151
|
Behrens S, Daffertshofer M, Hennerici MG. Stroke treatment guided by transcranial Doppler monitoring in a patient unresponsive to standard regimens. Cerebrovasc Dis 1999; 9:175-7. [PMID: 10207211 DOI: 10.1159/000015950] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
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.
Collapse
|
152
|
Grundmann-Kollmann M, Leiter U, Behrens S, Gottlöber P, Mooser G, Krähn G, Kerscher M. The time course of phototoxicity of topical PUVA: 8-methoxypsoralen cream-PUVA vs. 8-methoxypsoralen gel-PUVA. Br J Dermatol 1999; 140:988-90. [PMID: 10354061 DOI: 10.1046/j.1365-2133.1999.02855.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
153
|
Grundmann-Kollmann M, Behrens S, Peter RU, Kerscher M. Treatment of severe recalcitrant dermatoses of the palms and soles with PUVA-bath versus PUVA-cream therapy. PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE 1999; 15:87-9. [PMID: 10321522 DOI: 10.1111/j.1600-0781.1999.tb00063.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PUVA-bath therapy developed into a first line topical PUVA therapy, and gel and cream preparations have been described as alternative modes of topical 8-MOP application. Because bath-PUVA can be difficult to manage, topical PUVA therapy using 8-MOP gel or cream preparations may become an important alternative when treating localised skin diseases. However, controlled comparisons of efficacy with this alternative topical PUVA therapy are lacking. We therefore compared the efficacy of PUVA-cream therapy with PUVA-bath therapy in 12 patients with recalcitrant dermatoses of the palms and soles using a left/right trial design. These patients responded well to both treatment modalities, meaning that both could be used successfully to treat recalcitrant dermatoses of the palms and soles.
Collapse
|
154
|
Behrens S, von Kobyletzki G, Gruss C, Reuther T, Altmeyer P, Kerscher M. PUVA-bath photochemotherapy (PUVA-soak therapy) of recalcitrant dermatoses of the palms and soles. PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE 1999; 15:47-51. [PMID: 10321515 DOI: 10.1111/j.1600-0781.1999.tb00056.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PUVA-bath therapy has proven to avoid many side effects associated with oral 8-methoxypsoralen (8-MOP) treatment. In order to investigate the effectiveness of topical PUVA-bath therapy (PUVA-soak therapy) on chronic palmoplantar dermatoses, 30 patients with plaque-type psoriasis, pustular psoriasis, endogenous eczema, dyshidrotic eczema and hyperkeratotic dermatitis of the palms and soles were treated over 8 weeks with PUVA-soak using 8-MOP. No additional treatment except skin moisturising cream such as unguentum emulsificans aquosum was used during the study period. The single UVA-doses applied ranged from 0.3 to 3.0 J/cm2 (mean single dose of 1.8 J/cm2), with a mean cumulative dose of 48.6 J/cm2 per patient. Altogether 26 of 30 patients responded well within 8 weeks of treatment with 63% of all patients showing a complete remission and 23% showing considerable improvement, as shown by flattening of plaques, decreased scaling and erythema, as well as decreased vesicle and pustule formation. The condition responding best to our therapy was palmoplantar psoriasis followed by atopic eczema. Hyperkeratotic dermatitis displayed the poorest responding rates in this study. Unwanted side effects such as erythema, pain, blistering or patchy hyperpigmentation were not observed in any of the patients. We conclude that PUVA-soak therapy can be highly efficient in the treatment of palmoplantar dermatoses, especially in the management of palmoplantar psoriasis.
Collapse
|
155
|
Behrens S, Thron A. Long-term follow-up and outcome in patients treated for spinal dural arteriovenous fistula. J Neurol 1999; 246:181-5. [PMID: 10323315 DOI: 10.1007/s004150050331] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Clinical outcome was examined in 21 patients treated for spinal dural arteriovenous fistula after 5-50 months. We compared the neurological condition (motor function, pain, sensory disturbance, vegetative dysfunction) and Barthel index before and after fistula occlusion. Neurological impairment was assessed as improved, unchanged, or deteriorated. All patients initially showed paraparesis of varying degree, and a sensory loss with a defined level in 81% before treatment. The greatest postoperative change that we measured was in motor activity (67% improved), and the most important deterioration was in male potency (28% deteriorated). We observed unchanged or absent symptoms in pain in 71% of our patients. We were thus able not only to stop but even to reverse the progression of symptoms and the degree of disability. On average, neurological symptoms stabilized within 1 year. The results of this study confirm that spinal dural arteriovenous fistula should be treated as early as possible after diagnosis.
