Die Toxizität des Chelators für Zellelemente in vitro

Autori su ispitali citotoksičnost helatora (di- i tri- natrijeva sol EDTA, ph 7,05, Centralne ljekarne kliničkih bolnica u Ljubljani) na linijsku kulturu HeLa stanica in vitro. Najprije su odredili titraci- jom helatora u raznim razređenjima minimalnu citotoksičnu dozu za kulturu HeLa stanica (50 000 ml) u EME, koja je nađena u razrjeđenju od 1:61. Zatim su ispitali ulogu kalcijevih i magnezijevih iona na tijek dezintegracije međustanične supstancije kulture HeLa stanica, u mediju s kalcijevim i magnezi- jevim ionima (EME) i bez spomenutih iona (PBS) pri jednakim ph vrijednostima (ph 7,2). Rezultati pokazuju da se dezintegracija međustaničnih veza odvijala pri istom ph na identičan način, bez obzira na prisutnost kalcija i magnezija u hranljivom mediju. Na temelju toga izveden je zaključak, da je za helacijsko djelovanje potrebna mala količina kalcijevih i magnezijevih iona te da ih u mediju bez tih iona, helator izvlači iz međustanične supstancije i samih stanica. Nadalje se spominje, da bi ovi rezultati mogli biti važni za studij helacijskog fenomena na tkivo cakline, jer pokazuje, da uslijed velike osjetljivosti tkiva na helator (1:61), može brzo doći do dezintegracije interprizmatske supstancije, jer gustoća cakline nije bitna za cijeli mehanizam.The cytotoxicity of chelator and NaEDTA with a, pH of 7,05 — (Central Pharmacy of the Clinical Hospitals, Ljubljana) on the linear culture of He-La cells in vitro was investigated. The minimal cytotoxic dose for the He-La cells culture was at first determined by means of chelator titration in various dilutions (50 000/ml) in EME which was found in a dilution of 1:61. Subsequently the role of Calcium and Magnesium ions was investigated on the course of disintegration of intercellular substances of the HeLa cells culture in the media with calcium and magnesium ions (EME) and without the ions mentioned (PBS) at equal pH values (pH 7,2). The results show that the disintegration of intercellular connections developed at the same pH in an identical manner regardless of the presence of calcium and magnesium in the nutritive medium. On the base of this finding the authors conclude that a small quantity of calcium and magnesium ions is necessary for the chelating activity and that in a medium without these ions the chelator extracts it from the intercellular substance and from the very cells. The authors moreover mention that these results might be important for the study of the chelator phenomenon on the tissue of the dental enamel because it shows that on account of great sensitivity of the tissue to chelator activity (1:61) disintegration of the interprismatic substance may rapidly occur with regard to the fact that the density of the enamel is not essential for the entire mechanism.Die Autoren haben die Zellgiftigkeit des Chelators (Di- und Tri Natriumsalz EDTA, pH 7,05, Zentrale Apotheke der klinischen Krankenhäuser, Ljubljana),, auf Linienkultur der HeLa Zellen invitro, geprüft. Vorerst wurde durch Titration des Chelators in verschiedenen Verdünnungen die minimale zytotoxische Dosis für HeLa-Zellenkultur (50000 ml) im EME, welche in der Verdünnung von 1 : 61 befunden wurde, festgestellt. Sodiann wurde der Anteil der Kalzium und Magnesiumionen auf den Verlauf der Desintegration der Zwischenzellensubstanz in der HeLa-Zellen-Kultur im Medium mit Kalzium- und Magnesiumionen (EME), und ohne der genannten Ionen (PBS), bei gleichen pH-Werten von 7,2, geprüft. Die Resultate zeigen, dass die Desintegration der zwischenzelligen Verbindung bei gleichem pH- Wert auf die identische Art erfolgt, ohne Rücksicht auf die Anwesenheit von Kalzium und Magnesium im Nährmedium. Das weist darauf hin, dass für die Chelator-Wirkung nur eine geringe Menge von Kalzium- und Magnesiumionen nötig sind, und dass im Medium ohne diese Ionen der Chelator sie aus der Zwischenzellensubstanz und den Zellen selbst, entnimmt. Weiters wird hervorgehoben, dass diese Resultate für das Studium der Chelator-phenomene inbezug auf das Schmelzgewebe wichtig sein könnten, weil es erwiesen ist, dass wegen der grossen Empfindlichkeit der Gewebe auf den Chelator (1 : 61), die Desintegration der interprismatischen Substanz schnell erfolgt, mit Rücksicht darauf dass die Dichte des Schmelzes für den gesamten Mechanismus nicht wesentlich ist

