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Die Mitteldeutsche Kristallinzone (MKZ) ist eine der Schlüsselregionen, um die Entwicklung der Varisziden nachzuvollziehen. Deformationsprozesse im Böllsteiner Odenwald als integralem Bestandteil der MKZ sind in der Vergangenheit bereits untersucht worden, allerdings blieb der genaue Zeitrahmen unsicher. Daher wurde eine Studie im Steinbruch Weichberg durchgeführt, die Strukturanalyse und Altersdatierung (U-Pb an Zirkon) kombiniert. Der Kontakt zwischen metagranitoidem Kern und metasedimentärer Schieferhülle des Böllsteiner Odenwaldes ist hier gut sichtbar aufgeschlossen. Gesteine der Schieferhülle und darin intrudierte silurische granodioritische Sills zeigen mindestens zwei Faltungsphasen: Liegende enge bis isoklinale Falten sind überprägt von aufrechten schwach geöffneten Falten. Ein Pegmatitgang, der um 411 ±2 Ma in die Gesteine der Schieferhülle intrudiert, schneidet deren Foliation senkrecht, zeigt selbst aber nur eine gering ausgeprägte Foliation in Verbindung mit der Isoklinalfaltung. Folglich muss die Isoklinalfaltung bevor 411 ±2 Ma (Unterdevon), aber nach der silurischen Intrusion der granodioritischen Sills (ca. 423 Ma; Dörr et al. 2022) aktiv gewesen sein. Im Steinbruch Weichberg ist der Kern repräsentiert durch einen (Meta-)Granit ohne isoklinale Faltung, der um 404 ± 2 Ma in die Schieferhülle intrudiert. Eine deformierte Falte direkt am Kontakt zwischen Metagranit und Metasedimenten und Gänge, die am Kontakt abgeschnitten werden, deuten auf postintrusive tektonische Bewegungen entlang dieses Kontaktes. Die hier beschriebenen Deformationen resultieren möglicherweise aus der Kollision der MKZ mit dem NW-Rand der Saxothuringischen Zone. Ähnlichkeiten in Hinblick auf Intrusions- und Deformationsalter bzw. Deformationsstile können in anderen Einheiten der europäischen Varisziden wie beispielsweise dem Léon-Gebiet (z. B. Faure et al. 2010) oder der Ossa-Morena-Zone (z. B. Simancas et al. 2001) gefunden werden.

Die Mitteldeutsche Kristallinzone (MGCZ) ist ein integraler Teil der europäischen Varisziden. Sie ist ein heterogenes tektono-metamorphes Terran zwischen Armorica (Gondwana) und dem Old-Red-Kontinent (Laurussia). An der Devon-Karbon-Grenze intrudiert (362 ±9 Ma) der Frankenstein-Gabbro (Einheit I) des nördlichen Odenwaldes (MGCZ; mit niedrigen 87Sr/86Sri-Werten von 0,7035, positiven εNd-Werten von +3.8) in die höhere Kruste (4 km Tiefe) eines oberdevonischen (375 ±5 Ma, Frasnian) Inselbogens (Olivine-Gabbro und Wehrlite) oder in eine ausgedünnte kontinentale Kruste. Ar-Ar-Plagioklas-Abkühlungsalter von 359 ±3 Ma beweisen eine Exhumierung des Gabbros in die Nähe der Erdoberfläche bereits am Ende des Devons (Kirsch et al. 1988). Die kalk-alkalinen Gabbros, Diorite und Granodiorite bis Tonalite des zentralen Teils des West-Odenwalds (Einheit II) mit niedrigen 87Sr/86Sri-Werten (0,7047) und positiven εNd-Werten (+0.8 bis -0,3) sind Teil eines frühkarbonischen (354 ±
4 Ma bis 337 ±2 Ma) Komplexes plutonischer Gesteine, welche durch eine Subduktionszone gebildet wurden. Granodiorite und Quarzmonzonite bis Granite (346 ±1 bis 337 ±2 Ma) einer hoch-Kalium kalk-alkalinen bis shoshonitischen Serie mit höheren Werten von 87Sr/86Sri (0,7076 bis 0,708) und niedrigen von εNd (-2 bis -4) im südlichen Teil des West-Odenwaldes (Einheit III) sind zeitgleich mit den subduktionsbezogenen Plutonen der Einheit II und können durch einen höheren Anteil von Krustenkontamination der Schmelze während einer Kontinentkollision erklärt werden. Der südliche Teil des Odenwaldes kollidierte zuerst mit Laurussia. Während der zeitgleichen Subduktion und Kollision nehmen die tektonischen Einheiten des Odenwaldes verschiedene Positionen am nordwestlichen, aktiven Kontinentalrand von Armorica ein. Der finale tektonische Kontakt zwischen den Einheiten des West-Odenwaldes tritt etwa vor 323 Ma ein (Abkühlung unter 300 °C), am Ende der variszischen Kollision, aber nicht später als die oberkarbonische Extension (Bashkirium, 320 Ma), welche zur Bildung des kohleführenden Saar-Nahe-Beckens auf der Mitteldeutschen Kristallinzone führte. Im Vergleich zu anderen plutonischen Komplexen der variszischen Gebirgskette enthalten die meisten karbonischen Plutone des West-Odenwaldes eine hohe Anzahl ererbter Zirkone. Diese werden während der Schmelzbildung aus der unteren Kruste aufgenommen, die den silurischen bis devonischen Gneisen des Ost-Odenwaldes (Einheit IV, Böllstein-Odenwald) ähnelt oder ihr Äquivalent ist. Seit dem unteren Tournai bildet ein silurisches bis unterdevonisches Grundgebirge die untere Kruste des West-Odenwaldes.

