Major low-energy trauma results in non-specific immunoglobulin generation without evidence for specific autoantibody production: A prospective cohort study.

Cellular debris resulting from large trauma might overwhelm the scavenger mechanisms and lead to autoimmune reactions. We analysed whether a major well-defined trauma in humans induces laboratory signs of transient autoimmunity in the months after the insult. We included 50 patients with pertrochanteric femur fracture undergoing intramedullary nail osteosynthesis in a prospective cohort study and followed them at 3-4 days, 6 weeks, 12 weeks and 12 months postoperatively. By standard techniques, we assessed levels of total immunoglobulins, anti-nuclear antibodies (ANA), anti-cardiolipin antibodies, anti-dsDNA antibodies and anti-C1q antibodies, as well as antibodies against cytomegalovirus (CMV) as a control. Blood leukocyte differential and lymphocyte subpopulations were determined at baseline and in the first two postoperative samples. The mean age of the patients reached 80.1 years, and 23 (46%) completed all visits. Serum concentrations of total IgG, IgM and IgA increased at all follow-up time points. The ANA fluorescence light intensity units increased at 12 weeks and 12 months postoperatively (p < 0.0001), but the proportion of ANA-positive patients did not change (35%). The values of anti-C1q mildly increased at all follow-up visits, but not the ratio to total IgG. Anti-dsDNA remained negative in all patients, and anti-cardiolipin IgG/IgM antibodies did not change. Anti-CMV IgG antibodies increased significantly at all follow-up visits, without change in the ratio to total IgG. Flow cytometry showed an increased proportion of B-cells 3-4 days postoperatively. In conclusion, major musculoskeletal trauma in elderly patients induces a generalized non-specific increase in immunoglobulin production without laboratory signs for enhanced systemic autoimmunity.

Photosynthetic, Respirational, and Growth Responses of Six Benthic Diatoms from the Antarctic Peninsula as Functions of Salinity and Temperature Variations.

Temperature and salinity are some of the most influential abiotic parameters shaping biota in aquatic ecosystems. In recent decades, climate change has had a crucial impact on both factors­especially around the Antarctic Peninsula­with increasing air and water temperature leading to glacial melting and the accompanying freshwater increase in coastal areas. Antarctic soft and hard bottoms are typically inhabited by microphytobenthic communities, which are often dominated by benthic diatoms. Their physiology and primary production are assumed to be negatively affected by increased temperatures and lower salinity. In this study, six representative benthic diatom strains were isolated from different aquatic habitats at King George Island, Antarctic Peninsula, and comprehensively identified based on molecular markers and morphological traits. Photosynthesis, respiration, and growth response patterns were investigated as functions of varying light availability, temperature, and salinity. Photosynthesis−irradiance curve measurements pointed to low light requirements, as light-saturated photosynthesis was reached at <70 µmol photons m−2 s−1. The marine isolates exhibited the highest effective quantum yield between 25 and 45 SA (absolute salinity), but also tolerance to lower and higher salinities at 1 SA and 55 SA, respectively, and in a few cases even <100 SA. In contrast, the limnic isolates showed the highest effective quantum yield at salinities ranging from 1 SA to 20 SA. Almost all isolates exhibited high effective quantum yields between 1.5 °C and 25 °C, pointing to a broad temperature tolerance, which was supported by measurements of the short-term temperature-dependent photosynthesis. All studied Antarctic benthic diatoms showed activity patterns over a broader environmental range than they usually experience in situ. Therefore, it is likely that their high ecophysiological plasticity represents an important trait to cope with climate change in the Antarctic Peninsula.

The association between non-permanence of dogs in households and non-compliance with the principles of responsible animal guardianship: A survey in a medium-sized city in Brazil.

