Search Results - (Author, Cooperation:M. Bernhard)

2016-02-06

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Animals ; Autism Spectrum Disorder/*drug therapy/enzymology/genetics ; Chromosome Deletion ; Chromosome Disorders/genetics ; Chromosomes, Human, Pair 22/genetics ; Disease Models, Animal ; Down-Regulation ; Gene Knockdown Techniques ; Humans ; Insulin-Like Growth Factor I/metabolism ; Mice ; Molecular Sequence Data ; Multiprotein Complexes/metabolism ; Nerve Tissue Proteins/*genetics ; Neurons/enzymology ; Phosphorylation ; Protein Phosphatase 2/metabolism ; Protein-Serine-Threonine Kinases/*antagonists & inhibitors/metabolism ; Protein-Tyrosine Kinases/*antagonists & inhibitors/metabolism ; Proteomics ; Proto-Oncogene Proteins c-akt/genetics/metabolism ; Rats ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Photoelectron spectra of single crystals of eight aromatic compounds were measured at several UV wavelengths. Useful results were obtained when sample charging was eliminated by inducing photoconduction through subsidiary illumination of the sample crystal with low energy light, and/or by a vapor-deposited gold grid on the sample surface. The threshold ionization potential obtained for a single crystal was found always to be lower than that for the corresponding polycrystalline film.

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. In mammalian plasma, many different inhibitors of Na+/K+-ATPase are present, but it is not clear whether their net effect on Na+/K+-ATPase activity changes during the regulation of electrolyte and fluid balance. We studied Na+/K+-ATPase inhibition by plasma extracts in conscious rats during short-and long-term body fluid regulation.2. Male, adult, conscious, freely moving Wistar rats were subjected to one of the following protocols: (i) intracerebroventricular (i.c.v.) injections of angiotensin II (Angll; 1, 10 and 100 ng), the Angll receptor antagonist losartan (1μg), atrial natriuretic peptide (ANP-III; 1μg) or isotonic saline (IS); (ii) intra-arterial (i.a.) injections of IS (6 or 10 mL), hypertonic saline (HS; 1.2% NaCl, 5 mL) or hypertonic plasma expander (HPS; 3.5% hetastarch in HS, 5mL); or (iii) a low salt-high salt-low salt diet sequence (0.18/1.8/0.18% NaCl chow for S days each with controls receiving 0.18% NaCl on all days). Bodyweight, the intake of food and water, urine volume and Na+ concentration and weight of faeces were determined daily. Plasma samples were withdrawn repeatedly throughout the respective protocols, extracted on C18-reversed phase columns and assayed for their effect on the activity of different Na+/K+-ATPase preparations.3. The inhibition of rat brain Na+/K+-ATPase by plasma extracts was not significantly changed by i.c.v. injection of Angll, losartan, ANP-III and IS within the observation period (30 min from respective stimuli). Similarly, no significant changes occurred after acute volume expansion by i.a. injection of IS or HS within 120 min; upon HPS, however, Na+/K+-ATPase inhibition was decreased by approximately 20% (P〈0.05), probably due to passive dilution. During the high-salt diet, fluid retention was effectively counteracted by an adaptive increase of urinary sodium excretion. Throughout the protocol, inhibition of pig brain Na+/K+-ATPase by plasma extracts did not differ significantly between groups.4. It is concluded from these results that the short- or long-term control of body fluids in conscious rats is not associated with systematic changes in Na+/K+-ATPase inhibition by plasma factors.

