| development and utilization of complement-fixation and immune adherence tests for human hepatitis a virus and antibody. | the reliable propagation of cr326 strain of human hepatitis a virus in saguinus mystax marmosets has permitted the development of specific serum neutralization, complement-fixation (cf), and immune adherence (ia) assays for hepatitis a antigen and antibody. the cf and ia assay were made possible by the use of livers of cr326-infected marmosets as a source of hepatitis a antigen. all assays were shown to be specific for hepatitis a. patients with hepatitis b did not show development of hepatitis ... | 1975 | 53013 |
| localization of hepatitis a antigen in liver tissue by peroxidase-conjugated antibody method: light and electron microscopic studies. | hepatitis a antigen (haag) was localized in liver tissue from marmosets inoculated with human hepatitis a virus (hav) by light and electron microscopy by using a peroxidase-conjugated antibody method. the fine granular peroxidase staining was scattered throughout the cytoplasm of liver cells when viewed with the light microscope. the distribution of haag-positive cells was focal. virus-like particles, 24 to 27 nm in diameter, were observed in the cytoplasm of hepatocytes and smaller cells, resem ... | 1978 | 101591 |
| physical, chemical and morphologic dimensions of human hepatitis a virus strain cr326 (38578). | cr326 human hepatitis a virus purified by isopycnic banding from infected marmoset sera was shown to consist of 27 nm spherical particles on electron microscopic examination. the particles were identified as hepatitis a virus by tests for infectivity and by specific neutralization of infectivity with convalescent human hepatitis a serum. also, indentical 27 nm viruses in liver extracts gave specific reactions with hepatitis a antisera when tested by immune electron microscopy. the bouyant den ... | 1975 | 164674 |
| a specific complement-fixation test for human hepatitis a employing cr326 virus antigen. diagnosis and epidemiology. | a specific diagnostic complement-fixation test for hepatitis a antibody in human serum was described employing livers of marmosets infected with cr326 strain human hepatitis a virus. persons with hepatitis a, but not hepatitis b, developed hepatitis a cf antibody shortly after the onset of illness and this persisted thereafter. good agreement was noted in the development of cf and neutralizing antibodies in hepatitis a cases. hepatitis a was shown to occur in a person with hepatitis b antigenemi ... | 1975 | 165548 |
| specific immune adherence assay for human hepatitis a antibody application to diagnostic and epidemiologic investigations. | a specific immune adherence (ia) test for hepatitis a antibody in human serum was described employing liver extract of marmosets infected with cr326 strain human hepatitis a virus. persons with hepatitis a, but not hepatitis b, developed hepatitis a ia antibody soon after onset of the acute illness and this persisted thereafter. there was very close agreement in the tests for human hepatitis a immune adherence, complement fixing (cf) and neutralizing antibodies. ia antibodies appeared to develop ... | 1975 | 167376 |
| hepatitis in marmosets. | some species of marmosets are susceptible, not only by parenteral inoculation but also by oral exposure, to human hepatitis a virus present in sera or feces. the stools of animals inoculated parenterally or orally contained fecal antigen during certain times of the incubation period and the early, acute phase of the disease; viruslike particles were present in feces of orally infected animals and such feces were infectious when inoculated into marmosets. the fecal antigen crossreacted both with ... | 1975 | 171953 |
| biophysical and biochemical properties of cr326 human hepatitis a virus. | cr326 human hepatitis a virus purified by isopycnic banding from infected marmoset sera was shown to consist of 27 mmu spherical particles on electron microscopic examination. the particles were identified as hepatitis a virus by tests by infectivity and by specific neutralization of infectivity with convalescent human hepatitis a serum. also, identical 27 mmu viruses in liver extracts gave specific reactions with hepatitis a antisera when tested by immune electron microscopy. the buoyant densit ... | 1975 | 171955 |
| infectivity studies of hepatitis a and b in non-human primates. | we have induced hepatitis a in marmosets of the subspecies saguinus mystax following primary inoculation with human serum containing the ms-1 strain of hepatitis a virus (hav) and in 3 further marmoset subpassages using infective marmoset serum from each preceding passage. in each passage acquisition of serum antibody against 17 nm virus-like particles recovered from acute illness stools of human volunteers who developed hepatitis following inoculation with the ms-1 strain of hav, as well as fro ... | 1975 | 173599 |
