Biomedical subjects

Wolfgang Ritter

Publications and source records attributed to Wolfgang Ritter.

4 recordsLinked to original sources

PubMed2007

Development of a multiplex RT-PCR for the simultaneous detection of three viruses of the honeybee (Apis mellifera L.): acute bee paralysis virus, Black queen cell virus and Sacbrood virus.

A single-step multiple-target (multiplex) reverse transcription-PCR (RT-PCR) was developed for the simultaneous detection and differentiation of three economically important viruses of the honeybee Apis mellifera L.: Acute bee paralysis virus (ABPV), Black queen cell virus (BQCV) and Sacbrood virus (SBV). Three compatible sets of primers, specific for each virus, were designed in conserved regions of the viral genomes for use in a one-step (single tube) RT-PCR assay. The individual RT-PCR assays and the combined multiplex assay were optimized for highest sensitivity and specificity. The multiplex RT-PCR assay was tested on field samples collected from Austrian honeybee colonies. All three viruses were detected, and their identity was confirmed by sequencing of the PCR products. The described multiplex RT-PCR proved to be an accurate tool for rapid simultaneous detection of ABPV, BQCV and SBV directly in honeybee specimens.

Animals↗

PubMed2006

Aortocaval fistula after stent-graft repair.

PURPOSE: To report an aortocaval fistula after stent-graft repair and the feasibility of interventional treatment. CASE REPORT: A 78-year-old man with a 61-mm infrarenal aortic aneurysm (AA) was treated successfully with a Zenith bifurcated stent-graft. Three years later, the patient presented with deteriorating renal function and acute bronchial obstruction. Computed tomography showed an aortic diameter increased to 90 mm, dilatation of the inferior vena cava, and a distal type I endoleak. The patient's condition quickly deteriorated, and emergent imaging found a fistula with brisk flow between the aneurysm sac and the left iliac vein within a distal type I endoleak. During emergency endovascular repair, iliac extensions were implanted in the right common iliac artery and left external iliac artery. The left hypogastric artery was coil embolized to exclude flow into the aneurysm sac. After positioning the extensions, cardiac function improved, and the fistula was no longer palpable. The cardiac indices and renal function normalized, and he was discharged 20 days after admission. CONCLUSION: Aortocaval fistulas are a rare complication of AA stent-graft repair and may be successfully treated by interventional means.

Aged↗

PubMed2003

A novel transfecting peptide comprising a tetrameric nuclear localization sequence.

The transport of exogenous DNA into the nucleus of eukaryotic cells is a prerequisite for successful gene delivery. To favor nuclear transport we synthesized a tetramer of the nuclear localization signal (NLS) of the SV40 large T-antigen as a novel nonviral gene delivery vector. This 4.4-kDa lysine-rich peptide (NLSV404) binds and compacts DNA by electrostatic interaction and forms stable polyplexes. Apart from its sequence-specific potency to mediate nuclear accumulation of conjugated albumin, NLSV404 also displays properties of nuclear transport for plasmid DNA as confirmed by fluorescence in situ hybridization. Further, NLSV404 polyplexes are shown to efficiently transfect various cell lines such as 16HBE14o-, HeLa S6, and Cos7 cells. NLSV404 polyplexes displayed at least 20-fold higher transfection rates than analogous polyplexes formed by the nuclear transport-deficient mutant sequence cNLS. Using growth-arrested cells, NLSV404 complexes were at least 100-fold more efficient than cNLS complexes. Combination of NLSV404 peptide but not of cNLS peptide with preformed polyethylenimine and dendrimer DNA complexes resulted in a strong increase in transfection efficiency. Incubation of cells prior to transfection with NLSV404 polyplexes with excess free peptide NLSV404 but not with cNLS resulted in a dose-dependent dramatic decrease in the transfection rate, suggesting a sequence-specific competitive inhibition. These results indicate that NLSV404 mediates nuclear accumulation of transfected plasmid DNA and that it can be a highly useful component of nonviral gene vectors.

Active Transport, Cell Nucleus↗

PubMed2002

Phylogenetic analysis of acute bee paralysis virus strains.

Reverse transcription-PCR assays have been established for a quick, sensitive, and specific diagnosis of acute bee paralysis virus (ABPV), a common virus of the honeybee (Apis mellifera), directly from clinical samples. A 3,071-nucleotide fragment of the ABPV genome, which includes the entire capsid polyprotein gene, was amplified from Austrian, German, Polish, and Hungarian ABPV samples and sequenced, and the sequences were compared. The alignment of a smaller fragment with ABPV sequences from the United States and the United Kingdom revealed nucleotide identity rates between 89 and 96%, respectively. Phylogenetic trees which display the molecular relationship between the viruses of different geographic origin were constructed.

Animals↗