding, increased theta activity during intentional encoding may indicate perceptual binding processes, in accordance with the demands of the encoding task. Higher encoding-related alpha suppression in the older age groups, together with age differences in parietal theta activity during incidental learning in young children, is in line with recent theoretical accounts, emphasizing the role of perceptual processes in mnemonic processing in young children, whereas semantic encoding processes continue to mature throughout middle childhood.

Automated 3D quantitative assessment and measurement of alpha angles from the femoral head-neck junction using MR imaging

NASA Astrophysics Data System (ADS)

Xia, Ying; Fripp, Jurgen; Chandra, Shekhar S.; Walker, Duncan; Crozier, Stuart; Engstrom, Craig

2015-10-01

To develop an automated approach for 3D quantitative assessment and measurement of alpha angles from the femoral head-neck (FHN) junction using bone models derived from magnetic resonance (MR) images of the hip joint. Bilateral MR images of the hip joints were acquired from 30 male volunteers (healthy active individuals and high-performance athletes, aged 18-49 years) using a water-excited 3D dual echo steady state (DESS) sequence. In a subset of these subjects (18 water-polo players), additional True Fast Imaging with Steady-state Precession (TrueFISP) images were acquired from the right hip joint. For both MR image sets, an active shape model based algorithm was used to generate automated 3D bone reconstructions of the proximal femur. Subsequently, a local coordinate system of the femur was constructed to compute a 2D shape map to project femoral head sphericity for calculation of alpha angles around the FHN junction. To evaluate automated alpha angle measures, manual analyses were performed on anterosuperior and anterior radial MR slices from the FHN junction that were automatically reformatted using the constructed coordinate system. High intra- and inter-rater reliability (intra-class correlation coefficients  >  0.95) was found for manual alpha angle measurements from the auto-extracted anterosuperior and anterior radial slices. Strong correlations were observed between manual and automatic measures of alpha angles for anterosuperior (r  =  0.84) and anterior (r  =  0.92) FHN positions. For matched DESS and TrueFISP images, there were no significant differences between automated alpha angle measures obtained from the upper anterior quadrant of the FHN junction (two-way repeated measures ANOVA, F  <  0.01, p  =  0.98). Our automatic 3D method analysed MR images of the hip joints to generate alpha angle measures around the FHN junction circumference with very good reliability and reproducibility. This work has the potential to improve analyses of cam-type lesions of the FHN junction for large-scale morphometric and clinical MR investigations of the human hip region.

Rational design, synthesis, biologic evaluation, and structure-activity relationship studies of novel 1-indanone alpha(1)-adrenoceptor antagonists.

PubMed

Li, Minyong; Xia, Lin

2007-11-01

In the present report, a novel series of 1-indanone alpha(1)-adrenoceptor antagonists were designed and synthesized based on 3D-pharmacophore model. Their in vitro alpha(1)-adrenoceptor antagonistic assay showed that three compounds (2a, 2m, and 2o) had similar or improved alpha(1)-adrenoceptor antagonistic activities relative to the positive control prazosin. Based on these results, a three-dimensional quantitative structure-activity relationship study was performed using a Self-Organizing Molecular Field Analysis method to provide insight for the future development of alpha(1)-adrenoceptor antagonists.

Bovine alpha-lactalbumin stimulates mucus metabolism in gastric mucosa.

PubMed

Ushida, Y; Shimokawa, Y; Toida, T; Matsui, H; Takase, M

2007-02-01

Bovine alpha-lactalbumin (alpha-LA), a major milk protein, exerts strong gastroprotective activity against rat experimental gastric ulcers induced by ethanol or stress. To elucidate the mechanisms underlying this activity, the influence of alpha-LA on gastric mucus metabolism was investigated in vitro and in vivo. For the in vitro study, RGM1 cells (a rat gastric epithelial cell line) were selected for observation of the direct activity of alpha-LA on gastric mucosal cells and cultured in the presence of either alpha-LA or ovalbumin (OVA), a reference protein showing no gastroprotective activity. Amounts of synthesized and secreted mucin, a major component of mucus, were determined using [3H]glucosamine as a tracer, and prostaglandin E2 (PGE2) levels in the culture medium were determined by RIA. For the in vivo study, the thickness of the mucus gel layer, a protective barrier for gastric mucosa, was evaluated histochemically in rat gastric mucosa. alpha-Lactalbumin (3 mg/mL) significantly stimulated mucin synthesis and secretion in RGM1 cells and also increased PGE2 levels in the culture medium. In contrast, OVA showed no enhancing effects under identical conditions. Neither indomethacin, a cyclo-oxygenase inhibitor, nor AH23848, a prostaglandin EP4 receptor antagonist, affected alpha-LA-induced enhancement of mucin synthesis and secretion. In vivo, oral administration of alpha-LA (300 mg/kg x 3 times/d x 7 d) increased the thickness of the mucus gel layer in rats. These results indicate that alpha-LA fortifies the mucus gel layer by stimulating mucin production and secretion in gastric mucus-producing cells, and that this enhancing effect is independent of endogenous PGE2. Comparison of the efficacy of alpha-LA with OVA suggests that the activities observed in RGM1 cells are closely related to the gastroprotective effects in rat gastric ulcer models. In conclusion, alpha-LA stimulates mucus metabolism, and this action may be responsible for its gastroprotective activity.

Coronal X-ray enhancements associated with H-alpha filament disappearances

NASA Technical Reports Server (NTRS)

Webb, D. F.; Krieger, A. S.; Rust, D. M.

1976-01-01

The X-ray telescope experiment aboard the Skylab/ATM mission provided high-resolution soft X-ray images of the lower corona away from active regions, revealing frequent large-scale transient X-ray enhancements which could often be associated with the disappearance of H-alpha filaments. The X-ray emitting structures featured peak brightnesses similar to those of nonflaring active region structures, durations from 3 to 40 hours, shapes that in general outlined the preexisting H-alpha filaments to as large as 400,000 km, apparent expansion velocities of the order of tens of km/sec, and observed peak temperatures of the order of a few million degrees. One such event is described and analyzed in detail. Two explanations of the events are discussed: (1) excess cool material is present in the filament cavity, contributing to the X-ray enhancement, and (2) the enhancement is due to the compression of preexisting material by a changing magnetic field.

The influence of interferon alpha on the rat liver injured by chronic administration of carbon tetrachloride.

PubMed

Madro, Agnieszka; Słomka, Maria; Celiński, Krzysztof; Chibowski, Daniel; Czechowska, Grazyna; Kleinrok, Zdzisław; Karpińska, Agnieszka

2002-01-01

Due to their complex and not fully known etiopathogenesis as well as difficulties in treatment, chronic hepatitis and cirrhosis still remain one of the main problems of hepatologists. Nowadays, the use of IFN alpha is considered the most effective method of treatment in chronic hepatitis. Recently, a new property of IFN, i.e. its effects on the reduction of fibrosis, has been discovered. The aim of the paper was to examine the effects of IFN alpha on biochemical parameters (AlAt and AspAt activities), on the metabolic function of the liver and its morphologic picture observed under the light and electron microscope after the 3- and 6-week CCl4-induced damage. The experiments were carried out in Wistar male rats. To evaluate the liver function, the test of aminophenazone elimination in the isolated perfused rat livers was used according to Miller modified by Hafte. Additionally, AspAt and AlAt activities were determined. The liver specimens were analysed under the light and electron microscope and using immunohistochemical methods. The findings show that after the 3-week CCl4-induced liver damage, IFN alpha does not significantly affect AlAt and AspAt activities, irrespective of the dose used. IFN alpha administered after the 6-week damage significantly changes those activities when the doses used are high. It was found that carbon tetrachloride does not result in evident cirrhotic changes, however it activates Ito cells, causes focal retraction of the stroma and fibrosis. The increased number of Ito cells in Disse's space observed in immunohistochemical and ultrastructural examinations is indicative of the activation of liver fibrotic processes following CCl4 administration in both variants used. IFN alpha substantially weakens fibrogenesis of the CCl4-damaged liver which is visible in the decreased number of Ito cells and weaker expression of the stroma retraction. Moreover, IFN alpha administered to the experimental animals after the CCl4-induced injury of the liver increases aminophenazone clearance, especially when used in higher doses. Positive effects of IFN confirmed in the studies suggest that the drug may be used in patients with chronic hepatitis and early cirrhosis since it is likely not only to eliminate the virus but also to improve the liver function and reduce fibrosis.

Natural radioactive contaminants in solder

NASA Astrophysics Data System (ADS)

Bunzl, K.; Kracke, W.

1985-07-01

Comparatively high surface count rates for alpha- and beta-radiation were observed for several solders. They were identified as 210Pb and 210Po. The corresponding specific activities in solder were determined.

5Alpha-Reduced Steroids Are Major Metabolites in the Early Equine Embryo Proper and Its Membranes.

PubMed

Raeside, James I; Christie, Heather L; Betteridge, Keith J

2015-09-01

Steroid production and metabolism by early conceptuses are very important for the establishment and maintenance of pregnancy in horses. Our earlier work suggested the possible formation of 5alpha-reduced steroids in equine conceptuses. We have now demonstrated the formation of 5alpha-reduced metabolites of androstenedione, testosterone, and progesterone by the embryo and its membranes. A total of 44 conceptuses were collected from 26 mares between 20 and 31 days of pregnancy. Tissues from the embryo proper and from the separated components of the conceptus (bilaminar and trilaminar trophoblast, allantois) were incubated with tritium-labeled substrates. 5Alpha-reduced metabolites (5alpha-dihydro- and 3beta,5alpha-tetrahydro- steroids) as radiolabeled products were identified from a series of chromatographic steps using four solvent systems for high-performance liquid chromatography. Use of a 5alpha-reductase inhibitor confirmed the metabolites were indeed 5alpha-reduced steroids. For the embryo, the only products from androstenedione were 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione, with no evidence of more polar metabolites; there was some 3beta,5alpha-tetrahydrotestosterone but no 5alpha-dihydrotestosterone from testosterone, and formation of androstenedione was followed by the production of 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione. The major 5alpha-reduced product from progesterone was 3beta,5alpha-tetrahydroprogesterone, with lesser amounts of 5alpha-dihydroprogesterone. For the membranes, reductions to tetrahydro, 5alpha-reduced steroids were prominent in most instances, but also present were considerable amounts of products more polar than the substrates. The well-recognized activity of some 5alpha-reduced steroids--for example, 5alpha-dihydrotestosterone in male sexual differentiation--provokes interest in their even earlier appearance, as seen in this study, and suggests a possible role for them in early embryonic development in horses and, more generally, in other species. © 2015 by the Society for the Study of Reproduction, Inc.

Genetic ablation of the alpha 6-integrin subunit in Tie1Cre mice enhances tumour angiogenesis.

PubMed

Germain, Mitchel; De Arcangelis, Adèle; Robinson, Stephen D; Baker, Marianne; Tavora, Bernardo; D'Amico, Gabriela; Silva, Rita; Kostourou, Vassiliki; Reynolds, Louise E; Watson, Alan; Jones, J Louise; Georges-Labouesse, Elisabeth; Hodivala-Dilke, Kairbaan

2010-02-01

Laminins are expressed highly in blood vessel basement membranes and have been implicated in angiogenesis. alpha6beta1- and alpha6beta4-integrins are major receptors for laminins in endothelial cells, but the precise role of endothelial alpha6-integrin in tumour angiogenesis is not clear. We show that blood vessels in human invasive ductal carcinoma of the breast have decreased expression of the alpha6-integrin-subunit when compared with normal breast tissue. These data suggest that a decrease in alpha6-integrin-subunit expression in endothelial cells is associated with tumour angiogenesis. To test whether the loss of the endothelial alpha6-integrin subunit affects tumour growth and angiogenesis, we generated alpha6fl/fl-Tie1Cre+ mice and showed that endothelial deletion of alpha6-integrin is sufficient to enhance tumour size and tumour angiogenesis in both murine B16F0 melanoma and Lewis cell lung carcinoma. Mechanistically, endothelial alpha6-integrin deficiency elevated significantly VEGF-mediated angiogenesis both in vivo and ex vivo. In particular, alpha6-integrin-deficient endothelial cells displayed increased levels of VEGF-receptor 2 (VEGFR2) and VEGF-mediated downstream ERK1/2 activation. By developing the first endothelial-specific alpha6-knockout mice, we show that the expression of the alpha6-integrin subunit in endothelial cells acts as a negative regulator of angiogenesis both in vivo and ex vivo. Copyright 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Effects of a dietary Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle.

PubMed

Tricarico, J M; Abney, M D; Galyean, M L; Rivera, J D; Hanson, K C; McLeod, K R; Harmon, D L

2007-03-01

Three experiments were conducted to examine the effects of an Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle. In Exp. 1, 120 crossbred steers were used in a randomized complete block design to evaluate the effects of roughage source (alfalfa hay vs. cottonseed hulls) and supplemental alpha-amylase at 950 dextrinizing units (DU)/kg of DM. Significant roughage source x alpha-amylase interactions (P < 0.05) were observed for performance. In steers fed cottonseed hulls, supplemental alpha-amylase increased ADG through d 28 and 112 and tended (P < 0.15) to increase ADG in all other periods. The increases in ADG were related to increased DMI and efficiency of gain during the initial 28-d period but were primarily related to increased DMI as the feeding period progressed. Supplemental alpha-amylase increased (P = 0.02) the LM area across both roughage sources. In Exp. 2, 96 crossbred heifers were used in a randomized complete block design with a 2 x 3 factorial arrangement of treatments to evaluate the effects of corn processing (dry cracked vs. high moisture) and supplemental alpha-amylase concentration (0, 580, or 1,160 DU/kg of DM). Alpha-amylase supplementation increased DMI (P = 0.05) and ADG (P = 0.03) during the initial 28 d on feed and carcass-adjusted ADG (P = 0.04) across corn processing methods. Longissimus muscle area was greatest (quadratic effect, P = 0.04), and yield grade was least (quadratic effect, P = 0.02) in heifers fed 580 DU of alpha-amylase/kg of DM across corn processing methods. In Exp. 3, 56 crossbred steers were used in a randomized complete block design to evaluate the effects of supplemental alpha-amylase (930 DU/kg of DM) on performance when DMI was restricted to yield a programmed ADG. Alpha-amylase supplementation did not affect performance when DMI was restricted. We conclude that dietary alpha-amylase supplementation of finishing beef diets may result in increased ADG through increased DMI under certain dietary conditions and that further research is warranted to explain its mode of action and interactions with dietary ingredients.

An activating G{sub s}{alpha} mutation is present in fibrous dysplasia of bone in the McCune-Albright syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shenker, A.; Weinstein, L.S.; Spiegel, A.M.

1994-09-01

McCune-Albright syndrome (MAS) is a sporadic disease characterized by polyostotic fibrous dysplasia, cafe-au-lait spots, and multiple endocrinopathies. The etiology of fibrous dysplasia is unknown. Activating mutations of codon 201 in the gene encoding the {alpha}-subunit of G{sub s}, the G-protein that stimulates adenylyl cyclase, have been found in all affected MAS tissues that have been studied. Initial attempts to amplify DNA from decalcified paraffin-embedded bone specimens from frozen surgical bone specimens from five MAS patients using polymerase chain reaction and allele-specific oligonucleotide hybridization. Most of the cells in four specimens of dysplastic bone contained a heterozygous mutation encoding substitution ofmore » Arg{sup 201} of G{sub s}{alpha} with His, but the mutation was barely detectable in peripheral blood specimens from the patients. Only a small amount of mutant allele was detected in a specimen of normal cortical bone from the fifth patient, although this patients had a high proportion of mutation in other, affected tissues. The mosaic distribution of mutant alleles is consistent with an embryological somatic cell mutation of the G{sub s}{alpha} gene in MAS. The presence of an activating mutation of G{sub s}{alpha} in osteoblastic progenitor cells may cause them to exhibit increased proliferation and abnormal differentiation, thereby producing the lesions of fibrous dysplasia. 43 refs., 2 figs.« less

N-acetylcysteine attenuates TNF-alpha-induced p38 MAP kinase activation and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells.

PubMed

Hashimoto, S; Gon, Y; Matsumoto, K; Takeshita, I; Horie, T

2001-01-01

1. We have previously shown that tumour necrosis factor-alpha (TNF-alpha) activates p38 mitogen-activated protein (MAP) kinase to produce interleukin-8 (IL-8) by human pulmonary vascular endothelial cells. Reactive oxygen species (ROS) including H(2)O(2) generated by TNF-alpha can act as signalling intermediates for cytokine induction; therefore, scavenging ROS by anti-oxidants is important for the regulation of cytokine production. However, the effect of N-acetylcysteine (NAC), which acts as a precursor of glutathione (GSH) synthesis, on TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells has not been determined. To clarify these issues, we examined the effect of NAC on TNF-alpha-induced activation of p38 MAP kinase, MAP kinase kinase (MKK) 3 and MKK6 which are upstream regulators of p38 MAP kinase, and p38 MAP kinase-mediated IL-8 production. 2. Human pulmonary vascular endothelial cells that had been preincubated with NAC were stimulated with TNF-alpha and then the activation of p38 MAP kinase and MKK3/MKK6 in the cells and IL-8 concentrations in the culture supernatants were determined. 3. Intracellular GSH levels increased in NAC-treated cells. 4. NAC attenuated TNF-alpha-induced activation of p38 MAP kinase and MKK3/MKK6. 5. NAC attenuated p38 MAP kinase-mediated IL-8 production by TNF-alpha-stimulated cells. 6. These results indicate that the cellular reduction and oxidation (redox) regulated by intracellular GSH is critical for TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells, and we emphasize that anti-oxidant therapy is an important strategy for the treatment of acute lung injury.

Estrogen-related receptor {alpha} is essential for the expression of antioxidant protection genes and mitochondrial function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rangwala, Shamina M.; Li, Xiaoyan; Lindsley, Loren

2007-05-25

Estrogen-related receptor {alpha} (ERR{alpha}) is an important mediator of mitochondrial biogenesis and function. To investigate the transcriptional network controlling these phenomena, we investigated mitochondrial gene expression in embryonic fibroblasts isolated from ERR{alpha} null mice. Peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) stimulated mitochondrial gene expression program in control cells, but not in the ERR{alpha} null cells. Interestingly, the induction of levels of mitochondrial oxidative stress protection genes in response to increased PGC-1{alpha} levels was dependent on ERR{alpha}. Furthermore, we found that the PGC-1{alpha}-mediated induction of estrogen-related receptor {gamma} and nuclear respiratory factor 2 (NRF-2), was dependent on the presence of ERR{alpha}.more » Basal levels of NRF-2 were decreased in the absence of ERR{alpha}. The absence of ERR{alpha} resulted in a decrease in citrate synthase enzyme activity in response to PGC-1{alpha} overexpression. Our results indicate an essential role for ERR{alpha} as a key regulator of oxidative metabolism.« less

Succinate dehydrogenase activity and soma size of motoneurons innervating different portions of the rat tibialis anterior

NASA Technical Reports Server (NTRS)

Ishihara, A.; Roy, R. R.; Edgerton, V. R.