Electronic Resource

1365-2842

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The purpose of this study was to evaluate the fracture strength of four different types of anterior 3-unit bridges after thermo-mechanical fatigue in a dual-axis chewing simulator. Sixty-four human maxillary incisors were prepared and 32 bridges fabricated. The four groups of eight bridges each were – (GC): AGC® galvano-ceramic bridges (CA): Celay® In-Ceram® Alumina bridges (E2): heat-pressed lithium disilicate glass-ceramic bridges and (CM) ceramo-metal (control). Fracture loads were recorded after a dual-axis chewing simulator and in a universal testing machine. The survival rate after 5 years for the CM and the GC groups was 100%, for the E2 group 75% and for the CA group 37·5% (Kaplan–Mayer analysis). The mean fracture strengths (N) were 681·52 ± 151·90 (CM); 397·71 ± 59·02 (GC); 292·92 ± 46·45 (E2) and 239·95 ± 33·39 (CA), respectively. The log–rank test showed a significant difference between the CA and the GC or the CA and the CM groups. No significant differences between the E2 and the CA or the E2 and the GC groups were found. The study indicates that heat-pressed lithium disilicate glass-ceramic and AGC® galvano-ceramic bridges are alternatives to ceramo-metal 3-unit anterior bridges.

Electronic Resource

1546-170X

Nature Archives 1869 - 2009

Biology

Medicine

[Auszug] Positron emission tomography (PET) is now regularly used in the diagnosis and staging of cancer. These uses and its ability to monitor treatment response would be aided by the development of imaging agents that can be used to measure tissue and tumor proliferation. We have developed and tested ...

Electronic Resource

1546-170X

Nature Archives 1869 - 2009

Biology

Medicine

[Auszug] Immunization with myelin antigens leads to the development of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. The disease can also be induced by the transfer of encephalitogenic CD4+ T helper (TH) lymphocytes into naive mice. These T cells need to re-encounter ...

Electronic Resource

1574-6941

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Ambient concentrations and turnover rates of two amino acids, leucine and methionine, by total bacterioplankton and Prochlorococcus cyanobacteria were determined along a latitudinal transect across the Southern Atlantic gyre using a combined isotopic dilution and flow cytometric sorting technique. The ambient concentrations of methionine (0.2–0.65 nM) were about 2 times higher than the concentrations of leucine, while the turnover rates of the two amino acids were remarkably similar (0.1–0.7 nM d−1). The concentrations of both amino acids did not vary significantly with depth between 3 and 150 m but their turnover rates were 1.5–2 times higher in the top 3–80 m. Prochlorococcus took up amino acids in situ at high rates. Using a representative 35S-methionine precursor, about 25% of total bacterioplankton consumption of amino acids could be assigned to Prochlorococcus with low red fluorescence (Pro LRF) inhabiting the surface mixed layer down to 80 m and about 50% assigned to Prochlorococcus with high red fluorescence (Pro HRF) living below 100 m. In the same deep waters the cellular amino acid uptake of Pro LRF was less than 6% of that of the Pro HRF, indicating declining metabolic activity of the former. The mean cellular uptake rate of Pro HRF at depths below 120 m was 2.5 amol cell−1 d−1, 4 times higher than the rates of Pro LRF in the top 80 m. The difference could be partially explained by Pro HRF cellular biomass being twice that of Pro LRF. The biomass specific rates of Prochlorococcus were comparable or higher (particular of the Pro HRF) than that of other bacterioplankton. The reported findings could explain ecological success of mixotrophic Prochlorococcus cyanobacteria over both strictly autotrophic algae and heterotrophic bacteria in oligotrophic regions sustained by nutrient remineralisation.

Electronic Resource

1438-3888

Springer Online Journal Archives 1860-2000

Biology

Summary 1. Using 6 phytoplankton species and/or the copepodEuterpina acutifrons or larvae of the sea urchinArbacia lixula the potential inhibitory effects of chemicals released from some 70 different materials (mainly plastics) have been tested. In addition, the effects of 6 detergents have been examined. 2. Several materials, such as natural rubbers and polyvinyl chlorides, are highly toxic and should never be used when experimenting with living marine organisms. 3. Teflon (Algoflon), Perspex, Polyethylene, Tygon, Polypropylene, Polycarbonates (Makrolon) and Polyester (Gabraster) have been shown to be non-toxic and are, therefore, suitable for use in cultivation of marine organisms. Some materials had slightly negative effects on the organisms tested and should, therefore, be used only if no alternatives are available. 4. Some suggestions are advanced on how to construct non-toxic samplers and laboratory equipment used for experiments with marine organisms.