Die Toxizität des Chelators für Zellelemente in vitro

Autori su ispitali citotoksičnost helatora (di- i tri- natrijeva sol EDTA, ph 7,05, Centralne ljekarne kliničkih bolnica u Ljubljani) na linijsku kulturu HeLa stanica in vitro. Najprije su odredili titraci- jom helatora u raznim razređenjima minimalnu citotoksičnu dozu za kulturu HeLa stanica (50 000 ml) u EME, koja je nađena u razrjeđenju od 1:61. Zatim su ispitali ulogu kalcijevih i magnezijevih iona na tijek dezintegracije međustanične supstancije kulture HeLa stanica, u mediju s kalcijevim i magnezi- jevim ionima (EME) i bez spomenutih iona (PBS) pri jednakim ph vrijednostima (ph 7,2). Rezultati pokazuju da se dezintegracija međustaničnih veza odvijala pri istom ph na identičan način, bez obzira na prisutnost kalcija i magnezija u hranljivom mediju. Na temelju toga izveden je zaključak, da je za helacijsko djelovanje potrebna mala količina kalcijevih i magnezijevih iona te da ih u mediju bez tih iona, helator izvlači iz međustanične supstancije i samih stanica. Nadalje se spominje, da bi ovi rezultati mogli biti važni za studij helacijskog fenomena na tkivo cakline, jer pokazuje, da uslijed velike osjetljivosti tkiva na helator (1:61), može brzo doći do dezintegracije interprizmatske supstancije, jer gustoća cakline nije bitna za cijeli mehanizam.The cytotoxicity of chelator and NaEDTA with a, pH of 7,05 — (Central Pharmacy of the Clinical Hospitals, Ljubljana) on the linear culture of He-La cells in vitro was investigated. The minimal cytotoxic dose for the He-La cells culture was at first determined by means of chelator titration in various dilutions (50 000/ml) in EME which was found in a dilution of 1:61. Subsequently the role of Calcium and Magnesium ions was investigated on the course of disintegration of intercellular substances of the HeLa cells culture in the media with calcium and magnesium ions (EME) and without the ions mentioned (PBS) at equal pH values (pH 7,2). The results show that the disintegration of intercellular connections developed at the same pH in an identical manner regardless of the presence of calcium and magnesium in the nutritive medium. On the base of this finding the authors conclude that a small quantity of calcium and magnesium ions is necessary for the chelating activity and that in a medium without these ions the chelator extracts it from the intercellular substance and from the very cells. The authors moreover mention that these results might be important for the study of the chelator phenomenon on the tissue of the dental enamel because it shows that on account of great sensitivity of the tissue to chelator activity (1:61) disintegration of the interprismatic substance may rapidly occur with regard to the fact that the density of the enamel is not essential for the entire mechanism.Die Autoren haben die Zellgiftigkeit des Chelators (Di- und Tri Natriumsalz EDTA, pH 7,05, Zentrale Apotheke der klinischen Krankenhäuser, Ljubljana),, auf Linienkultur der HeLa Zellen invitro, geprüft. Vorerst wurde durch Titration des Chelators in verschiedenen Verdünnungen die minimale zytotoxische Dosis für HeLa-Zellenkultur (50000 ml) im EME, welche in der Verdünnung von 1 : 61 befunden wurde, festgestellt. Sodiann wurde der Anteil der Kalzium und Magnesiumionen auf den Verlauf der Desintegration der Zwischenzellensubstanz in der HeLa-Zellen-Kultur im Medium mit Kalzium- und Magnesiumionen (EME), und ohne der genannten Ionen (PBS), bei gleichen pH-Werten von 7,2, geprüft. Die Resultate zeigen, dass die Desintegration der zwischenzelligen Verbindung bei gleichem pH- Wert auf die identische Art erfolgt, ohne Rücksicht auf die Anwesenheit von Kalzium und Magnesium im Nährmedium. Das weist darauf hin, dass für die Chelator-Wirkung nur eine geringe Menge von Kalzium- und Magnesiumionen nötig sind, und dass im Medium ohne diese Ionen der Chelator sie aus der Zwischenzellensubstanz und den Zellen selbst, entnimmt. Weiters wird hervorgehoben, dass diese Resultate für das Studium der Chelator-phenomene inbezug auf das Schmelzgewebe wichtig sein könnten, weil es erwiesen ist, dass wegen der grossen Empfindlichkeit der Gewebe auf den Chelator (1 : 61), die Desintegration der interprismatischen Substanz schnell erfolgt, mit Rücksicht darauf dass die Dichte des Schmelzes für den gesamten Mechanismus nicht wesentlich ist

