Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039483 (giant cell arteritis)
 3,204 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of the anticodon and discriminator base in aminoacylation of tRNAs with tryptophan has been explored using a recently developed in vivo assay based on initiation of protein synthesis by mischarged mutants of the Escherichia coli initiator tRNA. Substitution of the methionine anticodon CAU with the tryptophan anticodon CCA caused tRNA(fMet) to be aminoacylated with both methionine and tryptophan in vivo, as determined by analysis of the amino acids inserted by the mutant tRNA at the translational start site of a reporter protein containing a tryptophan initiation codon. Conversion of the discriminator base of tRNA(CCA)fMet from A73 to G73, the base present in tRNA(Trp), eliminated the in vivo methionine acceptor activity of the tRNA and resulted in complete charging with tryptophan. Single base changes in the anticodon of tRNA(CCA)fMet containing G73 from CCA to UCA, GCA, CAA, and CCG (changes underlined) essentially abolished tryptophan insertion, showing that all three anticodon bases specify the tryptophan identity of the tRNA. The important role of G73 in tryptophan identity was confirmed using mutants of an opal suppressor derivative of tRNA(Trp). Substitution of G73 with A73, C73, or U73 resulted in a large loss of the ability of the tRNA to suppress an opal stop codon in a reporter protein. Base pair substitutions at the first three positions of the acceptor stem of the suppressor tRNA caused 2-12-fold reductions in the efficiency of suppression without loss of specificity for aminoacylation of the tRNA with tryptophan.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Conversion of a methionine initiator tRNA into a tryptophan-inserting elongator tRNA in vivo. 155 14

10 derivations of rat tracheal epithelial (RTE) cells, including normal cells, normal primary cultures, 7 tumorigenic cell lines and 1 nontumorigenic cell line transformed in vitro by treatment with 7,12-dimethylbenz[a]anthracene (DMBA), benzo[a]pyrene (BP) and/or 12-O-tetradecanoylphorbol-13-acetate (TPA) were examined for oncogene alterations. No abnormalities of Ha-ras or Ki-ras were seen that were suggestive of amplification, rearrangement or the presence of RFLPs. Analysis of specific-point mutations in Ha-ras using Pst I digestion (codon 12, GGA to GCA) or Ha-ras and Ki-ras using Xba I (codon 61, CAA to CTA) were negative. In one cell line derived by DMBA treatment, changes in the c-myc restriction digest pattern were seen after incubation with Bam HI and Hind III. Northern analysis revealed consistent differences between normal and transformed cells when probed with Ha-ras; c-myc expression was of low intensity, and the expression of Ki-ras could not be detected. Transfection of RTE cell DNAs into NIH/3T3 cells did not result in the appearance of morphologic transformants. The studies suggest that Ha-ras or Ki-ras codon 61 A to T transversions (CAA to CTA) are not associated with the immortal/tumorigenic phenotype in RTE cells transformed by DMBA or TPA, and are in contrast to results reported in some other biological systems.
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PMID:Oncogene alterations in in vitro transformed rat tracheal epithelial cells. 169 45

Point mutations in factor IX genes of four unrelated Chinese patients with hemophilia B have been identified by direct sequencing of amplified genomic DNA fragments. These four mutations occur in exon 8 of the factor IX gene. A C to T transition at nucleotide 30,863 changes codon 248 from Arg (CGA) to a new Stop codon (TGA), described in a previous family as factor IXMalmo3 (Green P M et al., EMBO J 1989; 8: 1067). A G to A transition at nucleotide 31,051 changes codon 310 from Trp (TGG) to a nonsense or Stop codon (TGA; factor IXChongquing2). A G to A transition at nucleotide 31,119 changes codon 333 which is for Arg (CGA) in normal factor IX, to one for Gln (CAA) in the variant previously described as factor IXLondon2 (Tsang T C et al., EMBO J 1988; 7: 3009) in a patient with moderately severe hemophilia B. The fourth patient has a novel C to A transversion at nucleotide 31,290, which corresponds to replacement of codon 390 which is for Ala (GCA) in normal factor IX, to one for Glu (GAA) in a patient with moderately severe hemophilia B (factor IXChongquing3). DNA sequences of amplified fragments from mothers of three showed both their son's variant and a normal nucleotide at the appropriate position, indicating that they are carriers. The fourth patient's (factor IXMalmo3) mother, whose DNA was not evaluable, was most probably a carrier because of her low plasma factor IX levels.
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PMID:Point mutations in four hemophilia B patients from China. 227 May 38

