Anomalous coulomb drag in electron-hole bilayers.

We report Coulomb drag measurements on GaAs-AlGaAs electron-hole bilayers. The two layers are separated by a 10 or 25 nm barrier. Below T approximately 1 K we find two features that a Fermi-liquid picture cannot explain. First, the drag on the hole layer shows an upturn, which may be followed by a downturn. Second, the effect is either absent or much weaker in the electron layer, even though the measurements are within the linear response regime. Correlated phases have been anticipated in these, but surprisingly, the experimental results appear to contradict Onsager's reciprocity theorem.

[Synovialectomy of the metacarpophalangeal joints with reconstruction of the radial collateral ligaments -- long-term results in patients suffering from rheumatoid arthritis]. / Synovialektomie der Fingergrundgelenke mit Rekonstruktion der radialen Seitenbänder -- Langzeitergebnisse bei Patienten mit rheumatoider Arthritis.

Rheumatoid arthritis may lead to destruction of MP joints and severe alteration of grip and other hand functions. Due to the improvement in medical treatment, synovialectomy of the MP joints is necessary only in late stages. Most centres prefer alloarthroplasties in late stages, as erosion of the cartilage and loosening of the ligaments have already led to destruction of the MP joints and destabilization of grip functions. We do not use alloarthroplasties as our first choice, but pay special attention to the reconstruction of the radial collateral ligaments. Therefore, the elongated radial ligaments are detached near their origin after synovialectomy of the dorsal aspects of the MP joint. After detachment of the radial ligament, the palmar aspects can be cleaned easily. The radial collateral ligaments are shortened and reinserted dorsally to gain slight supination. This study shows the long-term results of our patients. In a period of ten years, 74 patients (87 hands, 347 MP joints) were reexamined after an average of 55 months postoperatively. The loss of active motion was 18 degrees and ulnar deviation could be reduced from 25 degrees to 7 degrees. 71 % of the joints showed stable ligaments, 14 % loose, 15 % unstable ligaments. We saw recurrence of synovialitis in 18 % (10 % mild, 7 % significant, 1 % severe). Radiographs showed amelioration in 14 % of cases and deterioration in 39 %. There was no correlation between active range of motion, synovialitis and X-rays. Results were constant when compared with exams before and five years after surgery. Our investigation shows good and stable results, which can be easily compared with the outcome of other studies after alloarthroplasty. The main advantage in our procedure is the easy access to all parts of the MP joint, which allows complete synovialectomy. By shortening and reinserting the elongated radial collateral ligament, we achieve a mild supination and amelioration of grip strength. The results are constant in long terms. In case of recurrent synovialitis or loosening of the ligaments any other type of auto- and alloarthroplasties can still be performed.

[Plastic reconstructive therapy for postoncologic defect wounds in the pelvis]. / Plastisch-rekonstruktive Therapie bei postonkologischen Defekten im Bereich der Beckenregion.

Surgical or multimodal therapy of tumors of the pelvis often results in complex defects leading to functional and structural deficits, with the inability to sit or even lie without pain. Multimodal therapy may cause induration of soft tissues and muscles, obstruction of the small bowel, fistulas, and infected cavities. Early soft tissue reconstruction, preferably with myocutaneous flaps, reduces postoperative problems in these patients by early coverage of defects, closure of cavities, and prevention of wound healing complications and therefore allows earlier rehabilitation.

[Outpatient hand surgery--possibilities and limitations]. / Ambulante und kurzzeitstationäre Handchirurgie. Möglichkeiten und Grenzen.

On January 1st 2004, a new contract between the government, health insurance services, and hospitals was inaugurated in Germany. The aim of the contract is to decrease costs for surgical therapies by abolishing or at least minimizing hospitalization of patients. Hand surgery is widely affected by the new contract, since a very large part of surgical therapies for the hand was declared to be compulsory outdoor and another major part to be preferable outdoor. The surgeon may decide whether a patient needs inpatient or outpatient treatment but has to justify his decision. Hospitals and surgical clinics are both allowed to offer outpatient hand surgery and get the same payment under the same regulations. For most hospitals, structural changes will be necessary to offer outpatient surgery without financial loss. In our experience a personal and regular contact between patient and surgeon is most necessary for the best surgical result. Many of the compulsory outpatient operations in hand surgery can be done sufficiently and at high standard. This may not be the case for the second group to be handled not compulsory outdoor. The new contract allows hospitals to offer postoperative care for only 14 days, whereas many specific hand surgical procedures will need the surgeon's control and care for a much longer time. On the other hand, clinics and general practitioners have strict limitations for the prescription of hand therapies. We believe that the quality of hand surgery is highly dependent on sufficient postoperative treatment. If the postoperative care is neglected or restricted, secondary costs such as sick leave will increase.

