scholarly journals Characterization of Parvovirus B19 Genotype 2 in KU812Ep6 Cells

2005 ◽  
Vol 79 (22) ◽  
pp. 14197-14206 ◽  
Author(s):  
Johannes Blümel ◽  
Anna Maria Eis-Hübinger ◽  
Albert Stühler ◽  
Claudia Bönsch ◽  
Matthias Gessner ◽  
...  
Keyword(s):  
High Titer ◽  
Parvovirus B19 ◽  
Physical Stability ◽  
Amino Acid Sequences ◽  
Inverted Terminal Repeat ◽  
Genotype 1 ◽  
Genotype 2 ◽  
Cross Neutralization ◽  
Antigenic Relation

ABSTRACT An infectious parvovirus B19 (B19V) genotype 2 variant was identified as a high-titer contaminant in a human plasma donation. Genome analysis revealed a 138-bp insertion within the p6 promoter. The inserted sequence was represented by an additional 30 bp from the end of the inverted terminal repeat adjacent to a 108-bp element found also, in inverted orientation, at the extreme right end of the unique sequence of the genome. However, despite the profound variations in the promoter region, the pattern of gene expression and DNA replication did not differ between genotype 1 and genotype 2 in permissive erythroid KU812Ep6 cells. Capsid proteins of both genotypes differ in their amino acid sequences. However, equivalent kinetics of virus inactivation at 56°C or pH 4 indicated a comparable physicochemical stability of virus capsids. Sera from six individuals infected by B19V genotype 1 were investigated on cross-neutralization of B19V genotype 2 in vitro. Similar neutralization of both B19V genotypes was observed in sera from three individuals, while the sera from three other individuals showed weaker cross-neutralization for genotype 2. In conclusion, the in vitro replication characteristics and physical stability of B19V capsids are very similar between human parvovirus B19 genotypes 1 and 2, and cross-neutralization indicates a close antigenic relation of genotypes 1 and 2.

Contamination of coagulation factor concentrates with human parvovirus B19 genotype 1 and 2

2004 ◽  
Vol 92 (10) ◽  
pp. 838-845 ◽  
Author(s):  
Beate Schneider ◽  
Maria Becker ◽  
Hans-Hermann Brackmann ◽  
Anna Eis-Hübinger
Keyword(s):  
Parvovirus B19 ◽  
Simultaneous Detection ◽  
Coagulation Factor ◽  
Nucleic Acid Amplification ◽  
Clotting Factor ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Viral Inactivation ◽  
Genotype 2 ◽  
Coagulation Factor Concentrates

SummaryHuman parvovirus B19 (B19) DNA has frequently been detected in plasma-derived coagulation factor concentrates. Furthermore, transmission of B19 infection was observed, indicating presence of the infectious virus despite routine viral inactivation/removal procedures during the manufacturing process. Recently, human parvovirus DNA isolates, variant from B19, have been identified resulting in classification of B19 virus into three distinct genotypes, with all viruses previously classified as B19 belonging to genotype 1. So far, there is no information available on contamination of clotting factor concentrates with genotype 2. Therefore, we analysed 202 different factor concentrate lots for genotype 1 and 2 DNA by PCR. Analysis of one hundred eighty-one lots representing 13 different products, administered over the last three years, was compared to 21 lots (8 products) used until the early 1980s which had not been treated by viral inactivation procedures. Genotype 1 DNA was detected in 77/181 (42.5%) currently administered lots, and 17/21 (81%) previously used lots. The level of genotype 1 DNA contamination was similar in currently and previously administered concentrates. Genotype 2 DNA was found in 5/202 (2.5%) lots, all of which were co-contaminated with genotype 1 DNA. DNA sequence analysis showed that the PCR-double positive concentrates contained typical genotype 1 and genotype 2 DNA. Because genotype 2 appears to cause a similar spectrum of diseases as genotype 1, simultaneous detection of genotype 2 by nucleic acid amplification testing (NAT), now widely applied to plasma pools for genotype 1, would give an added level of safety to blood products.

scholarly journals Phylogenetic analysis of human parvovirus B19, indicating two subgroups of genotype 1 in Vietnamese patients

2006 ◽  
Vol 87 (10) ◽  
pp. 2941-2949 ◽  
Author(s):  
Nguyen L. Toan ◽  
Anja Duechting ◽  
Peter G. Kremsner ◽  
Le H. Song ◽  
Martin Ebinger ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Hepatitis B Virus ◽  
Parvovirus B19 ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Genotype 3 ◽  
Nucleotide Difference ◽  
Genotype 2 ◽  
B Virus ◽  
The Mean

