Oxo-Functionalized Graphene as a Cell Membrane Carrier of Nucleic Acid Probes Controlled by Aging.

We applied a fluorescein-containing oligonucleotide (ON) to probe surface properties of oxidized graphene (oxo-G) and observed that graphene-like patches are formed upon aging of oxo-G, indicated by enhanced probe binding and by FTIR spectroscopic analysis. By using a recently developed fluorogenic endoperoxide (EP) probe, we confirmed that during the aging process the amount of EPs on the oxo-G surface is reduced. Furthermore, aging was found to strongly affect cell membrane carrier properties of this material. In particular, freshly prepared oxo-G does not act as a carrier, whereas oxo-G aged for 28 days at 4 °C is an excellent carrier. Based on these data we prepared an optimized oxo-G, which has a low-defect density, binds ONs, is not toxic, and acts as cell membrane carrier. We successfully applied this material to design fluorogenic probes of representative intracellular nucleic acids 28S rRNA and ß-actin-mRNA. The results will help to standardize oxidized graphene derivatives for biomedical and bioanalytical applications.

[Dance sport: injury profile in Latin American formation dancing]. / Tanzsport: Verletzungsmuster im Lateinamerikanischen Formationstanz.

BACKGROUND: Latin American formation dancing ranks among the technical-compositional types of sport and represents a discipline of dance sport due to its performance- and competition-orientated mode. Despite its high degree of popularity and a movement profile favouring injuries, there has been a lack of studies as to health hazards and damage in Latin American formation dancing. The aim of this study is to analyse formation dance-related health hazards and their causes. METHODS: A total of n = 100 (m: n = 52, f: n = 48) Latin American dancers of the German top-level league participated in this anonymised retrospective cross-sectional investigation. RESULTS: Mean weights of the male dancers were 75.2 kg and respectively 58.2 kg for the females, mean body height/size were 1.82 m (m) and 1.67 m (f) and mean BMI 22.2 (m) and 20.0 (f), respectively. At least one each traumatic injury/chronic damage was sustained by 69.3 % (m) and 77.6 % (f) of the dancers in the course of their dance sport activities. Almost all (97.9 %) injuries occurred during the training. A total of 409 injuries/overuse damages (= 4.1 injuries/athlete) was reported with 80.4 % traumatic injuries and 19.5 % chronic damages. Female dancers were more often injured than their male counterparts. The lower extremity was the most commonly affected body region [64.5 % (m) and, respectively, 71.2 % (f)], followed by upper extremity (m: 21.2 %, f: 17.6 %) and spinal column/trunk region (m: 12.0 %, f: 8.5 %). Blockages and pulled muscles were the most common complaints reported by males with contusions and pulled muscles being reported by females. Chondropathy/osteoarthrosis were the most frequent chronic diseases. Of all injuries sustained, circa two thirds were caused by extrinsic and circa one third by intrinsic factors. CONCLUSION: The injury profiles/patterns in Latin American formation dancing show on the one hand parallels to the individual partner dances. On the other hand, typical and gender-specific movement elements seem to reflect in the injuries and chronic damages/diseases of formation dancers. This is to be taken into account when injury prevention measures are considered. There is also a need for further studies to allow a more differentiated analysis.

Concept for support and heating of plate-like samples in the ultra-high vacuum.

We present the concept for a sample holder designed for mounting and heating of plate-like samples that is based on a clamping mechanism for easy handling. The clamping mechanism consists of a U-shaped bracket encompassing the sample support plate from the rear. Two spring wires are fixed in the walls of the bracket spanning the sample to secure it with only two point contacts. This enables the sample to freely expand or contract during heating and cooling. To accommodate for a large variety in sample size, shape, and quality, we introduce two designs differing in the generation of the clamping force: One pressing the sample against the spring wires, the other one pulling the spring wires onto the sample. Both designs yield an automatically even alignment of the sample during the mounting process to achieve an even load distribution and reliable fixation specifically for brittle samples. For high temperature treatment, the sample holders are enhanced by a resistive heating plate. As only the sample and a small fraction of the sample holder are heated, temperatures of 1300 °C are reached with only 8 W heating power. The sample support and heating components are mounted on a 11 mm × 13 mm base plate with a handle that can be transferred between the sample entry stage, the preparation stage, and surface science experiments in the ultra-high vacuum system.

