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Biomedical subjects

D M Han

Publications and source records attributed to D M Han.

7 recordsLinked to original sources
PubMed1998

The uvsI gene of Aspergillus nidulans required for UV-mutagenesis encodes a homolog to REV3, a subunit of the DNA polymerase zeta of yeast involved in translesion DNA synthesis.

Defects in the uvsI gene of Aspergillus nidulans resulted in high UV sensitivity and reductions of spontaneous and UV-induced reversion of certain alleles, uvsl;uvsA double mutants exhibited high methyl methane sulfonate (MMS)-sensitivity in contrast to the slight sensitivity of the component single mutants. Using such a double mutant as recipient, a clone complementing uvsI501 has been isolated from a chromosome III specific library. The deduced amino acid sequence from the 1.1-kb sequenced region, a part of the 5.2-kb DNA fragment showing uvsI-complementing activity, had a 62% identity with REV3 of yeast. Disruptants of the cloned gene demonstrated the same level of sensitivity to UV light as uvsI and failed to complement uvsI501 in heterozygous diploids.

Amino Acid Sequence↗
PubMed1996

Structure and expression of the tenecin 3 gene in Tenebrio molitor.

A genomic DNA fragment encoding tenecin 3, an antifungal protein was cloned from the genomic DNA library of Tenebrio molitor. The DNA sequence analysis showed that the coding region is divided into two exons by an intron of 49 bp in the middle of the putative leader peptide coding region. Southern blot analysis suggests that the gene is present as a single copy. The transcription initiation site was determined by primer extension analysis and S1 mapping. The TATA box and CCAAT box sequences were found at -30, and -121, respectively, from the transcription initiation site. Tenecin 3 mRNA is abundantly expressed in larvae and adults, while little was detected in RNAs from pupae, suggesting that the expression of the tenecin 3 gene is developmentally regulated.

Amino Acid Sequence↗
PubMed1992

[Functional endoscopic sinus surgery].

Eighty-two cases of functional endoscopic sinus surgery were analyzed. It include 62 males and 20 females; the oldest was 72 years of age and the youngest eight years of age. A hard endoscope with a diameter of 4mm and the CCD micro-videorecorder produced by Circon and Olympus Company were used. Operations were done under general anesthesia in all cases. Twenty-three cases (28.1%) recovered in one stage and recovery was delayed in 28 cases (34.2%); late inflammation occurred in 23 cases (28.1%); 8 cases failed (9.8%). The cure rate was 62.2%. Two cases (2.4%) had operative complications namely injury to the lamina papyracea and anterior ethmoidal artery, all recovered uneventfully.

Adolescent↗
PubMed1991

Inhibition of topoisomerase I by NAD and enhancement of cytotoxicity of MMS by inhibitors of poly(ADP-ribose) polymerase in Saccharomyces cerevisiae.

The activity of DNA topoisomerase I present in the nuclear extract of yeast, Saccharomyces cerevisiae, was inhibited by additions of NAD, the substrate of poly (ADP-ribose) polymerase. This NAD-inhibited topoisomerase activity was restored to the normal level in a dose-dependent manner by adding 3-aminobenzamide (3-AB), an inhibitor of the polymerase. The 3-AB sensitive polymerase enzyme activity, as determined by the rate of incorporation of the radiolabelled NAD in permeabilized cells, increased by treatment of cells with methyl methanesulfonate (MMS) in a dose-dependent manner. While the additions of MMS increased the polymerase activity, it has caused a decrease in cell survival. However, this cell killing activity of MMS was markedly potentiated by adding benzamide, another inhibitor of polymerase. Thus, these results suggest that the mode of modification of nuclear proteins by altering the poly(ADP-ribosylation) in S. cerevisiae resembles with those observed in mammalian cells.

Benzamides↗
PubMed1990

[Biological characteristics and prognosis of supraglottic carcinoma--a multivariate correlation analysis of prognosis].

The biological characteristics of supraglottic carcinoma was studied with special reference to the correlations of various biological factors with the prognosis of the lesion. The study included 100 cases of supraglottic carcinoma treated by total laryngectomy in the First Hospital of China Medical University in the period from 1975 to 1978, and 7 factors including histopathological findings observed in serial sections of the whole larynx, clinical findings, clinical course, etc. These factors were statistically analyzed by multiple correlation analysis using the theory of quantification I to determine the relations of these factors to the prognosis, as well as their participations in post operative course. 1. Twenty-seven cases died within 5 years after surgery, and 4 cases could not be followed up. 3 and 5-year survival rates were 79.5% and 72.2%, respectively, as calculated in accordance with the UICC General Rule. 2. Histopathologically 5-year survival rate was 10.0% in cases with poorly differentiated carcinoma, 78.0% in cases with moderately differentiated type, and 83.5% in cases with well-differentiated type. It was remarkably lower in poorly differentiated carcinoma than that in moderately or well-differentiated carcinoma. 3. In cases having dense lymphocyte infiltration associated with lymph follicles in peripheral region of tumor, 5-year survival rate was higher (90.4%) than in the other cases. 4. It was found that, as tumor size increased, 5-year survival rate decreased and the risk of lymph node involvement increased in the neck region. 5. 5-year survival rate was lower (48.5%) in cases with lesion infiltrating the surrounding tissues than in cases with other growth patterns. 6. Multiple correlation coefficient between prognosis and the 7 factors analyzed was 0.766. The important factors were the degree of differentiation (0.735), the degree of lymphocyte infiltration (0.260), the size of primary tumor (0.215), the growth pattern of tumor (0.141) and neck metastasis (0.028).

Carcinoma, Squamous Cell↗