Search for the Pair Production of Dark Particles X with K_{L}

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110 MeV/c^{2} and 210-240 MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

Study of the K_{L}→π

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

[Restoration of knee extension with biceps femoris muscle transfer after resection of the quadriceps femoris muscle]. / Die Transposition des Musculus biceps femoris zum Ersatz des Kniegelenkstreckers nach Resektion des Musculus quadriceps.

OBJECTIVE: Improvement of gait and ability to stand by reconstruction of functional knee extension. INDICATIONS: Loss of function of the quadriceps femoris muscle due to tumour resection or traumatic damage of the muscle with loss of active knee extension. CONTRAINDICATIONS: Inadequate strength of the biceps femoris muscle. Recurrent tumour or ankylosis of the knee joint. SURGICAL TECHNIQUE: The tendon of the biceps femoris is dissected near the knee at the head of the fibula and is mobilized proximally. The underlying common peroneal nerve and the neurovascular supply of the biceps muscle must be spared. Through a ventral approach at the thigh the lateral intermuscular septum is opened and the biceps tendon is pulled through and sutured to the quadriceps tendon and periost of the patella. POSTOPERATIVE MANAGEMENT: The knee is immobilized in extension with a cast followed by a knee orthosis for 6 weeks, which is followed by intensive physiotherapy; however, the patient should not be forced to flex the knee extensively. The orthosis can be worn for another 3-4 weeks to stabilize the knee joint, while the muscles are intensively trained. RESULTS: Reliable reconstruction of functionally useful, active knee extension without an orthosis of a previously unstable knee joint in the sagittal plane, even if full extension is not to be expected.

[Carpal instability]. / Karpale Instabilität.

Carpal instability can be understood as a disturbed anatomical alignment between bones articulating in the carpus. This disturbed balance occurs either only dynamically (with movement) under the effect of physiological force or even statically at rest. The most common cause of carpal instability is wrist trauma with rupture of the stabilizing ligaments and adaptive misalignment following fractures of the radius or carpus. Carpal collapse plays a special role in this mechanism due to non-healed fracture of the scaphoid bone. In addition degenerative inflammatory alterations, such as chondrocalcinosis or gout, more rarely aseptic bone necrosis of the lunate or scaphoid bones or misalignment due to deposition (Madelung deformity) can lead to wrist instability. Under increased pressure the misaligned joint surfaces lead to bone arrosion with secondary arthritis of the wrist. In order to arrest or slow down this irreversible process, diagnosis must occur as early as possible. Many surgical methods have been thought out to regain stability ranging from direct reconstruction of the damaged ligaments, through ligament replacement to partial stiffening of the wrist joint.

[Certified breast centers in Germany : How much is plastic surgery involved?]. / Zertifizierte Brustzentren in Deutschland : Beteiligung der Plastischen Chirurgie.

INTRODUCTION: This study was designed to assess the degree of cooperation between plastic surgeons and gynecologists in certified breast centers in Germany. The rate of breast reconstruction after mastectomy remains low at 8-13%. In certified breast centers plastic surgeons are often not members of the team. METHODS: A total of 220 hospitals affiliated to the West German Breast Center (WBC) were contacted in 2007 and 80 breast centers and hospitals returned the questionnaire. This study is based on the data of approximately 24,000 patients. RESULTS: At the time of the investigation 60 out of the 80 hospitals (75%) were certified breast centers. Many different criteria have been applied for certified breast centers: the state of Nordrhein-Westfalen, the DKG/DGS (German Cancer Society/German Society of Senology), EUSOMA and others. In 8 hospitals (10%) a plastic surgeon was part of the team in the breast center. Most breast centers (44 out of 80) function with 3-4 attending specialists for breast surgery. DISCUSSION: The cooperation between gynecologists and plastic surgeons within a breast center can be strengthened. A microsurgical breast augmentation is not the ideal solution for every patient with a mastectomy but every patient has the right to obtain complete information about the whole spectrum of breast reconstruction including microsurgical free flap reconstruction.

Scaffold-free 3D cellulose acetate membrane-based cultures form large cartilaginous constructs.

