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Biomedical subjects

P Scheffler

Publications and source records attributed to P Scheffler.

At least 19 recordsLinked to original sources
PubMed2000

The influence of noise on blood flow in the basilar artery (BA) - measurements with transcranial color-coded duplex sonography (TCCD).

Acoustic stimuli are being reported as a cause of changes in resistance in the basilar artery (BA). It was the aim of this study to investigate this effect under standardized conditions dependent upon the intensity of the evoking stimulus. Twenty healthy subjects with normal hearing (male/female 14/6; mean age 26.4 years) were exposed to 'pink noise' for periods of 2 min at 75, 85 and 95 dB(A). Parallel to this, the Doppler spectrum of the BA and both the Pourcelot resistance index and the Gosling pulsatility index were measured by means of transcranial color-coded Doppler sonography. In comparison with the base value (at rest) a significant increase in resistance was noted during noise exposure. The noise-induced resistance changes could be interpreted as a consequence of changes in activity of the various centers of the auditory pathway and cerebral function. Further animal experiments may prove the connection between BA blood flow and resistance and their changes depending on different acoustic stimuli or different hearing pathophysiology.

Acoustic Stimulation↗
PubMed2000

[Paget-Schroetter syndrome caused by wrestling].

Upper extremity thrombosis (Paget-Schroetter syndrome) hints already at physical strains with regard to the synonymous term "effort thrombosis". We report two cases of upper extremity thrombosis caused by wrestling. Wrestling as an example of martial arts activity leads to traumatic venous intima lesions with resulting local activation of coagulation as a main reason in pathogenesis of these thromboses. The possibility of a Paget-Schroetter syndrome should be considered in differential diagnosis if upper extremity complaints of unknown origin occur after wrestling matches. This kind of subclavian vein thrombosis should be reported to the accident insurance.

Adult↗
PubMed1999

Randomized reliability study evaluating constant-load and graded-exercise treadmill test for intermittent claudication.

The aim of this randomized study was to compare the reliability of the treadmill test at constant-load (C-test, 3 km/hr; fixed grade of 12%) recommended in Germany with that of the graded-exercise test (G-test, 3 km/hr; increase in grade of 3.5% every 3 minutes) propagated in the United States. In 50 patients with an absolute claudication distance (ACD) in the C-test of between 50 and 400 m, the two treadmill tests were carried out in randomized order on one and the same day, and repeated on 3 days within 1 week. For the initial claudication distance (ICD), the intraclass correlation was 0.88 in the C-test and 0.87 in the G-test. For the ACD the coefficients were identical at 0.91. The within-subject variation (CVwithin) in the C-test and G-test was 25% and 27% for the ICD and for the ACD 24% and 21%, respectively. The between-subject variation was very similar with 72% and 73% (ICD) and with 78% and 68% (ACD). However, in ACDs below 100 m and between 100 to 150 m, the C-test showed significantly smaller coefficients of variation than the G-test: 13% vs 81% and 14% vs 50%, respectively. In conclusion, the results showed that both C-test and G-test are equally well reproducible.

Analysis of Variance↗
PubMed1997

Efficacy of a new prostaglandin E1 regimen in outpatients with severe intermittent claudication: results of a multicenter placebo-controlled double-blind trial.

For the first time efficacy and safety of a new prostaglandin E1 (PGE1) regimen in the treatment of intermittent claudication were evaluated in a randomized, double-blind, placebo-controlled multicenter clinical trial. The study involved 213 outpatients with a maximum walking distance of 50 to 200 m measured on the treadmill (3 km/hr, 12% grade). After a 2-week run-in phase they received a 2-hour intravenous infusion of 60 micrograms PGE1 or placebo 5 days a week for 4 weeks. It was followed by a 4-week interval treatment with the same medication administered only twice a week. Patients were monitored for 3 months when they received no study medication. In the PGE1 group the intention-to-treat analysis (n = 208) revealed an increase in walking distance after 4 weeks of 75% (placebo, 43%). At the end of the interval treatment the walking distance had improved to 101% (placebo, 60%). The results remained virtually constant during follow-up (PGE1, 104%, placebo, 63%). Between-group comparisons showed significant differences in favor of PGE1 for all three time points of measurement (p < 0.05, p < 0.01, and p < 0.05). PGE1 was well tolerated; the rate of adverse reactions related to the treatment was 12.8% (placebo, 7.7%). In summary, these results show that the new PGE1 regimen is effective and safe in the treatment of outpatients with intermittent claudication.