Kurzfassung Etwa 80 chemisch verschiedene Substanzen und Materialien wurden hinsichtlich einer möglichen toxischen Wirkung an mehreren Phytoplanktonarten, dem CopepodenEuterpina acutifrons und den Larven des SeeigelsArbacia lixula geprüft. Es zeigte sich, daß die Phytoplankter empfindlichere Testorganismen sind alsEuterpina acutifrons und die Larven vonArbacia lixula. Auch konnte zwischen den verschiedenen Phytoplanktonarten erhebliche Unterschiede in der Reaktion festgestellt werden. Detergentien erwiesen sich nur in relativ hohen Konzentrationen als toxisch. Viele Substanzen, die eine mannigfache Anwendung im Laboratorium finden, wie zum Beispiel roter und schwarzer Gummi oder Polyvinylchlorid, sind ausgesprochen toxisch und sollten nicht für Geräte benutzt werden, die zur Probeentnahme lebender Organismen dienen. Einige Substanzen, die sich zunächst als nicht toxisch erwiesen hatten, wurden toxisch, nachdem sie bei 0,5 atm 20 min in dem Kulturmedium sterilisiert wurden. Es konnte jedoch nachgewiesen werden, daß Polyäthylene (naturfarben), Gabraster (mit Katalysatoren), Perspex, Silicongummi, Algoflon (Teflon), Tygon, Silikon SE 1201 und Kautschuk (für Stöpsel) auch nach dem Sterilisieren optimales Wachstum der Testorganismen zulassen. Da aber Firmen oft die Zusammensetzung ihrer Materialien ändern, müssen die einzelnen Lieferungen immer wieder auf Toxizität geprüft werden. Nur so kann verhindert werden, daß Wasserschöpfer, Planktonnetze und andere Geräte, die zur Probenentnahme von lebenden Organismen benutzt werden, die Organismen nicht bereits negativ beeinflussen, bevor das eigentliche Experiment angesetzt worden ist. Das gleiche gilt natürlich auch für Materialien, die zur Konstruktion der Kulturgefäße und-apparate benutzt werden.

Electronic Resource

1432-0711

X-ray pelvimetry ; Cephalo-pelvic disproportion ; Forms of pelvis ; Management of labor in breech presentation

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung Der Stellenwert der radiologischen Pelvimetrie wird kontrovers beurteilt. Anhand von 164 radiologischen Beckenmessungen bei Bekkenendlagen und 112 Röntgenuntersuchungen nach Sectio caesarea wurde versucht, den prospektiven Wert dieser Untersuchung zu beurteilen. In 10% wurden radiologisch stark verengte Becken gefunden. Darunter waren am häufigsten Trichterbecken, nie Assimilationsbecken vertreten. Alle pathologisch verengten Trichterbecken und allgemein verengten Becken wurden auch durch die digitale Beckenaustastung erfaßt. Alle Fälle von Conjugata vera-Massen unter 10 cm betrafen allgemein verengte Becken und waren somit durch die digitale Beckenaustastung erfaßbar. Wir empfehlen, auf eine routinemäßige Durchführung der radiologischen Pelvimetrie zu verzichten. Die seitliche Beckenaufnahme kann in graviditate bei Schwierigkeiten mit der Festlegung des Geburtsmodus von Beckenendlagen und nach Sectio caesarea bei dringendem Verdacht auf Kopf-Becken-Mißverhältnis eine zusätzliche Hilfe sein.

