Zur Struktur des Enols von Benzoylaceton / On the Structure of the Enol of Benzoylacetone

A low temperature X-ray study of the enol of benzoylacetone indicates fixed positions of the C and O atoms within the enolic ring system and an extensive bond delocalisation over these atoms. The distribution of electron density between the two oxygen atoms shows that the enolic hydrogen is spread over a wide range. This is in accordance with a structural model proposed by de la Vega, whereupon the C and O atoms are kept fixed in their average positions during a tunneling process of the hydrogen between the two oxygen atoms. With this conception, the chemical shifts in the 17O and 13C NMR spectra, the 13C13C spin coupling constants and the temperature independance of these values can be explained.

Interactions and competition processes among tree species in young experimental mixed forests, assessed with chlorophyll fluorescence and leaf morphology

Chlorophyll a fluorescence (ChlF) and leaf morphology were assessed in two sites in Europe (Kaltenborn, Germany, and Satakunta, Finland) within a forest diversity experiment. Trees at Satakunta, planted in 1999, form a stratified canopy, while in Kaltenborn the trees are 7 years old, with no apparent canopy connection among broadleaf species. The following ChlF parameters from measured OJIP transient curves were examined: F(V)/F(M) (a proxy for maximum quantum yield); ΨEo (a proxy for efficiency in transferring an electron from reduced QA to the electron transport chain); I-P phase (a proxy for efficiency of reducing final acceptors beyond PSI); and PItot (total performance index for potential energy conservation from photons absorbed by PSII to reduction of PSI end acceptors). At Satakunta F(V)/F(M) and ΨEo in Betula pendula were higher in monocultures and lower in mixed plots, perhaps due to increasing light availability in mixed plots, which can induce photoinhibition. The opposite trend was observed in Picea abies, which was shaded in mixed plots. At Kaltenborn F(V)/F(M) decreased in Fagus sylvatica and P. abies in mixed plots due to competition both above- and belowground. At Satakunta LMA increased in B. pendula leaves with increasing species richness. Leaf area of ten leaves was reduced in F. sylvatica in mixed plots at Kaltenborn. By up-scaling the overall fluorescence response to plot level (PItot_plot ), a significant positive correlation with tree diversity was found at Kaltenborn, but not at Satakunta. This could suggest that competition/facilitation processes in mixed stands play a significant role in the early stages of forest establishment, but then tend to be compensated in more mature stands.

[Patient satisfaction in oncological aftercare--differential results of gender aspects in doctor-patient dyads]

OBJECTIVE

The aim of this study was to explore the role of gender of the physician and gender of the patient in explaining differences in patient satisfaction.

MATERIAL AND METHODS

Overall, 1,130 patients were assigned to one of 4 possible physician-patient sex dyads and were interviewed with a questionnaire about their patient satisfaction.

RESULTS

Female patients in a dyad with a female physician were most satisfied with the overall judgment of practice visit and the inclusion of life situation in comparison to all other dyads. Male patients in a dyad with a male physician were least satisfied.

CONCLUSION

In the future, the specific role of patient-physician dyads has to be considered more in the assessment of subdimensions of patient satisfaction.

Patient participation in the medical decision-making process in haemato-oncology--a qualitative study

Cancer patients are showing increased interest in shared decision-making. Patients with haematological illnesses, however, express considerably less desire for shared decision-making as compared with other oncological patient groups. The goal of the current project was to identify the reasons for the lower desire for shared decision-making among patients with haematological illness. We conducted qualitative, semi-structured interviews with 11 haematological patients (39-70 years old) after the beginning of therapy concerning the course and evaluation of medical shared decision-making. The patients were often overwhelmed by the complexity of the illness and the therapy and did not want to assume any responsibility in medical decision-making. They reported a great deal of distress and very traditional paternalistic role expectations with regards to their health care providers, which limited the patients' ability to partake in the decision-making process. In contrast to the socio-cultural support for many other oncological diseases, haematological diseases are not as well supported, e.g. there is a lack of self-help materials, systematic provision of information and support groups for patients, which may be related to a lower empowerment of this patient population. Results show the limits of patient participation in the context of highly complicated medical conditions. In addition to already researched preferences of the physicians and patients for shared decision-making, future research should pay greater attention to the process and other variables relevant to this aspect of the doctor-patient relationship.