A 6.4-kb DNA fragment containing the DNA gyrase gyrA and gyrB genes was cloned and sequenced from the quinolone-susceptible Staphylococcus aureus type strain ATCC 12600. An expression plasmid was constructed by inserting the cloned genes into the Escherichia coli-S. aureus shuttle vector pAT19, and deletion plasmids carrying only functional gyrA and gyrB genes were derived from this plasmid. An efficient transformation system for S. aureus RN4220 was established by using these plasmids. Quinolone-resistant mutants of S. aureus RN4220 were isolated by three-step selection with quinolones. The first- and second-step mutants were considered to be transport mutants, and the third-step mutants were divided into five groups with respect to their resistance patterns and transformation results with gyrA and gyrB genes. Sequencing analysis of the resulting mutant gyrase genes showed that they had the following point mutations: group 1, Ser-84 (TCA) to Leu (TTA) in GyrA; group 2, Ser-84 (TCA) to Ala (GCA), Ser-85 (TCT) to Pro (CCT), or Glu-88 (GAA) to Lys (AAA) in GyrA; group 3, Asp-437 (GAC) to Asn (AAC) in GyrB; group 4, Arg-458 (CGA) to Gln (CAA) in GyrB; and group 5, Ser-85 (TCT) to Pro (CCT) in GyrA and Asp-437 (GAC) to Asn (AAC) in GyrB. When the gyrA and/or gyrB mutants were transformed with the wild-type gyrA and/or gyrB plasmids, they became quinolone susceptible, but transformants with the plasmids having the same mutations on the gyrA and/or gyrB genes did not confer susceptibility. These results indicate that mutations in both gyrA and gyrB can be responsible for quinolone resistance in S. aureus.
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PMID:Quinolone resistance mutations in the DNA gyrase gyrA and gyrB genes of Staphylococcus aureus. 781 Oct 12

Giant cell arteritis (GCA) usually manifests as a transmural vascular infiltrate of mononuclear and multinucleated giant cells (MNGC). We describe six patients with GCA associated with severe cerebral amyloid angiopathy (CAA), all with cerebral hemorrhage or varying degrees of cerebral infarct, and histological evidence of Alzheimer's disease (cortical CAA often predominating over senile plaques and neurofibrillary tangles). One case showed mostly cortical involvement (with old microhemorrhages), and the others were primarily leptomeningeal (with involvement of the underlying cortex and extensive encephalomalacia of adjacent brain). Many vessels with CAA exhibited a pronounced adventitial and perivascular infiltrate of lymphocytes, histiocytes, and MNGC. Immunohistochemical staining showed deposition of beta/A4 peptide primarily in the thickened media of CAA vessels, and within the cytoplasm of MNGC--suggesting phagocytosis of insoluble peptide. Cystatin C antibody stained vascular amyloid and diffusely highlighted astrocytic and MNGC cytoplasm. HAM56-positive macrophages were frequently seen around amyloid-laden vessels. Anti-smooth muscle actin immunohistochemistry suggests the occurrence of medial destruction by amyloid, with relative preservation of intimal cells. Ultrastructural studies performed in one case confirmed the presence of intracytoplasmic amyloid in MNGC. The GCA seen in these cases of CAA most likely represents a foreign body response to amyloid proteins, causing secondary destruction of the vessel wall. DNA from brain tissues of five affected patients was examined to assess whether mutations were present in exon 17 of the APP gene or exon 2 of the cystatin C gene, a finding that might explain the foreign body giant cell response to amyloid proteins in these cases. However, restriction fragment mapping of amplified gene segments showed that previously described mutations were not present in these cases.
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PMID:Giant cell arteritis in association with cerebral amyloid angiopathy: immunohistochemical and molecular studies. 938 28

