Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have done two argon-laser iridotomies 24 and 72 hours before cataract surgery, to study ocular inflammation. We have taken aqueous samples to study IgA, IgG, C3 and AAT by laser immunonephelometry. All the proteins raised in the first 24 hours (P less than or equal to 0.01) except IgA in aqueous humor, taken with control levels, but only AAT (P less than or equal to 0.05), albumine at 72 hours (P less than or equal to 0.01) in aqueous humor. We tried to understand the observed gap by immunomodulation of released mediators.
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PMID:[Humoral immunity and the argon-laser]. 225 Sep 67

An investigation of the crystal structure of cytosolic pig-heart aspartate aminotransferase (AAT, E.C.2.6.1.1) was carried out to determine the structural requirements for ligand recognition by the active site. Structural differences were observed between the two active sites of the AAT dimer. The natural ligand, L-aspartate, was docked into both active sites using various methods. However, due to structural differences, the ligand was able to form all the necessary interactions for initial binding in only one of the active sites. The program GRID (P.J. Goodford, J. Med. Chem. 1985, 28, 849-857) was used to predict favorable binding sites for the functional groups of the aspartate ligand. These binding sites corresponded to the position of the docked aspartate ligand, indicating that substrate recognition takes place before any major conformational changes occur within the enzyme.
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PMID:Aspartate aminotransferase: investigation of the active sites. 228 53

Bone tumors, which consist largely of fibroblast-like cells, were categorized into ALPase-positive (3 ossifying fibromas and 2 fibroblastic osteosarcomas) and negative (4 non-ossifying fibromas and 5 MFHs) groups. They were investigated as to their ultrastructure and immunophenotype using antibodies of fibroblast markers (collagen I, III, aminopeptidase M, dipeptidylpeptidase IV and factor XIIIa), classical macrophage markers (AACT and AAT) and vimentin. In the case of the ALPase-positive group, fibroblast-like cells showed short, branching rough endoplasmic reticulum with bundles of microfibrils in their cytoplasms. They were often intermingled with osteoblastic cells particularly in proximity to osteoid tissue. Furthermore, these cells expressed fibroblast markers of collagen I, aminopeptidase M, dipeptidylpeptidase IV and factor XIIIa. Fibroblast-like cells of the ALPase-negative group more or less revealed phagosomes in addition to fibroblastic features admixed with histiocyte-like cells. They expressed classical macrophage markers, but rarely fibroblast markers. The above findings indicated that derivation from different precursor cells should be proposed between the two groups and that the tumors in the ALPase-positive group might be intimately related to a certain population of the bone marrow stromal cells.
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PMID:Alkaline phosphatase-positive and negative bone tumors. Ultrastructural and immunohistochemical studies of fibroblast-like tumor cells. 228 89

The three-dimensional structure of a complex between the dodecanucleotide d(CGCGAATTCGCG) and the anti-trypanocidal drug berenil, has been determined to a resolution of 2.5 A. The structure has been solved by molecular replacement and refined to an R factor of 0.177. A total of 49 water molecules have been located. The drug is bound at the 5'-AAT-3' region of the oligonucleotide. At one end of the drug the amidinium group is in hydrogen-bonded contact with N3 of the adenine base complementary to the thymine of the AAT. The other amidinium group does not make direct interactions with the DNA. Instead, a water molecule mediates between them. This is in hydrogen-bonded contact with an amidinium nitrogen atom, N3 of the 5' end adenine base and the ring oxygen atom of an adjacent deoxyribose. Molecular mechanics calculations have been performed on this complex, with the drug at various positions along the sequence. These show that the observed position is only 0.8 kcal/mol higher in energy than the best position. It is suggested that there is a broad energy well in the AATT region for this drug, and that water molecules as well as the neighbouring sequence, will determine precise positioning. More general aspects of minor groove binding are discussed.
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PMID:Crystal structure of a berenil-dodecanucleotide complex: the role of water in sequence-specific ligand binding. 232 43

The long-term administration of xenobiotics carcinogens o-aminoazotoluene (o-AAT) and benz(a)pyrene (BP) to rats was found to cause induction of the liver cytochrome P-450 system which gradually decreases in spite of continued administration of the agents. Induction of microsomal oxygenases under these conditions is followed by induction of the immune response to o-AAT and BP. The data obtained correspond to the conception of the immunochemical functional system of homeostasis implying that the cytochrome-450 system and the immunity system are functionally linked and are elements of the common functional adaptive system of the organism.
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PMID:[Cytochrome P-450 induction and the subsequent induction of an immune response in rats during the chronic administration of xenobiotics]. 232 3

The presence and distribution of AFP, AAT and HBsAg in peritumoral non-neoplastic hepatocytes (NNH) of 27 cases and, at the same time, in the neoplastic tissue of 37 liver cell carcinoma (HCC) were studied; AFP and HBsAg were more frequently found in NNH than in HCC cells; no differences were found for AAT. The presence of HBsAg also in normal liver without cirrhosis is probably best explained by its possible role in neoplastic transformation and by the inhibition of replication of the viruses AFP, considered to be expression of dedifferentiated cells, may possible be taken up by NNH for catabolic purposes.
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PMID:Immunohistochemical study of the appearance of some markers in liver adjoining hepatocellular carcinoma. 242 60