[STT-arthrodesis versus radial shortening osteotomy for Kienböck's disease]. / STT-Arthrodese versus Verkürzungsosteotomie des Radius bei Lunatumnekrosen Stadium 3 und 4 nach Decoulx.

Thirteen patients treated by STT fusion for Kienböck's disease (five stage 3 a, seven stage 3 b, and one stage 4) and 36 patients treated by radial shortening osteotomy (20 stage 3 a, 16 stage 3 b) were checked after 26 and 83 months average. The active range of motion and grip strength were compared by means of the Cooney score, discomfort and pain by the DASH score. X-rays were compared for the bone structure of the lunate and development or progress of carpal collapse. After STT fusion the active over-all range of motion decreased by about 10 degrees, grip strength improved slightly by approximately 10 %, pain and discomfort improved well. Consolidation of the lunate was seen in ten of thirteen patients. The patients treated with radial shortening osteotomy could all improve their range of motion by about 10 degrees and the grip strength by about 20 %, whereas discomfort and pain persisted in some cases. X-rays showed consolidation of the lunate in cases of eleven patients stage 3 a and twelve patients stage 3 b. Radiological results were not always corresponding to the clinical results and the patients' subjective estimation. A group of eight patients could be followed up after more than ten years; all of them showed excellent results. This may indicate the long-term result for those patients who benefit from radius shortening with early pain relief. We recommend both procedures for stage 3 a and 3 b and suggest to decide from case to case, according to the needs of the patient. Ulna minus variance or the patient's wish to restore full active range of motion indicate radial shortening.

Chest radiograph abnormalities associated with tuberculosis: reproducibility and yield of active cases.

SETTING: Tertiary care referral centre specialising in respiratory diseases. OBJECTIVES: Chest radiography is a major screening and diagnostic tool for tuberculosis (TB). We evaluated the reproducibility of a radiographic classification system for screening for active TB of immigration applicants to Canada. We also evaluated the validity of this classification system for detection of prevalent active TB among the screened applicants, as well as tuberculin-positive close contacts and symptomatic patients. METHODS: Reproducibility was assessed by re-reading a randomly selected 10% sample of screening chest films. Validity was estimated from the final clinical and microbiologic diagnosis of patients undergoing detailed clinical evaluation. RESULTS: Inter-reader agreement using five broad categories was moderate (kappas of 0.44-0.56), while intra-reader agreement was substantial (kappas of 0.59-0.72). After adjustment for age and patient group, the adjusted odds of active tuberculosis, relative to normal or minor findings or granulomas, for fibronodular changes was 10.2 (95% confidence interval [CI] 3.2-33), for mass or pleural effusion it was 11.6 (95%CI 3.6-37), and for parenchymal infiltrate it was 46.1 (95%CI 18-117). Among tuberculin-positive close contacts, the probability of active tuberculosis was more than 50% if the radiographs showed any mass, pleural disease, or parenchymal infiltrates. CONCLUSION: A simple classification of TB-related chest radiographic abnormalities into five broad categories had moderate to substantial reproducibility of readings, with reasonable validity.

[Functional results of medio-carpal partial arthrodesis with excision of the scaphoid]. / Funktionelle Ergebnisse nach mediokarpaler Teilarthrodese mit Exstirpation des Skaphoids.

Midcarpal arthrodesis with excision of the scaphoid for the treatment of painful carpal collapse has been performed in our hospital since 1993. A clinical study was carried out to evaluate the results and determine special factors, which might influence the results. 26 out of 29 patients operated until 1999 were reexamined after an average follow-up of 27 months. The results were evaluated according to the Mayo-modified wrist score. The DASH score and the pain-disability index (PDI) were calculated postoperatively. Standard X-rays of the wrist were analyzed for alteration of the radio-lunate joint space, the position of the lunate with respect to the radius and the correction of the carpal height as calculated by the Youm index. Carpal collapse was due to scapholunate pathology (SLAC) in 12 cases, long-standing scaphoid nonunion (SNAC) in ten cases, perilunate dislocation, which was only simply reduced, in three cases, and calcium pyrophosphate deposition disease in two cases. The Mayo-modified wrist score improved significantly from an average of 46 points before to 76 points after surgery. The DASH score postoperatively was 22, the PDI 13. All patients reported improvement of their situation after the operation, eight were completely free of pain. The average range of motion from extension to flexion was 64 degrees, which was almost identical to the average preoperative value. The average grip strength before surgery was 24 kg, after surgery 34 kg. There was a correlation between the position of the lunate to the radius in the lateral X-ray and the range of extension. If the lunate was positioned correctly, wrist extension was significantly better. The radiolunate joint space was maintained during the period of observation with only two exceptions. Apparent subchondral sclerosis was seen in most of the cases. It was not possible to restore carpal height completely. Some results after perilunate luxations and one case of calcium pyrophosphate deposition disease were unsatisfactory. Midcarpal arthrodesis with scaphoid excision is a reliable method for treating radioscaphoid arthrosis caused by carpal collapse. Correction of the hyperextended position of the lunate is important to obtain optimum results. In our hospital, a wrist arthrodesis is only rarely performed nowadays, except in the rheumatoid patient.