| immune adherence and complement-fixation tests for human hepatitis a. diagnostic and epidemiologic investigations. | the reliable propagation of cr326 strain of human hepatitis a virus in saguinus mystax marmosets has permitted the development of specific serum neutralization, complement-fixation (cf), and immune adherence (ia) assays for hepatitis a antigen and antibody. the cf and ia assays were made possible by the use of livers of cr326-infected marmosets as a source of hepatitis a antigen. all assays were shown to be specific for hepatitis a. cases of hepatitis b did not show development of hepatitis a an ... | 1975 | 173600 |
| characterization of cr326 human hepatitis a virus, a probable enterovirus. | cr326 human hepatitis a virus purified by isopycnic banding from infected marmoset sera was shown to consist of 27 mmu spherical particles on electron microscopic examination. the particles were identified as hepatitis a virus by tests for infectivity and by specific neutralization of infectivity with convalescent human hepatitis a serum. also, identical 27 mmu viruses in liver extracts gave specific reactions with hepatitis a antisera when tested by immune electron microscopy. the buoyant densi ... | 1975 | 173603 |
| suitability of the rufiventer marmoset as a host animal for human hepatitis a virus. | | 1977 | 195283 |
| studies on human hepatitis a virus in chimpanzees. | | 1977 | 199227 |
| viral hepatitis: enzyme assays and serologic procedures in the study of an epidemic. | an epidemic of viral hepatitis beginning in late 1975 in a residence for multiply handicapped children, recognized very early in its course, was investigated prospectively to permit comparison of enzymatic and serologic tests. thirty-three residents of the institution and 46 full- and part-time employees were studied by the immune adherence hemagglutination procedure for antibody (anti-hav) to hepatitis a virus (hav). of these, 31 residents and 37 staff members were susceptible at the beginning ... | 1977 | 201170 |
| hepatitis a virus infection: new insights from seroepidemiologic studies. | the prevalence of exposure to hepatitis a virus (hav) increases with increasing age; decreases with increasing socioeconomic class; increases with increasing serologic evidence of prior hepatitis b virus (hbv) exposure but is much more common than hbv exposure; is independent of sex and race; varies in different parts of the world as a function of hygienic, developmental, and unrecognized geographic factors; and is not affected by immune deficiency or immaturity. transmission of type a hepatitis ... | 1978 | 204711 |
| multiple buoyant densities of hepatitis a virus in cesium chloride gradients. | hepatitis a virus (hav) recovered from stools of human cases of hepatitis a and from stools of chimpanzees experimentally infected with hav was shown to possess multiple buoyant densities in cscl gradients. the greatest proportion of hav was most frequently found at a buoyant density of 1.32-1.34 g/cm3, however, large proportions of hav were also frequently found at higher densities, including 1.36-1.37, 1.40-1.42, and 1.45-1.48 g/cm3. these findings are consistent with the notion that hav may b ... | 1977 | 204743 |
| tests in rufiventer and other marmosets of susceptibility to human hepatitis a virus. | the rufiventer marmoset proved equally satisfactory to s. mystax for studies of human hepatitis a virus. c. jacchus, c. argentata, s. weddelli, and s. oedipomidas oedipus were not satisfactory. livers of rufiventer marmosets produced satisfactory cr326 strain hepatitis a antigen for immune adherence tests both in amount and specificity. rufiventer marmosets infected with human hepatitis a virus showed enzyme elevations and high titers of viral antigen in their livers as early as seven days after ... | 1978 | 205858 |
| experimental infection of marmosets with hepatitis a virus. | saguinus mystax marmosets were experimentally infected with two strains of human hepatitis a virus. one of these strains of hav was successfully subpassaged in this species of marmosets. in another experiment, the 1.32 and 1.41 g/cm3 buoyant density species of hav derived from an infected chimpanzee stool were shown to be infectious in three species of marmosets. the value of the marmoset as an experimental model for hepatitis a infection was demonstrated by these studies. | 1978 | 205859 |