Electronic Resource

1433-0423

Schlüsselwörter Ballonkatheter ; Führungsdrahtkanüle ; Stenosen und Verschlüsse ; Retrograde ; Dilatation ; Key words Balloon catheter ; Guide wire cannula ; Nasolacrimal duct stenosis and obstruction ; Retrograde dilation

Springer Online Journal Archives 1860-2000

Medicine

In dilation of nasolacrimal duct stenosis materials now being used originally were developed for percutaneous transluminal coronary angioplasty (PTCA). Suitable modifications of the angioplasty equipment could improve therapeutic results and thus influence the area of indication of this new technique. In addition to the standard PTCA equipment, we used a cannula designed to fit the guide wire, leading to less traumatic intubation of the lacrimal duct and allowing radiographic control of the recanalization procedure. Five patients showing relative stenosis and ten patients showing complete obstruction of the nasolacrimal duct were treated by dacryocystoplasty. Clinical and radiographic follow-up was done over a period of 6 months. In a total of seven patients, dilation proved successful. Out of these, four showed stenosis (80% recanalization rate) and three complete obstruction (30% recanalization rate) before dilation. Recanalization by dilation using balloon catheters seems to be possible even in cases of complete nasolacrimal duct obstruction. However, the success rate is considerably lower than in relative stenosis.

Für die Ballonkatheterdilatation von Tränenwegverlegungen werden Materialien genutzt, die für die perkutane transluminale Koronarangioplastie (PTCA) entwickelt worden sind. Ergänzungen des Angioplastiebestecks könnten Einfluß auf die Erfolgsquote und die Indikationsstellung ausüben. Wir haben das PTCA-Set um eine an den Führungsdraht angepaßte Kanüle erweitert. Dies erleichtert die atraumatische Sondierung des Tränenwegsystems und ermöglicht eine radiologisch gesteuerte Rekanalisation von Verschlüssen. Die Indikationsstellung galt sowohl Stenosen als auch Verschlüssen des Tränenwegsystems. Unter Bildwandlerkontrolle wurden insgesamt 5 Patienten mit Tränenwegstenose und 10 Patienten mit Tränenwegverschluß mit der Dakryozystoplastie behandelt. Nach erfolgter Dilatation wurden alle Patienten sowohl klinisch als auch radiologisch einem mittleren Beobachtungszeitraum von 6 Monaten unterzogen. Bei insgesamt 7 Patienten war die Dilatation erfolgreich, 4 Patienten wiesen dabei vor der Dilatation eine Stenose (Erfolgsrate 80%), 3 Patienten einen Verschluß auf (Erfolgsrate 30%). Eine Rekanalisation durch Ballonkatheterdilatation ist prinzipiell auch bei Verschlüssen möglich. Bei dem Ausgangsbefund Verschluß liegt die Erfolgsquote jedoch deutlich niedriger als bei Stenosen des Tränenwegs.

Electronic Resource

1436-5073

Auger electron spectroscopy ; iron ; surface segregation ; single crystal surfaces

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract The analysis of segregation phenomena in bicrystals is an important step for the understanding of combined effects of the elementary diffusion processes involved in the segregation in polycristalline systems. The segregation of Si and P in a Fe-6at.%Si bicrystal with a (100) and (110) surface has been investigated by means of AES (Auger electron spectroscopy). For these experiments the technique of a linearly increased temperature has been applied. Significant differences between the segregation kinetics at the two surfaces of the sample have been found on the one hand for the maximum coverage of P and on the other hand for the high temperature behaviour of Si. Additionally, model calculations based on the KTBIM (kinetic tight binding Ising model) have been performed to qualitatively describe the experimental results. It is shown, that the striking differences between the segregation behaviour at the two differently oriented surfaces can be explained by different segregation energies of P, whereas Si plays a minor role due to its relatively small segregation energy.

Electronic Resource

1573-093X

Springer Online Journal Archives 1860-2000

Physics

Electronic Resource

1573-093X

Springer Online Journal Archives 1860-2000

Physics

Abstract In the solar corona the opacities of some of the prominent X-ray emission lines are on the order of τ ≈ 1 over typical coronal path lengths. We present and discuss a particular solution of the radiative transfer problem involving an extended, spherically symmetric coronal shell radiating isotropic, homogeneous emission in which single-scattering also takes place. Within the context of this simplified model we find that scattered radiation is an important contribution to the total emergent resonance line flux and that for the He-like family of resonance (r), intercombination (i), and forbidden (f) lines, the ratio G=(f + i)/r would decrease as a function of optical depth for disk-center emission in an extended spherically symmetric corona.