1995-01-01

The spatial distribution, soma size and oxidative enzyme activity of gamma and alpha motoneurons innervating muscle fibres in the deep (away from the surface of the muscle) and superficial (close to the surface of the muscle) portions of the tibialis anterior in normal rats were determined. The deep portion had a higher percentage of high oxidative fibres than the superficial portion of the muscle. Motoneurons were labelled by retrograde neuronal transport of fluorescent tracers: Fast Blue and Nuclear Yellow were injected into the deep portion and Nuclear Yellow into the superficial portion of the muscle. Therefore, motoneurons innervating the deep portion were identified by both a blue fluorescent cytoplasm and a golden-yellow fluorescent nucleus, while motoneurons innervating the superficial portion were identified by only a golden-yellow fluorescent nucleus. After staining for succinate dehydrogenase activity on the same section used for the identification of the motoneurons, soma size and succinate dehydrogenase activity of the motoneurons were measured. The gamma and alpha motoneurons innervating both the deep and superficial portions were located primarily at L4 and were intermingled within the same region of the dorsolateral portion of the ventral horn in the spinal cord. Mean soma size was similar for either gamma or alpha motoneurons in the two portions of the muscle. The alpha motoneurons innervating the superficial portion had a lower mean succinate dehydrogenase activity than those innervating the deep portion of the muscle. An inverse relationship between soma size and succinate dehydrogenase activity of alpha, but not gamma, motoneurons innervating both the deep and superficial portions was observed. Based on three-dimensional reconstructions within the spinal cord, there were no apparent differences in the spatial distribution of the motoneurons, either gamma or alpha, associated with the deep and superficial compartments of the muscle. The data provide evidence for an interdependence in the oxidative capacity between a motoneuron and its target muscle fibres in two subpopulations of motoneurons from the same motor pool, i.e. the same muscle.

Naturally occurring disulfide-bound dimers of three-fingered toxins: a paradigm for biological activity diversification.

PubMed

Osipov, Alexey V; Kasheverov, Igor E; Makarova, Yana V; Starkov, Vladislav G; Vorontsova, Olga V; Ziganshin, Rustam Kh; Andreeva, Tatyana V; Serebryakova, Marina V; Benoit, Audrey; Hogg, Ronald C; Bertrand, Daniel; Tsetlin, Victor I; Utkin, Yuri N

2008-05-23

Disulfide-bound dimers of three-fingered toxins have been discovered in the Naja kaouthia cobra venom; that is, the homodimer of alpha-cobratoxin (a long-chain alpha-neurotoxin) and heterodimers formed by alpha-cobratoxin with different cytotoxins. According to circular dichroism measurements, toxins in dimers retain in general their three-fingered folding. The functionally important disulfide 26-30 in polypeptide loop II of alpha-cobratoxin moiety remains intact in both types of dimers. Biological activity studies showed that cytotoxins within dimers completely lose their cytotoxicity. However, the dimers retain most of the alpha-cobratoxin capacity to compete with alpha-bungarotoxin for binding to Torpedo and alpha7 nicotinic acetylcholine receptors (nAChRs) as well as to Lymnea stagnalis acetylcholine-binding protein. Electrophysiological experiments on neuronal nAChRs expressed in Xenopus oocytes have shown that alpha-cobratoxin dimer not only interacts with alpha7 nAChR but, in contrast to alpha-cobratoxin monomer, also blocks alpha3beta2 nAChR. In the latter activity it resembles kappa-bungarotoxin, a dimer with no disulfides between monomers. These results demonstrate that dimerization is essential for the interaction of three-fingered neurotoxins with heteromeric alpha3beta2 nAChRs.

Altered TNF-Alpha, Glucose, Insulin and Amino Acids in Islets Langerhans Cultured in a Microgravity Model System

NASA Technical Reports Server (NTRS)

Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.

2001-01-01

The present studies were designed to determine effects of a microgravity model system upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-1 17,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). A decrease in insulin concentration was demonstrated in the LPS stimulated HARV culture (p<0.05). We observed a greater glucose concentration and increased disappearance of arginine in islets cultured in HARVs. While nitrogenous compound analysis indicated a ubiquitous reliance upon glutamine in all experimental groups, arginine was converted to ornithine at a two-fold greater rate in the islets cultured in the HARV microgravity model system (p<0.05). These studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

Cell-extracellular matrix interactions can regulate the switch between growth and differentiation in rat hepatocytes: reciprocal expression of C/EBP alpha and immediate-early growth response transcription factors.

PubMed Central

Rana, B; Mischoulon, D; Xie, Y; Bucher, N L; Farmer, S R

1994-01-01

Previous investigations have shown that culture of freshly isolated hepatocytes under conventional conditions, i.e., on dried rat tail collagen in the presence of growth factors, facilitates cell growth but also causes an extensive down-regulation of most liver-specific functions. This dedifferentiation process can be prevented if the cells are cultured on a reconstituted basement membrane gel matrix derived from the Englebreth-Holm-Swarm mouse sarcoma tumor (EHS gel). To gain insight into the mechanisms regulating this response to extracellular matrix, we are analyzing the activities of two families of transcription factors, C/EBP and AP-1, which control the transcription of hepatic and growth-responsive genes, respectively. We demonstrate that isolation of hepatocytes from the normal quiescent rat liver by collagenase perfusion activates the immediate-early growth response program, as indicated by increased expression of c-jun, junB, c-fos, and c-myc mRNAs. Adhesion of these activated cells to dried rat tail collagen augments the elevated levels of these mRNAs for the initial 1 to 2 h postplating; junB and c-myc mRNA levels then drop steeply, with junB returning to normal quiescence and the c-myc level remaining slightly elevated during the 3-day culture period. Levels of c-jun mRNA and AP-1 DNA binding activity, however, remain elevated from the outset, while C/EBP alpha mRNA expression is down-regulated, resulting in a decrease in the steady-state levels of the 42- and 30-kDa C/EBP alpha polypeptides and C/EBP alpha DNA binding activity. In contrast, C/EBP beta mRNA production remains at near-normal hepatic levels for 5 to 8 days of culture, although its DNA binding activity decreases severalfold during this time. Adhesion of hepatocytes to the EHS gel for the same period of time dramatically alters this program: it arrests growth and inhibits AP-1 DNA binding activity and the expression of c-jun, junB, and c-myc mRNAs, but, in addition, it restores C/EBP alpha mRNA and protein as well as C/EBP alpha and C/EBP beta DNA binding activities to the abundant levels present in freshly isolated hepatocytes. These changes are not due merely to growth inhibition, because suppression of hepatocyte proliferation on collagen by epidermal growth factor starvation or addition of transforming growth factor beta does not inhibit AP-1 activity or restore C/EBP alpha DNA binding activity to normal hepatic levels. These data suggest that expression of the normal hepatic phenotype requires that hepatocytes exist in a G0 state of growth arrest, facilitated here by adhesion of cells to the EHS gel, in order to express high levels of hepatic transcription factors such as C/EBP alpha. Images PMID:8065319

Construction of promoter-probe shuttle vectors for Escherichia coli and corynebacteria on the basis of promoterless alpha-amylase gene.

PubMed

Ugorcáková, J; Bukovská, G; Timko, J

2000-01-01

We constructed new promoter-probe vectors for E. coli and corynebacteria based on the promoterless alpha-amylase gene originating from Bacillus subtilis. Vectors pJUPAE1 and pJUPAE2 are suitable for isolation of transcriptionally active fragments from plasmids, phages or genomic DNA. alpha-Amylase activity can be easily visually detected on agar plates containing a chromogenic substrate, or by direct measurement of alpha-amylase activity.

Constitutive activation of NF-kappa B and secretion of interleukin-8 induced by the G protein-coupled receptor of Kaposi's sarcoma-associated herpesvirus involve G alpha(13) and RhoA.

PubMed

Shepard, L W; Yang, M; Xie, P; Browning, D D; Voyno-Yasenetskaya, T; Kozasa, T; Ye, R D

2001-12-07

The Kaposi's sarcoma herpesvirus (KSHV) open reading frame 74 encodes a G protein-coupled receptor (GPCR) for chemokines. Exogenous expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi's sarcoma. We show here that expression of KSHV-GPCR in transfected cells results in constitutive transactivation of nuclear factor kappa B (NF-kappa B) and secretion of interleukin-8, and this response involves activation of G alpha(13) and RhoA. The induced expression of a NF-kappa B luciferase reporter was partially reduced by pertussis toxin and the G beta gamma scavenger transducin, and enhanced by co-expression of G alpha(13) and to a lesser extent, G alpha(q). These results indicate coupling of KSHV-GPCR to multiple G proteins for NF-kappa B activation. Expression of KSHV-GPCR led to stress fiber formation in NIH 3T3 cells. To examine the involvement of the G alpha(13)-RhoA pathway in KSHV-GPCR-mediated NF-kappa B activation, HeLa cells were transfected with KSHV-GPCR alone and in combination with the regulator of G protein signaling (RGS) from p115RhoGEF or a dominant negative RhoA(T19N). Both constructs, as well as the C3 exoenzyme from Clostritium botulinum, partially reduced NF-kappa B activation by KSHV-GPCR, and by a constitutively active G alpha(13)(Q226L). KSHV-GPCR-induced NF-kappa B activation is accompanied by increased secretion of IL-8, a function mimicked by the activated G alpha(13) but not by an activated G alpha(q)(Q209L). These results suggest coupling of KSHV-GPCR to the G alpha(13)-RhoA pathway in addition to other G proteins.

Endothelial monocyte activating polypeptide-II modulates endothelial cell responses by degrading hypoxia-inducible factor-1alpha through interaction with PSMA7, a component of the proteasome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tandle, Anita T.; Calvani, Maura; Uranchimeg, Badarch

The majority of human tumors are angiogenesis dependent. Understanding the specific mechanisms that contribute to angiogenesis may offer the best approach to develop therapies to inhibit angiogenesis in cancer. Endothelial monocyte activating polypeptide-II (EMAP-II) is an anti-angiogenic cytokine with potent effects on endothelial cells (ECs). It inhibits EC proliferation and cord formation, and it suppresses primary and metastatic tumor growth in-vivo. However, very little is known about the molecular mechanisms behind the anti-angiogenic activity of EMAP-II. In the present study, we explored the molecular mechanism behind the anti-angiogenic activity exerted by this protein on ECs. Our results demonstrate that EMAP-IImore » binds to the cell surface {alpha}5{beta}1 integrin receptor. The cell surface binding of EMAP-II results in its internalization into the cytoplasmic compartment where it interacts with its cytoplasmic partner PSMA7, a component of the proteasome degradation pathway. This interaction increases hypoxia-inducible factor 1-alpha (HIF-1{alpha}) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1{alpha} mediated transcriptional activity as well as HIF-1{alpha} mediated angiogenic sprouting of ECs. HIF-1{alpha} plays a critical role in angiogenesis by activating a variety of angiogenic growth factors. Our results suggest that one of the major anti-angiogenic functions of EMAP-II is exerted through its inhibition of the HIF-1{alpha} activities.« less

Groundwater quality of the Gulf Coast aquifer system, Houston, Texas, 2010

USGS Publications Warehouse

Oden, Jeannette H.; Brown, Dexter W.; Oden, Timothy D.

2011-01-01

Gross alpha-particle activities and beta-particle activities for all 47 samples were analyzed at 72 hours after sample collection and again at 30 days after sample collection, allowing for the measurement of the activity of short-lived isotopes. Gross alpha-particle activities reported in this report were not adjusted for activity contributions by radon or uranium and, therefore, are conservatively high estimates if compared to the U.S. Environmental Protection Agency National Primary Drinking Water Regulation for adjusted gross alpha-particle activity. The gross alpha-particle activities at 30 days in the samples ranged from R0.60 to 25.5 picocuries per liter and at 72 hours ranged from 2.58 to 39.7 picocuries per liter, and the "R" preceding the value of 0.60 picocuries per liter refers to a nondetected result less than the sample-specific critical level. Gross beta-particle activities measured at 30 days ranged from 1.17 to 14.4 picocuries per liter and at 72 hours ranged from 1.97 to 4.4 picocuries per liter. Filtered uranium was detected in quantifiable amounts in all of the 47 wells sampled. The uranium concentrations ranged from 0.03 to 42.7 micrograms per liter. One sample was analyzed for carbon-14, and the amount of modern atmospheric carbon was reported as 0.2 percent. Six source-water samples collected from municipal supply wells were analyzed for radium-226, and all of the concentrations were considered detectable concentrations (greater than their associated sample-specific critical level). Three source-water samples collected were analyzed for radon-222, and all of the concentrations were substantially greater than the associated sample-specific critical level.

Adenylyl cyclase and G-proteins in Phytomonas.

PubMed

Farber, M D; Montagna, A E; Paveto, C; Dollet, M; Sanchex-Moreno, M; Osuna, A; Torres, H N; Flawia, M M

1995-01-01

Phytomonas sp. membranes have an adenylyl cyclase activity which is greater in the presence of Mn2+ than with Mg2+. The Mg2+ and Mn2+ activity ratio varies from one membrane preparation to another, suggesting that the adenylyl cyclase has a variable activation state. A[35S]GTP-gamma-S-binding activity with a Kd of 171 nM was detected in Phytomonas membranes. Incubation of these membranes with activated cholera or pertussis toxin and [adenylate 23P]NAD+ led to incorporation of radioactivity into bands of about 40-44 kDa. Crude membranes were electrophoresed on SDS-polyacrylamide gels and analyzed, by Western blotting, with the 9188 anti-alpha[s] antibody and the AS/7 antibody (anti-alpha[i], anti-alpha[i1], and anti-alpha[i2]. These procedures resulted in the identification of polypeptides of approximately 40-44 kDa. Phytomonas adenylyl cyclase could be activated by treatment of membrane preparations with cholera toxin, in the presence of NAD+, while similar treatment with pertussis toxin did not affect this enzyme activity. These studies indicate that in Phytomonas, adenylyl cyclase activity is coupled to an unknown receptor entity through G alpha[s] proteins.

Radon daughter plate-out measurements at SNOLAB for polyethylene and copper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, Matthew; Bauer, Dan; Bunker, Ray

We report that polyethylene and copper samples were exposed to the underground air at SNOLAB for approximately three months while several environmental factors were monitored. Predictions of the radon-daughter plate-out rate are compared to the resulting surface activities, obtained from high-sensitivity measurements of alpha emissivity using the XIA UltraLo-1800 spectrometer at Southern Methodist University. From these measurements, we determine an average 210Pb plate-out rate of 249 and 423 atoms/day/cm 2 for polyethylene and copper, respectively, when exposed to radon activity concentration of 135 Bq/m 3 at SNOLAB. Finally, a time-dependent model of alpha activity is discussed for these materials placedmore » in similar environmental conditions.« less

Radon daughter plate-out measurements at SNOLAB for polyethylene and copper

DOE PAGES

Stein, Matthew; Bauer, Dan; Bunker, Ray; ...

2017-11-04

We report that polyethylene and copper samples were exposed to the underground air at SNOLAB for approximately three months while several environmental factors were monitored. Predictions of the radon-daughter plate-out rate are compared to the resulting surface activities, obtained from high-sensitivity measurements of alpha emissivity using the XIA UltraLo-1800 spectrometer at Southern Methodist University. From these measurements, we determine an average 210Pb plate-out rate of 249 and 423 atoms/day/cm 2 for polyethylene and copper, respectively, when exposed to radon activity concentration of 135 Bq/m 3 at SNOLAB. Finally, a time-dependent model of alpha activity is discussed for these materials placedmore » in similar environmental conditions.« less

Characterization of the early pulmonary inflammatory response associated with PTFE fume exposure

NASA Technical Reports Server (NTRS)

Johnston, C. J.; Finkelstein, J. N.; Gelein, R.; Baggs, R.; Oberdorster, G.; Clarkson, T. W. (Principal Investigator)

1996-01-01

Heating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.

Interconversion of the Specificities of Human Lysosomal Enzymes Associated with Fabry and Schindler Diseases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomasic, Ivan B.; Metcalf, Matthew C.; Guce, Abigail I.

2010-09-03

The human lysosomal enzymes {alpha}-galactosidase ({alpha}-GAL, EC 3.2.1.22) and {alpha}-N-acetylgalactosaminidase ({alpha}-NAGAL, EC 3.2.1.49) share 46% amino acid sequence identity and have similar folds. The active sites of the two enzymes share 11 of 13 amino acids, differing only where they interact with the 2-position of the substrates. Using a rational protein engineering approach, we interconverted the enzymatic specificity of {alpha}-GAL and {alpha}-NAGAL. The engineered {alpha}-GAL (which we call {alpha}-GALSA) retains the antigenicity of {alpha}-GAL but has acquired the enzymatic specificity of {alpha}-NAGAL. Conversely, the engineered {alpha}-NAGAL (which we call {alpha}-NAGAL{sup EL}) retains the antigenicity of {alpha}-NAGAL but has acquired themore » enzymatic specificity of the {alpha}-GAL enzyme. Comparison of the crystal structures of the designed enzyme {alpha}-GAL{sup SA} to the wild-type enzymes shows that active sites of {alpha}-GAL{sup SA} and {alpha}-NAGAL superimpose well, indicating success of the rational design. The designed enzymes might be useful as non-immunogenic alternatives in enzyme replacement therapy for treatment of lysosomal storage disorders such as Fabry disease.« less

AMP-activated protein kinase confers protection against TNF-{alpha}-induced cardiac cell death.

PubMed

Kewalramani, Girish; Puthanveetil, Prasanth; Wang, Fang; Kim, Min Suk; Deppe, Sylvia; Abrahani, Ashraf; Luciani, Dan S; Johnson, James D; Rodrigues, Brian

2009-10-01

Although a substantial role for 5' adenosine monophosphate-activated protein kinase (AMPK) has been established in regulating cardiac metabolism, a less studied action of AMPK is its ability to prevent cardiac cell death. Using established AMPK activators like dexamethasone (DEX) or metformin (MET), the objective of the present study was to determine whether AMPK activation prevents tumour necrosis factor-alpha (TNF-alpha) induced apoptosis in adult rat ventricular cardiomyocytes. Cardiomyocytes were incubated with DEX, MET, or TNF-alpha for varying durations (0-12 h). TNF-alpha-induced cell damage was evaluated by measuring caspase-3 activity and Hoechst staining. Protein and gene estimation techniques were employed to determine the mechanisms mediating the effects of AMPK activators on TNF-alpha-induced cardiomyocyte apoptosis. Incubation of myocytes with TNF-alpha for 8 h has increased caspase-3 activation and apoptotic cell death, an effect that was abrogated by DEX and MET. The beneficial effect of DEX and MET was associated with stimulation of AMPK, which led to a rapid and sustained increase in Bad phosphorylation. This event reduced the interaction between Bad and Bcl-xL, limiting cytochrome c release and caspase-3 activation. Addition of Compound C to inhibit AMPK reduced Bad phosphorylation and prevented the beneficial effects of AMPK against TNF-alpha-induced cytotoxicity. Our data demonstrate that although DEX and MET are used as anti-inflammatory agents or insulin sensitizers, respectively, their common property to phosphorylate AMPK promotes cardiomyocyte cell survival through its regulation of Bad and the mitochondrial apoptotic mechanism.

PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression possibly through PPAR{gamma} activation in the liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oishi, Katsutaka, E-mail: k-ooishi@aist.go.jp; Uchida, Daisuke; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki

Research highlights: {yields} PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression. {yields} Hepatic expressions of PPAR{gamma} and PCG-1{alpha} are induced by a ketogenic diet. {yields} PPAR{gamma} antagonist attenuates a ketogenic diet-induced PAI-1 expression. {yields} Ketogenic diet advances the phase of circadian clock in a PPAR{alpha}-independent manner. -- Abstract: An increased level of plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular diseases, and PAI-1 gene expression is under the control of molecular circadian clocks in mammals. We recently showed that PAI-1 expression is augmented in a phase-advanced circadian manner in mice fed with a ketogenic diet (KD).more » To determine whether peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) is involved in hypofibrinolytic status induced by a KD, we examined the expression profiles of PAI-1 and circadian clock genes in PPAR{alpha}-null KD mice. Chronic administration of bezafibrate induced the PAI-1 gene expression in a PPAR{alpha}-dependent manner. Feeding with a KD augmented the circadian expression of PAI-1 mRNA in the hearts and livers of wild-type (WT) mice as previously described. The KD-induced mRNA expression of typical PPAR{alpha} target genes such as Cyp4A10 and FGF21 was damped in PPAR{alpha}-null mice. However, plasma PAI-1 concentrations were significantly more elevated in PPAR{alpha}-null KD mice in accordance with hepatic mRNA levels. These observations suggest that PPAR{alpha} activation is dispensable for KD-induced PAI-1 expression. We also found that hyperlipidemia, fatty liver, and the hepatic expressions of PPAR{gamma} and its coactivator PCG-1{alpha} were more effectively induced in PPAR{alpha}-null, than in WT mice on a KD. Furthermore, KD-induced hepatic PAI-1 expression was significantly suppressed by supplementation with bisphenol A diglycidyl ether, a PPAR{gamma} antagonist, in both WT and PPAR{alpha}-null mice. PPAR{gamma} activation seems to be involved in KD-induced hypofibrinolysis by augmenting PAI-1 gene expression in the fatty liver.« less

Effect of neohesperidin dihydrochalcone on the activity and stability of alpha-amylase: a comparative study on bacterial, fungal, and mammalian enzymes.

PubMed

Kashani-Amin, Elaheh; Ebrahim-Habibi, Azadeh; Larijani, Bagher; Moosavi-Movahedi, Ali Akbar

2015-10-01

Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha-amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha-amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha-amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha-amylase surface in domain B. This domain shows differences in various alpha-amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact. Copyright © 2015 John Wiley & Sons, Ltd.

A New Approach for Alpha Radiography by Triple THGEM using Monte Carlo Simulation and Measurement

NASA Astrophysics Data System (ADS)

Khezripour, S.; Negarestani, A.; Rezaie, M. R.

2018-05-01

In this research, alpha imaging in Self Quenching Streamer (SQS) mode is investigated using a triple Thick Gas Electron Multiplier (THGEM) detector by Monte Carlo method and experimental data. First, a semi-empirical equation is derived to represent the relation between the SQS voltage and the alpha energy in every hole of the triple THGEM. The accuracy of this equation is tested and confirmed by a high degree of consistency. Secondly, the images of objects that are irradiated by Am-241 alpha source (5.49 MeV) are recorded by a CMOS camera using triple THGEM detector in the SQS mode. The resolution of images in this paper is a function of the exposure time. For an alpha source with 150 kBq activity, an optimal time interval for exposure is about 30 sec. For exposure time less or more than 30 sec, the images are incomplete and ambiguous, respectively. The overall objective of this work is to facilitate the alpha radiography in nuclear imaging through a triple THGEM without any amplifier or complicated electrical equipment.

Anti-fibrotic effects of thalidomide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats.

PubMed

Chong, Lee-Won; Hsu, Yi-Chao; Chiu, Yung-Tsung; Yang, Kuo-Ching; Huang, Yi-Tsau

2006-05-01

Tumor necrosis factor-alpha (TNF-alpha) plays a central role in cellular necrosis, apoptosis, organ failure, tissue damage, inflammation and fibrosis. These processes, occurring in liver injury, may lead to cirrhosis. Thalidomide, alpha-N-phthalidoglutarimide, (C(13)H(10)N(2))(4), has been shown to have immunomodulatory and anti-inflammatory properties, possibly mediated through its anti-TNF-alpha effect. In this study, we investigated the in vitro and in vivo effects of thalidomide on hepatic fibrosis. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with transforming growth factor-beta1 (TGF-beta1) or TNF-alpha. The inhibitory effects of thalidomide on the NFkappaB signaling cascade and fibrosis markers including alpha-smooth muscle actin (alpha-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats, which were randomly assigned to 1 of 4 groups: vehicle (0.7% carboxyl methyl cellulose, CMC), thalidomide (40 mg/kg), thalidomide (200 mg/kg), or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting after 1 week of DMN administration. Thalidomide (100-800 nM) concentration-dependently inhibited NFkappaB transcriptional activity induced by TNF-alpha, including IKKalpha expression and IkappaBalpha phosphorylation in HSC-T6 cells. In addition, thalidomide also suppressed TGF-beta1-induced alpha-SMA expression and collagen deposition in HSC-T6 cells. Fibrosis scores of livers from DMN-treated rats receiving high dose of thalidomide (0.89 +/- 0.20) were significantly reduced in comparison with those of DMN-treated rats receiving vehicle (1.56 +/- 0.18). Hepatic collagen contents of DMN rats were also significantly reduced by either thalidomide or silymarin treatment. Immunohistochemical double staining results showed that alpha-SMA- and NFkappaB-positive cells were decreased in the livers from DMN rats receiving either thalidomide or silymarin treatment. In addition, real-time PCR analysis indicated that hepatic mRNA expressions of TGF-beta1, alpha-SMA, collagen 1alpha2, TNF-alpha and iNOS genes were attenuated by thalidomide treatment. In conclusion, our results showed that thalidomide inhibited activation of HSC-T6 cells by TNF-alpha and ameliorated liver fibrosis in DMN-intoxicated rats.

Structural and mechanistic insights into Mps1 kinase activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei; Yang, Yuting; Gao, Yuefeng

2010-11-05

Mps1 is one of the several essential kinases whose activation is required for robust mitotic spindle checkpoint signalling. The activity of Mps1 is tightly regulated and increases dramatically during mitosis or in response to spindle damage. To understand the molecular mechanism underlying Mps1 regulation, we determined the crystal structure of the kinase domain of Mps1. The 2.7-{angstrom}-resolution crystal structure shows that the Mps1 kinase domain adopts a unique inactive conformation. Intramolecular interactions between the key Glu residue in the {alpha}C helix of the N-terminal lobe and the backbone amides in the catalytic loop lock the kinase in the inactive conformation.more » Autophosphorylation appears to be a priming event for kinase activation. We identified Mps1 autophosphorylation sites in the activation and the P+1 loops. Whereas activation loop autophosphorylation enhances kinase activity, autophosphorylation at the P+1 loop (T686) is associated with the active kinase. Mutation of T686 autophosphorylation site impairs both autophosphorylation and transphosphorylation. Furthermore, we demonstrated that phosphorylation of T676 may be a priming event for phosphorylation at T686. Finally, we identified two critical lysine residues in the loop between helices {alpha}EF and {alpha}F that are essential for substrate recruitment and maintaining high levels of kinase activity. Our studies reveal critical biochemical mechanisms for Mps1 kinase regulation.« less

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

PubMed

Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

1999-03-15

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

The damaging effect of UV-C irradiation on lens alpha-crystallin.

PubMed

Fujii, Noriko; Uchida, Hiroki; Saito, Takeshi

2004-11-02

To evaluate the effect of UV-C irradiation on the structural properties of alpha-crystallin and its chaperone activity. alpha- and betaL-crystallins were isolated from bovine lenses using gel chromatography. The purified alpha-crystallin was subjected to UV-C irradiation (254 nm; 1, 2, 5, 10, 20, 50 J/cm2). We measured the tryptophan fluorescence, circular dichroism (CD) spectroscopy in the far UV, and the chaperone activity of both irradiated and non-irradiated alpha-crystallin. The tryptophan fluorescence of alpha-crystallin decreased, whereas the N-formylkynurenine fluorescence increased markedly with increasing doses of UV-C irradiation. Both the oxidation of Met1 and the racemization of Asp151 of alphaA-crystallin increased at a dose of 1-2 J/cm2 and then gradually decreased. The CD spectrum showed that the secondary structure of alpha-crystallin altered with increasing radiation dose, and almost all of the beta-sheet structure was lost at doses above 50 J/cm2. The chaperone activity of alpha-crystallin irradiated with doses under 5 J/cm2 remained intact. However, it was reduced to only 40% after irradiation at 10 J/cm2. Our study suggests that photo-oxidation of tryptophan residues in alpha-crystallin may be one of the events that affects the three-dimensional packing array and chaperone activity of this lens protein.

The effects of thalidomide on the stimulation of NF-kappaB activity and TNF-alpha production by lipopolysaccharide in a human colonic epithelial cell line.

PubMed

Kim, You Sun; Kim, Joo Sung; Jung, Hyun Chae; Song, In Sung

2004-04-30

The immunomodulatory and anti-inflammatory effects of thalidomide are associated with inhibition of TNF-alpha levels. However, the mechanism by which thalidomide reduces TNF-alpha production remains elusive. NF-kappaB is known to play a central role in regulating inflammatory responses in patients with inflammatory bowel disease (IBD). We tested whether thalidomide acts through inhibiting NF-kappaB activity. HT-29 cells were stimulated with LPS (1 microg/ml) alone, or after pretreatment with thalidomide (100 microg/ml), and NF-kappaB activity was determined by gel mobility shift assays. RT-PCR was used to measure expression of the proinflammatory cytokine genes TNF-alpha, IL-1beta and IL-8. The level of TNF-alpha mRNA was also analyzed by real-time quantitative RT-PCR, and TNF-alpha protein was measured by ELISA. Thalidomide pretreatment did not affect NF-kappaB activity in HT-29 cells stimulated with LPS but production of TNF-alpha was depressed. Thalidomide was found to accelerate the degradation of TNF-alpha mRNA, but had little effect on IL-1beta or IL-8. These observations suggest that the immunomodulatory effect of thalidomide in colonic epithelial cells is associated with inhibition of TNF-alpha. However, it does not act by inhibiting NF-kappaB but rather by inducing degradation of TNF-alpha mRNA.

Quantitative immuno-electron microscopic analysis of depolarization-induced expression of PGC-1alpha in cultured rat visual cortical neurons.

PubMed

Meng, Hui; Liang, Huan Ling; Wong-Riley, Margaret

2007-10-17

Peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC- 1alpha) is a coactivator of nuclear receptors and other transcription factors that regulate several metabolic processes, including mitochondrial biogenesis, energy homeostasis, respiration, and gluconeogenesis. PGC-1alpha plays a vital role in stimulating genes that are important to oxidative metabolism and other mitochondrial functions in brown adipose tissue and skeleton muscles, but the significance of PGC-1alpha in the brain remains elusive. The goal of our present study was to determine by means of quantitative immuno-electron microscopy the expression of PGC-1alpha in cultured rat visual cortical neurons under normal conditions as well as after depolarizing stimulation for varying periods of time. Our results showed that: (a) PGC-1alpha was normally located in both the nucleus and the cytoplasm. In the nucleus, PGC-1alpha was associated mainly with euchromatin rather than heterochromatin, consistent with active involvement in transcription. In the cytoplasm, it was associated mainly with free ribosomes. (b) Neuronal depolarization by KCl for 0.5 h induced a significant increase in PGC-1alpha labeling density in both the nucleus and the cytoplasm (P<0.01). The heightened expression continued after 1 and 3 h of depolarizing treatment (P<0.01), but decreased from 5 h onward and returned to baseline level by 10 h. These results indicate that PGC-1alpha responds very early to increased neuronal activity by synthesizing more proteins in the cytoplasm and translocating them to the nucleus for gene activation. PGC-1alpha level in neurons is, therefore, tightly regulated by neuronal activity.

Phospholipase C-{delta}{sub 1} regulates interleukin-1{beta} and tumor necrosis factor-{alpha} mRNA expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Eric; Jakinovich, Paul; Bae, Aekyung

Phospholipase C-{delta}{sub 1} (PLC{delta}{sub 1}) is a widely expressed highly active PLC isoform, modulated by Ca{sup 2+} that appears to operate downstream from receptor signaling and has been linked to regulation of cytokine production. Here we investigated whether PLC{delta}{sub 1} modulated expression of the pro-inflammatory cytokines interleukin-1{beta} (IL-1{beta}), tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-6 (IL-6) in rat C6 glioma cells. Expression of PLC{delta}{sub 1} was specifically suppressed by small interfering RNA (siRNA) and the effects on cytokine mRNA expression, stimulated by the Toll-like receptor (TLR) agonist, lipopolysaccharide (LPS), were examined. Real-time polymerase chain reaction (RT-PCR) results showed that PLC{delta}{sub 1}more » knockdown enhanced expression IL-1{beta} and tumor necrosis factor-{alpha} (TNF-{alpha}) mRNA by at least 100 fold after 4 h of LPS stimulation compared to control siRNA treatment. PLC{delta}{sub 1} knock down caused persistently high Nf{kappa}b levels at 4 h of LPS stimulation compared to control siRNA-treated cells. PLC{delta}{sub 1} knockdown was also associated with elevated nuclear levels of c-Jun after 30 min of LPS stimulation, but did not affect LPS-stimulated p38 or p42/44 MAPK phosphorylation, normally associated with TLR activation of cytokine gene expression; rather, enhanced protein kinase C (PKC) phosphorylation of cellular proteins was observed in the absence of LPS stimulation. An inhibitor of PKC, bisindolylmaleimide II (BIM), reversed phosphorylation, prevented elevation of nuclear c-Jun levels, and inhibited LPS-induced increases of IL-1{beta} and TNF-{alpha} mRNA's induced by PLC{delta}{sub 1} knockdown. Our results show that loss of PLC{delta}{sub 1} enhances PKC/c-Jun signaling and up-modulates pro-inflammatory cytokine gene transcription in concert with the TLR-stimulated p38MAPK/Nf{kappa}b pathway. Our findings are consistent with the idea that PLC{delta}{sub 1} is a suppressor of PKC activity.« less

Glucocorticoid-dependent induction of interleukin-6 receptor expression in human hepatocytes facilitates interleukin-6 stimulation of amino acid transport.

PubMed

Fischer, C P; Bode, B P; Takahashi, K; Tanabe, K K; Souba, W W

1996-05-01

The authors studied the effects of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) on glutamine and alanine transport in isolated human hepatocytes. They also evaluated the role of dexamethasone in modulating this response and its effects on the expression of the plasma membrane high-affinity IL-6 receptor. Animal studies indicate that cytokines are important mediators of the increased hepatic amino acid uptake that occurs during cancer and sepsis, but studies in human tissues are lacking. The control of transport by cytokines and cytokine receptor expression in the liver may provide a mechanism by which hepatocytes can modulate amino acid availability during catabolic disease states. Human hepatocytes were isolated from wedge biopsy specimens and plated in 24-well trays. Interleukin-6 and TNF-alpha, in combination with the synthetic glucocorticoid dexamethasone, were added to hepatocytes in culture, and the transport of radiolabeled glutamine and alanine was measured. Fluorescent-activated cell sorter (FACS) analysis was used to study the effects of dexamethasone on IL-6 receptor number in the well-differentiated human hepatoma HepG2. Both IL-6 and TNF-alpha exerted a small stimulatory effect on alanine and glutamine transport. Dexamethasone alone did not alter transport rates, but pretreatment of cells augmented the effects of both cytokines on carrier-mediated amino acid uptake. Dexamethasone pretreatment and a combination of IL-6 and TNF-alpha resulted in a greater than twofold increase in transport activity. Fluorescent-activated cell sorter analysis demonstrated that dexamethasone induced a threefold increase in the expression of high-affinity IL-6 receptors. Interleukin-6 and TNF-alpha work coordinately with glucocorticoids to stimulate amino acid uptake in human hepatocytes. Dexamethasone exerts a permissive effect on cytokine-mediated increases in transport by increasing IL-6 receptor expression on the cell surface. It is likely that this upregulation of IL-6 receptors "primes" human liver cells for subsequent stimulation by cytokines. The resulting increase in hepatic amino acid transport provides the liver with substrate to support key metabolic pathways during catabolic states.

40 CFR 141.26 - Monitoring frequency and compliance requirements for radionuclides in community water systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, uranium, and... monitoring: Systems must conduct initial monitoring for gross alpha particle activity, radium-226, radium-228...) For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the State may waive...

SENESCENCE-ASSOCIATED DECLINE IN HEPATIC PEROXISOMAL ENZYME ACTIVITIES CORRESPONDS WITH DIMINISHED LEVELS OF RETINOID X RECEPTOR ALPHA, BUT NOT PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA1

EPA Science Inventory

Abstract

Aging is associated with alterations in hepatic peroxisomal metabolism and susceptibility to hepatocarcinogenecity produced by agonists of peroxisome proliferator-activated receptor alpha (PPARa). Mechanisms involved in these effects are not well understood. Howev...

Coordinated balancing of muscle oxidative metabolism through PGC-1{alpha} increases metabolic flexibility and preserves insulin sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Summermatter, Serge; Troxler, Heinz; Santos, Gesa

2011-04-29

Highlights: {yields} PGC-1{alpha} enhances muscle oxidative capacity. {yields} PGC-1{alpha} promotes concomitantly positive and negative regulators of lipid oxidation. {yields} Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. {yields} Balanced oxidation prevents detrimental acylcarnitine and ROS generation. {yields} Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1{alpha} on metabolic control and generation of insulin desensitizing agentsmore » in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1{alpha} in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1{alpha} induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1{alpha} enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1{alpha} boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1{alpha} coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1{alpha} does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1{alpha} mimic the beneficial effects of endurance training on muscle metabolism in this context.« less

The Stellar-IRIS Connection: Four Years of FUV Measurements of Alpha Centauri by HST/STIS

NASA Astrophysics Data System (ADS)

Ayres, Thomas R.