Aged↗
PubMed1997

Treadmill testing for evaluation of claudication: comparison of constant-load and graded-exercise tests.

OBJECTIVES: To compare the correlation and practicability of single-stage vs. graded treadmill protocols in the assessment of the absolute claudication distance (ACD). DESIGN: Randomized open study. MATERIAL AND METHODS: In 52 patients with peripheral arterial occlusive disease, the ACD on treadmill at 3 km/h and 12% grade (constant-load test = C-test) ranged form 50 to 400 m. The C-test and the graded-exercise test (walking on the treadmill at 3 km/h and 0% gradient for 3 min, with subsequent increase in gradient of 3.5% every 3 min = G-test) were carried out at random on the same day under standardized conditions. RESULTS: The ACD was higher in the G-test than in the C-test (360.4 +/- 208.8m vs. 166.5 +/- 93.6m; p < 0.001). The coefficients of variation were very similar (57.9% and 56.2%, respectively). In the subgroup of patients with an ACD of between 100 m and 150 m, a large difference was found both for the coefficient of variation (58.6% G-test, 9.6% C-test) and for the standard deviation (339.8 +/- 199.0m and 133.1 +/- 12.8m, respectively). CONCLUSIONS: For the assessment of the ACD in patients with severe claudication the C-test would seem to be more suitable than the G-test.

Exercise Test↗
PubMed1997

Improvement in the quality of life after i.v. PGE1 therapy for intermittent claudication.

BACKGROUND: Increasingly and justifiably, clinical studies are now being expected to investigate the influence of therapeutic measures also on the quality of life of the patient. PATIENTS AND METHODS: Since no data on the variability of changes in the quality of life of the patient following PGE1 treatment are so far available, the initial investigation was designed as an uncontrolled pilot study. 104 patients (median age 64.5 years) with a maximum of walking distance on the treadmill (3 km/12%) of 50-250 m were included and given a daily intravenous infusion of 60 micrograms PGE1 (Prostavasin) over a period of 4 weeks excluding weekends. This was followed by a treatment-free follow-up period of 3 months. Changes in the quality of life were recorded with both the newly developed disease-specific questionnaire PAVK-86, and the generic questionnaire SF 36; in addition, the pain-free and maximum walking distances on the treadmill were also established prior to and immediately following treatment, as also at the end of the follow-up period. RESULTS: The quality of life was significantly improved in all dimensions (functional status, complaints, pain, mood, anxiety, social life, treatment expectations) in addition to a marked increase in the median pain-free walking distance from 77 to 108 m (p < 0.001) and the maximum walking distance from 118 to 171 m (p < 0.001). At the end of the 3-month observation period, the improvement was essentially still demonstrable. CONCLUSION: The study has shown for the first time that treatment with intravenous PGE1 brings about not only the already known increase in the walking distance, but also a clinically relevant and significant improvement in the patient's quality of life.

Adult↗
PubMed1996

Progress in the prostaglandin E1-therapy of the intermittent claudication by means of bolus injections of LIPO-prostaglandin E1 (LIPO-PGE1).

