Investigation of the neutron contribution in the 6 MeV to 7 MeV high energy photon reference field.

In order to provide reference fields for the ionising radiation, PTB operates the ion accelerator facility. Referring to high energy photons, reference fields according to International Organization for Standardization 4037 series are produced. The neutron component of the 6-7 MeV photon field (R-F), which is produced by bombarding a CaF(2) target with protons with an energy of E(p) = 2.7 MeV, is investigated in detail for the first time. Two discriminative methods are used to determine the yield for neutrons produced in the CaF(2) target.

A new Clethrionomys-derived hantavirus from Germany: evidence for distinct genetic sublineages of Puumala viruses in Western Europe.

Puumala (PUU) viruses are the predominant etiologic agents of hantavirus infections in Europe. The most important reservoir is the bank vole, Clethrionomys glareolus (Cg), belonging to the subfamily Arvicolinae of the Muridae family. Here we report on the molecular characterization of the first rodent-derived sequence (PUU/Cg-Erft) from Germany. Comparison of the S and M segment coding regions revealed 92.5 and 92.8% identity, respectively, with PUU/H-9013, a human isolate from France. However, only 83.1% identity was found with the S segment of a previously reported PUU sequence from a German HFRS case (PUU/H-Berkel) indicating the co-existence of two distinct sublineages in Germany. Phylogenetic and alignment analyses of S and M segment coding regions enabled us to assign PUU viruses/sequences to at least six distinct genetic sublineages. Membership was defined by nucleotide sequence differences of < 8%, whereas a diversity of > 14% clearly outgrouped a virus/sequence. Based on S segment sequences the sublineage represented by Clethrionomys rufocanus-derived viruses from Japan diverged at a well supported node from the clade harbouring all Clethrionomys glareolus-derived European PUU viruses. A correlation between genetic relationship and geographic origin of PUU viruses was observed which may support a co-evolution of PUU viruses with distinct subspecies of their reservoir host.

Polymerase chain reaction detection of Puumala virus RNA in formaldehyde-fixed biopsy material.

BACKGROUND: Infections with hantaviruses, mainly Clethrionomys-derived Puumala viruses, are known causes of acute renal failure [hemorrhagic fever with renal syndrome (HFRS)] in western Europe. Laboratory diagnosis is primarily based on serology. At the time of clinical symptoms, viral RNA can hardly be detected in the blood or urine, indicating that polymerase chain reaction (PCR) is of little diagnostic value for these infections. Biopsy material is usually formaldehyde-fixed and, thus, regarded as poor quality for PCR applications. The aim of this study was to establish a technique to retrieve such material for laboratory diagnostic. METHODS: Formaldehyde-fixed, paraffin-embedded kidney biopsies of 14 patients with renal failure either clinically suspected for HFRS (7 cases) or caused by unknown (2 cases) or known other causes (drugs, sarcoidosis; 5 cases) were histologically investigated. An established S segment-specific PCR assay was applied to RNA isolated from the biopsies, and amplification products were verified by direct sequence determination. RESULTS: Investigations revealed a typical histopathological appearance for hantavirus infections in all seven suspected HFRS cases and one case of unknown cause. With five of the suspected HFRS cases, hantavirus-specific RNA was detected. Sequence comparison revealed a close relationship to corresponding nucleoproteins of known Puumala viruses. CONCLUSION: The established technique provides a simple and powerful tool that expands the diagnostic possibilities, especially for otherwise unidentified or retrospective cases. It further allows insight into the molecular epidemiology of HFRS-causing agents.

Failure to detect Borna disease virus infection in peripheral blood leukocytes from humans with psychiatric disorders.

The presence of antibodies reactive with Borna disease virus (BDV) in the sera of some patients with certain psychiatric illnesses has been taken as evidence that this veterinary neurotrophic virus may occasionally infect and cause psychiatric disorders in humans. In this paper, we report the results of our studies concerning the detection of BDV-specific RNA in blood cells from patients with psychiatric diseases. Contrary to the results obtained by others, we have found no evidence for the presence of BDV-RNA in such cells. Prior work with BDV sequences in the assay environment, together with the exquisite sensitivity of RT-PCR, may account for the sporadic appearance of false positive evidence that BDV-specific RNA is present in human blood cells.

Granulocyte colony-stimulating factor prophylaxis before operation protects against lethal consequences of postoperative peritonitis.

BACKGROUND: Postoperative peritonitis has a high mortality in human beings. It is accepted that cytokines are important mediators in pathophysiology of sepsis. The recent failure of clinical trials increased the necessity to proof new drugs in more clinically relevant animal models. The aim of this study was to examine the effect of granulocyte colony-stimulating factor (G-CSF) in addition to an antibiotic in postoperative peritonitis. METHODS: Dose-response curves and experimental conditions were developed in a total of 295 rats. The main experiment included three groups: control animals receiving a fecal inoculum, a group treated with antibiotic, and a third group receiving G-CSF in addition to the antibiotic. The main outcome was death, but in addition, serum tumor necrosis factor (TNF) level was determined. RESULTS: The mortality rate of 60% in antibiotic treated animals was considerably reduced by G-CSF to 20%. All animals of the control group died during the observation period of 120 hours. A correlation between TNF levels and mortality rate was observed. In G-CSF treated animals total suppression of TNF serum levels was accessible in contrast to the others. CONCLUSIONS: In a clinically relevant animal model G-CSF was effective as an additional concept of prophylaxis. These data are promising toward clinical trials.

Differentiation of selected members of the family Neisseriaceae (Alysiella, Eikenella, Kingella, Simonsiella and CDC groups EF-4 and M-5) by carbohydrate fingerprints and selected phenotypic features.

On the basis of nucleic acid relationships, the family Neisseriaceae consists of the genera Neisseria, Kingella, Simonsiella and of Alysiella filiformis, Eikenella corrodens, and the CDC groups EF-4 and M-5. Differentiation, especially of the new members of the family, by conventional phenotypic characteristics is difficult and in some cases leads to doubtful results. On the other hand, cellular components proved to be suitable for the characterization of bacterial taxa. We investigated the cellular carbohydrates derived from whole cell hydrolysates of the above mentioned taxa with the exception of Neisseria by gas chromatography/mass-spectrometry. The analysis revealed characteristic patterns for all taxa considered, although with some species of which only few strains were investigated so far only preliminary results could be established. With the method used, the carbohydrate analysis could be completed within six hours starting from a pure culture. All strains investigated exhibited a common pattern with ribose, arabinose, glucose, and galactose. Qualitative and quantitative differences in contents of fucose, sorbose, rhamnose, threose, heptose, galactosamine and an amino sugar similar to glucosamine discriminated members of the taxa investigated. To achieve a taxonomically precise differentiation of the species investigated by conventional phenotypic features as available in commercial rapid test kits, these tests should be completed by the carbohydrate analysis technique presented.