| apparent effect of immune serum globulin prophylaxis in the military on viral hepatitis incidence in the civilian population in israel. | since 1969, extensive use of immune serum globulin in the israel defence force for prophylaxis against hepatitis a virus (hav) infection has produced a sharp decline in the incidence of the disease. however, it is not clear whether this policy has affected the susceptibility of israeli adults to hav infection. in this study, we examined the effect of the immunisation policy on the incidence of hepatitis a virus infection in the civilian population in the 15-44 year age group, which includes all ... | 1989 | 2592909 |
| the lexington addicts, 1971-1972: demographic characteristics, drug use patterns, and selected infectious disease experience. | the demographics, drug habits, and medical complications of a cohort of 1,129 addicts treated at lexington in the period 1971-1972 were studied. these patients, admitted from 41 different states, had a mean period of addiction of 5.4 years. over one-third of the sample had engaged in pimping or prostitution, and there were no differences by gender in terms of involvement. eight-eight percent had shared injection equipment, and surprisingly, 78% admitted to some effort at sterilizing their "works ... | 1989 | 2599682 |
| hepatitis a in mauritius: an apparent transition from endemic to epidemic transmission patterns. | between january 1984 and december 1985 a large outbreak of viral hepatitis occurred in the island nation of mauritius (population 986,000). no hepatitis epidemics had occurred there since the 1930s. the outbreak involved 2428 reported cases; however, reporting levels were thought to be extremely low. all of the island's nine geographical districts were affected, but cases were concentrated in five districts mostly in the central and northern parts of the island. the highest attack rate occurred ... | 1989 | 2604458 |
| hepatitis a virus infection in children in sardinia, italy. | the prevalence of antibody to hepatitis a virus (anti-hav) in a sample of 1662 sardinian children aged 3 to 11 years was estimated by elisa. the overall anti-hav prevalence was 3.8 per cent; it increased from zero among children of 3 to 7.2 per cent in children of 11 years. a slight male predominance was observed (4 versus 3.6 per cent). anti-hav prevalence was inversely related to the number of years of education received by the father and positively related to the number of households in the s ... | 1989 | 2634514 |
| hepatitis a and b infections in yaoundé, cameroon. | hepatitis a and b virus infections are common in the tropics. there is, however, no information concerning hepatitis a virus (hav) infection in cameroon, while data on the hepatitis b virus (hbv) infection are incomplete. sera from 272 subjects attending the central hospital, yaoundé, for blood donations or mild ailments were tested by an elisa technique for the presence of anti-hav total antibody; antibody was found in 217 (79.8%). when 188 subjects (randomly chosen from the 272) were further t ... | 1989 | 2787924 |
| properties of a hepatitis a virus candidate vaccine strain. | this paper describes the biophysical and biochemical properties as well as electron microscopical studies of a candidate hepatitis a vaccine strain propagated in human fibroblast cells. our results indicated that, in cscl, the density of hepatitis a virus (hav) from cell culture supernatant and of hav extracted from infected cells was influenced by the quantity of lipid material associated with hav. antigenicity of untreated hav, therefore, was detected primarily in low density cscl fractions (1 ... | 1987 | 2821186 |
| biochemically silent posttransfusion non-a, non-b hepatitis interferes with superinfection by hepatitis a virus. | superinfection of a silently non-a, non-b (nanb)-infected chimpanzee with hepatitis a virus (hav) resulted in minimal liver enzyme elevations, lack of detectable hav in stool, and questionable presence of hav antigen in liver biopsy specimens obtained during the expected period of virus replication. our findings indicate that even biochemically silent nanb hepatitis can strongly interfere with infection by at least one other hepatotrophic virus. | 1987 | 2822600 |
| detection of hepatitis a virus by extraction of viral rna and molecular hybridization. | hepatitis a virus (hav) rna was extracted from cell culture, serum, liver, and feces and then detected by molecular hybridization with cloned hav cdna. hybridization was approximately 10-fold more sensitive than immune electron microscopy or radioimmunoassay was and less sensitive than was assays of hav infectivity in primates or in cell culture. as little as 10(3) 50% infective doses of hav, or approximately 0.1 pg of viral rna, was detected by this method. analysis of fecal specimens from an e ... | 1987 | 2822759 |
| expression of hepatitis a virus cdna in escherichia coli: antigenic vp1 recombinant protein. | the genome of hepatitis a virus (hav) was reverse transcribed into cdna and molecularly cloned. cdna clones coding for the capsid protein vp1 that carries the major hav antigen were cloned into the expression vector pur290 and expressed in escherichia coli. the recombinant fusion protein reacted in an immunoblot with rabbit anti-hav serum, suggesting that it possesses hav antigenicity. | 1987 | 2822970 |
| the entire nucleotide sequence of the genome of human hepatitis a virus (isolate mbb). | hepatitis a virus (hav) is an important human pathogen causing hepatitis, with high incidence in developed as well as in developing countries. no vaccines are available. in order to determine the primary structure of the hav genome, we have prepared cdnas from viral rna and cloned these into plasmid pbr322. these clones were used to determine the entire nucleotide sequence of the hav rna by rapid sequencing methods. we have compared this sequence of 7470 bases to known partial sequences, and one ... | 1987 | 2823500 |
| [hepatitis a in macaca fascicularis and m. arctoides infected by the java monkey-55 strain of hepatitis a virus]. | the results are presented dealing with experimental inoculation of m. fascicularis and m. arctoides with a strain of hepatitis a virus (hav), yam-55, isolated from a m. fascicularis with spontaneous hepatitis a, and parallel experiments on inoculation of these monkey species with hav preparations (strain has-15) obtained as a result of the strain propagation in frhk-4 cell culture and with specimens from human hepatitis a patients containing hav particles. the yam-55 strain of hav was found to b ... | 1987 | 2825433 |
| studies of prototype live hepatitis a virus vaccines in primate models. | we have prepared two prototype live hepatitis a virus (hav) vaccines by serial passage of the hm-175 strain of hav in african green monkey kidney cells. passage 21 (p-21) hm-175 virus shows evidence of attenuation for chimpanzees but not for marmosets; passage 32 (p-32) hm-175 virus shows evidence of attenuation for both species. animals that received p-32 hav had fewer elevations in levels of liver enzyme activity and evidence of less virus replication in the liver and excretion of virus in sto ... | 1988 | 2826614 |
| continuous production of hepatitis a virus in plc/prf/5 cell cultures: use of antigen for serology. | the strain cf53 of hepatitis a virus (hav) previously adapted to growth in plc/prf/5 cells was grown in 175 cm2 flasks, at different passages. after infection, cells were incubated at 32 degrees c in rpmi 1640 medium supplemented with 2.5% foetal calf serum (fcs) for 6-12 months. hav which was released continuously in the culture medium was harvested weekly. hepatitis a virus antigen (haag) and infectious virus production was stable during each passage. the antigen titre, determined by radioimmu ... | 1987 | 2828401 |
