Der Einfluss ionisierender Strahlen auf die Entwicklung der Sekundärkatarakt in vitro

BACKGROUND AND PURPOSE: Histologically, the posterior capsule opacification (PCO) corresponds to regenerative tissue of transformed lens epithelial cells (LECs) with extracellular matrix production. In this study, the influence of ionizing radiation on proliferating LECs and the development of PCO was investigated in vitro. MATERIAL AND METHODS: Each four and 14 pork lenses, respectively, were irradiated with 6 MeV electrons with single doses of 8, 10, 12, and 20 Gy. 1-2 h after irradiation the lens was removed by capsulorrhexis and hydrodissection. After fixation of the capsular bag in a special device the proliferation of residual LECs was examined daily. The experiment was considered to be finished when the capsular bag was completely opacified by confluent cell proliferates. RESULTS: Single dose irradiation with electrons in a dose range from 8 to 12 Gy significantly protracted the development of PCO with complete inhibition of PCO after application of 20 Gy. CONCLUSION: To inhibit PCO in vitro, a single dose of 20 Gy is necessary. The actual in vitro model allows an optimal investigation of PCO formation under different external influences and is therefore very suitable for radiobiological questions.     

Einfluss von Äthanol auf die Carboxyhämoglobinkonzentration bei tödlichen Kohlenmonoxidvergiftungen

In der gerichtlich-medizinischen Praxis hat man sehr oft mit der gleichzeitigen Wirkung von Kohlenmonoxid und ?thanol zu tun. Die vorliegende Untersuchung basiert auf kasuistischem Material aus den Jahren 1990– 1999, in dem mit den gleichen Analysenmethoden COHb- und ?thanolkonzentrationen untersucht wurden. Aus insgesamt 10752 Leichenblutproben wurden 373 Proben ausgew?hlt, bei denen der COHb-Gehalt h?her war als 30%. Bei 214 Proben (57,4% F?lle) wurde auch ?thanol festgestellt. Die Proben mit COHb wurden in 2 Gruppen eingeteilt – mit und ohne ?thanol. Unter Berücksichtigung der Messgenauigkeit wurden diese F?lle in 2 separaten Gruppen (in 5%-Schritten) aufgetragen. Bei den ?thanol enthaltenden Proben wurde die Konzentrationsverteilungskurve zu h?heren Werten verschoben. Die erhaltenen Ergebnisse weisen auf eine m?glicherweise schützende Wirkung von ?thanol bei Kohlenmonoxidvergiftungen hin.     

Der stereoselektive Nachweis von l- und d-Methadon in Blutproben von lebenden und verstorbenen Drogenabhängigen

In Germany, there is a special situation that racemic dl-methadone and the (biologically effective) l-form (levomethadone) are both used as a substitute for heroin. The therapeutic effect of methadone is stereo-specific and the metabolism is also enantioselective. Therefore an approach to the dose-effect relationship of methadone requires an enantioselective analytical separation. For this a HPLC method was optimised especially for post-mortem blood samples. After liquid/¶liquid extraction with 1-chlorobutane, the extract was separated on a column combination of 4 cm CN and 10 cm chiral AGP phases with the solvent AcN/ 0.01 M PO₄ buffer ¶pH 5.0/ dimethyloctlyamine (15/85/0.5). ¶The methadone enantiomers elute baseline separated at approx. 15 min (l-form) and ¶18 min (d-form). The two EDDP-enantiomers and drugs which are frequently consumed supplementary to methadone such as heroin, cocaine, benzodiazepines, tricyclic antidepressants, antiepileptics etc. , do not interfere with detection. With this method the methadone l/d-ratio was determined in 93 serum samples from living addicts and 106 post-mortem blood samples from drug deaths. From the l/d-ratio and the concentration of total methadone as determined by other methods (GC-MS or RP-HPLC) the l-methadone concentration was calculated. In approximately 50% of the post-mortem samples the l-methadone concentration was higher than 0.3 mg/l, whereas this level was exceeded in only one of the living persons. ¶If dl-methadone was taken, the individual l/d-ratio in blood samples from living as ¶well as deceased persons differed greatly ranging from approx. 25/75 to 75/25, with ¶a mean of 50/50. In samples from 1999, ¶l-methadone was found exclusively in approx. 20% of the cases. In some cases it was obvious that both l- and dl-methadone had been used. Fatal cases with high l-methadone concentrations (>1 mg/l) gave rise to concern, because the l/d-ratio greatly exceeded 50/50in all cases . This could be considered as an indication of an individually extremely slow metabolism of l-methadone in these cases, resulting in an accumulation of l-methadone. These examples from the forensic casework demonstrate the necessity of an enantioselective quantification of ¶l-methadone as used for therapeutic drug monitoring and in forensic cases.     