Morphology and nanostructure of CeO2(111) surfaces of single crystals and Si(111) supported ceria films.

The surface morphology of CeO(2)(111) single crystals and silicon supported ceria films is investigated by non-contact atomic force microscopy (NC-AFM) and Kelvin probe force microscopy (KPFM) for various annealing conditions. Annealing bulk samples at 1100 K results in small terraces with rounded ledges and steps with predominantly one O-Ce-O triple layer height while annealing at 1200 K produces well-ordered straight step edges in a hexagonal motif and step bunching. The morphology and topographic details of films are similar, however, films are destroyed upon heating them above 1100 K. KPFM images exhibit uniform terraces on a single crystal surface when the crystal is slowly cooled down, whereas rapid cooling results in a significant inhomogeneity of the surface potential. For films exhibiting large terraces, significant inhomogeneity in the KPFM signal is found even for best possible preparation conditions. Applying X-ray photoelectron spectroscopy (XPS), we find a significant contamination of the bulk ceria sample with fluorine while a possible fluorine contamination of the ceria film is below the XPS detection threshold. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) reveals an accumulation of fluorine within the first 5 nm below the surface of the bulk sample and a small concentration throughout the crystal.

Versatile system for the temperature-controlled preparation of oxide crystal surfaces.

We present a versatile system for the preparation of oxide crystal surfaces in the ultra-high vacuum (UHV) at temperatures up to 1300 K. Thermal treatment is accomplished by direct current heating of a tantalum foil in contact with the oxide sample. The sample temperature is measured by a thermocouple at a position close to the crystal and its reading is calibrated against the surface temperature determined by a second thermocouple temporarily attached to the surface. The design of the sample holder is based on a transferable plate originally developed for a commercial UHV scanning probe microscope. The system is, however, also suitable for the use with electron spectroscopy or electron diffraction based surface analytical techniques. We present results for the high-temperature preparation of CeO(2)(111) surfaces with atomically flat terraces exhibiting perfect atomic order and cleanliness as revealed by non-contact atomic force microscopy (NC-AFM) imaging. NC-AFM imaging is, furthermore, used to demonstrate the temperature-controlled aggregation of gold atoms on the CeO(2)(111) surface and their evaporation at high temperatures.

Mechanism of cGMP-mediated protection in a cellular model of myocardial reperfusion injury.

