Fermi surface and van Hove singularities in the itinerant Metamagnet Sr3Ru2O7.

The low-energy electronic structure of the itinerant metamagnet Sr3Ru2O7 is investigated by angle-resolved photoemission and density-functional calculations. We find well-defined quasiparticle bands with resolution-limited linewidths and Fermi velocities up to an order of magnitude lower than in single layer Sr2RuO4. The complete topography, the cyclotron masses, and the orbital character of the Fermi surface are determined, in agreement with bulk sensitive de Haas-van Alphen measurements. An analysis of the dxy band dispersion reveals a complex density of states with van Hove singularities near the Fermi level, a situation which is favorable for magnetic instabilities.

[Methodologic reflections on the establishment and interpretation of group median sagittal contours of the skull]. / Methodische Uberlegungen zur Erstellung und Interpretation median-sagittaler Gruppenrisse vom Hirnschädel.

The normal lateralis is by far the most interesting of the normae of cranium, being that which contour is usually drawn to illustrate the description of the skull. The methods to assemble individual cranial profiles to group-profiles in order to get a typological impression of a random sample vary considerably. Some of these methods are discussed in this paper. On the basis of six medieval skulls from Remlingen (district Wolfenbüttel, Lower Saxony) an attempt is made to obtain a better comparability of form-variation in the cranial profiles by eliminating the factor of different length. Additionally a comparison of the single elements of the cranial profile is made and a new method for the drawing of group-profiles is recommended, which provides smaller differences in the form of the skulls compared than former methods.

[Patient satisfaction with psychiatric services. Findings of a key date survey]. / Zufriedenheit psychiatrischer Patienten mit ihrem stationären Aufenthalt. Ergebnisse einer Stichtagserhebung.

The aim of this study was to gain more empirical ideas for the concept of patient satisfaction and its usefulness as an instrument for quality assurance by analyzing the relationship between inpatient experiences and inpatient satisfaction with psychiatric services. Data were obtained from 91 inpatients of the Psychiatric Hospital of the Ludwig-Maximilians-University in Munich (85% of all patients who had been in hospital at least 3 weeks and who could be asked) by questionnaires on a fixed day. Patients had been asked about their overall satisfaction as well as their experiences with special aspects of the services.Overall satisfaction was high, but there was a remarkable amount of adverse experience with components concerning patient information and time with a psychiatrist offered to the patients. The results give evidence that communication and empathy of the medical staff are key indicators of patient satisfaction and dissatisfaction. Furthermore, results suggest that global satisfaction scores should not be used as an instrument of quality assurance.

[Determinants of patient satisfaction: treatment and clinical factors, subjective concept of the illness and quality of life]. / Determinanten der Patientenzufriedenheit: behandlungsbezogene und klinische Variablen, subjektives Krankheitskonzept und Lebensqualität.

The aim of this study was to examine the associations between treatment factors, clinical factors and treatment satisfaction of psychiatric in-patients. Especially, the authors were interested in the question, whether treatment satisfaction in general and patient experiences in detail are equally affected by the factors mentioned above. Data were obtained from 91 in-patients of the Psychiatric Department of the Ludwig-Maximilians-University of Munich (85 % of all patients who had been in hospital since at least 3 weeks) by questionnaires on a fixed day. Global satisfaction and patients experiences with special aspects of the services were correlated to sociodemographic variables, diagnosis, psychopathological syndromes, actual mood state, patient's concept of the illness and quality of life. Global satisfaction and the rating of special treatment components are differently affected by the patients actual mood state and prior hospitalizations. Effects of gender, diagnosis and psychopathology are low; there is no correlation between education and satisfaction on both levels. In contrast, both rating levels correlate significantly with general trust in medication and physician. There are only weak correlations between global satisfaction and quality of life. Data indicate that global and specific satisfaction ratings are different in regard to some determinants but at the same time they are both affected by attitudinal factors.

Progesterone binding to uteroglobin: two alternative orientations of the ligand.

Progesterone binding to a homodimer of uteroglobin takes place in a hydrophobic cavity formed by the two subunits. Previous mutational analyses have shown that the tyrosine (21 and 21') and threonine (60 and 60') residues of the uteroglobin dimer are directly involved in progesterone binding. To analyze the contribution of each of the two tyrosines and threonines in the dimer, we have constructed a covalently linked uteroglobin dimer (UGcl) by fusing two uteroglobin cDNAs via a synthetic linker sequence. Escherichia coli expressed UGcl bound progesterone with the same affinity as the native dimeric protein. Replacement of both tyrosines by phenylalanines abolished progesterone binding. Replacement of either the C-terminal tyrosine 21 or the N-terminal tyrosine 21' separately, reduced the affinity for progesterone 3- to 4-fold, suggesting that both tyrosines participate in progesterone binding. In contrast, substitutions of the threonine residues of the C- or N-terminal moities had no effect, whereas the replacement of both threonines reduced the affinity for progesterone 2- to 3-fold. These data, together with computer models, suggest that progesterone docks in the internal binding pocket of uteroglobin in two different orientations.

Improvements in the computerized analysis of 2D INADEQUATE spectra.

The carbon skeleton of a molecule can be determined by using the powerful 2D INADEQUATE experiment, but the method suffers from very poor sensitivity at natural carbon-13 abundance. A computer program, described previously, has been significantly improved in its ability to recognize AB spectral patterns corresponding to carbon-carbon bonds which makes it possible to evaluate reliably spectra with rms S/N ratio as low as 2.5, i.e., nearly 1 order of magnitude below the level required for routine manual interpretation. Application of the INADEQUATE experiment to samples containing as little as 20 mumol of a compound of interest is now possible. The method is described in detail and critically evaluated by means of examples and simulations.

