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Traces of particulate radioactive iodine (131I) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 μBq m–3except at one location in western Russia where they reached up to several mBq m–3. Detections have been reported continuously over an 8-week period by about 30 monitoring stations. We examine possible emission source apportionments and rank them considering their expected contribution in terms of orders of magnitude from typical routine releases: radiopharmaceutical production units > sewage sludge incinerators > nuclear power plants > spontaneous fission of uranium in soil. Inverse modeling simulations indicate that the widespread detections of 131I resulted from the combination of multiple source releases. Among them, those from radiopharmaceutical production units remain the most likely. One of them is located in Western Russia and its estimated source term complies with authorized limits. Other existing sources related to 131I use (medical purposes or sewage sludge incineration) can explain detections on a rather local scale. As an enhancing factor, the prevailing wintertime meteorological situations marked by strong temperature inversions led to poor dispersion conditions that resulted in higher concentrations exceeding usual detection limits in use within the informal Ring of Five (Ro5) monitoring network.

The dead of Alexander Litvinenko in London in the late 2006 was linked with the visit of Dimitri Kovtun. So an investigation was started by the Hamburg Police. As the presence of polonium-210 was uncertain, the action was supported by the Federal Defense against Nuclear Hazards (NGA) of the Federal Office for Radiation Protection (BfS). Radiation measurements in some flats in Hamburg confirmed the suspicion of polonium-210 contaminations. As incorporations by ingestion or inhalation could not generally be excluded, the Coordinating Office on Incorporation Monitoring of the BfS (Leitstelle Inkorporationsüberwachung des BfS) was requested to clarify this issue. The BfS office then coordinated the required bioassay analyses of urine samples carried out at four officially appointed in-vitro laboratories for incorporation monitoring. The group of people to be examined included the members of the family involved living in the contaminated flats, the emergency forces, as well as potentially exposed members of the public. The calculation of the internal dose was based on standard assumptions and also conducted by the BfS. The internal radiation doses proved to be within the range of radiation doses due to natural exposures. Retrospectively it should be stressed that the collaboration and cooperation of all institutions involved in the operation in Hamburg was extremely good despite their differing organisational structures. As a result of the incident in Hamburg various middle and long-term measures have been taken since then by the BfS Coordinating Office on Incorporation Monitoring.

To investigate the mechanism of CD4T-cell help during the activation and differentiation of directly alloreactive CD8T cells, we examined the development of obliterative airways disease (OAD) following transplantation of airways into fully mismatched recipient mice deficient in CD4T cells. BALBc trachea allografts became fibrosed significantly less frequently in B6 CD4??recipients as compared to wildtype controls. Furthermore, class I-directed cytotoxicity failed to develop in the absence of CD4T cells. The infiltration of graft tissue by primed Ld-specific directly alloreactive 2C CD8T cells was not found to depend on the presence of CD4T cells. Nevertheless, graft-infiltrating 2C CD8T cells failed to express CD69 and granzyme B when CD4T-cell help was unavailable. Importantly, reconstitution of B6 CD4??recipient mice with graft peptide-specific TCR-Tg CD4T cells (OT-II or TEa) capable of recognizing antigen only on recipient APC allowed for full expression of CD69 and granzyme B by the directly alloreactive CD8T cells and restored the capacity of recipients to reject their allografts. These results demonstrate that indirectly alloreactive CD4T cells ensure the optimal activation and differentiation of graft-infiltrating directly alloreactive CD8T cells independent of donor APC recognition.

Lung and heart-lung transplantation are effective treatments for many diseases unresponsive to other therapy. However, long-term survival of recipients is limited by the development of obliterative bronchiolitis (OB). In this study, microarray analysis of a heterotopic mouse model of obliterative airway disease (OAD) was used to test the hypothesis that the expression and patterns of genes will correlate with specific changes in tracheal tissue developing a response to allotransplantation and the infiltrating cells manifesting these changes. Expression profiles observed were in accordance with the current paradigm of a predictable sequence of events, beginning with airway injury; an innate immune response followed by an adaptive immune response, including both cell-mediated and humoral components; and eventual loss of airway epithelial cells. These observations confirm and expand the list of genes and molecular processes that can be studied as potential surrogate markers or targets for intervention of OB.

Lung and heart‐lung transplantation are effective treatments for many diseases unresponsive to other therapy. However, long‐term survival of recipients is limited by the development of obliterative bronchiolitis (OB). In this study, microarray analysis of a heterotopic mouse model of obliterative airway disease (OAD) was used to test the hypothesis that the expression and patterns of genes will correlate with specific changes in tracheal tissue developing a response to allotransplantation and the infiltrating cells manifesting these changes. Expression profiles observed were in accordance with the current paradigm of a predictable sequence of events, beginning with airway injury; an innate immune response followed by an adaptive immune response, including both cell‐mediated and humoral components; and eventual loss of airway epithelial cells. These observations confirm and expand the list of genes and molecular processes that can be studied as potential surrogate markers or targets for intervention of OB.

