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Biomedical subjects

T Koda

Publications and source records attributed to T Koda.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Combination therapy with ofloxacin and chloramphenicol against typhoid fever].

Recently we experienced two male typhoid patients who required additional treatment with CP sodium succinate (CP succinate) to OFLX therapy. Although both of the cases were administered 900 mg/day of OFLX orally for three and four days, respectively, the clinical efficacies were not sufficient. We added 2.0 g/day of CP succinate intravenously for six days, although a lasting high fever returned to normal level in a few days. The administration of OFLX was continued up to 14 days. The daily doses of OFLX during the co-medication with CP succinate were 600 mg in one case and 900 mg in the other case. In both cases no recurrence was observed clinically and bacteriologically for six months after their discharge. No adverse reaction was observed throughout the therapy.

Adolescent↗
PubMed1989

High-performance liquid chromatographic estimation of eluates from denture base polymers.

A quantitative analytical method using high-performance liquid chromatography is developed to estimate elution profiles of dental acrylic polymers used for denture bases. The method is applied to elution studies in distilled water of resins polymerized by different representative methods. Elution properties or 'leachabilities' vary depending on polymerization conditions. Methyl methacrylate, methacrylic acid and benzoic acid are eluted from autopolymerized resins at the highest eluate concentrations and are followed by heat- and microwave-polymerized resins. These results appear to be comparable to residual amounts of the eluates in resins and their cytotoxic potencies reported.

Acrylic Resins↗
PubMed1989

Transformation of NIH3T3 cells with synthetic c-Ha-ras genes.

Synthetic human c-Ha-ras genes in which amino acid codons were altered to those which are frequently used in highly expressed Escherichia coli genes were ligated to the 3'-end of Rous sarcoma virus long terminal repeat. When NIH3T3 cells were transfected with the plasmids having those genes with valine at codon 12, leucine at codon 61 or arginine at codon 61, transformants were efficiently produced. These results indicated that the synthetic c-Ha-ras genes are expressed in a mammalian system even though their codon usage is altered to correspond with that of E. coli. This expression vector system should be useful for studies on the structure-function relationships of c-Ha-ras, since the synthetic gene can be easily modified to have multiple base alterations, and can also be used simultaneously for the production of large amounts of p21 in E. coli for biochemical and biophysical studies.

Avian Sarcoma Viruses↗
PubMed1989

[Basic studies on cutting of composite resin cores].

Filler contents, Knoop hardness, characteristics of cutting and surface texture of eight commercial composite resin cores were investigated. Two posterior composite resins and two silver alloys were used as controls. No differences were found in filler contents and Knoop hardness between the composite resin cores and posterior composite resins. In the composite resins, Knoop hardness was correlated to the filler content. The characteristics of cutting with a diamond point varied largely among materials. The composite resin cores were divided by deterioration of the characteristics of cutting into two groups. The degree of surface roughness of composite resins polished with a finishing diamond point was larger than that of the silver alloys. SEM examination revealed little differences in the composite resin surfaces cut with a diamond point but large differences in surfaces polished with a finishing diamond.

Composite Resins↗
PubMed1989

Comparative bond strengths of plastic teeth to microwave-curing, heat-curing and 4-META containing denture base resins.

Bond strength of hardened plastic teeth or acrylic resin teeth to microwave-curing, conventional heat-curing and 4-META-containing denture base resins were comparatively investigated in this study. Effects of grinding and monomer coating of the tooth ridge lap were also studied. Bond strength of plastic denture teeth to microwave-curing denture base resin was slightly higher than the other two resins. With all denture base resins used, an increased bond strength was obtained with hardened plastic teeth by treatment of tooth ridge lap but not with acrylic resin teeth. However, scattering of the bond strength was reduced by treatment of tooth ridge lap in acrylic resin teeth specimens. With hardened plastic teeth specimens, fracture in the base resin was increased by monomer coating. With acrylic resin teeth specimens, no specific fracture patterns were demonstrated by treatment of tooth ridge lap. Fracture occurred mostly in the acrylic resin teeth. These results suggest that bond strength of both denture teeth to microwave-curing or 4-META-containing denture base resin was increased or solidified by grinding or monomer coating of tooth ridge lap.

Acrylic Resins↗
PubMed1989

Abrasion resistance of microwave-curing denture base resin.