The permanence of a dog in a household is relevant in terms of public health and animal welfare because it implies that the animal is receiving better care and is unlikely to be abandoned. We have performed a survey in a medium-sized city in southeastern Brazil in order to identify predictors associated with the non-permanence of dogs in households as determined one year after the first visit. During the first of two visits to randomly selected domiciles, guardians were asked to complete a structured questionnaire regarding the traits and history of each dog in the household, features of the domicile, characteristics of the guardian and adherence to the principles of responsible companion animal guardianship (RCAG). A second visit to each domicile was performed one year later in order to establish in loco whether the dog still resided in the domicile and, where appropriate, to apply a further questionnaire concerning the fate of the missing animal. The total sample population comprised 513 dogs, of which 98 (19.1%) were verified as no longer resident in the domicile on the occasion of the second visit. Of the absent dogs, 59 had died as a result of fights with stray animals, traffic accidents, diseases or old age, 13 had been sent to alternative addresses, 8 had been donated to third parties and 7 had escaped from the domicile. The fates of the remaining 11 animals were not divulged by the guardians. Multiple regression analysis revealed that the risk of non-permanence was significantly higher (p < 0.05) among male dogs, those that were infested with ticks, had free access to the streets or resided in domiciles near a wooded area, but was significantly lower among wormed and neutered dogs. The adoption of RCAG principles is associated with the permanence of dogs in households and, consequently, in reduction of the stray population, animal well-being and prevention of zoonoses. On this basis, it is important to raise awareness about the concepts of RCAG and to strengthen accountability of guardians that do not take proper care of their animals.

Bone fracture healing within a continuum bone remodelling framework.

Bone fracture healing is a complex process which is still under research. Computer-aided patient-specific prediction of bone development, fracture risk, prevention and treatment approaches promises a significant milestone in clinical practice. With this long-term goal in mind, a novel model is presented and examined in this work in the context of continuum bone remodelling. Therein, a clear distinction is made between external mechanical stimulation and the biological healing process of an injured bone tissue. The model is implemented within a finite element framework and investigated for the example of a fractured proximal femur head. The results show promising perspectives for further application. Besides, the model offers the possibility of easily integrating other factors like age-dependency and the availability of nutrition. For the future, further studies with large clinical datasets are essential for validation.

Concurrent consideration of cortical and cancellous bone within continuum bone remodelling.

Continuum bone remodelling is an important tool for predicting the effects of mechanical stimuli on bone density evolution. While the modelling of only cancellous bone is considered in many studies based on continuum bone remodelling, this work presents an approach of modelling also cortical bone and the interaction of both bone types. The distinction between bone types is made by introducing an initial volume fraction. A simple point-wise example is used to study the behaviour of novel model options, as well as a proximal femur example, where the interaction of both bone types is demonstrated using initial density distributions. The results of the proposed model options indicate that the consideration of cortical bone remarkably changes the density evolution of cancellous bone, and should therefore not be neglected.

On biological availability dependent bone remodeling.

Modeling the evolution of bone density is relevant for understanding, simulation and possible prediction of bone response to external and internal influences. In this work we present a formulation for the bone density evolution process that takes into account not only the commonly considered mechanical stimulus, but, as novelty, also the influence of the availability of nutrients and hormones, with its implementation pursued within the finite element method. A simple uni-axial extension test is used to illustrate and compare our novel model against the classical approach. The results of the proposed modified model are promising for application to real-life problems.

On age-dependent bone remodeling.

A number of previous studies have investigated the possibilities of modelling the change in density of bones. Remodeling can be formulated at the constitutive or the kinematic level. In this work we introduce a formulation for the density growth process which takes not only the mechanical stimulus into account but also the influence of age on the evolution of growth. We demonstrate the implementation in the context of the finite element method. This novel approach is illustrated for a simple uniaxial extension test and is verified against previous numerical results. Moreover, two further physiologically motivated examples are performed. The results of the proposed modified model show excellent agreement with comparable results from literature and are promising for the application to real-life problems.

[Involvement of nonaccident-related diseases and ailments in assessments for private accident insurance : A problem discussion and assistance]. / Mitwirkung unfallfremder Krankheiten und Gebrechen in der Begutachtung für die private Unfallversicherung : Eine Problemdiskussion und Hilfestellung.

With the clarification by the Federal Court of Justice, the distinction between the principle of equivalence and the principle of adequacy for assessment has again come to the fore. In contrast to the equivalence principle for assessments in the German statutory accident insurance (DGUV), the principle of adequacy applies in private accident insurance. This means that an accident is always present whenever it does not lie completely outside the probability and the assessor has to carry out a further examination of the liability-based causality. Therefore, not only the accident occurrence has to be assessed but also the observance of the deadlines and, in the case of affirmation of the occurrence of a disability, whether or not unrelated ailments or diseases contributed to the accident. There are so far no points of reference for the estimation of participation. With the help of the theory of equivalence from linguistics, an attempt was made to provide assistance through definitions of the extent of participation.