2014-06-01

Since 2010 January, shortly after the miraculous repair of Hubble's Space Telescope Imaging Spectrograph (STIS) by SM4, the two sun-like stars of Alpha Centauri ("A" [G2V] and "B" [K1V]) have been recorded on a semi-annual basis utilizing STIS's far-ultraviolet (115-170 nm) medium resolution mode (about 8 km/s FWHM resolving power), jointly with an X-ray imaging study of AB by the Chandra Observatory. Both efforts are intended to assess the long-term behavior of high-energy (multimillion K) coronal, and subcoronal, processes on the two relatively low-activity solar-age dwarfs. In fact, the near-solar-twin Alpha Cen A has been mired in a coronal lull since 2005, originally recognized by XMM-Newton, and only recently has begun to climb out of the extended X-ray minimum. Meanwhile, the lower mass, lower luminosity, but coronally more active secondary has displayed a clear 8-year X-ray cycle, extending from the mid-1990's ROSAT era. The current study focuses on properties of the "transition zone" lines ( 100,000 K) of the Alpha Centauri stars, namely the bulk redshifts exhibited by the Si IV, C IV, and N V doublets; the multi-component nature of the hot-line profiles; behavior of the Fe XII 124 nm coronal forbidden line; and variability of the FUV fluxes relative to the higher-energy X-ray time series. These stellar measurements, with their high precision in wavelength and flux, complement the detailed high-spatial and high-temporal resolution spectral mapping of the solar corona and lower atmosphere being carried out by NASA's Interface Region Imaging Spectrograph (IRIS). [This work supported by GO grants 12758, 13060, and 13465 from Space Telescope Science Institute.

Suppression of no-longer relevant information in Working Memory: An alpha-power related mechanism?

PubMed

Poch, Claudia; Valdivia, María; Capilla, Almudena; Hinojosa, José Antonio; Campo, Pablo

2018-03-27

Selective attention can enhance Working Memory (WM) performance by selecting relevant information, while preventing distracting items from encoding or from further maintenance. Alpha oscillatory modulations are a correlate of visuospatial attention. Specifically, an enhancement of alpha power is observed in the ipsilateral posterior cortex to the locus of attention, along with a suppression in the contralateral hemisphere. An influential model proposes that the alpha enhancement is functionally related to the suppression of information. However, whether ipsilateral alpha power represents a mechanism through which no longer relevant WM representations are inhibited has yet not been explored. Here we examined whether the amount of distractors to be suppressed during WM maintenance is functionally related to alpha power lateralized activity. We measure EEG activity while participants (N = 36) performed a retro-cue task in which the WM load was varied across the relevant/irrelevant post-cue hemifield. We found that alpha activity was lateralized respect to the locus of attention, but did not track post-cue irrelevant load. Additionally, non-lateralized alpha activity increased with post-cue relevant load. We propose that alpha lateralization associated to retro-cuing might be related to a general orienting mechanism toward relevant representation. Copyright © 2018 Elsevier B.V. All rights reserved.

Cloning and expression of an alpha-1,3-glucanase gene from Bacillus circulans KA-304: the enzyme participates in protoplast formation of Schizophyllum commune.

PubMed

Yano, Shigekazu; Wakayama, Mamoru; Tachiki, Takashi

2006-07-01

A culture filtrate of Bacillus circulans KA-304 grown on a cell-wall preparation of Schizophyllum commune has an activity to form protoplasts from S. commune mycelia, and a combination of alpha-1,3-glucanase and chitinase I, which were isolated from the filtrate, brings about the protoplast-forming activity. The gene of alpha-1,3-glucanase was cloned from B. circulans KA-304. It consists of 3,879 nucleotides, which encodes 1,293 amino acids including a putative signal peptide (31 amino acid residues), and the molecular weight of alpha-1,3-glucanase without the putative signal peptide was calculated to be 132,184. The deduced amino acid sequence of alpha-1,3-glucanase of B. circulans KA-304 showed approximately 80% similarity to that of mutanase (alpha-1,3-glucanase) of Bacillus sp. RM1, but no significant similarity to those of fungal mutanases. The recombinant alpha-1,3-glucanase was expressed in Escherichia coli Rosetta-gami B (DE 3), and significant alpha-1,3-glucanase activity was detected in the cell-free extract of the organism treated with isopropyl-beta-D-thiogalactopyranoside. The recombinant alpha-1,3-glucanase showed protoplast-forming activity when the enzyme was combined with chitinase I.

{alpha}-Lipoic acid prevents lipotoxic cardiomyopathy in acyl CoA-synthase transgenic mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Young; Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854; Naseem, R. Haris

2006-05-26

{alpha}-Lipoic acid ({alpha}-LA) mimics the hypothalamic actions of leptin on food intake, energy expenditure, and activation of AMP-activated protein kinase (AMPK). To determine if, like leptin, {alpha}-LA protects against cardiac lipotoxicity, {alpha}-LA was fed to transgenic mice with cardiomyocyte-specific overexpression of the acyl CoA synthase (ACS) gene. Untreated ACS-transgenic mice died prematurely with increased triacylglycerol content and dilated cardiomyopathy, impaired systolic function and myofiber disorganization, apoptosis, and interstitial fibrosis on microscopy. In {alpha}-LA-treated ACS-transgenic mice heart size, echocardiogram and TG content were normal. Plasma TG fell 50%, hepatic-activated phospho-AMPK rose 6-fold, sterol regulatory element-binding protein-1c declined 50%, and peroxisome proliferator-activatedmore » receptor-{gamma} cofactor-1{alpha} mRNA rose 4-fold. Since food restriction did not prevent lipotoxicity, we conclude that {alpha}-LA treatment, like hyperleptinemia, protects the heart of ACS-transgenic mice from lipotoxicity.« less

Ethanol acts as an enhancer of steroid anesthetic activity in mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bukusoglu, C.; Mok, W.M.; Krieger, N.R.

1992-02-26

Ethanol and the steroid 3{alpha}-hydroxy-5{alpha}-pregnan-20-one (3{alpha}) are each potent general anesthetics that bring about the rapid loss of the righting response (LRR) in mice. Ethanol is known to enhance the actions of a range of sedative and anesthetic agents. However the effects of ethanol on steroid anesthesia have not previously been described. When ethanol was co-injected with 3{alpha} as compared to 3{alpha} injected alone, the percentage of mice that lost the righting response was substantially increased; the time to LRR was shortened; and 3{alpha} brain levels were increased. The interactions between the two agents were analyzed with the aid ofmore » an isobologram and they were found to be consistent with a hypothesis of additivity. The authors speculate that the role of ethanol as an enhancer of administered 3{alpha} activity described here may extend to the enhancement of endogenous 3{alpha} activity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hyeon Ho; Lee, Youngae; Laboratory of Cutaneous Aging Research, Department of Dermatology, Clinical Research Institutes, Seoul National University Hospital, 28 Yongon-dong, Jongno-gu, Seoul 110-744

Eicosapentaenoic acid (EPA) is an omega-3 ({omega}-3) polyunsaturated fatty acid (PUFA), which has anti-inflammatory and anti-cancer properties. Some reports have demonstrated that EPA inhibits NF-{kappa}B activation induced by tumor necrosis factor (TNF)-{alpha} or lipopolysaccharide (LPS) in various cells. However, its detailed mode of action is unclear. In this report, we investigated whether EPA inhibits the expression of TNF-{alpha}-induced matrix metalloproteinases (MMP)-9 in human immortalized keratinocytes (HaCaT). TNF-{alpha} induced MMP-9 expression by NF-{kappa}B-dependent pathway. Pretreatment of EPA inhibited TNF-{alpha}-induced MMP-9 expression and p65 phosphorylation. However, EPA could not affect I{kappa}B-{alpha} phosphorylation, nuclear translocation of p65, and DNA binding activity of NF-{kappa}B.more » EPA inhibited TNF-{alpha}-induced p65 phosphorylation through p38 and Akt inhibition and this inhibition was IKK{alpha}-dependent event. Taken together, we demonstrate that EPA inhibits TNF-{alpha}-induced MMP-9 expression through inhibition of p38 and Akt activation.« less

Guinea pig hepatocyte alpha 1A-adrenoceptors: characterization, signal transduction and regulation.

PubMed

García-Sáinz, J A; Romero-Avila, T; Olivares-Reyes, J A; Macías-Silva, M

1992-11-02

Activation of guinea pig hepatocyte alpha 1-adrenoceptors increases phosphatidylinositol (PI) labeling, [3H]inositol phosphate production and phosphorylase activity. These adrenergic actions were not altered by pretreatment with chlorethylclonidine but were blocked by 5-methyl urapidil and prazosin (the former being 3- to 10-fold more potent than the latter), indicating that alpha 1A-adrenoceptors were involved. When the cells were incubated in buffer without calcium and containing EGTA, the alpha 1A-adrenergic stimulation of PI labeling was diminished but not abolished and that of phosphorylase was not affected. The alpha 1A-adrenergic effects were insensitive to pertussis toxin treatment. Phorbol myristate acetate inhibited the alpha 1A-adrenergic actions, although at relatively large concentrations, and also those of other agents such as angiotensin II and NaF. Our data clearly indicate that guinea pig hepatocytes express alpha 1A-adrenoceptors whose activation stimulates phosphoinositide turnover, via a pertussis toxin-insensitive process; the alpha 1A-adrenergic effects were at least partially independent of extracellular calcium.

Three-dimensional cell organization leads to almost immediate HRE activity as demonstrated by molecular imaging of MG-63 spheroids using two-photon excitation microscopy.

PubMed

Indovina, Paola; Collini, Maddalena; Chirico, Giuseppe; Santini, Maria Teresa

2007-02-20

Hypoxia through HRE (hypoxia-responsive element) activity in MG-63 human osteosarcoma cells grown in monolayer and as very small, three-dimensional tumor spheroids was investigated using molecular imaging techniques. MG-63 cells were stably transfected with a vector constructed with multiple copies of the HRE sequence of the human vascular endothelial growth factor (VEGF) gene and with the enhanced green fluorescent protein (EGFP) coding sequence. During hypoxia when HIF-1alpha (hypoxia-inducible factor-1alpha) is stabilized, the binding of HIF-1 to the HRE sequences of the vector allows the transcription of EGFP and the appearance of fluorescence. Transfected monolayer cells were characterized by flow cytometric analysis in response to various hypoxic conditions and HIF-1alpha expression in these cells was assessed by Western blotting. Two-photon excitation (TPE) microscopy was then used to examine both MG-63-transfected monolayer cells and spheroids at 2 and 5 days of growth in normoxic conditions. Monolayer cells reveal almost no fluorescence, whereas even very small spheroids (<100 microm) after 2 days of growth contain regions of high fluorescence. For the first time in the literature, at least to our knowledge, it is demonstrated, using highly sensitive and non-perturbing molecular imaging techniques, that three-dimensional cell organization leads to almost immediate HRE activation. This activation of the HRE sequences, which control a wide variety of genes, suggests that monolayer cells and spheroids of the MG-63 cell line have different genes activated and thus diverse functional activities.

Akt mediates 17beta-estradiol and/or estrogen receptor-alpha inhibition of LPS-induced tumor necresis factor-alpha expression and myocardial cell apoptosis by suppressing the JNK1/2-NFkappaB pathway.

PubMed

Liu, Chung-Jung; Lo, Jeng-Fan; Kuo, Chia-Hua; Chu, Chun-Hsien; Chen, Li-Ming; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tzang, Bor-Show; Kuo, Wei-Wen; Huang, Chih-Yang

2009-09-01

Evidence shows that women have lower tumour necrosis factor-alpha (TNF-alpha) levels and lower incidences of heart dysfunction and sepsis-related morbidity and mortality. To identify the cardioprotective effects and precise cellular/molecular mechanisms behind estrogen and estrogen receptors (ERs), we investigated the effects of 17beta-estradiol (E(2)) and estrogen receptor alpha (ERalpha) on LPS-induced apoptosis by analyzing the activation of survival and death signalling pathways in doxycycline (Dox)-inducible Tet-On/ERalpha H9c2 myocardial cells and ERalpha-transfected primary cardiomyocytes overexpressing ERalpha. We found that LPS challenge activated JNK1/2, and then induced IkappaB degradation, NFkappaB activation, TNF-alpha up-regulation and subsequent myocardial apoptotic responses. In addition, treatments involving E(2), membrane-impermeable BSA-E(2) and/or Dox, which induces ERalpha overexpression, significantly inhibited LPS-induced apoptosis by suppressing LPS-up-regulated JNK1/2 activity, IkappaB degradation, NFkappaB activation and pro-apoptotic proteins (e.g. TNF-alpha, active caspases-8, t-Bid, Bax, released cytochrome c, active caspase-9, active caspase-3) in myocardial cells. However, the cardioprotective properties of E(2), BSA-E(2) and ERalpha overexpression to inhibit LPS-induced apoptosis and promote cell survival were attenuated by applying LY294002 (PI3K inhibitor) and PI3K siRNA. These findings suggest that E(2), BSA-E(2) and ERalpha expression exert their cardioprotective effects by inhibiting JNK1/2-mediated LPS-induced TNF-alpha expression and cardiomyocyte apoptosis through activation of Akt.

Screening alpha-glucosidase and alpha-amylase inhibitors from natural compounds by molecular docking in silico.

PubMed

Jhong, Chien-Hung; Riyaphan, Jirawat; Lin, Shih-Hung; Chia, Yi-Chen; Weng, Ching-Feng

2015-01-01

The alpha-glucosidase inhibitor is a common oral anti-diabetic drug used for controlling carbohydrates normally converted into simple sugars and absorbed by the intestines. However, some adverse clinical effects have been observed. The present study seeks an alternative drug that can regulate the hyperglycemia by down-regulating alpha-glucosidase and alpha-amylase activity by molecular docking approach to screen the hyperglycemia antagonist against alpha-glucosidase and alpha-amylase activities from the 47 natural compounds. The docking data showed that Curcumin, 16-hydroxy-cleroda-3,13-dine-16,15-olide (16-H), Docosanol, Tetracosanol, Antroquinonol, Berberine, Catechin, Quercetin, Actinodaphnine, and Rutin from 47 natural compounds had binding ability towards alpha-amylase and alpha-glucosidase as well. Curcumin had a better biding ability of alpha-amylase than the other natural compounds. Analyzed alpha-glucosidase activity reveals natural compound inhibitors (below 0.5 mM) are Curcumin, Actinodaphnine, 16-H, Quercetin, Berberine, and Catechin when compared to the commercial drug Acarbose (3 mM). A natural compound with alpha-amylase inhibitors (below 0.5 mM) includes Curcumin, Berberine, Docosanol, 16-H, Actinodaphnine/Tetracosanol, Catechin, and Quercetin when compared to Acarbose (1 mM). When taken together, the implication is that molecular docking is a fast and effective way to screen alpha-glucosidase and alpha-amylase inhibitors as lead compounds of natural sources isolated from medicinal plants. © 2015 International Union of Biochemistry and Molecular Biology.

Effects of alpha/beta-androstenediol immune regulating hormones on bone remodeling and apoptosis in osteoblasts.

PubMed

Urban, Nicole H; Chamberlin, Brett; Ramage, Samuel; Roberts, Zachary; Loria, Roger M; Beckman, Matthew J

2008-06-01

A large body of evidence suggests that the immune system directly impacts bone physiology. We tested whether immune regulating hormones (IRH), 17beta-androstenediol (beta-AED), 7beta,17beta-androstenetriol (beta-AET) or the 17alpha-androstenediol (alpha-AED), and 7alpha,17beta-androstenetriol (alpha-AET) metabolites could directly influence bone remodeling in vitro using human fetal osteoblasts (FOB-9). The impact on bone remodeling was examined by comparing the ratio of RANKL/OPG gene expression in response to AED and AET compounds. The alpha-AED was found to significantly increase in the ratio of RANKL/OPG gene expression and altering the morphology of RANKL stained FOB-9 cells. Cell viability was assessed using a Live/Dead assay. Again alpha-AED was unique in its ability to reduce the proportion of viable cells, and to induce mild apoptosis of FOB-9 cells. Treatment of FOB-9 cells with WY14643, an activator of PPAR-alpha and -gamma, also significantly elevated the percentage of dead cells. This increase was abolished by co-treatment with GW9962, a specific inhibitor of PPAR-gamma. Analysis of PPAR-gamma mRNA by Quantitative RT-PCR and its activation by DNA binding demonstrated that alpha-AED increased PPAR-gamma activation by 19%, while beta-AED conferred a 37% decrease in PPAR-gamma activation. In conclusion, alpha-AED opposed beta-AED by elevating a bone resorption scenario in osteoblast cells. The increase in RANKL/OPG is modulated by an activation of PPAR-gamma that in turn caused mild apoptosis of FOB-9 cells.

In vitro C3 mRNA expression in Pemphigus vulgaris: complement activation is increased by IL-1alpha and TNF-alpha.

PubMed

Feliciani, C; Toto, P; Amerio, P

1999-01-01

Pemphigus vulgaris (PV) is a potentially life-threatening disease, characterized immunohistologically by IgG deposits and complement activation on the surface of keratinocytes. Complement activation has been implicated in the pathogenesis with C3 deposits in about 90% of patients. In order to further elucidate the role of complement in PV and to define which cytokines play a role in C3 mRNA expression, we performed an in vitro study in human keratinocytes. Normal human epidermal keratinocytes (NHuK) were incubated with PV serum and C3 mRNA was measured. We previously had shown that IL-1alpha and TNF-alpha are expressed in PV in vivo and in vitro. Since cytokines are able to modulate complement activation, mRNA expression was evaluated in a similar experiment after pretreatment using antibodies against IL-1alpha and TNF-alpha. Incubation of NHuK with PV sera caused their detachment from the plates after 20-30 minutes with a complete acantholysis within 12 hours. An early C3 mRNA expression was seen after 30 minutes with a peak level after 1 hour. Blocking studies, using antibodies against human IL-1alpha and TNF-alpha in NHuK together with PV-IgG, showed reduction of in vitro induced acantholysis and inhibition of C3 mRNA expression. This study supports the hypothesis that complement C3 is important in PV acantholysis and that complement activation is increased by IL-1alpha and TNF-alpha.

Alpha-1-Adrenergic Receptors in Heart Failure: The Adaptive Arm of the Cardiac Response to Chronic Catecholamine Stimulation

PubMed Central

Jensen, Brian C.; O'Connell, Timothy D.; Simpson, Paul C.