For a long time, the 1.38 Ga old Dobra Gneiss (Type A) from the Lower Austrian Drosendorf Unit (Moldanubian Zone, Bohemian Massif) was considered the oldest rock of Austria. We now have dated zircons from a local mafic inlayer in the Dobra Gneiss Type A, termed Hauergraben Gneiss. This small-scale amphibole-bearing orthogneiss has a magmatic formation age of 1.40 Ga, and is, thus, to the present state of knowledge, the oldest rock of Austria. Based on geochemical investigations, the protolith of the Hauergraben Gneiss was a quartz-monzonite. It probably originated in a volcanic arc setting like the Dobra Gneiss, but shows distinctively higher transitional metal contents (especially Cr and Co), higher Ba and Sr, and higher light rare earth element contents, which hint at a lithospheric mantle input. This 1.40 Ga old mafic arc material was then incorporated into the 1.38 Ga old intrusive protolith of the Dobra Gneiss, probably in the form of enclaves. Considering the model that the Drosendorf Unit was part of Amazonia until the late Neoproterozoic, we propose that both, Dobra Gneiss Type A and Hauergraben Gneiss, originated at the western margin of the Columbia super-continent, where several long-lived Mesoproterozoic volcanic arcs existed and accreted over time. During the Variscan orogeny, the Hauergraben Gneiss experienced peak metamorphic temperatures of ~620 °C at pressures of ~6 kbar, as can be deduced from amphibole thermobarometry. This is in line with published peak-PTestimates from other parts of the Drosendorf Unit. Formation of secondary low-Al magnesiohornblende at the expense of the earlier edenitic/pargasitic peak amphibole indicates a subsequent retrograde overprint.

The present study is focusing on Variscan basement xenoliths, which are present inside pyroclastic rocks of the Miocene Vogelsberg volcanic field (VVF). The investigated samples have been collected from quarries situated at the SW margin of the Vogelsberg (Nickel quarry, Nidda Ober-Widdersheim) and at the NE margin of the Vogelsberg (Rauher Berg quarry, Alsfeld-Brauerschwend). Moreover, we investigated different types of trachyte, which are present (1) as xenoliths inside an alkali basaltic tuff breccia of the Nickel quarry, (2) as trachytic lava from an outcrop at the Häuserhof (Nidda Ober-Widdersheim), and (3) as part of a trachytic/phonolitic lava dome drilled in the central VVF near Schotten-Sichenhausen.Apart from one garnet-bearing sample, the investigated basement xenoliths consist of phyllite and basic to felsic metavolcanics. Both the metamorphic index minerals and the quartz deformation microfabrics suggest that these rocks underwent greenschist facies metamorphism, and thus can be attributed to the Northern Phyllite Zone of the Variscan chain. These findings allow tracing the Northern Phyllite Zone from the Rhenish Massif via the VVF to the Harz Mountains. Variscan basement underneath the VVF is also documented by inherited U-Pb zircon ages obtained from the Häuserhof trachyte (366 ± 8.5 Ma and 294 ± 3 Ma) and from the trachyte of the Sichenhausen-Eschwald drilling (323 ± 12 Ma to 344 ± 6 Ma and ages ranging from the Middle Proterozoic to Cambrian/Ordovician boundary). The Permian and Carboniferous ages correlate with widespread late-Variscan volcanic activity in Central Europe at ~290 Ma, and with granitoid intrusions along the Rheic suture during the main phase of the collision of the Rhenohercynian and Saxothuringian domains at ~340 Ma, respectively. For the Latest Devonian ages (366 ± 8.5 Ma) several scenarios are possible. Middle Proterozoic to Cambrian/Ordovician ages are regarded as reworking of pre-Variscan sedimentary and magmatic material. The new ages and the garnetbearing xenolith, the metamorphic grade of which does not fit with the greenschist facies rocks of the Northern Phyllite Zone, suggest that rocks of both the Northern Phyllite Zone and the Mid-German Crystalline Zone are present underneath the volcanic rocks of the VVF.The U-Pb zircon ages of trachytic xenoliths of the Nickel quarry suggest the emplacement of a trachytic lava dome at 66.7 ± 0.4 Ma. Similar ages have been obtained from camptonitic dykes and trachyte intrusions within Permian and Triassic sediments exposed at the southwestern margin of the VVF. The large amount of trachyte together with a significant positive magnetic anomaly in the southwestern VVF might indicate a magma chamber that developed at shallow crustal levels below the southwestern part of the present Vogelsberg during the Upper Cretaceous. The new results have been used to develop a model for the early evolution of the southwestern Vogelsberg.

