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S Mayr

Publications and source records attributed to S Mayr.

13 recordsLinked to original sources
PubMed2001

Minor cytotoxic and antibacterial compounds from the rhizomes of Amomum aculeatum.

A new cytotoxic 1,7-dioxa-dispiro[5.1.5.2]pentadeca-9,12-dien-11-one derivative, aculeatin D, and a new alkenone, 5-hydroxy-hexacos-1-en-3-one, have been isolated as minor compounds from the rhizomes of Amomum aculeatum. Their structures have been determined mainly by NMR spectroscopy and mass spectrometry. Aculeatin D showed high cytotoxicity against the KB and the L-6 cell line with IC(50) of 0.38 microg/ml and 1 microg/ml, respectively. Additionally, it revealed remarkable activity against two Plasmodium falciparum strains, as well as against Trypanosoma brucei rhodesiense and Trypanosoma cruzi. 5-Hydroxy-hexacos-1-en-3-one exhibited neither cytotoxic nor antiprotozoal activity, whereas antibacterial testing against Bacillus cereus, Escherichia coli and Staphylococcus epidermidis showed moderate to strong activity for both compounds.

Alkenes↗
PubMed2000

[Internet presence of surgical clinics in Germany. Current data and future prospects].

INTRODUCTION: The aim of this study was to obtain an overview of the use of the Internet by surgical departments in Germany as a presentation platform and information resource for their patients. METHODS: After a randomizing a total of 1,760 surgical departments in Germany, 200 were chosen and asked about their Internet use. RESULTS: Most of the questionnaires (81.5%) were received and analyzed; 32.5% of the German surgical departments are represented on the Internet; 81.4% of the clinics without a homepage are planning to have one in the future. The hospitals represent themselves on average on two HTML documents. CONCLUSION: Approximately a third of the German surgical departments currently give information over the Internet with a wide and heterogeneous spectrum. In the near future approx. 80% of the German surgical departments will have online presence. Therefore, the increasing demand for medical information by the patients will be fulfilled. The professionalism and effectiveness of the home-pages can be increased through registration with many search engines and the use of e-mail.

Forecasting↗
PubMed2000

Three-dimensional eye-movement responses to off-vertical axis rotations in humans.

We recorded three-dimensional eye movements elicited by velocity steps about axes that were tilted with respect to the earth-vertical. Subjects were accelerated in 1 s from zero to 100 degrees/s, and the axis of rotation was tilted by 15 degrees, 30 degrees, 60 degrees, or 90 degrees. This stimulus induced a constant horizontal velocity component that was directed opposite to the direction of rotation, as well as a modulation of the horizontal, vertical and torsional components with the frequency of the rotation. The maximum steady-state response in the horizontal constant-velocity component was much smaller than in other species (about 6 degrees/s), reaching a maximum at a tilt angle of about 60 degrees. While the amplitude of the horizontal modulation component increased up to a tilt angle of 90 degrees (8.4 degrees/s), the vertical and torsional modulation amplitudes saturated around 60 degrees (ca. 2.5 degrees/s). At small tilt angles, the horizontal modulation component showed a small phase lag with respect to the chair position, which turned into a small phase lead at large tilt angles. The torsional component showed a phase lead that increased with increasing tilt angle. The vertical and torsional velocity modulation at large tilt angles was not predicted by a recent model of otolith-canal interaction by Merfeld. Agreement between model and experimental data could be achieved, however, by introducing a constant force along the body's z-axis to compensate for the gravitational pull on the otoliths in the head-upright position. This approach had been suggested previously to explain the direction of the perceived subjective vertical during roll under different g-levels, and produced in our model the observed vertical and torsional modulation components at large tilt angles.

Adult↗
PubMed1999

Human skeletal muscle HSP70 response to training in highly trained rowers.

Previous studies have demonstrated exercise-induced heat shock protein 70 (HSP70) in animals. The purpose of this study was to investigate human skeletal muscle HSP70 response to rowing training. Ten male rowers trained for 4 wk with different forms, durations, and intensities of exercise. Biopsy was performed in the right musculus vastus lateralis before training and at the end of each week. HSP70 in 5 microg of total protein from the muscle sample was determined by using Western blot and immunodetection with chemiluminescence technique, by means of laser densitometer referring to a series of known standard HSP70. Compared with pretraining (100%), HSP70 increased during training (181, 405, 456, and 363% from the first to fourth training week, respectively) with the maximum HSP70 production at the end of second training week. Thus HSP70 is induced in highly trained human muscle by long-term training.

Adolescent↗
PubMed1998

Selective coupling of STAT factors to the mouse prolactin receptor.