Collapse
|
156
|
Behrens S, Daffertshofer M, Spiegel D, Hennerici M. Low-frequency, low-intensity ultrasound accelerates thrombolysis through the skull. ULTRASOUND IN MEDICINE & BIOLOGY 1999; 25:269-273. [PMID: 10320316 DOI: 10.1016/s0301-5629(98)00158-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Systemic thrombolysis of acute ischemic stroke with recombinant tissue plasminogen activator (rt-PA) has been established recently. Whereas the delay to and the rate of vessel recanalization are unknown, they are likely slower and smaller than for local application of rt-PA. This may contribute to the small benefits of recovery reported and stimulate further investigations to improve clot lysis. Pilot studies indicate that continuous-wave low-frequency ultrasound (US) can accelerate rt-PA-mediated recanalization of peripheral thrombotic vessel occlusion. For the hypothesized therapeutical purpose in stroke treatment, we measured the attenuation of ultrasound through the skull at different frequencies and intensities (33.3 and 71.4 kHz; 0.5 and 3.4 W/cm2), and investigated thrombolysis in vitro (n = 125 clots). Attenuation was lowest by transtemporal insonation of 33.3 kHz, 0.1 dB (0.9). Thrombolysis (artificial fibrin-rich clots) was significantly increased after 1 h (p < 0.025) and after 3 h (p < 0.01) for US treatment in combination with rt-PA vs. rt-PA alone. Results suggest that US increases rt-PA-mediated thrombolysis through the skull and may improve benefits of thrombolytic stroke treatment in vivo.
Collapse
|
157
|
Andresen D, Steinbeck G, Brüggemann T, Müller D, Haberl R, Behrens S, Hoffmann E, Wegscheider K, Dissmann R, Ehlers HC. Risk stratification following myocardial infarction in the thrombolytic era: a two-step strategy using noninvasive and invasive methods. J Am Coll Cardiol 1999; 33:131-8. [PMID: 9935019 DOI: 10.1016/s0735-1097(98)00516-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES We prospectively performed a two-step risk assessment in patients in the early phase after acute myocardial infarction (MI). BACKGROUND Noninvasive methods like Holter electrocardiographic monitoring (HM) and determination of the left ventricular ejection fraction (EF) as well as the invasive technique of programmed ventricular stimulation (PVS) have been used to identify patients in the late phase after MI as candidates for prophylactic implantation of a cardioverter/defibrillator. However, it is unclear whether these results can be transferred to patients following acute MI. METHODS A series of 657 patients with acute MI (< or = 75 years) underwent HM and EF. If one of the two methods yielded abnormal findings (HM > or = 20 ventricular ectopic beats/h/> or =10 ventricular pairs/day/ventricular tachycardia; EF < or = 40%), PVS was done (abnormal PVS: induction of monomorphic ventricular tachycardia, duration >10 s, cycle length > or = 230 ms). RESULTS Of 657 patients, 304 (46%) had either an abnormal HM or EF. The PVS performed in 146 of 304 patients was abnormal in 22. During a mean follow-up of 37 months, there were 106 (16%) deaths, being sudden in 24 (3.6%), nonsudden cardiac in 45 (6.8%). The incidence of arrhythmic events (sudden cardiac death, symptomatic ventricular tachycardia, cardiac arrest) was 18% (4/22) with an abnormal PVS and only 4% (5/124) with a normal PVS (odds ratio 4.0, p=0.032). CONCLUSIONS The rate of arrhythmic events is low in post-MI patients in the 1990s. Nevertheless, a two-step risk stratification is helpful in selecting candidates for a defibrillator trial aiming at primary prevention of sudden cardiac death after MI.
Collapse
|
158
|
Behrens S, Cornelius A, Schwartz A, Hennerici M. Spontaneous decrease of MCA-stenosis due to cerebral thromboembolism. Cerebrovasc Dis 1998; 8:362. [PMID: 9874591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
|
159
|
Dirschka T, Kastner U, Behrens S, Altmeyer P. Successful treatment of pyoderma gangrenosum with intravenous human immunoglobulin. J Am Acad Dermatol 1998; 39:789-90. [PMID: 9810896 DOI: 10.1016/s0190-9622(98)70052-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
160
|
Gruss C, Behrens S, von Kobyletzki G, Reuther T, Husebo L, Altmeyer P, Kerscher M. Effects of water temperature on photosensitization in bath-PUVA therapy with 8-methoxypsoralen. PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE 1998; 14:145-7. [PMID: 9826883 DOI: 10.1111/j.1600-0781.1998.tb00032.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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.
