11 research outputs found
Unidirectional triple and double hydrogen rearrangement reactions in the radical cations of gamma-arylalkanols
No full textKuck D, Filges U. Unidirectional triple and double hydrogen rearrangement reactions in the radical cations of gamma-arylalkanols. Organic Mass Spectrometry. 1988;23(9):643-653.A novel fragmentation reaction accompanied by the unidirectional migration of three hydrogen atoms has been found in the radical cations of -arylpropanols with electron-donating substituents in the para position. This triple hydrogen (3H) rearrangement reaction is the dominant fragmentation channel of the long-lived molecular ions of trans-2-(4-dimethylaminobenzyl)-l-indanol, 2, but it occurs also in simpler -arylpropanol ions. Deuterium labelling of 2 reveals that the three hydrogen atoms originate with extraordinarily high specificity from the C(l), C(2) and O positions of the alcohol moiety. Cis- and 3-substituted isomers do not undergo this reaction. Along with the 3H rearrangement reaction a unidirectional double hydrogen (2H) rearrangement reaction takes place independently and with less specificity in the trans-2-(4-X-benzyl)-l-indanol ions 1+· and 2+·. No hydrogen exchange occurs during the 3H and 2H rearrangement reactions. Mechanistic alternatives of these unusual fragmentation reactions are discussed; the experimental evidence strongly favours pathways via several intermediate ion-neutral complexes
Internal reactions of ion/molecule complexes from isomeric protonated formyl-and acetyl-naphthalenes
No full textFilges U, Grützmacher H-F. Internal reactions of ion/molecule complexes from isomeric protonated formyl-and acetyl-naphthalenes. International Journal of Mass Spectrometry and Ion Processes. 1988;83(1-2):111-133
Fragmentations of protonated acetophenones via intermediate ion-molecule complexes
No full textFilges U, Grützmacher H-F. Fragmentations of protonated acetophenones via intermediate ion-molecule complexes. Organic Mass Spectrometry. 1987;22(7):444-450
Remote fragmentations of protonated aromatic carbonyl compounds via internal reactions in intermediary ion-neutral complexes
No full textThielking G, Filges U, Grützmacher H-F. Remote fragmentations of protonated aromatic carbonyl compounds via internal reactions in intermediary ion-neutral complexes. Journal of the American Society for Mass Spectrometry. 1992;3(4):417-426.Protonated aromatic aldehydes and methyl ketones 1a-10a, carrying initially the proton at the carbonyl group, are prepared by electron impact-induced loss of a methyl radical from 1-arylethanols and 2-aryl-2-propanols, respectively. The aryl moiety of the ions corresponds to a benzene group, a naphthalene group, a phenanthrene group, a biphenyl group, and a terphenyl group, respectively, each substituted by a CH3OCH2 side-chain as remote from the acyl substituent as possible. The characteristic reactions of the metastable ions, studied by mass-analyzed ion kinetic energy spectrometry, are the elimination of methanol, the formation of CH3OCH2+ ions, and the elimination of an ester RCOOCH3 (R = H and CH3). The mechanisms of these fragmentations were studied by using D-labeled derivatives. Confirming earlier results, it is shown that the ester elimination, at least from the protonated aryl methyl ketones, has to proceed by an intermediate [acyl cation/arylmethyl methyl ether]-complex. The relative abundances of the elimination of methanol and of the ester decrease and increase, respectively, with the size of the aromatic system. Clearly, the fragmentation via intermediate ion-neutral complexes is favored for the larger ions. Furthermore, the acyl cation of these complexes can move unrestricted over quite large molecular distances to react with the remote CH3OCH2-side-chain, contrasting the restricted migration of a proton by 1,2-shifts ("ring walk") in these systems
Ion-Molekül-Komplexe: reaktive Zwischenstufen bei massenspektrometrischen Fragmentierungen von substituierten 1-Arylalkanolen
No full textFilges U. Ion-Molekül-Komplexe: reaktive Zwischenstufen bei massenspektrometrischen Fragmentierungen von substituierten 1-Arylalkanolen. Bielefeld; 1986
Proton migration in naphthalenium ions via [sigma] and [pi] complexes
No full textFilges U, Grützmacher H-F. Proton migration in naphthalenium ions via [sigma] and [pi] complexes. International Journal of Mass Spectrometry and Ion Processes. 1988;83(1-2):93-109
Fragmentations of protonated benzaldehydes via intermediate ion/molecule complexes
No full textFilges U, Grützmacher H-F. Fragmentations of protonated benzaldehydes via intermediate ion/molecule complexes. Organic Mass Spectrometry. 1986;21(10):673-680
Multidimensional Family Therapy (MDFT) for young people in treatment for non-opioid drug abuse: a systematic review .