| nucleic acid sequence of the vp1 region of attenuated ms-1 hepatitis a virus. | the nucleotide sequence of the vp1 region of marmoset-attenuated hepatitis a virus (hav), ms-1, was determined by incorporative dideoxynucleotide sequencing of the rna obtained from purified, liver-derived virus. comparison of this nucleotide sequence to those of four previously published isolates revealed that one of the isolates, hm-175, which was obtained from australia and passed three times in marmosets, had a 8.5-11% nucleotide variability compared to the remaining four isolates which were ... | 1987 | 2829458 |
| seroepidemiology of hepatitis a virus in japan. | a seroepidemiologic study to detect class-specific antibody against hepatitis a virus (hav) was made with 831 randomly collected sera (415 in 1973 and 416 in 1984) from healthy japanese. competitive-inhibition, igg, iga, and igm anti-hav enzyme-linked immunosorbent assays (elisa) were used. both collections showed a low prevalence of igg anti-hav in young age groups and it increased rapidly at middle age and plateued at greater than or equal to 94% prevalence in the older age groups. however, tw ... | 1987 | 2832647 |
| complete nucleotide sequence of a cell culture-adapted variant of hepatitis a virus: comparison with wild-type virus with restricted capacity for in vitro replication. | to determine the molecular changes associated with adaptation of hepatitis a virus (hav) to growth in cell culture, the genome of a cell culture-adapted variant of hm175 strain hav (p16 hm175, 16th in vitro passage level) was molecularly cloned and the complete nucleotide sequence of the virus was determined. compared with wild-type virus, p16 hm175 replicates efficiently in monkey kidney (bs-c-1) cells (approximately 58 rna-containing particles per one infectious unit, compared with 2.4 x 10(5) ... | 1988 | 2833008 |
| [spontaneous hepatitis similar to hepatitis a in african green monkeys]. | circulation of a virus similar to human hepatitis a virus by antigenic and some other properties was observed among african green monkeys imported from their natural habitats. in some of the monkeys this virus caused a disease similar to hepatitis a in many features. | 1987 | 2833034 |
| acute hepatitis a in singapore: importance of shellfish ingestion in a non-epidemic period. | a case-control study based on 28 serologically confirmed cases of hepatitis a and 42 home contacts with no recent or past evidence of hepatitis a virus (hav) infection was conducted to determine the importance of shellfish exposure in the transmission of hav during a non-epidemic period in singapore. it was found that consumption of partially-cooked cockles (anadara granosa) was significantly associated with the illness (p less than 0.001). no other types of locally available shellfish including ... | 1987 | 2833148 |
| [an experimental observation on rhesus monkeys continuously inoculated with human hepatitis a virus (hav)]. | | 1987 | 2835166 |
| antigenic and immunogenic properties of a hepatitis a virus capsid protein expressed in escherichia coli. | we have constructed a recombinant plasmid producing, in bacteria, a hepatitis a virus (hav) capsid protein that may be useful as a subunit vaccine. hav vp1 coding sequences were fused in-frame to nh2-terminal escherichia coli trpe coding sequences under the control of the tryptophan promoter. in the absence of exogenous tryptophan, e. coli containing this recombinant plasmid produced high levels of an 88-kilodalton fusion protein that was recognized in immunoblots by antibodies to trpe and hav. ... | 1988 | 2836522 |
| immune electron microscopy in the detection of viruses other than enteroviruses on cell culture in untreated sewage. | following the demonstration of enteroviruses in samples of untreated sewage by inoculation of cell cultures with an eluate fraction, immune electron microscopy (iem) was employed in two stages to detect adenoviruses and the hepatitis a virus (hav). 6/12 samples contained adenoviruses and 5/15 other samples contained viruses having characteristics of hav. cell culture can thus be usefully allied with iem in the more precise determination of the potential health hazards of waste water. | 1988 | 2839942 |
| large scale production of hepatitis a virus in cell culture: effect of type of infection on virus yield and cell integrity. | approaches to cell culture propagation of hepatitis a virus (hav) have used either acute infection by passage of infected cell lysates or supernatants into uninfected cells or the passage of persistently infected cells. the findings presented here demonstrate that the growth and recovery of purified virus from foetal rhesus monkey kidney (frhk4) cells persistently infected with hav isolate has-15 decreased over a 2 to 3 month period. in contrast, high multiplicity acute infection of frhk4 cells ... | 1988 | 2841419 |
| expression of hepatitis a virus capsid sequences in insect cells. | a cdna coding for hepatitis a virus (hav) vp1 and portions of the flanking vp3 and p2 sequences was inserted into the genome of autographa californica nuclear polyhedrosis virus under the control of the polyhedrin promoter and translational start codon. cells infected with recombinant virus produced high levels of a 55 kda protein, identified as containing hav vp1 by reactivity with anti-vp1 serum. the expressed protein also reacted on immunoblots with human hav convalescent sera as well as sera ... | 1988 | 2842974 |
| human gamma interferon production by cytotoxic t lymphocytes sensitized during hepatitis a virus infection. | the production of interferon (ifn) during a chromium-51 release assay with hepatitis a virus (hav)-infected fibroblasts and autologous peripheral blood lymphocytes from patients with acute hav infection was studied to determine whether ifn plays a role in immunopathogenesis of hepatitis a infection in humans. skin fibroblasts of eight patients after acute hav infection and from two control persons without history of current or past hav infection were infected with hav. peripheral blood lymphocyt ... | 1988 | 2843673 |
| restricted replication of hepatitis a virus in cell culture: encapsidation of viral rna depletes the pool of rna available for replication. | the replication of hepatitis a virus (hav) in bs-c-1 cells was examined under single-cycle growth conditions by using strand-specific probes for detection of viral rna species. no measurable lag phase was demonstrated between accumulation of positive-strand hav rna and production of infectious virions, indicating that replication of virion rna is rate limiting for the production of infectious virus. intracellular viral rna was further analyzed by using 2 m licl to fractionate the insoluble nonvi ... | 1988 | 2845131 |
| [epidemiologic evaluation of the immunologic structure of groups with respect to hepatitis a virus]. | the members of a newly formed group of persons have been found to be dissimilar in the intensity of their immunity to hepatitis a virus (hav), the character of changes in the specific antibody level and the time of its retention. in groups with the favorable situation with respect to hepatitis a, the epidemic process takes a latent course. the continuous circulation of the infective agent is ensured by the presence of the asymptomatic and inapparent forms of this infection. changes in the specif ... | 1988 | 2847451 |