Scaffold-free three-dimensional (3D) cultures provide clinical potential in cartilage regeneration. The purpose of this study was to characterize a scaffold-free 3D membrane-based culture system, in which human articular chondrocytes were cultivated on a cellulose acetate membrane filter, and compare it to pellet and monolayer cultures. Chondrocytes were expanded in monolayer culture for up to 5 passages, transferred to membrane-based or pellet cultures and harvested after 7 or 21 days. The chondrogenic potential was assessed by histology (toluidine blue, safranin-O), immunohistochemistry for collagen type II and quantitative analysis of collagen type II α(1) (COL2A1). Membrane-based cultures (P1) formed flexible disc-like constructs (diameter 4000 µm, thickness 150 µm) with a large smooth surface after 7 days. Positive safranin-O and collagen type II staining was found in membrane-based and pellet cultures at P1-3. Expression of COL2A1 after 7 days was increased in both culture systems compared to monolayer culture up to P3, whereas cells from monolayer > P3 did not redifferentiate. The best results for COL2A1 expression were obtained from membrane-based cultures at P1. After 21 days the membrane-based cultures did not express COL2A1. We concluded that membrane-based and pellet cultures showed the ability to promote redifferentiation of chondrocytes expanded in monolayer culture. The number of cell passages had an impact on the chondrogenic potential of cells. Membrane-based cultures provided the highest COL2A1 expression and a large, smooth and cartilage-like surface. As these are appropriate features for clinical applications, we assume that membrane-based cultures might be of use in cartilage regeneration if they displayed similar results in vivo.

Percutaneous collagen induction-regeneration in place of cicatrisation?

BACKGROUND: Ablative procedures that are used for the improvement of a degenerative process that leads to a loss of skin elasticity and integrity, injure or destroy the epidermis and its basement membrane and lead to fibrosis of the papillary dermis. It was recently shown in clinical and laboratory trials that percutaneous collagen induction (PCI) by multiple needle application is a method for safely treating wrinkles and scars and smoothening the skin without the risk of dyspigmentation. In our study, we describe the effect of PCI on epidermal thickness and the induction of genes relevant for regenerative processes in the skin in a small animal model. METHODS: The purpose of this study in a rat model was to determine the effects of PCI on the skin both qualitatively and quantitatively. The epidermal and dermal changes were observed by histology and immunofluorescence. The changes in gene expression were measured by array analysis for cytokines, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)-7, epidermal growth factor (EGF) and extracellular matrix molecules such as collagen type I and type III. RESULTS: The present study showed that PCI with topical vitamins resulted in a 140% increase in epidermal thickness; an increase in gene and protein expression of collagen I, glycosaminoglycans (GAGs) and growth factors such as VEGF, EGF and FGF7. The collagen fibre bundles were increased, thickened, and more loosely woven in both the papillary and reticular dermis. CONCLUSION: We were able to show that PCI modulates gene expression in skin of those genes that are relevant for extracellular matrix remodelling.

Percutaneous collagen induction. Scarless skin rejuvenation: fact or fiction?

Photoageing is generally treated by ablative procedures that injure the epidermis and basement membrane, and lead to fibrosis of the dermis. Percutaneous collagen induction (PCI) therapy is an alternative treatment for photoaged skin that does not result in clinical signs of dermal fibrosis. In this study, the immediate effects of PCI on the skin were assessed, including the systemic inflammatory response and the production and gene expression of transforming growth factor (TGF) isoforms beta1, beta2 and beta3. Eighty rats were split into four groups: group 1 (n = 24; PCI plus skin care); group 2 (n = 24; skin care only); group 3 (n = 24; PCI only) and group 4 (n = 8; controls). Microarray analysis showed that TGF-beta3, an essential marker for preventing scarring, was upregulated and expressed for 2 weeks postoperatively. PCI might offer a regenerative therapy to improve skin appearance and quality and to improve or even prevent scarring.

[A survey of preoperative perforator mapping in perforator flap surgery]. / Umfrage zu Methoden der präoperativen Lokalisation von Perforans-Gefässen zur erleichterten Planung von Perforans-Lappenplastiken.

INTRODUCTION: The frequency of perforator flap surgery is increasing. As such, the claim to identify and localize the perforators is closely related to preoperative perforator imaging. Starting with Doppler sonography magnetic resonance imaging (MRI) followed early in the 90s. Recently, three- and four-dimensional computer tomographic angiography and venography present impressive preoperative illustrations of perforators. HYPOTHESIS: Duplex ultrasound dominates in clinical practice for perforator imaging. METHODS: We performed a survey using a multiple choice questionnaire which was distributed among consultants of the German plastic surgery society (DGPRAC). Response rate was 46% with 132 institutions responding. RESULTS: Preoperative perforator imaging is applied in 77%. Duplex sonography is predominant with 70%, followed by colour Doppler ultrasound (42%). CT angiography (7%) and MRI angiography (8%) are currently underutilized. The amount of perforator flaps performed did not favor any preoperative perforator diagnostic. However, among those performing more than 30 perforator flaps per year, only 2% did not perform any perforator diagnostic at all. CONCLUSION: Preoperative perforator imaging is applied in 3/4 of all perforator flaps with duplex ultrasound dominating. Angio-CT and Angio-MRI are currently infrequently used for preoperative perforator imaging in Germany to date.