We investigated volcanic and sedimentary rocks of the Toplou Beds, which constitute the uppermost part of the Tyros Unit of eastern Crete. U-Pb TIMS analyses of zircons, separated from a metarhyolite of the lower Toplou Beds, yielded concordant ages at 361.2 ± 1.2, 307.4 ± 1.2 and 228 ± 1.7 Ma. The youngest age is interpreted to reflect the timing of melt emplacement in Carnian times. The older ages are inherited from zircons, which belong to the crystalline basement through which the rhyolite melt was ascending. At higher stratigraphic levels we found fern fragments inside black slates, which are intercalated with Carnian metasandstones and metaconglomerates. The fern fragments resemble most closely the genus Phlebopteris, which is typical for the Triassic to Early Jurassic of Europe. Findings of the foraminifera Gandinella falsofriedliinside dolomite of the uppermost part of the Toplou Beds suggest a Norian/Rhaetian age. As the basal parts of the Tripolitza Nappe yielded Ladinian and Carnian ages, the Tyros Unit cannot continue upwards into the Tripolitza Platform. The misfit in ages and the inversion in metamorphic grade of Tyros and Tripolitza rocks suggest a thrust contact between both units.The Triassic records inside the Tyros Unit can be explained by subduction and collision following the closure of the Palaeotethys. Subduction underneath the Cimmerian ribbon continent is documented by metaandesite in the basal parts of the Tyros Unit (Chamezi Beds), which rest unconformably on top of Carboniferous/Permian crystalline basement. The andesites and shallow marine clastics are interpreted to have been deposited in a fore-arc position. Redeposited neritic carbonates in the form of pebbles in Lower Triassic and Anisian conglomerates of the Chamezi and Tripokefala beds, respectively, suggest uplift and erosion of pre-existing carbonate platforms. This phase of uplift and erosion is attributed to collision of Pelagonia with the Cimmerian ribbon continent following the closure of the Palaeotethys. Uplift and erosion were still active in Ladinian times explaining the lack of Ladinian fossils inside the Tyros Unit. The shallow-marine and terrestrial conditions during Carnian sedimentation of the Toplou Beds can be well correlated with the conditions during deposition of the Cassianer/Raibler Beds of the Southern Alps.GermanDie Toplou-Schichten bilden die tektonostratigrafisch höchste Einheit der ostkretischen Tyros-Schichten. U-Pb-TIMS-Analysen von Zirkonen eines Metarhyoliths der unteren Toplou-Schichten ergaben konkordante Alter von 361,2 ± 1,2, 307,4 ± 1,2 und 228 ± 1,7 Ma. Das jüngste Alter wird als karnisches Platznahmealter des Rhyoliths interpretiert. Die höheren Alter stammen von ererbten Zirkonen aus dem unterlagernden Grundgebirge. In höheren stratigrafischen Einheiten der Toplou-Schichten liegen gut erhaltene Farn-Fragmente in schwarzen Schiefern vor, die mit karnischen Metasandsteinen und Metakonglomeraten in Wechsellagerung stehen. Die Farn-Fragmente gehören mit höchster Wahrscheinlichkeit zum Genus Phlebopteris, der charakteristisch für die triassischen bis frühjurassischen Sedimente in Europa ist. Foraminiferen der Gattung Gandinella falsofriedliin Dolomiten der obersten Toplou-Schichten zeigen ein norisch-rhaetisches Alter an. Da die basalen Tripolitza-Einheiten zum Teil ein ladinisches bis karnisches Alter aufweisen, können die Tyros-Schichten nicht das sedimentäre Unterlager der Tripolitza-Einheit darstellen. Dieser Sachverhalt und die Inversion im Metamorphosegrad zwischen Tyros- und Tripolitza-Gesteinen belegen einen Überschiebungskontakt zwischen beiden.Die triassischen Überlieferungen in den Tyros-Schichten können durch Subduktion und Kollision in Folge der Schließung der Paläotethys erklärt werden. Subduktion von Lithosphäre unter den Kimmerischen Streifenkontinent ist durch mächtige Metaandesitfolgen dokumentiert, die den basalen Teil der Tyros-Schichten (Chamezi-Schichten) darstellen. Diese lagern diskordant auf einem karbonisch/permischen kristallinen Grundgebirge. Die Andesite und flach-marine Klastite wurden vermutlich in einer ,,fore-arc“-Position abgelagert. Umgelagerte neritische Karbonate in Form von Geröllen innerhalb der untertriassischen und anisischen Konglomerate der Chamezi- und Tripokefala-Schichten zeigen Heraushebung und Abtragung von prä-existierenden Karbonatplattformen an. Diese Phase ging einher mit der Kollision von Pelagonia und dem Kimmerischen Streifenkontinent. Das Fehlen von ladinischen Fossilien in den Tyros-Schichten zeigt anhaltende Heraushebung und Abtragung im Ladin an. Die flachmarinen bis terrestrischen Bedingungen während der karnischen Sedimentation der Toplou-Schichten stehen in Einklang mit den Sedimentationsbedingungen der Cassianer/Raibler Schichten der südlichen Alpen.