| localization of hepatitis a antigen in marmoset organs during acute infection with hepatitis a virus. | twelve marmosets (saguinus mystax) were inoculated intravenously (iv) with hepatitis a virus (hav). one died early (day 12); seven were sacrificed at the time of elevation in level of alanine aminotransferase (serum glutamic-pyruvic transaminase), and four without elevation were not sacrificed but seroconverted. in the seven marmosets sacrificed during the acute stage of illness, hepatitis a antigen (ha ag) was detected in the liver by immunofluorescence in all cases, by immune electron microsco ... | 1978 | 212488 |
| thermal treatment and infectivity of hepatitis a virus in human feces. | the susceptibility of white-lipped marmoset monkeys (saguinus sp) to human hepatitis a virus (hav) provides a system for evaluation of thermal inactivation of hav in feces and contaminated shellfish. intramuscular or oral administration of hav derived from feces of four patients with acute hepatitis a induced hepatitis in 28--100% of the inoculated marmosets. a 10% (w/v) fecal pool (gbg-bm) prepared from two patients (gbg and gbm) induced hepatitis in marmosets (2/4 with 1 ml; 2/2 with 3 ml) whe ... | 1978 | 212524 |
| asymptomatic viral hepatitis types a and b in an adolescent population. | sera from 95 adolescents were examined for markers of hepatitis b virus (hbv) infection and hepatitis a virus (hav) infection. hbv markers were found in eight adolescents (8%) and evidence of previous hav infection was found in 18 adolescents (19%); none had a history of clinically recognizable hepatitis. these findings support the growing evidence that hbv and hav infections are diseases of the pediatric age group, and that testing of hbv vaccines when they become available for patient use will ... | 1978 | 215959 |
| propagation of human hepatitis a virus in cell culture in vitro. | | 1979 | 217023 |
| isolation and characterization of hepatitis a virus. | this paper presents current isolation technics of hepatitis a virus (hav) from human and chimpanzee stool, liver, and bile specimens, as well as comparative characterizations of hav buoyant density properties of human and chimpanzee stool-derived particles. in addition, methods designed for the extraction and purification of hav from large samples of stool and liver tissues, including agar gel filtration, are discussed in detail. | 1976 | 218442 |
| serodiagnosis of viral hepatitis a by a modified competitive binding radioimmunoassay for immunoglobulin m anti-hepatitis a virus. | a competitive binding radioimmunoassay (cba) for antibody to hepatitis a virus (hav) was evaluated and compared with a standard solid-phase radioimmunoassay for anti-hav, cba was found to be sensitive and specific for the detection of anti-hav, as demonstrated by the 98% concordance of cba and solid-phase radioimmunoassay test results. the standard cba test was modified for the differential detection of acute (immunoglobulin m) and convalescent (immunoglobulin g) anti-hav by incorporation of a s ... | 1979 | 219016 |
| simultaneous acute infections with hepatitis a and hepatitis b viruses in a chimpanzee. | the unexpected occurrence of a hepatitis b virus (hbv) infection in a chimpanzee experimentally inoculated with hepatitis a virus (hav) provided an opportunity to examine the course of simultaneous acute infections with both agents. a chimpanzee inoculated intravenously with hav developed elevated levels of aminotransferases in serum, detectable excretion of hepatitis a antigen in feces, and a marked antibody response to hav. during the acute phase of this experimentally induced infection with h ... | 1979 | 221596 |
| [hepatitis a of children. seroepidemiological study among french urban population (author's transl)]. | a prevalence survey of hepatitis a antibody (anti-hav) was conducted among 145 children living in the area of tours (france). thirty-four per cent of children's sera was found anti-hav positive when tested by both immune adherence hemagglutination assay (iaha) and specific radio-immunoassay (ria). the prevalence of anti-hav among infants less than one year and children between 1 to 5 years, was 35 per cent and 15 per cent respectively. from 6 years old, the prevalence of anti-hav increased abrup ... | 1979 | 221882 |
| demonstration of specific antibodies to a coxsackie-like virus in patients of a hepatitis outbreak. | lynchburg fecal virus (lfv), originally isolated from the stool of an infectious hepatitis patient, was passaged 15 times in wi-38 cells and partially characterized. its properties are as follows: rna virus; 27 nm in diameter, picornavirus-like morphology; inactivated at 56 c for 60 minutes; resistant to treatment with hydrochloric acid (ph 3.0), chloroform (33%), and diethyl ether (20%). neutralization studies indicated that lfv is antigenically related to coxsackievirus a-24 but not to prototy ... | 1979 | 223437 |
