Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Type III Purkinje cells (P-cells), which are excited with both directions of horizontal rotation, are found in high numbers in the frog auricular lobe and adjacent cerebellar areas. To examine the mechanisms underlying these responses, recordings were made from P-cells in curarized animals during rotational stimulation of the horizontal canals. The horizontal canal input to these cells was then modified unilaterally by VIIth nerve section, intraperilymphatic injection of local anesthetic, or by caloric stimulation. Control recordings were also obtained from peripheral canal neurons. Type III responses were abolished by unilateral lesions or reversible blockage of the VIIIth nerve with local anesthetic. The remaining responses were attributable only to the unaffected horizontal canal, ie. only type II or type I responses were observed upon interruption of the ipsi-or contralateral nerve, respectively. The level of spontaneous activity of cerebellar input fibers was low and during rotation produced 'cell silencing' response waveform asymmetries (facilitation greater than disfacilitation). When the level of peripheral resting activity was increased (warm water irrigation), thereby increasing horizontal canal response symmetry, type III responses were reduced in magnitude or abolished. Conversely, cold water irrigation, which decreases the resting rate and response symmetry of input fibers, enhanced type III response magnitudes. On the basis of these results, it is suggested that type III responses result from the fact that single P-cells receive a facilitatory input from both horizontal canals. Since these inputs are 180 degrees phase-reversed and their response waveforms asymmetrical, their resulting postsynaptic effect is a net excitation during both portions of the stimulus cycle.
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PMID:A mechanism for type III vestibular responses of frog cerebellar Purkinje cells. 30 75

Nasal airway resistance (NAR) is normally asymmetrical due to the nasal cycle. The aims of this study were to determine the degree of this asymmetry in healthy subjects and those with acute rhinitis associated with common cold, and to investigate how the administration of a topical nasal decongestant (xylometazoline) influenced the asymmetry in NAR. Unilateral NAR was measured by active anterior rhinomanometry, and was shown to be asymmetrical in both healthy subjects and those suffering with acute rhinitis. The asymmetry in NAR was greater in those with acute rhinitis than in the healthy group, with a ratio between "high" and "low" sides of 2.3:1 in the rhinitis group compared to a ratio of 1.7:1 in the healthy subjects. Administration of a topical nasal decongestant caused a significant decrease in total NAR in both groups and abolished the asymmetry in NAR in the healthy subjects (ratio is 1:1 after decongestion). However, significant asymmetry of NAR was still present in the group with acute rhinitis following the administration of decongestant (ratio is 1.5:1 after decongestion). These findings show that the normal asymmetry in NAR was increased during acute rhinitis associated with common cold, and that in healthy subjects (but not in those with rhinitis) the asymmetry was abolished by administration of a topical decongestant. The results are discussed in relation to nasal sympathetic tone and nasal blood flow.
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PMID:Nasal airflow asymmetry and the effects of a topical nasal decongestant. 128 24

DNA preparations obtained from 122 species of fishes, 5 species of amphibians, and 13 species of reptiles were investigated in their compositional properties by analytical equilibrium centrifugation in CsCl density gradients. These species represented 21 orders of Osteichthyes, 3 orders of Chondrichthyes, 2 orders of amphibians, and 3 orders of reptiles. Modal buoyant densities of fish DNAs ranged from 1.696 to 1.707 g/cm3, the vast majority of values falling, however, between 1.699 and 1.704 g/cm3, which is the range covered by the DNAs of amphibians and reptiles. In all cases, DNA bands in CsCl were only weakly asymmetrical and only very rarely were accompanied by separate satellite bands (mostly on the GC-rich side). Intermolecular compositional heterogeneities were low in the vast majority of cases, and, like CsCl band asymmetries, at least partially due to cryptic or poorly resolved satellites. The present findings indicate, therefore, that DNAs from cold-blooded vertebrates are characterized by a number of common properties, namely a very wide spectrum of modal buoyant densities, low intermolecular compositional heterogeneities, low CsCl band asymmetries, and, in most cases, small amounts of satellite DNAs. In the case of fish DNAs a negative correlation was found between the GC level and the haploid size (c value) of the genome. If polyploidization is neglected, this phenomenon appears to be mainly due to the fact that increases and decreases in GC are associated with contraction and expansion phenomena, respectively, of intergenic noncoding sequences, which are GC poor relative to coding sequences.
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PMID:Compositional patterns in the nuclear genome of cold-blooded vertebrates. 212 75