The subsolidus Variscan evolution of several small granitic bodies from the southern Bayerischer Wald (Bavarian Forest) indicates the presence of a new deformation phase referred to as D3. The principal compression direction was N–S to NNW–SSE during a long period of time and in a wide temperature range, leading to the development of the Bayerischer Pfahl shear zone system and to the deformation by dextral shear of the migmatites located in the surroundings of the Fürstenstein Pluton. The “D3shear zone system” consists of an array of sinistral shear zones trending ENE to ESE, which are commonly found in granitoids. D3took place under upper greenschist to lower amphibolite facies conditions, as supported by the observed fabrics and quartz textures. Both, the intrusion and the deformation of the granitoids affected by D3occurred at deep to intermediate levels of the crust. New and pre-existing geochronological data constrain the age of D3to about ∼315 Ma, whereas the intrusion of at least some of the sheared granitoids was pre-kinematic with respect to D3, as exemplified by the Saunstein dyke (324.4 ± 0.8 Ma). D3was triggered by rotation of the principal compression direction towards a NE–SW direction. This rotation was either related to the late-Variscan switch in the convergence direction between Laurussia and Gondwana, or was caused by local perturbations of the regional stress field. Those perturbations may be related either to the intrusion of large stocks, such as the Saldenburg granite, or to the existence of ephemeral releasing bends at the Bayerischer Pfahl shear zone.

Abstract: The broad application of low energy X-rays below about 50 keV in radiation therapy and diagnostics and especially in mammography substantiates the precise determination of their relative biological effectiveness (RBE). A quality factor of 1 is stated for photons of all energies in the International Commission on Radiological Protection Recommendations. However, the RBE of low-energy X-rays compared to high-energy photons was found to be dependent on photon energy, cell line and endpoints studied, hence varying from less than one up to about four. In the present study, the human mammary epithelial cell line MCF-12A has been chosen due to the implementation of the results in the estimation of risk from mammography procedures. The RBE of 25 kV X-rays (W anode, 0.3 mm Al filter) relative to 200 kV X-rays (W anode, 0.5 mm Cu filter) was determined for clonogenic survival in the dose range 1–10 Gy and micronuclei (MN) induction in the range 0.5–3.5 Gy. The RBE for clonogenic survival was found to be significantly higher than 1 for surviving fractions in the range 0.005 < S < 0.2. The RBE decreased with increasing survival, with an RBE0.1 at 10% survival of 1.13 ± 0.03. The effectiveness of soft X-rays for MN induction was found to be 1.40 ± 0.07 for the fraction of binuclear cells (BNC) with MN and 1.44 ± 0.17 for the number of MN per BNC. In contrast, the RBE determined from the number of MN per MN-bearing BNC was found to be 1.08 ± 0.32. This indicates that the effectiveness of 25 kV X-rays results from an increase in the number of damaged cells, which, however, do not have higher number of MN per cell.

