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Biomedical subjects

Peter Wutzler

Publications and source records attributed to Peter Wutzler.

At least 19 recordsLinked to original sources
PubMed2007

Antiviral effects of pan-caspase inhibitors on the replication of coxsackievirus B3.

The induction of apoptosis during coxsackievirus B3 (CVB3) infection is well documented. In order to study whether the inhibition of apoptosis has an impact on CVB3 replication, the pan-caspase inhibitor Z-VAD-FMK was used. The decreased CVB3 replication is based on reduced accumulation of both viral RNA and viral proteins. These effects are due to an inhibitory influence of Z-VAD-FMK on the proteolytic activity of the CVB3 proteases 2A and 3C, which was demonstrated by using the target protein poly(A)-binding protein (PABP). The antiviral effect of the structurally different pan-caspase inhibitor Q-VD-OPH was independently of the viral protease inhibition and resulted in suppression of virus progeny production and impaired release of newly produced CVB3 from infected cells. A delayed release of cytochrome c into the cytoplasm was detected in Q-VD-OPH-treated CVB3-infected cells pointing to an involvement of caspases in the initial steps of mitochondrial membrane-permeabilization.

Amino Acid Chloromethyl Ketones↗
PubMed2007

[Varicella during pregnancy and in neonates].

Varicella belongs to the most common vaccine-preventable diseases in Germany. During pregnancy, varicella may have serious consequences for the pregnant women and for the fetus or newborn. Pregnant women who contract varicella are at risk of pneumonia which must be regarded as a medical emergency. Chicken pox between the 5th and 24th weeks of pregnancy may lead to the congenital varicella syndrome. In case of maternal varicella during the last few weeks of pregnancy or shortly after delivery, the virus can cause chicken pox in the newborn. Life-threaten ing disseminated neonatal varicella must be expected if the mother develops chicken pox between 5 days before and 2 days after delivery. Using currently available diagnostics, immuno-prophylactic and therapeutic opportunities, these serious consequences of varicella during pregnancy can be prevented.

Chickenpox↗
PubMed2006

Amantadine resistance among porcine H1N1, H1N2, and H3N2 influenza A viruses isolated in Germany between 1981 and 2001.

This study was designed to gain insight into amantadine susceptibility of porcine influenza A viruses isolated in Germany between 1981 and 2001. The 12 studied H1N1, H1N2, and H3N2 porcine influenza virus strains were isolated in chicken eggs and passaged once in MDCK cells. Plaque reduction assays were applied to examine virus susceptibility to amantadine. Genotyping was used to confirm drug resistance. In the results of these antiviral studies, only 3 of the 12 isolates were shown to be amantadine-susceptible. All resistant strains contained the AA substitutions G16E, S31N, and R77Q in the membrane protein 2 (M2). Additionally, L27A was detected in two H1N1 strains. S31N and/or L27A are well-known amino acid substitutions in M2 that confer amantadine resistance. The role of the pig as an intermediate host of avian and human influenza A viruses, the possible involvement of genetic reassortment, and the high incidence of naturally amantadine-resistant porcine influenza A viruses suggest a real risk of emergence of amantadine resistant human viruses. Therefore, drug susceptibility monitoring appears to be warranted for effective application of those drugs.

Amantadine↗
PubMed2006

Antiviral activity of cyclosaligenyl prodrugs of the nucleoside analogue bromovinyldeoxyuridine against herpes viruses.

A series of 42 lipophilic bromovinyldeoxyuridine monophosphates (BVDUMPs) are presented as potential prodrugs of the antiviral agent (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU). The 5'-cycloSal-masking group technique has been applied to this cyclic nucleoside analogue to achieve delivery of the monophosphate of BVDU inside the target cells. The new substances have been tested for their antiviral activity against herpes simplex virus types 1 and 2 (HSV-1 and -2), thymidine kinase-deficient (TK(-)) HSV-1, varicella-zoster virus (VZV), human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The XTT-based tetrazolium reduction assay EZ4U (for HSV), the plaque inhibition test (for VZV and HCMV) and a DNA hybridisation assay (for EBV) were used to assess antiviral activity. The results indicate that cycloSal-BVDUMP triesters proved to be potent and selective inhibitors of HSV-1 comparable with aciclovir. VZV replication was inhibited by very low concentrations, and two substances had a slightly better anti-VZV activity than the parent compound BVDU. No antiviral effect could be demonstrated against TK(-)-HSV-1, HSV-2 and HCMV, most likely owing to the lack of phosphorylation to BVDU diphosphate. Most remarkably, several cycloSal-BVDUMP triesters yielded promising anti-EBV activity whereas the parent compound BVDU was entirely inactive.