Little is known about the presence of common medical pathogens in the human oral cavity. Using a 16S rRNA-based PCR identification method, this study determined the occurrence of Porphyromonas asaccharolytica, Bacteroides fragilis and Chlamydia pneumoniae in subgingival plaque from 50 adults with advanced periodontitis. Each patient contributed samples from 3 deep periodontal pockets collected by paper points. The PCR primers were for P. asaccharolytica 5'-CTC TAG CTA GAG TGT ACT GG-3' and 5'-ATA GGG TTT ATA GAT TAG CTC TCT-3', for B. fragilis 5'-AAT GAT TCC GCA TGG TTT CAT TA-3' and 5'-GCG GTG ATT GCT CAC TGA CA-3', and for C. pneumoniae 5'- TGA CAA CTG TAG AAA TAC AGC-3' and 5'-CGC CTC TCT CCT ATA AAT-3'. The primers yielded a single amplicon with the respective reference strains and produced no amplicon with colonies of 25 groups of oral organisms. None of the three test species were detected in any of the 50 pooled subgingival samples tested. P. asaccharyolytica, B. fragilis and C. pneumoniae do not seem to be part of the periodontopathic microbiota in humans.
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PMID:Absence of Porphyromonas asaccharolytica, Bacteroides fragilis and Chlamydia pneumoniae in human subgingival plaque. 957 14

Mxi1 is thought to negatively regulate Myc function and may therefore be a potential tumor suppressor gene. Little effort has yet been made to find alterations involving this gene in human solid tumors. We screened 31 human gastric cancers, 7 esophageal cancers, 85 bone and soft tissue tumors of various types, including 4 neurofibrosarcomas. We also examined 29 human tumor cell lines consisting of 12 esophageal cancers, 7 glioma/glioblastomas and 10 others for Mxi1 mutations in exons 1, 2, 4 (HLH domain), 5 and 6. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and subsequent sequencing revealed three distinct polymorphisms in the intron-exon boundary upstream from exon 6. We discovered a missense mutation, GCA to GTA (Ala 54 Val), in exon 2 in a neurofibrosarcoma patient (case 1), two missense mutations, AAA to CAA (Lys 118 Gln) and GAA to GGA (Glu 154 Gly) in exon 5 of another neurofibrosarcoma patient (case 2), and 3 amino acid substitutions, GTG to GCG (Val 179 Ala), GTT to GCT (Val 181 Ala) and TTC to CTC (Phe 186 Leu), in a third neurofibrosarcoma patient (case 3). In case 3, loss of heterozygosity was also demonstrated by informative (TTC)3/(TTC)2 polymorphism. Our data demonstrate that mutations occur in the Mxi1 gene in neurofibrosarcoma. Missense mutations in the functional domain of Mxi1 in these cases may be involved in the pathogenesis of neurofibrosarcoma.
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PMID:Mxi1 mutations in human neurofibrosarcomas. 1047 Feb 86

Glioblastomas, the most malignant human brain tumors, are characterized by marked aneuploidy, suggesting chromosomal instability which may be caused by a defective mitotic spindle checkpoint. We screened 22 glioblastomas for mutations in the mitotic spindle check-point genes hBUB1, hBUBR1 and hBUB3. DNA sequencing revealed a silent mutation at codon 144 of hBUB1 (CAG-->CAA, Gln-->Gln) in one glioblastoma, a silent mutation at codon 952 of hBUBR1 (GAC-->GAT, Asp-->Asp) in another glioblastoma, and a silent mutation at codon 388 of the hBUBR1 gene (GCG-->GCA, Ala-->Ala) in 8 glioblastomas. We also observed a known polymorphism at hBUBR1 codon 349 (CAA/CGA, Gln/Arg), with an allelic frequency of 0.75 for Gln and 0.25 for Arg, which is similar to that among healthy Caucasian individuals (0.73 vs 0.27). The coding sequence of the hBUB3 gene did not contain any mutation, but in 4 glioblastomas (18%), a C-->T point mutation was detected at position -6 (6 nucleotides upstream of the ATG initiator codon). Analysis of blood DNA of these patients showed identical sequence alterations, indicating that this is a polymorphism. Again, the frequency in glioblastomas was similar to that in healthy Caucasians (15%). We further screened hBUB1 in 18 cases of giant cell glioblastoma, a variant characterized by a predominance of bizarre, multinucleated giant cells. There were no changes, except for a silent mutation at codon 144 in two cases. These results suggest that mutations in these mitotic spindle checkpoint genes do not play a significant role in the causation of chromosomal instability in glioblastomas.
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PMID:Mutation analysis of hBUB1, hBUBR1 and hBUB3 genes in glioblastomas. 1135

