Perturbation theory of a superconducting 0 - π impurity quantum phase transition.

A single-level quantum dot with Coulomb repulsion attached to two superconducting leads is studied via the perturbation expansion in the interaction strength. We use the Nambu formalism and the standard many-body diagrammatic representation of the impurity Green functions to formulate the Matsubara self-consistent perturbation expansion. We show that at zero temperature second order of the expansion in its spin-symmetric version yields a nearly perfect agreement with the numerically exact calculations for the position of the 0 - π phase boundary at which the Andreev bound states reach the Fermi energy as well as for the values of single-particle quantities in the 0-phase. We present results for phase diagrams, level occupation, induced local superconducting gap, Josephson current, and energy of the Andreev bound states with the precision surpassing any (semi)analytical approaches employed thus far.

Vertex corrections to the mean-field electrical conductivity in disordered electron systems.

The mean-field theory for noninteracting disordered electron systems is widely and successfully used to describe equilibrium properties of alloys over the whole range of disorder strengths. However, it fails to take into account the effects of quantum coherence and localizing backscattering effects when applied to transport phenomena. Vertex corrections due to multiple backscatterings may turn the electrical conductivity negative and make expansions around the mean field in strong disorder problematic. We show how to stabilize such an expansion with the inverse of the number of nearest neighbors on hypercubic lattices as a small parameter and how to include vertex corrections to the mean-field approximation in such a way that the conductivity remains non-negative in all disorder regimes.

[Clinical outcomes of surgical management of acromioclavicular dislocation with and without ligament suturing]. / Klinické výsledky operacního resení acromioclaviculárni luxace se suturou a bez sutury vazu.

INTRODUCTION: The aim of the study was to present a retrospective assessment of clinical outcomes of acromioclavicular (AC) dislocation surgery with and without suturing of the coracoclavicular ligament (CC). MATERIAL AND METHODS: Patients regardless of their age and gender were included in the study. All the subjects were operated by the same surgeon using the same surgical technique--traction cerclage. Every odd-numbered patient's procedure included ligament suturing and every even-numbered patient was operated without ligament suturing. The patients underwent clinical follow up at identical time intervals, had Pruban (elastic net bandage) fixation applied for one week and had the same rehabilitation regime for 6 weeks. The wires were extracted at 6-8 months. A total of 42 patients were included in the study. All the subjects were classified according to Tossy III, based on x-ray findings. The study group included 36 males and 6 females. The average age was 31.8 years (17-55). In 14 cases, preoperative stress x-rays of the upper extremity were performed. CC ligmanet suture was completed in 21 patients and 21 patients underwent procedures without CC suturing. The clinical outcome was assessed after wire extraction. RESULTS: Painful complications were recorded in 2 subjects and they reported the pain to be intermittent. The pain was classified as maximum grade 4, based on VAS (Visual analogue score). In one patient, the authors recorded pain sensation in the area of Kirschner's wires endings. In this particular patient, the wires were extracted 6 weeks after the procedure and following that, the patient was symptom-free. CONCLUSION: Based on the findings, the authors recorded no differences in the clinical outcomes of AC surgery with or without CC ligament suturing.

[Transplantation of deep frozen menisci]. / Transplantace hluboce mrazených menisku.