Bi-allelic loss-of-function variants in BCAS3 cause a syndromic neurodevelopmental disorder.

BCAS3 microtubule-associated cell migration factor (BCAS3) is a large, highly conserved cytoskeletal protein previously proposed to be critical in angiogenesis and implicated in human embryogenesis and tumorigenesis. Here, we established BCAS3 loss-of-function variants as causative for a neurodevelopmental disorder. We report 15 individuals from eight unrelated families with germline bi-allelic loss-of-function variants in BCAS3. All probands share a global developmental delay accompanied by pyramidal tract involvement, microcephaly, short stature, strabismus, dysmorphic facial features, and seizures. The human phenotype is less severe compared with the Bcas3 knockout mouse model and cannot be explained by angiogenic defects alone. Consistent with being loss-of-function alleles, we observed absence of BCAS3 in probands' primary fibroblasts. By comparing the transcriptomic and proteomic data based on probands' fibroblasts with those of the knockout mouse model, we identified similar dysregulated pathways resulting from over-representation analysis, while the dysregulation of some proposed key interactors could not be confirmed. Together with the results from a tissue-specific Drosophila loss-of-function model, we demonstrate a vital role for BCAS3 in neural tissue development

Human Factors Engineering Program Review Model (NUREG-0711)Revision 3: Update Methodology and Key Revisions

The U.S. Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) programs of applicants for nuclear power plant construction permits, operating licenses, standard design certifications, and combined operating licenses. The purpose of these safety reviews is to help ensure that personnel performance and reliability are appropriately supported. Detailed design review procedures and guidance for the evaluations is provided in three key documents: the Standard Review Plan (NUREG-0800), the HFE Program Review Model (NUREG-0711), and the Human-System Interface Design Review Guidelines (NUREG-0700). These documents were last revised in 2007, 2004 and 2002, respectively. The NRC is committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool. To this end, the NRC is updating its guidance to stay current with recent research on human performance, advances in HFE methods and tools, and new technology being employed in plant and control room design. NUREG-0711 is the first document to be addressed. We present the methodology used to update NUREG-0711 and summarize the main changes made. Finally, we discuss the current status of the update program and the future plans

Reviewing Consensus HFE Standards for NRC Use: A Case Study using the IEEE Standard for Computerized Operating Procedure Systems

The U.S. Nuclear Regulatory Commission’s (NRC’s) endorsement of consensus standards provides a cost-effective means of enhancing the staff’s ability to review state-of-the-art designs. Although the NRC endorsed consensus standards in many technical disciplines, it yet has to do so in human factors engineering (HFE). The purpose of our study was to develop a standardized methodology whereby to evaluate a consensus HFE standard to determine its appropriateness to, and adequacy for using in licensing reviews. The high-level objective of the methodology is to ensure that the guidance meets the NRC’s requirements on scientific- and engineering-rigor that they use in developing their own guidance. We propose four criteria for endorsing a consensus standard: (1) It should meet an existing need for NRC’s licensing and safety reviews; (2) it should be based on sound HFE principles; (3) it should be thoroughly peer-reviewed; and, (4) it should address human performance issues identified in the literature. Our methodology offers a means to assess these four criteria. We used it to evaluate an Institute of Electrical and Electronics Engineers’ (IEEE) draft standard on computerized operating procedure systems. We concluded that the IEEE standard generally met the established criteria, although several areas were identified that needed further clarification. Our evaluation methodology particularly was useful for identifying issues to be resolved, and for providing a basis for judging whether the staff should consider endorsing the standard. The methodology also helped recognize criteria in the proposed standard that may benefit from additional scrutiny by the staff. The evaluation methodology developed is applicable generally to reviewing other HFE standards that the NRC is considering for use or endorsement