[Scaphoid fracture in motocross riders]. / Kahnbeinfrakturen bei Motocrossfahrern.

Motocross racing is a demanding motorcycling discipline with significant physiological and psychological demands. Upper extremity injuries are frequently encountered. Interestingly, motocross riders present with a significantly stronger left arm, even if the left hand is not dominant. This difference is attributed to the use of the clutch lever with the left hand, which is more frequent in motocross than in Enduro or desert rally. The wrist has been reported to be involved especially among motocross racers in contrast to road racing. Besides wrist fractures, scaphoid fractures have been previously without a detailed analysis of the injury mechanism. We report on three patients suffering scaphoid fractures caused by extreme hyperextension of the wrist during landing after a motocross jump. Two patients presented late three months following the initial trauma (both Herbert type C fractures), while one motocross athlete with a B 2-type scaphoid fracture was admitted to wrist surgery within a week. The B 2-type fracture was treated with open reduction and Herbert-screw fixation, while the C-type fractures were treated by Herbert-screw fixation in addition to a cortico-cancellous bone graft. Within ten weeks after the surgery the patients were back in sport at their given preoperative level. Hyperextension rather than wrist flexion appears as the predominant mechanism of wrist injuries in motocross riders. A more axial impact on the wrist is more likely to produce a radial fracture during the landing phase. Preventive strategies are internal muscular wrist stabilisation using eccentric training and external stabilisation by rigid gloves allowing only limited hyperextension.

[Diagnostic value of unspecific requested and implemented MRI for detecting intracarpal lesions, compared to arthroscopic findings at 217 patients]. / Wertigkeit unspezifisch angeforderter und durchgeführter MRT-Diagnostik bei intrakarpalen Verletzungen im Vergleich zum Arthroskopiebefund an 217 Patienten.

AIM: The purpose of this study was to evaluate the diagnostic value of MRI for detecting intracarpal lesions in clinical routine. PATIENTS AND MATERIALS: In a retrospective study, we reviewed the charts of 506 patients who had undergone wrist arthroscopy in our department between May 1998 and November 2002. Out of 506 patients 217 had an MRI. The MRI was performed at 31 different radiology facilities using a number of techniques. The MRI results were compared with the arthroscopic findings, taking the arthroscopic results as a "gold standard" (sensitivity = SEN, specificity = SPE, positive predictive value = PPV, negative predictive value = NPV, accuracy = ACC). RESULTS: The following results were found: For tears of the scapholunate ligament the avalues are SEN 18.5 %, SPE 95 %, PPV 71 %, NPV 66 %, ACC66 %. Not one of 16 tears of the lunotriquetral ligament was found by MRI. CONCLUSION: In our data we found a low sensitivity for unspecific requested and implemented MRI for detecting intracarpal lesions. Therefore the indication for MRI should only be made after experienced hand surgeons have examined the wrist. In our opinion, only direct MR-arthrography is equal to arthroscopy, so that only an experienced radiologist who is familiar with this technique should perform the MRI diagnostics of the hand.

[A flap simulator for training in local defect coverage]. / Lappensimulator für lokale Defektdeckungen: Flap Lab I der MHH.

The Hannover Medical School (Germany) developed the"Flap Lab I" flap simulator, a practical improvement to surgeon training. It provides realistic conditions for understanding and following the principles for planning and performing local flaps for coverage of skin defects. The Flap Lab I has proved to be a very good training model in several training courses. This article introduces among others the Z-flap, reverse Z-flap (so-called hanging man), and Limberg flap.

[Breast reconstruction for patients with breast carcinoma : an analysis based on the data of 4,335 patients from 16 hospitals]. / Brustrekonstruktionen bei Patientinnen mit Mammakarzinom : Eine Analyse anhand der Daten von 4335 Patientinnen aus 16 Kliniken.

BACKGROUND: [corrected] The rate of breast reconstructions after mastectomy because of breast carcinoma has not been thoroughly studied, based on a representatively large data pool. METHODS: We analyzed the data of 4,335 patients with breast carcinoma from 16 hospitals together with the German Breast Center (Westdeutsches Brustcentrum). RESULTS: Of the studied patients, 34% (1,488 of 4,335) had mastectomies. Breast reconstruction was performed in 13% (197) of those with mastectomy. None of the 197 with breast reconstruction was operated on by a plastic surgeon or had a microsurgical reconstructive procedure (free flap). CONCLUSION: The aim of this study is to increase the number of breast reconstructions after mastectomy, including microsurgical procedures, and to improve cooperation between gynecologists and plastic surgeons.