OBJECTIVE: Reperfusion injury of the myocardium is characterised by development of cardiomyocyte hypercontracture. Previous studies have shown that cGMP-mediated stimuli protect against reperfusion injury, but the cellular mechanism is still unknown. METHODS: To simulate ischemia/reperfusion, adult rat cardiomyocytes were incubated anoxically (pH(o) 6.4) and then reoxygenated (pH(o) 7.4). Cytosolic calcium [Ca(2+)](i) (fura-2 ratio), pH(i) (BCECF ratio), cell length, and phospholamban phosphorylation were analysed. Under simulated ischemia cardiomyocytes develop [Ca(2+)](i) overload. When reoxygenated they rapidly undergo hypercontracture, triggered by oscillations of [Ca(2+)](i). We investigated whether cGMP-mediated stimuli can modulate [Ca(2+)](i) or pH(i) recovery and whether this contributes to their protective effect. Membrane-permeable cGMP analogues, 8-bromo-cGMP (1 mmol/L) or 8-pCPT-cGMP (10 micrommol/L), or a receptor-mediated activator of particulate guanylyl cyclase, urodilatin (1 micromol/L), were applied. RESULTS: The investigated stimuli protect against reoxygenation-induced hypercontracture (cell length as percent of end-ischemic length; control: 68+/-1.6; 8-bromo-cGMP: 88+/-1.5*; 8-pCPT-cGMP: 84+/-2.9*; urodilatin: 87+/-1.1*; n=24; *p<0.05). Recovery from [Ca(2+)](i) overload after 2 min reoxygenation [fura-2 ratio (a.u.); control: 1.43+/-0.15; 8-bromo-cGMP: 1.86+/-0.15*; 8-pCPT-cGMP: 1.92+/-0.19*; urodilatin: 1.93+/-0.24*; n=25; *p<0.05] was accelerated, and the frequency of [Ca(2+)](i) oscillations (min(-1)) was significantly reduced (control: 49+/-5.0 min(-1); 8-bromo-cGMP: 18+/-3.5* min(-1); 8-pCPT-cGMP: 18+/-4.5* min(-1); urodilatin: 16+/-4.1* min(-1); n=24; *p<0.05). cGMP-mediated stimuli increased sarcoplasmic Ca(2+) sequestration (caffeine-releasable Ca(2+) pool: 2-3 fold increase vs. control). Inhibition of sarcoplasmic Ca(2+)-ATPase (SERCA) by thapsigargin (150 nmol/L) or of protein kinase G with KT-5823 (1 micromol/L) abolished the effect of these stimuli on [Ca(2+)](i) recovery. The investigated stimuli significantly enhanced phospholamban phosphorylation. CONCLUSIONS: We conclude that cGMP-dependent signals activate SERCA via a protein kinase G-dependent phosphorylation of phospholamban. The increase in SERCA activity seems to reduce peak [Ca(2+)](i) and [Ca(2+)](i) oscillation during reoxygenation and to attenuate the excessive activation of the contractile machinery that otherwise leads to the development of hypercontracture.

Humeral torsion in the throwing arm of handball players.

Sport-specific upper extremity strain, mostly unilateral, during growth may lead to adaptations in soft tissue and bone. We investigated 51 male professional handball players between 18 and 39 years of age (average, 27 years), 39 right-handed and 12 left-handed. Thirty-eight players had no shoulder problems, and 13 had chronic shoulder pain. Humeral retrotorsion was determined by radiograph. The differences between the throwing and contralateral arms were compared with those of 37 controls who had no history of unilateral strain either through sports or profession. Standard statistical analysis was performed using the t-test. The retrotorsional angle of the humerus in the handball professionals' throwing arm was an average of 9.4 degrees larger in the dominant side than in the nondominant, with a side-to-side difference up to 29 degrees. In the control group, no statistically significant difference was found. In the group without chronic shoulder pain, the side-to-side difference was an average of 14.4 degrees more in the throwing arm than the other side. Players with chronic shoulder pain did not exhibit this increase, even showing an average decrease of humeral retrotorsion of 5.2 degrees in the throwing arm. The humeral retrotorsion increase can be explained as an adaptation to extensive external rotation in throwing practice during growth. Athletes who do not adapt this way seem to have more strain on their anterior capsules at less external rotation and develop chronic shoulder pain because of anterior instability.

Mediomalleolar fracture combined with Achilles tendon rupture--a rare simultaneous injury of the ankle.

Achilles tendon injuries are rarely associated with osseous lesions. The combination of mediomalleolar fracture with Achilles tendon rupture has been reported as a rare combination injury in alpine skiers, but never before in basketball. This report presents an Achilles tendon rupture in a senior basketball player in combination with a non-displaced fracture of the medial malleolus. The osseous lesion was initially missed, because the tendon injury with all typical clinical and sonographical signs predominated. The routine X-ray examination was only done in the lateral and axial plane, because the examiner did not even think of an ankle fracture, since the description of the sports accident and the clinical signs were so typical for a sole tendon injury. This case report should remind us not to exclude an osseous or ligamentous ankle injury in those cases of acute Achilles tendon rupture especially if postoperative swelling and pain persist for a prolonged period.

Anatomic variation of the coracoacromial ligament: a macroscopic and microscopic cadaveric study.

