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Biomedical subjects

M Fischer

Publications and source records attributed to M Fischer.

At least 73 records · Page 4Linked to original sources
PubMed2003

[Diagnostic impact of multiplanar reformations in multi-slice CT of laryngeal and hypopharyngeal carcinomas].

PURPOSE: Assessment of the diagnostic value of multiplanar reformations (MPR) in multi-slice computed tomography (MSCT) by comparing relevant anatomic structures of the larynx and hypopharynx. MATERIALS AND METHODS: MSCT of the neck was performed in 69 consecutive patients (including 30 laryngeal and 12 hypopharyngeal carcinomas). From a 4 x 1.0 mm collimation data set, 3.0-mm and 1.25-mm axial slices as well as 3-mm coronal and sagittal slices were reconstructed. Using the histological examination as gold standard, sensitivity and specificity regarding tumor infiltration for all relevant anatomical structures of the larynx and the hypopharynx were determined for each reconstruction and compared with the McNemar test. Moreover, 42 patients with laryngeal and/or hypopharyngeal carcinoma were subjectively evaluated to determine whether the respective reconstructions enables a better topographical visualization of the tumor in relation to surrounding structures and, furthermore, whether this has an influence on the therapeutical strategy (operation versus radiation therapy, type of operation, surgical approach). RESULTS: Sensitivities and specificities were not significantly different between the reconstructions. However, coronal and sagittal MPR provided a better topographical visualization of the tumor in 14 of 42 (33 %) of the patients, and influenced the therapeutical strategy in 8 of 42 (19 %) of the patients. A lowered signal-to-noise ratio impeded the evaluation of the relatively thin 1.25-mm axial slices in more than 23 % of the cases. CONCLUSION: Besides the 3-mm axial slices, coronal and sagittal MPR can improve the topographical visualization of laryngopharyngeal tumors and are recommended for preoperative MSCT of laryngeal and/or hypopharyngeal carcinomas. Additionally reconstructed 1.25-mm axial slices can be discarded since they do not hold a higher value compared to 3-mm axial reconstructions.

Adult↗
PubMed2003

[Comparison of the emergency medical services systems of Birmingham and Bonn: process efficacy and cost effectiveness].

OBJECTIVE: Due to rising health care costs there is a need to verify that the treatment by Emergency Medical Services (EMS) systems is efficient and cost effective. The integration of emergency physicians is inherent part of out-of-hospital emergency care and regulated by law in Germany but not in England and the United States of America. Aim of this study therefore was to conduct a cost performance analysis by evaluating the underlying structure, the costs incurred and the achieved performance in two EMS systems with paramedics or emergency physicians on scene. METHODS: The study was carried out in West-Birmingham, a part of the West-Midlands-Ambulance-Service (WMAS), and the EMS of Bonn. Pre defined questionnaires, EMS protocols, calculations of purchasing power parity and recent publications concerning out-of-hospital resuscitation (CPR) were used to evaluate the operating costs, to describe the structure and to measure the quality of performance. Significance was assumed at p < 0.01 for CHI(2)- or t-test, respectively. RESULTS: Birmingham used state of the art technology for dispatch and logistics whereas Bonn trusted in high qualified personnel. In the 1st quarter 1997 the Mainz-Emergency-Evaluation Score could be achieved before (MEES A) and after preclinical treatment (MEES B) in 3502 and 3422 patients in Birmingham and Bonn, respectively. In Birmingham 7.5 % and in Bonn 17 % of all patients could be improved by the EMS treatment, respectively (p < 0.01). Looking at severely ill patients (MEES A < 22) the EMS in West-Birmingham achieved an improvement in 27.9 % of these patients with an averaged change in MEES of 0.9 +/- 1.7 points in all of them. In contrast the Bonn EMS improved the status in 47.8 % of these patients and MEES A could be improved considerably by 2.3 +/- 3.4 points (p < 0.01). Pharmacological treatment was less frequently used in Birmingham than in Bonn (12.9 % vs. 32.4 %, respectively; p < 0.01). At equal incidences of CPR attempts discharge rate after CPR was only 4 % in WMAS compared to 14.7 % in Bonn-North (p < 0.01). Per inhabitant and year total costs amounted to 10.43 euro for the EMS system in Birmingham, which is 42 % less than in Bonn. Unit hour utilisation reached 0.6 in Birmingham and only 0.33 in Bonn. In severely ill patients the improvement of MEES A by 0.1 points cost per inhabitant and year 1.16 euro in Birmingham and only 0.65 euro in Bonn. The survival of one patient after CPR was calculated to 0.7 euro in Birmingham and 0.17 euro in Bonn. CONCLUSIONS: The provider of the EMS in West-Birmingham--WMAS--organised a reliable system with high efficiency concerning unit hour utilisation and response time reliability. In the EMS of Bonn, in contrast, the complex therapy by the emergency physicians improved MEES considerably and increased probability of survival after CPR at a higher level of efficiency. Further investigations however are necessary to evaluate the presented parameter of efficiency.