| a solid-phase radioimmunoassay for detection of igm antibodies to hepatitis a virus. | the conditions for a sensitive and specific solid-phase radioimmunoassay (ria) for the detection of igm antibodies to hepatitis a virus (hav) were optimized, and the ria was used to assay sera from patients with hepatitis. igm antibodies to hav reached highest concentrations between one and three weeks after onset of icterus and were measurable in follow-up sera for at least 12 months after infection. to prove the specificity, the igg antibodies were separated from patient sera by sucrose densit ... | 1979 | 225390 |
| propagation of human hepatitis a virus in a hepatoma cell line. | hepatitis a virus (hav) was isolated directly from human feces and propagated serially in an hbsag producing human hepatoma cell line. no cytopathic effect was observed in the tissue culture and no detectable amounts of hav were present in the tissue culture supernatant fluid. however, increasing amounts of hepatitis a antigen (haag) were detected by radioimmunoassay in the cell extracts obtained by freezing and thawing of cells. specificity of the haag determination was shown by neutralization ... | 1979 | 232698 |
| the diagnosis and management of acute viral hepatitis. | while there is a declining incidence of many infectious diseases, viral hepatitis persists as a major problem. in fact, there would appear to be an increasing incidence of hepatitis b paralleling the rising problem of drug addiction. the discovery of australia antigen, now called hepatitis b surface antigen (hbsag), represented a major breakthrough in our understanding of viral hepatitis. more recently, serological tests have become available for hepatitis a virus (hav) which will further facili ... | 1977 | 603455 |
| prevalence of hepatitis a and b infections in multiply transfused thalassaemic patients. | evidence of hepatitis b virus (hbv) and hepatitis a virus (hav) infections was south in 148 multiply transfused patients with thalassaemia and in healthy controls (2040 for hbv and 217 for hav). the prevalence of the hbv surface antigen or antibody to it was significantly higher in patients than in controls and increased with the number of blood transfusions. in contrast, the prevalence of antibody to hav was significantly lower in patients than in controls and decreased with the number of blood ... | 1978 | 630296 |
| [viral hepatitis]. | viral hepatitis is one of the most frequent infectious diseases of our time. it is of great concern to the epidemiological risk groups such as research laboratories, dialysis units and other public health agencies. the result of epidemiological, immunological, morphological and biochemical studies have demonstrated, that this disease is caused by at least two different viruses. the hepatitis a virus (hav) induces the type a hepatitis and the hepatitis b virus (hbv) the type b hepatitis. two anti ... | 1978 | 697524 |
| methisoprinol-effect on the replication cycle of human hepatitis a virus. | the antiviral activity of methisoprinol was investigated under different conditions using a strain of hepatitis a virus (hav), that shows a strong cytopathic effect on the frp/3 cell line 7-9 days post-infection. treatment of frp/3 at a dose range of 125-1200 micrograms/ml had no toxic effect and showed a dose dependent inhibition of the hav replication cycle. at the methisoprinol dose of 500 micrograms/ml the cytopathic effect was completely abolished and hav antigen production reduced by 50% a ... | 1992 | 1279362 |
| identification of amino acids located in the antibody binding sites of human hepatitis a virus. | antigenic mutants of human hepatitis a virus (human-hav) were isolated by their resistance to neutralizing monoclonal antibodies raised to human-hav. the nucleotide sequence determined for the capsid regions of 12 mutants identified amino acid changes that clustered in three non-overlapping sites; one in vp3 and two in vp1. all mutants had a change at amino acid residue 70 in vp3, indicating its primary importance for antibody binding. ten mutants had two amino acid changes occurring in the vp3 ... | 1992 | 1280386 |
| the epidemiology and control of hepatitis a. | hepatitis a virus (hav) infection is endemic in developing countries and remains a public health problem elsewhere. a total of 7430 cases was notified in england and wales in 1991. children and young adults were most frequently affected. risk factors include travel to countries of high endemicity, contact with an infected person and shellfish consumption. person-to-person spread is common within families, closely knit communities and schools (especially nurseries). the provision of safe water an ... | 1992 | 1284926 |