Nasal congestion associated with the common cold or allergy is associated with a decreased sensitivity of the sense of smell. This study was designed to detect any relationship between nasal resistance to airflow and the ability to detect odors presented to the nose. In particular we were interested to determine if the asymmetrical nasal resistance to airflow associated with the nasal cycle influenced nasal thresholds to menthol which is detected by trigeminal nerves and vanillin which is detected by olfactory nerves. Nasal resistance to airflow and the thresholds for L-menthol and vanillin were measured for each nasal passage in 17 normal volunteer subjects. Nasal resistance to airflow was asymmetrical due to the nasal cycle with a resistance on the high side of 0.94 +/- 0.15 Pa/cm3 s (mean +/- S.E. n = 17). and 0.48 +/- 0.04 Pa/cm3 s on the low side. The range of unilateral nasal resistances varied from 0.31-2.55 Pa/cm3 s. Despite these variations in nasal resistance to airflow no relationship was found between nasal resistance to airflow and thresholds for menthol or vanillin. Since threshold and nasal resistance are not related in normal subjects this may indicate that it is not the level of nasal congestion that affects the sense of smell in nasal infection and allergy, but some other factor related to the inflammatory response of the nasal mucosa.
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PMID:Olfactory and trigeminal thresholds and nasal resistance to airflow. 281 41

Nonpigmenting fixed drug eruption is a distinctive, clinically recognizable entity. Characteristically, the lesions are large, symmetrical, well-circumscribed tender erythematous plaques that suddenly appear and reappear in exactly the same sites. They fade without pigmentation or any other trace over a 2- to 3-week period. Management requires recognition and avoidance of the responsible drug. Acute attacks may call for short-term systemic steroid therapy. Three examples of this overlooked reaction pattern are presented. The first case was associated with Night-Time cold formula and was proved by specific component challenge to be due to d-pseudoephedrine hydrochloride. The second case was due to PediaCare 3 Children's Cough Syrup, also containing d-pseudoephedrine hydrochloride. The third case was due to Visine eye drops, which contain an imidazole derivative, tetrahydrozoline. There is a need to increase our awareness that fixed drug eruptions come in two very different clinical forms: the classic pigmenting asymmetrical form, and the nonpigmenting symmetrical erythematous plaque form, in both of which the patient will give a history of the eruption being recurrent in the same area.
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PMID:Nonpigmenting fixed drug eruption as a distinctive reaction pattern: examples caused by sensitivity to pseudoephedrine hydrochloride and tetrahydrozoline. 1221 20

We have presented the results of experiments with IS903- and IS10- derived transposons that have led us to the following conclusions: The predominant mechanism of transpositional recombination of these IS elements is a donor-suicide process that results intermolecularly in a simple IS insertion. This process presumably involves little or no replication of the IS. Intramolecular transposition by this process normally results in nonviable products. However, in the particular situation where the transpositional target lies within the transposon, viable products are obtained; these are deletions and deletion-inversions. Deletions between an IS and a target lying outside the element (the conventional "adjacent deletion") occur by a fully replicative process analogous to the formation of cointegrate molecules in intermolecular transposition. The ability of an IS to promote adjacent deletions correlates closely with its ability to fuse replicons into a cointegrate. Before transposition can occur, a complex of the transposase and both IS ends is probably formed. Requirement for such a pretranspositional complex is suggested by the effect on transpositional frequency of changing the distance between the ends. Our results do not support any of the asymmetrical models for transposition. They are, however, compatible with a modified version of the symmetric model proposed by Shapiro (1979). It is interesting to note the similarity between the structures generated by intramolecular simple transposition of an inverse transposon and the circular structures apparently formed by retroviral and copia autointegrative transposition. Shoemaker et al. (1981a,b) and Flavell and Ish-Horowicz (1983) have characterized circular molecules from retrovirally infected cells and Drosophila tissue-culture cells, respectively. The structures of some of the circular molecules resemble deletions and deletion-inversions (Fig. 3B). To our knowledge, a circular species containing two long terminal repeats (LTRs) and an adjacent deletion, which we predict could only occur by a fully replicative process given the similarity in geometry of an LTR to an IS, have not been found. It would appear, then, that the molecule containing two LTRs acts as an inverse transposon, integrating into itself. Shoemaker et al. (1981b) and Flavell and Ish-Horowicz (1983) have also suggested that these products arise from molecules containing two LTRs. We suggest that the two inside LTR ends interact in a conservative, intramolecular, simple transpositionlike event.
Cold Spring Harb Symp Quant Biol 1984
PMID:Replicative and conservative transpositional recombination of insertion sequences. 609 40

An asymmetrical LH-RH distribution in rat hypothalamus has been found. In Wistar rats LH-RH content in the right hypothalamus exceeds that in the left one; in albino rats a contrary distribution is observed. LH-RH lateralization changes during a 24-h period. Unilateral castration or cold stress lead to a shift in LH-RH distribution in the hypothalamus.
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PMID:Lateralization of LH-RH in rat hypothalamus. 636 92