The total synthesis of C-glycosides with completely resolved seven-carbon backbone polyol stereochemistry: stereochemical correlations and access to L-configured and other rare carbohydrates.

The de novo synthesis of a full set of hydroxymethyl C-glycosides from only two precursors is described. The seven-carbon target molecules contain five stereocentres and bridge the stereochemical gap between natural D-configured and non-natural L-configured series of hexoses. Key steps include hydroxylation, differential protection, stereoselective reduction and desymmetrization of 8-oxabicyclo[3.2.1]oct-6-enes. C-Terminus differentiation and C-terminus excision of the seven-carbon polyol backbone lead to hexoses, including those of the L-series. A stereochemical and genetic classification of C-glycosides is presented.

Interchain cysteine bridges control entry of progesterone to the central cavity of the uteroglobin dimer.

The progesterone-binding protein uteroglobin has been expressed in Escherichia coli in an unfused, soluble form. Like mature uteroglobin from rabbit endometrium (UG), the E.coli produced uteroglobin (UG1) dimerizes in vitro, forms an antiparallel dimer with Cys3-Cys69' and Cys69-Cys3' disulfide bonds and binds progesterone under reducing conditions. In order to analyze the dimerization and the reduction dependence of progesterone binding in more detail, we separately replaced cysteine 3 and cysteine 69 by serines. Under reducing conditions, both uteroglobin variants (UG1-3Ser and UG1-69Ser) bind progesterone with the same affinity as the wild-type suggesting that both cysteine residues are not directly involved in progesterone binding. In contrast to the wild-type protein, both cysteine variants also bind progesterone with high affinity in the absence of reducing agents. In addition, UG1-3Ser and UG1-69Ser both form covalently linked homodimers. Thus, unnatural Cys69-69' and Cys3-3' disulfide bonds exist in UG1-3Ser and UG1-69Ser, respectively. These data together with computer models based on X-ray diffraction data strongly support the idea that progesterone reaches its binding site located in an internal hydrophobic cavity via a hydrophobic tunnel along helices 1 and 4. Under non-reducing conditions the tunnel is closed by two disulfide bridges (Cys3-Cys69' and Cys69-Cys3') that lie in the most flexible region of the dimer. Reduction or replacement of a cysteine residue enables conformational changes that open the channel allowing progesterone to enter.

Effect of capsaicin-containing red pepper sauce suspension on upper gastrointestinal motility in healthy volunteers.

Afferent nerves play a major role in the regulation of gastrointestinal motility. The questions remains if specific food ingredients can selectively activate such fibers. The aim of the study was to investigate the effect of intraesophageal application of a capsaicin-containing red pepper sauce (Tabasco) suspension on upper gastrointestinal motility in a controlled trial. After a baseline recording [esophageal motility, balloon distension, electrogastrogram (EGG)], red pepper or saline solution was infused intraesophageally in seven healthy volunteers. At 30 min gastric emptying and orocecal transit time were determined using a [13C]acetate and H2-lactulose breath test. Infusion of red pepper sauce suspension significantly increased the amplitudes (65.8 +/- 3 to 78.5 +/- 4.7 mm Hg, P < 0.05) and propagation velocity (2.9 +/- 0.3 to 4.25 +/- 0.3 sec, P < 0.05) of esophageal pressure waves and LES pressure (17.8 +/- 1.4 to 23.7 +/- 2.6 mm Hg, P < 0.05). It significantly decreased perception and discomfort threshold of intraesophageal balloon distension, reduced the percentage of normal electrical activity in the EGG, and delayed gastric emptying (saline: T(1/2) 42.9 +/- 12.0 min vs red pepper: T(1/2) 66.8 +/- 19.0 min, P < 0.05). Despite the prolongation of gastric emptying, orocecal transit time was not altered, indicating an actual increase of intestinal transit. Esophageal application of capsaicin-containing red pepper sauce suspension had profound changes on upper gastrointestinal motility, which could improve clearance and protection of the esophagus and could lead to retention of the irritant in the stomach and faster transit through the small bowel.

Biomagnetic 3-dimensional spatial and temporal characterization of electrical activity of human stomach.

Biomagnetic measurements are based on the noninvasive recording of magnetic signals produced by biological sources such as nervous system and muscle. The aim of this study was to obtain multichannel magnetic field recordings from the human gastrointestinal tract and to localize the sources of these signals three-dimensionally. The magnetic field was recorded in eight human healthy subjects using a sensor array with 37 superconducting quantum interference devices (SQUIDs); an electrogastrogram was recorded simultaneously. Biomagnetic source localization was carried out with an iterative nonlinear optimization algorithm using the model of an equivalent current dipole (ECD) and correlated to magnetic resonance imaging (MRI) in four volunteers. Magnetogastrograms and electrogastrograms demonstrated a similar frequency distribution with a peak at 3/min. In all subjects the centers of the calculated dipoles plotted vs time showed a characteristic migration across the stomach area. One volunteer demonstrated tachygastric episodes, during which his magnetic field amplitudes increased fivefold and his dipole migration disappeared. In absence of an attack his recordings changed to normal. This demonstrates multichannel magnetic recordings can be used to localize the sources of the biomagnetic field, which could be useful for the understanding of motility disturbances.

Applications of the improved computerized analysis of 2D INADEQUATE spectra.

This paper illustrates the use of the program CCBond to determine the carbon skeletons of bioorganic molecules in low concentration samples. Discussed is the structure elucidation of bistramide A, a compound extracted from a Fijian Lissoclinum sp. and cholesterol in 71- and 20-mumol samples, respectively. The detection limit of the automated bond extraction is shown to be dramatically improved compared to the manual interpretation of 2D INADEQUATE spectra.