PURPOSE OF THE STUDY: Subtotal or total meniscectomy will increase weight-bearing per square unit of the cartilage surface approximately threeand- half-times. A long-term overloading of cartilage is clinically manifested by pain, swelling and a rapid onset of early arthritic lesions discernible on radiograms. One of the options for the treatment of degenerative changes in the joint is meniscal transplant. The authors present their first experience with the transplantation of deep frozen meniscal tissue in the Czech Republic. MATERIAL: By September 2006, we had treated 26 patients with clinical problems following subtotal or total meniscectomy. The patients, 15 women and 11 men, were between 24 and 46 years of age. Eighteen patients underwent transplantation of the medial meniscus and eight received a lateral meniscal transplant. Concomitant repair of the anterior cruciate ligament (ACL) was indicated in 11 patients, of whom 10 were treated with semitendinosus tendon graft and one with patellar ligament allograft. One patient with a lateral meniscal transplant and ACL reconstruction also had suture of the medial meniscus for a previously sustained injury. In 16 patients, chondromalacia was at the level of Outerbridge grade II and, only in five patients, the finding was Outerbridge grade I. Five patients with grade III chondromalacia were treated using the microfracture technique. Valgus or varus osteotomy was not indicated at all. METHODS: The goal of meniscal transplant surgery is: 1) to relieve pain after meniscectomy; 2) to prevent degenerative changes of cartilage; 3) to eliminate or reduce the risk of development of osteoarthritic lesions; 4) to restore normal mechanics of the knee joint. Patient selection is important and it is necessary to take into consideration: 1) level of cartilage degenerative changes; 2) knee alignment; 3) knee joint stability; 4) graft size. In patients with instability of the knee and indications for meniscal graft, it is necessary to stabilize the joint by ligament reconstruciton prior to transplantation; in the case of malalignment corrective osteotomy is required. RESULTS: All patients healed without complications. At the end of the third follow-up month, the range of motion was S-0-0-130 in 22 patients and S-0-0-120 in three patients. Only one patient had the range of motion restricted to S-0-0-110. Evaluation showed improvement from pre-operative values to those at 6 months and two years post-operatively as follows: IKDS score, 57-64 to 73-80 to 76-84; Lysholm score, 50-76 to 80-90 to 85-95; and Tegner score, 2-4 to 4-7 to 5-8. No complications associated with meniscal transplant incorporation were recorded. Also in five patients with Outbridge grade III degenerative changes, meniscal transplantation was successfully carried out. In four patients, of which two had a cartilage defect treated, second-look arthroscopy showed that the lesions healed with healthy fibrocartilaginous tissue. CONCLUSIONS: All patients reported resolution of subjective complaints, as seen from the results of the IKDC, Lysholm and Tegner scoring systems. It was obvious that when biomechanics of the knee joint were restored, conditions facilitating healing of chondral defects were provided. Based on this experience, the authors conclude that meniscal transplantation improves the quality of life in biologically young patients with clinical problems after meniscectomy.

Evidence for an influence of chemokine ligand 3-like 1 (CCL3L1) gene copy number on susceptibility to rheumatoid arthritis.

OBJECTIVE: There is increasing evidence that gene copy-number variation influences phenotypic variation. Chemokine ligand 3-like 1 (CCL3L1) is encoded by a variable copy-number gene, and binds to several pro-inflammatory cytokine receptors, including chemokine receptor 5 (CCR5). Considering lymphocyte recruitment by beta-chemokines is a feature of autoimmunity, and that the CCR5Delta32 variant is associated with protection to rheumatoid arthritis (RA), we hypothesised that CCL3L1 copy-number influences susceptibility to RA and type 1 diabetes (T1D). METHODS: We measured CCL3L1 copy-number in 1136 RA cases from New Zealand (NZ) and the UK, 252 NZ T1D cases and a total of 1470 controls. All subjects were ancestrally Caucasian. RESULTS: A copy-number higher than 2 (the most common copy number) was a risk factor for RA in the NZ cohort (odds ratio (OR) 1.34, 95% CI 1.08-1.66, p = 0.009) but not the smaller UK RA cohort (OR 1.09, 95% CI 0.75-1.60, p = 0.643). There was evidence for association in the T1D cohort (OR 1.46, 95% CI 0.98-2.20, p = 0.064) and in the combined RA/T1D cohort (OR 1.30, 95% CI 1.00-1.54, p = 0.003). Genetic interaction between CCL3L1 dosage and CCR5 genotype was found; the increased genetic risk conferred by higher CCL3L1 copy-number was ablated by a dysfunctional CCR5 (CCR5Delta32). CONCLUSIONS: These data suggest that increased CCL3L1 expression may enhance inflammatory responses and increase the chance of autoimmune disease. Genetic interaction data were consistent with a biologically plausible model; CCR5Delta32 protects against RA and T1D by blocking signalling through the CCR5 pathway, mitigating the pro-inflammatory effects of excess CCL3L1.

Evidence for negative association of the chemokine receptor CCR5 d32 polymorphism with rheumatoid arthritis.