Recently, three distinct genotypes (1, 2 and 3) of human parvovirus B19 (B19) have been identified. However, the characteristics and distribution of B19 genotypes in Vietnam have not been investigated. Phylogenetic analysis using 49 subgenomic NS1/VP1u regions and two coding NS1–VP1/VP2 regions has been applied to investigate the prevalence of B19 genotypes in Vietnamese patients co-infected with Hepatitis B virus. Genetic analysis of the subgenomic NS1/VP1u region of B19 revealed that two genotypes of B19 were identified in these populations, with predominance of genotype 1 (47/49, 96 %) followed by genotype 2 (2/49, 4 %), but not genotype 3. Further, phylogenetic analysis of subgenomic B19 genomes revealed two major subgroups within genotype 1 (B19-1A and B19-1B) with an estimated nucleotide difference of >5 % between each subgroup, forming different branches. The mean percentage of amino acid variation between subgroup B19-1A and B19-1B was >2 % of the NS1, VP1 and VP2 proteins. Our results indicated that two of the three known genotypes of B19 were present in Vietnamese patients, with genotype 1 predominating, and that this genotype can be classified into at least two subgroups, B19-1A and B19-1B.

scholarly journals Ancient human parvovirus B19 in Eurasia reveals its long-term association with humans

2018 ◽  
Vol 115 (29) ◽  
pp. 7557-7562 ◽  
Author(s):  
Barbara Mühlemann ◽  
Ashot Margaryan ◽  
Peter de Barros Damgaard ◽  
Morten E. Allentoft ◽  
Lasse Vinner ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Parvovirus B19 ◽  
Recent Common Ancestor ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Most Recent Common Ancestor ◽  
Genotype 2 ◽  
Order Of Magnitude ◽  
The 1960S

Human parvovirus B19 (B19V) is a ubiquitous human pathogen associated with a number of conditions, such as fifth disease in children and arthritis and arthralgias in adults. B19V is thought to evolve exceptionally rapidly among DNA viruses, with substitution rates previously estimated to be closer to those typical of RNA viruses. On the basis of genetic sequences up to ∼70 years of age, the most recent common ancestor of all B19V has been dated to the early 1800s, and it has been suggested that genotype 1, the most common B19V genotype, only started circulating in the 1960s. Here we present 10 genomes (63.9–99.7% genome coverage) of B19V from dental and skeletal remains of individuals who lived in Eurasia and Greenland from ∼0.5 to ∼6.9 thousand years ago (kya). In a phylogenetic analysis, five of the ancient B19V sequences fall within or basal to the modern genotype 1, and five fall basal to genotype 2, showing a long-term association of B19V with humans. The most recent common ancestor of all B19V is placed ∼12.6 kya, and we find a substitution rate that is an order of magnitude lower than inferred previously. Further, we are able to date the recombination event between genotypes 1 and 3 that formed genotype 2 to ∼5.0–6.8 kya. This study emphasizes the importance of ancient viral sequences for our understanding of virus evolution and phylogenetics.

scholarly journals Rapid Sequence Change and Geographical Spread of Human Parvovirus B19: Comparison of B19 Virus Evolution in Acute and Persistent Infections

2008 ◽  
Vol 82 (13) ◽  
pp. 6427-6433 ◽  
Author(s):  
Päivi Norja ◽  
Anna Maria Eis-Hübinger ◽  
Maria Söderlund-Venermo ◽  
Klaus Hedman ◽  
Peter Simmonds
Keyword(s):  
Substitution Rate ◽  
Sequence Data ◽  
Rna Virus ◽  
Parvovirus B19 ◽  
Horizontal Transmission ◽  
Last Common Ancestor ◽  
Genotype 1 ◽  
Sequence Change ◽  
Short Period ◽  
Genotype 2

ABSTRACT Parvovirus B19 is a common human pathogen maintained by horizontal transmission between acutely infected individuals. However, B19 virus can also be detected in tissues throughout the life of the host, although little is understood about the nature of such persistence. In the current study, we created large VP1/2 sequence data sets of plasma- and tissue (autopsy)-derived variants of B19 virus with known sample dates to compare the rates of sequence change in exogenous virus populations with those in persistently infected individuals. By using linear regression and likelihood-based methods (such as the BEAST program), we found that plasma-derived B19 virus showed a substitution rate of 4 × 10−4 and an unconstrained (synonymous)-substitution rate of 18 × 10−4 per site per year, several times higher than previously estimated and within the range of values for mammalian RNA viruses. The underlying high mutation frequency implied by these substitution rates may enable rapid adaptive changes that are more commonly ascribed to RNA virus populations. These revised estimates predict that the last common ancestor for currently circulating genotype 1 variants of B19 virus existed around 1956 to 1959, fitting well with previous analyses of the B19 virus “bioportfolio” that support a complete cessation of genotype 2 infections and their replacement by genotype 1 infections in the 1960s. In contrast, the evolution of B19 virus amplified from tissue samples was best modeled by using estimated dates of primary infection rather than sample dates, consistent with slow or absent sequence change during persistence. Determining what epidemiological or biological factors led to such a complete and geographically extensive population replacement over this short period is central to further understanding the nature of parvovirus evolution.

