Quality evaluation of tandem mass spectral libraries

Tandem mass spectral libraries are gaining more and more importance for the identification of unknowns in different fields of research, including metabolomics, forensics, toxicology, and environmental analysis. Particularly, the recent invention of reliable, robust, and transferable libraries has increased the general acceptance of these tools. Herein, we report on results obtained from thorough evaluation of the match reliabilities of two tandem mass spectral libraries: the MSforID library established by the Oberacher group in Innsbruck and the Weinmann library established by the Weinmann group in Freiburg. Three different experiments were performed: (1) Spectra of the libraries were searched against their corresponding library after excluding either this single compound-specific spectrum or all compound-specific spectra prior to searching; (2) the libraries were searched against each other using either library as reference set or sample set; (3) spectra acquired on different mass spectrometric instruments were matched to both libraries. Almost 13,000 tandem mass spectra were included in this study. The MSforID search algorithm was used for spectral matching. Statistical evaluation of the library search results revealed that principally both libraries enable the sensitive and specific identification of compounds. Due to higher mass accuracy of the QqTOF compared with the QTrap instrument, matches to the MSforID library were more reliable when comparing spectra with both libraries. Furthermore, only the MSforID library was shown to be efficiently transferable to different kinds of tandem mass spectrometers, including "tandem-in-time" instruments; this is due to the coverage of a large range of different collision energy settings-including the very low range-which is an outstanding characteristics of the MSforID library.

[Analgesia for pediatric patients. Standards and special aspects]

In this paper we describe the assessment and medical treatment of pain in children according to the concept of the Centre of Pediatrics and Adolescent Medicine at the university of Freiburg, Germany. Opiate therapy in children as well as novel data about the association of paracetamol (acetaminophen) and wheezing/asthma bronchiale in children are discussed. Special aspects of analgesia for painful procedures and a nitrous oxide/oxygen mixture which has been recently introduced in Germany are described. The second part of the paper presents results of our prospective study about continuous infusion of fentanyl and midazolam in a fixed combination in 19 critically ill patients with a median age of 46 months, 40% of these patients had an ARDS. The mortality rate was 21%. A median dose of fentanyl of 3.9 microg/kg/h (midazolam 0.26 mg/kg/h) was infused. The fentanyl serum level (median 4.2 ng/ml, range 1.7-17.8 ng/ml) correlated significantly with the administered dose while the midazolam serum levels (median 911 ng/ml, range 234-4 651 ng/ml) correlated neither with the administered dose nor with any of the analysed parameters. Conclusion: A standard protocol for the assessment and treatment of pain should be established in every pediatric hospital. The data about the association of asthma bronchiale and paracetamol cannot be interpreted conclusively, but show that even for well known substances clinical trials may lead to new awareness. The study data about continuous infusion of fentanyl and midazolam show a good correlation of the fentanyl application to serum levels, while midazolam appears to be not the optimal substance for continuous sedation in this setting.

Erhöhung der Achtsamkeit durch Taiji-Training - Ergebnisse aus einer randomisierten Warteliste-kontrollierten Studie mit gesunden Versuchspersonen

Hintergrund: Taiji ist eine meditative Bewegungsform mit Ursprung in den chinesischen Kampfkünsten. In mehreren Studien konnten positive Effekte von Taiji auf das psychische und körperliche Wohlbefinden nachgewiesen werden. Eine mögliche Wirkkomponente von Taiji könnte die Förderung von Achtsamkeit sein. Studienergebnisse, welche eine Verbesserung der Körperwahrnehmung durch Taiji nahe legen, stützen diese Annahme. Mit der vorliegenden Arbeit wurde untersucht, inwiefern sich Taiji auf die allgemeine Achtsamkeit im Sinne eines erweiterten multidimensionalen Konzeptes als auch auf den achtsamen Umgang mit sich selbst in belastenden Situationen auswirkt. Methoden: 70 gesunde Versuchspersonen wurden randomisiert einer Taiji-Interventionsgruppe oder zu einer Warteliste-Kontrollgruppe zugeteilt. Die Interventionsgruppe erhielt während drei Monaten zweimal wöchentlich je eine Stunde Taiji-Unterricht. Die allgemeine Achtsamkeit wurde mittels dem Freiburger Fragebogens zur Achtsamkeit (FFA-Kurzform), die Achtsamkeit in belastenden Situationen wurde über die Subskala „Achtsamkeit“ der Self-Compassion-Scale (SCS) vor Beginn und nach Beendigung der Intervention gemessen. Resultate: Die Interventionsgruppe (N=28) wies nach Kursende im Vergleich zur Kontrollgruppe (N=31) einen signifikanten Anstieg der Achtsam-keitswerte im FFA (F(1, 34.70) = 4.29, p = 0.043) und in der SCS-Subskala (F(1, 3.58) = 4.62, p = 0.036) auf. Schlussfolgerung: Die gegenwärtigen Studienergebnisse sprechen dafür, dass bei gesunden Personen Achtsamkeit im Allgemeinen als auch in schwierigen Lebenslagen durch das Üben von Taiji gefördert werden kann.