Allied Health Personnel↗
PubMed2003

[Hemobahn-endoprosthesis: long-term experience (< or = 4 years follow-up) with percutaneous application in stenoses and occlusions of the superficial femoral artery].

We tested the value of hemobahn-endoprosthesis in a prospective, nonrandomized, clinical trial in PAD-patients with femoral artery occlusive disease. During 4 years we placed in 52 patients (55 extremities) a total of 78 hemobahn-endoprostheses for treatment of stenoses (15%) or occlusions (85%) of femoral artery. The average length of the treated lesions was 11.6 cm, the mean length of the hemobahn-endoprosthesis was 15.9 cm, the average device diameter 6.1 mm. In 45% of the patients we used cross-over and in 55% ipsilateral antegrade technique. Fontaine's clinical stages were II b (89%), III (2%) and IV (9%); there were 15 diabetics. The average period of follow-up was 33 months (1-52 months). The primary/secondary patency rates after the first year (n = 50) were 64% vs. 78%, after 2 years (n = 46) 61% vs. 76%, after 3 years (n = 32) 53% vs. 66% and after 4 years (n = 14) 29% vs. 50%. After the first experiences in 1998 with 10 stent-occlusions in 14 treated extremities, indications were checked and thereafter hemobahn was only used in "ideal indications" as segments with a length of > or = 1 cm proximal and distal without any obstruction, no lesions in the popliteal artery, at least one open lower leg vessel and no severe calcifications. The primary/secondary patency rates were significantly better after exclusion of nonideal patients treated during the first year: Thus, primary/secondary patency rates were 76 % vs. 90% after first year (n = 32), 74 % vs. 89% after second year (n = 38) and 71% vs. 83% after third year (n = 24); after 4 years of 8 treated arteries 4 were primary and 7 were secondary open. Hemobahn-endoprostheses are suitable for treatment of long femoral artery occlusions. The medium patency rate in "ideal indications" is higher than that obtained by angioplasty with or without uncovered stents.

Aged↗
PubMed2003

Migration of metal-on-metal versus ceramic-on-polyethylene hip prostheses.

In a prospective randomized study, 32 metal-on-metal prostheses and 29 ceramic-on-polyethylene prostheses of similar design were implanted in 59 patients. Radiolucency, cup migration, wear, and function were examined after a minimum of 2 years followup (followup rate, 87%). The purpose of the current study was to evaluate whether higher frictional torque of metal-on-metal will lead to a higher rate of early metal-on-metal cup loosening. A computer-assisted method was used for wear and migration measurements of the acetabular component. Metal-on-metal prostheses migrated in a craniocaudad direction significantly less than ceramic-on-polyethylene prostheses. The mean total migration for both types of prostheses exceeded 1.5 mm at 2 years. Clinically, no difference between the two prostheses regarding activity, pain, or range of motion was found at 2 years. As migration of metal-on-metal prostheses was not higher in comparison with ceramic-on-polyethylene prostheses, the expected higher frictional torque of metal-on-metal prostheses did not increase migration during short-term followup. The different debris produced by both bearings did not influence the short-term results of this study, but might cause different long-term results.

