First observation of the exchange of transverse and longitudinal emittances.

An experimental program to demonstrate a novel phase-space manipulation in which the horizontal and longitudinal emittances of a particle beam are exchanged has been completed at the Fermilab A0 Photoinjector. A new beam line, consisting of a TM(110) deflecting mode cavity flanked by two horizontally dispersive doglegs has been installed. We report on the first direct observation of transverse and longitudinal emittance exchange.

Kryotechnik in der Varicenchirurgie. Ein neues Konzept zur Reduktion des Operationstraumas.

Cryophlebectomy, a more recent technique in varicose veins surgery, was evaluated in comparision with conventional techniques. Group IA: Microphlebectomy, invaginative stripping of the long saphenous vein, tourniquet, n = 90; group IB: only microphlebektomie and tourniquet, n = 72. Group IIA: Cryostripping of the long saphenous vein in combination with cryosurgical distal avulsion of varicosities and microphlebectomy, n = 112; gr. IIB: only cryosurgical distal avulsion of varicosities and microphlebectomy. Data were compared regarding duration of operation and hospitalisation and cosmetic outcome. Hospital stay (gr. IA: 9.1 +/- 5.1 d vs. gr. IIA: 6.1 +/- 2.1 d, gr. IB: 5.5 +/- 2.3 d vs. gr. IIB: 4.8 +/- 2.5 d) and duration of operation (gr. IA: 113.6 +/- 35 min vs. gr. IIA: 67 +/- 21.3 min, gr. IB: 74.4 +/- 35.3 min vs. gr. IIB: 53.3 +/- 15.5 min) were found to be significantly shorter and cosmetic result and postoperative discomforts improved in the cryophlebectomy-group. We conclude that the use of this combination of methods reduces invasivity, rises the patient's well-being and helps in cost-reduction.

Sympathetic neuronal activity in diabetic and non-diabetic subjects with peripheral arterial occlusive disease.

Despite the vasoconstrictory influence of the alpha-adrenergic system on the peripheral blood circulation the results of the sympathectomy were not satisfying in the therapy of peripheral arterial occlusive disease (PAOD). The aim of the present investigation was to clarify the pathophysiologic mechanisms of this clinical observation. Free and sulfoconjugated catecholamines were determined in the femoral artery, vein, and cubital vein of 19 healthy controls, 21 non-diabetic patients with PAOD stage II, 8 non-diabetic (PAOD IV) and 20 diabetic patients (D IV) with PAOD stage IV. In comparison with controls and group PAOD II an increased sympathoneuronal tone in group PAOD IV was evident at rest. Sympathetic activation was not restricted to the affected limb, since femoral and cubital venous norepinephrine levels were not different and plasma epinephrine fractional extraction (PEFE) was not altered by angiopathy. The lower sympathoneuronal activation in the group D IV may be attributed to an impaired pain perception or a reduced dopamine beta-hydroxylase activity indicated by a lower ratio of norepinephrine to dopamine. The failing long-term efficacy of lumbar sympathectomy in critical arterial limb disease may be explained by marked spontaneous sympathicolysis in diabetics, whereas in non-diabetics with sympathetic activation other mechanisms like development of unilateral Mönckeberg sclerosis, progression of proximal arterial occlusion or induction of steal effects have to be discussed.

Influence of peripheral arterial occlusive disease on muscular metabolism. Part 1: Changes in lactate, ammonia, and hypoxanthine concentration in femoral blood.

The concentrations of lactate, ammonia and hypoxanthine were determined in blood from the femoral artery, femoral vein and cubital vein under resting conditions in 23 patients with stage II, 10 patients and 20 diabetics with stage IV peripheral arterial occlusive disease (PAOD) and in 19 healthy subjects. The metabolite concentrations were also measured immediately and 20 min after calf exercise in the patients with stage II PAOD and in the controls. At rest, there was a negative arteriovenous difference in femoral lactate level and a positive arteriovenous difference in the ammonia level in all groups. After exercise to the claudication limit, the femoral venous concentration and arteriovenous difference for lactate increased in the patient group significantly higher than in the controls, who were exercised three times as heavily. Furthermore, there was a significant rise in femoral venous ammonia concentration with inversion of the arteriovenous difference into the negative range and an increase in femoral venous hypoxanthine concentration only in the patients with PAOD and not in the controls. A significant correlation was found between the exercise-induced increases in lactate and ammonia. The results indicate activation of the purine nucleotide cycle in the muscles of limbs with impaired circulation, even for a short duration of load. This can be explained by activation of the AMP-deaminase in type I and type IIa muscle fibres by anoxaemia. The purine nucleotide cycle has an emergency metabolic function in ischaemia to maintain muscle contractility. Ammonia determination in femoral blood permits, in association with lactate and hypoxanthine determination, a precise quantitative assessment of the metabolic effects of PAOD.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of peripheral arterial occlusive disease on muscular metabolism. Part 2: Changes in pyruvate, alanine, and urea concentration in femoral blood.

The metabolites pyruvate, alanine and urea were determined under resting conditions in blood from the femoral artery, femoral vein and cubital vein of 23 patients with stage II, 10 patients and 20 diabetics with stage IV PAOD as well as 19 healthy volunteers. Measurements were also carried out immediately and 20 min after ergometric calf exercise in the patients with stage II PAOD and the controls. In both patient groups with stage IV PAOD, there were lower arterial and venous alanine levels and higher urea concentrations at rest than in patients with adequate resting circulation, which is evidence for increased hepatic alanine extraction. After exercise, a significantly higher increase in the arteriovenous difference of pyruvate concentration was to be found in the patient group with stage II PAOD than in the control group. Moreover, there was a significant increase in femoral venous concentration and a rise in the arteriovenous difference of alanine, indicating muscular release, only in the PAOD patients and not in the volunteers in spite of a three times higher exercise load. The exercise-induced rise in femoral venous alanine correlated closely with those of pyruvate and ammonia. Alanine formation fulfills the function of a non-toxic carrier of muscularly produced amino groups and represents in PAOD a compensating mechanism that delays the limitation of muscular contractility. Alanine determination, especially in association with an exercise test, appears to be suitable for assessing the extent of anaerobic energy production in muscles of limbs affected by PAOD.