Resistance to Direct-Acting Antiviral Agents in Treatment of Hepatitis C Virus Infections

Compounds targeting nonstructural (NS) proteins of hepatitis C virus (HCV) demonstrate clinical promise, suggesting that NS3/NS4a, NS5A, or NS5B inhibitors are potential components in direct-acting antiviral (DAA) combination therapies. In vitro studies revealed dramatic inhibition of viral replication or alteration in subcellular localization of NS proteins. DAAs bind either to catalytic sites (NS3 and NS5B) or to domain-1 of NS5A. Although >90% of the patients clear HCV RNA from their sera, a significant portion of cirrhotic patients suffer from resistance or virological relapse. Mutations in specific residues (Q80K) in NS3 (M28, A30, L31, and Y93 in genotypes 1a and 1b or L28, L30, M31, and Y93 in genotype 4) in NS5A and A282T in NS5B are associated with resistance to DAA [resistance-associated variants (RAVs)]. Current knowledge on the NS functions, mode of action of DAAs, and impacts of RAVs on treatment response are discussed. Not only mutations affecting the binding of DAAs to target proteins but also substitutions affecting the replication fitness of mutant quasispecies are major determinants of treatment failures. These resistance-associated substitutions (RASs) are now considered the major viral mutants that influence the virological outcome after DAA treatment

The Source of Auroral Omegas

The auroral wave-like structures called “omega bands” appear within the post-midnight sector auroral oval with shapes resembling the Greek letter omega, and are typically associated with the recovery phase of substorms. Prior work and MHD simulations suggest both high speed earthward flows and postmidnight flow shears are possible omega band source mechanisms. However, what produces omega bands is not well understood. It is most likely that the paucity of concurrent magnetospheric data has limited our ability to understand fully the mechanism responsible for the generation of the omega bands. We have identified about 263 auroral omegas in seven different THEMIS all sky cameras (ASCs) over a 10 year period. A fraction appear to form from north-south streamers, but some appear to form from east-west auroral arcs. Fifty-one of the 263 Ω also have conjugate or near conjugate THEMIS and GOES spacecraft data. There is evidence in about 80% of these events that high speed earthward flows have occurred prior to or at about the same time as the auroral omega observation. This evidence consists of high speed earthward flows, magnetic field dipolarizations, particle injections into the inner magnetosphere, and auroral streamers. 11 events also show plasma flow data azimuthally along the inner magnetosphere, but for six of these events the Vy component is inconsistent with the auroral omega direction of motion. Of the remaining five events, four have Vy flow shear events but also show evidence of magnetic field dipolarizations, particle injections into the inner magnetosphere, and auroral streamers. Our observations suggest high speed earthward flows are more likely to be the source of auroral omega bands

A Novel Approach in Pigment Printing Using Nano-keratin Based Binder

This study is devoted to preparation and characterization of nano-keratin based binder (NKBB) from cheap renewable natural resources, namely coarse Egyptian wool or feather. The prepared NKBB is utilized as a biodegradable, environment-friendly and relatively cheap binder in textile pigment printing of polyester, pure polyacrylic, viscose, polyester/viscose, and polyester/acrylic fabrics. Different concentrations of the prepared NKBB as well as its mixture with commercially produced one are used in the pigment printing paste. The colour strength of the printed fabrics as well as their fastness properties to light, washing, and perspiration are evaluated. The effect of the used binder on the bending stiffness of the printed fabrics is also assessed. Results show that the NKBB gives almost the same colour strength and fastness properties as the commercial binder with improved stiffness of the printed samples in relation to that printed with commercial one

Biomarker characteristics of the Turonian–Eocene succession, Belayim oilfields, central Gulf of Suez, Egypt

We are grateful to the Belayim Petroleum Company (PETROBEL) for providing the samples for this study. Gratitude is also expressed to STRATOCHEM Services, New Maadi, Cairo, Egypt for supporting GC–MS analyses. Two anonymous reviewers and the Editor are thanked for their critical comments and suggested revisions that improved the text.Peer reviewedPublisher PD

Antisense oligonucleotide inhibition of hepatitis C virus genotype 4 replication in HepG2 cells

BACKGROUND: Hepatitis C (HCV) viral infection is a serious medical problem in Egypt and it has a devastating impact on the Egyptian economy. It is estimated that over 15% of Egyptians are infected by the virus and thus finding a cure for this disease is of utmost importance. Current therapies for hepatitis C virus (HCV) genotype 4 with interferon/ribavirin have not been successful and thus the development of alternative therapy for this genotype is disparately needed. RESULTS: Although previous studies utilizing viral subgenomic or full cDNA fragments linked to reporter genes transfected into adhered cells or in a cell free system showed promise, demonstration of efficient viral replication was lacking. Thus, we utilized HepG2 cells infected with native HCV RNA genomes in a replication competent system and used antisense phosphorothioate Oligonucleotides (S-ODN) against stem loop IIId and the AUG translation start site of the viral polyprotein precursor to monitor viral replication. We were able to show complete arrest of intracellular replication of HCV-4 at 1 uM S-ODN, thus providing a proof of concept for the potential antiviral activity of S-ODN on native genomic replication of HCV genotype 4. CONCLUSION: We have successfully demonstrated that by using two S-ODNs [(S-ODN1 (nt 326–348) and S-ODN-2 (nt 264–282)], we were able to completely inhibit viral replication in culture, thus confirming earlier reports on subgenomic constructs and suggesting a potential therapeutic value in HCV type 4