Aged↗
PubMed2003

Treatment of Helicobacter pylori in functional dyspepsia resistant to conventional management: a double blind randomised trial with a six month follow up.

BACKGROUND: Previous studies on the treatment of Helicobacter pylori infection in functional dyspepsia have shown little, if any, effect on dyspeptic symptoms. However, whether such treatment might be of benefit in patients resistant to acid inhibitors has not been formally tested. AIM: The present study investigated the effect of H pylori treatment in patients with functional dyspepsia resistant to conventional treatment. PATIENTS: A total of 181 H pylori positive patients with chronic functional dyspepsia who had not responded to a one week antacid run-in and two week double blind antisecretory or placebo treatment were included. METHODS: Patients were randomised to two weeks of treatment with omeprazole 40 mg twice daily combined with amoxicillin 1 g twice daily or omeprazole 20 mg once daily alone. The primary outcome variable ("response") was defined as no need for further therapy or investigations for dyspeptic symptoms 4-6 months after treatment. RESULTS: H pylori infection was healed in 10% of patients after omeprazole and in 52% after omeprazole plus amoxicillin. The respective "response" rates were 66% and 62% (NS). H pylori treatment and cure of H pylori infection had no effect on complete resolution of all dyspeptic symptoms, individual symptoms, or various aspects of quality of life. CONCLUSION: In functional dyspepsia, H pylori treatment and cure of H pylori are no more effective for symptoms over six months than short term acid inhibition. These results do not support treatment of H pylori in functional dyspepsia.

Adult↗
PubMed2002

Effects of the calcium antagonist nifedipine on the afferent impulse activity of isolated cat muscle spindles.

The impulse activity of muscle spindles isolated from the cat tenuissimus muscle was investigated under varying concentrations of the L-type calcium channel blocker nifedipine. At a concentration of 25 microM nifedipine impulse activity was clearly diminished in both primary and secondary endings. However, low concentrations of the drug (5-10 microM) exerted unexpected excitatory effects. The dynamic properties of primary endings in particular were augmented; those of secondary endings were also increased, although only slightly. A detailed analysis of the afferent discharge patterns obtained under ramp-and-hold stretches yielded the following effects of 10 microM nifedipine. (1) The initial burst at the beginning of the ramp phase of a stretch was increased in primary endings; (2) the peak dynamic discharge frequency at the end of the ramp phase was considerably increased in most primary endings; (3) the sensitivity of the peak dynamic discharge value to varying amplitudes and velocities of stretch was significantly enhanced in primary endings, and also increased, although only slightly, in secondary endings; (4) the rise in the discharge frequency during the ramp phase of a stretch was augmented in both types of ending, the effect being again stronger in primary endings; (5) the fast adaptive decay of the impulse frequency following the ramp phase of a ramp-and-hold stretch was significantly increased in primary endings, but remained unaffected in secondary endings. The enhanced dynamic properties of primary endings were also observed under small sinusoidal stretch stimuli (10 microm, 40 Hz), where nifedipine induced a significant shift in the position of the 1:1 driven action potentials toward smaller phase values. In view of an increase in tension in the isolated muscle spindle and an increased initial burst in primary endings in the presence of nifedipine, it is suggested that the drug facilitates the attachment of cross-bridges in the poles of the intrafusal muscle fibers. The increase in the dynamic properties of primary endings points to the possibility that the drug preferentially affects the nuclear bag(1) fiber. The inhibitory effect on the afferent discharge rate at high doses of the drug is interpreted as the consequence of a calcium channel block in the membranes of the sensory endings. The membrane potential of sensory endings appears to be highly dependent on sustained Ca(2+) conductance.

