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Biomedical subjects

W Neubert

Publications and source records attributed to W Neubert.

18 recordsLinked to original sources

Nuclear stopping from 0.09A to 1.93A GeV and its correlation to flow.

We present a complete systematics (excitation functions and system-size dependences) of global stopping and side flow for heavy ion reactions in the energy range between 0.09A and 1.93A GeV. For the heaviest system, Au+Au, we observe a plateau of maximal stopping extending from about 0.2A to 0.8A GeV with a fast drop on both sides. The degree of stopping, which is shown to remain significantly below the expectations of a full stopping scenario, is found to be highly correlated to the amount of side flow.

Journal Article↗

Azimuthal dependence of collective expansion for symmetric heavy-ion collisions.

Detailed studies of the azimuthal dependence of the mean fragment and flow energies in the Au+Au and Xe+CsI systems are reported as a function of incident energy and centrality. Comparisons between data and model calculations show that the flow energy values along different azimuthal directions could be viewed as snapshots of the fireball expansion with different exposure times. For the same number of participating nucleons more transversally elongated participant shapes from the heavier system produce less collective transverse energy. Good agreement with Boltzmann-Uehling-Uhlenbeck calculations is obtained for a soft nuclear equation of state.

Journal Article↗

Measles virus in otosclerosis and the specific immune response of the inner ear.

Histologic and immunohistochemical studies of otosclerotic lesions have shown that there is a chronic inflammatory reaction of the otic capsule with bone resorption resulting from vascular invasion accompanied by inflammatory cells. During the active lytic stage of otosclerosis, paramyxoviral structures have been identified by electron microscopy and measles virus antigen expression by immunohistochemistry. Recently, measles virus related sequences have been detected in tissue of otosclerotic lesions. Because the otosclerotic focus has a close relation to the perilymphatic space, the expression of measles virus antigens within it should represent an immunologic challenge to the immune system of the endolymphatic sac. In this study, measles virus specific antibodies were detected in all of the perilymph samples from 19 patients suffering from otosclerosis, and the relative amount of these IgG antibodies was much higher than in serum samples of the same patients or in perilymph of control patients. These findings support the hypothesis that measles viruses play an crucial role in the pathogenesis of otosclerosis.

Antibodies, Viral↗

In situ amplification of measles virus RNA by the self-sustained sequence replication reaction.

BACKGROUND: The self-sustained sequence replication (3SR) reaction is an isothermal method for nucleic acid amplification that has several features that make it an attractive alternative to PCR. We have studied the feasibility of the in situ 3SR reaction in cells using a measles virus-infected cell line as a model. EXPERIMENTAL DESIGN: The study was carried out in four steps. First, using RNA extracted from a measles-infected Vero Green monkey kidney cell line, conditions for the in vitro amplification of a segment of the nucleocapsid portion of the RNA viral genome were optimized for 420- and 119-bp 3SR products, and the results were compared. Second, 3SR was performed on intact infected cells in suspension, and the amount of RNA product was compared with infected cells without 3SR. Then, the 3SR reaction was conducted on cytospin preparation slides, followed by in situ hybridization for detection of the amplification product. Finally, 3SR was carried out on sections of formalin-fixed, paraffin-fixed, paraffin-embedded cells, and the degree of amplification as detected by ISH was quantified and compared between infected cells with and without 3SR reaction. RESULTS: Specific amplification of measles was observed in each of these types of preparations with an 8.5-fold rate of amplification in paraffin sections of formalin-fixed cells (a mean of 272.5 +/- 65.3 grains/cell after 3SR amplification in comparison to 31.97 +/- 4.2 grains/cell without amplification). CONCLUSIONS: A significant amount of amplification of RNA is possible with in situ 3SR (IS-3SR) and, in combination with ISH, offers several advantages compared with in situ PCR (IS-PCR), such as ease of use, lack of conditions that lead to cell damage, and a specificity for RNA amplification. This is the first report of specific amplification of RNA within cells using the IS-3SR procedure, a technique that has a wide range of potential applications in pathology and molecular biology.

Animals↗

The hypervariable C-terminal tail of the Sendai paramyxovirus nucleocapsid protein is required for template function but not for RNA encapsidation.