| the association of infective hepatitis type a (hav) and diabetes mellitus. | the cases of three patients who developed diabetes mellitus (dm) within 2-3 weeks of acute hepatitis a virus (hav) infection associated with diabetic ketoacidosis are reported. the ketoacidosis was considered an index of insulin dependent diabetes mellitus most likely precipitated by the acute virus infection. | 1992 | 1295148 |
| host antibody response to viral structural and nonstructural proteins after hepatitis a virus infection. | subgenomic hepatitis a virus (hav) rna sequences were translated in vitro to produce proteins representing the structural (p1) and nonstructural (p2 and p3) domains of the viral polyprotein. these proteins were used as antigens to detect the presence of antibodies in sera from acute and convalescent humans and an experimentally infected chimpanzee. all infected individuals tested had antibodies that recognized uncleaved p1 proteins as well as nonstructural proteins. antibodies in sera from infec ... | 1992 | 1309847 |
| antigenic structure of human hepatitis a virus defined by analysis of escape mutants selected against murine monoclonal antibodies. | we examined the antigenic structure of human hepatitis a virus (hav) by characterizing a series of 21 murine monoclonal-antibody-resistant neutralization escape mutants derived from the hm175 virus strain. the escape phenotype of each mutant was associated with reduced antibody binding in radioimmunofocus assays. neutralization escape mutations were identified at the asp-70 and gln-74 residues of the capsid protein vp3, as well as at ser-102, val-171, ala-176, and lys-221 of vp1. with the except ... | 1992 | 1312628 |
| expression and characterization of recombinant hepatitis a virus 3c proteinase. | the 3c proteinase from the hepatitis a virus (hav) was cloned into a multicopy expression vector in escherichia coli under control of the tac promoter. the resulting plasmid construction produced 3c proteinase as a soluble and active enzyme constituting approximately 10% of total cellular proteins. the enzyme was purified to apparent homogeneity as judged by sds gel electrophoresis and hplc reversed-phase and fplc ion-exchange chromatography. a colorimetric assay was developed, and synthetic pep ... | 1992 | 1313294 |
| [inapparent infection with hepatitis a virus and glomerulonephritis in a child]. | a 9-year-old boy developed inapparent infection with hepatitis a virus (hav) and glomerulonephritis, simultaneously. the diagnosis was confirmed by the finding of serum anti-hav igm. we suggest that the kidney involvement was also caused by hav. recovery was uneventful. | 1992 | 1314215 |
| immunogenicity and antigenicity of chimeric picornaviruses which express hepatitis a virus (hav) peptide sequences: evidence for a neutralization domain near the amino terminus of vp1 of hav. | we evaluated the antigenic characteristics of chimeric picornaviruses created by inserting peptide sequences from hepatitis a virus (hav) capsid proteins into the b-c loop of vp1 of sabin strain type 1 poliovirus (pv-1). fifteen viable chimeras were generated. each retained the ability to be neutralized by polyclonal pv-1 antisera. two chimeras (h15 and h2) stimulated production of low levels of hav neutralizing antibodies in immunized rabbits or mice, although in both cases only a small fractio ... | 1992 | 1314456 |
| survival of hepatitis a virus on human hands and its transfer on contact with animate and inanimate surfaces. | the survival of hepatitis a virus (hav; strain hm175) on the hands of five volunteers was determined by depositing 10 microliters of fecally suspended virus on each fingerpad and eluting the inoculum after 0, 20, 60, 120, 180, and 240 min. the amount of virus recovered from each fingerpad at 0 min was approximately 6.0 x 10(4) pfu. at the end of 4 h, 16 to 30% of the initially recoverable virus remained detectable on the fingerpads. hav inocula (10 microliters; approximately 1.0 x 10(4) pfu) pla ... | 1992 | 1315331 |
| characterization of a genetic variant of human hepatitis a virus. | human isolates of hepatitis a (hav) are a single serotype; however, recent genetic surveys using limited nucleotide sequencing have provided evidence that more than one genotype is responsible for hav infection in different parts of the world (jansen et al. [1990]: proc natl acad sci usa 87:2867-2871; robertson et al. [1991] j infect dis 163:286-292). one of these genotypes was originally isolated from panamanian owl monkeys (strain pa21), but has subsequently been found associated with human ca ... | 1992 | 1316423 |
| genetic relatedness of hepatitis a virus strains recovered from different geographical regions. | a pairwise comparison of the nucleic acid sequence of 168 bases from 152 wild-type or unique cell culture-adapted strains of hepatitis a virus (hav) revealed that hav strains can be differentiated genetically into seven unique genotypes (i to vii). in general, the nucleotide sequence of viruses in different genotypes differs at 15 to 25% of positions within this segment of the genome. viruses from four of the genotypes (i, ii, iii and vii) were recovered from cases of hepatitis a in humans, wher ... | 1992 | 1318940 |