| a technology of preparing hepatitis a virus (hav) from human stools. | two-step differential centrifugation through 40% and 20% sucrose of 20% water extracts of hav-positive stools yielded specific defined antigens for hepatitis a serological diagnosis by 3rd-generation methods. the antigens would be suitable also for other purposes. products of comparable quality were obtained from hav-positive stools yielding different amounts of virus. optimal were incubation-period stools, where the loss in hav yield was minimal; these preparations displayed the highest antigen ... | 1988 | 2848884 |
| appearance of immune complexes during experimental hepatitis a infection in chimpanzees. | circulating immune complexes (cics) were detected during the course of experimental hepatitis a virus (hav) infection in 8 of 9 chimpanzees. in all cases, the predominant class of antibody detected in the cic was igm. the appearance of igm-cic usually preceded the onset of liver enzyme elevations, and in all instances, the appearance of igm-cic correlated with the presence of igm anti-hav. six of 8 animals tested had significant depression of c3 concentrations during the course of infection, and ... | 1988 | 2849636 |
| detection of enterovirus rna in experimentally infected mice by molecular hybridisation: specificity of subgenomic probes in quantitative slot blot and in situ hybridisation. | subgenomic cdna clones representing defined regions of the genome of coxsackie b3 virus were used as hybridisation probes to detect rna of various enteroviruses in cell culture and mouse model systems. radiolabelled probes were used in slot blots to quantitate the rna in samples; biotinylated probes were used to localise virus rna at the cellular level by in situ hybridisation with monolayers of infected cells or thin sections of tissue samples. probes derived from the 5' or 3' terminal regions ... | 1988 | 2850342 |
| long-term survival of hepatitis a virus and poliovirus type 1 in mineral water. | the survival in mineral water of hepatitis a virus (hav) and poliovirus type 1 was compared, under controlled experimental conditions, at 4 degrees c and room temperature. viral infectivity titers were determined by cell culture titration, while hav antigenicity was monitored by radioimmunoassay-endpoint titration. both viruses persisted longest at 4 degrees c. at this temperature, after 1 year of exposure, the inactivation of either hav or poliovirus type 1 was not important. at room temperatur ... | 1988 | 2850763 |
| [detection of hepatitis a virus rna by molecular hybridization]. | hepatitis a virus (hav) was propagated in continuous rhesus monkey embryo kidney cells (frhk-4 line). hav rna extracted with phenol from purified hav pretreated with proteinase k was used for molecular cloning experiments. two radioactive plasmids, phav-23 and phav-5p, containing hav cdna fragments complementary to structural and nonstructural parts of hav genome, respectively, were found to be useful for discrimination between mature virions and subviral structures. hav cdna-rna hybridization s ... | 1988 | 2851219 |
| the genomic map of hepatitis a virus: an alternate analysis. | recently najarian et al. reported a complete cdna sequence of the genomic rna of hepatitis a virus (hav) and the amino acid sequence inferred from it. as a picornavirus, hav contains a single-stranded plus-sense rna encoding a single 'polyprotein' which is post-translationally cleaved to yield the mature structural and non-structural proteins. in order to identify putative cleavage sites a combined function of predicted secondary structure and hydropathy was calculated by najarian et al. for the ... | 1986 | 2854598 |
| isolation and propagation of hepatitis a virus in hepatoma cell cultures. | hepatitis a virus (hav) was isolated directly from human faeces in plc/prf/5 cells. in the first passage cell-bound and supernatant viruses were found by immune electron microscopy and by enzymeimmunoassay. serial passaging of hav in plc/prf/5 cells resulted in its adaptation to the cell line and in reduction of the incubation time. hav was still detectable after 10 cell passages. cell-bound as well as supernatant hav were employed as antigens in anti hav igm-enzymeimmunoassay. | 1985 | 2869659 |
| propagation of hepatitis a virus in human diploid fibroblast cells. | human hepatitis a virus (hav) was propagated in human diploid fibroblast cultures (2bs cells) in vitro. replication of the virus was followed by immunofluorescent staining (if), indirect elisa, and by immune electron microscopy. when 2bs cells were inoculated with faecal extracts containing hav, synthesis of hepatitis a antigen (haag) could be detected in the cytoplasm by if. its concentration reached a maximum at four weeks post-inoculation. measured by solid-phase indirect elisa, the positive/ ... | 1986 | 2881465 |
| sensitive assays for viral antibodies in saliva: an alternative to tests on serum. | paired serum and saliva specimens were tested by conventional assays and by igg-capture radioimmunoassays (gacria) and enzyme-linked immunosorbent assays (gacelisa) for antibody to hepatitis a virus (hav, 100 pairs), human immunodeficiency virus (hiv, 53), hepatitis b virus core (hbc, 62), and rubella virus (30). conventional assays failed to detect viral antibodies in the saliva of 93 of 119 seropositive subjects. however, gacria detected the antibodies in both serum and saliva of all subjects ... | 1987 | 2885575 |
| aetiological association of a virus-like particle with enterically transmitted non-a, non-b hepatitis. | virus-like particles, approximately 27 nm in diameter, were identified in faeces from an indian patient with enterically transmitted non-a, non-b (enanb) hepatitis. they were serologically distinct from hepatitis a virus (hav). nucleic acid extracted from the particles did not hybridize with cdna probes representing the genomes of hav, enteroviruses, and cardioviruses. chimpanzees were experimentally inoculated with faecal suspensions containing this 27 nm particle or with faeces from another ca ... | 1988 | 2894491 |
| review of hepatitis non-a, non-b: the potential hazards in dental care. | several of the common viral agents that can cause hepatitis have been detected in body fluids, including saliva and blood, which may both form important routes for transmission of disease. the viruses most commonly implicated include hepatitis a virus (hav), hepatitis b virus (hbv), cytomegalovirus (cmv), and epstein-barr virus. hepatitis delta virus (hdv) can be found in persons positive for hepatitis b surface antigen (hbsag) and presumably follows the same routes of transmission as hbv. herpe ... | 1988 | 2963986 |
| etiopathogenetic aspects of hepatitis a. i. excretion of hepatitis a virus, biochemistry of liver function, and humoral immune response in patients with hepatitis a on admission to hospital. | the excretion of hepatitis a virus (hav) in stools from 30 patients with clinically overt hepatitis a infection on the day of their admission to the hospital was determined and compared with the dynamics and values of biochemical indices of hepatocyte injury as well as with the immune response to hav. virus was found in 16 out of 30 stools (53%) collected within 1 week after the appearance of clinical symptoms. in sera obtained on the day of hospitalization both igm and iga anti-hav were detecte ... | 1985 | 2983007 |
