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Biomedical subjects

U Schroeder

Publications and source records attributed to U Schroeder.

45 records · Page 3Linked to original sources
PubMed1978

[Gagging as a symptom of induced anxiety reactions].

In the light of personal studies and relevant reports in the literature, the authors deal with gagging during dental treatment and after denture insertion. In this connection, aetiopathologic and therapeutic aspects of the gagging syndrome are analysed. It is postulated that the gagging reaction is a conditioned anxiety reaction.

Anxiety↗
PubMedDate not supplied

Dentist phobia.

This study analyzes so-called hopeless gaggers, i.e., patients in whom dental treatment and wearing of a prosthesis produced a retching or vomiting reaction, in order to investigate the sources and properties of this pathologic reaction. In 35 patients, an anamnestic inquiry, a determination of the reflexogenic zone, a recording of the peripheral pattern of the pathologic reflex, and extinction training were performed. A group of six normal persons served as a comparison group. It was shown that patients, in comparison with normals, had an enlarged receptive field, were sensitive to a broader population of stimuli, and showed precursors and aftereffects of the retching-vomiting not found in normals. This pathologic reaction was the symptom of different psychopathologic processes, such as specific fear, repugnance-fear-based disturbances, diffuse anxiety, goal-directed behavior, depressive states and, at least in one case, visceral pathology. The various patients differed with respect to properties of the reaction as well as in the sensitivity to the extinction procedure. It is discussed that different integrative nervous processes play a role in the origin and development of the syndrome: activation of unconditional reflexes, activation of classic and instrumental conditional reflexes, activation of such reflexes by an increase of the reactivity level of specific and unspecific structures of the brain, generalization of stimuli, etc.

Adult↗
PubMedDate not supplied

Long-term stability of PBCA nanoparticle suspensions.

In this study, the stability of poly(butyl cyanoacrylate) (PBCA) nanoparticle suspensions was examined for up to 1 year by measuring the nanoparticle sizes. The nanoparticles were prepared with different stabilizers (dextran 70.000, poloxamer 188, or polysorbate 85), and the particle size was determined before and after purification by centrifugation and after dilution with different solutions (0.1 N HCl, 0.01 N HCl, H2O, and PBS). The most constant sizes were with the untreated acidic nanoparticle suspensions. In all other cases, agglomeration of the particles occurred: the extent of this agglomeration and the time at which the agglomeration occurred depended on the experimental conditions. Nanoparticle polymer degradation, as indicated by size decrease, was not observed. Thus, PBCA nanoparticles can be stored as suspensions, making the lyophilization and the sometimes problematic resuspension by ultrasonication, unnecessary, which is advantageous for clinical applications.

Capsules↗