[Functional results following surgical management of palmar fibrocartilagenous injuries]. / Funktionelle Ergebnisse nach operativer Versorgung von Verletzungen der Fibrocartilago palmaris.

Lesions of the palmar plate of PIP-joints were treated surgically during the past ten years in cases of dislocation of the PIP-joint, lesions to the collateral ligaments, or lesions to the extensor apparatus (according to types 3, 4 and 5 of Hintringer's classification). A followup of 97 patients showed nearly 90% good results in cases of ligamentous injuries, comparable to results after conservative treatment in other centres. In cases of fracture dislocation and open injuries, results were only fair. Conservative treatment is now preferred in most cases.

[Color-coded duplex ultrasound as a screening method in trauma surgery]. / Farbkodierte Duplexsonographie als Screening-Methode in der Unfallchirurgie.

Deep vein thrombosis with consecutive pulmonary embolism is one of the most important complications for trauma patients. At the University Hospital of Mainz, Department of Traumatology, colour duplex ultrasound is used as screening method in trauma patients. Fractures of thoracic and lumbal spinal bones, pelvis, hip and lower extremities, endoprosthesis of hip and knee joints and longer immobilisation are considered as special risk for the genesis of deep vein thrombosis. Out of 326 patients investigated with colour duplex ultrasound, 24 patients suffered from unknown deep vein thrombosis, 8 developing pulmonary embolism. We recommend colour duplex sonography on day 10, after the third week, and after longer immobilisation. Colour duplex sonography provides an easy performable and noninvasive method for screening evaluation of deep vein thrombosis in trauma patients.

[Ulnar groove syndrome following elbow injuries]. / Sulcus ulnaris Syndrom nach Traumen im Ellenbogenbereich.

For a large scaled test 52 patients with anterior transposition of the ulnar nerve and 62 patients with elbow injuries were examined by questionnaire, physical examination and electroneurography. In conformity with existing literature 24 patients out of 52 suffering from cubital tunnel syndrome had an elbow trauma previously. To our great surprise in seven patients out of 46 with elbow injuries a cubital tunnel syndrome could be found for the first time. The cubital tunnel syndrome appears to be a frequent complication of elbow injuries. Besides the well known fractures of the medial epicondyle and pericondylar fractures leading to cubital tunnel syndrome, in our study fractures of the head of the radius and processus coronoideus were found quite often. Patients having typical anamnesis and complaints should be checked by electroneurography in order to permit a quick operation and to prevent incurable damages of the nerve. The diagnosis leading to operation of the elbow should however be made with greatest care. In case the operation is unavoidable, the ulnar nerve should be thoroughly checked and anterior transposition should be carried out.

[Clinical and neurologic results after surgical management of the cubital tunnel syndrome]. / Klinische und neurologische Ergebnisse nach operativer Versorgung des Ulnarisrinnensyndroms.

Fourty-two patients suffering from cubital tunnel syndrome were reexamined after anterior subcutaneous transposition of the ulnar nerve. In 25 patients, electrophysiological results could be compared pre- and postoperatively. Only few patients recovered completely, however, electrophysiological results showed an improvement in most of the patients. Sensory velocity proved to be more sensitive than motor velocity. We advice patients for early operation to avoid aggravation of symptoms, even if remission will be incomplete.

[Development of thromboses in hip joint endoprostheses. A study with color-coded duplex ultrasound]. / Zur Entstehung der Thrombosen in der Hüftgelenkendoprothetik. Eine Studie mit der farbcodierten Duplexsonographie.

After 102 hip replacements in a surgical technique that avoids bone-marrow intravasation as much as possible, color-coded duplex sonography revealed thigh thrombi in only 4 cases without any signs of thrombosis. This rate is lower than that found in all other comparable studies. The investigations stress the role of bone-marrow intravasation in the induction of deep vein thrombosis in hip replacement. With an optimal surgical technique, thigh thrombi can be greatly reduced in hip replacements, which have a higher rate than all other operations.