2013-01-01

Alpha-1-adrenergic receptors are G-protein coupled receptors (GPCRs) activated by catecholamines. The alpha-1A and alpha-1B subtypes are expressed in mouse and human myocardium, whereas the alpha-1D protein is found only in coronary arteries. There are far fewer alpha-1-ARs than beta-ARs in the non-failing heart, but their abundance is maintained or increased in the setting of heart failure, which is characterized by pronounced chronic elevation of catecholamines and b□eta-AR dysfunction. Decades of evidence from gain- and loss-of-function studies in isolated cardiac myocytes and numerous animal models demonstrate important adaptive functions for cardiac alpha-1-ARs, to include physiological hypertrophy, positive inotropy, ischemic preconditioning, and protection from cell death. Clinical trial data indicate that blocking alpha-1-ARs is associated with incident heart failure in patients with hypertension. Collectively, these findings suggest that alpha-1-AR activation might mitigate the well-recognized toxic effects of beta-ARs in the hyperadrenergic setting of chronic heart failure. Thus, exogenous cardioselective activation of alpha-1-ARs might represent a novel and viable approach to the treatment of heart failure. PMID:24145181

Overexpression of hypoxia-inducible factor 1 alpha improves immunomodulation by dental mesenchymal stem cells.

PubMed

Martinez, Victor G; Ontoria-Oviedo, Imelda; Ricardo, Carolina P; Harding, Sian E; Sacedon, Rosa; Varas, Alberto; Zapata, Agustin; Sepulveda, Pilar; Vicente, Angeles

2017-09-29

Human dental mesenchymal stem cells (MSCs) are considered as highly accessible and attractive MSCs for use in regenerative medicine, yet some of their features are not as well characterized as other MSCs. Hypoxia-preconditioning and hypoxia-inducible factor 1 (HIF-1) alpha overexpression significantly improves MSC therapeutics, but the mechanisms involved are not fully understood. In the present study, we characterize immunomodulatory properties of dental MSCs and determine changes in their ability to modulate adaptive and innate immune populations after HIF-1 alpha overexpression. Human dental MSCs were stably transduced with green fluorescent protein (GFP-MSCs) or GFP-HIF-1 alpha lentivirus vectors (HIF-MSCs). A hypoxic-like metabolic profile was confirmed by mitochondrial and glycolysis stress test. Capacity of HIF-MSCs to modulate T-cell activation, dendritic cell differentiation, monocyte migration, and polarizations towards macrophages and natural killer (NK) cell lytic activity was assessed by a number of functional assays in co-cultures. The expression of relevant factors were determined by polymerase chain reaction (PCR) analysis and enzyme-linked immunosorbent assay (ELISA). While HIF-1 alpha overexpression did not modify the inhibition of T-cell activation by MSCs, HIF-MSCs impaired dendritic cell differentiation more efficiently. In addition, HIF-MSCs showed a tendency to induce higher attraction of monocytes, which differentiate into suppressor macrophages, and exhibited enhanced resistance to NK cell-mediated lysis, which supports the improved therapeutic capacity of HIF-MSCs. HIF-MSCs also displayed a pro-angiogenic profile characterized by increased expression of CXCL12/SDF1 and CCL5/RANTES and complete loss of CXCL10/IP10 transcription. Immunomodulation and expression of trophic factors by dental MSCs make them perfect candidates for cell therapy. Overexpression of HIF-1 alpha enhances these features and increases their resistance to allogenic NK cell lysis and, hence, their potential in vivo lifespan. Our results further support the use of HIF-1 alpha-expressing dental MSCs for cell therapy in tissue injury and immune disorders.

Mechanism for acivicin inactivation of triad glutamine amidotransferases.

PubMed

Chittur, S V; Klem, T J; Shafer, C M; Davisson, V J

2001-01-30

Acivicin [(alphaS,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid] was investigated as an inhibitor of the triad glutamine amidotransferases, IGP synthase and GMP synthetase. Nucleophilic substitution of the chlorine atom in acivicin results in the formation of an imine-thioether adduct at the active site cysteine. Cys 77 was identified as the site of modification in the heterodimeric IGPS from Escherichia coli (HisHF) by tryptic digest and FABMS. Distinctions in the glutaminase domains of IGPS from E. coli, the bifunctional protein from Saccharomyces cerevisiae (HIS7), and E. coli GMPS were revealed by the differential rates of inactivation. While the ammonia-dependent turnover was unaffected by acivicin, the glutamine-dependent reaction was inhibited with unit stoichiometry. In analogy to the conditional glutaminase activity seen in IGPS and GMPS, the rates of inactivation were accelerated > or =25-fold when a nucleotide substrate (or analogue) was present. The specificity (k(inact)/K(i)app) for acivicin is on the same order of magnitude as the natural substrate glutamine in all three enzymes. The (alphaS,5R) diastereomer of acivicin was tested under identical conditions as acivicin and showed little inhibitory effect on the enzymes indicating that acivicin binds in the glutamine reactive site in a specific conformation. The data indicate that acivicin undergoes a glutamine amidotransferase mechanism-based covalent bond formation in the presence of nucleotide substrates or products. Acivicin and its (alphaS,5R) diastereomer were modeled in the glutaminase active site of GMPS and CPS to confirm that the binding orientation of the dihydroisoxazole ring is identical in all three triad glutamine amidotransferases. Stabilization of the imine-thioether intermediate by the oxyanion hole in triad glutamine amidotransferases appears to confer the high degree of specificity for acivicin inhibition and relates to a common mechanism for inactivation.

Short-term therapy with peroxisome proliferation-activator receptor-alpha agonist Wy-14,643 protects murine fatty liver against ischemia-reperfusion injury.

PubMed

Teoh, Narci C; Williams, Jacqueline; Hartley, Jennifer; Yu, Jun; McCuskey, Robert S; Farrell, Geoffrey C

2010-03-01

Steatosis increases operative morbidity/mortality from ischemia-reperfusion injury (IRI); few pharmacological approaches have been protective. Using novel genetic/dietary models of nonalcoholic steatohepatitis (NASH) and simple steatosis (SS) in Alms1 mutant (foz/foz) mice, we characterized severity of IRI in NASH versus SS and lean liver and tested our hypothesis that the lipid-lowering effects of the peroxisome proliferation-activator receptor (PPAR)-alpha agonist Wy-14,643 would be hepatoprotective. Mice were subjected to 60-minute partial hepatic IRI. Microvascular changes were assessed at 15-minute reperfusion by in vivo microscopy, injury at 24 hours by serum alanine aminotransferase (ALT), and hepatic necrosis area. Injury and inflammation mediators were determined by way of immunoblotting for intercellular cellular adhesion molecule, vascular cellular adhesion molecule, p38, c-jun N-terminal kinase, IkappaB-alpha, interleukin (IL)-1a, IL-12, tumor necrosis factor-alpha (TNF-alpha) and IL-6, cell cycle by cyclin D1 and proliferating cell nuclear antigen immunohistochemistry. In foz/foz mice fed a high-fat diet (HFD) to cause NASH or chow (SS), IRI was exacerbated compared with HFD-fed or chow-fed wild-type littermates by ALT release; corresponding necrotic areas were 60 +/- 22% NASH, 29 +/- 9% SS versus 7 +/- 1% lean. Microvasculature of NASH or SS livers was narrowed by enormous lipid-filled hepatocytes, significantly reducing numbers of perfused sinusoids, all exacerbated by IRI. Wy-14,643 reduced steatosis in NASH and SS livers, whereas PPAR-alpha stimulation conferred substantial hepatoprotection against IRI by ALT release, with reductions in vascular cellular adhesion molecule-1, IL-1a, TNF-alpha, IL-12, activated nuclear factor-kappaB (NF-kappaB), p38, IL-6 production and cell cycle entry. NASH and SS livers are both more susceptible to IRI. Mechanisms include possible distortion of the microvasculature by swollen fat-laden hepatocytes, and enhanced production of several cytokines. The beneficial effects of Wy-14,643 may be exerted by dampening adhesion molecule and cytokine responses, and activating NF-kappaB, IL-6 production, and p38 kinase to effect cell cycle entry.

Neurofeedback in Learning Disabled Children: Visual versus Auditory Reinforcement.

PubMed

Fernández, Thalía; Bosch-Bayard, Jorge; Harmony, Thalía; Caballero, María I; Díaz-Comas, Lourdes; Galán, Lídice; Ricardo-Garcell, Josefina; Aubert, Eduardo; Otero-Ojeda, Gloria

2016-03-01

Children with learning disabilities (LD) frequently have an EEG characterized by an excess of theta and a deficit of alpha activities. NFB using an auditory stimulus as reinforcer has proven to be a useful tool to treat LD children by positively reinforcing decreases of the theta/alpha ratio. The aim of the present study was to optimize the NFB procedure by comparing the efficacy of visual (with eyes open) versus auditory (with eyes closed) reinforcers. Twenty LD children with an abnormally high theta/alpha ratio were randomly assigned to the Auditory or the Visual group, where a 500 Hz tone or a visual stimulus (a white square), respectively, was used as a positive reinforcer when the value of the theta/alpha ratio was reduced. Both groups had signs consistent with EEG maturation, but only the Auditory Group showed behavioral/cognitive improvements. In conclusion, the auditory reinforcer was more efficacious in reducing the theta/alpha ratio, and it improved the cognitive abilities more than the visual reinforcer.

EEG alpha power and creative ideation☆

PubMed Central

Fink, Andreas; Benedek, Mathias

2014-01-01

Neuroscientific studies revealed first insights into neural mechanisms underlying creativity, but existing findings are highly variegated and often inconsistent. Despite the disappointing picture on the neuroscience of creativity drawn in recent reviews, there appears to be robust evidence that EEG alpha power is particularly sensitive to various creativity-related demands involved in creative ideation. Alpha power varies as a function of creativity-related task demands and the originality of ideas, is positively related to an individuals’ creativity level, and has been observed to increase as a result of creativity interventions. Alpha increases during creative ideation could reflect more internally oriented attention that is characterized by the absence of external bottom-up stimulation and, thus, a form of top-down activity. Moreover, they could indicate the involvement of specific memory processes such as the efficient (re-)combination of unrelated semantic information. We conclude that increased alpha power during creative ideation is among the most consistent findings in neuroscientific research on creativity and discuss possible future directions to better understand the manifold brain mechanisms involved in creativity. PMID:23246442

Rilmenidine produces mydriasis in cats by stimulation of CNS alpha 2-adrenoceptors.

PubMed

Koss, M C

2003-02-01

1. Experiments were undertaken to determine if the imidazoline/alpha2-adrenoceptor agonist, rilmenidine, would produce mydriasis in cats and, if so, to delineate its site of action and determine if this effect is mediated by imidazoline receptors or alpha2-adrenoceptors. 2. Rilmenidine produced dose-related pupillary dilator responses in pentobarbital anaesthetized cats that were independent of sympathetic innervation to the iris but were dependent upon intact parasympathetic neuronal tone. The ED50 for rilmenidine-induced pupillary dilation was approximately 200 microg kg(-1), i.v., and was sustained for at least 1 h. 3. The highly selective alpha2-adrenoceptor antagonist, RS-79948, administered either before or after rilmenidine, antagonized rilmenidine-induced mydriasis. Neuronally induced reflex inhibition of parasympathetic nerve activity was also inhibited by administration of RS-79948. 4. These results suggest that rilmenidine acts like clonidine to produce pupillary dilation by inhibition of parasympathetic tone to the iris sphincter and that this central nervous system parasympatho-inhibition is mediated by alpha2-adrenoceptors, rather than imidazoline receptors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aratani, Satoko; Oishi, Takayuki; Fujita, Hidetoshi

RNA helicase A (RHA), an ATPase/helicase, regulates the gene expression at various steps including transcriptional activation and RNA processing. RHA is known to shuttle between the nucleus and cytoplasm. We identified the nuclear localization signal (NLS) of RHA and analyzed the nuclear import mechanisms. The NLS of RHA (RHA-NLS) consisting of 19 amino acid residues is highly conserved through species and does not have the consensus classical NLS. In vitro nuclear import assays revealed that the nuclear import of RHA was Ran-dependent and mediated with the classical importin-{alpha}/{beta}-dependent pathway. The binding assay indicated that the basic residues in RHA-NLS weremore » used for interaction with importin-{alpha}. Furthermore, the nuclear import of RHA-NLS was supported by importin-{alpha}1 and preferentially importin-{alpha}3. Our results indicate that the nuclear import of RHA is mediated by the importin-{alpha}3/importin-{beta}-dependent pathway and suggest that the specificity for importin may regulate the functions of cargo proteins.« less

Cloning and characterization of the mouse alpha1C/A-adrenergic receptor gene and analysis of an alpha1C promoter in cardiac myocytes: role of an MCAT element that binds transcriptional enhancer factor-1 (TEF-1).

PubMed

O'Connell, T D; Rokosh, D G; Simpson, P C

2001-05-01

alpha1-Adrenergic receptor (AR) subtypes in the heart are expressed by myocytes but not by fibroblasts, a feature that distinguishes alpha1-ARs from beta-ARs. Here we studied myocyte-specific expression of alpha1-ARs, focusing on the subtype alpha1C (also called alpha1A), a subtype implicated in cardiac hypertrophic signaling in rat models. We first cloned the mouse alpha1C-AR gene, which consisted of two exons with an 18 kb intron, similar to the alpha1B-AR gene. The receptor coding sequence was >90% homologous to that of rat and human. alpha1C-AR transcription in mouse heart was initiated from a single Inr consensus sequence at -588 from the ATG; this and a putative polyadenylation sequence 8.5 kb 3' could account for the predominant 11 kb alpha1C mRNA in mouse heart. A 5'-nontranscribed fragment of 4.4 kb was active as a promoter in cardiac myocytes but not in fibroblasts. Promoter activity in myocytes required a single muscle CAT (MCAT) element, and this MCAT bound in vitro to recombinant and endogenous transcriptional enhancer factor-1. Thus, alpha1C-AR transcription in cardiac myocytes shares MCAT dependence with other cardiac-specific genes, including the alpha- and beta-myosin heavy chains, skeletal alpha-actin, and brain natriuretic peptide. However, the mouse alpha1C gene was not transcribed in the neonatal heart and was not activated by alpha1-AR and other hypertrophic agonists in rat myocytes, and thus differed from other MCAT-dependent genes and the rat alpha1C gene.

AtFXG1, an Arabidopsis gene encoding alpha-L-fucosidase active against fucosylated xyloglucan oligosaccharides.

PubMed

de La Torre, Francisco; Sampedro, Javier; Zarra, Ignacio; Revilla, Gloria

2002-01-01

An alpha-L-fucosidase (EC 3.2.1.51) able to release the t-fucosyl residue from the side chain of xyloglucan oligosaccharides has been detected in the leaves of Arabidopsis plants. Moreover, an alpha-L-fucosidase with similar substrate specificity was purified from cabbage (Brassica oleracea) leaves to render a single band on SDS-PAGE. Two peptide sequences were obtained from this protein band, and they were used to identify an Arabidopsis gene coding for an alpha-fucosidase that we propose to call AtFXG1. In addition, an Arabidopsis gene with homology with known alpha-L-fucosidases has been also found, and we proposed to name it as AtFUC1. Both AtFXG1 and ATFUC1 were heterologously expressed in Pichia pastoris cells and the alpha-L-fucosidase activities secreted to the culture medium. The alpha-L-fucosidase encoded by AtFXG1 was active against the oligosaccharides from xyloglucan XXFG as well as against 2'-fucosyl-lactitol but not against p-nitrophenyl-alpha-L-fucopyranoside. However, the AtFUC1 heterologously expressed was active only against 2'-fucosyl-lactitol. Thus, the former must be related to xyloglucan metabolism.

IGF-1-dependent subunit communication of the IGF-1 holoreceptor: Interactions between. alpha. beta. heterodimeric receptor halves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilden, P.A.; Treadway, J.L.; Morrison, B.D.

1989-12-12

Examination of {sup 125}I-IGF-1 affinity cross-linking and {beta}-subunit autophosphorylation has indicated that IGF-1 induces a covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptors into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state, in a similar manner to that observed for the insulin receptor. The formation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 receptor complex from the partially purified {alpha}{beta} heterodimers was time dependent with half-maximal formation in approximately 30 min at saturating IGF-1 concentrations. The IGF-1-dependent association of the partially purified {alpha}{beta} heterodimers into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state was specific for the IGF-1 receptors since IGF-1 was unable to stimulatemore » the protein kinase activity of the purified {alpha}{beta} heterodimeric insulin receptor complex. Incubation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 holoreceptor with the specific sulfhydryl agent iodoacetamide (IAN) did not alter {sup 125}I-IGF-1 binding or IGF-1 stimulation of protein kinase activity. However, IAN treatment of the {alpha}{beta} heterodimeric IGF-1 receptors inhibited the IGF-1 dependent covalent formation of the disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric complex. These data indicate that IGF-1 induces the covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptor complexes into a disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric state whereas Mn/MgATP induces a noncovalent association. Therefore, unlike the insulin receptor in which noncovalent association is sufficient for kinase activation, only the covalent assembly of the IGF-1 receptor {alpha}{beta} heterodimers into the {alpha}{sub 2}{beta}{sub 2} heterotetrameric holoreceptor complex is associated with ligand-stimulated protein kinase activation.« less

The regulatory mechanism of Hsp90{alpha} secretion from endothelial cells and its role in angiogenesis during wound healing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Xiaomin; Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084; Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084

2010-07-16

Research highlights: {yields} Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90{alpha} secretion from endothelial cells. {yields} Secreted Hsp90{alpha} localizes on the leading edge of activated endothelial cells. {yields} Secreted Hsp90{alpha} promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90{alpha} (Hsp90{alpha}) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90{alpha} can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation andmore » migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90{alpha} from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90{alpha} in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90{alpha} but not Hsp90{beta} is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90{alpha} localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90{alpha} neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90{alpha} localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90{alpha} can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90{alpha} as a stimulator for wound repair.« less

Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-alpha therapy.

PubMed

Fekkes, Durk; Van Gool, Arthur R; Bannink, Marjolein; Sleijfer, Stefan; Kruit, Wim H J; van der Holt, Bronno; Eggermont, Alexander M M; Hengeveld, Michiel W; Stoter, Gerrit

2009-10-01

Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-alpha (IFN-alpha). Animal studies showed that IFN-alpha administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H(2)O(2) generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-alpha. NO synthesis was quantitated by measuring both the ratio of citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-alpha, of which the association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-alpha are unlikely to contribute to definite psychiatric disturbance.

Nuclear receptor ERR alpha and coactivator PGC-1 beta are effectors of IFN-gamma-induced host defense.

PubMed

Sonoda, Junichiro; Laganière, Josée; Mehl, Isaac R; Barish, Grant D; Chong, Ling-Wa; Li, Xiangli; Scheffler, Immo E; Mock, Dennis C; Bataille, Alain R; Robert, Francois; Lee, Chih-Hao; Giguère, Vincent; Evans, Ronald M

2007-08-01

Macrophage activation by the proinflammatory cytokine interferon-gamma (IFN-gamma) is a critical component of the host innate response to bacterial pathogenesis. However, the precise nature of the IFN-gamma-induced activation pathway is not known. Here we show using genome-wide expression and chromatin-binding profiling that IFN-gamma induces the expression of many nuclear genes encoding mitochondrial respiratory chain machinery via activation of the nuclear receptor ERR alpha (estrogen-related receptor alpha, NR3B1). Studies with macrophages lacking ERR alpha demonstrate that it is required for induction of mitochondrial reactive oxygen species (ROS) production and efficient clearance of Listeria monocytogenes (LM) in response to IFN-gamma. As a result, mice lacking ERR alpha are susceptible to LM infection, a phenotype that is localized to bone marrow-derived cells. Furthermore, we found that IFN-gamma-induced activation of ERR alpha depends on coactivator PGC-1 beta (peroxisome proliferator-activated receptor gamma coactivator-1 beta), which appears to be a direct target for the IFN-gamma/STAT-1 signaling cascade. Thus, ERR alpha and PGC-1 beta act together as a key effector of IFN-gamma-induced mitochondrial ROS production and host defense.