No full textThis is a Campbell Systematic Review of the effect of Multidimensional Family Therapy (MDFT) for treating abuse of cannabis, amphetamine, ecstasy or cocaine (referred to here as non-opioid drugs) among young people aged 11-21 years. The misuse of prescription drugs and the use of ketamine, nitrous oxide and inhalants such as glue and petrol are not considered in this review.
Youth drug abuse is a severe problem worldwide and recent reports describe ominous trends of youth drug abuse and a lack of effective treatment. This review is concerned with drug abuse that is severe enough to warrant treatment. It focuses on young people who are receiving MDFT specifically for non-opioid drug abuse.
MDFT is a manual-based, family-oriented treatment, designed to eliminate drug abuse and associated problems in young people’s lives. MDFT takes a number of risk and protective factors into account; the approach acknowledges that young people’s drug abuse is linked to dimensions such as home life, friends, school and community (Liddle et al., 2004). MDFT aims to modify multiple domains of functioning by intervening with the young person, family members, and other members of the young person’s support network (Austin et al., 2005). MDFT is thus based on a number of therapeutic alliances, with the young drug abuser, his or her parents and other family members, and sometimes with school and juvenile justice officials.
After a rigorous search of the literature, five randomized controlled studies with samples of 83-450 participants were identified. Three studies were conducted by MDFT program developers, one study was conducted by an independent investigator with the program developer as a co-author, and one study was conducted by independent investigators. Four studies were performed in the US, while the other was performed across five European countries.
We used meta-analytic procedures to summarise the available evidence on the effects of MDFT in comparison with other interventions on drug abuse, education, family functioning, risk behavior and retention in treatment. In this review, we interpret a value of the standardised mean difference, SMD=0.20 as a small effect size, in line with the general practice (Cohen, 1988). We note, however, the possibility that such a value might actually represent a larger effect if it is equivalent to a large reduction in the percentage of days a youth uses drugs, but we cannot comment further as we were unable to analyse the absolute effect of MDFT given that no studies comparing MDFT to no other treatment were available. The findings are as follows:
- On drug abuse: Based on the available evidence we conclude that MDFT has an effect on drug abuse reduction compared to other treatments, although the difference is small.
- On education: There is insufficient evidence to conclude whether MDFT has an effect on education compared to other treatments.
- On family functioning: There is no available evidence to conclude whether MDFT has an effect on family functioning compared to other treatments.
- On risk behavior and other adverse effects: There is no available evidence to conclude whether MDFT has an effect on risk behavior and other adverse effects compared to other treatments.
- On treatment retention: MDFT may result in improved treatment retention in young drug abusers compared to other interventions
The evidence found was limited as only five studies were included, and two studies had significant amounts of missing data. The evidence was very limited in terms of the outcomes reported on education, family functioning and risk behavior, and was insufficient for firm conclusions to be drawn on the effectiveness of the treatment with regard to such outcomes.
There is evidence that MDFT is slightly more effective in treating young people’s drug abuse than other treatments; however, the difference is small. Furthermore, none of the five included studies could be characterised as a robust RCT with a low risk of bias on all assessed domains. One study provided insufficient information on core issues for the risk of bias to be assessed and therefore we find reason to question the validity of this study.
Well-designed, randomized controlled trials within this population are needed. More research is also required to identify factors which modify the effect of MDFT and to identify which particular youth subgroups may be most likely to respond
Hormonal and genetic modulation of memory processes in healthy humans: focus on cortisol and "HDAC5"
No full textIndividual differences in memory performance can be due to the influence of various hormones as well as genetic variations and epigenetic modifications. These complex molecular and genetic mechanisms can impact learning, memory consolidation and retrieval differentially. This thesis deals with the modulation of memory processes in healthy human subjects focusing on two viewpoints. Firstly, by addressing the influence of the stress hormone cortisol, as evidence from animal and human studies shows that cortisol can enhance memory consolidation and impair retrieval. Secondly, by analyzing genetic and epigenetic data to find a target associated with synaptic plasticity and memory formation.
To investigate if stress, induced by the cold pressor test, affects memory processes, a fear-conditioning paradigm was used. The stress group showed an increase in the cortisol level and reduced retrieval of the conditioned fear memory. In a further study, we investigated if inter-individual changes in basal cortisol levels affect episodic memory. Results showed an association between stronger decreases in cortisol levels during retrieval and a better recall performance.
In a large genetic study we focused on genetic polymorphisms tagging histone deacetylase 5 (HDAC5), a gene associated with synaptic plasticity and memory formation in animal models. We detected significant associations between these polymorphisms and episodic memory performance, especially for emotional information. Surprisingly, these polymorphisms were strongly associated with expression levels of a transcript in the vicinity of HDAC5.
These results may have implications for the understanding of the mechanisms underlying memory formation in healthy subjects and the interpretation of genetic data. Additionally, our results may have clinical implications for different neuropsychiatric disorders, such as depression, anxiety disorders or posttraumatic stress disorder, for which learning and memory play an important role