scholarly journals Simultaneous persistence of multiple genome variants of human parvovirus B19

2008 ◽  
Vol 89 (1) ◽  
pp. 164-176 ◽  
Author(s):  
Beate Schneider ◽  
Andrea Höne ◽  
René H. Tolba ◽  
Hans-Peter Fischer ◽  
Johannes Blümel ◽  
...  
Keyword(s):  
Parvovirus B19 ◽  
Acute Infection ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Genotype 3 ◽  
Viral Dna ◽  
Antiviral Immune Response ◽  
Sequence Heterogeneity ◽  
Genotype 2 ◽  
Genome Variants

The species human parvovirus B19 (B19V) can be divided into three genotypes. In this study, we addressed the question as to whether infection of an individual is restricted to one genotype. As viral DNA is detectable in tissue for long times after acute infection, we examined 87 liver specimens from adults for the presence of B19V DNA. Fifty-nine samples were found to be positive, 32 of them for genotype 1, 27 for genotype 2 and four for genotype 3. In four samples, DNA of two genotypes was detected; samples from three individuals were positive for genotypes 1 and 2 and a sample from one individual was positive for genotypes 1 and 3. Surprisingly, significant sequence heterogeneity was observed at approximately 1 % of the nucleotides of the genotype 1 genomes from individuals with double genotype 1 and 2 infection. Controls using different enzymes for genome amplification and dilutions of the template verified that nucleotide heterogeneity was due to the presence of three or more genome variants of genotype 1. In summary, the evidence shows that individuals can be infected with two different genotypes, and B19V DNA can persist as a population of different genomes. The results may have implications for the understanding of the antiviral immune response and the development of vaccines against B19V.

Influence of β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin on Enhancement of Solubility and Dissolution of Isradipine

2017 ◽  
Vol 10 (3) ◽  
pp. 3752-3757
Author(s):  
Narendar D ◽  
Ettireddy S
Keyword(s):  
Inclusion Complex ◽  
Dissolution Rate ◽  
Solid Dispersions ◽  
Physical Stability ◽  
Molecular Complexes ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Phase Solubility ◽  
Cyclodextrin Complexation

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies.  Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.   

scholarly journals Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  
Keyword(s):  
Dna Binding ◽  
Host Range ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Broad Host Range ◽  
Biophysical Properties ◽  
Dna Binding Sites ◽  
In Silico Studies ◽  
Wide Range

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

scholarly journals Production and Characterization of Chitosan–Polyanion Nanoparticles by Polyelectrolyte Complexation Assisted by High-Intensity Sonication for the Modified Release of Methotrexate

2020 ◽  
Vol 13 (1) ◽  
pp. 11 ◽  
Author(s):  
Yhors Ciro ◽  
John Rojas ◽  
Maria Alhajj ◽  
Gustavo Carabali ◽  
Constain Salamanca
Keyword(s):  
Zeta Potential ◽  
Maleic Acid ◽  
High Intensity ◽  
Physical Stability ◽  
Release Mechanism ◽  
Diffusion Controlled ◽  
Polyelectrolyte Complexation ◽  
Anticancer Treatment ◽  
Particle Parameters

A promising strategy to improve the effectivity of anticancer treatment and decrease its side effects is to modulate drug release by using nanoparticulates (NPs) as carriers. In this study, methotrexate-loaded chitosan–polyanion nanoparticles were produced by polyelectrolyte complexation assisted by high-intensity sonication, using several anionic polymers, such as the sodium and potassium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene), here named PAM-2 and PAM-18, respectively. Such NPs were analyzed and characterized according to particle size, polydispersity index, zeta potential and encapsulation efficiency. Likewise, their physical stability was tested at 4 °C and 40 °C in order to evaluate any change in the previously mentioned particle parameters. The in vitro methotrexate release was assessed at a pH of 7.4, which simulated physiological conditions, and the data were fitted to the heuristic models of order one, Higuchi, Peppas–Sahlin and Korsmeyer–Peppas. The results revealed that most of the MTX-chitosan–polyanion NPs have positive zeta potential values, sizes <280 nm and monodisperse populations, except for the NPs formed with PAM-18 polyanions. Further, the NPs showed adequate physical stability, preventing NP–NP aggregation. Likewise, these carriers modified the MTX release by an anomalous mechanism, where the NPs formed with PAM-2 polymer led to a release mechanism controlled by diffusion and relaxation, whereas the NPs formed with PAM-18 led to a mainly diffusion-controlled release mechanism.

