Unchanged Fatality Rate on Austrian Ski Slopes during the COVID-19 Lockdown.

Fatalities on ski slopes are very rare, with about one death per one million skier days. Whether the fatality rate is affected by substantial changes in the number of skier days and potentially associated alterations in the structure of the skier population is unknown. Thus, we compared the fatality rate on Austrian ski slopes in the winter season of 2020/21, when skiing activities were dramatically restricted during the COVID-19 lockdown, with those of the previous winter seasons. As a consequence of COVID-19 measures, the number of skier days dropped from over 50 million in previous years to 9.2 million skier days in the winter season of 2020/21. Still, the fatality rate (6.5 deaths/10 million skier days) was not different when compared to any of the seasons from 2011/12 to 2019/20. Despite the lack of international skiers and the reduction in skier days by more than 80%, the fatality rate remained surprisingly unchanged. The weather and snowfall conditions were on average comparable to those of previous winters, and, except for nationality, the composition of the skier population appears to have remained relatively unaltered. In conclusion, the fatality rate during downhill skiing is low and the absolute fatality numbers are primarily a function of the number of skier days

Mortality in Recreational Mountain-Biking in the Austrian Alps: A Retrospective Study over 16 Years.

Despite recreational mountain-biking's growing popularity worldwide, the literature on mortality in this leisure sporting activity is scarce. Therefore, the aim of the present study was to investigate the characteristics of fatal accidents as well as resulting dead victims during recreational mountain-biking in the Austrian Alps over the past 16 years. For this purpose, a retrospective study based on Austrian institutional documentation from 2006 to 2021 was conducted. In total, 97 fatalities (1 woman) with a mean age of 55.6 ± 13.9 years were recorded by the Austrian Alpine Police. Of those, 54.6% died due to a non-traumatic (mostly cardio-vascular) and 41.2% due to a traumatic event. Mountain-bikers fatally accidented for non-traumatic reasons frequently belonged to older age classes (p = 0.05) and mostly (73.6%) died during the ascent, whereas traumatic events mainly (70.0%) happened during the descent (p < 0.001). Throughout the examined period, the absolute number of fatalities slightly increased, whereas the mortality index (proportion of deaths/accidented victims) did not (mean value: 1.34 ± 0.56%). Factors such as male sex in general, above average age and uphill riding for non-traumatic accidents, as well as downhill riding for traumatic events, seem to be associated with fatalities during recreational mountain-biking in the Austrian Alps. These results should be considered for future preventive strategies in recreational mountain-biking

Sphingosine 1-phosphate modulates antigen capture by murine langerhans cells via the S1P2 receptor subtype

Dendritic cells (DCs) play a pivotal role in the development of cutaneous contact hypersensitivity (CHS) and atopic dermatitis as they capture and process antigen and present it to T lymphocytes in the lymphoid organs. Recently, it has been indicated that a topical application of the sphingolipid sphingosine 1-phosphate (S1P) prevents the inflammatory response in CHS, but the molecular mechanism is not fully elucidated. Here we indicate that treatment of mice with S1P is connected with an impaired antigen uptake by Langerhans cells (LCs), the initial step of CHS. Most of the known actions of S1P are mediated by a family of five specific G protein-coupled receptors. Our results indicate that S1P inhibits macropinocytosis of the murine LC line XS52 via S1P2 receptor stimulation followed by a reduced phosphatidylinositol 3-kinase (PI3K) activity. As down-regulation of S1P2 not only diminished S1P-mediated action but also enhanced the basal activity of LCs on antigen capture, an autocrine action of S1P has been assumed. Actually, S1P is continuously produced by LCs and secreted via the ATP binding cassette transporter ABCC1 to the extracellular environment. Consequently, inhibition of ABCC1, which decreased extracellular S1P levels, markedly increased the antigen uptake by LCs. Moreover, stimulation of sphingosine kinase activity, the crucial enzyme for S1P formation, is connected not only with enhanced S1P levels but also with diminished antigen capture. These results indicate that S1P is essential in LC homeostasis and influences skin immunity. This is of importance as previous reports suggested an alteration of S1P levels in atopic skin lesions

Limited Transplantation of Antigen-Expressing Hematopoietic Stem Cells Induces Long-Lasting Cytotoxic T Cell Responses

Harnessing the ability of cytotoxic T lymphocytes (CTLs) to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs) following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4–6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8+ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS

VLPs and particle strategies for cancer vaccines

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High Temperature Oxidation of a Commercial Cr-Mn Austenitic Steel in Air

THE OXIDATION OF AN AUSTENITIC STEEL CONTAINING 18 PERCENT CHROMIUM AND 12.3 PERCENT MANGANESE AT 800-1000 DEGREES C IN AIR OCCURS AT A SLOWER RATE THAN THAT OF A STEEL CONTAINING 9.5 PERCENT CHROMIUM AND 17.5 PERCENT MANGANESE. HOWEVER, THE RATE OF CORROSION OF THIS 18 PERCENT CHROMIUM ALLOYS IS STILL LARGE IN COMPARISON WITH THE CASE OF FORMATION OF A CONTINUOUS CHROMIA SCALE AT THE BASE OF SCALE LAYER. THIS RESULT IS ATTRIBUTED TO THE NEGATIVE EFFECT OF THE MANGANESE OF THE THERMODYNAMIC STABILITY OF CR2O3.NA-NOT AVAILABL