Purpose:: To quantify the reduction of radiation-induced oral mucositis by amifostine as a function of administration route.Material and Methods:: Mucosal ulceration of lower mouse tongue epithelium was analyzed. Amifostine was injected at 1.8 mg/injection subcutaneously (s.c.) or intravenously (i.v.), 45 min or 10 min prior to irradiation. With single-dose irradiation, a single amifostine injection was given. During daily fractionated irradiation (5 3 Gy) for 1 week, amifostine was administered s.c. or i.v. twice (days 0, 3), or s.c. on all irradiation days (days 0–4). With ten fractions over 2 weeks, five s.c. injections were given in week 1 (days 0–4) or week 2 (days 7–11), or both. Two i.v. injections were given either in week 1 (days 0, 3) or week 2 (days 7, 10). All fractionation protocols were terminated by graded test doses to generate full dose-effect curves.Results:: In a single-dose control experiment, the ED50(dose after which ulcer induction is expected in 50% of the mice) was 11.7 1.4 Gy. Intravenous application of amifostine increased the ED50to 14.0 1.4 Gy (p = 0.024), while s.c. administration had no significant effect. The ED50for test irradiation after 5 3 Gy was 5.8 1.4 Gy. Two s.c. or i.v. amifostine injections yielded ED50values of 7.2 1.1 Gy (p = 0.0984) or 7.6 1.2 Gy (p = 0.0334); five s.c. injections increased the ED50to 8.2 0.9 Gy (p = 0.0039). The ED50after 10 3 Gy/2 weeks was 6.6 1.8 Gy. Subcutaneous or intravenous administration of amifostine in week 1 yielded a significant increase in ED50to 9.4 2.5 Gy (p = 0.0099) and 10.0 2.2 Gy (p = 0.0014). By contrast, amifostine administration in week 2 had no significant effect. Administration in weeks 1 and 2 resulted in an ED50of 10.8 3.6 Gy (p = 0.0053).Conclusion:: Amifostine during daily fractionated irradiation is effective only if administered in the initial treatment phase, i.e., week 1 in the mouse. The differences in the effect in weeks 1 and 2 suggest mechanisms of action other than radical scavenging.

Purpose:: To compare tests for intestinal function with clinical scores after abdominal irradiation. Patients and Methods:: At the Department of Radiotherapy, Erfurt, Germany, intestinal changes were studied in 91 patients receiving abdominal radiotherapy between 1992 and 1996. Conventional fractionation (1.8–2 Gy per fraction, total doses 30.6–62.5 Gy) was applied. Before and at weekly intervals during radiotherapy, the clinical response was scored according to RTOG/EORTC for the upper and lower gastrointestinal (GI) tract. Resorption tests for vitamin B12and D-xylose were performed before the onset and immediately after treatment. Results:: The clinical response displayed a well-defined dose-effect relationship with grade 1 effects in 5% and 50% of the patients at about 10 Gy and 50 Gy, respectively. For grade 2 reactions, 5%- and 50%-effective doses were 20–30 Gy and 60–80 Gy. Effects in the upper and lower GI tract were highly correlated. Changes in body weight did not show a correlation with other clinical symptoms. Changes in resorption also displayed a significant dose effect. However, no correlation was found with the clinical symptoms in the individual patient. Conclusion:: In the present study, the clinical manifestation of intestinal side effects according to RTOG/EORTC criteria was reflected by neither the vitamin B12nor by the D-xylose resorption test. Hence, these tests cannot be regarded as useful for objective quantitation of intestinal radiation injury.

