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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evidence from psychiatric patients has suggested that depressive affect may coincide with a decrement in the functioning of the right cerebral hemisphere. We have observed that college students who reported greater depression also reported less vivid imagery. Students undergoing experimental induction of depressive and euphoric moods in the laboratory showed an auditory attentional bias and impaired imagery during the depression condition, while their arithmetic task performance was unchanged. A second mood-induction experiment indicated a depressed mood to be characterized by asymmetrical EEG activation over the frontal lobes, with relatively greater activity in the right frontal region. These observations suggest that anterior regions of the brain may modulate the differential effects of emotional arousal on the information-processing capacities of the cerebral hemispheres.
Arch Gen Psychiatry 1981 Feb
PMID:Right frontal lobe activation and right hemisphere performance. Decrement during a depressed mood. 721 43

Background Cl channels in neurons and skeletal muscle are significantly permeable for alkali cations when tested with asymmetrical concentrations of the same salt. Both anion and cation permeation were proposed to require binding of an alkali cation with the pore (Franciolini, F., and W. Nonner. 1987. Journal of General Physiology. 90:453-478). We tested this hypothesis by bilaterally substituting large alkali cations for Na and found no significant changes of unitary conductance at 300 mM symmetrical concentrations. In addition, all organic cations examined were permeant in a salt gradient test (1,000 mM internal@300 mM external), including triethanolamine, benzyltrimethylamine, and bis-tris-propane (BTP, which is divalent at the tested pH of 6.2). Inward currents were detected following substitution of internal NaCl by the Na salts of the divalent anions of phosphoric, fumaric, and malic acid. Zero-current potentials in gradients of the Na and BTP salts of varied anions (propionate, F, Br, nitrate) that have different permeabilities under bi-ionic conditions, were approximately constant, as if the permeation of either cation were coupled to the permeation of the anion. These results rule out our earlier hypothesis of anion permeation dependent on a bound alkali cation, but they are consistent with the idea that the tested anions and cations form mixed complexes while traversing the Cl channel.
J Gen Physiol 1994 Oct
PMID:Anion-cation interactions in the pore of neuronal background chloride channels. 783 38

Complexity is proposed as an important psychological factor in search and segregation tasks. Displays were presented with target and nontarget areas that were each built up of one type of randomly rotated micropatterns. We manipulated experimentally (a) the complexity of the target elements, as measured by Garner's (1970) invariance criterion; (b) the complexity of the target region; (c) the complexity of the nontargets; and (d) the number of elements within a target region. The main result is that detectability increases when the within-region complexity of the target and the nontarget regions decreases. Furthermore, interactions between the target and nontarget areas affect detectability too: We found that search asymmetry is produced by the asymmetrical effect of complexity when target and nontarget areas are interchanged.
J Gen Psychol 1994 Jan
PMID:Visual search and segregation as a function of display complexity. 802 32

In the present study, we investigated how 3- and 4-year-old children perceived mirror-image stimuli traced on their foreheads. First, the subjects were taught matching-to-sample tasks with symmetrically shaped and asymmetrically shaped figures (called mirror-image stimuli) on cards. Then the subjects were taught cutaneous perception of a figure traced by the experimenter's finger on the forehead. Last, the subjects were tested with mirror-image stimuli in cutaneous perception tasks. The results of these experiments indicated that the subjects who could discriminate the mirror-image stimuli could also perceive asymmetrical stimuli as mirror reversals.
J Gen Psychol 1994 Apr
PMID:Cutaneous pattern perception on foreheads in 3- and 4-year-old children. 808 71

A digit memory task and a delayed visual aiming task were used in a test of resource capacity theories. These tasks were run either singly, with short- or long-retention intervals, or in pairs. In the dual-task conditions, the short version of one was inserted into the longer version of the other. Delay by itself had no effect on retention, but the dual-task combinations showed asymmetrical interference: Inserting verbal memory into the visual-motor delay had little effect on either task, but inserting the motor task into the verbal retention interval disrupted both. These results thus support neither single nor multiple resource models, but can be explained with reference to component processes in working memory.
J Gen Psychol 1993 Jul
PMID:Sharing verbal and visuospatial resources in working memory. 813 94