Prolactin has been reported to induce distinct sets of signal transducers and activators of transcription (STAT) in a cell-type-specific fashion. In the mammary epithelium, although STAT1, STAT3, STAT5A, STAT5B and STAT6 are present in a latent form, only STAT5A and STAT5B are activated. This selective activation of STAT5 by prolactin was also observed in COS-7 cells cotransfected with the long form of the mouse prolactin receptor (PRL-R) and expression vectors for STAT1, STAT3, STAT5 and STAT6. Mutated PRL-Rs and chimeric erythropoietin/gp130 (EPO/gp130) receptors with a tyrosine-containing motif attached at the carboxy terminus were employed to determine the sites in the PRL-R required for the specific activation of STAT5. The experiments revealed the importance of two motifs containing Y477 and Y578 in the PRL-R. When linked to the EPO/gp130 receptor, these sequences were sufficient to specifically induce DNA binding of STAT5 and to activate transcription from the beta-casein gene promoter. By contrast, only weakly they induced DNA binding of STAT6 and STAT3 and did not induce STAT1. A synthetic nonapeptide with phosphorylated Y477 was able to disrupt STAT5 DNA binding in vitro. Our results define structural domains within the carboxy terminus of the PRL-R which recruit STAT5 for signalling and which are capable of distinguishing STAT5 from other STAT proteins. The activity of STAT5 forms with deletions of the carboxy terminus was induced more strongly than that of their full-length counterparts 2 min after activation of the PRL-R. This effect was not dependent on the presence of Y477 and Y578 in the PRL-R, indicating that facilitated activation of short STAT5 isoforms relies on mechanisms other than increased coupling to specific regions of the PRL-R.

Animals↗
PubMed1996

Differential Ca2+ signaling induced by activation of the epidermal growth factor and nerve growth factor receptors.

Stimulation by epidermal growth factor (EGF) of NIH3T3 cells overexpressing the EGF receptor (EGFR) results in a release of Ca2+ from internal stores. Ca2+ release is followed by an influx of extracellular calcium which can be recorded by the influx of the calcium surrogate Mn2+. Both Ca2+ release and Mn2+/Ca2+ influx are inhibited by expression of the dominant negative Asn17-Ras mutant and abrogated by microinjected neutralizing anti-Ras antibody Y13-259, whereas microinjection of the anti-Ras antibody Y13-238 which does not interact with the effector binding domain of Ras is without any effect on the EGF-induced Ca2+ transient. Neither Asn17-Ha-Ras nor the Y13-259 antibody interferes with the thapsigargin-induced Mn2+/Ca2+ influx. The nerve growth factor receptor (Trk)-mediated Ca2+ transient was found to be unaffected by the dominant negative Ras mutant or microinjected neutralizing anti-Ras antibodies. Substitution of the phospholipase Cgamma1 (PLCgamma1) binding site of the EGFR by the PLCgamma binding domain of Trk renders the EGFR-induced Ca2+ influx insensitive to the expression of Asn17-Ha-Ras, whereas the Ca2+ signal induced by Trk carrying the PLC binding site of EGFR is Ras-dependent and abrogated by the dominant negative Ras mutant. It is concluded that the Ca2+ transient induced by the activated EGFR, not, however, the Ca2+ transient elicited by the activated NGFR/Trk, is a Ras-mediated phenomenon and that the role of Ras in regulating EGFR-induced Ca2+ influx depends on the structure of the PLCgamma binding domain.

3T3 Cells↗
PubMed1992

Laser-enhanced NMR spectroscopy.

Experimental studies show that optical irradiation far from any absorption bands can shift the resonances in a nuclear magnetic resonance (NMR) spectrum without significant heating. This effect may lead to increased dispersion in NMR studies of complex molecules.

Camphor↗
PubMed1990

Interpersonal types among alcohol abusers: a comparison with drug abusers.

Interpersonal types among alcohol abusers were examined with Calsyn, Roszell, and Anderson's (1988) nine-type system for classifying FIRO-B profiles. The frequencies of the nine FIRO-B types among a sample of 135 male veteran alcohol abusers were compared with Calsyn et al.'s (1988) previously published data for a sample of male veteran drug abusers, a normative veteran sample, and a general population sample. The alcohol abusers, like Calsyn et al.'s sample of drug abusers, were more likely to be categorized as "loners," "rebels," and "pessimists" than was the general population sample. While exhibiting preferences for interpersonal types that emphasized social withdrawal, avoidance of responsibility, and mistrust of others, both the alcohol abusers and the drug abusers were heterogeneous groups whose members demonstrated a variety of interpersonal types.

Adult↗
PubMed1990

The Io syndrome: symptom formation in victims of sexual abuse.

The sexual abuse of women today is analyzed alongside the mythology of Ovid's Metamorphoses. Two thousand years ago, Ovid unfolded a world view of human beliefs and practices that make up today's symptom formation and psychodynamic in victims of sexual abuse. Herewith the mythology of Io. Her rape and subsequent symptom formation is understood as a clinical account of rape-trauma syndrome and post-traumatic stress disorder.

Adult↗