[Coronaviruses as the cause of respiratory infections]. / Coronaviren als Ursache respiratorischer Infektionen.

BACKGROUND: There are six human pathogenic coronaviruses (CoV), which mainly cause infections of the respiratory system. In everyday clinical practice, it is helpful to know the relevance and characteristics of these pathogens. OBJECTIVE: To present the epidemiology, clinical picture and differences of human pathogenic CoV and to provide information on the diagnostics and treatment of patients suspected of having CoV infections. MATERIAL AND METHODS: Selective literature search, presentation of results and discussion of fundamental works and expert recommendations, including publications by the World Health Organization (WHO), the European Centre for Disease Prevention and Control (ECDC) and the Robert Koch Institute. RESULTS: The four endemic human CoVs (HCoV-NL63, HCoV-229E, HCoV-OC43 and HCoV-HKU1) mainly cause mild respiratory tract infections. In addition to these four endemic HCoV, the two epidemic CoV, severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV can cause severe pneumonia. The SARS-CoV has not been detected in humans in the last 15 years and MERS-CoV has been circulating mainly on the Arabian Peninsula since 2012; however, neither a specific treatment nor approved vaccines exist for any of the six human pathogenic CoVs. CONCLUSION: All six human CoVs can be diagnosed using RT-PCR on respiratory specimens but this is rarely necessary for the four endemic strains. In current clinical practice SARS-CoV has no importance as it has not been detected in humans for 15 years; however, a possible MERS-CoV infection should be taken into account in patients with typical symptoms and travel history to endemic regions. In this case, rapid diagnostic and general hygiene practices are important to prevent further transmission.

[New Pathogenetic Concepts and Pharmacological Studies on Adjuvant Therapy in Severe Pneumonia]. / Neue pathogenetische Konzepte und pharmakologische Studien zur adjuvanten Therapie bei schwerer Pneumonie.

Acute lung injury secondary to pneumonia results from inadequate activation of the innate immune system with hyperinflammation and alveolar-capillary barrier dysfunction. To date, effective strategies for prevention or treatment of acute lung injury in pneumonia besides antibiotics are lacking. In preclinical studies, promising therapeutic targets have been identified and novel strategies demonstrated to protect against lung failure in pneumonia. This review highlights some adjuvant therapeutic strategies for modulation of inflammation and stabilization of lung barrier function in pneumonia.

Rodent animal models of delayed bone healing and non-union formation: a comprehensive review.

Despite the growing knowledge on the mechanisms of fracture healing, delayed healing and non-union formation remain a major clinical challenge. Animal models are needed to study the complex process of normal and impaired fracture healing and to develop new therapeutic strategies. Whereas in the past mainly large animals have been used to study normal and impaired fracture healing, nowadays rodent models are of increasing interest. New osteosynthesis techniques for rat and mice have been developed during the last years, which allowed for the first time stable osteosynthesis in these animals comparable to the standards in large animals and humans. Based on these new implants, different models in rat and mice have been established to study delayed healing and non-union formation. Although in humans the terms delayed union and non-union are well defined, in rodents definitions are lacking. However, especially in scientific studies clear definitions are necessary to develop a uniform scientific language and allow comparison of the results between different studies. In this consensus report, we define the basic terms "union", "delayed healing" and "non-union" in rodent animal models. Based on a review of the literature and our own experience, we further provide an overview on available models of delayed healing and non-union formation in rats and mice. We further summarise the value of different approaches to study normal and delayed fracture healing as well as non-union formation, and discuss different methods of data evaluation.

Small animal bone healing models: standards, tips, and pitfalls results of a consensus meeting.

Small animal fracture models have gained increasing interest in fracture healing studies. To achieve standardized and defined study conditions, various variables must be carefully controlled when designing fracture healing experiments in mice or rats. The strain, age and sex of the animals may influence the process of fracture healing. Furthermore, the choice of the fracture fixation technique depends on the questions addressed, whereby intra- and extramedullary implants as well as open and closed surgical approaches may be considered. During the last few years, a variety of different, highly sophisticated implants for fracture fixation in small animals have been developed. Rigid fixation with locking plates or external fixators results in predominantly intramembranous healing in both mice and rats. Locking plates, external fixators, intramedullary screws, the locking nail and the pin-clip device allow different degrees of stability resulting in various amounts of endochondral and intramembranous healing. The use of common pins that do not provide rotational and axial stability during fracture stabilization should be discouraged in the future. Analyses should include at least biomechanical and histological evaluations, even if the focus of the study is directed towards the elucidation of molecular mechanisms of fracture healing using the largely available spectrum of antibodies and gene-targeted animals to study molecular mechanisms of fracture healing. This review discusses distinct requirements for the experimental setups as well as the advantages and pitfalls of the different fixation techniques in rats and mice.

Time kinetics of bone defect healing in response to BMP-2 and GDF-5 characterised by in vivo biomechanics.

