Postprandial changes in the exhalation rate of radon produced in vivo.

The rate of exhalation of radon by persons with long-standing radium burdens increases about twofold shortly after a meal. The increase is short-lived and "normal" values are regained in 1.5 to 2 hours. The effect may account in part for the poor reproducibility in estimates of the freely emanating part of the radium content.

Radioactivity measurements of former military personnel exposed to weapon debris.

Sixteen former military personnel who were present at the "Smoky" atmospheric nuclear weapon test have been investigated for internal deposits of radioactivity. Whole-body and thorax gamma-ray measurements, thorax and skeletal actinide measurements, and urinalyses for plutonium-239 and strontium-90 indicated no evidence of radioactivity in excess of that found in the general population.

Distribution and retention in bone of 226Ra and comparison with the ICRP 20 model.

Analyses are presented of the ratios of 226Ra to calcium in over 650 samples of compact and cancellous bone from 66 female and 26 male subjects who had died from less than 1 to 60 yr after first exposure to radium. The 226Ra/Ca ratios were normalized to the terminal 226Ra skeletal content. The 226Ra/Ca ratios for vertebrae were essentially identical to those for other cancellous bone for a given subject. Comparisons of the data with predictions of the ICRP model of alkaline earth metabolism show that for female cancellous bone the normalized 226Ra/Ca ratios tended to be greater than predicted, while those for female cortical bone (femoral and tibial shaft) tended to be less. The data for males were fitted better by the model. A modification of the model to reduce the amount of radium deposited in soft tissue fitted the data better in some respects. A straight line linear least squares fit to the data appeared to fit as well as, or better than, the models. A radiation effect was suggested in that the normalized 226Ra/Ca ratio for vertebrae relative to the ratio expected increased with skeletal absorbed dose for vertebrae. However, no such effect was apparent for compact bone or for the cancellous bone as a whole.

[Anti-proliferative effects of tumor necrosis factor and gamma interferon on human ovarian cancer cell lines].

Two ovarian cancer cell lines, 3AO and NIH: OVCAR-3, were used in this study to assess the synergistic effect of TNF and IFN gamma in combination. The result showed that these two ovarian cancer cell lines were all resistant to TNF and IFN gamma individually, but sensitive to the combined administration of TNF and IFN gamma. Concentration of 1 x 10(4) U/L of TNF and IFN gamma significantly inhibited 3AO and NIH: OVCAR-3 ovarian cancer cells (P < 0.05). Administration of 1 x 10(6) U/L TNF and IFN gamma could inhibit the growth of 3AO cells by 55% and NIH: OVCAR-3 cells by 75% (P < 0.01). It suggests that in some ovarian cancer cells which resistant to TNF could be changed to TNF sensitive cells by IFN gamma. anticancer treatment higher antitumor activity could be achieved by combined administration of TNF and IFN gamma.

[Changes in blood oxytocin levels in cases of pregnancy induced hypertension].

Serial measurements of plasma oxytocin concentration were done by radioimmunoassay in 38 cases of pregnancy induced hypertension (PIH) and 38 cases of normal pregnancy (NP). The results showed that there was no obvious difference in the plasma oxytocin concentration between patients with early PIH and NP, but a higher concentration in cases with PIH at term pregnancy than that in NP and a significantly higher level in intrapartum women with PIH. The results also indicated a much higher oxytocin concentration in cases of moderate and severe PIH as compared to that of NP. An obviously higher level of plasma oxytocin was found in severe PIH than in mild PIH. Based on this study we suggest that the clinical use of oxytocin in cases with PIH should be different from that in NP.