| the effects of ultraviolet and ionizing radiation on herpesviruses, sv40 and adenoviruses in relation to the small-plaque effect. | the small-plaque effect occurs with a wide range of herpesviruses following irradiation with ultraviolet light. the 37 per cent survival (d37) values, or dose required for one lethal hit (e-1), for herpes simplex, pseudorabies and pigeon herpesviruses in different cells indicate a broad spectrum of host-cell repair capacity. other dna-containing viruses such as sv40 and adenoviruses, which also replicate in the cell nucleus, show the small-plaque effect. ionizing irradiation of herpes simplex vi ... | 1979 | 231946 |
| induction of nad(p)h:quinone reductase in human peripheral blood lymphocytes. | the induction of quinone reductase [qr; nad(p)h:(quinone acceptor) oxidoreductase; ec 1.6.99.2] in cultured cells and animal tissues of rodents has provided useful information on mechanisms of protection against carcinogens. we have developed a simple and efficient microtiter plate assay for the direct measurement of qr basal activity and inducibility in human peripheral blood lymphocytes (unstimulated, mitogen-stimulated and epstein-barr virus-transformed) grown in suspension culture. in these ... | 1991 | 1660793 |
| novel non-nucleoside inhibitors of hiv-1 reverse transcriptase. 1. tricyclic pyridobenzo- and dipyridodiazepinones. | novel pyrido[2,3-b][1,4]benzodiazepinones (i), pyrido[2,3-b][1,5]benzodiazepinones (ii), and dipyrido[3,2-b:2',3'-e][1,4]diazepinones (iii) were found to inhibit human immunodeficiency virus type 1 (hiv-1) reverse transcriptase in vitro at concentrations as low as 35 nm. in all three series, small substituents (e.g., methyl, ethyl, acetyl) are preferred at the lactam nitrogen, whereas slightly larger alkyl moieties (e.g., ethyl, cyclopropyl) are favored at the other (n-11) diazepinone nitrogen. ... | 1991 | 1712395 |
| influence of estuarine sediment on virus survival under field conditions. | the survival of poliovirus 1 (lsc) and echovirus 1 (farouk) in estuarine water and sediment was studied in galveston bay, texas. viruses were suspended in estuarine water and sediment both in dialysis tubing and in chambers constructed with polycarbonate membrane walls. virus inactivation rates in seawater were similar in both types of chambers. virus adsorption to sediment greatly increased survival time. the time required to inactivate 99% (t-99) of poliovirus increased from 1.4 days in seawat ... | 1980 | 6246838 |
| method for recovery of enteric viruses from estuarine sediments with chaotropic agents. | an evaluation was made of the ability of chaotropes, low-molecular-weight ionic compounds which enhance the solubilization of hydrophobic compounds in water, to improve the recovery of enteric viruses from highly organic estuarine sediments. chaotropic agents alone were poor eluents of polioviruses from sediment but were effective when combined with 3% beef extract. chaotropes of lower potency, nano3, nacl, and kcl, were more efficient eluents than the stronger chaotropes, guanidium hydrochlorid ... | 1983 | 6312884 |
| virus transport and survival after land application of sewage sludge. | the survival and transport patterns of poliovirus 1 and echovirus 1 were studied in undisturbed soil cores which were treated with digested sludge and exposed to natural weather conditions prevailing in north central florida. it was shown that, under those experimental conditions, enteroviruses are relatively rapidly inactivated in the soil. a more rapid virus decline was observed during the warm and dry fall season than during the warm and wet summer season. the monitoring of soil core leachate ... | 1984 | 6331308 |
| lack of correlation between sendai virus p/c mrna structure and its utilization of two aug start sites from alternate reading frames: implications for viral bicistronic mrnas. | the polycistronic p/c mrna of sendai virus encodes five proteins (c', p, c, y1, and y2) each of which initiates from a distinct start site. two major proteins, p and c, are expressed in approximately equimolar amounts from two consecutive augs in overlapping reading frames. to better understand the mechanism of expression of the c protein from a downstream aug, site-directed mutants of the p/c mrna were created and expressed in cos1 cells. the secondary structure of the mrna was examined to dete ... | 1996 | 8573577 |
