Biomedical subjects

Tatsuo Tanaka

Publications and source records attributed to Tatsuo Tanaka.

23 records · Page 2Linked to original sources

PubMed2002

Location of 2(')-O-methyl nucleotides in 26S rRNA and methylation guide snoRNAs in Caenorhabditis elegans.

Many nucleotides in rRNAs are modified. We devised a method to locate 2(')-O-methyl nucleotide residues using a conventional DNA sequencer. We found 38 2(')-O-methyl nucleotides in the 26S rRNA of Caenorhabditis elegans using this method. Fourteen of the 38 residues are conserved in both human and yeast rRNAs and 14 residues are conserved in either human or yeast rRNA. The remaining 10 nucleotides are uniquely methylated in C. elegans 26S rRNA. We searched the C. elegans genomic sequence for small nucleolar RNAs (snoRNAs), which guide the methylation of ribose residues, and predicted 18 snoRNA sequences that are expected to guide the methylation of some of these nucleotide residues.

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PubMed2002

Prevention of liver metastasis of human colon cancer by selective matrix metalloproteinase inhibitor MMI-166.

MMI-166 is a selective inhibitor of matrix metalloproteinase (MMP)-2 and MMP-9. Mice implanted a human colon cancer orthotopically received 200 mg/kg of MMI-166 orally for 5 weeks. Gelatin zymography demonstrated that the administration of MMI-166 remarkably decreased the active MMP-2 expression. Histological examination revealed that MMI-166 showed prominent effect on reduction of the invasive feature of the cancer cells and showed inhibitory effect on tumor vasculature, resulting in the significant decrease of microvessel density of the implanted tumor and liver metastasis compared with the control group. Conclusively, MMI-166 is a potent antiangiogenic oral agent for a human colon cancer.

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PubMed2002

Gastrojejunocolic fistula after gastrectomy with Billroth II reconstruction: report of a case.

We herein report the case of a 65-year old man with gastrojejunocolic fistula. The patient was admitted to our hospital because of edema of the lower limbs, diarrhea, and weight loss. His history included a distal gastric resection and Billroth II reconstruction for a duodenal ulcer 20 years previously. The laboratory data on admission revealed hypoproteinemia and hypoalbuminemia. An upper gastrointestinal X-ray series revealed a fistula between the transverse colon and upper jejunum. After improving his state of malnutrition, a partial resection of the remnant stomach, transverse colon, and jejunum, which were involved in the fistula, was performed. The postoperative course was uneventful and the patient was discharged on the 26th postoperative day. Gastrojejunocolic fistula is one of the severe complications of a stomal ulcer after a gastric resection with Billroth II reconstruction, which is considered to be induced by an inadequate resection of the stomach. As a result of the recent development of improved agents for the treatment of peptic ulcers, the occurrence of gastrojejunocolic fistula has decreased remarkably. However, gastrojejunocolic fistula should be recognized as one of the late severe complications observed after a gastrectomy with Billroth II reconstruction, since this disease may occur even 20 years after the first operation for peptic ulcer.

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PubMed2002

Pancreaticoduodenectomy for perforated gastric malignant lymphoma: report of a case.

We herein report the case of a 65-year old man with gastroduodenal malignant lymphoma (diffuse large B-cell type) accompanied with a bulbar perforation. A pancreaticoduodenectomy was performed because the duodenal second portion and pancreatic head were involved. However, extensive lymphadenectomy was not carried out because many lymph nodes were involved. The postoperative course was uneventful and CHOP therapy (pirarubicin 30 mg/m2, cyclophosphamide 500 mg/m2, vincristine 1 mg/m2, prednisolone 30 mg/m2) was started 1 month after surgery. Seven cycles of CHOP therapy markedly reduced the residual lesions including lymph nodes, and a computed tomography scan after the final chemotherapy revealed no obvious lesions. Complete remission was obtained and the patient was discharged 9 months after surgery.

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PubMed2002

The human ribosomal protein genes: sequencing and comparative analysis of 73 genes.

The ribosome, as a catalyst for protein synthesis, is universal and essential for all organisms. Here we describe the structure of the genes encoding human ribosomal proteins (RPs) and compare this class of genes among several eukaryotes. Using genomic and full-length cDNA sequences, we characterized 73 RP genes and found that (1) transcription starts at a C residue within a characteristic oligopyrimidine tract; (2) the promoter region is GC rich, but often has a TATA box or similar sequence element; (3) the genes are small (4.4 kb), but have as many as 5.6 exons on average; (4) the initiator ATG is in the first or second exon and is within plus minus 5 bp of the first intron boundaries in about half of cases; and (5) 5'- and 3'-UTRs are significantly smaller (42 bp and 56 bp, respectively) than the genome average. Comparison of RP genes from humans, Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae revealed the coding sequences to be highly conserved (63% homology on average), although gene size and the number of exons vary. The positions of the introns are also conserved among these species as follows: 44% of human introns are present at the same position in either D. melanogaster or C. elegans, suggesting RP genes are highly suitable for studying the evolution of introns.

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