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Publications and source records attributed to P Rehak.
Experiment 865 at the Brookhaven Alternating Gradient Synchrotron obtained 410 K+-->e(+)nue(+)e(-) and 2679 K+-->mu(+)nue(+)e(-) events including 10% and 19% background. The branching ratios were measured to be [2.48+/-0.14(stat)+/-0.14(syst)]x10(-8) (m(ee)>150 MeV) and (7.06+/-0.16+/-0.26)x10(-8) (m(ee)>145 MeV), respectively. Results for the decay form factors are presented.
OBJECTIVES: In this single-center study we reviewed our experience with a significant number of cardiac myxoma cases occurring over the past two decades. PATIENTS AND METHODS: Cardiac myxomas represented 86% of all surgically treated cardiac tumors at our center. Specifically, there were 49 consecutive patients, each with at least one myxoma. A detailed clinical, immunological, and echocardiographic long-term examination of 37 patients revealed one recurrent myxoma. RESULTS: Most myxomas originated from the left atrium (87.7%), but also much less frequently from the mitral valve (6.1%), from the right atrium (4.1%), and from the left and right atria (2.0%). The myxomas produced a prolapse into the left ventricle in 40.8% of the patients, mitral stenosis in 10.2%, and threatened left ventricular outflow tract obstruction in 2.0%. Multiple myxomas were found in 20.4% of the patients. Cardiac signs appeared in 93.9% of the patients. Preoperative embolic events had occurred in 26.5%. Immunologic alterations were present in 87.5%. For resection, a bilateral atriotomy was used. An additional aortotomy was needed to expose one mitral valve myxoma. Postoperatively, 81.1% of the patients remained without cardiac symptoms. The early mortality rate was 2.0% and the late mortality rate was 6.1%. Long-term prognosis was excellent with an actuarial survival rate of 0.74. Specific immunologic alterations were found in 71.4% of the patients. The actuarial freedom from reoperation of the myxoma was 0.96. The rate of reoperations was low with 2.0% after 24 years. CONCLUSIONS: Myxomas were usually detected and operated on in symptomatic patients. A high index of suspicion seems important for early diagnosis. Immunologic findings may play an additional role in confirming the diagnosis and the recurrence of a myxoma. Immediate surgical treatment was indicated because of the high risk of embolization or of sudden cardiac death. Also, a familial genesis must be excluded in myxoma patients.
BACKGROUND AND OBJECTIVE: Amiodarone is very effective against a variety of dysrhythmias but has poor pharmacodynamic properties and many undesired side-effects. Its short- and rapid-acting derivative E 047/1 may circumvent some of these drawbacks. It is easier to titrate while retaining the high efficacy of amiodarone and may have acceptable influences on haemodynamics and cardiac conduction in patients who develop serious, destabilizing ventricular tachydysrhythmias after cardiac surgery. METHODS: Testing E 047/1 was performed prospectively in two consecutive phase II open, clinical studies. Out of 504 patients scheduled for surgery using cardiopulmonary bypass for coronary artery grafting and/or valve repair, 35 developed serious, haemodynamically destabilizing ventricular dysrhythmias (Lown 2-Lown 4b) after surgery and were treated with a 1 mg kg(-1) (pilot study, n = 15) or randomized to a 2 or 3 mg kg(-1) bolus of E 047/1, followed by a 1 mg kg(-1) h(-1) continuous infusion for 2 h (n = 10 in each group). Dysrhythmias, PQ, QTc intervals and haemodynamics using the thermodilution technique were evaluated for up to 24 h after drug initiation. RESULTS: At the time of final inclusion the patients had between 6 and 12 (or more) ventricular ectopics per minute. Within the first 2-3 min of application in the pilot trial E 047/1 induced a decrease of ventricular dysrhythmias to between 0 and 4 per min, a decrease that held for the duration of treatment. The area under the curve decreased from 434 (322, 855; median, quartiles) to 114 (9, 477, P < 0.01) events per hour. In the randomized trial, E 047/1 administered in either dose rapidly reduced ventricular dysrhythmias at least as effectively as in the pilot trial 565 (478, 701) to 33 (8, 238, P < 0.05) after a 2 mg bolus; 482 (339, 482) to 95 (13, 540, P < 0.01) events per hour after a 3 mg bolus. Approximately 4-6 h after drug termination, dysrhythmias reappeared in the majority of patients. In only three patients did the incidence of dysrhythmias return to inclusion criteria levels. In contrast to the pilot trial, in the randomized trial there was a slight increase of mean pulmonary artery pressure, central venous pressure and pulmonary arterial wedge pressure and a slight decrease of LCWI in both groups. E 047/1 did not cause QTc prolongation. CONCLUSIONS: E 047/1 appears to be a safe alternative to amiodarone in the perioperative setting of cardiac surgery when serious, destabilizing dysrhythmias occur.
