Edward Siegel

Cellular attachment as a sensitive indicator of the effects of diagnostic ultrasound exposure on cultured human cells.

Dispersed cultured human cells (T-1 kidney, FL embryonic kidney, ES amniotic, and JHA amniotic) were seeded into plastic Petri dishes, incubated for 45 minutes, exposed to a clinical ultrasound source [total power output, 1.76 +/- 0.18 (S.D.) mW] for 0.25-60 minutes, and the medium replaced. Attachment was significantly reduced after only 0.50 minute of exposure. For all exposures, sensitivity of the JHA amniotic cells was greater than that of the kidney lines. Like incremental reduction in attachment, differential sensitivity among cell lines became less pronounced with protracted exposures. Thus cellular attachment is a sensitive parameter for studying the effects of diagnostic ultrasound.

Distribution in Blood and Excretion of Znc65 in Man.

Summary Distribution and concentration of Zn65 in whole blood, plasma and red cells were studied following intravenous infusion. Analyses of concentration curves suggest that they can be resolved into exponential components. Plasma Zn65 becomes protein-bound by 3 hrs following its injection and remains non-dialyzable at least up to 40 days. Red cell Zn65 becomes protein-bound and cannot be removed by dialysis from the hemoglobin solution. Excretion of Zn65 in the urine occurs presumably as an inorganic compound. Fecal excretion of Zn65 is variable and may depend on tissue saturation. The possibility exists that prolonged diarrhea may lead to zinc depletion. We acknowledge excellent technical assistance of Joseph V. Marino and other members of Laboratory staff.

BLOOD RADIATION DOSE DURING RADIOIODINE THERAPY OF METASTATIC THYROID CARCINOMA

At Montefiore Hospital, in the course of the last ten years, we have had an opportunity to study the effects of administration of large quantities of radioiodine to a considerable number of patients with metastatic thyroid carcinoma. Relatively early in our experience it became evident that radioiodine dosage is limited primarily by the effects of radiation delivered to the hematopoietic system by the circulating isotope. Assuming that the radiation dose to the blood-forming organs is correlated with the radiation dose to the circulating blood, studies of blood radiation dosage during radioiodine therapy, together with the resulting effect on the hematologic picture, may establish the degree of radioisotope toxicity. Marinelli and Hill (1) studied the blood radioiodine concentration in a number of patients, including 7 of the Montefiore Hospital series, and have calculated the resulting radiation received by the blood. Rawson, Rall, and Peacock (2) have discussed the effects of irradiation on some of the ...

Conversion of 6,7-H3-Estradiol-17β into Estrone and Estradiol-17α in the Mature Male Dog.

Summary 1. H3-labelled estrone, estradiol-17β and estradiol-17α were isolated from dog urine after intravenous injection of 6,7-H3-estradiol-17β. 2. The urinary estrogens were mostly bound to glucuronic acid. 3. Estradiol-17α is a major metabolite in the urine.

IRRADIATION PRODUCED RISE IN BLOOD RADIOIODINE CONCENTRATION FOLLOWING INGESTED THERAPEUTIC DOSE FOR METASTATIC THYROID CARCINOMA

Summary Four to 8 days after ingestion of therapeutic doses of radioiodine (50-200 mc) by patients with metastatic thyroid carcinoma, a rise occurs in blood radioiodine concentration which we attribute to irradiation damage to the thyroid gland or thyroid tumor tissue. This increase we have termed the irradiation produced rise. In a series of patients the magnitude of the IPR in general has been found to increase during radiation thyroidectomy with the quantity of radioiodine retained by the thyroid. In a given patient the magnitude and incidence of the IPR decrease with successive doses as functioning thyroid tissue is progressively destroyed. Finally, when there is no longer any functioning tissue, as demonstrated by absence of I∗ uptake, the blood radioiodine concentration rapidly falls to very low levels and there is no IPR. The blood of 21 patients, in various stages of therapy, was studied. For all of 7 radiation thyroidectomy doses, significant IPRs were found; in thyroidectomized patients with functioning metastases, IPRs were demonstrated in 8 of 33 doses. However, no such rise in blood iodine concentration was observed following four doses to thyroidectomized patients lacking demonstrable I∗ uptake. Since no such rise is found in the absence of functioning thyroid tissue, either neoplastic or non-neoplastic, the occurrence of an IPR in a thyroidectomized patient may, therefore, be considered evidence of the existence of viable functioning thyroid carcinoma metastases.

Fate of Radiosulfate in Multiple Myeloma.

Summary Radiosulfur (S35) as sodium sulfate was administered intravenously in doses ranging from 0.867 to 2.07 mc, to 9 patients with multiple myeloma and to 10 patients with other neoplasms. The fate of administered sulfate was apparently the same for both groups of patients. S35 was rapidly turned over and excreted; 30 to 90% appeared in urine within 48 hours. Blood levels of S35 closely paralleled those of plasma and decreased rapidly. It was possible to demonstrate that 3 exponential rates governed the disappearance of S35 from whole blood and plasma. The mean zero-time radiosulfate space of dilution was 9.29 ± 2.16 liters for patients with multiple myeloma and 11.4 ± 2.87 liters for those with other neoplasms. By technics employed, a preferential retention of sulfate could not be demonstrated in multiple myeloma as compared to other neoplasms.

Radiobiology for the Radiologist

Organized into two sections. Part 1 is sufficient for students of Radiology and Nuclear Medicine and follows the syllabus published by RSNA. Students in Radiation Oncology need the general information contained in Part 1, but also need the more specialized information contained in Part 2. New chapters introduce new therapies on medical countermeasures to radiation exposure and new molecular techniques in radiology. Mirrors the format of the Syllabus in Radiation Biology prepared by the Radiological Society of North America (RSNA). Written for residents, researchers, and graduate students in radiology, nuclear medicine, radiation oncology, and medical physics. Generally considered the most comprehensive textbook on cellular and molecular radiobiology.