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Biomedical subjects

S Behrens

Publications and source records attributed to S Behrens.

132 records · Page 8Linked to original sources
PubMedDate not supplied

Classic conditioning and dysfunctional cognitions in patients with panic disorder and agoraphobia treated with an implantable cardioverter/defibrillator.

OBJECTIVE: A model for the development of anxiety disorders (panic disorder with or without agoraphobia) is needed. Patients with an implantable cardioverter/defibrillator (ICD) are exposed to repeated electric shocks. If the theory of anxiety development by aversive classic conditioning processes is valid, these repeated shocks should lead to an increased risk of anxiety disorders. To study this hypothesis, we retrospectively studied 72 patients after implantation of an automatic ICD. METHODS: Patients were assessed with the semistructured Diagnostic Interview of Psychiatric Disease 1 to 6 years after implantation of an automatic ICD. Panic disorder and/or agoraphobia was diagnosed in patients who fulfilled all DSM-III-R criteria for those conditions. RESULTS: Anxiety disorder developed in 15.9% of patients after ICD implantation. This was significantly related to the frequency of repeated defibrillation (shocks) to stop malignant ventricular arrhythmias. Dysfunctional cognitions are an additional vulnerability factor. CONCLUSIONS: The data support both the conditioning hypothesis and the cognitive model of anxiety development. These findings suggest that ICD patients are an appropriate risk population for a prospective study of the development of anxiety disorders.

Aged↗
PubMedDate not supplied

Time course of 8-methoxypsoralen-induced skin photosensitization in PUVA-bath photochemotherapy.

In recent years PUVA-bath photochemotherapy has been shown to be an effective treatment modality for several dermatoses. A limitation of PUVA-bath photochemotherapy has been the lack of guidelines for optimal performance, including the time course of photosensitization of the skin exposed to the 8-methoxypsoralen (8-MOP) bath water solution. In the present study 12 healthy volunteers were exposed to a 20 min bath in 150 l of an 8-MOP water solution (0.5 mg/l, 37 degrees C). Immediately, as well as 1, 2, 3 and 5 h after the 8-MOP bath, irradiation was performed with increasing doses of UVA (0.5, 1, 2, 3, 5 J/cm2) on 2 cm2 test areas. The minimal phototoxic dose (MPD) was determined 72 h after the UVA exposure. In all volunteers, photosensitization was highest immediately after the bath, with a MPD significantly below 5 J/cm2 (0.5-2 J/cm2). One hour after the bath, erythema could be induced by 2 to 5 J/cm2 UVA. Two hours after the bath, erythema could be induced using irradiation of 5 J/cm2 only in two volunteers. Three and five hours after the 8-MOP bath, no erythema could be induced in any volunteer by UVA doses up to 5 J/cm2. Our results indicate that optimal bath-PUVA requires UVA irradiation immediately after the 8-MOP bath. Further, these results imply that no restrictions on further sun exposure are mandatory 3 h after the 8-MOP bath, thus allowing the patient to pursue normal life activities.

Erythema↗
PubMedDate not supplied

Effects of water temperature on photosensitization in bath-PUVA therapy with 8-methoxypsoralen.

The pharmacokinetic aspects of bath-PUVA are not completely clarified. Therefore, we determined the phototoxic response of human skin following psoralen baths at temperatures ranging from 32 degrees C to 42 degrees C (71.6-107.6 degrees F) and UVA doses ranging from 0.5 to 5.5 J/cm2. The highest therapeutical photosensitization (i.e., lowest minimal phototoxic dose) was assessed at temperatures of 37 degrees C (98.6 degrees F) and above. Photosensitization was significantly decreased at lower temperatures. These data indicate that a bath temperature of 37 degrees C (98.6 degrees F) should be used to gain optimal therapeutic efficiency in a clinical setting. Furthermore, in order to minimize the risk of adverse phototoxic effects in bath-PUVA, it is important to use a constant temperature during the psoralen bath.

Adult↗
PubMedDate not supplied

Stroke treatment guided by transcranial Doppler monitoring in a patient unresponsive to standard regimens.

Today secondary prevention of stroke is based on large clinical trials with the disadvantage of a lack of individual pathophysiological aspects. This is mainly due to the difficulty in identifying the source of stroke reliably and rapidly in these patients. Recurrent microembolic events detected by transcranial Doppler monitoring (TCM) has been suggested to individualize treatment. We describe a patient with recurrent ischemic events in the posterior circulation. Repeated TCM of the PCA disclosed microembolic events in the course of an acute embolic lesion pattern demonstrated by MRI. Detection of high-intensity transient signals by TCM provided a useful guidance of pathophysiologically oriented treatment in this patient.

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