BACKGROUND: Ligands of chemokine receptor CCR5, including MIP-1 alpha, MIP-1 beta, and RANTES, have been implicated in rheumatoid arthritis. OBJECTIVE: To test whether CCR5 d32 polymorphism has a negative association with rheumatoid arthritis in a New Zealand cohort. METHODS: 516 white patients with rheumatoid arthritis and 985 healthy controls were investigated by PCR amplification of the region flanking the known CCR5 d32 deletion, and the frequencies of CCR5 d32 compared. An early rheumatoid arthritis (ERA) cohort of 92 patients was followed prospectively for two years; disease severity and outcome were correlated with CCR5 d32 status. RESULTS: 12 control subjects (1.2%) were homozygous for d32; no d32 homozygous rheumatoid patients were detected (p = 0.012); 56 patients (10.9%) were heterozygous for the d32 polymorphism (d32/wt), compared with 169 controls (17.2%) (p = 0.0011). The CCR5 d32 allele frequency was lower in the rheumatoid patients than in the controls (frequencies of 0.054 and 0.098, respectively; p = 3.7 x 10(-5)). The frequency of CCR5 d32 did not differ significantly according to disease severity or outcome in the prospective ERA cohort, nor with HLA-DRB1 status. CONCLUSIONS: This study provides further evidence for a protective effect of the CCR5 d32 variant on rheumatoid arthritis, consistent with a role for CCR5 and its ligands in disease pathogenesis.

[Arthroscopic stabilization of a primary traumatic dislocation of the glenohumeral joint]. / ASKP stabilizace první traumatické luxace GH kloubu.

PURPOSE OF THE STUDY: The authors present their experience with arthroscopic stabilization of a primary traumatic dislocation of the glenohumeral joint in young patients. MATERIAL: In up to 80% of patients younger than 25 years, traumatic dislocation of the glenohumeral joint is associated with its recurrence within one year of treatment even in well performed conservative therapy. Repeated dislocations gradually damage the joint and eventually result in the development of arthritis. The articular capsule becomes loose, glenoid surface is reduced and cartilage of the humeral head is affected. Repeated dislocation, reduction and immobilization are causes of patients' discomfort as well as morbidity. For these reasons, the stabilization of recurrent dislocations of the glenohumeral joint is performed by an open procedure or, most recently, arthroscopic method. Arthroscopic stabilization of a primary traumatic dislocation of the glenohumeral joint is an invasive yet gentle method that permits an exact reconstruction of the injured articular capsule and provides good conditions for complete healing of the affected tissues. METHOD: In order to prevent dislocations from recurring, we offered to perform minimal invasive arthroscopic stabilization in 30 patients who had undergone reduction of a primary dislocation of the glenohumeral joint in the 1999/2001 period. Of these, 18 (45%) accepted this offer. In 11 men and 7 women (average age, 22 years) 12 right and six left glenohumeral joints were treated arthroscopically with the use of absorbable or non-absorbable sutures. The procedure was performed at 2 to 7 days after injury and reduction. The joint was immobilized in an elastic Desault bandage for 6 weeks, but with exercising the elbow. From the 4th postoperative week, the glenohumeral joint was passively exercised in the sagittal plane, but abduction and external rotation were avoided. From the 7th week on, the joint was exercised to achieve its full range of motion. RESULTS: The patients were followed up for 12 to 26 months. No repeated dislocation occurred. The range of motion comparable with the contralateral healthy joint was achieved in all patients by 12 weeks after surgery. One patient with a combined injury involving fracture of the first lumbar vertebra with signs of articular fibrosis underwent redress of the glenohumeral joint under general anesthesia at 6 weeks after arthroscopy. All patients returned to their previous everyday life, working and sports activities. DISCUSSION: Arthroscopic stabilization of the glenohumeral joint is an invasive though gentle method which, when exactly performed and followed by adequate postoperative rehabilitation, can considerably or even completely reduce recurrence of joint dislocation. Its disadvantages include costs of surgery and hospital stay, and a risk of potential intra- or post-operative complications. The statistical evaluation of primary dislocations in young patients showed that, in 80% of them, recurrent dislocations would probably require surgical treatment. In addition, a joint suffering from repeated dislocation may develop lesions to such an extent that dislocation may continue to recur even after surgical treatment; this happens in about 10% of the cases. Our estimate was that only 20% of the patients with primary traumatic dislocation (ruptured articular capsule) would not be in need of further repair. However, it was impossible to determine who they would be. Our results, i. e., the absence of recurrent dislocations, suggest a way of reducing the recurrence of dislocations following a primary injury of the glenohumeral joint. CONCLUSIONS: Arthroscopic stabilization of a primary traumatic dislocation of the glenohumeral joint in young patients (under 25 or maximally 30 years of age) is the method that allows us, invasively but with a good outcome, to reduce a high number of post-traumatic dislocations and to return sporting and/or manually working subjects to their previous way of life.