Length differences among trinucleotide-based microsatellite alleles can be more easily detected and frequently produce fewer "stutter bands" as compared to dinucleotide-based microsatellite markers. Our objective was to determine which trinucleotide motif(s) would be the most-polymorphic and abundant source of trinucleotide microsatellite markers in wheat ( Triticum aestivumL.). Four genomic libraries of cultivar 'Chinese Spring' were screened with nine trinucleotide probes. Based on the screening of 28550 clones, the occurrences of (CTT/GAA) (n), (GGA/CCT) (n), (TAA/ATT) (n), (CAA/GTT) (n), (GGT/CCA) (n), (CAT/GTA) (n), (CGA/GCT) (n), (CTA/GAT) (n), and (CGT/GCA) (n) repeats were estimated to be 5.4x10(4), 3.5x10(4), 3.2x10(4), 1.2x10(4), 6.3x10(3), 4.9x10(3), 4.5x10(3), 4.5x10(3) and 3.6x10(3), i.e., once every 293 kbp, 456 kbp, 500 kbp, 1.3 Mbp, 2.6 Mbp, 3.2 Mbp, 3.6 Mbp, 3.6 Mbp and 4.5 Mbp in the wheat genome, respectively. Of 236 clones selected for sequencing, 38 (93%) (TAA/ATT) (n), 30 (43%) (CTT/GAA) (n), 16 (59%) (CAA/GTT) (n), 3 (27%) (CAT/GTA) (n) and 2 (4%) (GGA/CCT) (n) clones contained microsatellites with eight or more perfect repeats. From these data, 29, 27 and 16 PCR primer sets were designed and tested to the (TAA/ATT) (n), (CTT/GAA) (n) and (CAA/GTT) (n) microsatellites, respectively. A total of 12 (41.4%) primers designed to (TAA/ATT) (n), four (14.8%) to (CTT/GAA) (n), and two (12.5%) to (CAA/GTT) (n) resulted in polymorphic markers. The results indicated that (TAA/ATT) (n) microsatellites would provide the most-abundant and the most-polymorphic source of trinucleotide microsatellite markers in wheat.
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PMID:Characterization of trinucleotide SSR motifs in wheat. 1258 99

Hepatopancreatic parvovirus is an emerging disease in crustacean aquaculture. Consequently, methods of detection are needed that enable the sensitive detection and confirmation of the virus better than currently used methods such as histology and conventional polymerase chain reaction (PCR). A TaqMan based real-time PCR assay was developed for the detection of the Australian isolate of hepatopancreatic parvovirus which is only 85% similar to its nearest known relative. The TaqMan assay was developed within the capsid protein region of the genome and is optimised to detect as little as 10 copies of the targeted sequence per PCR vial. The hepatopancreatic parvovirus primers and probe were HPV140F 5'-CTA CTC CAA TGG AAA CTT CTG AGC-3', HPV140R 5'-GTG GCG TTG GAA GGC ACT TC-3' and HPV140probe 5'-FAM TAC CGC CGC ACC GCA GCA GC TAMRA-3', respectively. The assay was specific for the hepatopancreatic parvovirus strain from Australian Penaeus merguiensis as it did not detect related crustacean and canine parvoviruses from Australia. In addition, the very low homology of the target sequence with published sequences from the Thai and Korean strains of hepatopancreatic parvovirus and other prawn viruses such as WSSV, suggested this assay would be specific for the Australian hepatopancreatic parvovirus isolate. Furthermore, it detected hepatopancreatic parvovirus in 22/22 wild-caught P. merguiensis clinical samples and 473/545 (87%) farmed P. merguiensis. This assay has the potential to be used for diagnostic purposes and in robotic applications, particularly for the detection and quantitation of low-grade infections.
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PMID:TaqMan real-time PCR for detection of hepatopancreatic parvovirus from Australia. 1711 64


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