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)

In adult guinea pigs, unilateral labyrinthine lesions were inflicted by chloroform injections into the middle ear. Immunoreactivity for S100 protein (S100) in the vestibular nuclei was studied during compensation of lesion-induced postural asymmetry symptoms, i.e., nystagmus, asymmetrical head position. 1 h after unilateral labyrinthectomy, increased levels of astroglial S100 immunoreactivity were found in the superior vestibular nucleus and in the medial/lateral vestibular nucleus border region on the side contralateral to the deafferentation. Bilaterally, the astrocytic S100 immunoreaction increased in the lateral vestibular nuclei around Deiters neurons. Maximal expression of S100 was noted 3 h after the lesion. Subsequently, it diminished. Our data reveal that transsynaptically altered neuronal activity induces an astrocytic reaction which provides increased levels of S100 to the local neuropil. Calcium and zinc binding S100 proteins may play a functional role for the neuroplasticity during vestibular compensation.
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PMID:Expression of S100 protein in the vestibular nuclei during compensation of unilateral labyrinthectomy symptoms. 854 26

The reason for a post and core preparation is to provide an anchoring system for a final restoration to the tooth root. This experiment was divided into two groups with the following systems; ExactaCast and Parapost. Casts for these systems were fabricated in photoelastic plastic and cemented with zinc phosphate cement. These photoelastic blocks were placed in a special jig on a universal testing machine. The experiment compared the photoelastic stresses generated for these two systems in two different stress modes; vertically at 30 pounds and obliquely (at a 26 degree angle) at 20 and 30 pounds. Specimens were then photographed after cementation in the unloaded and loaded states. Minimal stresses were observed for the ExactaCast in the unloaded state, while symmetric, even patterns of stresses concentrated coronally were present in the loaded vertical and oblique states. Minimal stresses were observed for the Parapost in the unloaded state, while asymmetric, uneven patterns of stresses concentrated apically were present in the loaded vertical and oblique states. The presence of the multiple tiered system for the Exacta-Cast clearly directs stresses in a symmetric pattern, while the single tiered Parapost system directs stresses in asymmetrical pattern. The symmetric even stresses for the ExactaCast are more favorable than the asymmetric, uneven stresses for the Parapost.
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PMID:Comparison of the photoelastic stress properties for two combination prefabricated cast post systems. 877 35

Previous studies have demonstrated formation of recurrent excitatory circuits between sprouted mossy fibers and granule cell dendrites in the inner molecular layer of the dentate gyrus (9, 28, 30). In addition, there is evidence that inhibitory nonprincipal cells also receive an input from sprouted mossy fibers (39). This study was undertaken to further characterize possible target cells for sprouted mossy fibers, using immunofluorescent staining for different calcium-binding proteins in combination with Timm histochemical staining for mossy fibers. Rats were injected intraperitoneally with kainic acid in order to induce epileptic convulsions and mossy fiber sprouting. After 2 months survival, hippocampal sections were immunostained for parvalbumin, calbindin D28k, or calretinin followed by Timm-staining. Under a fluorescent microscope, zinc-positive mossy fibers in epileptic rats were found to surround parvalbumin-containing neurons in the granule cell layer and to follow their dendrites, which extended toward the molecular layer. In addition, dendrites of calbindin D28k-containing cells were covered by multiple mossy fiber terminals in the inner molecular layer. However, the calretinin-containing cell bodies in the granule cell layer did not receive any contacts from the sprouted fibers. Electron microscopic analysis revealed that typical Timm-positive mossy fiber terminals established several asymmetrical synapses with the soma and dendrites of nonpyramidal cells within the granule cell layer. These results provide direct evidence that, in addition to recurrent excitatory connections, inhibitory circuitries, especially those responsible for the perisomatic feedback inhibition, are formed as a result of mossy fiber sprouting in experimental epilepsy.
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PMID:Characterization of target cells for aberrant mossy fiber collaterals in the dentate gyrus of epileptic rat. 927 41