Insular dysfunction and descending pain inhibition in anorexia nervosa

OBJECTIVE

Reduced perception of pain is a well-established phenomenon in patients with anorexia nervosa (AN). We tested the hypothesis that altered processing of pain within the insula might account for reduced perception of pain.

METHOD

Heat pain thresholds were obtained in nineteen patients with AN and matched controls. Thereafter, a thermode was used to deliver thermal painful stimuli to the right arm during functional magnetic resonance imaging (fMRI) measurements. Stimuli were initiated for 10 s from a baseline resting temperature (32°C) to three different levels (37, 42, 45°C).

RESULTS

Significantly increased heat pain thresholds were observed in patients. A stronger activation during heat pain perception was found in the left posterior insula in controls. In contrast, higher levels of activity were shown in the ipsilateral pons in patients when compared to controls. In patients, we found a significant interrelation between the depression score (Beck depression inventory) and heat pain activations.

CONCLUSION

We suggest that reduced activity in the left posterior insula might contribute to increased pain thresholds in patients, while increased activations in the right anterior insula and pons mirror augmented sympathetic modulation putatively related to amplification of adrenergic descending pain inhibition. In addition, pain thresholds and brain activations were influenced by disease-inherent depressed mood.

Biologically based strategies to augment rotator cuff tears

Lesions of the rotator cuff (RC) are among the most frequent tendon injuries. In spite of the developments in both open and arthroscopic surgery, RC repair still very often fails. In order to reduce the failure rate after surgery, several experimental in vitro and in vivo therapy methods have been developed for biological improvement of the reinsertion. This article provides an overview of the current evidence for augmentation of RC reconstruction with growth factors. Furthermore, potential future therapeutic approaches are discussed. We performed a comprehensive search of the PubMed database using various combinations of the keywords “tendon,” “rotator cuff,” “augmentation,” “growth factor,” “platelet-rich fibrin,” and “platelet-rich plasma” for publications up to 2011. Given the linguistic capabilities of the research team, we considered publications in English, German, French, and Spanish. We excluded literature reviews, case reports, and letters to the editor.

Geometric phase and nonadiabatic effects in an electronic harmonic oscillator

Steering a quantum harmonic oscillator state along cyclic trajectories leads to a path-dependent geometric phase. Here we describe its experimental observation in an electronic harmonic oscillator. We use a superconducting qubit as a nonlinear probe of the phase, which is otherwise unobservable due to the linearity of the oscillator. We show that the geometric phase is, for a variety of cyclic paths, proportional to the area enclosed in the quadrature plane. At the transition to the nonadiabatic regime, we study corrections to the phase and dephasing of the qubit caused by qubit-resonator entanglement. In particular, we identify parameters for which this dephasing mechanism is negligible even in the nonadiabatic regime. The demonstrated controllability makes our system a versatile tool to study geometric phases in open quantum systems and to investigate their potential for quantum information processing.

[Traumatic brain injury in children]

The general practitioner has an important role in the acute management and during the rehabilitation process of children after a traumatic head injury. Latest research shows that sequelae may occur even after a mild head injury without loss of consciousness. Recognizing the warning signs and symptoms after a head injury allows the general practitioner to counsel the child and parents in secondary prevention, particularly in order to avoid any further head injury during the recovery phase. Under the supervision of the general practitioner, a gradual progressive return to the child's everyday activities optimizes the chances of a rapid and complete recovery.