| infectious hepatitis a virus particles produced in cell culture consist of three distinct types with different buoyant densities in cscl. | although hepatitis a virus (hav) released by infected bs-c-1 cells banded predominantly at 1.325 g/cm3 (major component) in cscl, smaller proportions of infectious virions banded at 1.42 g/cm3 (dense hav particles) and at 1.27 g/cm3 (previously unrecognized light hav particles). cdna-rna hybridization confirmed the banding of viral rna at each density, and immune electron microscopy demonstrated apparently complete viral particles in each peak fraction. the ratio of the infectivity (radioimmunof ... | 1985 | 2983123 |
| sequence analysis of hepatitis a virus cdna coding for capsid proteins and rna polymerase. | we report here the nucleotide sequence corresponding to two large regions of the hepatitis a virus (hav) genome. these comprise a sequence of 3274 bases corresponding to the 5' end of the genome, which includes the putative capsid protein region of this picornavirus, and 1590 bases corresponding to the 3' end of the genome, terminating in a 15-base poly(a) tract. these sequences revealed that hav had the characteristic genomic organization of picornaviruses: an open reading frame beginning appro ... | 1985 | 2984684 |
| primary structure and gene organization of human hepatitis a virus. | the rna genome of human hepatitis a virus (hav) was molecularly cloned. recombinant dna clones representing the entire hav rna were used to determine the primary structure of the viral genome. the length of the viral genome is 7478 nucleotides. an open reading frame starting at nucleotide 734 and terminating at nucleotide 7415 encodes a polyprotein of mr 251,940. comparison of the hav nucleotide sequence with that of other picornaviruses has failed to reveal detectable areas of homology. however ... | 1985 | 2986127 |
| [hepatitis a foci in children's collectives studied by using clinico-biochemical, virological and serological diagnostic methods]. | in 4 foci of hepatitis a (ha) at children's institutions in moscow 218 children and 30 staff members were examined. simultaneously with clinico-biochemical studies, specific igm and igg in the blood and hepatitis a virus (hav) antigen in feces were determined by radioimmunoassay. different forms of ha were detected in 29.1% of children in kindergartens, 19.4% of school children and 3.3% of adults, which was due to great differences in the size of the immune stratum among them (igg to hav was det ... | 1985 | 2986394 |
| persistently infected cultures as a source of hepatitis a virus. | primary african green monkey kidney, continuous african green monkey kidney cell line bs-c-1, and buffalo green monkey kidney cultures were infected with a uniform inoculum of hepatitis a virus (hav). although both the cell line bs-c-1 and primary african green monkey kidney cultures produced useful amounts of virus, hav was detected earlier and in greater quantities in primary african green monkey kidney cultures. a persistently infected primary african green monkey kidney culture was developed ... | 1985 | 2988436 |
| a simple method for clonal selection of hepatitis a virus based on recovery of virus from radioimmunofocus overlays. | hepatitis a virus (hav), a non-cytopathic picornavirus, has been quantitated in cell culture by autoradiographic detection of foci of viral replication developing beneath an agarose overlay following fixation and 'staining' of the cell sheet with radiolabelled antibody (radioimmunofocus assay). using a modification of this basic technique, a clonal variant of hm-175 strain hav was isolated from agarose overlying individual radioimmunofoci. virus recovered from the agarose was amplified in small ... | 1985 | 2991315 |
| isolation and immunizations with hepatitis a viral structural proteins: induction of antiprotein, antiviral, and neutralizing responses. | an immune affinity purification procedure for hepatitis a virus (hav) was designed which yielded milligram quantities of the virus with greater than 95% purity. the major structural proteins vp-1, vp-2, and vp-3 were isolated from the purified virus by electroelution from sodium dodecyl sulfate-polyacrylamide gels and used to immunize lewis rats (three to four doses, 10 to 15 micrograms per dose). the two lewis rats immunized with vp-1 developed a strong antibody response to vp-1, as determined ... | 1985 | 2991564 |
| induction of hepatitis a virus-neutralizing antibody by a virus-specific synthetic peptide. | comparative surface feature analyses of the vp1 sequences of hepatitis a virus (hav) and poliovirus type 1 allowed an alignment of the two sequences and an identification of probable hav neutralization antigenic sites. a synthetic peptide containing the hav-specific amino acid sequence of one of these sites induced anti-hav-neutralizing antibodies. it is concluded that a structural homology exists between the two viruses, despite minimal primary sequence conservation. | 1985 | 2991600 |
| [viral hepatitis and aids-associated htlv iii/lav virus infections in drug addicts]. | in 1984 intravenous drug users accounted for 25% of all cases of acute hepatitis b and for 32% of all cases of non-a/non-b hepatitis recorded in the canton of zürich. drug addicts also represented an important risk group for hepatitis a, which occurred in small epidemics. among 141 "healthy" drug users, 10 (7%) individuals showed signs of ongoing hepatitis b virus (hbv-) infection, 26 (19%) individuals had the finding "anti-hbc-alone" (unresolved hbv-infection) and another 69 (49%) individuals w ... | 1985 | 2994210 |
| isolation and adaptation characteristics of hepatitis a virus in primary african green monkey kidney cells: production of antigen useful for elisa serology. | four strains of hepatitis a virus (hav) were isolated from four fecal samples of patients with type a hepatitis by using primary african green monkey kidney (pagmk) cells or frhk-4 cells. in all four samples viral antigen became detectable in pagmk cells at the 3rd passage level after 9 weeks of incubation; detectable levels of antigen were reached earlier in frhk-4 cells. an enzyme-linked immunosorbent assay (elisa) was used to detect hav antigen (hav-ag). blocking experiments with negative and ... | 1985 | 2997078 |
| incomplete neutralization of hepatitis a virus in vitro due to lipid-associated virions. | hepatitis a virus (hav) released from infected bs-c-1 cells was incompletely neutralized when incubated with a variety of convalescent sera (non-neutralizable fraction of 17 to 32%). chloroform extraction of virus resulted in a substantial reduction of the non-neutralizable fraction (to less than 1%), suggesting that non-neutralizable virions might be associated with lipids. non-neutralizable hav recovered from untreated cell culture supernatant fluids sedimented heterogeneously and less rapidly ... | 1985 | 2997380 |
| isolation and molecular cloning of a fast-growing strain of human hepatitis a virus from its double-stranded replicative form. | a fast-growing strain of human hepatitis a virus was selected and characterized. the virus has the unusual property of developing a strong cytopathic effect in tissue culture in 7 to 10 days. sequences of the viral genome were cloned into recombinant plasmids with the double-stranded replicative form as a template for the reverse transcription of cdna. restriction analysis and direct sequencing indicate that this strain is different from that described by ticehurst et al. (proc. natl. acad. sci. ... | 1985 | 2997478 |