Antiviral Agents↗
PubMed2006

Co-expression of interleukin-2 by a bicistronic plasmid increases the efficacy of DNA immunization to prevent influenza virus infections.

A promising approach to protect susceptible individuals against severe diseases is the inoculation of plasmids. Such DNA vaccines against influenza virus infections were quite efficient in different animal models; but still this procedure is not in clinical use until today. The present study reports the generation and characterization of bicistronic plasmids which enables the expression of influenza A virus gene sequences together with immunostimulatory cytokines demonstrating that among these cytokines especially interleukin-2 (IL-2) was efficient to prevent a lethal influenza virus infection in mice.

Adjuvants, Immunologic↗
PubMed2006

Fatal outcome of herpes simplex virus type 1-induced necrotic hepatitis in a neonate.

In neonates, herpes simplex virus (HSV) infections can lead to severe diseases associated with high mortality. We report a 6-day-old girl who developed clinical signs of fulminant hepatic failure accompanied by infectious-toxic shock and disseminated coagulopathy secondary to HSV type 1 (HSV-1) infection. The diagnosis was performed postmortem by demonstration of HSV-1 DNA in liver tissue as well as by retrospective detection of HSV-specific antibodies.

Antibodies, Viral↗
PubMed2006

Comparison of a LightCycler-based real-time PCR for quantitation of Epstein-Barr viral load in different clinical specimens with semiquantitative PCR.

Measurement of viral load is important in predicting and monitoring of Epstein-Barr virus (EBV)-associated diseases especially in immunocompromised patients. The objectives of this study were the development of a LightCycler-based real-time PCR assay using primers and probes which recognize the virus capsid antigen p23-encoding region and its comparison to the semiquantitative PCR. The LightCycler protocol shows a high degree of specificity and inter- and intra-assay reproducibility. Concerning sensitivity, a good correlation between both methods was demonstrated for standard plasmid DNA, reference DNA isolated from the EBV-genome containing Namalwa cell line, and DNA extracted from plasma/cerebrospinal fluid (CSF). The detection limit was determined with 1 copy/microl eluate for the standard plasmid DNA and with 500 copies/ml plasma or CSF. For DNA derived from peripheral blood mononuclear cells (PBMCs), a decrease of sensitivity by factor 10-100 was found when larger amounts of background DNA (500 and 100 ng) were used presuming an inhibitory effect of cellular DNA. This was supported by running dilutions of the plasmid standard carried out with EBV-negative Ramos cell DNA. Thus, the cut-off level was estimated with 100-500 copies/10(5) PBMCs, when 50 or 10 ng total DNA were tested. The results indicate that the real-time PCR described here is a first line tool for the determination of viral load in plasma and CSF. Semiquantitative nested PCR is used for screening of PBMCs viral load. Positive specimens containing more than 500 copies/10(5) cells are measured for exact values by real-time PCR. To circumvent inhibitory effects of cellular DNA, measurements should be carried out generally with 50-10 ng DNA.

Capsid Proteins↗
PubMed2006

Prevalence of BK virus subtype I in Germany.

The primary infection with human polyomavirus BK (BKV) occurs in early childhood and leads to viral latency within the urogenital tract. Up to 90% of the adult population are seropositive. In immunosuppressed patients, the BKV may be reactivated resulting in typical disease patterns like hemorrhagic cystitis and tubulointerstitial nephritis. Based on serological and molecular methods, BKV isolates were classified into four subtypes previously. Sixty specimens obtained from German renal and bone marrow transplant recipients were analyzed to gain data on the prevalence of BKV subtypes in Germany. With 90.9%, BKV subtype I was found to be predominant in both patient groups. 6.1% of BKV strains were classified as subtype IV. This pattern of phylogenetic distribution is similar to that demonstrated previously in England, Tanzania, the United States and Japan. Remarkably, there was one German BKV virus with a sequence which clusters together with strain SB in subtype II. The BKV subtype I was found to consist of at least three subgroups designated as Ia, Ib, and Ic. While the majority of the German sequences represent subgroup Ic, most of the Japanese sequences are clearly distinct. These findings support the hypothesis of distinct geographical prevalence of BKV subgroups. For the genotyping region, a relationship of BKV subgroups to disease patterns like hemorrhagic cystitis or tubulointerstitial nephritis could not be demonstrated.

