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Biomedical subjects

C Ranke

Publications and source records attributed to C Ranke.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Dose-dependent side effects of acetylsalicylic acid therapy. Results of a prospective randomized clinical study in patients with peripheral arterial occlusive disease].

BACKGROUND AND METHODS: In 359 patients with peripheral arterial occlusive disease who had undergone percutaneous transluminal angioplasty (PTA), a randomized double-blind, controlled clinical study was done to investigate the tolerability of acetyl salicylic acid (ASA) given for reocclusion prophylaxis. A comparison was made between a conventional daily dose of 900 mg ASA and a dose of 50 mg ASA. RESULTS: Within an observation period of one year following PTA, 35 patients (20%) in the 900 mg group, and 32 patients (17%) in the 50 mg group left the trial because of side effects (p = NS). Under the higher dose, however, severe gastrointestinal side effects (ulcer, haemorrhagic gastritis requiring transfusion) were significantly more common (nine patients delta 5.1% vs two patients delta 1.1%, respectively; p = 0.03). Overall, 107 patients (30%) reported subjective side effects such as upper abdominal pain, a sensation of fullness or nausea during the course of the trial. 62 of these patients were from the 900 mg group (35%) as compared with 45 patients (24%) in the 50 mg group (p = 0.02). Self-scoring of epigastric pain on the basis of a visual analogue scale revealed a score of 1.3 (95% confidence interval 0.9 to 1.6) in the 900 mg group and 0.8 (95% confidence interval 0.6 to 1.0) in the 50 mg group. The subjective pain intensity showed a uniform time course for all three types of symptom, with a maximum after three months. CONCLUSION: Our results confirm the superior tolerability of the lower dose, in particular in elderly patients. For long-term treatment, the smallest possible effective dose should be chosen.

Aged↗
PubMed1993

Dose-dependent effect of aspirin on carotid atherosclerosis.

BACKGROUND: Antiplatelet treatment with aspirin is well established as secondary prophylaxis after a transient ischemic attack or minor ischemic stroke, but the effect of aspirin treatment on the course of carotid atherosclerosis is unknown. We investigated the effect of aspirin on the initial stages of carotid atherosclerosis. METHODS AND RESULTS: Patients were recruited from a prospective, randomized, double-blind clinical trial to compare two doses of aspirin (900 mg versus 50 mg daily) with regard to restenoses after lower limb angioplasty. Of the 383 patients admitted to the angioplasty trial, 27 patients with 104 small carotid atheroma (< 50% lumen narrowing) were examined at entry and after 1 year of aspirin treatment with the use of a high-resolution ultrasound duplex system. Disease progression and regression were defined by a change of maximal plaque area (as measured by longitudinal ultrasound sections) of more than 2 SDs of the method. The change in plaque area was significantly different for the treatment groups: Average plaque size remained unchanged after treatment with 900 mg aspirin daily but increased markedly after treatment with 50 mg aspirin daily (p = 0.011). There were significantly more lesions in the 50-mg group showing progression than in the 900-mg group (23 plaques [47%] versus 13 plaques [24%], p = 0.025). Ultrasonic disappearance of a lesion was observed only in the 900-mg group in nine cases (seven soft plaques and two ulcerative plaques, p = 0.018). The six patients on 50 mg aspirin who continued smoking during the study showed significantly more progression compared with the seven nonsmokers in the 50-mg group (17 plaques [59%] versus six plaques [30%], p = 0.038). CONCLUSIONS: The results of our study indicate that aspirin treatment slows carotid plaque growth in a dose-dependent fashion, with a dose of 900 mg daily more efficient than 50 mg daily.

Aspirin↗
PubMed1992

Duplex scanning of the peripheral arteries: correlation of the peak velocity ratio with angiographic diameter reduction.

The correlation of the peak systolic velocity (PSV) and the peak velocity ratio (PVR, calculated as intrastenotic PSV divided by proximally recorded PSV) with percent diameter reduction was studied in 62 patients with peripheral arterial occlusive disease. PSV values correlated well with angiographic diameter reduction (r = 0.81, n = 106 stenoses), but due to large variability the sensitivity and specificity in the detection of greater than 50% stenoses were only 66% and 80% (for a cutoff value of 180 cm/s). The PVR showed less interindividual variability and exhibited a strong correlation with percent diameter reduction (r = 0.93,n = 106 stenoses). A 2.4 fold increase of the peak systolic velocity values with respect to the proximal site (i.e., PVR = 2.4) or more indicated a more than 50% stenosis with a sensitivity of 87% and a specificity of 94%. Figures for PVR are provided to quantitate the degree of stenoses in the 50-99% range. Calculation of PVR may normalize for patient variation and allow noninvasive quantification of lumen narrowing with high sensitivity and specificity.

Arterial Occlusive Diseases↗
PubMed1991

[Hemodynamic effects of intermittent intra-arterial infusion treatment with prostaglandin E1 in peripheral arterial occlusive disease].