The paramyxovirus nucleocapsid proteins (NPs) are relatively well conserved, except for the C-terminal 20% (or ca. 100 amino acids), referred to as the tail. We have examined whether this hypervariable tail is required for genome synthesis, both in vitro, where synthesis is predominantly from the input templates, and in vivo, where multiple rounds of amplification occur. In these viruses, genome synthesis and assembly of the nascent chain are coupled. We find that the tail is required in vivo but not in vitro. Closer examination of the in vivo system showed that the tailless NP could encapsidate the genome chain but that amplification did not occur. We interpret these results as indicating that the tail is not required for RNA assembly but is required for the template to function in RNA synthesis. Relatively small deletions within the conserved N-terminal 80% of the protein, on the other hand, rendered the protein nonfunctional in either system. The possible functions of the tail in RNA synthesis are discussed.

Amino Acid Sequence↗

Simulated car driving as a useful technique for the determination of residual effects and alcohol interaction after short- and long-acting benzodiazepines.

SUBJECTS AND METHODS: 54 healthy volunteers took part in 3 placebo controlled double-blind trials designed partly as crossover, partly as parallel group studies. The long-acting (elimination half-life greater than 24 h) test drugs diazepam (DIA 5; 10 mg) and flurazepam (FLU 30 mg) were compared to the short-acting drugs (elimination half-life less than 12 h) lormetazepam (LOR 1.5; 2 mg) and mepindolol sulfate (MEP 10 mg; betablocker) following acute or subchronic application. Alcohol (ALC; 0.4-0.8 per mill blood ALC concentration) was used as a compound interfering with the test drugs. Measurements with the driving simulator TS2 were taken at different times between 1 h and 15 h p.a. RESULTS: Subchronic use of FLU causes significant impairment of driving performance the next morning in contrast to LOR which even increases the driving ability. The ALC potentiating effect of LOR is larger than that of DIA after acute intake. MEP acts like placebo but reduces blood pressure and heart rate. Interaction of LOR and ALC in the evening does not result in a prolonged hangover effect which could disturb driving performance the next morning. DISCUSSION: Short-acting benzodiazepines without active metabolites have a profound advantage over those with long-acting accumulating characteristics in respect to matutinal car driving ability, if those drugs are used as nighttime hypnotics. These results highlight the necessity of screening hypnotic and tranquilizing drugs concerning their influence on car driving performance at different times after intake and under conditions of interactions with psychotropic drugs, especially alcohol. In view of future methodological requirements a revised model of driving simulation is presented. It is based on a coherent description of the system "driver-vehicle environment" at the level of visual conditions, vehicle behaviour and driver performance. Preliminary data are shown.

Anti-Anxiety Agents↗

Alcohol interaction of lormetazepam, mepindolol sulphate and diazepam measured by performance on the driving simulator.

Sixteen healthy volunteers of a mean age of means = 26.4 years took part in a driving simulator test in an eightfold crossover study under double-blind conditions. The additional influence of alcohol was tested acutely after a single administration of 2 mg lormetazepam, a new, highly effective derivative from the benzodiazepine class, 10 mg mepindolol sulphate, a new betablocker without sedating properties, and 10 mg diazepam. All drugs were compared with placebo and the test was performed 1, 2 and 3 hours after oral intake. The aim was to investigate particularly the risks relevant in road traffic caused by simultaneous intake of these substances with alcohol. For this purpose, besides the driving simulator, an accurate reaction test ( WDG ) and self-rating scales were used, the latter in order to assess subjective stress and anxiety levels. Lormetazepam, due to its strong sedating property, showed a reduction in driving performance and an increase in reaction time and pulse rate as compared with placebo, and these effects were highly potentiated by alcohol. Mepindolol sulphate expectedly reduced pulse rate when compared with placebo, otherwise there were no significant differences. Diazepam, when compared with placebo, like lormetazepam caused a reduction in driving performance and reaction capacity and an increase in pulse rate, but intensity and duration of this effect were less than with lormetazepam and did not reach statistical significance. No significant potentiating effects were observed after the additional application of alcohol.

Adult↗