The operative management of the subacromial impingement syndrome includes reconstruction in cases with ruptured tendons and enlargement of the subacromial space by arthroscopic or open resection of the coracoacromial ligament and acromioplasty. In nearly 20% of all cases, however, surgical treatment fails. This study was conducted with 124 cadaver shoulders of older specimens with a balanced male/female ratio. The coracoacromial ligament did not present homogenous morphologic characteristics. We found 25.8% of all ligaments undivided, 59.7% bipartite, and 14.5% consisted of three parts. The third part, located most medially, took a hidden path to the coracoid process and was not visible during dissection until after the clavicle was resected. This medially situated third part of the coracoacromial ligament has not been described in the medical literature before the time of our investigation. It could well be responsible for persisting subacromial pain after surgery, if it is not identified and resected during surgery.

[Bone hypertrophy as a results of training]. / Die Knochenhypertrophie als Trainingseffekt.

It is well known that adaptational processes following athletic training affect not only muscles and tendons, but also the skeletal system of the athlete. Functional adaptation of the bone is shown by an increase in cortical thickness, frequent development of bony spurs at the insertion of tendons and joint capsules, an increase of density of the bone substance, and bony changes as a reaction to increased mobility of bony junctions such as the symphysis of the pubic bones of the sacro-iliac joints. Recently, in an investigation involving 20 professional tennis players, we demonstrated that--in addition to the adaptational processes mentioned above--stimulation of longitudinal bone growth and widening of the joint space (cartilage hypertrophy) occur. The possibility of bony hypertrophy as a result of athletic training, especially with regard to increases in of bone density and bone diameter, should lead to incorporation of sports medical considerations into the prophylaxis and therapy of osteoporosis.

Stimulation of bone growth through sports. A radiologic investigation of the upper extremities in professional tennis players.

This contribution addresses the following questions: Does unilateral sports-specific strain affect the skeletal system of the athlete? Specifically, can any differences be found in longitudinal growth of the bones of the forearm and hand in professional tennis players between the stroke arm and the contralateral arm? An investigation was conducted involving 20 high-ranking professional tennis players (12 male and eight female players) between 13 and 26 years of age as well as 12 controls of the same age range. The radiologic examinations of the bones of the forearm and hand yielded an increase in density of bone substance and bone diameter as well as length in the stroke arm as compared with the contralateral arm. Whereas the first results confirm previous findings, the stimulation of longitudinal growth has never been reported. This change in bone structure and size can be attributed to two factors: mechanical stimulation and hyperemia of the constantly strained extremity. It may thus be regarded as a biopositive adaptation process.

Impingement of the rotator cuff in athletes caused by instability of the shoulder joint.

An impingement of the rotator cuff can be caused by chronic anterior instability of the shoulder joint. This particular disease is often found in athletes engaged in overhead motion in abduction/external rotation of the arm, such as in ball sports like volleyball or European handball, racket sports like tennis or badminton, or swimming. For those patients that cannot be cured by conservative treatment such as muscular stabilization, surgical treatment is indicated: anterior reconstruction of the capsule and/or the glenoid labrum, and in addition--if necessary--subacromial decompression and revision of the rotator cuff. Between October 1988 and April 1992, we operated on 66 shoulders in 64 top athletes suffering from chronic anterior or multidirectional instability of the shoulder joint that had caused an impingement syndrome of the rotator cuff. In all cases, the athlete was unaware of the instability. Conservative treatment had been unsuccessful. Surgical treatment was successful in close to 90% of the athletes.

[Biophysical research on condylar temporomandibular joint growth]. / Biophysikalische Untersuchungen zum kondylären Kiefergelenkwachstum.

On the basis of results obtained from the study of mechanically induced potentials and pulsed 1H-NMR investigations of the condylar cartilage of the TMJ in vitro, the hypothesis is advocated that the internal regulation of condylar growth takes place with the aid of bioelectric signals. Reference in made to the importance of the studies for a future noninvasive diagnosis of condylar growth in the course of functional orthopedic treatment, using "dynamic" magnetic resonance imaging.