Action Potentials↗
PubMed2002

The value of ablating oto-rhino-laryngological (ORL) foci before haematopoietic stem cell transplantation (HSCT).

Between June 1996 and May 1997, 92 patients underwent haematopoietic stem cell transplantation (HSCT) for haematological malignancies. To participate in a prospective single-centre trial to evaluate oto-rhino-laryngological (ORL) related problems, 43 of these patients (27 male, 16 female, median age 38) signed an informed consent. A questionnaire about ORL related problems was assessed before and after HSCT. Only 21 of the patients (49%) could be fully examined after transplantation because of overall mortality and follow-up realised by other health care centres. In the deceased patients, however, a close review of the patients' notes was carried out. An ORL focus was not identified as the cause of death in any of the deceased. Pre-transplant examination revealed 15 patients with ORL relevant infectious foci. To make urgent HSCT possible, surgical pre-transplant ablation of chronic ORL infection sites took place in four patients only. In this cohort, pre-transplant ORL pathology was not amplified after HSCT. None of the 11 patients presenting ORL foci before transplantation experienced enhancement of ORL disease. These data suggest that the indication for surgical intervention with regards to ORL infection prior to HSCT should be regarded cautiously. However, the potential risk of dissemination of a pre-existing fungal infection from an ORL site should be considered and treated on a case-by-case basis.

Adult↗
PubMed2002

Semiautomated registration using new markers for assessing the accuracy of a navigation system.

OBJECTIVES: New markers are described that can be used for an improved registration procedure and for the exact comparison of navigation systems. The advantages of the markers are demonstrated, together with an automated segmentation algorithm for locating the centroid of the markers in image space. Compared to manual registration, this method shows an improved registration accuracy. MATERIALS AND METHODS: The new markers are detected completely automatically within all scan images. This allows a semiautomatic registration, as a preregistration is performed via the algorithm. Furthermore, the exact coordinates within one scan slice are now determined with the calculation procedure. The calculated data from the preregistration were matched up with a manual preregistration and some reference data, so as to confirm the quality of this new algorithm. The accuracies of several manual and semiautomatic registrations were also compared. RESULTS: The average deviation between the coordinates of the algorithm and the reference data (coordinate measuring machine) was 0.3 mm. The standard deviation amounted to 0.131 mm. Comparing several manual registrations with the reference data showed that the middle fiducial registration error (FRE) was between 0.7 and 2 mm. In comparison, the FRE remained constant at around 0.7 mm for the semiautomatic registration procedure. CONCLUSIONS: The measured results show a significant improvement in the preregistration data using the new markers together with the algorithm. This improvement leads to a reproducible and more accurate registration. The combination of the new marker type with the automated segmentation algorithm minimizes the human error factor, and provides the opportunity to directly compare image-guided and robotic systems.

Algorithms↗
PubMed2002

[Ulcerating Herpes simplex infections in intensive care patients].

Herpes simplex infections are potentially a life-threatening situation for immunocompromised as well as critically ill patients. The correct diagnosis is made more difficult in comatose patients by the fact that the characteristic symptom of extreme pain cannot be registered. The clinical dermatological findings (polycyclic configuration, easily bleeding ulcers) are thus especially important in patients under intensive care conditions. As examples, the cases of 3 critically ill patients (subarachnoid bleeding or head injury) developing therapy-resistant, flat sacral or perioral skin ulcers with peripheral blisters are presented. Herpes simplex virus was confirmed immunohistologically and in the smear test. All patients subsequently died. These cases emphasize that patients in the intensive care unit are in danger of developing a chronic persistent Herpes simplex infection due to latent immunosuppression. Chronic persistent Herpes infections may be underrated in intensive therapy, and must always be ruled out in case of therapy-resistant erosions or ulcerations.

Acyclovir↗
PubMed2002

[Sucessful treatment with clofazimine and itraconazole in a 46 year old patient after 32 years duration of disease].