| [adaptation to the cell line plc/prf/5 of hepatitis a virus released in the cell culture medium]. | the propagation of hepatitis a virus (hav), cf53 strain, released without any cytopathic effect into the plc/prf/5 cells supernatant, was studied in the course of six serial passages (6th to 11th). the decrease (from 5 to 1 week) of incubation time required to detect hav, by ria, in culture supernatant, the increase in hepatitis a antigen (from 777 to 10,038 c.p.m./50 microliter) and infectivity titre (from 10(3.0) tcid 50/ml to 10(4.5) tcid 50/ml) were consistent with the adaptation of this vir ... | 1985 | 2998570 |
| combined immunoaffinity cdna-rna hybridization assay for detection of hepatitis a virus in clinical specimens. | to apply cdna-rna hybridization methods to the detection of hepatitis a virus (hav) in clinical materials, we developed a two-step method in which a microtiter-based, solid-phase immunoadsorption procedure incorporating a monoclonal anti-hav capture antibody was followed by direct blotting of virus eluates to nitrocellulose and hybridization with 32p-labeled recombinant hav cdna. this immunoaffinity hybridization method is simple and involves few sample manipulations, yet it retains high sensiti ... | 1985 | 2999190 |
| variation among hepatitis a virus strains. i. genomic variation detected by t1 oligonucleotide mapping. | the genomes of eight hepatitis a virus (hav) strains originating from far distant geographic regions such as europe, north africa, middle and north america, australia and the people's republic of china were compared by rnase t1 oligonucleotide mapping. for this purpose, the viruses were propagated in cell cultures and viral rna was isolated from highly purified mature virions. it could be shown that variation in nucleotide sequence is common among hav isolates, but is in the order of magnitude r ... | 1985 | 3002070 |
| localization of hepatitis a virus in marmoset liver tissue during the acute phase of experimental infection. | electron microscopic and virological studies of marmoset liver tissue with acute infection of hepatitis a virus (hav), especially in the earlier stages of infection, were carried out to characterize the maturation process of hav. four marmosets were inoculated intravenously with hav suspension and sacrificed 1 week, 2 weeks, 3 weeks and 4 weeks after inoculation respectively. hepatitis a antigen (haag) in 10% liver homogenates of marmosets was examined by radioimmunoassay and a large amount of h ... | 1985 | 3002896 |
| evaluation of methods for concentrating hepatitis a virus from drinking water. | by using recently developed cultivation and assay systems, currently available methods for concentrating enteric viruses from drinking water by adsorption to and subsequent elution from microporous filters followed by organic flocculation were evaluated for their ability to recover hepatitis a virus (hav). cell culture-adapted hav (strain hm-175) in seeded tapwater was efficiently adsorbed by both electronegative (filterite) and electropositive (virosorb 1mds) filters at ph and ionic conditions ... | 1985 | 3004331 |
| antibody against hepatitis a in saudi arabians and in expatriates from various parts of the world working in saudi arabia. | the age-specific rate of exposure to hepatitis a virus (hav) was studied in 1015 native saudi arabians (504 males, 511 females) from the riyadh area. the relatively high prevalence of antibody to hav (anti-hav) (38.6%) in children between 1 and 4 years of age indicates that infection is acquired early in life in the saudi arabian population. the prevalence of anti-hav was found to increase steadily so that by the age of 30 years 91.0% of saudi arabians have anti-hav. the prevalence in adult saud ... | 1986 | 3009629 |
| hepatitis a virus replication in tamarins and host immune response in relation to pathogenesis of liver cell damage. | hepatitis a virus (hav) shedding in the faeces, appearance of hav-ag (antigen) in the liver, and development of humoral immunity to hav have been studied in experimentally infected tamarins. the appearance of liver damage measured by transaminase elevation and histology, in relation to the above variables, suggests that the virus is not cytopathic and the immune system contributes to the production of liver cell damage. preliminary data suggest that hav replication may occur in the mucosa of the ... | 1986 | 3009699 |
| an inactivated hepatitis a viral vaccine of cell culture origin. | hepatitis a virus (hav) strain cr326, adapted to grow in llc-mk2 cells, was highly purified, inactivated with formalin, adsorbed to alum, and tested for capacity to induce antibody to hav in both mice and marmosets. the minimum dose of hav antigen necessary to produce antibody in 50% of mice was 10 ng. as little as three doses of 1 ng each produced antibody in 50% of marmosets. further, all marmosets with any detectable antibody to hav, as a result of vaccination, were protected against virulent ... | 1986 | 3009703 |
| viral hepatitis markers in patients on haemodialysis in a hyperendemic area. | antibody profiles for cytomegalovirus (cmv), hepatitis a virus (hav), hepatitis b virus (hbv) and the delta-agent were determined on 55 serum samples drawn from 55 saudi patients on maintenance haemodialysis for periods ranging from 1.5 months to 2 years. the exposure rates for cmv, hav, and hbv were 100%, 100%, and 72.7%, respectively. there was no intersex difference in positivity for hbv surface antigen (hbsag), antibody to hbsag (anti-hbs), antibody to hbv core antigen (anti-hbc); 15.4%, 65. ... | 1986 | 3009704 |
| structure of the hepatitis a virion: peptide mapping of the capsid region. | milligram amounts of highly purified hepatitis a virus (hav) were obtained from persistently infected cell cultures. the hav polypeptides were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose for detection by an enzyme-linked immunotransfer blot procedure. the hav nucleotide-derived amino acid sequence was subjected to computer analysis to identify potential immunogenic regions within the hav capsid polypeptides. synthetic peptides correspo ... | 1986 | 3009847 |
| unusual viral causes of transverse myelitis: hepatitis a virus and cytomegalovirus. | twenty to 40% of cases of acute transverse myelitis are attributed to viral infections, although the specific viral etiology is only rarely identified. we studied two patients with transverse myelitis in association with acute hepatitis a virus (hav) infection and acute primary cytomegalovirus (cmv) infection. this is the first well-documented report of an association between hav infection and transverse myelitis, and only the fourth documented case of transverse myelitis in association with cmv ... | 1986 | 3010183 |
| influence of twenty potentially antiviral substances on in vitro multiplication of hepatitis a virus. | a multiwell tissue culture system was developed to study the influence of various substances on hepatitis a virus (hav) propagation. a panel of 20 substances of different structure types, each with known effect against at least some viruses, was studied at a concentration of 100 microm. three substances showed reproducible inhibition. the strongest inhibitor, arabinosylcytosine, also produced cytotoxic changes in cells down to a concentration of 1 microm, and its effect was considered as nonspec ... | 1986 | 3010855 |
| fecal excretion of greek strains of hepatitis a virus in patients with hepatitis a and in experimentally infected chimpanzees. | the presence of hepatitis a virus (hav) in stool samples was determined in 36 children (mean age, 8.9 years) and 38 adults (mean age, 19.9 years) with acute type a hepatitis. three stool samples, taken on admission and thereafter at three-to-five-day intervals, were collected from each patient. the first day of dark urine was considered to be the onset of illness. molecular hybridization of cloned hav cdna to fecal extracts was used to detect hav rna; radioimmunoassay was used to detect hav anti ... | 1986 | 3014009 |
