Types of Viruses

To assess clinical and subclinical characteristics of Dengue pediatric patients with gastrointestinal bleeding in Nhi Dong 1 Hospital from 12/2014 to 12/2015. To evaluate the relationship between gastrointestinal bleeding and clinical, subclinical characteristics and virus type of Dengue pediatric patients at Nhi Dong 1 Hospital from 12/2014 to 12/2015.

30p angicungduoc6 21-07-2020 18 3   Download

The human immunodeficiency virus type 1, HIV-1, genome encodes a highly conserved regulatory gene product, Vpr (96 amino acids), which is incorporated into virions in quantities equivalent to those of the viral Gag protein. In infected cells, Vpr is believed to function during the early stages of HIV-1 replication (such as transcription of the proviral genome and migration of preintegration nuclear complex), blocks cells in G2 phase and triggers apoptosis.

10p system191 01-06-2013 46 4   Download

Human immunodeficiency virus type 1 protein R (HIV-1 Vpr) promotes nuclear entry of viral nucleic acids in nondividing cells, causes G2 cell cycle arrest and is involved in cellular differentiation and cell death. Vpr subcellular localization is as variable as its functions. It is known, that consistent with its role in nuclear transport, Vpr localizes to the nuclear envelope of human cells. Further, a reported ion channel activity of Vpr is clearly dependent on its localization in or at membranes.

6p system191 01-06-2013 33 4   Download

We have recently expressed in bacteria the enzymatically active reverse transcriptase (RT) of bovine leukemia virus (BLV) [Perach, M. & Hizi, A. (1999) Virology 259, 176–189]. In the present study, we have studied in vitro two features of the DNA polymerase activity of BLV RT, the processivity of DNA synthesis and the fidelity of DNA synthesis. These properties were compared with those of the well-studied RTs of human immunodeficiency virus type 1 (HIV-1) and murine leukaemia virus (MLV).

9p research12 01-06-2013 42 4   Download

Double-stranded RNA-activated protein kinase (PKR), a serine/threonine kinase, is activated in virus-infected cells and acts as an antiviral machinery of type I interferons. PKR controls several stress response pathways induced by double-stranded RNA, tumor necrosis factor-aor lipo-polysaccharide, which result in the activation of stress-acti-vated protein kinase/c-Jun NH2 -terminal kinase and p38 of the mitogen-activated protein kinase family.

7p tumor12 22-04-2013 47 3   Download

Spatial organizationofwild-type (strainU1) tobaccomosaic virus (TMV) and of the temperature-sensitive TMV ts21–66 mutant was compared by tritium planigraphy. The ts21–66 mutant contains two substitutions in the coat protein (Ile21fiThr and Asp66fiGly) and, in contrast withU1, induces a hypersensitive response (formation of necroses) on the leaves of plants bearing a host resistance geneN¢(for example Nicotiana sylvestris); TMV U1 induces systemic infection (mosaic) on the leaves of such plants.

9p fptmusic 16-04-2013 51 4   Download

The multisubstrate deoxyribonucleoside kinase ofDroso-phila melanogaster (Dm-dNK) is sequence-related to three human deoxyribonucleoside kinases and to herpes simplex virus type-1 thymidine kinase. Dm-dNK phos-phorylates both purine and pyrimidine deoxyribonucleo-sides and nucleoside analogues although it has a preference for pyrimidine nucleosides. We performed site-directed mutagenesis on residues that, based on structural data, are involved in substrate recognition.

6p fptmusic 16-04-2013 36 3   Download

Although efficient vaccines are available, chronic hepatitis B (HBV) infection poses a major health problem worldwide, and prolonged treatment of chronicallyinfected HBV patients with nucleoside analogs often results in drug-resistantHBVvariants.Therefore, it is critical toevaluate the contribution of the HBV polymerase to mutations. FLAG-taggedwild-type (FPolE) andmutant (FPolE/D551A)HBV polymerases have been expressed in insect cells and purified. The purified FPolE showed DNA polymerase activity, but FPolE/D551A did not, implying that the activity was derived from FPolE....

8p fptmusic 16-04-2013 41 3   Download

The immune coagulant fgl2/fibroleukin has been previously shown to play a pivotal role in the pathogenesis of murine and human fulminant hepatitis and fetal loss syndrome. Constitutive expression of fgl2 transcripts at low levels are seen in cytotoxic T cells, endothelial, intestinal and tropho-blast cells, while specific factors (such as virus and cytokines) are required to induce high levels of fgl2 expression in other cell types including monocytes/macrophages.

13p fptmusic 16-04-2013 37 5   Download

Viral subversion of apoptosis regulation plays an important role in the outcome of host⁄virus interactions. Although human cytomegalovirus (HCMV) encodes several immediate early (IE) antiapoptotic proteins (IE1, IE2, vMIA and vICA), no proapoptotic HCMV protein has yet been iden-tified. Here we show that US28, a functional IE HCMV-encoded chemo-kine receptor, which may be involved in both viral dissemination and immune evasion, constitutively induces apoptosis in several cell types.