Transcutaneous video microscopy opens a way to measure capillary red blood cell speed, to analyzed transcapillary diffusion and pericapillary distribution of Na-fluorescein injected i.v. and to depict the superficial lymphatic capillaries by subepidermal microinjection of FITC-labelled dextran in human skin. The dynamic phenomena may be quantitiated by video densitometers provided the information is stored on video tape. Already, some physiological and clinical data have been obtained. The velocity pattern of erythrocytes in nailfold capillaries is continuous or intermittent with flow stops. Standardized cold provocation tests are useful to evaluate Raynaud's disease. In patients with scleroderma the transcapillary passage of Na-fluorescein is increased, the physiological pericapillary halo partially destroyed and the interstitial distribution of the dye asymmetrical. In primary lymphedema the lymphatic network filled from the deposit of fluorescent dextran extends much more than in healthy controls. Pathological lymphatic microvessels occur.
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PMID:[New ways of studying the cutaneous microcirculation in clinical medicine (author's transl)]. 719 91

Periportal and perivenous hepatocytes were isolated from rats subjected to different treatments that induce (starvation, cold exposure) or depress (refeeding after starvation) hepatic fatty acid oxidation. These experiments were designed to determine factors that may be involved in creating and maintaining the asymmetrical distribution of this metabolic pathway in the acinus of the liver. The uneven distribution of mitochondrial [14C]-palmitate oxidation within the acinus (i) was very flexible and changed markedly with the physiological status of the animal (periportal/perivenous ratio: 1.5, 2.0, 1.0 and 0.4 for fed, starved, refed and cold-exposed animals respectively), (ii) coincided with a similar zonation of carnitine palmitoyltransferase I activity in fed as well as in cold-exposed animals, (iii) was paralleled by a comparable zonation of mitochondrial 3-hydroxy-3-methyl-glutaryl-CoA synthase activity in starved animals, and (iv) was not determined by zonal differences in any of the following parameters: sensitivity of carnitine palmitoyltransferase I to malonyl-CoA, intracellular concentration of malonyl-CoA, fatty acid synthesizing capacity, acetyl-CoA carboxylase activity, fatty acid synthase activity or relative content of the two hepatic acetyl-CoA carboxylase isoforms. Unlike mitochondrial oxidation, peroxisomal [14C]palmitate oxidation was always zonated towards the perivenous zone of the liver irrespective of the physiological status of the animal. The data presented show that changes in the acinar distribution of mitochondrial long-chain fatty acid oxidation involve specific long-term mechanisms under different physiological conditions.
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PMID:Flexibility of zonation of fatty acid oxidation in rat liver. 748 41

The effects of left, right or bilateral depletion of the mesocortical dopamine innervation (medial prefrontal and anterior cingulate) with 6-hydroxydopamine were examined in male Sprague-Dawley rats tested for susceptibility to cold restraint-induced gastric stress pathology. All three types of lesions tended to potentiate the development of stress pathology (i.e. ulceration) in comparison to restrained shams, but only right cortical dopamine depletion produced a highly significant increase. The results support a protective role for mesocortical dopamine in helping the organism cope with stressful situations, and extend previous findings suggesting that dopamine activation in the right cortex is preferentially associated with uncontrollable stress. The right cortex is hypothesized to be at the top of a hierarchy in the processing of such stressful inputs, and endogenous dopaminergic modulation facilitates adaptive responses. Subcortical dopamine terminal regions were also examined for dopamine content and turnover. In addition to depleting cortical dopamine, the three lesion groups showed highly specific alterations in the status of subcortical dopamine systems, compared to either restrained or non-restrained shams. Left brain lesions resulted in significant bilateral increases in amygdala dopamine turnover. Right cortical lesions induced significant bilateral reductions of striatal dopamine content. Bilateral lesions increased dopamine content in the left amygdala and decreased dopamine in the right nucleus accumbens. Also in this group, dopamine turnover was increased in the right nucleus accumbens and decreased in the right amygdala. The data suggest that increases in stress vulnerability induced by cortical lesions may be related, in part, to neurochemical alterations in subcortical structures previously shown to modulate gastric stress pathology. The results also indicate that brain organization is inherently asymmetrical with respect to the regulation of responses to stress, which may be of significance for human psychopathology and its exacerbation by stress.
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PMID:Asymmetrical influence of mesocortical dopamine depletion on stress ulcer development and subcortical dopamine systems in rats: implications for psychopathology. 760 74


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