Electronic Resource

1573-093X

Springer Online Journal Archives 1860-2000

Physics

Abstract An overview of the many topics discussed at IAU Colloquium No. 104 is presented as an introduction to the Proceedings. Suggested areas for future research emerging from the conference are summarized.

Electronic Resource

1432-055X

Springer Online Journal Archives 1860-2000

Medicine

Unter dem Motto “Ein Fenster ins 21. Jahrhundert” fand vom 20. bis 23. Januar diesen Jahres in San Diego das Jahrestreffen der amerikanischen Gesellschaft für Technologie in der Anästhesie (STA) statt. Ziel dieser Vereinigung ist es, neueste Trends auf dem Gebiet der anästhesierelevanten Technologien aufzuzeigen, wissenschaftliche Arbeiten hierzu zu fördern und Denkanstöße für zukünftige Entwicklungen zu geben. Die 1994 neu gegründete Gesellschaft läßt neben klinisch und wissenschaftlich tätigen Anästhesisten auch Mitarbeiter von medizinischen Geräteherstellern als Mittglieder zu, so daß der Erfahrungsaustausch zwischen Technologieanbietern und -nutzern in zukünftige Entwicklungen einfliessen kann. Ein inhaltlicher Schwerpunkt der STA-Treffen ist das Gebiet der Anästhesiesimulation.

Electronic Resource

1432-069X

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung All-trans-Retinsäure und ihr Derivat Retinoid, zwei neue Substanzen mit zunehmender Bedeutung für die dermatologische Therapie, wurden in ihrer Auswirkung auf den Sauerstoffverbrauch von Zellen und von überlebenden Hautschnitten und auf Enzymaktivitäten (Reinenzym G-6-PDH; Hauthomogenat) untersucht. Sowohl Retinsäure als auch Retinoid bewirkten eine Steigerung des Sauerstoffverbrauches der Rattenhaut. Der Sauerstoffverbrauch menschlicher Haut erfuhr nur in Gegenwart von Retinoid eine signifikante Steigerung. An ruhenden Hefen verursachte keine der beiden untersuchten Substanzen einen Anstieg des Sauerstoffverbrauchs. — Schon in Konzentrationen von 5 µg/ml (etwa 15 µmol/l) hemmen Retinsäure und Retinoid die G-6-PDH-Aktivität (Reinenzym). Im Hauthomogenat (menschliche Haut) hemmte Retinsäure die Aktivitäten der LDH, GAPDH und G-6-PDH, während GOT-, LAP- und ALD-Aktivitäten unbeeinflußt blieben, zumindest durch Konzentrationen zwischen 1 und 100 µg/ml. (Retinoid wurde in diesen Versuchen nicht geprüft.) — Die Untersuchungsergebnisse werden im Hinblick auf die Anwendung von Retinsäure und Retinoid zur Behandlung der Psoriasis kurz diskutiert.

Summary All-trans retinoic acid and its derivative retinoid, two new compounds with expanding therapeutic spectrum in dermatology, were investigated in biochemical assays. Both substances provoke an increase in oxygen consumption of rat skin whereas in human skin only retinoid was found active in this respect. In resting yeast cells, both substances failed to exert any significant influence on oxygen consumption. — Pure G-6-PDH was inhibited by retinoic acid and retinoid in concentrations as low as 5 µg/ml. In human skin homogenates, LDH-, GAPDH-, and G-6-PDH-activities were inhibited by retinoic acid whereas GOT-, LAP-, and ALD-acitivites remained practically unchanged following an incubation with retinoic acid in concentrations between 1 and 100 µg/ml for 60 min. — The data collected in this study were briefly discussed with regard to the use of retinoic acid and its derivatives in psoriasis.

