Comparison of the oxime-induced reactivation of erythrocyte and muscle acetylcholinesterase following inhibition by sarin or paraoxon, using a perfusion model for the real-time determination of membrane-bound acetylcholinesterase activity

The purpose of these experiments was to compare oxime-induced reactivation rate constants of acetylcholinesterase from different human tissue sources inhibited by organophosphorus compounds. To this end, preliminary testing was necessary to generate a stable system both for working with erythrocytes and musculature. We established a dynamically working in vitro model with a fixed enzyme source in a bioreactor that was perfused with acetylthiocholine, Ellman's reagent and any agent of interest (e.g. nerve agents, oximes) and analyzed in a common HPLC flow-through detector. The enzyme reactor was composed of a particle filter (Millex-GS, 0.22 microm) containing a thin layer of membrane-bound acetylcholinesterase and was kept at constant temperature in a water bath. At constant flow the height of absorbance was directly proportional to the enzyme activity. To start with, we applied this system to human red cell membranes and then adapted the system to acetylcholinesterase of muscle tissue. Homogenate (Ultra-Turrax and Potter-Elvehjem homogenizer) of human muscle tissue (intercostal musculature) was applied to the same particle filter and perfused in a slightly modified way, as done with human red cell membranes. We detected no decrease of acetylcholinesterase activity within 2.5h and we reproducibly determined reactivation rate constants for reactivation with obidoxime (10 microM) or HI 6 (30 microM) of sarin-inhibited human muscle acetylcholinesterase (0.142+/-0.004 min(-1) and 0.166+/-0.008 min(-1), respectively). The reactivation rate constants of erythrocyte and muscular acetylcholinesterase differed only slightly, highlighting erythrocyte acetylcholinesterase as a proper surrogate marker.     

Live births after management of severe OHSS by GnRH antagonist administration in the luteal phase

Ovarian hyperstimulation syndrome (OHSS) is a serious complication of ovarian stimulation protocols. Currently, no curative therapy exists and the main preventive option is cycle cancellation. Gonadotrophin-releasing hormone (GnRH) antagonist administration in the luteal phase was recently proposed as a new approach for the management of patients with established severe OHSS. Three polycystic ovarian syndrome patients undergoing IVF treatment developed severe OHSS, diagnosed 6 days after oocyte retrieval. On day 6, the patients underwent blastocyst transfer and received GnRH antagonist for 4 days, combined with luteal phase support using exogenous oestradiol and progesterone. Two patients had successful pregnancies that resulted in births of healthy infants, while one patient had a biochemical pregnancy. In all patients, established severe OHSS regressed to a moderate form of the syndrome, no pregnancy-induced life-threatening OHSS was observed, while a short monitoring period was required at an outpatient level, avoiding the need for patient hospitalization. This is the first report in the literature on GnRH antagonist administration in the luteal phase, combined with embryo transfer and exogenous oestradiol and progesterone supplementation. This novel treatment was effective in the regression of established severe OHSS, and resulted in the birth of healthy infants.     

颈动脉支架置入术和内膜剥脱术治疗颈动脉狭窄的随机对照研究

背景:颈动脉狭窄是脑卒中的重要原因.颈动脉支架置入术(carotid-artery stenting,CAS)和颈动脉内膜剥脱术(carotid endarterectomy,CEA)是治疗颈动脉狭窄的可选择手段,但以往对比研究,如症状性重度颈动脉狭窄患者动脉内膜剥脱术与血管成形术比较(EVA-3S)、保护性支架血管成形术与颈动脉内膜剥脱术比较(SPACE)及国际颈动脉支架研究(ICSS)关于CAS和CEA孰优孰劣的报道存在矛盾.     

Zur Frage der Schanker-Excision

Ohne Zusammenfassung     

Ineffectiveness of sun awareness posters in dermatology clinics

Background Although sun awareness posters have been used in doctors’ offices and clinics for decades to promote sun protective behaviour, there is no evidence of their usefulness. Objectives To investigate whether sun awareness posters lead to inquiry of skin cancer and sun protection measures. Method Patients considered at risk for skin cancer seen at a dermatology clinic were randomly asked to complete a questionnaire designed to assess the effectiveness of three different sun awareness posters placed in patient rooms. The posters were selected on the basis of their catchy slogan and eye‐appealing images, and included those featuring parental interest, sex appeal and informative advice. Results Only half of the patients noticed the posters (50.6%). The poster with sex appeal garnered the most attention (67.8%), followed by the informative poster (49.2%) and the parental interest poster (35.8%) (P < 0.001). Although patients who noticed the sun awareness poster inquired about cutaneous cancers and sun protection practices twice as often as those who did not notice the poster, only one‐tenth of such inquiries were attributed to the poster (～5% of the target population). As reported in the questionnaire, the posters themselves were less effective than the advice of physicians in influencing patient attitudes towards sun protection measures. Conclusion Organizations that produce and disseminate posters should consider beyond focus groups when they design their posters and should consider field testing their products to ensure that they are reaching the targeted audience and are having the expected beneficial effect, otherwise their posters are simply decorative.