Two-point phase correlations of a one-dimensional bosonic Josephson junction.

We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows us to measure the coupling strength and temperature and hence a full characterization of the system.

[Therapeutic ultrasound for the recanalization of peripheral vascular occlusions]. / Einsatz des therapeutischen Ultraschalls zur Rekanalisation peripherer Gefässverschlüsse.

Since the development of percutaneous transluminal angioplasty several techniques such as laser or atherectomy devices have been developed for recanalization of peripheral arterial occlusions. In a first clinical study we investigated if also the application of intravascular ultrasound can be useful for recanalization of occluded peripheral arteries. We applied an ultrasound angioplasty device (ACOLYSIS, ANGIOSONICS, USA) in a percutaneous approach in 8 patients with peripheral arterial occlusions (7 femoro-popliteal segments, 1 external iliac artery-occlusion). All patients suffered from severe leg ischemia due to subacute thrombotic occlusions. The ultrasound transmitter was introduced and advanced under fluoroscopic guidance to the site of the lesion. After activation the ultrasound transmitter was slowly advanced into the occlusion easily creating a channel within the occlusive material. Depending on the length of the occlusion (5-16 cm) treatment times ranged from 120-480 s. To further reduce the mass of the occlusive material an aspiration thrombectomy was performed in all cases leading to a complete recanalization in 6 cases. In 2 cases a remaining stenosis was successfully dilated. Intra-vascular ultrasonic devices can be useful for recanalization of occluded peripheral arteries. With the use of high-energy ultrasound a selective injury of the occlusive material can be induced without damaging the surrounding arterial wall. This selectivity is based on the differences in elasticity between the atherosclerotic plaque and the media layers. Especially if thrombolytic therapy of longer peripheral arterial occlusions fails or is contraindicated ultrasound angioplasty may be a new approach for recanalization.

[Dorsal capsular imbrication for dorsal instability of the distal radioulnar joint]. / Die dorsale Kapseldoppelung zur Therapie der dorsalen Instabilität des distalen Radioulnargelenks.

OBJECTIVE: To stabilize the distal radioulnar joint (DRUJ) by performing dorsal capsular imbrication in patients presenting with dorsal instability. The goal was to reduce pain and prevent the occurrence of posttraumatic arthrosis. INDICATIONS: Posttraumatic dorsal instability of the DRUJ with missing block while performing translational activities in the DRUJ or subluxation while actively rotating the forearm. Cases, in which other stabilizing techniques, such as, sutures of the triangular fibrocartilage complex failed. CONTRAINDICATIONS: DRUJ arthrosis, previous surgical interventions to the capsule area of the DRUJ, instabilities due to osseous reasons (malposition or pseudarthrosis) should already have been treated. SURGICAL TECHNIQUE: Dorsal approach and opening of the 5th extensor compartment to expose the dorsal joint capsule. A longitudinal division of the capsule was performed and sufficient tissue on the radial and ulnar border was retained to ensure a solid suture technique. Then 2 U-shaped sutures using FiberWire suture material were made. Correction of the malposition and repositioning the forearm into supination. Tightening of the prepared capsule sutures and closing of the retinaculum with a resorbable suture. POSTOPERATIVE MANAGEMENT: Patients wore a long-arm cast with the forearm being in supination for a period of 4 weeks. Following cast removal, patients wore a forearm splint for a period of 4 weeks to limit forearm pronation/supination at 45°. Full load on the wrist was allowed after 12 weeks. RESULTS: The subjective and functional outcomes of 20 patients having received capsular imbrication using this technique were good and entailed no significant complications. The postoperative DASH was 15.8 points. Of the 20 patients, 17 patients (85%) had a reduction of pain. Symptoms of DRUJ instability could be reduced in 18 patients (90%). Pronation/supination of the wrist was not restricted postoperatively.

[Endoscopic decompression of the ulnar nerve in the cubital tunnel syndrome: about 55 patients]. / Décompression endoscopique du nerf ulnaire dans le syndrome cubital au coude: à propos de 55 patients.

INTRODUCTION: Sulcus ulnaris syndrome is the second most common neurocompression syndrome in the upper limb after carpal tunnel syndrome. Its severity can be appreciated by the Dellon Classification. We present our experience and results after endoscopic decompression. PATIENTS AND METHODS: A retrospective chart review of 55 patients operated over a 3-year period was performed. The patients, 37 men and 18 women, had an average age of 54 years (range: 27-82 years) at the time of surgery. The clinical diagnostic was always confirmed by a neurophysiological examination of the nerve conduction. According to the Dellon Classification, 11 patients had mild sulcus ulnaris syndrome, 31 had moderate and 13 had severe. The mean follow-up time was 21 months (range: 6-42 months). RESULTS: The sensibility was normalised in 85% of the patients. Compared to the contralateral non-operated side, the mean grip strength improved from 68 to 94% and the mean pinch grip from 72 to 95%. The rate of nerve luxation did not change (5.5%). According to the modified Bishop rating system, 38 patients (69%) had excellent, 13 patients (23.5%) good and four patients (7.5%) fair results. One haematoma necessitating a revision, a minimal lesion of the ulnar nerve with restitution ad integrum and a hypoesthesia of the elbow, occurred after surgery resulting in a complication rate of 5.5%. Ninety-eight percent of the patients responded that they would undergo the endoscopic procedure again if needed. CONCLUSION: Endoscopic decompression of the ulnar nerve in sulcus ulnaris syndrome is very well appreciated by patients and also provides promising clinical results.

Interventional therapy of vascular complications caused by the hemostatic puncture closure device angio-seal.