| myelopoiesis in vitro is suppressed by hepatitis a virus. | perturbations of hematopoietic regulation ranging from transient granulocytopenia to rare cases of bone marrow failure are associated with infections due to hepatitis a virus (hav). in an attempt to elucidate the pathogenetic mechanisms we had previously established that hav has a direct suppressive effect on human bone marrow progenitors (cfu-gm, -gemm, bfu-e). these studies were extended to long-term bone marrow cultures (ltbmc): inoculation of bone marrow mononuclear cells with hav did not in ... | 1992 | 1322183 |
| multistate outbreak of hepatitis a associated with frozen strawberries. | a multistate outbreak of hepatitis a was traced to frozen strawberries processed at a single plant. among 827 students and 60 teachers at an elementary school in georgia during a 2-week period, 15 developed hepatitis a. three months later, among 174 residents and 467 staff in an institution for the developmentally disabled in montana during a 3-week period, 13 developed hepatitis a. primary attack rates were 10% in the school and 8% in the institution. cohort analysis in the school implicated co ... | 1992 | 1323618 |
| intermolecular cleavage of hepatitis a virus (hav) precursor protein p1-p2 by recombinant hav proteinase 3c. | active proteinase 3c of hepatitis a virus (hav) was expressed in bacteria either as a mature enzyme or as a protein fused to the entire polymerase 3d or to a part of it, and their identities were shown by immunoblot analysis. intermolecular cleavage activity was demonstrated by incubating in vitro-translated and radiolabeled hav precursor protein p1-p2 with extracts of bacteria transformed with plasmids containing recombinant hav 3c. identification of cleavage products p1, vp1, and vpo-vp3 by im ... | 1992 | 1328690 |
| assessment of inactivation of hepatitis a vaccine by compound pcr. | assuring the complete inactivation of hepatitis a virus (hav) vaccine commonly requires prolonged tissue culture amplification, followed by detection of virus antigen in cell lysates. a reliable, but faster, alternative procedure is highly desirable since it will permit the prescreening of experimental batches of killed hav, prior to tissue-culture amplification. we established experimental conditions for simultaneous, polymerase chain reaction (pcr)-based amplification of viral and cellular mrn ... | 1992 | 1331145 |
| [family-acquired hepatitis a--prevalence of hepatitis a among the family in aichi prefecture, 1990]. | we studied the transmission of hepatitis a virus (hav) in 45 families, which members were diagnosed as hepatitis a in 8 hospitals in 1990. feces and sera from 50 patients and their 126 family members were tested for hav-specific antigen and igm antibody by elisa or polymerase chain reaction (pcr) technology. from the interval of the onset of hepatitis or detection of hav antigen in feces, hav transmission was recognized in 11 (24.4%) of 45 families. the transmission was found to be concerned wit ... | 1992 | 1331263 |
| accumulation and persistence of hepatitis a virus in mussels. | accumulation and persistence of hepatitis a virus (hav) in the mussel mytilus chilensis was evaluated. under optimal filtration activity of mussels (temperature 12 degrees c, salinity 3%, feeding twice a day with dunaliella marina), hav was concentrated 100-fold from the surrounding water. similar concentrations of hav were reached in the filtration apparatus and in the digestive system (hepatopancreas). hav persisted for about 7 days in mussels. elimination of hav from mussels was slower than e ... | 1992 | 1331305 |
| identification of precursors of structural proteins vp1 and vp2 of hepatitis a virus. | the morphogenetic pathway of hepatitis a virus (hav), classified as a member of the enteroviruses within the picornaviridae, still remains obscure and seems to differ considerably from that of poliovirus, the most studied representative of this genus. in order to elucidate the precursor/product relationship of hav structural proteins, subviral particles, which represent more than 50% of the viral antigen produced in infected cells, were separated from mature virions and their polypeptide pattern ... | 1992 | 1331311 |