Collapse
|
161
|
Behrens S, Reuther T, von Kobyletzki G, Kastner U, Dirschka T, Kerscher M, Altmeyer P. [Bleomycin-induced PSS-like pseudoscleroderma. Case report and review of the literature]. DER HAUTARZT 1998; 49:725-9. [PMID: 9794163 DOI: 10.1007/s001050050817] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Although the association between administration of the antitumor agent bleomycin and the development of cutaneous fibrosis is established, there are only a small number of cases of bleomycin-induced scleroderma described in the literature. We report the development of generalised scleroderma with wide spread hyperpigmentation in a 52-year-old male patient, who received a total dose of 360 mg bleomycin in combination with cisplatin and etoposid for therapy of a malignant testicular seminoma. The clinical cutaneous alterations as well as the histological findings were indistinguishable from those encountered in progressive systemic sclerosis (PSS). In contrast to PSS however, Raynaud's phenomenon, cutaneous calcinosis, teleangiectasia, arthritis and involvement of additional organs were all absent. PSS-typical auto-antibodies were negative. Even 18 months after discontinuation of the drug and treatment with UVA1 phototherapy (3-4 times per week with 20 J/cm2) as well as physiotherapy, the skin changes had still not resolved. Based on our case and a detailed review of the literature, we discuss characteristics of bleomycin-induced scleroderma including pathogenesis, treatment modalities and course.
Collapse
|
162
|
Gruss C, Behrens S, Reuther T, Husebo L, Neumann N, Altmeyer P, Lehmann P, Kerscher M. Kinetics of photosensitivity in bath-PUVA photochemotherapy. J Am Acad Dermatol 1998; 39:443-6. [PMID: 9738780 DOI: 10.1016/s0190-9622(98)70322-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Bath-PUVA is used to treat a variety of dermatoses. However, the kinetics of 8-methoxypsoralen during treatment are not completely clarified. OBJECTIVE The purpose of this study was to investigate the intensity of the phototoxic response and the persistence of phototoxicity after bath-PUVA. METHODS Twelve volunteers were exposed to UVA doses ranging from 0.5 to 40 J/cm2 from 10 to 240 minutes after bath-PUVA treatment. The resulting phototoxic response of the skin was determined. RESULTS Irradiation 10 minutes after the psoralen bath led to the lowest assessed minimal phototoxic dose (MPD) of 1.42 J/cm2 (mean, SD +/- 0.29). Thereafter, the MPD increased significantly and sharply every hour. At 4 hours after the psoralen bath, UVA doses up to 40 J/cm2 failed to induce any phototoxic erythema (MPD). CONCLUSION For optimal effects, UVA irradiation has to be administered immediately after the psoralen bath; no restrictive behavior is necessary after bath-PUVA treatment.
Collapse
|
163
|
Behrens S, Reuther T, Gruss C, Auer T, Altmeyer P, Kerscher M. Disseminated pagetoid reticulosis: response to bath PUVA. Br J Dermatol 1998; 139:343-4. [PMID: 9767259 DOI: 10.1046/j.1365-2133.1998.02380.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
164
|
Behrens S, Pohlmann-Eden B. Postpartum brain death as a late fatal sequel of a previous skull base fracture. Intensive Care Med 1998; 24:890-1. [PMID: 9757939 DOI: 10.1007/pl00012690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
165
|
Häfner H, an der Heiden W, Behrens S, Gattaz WF, Hambrecht M, Löffler W, Maurer K, Munk-Jørgensen P, Nowotny B, Riecher-Rössler A, Stein A. Causes and consequences of the gender difference in age at onset of schizophrenia. Schizophr Bull 1998; 24:99-113. [PMID: 9502549 DOI: 10.1093/oxfordjournals.schbul.a033317] [Citation(s) in RCA: 221] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The ABC (age, beginning, course) schizophrenia study was commenced in 1987 to generate and test hypotheses about pathogenic aspects of schizophrenia. One of the main branches of the study focused on how gender influences the age distribution of onset, symptomatology, illness behavior, and early course in schizophrenia. Proceeding from one of the rare, strikingly deviating, consistent findings--the gender difference in age at first admission--we launched a systematic search for explanations by generating and testing hypotheses in a series of substudies. We moved from the epidemiological to the neurobiological and finally to the clinical level. The present article is an attempt to provide a brief overview of the individual stages of the ABC study and the different levels of investigation involved in formulating and testing the estrogen hypothesis in animal experiments and in demonstrating its applicability to human schizophrenia. From these results, three hypotheses were formulated and tested on data from an ABC study sample of 232 first-episode cases of schizophrenia. The analyses described here represent the latest stages of the ABC study.