scholarly journals Synthesis, Characterization and Evaluation of Peptide Nanostructures for Biomedical Applications

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4587
Author(s):  
Fanny d’Orlyé ◽  
Laura Trapiella-Alfonso ◽  
Camille Lescot ◽  
Marie Pinvidic ◽  
Bich-Thuy Doan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biomedical Applications ◽  
Chemical Reactivity ◽  
Physical Stability ◽  
Chemical Properties ◽  
Building Blocks ◽  
Imaging Probes ◽  
Therapeutic Molecules

There is a challenging need for the development of new alternative nanostructures that can allow the coupling and/or encapsulation of therapeutic/diagnostic molecules while reducing their toxicity and improving their circulation and in-vivo targeting. Among the new materials using natural building blocks, peptides have attracted significant interest because of their simple structure, relative chemical and physical stability, diversity of sequences and forms, their easy functionalization with (bio)molecules and the possibility of synthesizing them in large quantities. A number of them have the ability to self-assemble into nanotubes, -spheres, -vesicles or -rods under mild conditions, which opens up new applications in biology and nanomedicine due to their intrinsic biocompatibility and biodegradability as well as their surface chemical reactivity via amino- and carboxyl groups. In order to obtain nanostructures suitable for biomedical applications, the structure, size, shape and surface chemistry of these nanoplatforms must be optimized. These properties depend directly on the nature and sequence of the amino acids that constitute them. It is therefore essential to control the order in which the amino acids are introduced during the synthesis of short peptide chains and to evaluate their in-vitro and in-vivo physico-chemical properties before testing them for biomedical applications. This review therefore focuses on the synthesis, functionalization and characterization of peptide sequences that can self-assemble to form nanostructures. The synthesis in batch or with new continuous flow and microflow techniques will be described and compared in terms of amino acids sequence, purification processes, functionalization or encapsulation of targeting ligands, imaging probes as well as therapeutic molecules. Their chemical and biological characterization will be presented to evaluate their purity, toxicity, biocompatibility and biodistribution, and some therapeutic properties in vitro and in vivo. Finally, their main applications in the biomedical field will be presented so as to highlight their importance and advantages over classical nanostructures.

scholarly journals Isolation, Identification, and Genomic Analysis of a Novel Reovirus from Healthy Grass Carp and Its Dynamic Proliferation In Vitro and In Vivo

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 690
Author(s):  
Ke Zhang ◽  
Wenzhi Liu ◽  
Yiqun Li ◽  
Yong Zhou ◽  
Yan Meng ◽  
...  
Keyword(s):  
Cell Lines ◽  
Grass Carp ◽  
Amino Acid Sequences ◽  
Gibel Carp ◽  
Fish Cell ◽  
Fish Cell Lines ◽  
Total Size ◽  
Sequence Comparisons ◽  
Grass Carp Reovirus

A new grass carp reovirus (GCRV), healthy grass carp reovirus (HGCRV), was isolated from grass carp in 2019. Its complete genome sequence was determined and contained 11 dsRNAs with a total size of 23,688 bp and 57.2 mol% G+C content, encoding 12 proteins. All segments had conserved 5' and 3' termini. Sequence comparisons showed that HGCRV was closely related to GCRV-873 (GCRV-I; 69.57–96.71% protein sequence identity) but shared only 22.65–45.85% and 23.37–43.39% identities with GCRV-HZ08 and Hubei grass carp disease reovirus (HGDRV), respectively. RNA-dependent RNA-polymerase (RdRp) protein-based phylogenetic analysis showed that HGCRV clustered with Aquareovirus-C (AqRV-C) prior to joining a branch common with other aquareoviruses. Further analysis using VP6 amino acid sequences from Chinese GCRV strains showed that HGCRV was in the same evolutionary cluster as GCRV-I. Thus, HGCRV could be a new GCRV isolate of GCRV-I but is distantly related to other known GCRVs. Grass carp infected with HGCRV did not exhibit signs of hemorrhage. Interestingly, the isolate induced a typical cytopathic effect in fish cell lines, such as infected cell shrank, apoptosis, and plague-like syncytia. Further analysis showed that HGCRV could proliferate in grass carp liver (L28824), gibel carp brain (GiCB), and other fish cell lines, reaching a titer of up to 7.5 × 104 copies/μL.

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