| molecular cloning of cdna from hepatitis a virus strain hm-175 after multiple passages in vivo and in vitro. | hepatitis a virus (hav) strain hm-175 was passaged six times in marmosets, 59 times in cell culture and purified from infected cell culture supernatant fluid. the viral rna was extracted, copied into cdna and the cdna:rna hybrids were cloned into the psti site of plasmid pbr322. the cdna clones were authenticated by hybridization to rna extracted from hav-infected cells and clones representing the 3' end of the genome were identified using a previously authenticated cdna clone. the clones repres ... | 1986 | 3016162 |
| detection of a genome-linked protein (vpg) of hepatitis a virus and its comparison with other picornaviral vpgs. | the nucleotide sequence corresponding to the p3 region of the hepatitis a virus (hav) polyprotein genome was determined from cloned cdna and translated into an amino acid sequence. comparison of the amino acid sequences of the genome-linked proteins (vpgs) of other picornaviruses with the predicted amino acid sequence of hav was used to locate the primary structure of a putative vpg within the genome of hav. the sequence of hav vpg, like those of other picornaviral vpg molecules, contains a tyro ... | 1986 | 3018280 |
| preliminary characterization of a fast-growing strain of human hepatitis a virus. | a fast-growing strain of human hepatitis a (hha) virus was selected by progressively shortening by the time between serial passages of the isolate in the simian cell line frp/3. the virus so selected infected 90-95% of the cells in 7-10 days, and developed a strong cytopathic effect (cpe). the synthesis of hha-specific antigens and the cpe were neutralized simultaneously by standard anti-hha sera. this fast-growing strain has the characteristics of a picornavirus. | 1986 | 3018450 |
| lack of complement-dependent cytolytic antibodies in hepatitis a virus infection. | sera collected from patients with acute hepatitis a virus (hav) infection and convalescent sera were examined for cytolytic activity against hav-infected human-embryo lung fibroblasts (hav carrier fibroblasts). using the 51chromium release assay, no complement dependent antibody mediated cytolytic activity against hav carrier cells could be detected. in control experiments with identical cell strains, anti-herpes simplex virus (hsv) positive sera and complement caused specific lysis of hsv type ... | 1986 | 3020167 |
| [association of the hepatitis a virus with the membranes of infected cells]. | "light" viral antigen (haag) with buoyant density 1.20 g/cm2 and sedimentation coefficient 92s are accumulated together with mature viral particles in hepatitis a virus (hav) infected frhk-4 cells. this haag is localized predominantly in endoplasmic reticulum fraction of infected cells, while nature virions are localized in cytosol. in contrast to mature virus, "light" haag is sensitive to trypsin digestion and is not able to hybridize with synthetic oligodeoxinucleotide which is complementary t ... | 1986 | 3020806 |
| prevalence of antibodies to enteroviruses and varicella-zoster virus among residents and overseas volunteers at agricultural settlements in israel. | within the framework of a comprehensive study of the correlation between enteric diseases and wastewater utilization in agricultural settlements (kibbutzim) the prevalence of several viral antibodies was examined among kibbutz residents and overseas volunteers. the latter were assumed to be a group highly susceptible to local pathogens. for the purpose of this study the presence of antibodies against eight enteroviruses [coxsackieviruses (cox) types a9, b1, b3, and b4, echoviruses (echo) types 4 ... | 1986 | 3021900 |
| kaposi's sarcoma and htlv-iii: a study in nigerian adult males. | sera from 37 adult nigerian men with kaposi's sarcoma (ks), 30 contemporaneous controls bearing primary cell carcinoma of the liver (pcl), and 150 healthy non-tumour-bearing negative controls were tested for antibody to human t-cell lymphotropic virus type iii/lymphadenopathy associated virus (htlv-iii/lav) by enzyme-linked immunosorbent assays (elisa). certain immunocellular functions were also measured: the chemotactic locomotion of peripheral blood monocytes towards casein, delayed-type cutan ... | 1986 | 3021963 |
| detection of hepatitis a virus in seeded estuarine samples by hybridization with cdna probes. | the development and trials of a nucleic acid hybridization test for the detection of hepatitis a virus (hav) in estuarine samples within 48 h are described. approximately 10(4) physical particles of hav per dot could be detected. test sensitivity was optimized by the consideration of hybridization stringency, 32p energy level, probe concentration, and nucleic acid binding to filters. test specificity was shown by a lack of cross-hybridization with other enteroviruses and unrelated nucleic acids. ... | 1986 | 3022645 |
| complete nucleotide sequence of wild-type hepatitis a virus: comparison with different strains of hepatitis a virus and other picornaviruses. | the complete nucleotide sequence of wild-type hepatitis a virus (hav) hm-175 was determined. the sequence was compared with that of a cell culture-adapted hav strain (r. najarian, d. caput, w. gee, s.j. potter, a. renard, j. merryweather, g.v. nest, and d. dina, proc. natl. acad. sci. usa 82:2627-2631, 1985). both strains have a genome length of 7,478 nucleotides followed by a poly(a) tail, and both encode a polyprotein of 2,227 amino acids. sequence comparison showed 624 nucleotide differences ... | 1987 | 3023706 |
| study of the chemical nature of frp/3 cell recognition units for hepatitis a virus. | research has been carried out in order to clarify the chemical nature of cell receptors interacting with a fast growing strain of hepatitis a virus (hav) producing a cytopathic effect on frp/3 cells. cell surface susceptibility to hav attachment has been studied after treatment with enzymes acting on different chemical groupings. results obtained showed a lowering of cell susceptibility to hav infection following the action of phospholipase a2, phospholipase c, trypsin and beta-galactosidase. th ... | 1987 | 3029555 |
| replicative events in hepatitis a virus-infected mrc-5 cells. | replication of hepatitis a virus (hav) in mrc-5 cells was studied under one-step growth conditions. viral replication neither interfered detectably with cellular dna, rna, and protein synthesis, nor could cytopathologic changes be recorded over a prolonged period of incubation. synthesis of mature, infectious hav particles could be detected as early as 2-4 days p.i. and occurred at a maximal rate around 8 days p.i., shortly before infectivity titers reached a plateau. synthesis of total viral rn ... | 1987 | 3029972 |
| [dynamics of the accumulation of virus particles with different physico-chemical properties in frhk-4 cells infected with hepatitis a virus]. | the propagation time-course of hepatitis a virus (hav, strain has-15) in continuous culture of the foetal rhesus monkey kidney cells (frhk-4) was investigated. the hav infectivity and viral rna content in the infected cells reached the maximal level 5-8 days after infection, while accumulation of hepatitis a antigen (haag) continued for 2-3 weeks more. viral particles with the densities 1.27-1.28 g/cm3 and 1.18-1.22 g/cm3 were isolated from the infected cells as well as the mature virions with t ... | 1987 | 3031492 |