Hintergrund: Über die Auswirkungen einer Bestrahlung im Kindesalter am Zahnapparat gibt es bisher nur wenige Mitteilungen. Ursache für einen frühzeitigen Zahnverlust scheint eine Verkleinerung der Wurzeloberfläche nach Strahleneinwirkung zu sein. Die Schädigung des Zahnhalteapparats ist in der Regel eine Folge der bei Neoplasien im Kindesalter üblicherweise angewandten Radiochemotherapien. Auch die alleinige Chemotherapie resultiert in Störungen der Entwicklung des Zahnhalteapparats. Fallbericht: Es wird über einen 33-jährigen Patienten berichtet, der im Alter von 11 Jahren wegen einer akuten lymphatischen Leukämie mit Rezidiv eine intensive Chemotherapie und eine Neuroachsen- und Hirnschädelbestrahlung erhielt. Der Patient wurde in der Implantationssprechstunde der Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie vorstellig, da er schwere Zahnveränderungen mit Zahnverlust trotz guter zahnärztlicher Betreuung und Mundhygiene aufwies. Die Dosen der Bestrahlung im Kindesalter am Ober- und Unterkiefer wurden auf 8–25 Gy geschätzt. Schlussfolgerung: Eine intensive lebenslange zahnärztliche Nachbetreuung von Patienten mit durchgemachten Tumorerkrankungen im Kindesalter muss gefordert werden, um einerseits die Therapiefolgen an den Zähnen durch geeignete Pflegemaßnahmen zu verringern, zum anderen aber auch rechtzeitig die notwendigen zahnärztlichen prothetischen Maßnahmen einzuleiten.

Low energy x-rays (E ph =50 keV) are widely used in diagnostic radiology and radiotherapy. However, data on their relative biological effectiveness (RBE) are scarce. Of particular importance for risk estimation are the RBE values of x-rays in the range which is commonly used in mammography (10–30 keV). We have determined clonogenic survival after low-energy x-ray irradiation for three cell lines: primary human epidermal keratinocytes (HEKn), mouse fibroblasts (NIH/3T3) and Chinese hamster fibroblasts (V79). Experiments were performed with a 25 kV x-ray tube and compared to 200 kV x-rays as a reference. Compared to the effect of 200 kV x-rays, irradiation with 25 kV x-rays resulted in a decreased survival rate in the murine fibroblasts, but not in the human epithelial cell line. The RBE value was calculated for 10% surviving fraction. For HEKn cells, RBE was 1.33±0.27, for NIH/3T3 cells 1.25±0.07 and for V79 cells 1.10±0.09, respectively. No consistently increased RBE was observed in the various cell lines. Nevertheless, a potential of increased cytogenetic changes has to be considered for risk estimation of low-energy x-rays.

A relative biological effectiveness (RBE) not much larger than unity is usually assumed for soft x-rays (up to ≈50 keV) that are applied in diagnostic radiology such as mammography, in conventional radiotherapy and in novel radiotherapy approaches such as x-ray phototherapy. On the other hand, there have been recent claims of an RBE of more than 3 for mammography and respective conventional x-rays. Detailed data on the RBE of soft x-rays, however, are scarce. The aim of the present study was to determine the effect of low-energy x-rays on chromosomal damage in vitro, interms of micronucleus induction. Experiments were performed with 25 kV x-rays and a 200 kV x-ray reference source. The studies were carried out on primary human epidermal keratinocytes (HEKn), human fibroblasts (HFIB) and NIH/3T3 mouse fibroblasts. Micronucleus (MN) induction was assayed after in vitro irradiation with doses ranging from 1 to 5.2 Gy. Compared to the effect of 200 kV x-rays, 25 kV x-rays resulted in moderately increased chromosomal damage in all cell lines studied. This increase was observed for the percentage of binucleated (BN) cells with micronuclei as well as for the number of micronuclei per BN cell. Moreover, the increased number of micronuclei per micronucleated BN cell in human keratinocytes and 3T3 mouse fibroblasts suggests that soft x-rays induce a different quality of damage. For all cell lines studied the analysis of micronucleus induction by 25 kV soft x-rays compared to 200 kV x-rays resulted in an RBE value of about 1.3. This indicates a somewhat enhanced potential of soft x-rays for induction of genetic effects.

The present study was initiated to identify radiotherapy-related parameters influencing the development of second malignancies. Between 1969 and 1989, about 31 000 patients were treated with radiotherapy in Dresden. Of these, 203 were re-admitted for radiotherapy of a newly developed malignancy. Based on completeness of documentation, definition of site of origin and exclusion of recurrent or metastatic tumours, 85 patients were selected for analysis of spatial relation between new tumour and primary treatment fields, and of dose at the site of origin. The majority of second tumours were seen within the margin region of the treatment volume, defined as the volume from 2.5 cm inside to 5 cm outside the margin of the planning target volume (PTV). Fewer than 10% of the second tumours occurred inside the PTV and 11% developed outside the margin region. The majority of second tumours were observed in the volume receiving &lt;6 Gy. Similar results were obtained in a group of 31 patients initially irradiated for benign diseases. This should be considered in radiotherapy, particularly with multiple-field techniques or intensity-modulated radiotherapy, where the volume receiving &lt;6 Gy is substantially increased.

