[Anticoagulation for atrial fibrillation : the future has begun]

According to new criteria based on the CHAD(2)DS(2)-VASc score, the threshold for administering anticoagulation therapy for atrial fibrillation patients is being increasingly lowered. With the development of new anticoagulants, more therapy options are available. Currently, vitamin K antagonists are still the standard treatment. However, this therapy is problematic for some patients. Because of the increased bleeding risk and need for continuous blood tests to monitor coagulation, many patients needing anticoagulation therapy are not treated. The new anticoagulants apixaban, rivaroxaban and dabigatran were developed with the goal of avoiding these problems. Dabigatran has already been approved for thromboembolism prophylaxis for patients with atrial fibrillation. All three substances do not require routine control blood tests. Whether the costs saved by this together with the prevention of ischemic and bleeding events justify the higher price of these drugs compared to vitamin K antagonists needs to be examined by socioeconomic studies.

Fifty years of individual monitoring of ionising radiation in Switzerland: history, trends and perspectives

In the last 50 y, individual monitoring of ionising radiation in Switzerland underwent substantial development, strongly influenced by type of applications of ionising radiation, monitoring technologies, knowledge of health risks, protection philosophies and regulatory frameworks. The role of individual monitoring in the system of radiation protection moved from a passive, a posteriori control of limits towards an important and more interactive tool for optimisation. Dose trends for occupational exposures document these developments. In the future, new and emerging dose intensive applications in medicine and an increasing demand for international harmonisation, particularly in Europe, will pose new challenges in individual monitoring.

Numerical analysis of a unique mode of locomotion: vertical climbing by Pacific lamprey

Pacific lampreys are capable of climbing vertical wetted surfaces through a two-phase (bending and stretching) locomotion mode using the oral disc for adherence. We investigate the physical mechanism and performance of this process by using a continuous beam model. Two mechanisms, one akin to the jumping process and the other related to the fast stretching of the body, have been identified. This locomotion mode may inspire biomimetic designs of anguilliform swimming devices capable of overcoming steep obstacles. By using a genetic algorithm simulation we identify the combination of kinematic parameters corresponding to optimal efficiency (defined as the gravitational potential energy gained in each climbing step divided by the energy spent to activate the motion). These parameters are similar to laboratory observations of lamprey motion, suggesting that this type of locomotion has been optimized for maximum efficiency through evolution.

Six weeks' sebacic acid supplementation improves fasting plasma glucose, HbA1c and glucose tolerance in db/db mice

AIM

To investigate the impact of chronic ingestion of sebacic acid (SA), a 10-carbon medium-chain dicarboxylic acid, on glycaemic control in a mouse model of type 2 diabetes (T2D).

METHODS

Three groups of 15 db/db mice were fed for 6 weeks either a chow diet (Ctrl) or a chow diet supplemented with 1.5 or 15% (SA(1.5%) and SA(15%) , respectively) energy from SA. Fasting glycaemia was measured once a week and HbA1c before and after supplementation. An oral glucose tolerance test (OGTT) was performed at the end of the supplementation. Gene expression was determined by transcriptomic analysis on the liver of the Ctrl and SA(15%) groups.

RESULTS

After 42 days of supplementation, fasting glycaemia and HbA1c were ∼70 and 25% lower in the SA(15%) group compared with the other groups showing a beneficial effect of SA on hyperglycaemia. During OGTT, plasma glucose area under the curve was reduced after SA(15%) compared with the other groups. This effect was associated with a tendency for an improved insulin response. In the liver, Pck1 and FBP mRNA were statistically decreased in the SA(15%) compared with Ctrl suggesting a reduced hepatic glucose output induced by SA.

CONCLUSION

Dietary supplementation of SA largely improves glycaemic control in a mouse model of T2D. This beneficial effect may be due to (i) an improved glucose-induced insulin secretion and (ii) a reduced hepatic glucose output.

Enhanced cartilage regeneration in MIA/CD-RAP deficient mice

Melanoma inhibitory activity/cartilage-derived retinoic acid-sensitive protein (MIA/CD-RAP) is a small soluble protein secreted from chondrocytes. It was identified as the prototype of a family of extracellular proteins adopting an SH3 domain-like fold. In order to study the consequences of MIA/CD-RAP deficiency in detail we used mice with a targeted gene disruption of MIA/CD-RAP (MIA−/−) and analyzed cartilage organisation and differentiation in in vivo and in vitro models. Cartilage formation and regeneration was determined in models for osteoarthritis and fracture healing in vivo, in addition to in vitro studies using mesenchymal stem cells of MIA−/− mice. Interestingly, our data suggest enhanced chondrocytic regeneration in the MIA−/− mice, modulated by enhanced proliferation and delayed differentiation. Expression analysis of cartilage tissue derived from MIA−/− mice revealed strong downregulation of nuclear RNA-binding protein 54-kDa (p54^nrb), a recently described modulator of Sox9 activity. In this study, we present p54^nrb as a mediator of MIA/CD-RAP to promote chondrogenesis. Taken together, our data indicate that MIA/CD-RAP is required for differentiation in cartilage potentially by regulating signaling processes during differentiation.

Anti-CTLA-4 treatment induces IL-10-producing ICOS+ regulatory T cells displaying IDO-dependent anti-inflammatory properties in a mouse model of colitis

BACKGROUND AND AIMS

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) has been shown to act as a negative regulator of T cell function and has been implicated in the regulation of T helper 1 (Th1)/Th2 development and the function of regulatory T cells. Tests were carried out to determine whether anti-CTLA-4 treatment would alter the polarisation of naive T cells in vivo.