Neutralizing activities of caprine antibodies towards conserved regions of the HCV envelope glycoprotein E2

Anti HCV vaccine is not currently available and the present antiviral therapies fail to cure approximately half of the treated HCV patients. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 and test their neutralizing activities in a step towards developing therapeutic and/or prophylactic immunogens against HCV infection. Antibodies were generated by vaccination of goats with synthetic peptides derived from HCV E2. Viral neutralizing capacity of the generated anti E2 antibodies was tested using in vitro assays. Goats immunized with E2 synthetic peptides termed p412 [a.a 412-419], p430 [a.a 430-447] and p517 [a.a 517-531] generated high titers of antibody responses 2 to 4.5 fold higher than comparable titers of antibodies to the same epitopes in chronic HCV patients. In post infection experiments of native HCV into cultured Huh7.5 cells anti p412 and anti p 517 were proven to be neutralizing to HCV genotype 4a from patients' sera (87.5% and 75% respectively). On the contrary anti p430 exhibited weak viral neutralization capacity on the same samples (31.25%). Furthermore Ab mixes containing anti p430 exhibited reduced viral neutralization properties. From these experiments one could predict that neutralization by Abs towards different E2-epitopes varies considerably and success in the enrichment of neutralization epitope-specific antibodies may be accompanied by favorable results in combating HCV infection. Also, E2 conserved peptides p517 and p412 represent potential components of a candidate peptide vaccine against HCV infection

ETIOLOGY OF FUNGI ASSOCIATED WITH GRAPEVINE DECLINE AND THEIR PATHOLOGICAL POTENTIAL

Decline of grapevine due to soil borne fungi was surveyed during 2013- 2015 summer growing seasons at El-Fayoum, El-Gharbeia and El-Beheira governorates, Egypt, Syndromes of declined grapevine plants included growth retardant of shoot system and root-rot as well as decrease of grapevine fruit yield  quality. Isolation trails from root of declined trees of different grapevine cultivars i.e., superior, flame seedless, King robi and crimson was carried out. The most soil borne fungi associated with root-rotted grapevine were Fusarium oxysporum Schlechtend, Fusarium solani (Mart.) Sacc, Botryodiplodia theobromae, Rhizoctonia solaniKuhn and Macrophomina phaseolina(Tassi) Gold. Fusarium spp. are the main fungal associated with different infection types of declined root of grapevine either a singly or in combination with B. theobromae or R. solani as second infection type and third infection type with B. theobromae + R. solani. Under soil artificially infested with 5% (w/w) of each fungal isolates inocula of fourteen isolates obtained were varied for causing wilt and root-rot symptoms of grapevine trees and reducing growth parameters plant height, root length, root size, fresh and dry weight of shoot and root than the control. Botrydiplodia theobromae isolate No. (7)was the most caused root-rot and disease severity of shoot and root of grapevine plant(100%)  followed by Fusarium avenacum caused (87.5%) of root –rot and disease severity of shoot and root. Fouthermore, Fusarium avenacum isolate was the most fungal isolate in reducing growth parameters expect root length.  This is first record that Fusarium avenacum as a causal organism causing root rot disease of grapevine in Egypt

Conserved peptides within the E2 region of Hepatitis C virus induce humoral and cellular responses in goats

The reason(s) why human antibodies raised against hepatitis C virus (HCV) E2 epitopes do not offer protection against multiple viral infections may be related to either genetic variations among viral strains particularly within the hypervariable region-1 (HVR-1), low titers of anti E2 antibodies or interference of non neutralizing antibodies with the function of neutralizing antibodies. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 as potential therapeutic and/or prophylactic vaccines against HCV infection. Goats immunized with E2-conserved synthetic peptides termed p36 (a.a 430–446), p37(a.a 517–531) and p38 (a.a 412–419) generated high titers of anti-p36, anti-p37 and anti-P38 antibody responses of which only anti- p37 and anti- p38 were neutralizing to HCV particles in sera from patients infected predominantly with genotype 4a. On the other hand anti-p36 exhibited weak viral neutralization capacity on the same samples. Animals super-immunized with single epitopes generated 2 to 4.5 fold higher titers than similar antibodies produced in chronic HCV patients. Also the studied peptides elicited approximately 3 fold increase in cell proliferation of specific antibody-secreting peripheral blood mononuclear cells (PBMC) from immunized goats. These results indicate that, besides E1 derived peptide p35 (a.a 315–323) described previously by this laboratory, E2 conserved peptides p37 and p38 represent essential components of a candidate peptide vaccine against HCV infection