| hepatitis a vaccination by intracutaneous low dose administration: a less expensive alternative. | we investigated the immune response to three different intracutaneous (i.c.) doses of inactivated hepatitis a vaccine: 72, 144, and 216 elisa units (eu). the response was measured using a quotient score derived from a commercial enzyme-linked immunosorbent assay (havab abbott) and translated to iu per liter using a world health organization standard serum for hepatitis a virus antibody. the results were compared with the results obtained after an intramuscular (i.m.) full dose, i.e. 1,440 eu, at ... | 1996 | 8953668 |
| structure determination of echovirus 1. | the atomic structure of echovirus 1 (a member of the enterovirus genus of the picornavirus family) has been determined using cryo-crystallography and refined to 3.55 a resolution. echovirus 1 crystallizes in space group p22121 with a = 352.45, b = 472.15 and c = 483.20 a. the crystals contain one full virus particle in the asymmetric unit allowing for 60-fold noncrystallographic symmetry averaging. the diffraction pattern shows strong pseudo-b-centering with reflections with h + l = 2n + 1 being ... | 1998 | 10089503 |
| a four year review of acute viral hepatitis cases in the east coast of peninsular malaysia (1994-1997). | a total of 1,157 sera from jaundiced patients with clinical and biochemical evidence of liver disease received from government hospital in kelantan and terengganu, during the period from 1994 to 1997, were investigated to determine the cause. hepatitis a virus was found to be the main cause in 26.1% (24/92) of symptomatic clinical hepatitis cases in 1994, 47.8% (63/132) in 1995, 66.4% (613/923) in 1996 and 20% (2/10) in 1997. sera received in 1996 were also tested for hepatitis b, hepatitis c, h ... | 1999 | 10695797 |
| mutation of gln125 to asn selectively abolishes the thymidylate kinase activity of herpes simplex virus type 1 thymidine kinase. | the broad substrate specificity of herpes simplex virus type 1 (hsv-1) thymidine kinase (tk) has provided the basis for selective antiherpetic therapy and, more recently, suicide gene therapy for the treatment of cancer. we have now constructed an hsv-1 tk mutant enzyme, in which an asparagine (n) residue is substituted for glutamine (q) at position 125, and have evaluated the effect of this amino acid change on enzymatic activity. in marked contrast with wild-type hsv-1 tk, which displays both ... | 2001 | 11160865 |
| identification of echovirus 1 and coxsackievirus a9 receptor molecules via a novel flow cytometric quantification method. | background: virus-receptor binding is an essential step in every virus infectious process. many viruses employ more than one receptor molecule or even receptor complexes for attachment. in this study, we investigate the binding of echovirus 1 (echo1) and coxsackievirus a9 (cav-9) on cell surface molecules. cav-9 has been reported to utilize integrin alpha v beta(3) in binding to cells, whereas echo1 has been known to utilize integrin alpha 2 beta(1). methods and results we directly test whether ... | 2001 | 11260595 |
| novel ring-expanded nucleoside analogs exhibit potent and selective inhibition of hepatitis b virus replication in cultured human hepatoblastoma cells. | novel ring-expanded nucleoside (ren) analogs (1-3) containing 5:7 fused ring systems as the heterocyclic base were found to be potent and selective inhibitors of hepatitis b virus (hbv) replication in cultured human hepatoblastoma 2.2.15 cells. the most active compound, 6-amino-4,5-dihydro-8h-1-(beta-d-ribofuranosyl)imidazo[4,5-e][1,3]diazepine-4,8-dione (1), inhibited the synthesis of intracellular hbv replication intermediates and extracellular virion release in 2.2.15 cells with 50% effective ... | 2002 | 11750942 |
| sphingomyelin and cholesterol promote hiv-1 gp41 pretransmembrane sequence surface aggregation and membrane restructuring. | the interfacial sequence dkwaslwnwfnitnwlwyik, preceding the transmembrane anchor of gp41 glycoprotein subunit, has been shown to be essential for fusion activity and incorporation into virions. hiv(c), a peptide representing this region, formed lytic pores in liposomes composed of the main lipids occurring in the human immunodeficiency virus, type 1 (hiv-1), envelope, i.e. 1-palmitoyl-2-oleoylphosphatidylcholine (popc):sphingomyelin (spm):cholesterol (chol) (1:1:1 mole ratio), at low (>1:10,000 ... | 2002 | 11929877 |