Two MCAT elements of the SM alpha-actin promoter function differentially in SM vs. non-SM cells.

PubMed

Swartz, E A; Johnson, A D; Owens, G K

1998-08-01

Transcriptional activity of the smooth muscle (SM) alpha-actin gene is differentially regulated in SM vs. non-SM cells. Contained within the rat SM alpha-actin promoter are two MCAT motifs, binding sites for transcription enhancer factor 1 (TEF-1) transcriptional factors implicated in the regulation of many muscle-specific genes. Transfections of SM alpha-actin promoter-CAT constructs containing wild-type or mutagenized MCAT elements were performed to evaluate their functional significance. Mutation of the MCAT elements resulted in increased transcriptional activity in SM cells, whereas these mutations either had no effect or decreased activity in L6 myotubes or endothelial cells. High-resolution gel shift assays resolved several complexes of different mobilities that were formed between MCAT oligonucleotides and nuclear extracts from the different cell types, although no single band was unique to SM. Western blot analysis of nuclear extracts with polyclonal antibodies to conserved domains of the TEF-1 gene family revealed multiple reactive bands, some that were similar and others that differed between SM and non-SM. Supershift assays with a polyclonal antibody to the TEF-related protein family demonstrated that TEF-1 or TEF-1-related proteins were contained in the shifted complexes. Results suggest that the MCAT elements may contribute to cell type-specific regulation of the SM alpha-actin gene. However, it remains to be determined whether the differential transcriptional activity of MCAT elements in SM vs. non-SM is due to differences in expression of TEF-1 or TEF-1-related proteins or to unique (cell type specific) combinatorial interactions of the MCAT elements with other cis-elements and trans-factors.

IgE enhances Fc epsilon RI expression and IgE-dependent TNF-alpha release from canine skin mast cells.

PubMed

Brazís, P; De Mora, F; Ferrer, L; Puigdemont, A

2002-03-01

The role of IgE on mast cell (MC) activation is well known. Recent studies have demonstrated that IgE also has the ability to up-regulate the high affinity IgE receptor (Fc epsilon RI) on the surface of human and murine MC, leading to an increased production of cytokines and chemokines. In the present study, we have examined the influence of IgE levels on Fc epsilon RI expression, and its consequences on TNF-alpha production from canine skin MC. Mature MC were enzymatically dispersed from the skin biopsies of 6-8 dogs and were cultured for up to 5 days in medium supplemented with recombinant canine stem cell factor (SCF) (6 ng/ml), in the presence of increasing serum IgE concentrations (ranging from 0 to 80 microg/ml). Subsequently, skin MC were activated with anti-IgE, and TNF-alpha concentration was assessed 5h post-activation by a cytotoxic bioassay. Fc epsilon RI receptors were identified in MC surface by flow cytometry. MC cultured for up to 5 days in the presence of high serum IgE concentration (8 microg/ml) produced twice the quantity of TNF-alpha than MC cultured in the absence of serum IgE, in response to stimulation with anti-IgE. Moreover, the percentage of Fc epsilon RI-positive skin cells was found to be approximately double in cells cultured with serum IgE compared to that cultured in the absence of IgE, following saturation of IgE receptors. These results suggest that, as found in human and murine MC, IgE may induce an up-regulation of the Fc epsilon RI density and an enhancement in the secretory activity of canine skin MC. This study could be of great interest in designing new therapeutic strategies for controlling MC activation in inflammatory and allergic processes.

H(alpha) Proxies for EIT Crinkles: Further Evidence for Preflare "Breakout"-Type Activity in an Ejective Solar Eruption

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.; Qiu, Jiong; Wang, Haimin; Moore, Ronald L.

2001-01-01

We present H(alpha) observations from Big Bear Solar Observatory of an eruptive flare in NOAA Active Region 8210, occurring near 22:30 UT on 1998 May 1. Previously, using the Extreme Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO) spacecraft, we found that a pattern of transient, localized brightenings, which we call 'EIT crinkles,' appears in the neighborhood of the eruption near the time of flare onset. These EIT crinkles occur at a location in the active region well separated from the sheared core magnetic fields, which is where the most intense features of the eruption are concentrated. We also previously found that high-cadence images from the Soft X-ray Telescope (SXT) on Yohkoh indicate that soft X-ray intensity enhancements in the core begin after the start of the EIT crinkles. With the H(alpha) data, we find remote flare brightening counterparts to the EIT crinkles. Light curves as functions of time of various areas of the active region show that several of the remote flare brightenings undergo intensity increases prior to the onset of principal brightenings in the core region, consistent with our earlier findings from EIT and SXT data. These timing relationships are consistent with the eruption onset mechanism known as the breakout model, introduced by Antiochos and colleagues, which proposes that eruptions begin with reconnection at a magnetic null high above the core region. Our observations are also consistent with other proposed mechanisms that do not involve early reconnection in the core region. As a corollary, our observations are not consistent with the so-called tether-cutting models, which say that the eruption begins with reconnection in the core. The H(alpha) data further show that a filament in the core region becomes activated near the time of EIT crinkle onset, but little if any of the filament actually erupts, despite the presence of a halo coronal mass ejection (CME) associated with this event.

Isotopic analysis of uranium in natural waters by alpha spectrometry

USGS Publications Warehouse

Edwards, K.W.

1968-01-01

A method is described for the determination of U234/U238 activity ratios for uranium present in natural waters. The uranium is coprecipitated from solution with aluminum phosphate, extracted into ethyl acetate, further purified by ion exchange, and finally electroplated on a titanium disc for counting. The individual isotopes are determined by measurement of the alpha-particle energy spectrum using a high resolution low-background alpha spectrometer. Overall chemical recovery of about 90 percent and a counting efficiency of 25 percent allow analyses of water samples containing as little as 0.10 ?g/l of uranium. The accuracy of the method is limited, on most samples, primarily by counting statistics.

New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

PubMed

Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

2015-12-01

The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cryptic MCAT enhancer regulation in fibroblasts and smooth muscle cells. Suppression of TEF-1 mediated activation by the single-stranded DNA-binding proteins, Pur alpha, Pur beta, and MSY1.

PubMed

Carlini, Leslie E; Getz, Michael J; Strauch, Arthur R; Kelm, Robert J

2002-03-08

An asymmetric polypurine-polypyrimidine cis-element located in the 5' region of the mouse vascular smooth muscle alpha-actin gene serves as a binding site for multiple proteins with specific affinity for either single- or double-stranded DNA. Here, we test the hypothesis that single-stranded DNA-binding proteins are responsible for preventing a cryptic MCAT enhancer centered within this element from cooperating with a nearby serum response factor-interacting CArG motif to trans-activate the minimal promoter in fibroblasts and smooth muscle cells. DNA binding studies revealed that the core MCAT sequence mediates binding of transcription enhancer factor-1 to the double-stranded polypurine-polypyrimidine element while flanking nucleotides account for interaction of Pur alpha and Pur beta with the purine-rich strand and MSY1 with the complementary pyrimidine-rich strand. Mutations that selectively impaired high affinity single-stranded DNA binding by fibroblast or smooth muscle cell-derived Pur alpha, Pur beta, and MSY1 in vitro, released the cryptic MCAT enhancer from repression in transfected cells. Additional experiments indicated that Pur alpha, Pur beta, and MSY1 also interact specifically, albeit weakly, with double-stranded DNA and with transcription enhancer factor-1. These results are consistent with two plausible models of cryptic MCAT enhancer regulation by Pur alpha, Pur beta, and MSY1 involving either competitive single-stranded DNA binding or masking of MCAT-bound transcription enhancer factor-1.

PPAR alpha and PPAR gamma coactivation rapidly induces Egr-1 in the nuclei of the dorsal and ventral urinary bladder and kidney pelvis urothelium of rats.

PubMed

Egerod, Frederikke Lihme; Svendsen, Jette Eldrup; Hinley, Jennifer; Southgate, Jennifer; Bartels, Annette; Brünner, Nils; Oleksiewicz, Martin B

2009-12-01

To facilitate studies of the rat bladder carcinogenicity of dual-acting PPAR alpha+gamma agonists, we previously identified the Egr-1 transcription factor as a candidate carcinogenicity biomarker and developed rat models based on coadministration of commercially available specific PPAR alpha and PPAR gamma agonists. Immunohistochemistry for Egr-1 with a rabbit monoclonal antibody demonstrated that male vehicle-treated rats exhibited minimal urothelial expression and specifically, no nuclear signal. In contrast, Egr-1 was induced in the nuclei of bladder, as well as kidney pelvis, urothelia within one day (2 doses) of oral dosing of rats with a combination of 8 mg/kg rosiglitazone and 200 mg/kg fenofibrate (specific PPAR gamma and PPAR alpha agonists, respectively). These findings were confirmed by Western blotting using a different Egr-1 antibody. Egr-1 was induced to similar levels in the dorsal and ventral bladder urothelium, arguing against involvement of urinary solids. Egr-1 induction sometimes occurred in a localized fashion, indicating physiological microheterogeneity in the urothelium. The rapid kinetics supported that Egr-1 induction occurred as a result of pharmacological activation of PPAR alpha and PPAR gamma, which are coexpressed at high levels in the rat urothelium. Finally, our demonstration of a nuclear localization supports that the Egr-1 induced by PPAR alpha and PPAR gamma coactivation in the rat urothelium may be biologically active.

Putative EEG measures of social anxiety: Comparing frontal alpha asymmetry and delta-beta cross-frequency correlation.

PubMed

Harrewijn, A; Van der Molen, M J W; Westenberg, P M

2016-12-01

The goal of the present study was to examine whether frontal alpha asymmetry and delta-beta cross-frequency correlation during resting state, anticipation, and recovery are electroencephalographic (EEG) measures of social anxiety. For the first time, we jointly examined frontal alpha asymmetry and delta-beta correlation during resting state and during a social performance task in high (HSA) versus low (LSA) socially anxious females. Participants performed a social performance task in which they first watched and evaluated a video of a peer, and then prepared their own speech. They believed that their speech would be videotaped and evaluated by a peer. We found that HSA participants showed significant negative delta-beta correlation as compared to LSA participants during both anticipation of and recovery from the stressful social situation. This negative delta-beta correlation might reflect increased activity in subcortical brain regions and decreased activity in cortical brain regions. As we hypothesized, no group differences in delta-beta correlation were found during the resting state. This could indicate that a certain level of stress is needed to find EEG measures of social anxiety. As for frontal alpha asymmetry, we did not find any group differences. The present frontal alpha asymmetry results are discussed in relation to the evident inconsistencies in the frontal alpha asymmetry literature. Together, our results suggest that delta-beta correlation is a putative EEG measure of social anxiety.

[Vitamin E activity of some alpha-tocopherol derivatives and their effect on the ubiquinone level in rat liver in vitro].

PubMed

Donchenko, G V; Kovalenko, V N; Zolotashko, O M; Makovetskiĭ, V P; Basalkevich, E D; Sivachek, T E; Svishchuk, A A; Khalmuradov, A G

1979-01-01

An addition of alpha-tocopherol (I) and its synthetic derivatives (alpha-tocopheryl quinone (II), its short-chained analog (III), alpha-tocopherol lactone (IV), and short-chained alpha-tocopheryl acetate (V)) to the homogenized liver of vitamin E deficient rats resulted in a significant increase of ubiquinone after 2 hour incubation. Activity of the above derivatives (II-V) was not associated directly with their transformation into I or with a noticeable increase of the I content. There is a certain correlation between the chemical structure and the level of vitamin E activity of alpha-tocopherol derivatives that led to an increase in the ubiquinone content and prevented the decrease of tissue respiration and termination of pregnancy in rats.

Regulation of the human SLC25A20 expression by peroxisome proliferator-activated receptor alpha in human hepatoblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tachibana, Keisuke, E-mail: nya@phs.osaka-u.ac.jp; Takeuchi, Kentaro; Inada, Hirohiko

2009-11-20

Solute carrier family 25, member 20 (SLC25A20) is a key molecule that transfers acylcarnitine esters in exchange for free carnitine across the mitochondrial membrane in the mitochondrial {beta}-oxidation. The peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is a ligand-activated transcription factor that plays an important role in the regulation of {beta}-oxidation. We previously established tetracycline-regulated human cell line that can be induced to express PPAR{alpha} and found that PPAR{alpha} induces the SLC25A20 expression. In this study, we analyzed the promoter region of the human slc25a20 gene and showed that PPAR{alpha} regulates the expression of human SLC25A20 via the peroxisome proliferator responsive element.

A conjugate of camptothecin and a somatostatin analog against prostate cancer cell invasion via a possible signaling pathway involving PI3K/Akt, alphaVbeta3/alphaVbeta5 and MMP-2/-9.

PubMed

Sun, Li-Chun; Luo, Jing; Mackey, L Vienna; Fuselier, Joseph A; Coy, David H

2007-02-08

Camptothecin (CPT) was conjugated to the N-terminal of a somatostatin analog (SSA) directly via a carbamate group and a basic N-terminal linking motif, D-Lys-D-Tyr-Lys-D-Tyr-D-Lys. This new CPT-SSA conjugate termed JF-10-81 was evaluated as a receptor-specific delivery system for its anti-invasive and anti-angiogenic activities. It was found that, in addition to blocking migration and invasion of highly invasive prostate cancer PC-3 cells, this conjugate also inhibited in vitro capillary-like tube formation of endothelial cells and in vivo angiogenesis in C57B1/6N female mice. JF-10-81 was found to block PC-3 cell attachment to various extracellular matrix components, mainly to vitronectin, the ligand of cell surface receptors integrin alphaVbeta3 and alphaVbeta5. Additionally, JF-10-81 reduced expression of integrins alphaVbeta3 and alphaVbeta5 on PC-3 cell surfaces, without effects on beta1 or any alphabeta1 heterodimers. This conjugate also inactivated phosphorylation of protein kinase B (PKB/Akt), down-regulated the expression of latent matrix metalloproteinase (MMP) -2 and MMP-9, but had little effect on MMP-3/-10. Meanwhile, membrane type-1 matrix metalloproteinase (MT1-MMP) and the tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) were not detectable in PC-3 cells. alphaVbeta3/alphaVbeta5 and MMP-2/-9 are known to be highly expressed in many tumor cells and play an important role in tumor progression. Our results support that this conjugate could possibly inhibit prostate cancer PC-3 cell invasion through a signaling pathway involving PI3K/Akt, alphaVbeta3/alphaVbeta5 and MMP-2/-9, and this SSA could be used as an efficient vector to deliver CPT or other cytotoxic agents to target sites for cancer therapy.

The electrophoretically 'slow' and 'fast' forms of the alpha 2-macroglobulin molecule.

PubMed Central

Barrett, A J; Brown, M A; Sayers, C A

1979-01-01

alpha 2-Macroglobulin (alpha 2M) was isolated from human plasma by a four-step procedure: poly(ethylene glyco) fractionation, gel chromatography, euglobulin precipitation and immunoadsorption. No contaminants were detected in the final preparations by electrophoresis or immunoprecipitation. The protein ran as a single slow band in gel electrophoresis, and was designated 'S-alpha 2M'. S-alpha 2M bound about 2 mol of trypsin/mol. Treatment of S-alpha 2M with a proteinase or ammonium salts produced a form of the molecule more mobile in electrophoresis, and lacking proteinase-binding activity (F-alpha 2M). The electrophoretic mobility of the F-alpha 2M resulting from reaction with NH4+ salts was identical with that of proteinase complexes. We attribute the change in electrophoretic mobility of the alpha 2M to a conformation change, but there was no evidence of a change in pI or Strokes radius. Electrophoresis of S-alpha 2M in the presence of sodium dodecylsulphate gave results consistent with the view that the alpha 2M molecule is a tetramer of identical subunits, assembled as a non-covalent pair of disulphide-linked dimers. Some of the subunits seemed to be 'nicked' into two-thires-length and one-third-length chains, however. This was not apparent with F-alpha 2M produced by ammonium salts. F-alpha 2M produced by trypsin showed two new bands attributable to cleavage of the subunit polypeptide chain near the middle. Immunoassays of F-alpha 2M gave 'rockets' 12-29% lower than those with S-alpha 2M. The nature of the interactions between subunits in S-alpha 2M and F-alpha 2M was investigated by treating each form with glutaraldehyde before electrophoresis in the presence of sodium dodecyl sulphate. A much greater degree of cross-linking was observed with the F-alpha 2M, indicating that the subunits interact most closely in this form of the molecule. Exposure of S-alpha 2M to 3 M-urea or pH3 resulted in dissociation to the disulphide-bonded half-molecules; these did not show the proteinase-binding activity characteristic of the intact alpha 2M. F-alpha 2M was less easily dissociated than was S-alpha 2M. S-alpha 2M was readily dissociated to the quarter-subunits by mild reduction, with the formation of 3-4 new thiol groups per subunit. Inact reactive alpha 2M could then be regenerated in high yield by reoxidation of the subunits. F-alpha 2M formed by reaction with a proteinase or ammonium salts was not dissociated under the same conditions, although the interchain disulphide bonds were reduced. If the thiol groups of the quarter-subunits of S-alpha 2M were blocked by carboxymethylation, oxidative reassociation did not occur. Nevertheless treatment of these subunits with methylammonium salts or a proteinase caused the reassembly of half-molecules and intact (F-) tetramers. It is emphasized that F-alpha 2M does not have the properties of a denatured form of the protein... Images Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:91367

alpha-Mannosidosis in the guinea pig: cloning of the lysosomal alpha-mannosidase cDNA and identification of a missense mutation causing alpha-mannosidosis.

PubMed

Berg, Thomas; Hopwood, John J

2002-03-16

alpha-Mannosidosis is a lysosomal storage disorder caused by deficient activity of the lysosomal alpha-mannosidase. We report here the sequencing and expression of the lysosomal alpha-mannosidase cDNA from normal and alpha-mannosidosis guinea pigs. The amino acid sequence of the guinea pig enzyme displayed 82-85% identity to the lysosomal alpha-mannosidase in other mammals. The cDNA of the alpha-mannosidosis guinea pig contained a missense mutation, 679C>T, leading to substitution of arginine by tryptophan at amino acid position 227 (R227W). The R227W allele segregated with the alpha-mannosidosis genotype in the guinea pig colony and introduction of R227W into the wild-type sequence eliminated the production of recombinant alpha-mannosidase activity in heterologous expression studies. Furthermore, the guinea pig mutation has been found in human patients. Our results strongly indicate that the 679C>T mutation causes alpha-mannosidosis and suggest that the guinea pig will be an excellent model for investigation of pathogenesis and evaluation of therapeutic strategies for human alpha-mannosidosis.