BACKGROUND: Propofol has been widely used in general anesthesia. Although it is also often used in pediatric anesthesia, there has been only limited scientific evidence on the use of propofol in children up to 3 years. METHODS: A prospective, randomized, double-blind, therapeutic equivalence study comparing two propofol 1% emulsions (Propofol 1% Fresenius vs. Diprivan 1%) was performed in 60 patients scheduled for routine surgery or for diagnostic laparoscopic procedures requiring anesthesia. To guarantee comparability of age distribution between the two groups, a stratified randomization with patients younger than 12 months of age in a low age group and with patients aged 12 months to 3 years in a high age group was used. The average propofol induction dose and the average propofol infusion dose were analyzed to prove equivalence. The side-effects profile was analyzed to compare the safety profiles of the two propofol formulations in this study. RESULTS: There were no differences in baseline characteristics between the two treatment groups of high and low age. Medications used for induction and maintenance of anesthesia, and side-effects profiles were comparable, as were the average propofol dose for induction of anesthesia (range of the mean dose 4.0-4.2 mg/kg) and for maintenance of anesthesia (range of the mean dose in the first hour 8.74-9.42 mg x kg(-1) x h(-1)). CONCLUSIONS: The two 1% propofol formulations were equally effective in our patient population of infants and young children between 1 month and 3 years of age. No differences between the two propofol formulations were found with regard to the circulatory reaction, lipid metabolism, dosages, and recovery profile in the studied age groups.
A sample of 4 x 10(5) events from the decay K(+)-->pi(+)pi(-)e(+)nu(e) (K(e4)) has been collected in experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The analysis of these data yields new measurements of the K(e4) branching ratio [(4.11+/-0.01+/-0.11) x 10(-5)], the s-wave pi pi scattering length [a(0)(0) = 0.216+/-0.013(stat)+/-0.004(syst)+/-0.005(theor)], and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi pi mass.
BACKGROUND AND OBJECTIVE: Polyhematoporphyrin (Photosan) as sensitizers for photodynamic therapy (PDT) in advanced esophageal cancer carry the risk of prolonged photosensitivity of the skin. New sensitizers such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared to Photosan for PDT in advanced esophageal carcinoma regarding phototoxicity of the skin, reduction of dysphagia, tumor stenosis, and tumor length and Karnovsky performance status. STUDY DESIGN/MATERIALS AND METHODS: After diagnostic work-up, photosensitization was done in 22 patients with ALA (60 mg/kg body weight, oral, 6-8 hours prior to PDT) and in 27 patients with Photosan (2 mg/kg body weight, i.v., 48 hours before PDT). The light dose was calculated as 300 J/cm fibre tip. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure. RESULTS: Improvement regarding dysphagia, stenosis diameter, and tumor length could be obtained in both treatment arms with a significant difference in favour of the Photosan-group, P = 0.02; P = 0.0000; and P = 0.000014, respectively. The Karnovsky performance status also improved in both groups and showed no significant difference (P = 0.12). The median survival time for the ALA-group was 8.0 months, compared with 9.0 months for the Photosan group. No sunburn or other major treatment related complication occurred in both treatment arms. Thirty-day mortality was 0%. CONCLUSION: Despite the limitations of a non-randomized study, photosensitzation with Photosan seems to be more effective in PDT of advanced esophageal carcinoma compared to ALA.
BACKGROUND: Hematoporphyrin derivatives (HpD) as sensitizers for photodynamic therapy (PDT) in advanced esophageal cancer carry the risk of prolonged photosensitivity of the skin. New sensitizers such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared with HpD for PDT in advanced esophageal carcinoma regarding phototoxicity of the skin, reduction of dysphagia, tumor stenosis and length, and Karnovsky performance status. METHODS: After diagnostic workup, photosensitization was done in 22 patients with ALA (60 mg/kg body weight, oral, 6 to 8 hours before PDT) and in 27 patients with a hematoporphyrin derivative (2 mg/kg body weight, intravenously, 48 hours before PDT). The light dose was calculated as 300 J/cm fiber tip. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure. RESULTS: Improvement regarding dysphagia, stenosis diameter, and tumor length could be obtained in both treatment arms with a significant difference in favor of the HpD group (p = 0.02; p = 0.0000; and p = 0.000014, respectively). A questionnaire of patients in the HpD group confirmed that the ability of swallowing a meal was superior compared with the discomfort from limitation to sun exposure. No sunburn or other major treatment-related complication occurred in both treatment arms. CONCLUSIONS: Despite the limitations of a nonrandomized study, photosensitzation with HpD seems to be more effective in PDT of advanced esophageal carcinoma compared with ALA.