Purpose: The aim of the present analysis was to identify radiotherapy-related parameters that influence the development of second malignancies. Patients and Methods: Between 1969 and 1989, about 31,000 patients were treated in Dresden with low voltage (≤ 180 kV X-rays) or telecobalt radiotherapy or a combination of both. Of these 203 were readmitted after earlier radiotherapy, for radiotherapy of a newly developed malignancy. Based on definitive diagnosis of a secondary tumor and completeness of documentation 53 patients were selected for further analysis. This included the spatial relation between the new tumor and the primary treatment fields, and the incidence in relation to the dose at the site of origin. The material does not allow for risk estimation Results: Primary malignancies comprised breast and gynecological tumors in female, and tumors of prostate, head and neck and lymphomas in male patients. Second tumors developed mainly in corpus uteri, respiratory, gastrointestinal and urinary tract. The high incidence of 9.9% second primary corpus/cervix uteri tumors in patients with primary breast cancers suggests a common etiology. The majority of second tumors was observed within the margin of the planning target volume (PTV), which was defined as the volume 2.5 cm inside to 5 cm outside the field margin proper. Inside the PTV developed &lt; 10%, outside 11% of the second tumors. With regard to dose the majority of second tumors was observed in the region receiving &lt; 6 Gy. Conclusions: A significant number of second primary tumors is found in the volume receiving ≤ 6 Gy, i. e. at the margins of the PTV. This should be considered for multiple field radiotherapy and IMRT, where the relevant volumes may be substantially increased. Hintergrund: Ziel der vorliegenden Untersuchung war die Identifikation von Faktoren der Strahlentherapie maligner Erkrankungen, die möglicherweise die Entwicklung von Sekundärtumoren beeinflussen. Patienten und Methoden: Im Zeitraum zwischen 1969 und 1989 wurden in Dresden etwa 31 000 Patienten mit weicher Röntgenstrahlung (≤ 180 kV), ⁶⁰Co-γ-Strahlung oder einer Kombination aus beiden behandelt. Von diesen wurden 203 zur erneuten Strahlentherapie aufgrund eines neu enstandenen Tumors vorgestellt. Ausgehend von der sicheren Diagnose eines Sekundärtumors und der Vollständigkeit der Dokumentation der initialen Strahlenbehandlung wurden 53 Patienten zur Analyse ausgewählt. Diese beinhaltete die räumliche Beziehung zwischen dem Entstehungsort des neuen Tumors und den ursprünglichen Bestrahlungsfeldern und die Tumorinzidenz in Abhängigkeit von der Dosis am Enstehungsort. Eine Risikoabschätzung ist aus dem vorhandenen Material nicht möglich. Ergebnisse: Die Primärtumoren umfassten im Wesentlichen Mamma- und gynäkologische Tumoren bei Frauen sowie Prostata- und Kopf-Hals-Tumoren bei Männern. Sekundärtumoren wurden hauptsächlich in Corpus uteri, Atemwegen, Gastrointestinal- und Harnorganen beobachtet. Die mit 9,9% hohe Inzidenz von Sekundärtumoren von Corpus/Cervix uteri bei Patientinnen mit primären Mammatumoren deutet auf eine gemeinsame Ätiologie hin. Der Hauptteil der Sekundärtumoren wurde an den Rändern des ursprünglichen Planungszielvolumens (PTV) gefunden, welche als das Volumen von 2,5 cm innerhalb bis 5 cm außerhalb des eigentlichen Feldrandes definiert wurden. Innerhalb des PTV fanden sich &lt; 10%, außerhalb des Randbereiches 11% der Sekundärtumoren (Abbildung 1). In Bezug auf die Dosis am Entstehungsort wurde der Hauptteil der Sekundärtumoren in der mit &lt; 6 Gy belasteten Region beobachtet (Abbildung 2). Schlussfolgerung: Eine signifikante Anzahl an Sekundärtumoren findet sich in dem mit ≤ 6 Gy belasteten Volumen, d. h. an den Rändern des PTV. Dies sollte bei Mehrfelder- und intensitätsmodulierter Strahlentherapie in Betracht gezogen werden, da hier die relevanten Volumina deutlich ausgeweitet sein können.

