Dopaminergic mechanisms in self-inflicting biting behavior

Dopaminergic mechanisms involved in self-inflicting biting behavior (SBB) were investigated in two animal models: monkeys with unilateral ventromedial tegmental (VMT) lesions of the brainstem and rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal dopamine (DA) neurons. The administration of mixed D1/D2 DA agonists to some monkeys with unilateral VMT lesions of the brainstem elicits SBB of the forelimb digits contralateral to the lesion and spasticity of the contralateral hindlimb. This behavior is prevented by pretreatment with the selective D1 antagonist SCH 23390 and with the D1/D2 antagonist fluphenazine. The combined administration of the D1 DA agonist SKF 38393 with the D2 DA agonist quinpirole produces SBB at doses that were ineffective when these drugs were administered individually. The intrastriatal (middle ventrolateral area [MVL]) microinjection of the D1/D2 DA agonist apomorphine (Apo) to rats with unilateral 6-OHDA lesions elicits SBB. This behavior is not prevented by systemic administration of SCH 23390 and partially prevented by the selective D2 antagonist raclopride. However, the combined administration of SCH 23390 and raclopride completely prevents the Apo-induced SBB. Thus, the pharmacological characteristics of the DA agonist-induced SBB in monkeys with unilateral VMT lesions of the brainstem seem to differ from those induced by intrastriatal (MVL area) administration of DA agonists into rats with 6-OHDA lesions of the nigrostriatal DA neurons. The role of DA neuronal systems in the expression of SBB in Lesch-Nyhan syndrome and in some patients with mental retardation, as well as the link between hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency and abnormal dopaminergic function in Lesch-Nyhan syndrome, is discussed.     

Effects of gamma-interferon on the endocrine system: results from a phase I study

Interferon causes profound biological changes when given to patients with cancer and many of these could not be predicted from in vitro or animal model systems. We documented significant changes in hormonal levels for a group of 18 patients who were participants in a Phase I gamma-interferon trial. Adrenocorticotropic hormone, cortisol, and growth hormone were all significantly elevated 2 h after treatment with gamma-interferon, with cortisol and adrenocorticotropic hormone returning to base line by 24 h. A placebo group failed to show this change, suggesting a specific interferon effect. Possible mechanisms for these findings and implications for the use of interferons are discussed.     

Profilometer, SEM, and visual assessment of porcelain polishing methods

Research has indicated that polishing ground porcelain is essential to control the wear of opposing occlusal surfaces and reduce the inflammation of contacted soft tissue. Five popular methods for polishing porcelain were evaluated by use of a profilometer, SEM, and normal vision. Seventy disks, 35 Biobond disks and 35 Ceramco disks, were roughened with a green stone and polished with one of the methods according to the manufacturers' directions. Brasseler, Dedeco, Dentsply, and Shofu porcelain polishing systems were suitable for restoring ground porcelain. However, clinical evaluations correlated to the profilometer and SEM readings revealed that the Brasseler system was superior for polishing Ceramco porcelain whereas the Den-Mat system was unacceptable.     

Transcranial sonography through the burr hole for detection of ventriculomegaly. A preliminary report

Detection of ventriculomegaly in a child with a ventricular shunt is important in the diagnosis of shunt malfunction. The feasibility of visualizing the ventricles through a 2-cm burr hole, with the use of a small-footprint 7-MHz transducer, was evaluated in five infants. Each burr hole remained patent during the study (2-6 months), and in all infants correlation between views through the anterior fontanelle and the burr hole were in agreement. When ventriculomegaly can be detected by this technique, the need for CT evaluation may be obviated. Further study is necessary to evaluate extended burr holes in older children compared to their CT examinations.     

Buchbesprechungen

Ohne Zusammenfassung     

The effects of live therapeutic music on patient's affect and perceptions of care: A randomized field study

AimThis article examines the effects of live therapeutic music (LTM) on patients in a hospital setting. LTM was hypothesized to directly increase patients' positive affect and to indirectly influence their perceptions of the care they received.MethodOne hundred patients participated in a two group (fifty per group), quasi-experimental design in which they completed a very brief questionnaire assessing their affect and perceptions of care. Half of the participants were exposed to LTM at the bedside. The other half served as a comparison group. A structural equation model was used to test the hypothesized effects of LTM.ResultsThe model explained 63% of the variance in patient's affect and 10% of the variance in perceptions of care.ConclusionsPatients respond to LTM with increased positive affect and by assigning higher ratings to the care they receive. LTM could be used as a viable means to improve patient outcomes and satisfaction.