| cellular changes associated with persistent hepatitis a infection in vitro. | the rate of division, morphology and ultrastructure of bsc-1 cells, persistently infected with hepatitis a virus (hav), were compared with uninfected cells for 60 days after splitting of the cells. both control and infected cells showed a biphasic growth pattern marked firstly by increasing cell density and high mitotic rate (exponential phase) and then high constant cell density and little mitosis (stationary phase). immunoperoxidase studies showed that hepatitis a antigen (haag) appeared as cy ... | 1987 | 3034206 |
| comparison of indirect immunofluorescence and radioimmunoassay for detecting antibodies against hepatitis a virus of the igg and igm classes. | indirect immunofluorescence test (iif) and radioimmunoassay (ria) were compared for determining anti-hepatitis a virus (hav) igg and igm. 142 sera were tested for anti-hav igg and 16 for anti-hav igm, both with iif and ria techniques. the correlation between the results reached 98.6% for anti-hav igg and 93.75% for anti-hav igm detection, confirming the specificity and sensibility of iif. | 1986 | 3034306 |
| relationship of theiler's murine encephalomyelitis viruses to the cardiovirus genus of picornaviruses. | sequence analysis of vp1 in the da strain of theiler's murine encephalomyelitis viruses (tmev) showed that 13 of the first 23 n-terminal amino acids were identical to those in the corresponding protein of encephalomyocarditis virus. there was little similarity to the corresponding vp1 sequences of poliovirus types 1, 2 and 3, coxsackievirus b3, human rhinoviruses 2 and 14, human hepatitis a virus or foot-and-mouth disease virus. these results, as well as serological relationships detected by imm ... | 1986 | 3034822 |
| demonstration of hepatitis a virus in cell culture by electron microscopy with immunoperoxidase staining. | virus-like particles were demonstrated by electron microscopy in bs-c-1 cells infected with hepatitis a virus (hav). particles were usually enclosed within vesicles and accompanied by myelin-like membranous structures. less often they were seen free in the cytoplasm. they were never observed in the nucleus. by immunoperoxidase staining particles were found to contain hav antigens. these antigens were also found in the membrane of the vesicles surrounding the masses of particles and adjacent part ... | 1987 | 3034945 |
| cytopathology, plaque assay, and heat inactivation of hepatitis a virus strain hm175. | hepatitis a virus (hav) strain hm175 derived after repeated subculture of persistently infected b-sc-1 cells caused a specific cytopathic effect upon acute infection of b-sc-1 cells. the virus formed visible plaques on b-sc-1 cell monolayers after 9 to 14 days of incubation at 34 degrees c, and virus can therefore be titrated by plaque assay. virus could be re-isolated from plaques of infected cells, which allows the clonal isolation of hav variants. the stability of a plaque-purified variant of ... | 1987 | 3035078 |
| development of a plaque assay for a cytopathic, rapidly replicating isolate of hepatitis a virus. | most hepatitis a virus (hav) replication in cell culture has been reported to be nonlytic and relatively slow. a rapidly replicating isolate of strain hm-175 from persistently infected, serially passed cell cultures (phm-175) was found to induce a cytopathic effect. this observation allowed the development of a classic plaque assay for phm-175 in frhk-4 cells. the plaques were neutralized by polyclonal and monoclonal antisera to hav. | 1987 | 3035079 |
| effect of antiviral substances on hepatitis a virus replication in vitro. | the effect of protamine, atropine, selenocystamine, taxifolin, and catechin on the infectivity and antigenicity of the cell culture-adapted hepatitis a virus (hav) strain cf 53 was studied. the toxicity on uninfected plc/prf/5 cells was examined for each antiviral compound by morphological and biochemical methods, in order to determine concentrations without cytotoxic effect. at these concentrations, protamine and taxifolin, added to infected cells for a 15-day period, caused concentration-depen ... | 1987 | 3035080 |
| immunogenicity of a hepatitis a virus vaccine. | hepatitis a virus (hav) strain hav/hfs/gbm was adapted to and grown in human diploid fibroblast cells. the hav was concentrated by ammonium sulphate precipitation and high-speed centrifugation. the virus was inactivated by beta-propiolacton and purified by sedimentation through a 20% solution of sucrose and by cscl gradient centrifugation. the immunogenicity of different preparations was tested in mice, guinea pigs, and goats. the immune response after vaccination was tested by determination of ... | 1987 | 3035082 |
| studies on heat inactivation of hepatitis a virus with special reference to shellfish. part 1. procedures for infection and recovery of virus from laboratory-maintained cockles. | the consumption of bi-valve molluscan shellfish has been associated with outbreaks of viral gastroenteritis and hepatitis a. investigations were undertaken to determine the heat inactivation conditions necessary to render shellfish such as cockles safe for the consumer. conditions for the laboratory maintenance of live cockles are described. in preliminary experiments either poliovirus (10(6) tcid50/ml seawater) or hepatitis a virus (hav) (approx. 10(4) rfu/ml seawater) was introduced into the s ... | 1987 | 3036554 |
| effect of glutaraldehyde on the antigenicity and infectivity of hepatitis a virus. | the effect of glutaraldehyde on the antigenicity and infectivity of hepatitis a virus (hav) was examined. the cf 53 strain, adapted to human hepatoma plc/prf/5 cells, was treated with glutaraldehyde using three different concentrations, 0.02, 0.10, and 0.50%, for various periods of time, 3, 10, and 30 min, respectively. after the virucidal assays, glutaraldehyde and hav were separated by gel filtration, then the antigen (radioimmunoassay) titer and the infectivity titer were determined. the grea ... | 1987 | 3038939 |
| hepatitis a virus cdna and its rna transcripts are infectious in cell culture. | a full-length cdna copy of an attenuated, cell culture-adapted hepatitis a virus (hav hm-175/7 mk-5) genome was constructed in the psti site of plasmid vector pbr322. transfection of monkey kidney cells with this plasmid failed to induce the production of hepatitis a virus (hav). the hav cdna was excised from pbr322 and inserted, without the oligo(dg) x oligo(dc) tails, into an rna transcription vector to yield plasmid phav/7. transfection of monkey kidney cells with phav/7 dna induced hav infec ... | 1987 | 3041024 |
| fulminant hepatitis in asymptomatic hepatitis b surface antigen carriers in greece. | eleven male fulminant hepatitis (fh) patients (mean age: 47.7 +/- 16 years) positive for hepatitis b surface antigen (hbsag) but negative for igm antibody to hepatitis b core antigen (igm anti-hbc) were admitted consecutively to the athens hospital for infectious diseases between may 1981 and november 1983. because of the absence of igm anti-hbc, determined by an enzyme immunoassay, these patients were considered to be hbsag carriers with a superimposed acute hepatitis. three of the 11 patients ... | 1986 | 3098915 |