15p fptmusic 11-04-2013 37 1   Download

Hu-K4 is a human protein homologous to the K4L protein of vaccinia virus. Due to the presence of two HKD motifs, Hu-K4 was assigned to the family of Phospholipase D proteins although so far no catalytic activity has been shown. The Hu-K4 mRNA is found in many human organs with highest expression levels in the central nervous system. We extended the ORF of Hu-K4 to the 5¢ direction. As a consequence the protein is 53 amino acids larger than originally predicted, now harbouring a putative transmembrane domain....

0p awards 06-04-2013 39 3   Download

The crystal structure of the complex between human immunodeficiency virus type 1 (HIV-1) protease and a peptidomimetic inhibitor of ethyleneamine type has been refined toRfactor of 0.178 with diffraction limit 2.5 A ˚ .The peptidomimetic inhibitor Boc-Phe-Y[CH2CH2 NH]-Phe-Glu-Phe-NH2 (denoted here as OE) contains the ethylene-amine replacement of the scissilepeptidebond. The inhibitor lacks the hydroxyl group which is believed to mimic tetra-hedral transition state of proteolytic reaction and thus is suspected to be necessary for good properties of peptido-mimetic HIV-1 protease inhibitors.

11p awards 05-04-2013 38 4   Download

The primary structures of N-terminal 19-mer peptides, released by limited trypsin treatment of coat protein (CP) subunits in intact virions of three potato virus X (PVX) isolates, were analyzed. Twowild-type PVXstrains,Russian (Ru) andBritish (UK3),wereusedandalso theSTmutantof UK3 inwhich all 12 serine and threonine residues in the CP N-terminal segment were replaced by glycine or alanine.

10p awards 05-04-2013 46 3   Download

Epstein–Barr virus (EBV) is a potent mitogenic and anti-apoptotic agent for B lymphocytes and is associated with several different types of human tumour. The abundantly expressed small viral RNA, EBER-1, binds to the growth inhibitory and pro-apoptotic protein kinase R (PKR) and blocks activation of the latter by double-stranded RNA. Recent evidence has suggested that expression of EBER-1 alone in EBV-negative B cells promotes a tumorigenic phe-notype and that this may be related to inhibition of the pro-apoptotic effects of PKR....

11p dell39 03-04-2013 42 3   Download

Although the type-2 ribosome-inactivatingproteins (SNA-I, SNA-V, SNLRP) from elderberry (Sambucus nigraL.) are all devoid of rRNAN-glycosylase activity towards plant ribosomes, some of them clearly show polynucleotide– adenosine glycosylase activity towards tobaccomosaic virus RNA. This particular substrate specificity was exploited to further unravel the mechanism underlying the in planta antiviral activity of ribosome-inactivating proteins. Trans-genic tobacco (Nicotiana tabacumL.

8p dell39 03-04-2013 39 4   Download

Integrase of the human immunodeficiency virus type-1 (HIV-1) recognizes specific sequences located in the U3 and U5 regions at the ends of viral DNA. We synthesizedDNA duplexes mimicking the U5 region and containing either 2¢-aminonucleosides or non-nucleoside 1,3-propanediol insertions at the third and terminal positions and studied their interactions with HIV-1 integrase. Both modifications introduced a local structural distortion in the DNA double helix.

7p dell39 03-04-2013 31 2   Download

We have developed a novel plasmid vector, pEBTetD, for full establish-ment of doxycycline-inducible protein expression by just a single transfec-tion. pEBTetD contains an Epstein–Barr virus origin of replication for stable and efficient episomal propagation in human cell lines, a cassette for continuous expression of the simple tetracycline repressor, and a cytomega-lovirus-type 2 tetracycline operator (tetO2)-tetO2 promoter.

8p galaxyss3 21-03-2013 38 3   Download

Herpes simplex virus 1 (HSV-1) demonstrates a unique ability to infect a variety of host cell types. Retinal pigment epithelial (RPE) cells form the outermost layer of the retina and provide a potential target for viral inva-sion and permanent vision impairment.

14p vinaphone15 28-02-2013 24 3   Download

Herpes simplex virus type-1 and type-2 are highly prevalent human patho-gens causing life-long infections. The process of infection begins when the virions bind heparan sulfate moieties present on host cell surfaces. This ini-tial attachment then triggers a cascade of molecular interactions involving multiple viral and host cell proteins and receptors, leading to penetration of the viral nucleocapsid and tegument proteins into the cytoplasm.

9p viettel02 20-02-2013 49 3   Download

Type I interferons (IFN) are important components of the innate antiviral response. A key signalling pathway activated by IFNais the Janus kinase⁄ signal transducer and activator of transcription (JAK⁄STAT) pathway. Major components of the pathway have been identified. However, critical kinetic properties that facilitate accelerated initiation of intracellular antiviral signalling and thereby promote virus elimination remain to be determined.

14p viettel02 19-02-2013 39 3   Download