Indirect recognition of minor histocompatibility antigens (mHAg) and/or MHC-encoded allopeptides is an important barrier to long-term allograft acceptance following solid organ transplantation. Efficient priming of CD8+T cells can occur after allotransplantation as a consequence of cross-presentation of donor-derived proteins by the graft recipient's APC. Consistent with this, draining lymph node clonal expansion of OVA- reactive OT-ICD8+T cells following placement of OVA-transgenic skin grafts did not depend on graft expression of Kb. However, OT-I T cells did accumulate in OVA-transgenic skin grafts most efficiently only when both the donor and host expressed Kb. OT-I infiltration of (B6-OVA × BALB/c)F1grafts in B6 recipients was not suppressed by graft expression of H-2d. Furthermore, B6 animals transplanted with both B6-OVA and BALB/c-OVA skin had more OT-I T cells infiltrating their B6-OVA MHC-matched graft. Therefore, class I MHC matching between donor and host may not always favor an avoidance of alloreactivity within the graft tissue.

Indirect recognition of minor histocompatibility antigens (mHAg) and/or MHC-encoded allopeptides is an important barrier to long-term allograft acceptance following solid organ transplantation. Efficient priming of CD8+ T cells can occur after allotransplantation as a consequence of cross-presentation of donor-derived proteins by the graft recipient's APC. Consistent with this, draining lymph node clonal expansion of OVA-reactive OT-I CD8+ T cells following placement of OVA-transgenic skin grafts did not depend on graft expression of Kb. However, OT-I T cells did accumulate in OVA-transgenic skin grafts most efficiently only when both the donor and host expressed Kb. OT-I infiltration of (B6-OVA × BALB/c)F1 grafts in B6 recipients was not suppressed by graft expression of H-2d. Furthermore, B6 animals transplanted with both B6-OVA and BALB/c-OVA skin had more OT-I T cells infiltrating their B6-OVA MHC-matched graft. Therefore, class I MHC matching between donor and host may not always favor an avoidance of alloreactivity within the graft tissue.

In case of a radioactive emergency radioactive plumes may be expected in heights up to the tropopause. For this reason aircraft measurements are necessary as a supplement to ground-based measuring sites. The authors present an aircraft type Learjet 35A used for localizing and analyzing radioactive contaminated air masses up to 12,000 m. The aircraft is equipped with an isokinetic high-volume sampler to collect aerosols on filters outside the pressurized cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyze the filters during flight as well as a dose ratemeter, a radon daughter monitor and equipment to collect gaseous iodine and noble gases. The meteorological parameters temperature, atmospheric pressure, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted from the plane to the headquarter of the German Meteorological Service (Deutscher Wetterdienst, DWD) and used for verifying the prognosis.

The measurement of radioactivity concentrations in urine samples is an important tool for monitoring possible radionuclide intakes by occupationally exposed workers, especially for radionuclides emitting alpha or beta radiation. Quality assurance requires systematic intercomparisons involving all laboratories responsible for these measurements. Such analyses were performed by the German--Swiss Radiation Protection Association. The main purpose of these measurements was the specification of criteria for the acceptance of laboratories by radiation protection authorities. This contribution presents some measurement results of Th-nat, 90 Sr, and 241 Am in urine and discusses the implications for internal dosimetry.

Thorium is a natural radioactive element and has numerous applications. The extremely low annual limits on intake of national and international regulations and the extreme difficulties in detecting thorium in the body or excreta makes high demands on the techniques used for monitoring of exposed workers. In addition, there are problems resulting from a lack of information on the biokinetics of thorium and its radioactive decay products. A programme for monitoring thorium intakes on the basis of new regulations in Germany, is described.

The measurement of radioactivity concentrations in urine samples is an important tool for the monitoring of possible radionuclide intakes by occupationally exposed workers, especially for those radionuclides emitting alpha or beta radiation. The new German guideline for requirements for measuring laboratories requires measures for standardisation and quality assurance by all laboratories responsible for such measurements. For this purpose the working group 'Incorporation Monitoring (AKI)' of the German-Swiss Radiation Protection Association has already performed, in the period from 1981 to 1997, interlaboratory comparisons of uranium, thorium, americium, lead, strontium and tritium in urine. The results and their implications for internal dosimetry are presented.