Mammalian alkaline phosphatases (APs) are zinc-containing metalloenzymes encoded by a multigene family and functional as dimeric molecules. Using human placental AP (PLAP) as a paradigm, we have investigated whether the monomers in a given PLAP dimer are subject to cooperativity during catalysis following an allosteric model or act via a half-of-sites model, in which at any time only one single monomer is operative. Wild type and mutant PLAP homodimers and heterodimers were produced by stably transfecting Chinese hamster ovary cells with mutagenized PLAP cDNAs followed by enzyme extraction, purification, and characterization. [Gly429]PLAP manifested negative cooperativity when partially metalated as a consequence of the reduced affinity of the incompletely metalated AP monomers for the substrate. Upon full metalation with Zn2+, however, the negative cooperativity disappeared. To distinguish between an allosteric and a half-of-sites model, a [Gly429]PLAP-[Ser84]PLAP heterodimer was produced by combining monomers displaying high and low sensitivity to the uncompetitive inhibitor L-Leu as well as a [Gly429]PLAP-[Ala92]PLAP heterodimer combining a catalytically active and inactive monomer, respectively. The L-Leu inhibition profile of the [Gly429]PLAP-[Ser84]PLAP heterodimer was intermediate to that for each homodimer as predicted by the allosteric model. Likewise, the [Gly429]PLAP-[Ala92]PLAP heterodimer was catalytically active, confirming that AP monomers act independently of each other. Although heterodimers are structurally asymmetrical, they migrate in starch gels with a smaller than expected weighted electrophoretic mobility, are more stable to heat denaturation than expected, and are more sensitive to L-Leu inhibition than predicted by a strict noncooperative model. We conclude that fully metalated mammalian APs are noncooperative allosteric enzymes but that the stability and catalytic properties of each monomer are controlled by the conformation of the second AP subunit.
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PMID:Mammalian alkaline phosphatases are allosteric enzymes. 927 39

The regulation of nitrate assimilation seems to follow the same pattern in all ascomycetes where this process has been studied. We show here by in vitro binding studies and a number of protection and interference techniques that the transcription factor mediating nitrate induction in Aspergillus nidulans, a protein containing a binuclear zinc cluster DNA binding domain, recognizes an asymmetrical sequence of the form CTCC GHGG. We further show that the protein binds to its consensus site as a dimer. We establish the role of the putative dimerization element by its ability to replace the analogous element of the cI protein of phage lambda. Mutagenesis of crucial leucines of the dimerization element affect both the binding ability of the dimer and the conformation of the resulting protein-DNA complex. This is the first case to be described where a dimer recognizes such an asymmetrical nonrepeated sequence, presumably by each monomeric subunit making different contacts with different DNA half-sites.
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PMID:The regulator of nitrate assimilation in ascomycetes is a dimer which binds a nonrepeated, asymmetrical sequence. 948 49

Serum zinc and copper levels and serum interleukin 1 beta (IL1 beta) and tumour necrosis factor alpha (TNF alpha) levels were evaluated in 57 female patients with active rheumatoid arthritis (RA) to investigate a possible role of IL1 beta and TNF alpha on zinc and copper homeostasis in RA. Serum zinc levels were significantly lower and serum copper levels significantly higher in RA patients when compared with osteoarthritis or asymmetrical psoriatic oligoarthritis patients and with normal controls. No differences were observed in serum IgM rheumatoid factor positive and serum IgM rheumatoid factor negative patients as regards serum zinc and copper concentration. In RA patients the erythrocyte sedimentation rate and acute-phase proteins correlated negatively with serum zinc and positively with serum copper. IL1 beta and TNF alpha were found to correlate negatively with zinc and positively with copper in RA patients. Lower levels of zinc may be due to an accumulation of zinc-containing proteins in the liver and in the inflamed joints in RA. Elevated serum copper levels seem to be linked to the increased synthesis of ceruloplasmin by the liver.
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PMID:Serum zinc and copper in active rheumatoid arthritis: correlation with interleukin 1 beta and tumour necrosis factor alpha. 980 81