| a cis-acting element within the hepatitis a virus 5'-non-coding region required for in vitro translation. | every picornavirus studied thus far has a sequence within the 5'-non-coding region that is required for internal ribosome binding and translation of the polyprotein. in an attempt to identify this region in hepatitis a virus we constructed a truncated hepatitis a virus (hav) cdna clone that contains the entire 736 bp 5' non-coding region (5'-ncr) and 754 base pairs of the viral capsid coding region (p1) under control of the sp6 promoter. in vitro transcription and translation of this transcript ... | 1992 | 1332279 |
| [the circulation of the hepatitis a and b viruses in the somali population]. | we report the results of a study carried out to evaluate the extent of hepatitis a virus (hav) and hepatitis b virus (hbv) circulation in somalia. serum samples were collected from 593 subjects (age range 0-83 years) and tested for anti-hepatitis a (hav) and anti-hav igm. serum samples taken from 1272 individuals (age range 0-83 years) were tested for hbsag, anti-hbsag, anti-hbcag, hbeag and anti-hbeag. we confirmed a very high rate of hav exposure (about 90% of the subjects tested had circulati ... | 1992 | 1334688 |
| immunopotentiating reconstituted influenza virus virosome vaccine delivery system for immunization against hepatitis a. | hepatitis a virus (hav) was purified from mrc-5 human diploid cell cultures, inactivated with formalin, and evaluated for safety and immunogenicity in humans. three vaccine formulations were produced: (a) a fluid preparation containing inactivated hav, (b) inactivated hav adsorbed to al(oh)3, and (c) inactivated hav coupled to novel immunopotentiating reconstituted influenza virosomes (iriv). iriv were prepared by combining phosphatidylcholine, phosphatidylethanolamine, phospholipids originating ... | 1992 | 1334977 |
| prevention of viral hepatitis a: past, present and future. | before hepatitis a virus (hav) was identified, spread of hepatitis a was prevented by public health measures. the first specific, preventive measure for hepatitis a was passive protection with standard, pooled human immune globulins. human immune globulin contained sufficient hav neutralizing antibodies for short-term, prophylactic passive protection and for control of the spread of local outbreaks. after many unsuccessful attempts, hav was propagated in cell cultures and the development of vacc ... | 1992 | 1335635 |
| serological approaches to distinguish immune response to hepatitis a vaccine and natural infection. | currently, the immune status of an individual exposed to hepatitis a virus (hav) is determined by assays which measure antibodies against the capsid proteins. these assays indicate exposure to the viral capsid that could result from either infection or from vaccination. recent data indicate that proteins from the non-structural genome region of the virus (p2 or p3), which are only produced during active virus replication, generate antibodies after clinical disease. a sub-genomic cdna segment of ... | 1992 | 1335637 |
| inactivated hepatitis a vaccine: active and passive immunoprophylaxis in chimpanzees. | studies of active and passive immunoprophylaxis were carried out in chimpanzees to determine whether a candidate hepatitis a virus (hav) vaccine could stimulate antibody to hav (anti-hav) that was qualitatively similar to anti-hav stimulated by natural infection. normal immune globulin (ig) was prepared from plasma obtained from human volunteers before and after vaccination with the hav vaccine, and these preparations or commercially prepared ig were administered to chimpanzees. protective effic ... | 1992 | 1335648 |
| clinical manifestations and diagnosis of hepatitis a virus infection. | hepatitis a is an acute, necroinflammatory disease of the liver which results from infection by the hepatitis a virus (hav). the mean incubation period is approximately 30 days. although the disease is usually self-limited, the severity of illness is age-dependent. in children, hepatitis a is usually asymptomatic, while in adults, symptomatic infection is characteristic and jaundice is common. fulminant hepatitis a is rare and is also age-dependent. the onset of hepatitis a is often abrupt and c ... | 1992 | 1335649 |
| clinical assessment of the safety and efficacy of an inactivated hepatitis a vaccine: rationale and summary of findings. | the objectives for the clinical testing of the inactivated hepatitis a vaccine developed by smithkline beecham biologicals are reviewed and the results obtained are summarized. the first studies were carried out in healthy young adult volunteers using pilot vaccine lots prepared from the clf and hm175 strains of hepatitis a virus (hav). it was established that the candidate vaccines were well-tolerated, caused no hypersensitivity reactions and elicited a strong antibody response. as the yield in ... | 1992 | 1335652 |