Transforming growth factor-beta1 genotype and susceptibility to chronic obstructive pulmonary disease.

BACKGROUND: Only a few long term smokers develop symptomatic chronic obstructive pulmonary disease (COPD) and this may be due, at least in part, to genetic susceptibility to the disease. Transforming growth factor beta1 (TGF-beta1) has a number of actions that make it a candidate for a role in the pathogenesis of COPD. We have investigated a single nucleotide polymorphism at exon 1 nucleotide position 29 (T-->C) of the TGF-beta1 gene that produces a substitution at codon 10 (Leu-->Pro). METHODS: The frequency of this polymorphism was determined in 165 subjects with COPD, 140 healthy blood donors, and 76 smokers with normal lung function (resistant smokers) using the polymerase chain reaction and restriction enzyme fragment length polymorphism. RESULTS: The distribution of genotypes was Leu-Leu (41.8%), Leu-Pro (50.3%), and Pro-Pro (7.9%) for subjects with COPD, which was significantly different from the control subjects (blood donors: Leu-Leu (29.3%), Leu-Pro (52.1%) and Pro-Pro (18.6%), p=0.006; resistant smokers: Leu-Leu (28.9%), Leu-Pro (51.3%) and Pro-Pro (19.7%), p=0.02). The Pro10 allele was less common in subjects with COPD (33%) than in blood donors (45%; OR=0.62, 95% CI 0.45 to 0.86, p=0.005) and resistant smokers (45%; OR=0.59, 95% CI 0.40 to 0.88, p=0.01). CONCLUSIONS: The proline allele at codon 10 of the TGF-beta1 gene occurs more commonly in control subjects than in individuals with COPD. This allele is associated with increased production of TGF-beta1 which raises the possibility that TGF-beta1 has a protective role in COPD.

[Arthroscopic treatment of the unstable knee joint by ligament reconstruction using allografts]. / Resení nestability kolenního kloubu artroskopicky provádenou plastikou vazu pomocí alogenních stepu.

PURPOSE OF THE STUDY: Recurring and multidirectional instability of the knee joint is a therapeutic problem mainly due to a limited possibility of harvesting grafts for its treatment. The authors present the methodology of the solution of recurring and multidirectional instabilities of the knee joint by means of allografts. They inform about the technique of harvesting and preservation of grafts and include the necessary examinations and early results. MATERIAL: Due to the above mentioned reasons the authors concentrated on the possibility of harvesting grafts for ligamentoplasty from donors. They developed the technique of harvesting, examination and preservation of allografts and their application by arthroscopy both in recurring and multidirectional instability. They used grafts from lig. patellae and m. quadriceps femoris. In the group of 21 patients operated on they used allograft for ligamentoplasty of 15 anterior cruciate ligaments (ACL) and 9 posterior cruciate ligaments (PCL), (4 times multidirectional instability of ACL + PCL, 14 times patellar tendon and 10 times tendon of m. quadriceps femoris). METHODS: Harvesting of grafts for ligamentoplasty from donors, examination according to EATB rules, preservation at the temperature of -80 degrees C. Prior to the application an antibiotic bath for 10 minutes. Application of grafts by arthroscopy, for ACL the grafts were used from patellar tendon and m. quadriceps femoris, for PCL the grafts from m. quadriceps femoris anchored in two channels. Operation in multidirectional instabilities in one step procedure--ACL, PCL and posterolateral capsular complex. Fixation by orthesis for 6-8 weeks according to the type of operation, early physiotherapy starting from 2nd day after operation. RESULTS: No differences were found in the postoperative course (immune or any other reaction) in comparison with autografts (duration of hospitalization, postoperative regime, pain), physiotherapy in the replacement of one ligament is faster in comparison with autografts. Ingrowth of allografts according to radiographs is without any special reaction. Results were evaluated according to Lysholm score and they show a significant improvement as compared to the condition prior to operation. No peroperative and postoperative complications were found. There was no immune reaction after the operation, in all patients there occurred a significant improvement of the stability of the knee joint. The results according to Lysholm score prior to the operation and after the ligamentoplasty show both a subjective and objective improvement after the operation. DISCUSSION: Application of allografts for the reconstruction of recurring and multidirectional instability of the knee joint is a method offering new possibilities. Its advantages include reduction of the duration of surgery, significantly reduced morbidity of the joint operated on, the possibility of adjustment of the graft, if need be. Disadvantages are the following: the possibility of a transfer of a virus disease which can be eliminated by a careful examination of donors; a longer period of graft remodelling, which can be compensated by a correct physiotherapy and postoperative regime. CONCLUSION: Application of allografts in the surgical treatment of instability of the knee joint is suitable in the current period of well developed examinations and surgical techniques. Early results are optimistic. Observation of all rules for the application of allografts will allow to extend in the correct indications the range of the possibilities of surgical treatment of recurring and multidirectional instabilities of the knee joint.