This study was designed to test the abrasion resistance of microwave-curing denture base resin. We also studies the effects of surface smoothing treatment on abrasion resistance. Test resin was allowed to polymerize, and then buff polished or treated by surface smoothing. Knoop hardness was measured both prior to and following surface treatment. Then, the test material was subjected to brushing using a newly developed toothbrushing machine. Volume and surface roughness of the material were measured before and after brushing, and the surface structure of the material was examined with SEM. Microwave-curing denture base resin is equal in Knoop hardness and abrasion resistance to its conventional heat-curing counterpart, although it is smoother at the surface. The resin improved both in hardness and abrasion resistance when it underwent surface smoothing treatment regardless of whether it was heat-cured or microwave-cured. As was evident from SEM observations that both types of resins suffered superficial chipping following severe brushing, which is in accordance with our previous clinical findings.

Acrylic Resins↗
PubMed1988

Human HST1 (HSTF1) gene maps to chromosome band 11q13 and coamplifies with the INT2 gene in human cancer.

The human HST1 gene, previously designated the hst gene, and now assigned the name HSTF1 for heparin-binding secretory transforming factor in human gene nomenclature, was originally identified as a transforming gene in DNAs from human stomach cancers by transfection assay with mouse NIH 3T3 cells. The amino acid sequence of the product deduced from DNA sequences of the HST1 cDNA and genomic clones had approximately 40% homology to human basic and acidic fibroblast growth factors and mouse Int-2-encoded protein. We have mapped the human HST1 gene to chromosome 11 at band q13.3 by Southern blot hybridization analysis of a panel of human and mouse somatic cell hybrids and in situ hybridization with an HST1 cDNA probe. The HST1 gene was found to be amplified in DNAs obtained from a stomach cancer and a vulvar carcinoma cell line, A431. In all of these samples of DNA, the INT2 gene, previously mapped to human chromosome 11q13, was also amplified to the same degree as the HST1 gene.

Animals↗
PubMed1988

[ret gene from a human stomach cancer].

DNAs from 15 samples of primary stomach cancer were transfected into NIH3T3 cells. Five stomach cancer DNAs (ST1, ST3, ST6, ST7, and ST15) showed transforming activity. These transformations were caused by human cancer DNAs since human Alu repetitive sequences were detected in transformant DNAs. DNAs from transformants were screened with 22 oncogene probes available, including Ha-ras, Ki-ras, and N-ras. However, these probes did not hybridize with any human DNA in transformants. A transforming gene was cloned from an ST6-derived transformant, which turned out to be hst oncogene. By use of a probe derived from the cloned hst gene, it was shown that additional two transformants (ST7- and ST15-derived) also harboured human hst. Here I report molecular cloning of another transforming gene from an ST1-derived transformant. The transforming gene was cloned by cosmid rescue method being tagged with pSV2-gpt. The normal counterpart of the transforming gene was also cloned from a genomic phage library of human placenta DNA. Surprisingly, the transforming gene was not colinear with the placenta DNA, but was generated by the recombination of two separate genes. Comparison of the restriction maps of these genes with those of reported oncogenes showed that 3'-half of the cloned transforming gene was colinear with the 3'-half of the ret oncogene, which encodes tyrosine kinase domain. It was suggested that this gene was activated by DNA rearrangement upon transfection, placing a transcriptionally active promoter on upstream of the kinase domain. Among 4 primary transformants derived from ST1 two did not have human ret oncogene, indicating that other transforming genes were involved in these transformation events.

Cloning, Molecular↗
PubMed1987

[A case of gastric cancer in which long-term administration of 5'-deoxy-5-fluorouridine (5'-DFUR) proved effective].

A patient with gastric cancer (mucinous adenocarcinoma), classified as Borrmann Type 4, refused surgery and a chemotherapy regimen was applied. 5'-DFUR (5'-deoxy-5-fluorouridine) was administered orally at 1,200 mg/day for 23 weeks, for a total dosage of 110.8 g. The patient showed marked remission: the tumor nearly disappeared, distensibility reappeared from the central region of the corpus ventriculi to the incisura angularis, and only small protrusions classified by Yamada's criteria as Type I, remained on the anterior and posterior wall and pars pylorica of the lesser curvature. Side effects were slight anorexia and diarrhea. These could be avoidable by temporal interruption of administration or dosage reduction, to allow long-term treatment. This case can be considered to be one example in which 5'-DFUR proved effective against gastric cancer.

Adenocarcinoma, Mucinous↗