| [acute hepatitis in childhood. study of 96 cases and 1-year follow-up]. | authors studied 96 children, 56 boys and 40 girls, aged 1 to 16 years, with acute viral hepatitis. 53 patients were diagnosed of hepatitis a virus (hav) detecting antibodies to hav of the igm class; 11 patients were diagnosed of hepatitis b virus (hbv) detecting serologic markers; 32 patients were diagnosed of non a-non b hepatitis. there were no serologic evidence of infection with cytomegalovirus and epstein-barr virus. they report an analytical and clinical comparative study of acute viral he ... | 1986 | 3103507 |
| acute non-a, non-b hepatitis in kuwait. | in a prospective study of acute hepatitis in kuwait covering the period february 1983 to january 1984, a total of 1781 cases were diagnosed as having an acute viral hepatitis. 1,384 (77.7%) were found to be due to hepatitis a virus (hav), 206 (11.5%) hepatitis b virus (hbv), 8 (0.4%) coinfection with hbv and delta virus (hdv), 8 (0.4%) superinfection of hdv on chronic hbsag carriers and 157 (9%) non-a, non-b virus (nanb). 13 cases of cmv and 5 of ebv infections were also diagnosed. nanb viral he ... | 1987 | 3126547 |
| spontaneous and experimental hepatitis a in old world monkeys. | virologic, serologic, biochemical, and morphological data characterizing spontaneous hepatitis a (ha) in cynomolgus macaques (macaca fascicularis) and green monkeys (cercopithecus aethiops) are reported. experimental ha was induced in macaques as a result of infection with human hepatitis a virus (hav-h). disease similar to human ha was induced in cynomolgus macaques by hav isolates from spontaneously sick rhesus (m. mulatta) and green monkeys. this experimental model of ha in macaques can be us ... | 1988 | 3193448 |
| persistence of a positive test for igm antibodies to hepatitis a virus in late convalescent sera. | we had the opportunity to carry out a long-term follow up of 15 patients with viral hepatitis type a. the serum igm response to hepatitis a virus (hav) was investigated with a commercially available kit (havab-m). igm antibodies were detected in all specimens collected during the acute phase of the disease and during early convalescence (first 3 months). however, there was a clear decrease in the "sample-to-cutoff" ratio (s/co ratio) after the first 2 months. serum samples were available from si ... | 1987 | 3583701 |
| induced oral infection of the owl monkey (aotus trivirgatus) with hepatitis a virus. | several species of nonhuman primates have served as animal models for hepatitis a virus (hav) infection and disease. this study was to determine the suitability of aotus trivirgatus as an orally induced model for hav infection and to reconfirm the owl monkey's susceptibility to the intravenous route of inoculation. animals were inoculated, either orally or intravenously, with varying concentrations of pa-33 strain of hav. serum enzymes alt, ast and ggtp levels were monitored and liver biopsies p ... | 1987 | 3586603 |
| incidence of hepatitis a virus (hav) infection in rural liberia. | to provide background for future hepatitis a vaccine trials, sera were collected from 0- to 4-year-old liberian infants and their mothers on two occasions an average of 14.75 months apart and tested for antibody to hepatitis a virus (anti-hav). the prevalence of anti-hav rose from 2.5% in infants 0-6 months of age to 70% in children 3-4 years of age and did not differ between male and female infants. the annual incidence of new infections was slightly lower in the first year of life (35%) than i ... | 1985 | 3981150 |
| monoclonal antibodies to hepatitis a virus. | this paper describes the development of monoclonal antibodies generated against hepatitis a virus (hav). monoclonal antibodies (mcabs) from two murine hybridoma cell lines were found to bind to an epitope recognized in the sera of patients recovering from infection with hav. ascites fluids containing mcabs from one hybridoma (h1 c19) inhibited a maximum of 70% of the 125i-labeled polyclonal human anti-hav from binding to hav-antigen in a competitive radioimmunoassay, indicating that the mcab rec ... | 1984 | 6086829 |
| [effect of the content of hepatitis a antibodies in immunoglobulin preparations on the effectiveness of the immunoglobulin prophylaxis of hepatitis a]. | the results of a strictly controlled experiment showed that prevention of hepatitis a by the injection of immunoglobulin with hepatitis a virus (hav) antibody titer 1:10000 was 3 times as effective as that achieved with immunoglobulin containing hav antibodies in titer 1:2500. it is recommended to determine the level of specific hav antibodies in immunoglobulins and to use immunoglobulins with a high level of hav antibodies for prevention of hepatitis a. | 1984 | 6087581 |
| interference between human hepatitis a virus and an attenuated apathogenic avian virus. | the effect of an attenuated apathogenic avian bursa virus on the course of human hepatitis a viral infection was studied in marmoset monkeys. the monkeys were infected with human hepatitis a virus, then superinfected with avian bursa virus one and three weeks after initial inoculation with human hepatitis a virus. the superinfected monkeys did not show the characteristic serum glutamic pyruvic transaminase (sgpt) elevation. also their liver biopsies showed no pathologic changes. the virus contro ... | 1984 | 6087596 |
| virus-binding activity of fibronectin: masking of hepatitis a virus. | human plasma fibronectin interacts with viruses. when fibronectin-containing human sera negative for antibodies to hepatitis a virus (hav) were added to suspensions of hav, radioimmunological detection of hav was reduced. this masking effect seemed to depend on the fibronectin concentration of the sera: plasma fibronectin purified by cryoprecipitation and affinity chromatography showed a masking effect on purified hav which was dependent on the concentrations of fibronectin and hav. fibronectin ... | 1984 | 6088567 |
| hepatitis a-virus in cell culture. v. neutralizing antibodies against hepatitis a-virus. | a test system for the detection of neutralizing antibodies against hepatitis a-virus (anti-hav-nt) is presented. the anti-hav-nt assay is performed with frhk-4/r cells and the hepatitis a virus (hav) strain gbm/frhk-4/r which has been adapted to these cells. non-neutralized hav is demonstrated 14 days after infection of frhk-4/r cells using a radio-immunoassay for detecting newly grown hav. the influence of differing amounts of hav on the anti-hav-nt titre and the effect of variations in incubat ... | 1984 | 6088963 |
| translation in vitro of hepatitis a virus rna. | rna extracted from highly purified hepatitis a virus (hav) particles was translated in an rna-dependent, cell-free reticulocyte lysate system, and the products were analyzed by sds-polyacrylamide gel electrophoresis and compared with proteins translated from rna of poliovirus. the efficiency of translation in vitro of hav rna was comparable to that of poliovirus rna. processing of the putative precursor molecules of hav proteins, studied in pulse-chase experiments, was impaired when compared wit ... | 1984 | 6089414 |
| diagnosis of hepatitis a infection: comparative specificity of igm capture assays using antigens derived from tissue cultures and marmoset faeces. | hepatitis a virus (hav) antigens from two tissue culture sources were compared with that from the faeces of infected marmosets to determine whether the former were satisfactory substitutes. sera from 313 healthy blood donors and 417 patients with various clinical conditions were tested for igm class antibody to hav (anti-hav igm) using an igm antibody capture assay (macria) with each of the 3 antigens. forty-eight specimens, all from cases of acute hepatitis, were positive in macria with all 3 a ... | 1984 | 6094607 |