Interferon-gamma microsatellite and rheumatoid arthritis.

Several non-HLA genes contribute to the susceptibility to rheumatoid arthritis (RA). A recent report noted an allele (126 bp [CA(13)]) of the interferon-gamma intron A microsatellite repeat strongly associated with both the occurrence and the severity of RA. We assessed this locus in an independent set of 128 controls and 93 prospectively recruited patients with early RA. The reported association could not be confirmed. This discrepancy might be due to technical problems, which could be avoided by the use of reference samples.

Epilepsy in adolescents: hormonal considerations.

A correlation between seizure disorders and reproductive hormones has been recognized for centuries. Through basic scientific and clinical studies, an understanding of the interrelationships has become clearer. Puberty does not increase the incidence of seizures. Catamenial seizures, when diagnosed, may be improved with hormonal manipulation. Therapeutic regimens for those treated unsuccessfully with antiepileptic therapy need continued validation. Patients with seizure disorders have an increased incidence of menstrual disorders. Hormonal contraception is not contraindicated in this population, yet requires a more cautious approach to avoid failure.

[Treatment of chondral and osteochondral defects of the knee]. / Soucasné moznosti resení chondrálních a osteochondrálních defektu kolene.

Chondral and osteochondral defects play an important role in the knee surgery. The knee traumas are often followed by preterm development of osteoarthritis due to limited reparative processes in the cartilage. Today's diagnostic possibilities and progress in arthroscopic techniques promote the early diagnostic and exact classification of osteochondral defects. The prognosis of these injuries is improved by following early treatment. Authors present therapeutic ways of solving the defects of cartilage and adjacent part of the subchondral bone. The new possible method of solving the deep chondral defects on the weight-bearing site of the knee by combined mosaic plasty and autologous cultivated chondrocytes is described.

Evaluation of gaseous hydrogen fluoride as a convenient reagent for parallel cleavage from the solid support.

We have tested the limits of gaseous hydrogen fluoride as an agent for parallel detachment of organic molecules from the solid support. Peptides were chosen as relatively sensitive models for this reaction. Acid-catalyzed amide bond hydrolysis, side chain modification (tryptophan and other unnatural amino acids) by the protecting group residues as well as dehydration of serine and asparagine was followed. The technique of cleavage of side chain protection prior to the resin cleavage has given satisfactory results. Two-step deprotection and cleavage from benzhydrylamine resin by TFA and HF was compared to the deprotection and cleavage by TFA from Knorr resin.

[Mosaicplasty in treatment of deep chondral knee defects - first experience.]. / Resení hlubokých chondrálních defektu kolene mozajkovou plastikou - první zkusenosti.

The mosaicplasty as a method for solving the deep chondral defects is a one-stage technology with autogenous osteochondral graft application. The small cylinder's forming graft are obtained from a nonweightbearing site of knee cartilage and graft is further applied by press-fit technique to former prepared cartilage defects on the weightbearing site. Authors analyse the indications of this method and mention the possible risk and technical troubles during the treatment of the first group of patients. Key words: mosaicplasty, deep chondral defects, autologous osteochondral transplantation.

Modification of the Polaron sputter-coater unit for glow-discharge activation of carbon support films.

We describe a modification of the Polaron sputter-coater unit series 11 HD enabling activation of carbon support films for electron microscopy of macromolecules and macromolecular assemblies. The modification is simple and the device can be used in two modes, for sputter-coating of SEM samples and for glow-discharge activation of carbon support films. Examples of protein-free spreading of DNA and negative staining of bacteriophage particles on activated carbon support films are presented.