Collapse
|
166
|
Abstract
Dispersion of ventricular repolarization, assessed as QT dispersion in the ECG or by multiple monophasic action potential (MAP) recordings, is defined as the difference between the earliest and latest repolarization. It is thus measured in the time domain. However, myocardial refractoriness is primarily a function of the membrane potential during phase 3 repolarization. The purpose of this study, therefore, was to measure dispersion of ventricular repolarization in the voltage domain and to study its relation to VF inducibility. To further validate this concept, the effect of chronic amiodarone treatment on the voltage dispersion were assessed. MAPs were recorded simultaneously at 10 epicardial and endocardial sites in isolated rabbit hearts, both under baseline conditions (n = 8) and after chronic amiodarone treatment (n = 8). Repolarization dispersion in the voltage domain was calculated as the difference between the highest and lowest repolarization level of all 10 MAPs at 10-ms steps, starting from the MAP plateau level to complete repolarization. Plotting these voltage differences along the time axis resulted in a dispersion curve, which rose during early repolarization, reached a peak during phase 3 repolarization, and thereafter declined toward zero. There was a close correlation between VF vulnerability in response to electrical field stimuli and the time during which voltage dispersion was maximal (r = 0.828, P < 0.0001). Amiodarone caused a right-ward shift of both the dispersion curve (P = 0.007) and VF vulnerability (P = 0.025), but did not change the magnitude nor the shape of the voltage dispersion curve and its relation to VF vulnerability. Repolarization dispersion in the voltage domain describes an alternate approach for evaluating the heterogeneity of ventricular repolarization and may help to characterize arrhythmia susceptibility under experimental conditions.
Collapse
|
167
|
Behrens S, Bettenhausen M, Eichhöfer A, Fenske D. Darstellung und Struktur von [Cd10Se4(SePh)12(PPh3)4] und [Cd16(SePh)32(PPh3)2]. Angew Chem Int Ed Engl 1997. [DOI: 10.1002/ange.19971092413] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
168
|
Behrens S, von Kobyletzki G, Hoffmann K, Altmeyer P, Kerscher M. [PUVA-bath photochemotherapy in Hallopeau's acrodermatitis continua suppurativa]. DER HAUTARZT 1997; 48:824-7. [PMID: 9518245 DOI: 10.1007/s001050050668] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A 73-year-old man presented with severe, relapsing acrodermatitis continua of Hallopeau, which had been resistant to prior local and systemic therapy for eight years. The patient was treated with selective hand PUVA-bath photochemotherapy. The cumulative dose of UVA used over 10 weeks of treatment was 54.6 J/cm2 on the palms and 26.8 J/cm2 on the dorsum of the hands. The single UVA doses ranged from 0.5 to 2.5 J/cm2 on the palms and 0.2 to 1.4 J/cm2 on the dorsum of the hands. After 16 treatment sessions, the acrodermatitis continua started to improve, and after 24 treatments, had cleared completely. In the four months following the PUVA therapy, there was no relapse. PUVA-bath photochemotherapy is an efficient therapeutic alternative in the treatment of acrodermatitis continua due to its clinical effectiveness and lack of any systemic side effects. It also possesses the advantage of allowing selective photosensitization of certain areas of the skin such as the hands.