The Recalled Childhood Gender Questionnaire-Revised: a psychometric analysis in a sample of women with congenital adrenal hyperplasia.

PubMed

Meyer-Bahlburg, Heino F L; Dolezal, Curtis; Zucker, Kenneth J; Kessler, Suzanna J; Schober, Justine M; New, Maria I

2006-11-01

We administered the 18-item Recalled Childhood Gender Questionnaire-Revised (RCGQ-R), female version, to 147 adult women with congenital adrenal hyperplasia (CAH) representing three different degrees of prenatal androgenization due to 21-hydroxylase deficiency and to non-CAH controls. A principal components analysis generated three components accounting for 46%, 9%, and 6% of the variance, respectively. Corresponding unit-weighted scales (high scores = feminine) were labeled Gender Role (13 items; Cronbach alpha = .91), Physical Activity (3 items; alpha = .64), and Cross-Gender Desire (2 items; alpha = .47). Discriminant validity was demonstrated in terms of highly significant comparisons across the four groups. We conclude that the first 2 RCGQ-R scales show good psychometric qualities, but that the third scale needs to be further evaluated in a sample that includes women with gender identity disorder.

Quantum Dot-Induced Phase Stabilization of ..alpha..-CsPbI3 Perovskite for High-Efficiency Photovoltaics

DOE PAGES

Swarnkar, Abhishek; Marshall, Ashley R.; Sanehira, Erin M.; ...

2016-10-07

Here, we show nanoscale phase stabilization of CsPbI 3 quantum dots (QDs) to low temperatures that can be used as the active component of efficient optoelectronic devices. CsPbI 3 is an all-inorganic analog to the hybrid organic cation halide perovskites, but the cubic phase of bulk CsPbI3 (..alpha..-CsPbI 3) -- the variant with desirable band gap -- is only stable at high temperatures. We also describe the formation of ..alpha..-CsPbI 3 QD films that are phase-stable for months in ambient air. The films exhibit long-range electronic transport and were used to fabricate colloidal perovskite QD photovoltaic cells with an open-circuitmore » voltage of 1.23 volts and efficiency of 10.77%. Furthermore, these devices function as light-emitting diodes with low turn-on voltage and tunable emission.« less

Identification of the functional domain in the transcription factor RTEF-1 that mediates alpha 1-adrenergic signaling in hypertrophied cardiac myocytes.

PubMed

Ueyama, T; Zhu, C; Valenzuela, Y M; Suzow, J G; Stewart, A F

2000-06-09

Cardiac myocytes respond to alpha(1)-adrenergic receptor stimulation by a progressive hypertrophy accompanied by the activation of many fetal genes, including skeletal muscle alpha-actin. The skeletal muscle alpha-actin gene is activated by signaling through an MCAT element, the binding site of the transcription enhancer factor-1 (TEF-1) family of transcription factors. Previously, we showed that overexpression of the TEF-1-related factor (RTEF-1) increased the alpha(1)-adrenergic response of the skeletal muscle alpha-actin promoter, whereas TEF-1 overexpression did not. Here, we identified the functional domains and specific sequences in RTEF-1 that mediate the alpha(1)-adrenergic response. Chimeric TEF-1 and RTEF-1 expression constructs localized the region responsible for the alpha(1)-adrenergic response to the carboxyl-terminal domain of RTEF-1. Site-directed mutagenesis was used to inactivate eight serine residues of RTEF-1, not present in TEF-1, that are putative targets of alpha(1)-adrenergic-dependent kinases. Mutation of a single serine residue, Ser-322, reduced the alpha(1)-adrenergic activation of RTEF-1 by 70% without affecting protein stability, suggesting that phosphorylation at this serine residue accounts for most of the alpha(1)-adrenergic response. Thus, these results demonstrate that RTEF-1 is a direct target of alpha(1)-adrenergic signaling in hypertrophied cardiac myocytes.

Mutant HNF-1{alpha} and mutant HNF-1{beta} identified in MODY3 and MODY5 downregulate DPP-IV gene expression in Caco-2 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu Ning; Laboratory of Neurochemistry, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto; Adachi, Tetsuya

2006-08-04

Dipeptidylpeptidase IV (DPP-IV) is a well-documented drug target for the treatment of type 2 diabetes. Hepatocyte nuclear factors (HNF)-1{alpha} and HNF-1{beta}, known as the causal genes of MODY3 and MODY5, respectively, have been reported to be involved in regulation of DPP-IV gene expression. But, it is not completely clear (i) that they play roles in regulation of DPP-IV gene expression, and (ii) whether DPP-IV gene activity is changed by mutant HNF-1{alpha} and mutant HNF-1{beta} in MODY3 and MODY5. To explore these questions, we investigated transactivation effects of wild HNF-1{alpha} and 13 mutant HNF-1{alpha}, as well as wild HNF-1{beta} and 2more » mutant HNF-1{beta}, on DPP-IV promoter luciferase gene in Caco-2 cells by means of a transient experiment. Both wild HNF-1{alpha} and wild HNF-1{beta} significantly transactivated DPP-IV promoter, but mutant HNF-1{alpha} and mutant HNF-1{beta} exhibited low transactivation activity. Moreover, to study whether mutant HNF-1{alpha} and mutant HNF-1{beta} change endogenous DPP-IV enzyme activity, we produced four stable cell lines from Caco-2 cells, in which wild HNF-1{alpha} or wild HNF-1{beta}, or else respective dominant-negative mutant HNF-1{alpha}T539fsdelC or dominant-negative mutant HNF-1{beta}R177X, was stably expressed. We found that DPP-IV gene expression and enzyme activity were significantly increased in wild HNF-1{alpha} cells and wild HNF-1{beta} cells, whereas they decreased in HNF-1{alpha}T539fsdelC cells and HNF-1{beta}R177X cells, compared with DPP-IV gene expression and enzyme activity in Caco-2 cells. These results suggest that both wild HNF-1{alpha} and wild HNF-1{beta} have a stimulatory effect on DPP-IV gene expression, but that mutant HNF-1{alpha} and mutant HNF-1{beta} attenuate the stimulatory effect.« less

General Subject 1. Report to ICUMSA on the determination of commercial alpha-amylase activity by a spectrophotometric method

USDA-ARS?s Scientific Manuscript database

A report is given on a new industrial method for the determination of the activity or strength of commercial alpha-amylase at a sugarcane factory or refinery, as well as a recommendation. At the present time, the activities or strengths of commercial alpha-amylases cannot be directly compared becau...

Antiapoptotic property of human alpha-synuclein in neuronal cell lines is associated with the inhibition of caspase-3 but not caspase-9 activity.

PubMed

Li, Wenxue; Lee, Michael K

2005-06-01

Abnormalities of alpha-synuclein (alpha-Syn) are mechanistically linked to Parkinson's disease (PD) and other alpha-synucleinopathies. To gain additional insights into the relationships between alpha-Syn expression and cell death, we examined the effects of expressing human alpha-Syn (Hualpha-Syn) variants on the cellular vulnerability to apoptotic stimuli. We show that the expression of wild-type (WT) and A30P mutant, but not A53T mutant, Hualpha-Syn leads to the protection of neuronal cell lines from apoptosis but not necrosis. Significantly, Hualpha-Syn did not protect non-neuronal cell lines from apoptosis. We also show that A53T mutant is a loss of function in regards to the antiapoptotic property since the expression of WT Hualpha-Syn with an excess of A53T mutant Hualpha-Syn leads to protection of the cells from apoptosis. The antiapoptotic property is specific to human alpha-Syn as neither beta-Syn nor mouse alpha-Syn protected cells from apoptosis, and the carboxy-terminal 20 amino acids are required for the antiapoptotic property. Analyses of capase-3 and caspase-9 activation reveal that the antiapoptotic property of Hualpha-Syn in neuronal cell lines is associated with the attenuation of caspase-3 activity without affecting the caspase-9 activity or the levels of cleaved, active caspase-3. We conclude that Hualpha-Syn modulates the activity of cleaved caspase-3 product in neuronal cell lines.

Potentiation by adrenaline of human platelet activation and the inhibition by the alpha-adrenergic antagonist nicergoline of platelet adhesion, secretion and aggregation.

PubMed

Lanza, F; Cazenave, J P; Beretz, A; Sutter-Bay, A; Kretz, J G; Kieny, R

1986-08-01

Adrenaline (1 to 10 microM) can induce the aggregation of human platelets suspended in citrated plasma but does not induce the aggregation of washed human platelets at doses as high as 1 mM, although these platelets respond normally to ADP, PAF-acether, collagen, arachidonic acid, thrombin, the endoperoxide analog U-46619 and the Ca2+ ionophore A23187. Adrenaline (0.5 microM) potentiates the aggregation and secretion induced by all the previous agonists in citrated platelet-rich plasma (cPRP) or in washed platelets. The activation by adrenaline of human platelets is mediated by alpha 2-adrenergic receptors, as demonstrated by inhibition with a series of adrenergic antagonists. The alpha-adrenergic antagonist nicergoline inhibits the activation of human platelets by adrenaline in the following situations: nicergoline inhibits the aggregation and secretion caused by adrenaline in cPRP (IC50 0.22 microM and 0.28 microM respectively); nicergoline inhibits the aggregation and secretion induced by the combination of adrenaline and each aggregating agent listed above in cPRP (IC50 ranging from 0.1 to 2.5 microM) or in washed platelets (IC50 ranging from 0.1 to 0.8 microM); nicergoline inhibits the binding of 3H-yohimbine to washed human platelets (IC50 0.26 microM); the intravenous administration of nicergoline (0.5 mg/kg per day) to patients inhibits significantly the ex vivo response of their platelets to adrenaline in cPRP. High concentrations of nicergoline also inhibit the aggregation and secretion induced by the aggregating agents listed above in cPRP (IC50 range 108 to 670 microM) and in washed platelets (IC50 range 27 to 140 microM) and the adhesion of platelets to collagen-coated surfaces. This latter effect is not mediated through blockade of alpha-adrenoceptors. A possible role of adrenaline in platelet activation in vivo could justify the use of nicergoline (Sermion), an alpha-adrenergic antagonist in combination therapy to prevent arterial thrombosis.

Relative changes in the abundance of branchial Na(+)/K(+)-ATPase alpha-isoform-like proteins in marine euryhaline milkfish (Chanos chanos) acclimated to environments of different salinities.

PubMed

Tang, Cheng-Hao; Chiu, Yu-Huei; Tsai, Shu-Chuan; Lee, Tsung-Han

2009-08-01

Previous studies revealed that upon salinity challenge, milkfish (Chanos chanos), the euryhaline teleost, exhibited adaptive changes in branchial Na(+)/K(+)-ATPase (NKA) activity with different Na(+) and K(+) affinities. Since alteration of activity and ion-affinity may be influenced by changes in different isoforms of NKA alpha-subunit (i.e., the catalytic subunit), it is, thus, intriguing to compare the patterns of protein abundance of three major NKA alpha-isoform-like proteins (i.e., alpha1, alpha2, and alpha3) in the gills of euryhaline milkfish following salinity challenge. The protein abundance of three NKA alpha-isoform-like proteins in gills of milkfish reared in seawater (SW), fresh water (FW), as well as hypersaline water (HSW, 60 per thousand) were analyzed by immunoblotting. In the acclimation experiments, the SW group revealed significantly higher levels of NKA alpha1- and alpha3-like proteins than the FW or HSW group. Time-course experiments on milkfish that were transferred from SW to HSW revealed the abundance of branchial NKA alpha1-like and alpha3-like proteins decreased significantly after 96 and 12 hr, respectively, and no significant difference was found in NKA alpha2-like protein. Furthermore, when fish were transferred from SW to FW, the amounts of NKA alpha1- and alpha3-like proteins was significantly decreased after 96 hr. Taken together, acute and chronic changes in the abundance of branchial NKA alpha1- and alpha3-like proteins may fulfill the requirements of altering NKA activity with different Na(+) or K(+) affinity for euryhaline milkfish acclimated to environments of various salinities. 2009 Wiley-Liss, Inc.

Evaluation of the use of reverse osmosis to eliminate natural radionuclides from water samples.

PubMed

Nieto, Antonio; Palomo, Marta; Ruana, Josep; Peñalver, Alejandra; Aguilar, Carme; Borrull, Francesc

2013-12-01

The objective of drinking water treatment plants (DWTP) is to supply the population with tap water that is in optimal condition and in compliance with water quality regulations. In the DWTP of L'Ampolla (Tarragona, Spain), slightly high values of gross alpha activity and the amount of salts in the raw water have been observed. Conventional treatment has reduced these levels only minimally. This study tested a tertiary treatment based on reverse osmosis is tested in an industrial pilot plant (240 m3/day) The efficiency of this pilot plant to reduce the gross alpha and beta activities and the activity of some individual radioisotopes (U(238), U(234), U(235) and Ra(226)) was tested. Results showed that the elimination of alpha emitters was greater than 90%, whereas the elimination of beta emitters was about 35%. Overall, the data provided evidence that the pilot plant is effective for removing different radionuclides that can be present in the incoming water treated. Therefore, tertiary treatment based on reverse osmosis has a positive effect in water quality.

Discrete microfluidics for the isolation of circulating tumor cell subpopulations targeting fibroblast activation protein alpha and epithelial cell adhesion molecule.

PubMed

Witek, Małgorzata A; Aufforth, Rachel D; Wang, Hong; Kamande, Joyce W; Jackson, Joshua M; Pullagurla, Swathi R; Hupert, Mateusz L; Usary, Jerry; Wysham, Weiya Z; Hilliard, Dawud; Montgomery, Stephanie; Bae-Jump, Victoria; Carey, Lisa A; Gehrig, Paola A; Milowsky, Matthew I; Perou, Charles M; Soper, John T; Whang, Young E; Yeh, Jen Jen; Martin, George; Soper, Steven A

2017-01-01

Circulating tumor cells consist of phenotypically distinct subpopulations that originate from the tumor microenvironment. We report a circulating tumor cell dual selection assay that uses discrete microfluidics to select circulating tumor cell subpopulations from a single blood sample; circulating tumor cells expressing the established marker epithelial cell adhesion molecule and a new marker, fibroblast activation protein alpha, were evaluated. Both circulating tumor cell subpopulations were detected in metastatic ovarian, colorectal, prostate, breast, and pancreatic cancer patients and 90% of the isolated circulating tumor cells did not co-express both antigens. Clinical sensitivities of 100% showed substantial improvement compared to epithelial cell adhesion molecule selection alone. Owing to high purity (>80%) of the selected circulating tumor cells, molecular analysis of both circulating tumor cell subpopulations was carried out in bulk, including next generation sequencing, mutation analysis, and gene expression. Results suggested fibroblast activation protein alpha and epithelial cell adhesion molecule circulating tumor cells are distinct subpopulations and the use of these in concert can provide information needed to navigate through cancer disease management challenges.

Unheated Cannabis sativa extracts and its major compound THC-acid have potential immuno-modulating properties not mediated by CB1 and CB2 receptor coupled pathways.

PubMed

Verhoeckx, Kitty C M; Korthout, Henrie A A J; van Meeteren-Kreikamp, A P; Ehlert, Karl A; Wang, Mei; van der Greef, Jan; Rodenburg, Richard J T; Witkamp, Renger F

2006-04-01

There is a great interest in the pharmacological properties of cannabinoid like compounds that are not linked to the adverse effects of Delta(9)-tetrahydrocannabinol (THC), e.g. psychoactive properties. The present paper describes the potential immuno-modulating activity of unheated Cannabis sativa extracts and its main non-psychoactive constituent Delta(9)-tetrahydrocanabinoid acid (THCa). By heating Cannabis extracts, THCa was shown to be converted into THC. Unheated Cannabis extract and THCa were able to inhibit the tumor necrosis factor alpha (TNF-alpha) levels in culture supernatants from U937 macrophages and peripheral blood macrophages after stimulation with LPS in a dose-dependent manner. This inhibition persisted over a longer period of time, whereas after prolonged exposure time THC and heated Cannabis extract tend to induce the TNF-alpha level. Furthermore we demonstrated that THCa and THC show distinct effects on phosphatidylcholine specific phospholipase C (PC-PLC) activity. Unheated Cannabis extract and THCa inhibit the PC-PLC activity in a dose-dependent manner, while THC induced PC-PLC activity at high concentrations. These results suggest that THCa and THC exert their immuno-modulating effects via different metabolic pathways.

Nicotinic receptor abnormalities in the cerebellar cortex in autism.

PubMed

Lee, M; Martin-Ruiz, C; Graham, A; Court, J; Jaros, E; Perry, R; Iversen, P; Bauman, M; Perry, E

2002-07-01

Autism is a common developmental disorder associated with structural and inferred neurochemical abnormalities of the brain. Cerebellar abnormalities frequently have been identified, based on neuroimaging or neuropathology. Recently, the cholinergic neurotransmitter system has been implicated on the basis of nicotinic receptor loss in the cerebral cortex. Cerebellar cholinergic activities were therefore investigated in autopsy tissue from a series of autistic individuals. The presynaptic cholinergic enzyme, choline acetyltransferase, together with nicotinic and muscarinic receptor subtypes were compared in the cerebellum from age-matched mentally retarded autistic (eight), normal control (10) and non-autistic mentally retarded individuals (11). The nicotinic receptor binding the agonist epibatidine (the high affinity receptor subtype, consisting primarily of alpha3 and alpha4, together with beta2 receptor subunits) was significantly reduced by 40-50% in the granule cell, Purkinje and molecular layers in the autistic compared with the normal group (P < 0.05). There was an opposite increase (3-fold) in the nicotinic receptor binding alpha-bungarotoxin (to the alpha7 subunit) which reached significance in the granule cell layer (P < 0.05). These receptor changes were paralleled by a significant reduction (P < 0.05) and non-significant increase, respectively, of alpha4 and alpha7 receptor subunit immunoreactivity measured using western blotting. Immunohistochemically loss of alpha(4 )reactivity was apparent from Purkinje and the other cell layers, with increased alpha7 reactivity in the granule cell layer. There were no significant changes in choline acetyltransferase activity, or in muscarinic M1 and M2 receptor subtypes in autism. In the non-autistic mentally retarded group, the only significant abnormality was a reduction in epibatidine binding in the granule cell and Purkinje layers. In two autistic cases examined histologically, Purkinje cell loss was observed in multiple lobules throughout the vermis and hemispheres. This was more severe in one case with epilepsy, which also showed vermis folial malformation. The case with less severe Purkinje cell loss also showed cerebellar white matter thinning and demyelination. These findings indicate a loss of the cerebellar nicotinic alpha4 receptor subunit in autism which may relate to the loss of Purkinje cells, and a compensatory increase in the alpha7 subunit. It remains to be determined how these receptor abnormalities are involved in neurodevelopment in autism and what is the relationship to mental function. Since nicotinic receptor agonists enhance attentional function and also induce an elevation in the high affinity receptor, nicotinic therapy in autism may be worth considering.

