[Comparative studies on the radioactivity of bone cements containing x-ray contrast media and of the contrast media]. / Vergleichende Untersuchungen zur Radioaktivität von Knochenzementen und der darin enthaltenen Röntgenkontrastmittel.

Various PMMA bone cements containing zirconium oxide (ZrO2) as an X-ray contrast medium and zirconium oxides of several manufacturers were tested for their radioactivity by means of a gamma spectrometer. All the bone cements tested (Implast, Palacos R, and Sulfix-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. The examination of various zirconium oxides showed some high radioactive emissions. The risk of radiation-induced cancer seems to be small, because the cements are normally implanted in humans older than 60 years. In view of the fact that these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be replaced by high-purity radiation-free zirconium oxide or barium sulphate as soon as possible.

About radioactivity in some PMMA bone cements.

Various bone cements containing zirconium oxide (ZrO2) as X-ray contrast medium were tested for radioactivity by means of a gamma spectrometer. All measured bone cements (PALACOS, IMPLAST, SULFIX-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. As these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be substituted by high purity radiation-free zirconium oxide or barium sulfate.

[Comparative animal experiments on tissue compatibility and measurement of radioactivity of various roentgen contrast media]. / Vergleichende tierexperimentelle Untersuchung zur Gewebsverträglichkeit und Messungen der Radioaktivität verschiedener Röntgenkontrastmittel.

In a comparative study the tissue reaction of several X-ray contrast materials was examined by subcutaneous and intraperitoneal application on rats. There were tested Bariumsulphate (BaSO4) and three Zircondioxyde (ZrO2) samples of several manufactures (cubic and monocline ZrO2-Feldmühle; Optipur-Merck). In the histologic evaluation no inflammatory signs could be seen. In case of BaSO4 the tissue reaction was more distinct than in the ZrO2 samples. Within the tested ZrO2 samples the differences were small; the cubic ZrO2 showed the slightest, the monocline one the relatively strongest cellular reaction. We also measured the radioactive emission by the contrast media. Here the monocline and--first of all--the cubic ZrO2 showed an alarming radioactive emission (radium 3000-11,500 Bq/kg). Only the Optipur (Merck) was free of radiation and can so be recommended for human implantation. Also the BaSO4 had no measurable radioactive Emission. Therefore only these two X-ray contrast media can be recommended for human implantation.

Investigations on fly-ash and soil samples in the environment of a coal-fired power plant.

In the main wind direction of a coal-fired power plant dust and soil samples have been collected to analyse the content of fly-ash coming from the power plant. The fly-ash particles are spherical and contain the natural radionuclides mainly Ra-226, Pb-210, Po-210 and K-40 in a higher concentration when compared with the original coal. The investigation of soil samples results in increased Pb-210 and Po-210 concentrations when compared with the natural environment. By presence of spherical particles in dust and soil samples the power plant can be identified as the emitter.

[Changes in iodine metabolism in patients with burns treated topically with PVP-iodine]. / Jodstoffwechselveränderungen bei Brandverletzten unter PVP-Jod Oberflächentherapie.

Under exposure treatment of 33 burn patients with povidone-iodine (polyvinylpyrrolidon-iodine) preparations (Betaisodona ointment and solution) massive absorption of the iodine by the body and temporary changes in the thyroid hormones (T3 and T4 lowered, TSH raised) were found. No other clinical or laboratory-chemical side effects were observed in the patients. TRH stimulation test was carried out on 18 patients 3-6 months after ceasing povidone-iodine application. The results showed normoreaction of the hypothalamus-pituitary regulation. Povidone-iodine topical treatment of the burn patients involves them in substantial exposure to iodine, but offers no additional risk to the patients.

[Iodine resorption from PVP-iodine preparations after their use in humans]. / Resorption von Jod aus PVP-Jod-Präparaten nach Anwendung am Menschen.

The absorption of iodine from iodine-containing PVP preparations and the possibility of iodide being split off from the organic compound were tested in subjects with normal thyroid function after they had used PVP-iodine as mouth-antiseptic (15 subjects), vaginal gel (20 subjects) or liquid soap (20 subjects). Serum I-, T3, T4, TSH and urinary iodide excretion were measured, as an index of thyroid function, before and after the PVP application. Increase in iodine supply was up to 2 mg daily in the test subjects. The overwhelming proportion of the absorbed iodine (greater than 75%) was as organically bound iodine. In none of the subjects was there evidence of developing hyper- or hypothyroidism as a result of the additional iodine supply. Approximate values for the biological half-life and the distribution volume of total iodine in the body were also obtained.

Age dependent concentration of 226Ra in human bone and some transfer factors from diet to human tissues.

The concentration of 226Ra in more than 1000 human bone samples, still born infants, fetuses, blood, mixed diet, drinking water and mineral water has been measured. An age dependence of 226Ra concentration in human bone could be demonstrated. Up to an age of 20 yr two maxima of 226Ra concentration in bone occur, coinciding with the increased velocity of skeleton growth. Normally, the main source for uptake of radium by man is food. In Germany the transfer factor from diet to bone is about 0.098. Compared with data from literature for other countries, mainly the U.S.A., the German value is higher by a factor of about 1.5. This difference may be due to the lower calcium uptake in Germany which leads to higher resorption of radium. Two methods for measuring natural radium concentrations is biological material and water samples are briefly described: a gamma-gamma-coincidence method for indirect measurement of 226Ra via the short lived 214Bi(RaC) and an alpha-spectrometric method for direct measurement of the alpha-emission of 226Ra.

[Determination of iodine in plasma and biological fluids in the range 2 nmol/l with the aid of an autoanalyser (author's transl)]. / Jodbestimmung in Plasma und biologischen Flüssigkeiten in nmol/l-Bereich mittels Autoanalyzer.

An automated continuous flow method is described for the determination of iodine in biological fluids with a detection limit of 0.4 nmol/l. Our method uses the kinetics of the Sandell-Kolthoff-Reaction in sulfuric acid for the determination of iodide. The following applications are described: plasma inorganic iodine, total plasma iodine, protein bound iodine, total iodine in urine, drinking water and milk, total iodine in vegetables and laboratory diet for rats.

[Peripheral conversion of T4 and T3 in man]. / Periphere Umwandlung von T4 zu T3 beim Menschen

Our investigations of the peripheral metabolism of T4 and T3 in man demonstrate clearly that T3 is secreted by the thyroid gland and is peripherally formed by conversion from T4. The calculation of the disposal rates indicate furthermore that 40% of the daily metabolised T4 is converted to T3. In this way more than 60% of the daily production of T3 results from peripheral conversion of T4. Our results support the hypothesis that the physiological action of the thyroid hormones is effected mainly by T3.