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The detection of galactomannan antigen in urine was investigated in 26 bone marrow transplant recipients using an Aspergillus latex agglutination test (Pastorex). After modification of the method, which was originally devised for serum testing, the detection limit in native urine was approximately 20 ng/ml. Antigen was found in 79 (36.4%) of 217 serial urine samples, compared to 40 (11.8%) of 340 serum samples. As a rule, antigenuria preceded antigenemia and was more persistent. The sensitivity, specificity, positive predictive value and negative predictive value of antigenuria for autopsy-proven aspergillosis and clinically suspected Aspergillus infection were 57%, 53%, 31% and 77%, respectively, while those of antigenemia were 43%, 53%, 25% and 71%. It is concluded that urine testing is more reliable than serum testing for the detection of Aspergillus galactomannan. The detection of antigen, however, whether in serum or in urine, allows no clear distinction between Aspergillus infection and exposure to non-infectious Aspergillus antigens.

Latent infection with Toxoplasma gondii has repeatedly been shown to be associated with behavioral changes that are commonly attributed to a presumed increase in dopaminergic signaling. Yet, virtually nothing is known about its effects on dopamine-driven reward processing. We therefore assessed behavior and event-related potentials in individuals with vs. without latent toxoplasmosis performing a rewarded control task. The data show that otherwise healthy young adults with latent toxoplasmosis show a greatly diminished response to monetary rewards as compared to their non-infected counterparts. While this selective effect eliminated a toxoplasmosis-induced speed advantage previously observed for non-rewarded behavior, Toxo-positive subjects could still be demonstrated to be superior to Toxo-negative subjects with respect to response accuracy. Event-related potential (ERP) and source localization analyses revealed that this advantage during rewarded behavior was based on increased allocation of processing resources reflected by larger visual late positive component (LPC) amplitudes and associated activity changes in the right temporo-parietal junction (BA40) and left auditory cortex (BA41). Taken together, individuals with latent toxoplasmosis show superior behavioral performance in challenging cognitive control situations but may at the same time have a reduced sensitivity towards motivational effects of rewards, which might be explained by the presumed increase in dopamine.

Summary. The infection of two Helicobacter pylori strains with a phage-containing supernate of the lysogenic H. pylori strain IMMi 290/89 resulted in a lytic cycle and propagation of phage HP1. In negatively-stained preparations, the empty phage heads measured 55-60 nm in diameter and mature heads measured 50 nm. The flexible, striated phage tail was c. 170 nm in length and 9-5 nm in diameter. The phage showed a mean density of 1.40 g/cm3 in sucrosedensity gradients and contained double-stranded DNA c. 22000 bp in length.

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