OBJECTIVE: We compared the efficacy of a bolus injection (5 min) of LIPO-PGE1 (Prostaglandin E1 in lipid emulsion) with conventional PGE1-cyclodextrin (PGE1-cyclodextrin) infusions (2 h) in patients with intermittent claudication. The quantitative blood-flow in the common femoral artery was measured using a computerized ultrasound Doppler system (MAVIS). We also monitored the transcutaneous oxygen pressure, the skin temperature on the foot, and the reactive change in blood pressure and pulse as well as side effects. RESULTS: Dose finding of LIPO-PGE1: After bolus injection of 30, 50, and 80 micrograms LIPO-PGE1 a significant dose-dependent increase of the blood flow in the leg (+96.9%, 80 micrograms) with a peak 3 h after injection was seen. After LIPO-PGE1 we observed an enhanced microcirculation (significant rise in the transcutaneous oxygen pressure and the skin temperature on the foot). We noted longer lasting pharmacodynamic properties with LIPO-PGE1 (50 micrograms) compared to PGE1-cyclodextrin (60 micrograms). Comparison to PGE1-cyclodextrin: In a cross-over, placebo-controlled study, 20 patients with intermittent claudication received 4 weeks therapy with a bolus of 50 micrograms LIPO-PGE1 or a 2 h infusion of 60 micrograms PGE1-cyclodextrin per day. A significant increase in the blood flow was measured at the end of 4 weeks therapy compared to the initial values before treatment. This rise correlates significantly with the increase in the patient's maximal walking distance (+112%, LIPO-PGE1). Compared to conventional PGE1-cyclodextrin infusions given over 2 h, a clearly prolonged increase in perfusion of the affected limb after LIPO-PGE1 was demonstrated. No serious adverse effects were observed.

Aged↗
PubMed1994

Intensive vascular training in stage IIb of peripheral arterial occlusive disease. The additive effects of intravenous prostaglandin E1 or intravenous pentoxifylline during training.

In a randomized open study, the combination of either prostaglandin E1 (PGE1) or pentoxifylline with controlled vascular training was compared with vascular training alone in patients with peripheral arterial occlusive disease in stage IIb. Forty-four patients were randomly assigned to treatment either of intensive vascular training alone (n = 15) or in combination with either i.v. pentoxifylline (200 mg over 2 hours BID, n = 15) or PGE1 (40 micrograms over 2 hours BID, n = 14). The basic therapy was a well-defined routine for vascular training, which was identical for all groups. The duration of therapy was 4 weeks. In all three test groups, there was a significant increase in the walking distance. There was a 119% increase in symptom-free walking distance in the exercise-only group. In comparison with exercise alone, the additional administration of pentoxifylline produced no greater effect; the increase was 105%. In contrast, administration of PGE1 combined with exercise achieved a remarkable improvement of 604%. Between-group comparison revealed the significant superiority of treatment with PGE1 (P < .05). During the 1-year follow-up, there was a reduction in the walking performance in all groups, albeit of variable extent. In the exercise-only and the pentoxifylline groups, the maintained increase in walking distance was only 30% compared with baseline values before the beginning of therapy. In the PGE1 group, on the other hand, the maintained improvement was 149%. Nine of 14 patients were still in stage IIa of peripheral arterial occlusive disease 1 year after PGE1 therapy.

Alprostadil↗
PubMed1994

[Noninvasive studies of macro- and microcirculation in follow-up of femoropopliteal bypass operation in IIb peripheral arterial occlusive disease].

In 42 patients with POAD in stage IIb the blood-flow in the common femoral artery and in the superficial femoral artery was measured before, 10 days after, 3 and 12 months after femoro-popliteal bypass surgery. Blood-flow was detected noninvasively using a multichannel ultrasound computer system (MAVISR). Simultaneously Doppler pressure, skin temperature and tcPO2-values were measured. Thereafter the patients had to undergo treadmill tests (painfree and maximal walking distance). Compared to healthy volunteers preoperative blood-flow was significantly (p < 0.001) reduced in the common femoral artery and in the superficial femoral artery. Postoperatively the blood-flow increased significantly (p < 0.001) in patients with an open bypass. This increase could still be demonstrated up to one year after bypass surgery. Surprisingly, a significant (p < 0.01) postoperative rise in blood-flow was also observed in the non-operated leg. Doppler pressure, tcPO2-values (calf) in the operated leg and walking distance increased significantly (p < 0.001). The MAVISR as a noninvasive procedure allows to check the further development of the bypass-function independently of subjective influences, because quantitative changes in blood-flow are documented.