Amino Acid Sequence↗
PubMed2006

Molecular-based reclassification of the bovine enteroviruses.

Bovine enteroviruses are currently classified into two serotypes within the species Bovine enterovirus (BEV). Comparison of the sequences of six American and eleven German BEV isolates with published BEV sequences revealed the necessity to revise the taxonomy of these viruses. Molecular data indicate that the bovine enteroviruses are composed of two clusters (designated BEV-A and -B) each with two and three geno-/serotypes, respectively. Whereas low amino acid identity of the capsid proteins 1C (VP3) and 1D (VP1) is the main criterion for the discrimination of geno-/serotypes, the BEV clusters, presumably representing species, differ in sequence identity of all viral proteins. In addition, characteristic lengths of (i) the capsid proteins 1B, 1C and 1D, (ii) the 2C protein, and (iii) the 3'-non-translated region are observed. The BEVs can be distinguished from the other enteroviruses by sequence identity and unique features of the 5'-non-translated region, i.e. a conserved second cloverleaf and characteristic RNA structures of the internal ribosome entry site. Phylogenetically, the closest relatives of the bovine enteroviruses are the porcine enteroviruses. Incongruent phylogenies of the 5'-non-translated region, the capsid proteins and the 3D polymerase indicate frequent intraserotypic and interserotypic recombination within the non-capsid and the capsid region of the BEV genome.

3' Untranslated Regions↗
PubMed2006

N- and 6-O-sulfated heparan sulfates mediate internalization of coxsackievirus B3 variant PD into CHO-K1 cells.

Recently, it was demonstrated that the coxsackievirus B3 variant PD (CVB3 PD) is able to infect coxsackievirus-adenovirus receptor (CAR)-lacking cells by using heparan sulfates (HS) as additional receptors (A. E. Zautner, U. Korner, A. Henke, C. Badorff, and M. Schmidtke, J. Virol. 77:10071-10077, 2003). For this study, competition experiments with growth factors binding to known HS sequences as well as with specifically desulfated heparins were performed with Chinese hamster ovary cells (CHO-K1) to determine the structural requirements of HS for interaction with CVB3. Hepatocyte growth factor interacting with HS sequences containing [IdUA-GlcNSO(3)(6OSO(3))](n), but not basic fibroblast growth factor binding to [HexUA-GlcNSO(3)-HexUA-GlcNSO(3)-IdUA(2OSO(3))](n), was shown to compete effectively with CVB3 PD for cell surface HS. Whereas unmodified heparin and 2-O-desulfated heparin strongly inhibited the CVB3 PD-induced cytopathic effect, the antiviral activity was markedly reduced after N-, O- and 6-O-desulfation of heparin. Taken together, these results indicate that 6-O- and N-sulfation of GlcNAc of HS is crucial for HS interaction with CVB3 PD and that the disaccharide [IdUA-GlcNSO(3)(6OSO(3))](n) is involved in viral binding. Results from experiments with various inhibitors of endocytic pathways suggest that HS-mediated virus internalization is pH dependent. Despite the fact that CVB3 PD initiates infection about four times slower by making use of HS as a receptor than by using CAR, the time required for a complete viral life cycle in Chinese hamster ovary cells was independent of the utilized receptor.

Animals↗
PubMed2006

Inhibitory efficacy of cyclosal-nucleoside monophosphates of aciclovir and brivudin on DNA synthesis of orthopoxvi ruses.

Previous studies have shown that cycloSaligenyl-monophosphate (cycloSal-MP) derivatives of aciclovir (ACV), penciclovir (PCV) and brivudin (BVDU) can act as inhibitors of vaccinia virus and cowpox virus replication in vitro. The aim of the present study was to evaluate the inhibatory efficacy on DNA synthesis in vaccinia and cowpox viruses of several cycloSal-pro-nucleotides of ACV and BVDU, which have proven activity against pox viruses. Viral DNA was quantified in treated and non-treated virus-infected cells by semi-quantitative PCR on the basis of the haemagglutinin protein gene of orthopoxviruses. As result, an inhibitory efficacy on vaccinia and cowpox virus DNA replication could be demonstrated for 3-methyl-cycloSal-ACVMP, 5-H-cycloSal-ACVMP, 6-chloro-7-ECM-cycloSal-3'-OH-BVDUMP, and 6-chloro-7-methyl-cycloSal-3'-OH-BVDUMP. At concentrations of 32-128 mg/ml, 3-methyl-cyc/oSal-ACVMP and 6-chloro-7-ECM-cycloSal-3'OH-BVDUMP inhibited synthesis of viral DNA to a similar extent as the well-known inhibitors of pox viruses, cidofovir and 5-iodo-dUrd (deoxyuridine). When concentrations of 128 mg/ml were administered, both test substances diminished the amount of viral genome copies by > or =4 log10 corresponding to > or =99.99% reduction. In conclusion, selected cycloSal-pro-nucleotide derivatives of ACV and BVDU can inhibit orthopoxviral DNA synthesis. The high inhibitory efficacy on both replication of viral DNA and infectious viral particles in cell cultures makes these compounds promising candidates for in vivo experiments.