A transgenic approach to identify thyroxine transporter-expressing structures in brain development

Transporters are essential in thyroid hormone metabolism. Thyroxine (T4) is transported by solute carrier organic anion transporter 1c1 (SLCO1C1, OATP14) into the adult brain, where T4 is converted to 3,5,3'-triiodothyronine (T3). In adults, SLCO1C1 expression is found in two brain barrier structures: the blood-brain barrier (BBB) and choroid plexus. However, little is known about how T4 is transported in the developing brain, when the BBB is not yet completely formed. We employed bacterial artificial chromosome recombineering to generate transgenic mice carrying Cre recombinase in the Slco1c1 locus (Slco1c1-Cre mice). In Slco1c1-Cre mice Cre was expressed at the sites that have been previously reported for SLCO1C1 in adults. To trace Cre expression during development, we crossed Slco1c1-Cre transgenic mice with Rosa26 reporter mice. β-galactosidase staining showed Cre activity in neurones of various brain structures, such as cortical layer 2/3 and the hippocampus, suggesting transient Slco1c1 expression during brain development. At embryonic day15, SLCO1C1 was expressed at the same site as TBR2, a marker of neuronal progenitors. Neurones that express SLCO1C1 during their development could be T4 sensitive. In support of this hypothesis, hypothyroxinaemia induced by propylthiouracil treatment of dams decreased the number of β-galactosidase-positive neurones in cortical layer 2/3 of newborn Slco1c1-Cre/Rosa26 mice. In conclusion, by generating Slco1c1-Cre transgenic mice, we demonstrated that SLCO1C1 is expressed in the neuronal cell lineage during brain development. Expression of SLCO1C1 may underlie the extraordinary sensitivity of specific neuronal populations to hypothyroxinaemia.

A randomized cross-over trial comparing single-agents capecitabine (C) and UFT plus leucovorin (LV) in patients (Pts) with advanced colorectal cancer (CRC): Preliminary data of a patient preference study

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Background: Oral fluoropyrimidines such as C and UFT plus LV (U) are widely used pro-drugs dedicated to the care of CRC. Although their toxicity profile may slightly differ, no direct comparison between these treatments has been done as both molecules are converted into fluorouracil. To help the physicians to choose between C and U, we initiated this randomized cross-over trial aimed to assess patient's preference.

Methods: Pts with advanced CRC received either a first cycle of C (1,250mg/m2 x 2/d for 14 days, q3 wks) or a first cycle of U (UFT 300mg/m2/d plus LV 75 mg/d in 3 divided doses every 8 hrs for 28 days, repeated at 35-day intervals). Patients were randomized to receive C at cycle 1 followed by U (arm A) or U at cycle 1 followed by C (arm B). After 2 cycles, pts were asked which treatment they preferred. Treatment was then continued with the chosen regimen. Preferences rates are presented with 95% confidence intervals and the two groups are compared with the chi-squared test.

Results: 89 pts were enrolled from 10/2005 to 6/2010. Treatment arms were well balanced for baseline characteristics: male 57%; median age 66 years; PS 0-1 81%. Most of the pts were heavily pretreated (0/1/2/ and >2 previous chemotherapy lines: 6/2/15/66). 64 (arm A: 35, arm B: 29)/89 pts received at least 2 cycles of chemotherapy and were evaluable for preference. At cycle 1, 21% and 43% of the pts presented at least 1 severe toxic event with C and U, respectively. Pts with U at cycle 1 presented more likely with severe fatigue and anorexia. There was 1 toxic death under C (gr. 3 diarrhea, gr.4 neutropenia) at cycle 1. Overall, 66% (95%CI: 52-77%) of evaluable pts expressed preference for C, and there was a statistically significant difference between arms A and B (p<0.02) with more pts preferring C in arm A: 79% (95%CI: 61-91%), as compared to arm B: 50% (95%CI: 31-79%).

Conclusions: Pts with advanced CRC preferred C over U, especially when given during the first cycle.

No significant financial relationships to disclose.