Adult↗
PubMed1994

[The effectiveness of standardized exercise training in intermittent claudication].

In stage II peripheral arterial occlusive disease (PAOD) physical training is generally the therapy of choice if no reopening procedures are indicated. The aim of this pilot study was to ascertain the increase in claudication distance due to the exclusive implementation of an intensive exercise programme under standardized conditions, for a planned double blind placebo controlled study regarding the efficacy of pharmacotherapy in addition to physical training. 23 in-patients (median age 62 years) with an absolute claudication distance on treadmill of between 50 m and 200 m (12% inclination, 3 km/h walking speed) participated 5 days a week in the following intensive standardized physical training programme: in the morning and afternoon supervised gymnastics for about 30 minutes, followed by 2 cycles of treadmill exercise each amounting to 66% of the absolute claudication distance. After a training programme of 4 weeks the mean initial claudication distance rose significantly from 83 m to 134 m (61%), as did the mean absolute claudication distance from 127 m to 222 m (75%). If an increase in claudication distance of at least 60% is taken as criterion of efficacy, 48% of the patients can be defined as responders. After completion of personal inquiries 62% of the patients were willing to participate in a similar training programme again.

Exercise Test↗
PubMed1992

[Risks and benefits of thrombendarterectomy in bilateral internal carotid artery stenosis].

Among the patients who were operated for cerebrovascular insufficiency, one third suffered from bilateral stenoses of the internal carotid artery. In a retrospective analysis of 47 patients who were operated in consecution and of 28 patients who refused operation and were treated conservatively, the outcome was compared to cases with a one-sided stenosis. 31 patients were operated on one side and 16 on both sides. 28 of the surgically treated cases were followed up for an average of 32 months. The morbidity of 3.2% of the bilateral cases was twice as high as that of the unilateral cases. A permanent neurological deficit was observed in 2 patients after reconstruction of the asymptomatic but higher grading stenosis, but in none of the 18 cases after reconstruction of the symptomatic side although the stenosis of the other side was not removed. Patients with bilateral stenoses of the internal carotid artery should therefore be operated first on the symptomatic side. The frequently concomitant coronary artery disease of these patients prevents an improvement of the survival period in the group of bilaterally operated patients. The success in these cases concerns only the quality of life. The risk of a subsequent stroke in the 28 not operated cases with bilateral stenoses was 14.6% and therefore much higher than in the group of operated patients. Increase of the stenoses during the observation period is a prognostically unfavorable sign. Low dose treatment with platelet aggregation inhibitors (less than 500 mg ASS) increased the risk of an apoplectic insult.

Carotid Artery, Internal↗
PubMed1991

[The value of 31 P nuclear magnetic resonance spectroscopy in follow up of Fontaine stage IIb peripheral arterial occlusive disease].

The method of nuclear magnetic resonance (NMR) spectroscopy compared to the parameters absolute-, pain-free walking distance and ankle/arm coefficient in Doppler pressure was used for observation of patients with peripheral arterial occlusive disease stage IIb according to Fontaine. While the classic parameters (walking distances, ankle/arm coefficient) described a homogenous group, NMR-spectroscopy parameters showed marked inter- and intraindividual variations during exercise. Further studies on high magnetic power fields, exercise patterns and muscle recreation analysis have to be carried out to develop a reliable system of non invasive muscle energy monitoring in vascular diseases.

Aged↗