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In addition to gamma radiation of 140 keV 99mTc emits during the transition to 99Tc electrons of low energy and tiny path-lengths. These Auger electrons cannot be utilized in diagnostic procedures. However, they were discussed frequently for therapeutic application. Hitherto proof of effect of the Auger electrons from 99mTc is missing which is supplied now in an in vitro-system in comparison to beta-emitter 131I.The thyroid cell line PCCl3 (sodium iodide symporter (NIS)-positive) was incubated with 131I-sodium iodide (131I) or 99mTc-pertechnetate (99mTc) in presence or absence of perchlorate. For comparison the amount of radioactivity was adjusted to obtain the same dose from extracellular irradiation for both radionuclides. The colony forming assay detects the clonogenic cell survival as surviving fraction. In addition, intracellular radionuclide uptake was quantified.Dose effect curves were established for 131I and 99mTc for variable extra- and intracellular distribution of the radioactivity. In presence of perchlorate no cellular uptake of radioactivity was detectable. Survival curves were largely comparable confirming the dosimetric calculations. In absence of perchlorate cellular radiotracer uptake varied from 1.39% (131I) to 1.90% 99mTc). Effects on survival were twice for the beta-emitter and ten-fold higher for 99mTc.Intracellular uptake of 131I and 99mTc increases DNA-damage compared to strict extracellular radiotracer distribution which was demonstrated by means of colony forming assay. Increasing radiotoxicity from intracellular 99mTc is explained most likely by increased dose deposition in cellular structures due to Auger- and conversion-electrons of low range and high local energy deposition.

2,3,7,8-Tetrabrombicyclo[4.1.1]oct-3-en (7) ging mit LiAlH4 unter Allylumlagerung in das Tribromid 8 uber, das bei der Einwirkung von n-Butyllithium 4-Bromtricyclo[5.1.0.02,8]oct-3-en (9) lieferte. Letzteres ergab mit Natrium/tert-Butylalkohol Tricyclo[5.1.0.02,8]oct-3-en (4). Die Hydrierung von 4 zu Tricyclo[5.1.0.02,8]octan (6) wurde mit Diimin ausgefuhrt und war von der Bildung von Bicyclo[5.1.0]oct-2-en (10) begleitet. Mit Natriumiodid brachte 7 das nicht umgelagerte Iodid 12 hervor, und die Reduktion von 7 mit Natrium in flussigem Ammoniak fuhrte in geringer Ausbeute zu Bicyclo[4.2.0]octa-3,7-dien (11). AgNO3 wandelte 7 unter Allylumlagerung in das Nitrat 13 um, das mit LiAlH4, wieder unter Allylumlagerung, das Tribromid 14 ergab. Bei der Behandlung von 14 mit n-Butyllithium fiel 4-Bromtricyclo[5.1.0.02,8]oct-4-en (15) an, und daraus wurde mit Natrium/tert-Butylalkohol Tricyclo[5.1.0.02,8]oct-4-en (5) gewonnen. Ein neuer Weg zu Octavalen (1), auf dem praktisch kein Cyclooctatetraen als Nebenprodukt entsteht, wurde durch Umsetzung von 4-Bromoctavalen (16) mit tert-Butyllithium und anschliesende Hydrolyse gefunden. – Bei 100°C ging 4 praktisch quantitativ in Dihydrosemibullvalen (17) uber (t1/2 ≈ 40 min). Der Zerfall von 5 lieferte bei 200°C (t1/2 ≈ 25 h) ein komplexes Gemisch, in dem nur 11 identifiziert wurde. Der gesattigte Kohlenwasserstoff 6 lagerte bei 160°C nahezu quantitativ in ein 5.5:1-Gemisch aus 3-Methylencyclohepten (18) und 1,3-Cyclooctadien (19) um (t1/2 ≈ 8 h). Mogliche Mechanismen dieser Thermolysen werden diskutiert. Tricyclo[5.1.0.02,8]-oct-3-ene, -oct-4-ene, and -octane: Preparation and Thermolysis of the Hydro Derivatives of Octavalene On treatment of 2,3,7,8-tetrabromobicyclo[4.1.1]oct-3-ene (7) with LiAlH4 an allylic rearrangement occurred with formation of tribromide 8, which was converted into 4-bromotricyclo[5.1.0.02,8]oct-3-ene (9) by n-butyllithium. Sodium/tert-butyl alcohol and 9 reacted to give tricyclo[5.1.0.02,8]oct-3-ene (4). Hydrogenation of 4 was achieved with diimine and afforded tricyclo[5.1.0.02,8]octane (6) along with some bicyclo[5.1.0]oct-2-ene (10). Sodium iodide transformed 7 into the unrearranged iodide 12. Reduction of 7 with sodium in liquid ammonia led to bicyclo[4.2.0]octa-3,7-diene (11) in low yield. An allylic rearrangement took place when 7 was treated with AgNO3 to give nitrate 13. In another allylic rearrangement tribromide 14 was formed from 13 and LiAlH4. The reaction of 14 with n-butyllithium afforded 4-bromotricyclo[5.1.0.02,8]oct-4-ene (15), and from 15 tricyclo[5.1.0.02,8]oct-4-ene (5) was obtained by means of sodium/tert-butyl alcohol. By treatment of 4-bromooctavalene (16) with tert-butyllithium and subsequent hydrolysis, a new route to octavalene (1) was elaborated with virtually no formation of cyclooctatetraene as side product. – At 100°C 4 rearranged (t1/2 ≈ 40 min) almost quantitatively to dihydrosemibullvalene (17). The decomposition of 5 at 200°C (t1/2 ≈ 25 h) gave a complex mixture, in which only 11 has been identified. The saturated hydrocarbon 6 was converted virtually quantitatively into a 5.5:1 mixture of 3-methylenecycloheptene (18) and 1,3-cyclooctadiene (19) at 160°C (t1/2 ≈ 8 h). Possible mechanisms of these rearrangements are discussed.

Every varicosis can be treated without operation if injection therapy is correctly carried out. The patient stands upright, a thick needle (1.2 mm) is inserted into the varix. The venous blood flows out, the patient lies down. Injection is made with the leg in a high position (30 degrees), compression follows each sclerosing injection. Intraarterial injections can be avoided by using a thick needle. Retained intravaricose blood should be incised to avoid pigmentation. Rapid treatment is possible with 3-5 days. As with our ordinary treatment, we give 5-10 injections daily with Varigloban 2-8%.