14 femoral arteries of twelve patients with peripheral arterial occlusive disease (Fontaine stage II: n = 4, stage III/IV: n = 10) were investigated before, immediately after a series of 26 (ten to 52) intraarterial infusions with prostaglandin E1, and 30 weeks later. Using combined B-mode and pulsed Doppler (duplex) ultrasound blood flow measurements were performed in the common femoral, the superficial femoral, and the deep femoral artery. There was a significant decrease of resting blood flow volume in the common femoral artery after therapy (418.5----362.2 [p less than 0.01]----324.5 ml/min [p less than 0.05]) in the group of patients treated successfully. The peak flow (maximum value of blood flow volume during reactive hyperaemia) in the common femoral artery increased significantly after therapy (597.3----779.1 [p less than 0.05]----843.7 ml/min). The increase of peak flow correlated well with clinical improvement. Other parameters (blood flow velocities, pulse rise time, pulse decrease time, pulsatility index) changed without correlation to clinical outcome. The increase of peak flow after therapy might be caused by an improved collateral circulation, and the decrease of resting blood flow might be due to metabolic effects of prostaglandin E1 (improved oxygen utilization).

Aged↗
PubMed1991

[The instrumental diagnosis of arterial diseases especially of arterial occlusive diseases].

Ultrasound Doppler sonography is the most important tool in the assessment of peripheral arterial occlusive disease. The determination of systolic ankle pressure gives an useful overview of the degree of the disease. In a normotensive patient with a systolic blood pressure of 140 mm Hg systolic ankle pressures between 100 and 140 mm Hg are present when the occlusive disease is in the stage of good compensation. Severe claudication will appear with ankle pressures between 70 and 95 mm Hg, lower values are indicating a critical limb ischaemia. Treadmill exercise is helpful for documentation of painfree and maximal walking distances. When a patient is suggested to be treated by percutaneous transluminal angioplasty or bypass surgery a duplex sonography or angiography is mandatory. In evaluating the Raynaud's phenomenon under the noninvasive techniques capillaroscopy of the nailfold is a useful tool. The diagnosis of thromboangiitis obliterans is usually established by clinical criterias. The radiographic findings may give important hints. In many cases of acute arterial occlusions angiography is necessary for finding the optimal therapy. The aneurysm of the abdominal aorta will be evaluated by ultrasound and computer tomography.

Angiography↗
PubMed1990

[Duplex sonography: accuracy, reproducibility and possibilities for error. Checking quantitative flow measurements against an in vitro model].

Using a pulsatile model of tubes, duplex-sonographic measurements of flow were compared with actual flow. The correlation coefficient between actual and duplex-sonographically obtained flow was 0.975, mean percentage deviation being -18.1% (P less than 0.0001). The obvious scatter (margin of error -69.2 to +50%) is to be explained by the simulation closely imitating a real situation: the transducer was hand-held and tubes were placed in muscle or fat tissue. Accuracy was increased by multiple measurements, especially when taking into account only the maximal value of any series of measurements. Vessel diameter was easy to measure accurately (mean error less than 0.01% [-18.7 to +9.4%]). Repeated measurements of flow velocity had only a small scatter (coefficient of variance 0.064). In muscle or fat the Doppler signal was attenuated and the error the greater the deeper the level at which measurements were made. Low flow (common in patients with obstructive vascular disease) can also cause faulty results.

Analysis of Variance↗
PubMed1990

[Phantom studies of the value of color-coded Doppler sonography in arterial occlusive disease of the lower extremities].

A new practically orientated phantom for evaluating Doppler Duplex equipment was developed and used to determine the possibilities and limits of color coded Doppler Sonography (Angiodynography) in the diagnosis of arterial occlusive disease of the lower extremity. The problems that may occur in quantifying flow in these arteries are analyzed. The influence of superimposed slices of various soft-tissues on flow quantification, on the spectral waves and on color coded visualisation of the arteries and the possibility to compensate those changes by the use of sonographic contrast agents are discussed.

Arterial Occlusive Diseases↗
PubMed1990

[Duplex ultrasound measurement of morphologic parameters before and following repeated puncture of the femoral artery for intermittent infusion therapy].

In order to estimate morphologic changes of the femoral artery after an intermittent intraarterial infusion therapy duplex scanning was performed before therapy, immediately after a series of 26 (10 to 52) infusions, and 30 weeks after hospital discharge. Minimum and maximum values of internal and external vessel diameter and thickness of wall were estimated in the common femoral artery, superficial femoral artery, and deep femoral artery. The external diameter values and the thickness of wall increased significantly after therapy. After 30 weeks these values decreased but did not reach the initial values.

Alprostadil↗
PubMed1989

[Portal hypertension and chronic arsenic exposure. A differential diagnostic challenge].

We are reporting on a 62 year old female patient with portal hypertension (splenomegaly, esophageal varicosis) without signs of liver cirrhosis, who was hospitalized for sclerotherapy of her esophageal varices. Physical examination showed up palmar- and plantar hyperkeratosis and Morbus Bowen or basalioma-like skin lesions++. Anamnestic evaluation revealed, that the patient's psoriasis had been treated with arsenic for many years. This kind of treatment may have induced intraluminal proliferation and obliteration of the portal vein's endothelium, thus being the etiologic factor responsible for noncirrhotic portal hypertension in this patient.

Arsenates↗