| sesquiterpenes and alkaloids from lindera chunii and their inhibitory activities against hiv-1 integrase. | three new eudesmane type sesquiterpenoid lindenanolides e (1), f (2) and g (3), and two new aporphine alkaloid lindechunines a (18) and b (20) were isolated from roots of lindera chunii merr., together with seven known sesquiterpenes including a new naturally-occurring lindenanolide h (4) and eight known aporphine alkaloids. the structures of these compounds were determined by spectroscopic means. of the isolated compounds, hernandonine (14), laurolistine (16), 7-oxohernangerine (17) and lindech ... | 2002 | 12237535 |
| comparative inactivation of enteroviruses and adenovirus 2 by uv light. | the doses of uv irradiation necessary to inactivate selected enteric viruses on the u.s. environmental protection agency contaminant candidate list were determined. three-log reductions of echovirus 1, echovirus 11, coxsackievirus b3, coxsackievirus b5, poliovirus 1, and human adenovirus type 2 were effected by doses of 25, 20.5, 24.5, 27, 23, and 119 mw/cm(2), respectively. human adenovirus type 2 is the most uv light-resistant enteric virus reported to date. | 2002 | 12324370 |
| echovirus 1 endocytosis into caveosomes requires lipid rafts, dynamin ii, and signaling events. | binding of echovirus 1 (ev1, a nonenveloped rna virus) to the alpha2beta1 integrin on the cell surface is followed by endocytic internalization of the virus together with the receptor. here, video-enhanced live microscopy revealed the rapid uptake of fluorescently labeled ev1 into mobile, intracellular structures, positive for green fluorescent protein-tagged caveolin-1. partial colocalization of ev1 with sv40 (sv40) and cholera toxin, known to traffic via caveosomes, demonstrated that the vesic ... | 2004 | 15356270 |
| viral entry, lipid rafts and caveosomes. | lipid rafts and caveolae are detergent-insoluble plasma membrane microdomains, involved in cellular endocytic processes and signalling. several viruses, including a human pathogen, echovirus 1, and an extensively studied simian virus 40 utilize these domains for internalization into the host cells. interaction of viruses with receptors on the cell surface triggers specific conformational changes of the virus particle and can give rise to signalling events, which determine the mechanisms of virus ... | 2005 | 16203612 |
| de novo parallel design, synthesis and evaluation of inhibitors against the reverse transcriptase of human immunodeficiency virus type-1 and drug-resistant variants. | we used molecular modeling to design de novo broad-range inhibitors against wild type and drug-resistant variants of the reverse transcriptase (rt) of human immunodeficiency virus type-1 (hiv-1). first, we screened for small fragments that would interact with each one of four rt structures (one wild type and three mutants). then, these fragments were linked to build a scaffold molecule. out of 27 different compounds that were synthesized, four inhibited the dna polymerase activity of rt with ic5 ... | 2007 | 17458947 |
| molecular mechanism of alpha2beta1 integrin interaction with human echovirus 1. | conformational activation increases the affinity of integrins to their ligands. on ligand binding, further changes in integrin conformation elicit cellular signalling. unlike any of the natural ligands of alpha2beta1 integrin, human echovirus 1 (ev1) seemed to bind more avidly a 'closed' than an activated 'open' form of the alpha2i domain. furthermore, a mutation e336a in the alpha2 subunit, which inactivated alpha2beta1 as a collagen receptor, enhanced alpha2beta1 binding to ev1. thus, ev1 seem ... | 2010 | 19927126 |
| determinants of the specificity of rotavirus interactions with the alpha2beta1 integrin. | the human α2β1 integrin binds collagen and acts as a cellular receptor for rotaviruses and human echovirus 1. these ligands require the inserted (i) domain within the α2 subunit of α2β1 for binding. previous studies have identified the binding sites for collagen and echovirus 1 in the α2 i domain. we used cho cells expressing mutated α2β1 to identify amino acids involved in binding to human and animal rotaviruses. residues where mutation affected rotavirus binding were located in several exposed ... | 2010 | 21138834 |