Biomedical subjects

Uta Gölnitz

Publications and source records attributed to Uta Gölnitz.

3 recordsLinked to original sources

PubMed2005

Rapid turnover of Plasmodium falciparum var gene transcripts and genotypes during natural non-symptomatic infections.

The var genes of Plasmodium falciparum code for the antigenically variant erythrocyte membrane proteins 1 (PfEMP1), a major factor for cytoadherence and immune escape of the parasite. Herein, we analyzed the var gene transcript turnover in two ongoing, non-symptomatic infections at sequential time points during two weeks. The number of different circulating genomes was estimated by microsatellite analyses. In both infections, we observed a rapid turnover of plasmodial genotypes and var transcripts. The rapidly changing repertoire of var transcripts could have been caused either by swift elimination of circulating var-transcribing parasites stemming from different or identical genetic backgrounds, or by accelerated switching of var gene transcription itself.

Adult↗

PubMed2004

Replicon system for Lassa virus.

Lassa virus is endemic to West Africa and causes hemorrhagic fever in humans. To facilitate the functional analysis of this virus, a replicon system was developed based on Lassa virus strain AV. Genomic and antigenomic minigenomes (MG) were constructed consisting of the intergenic region of S RNA and a reporter gene (Renilla luciferase) in antisense orientation, flanked by the 5' and 3' untranslated regions of S RNA. MGs were expressed under the control of the T7 promoter. Nucleoprotein (NP), L protein, and Z protein were expressed from plasmids containing the T7 promoter and internal ribosomal entry site. Transfection of cells stably expressing T7 RNA polymerase (BSR T7/5) with MG in the form of DNA or RNA and plasmids for the expression of NP and L protein resulted in high levels of Renilla luciferase expression. The replicon system was optimized with respect to the ratio of the transfected constructs and by modifying the 5' end of the MG. Maximum activity was observed 24 to 36 h after transfection with a signal-to-noise ratio of 2 to 3 log units. Northern blot analysis provided evidence for replication and transcription of the MG. Z protein downregulated replicon activity close to background levels. Treatment with ribavirin and alpha interferon inhibited replicon activity, suggesting that both act on the level of RNA replication, transcription, or ribonucleoprotein assembly. In conclusion, this study describes the first replicon system for a highly pathogenic arenavirus. It is a tool for investigating the mechanisms of replication and transcription of Lassa virus and may facilitate the testing of antivirals outside a biosafety level 4 laboratory.

Animals↗

PubMed2003

Imported Lassa fever in Germany: surveillance and management of contact persons.

This study sought to assess the risk of secondary transmission after import of Lassa fever into Europe. A total of 232 persons exposed to a case of Lassa fever imported into Germany were identified. The level of exposure was determined for 157 persons (68%), and 149 (64%) were tested serologically. High-risk or close contact was reported by 30 (19%) of 157 persons. No symptomatic secondary infections were observed. However, Lassa virus-specific immunoglobulin G antibodies were detected in a serum sample obtained from a physician who examined the index patient on day 9 of illness. The physician received ribavirin prophylaxis and did not develop symptoms of Lassa fever. On the basis of these data, the contact was classified as having a probable secondary infection. The study indicates a low risk of transmission during the initial phase of symptomatic Lassa fever, even with high-risk exposures. The risk may increase with progression of disease and increasing virus load.

Animals↗