Use of GFP-GvpE fusions to quantify the GvpD-mediated reduction of the transcriptional activator GvpE in haloarchaea.

Gas vesicle formation of Halobacterium salinarum is regulated by the transcriptional activator GvpE, and in the presence of the repressing protein GvpD, the amount of GvpE is strongly reduced. The green fluorescence protein was used to report this GvpD-mediated reduction of GvpE in vivo in Haloferax volcanii transformants. Both N- or C-terminal fusions of GFP to GvpE were tested, but only the N-terminal fusion reported the reduction. The fluorescence of GFP-GvpE was 62 % reduced with GvpD wild type (DWT), 78 % with the super-repressor D3-AAA, and only 10 % with the repression defect DMut6. Further analysis of D3-AAA indicated that the super-repression was due to the alteration R496A. GFP-GvpE variants defect in promoter activation was tested in the presence of DWT, D3-AAA and DMut6, and two of them were more stable. Overall, the GFP-GvpE fusion was suitable to study and quantify the amount of GvpE in vivo.

The Effects of Hook Plates on the Subacromial Space. A Clinical and MRI Study.

The disruption of the acromioclavicular joint is a relatively common injury of the shoulder girdle, often occurring in young athletes. The therapy of third degree injuries (Tossy III or Rockwood III-VI) is still controversial, and several operative techniques are practiced. In a retrospective study, 28 (= 72%) of the total number of 39 cases with a Tossy III disruption operated in our hospital between January 1998 until December 2002 with a hook plate according to Dreithaler were followed up. The average reexamination interval was 3.0 years (range 1.2-5.6 years) after surgery. Special emphasis was laid upon the question, if the hook had any effects on the subacromial space. The study included clinical, sonographic and MRI examinations of both shoulders in direct side-to-side comparison. About 86% of the patients were satisfied with the functional outcome, but only 54% with the cosmetic result. This was mostly due to remaining elevation of the lateral clavicula and heterotopic ossifications around the acromioclavicular joint, which were found in 43% of the patients without any functional deficit. The outcome-scores (DASH, Taft, Constant-Murley) yielded on the whole very good and good results. Instability of the AC-joint under load was found in seven patients, in three of these instability was severe, and two patients had a chronic subluxation with functional impairment.The sonographic investigation revealed no specific lesions of the rotator cuff in any patient. Age related degenerative changes were seen in 46%, however, the accentuation of the operated side was only 14%. In MRI there was no case of a complete rotator cuff tear. Corresponding to the sonographic examination increased numbers of exostoses, heterotopic ossifications, and arthrosis of the AC-joint were observed.

A biomechanical evaluation to optimize the configuration of a hinged external fixator for the primary treatment of severely displaced intraarticular calcaneus fractures with soft tissue damage.

The purpose of this investigation was to develop an optimized hinged external fixator for the primary treatment of dislocated, intra-articular calcaneus fractures with associated soft tissue damage. To this end, a calcaneus model was made out of a polyurethane block, and a steel cylinder served as the ankle joint and was connected to a synthetic model of the tibia via a metal clamp. A saw cut served as the fracture in the model. A Steinmann nail and Schanz screw were placed in defined positions in the model and connected medially and laterally with longitudinal support rods. The fixator allowed a total of 20 degrees of plantar- and dorsiflexion, with rotation in the virtual axis of the upper ankle joint. Changes in the model fracture were measured during cyclical strain, and at different screw positions in the model tibia and calcaneus. Miniature force sensors located on the longitudinal support rods, and a plantar tension spring, were used to measure pressure and tension. Reproducible values were determined and, with the optimal configuration, shifting within the osteotomy was minimal. In the experimental configuration, optimal tibial screw placement was 70 mm proximal to the rotation axis of the upper ankle joint, and optimal placement of the Steinmann nail was in the posterior surface of the calcaneus. These findings indicated that the hinged fixator allows 20 degrees of ankle movement without alteration of the rotation axis, and suggest that this type of external fixator can be used in all types of calcaneal fracture regardless of the soft tissue damage. ACFAS Level of Clinical Evidence: 5c.