This study reports that treatment of osseous defects with different growth factors initiates distinct rates of repair. We developed a new method for monitoring the progression of repair, based upon measuring the in vivo mechanical properties of healing bone. Two different members of the bone morphogenetic protein (BMP) family were chosen to initiate defect healing: BMP-2 to induce osteogenesis, and growth-and-differentiation factor (GDF)-5 to induce chondrogenesis. To evaluate bone healing, BMPs were implanted into stabilised 5 mm bone defects in rat femurs and compared to controls. During the first two weeks, in vivo biomechanical measurements showed similar values regardless of the treatment used. However, 2 weeks after surgery, the rhBMP-2 group had a substantial increase in stiffness, which was supported by the imaging modalities. Although the rhGDF-5 group showed comparable mechanical properties at 6 weeks as the rhBMP-2 group, the temporal development of regenerating tissues appeared different with rhGDF-5, resulting in a smaller callus and delayed tissue mineralisation. Moreover, histology showed the presence of cartilage in the rhGDF-5 group whereas the rhBMP-2 group had no cartilaginous tissue. Therefore, this study shows that rhBMP-2 and rhGDF-5 treated defects, under the same conditions, use distinct rates of bone healing as shown by the tissue mechanical properties. Furthermore, results showed that in vivo biomechanical method is capable of detecting differences in healing rate by means of change in callus stiffness due to tissue mineralisation.

Campylobacter spp. in broiler flocks at farm level and the potential for cross-contamination during slaughter.

Screening of broiler flocks for their Campylobacter carriage on farm level and consequently the spread of Campylobacter spp. during slaughtering can help to identify hygiene control points. Therefore, between December 2001 and August 2002 in total 51 broiler flocks from three farms of different geographical regions in Germany were analysed for thermophilic Campylobacter. Campylobacter spp. were isolated from 45% of the broiler flocks examined. Subsequently, 1101 samples were taken from 22 flocks during different stages of processing. Samples were collected from: transport crates before and after cleaning/disinfection, evisceration, post-scalded and post-chilled carcasses and endproducts. Additionally, 45 selected Campylobacter isolates of droppings were genotyped by pulsed-field gel electrophoresis (PFGE). Campylobacter carriage of flocks showed seasonal variation, with the highest contamination rate during the period of June to August. No evidence was found for a horizontal transmission from one broiler flock to the next via a persistent house-contamination. In each positive flock, one to three different genotypes were found. One or two clones dominated isolations obtained from the farm level. The fact that in different flocks indistinguishable isolates of clonal origin were detected during the same rearing period suggested a transmission between the broiler flocks or an intermittent common external source. In one case, isolates of clonal origin were detected in various farms during different rearing periods. Sampling during processing confirmed that the entrance of a positive flock resulted in contamination of the abattoir environment. Campylobacter spp. were isolated from all sampling stages along the processing line, with a percentage of 91.1-100 of isolates at different stages of slaughtering.

[Therapy of peripheral vessel stenosis and occlusion in patients with thromboangiitis obliterans]. / Therapie peripherer Gefäßstenosen und -verschlüsse bei Thromboangiitis obliterans.

Vasculitis consists of a group of diseases characterized by an inflammatory process of the vessel wall. There is a wide variation in symptoms and almost any organ or tissue can be affected. Thromboangiitis obliterans (TAO; also known as Buerger's disease) is a special form of vasculitis with recurring inflammation and thrombosis of small and medium size arteries and veins of the hands and feet. To date the etiology still remains unclear but there is a strong association with the use of tobacco products. Ulcerations and gangrene of the extremities are common complications often resulting in the need for amputation of the extremity involved. Treatment of TAO includes both surgical and non-surgical methods but there is still no agreement concerning the optimal treatment strategy. In this contribution the advantages and disadvantages of different treatment options will be addressed and representative cases will be discussed.

Digital image correlation: a technique for determining local mechanical conditions within early bone callus.

Local mechanical conditions are known to play a role during the regeneration of musculoskeletal tissues, and histomorphometrical investigations of the time course of healing have enabled specific conclusions regarding the mechanosensitivity of tissue differentiation. However, the mechanism for this influence is not clearly understood. In order to extend this analysis, it is essential to link local histological understanding with direct characterisation of the local mechanical environment. Digital image correlation (DIC) is a computer-based image analysis technique that enables the non-contact measurement of strains on material surfaces and is finding application in many areas of biomechanics. Here we report a DIC technique to investigate the local distribution of mechanical strain within regenerating soft tissue sections. We provide exemplary data from analysis of a section of sheep bone callus. An assessment of displacement measurement accuracy gave an RMS error of 4.2 microm, corresponding to an estimated strain error of 1.4%. The sections showed concentrations of up to four times the applied strain and comparison of the strain patterns with histological analysis confirmed that these concentrations reflected boundaries between hard and soft callus.