Collapse
|
169
|
Zabel M, Hohnloser SH, Behrens S, Woosley RL, Franz MR. Differential effects of D-sotalol, quinidine, and amiodarone on dispersion of ventricular repolarization in the isolated rabbit heart. J Cardiovasc Electrophysiol 1997; 8:1239-45. [PMID: 9395166 DOI: 10.1111/j.1540-8167.1997.tb01014.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Increased dispersion of ventricular repolarization has been suggested as a cause of proarrhythmic effects of Class IA or III antiarrhythmic drugs, such as d-sotalol, quinidine, and amiodarone. METHODS AND RESULTS The influence of d-sotalol, quinidine, and amiodarone on the dispersion of monophasic action potential (MAP) durations was studied in 55 isolated Langendorff-perfused rabbit hearts at different pacing cycle lengths (CLs). MAP duration measured at 90% repolarization (APD90) was determined from 6 to 8 endocardial and epicardial MAP recordings with dispersion of ventricular repolarization defined as the range of APD90. The protocol was repeated 60 minutes after initiation of a perfusate containing increasing concentrations of d-sotalol (n = 12, 10[-6] M, 10[-5] M, and 5 x 10[-5] M) and quinidine (n = 8, 10[-6] M and 10[-5] M). Seventeen rabbits were fed with an aqueous solution of amiodarone (50 mg/kg per day over 4 weeks). The data of these experiments (n = 17) were compared with a series of 18 untreated control rabbits. Dispersion of ventricular repolarization was unchanged with the low concentration of d-sotalol (10[-6] M) but was increased-particularly at long CLs-with higher d-sotalol concentrations. With both concentrations of quinidine, dispersion of ventricular repolarization was increased in a rate-independent manner. Amiodarone did not affect dispersion of ventricular repolarization. CONCLUSIONS Rate-dependent and concentration-dependent increases in dispersion of ventricular repolarization by d-sotalol and quinidine in this isolated rabbit heart model may help explain their proarrhythmic effects while the absence of an increase in dispersion of ventricular repolarization with amiodarone correlates with its clinically observed lower incidence of proarrhythmia.
Collapse
|
170
|
Behrens S, Reuther T, von Kobyletzki G, Altmeyer P, Kerscher M. [PUVA-turban therapy]. DER HAUTARZT 1997; 48:842-3. [PMID: 9518250 DOI: 10.1007/s001050050673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
171
|
Reuther T, Gruss C, Behrens S, von Kobyletzki G, Neumann N, Lehmann P, Altmeyer P, Kerscher M. Time course of 8-methoxypsoralen-induced skin photosensitization in PUVA-bath photochemotherapy. PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE 1997; 13:193-6. [PMID: 9542757 DOI: 10.1111/j.1600-0781.1997.tb00229.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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.
Collapse
|
172
|
Zabel M, Hohnloser SH, Behrens S, Li YG, Woosley RL, Franz MR. Electrophysiologic features of torsades de pointes: insights from a new isolated rabbit heart model. J Cardiovasc Electrophysiol 1997; 8:1148-58. [PMID: 9363818 DOI: 10.1111/j.1540-8167.1997.tb01001.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION The exact electrophysiologic mechanism of torsades de pointes (TdP) is under intense investigation. No isolated animal heart model of this particular arrhythmia exists. METHODS AND RESULTS In isolated rabbit hearts, TdP was induced by means of bradycardia in the presence of a high concentration of d-sotalol (10(-4) M) and shortly after lowering the concentration of potassium and magnesium in the perfusate. Multiple simultaneous epicardial and endocardial monophasic action potentials (MAPs) and volume-conducted 12-lead ECGs were recorded. d-Sotalol prolonged repolarization and increased dispersion of ventricular repolarization compared to baseline recordings. With the onset of low potassium and magnesium concentrations, repolarization was further prolonged and dispersion of repolarization was further increased followed by the occurrence of early afterdepolarizations (EADs) in the majority of MAP recordings, i.e., at both endocardial and epicardial locations of both ventricles. Upon increase of EAD amplitude, triggered arrhythmias with TdP of up to 42 beats ensued in 10 of 11 hearts studied. MAP duration at 90% repolarization (APD90), dispersion of APD90, and the incidence of EADs as well as dispersion of the QT interval and T wave area were significantly higher in beats triggering bigemini, couplets, or runs of TdP. CONCLUSION TdP observed in this new isolated heart model was associated with markedly increased dispersion of ventricular repolarization and the occurrence of EADs in multiple locations of the heart. TdP is initiated when the amplitude of an EAD reaches threshold for initiation of the first beat of an episode.