The acute response of pig skin to treatment with high energy carbon ions (plateau region) at the Gesellschaft für Schwerionenforschung (GSI, Darmstadt, Germany) was compared with changes after 200 kV x-irradiation. Carbon doses isoeffective to the x-ray doses were computed with a recently established model for calculation of the biological effect of heavy ions. Clinical changes and physiological symptoms (blood flow, erythema, trans-epidermal water loss, skin hydration) were scored. The parameters analyzed were maximum and mean values of each symptom during days 24 to 70 after irradiation, and the quantal endpoints for the establishment of dose-effect curves were the median values of these. With exception of the maximum change in the red blood cell concentration (p < 0.02) nosignificant differences could be found in the response to x-rays and RBE-corrected heavy ions. These results indicate that the model is valid for the calculation of biological effects of 12C-ions (plateau region) and may at least for epidermis be applied to treatment planning.

The application of repeated cystometric measurements in longitudinal long-term studies both in patients and experimental animals requires detailed knowledge of factors causing intraindividual variability. In the present study, the effect of age, body weight, estrus cycle phase, rectal temperature and premeasurement bladder volume on the results of cystometry in mice have been assessed.

Meaningful interpretation of cystometric measurements in experimental animals requires detailed analysis of factors that could affect the results. In the present study, the effect of catheter size and bladder filling rate were studied in detail; in addition, the influence of (day) time on bladder compliance was assessed by cystometry in mice.

Das Gebiet der östlichen Lahnmulde bietet einen nahezu vollständigen Querschnitt durch die Paläogeographie und Fazies des Rheinischen Schiefergebirges. In tektonischer Hinsicht handelt es sich sogar um ein Schlüsselgebiet für unsere Auffassung von der Krustenstruktur in Mitteleuropa. Wir nehmen daher die Tagung des Oberrheinischen Geologischen Vereins zum Anlaß, neue Untersuchungsergebnisse und offene Fragen in einem etwas ausführlicheren Beitrag zusammenzustellen. Einführungstext und Aufschluß-Beschreibungen gehen daher deutlich über den Bedarf einer eintägigen Exkursion hinaus.

U–Pb zircon dating of three metagranitoids, situated within a tilted crustal section at the northwestern border of the Teplá Barrandian unit (Teplá crystalline complex, TCC), yields similar Cambrian ages. The U–Pb data of zircons of the Teplá orthogneiss define an upper intercept age of 513 +7/–6 Ma. The 207Pb/206Pb ages of 516±10 and 511±10 Ma of nearly concordant zircons of the Hanov orthogneiss and the Lestkov granite are interpreted to be close to the formation age of the granitoid protolith. Similar to the Cambrian granitoids of the southwestern part of the Teplá Barrandian unit (Domažlice crystalline complex, DCC) the Middle Cambrian emplacement of the TCC granitoids postdates Cadomian deformation and metamorphism of the Upper Proterozoic country rocks, but predates Variscan tectonometamorphic imprints. Structural data as well as sedimentological criteria suggest a dextral transtensional setting during the Cambrian plutonism, related to the Early Paleozoic break-up of northern Gondwana. Due to strong Variscan crustal tilting, the degree of Variscan tectonometamorphic overprint is strikingly different in the dated granitoids. It is lowest in the weakly or undeformed Lestkov granite, located in the greenschist-facies domain. The Teplá orthogneiss in the north underwent pervasive top-to-NW mylonitic shearing under amphibolite-facies conditions. There is no indication for a resetting of the U–Pb isotopic system of the Teplá orthogneiss zircons that could be attributed to this imprint. Radiation damages accumulated until recent have probably caused lead loss. [ABSTRACT FROM AUTHOR]

•Irradiation may cause Multiple Sclerosis in the radiated part of the spinal cord

Purpose:: This review summarizes information about modulation of radiation effects in tumor cells and tissues by selenium. Results:: In vitro, clonogenic survival to ionizing radiation was found to be reduced, depending on selenite concentration and duration of administration, by a factor of 1.5–4.4. In experimental animal tumors, a positive effect of selenium was observed with chemotherapy. The only available study in combination with irradiation did not show any benefit of selenium with clinically relevant radiotherapy protocols in R1H tumors. None of the investigations demonstrated a negative effect on the tumor response to therapy. Conclusion:: The only study with fractionated irradiation was performed in a rat R1H tumor, which does not show accelerated repopulation. Therefore, interaction of selenium with such repopulation processes, potentially resulting in increased tumor tolerance, could not be detected. For local administration of normal tissues with selenium, potential tumor effects may be of less importance, but these may be relevant for systemic administration. Therefore, well-designed studies with relevant tumor models and endpoints, and with clinically relevant fractionation protocols are recommended.

No abstract.

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