METHODS

Mice were treated with anti-CTLA-4 monoclonal antibody (mAb) (UC10-4F10) at the time of immunisation or colonic instillation of trinitrobenzene sulfonic acid (TNBS). The cytokines produced by lymph node cells after in vitro antigenic stimulation and the role of indoleamine 2,3 dioxygenase (IDO) and of interleukin-10 (IL-10) were tested, and the survival of mice was monitored.

RESULTS

Injection of anti-CTLA-4 mAb in mice during priming induced the development of adaptive CD4(+) regulatory T cells which expressed high levels of ICOS (inducible co-stimulator), secreted IL-4 and IL-10. This treatment inhibited Th1 memory responses in vivo and repressed experimental intestinal inflammation. The anti-CTLA-4-induced amelioration of disease correlated with IDO expression and infiltration of ICOS(high) Foxp3(+) T cells in the intestine, suggesting that anti-CTLA-4 acted indirectly through the development of regulatory T cells producing IL-10 and inducing IDO.

CONCLUSIONS

These observations emphasise the synergy between IL-10 and IDO as anti-inflammatory agents and highlight anti-CTLA-4 treatment as a potential novel immunotherapeutic approach for inducing adaptive regulatory T cells.

[The role of thrombin in angiogenesis]

The formation of vasculature is a key step during embryogenesis. The vasculature and the intravascular blood compartment, which uses the former as a means of transportation, develop in a close spatial and temporal relationship. This review discusses the role of the blood coagulation system, particularly thrombin, as a tool to coordinate blood vessel formation. Mouse models indicate that a lack of coagulation factors results in impaired thrombin generation and consequently display a phenotype of disturbed cardiovascular development. Similar phenotypes are present in mouse models of impaired thrombin binding to its cellular receptor PAR1 or of disrupted signaling via G-proteins. Moreover, there is compelling evidence that thrombin signaling in vascular development cannot be explained by a model based only on the classical extrinsic and intrinsic coagulation pathways. As angiogenesis in adults follows the same signaling patterns as in embryos, it is of importance to learn about these pathways, hoping that they may serve as therapeutic targets in cardiovascular disease.

[The role of microparticles in vascular diseases]

Microparticles (MP) are small cell vesicles that are released by activated or apoptotic cells and that are amenable to quantification in peripheral blood. MP consist of the cytoplasm and the cell membrane of their cell of origin, which allows for their assignment to these cells. By the detection of the respected MP one can conclude to the functional status of the cell of origin. It is known that MP confer specific information between cells and contribute to inflammatory and coagulatory processes. They are detectable in many acute and chronic vascular diseases as a surrogate marker for disease activity but also play a role in the pathophysiology of vascular diseases.

Blood clots in the cumulus-oocyte complex predict poor oocyte quality and post-fertilization development

Assessment of oocyte maturity and quality (morphological appearance) at the time of retrieval is difficult as the egg is obscured by a large cumulus mass that hinders adequate scoring. Since no data are available on the possible relationship between the cumulus-oocyte complex (COC) and oocyte morphology, this prospective intracytoplasmic sperm injection study was set up in 87 consecutive patients. COC were grouped according to expansion of both corona radiata and cumulus matrix. Special emphasis was placed on recording morphological anomalies of COC (inclusion of blood clots and amorphous clumps). For all mature ovae, quality was assessed and preimplantation development followed up to blastocyst stage if fertilized. The risk of not harvesting an oocyte was higher in COC with blood clots compared with normal cumulus matrices (P = 0.004). COC expansion did not allow for prediction of either nuclear status or quality of the egg. The presence of blood clots within the cumulus matrix was associated with reduced oocyte quality (dense central granulation), fertilization rate and blastocyst formation, compared with unaffected COC (P < 0.05). It may be postulated that COC showing blood inclusions derive from poor quality follicles, which has a detrimental effect on oocyte quality and further cleavage to blastocyst stage. Consequently, mechanical removal of blood clots cannot rescue the corresponding embryo.

Surface and Bulk Degradation of Teflon® FEP Retrieved from the Hubble Space Telescope Solar Arrays

Teflon® fluorinated ethylene propylene (FEP) is used on the Hubble Space Telescope (HST) as the outer layer of multilayer insulation (MLI) blankets. During space shuttle servicing missions (SM) to HST through thickness cracks were observed in the FEP layers. Material brought to Earth for investigation showed signs of severe degradation. During servicing mission 3B, the 4th servicing mission to HST in March 2002, the second pair of European Space Agency ESA built solar arrays was retrieved and flown back to Earth after 8.25 years in space. Samples of the MLI thermal control material were taken from the solar array drive arm (SADA) and investigated for surface and bulk degradation. The MLI was enveloped around the SADA and thus allowed the examination of FEP degradation in dependence of the orientation of space exposed areas with respect to the Sun. Therefore micrographs of FEP surfaces and fractographs of through thickness cracks were taken and the solar absorptance αS and the normal emittance εN was measured on the entire MLI. Differential scanning calorimetrical analyses as well as electron spectroscopy for chemical analyses were conducted to analyze chemical changes of the bulk polymer and the surface layer, respectively. Tensile properties and mass losses of the space exposed material were evaluated as well. Results of the investigated thermal control material are compared with samples exposed on the ground to thermal cycling, soft X-rays and vacuum ultra-violet radiation as well as to previously reported results on space-exposed FEP. The paper thus gives further insight into the mechanism and processes contributing to the on orbit degradation of Teflon® FEP and correlates the presented data with exposure levels and exposure conditions.