Salivary Alpha-Amylase Activity Levels in Catatonic Schizophrenia Decrease after Electroconvulsive Therapy.

PubMed

Kanayama, Misako; Miyaoka, Tsuyoshi; Araki, Tomoko; Hayashida, Maiko; Hashioka, Sadayuki; Horiguchi, Jun

2018-01-01

Dysfunction of the autonomic nervous system (ANS) in schizophrenia has been detected by electrophysiological methods, but the underlying mechanisms remain unknown. Several studies have suggested that measuring salivary alpha-amylase activity levels is useful for evaluating the ANS activity and that sAA levels increase in schizophrenia and correlate with Brief Psychiatric Rating Scale (BPRS) scores. However, no study has examined the relationship between sAA activity levels and symptoms of schizophrenia with catatonic state. We present the case of a 59-year-old female with persistent catatonic schizophrenia treated by electroconvulsive therapy. We evaluated the ANS activity by measuring sAA activity levels before and after ECT, and we evaluated her symptoms using the BPRS and Bush-Francis Catatonia Rating Scale (BFCRS). ECT was highly effective and BPRS and BFCRS scores substantially decreased. sAA activity levels decreased from 125 kU/l to 33 kU/l. sAA activity levels could be a potential biomarker of schizophrenia with catatonic state.

X-ray emission on hybird stars: ROSAT observations of alpha Trianguli Australis and iota Aurigae

NASA Technical Reports Server (NTRS)

Kashyap, V.; Rosner, R.; Harnden, F. R., Jr.; Maggio, A.; Micela, G.; Sciortino, S.

1994-01-01

We report on deep ROSAT observations of two Hybrid atmosphere stars, alpha TrA and iota Aur, and our analysis of these observations. We detect high-energy transient phenomena on alpha TrA and consider the implications of this discovery to the atmospheres of Hybrid stars. We detect iota Aur in the high-energy passband of ROSAT, implying the existence of multimillion degree plasma on the star. Our major results include the following: discovery of two large flare events, detected during pointed observations of alpha TrA; the demonstration that the flare emission most likely comes from the giant itself, rather than from a previously unseen low-mass companion star; the demonstration that the plasma characteristics associated with the flares and with the 'quiescent' component are essentially indistinguishable; and that the geometric dimensions of the emitting plasma are considerably smaller than the critical dimension characterizing stable 'hot' coronal loop structures. Our results suggest that alpha TrA does not have any steady X-ray emission consistent with theoretical expectations, and support the argument that Hybrid stars constitute a transitional type of object in which large-scale magnetic dynamo activity ceases, and the dominant spatial scales characterizing coronal structure rapidly decline as such stars evolve across the X-ray 'Dividing Line' in the H-R diagram.

Evaluation of elevated dietary corn fiber from corn germ meal in growing female pigs.

PubMed

Weber, T E; Trabue, S L; Ziemer, C J; Kerr, B J

2010-01-01

To evaluate the effects of dietary hemicellulose from corn on growth and metabolic measures, female pigs (n = 48; initial BW 30.8 kg) were fed diets containing 0 to 38.6% solvent-extracted corn germ meal for 28 d. Increasing the hemicellulose level had no impact on ADG or ADFI, but resulted in a quadratic response (P < 0.03) on G:F. To investigate physiological changes that occur with increased dietary hemicellulose, blood, colon contents, and tissue samples from the liver and intestine were obtained from a subset (n = 16; 8 pigs/treatment) of pigs fed the least and greatest hemicellulose levels. The abundance of phospho-adenosine monophosphate-activated protein kinase (AMPK) and the mitochondrial respiratory protein, cytochrome C oxidase II (COXII) were determined in liver, jejunum, ileum, and colon by Western blotting. The mRNA expression levels of AMPKalpha1, AMPKalpha2, PPAR coactivator 1alpha (PGC1-alpha), PPARgamma2, and sirtuin 1 (Sirt1) were determined in liver and intestinal tissues. When compared with pigs fed the control diet, pigs fed the high hemicellulose diet had increased (P < 0.02) plasma triglycerides, but there was no difference in plasma cholesterol, glucose, or insulin. Absolute and relative liver weights were decreased (P < 0.03) in pigs consuming the high hemicellulose diet. The high-fiber diet led to a tendency (P < 0.12) for decreased liver triglyceride content. In pigs fed the high hemicellulose diet, ileal mucosal alkaline phosphatase activity was increased (P < 0.08) and sucrase activity tended (P < 0.12) to be increased. The high hemicellulose diet had no effect on phospho-AMPK, AMPK mRNA, or colonic VFA, but in pigs consuming the high fiber diet there was a greater (P < 0.05) abundance of COXII in colon tissue. The expression of PGC1-alpha, PPARgamma, or Sirt1 mRNA was not altered by dietary fiber in liver, jejunum, or ileum tissue. In colon tissue from pigs fed the high fiber diet there was an increase (P < 0.09) in Sirt1 mRNA and a trend (P < 0.12) toward increased of PGC1-alpha mRNA. These data suggest that alterations in metabolism involved in adaptation to a diet high in hemicellulose are associated with increased colonic Sirt1 mRNA and COXII expression, indicating an increased propensity for oxidative metabolism by the intestine.

[Acetylcholine activation of alpha-ketoglutarate oxidation in liver mitochondria].

PubMed

Shostakovskaia, I V; Doliba, N M; Gordiĭ, S K; Babskiĭ, A M; Kondrashova, M N

1986-01-01

Activation of alpha-ketoglutarate oxidation in the rat liver mitochondria takes place 15 and 30 min after intraperitoneal injection of acetyl choline. This mediator in doses of 25, 50 and 100 micrograms per 100 g of body weight causes a pronounced stimulation of phosphorylation respiration rate and calcium capacity of mitochondria with alpha-ketoglutarate oxidation. Acetyl choline is found to have a moderate inhibitory action on oxidation of lower (physiological) concentrations of succinate. Its stimulating action on alpha-ketoglutarate oxidation is associated with activation of M-cholinoreceptors; atropine, a choline-blocker, removes completely this effect. It is supposed that alpha-ketoglutarate and succinate are included into the composition of two reciprocal hormonal-substrate nucleotide systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molina-Molina, Jose-Manuel; INSERM, U896, Montpellier, F-34298; Universite Montpellier1, Montpellier, F-34298

Benzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2',4,4'-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4'-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hER{alpha}), and there has been no comprehensive analysis of their potency in a system allowing comparison between hER{alpha} and hER{beta} activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fishmore » origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hER{alpha} and hER{beta} agonists (BP2 > THB > BP1) and displayed a stronger activation of hER{beta} compared with hER{alpha}, the opposite effect to that of estradiol (E{sub 2}). Unlike E{sub 2}, BPs were more active in rainbow trout ER{alpha} (rtER{alpha}) than in hER{alpha} assay. All four BP derivatives showed anti-androgenic activity (THB > BP2 > BP1 > BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ER{beta} versus ER{alpha} activation, support further investigation of their role as endocrine disrupters in humans and wildlife.« less

The metabolic activator FOXO1 binds hepatitis B virus DNA and activates its transcription

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shlomai, Amir, E-mail: amirsh@tasmc.health.gov.il; Institute for Gastroenterology and Liver disease, Tel-Aviv Sourasky Medical Center, 6 Weizmann street, Tel-Aviv; Shaul, Yosef

2009-04-17

Hepatitis B virus (HBV) is a small DNA virus that targets the liver and infects humans worldwide. Recently we have shown that the metabolic regulator PGC-1{alpha} coactivates HBV transcription thereby rendering the virus susceptible to fluctuations in the nutritional status of the liver. PGC-1{alpha} coactivation of HBV is mediated through the liver-enriched nuclear receptor HNF4{alpha} and through another yet unknown transcription factor(s). Here we show that the forkhead transcription factor FOXO1, a known target for PGC-1{alpha} coactivation and a central mediator of glucose metabolism in the liver, binds HBV core promoter and activates its transcription. This activation is further enhancedmore » in the presence of PGC-1{alpha}, implying that FOXO1 is a target for PGC-1{alpha} coactivation of HBV transcription. Thus, our results identify another key metabolic regulator as an activator of HBV transcription, thereby supporting the principle that HBV gene expression is regulated in a similar way to key hepatic metabolic genes.« less

The water avoidance stress induces bladder pain due to a prolonged alpha1A adrenoceptor stimulation.

PubMed

Matos, Rita; Serrão, Paula; Rodriguez, Larissa; Birder, Lori Ann; Cruz, Francisco; Charrua, Ana

2017-08-01

Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) remains an elusive disease with the cause for the pain unclear. BPS/IC patients present increased sympathetic activity and high levels of urinary noradrenaline. At the experimental level, it has been shown that chronic adrenergic stimulation produces pain and bladder changes through an alpha 1A adrenoceptor mediated mechanism. Water avoidance stress (WAS) in rodents reproduces signs of nociception and bladder changes seen in BPS/IC patients. In this study, we explore the possible role of alpha 1A adrenoceptor in bladder pain and morphological changes. WAS was induced in a group of female Wistar rats. A separate WAS group received 0.2 mg/kg day silodosin (WAS + S). Lower abdominal pain was determined by performing sensitivity to Von Frey filaments. Bladder reflex activity was determined by cystometry in anaesthetised animals. Urine was collected for noradrenaline quantification by HPLC. Bladders were harvested and stained with Haematoxylin-eosin (to analyse urothelial morphology and to determine the disruption of surface umbrella cells) or with Toluidine Blue 0.1% to analyse mast cell infiltration. WAS increased urinary noradrenaline level and bladder frequency and decreased mechanical pain threshold, which was reversed by silodosin. WAS induced lymphocytic and mast cells infiltration in the mucosa and mild urothelial disruption, which was absent in WAS + S group. Alpha 1A adrenoceptor stimulation has an important role in the appearance of bladder pain in rats. Since BPS/IC patients present high levels of noradrenaline, alpha 1A stimulation may be an additional trigger for bladder dysfunction presented by these patients. Further studies will determine the clinical relevance of this finding in the treatment of BPS/IC patients.

An isozyme of acid alpha-glucosidase with reduced catalytic activity for glycogen.

PubMed

Beratis, N G; LaBadie, G U; Hirschhorn, K

1980-03-01

Both the common and a variant isozyme of acid alpha-glucosidase have been purified from a heterozygous placenta with CM-Sephadex, ammonium sulfate precipitation, dialysis, Amicon filtration, affinity chromatography by Sephadex G-100, and DEAE-cellulose chromatography. Three and two activity peaks, from the common and variant isozymes, respectively, were obtained by DEAE-cellulose chromatography using a linear NaCl gradient. The three peaks of activity of the common isozyme were eluted with 0.08, 0.12, and 0.17 M NaCl, whereas the two peaks of the variant, with 0.01 and 0.06 M NaCl. The pH optimum and thermal denaturation at 57 degrees C were the same in all enzyme peaks of both isozymes. Rabbit antiacid alpha-glucosidase antibodies produced against the common isozyme were found to cross-react with both peaks of the variant isozyme. The two isozymes shared antigenic identity and had similar Km's with maltose as substrate. Normal substrate saturation kinetics were observed with the common isozyme when glycogen was the substrate, but the variant produced an S-shaped saturation curve indicating a phase of negative and positive cooperativity at low and high glycogen concentrations, respectively. The activity of the variant was only 8.6% and 19.2% of the common isozyme when assayed with nonsaturating and saturating concentrations of glycogen, respectively. A similar rate of hydrolysis of isomaltose by both isozymes was found indicating that the reduced catalytic activity of the variant isozyme toward glycogen is not the result of a reduced ability of this enzyme to cleave the alpha-1,6 linkages of glycogen.

SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Tae Rim; Lee, Hee Min; Lee, So Yong

Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confersmore » resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.« less

Immunostimulatory effects of natural human interferon-alpha (huIFN-alpha) on carps Cyprinus carpio L.

PubMed

Watanuki, Hironobu; Chakraborty, Gunimala; Korenaga, Hiroki; Kono, Tomoya; Shivappa, R B; Sakai, Masahiro

2009-10-15

Human interferon-alpha (huIFN-alpha) is an important immunomodulatory substance used in the treatment and prevention of numerous infectious and immune-related diseases in animals. However, the immunostimulatory effects of huIFN-alpha in fish remain to be investigated. In the current study, the immune responses of the carp species Cyprinus carpio L. to treatment with huIFN-alpha were analyzed via measurement of superoxide anion production, phagocytic activity and the expression of cytokine genes including interleukin-1beta, tumor necrosis factor-alpha and interleukin 10. Low doses of huIFN-alpha were administered orally once a day for 3 days, and sampling was carried out at 1, 3 and 5 days post-treatment. Our results indicate that a low dose of huIFN-alpha significantly increased phagocytic activity and superoxide anion production in the carp kidney. The huIFN-alpha-treated fish also displayed a significant upregulation in cytokine gene expression. The current study demonstrates the stimulatory effects of huIFN-alpha on the carp immune system and highlights the immunomodulatory role of huIFN-alpha in fish.

A pro-inflammatory role of deubiquitinating enzyme cylindromatosis (CYLD) in vascular smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shuai; Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC 29208; Lv, Jiaju

2012-03-30

Highlights: Black-Right-Pointing-Pointer Cyld deficiency suppresses pro-inflammatory phenotypic switch of VSMCs. Black-Right-Pointing-Pointer Cyld deficiency inhibits MAPK rather than NF-kB activity in inflamed VSMCs. Black-Right-Pointing-Pointer CYLD is up-regulated in the coronary artery with neointimal hyperplasia. -- Abstract: CYLD, a deubiquitinating enzyme (DUB), is a critical regulator of diverse cellular processes, ranging from proliferation and differentiation to inflammatory responses, via regulating multiple key signaling cascades such as nuclear factor kappa B (NF-{kappa}B) pathway. CYLD has been shown to inhibit vascular lesion formation presumably through suppressing NF-{kappa}B activity in vascular cells. However, herein we report a novel role of CYLD in mediating pro-inflammatory responsesmore » in vascular smooth muscle cells (VSMCs) via a mechanism independent of NF-{kappa}B activity. Adenoviral knockdown of Cyld inhibited basal and the tumor necrosis factor alpha (TNF{alpha})-induced mRNA expression of pro-inflammatory cytokines including monocyte chemotactic protein-1 (Mcp-1), intercellular adhesion molecule (Icam-1) and interleukin-6 (Il-6) in rat adult aortic SMCs (RASMCs). The CYLD deficiency led to increases in the basal NF-{kappa}B transcriptional activity in RASMCs; however, did not affect the TNF{alpha}-induced NF-{kappa}B activity. Intriguingly, the TNF{alpha}-induced I{kappa}B phosphorylation was enhanced in the CYLD deficient RASMCs. While knocking down of Cyld decreased slightly the basal expression levels of I{kappa}B{alpha} and I{kappa}B{beta} proteins, it did not alter the kinetics of TNF{alpha}-induced I{kappa}B protein degradation in RASMCs. These results indicate that CYLD suppresses the basal NF-{kappa}B activity and TNF{alpha}-induced I{kappa}B kinase activation without affecting TNF{alpha}-induced NF-{kappa}B activity in VSMCs. In addition, knocking down of Cyld suppressed TNF{alpha}-induced activation of mitogen activated protein kinases (MAPKs) including extracellular signal-activated kinases (ERK), c-Jun N-terminal kinase (JNK), and p38 in RASMCs. TNF{alpha}-induced RASMC migration and monocyte adhesion to RASMCs were inhibited by the Cyld knockdown. Finally, immunochemical staining revealed a dramatic augment of CYLD expression in the injured coronary artery with neointimal hyperplasia. Taken together, our results uncover an unexpected role of CYLD in promoting inflammatory responses in VSMCs via a mechanism involving MAPK activation but independent of NF-{kappa}B activity, contributing to the pathogenesis of vascular disease.« less

High energy phosphate transfer by NDPK B/Gbetagammacomplexes--an alternative signaling pathway involved in the regulation of basal cAMP production.

PubMed

Hippe, Hans-Joerg; Wieland, Thomas

2006-08-01

The activation of heterotrimeric G proteins induced by G protein coupled receptors (GPCR) is generally believed to occur by a GDP/GTP exchange at the G protein alpha -subunit. Nevertheless, nucleoside diphosphate kinase (NDPK) and the beta-subunit of G proteins (Gbeta) participate in G protein activation by phosphate transfer reactions leading to the formation of GTP from GDP. Recent work elucidated the role of these reactions. Apparently, the NDPK isoform B (NDPK B) forms a complex with Gbetagamma dimers in which NDPK B acts as a histidine kinase phosphorylating Gbeta at His266. Out of this high energetic phosphoamidate bond the phosphate can be transferred specifically onto GDP. The formed GTP binds to the G protein alpha-subunit and thus activates the respective G protein. Evidence is presented, that this process occurs independent of the classical GPCR-induced GTP/GTP exchange und thus contributes, e.g. to the regulation of basal cAMP synthesis in cells.

Dysregulation of glucocorticoid metabolism in murine obesity: comparable effects of leptin resistance and deficiency.

PubMed

Livingstone, Dawn E W; Grassick, Sarah L; Currie, Gillian L; Walker, Brian R; Andrew, Ruth

2009-05-01

In obese humans, metabolism of glucocorticoids by 11 beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) and A-ring reduction (by 5 alpha- and 5 beta-reductases) is dysregulated in a tissue specific manner. These changes have been recapitulated in leptin resistant obese Zucker rats but were not observed in high-fat fed Wistar rats. Recent data from mouse models suggest that such discrepancies may reflect differences in leptin signalling. We therefore compared glucocorticoid metabolism in murine models of leptin deficiency and resistance. Male ob/ob and db/db mice and their respective littermate controls (n=10-12/group) were studied at the age of 12 weeks. Enzyme activities and mRNA expression were quantified in snap-frozen tissues. The patterns of altered pathways of steroid metabolism in obesity were similar in ob/ob and db/db mice. In liver, 5 beta-reductase activity and mRNA were increased and 11 beta-HSD1 decreased in obese mice, whereas 5 alpha-reductase 1 (5 alpha R1) mRNA was not altered. In visceral adipose depots, 5 beta-reductase was not expressed, 11 beta-HSD1 activity was increased and 5 alpha R1 mRNA was not altered in obesity. By contrast, in subcutaneous adipose tissue 11 beta-HSD1 and 5 alpha R1 mRNA were decreased. Systematic differences were not found between ob/ob and db/db murine models of obesity, suggesting that variations in leptin signalling through the short splice variant of the Ob receptor do not contribute to dysregulation of glucocorticoid metabolism.