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S J Yang

Publications and source records attributed to S J Yang.

88 records · Page 5Linked to original sources
PubMed1983

Effect of spirogermanium on V79 Chinese hamster cells.

Chinese hamster V79 cells were exposed to spirogermanium (SG), and their mitotic activity, population growth, plating efficiency, viability (dye exclusion), and clonogenicity were assayed. Mitotic frequency of cultures in SG decreased initially with increasing drug concentration and later plateaued at varying levels depending on drug concentration. Cultures continuously exposed to SG showed drug concentration-dependent growth inhibition, with no effect at 0.1-0.2 micrograms/ml and increasing toxicity above 0.5 microgram/ml. Cytolysis was enhanced by the simultaneous presence of amphoterocin B and by exposing cells to SG at 42 degrees C. Hypoxia protected cells from drug-induced lysis. The loss of membrane-intact cells was inversely related with population density at the time of drug exposure. Short exposures (up to 5 hours) at 20 micrograms/ml showed that cell killing was primarily through reduction of dye-excluding cells within a matter of hours and secondarily through loss of proliferative capacity. Prolonged drug contact (24 hours) at lower concentrations (1-5 micrograms/ml) accentuated the effect on clonogenicity. These results suggest that for clinical potency, prolonged drug contact may be beneficial.

Amphotericin B↗
PubMed1978

Changes in cell-mediated immunity in patients undergoing radiotherapy.

The cell-mediated immune status of 147 patients who received radiotherapy was evaluated using in vitro tests (PHA, E-rosette and spontaneous blastogenesis) both before and 6 weeks after the end of radiation. All patients had verified malignancies, involving the bronchus in 29 cases, breast in 28, female genital system in 26, head and neck in 20 and bladder in 15. Patients suffering from bronchogenic carcinomas or malignancies of the head and neck showed a relative high degree of immune suppression. Our findings indicate a trend towards some improvement in PHA reactivity, as well as in as the percentage of E-rosette-forming cells after treatment, which is more noticeable in patients with pelvic or breast tumors. A relationship seems to exist between the tumor load and the immune status, which reverts to a normal pattern when the former is extinguished. Moreover, patients with poor clinical response display a profoundly depressed level of immune status without any improvement after treatment.

Adult↗
PubMedDate not supplied

Reproducibility of LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color deoxyribonucleic acid probe kit. For enumeration of gene amplification in paraffin-embedded specimens: a multicenter clinical validation study.

Overexpression and/or amplification of HER-2/neu gene have been found to be prognostic and predictive in breast and other cancers. Fluorescence in situ hybridization (FISH) assay, with its sensitivity and specificity, can be a superior method of detection when its performance characteristics are demonstrated. A multicenter study was initiated to evaluate the reproducibility of the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe for enumeration of both the HER-2/neu gene and chromosome 17 (signals) in interphase cells. Section slides were prepared from four cell lines (H, E, R, and N) with known ratios of the HER-2/neu to CEP 17 copy numbers (approximately H = 1.10, E = 1.70, R = 4.50, N = 9.0). The study variable was the ratios of the HER-2/neu to chromosome 17 copy numbers. Reproducibility with respect to assay, site, lot, day and reader was evaluated at 3 centers. Out of 120 specimen slides, 100 percent were successfully assayed. There were no significant differences among: (1) four repeated assays of the same specimen (p = 0.99), (2) the four probe lots (p = 0.33), or (3) the four study days (p = 0.54). There was statistically significant, but not important differences among centers and between readers. The ratios of the HER-2/neu to chromosome 17 copy numbers were estimated with accuracy and precision; the mean ratios (and sd) for specimens, H, E, R, and N were 1.05 (0.06), 1.81 (0.12), 4.48 (0.28), and 8.60 (1.23), respectively. In summary, assays with the LSI HER-2/neu and CEP 17 Dual Color DNA Probe Kit, conducted at three sites by 6 different technicians, over 8 assay days, using kits from four lots, were performed with a high success rate in paraffin-embedded specimens. The signal enumeration was also accurate and precise. This study demonstrated that the results obtained by using the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe Kit are reliable and reproducible.

Breast Neoplasms↗