Acyclovir↗
PubMed2005

Susceptibility of coxsackievirus B3 laboratory strains and clinical isolates to the capsid function inhibitor pleconaril: antiviral studies with virus chimeras demonstrate the crucial role of amino acid 1092 in treatment.

OBJECTIVES: At present, most promising compounds to treat enterovirus-induced diseases are broad-spectrum capsid function inhibitors which bind into a hydrophobic pocket in viral capsid protein 1 (VP1). Coxsackievirus B3 (CVB3) Nancy was the only prototypic enterovirus strain shown to be pleconaril-resistant. This study was designed to better understand the polymorphism of the hydrophobic pocket in CVB3 laboratory strains and clinical isolates and its implications for treatment with the capsid function inhibitor pleconaril. METHODS: Pleconaril susceptibility was determined in cytopathic effect-inhibitory, plaque reduction or virus yield assays. Sequence analysis of the genome region coding for VP1 and/or subsequent alignment of amino acids lining the hydrophobic pocket of five CVB3 laboratory strains and 20 clinical isolates were carried out. Virus chimeras and computational analysis were used to prove the role of amino acid 1092. RESULTS AND CONCLUSIONS: Despite high conservation of pocket amino acids, polymorphism was detected at positions 1092, 1094 and 1180. Neither Pro-1094-->Thr nor Val-1180-->Ile altered efficacy of pleconaril treatment. But the amino acid at position 1092 was strongly associated with susceptibility of CVB3 to the capsid inhibitor. Whereas leucine was involved in resistance, isoleucine and valine were detected in pleconaril-susceptible CVB3. Results from antiviral assays with hybrid viruses demonstrate the crucial role of amino acid 1092 in pleconaril susceptibility. A resistant cDNA-generated CVB3 became pleconaril-susceptible after accepting parts from the genome region encoding Ile-1092 into its capsid. Computational analysis suggests that conformational changes in the hydrophobic pocket occur when leucine is substituted for isoleucine or valine and that this change leads to susceptibility to pleconaril.

Amino Acid Substitution↗
PubMed2005

Novel [(biphenyloxy)propyl]isoxazole derivatives for inhibition of human rhinovirus 2 and coxsackievirus B3 replication.

OBJECTIVES: During this study, novel biphenyl derivatives were synthesized and tested for antiviral activity. METHODS: A new method based on the Suzuki coupling reaction has been established for the synthesis of these polysubstituted chain systems. In parallel with cytotoxicity, the antiviral activity of biphenyl derivatives has been determined in cytopathic effect (CPE)-inhibitory assays with the pleconaril-resistant coxsackievirus B3 (CVB3) strain Nancy, human rhinovirus 2 (HRV-2) and 14 (HRV-14) and in plaque reduction assays with the pleconaril-sensitive human isolate CVB3 97-927 in HeLa cells. Based on the results from these investigations the selectivity index (SI) was determined as the ratio of the 50% cytotoxic concentration to the 50% inhibitory concentration. RESULTS: The new method based on the Suzuki coupling reaction includes the condensation of 2,6-dimethyl-4-bromophenol with pentyne chloride by means of potassium carbonate and potassium iodide in N-methylpyrrolidone-2 and yields 5-bromo-1,3-dimethyl-2-(4-pentynyloxy)benzene. Its condensation with methylacetaldoxime results in 3-methylisoxazole derivatives. The following reaction with different benzeneboronic acids by means of tetrakis(triphenylphosphine)-palladium(0) finally yields the corresponding derivatives. Several of the novel synthesized derivatives demonstrated a good antiviral activity on CVB3 (SI > 2 to > 37.5) and a strong anti-HRV-2 activity (SI > 50 to > 200). In contrast, none of the compounds inhibited the HRV-14-induced CPE. CONCLUSIONS: These results indicate that [(biphenyloxy)propyl]isoxazole derivatives are potential inhibitors of HRV-2 and CVB3 replication, and make them promising agents for the specific treatment of these virus infections.