The hemostatic puncture closure device Angio-Seal is a quick, safe, and easy-to-use system, allowing rapid sealing of the vascular access site following coronary angiography and interventional procedures. It is advantageous for patients in whom early mobilization is desired and may therefore decrease hospital costs. Despite the documented low complication rate, there are some specific problems. Reporting on five cases, we describe problems in diagnosis and possible interventional therapy of Angio-Seal-associated complications such as stenosis, occlusion, or peripheral embolism. Our experience led to the concept of precise diagnosis in any patient with leg symptoms and early interventional treatment with the aim of complete removal of the intra-arterial parts of the Angio-Seal device. Any delay in diagnosis and treatment increases the risk of additional thrombotic occlusion. Spontaneous dissolution of the Angio-Seal sponge limits interventional possibilities of complete removal. Cathet. Cardiovasc. Intervent. 49:142-147, 2000.

New technique for increasing retention of arginine on an anion-exchange column.

A method is described for enhancing retention of arginine on a pellicular anion-exchange column. Arginine exhibits adjustable increases of retention time that are dependent on the acidity of standard or sample matrix. This effect is based on interactions of the protonated form of arginine with the residual cation-exchange groups on the core beads of pellicular particles. The relative magnitude of retention time shift of arginine is evaluated for identical concentrations of hydrochloric, sulfuric, and perchloric acids. Although the direct addition of acid is very effective in influencing the retention of arginine, it affects peak shapes and retention of other peaks in the chromatographic separation. The new technique-acid coinjection-achieves a similar retention enhancement for arginine with only a minimal effect on the rest of the separation. Detection limits, reproducibility results, and calibration data are presented for the chromatography of amino acids with acid coinjection. Improved resolution of arginine is demonstrated with chromatograms of soybean hydrolysate and cell culture samples.

Simplified in-line sample preparation for amino acid analysis in carbohydrate containing samples.

This report describes a new, automated chromatographic procedure eliminating carbohydrates from amino acid samples prior to their analysis by anion-exchange chromatography and integrated amperometric detection. In the first step, a sample is brought onto a short cation-exchange column (trap column) in hydrogen form. Carbohydrates are passing through this column, while only amino acids are retained. Subsequently, the cation-exchange column, holding the amino acid fraction, is switched in-line with the gradient pump and separator column. The mobile phase used at the beginning of the separation (NaOH; pH 12.7) transfers amino acids from the trap column onto the anion-exchange column and the amino acid separation is completed without any interference by carbohydrates. All common amino acids are recovered following the carbohydrate removal step. The average value of their recovery is 88.1%. The calibration plots were tested between 12.5 and 500 pmol (amounts injected). The mean value of correlation coefficients of calibration plots was calculated as 0.99. The mean value of relative standard deviations from five replicates was 3.9%. The usefulness of the method is illustrated with two chromatograms of a carrot juice sample obtained before and after the in-line removal of carbohydrates.

[Difficulties in the detection of heparin-induced thrombocytopenia type II]. / Schwierigkeiten in der Erkennung der Heparin-induzierten Thrombozytopenie Typ II.

We report about a 29 year old female who developed right-sided leg vein thrombosis over three levels. Thrombectomy was attempted followed by intravenous anticoagulation with heparin. The platelet count dropped acutely from 176,000/microliter to 11,000/microliter after the sixth day. A lung perfusion-ventilation-scintigraphy suggested recent pulmonary embolism by lateral, predominantly right-sided perfusion deficits. ACT scan of the pelvic region showed rethrombosis of the right common iliac vein. The clinical suspicion of heparin-induced thrombocytopenia (HIT) type II was confirmed by a positive heparin-induced platelet aggregation test and the detection of antibodies by heparin-platelet factor 4-ELISA. The patient was treated with lepirudin at body-weight-adapted dose. After recovery of the platelet count to 102,000/microliter within seven days the treatment was changed to Orgaran after exclusion of immunologic cross reactivity. An overlapping oral anticoagulation with Marcoumar was initiated. Although HIT type II usually develops over a few days, acute thrombopenia can also occur. There is therefore no safe diagnostic interval permitting a timely detection.

The ADP release step of the smooth muscle cross-bridge cycle is not directly associated with force generation.

When smooth muscle myosin subfragment 1 (S1) is bound to actin filaments in vitro, the light chain domain tilts upon release of MgADP, producing a approximately 3.5-nm axial motion of the head-rod junction (Whittaker et al., 1995. Nature. 378:748-751). If this motion contributes significantly to the power stroke, rigor tension of smooth muscle should decrease substantially in response to cross-bridge binding of MgADP. To test this prediction, we monitored mechanical properties of permeabilized strips of chicken gizzard muscle in rigor and in the presence of MgADP. For comparison, we also tested psoas and soleus muscle fibers. Any residual bound ADP was minimized by incubation in Mg2+-free rigor solution containing 15 mM EDTA. The addition of 2 mM MgADP, while keeping ionic strength and free Mg2+ concentration constant, resulted in a slight increase in rigor tension in both gizzard and soleus muscles, but a decrease in psoas muscle. In-phase stiffness monitored during small (<0.1%) 500-Hz sinusoidal length oscillations decreased in all three muscle types when MgADP was added. The changes in force and stiffness with the addition of MgADP were similar at ionic strengths from 50 to 200 mM and were reversible. The results with gizzard muscle were similar after thiophosphorylation of the regulatory light chain of myosin. These results suggest that the axial motion of smooth muscle S1 bound to actin, upon dissociation of MgADP, is not associated with force generation. The difference between the present mechanical data and previous structural studies of smooth S1 may be explained if geometrical constraints of the intact contractile filament array alter the motions of the myosin heads.