Collapse
|
173
|
Andresen D, Brüggemann T, Behrens S, Ehlers C. Risk of ventricular arrhythmias in survivors of myocardial infarction. Pacing Clin Electrophysiol 1997; 20:2699-705. [PMID: 9358517 DOI: 10.1111/j.1540-8159.1997.tb06119.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The most recent studies have made it clear that the prognosis of asymptomatic post-MI patients has significantly improved in the last two decades. Holter monitoring as well as a low LVEF still is an important method for the risk stratification in the thrombolytic era of patients with post-MI. Patients with normal noninvasive tests do have a good prognosis. The electrophysiological stimulation seems to be the clinically most valuable single method to predict arrhythmic events. However, as an invasive procedure it is not suitable as a screening test for a large cohort. The stepwise risk stratification technique using first noninvasive followed by invasive procedures seem to be most suitable and effective for identifying asymptomatic infarct survivors which incidence of arrhythmic events is as high as the recurrence rate of patients who had been resuscitated from ventricular fibrillation. Consequently, prophylactic implantation of a defibrillator in asymptomatic MI patients, whose positive predictive value is around 30% becomes more and more interesting.
Collapse
|
174
|
Behrens S, Li C, Franz MR. Effects of long-term amiodarone treatment on ventricular-fibrillation vulnerability and defibrillation efficacy in response to monophasic and biphasic shocks. J Cardiovasc Pharmacol 1997; 30:412-8. [PMID: 9335398 DOI: 10.1097/00005344-199710000-00002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Antiarrhythmic drugs, most notably amiodarone, are often used to combat life-threatening tachyarrhythmias simultaneous with implantable cardioverter defibrillators. However, the effects of long-term amiodarone treatment on ventricular fibrillation (VF) vulnerability and the defibrillation threshold (DFT) remain incompletely understood. VF vulnerability and the DFF for monophasic and biphasic shocks were studied in 10 isolated perfused hearts of rabbits treated over the long term with amiodarone (50 mg/kg/day orally for 28 days) before the experiment. The results were compared with those of a control group (n = 10). Monophasic action potentials were recorded from 10 sites simultaneously to determine ventricular activation and repolarization. Myocardial tissue concentrations were 17.1 +/- 14.8 microg/g for amiodarone and 4.6 +/- 4.4 microg/g for desethylamiodarone. Amiodarone treatment prolonged action-potential duration by 12.9 ms (p = 0.025) and ventricular repolarization by 16.5 ms (p = 0.03) without changing ventricular activation and dispersion of repolarization. Amiodarone treatment caused a rightward shift of the vulnerable window for monophasic and biphasic shocks by 13-17 ms (p < 0.05). The width of the vulnerable window, the upper (ULV) and lower (LLV) limits of VF vulnerability, and the DFT remained unchanged. The fact that ULV and DFT remained unchanged suggests that the ULV still may be valid surrogate for the DFT during long-term amiodarone therapy.
Collapse
|
175
|
Behrens S, Li C, Franz MR. Timing of the upper limit of vulnerability is different for monophasic and biphasic shocks: implications for the determination of the defibrillation threshold. Pacing Clin Electrophysiol 1997; 20:2179-87. [PMID: 9309741 DOI: 10.1111/j.1540-8159.1997.tb04234.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The upper limit of vulnerability (ULV) has been used in clinical studies to predict the DFT in patients with ICDs. Despite the ULV-DFT correlation, uncertainties about the optimal timing of the ULV determination remain. Previous studies using monophasic or biphasic shock waveforms reported differences in the ULV timing with respect to the electrocardiographic T wave. The purpose of this study was to directly compare the ULV timing for mono- versus biphasic T wave shocks. In ten isolated rabbit hearts, mono- and biphasic shocks were delivered randomly during the vulnerable window and at varying shock strengths to determine the ULV. The ULV timing was expressed as the coupling interval at the ULV, the myocardial repolarization state at the ULV measured by monophasic action potential recordings, and the relation between the ULV and the peak of the simultaneously recorded volume conducted T wave. The ULV for biphasic shocks occurred at longer coupling intervals than for monophasic shocks (188.0 +/- 9.5 ms vs 173.5 +/- 8.8 ms, P < 0.001). This resulted in a more repolarized myocardial state at the ULV for biphasic than for monophasic shocks (81.1% +/- 7.5% vs 66.9% +/- 9.0%, P = 0.002). The ULV for monophasic shocks occurred predominantly during the upslope of the T wave (8.0 +/- 9.7 ms before the peak of the T wave) whereas the ULV for biphasic shocks occurred at or after the peak of the T wave (5.9 +/- 9.3 ms after the peak of the T wave) (P < 0.001). Biphasic shocks delay the timing of the ULV as compared to monophasic shocks. This is important for the prediction of the DFT by ULV measurements.
Collapse
|