Using experimental model of pregnant rats with asymmetrical intrauterine fetal growth retardation induced by passive smoking, the effects of natural herb "Jia Wei Fo Shou San" on erythrocyte membrane calcium, zinc concentration were observed by atomic absorption spectrophotometry. The results showed that the mean fetal birth weight, zinc concentration of erythrocyte membrane were found to be decreased in the model group as compared with the control group (P < 0.01, P < 0.01). On the other hand, the element of calcium onto erythrocyte membrane were higher in model group than that in control group (P < 0.05). These changes were significantly mild in the treated group and were similar to those of the control group (P > 0.05). Furthermore, our findings indicated that the zinc concentration of erythrocyte membrane seems to be positively correlated with the birth weight (P < 0.01). Calcium composition of red cell membrane showed a significant negative relation to the birth weight (P > 0.05). Our results provided an experimental evidence that normal concentrations of calcium and zinc onto erythrocyte play an important part in fetal growth. One of the mechanisms of "Jia Wei Fo Shou San" in improving fetal growth may have something to do with modulation of erythrocyte calcium, zinc element, thereby protecting bio-functions of erythrocyte and promoting blood circulation.
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PMID:Effect of "jia wei fo shou san" on erythrocyte membrane calcium, zinc concentration in pregnant rats with asymmetrical intrauterine growth retardation induced by passive smoking. 981 83

The present study was designed to localize zinc-enriched (ZEN) terminals in mouse olfactory bulb by means of ZnT3 immunocytochemistry (ICC) and zinc autometallography (AMG). The immunocytochemical staining of ZnT3 was closely correlated with the AMG pattern. ZEN terminals were defined as terminals showing both ZnT3 immunoreactivities and AMG granules. At the light microscopic level, dense staining patterns for ZnT3 immunoreactivity were seen in the granule cell layer and the olfactory glomerular layer. At the ultrastructural level, ZEN terminals were restricted to presynaptic terminals with single or multiple postsynaptic thickenings. The postsynaptic profiles contacting ZEN terminals appeared to be dendrites or somata of granule cells in the granule cell layer and periglomerular cells and mitral/tufted (M/T) cells in the olfactory glomerular layer. This suggests that two main sources of ZEN terminals are present in mouse olfactory bulb: (1) centrifugal fibres making asymmetrical synapses with granule cells and periglomerular cells, and (2) olfactory receptor terminals contacting dendritic profiles of M/T cells or periglomerular cells. The close correlation between ZEN terminals and the glutamatergic system is discussed.
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PMID:Zinc-enriched (ZEN) terminals in mouse olfactory bulb. 1082 25

We have investigated photoinduced electron transfer (ET) reactions between zinc-substituted cytochrome P450cam (ZnP450) and several inorganic reagents by using the laser flash photolysis method, to reveal roles of the electrostatic interactions in the regulation of the ET reactions. The laser pulse irradiation to ZnP450 yielded a strong reductant, the triplet excited state of ZnP450, (3)ZnP450, which was able to transfer one electron to anionic redox partners, OsCl(6)(2-) and Fe(CN)(6)(3-), with formation of the porphyrin pi-cation radical, ZnP450(+). In contrast, the ET reactions from (3)ZnP450 to cationic redox partners, such as Ru(NH(3))(6)(3+) and Co(phen)(3)(3+), were not observed even in the presence of 100-fold excess of the oxidant. One of the possible interpretations for the preferential ET to the anionic redox partner is that the cationic patch on the P450cam surface, a putative interaction site for the anionic reagents, is located near the heme (less than 10 A from the heme edge), while the anionic surface is far from the heme moiety (more than 16 A from the heme edge), which would yield 8000-fold faster ET rates through the cationic patch. The ET rate through the anionic patch to the cationic partner would be substantially slower than that of the phosphorescence process in (3)ZnP450, resulting in no ET reactions to the cationic reagents. These results demonstrate that the asymmetrical charge distribution on the protein surface is critical for the ET reaction in P450cam.
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PMID:Electron transfer reactions in Zn-substituted cytochrome P450cam. 1099 36

Detection of vesicular zinc and immunohistochemistry against markers for different interneuron subsets were combined to study the postsynaptic target selection of zinc-containing recurrent mossy fiber collaterals in the dentate gyrus. Mossy fiber collaterals in the granule cell layer selectively innervated parvalbumin-containing cells, with numerous contacts per cell, whereas the granule cells were avoided. Under the electron microscope, those boutons made asymmetrical contacts on dendrites and somata. These findings suggest that, in addition to the hilar perforant path-associated (HIPP) interneurons, the basket and chandelier cells also receive a powerful feed-back drive from the granule cells, and thereby are able to control population synchrony in the dentate gyrus. On the other hand, the amount of monosynaptic excitatory feed-back among granule cells is shown to be negligible.
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PMID:Recurrent mossy fibers preferentially innervate parvalbumin-immunoreactive interneurons in the granule cell layer of the rat dentate gyrus. 1104 52


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