Antiviral Agents↗
PubMed2005

Influenza vaccination coverage rates in Germany a population-based cross-sectional analysis of the seasons 2002/2003 and 2003/2004.

BACKGROUND AND PURPOSE: Influenza continues to be a considerable health problem in Europe. Vaccination is the only preventive measure, reducing mortality and morbidity of influenza in all age groups. The objectives of this survey were to assess the level of influenza vaccination coverage in the 2002/2003 season compared with the 2003/2004 season in Germany, to understand the driving forces and barriers to vaccination, and to determine vaccination intentions for the following winter. METHODS: The authors conducted a random-sampling, telephone-based household survey among noninstitutionalized individuals representative of the population aged > or = 14. The surveys for 2002/2003 and 2003/2004 used the same questionnaire and were subsequently pooled. Four target groups were determined for analysis: (1) persons aged > or = 60; (2) people working in the medical field; (3) persons suffering from chronic illness; and (4) a group composed of persons aged > or = 60 or working in the medical field or suffering from a chronic illness. RESULTS: The overall sample consisted of 4,011 people. The influenza vaccination coverage rate in Germany increased from 22.3% in 2002/2003 to 25.1% in 2003/2004. This increase is not significant. The most frequent reasons for being vaccinated given by vaccinees were: influenza considered to be a serious illness, which people wanted to avoid (90.1%), having received advice from the family doctor or nurse to be vaccinated (71.3%), and not wanting to infect family and friends (70.4%). Reasons for not being vaccinated mentioned by people who have never been vaccinated were: thinking about it, however, not being vaccinated in the end (47.7%), not expecting to catch influenza (43.6%), and not having received a recommendation from the family doctor to be vaccinated (36.6%). Options encouraging influenza vaccination are: recommendation by the family doctor or nurse (66.6%), more available information on the vaccine regarding efficacy and tolerance (54.2%), and more information available about the disease (52.4%). CONCLUSION: The vaccination coverage in the 2003/2004 season increased in comparison to the 2002/2003 season, although not significantly. The family doctor is the most important source of encouragement for people to be vaccinated against influenza. It seems that the public would be more likely to be vaccinated if they had more information on the efficacy and tolerance of the vaccine, as well as the disease. It is therefore suggested that family doctors be better informed on influenza vaccine and the disease itself, so that they can actively inform their patients on these topics.

Adolescent↗
PubMed2005

Interferon-gamma-induced activation of nitric oxide-mediated antiviral activity of macrophages caused by a recombinant coxsackievirus B3.

Cardiovascular disease is one of the major causes of human death and has been linked to many different risks including viral infections. Coxsackievirus B3 (CVB3) is one of the most important pathogens responsible for virus-induced myocarditis. Cytokines are normally involved in the control of CVB3 replication and pathogenesis. Among them, interferon-gamma (IFN-gamma) in particular is highly protective against CVB3. A novel strategy to circumvent virus-caused heart disease is based on the development of cytokine-expressing recombinant virus vectors. Using in vitro co-culture experiments, the release of IFN-gamma by the recombinant virus variant CVB3/IFN-gamma activates the expression of the inducible nitric oxide synthase (iNOS) in CVB3 non-susceptible murine macrophages and the release of nitric oxide (NO), which reduce coxsackieviral replication directly. In addition, the expression of IFN-gamma by CVB3/IFN-gamma contributes to protect mice from lethal infections by iNOS induction in murine peritoneal macrophages, viral load reduction, and pancreatic tissue protection.

Animals↗
PubMed2005

Linkage map of protein-protein interactions of Porcine teschovirus.

A yeast two-hybrid study was conducted to catalogue the protein-protein interactions of the Porcine teschovirus non-structural proteins. Five homodimer, three reciprocal heterodimer and four unidirectional heterodimer interactions were observed. While several interactions are similar to those described in previous studies using enteroviruses, such as homo- and heterodimeric interactions of the 2B, 3CD and 3D proteins, several were not found previously. Among these is the binding of the leader protein L to the proteinases 3C and 3CD. Unlike the poliovirus 3C, the teschovirus 3C proteinase dimerizes and interacts with 2BC, 3CD and 3D. The strongest interactions were observed for L-3C, L-3CD and 3C-3CD.

3C Viral Proteases↗