[Dorsal capsulodesis versus triscaphe arthrodesis in patients with scapholunate dissociation. Do the results depend on the diagnosis or the operation?]. / Differenzialindikation der dorsalen Kapsulodese und der STT-Arthrodese bei Patienten mit einer skapholunären Dissoziation. Ist das Ergebnis abhängig von der Diagnose oder dem Operationsverfahren?

BACKGROUND: Dorsal capsulodesis and triscaphe arthrodesis are possible treatment modalities for patients with scapholunate dissociation. In light of overlapping indications for either operation for patients with carpal instability, it is important to compare the postoperative results. METHODS: From 1998 until 2002, we operated on 87 patients suffering from scapholunate dissociation. 52 patients were treated by dorsal capsulodesis after R. Berger and 35 patients were treated by triscaphe arthrodesis as published by Watson. Of these 87 patients, we managed to follow-up 77 patients (47 dorsal capsulodesis und 30 triscaphe arthrodesis) with a physical examination, X-ray of the wrists and Krimmer Score. RESULTS: In terms of grip-strength, range of motion, functional outcome (Krimmer Score), duration of the operation and hospitalisation, the dorsal capsulodesis group performed better (p < 0.05) than the triscaphe arthrodesis group at the time of follow-up. At follow-up, pain reduction was significant in both groups (p < 0.05). Krimmer Score (functional outcome) and the rate of complication was clearly better for the dorsal capsulodesis group as compared to the triscaphe arthrodesis group. CONCLUSION: In case of non-static scapholunate dissociation, dorsal capsulodesis should be the first choice treatment. In case of a young manually working man with static scapholunate dissociation, it should be a case-to-case decision whether performing a triscaphe arthrodesis or a dorsal capsulodesis. With this investigation we wanted to discuss and demonstrate the difficulties with the differential-indication for the two operations. Generally speaking the postoperative results did not depend on the type of scapholunate dissociation (dynamic versus static) but rather on the chosen surgical procedure.

Redox properties of the iron-sulfur clusters in activated Fe-hydrogenase from Desulfovibrio vulgaris (Hildenborough).

The periplasmic Fe-hydrogenase from Desulfovibrio vulgaris (Hildenborough) contains three iron-sulfur prosthetic groups: two putative electron transferring [4Fe-4S] ferredoxin-like cubanes (two F-clusters), and one putative Fe/S supercluster redox catalyst (one H-cluster). Combined elemental analysis by proton-induced X-ray emission, inductively coupled plasma mass spectrometry, instrumental neutron activation analysis, atomic absorption spectroscopy and colorimetry establishes that elements with Z > 21 (except for 12-15 Fe) are present in 0.001-0.1 mol/mol quantities, not correlating with activity. Isoelectric focussing reveals the existence of multiple charge conformers with pI in the range 5.7-6.4. Repeated re-chromatography results in small amounts of enzyme of very high H2-production activity determined under standardized conditions (approximately 7000 U/mg). The enzyme exists in two different catalytic forms: as isolated the protein is 'resting' and O2-insensitive; upon reduction the protein becomes active and O2-sensitive. EPR-monitored redox titrations have been carried out of both the resting and the activated enzyme. In the course of a reductive titration, the resting protein becomes activated and begins to produce molecular hydrogen at the expense of reduced titrant. Therefore, equilibrium potentials are undefined, and previously reported apparent Em and n values [Patil, D. S., Moura, J. J. G., He, S. H., Teixeira, M, Prickril, B. C., DerVartanian, D. V., Peck, H. D. Jr, LeGall, J. & Huynh, B.-H. (1988) J. Biol. Chem. 263, 18,732-18,738] are not thermodynamic quantities. In the activated enzyme an S = 1/2 signal (g = 2.11, 2.05, 2.00; 0.4 spin/protein molecule), attributed to the oxidized H cluster, exhibits a single reduction potential, Em,7 = -307 mV, just above the onset potential of H2 production. The midpoint potential of the two F clusters (2.0 spins/protein molecule) has been determined either by titrating active enzyme with the H2/H+ couple (E,m = -330 mV) or by dithionite-titrating a recombinant protein that lacks the H-cluster active site (Em,7.5 = -340 mV). There is no significant redox interaction between the two F clusters (n approximately 1).

Code of conduct as corporate culture.

The purpose of any code of conduct is to define the limits of acceptable behavior of the employees being managed. An effective code results from trade-offs among the key elements of notice, discretion, risk and tone, which reflect the culture of the organization.