Der Einfluss der Ethnie auf die bei strafrechtlichen Alterssch?tzungen untersuchten Merkmale

Die Frage nach dem Einfluss der Ethnie auf die bei strafrechtlichen Alterssch?tzungen bei Lebenden untersuchten Merkmale ist von gro?er praktischer Bedeutung. Beim Vorliegen gravierender interethnischer Differenzen würde die Anwendung der gebr?ulichen Referenzstudien auf andere ethnische Gruppen zu Fehlsch?tzungen führen. Es wurden mehr als 500 Publikationen zu Ossifikation, Dentition und sexueller Reifeentwicklung bei zahlreichen Populationen ausgewertet. Danach ergab sich, dass definierte Entwicklungsstadien von allen ethnischen Hauptgruppen in derselben Reihenfolge durchlaufen werden. W?hrend die Ossifikation und die Weisheitszahnmineralisation in der betreffenden Altersgruppe offenbar nicht relevant von der ethnischen Zugeh?rigkeit beeinflusst werden, besteht bezüglich einer m?glichen vergleichsweisen Akzeleration von Afrikanern bei der Weisheitszahneruption und der sexuellen Reifeentwicklung weiterer Forschungsbedarf.     

Biomechanische Aspekte der Rotatorenmanschettennaht: Einfluss von Nahtmaterial,Knotentechnik und Nahttechnik auf die Primärstabilität

BackgroundThe treatment of Rotator cuff (RC) tears has made significant chances in the last decades. Due to arthroscopic procedures new material and technologies have been developed. Up to now, attention was focused mainly on the development of material with higher mechanical strength, stronger suture material, or improving of suturing and knotting. The present study focusses on all different aspects together which influence the biomechanical stability of rotator cuff tear reconstructions.Materials and MethodsDiverse kinds of suture anchors (different designs and materials) and transosseous sutures were tested biomechanically in human humeral specimen. Arthroscopic sliding and nonsliding-nodes were tested with conventional (Ethibond and PDS) and new UHMWPE sutures for biomechanical features. Additionally we tested three arthroscopic suture techniques (single-, matress-, arthroscopic Mason Allen- stitch) with above mentioned materials in human RC tendons. All tests were performed under cyclic loading on the Zwick universal Testing machine. The maximum failure rate, the clinical failure rate at 3 mm irreversible expension and the failure mechanism were evaluated.ResultsBetween the different suture anchors were found significantly differences only in healthy human humeral specimen. In osteoporotic bone all different suture anchors were comparable with failure values less than 200 N. Subcortical fixed suture anchors tend to have a higher stability than in cancellous bone fixed suture anchors. Transosseos sutures showed no benefits in osteoporotic bone. With up to 300 N the UHMWPE sutures had a significantly higher strength than Ethibond / PDS sutures. Though, depending on the node type, even UHMWPE sutures showed a relevant elongation at values between 100-200 N. The lowest biomechanical strength showed the tendon-suture construct. Even though the Mason Allen stitch with UHMWPE sutures showed the highest stability (>200 N) clinical failure appeared at about 100 N. The weakest link in the failure of RC repair seems to be the suture-tendon interface. Even when using UHMWPE sutures and a biomechanical stable suture technique clinical failure was observed at approx. 100 N.ConclusionsThese results suggest that the development of suture anchors with rising diameter seems to be irrelevant. Rather, the technical development should focus on small anchors with a subcortical fixation and therefore better biomechanical stability. Especially in revision cases this seems to be relevant. Post-operative treatment should be moderate because clinical failure can appear from only 100 N of load.Level of evidenceLevel IV.     

Ist die Anwendung von Narkoanalyse im Strafverfahren zulässig?

Ohne ZusammenfassungHerrn Professor Dr. V. MÜller-Hess zum 70. Geburtstag gewidmet.     

Veränderungen einiger Metaboliten des Kohlenhydratstoffwechsels im Hinblick auf die Todeszeit

Ohne Zusammenfassung