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OBJECTIVES: Left ventricular hypertrophy in patients with critical aortic stenosis (AS) is an adaptive process that compensates for high intracavitary pressure and reduces systolic wall stress followed by an increase in myocardial masses. In the present prospective clinical trial, we investigated long-term compensatory changes in left ventricular geometry and function after aortic valve replacement using mechanical bileaflet prostheses with the main emphasis on the small-sized aortic annulus and valve prosthesis-patient mismatch. METHODS: A total of 58 patients with critical AS were assigned to the following groups according to the predictive value of prosthetic valve area index (VAI): group EXMIS: 29 patients (VAI < or =0.99), expected mismatch; group NOMIS: 29 patients (VAI < or =0.99), no mismatch. At controls T(0) (before operation/operation (OP), T(1) and T(2) (4 and 20 months after OP) the left ventricular geometry was recorded by means of Imatron electron beam tomography and the transprosthetic velocities were measured by echocardiography. RESULTS: Statistical analysis showed a consistent reduction in the absolute (P=0.04) and indexed (P=0.04) left ventricular myocardial mass for both cohorts; furthermore, there was a significant difference between EXMIS and NOMIS patients concerning the factors, time and mass reduction (P=0.005), because of distinct baselines. A logistic regression report revealed preoperative cardiac output, absolute left ventricular myocardial mass, perfusion, body surface area and the native valve orifice area as predicting coefficients and factors for a minimum mass reduction of 25%. We explain a mathematical formula that turned out to be the most sensitive for correctly classified factors. CONCLUSIONS: The left ventricular geometry and transprosthetic velocities resulted in the same postoperative recovery for both EXMIS and NOMIS patients. The presented data showed that valve prosthesis-patient mismatch had no influence in several stepwise logistic regression models. We conclude that modern mechanical bileaflet prostheses allow both acceptable hemodynamics and recovery of left ventricular hypertrophy, even in small aortic annuli.
Plastic surgeons are increasingly taking advantage of information opportunities offered by the internet. Between October 1998 and March 1999, 87 individuals returned by e-mail a feed-back form included in the homepage of the Division of Plastic Surgery, Department of Surgery, Karl-Franzens University School of Medicine, Graz, Austria. Most of the responses originated from Austria or other European countries; 10% were from overseas. The most frequent reason for visiting our homepage was to gain information on scientific activities in our department (43 visitors), followed by interest in plastic surgical procedures on the part of patients or referring physicians (35 visitors). Other reasons were interest in educational matters, positions, and general interest in plastic surgery. Our results show that physicians, medical students, and laypersons are increasingly inclined to seek information on plastic surgery via the internet. This in turn should encourage plastic surgery services to present themselves in the World Wide Web.
UNLABELLED: Cardiac surgery correlates with increased perioperative stress and anxiety. We tested whether preoperative extensive oral information in combination with more personal attention by the surgeon is associated with any effect on patients' perioperative stress, anxiety, and well-being. Sixty patients awaiting open heart surgery were divided into two groups. Group I consisted of 30 patients who received routine medical information through an informative pamphlet. In Group II (n = 30 patients), additional, extensive oral medical information and more personal attention by the surgeon was provided before surgery. Salivary cortisol, plasma cortisol, state anxiety, and patients' well-being were measured perioperatively. Extensive preoperative oral information in combination with more personal attention by the physician did not have any significant influence on the perioperative psychoendocrinologic course of stress. During transport to the operating room, salivary cortisol increased significantly (P < 0.001) in both groups (ranges are 95% confidence intervals) (Group I, 23.2 nmol/L [17.1-31.5]; Group II, 14.6 nmol/L [9.9-21.3]) versus the first day in the hospital (Group I, 8.4 nmol/L [6.2-11.4]; Group II, 6.7 nmol/L [5.3-8.6]). After the induction of anesthesia, plasma cortisol decreased significantly (P < 0.001) in both groups (Group I, 170.1 nmol/L [143.6-201.4]; Group II, 172.0 nmol/L [142.2-208.1]) versus preoperative levels. After surgery, well-being decreased (P = 0.003) in all patients, and patients' state anxiety was reduced (P = 0.001) after surgery. Our data demonstrate a lack of effect of extensive oral medical information that was presented as part of clinical routine on the perioperative psychoendocrinologic course of stress. High levels of stress during transport to the operating room were detected. IMPLICATIONS: The quantity of stress during transport to the operating room and the perioperative psychoendocrinologic course of stress in combination with two different methods of preoperative medical information are described in 60 consecutive patients awaiting cardiac surgery.