Electronic Resource

1432-086X

Key words: Renal arteries, stenosis or obstruction—Transluminal angioplasty—Ultrasound, Doppler studies

Springer Online Journal Archives 1860-2000

Medicine

Abstract Purpose: To examine the extent of the changes in the intrarenal spectral waveform patterns after percutaneous transluminal angioplasty (PTA) and whether there is a correlation with the angiographic and clinical results. Methods: In 44 patients with 68 PTAs we analyzed the intrarenal spectral waveform regarding the existence of a tardus–parvus pattern before and after PTA. Results: In 51 of the 60 cases with a tardus–parvus pattern prior to PTA, a complete normalization of the spectral waveform was noted. There was no correlation between the Doppler result after PTA and the angiographic and clinical result. In contrast there was a significant correlation between the Doppler result before PTA and the clinical outcome: patients with a normal intrarenal spectral waveform before PTA showed no improvement in their arterial hypertension. Conclusion: Our results indicate that a patient with a normal spectral waveform analysis does not response to PTA. However, there is still an unpredictable clinical response even if a patient has an abnormal intrarenal spectral waveform prior to PTA and a complete normalization after PTA.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Trace metals were analyzed in the muscle and other organs from several species of deep-water sharks (particularly Centrophorus granulosus and Galeus melastomus) from 1280 to 1500 m depth in the eastern Mediterranean between 1985 and 1991. As has been shown with other pelagic fish, there was a significant correlation between specimen size and the mercury concentration in the muscle as well as in the liver and kidneys. For a given size, the level of mercury in sharks from the eastern Mediterranean was considerably higher compared with the same species caught off the west coast of Italy. There was no significant correlation between the concentrations of Cd, Cu, Zn and Fe in the muscle (or other organs) and body size. The overall trace metal content was considerably higher in the specimens from the eastern Mediterranean compared with the same species from the N. E. Atlantic. It is suggested that these higher-than-expected trace metal levels might be due to a relatively high trace metal content in the waters of the region or to the unusual physiology of these fish, possibly related to the extreme oligotrophic conditions in the area.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract A sampler is described which can be used for the collection of microbiological, phytoplanktological, and chemical sea-water samples. The sampler consist of a polyvinylchloride (PVC) frame on which a sterile silicone-rubber container (500 ml) is assembled. The sampler is fitted with a couple of reversing thermometers. All materials used, including the hydrographic cable and the messenger, have been tested for toxicity. The container, actuated by the messenger, fills and then is closed by a stop-cock to prevent any contamination with upper-level sea water during hauling aboard. The reversing thermometers reverse only when the sample has been taken properly. Thus, the thermometers guarantee good functioning of the sampler and supply also information on the exact depth at which the sample was collected. The device can operate at any depth and several devices can be operated in one cast. During normal operation, contamination due to microorganisms attached to the frame and container is negligible.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract The sampling performance of two high-speed samplers, (Delfino I and II), fitted with a calibrated flow meter, was studied in the open Ligurian Sea using a battery comprising 6 such Delfinos linked together. Since, in plankton counts, only those organisms should be counted which are definitely retained in the nets, several techniques for the separation of the organisms which pass through the pore of a net of a given pore size and those which are safely retained were tested. Attempts to separate these two fractions by filtration of the fixed sample through nets of different pore sizes were not successful, as living organisms were able to pass through pore sizes which retained dead organisms. However, optical sizing under the dissecting microscope during counting gave reproducible results. Using this counting technique, the influence of the pore size of plankton nets on the reproducibility of sampling of natural populations was studied. The results obtained show that live plankton passes through the net pores at a size at which fixed plankton is retained. Hence, the minimum retention size for living and dead plankton is different. By comparing samples taken with nets of different pore sizes, and counting the organisms caught according to different sizes, it was possible to determine the minimum retention size of live plankton organisms for several different net pore-sizes. The minimum retention size is, therefore, the smallest pore size at which the organisms of a certain width cannot escape through the pores of the net and are, thus, quantitatively retained in the net. By applying the criterion of minimum retention size, the influence of speed towing on the number of plankton organisms caught was studied. It was shown that the number of organisms which are safely retained, i.e., do not escape through the pores, increased with speed, reaching a plateau at 5 to 7 knots.

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