Primary liver carcinoma (PLC) may express a certain number of markers. Here we communicate results of an analysis of five such markers (alpha-1-antitrypsin--AAT--, carcino-embryonic antigen --CEA--, alpha-fetoprotein --AFP--, and superficial --HBsAg-- and core --HBcAg-- antigens of hepatitis B virus) by means of PAP techniques in 130 cases of PLC, comparing the neoplastic tissue and the non-tumorous liver. Three variants of PLC are distinguished: hepatocarcinoma (HC) (108 cases); cholangiocarcinoma (CC) (19 cases); and three cases of hepatocholangiocarcinoma (HCC). AAT was positive in 29 HC, 2 HCC, and negative in all 19 CC. CEA appeared positive in 16 HC, 16 CC and only one HCC. AFP was positive in two HC, and negative in all CC and HCC. HBsAg displayed positivity in 15 HC and one HCC, being negative in all 19 CC. HBcAg was positive in 4 HC, and negative in all CC and HCC. HBsAg was also positive in two neoplastic emboli associated with HC. On the non-tumorous liver tissue the immunohistochemical results showed positivity for AAT and CEA, but not for AFP. Therefore the present results confirm that in the geographical area from which these tumors proceed, PLC is closely correlated with HBsAg positivity and with cirrhosis.
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PMID:Immunohistochemical characterization of 130 cases of primary hepatic carcinomas. 244 80

To obtain further insights into the rehabilitation outlook in different baseline conditions, a comparison was made of data and treatment outcomes in 92 patients having aphasias of different etiology and disease duration. Rating as "improved" was contingent on significant changes in at least 2 subtests of the AAT (Aachener Aphasietest), which is a fairly stringent requirement. This criterion was met by some 35% of the patients overall, independent of their age; the percentage increased to 45% in case of treatment onset during the first year, while in later onset, significant improvement was achieved in 15% only. Aphasic syndromes secondary to hemorrhage, trauma, tumors, or infections, usually are less severe than the predominant classical syndromes, i.e. Global, Broca and Wernicke aphasia, caused by ischemic stroke. CT lesion size did not yield any definite information. Minor improvements below the required significance levels, and, above all, gains in communication performance, i.e. further consolidation, could be achieved by appropriate management even after the crucial initial year, which, however, does not imply any fundamental changes in the rehabilitation prognosis as such.
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PMID:[Rehabilitation prognosis of aphasias of various etiologies with reference to clinical, neurolinguistic and computerized tomography findings]. 245 41

1. Gel electrophoresis of aspartate aminotransferase released from boar spermatozoa after cold shock showed one band migrating towards anode. 2. Physico-chemical and kinetic properties of isolated enzyme were similar to cytoplasmic isoenzyme of AAT from somatic tissues.
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PMID:Isolation and characteristics of aspartate aminotransferase from boar spermatozoa. 251 80

Virus inducible elements (IE) in promoters of mouse alpha-interferon and human beta 1-interferon genes contain multiple copies of the hexanucleotide sequence AGT-GAA or its variants which are also found in the interferon-stimulated response element of genes transcriptionally induced by interferon. We have examined the similarities between virus and interferon induction of gene expression and the role of AGTGAA and AAT-GAA hexamers in these responses. Hybrid plasmids were constructed by inserting the IE region, the alpha 4 promoter, or the multiple copies of AGTGAA or AAT-GAA 5' to the inactive-45 human immunodeficiency-chloramphenicol acetyltransferase hybrid gene, and their inducible expression was studied in a transient expression assay. In L-cells, multiple hexamers were efficiently induced both by infection with Newcastle disease virus and by interferon treatment; while the alpha 4 promoter and the IE inducible region were induced predominantly by virus rather than by interferon. In order to dissociate the effect of virus and endogenous interferon on the induction process, we examined the gene expression in Vero cells, which have undergone homozygous deletion of type 1 interferon genes, and in VNPT-159 cells, which were derived from Vero cells by insertion of an inducible human interferon beta 1 gene. The results show that while the alpha 4 promoter was efficiently induced only by virus in both cell types, the constructs containing shorter segments of the IE were induced by both virus and interferon in Vero cells. However, the inducibility by interferon was not detected in VNPT-159 cells, suggesting that the presence of endogenous interferon suppresses interferon-induced expression of hexanucleotide repeats and the short inducible region. In contrast, virus inducibility of endogenous interferon-stimulated genes, ISG-15 and ISG-54, was about 100-fold more efficient in VNPT-159 cells than in Vero cells, suggesting that this induction is largely mediated through synthesis of endogenous interferon. Hence, endogenous interferon may play a role in the autoregulation of both interferon genes and interferon-stimulated genes.
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PMID:Virus infection and interferon can activate gene expression through a single synthetic element, but endogenous genes show distinct regulation. 255 Apr 51


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