A search for lepton flavor violating decays, K+ --> mu+ mu+ pi-, K+ --> e+ e+ pi-, K+ --> pi+ e+ mu-, K+ --> mu+ e+ pi-, and pi0 --> e+ mu-, was performed using the data collected in Experiment E865 at the Brookhaven Alternating Gradient Synchrotron. No signal was found in any of the decay modes. At the 90% confidence level, the branching ratios are less than 3.0x10(-9), 6.4x10(-10), 5. 2x10(-10), 5.0x10(-10), and 3.4x10(-9), respectively.
More than 400 K+-->pi(+)&mgr;(+)&mgr;(-) events were observed in a rare K+ decay experiment at the Brookhaven Alternating Gradient Synchrotron. Normalized to the K+-->pi(+)pi(+)pi(-) decay, the branching ratio is determined to be [9.22+/-0.60(stat)+/-0. 49(syst)]x10(-8). This branching ratio and the &mgr;&mgr; mass spectrum is in very good agreement with the measurement of the K+-->pi(+)e(+)e(-) decay, but deviates significantly from the previous measurement.
BACKGROUND AND OBJECTIVE: The photochemical reaction of photodynamic therapy (PDT) depends on the presence of molecular oxygen. Because of anoxic regions in tumor tissue and vascular shutdown during PDT, the efficiency is limited. Therefore, the use of hyperbaric oxygen, which increases the oxygen in tumor tissue, as well as the amount of singlet oxygen, may enhance the efficiency of PDT. STUDY DESIGN/MATERIALS AND METHODS: After diagnostic work-up, photosensitization was carried out with a hematoporphyrin-derivate 2 mg/kg body weight 48 hours before PDT. The light dose was calculated as 300 J/cm of fiber tip. Twenty-three patients were treated by PDT alone and 29 patients received PDT under hyperbaric oxygen at a level of two absolute atmospheric pressures. RESULTS: Improvement regarding dysphagia and stenosis-diameter could be obtained in both treatment arms with no significant difference (P = 0.43 and P = 0. 065, respectively). The tumor length also decreased in both groups and showed a significant difference in favour of the PDT/HBO group (P = 0.002). The mean overall survival was 11.3 months. The mean survival time for the PDT group was 8.7 months and for the PDT/HBO group 13.8 months (P = 0.021). CONCLUSION: According to this pilot study, combined PDT/HBO represents a new approach in the treatment of esophageal and cardia cancer, which appears to have enhanced the efficiency of PDT.
UNLABELLED: Background and Objective We wanted to determine the role of additional photodynamic therapy in a multimodal approach for the treatment of patients with advanced cancer of the gastro-esophageal junction. Study Design/Materials and Methods We reviewed 53 patients, after endoluminal palliation, with advanced cancer of the gastro-esophageal junction. Combined dilatation and retrograde tumor disobliteration with Nd-YAG laser before photodynamic therapy (PDT), brachyradiotherapy, or both, became necessary in 12 patients. Brachyradiotherapy was carried out in all patients. PDT before brachyradiotherapy was performed in 25 patients. The endoluminal treatment was completed by external beam irradiation in 30 patients (15 cases with PDT and 15 without PDT) with an at least fair performance status. RESULTS: Photodynamic therapy showed a significant difference regarding the mean opening of the tumor stenosis (mean, 6.4 mm; P = 0.0002), the mean decrease in tumor length (3.1 cm; P = 0.00001) and the increase in median survival (13. 8 months; P = 0.001). The combined multimodal approach by using PDT, brachyradiotherapy and external beam irradiation showed a median survival of 16.8 months. However, additional external beam irradiation showed no significant difference (P = 0.11). The rate of severe complications was 5.7%. The mortality rate was 1.9%. CONCLUSION: Photodynamic therapy has been shown to be an effective treatment for palliation of advanced cancer at the gastro-esophageal junction. The use of PDT combined with irradiation was associated with an acceptable survival rate, low rates of complications and reasonable quality of life.