Preparation and biological activity of new substituted antimalarial diaminodiphenylsulfones.

Starting from 4,4'-diamino-diphenylsulfone (DDS) as a lead structure, new 2-substituted analogues as well as new 2-substituted 4-alkylamino-4'-amino diphenylsulfones have been designed and synthetized in different ways. This has led to compounds the inhibitory activity of which against 7,8-dihydropteroic acid synthase of plasmodia and mycobacteria is clearly superior to that of sulfadoxine and in most cases to that of DDS. Of special interest is 4'-amino-4-n-propylamino-2-methyl-diphenylsulfone. Together with inhibitors of 7,8-dihydrofolate reductase in vitro and in vivo it possesses a marked synergistic inhibitory activity against plasmodia. In contrast to DDS in doses up to 200 mg/kg p.o. (cat) no methemoglobin formation is observed. The compound has been selected for further studies.

[Muscular imbalance in elite swimmers and the resulting sports damage of the lumbar spine and knee joints]. / Muskuläre Dysbalancen bei Leistungsschwimmern und daraus resultierende Sportschäden an Lendenwirbelsäule und Kniegelenken.

Elite swimmers often show typical sportspecific lesions, the cause of which is thought to be technical faults, overtraining, or wrong use of training equipment. In order to look for additional causes in the development of these sports lesions, 46 male and female elite swimmers of the 1st and 2nd swimming division (1. and 2. Bundesliga) were examined orthopaedically. Especially by using Janda's "Functional Muscular Diagnostics", specific muscular imbalances can be found. This paper demonstrates a relation between these muscular imbalances and the typical sports lesions of the locomotor system.

Shoulder dislocation in skiing: choice of surgical method depending on the degree of humeral retrotorsion.

Shoulder dislocation is one of the typical upper extremity injuries in skiing, first following a violent accident but quite frequently recurring without new trauma. This article discusses the retrotorsional angle of the humerus as an etiological factor in the occurrence of an initial dislocation and as a triggering element for its recurrence. It focuses on the consequences to be drawn for the surgical treatment of recurrent shoulder dislocation. A technique for exact determination of the humeral angle of retrotorsion by X-ray is presented. In patients with recurrent anterior dislocations of the shoulder joint, the retrotorsional angle of the humerus is pathologically reduced as compared to the control group. The method of surgical therapy is determined by the individual deviance from the average value.

Changes in circulating blood volume influence aortic characteristic impedance in awake dogs.

Experiments on five chronically instrumented dogs were performed to study the effects of changes in circulating blood volume on the aortic smooth muscle activity in awake animals. The external diameter of the proximal descending aorta was measured with a sonomicrometer. Aortic pressure was measured in the same cross-sectional area with a catheter-tip transducer. Acute hemorrhage of 15% of the estimated blood volume was performed 17 times by quickly withdrawing blood through a jugular cannula. At any given arterial pressure within the range of overlap the aortic diameter (D) was always decreased after hemorrhage compared with control, and the pressure-strain elastic modulus (Ep) and the characteristic impedance (Zc) were always increased. For example at 140 kdyn X cm-2 (104.5 mmHg) delta D = -0.61 +/- 0.12 mm or delta D = -3.44 +/- 0.68% of control, delta Ep = 31.0 +/- 8.6%, and delta Zc = 22.6 +/- 4.5%. Each of these changes was significant with P less than 0.01. Volume expansion of 30% was performed eight times by infusing warm saline. At any given arterial pressure D was always increased and Ep and Zc were always decreased. At 140 kdyn X cm-2 delta D = 0.55 +/- 0.15 mm or delta D = 3.12 +/- 0.95% of control, delta Ep = -12.4 +/- 3.2%, and delta Zc = -12.0 +/- 2.1%. Each of these changes was significant with P less than 0.01. Since in these awake animals the changes in circulatory blood volume modified the arterial pressure only slightly, the contribution of viscoelasticity and myogenicity to the observed responses was minimal.