The aim of this study was to assess the prevalence of hearing loss among people aged 65 years and over and to offer hearing aids where necessary. The study was carried out in a large health centre practice in Birmingham with a computerized record system. All patients aged 65 years, and a 20% random sample of patients aged 66 years and over were invited for interview. They were questioned about hearing loss and examined audiometrically. All patients with a hearing loss in the better ear of 35 decibels or more over the speech frequencies (0.5-4 kHz) were offered a hearing aid. A total of 322 patients attended (72% of those invited) and of these 34 patients already had a hearing aid. A further 142 patients were identified for whom an aid was recommended and 69 of these accepted. The acceptance rate was higher among men than women (57% compared with 43%). Sixty one patients (19% of those screened) had an asymmetrical hearing loss and of these 24 required consultant assessment; none had serious underlying pathology. There is a large unmet need for hearing aid provision. Simple audiometric assessment in health centres provides an opportunity to meet this need.
Br J Gen Pract 1993 Oct
PMID:Prevalence of hearing loss among people aged 65 years and over: screening and hearing aid provision. 826 Feb 17

The whole cell configuration of the patch clamp technique was used to investigate the mechanism underlying rectification of the isoproterenol-activated chloride (Cl-) current in isolated guinea pig ventricular myocytes. When extracellular Cl- was replaced with either bromide (Br-), glutamate (Glut), iodide (I-), isethionate (Iseth), or nitrate (NO3-), the magnitude of the shift in reversal potential of the macroscopic current suggested the following selectivity sequence: NO3- > Br- > or = Cl- > or = I- > Iseth > or = Glut. This information was used to investigate the role of permeant ions in rectification of this current. Consistent with previous observations, when the concentration of intracellular Cl- (Cli-) was less than the concentration of extracellular Cl- (Clo-) (40 mM Cli-/150 mM Clo-) the current exhibited outward rectification, but when Cli- was increased to equal that outside (150 Cli-/150 Clo-), the current no longer rectified. Rectification in the presence of asymmetrical concentrations of permeant ions on either side of the membrane is predicted by constant field theory, as described by the Goldman-Hodgkin-Katz current equation. However, when the Cl- gradient was reversed (150 Cli-/40 Clo-) the current did not rectify in the opposite direction, and in the presence of lower symmetrical concentrations of Cl- inside and out (40 Cli-/40 Clo-), outward rectification did not disappear. Reducing Cli- by equimolar replacement with glutamate caused a concentration dependent increase in the degree of rectification. However, when Cli- was replaced with more permeant anions (NO3- and Br-), rectification was not observed. These results can be explained by a single binding site model based on Eyring rate theory, indicating that rectification is a function of the concentration and the permeability of the anions in the intracellular solution.
J Gen Physiol 1993 Nov
PMID:On the mechanism of rectification of the isoproterenol-activated chloride current in guinea-pig ventricular myocytes. 830 Dec 61

The existence of a high-conductance voltage sensitive chloride channel in BC3H1 myoblasts is documented. The conductance of the channel in symmetrical 150 mmol/l sodium chloride is around 400 pS. The probability of the channel being in the open state decreases with increasing of the imposed voltage from holding potential (0 mV) in both the depolarizing and the hyperpolarizing direction respectively. The bell-shaped open probability plot is asymmetrical, and can be fitted by two Boltzmann equations with different Vh and kn constants; the fitted values were -53 mV and -8.4 respectively for the negative side and +41 mV and +10.2 for the right side. When the unit Cl currents to rectangular pulses are summated the resulting total ionic Cl current shows relaxation, which increases with the amplitude of the pulse. The activation as well as the shape of the current can be significantly influenced by varying the amplitude and the direction of prepulses or holding potential. The high-conductance Cl channel shows several substrates (at least four with amplitudes of around 100 pS); frequently accompanied by flickerings.
Gen Physiol Biophys 1993 Apr
PMID:High-conductance chloride channels in BC3H1 myoblasts. 840 20