BACKGROUND AND OBJECTIVE: Dose dependence of light cannot be discussed on the basis of dose alone. On a more fundamental scientific level, the propagation of light in tissue depends on optical parameters of treated tumor tissue. In a prospective, nonrandomized study, in vivo optical parameters of esophageal carcinoma were studied. STUDY DESIGN/MATERIALS AND METHODS: Nineteen intraoperative measurements of tumor optical parameters in six patients with esophageal carcinoma were performed. After diagnostic work-up and clinical staging, right-sided, posterolateral thoracotomy, and dissection of the esophagus were carried out. The tumor site was exposed and continuous endoluminal irradiation was started during determination of light penetration at the level of the adventitia of the esophagus. The tumors were located exactly between the endoluminal irradiation source and measurement probe in the thoracic cavity. Measurements were performed on tumors having different diameters to show the relationship between tumor diameter, extinction coefficient, and light penetration depth. RESULTS: The endoluminal incident intensity was 18.5 mW/cm(2). At a tumor diameter of 4, 6, 8, and 9 mm measured intensity of 5.12, 2.28, 0.88 and 0.65 mW/cm(2), an extinction coefficient of 0.321, 0.349, 0.381, and 0.373, as well as penetration depth of 3.21, 2.87, 2.62, and 2. 68 mm, respectively, could be measured. The correlation of tumor optical parameters, tumor diameter, penetration depth, and treatment time were expressed by the relative correction factor for different tumor diameters. CONCLUSION: The knowledge of tumor optical properties seems to be necessary to adapt dosimetry to the individual situation and manage optimal results of PDT in esophageal cancer.
BACKGROUND: We wanted to determine the role of photodynamic therapy in a multimodal approach for the treatment of patients with advanced cancer of the esophagus. METHODS: We reviewed the cases of 119 patients with nonresectable esophageal carcinoma who underwent endoluminal palliation. Twenty-one patients required initial dilation and tumor obliteration with a neodymium: yttrium-aluminum-garnet laser prior to therapy. Forty-four patients received photodynamic therapy followed by brachyradiotherapy, and 75 patients were treated with brachyradiotherapy. In both groups, some patients also received external-beam irradiation. RESULTS: Photodynamic therapy produced a significant difference in relieving stenosis caused by tumor stenosis (mean, 6.6 mm; p = 0.0000). The dysphagia score improved by one to three levels in all patients, with a significant difference in favor of PDT (p = 0.0003). The mean number of overall treatment sessions was four (range, one to seven). The rate of major complications was 9.2%. Four esophageal perforations occurred, three after intervention and one spontaneously 5 months later. Four esophagorespiratory tract fistulas developed several months after combined PDT and irradiation. The mean overall survival was 7.7 months, and analysis of variance revealed a significant difference in favor of PDT and external-beam irradiation (p = 0.0129 and p = 0.0001, respectively). CONCLUSIONS: Photodynamic therapy has been shown to be an effective palliative treatment of advanced esophageal cancer. However, proper patient selection is necessary to prevent serious complications.
STUDY OBJECTIVE: To investigate whether there is an association between Troponin T (TnT), reflecting myocardial cell injury, and cortisol, reflecting the degree of surgical trauma and associated stress, in light of our recent evaluation of TnT as a marker of perioperative myocardial cell injury. DESIGN: Prospective, cohort study. PATIENTS: 70 patients (67.4 +/- 8.7 yrs) with definite or at-risk coronary artery disease (CAD) undergoing elective noncardiac surgery (vascular n = 38, abdominal n = 21, orthopedic n = 8) with general (n = 63) or regional (n = 4) anesthesia with postoperative on-demand analgesia. MEASUREMENTS AND MAIN RESULTS: Morning blood samples for TnT (upper limit of normal: <0.2 ng/mL), CK-MB (reference range </=12 U/L), and cortisol (normal morning range 7-25 mcg/dL) were taken on the day before surgery, on the morning of surgery before induction of anesthesia, and on the first 5 postoperative days. Data were compared by analysis of variance. Three patients were excluded from the study because of incomplete blood samples of TnT or cortisol. Preoperative mean cortisol levels (mcg/dL +/- SD) were within the normal range and equal in TnT positive (n = 13) and negative (n = 54) patients (16.1 +/- 4.5 vs. 15.6 +/- 5.8). On the 1st postoperative day, there was a substantial increase of cortisol in the TnT positive group (35.7 +/- 26.9). Cortisol remained high until the 5th postoperative day (24.7 +/- 9. 4). There was a significant difference in the cortisol concentration in TnT-positive compared to TnT-negative patients (p < 0.001), a significant difference in the perioperative cortisol concentration over time (p < 0.05), and a significant interaction (p < 0.001). But there was no consistent temporal relationship between the increase of TnT and the increase of cortisol. CONCLUSIONS: The significant relationship between a highly sensitive and specific marker of myocardial cell injury and a marker of stress suggests that cardiac-risk patients undergoing stressful surgical procedures might benefit from close perioperative TnT monitoring with early recognition of myocardial cell injury.