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Biomedical subjects

J Y Hwang

Publications and source records attributed to J Y Hwang.

11 recordsLinked to original sources

Tamoxifen stimulates human papillomavirus type 16 gene expression and cell proliferation in a cervical cancer cell line.

The widely adopted use of tamoxifen as a chemotherapeutic agent is primarily based on its inhibition of cancer cell growth. However, we report that tamoxifen at low concentrations (10(-9) and 10(-11) M) causes stimulation of cell proliferation in a cervical cancer cell line, SFR. The facts that SFR cells do not contain estrogen receptors and are estrogen nonresponsive imply the existence of an antiestrogen-specific binding protein and suggest that the effect of tamoxifen is possibly mediated through a pathway other than estrogen receptors. Tamoxifen at low concentrations stimulated human papillomavirus type 16 (HPV-16) gene transcription and E7 protein production. Levels of HPV-16 mRNA and E7 protein reached a peak at approximately 2-4 h after tamoxifen treatment, persisted for several hours, and subsequently decreased to their prestimulation levels by about 24 h after treatment. Our results indicate for the first time that tamoxifen stimulates cell proliferation of cervical cancer cells, and we suggest that the enhanced HPV-16 mRNA and E7 protein levels are probably responsible.

Cell Division

An experimental comparison of four hearing aid prescription methods.

Four hearing aid prescription methods were compared. A digital master hearing aid was used to produce the prescribed frequency gain characteristics. Measures of speech recognition and paired comparison judgments of relative speech intelligibility and speech quality were obtained at three output levels for each of the experimental frequency gain characteristics. No single prescriptive method emerged as being clearly superior. Relative performance of the four prescriptive methods varied as a function of output level. Similar results were observed for both speech recognition testing and paired comparison testing.

Adult

Nasal absorption of nafarelin acetate, the decapeptide [D-Nal(2)6)]LHRH, in rhesus monkeys. I.

Nafarelin acetate, [D-Nal(2)6]LHRH, a highly potent superagonist of luteinizing hormone-releasing hormone, was given intranasally to six female rhesus monkeys. Absorption was rapid and very reproducible, with peak levels occurring at 15-30 min and a bioavailability of approximately 2% relative to a subcutaneous dose. The nasal dose response was highly nonlinear. The nonlinearity was apparently associated with the absorption phase, since elimination profiles at all doses were similar.

Absorption

Transcription-termination factor Rho from Bacills subtilis.

A protein has been isolated from Bacillus subtilis which has functions similar to that of transcription termination factor rho (rho) from Escherichia coli. The apparent molecular weight of the B. subtilis rho factor is about 80000-95000 as estimated by a non-denaturing polyacrylamide gel electrophoresis method. It contains two subunits with a molecular weight of 47000 as determined by sodium dodecylsulfate/polyacrylamide gel electrophoresis. The rho factor shows poly(C)-dependent beta-gamma ATPase activity and depresses the activity of RNA synthesis from B. subtilis phage rho 29 DNA template with purified B. subtilis RNA polymerase holoenzyme. The specific activity of the poly(C)-dependent ATPase of the B. subtilis rho factor was significantly less than that of the E. coli rho factor. In the presence of rho factor fewer RNA transcripts were produced overall from the rho 29 template and smaller RNA transcripts with discrete sizes were made. These results suggest that the B. subtilis rho factor can catalyze transcription termination at specific sites on rho 29 phage DNA in vitro.

Adenosine Triphosphatases

Apolipoproteins A-I and B in non-insulin-dependent diabetes mellitus.

In recent years apolipoproteins A-I and B examinations have been performed on patients with coronary artery disease as a better predictor of the severity of atherosclerosis. In the present study, 21 treated male and 22 treated female patients with non-insulin-dependent diabetes mellitus (NIDDM) were examined and compared with controls of the same sex, age and body mass (23 males, 21 females). Cholesterol, triglyceride, LDL-cholesterol in male and female patients with NIDDM were significantly higher than in male and female controls. HDL-cholesterol in male and female patients with NIDDM was not different from those of male and female controls. Apolipoproteins A-I and B in male and female patients with NIDDM were higher than in male and female controls. [Apolipoproteins A-I (g/L) male 1.40 +/- 0.21 vs 1.25 +/- 0.15, p less than 0.005; female 1.56 +/- 0.23 vs 1.42 +/- 0.24, p less than 0.025. Apolipoproteins B (g/L) male 1.29 +/- 0.30 vs 0.97 +/- 0.22, p less than 0.001; female 1.34 +/- 0.34 vs 0.98 +/- 0.35, p less than 0.001.] Discrepancy between the higher apolipoprotein A-I and the normal HDL-cholesterol in in NIDDM supports the theory of altered composition of HDL particles in diabetic patients. The controversy between the higher apolipoprotein A-I and the higher incidence of atherosclerosis in patients with NIDDM makes the clinical usefulness of this laboratory measurement doubtful in these patients.

Adult

[Relationship between thyroid echogram and thyroid function in Hashimoto's thyroiditis].

Seventeen cases of untreated Hashimoto's thyroiditis were selected from the files of the Taipei Municipal Jen-Ai Hospital during the period from Jan. 1985 to Jan. 1986. All the cases were confirmed by a physical examination, determination of thyroid antibodies and fine needle aspiration cytology. Thyroid function was also determined. According to the echogenicity of the thyroid, they were divided into 2 groups, group A (8 cases) and group B (9 cases). In group A, homogeneous hypoechogenicity of the thyroid was noted and was lower than that of the adjacent muscles. In group B, heterogeneous echogenicity of the thyroid with equal or higher echogenicity than that of the adjacent muscles was noted. Group A showed a significantly lower serum T4, T3 and a higher serum TSH in comparison with group B. Five cases in group A presented hypothyroidism clinically while only 1 in group B presented. In conclusion, in the cases of Hashimoto's thyroiditis, the homogeneous hypoechogenicity of the thyroid echogram suggested the possibility of hypothyroidism. Statistically, the sensitivity was 83.3%, specificity 72.8%, positive prediction value 62.5% and the negative prediction value was 88.9%.

Adolescent