The effects of varying pH and ionic strength on the force-velocity relations and tension transients of skinned rabbit skeletal muscle were studied at 1-2 degrees C. Both decreasing pH from 7.35 to 6.35 and raising ionic strength from 125 to 360 mM reduced isometric force by about half and decreased sarcomere stiffness by about one-fourth, so that the stiffness/force ratio was increased by half. Lowering pH also decreased maximum shortening velocity by approximately 29%, while increasing ionic strength had little effect on velocity. These effects on velocity were correlated with asymmetrical effects on stiffness. The increase in the stiffness/force ratio with both interventions was manifest as a greater relative force change associated with a sarcomere length step. This force difference persisted for a variable time after the step. At the high ionic strength the force difference was long-lasting after stretches but relaxed quickly after releases, suggesting that the structures responsible would not impose much resistance to steady-state shortening. The opposite was found in the low pH experiments. The force difference relaxed quickly after stretches but persisted for a long time after releases. Furthermore, this force difference reached a constant value of approximately 8% of isometric force with intermediate sizes of release, and was not increased with larger releases. This value was almost identical to the value of an internal load that would be sufficient to account for the reduction in maximum velocity seen at the low pH. The results are interpreted as showing that both low pH and high ionic strength inhibit the movement of crossbridges into the force-generating parts of their cycle after they have attached to the actin filaments, with very few other effects on the cycle. The two interventions are different, however, in that detained bridges can be detached readily by shortening when the detention is caused by high ionic strength but not when it is caused by low pH.
J Gen Physiol 1993 Apr
PMID:High ionic strength and low pH detain activated skinned rabbit skeletal muscle crossbridges in a low force state. 850 25

1. The present experiments were designed to investigate the effect of long-term oral nicotine (10 mg/200 ml/kg/day for 7 weeks) on the intimal hyperplasia after endothelial removal of the rabbit carotid artery. 2. The plasma concentrations of nicotine were determined to be 11.7-12.5 ng/ml during the term of administration and corresponded to the plasma levels in human smokers. 3. Six weeks after the endothelial removal, light microscopy revealed a marked intimal hyperplasia. Administration of nicotine tended to accelerate the intimal hyperplasia, which was estimated by comparing the histological findings, DNA content and wet weight of the vessel wall. 4. Acetylcholine- and A23187-induced endothelium-dependent relaxations were greatly impaired in the hyperplastic artery strips. The impairment of relaxations tended to be accelerated in the nicotine group. Sodium nitroprusside-induced relaxation was not different between the control and the hyperplastic artery strips and remained unaffected in the nicotine group. 5. The concentrations of endogenous nitric oxide (NO) synthesis inhibitors, NG-monomethyl-L-arginine (L-NMMA) and asymmetrical NG,NG-dimethyl-L-arginine (ADMA) were significantly more increased in the regenerated endothelial cells compared with those in the control endothelial cells. The concentrations of L-NMMA and ADMA in the regenerated endothelial cells were significantly increased by as much as 1.3 x 10(-6) and 5.6 x 10(-7) M, respectively, in the nicotine group. 6. Immunoreactive endothelin-1 was significantly increased in the hyperplastic vessel wall (2.4 times that of the control) in 6 weeks. Administration of nicotine tended to increase the level. 7. It seems possible to assume from these results that, although, under the present experimental conditions, nicotine exhibited a tendency to accelerate the intimal hyperplasia after endothelial removal, the longer exposure to nicotine or a higher dose of the agent or both would significantly accelerate the intimal hyperplasia through the enhanced impairment of endothelium-derived relaxing factor/ NO production, which might be brought about by the enhanced increases in L-NMMA and ADMA concentrations, and the enhanced increase in endothelin-1 in the vessel wall.
Gen Pharmacol 1997 May
PMID:Effect of nicotine on the intimal hyperplasia after endothelial removal of the rabbit carotid artery. 918 97


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