Lobomycosis, caused by the fungal pathogen Lacazia loboi, is a chronic deep mycosis and is only found in Central and South America. Clinically the disease is characterized by shiny keloidal nodules appearing mainly on the exposed parts such as face and the upper and lower extremities. Therapeutically the surgical removal of the lesions is considered as the only successful treatment. We describe the therapeutic response of a patient with Lobo's disease treated for one year with a combination of clofazimine (100 mg/day) and itraconazole (100 mg/day). A complete clinical and histopathological remission of the disease was observed. The patient has been followed for three years.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

The efficacy and safety of Tanacetum parthenium (feverfew) in migraine prophylaxis--a double-blind, multicentre, randomized placebo-controlled dose-response study.

Tanacetum parthenium (feverfew), is a well-known herb for the prophylactic treatment of migraine. The primary objective was to show a dose-response of a new stable extract (MIG-99) reproducibly manufactured with supercritical CO2 from feverfew (T. parthenium). Furthermore, the study should provide data on the safety and tolerability of MIG-99. In a randomized, double-blind, multicentre, controlled trial with an adaptive design, the clinical efficacy and safety of three dosages of MIG-99 (2.08 mg; 6.25 mg; 18.75 mg t.i.d.) were compared with placebo. The patients (n = 147) suffered from migraine with and without aura according to International Headache Society (IHS) criteria and were treated with one of the study medications for 12 weeks after a 4-week baseline period. The primary efficacy parameter was the number of migraine attacks during the last 28 days of the treatment period compared with baseline. Secondary endpoints were total and average duration and intensity of migraine attacks, mean duration of the single attack, number of days with accompanying migraine symptoms, number of days with inability to work due to migraine as well as type and amount of additionally taken medications for the treatment of migraine attacks. The design of the study included a pre-planned adaptive interim analysis for patients with at least four migraine attacks within the baseline period. With respect to the primary and secondary efficacy parameter, a statistically significant difference was not found between the overall and the confirmatory intention-to-treat (ITT) sample in the exploratorily analysed four treatment groups. The frequency of migraine attacks for the predefined confirmatory subgroup of patients (n = 49) with at least four migraine attacks during the baseline period decreased in a dose-dependent manner (P = 0.001). The highest absolute change of migraine attacks was observed under treatment with 6.25 mg t.i.d. (mean +/- SD = -1.8 +/- 1.5 per 28 days) compared with placebo (-0.3 +/- 1.9; P = 0.02). Overall, 52 of 147 (35%) patients reported at least one adverse event (AE). The incidence of AEs in the active treatment groups was similar to that in the placebo group, and no dose-related effect was observed in any safety parameter. MIG-99 failed to show a significant migraine prophylactic effect in general. Accordingly, in the ITT analysis a dose-response relationship could not be observed. MIG-99 was shown to be effective only in a small predefined subgroup of patients with at least four attacks during the 28-day baseline period where the most favourable benefit-risk ratio was observed with a dosage of three capsules of 6.25 mg MIG-99 extract per day. Because of the low number of patients, these findings need to be verified in a larger sample. The incidence of AEs was similar for all treatment groups.

Adolescent↗
PubMed2002

[Relationship between psychosomatic medicine and psychotherapy in theory and practice].

Initially, the different operationalizations of 'psychosomatic' are presented. Etiological concepts of psychosomatic illness include stressful life events, developmental factors and the individual psychic structure. At the Department for Psychotherapy and Psychoanalysis of Vienna University, the initial diagnostic interview includes subjective illness theories as possible pathway to psychotherapy, motivational factors and the patient's ability to transfer the experience from this interview into psychotherapy proper. The psychotherapeutic method applied to psychosomatic patients should offer a theoretical concept concerning psychosomatic illness, as it is the case in psychoanalytic psychotherapy. Finally, the importance of supervision for psychotherapists working in an institutional setting with in-patients is stressed.

Austria↗