| properties and classification of hepatitis a virus. | hepatitis a virus (hav) is a member of the picornavirus family. it was first provisionally classified as enterovirus 72, but subsequent determinations of its nucleotide and amino acid sequences showed them to be sufficiently distinct to assign the virus to a new genus. heparna-virus (hep-a-rna-virus) has been suggested as the genus name. hav shares the key properties of the picornavirus family: an icosahedral particle 28 nm in diameter with cubic symmetry, composed of 30% rna and 70% protein. th ... | 1992 | 1335653 |
| natural hosts of hepatitis a virus. | the host range for hepatitis a virus (hav) is limited to man and several species of non-human primates, and involvement of vertebrates other than primates in hav circulation is unlikely. spontaneous hepatitis a infection has been reported to occur in captive non-human primates including the great apes (chimpanzee) as well as old world (cynomolgus, african vervet, stump-tailed) and new world (aotus) monkeys. the presence of anti-hav antibody in the sera of newly captured monkeys of these species ... | 1992 | 1335654 |
| replication of hepatitis a virus and processing of proteins. | isolation and propagation of hepatitis a virus (hav) in cell culture is routinely possible. all primary hav isolates and most established virus strains, however, show a protracted replication behaviour and tend to establish a persistent infection. rapidly replicating, cytolytic variant viruses can be selected from persistently infected cultures under distinct conditions. factors critical for the outcome of hav infection include the genetics of the virus, the physiological state of the infected c ... | 1992 | 1335655 |
| genetic, antigenic and biological differences between strains of hepatitis a virus. | recent studies have documented a considerable degree of genetic divergence among wild-type hepatitis a virus (hav) strains recovered from different geographical locations. human hav strains can be grouped into four genotypes (i, ii, iii and vii) and unique simian strains belong to three additional genotypes (iv, v and vi). between each of these genotypes, the nucleotide sequence varies at 15-25% of base positions in the p1 region. despite this, there is good evidence that most, if not all, human ... | 1992 | 1335657 |
| passive immunization against hepatitis a. | administration of human serum immune globulin (ig) is an effective means of protecting individuals against hepatitis a virus (hav) infection and disease. several large field studies have demonstrated that if given before exposure, ig will prevent infection with hav. furthermore, if ig is given during the incubation period of hepatitis a, the severity of infection may be reduced and potentially clinical infections may be converted into subclinical ones. although uncommon, infection which occurs i ... | 1992 | 1335658 |
| possible approaches to develop vaccines against hepatitis a. | more than a decade ago, successful replication of hepatitis a virus (hav) in cell culture opened the way to the development of live attenuated and inactivated vaccine candidates. serial passages of hav in cell culture led to attenuation as demonstrated by experiments in non-human primates. several live vaccine candidates obtained through serial passages have been evaluated in volunteers. significant improvements in the yield of viral antigen from infected cell cultures stimulated the development ... | 1992 | 1335659 |
| epidemiological patterns of hepatitis a in different parts of the world. | serological surveys in many communities show a high prevalence of antibodies to hepatitis a virus (hav) in people over the age of 50 years. however, few of that age can recall a previous episode of hepatitis, indicating that subclinical infections are common. the outcome of infection with hav depends on the age at which infection occurs and, perhaps, the infectious dose. fulminant disease is well recorded, with the frequency varying from one to eight per 1000 cases. information on the frequency ... | 1992 | 1335660 |
| epidemiology of hepatitis a in mediterranean countries. | infection with hepatitis a virus (hav) is still endemic in some mediterranean areas. in most northern mediterranean countries, the incidence of acute icteric hepatitis in adults is increasing. this is due to the shifting of hav infection to adulthood as a result of the decline of its overall prevalence due to improvements in socioeconomic, sanitary and hygienic conditions. the majority of adults remain susceptible and develop overt disease when infected, since the severity of disease is highly a ... | 1992 | 1335662 |
| ecology and prevention of a shellfish-associated hepatitis a epidemic in shanghai, china. | during a shellfish-borne hepatitis a outbreak in shanghai during the first quarter of 1988, 300,000 cases were reported in two months. using cell culture and experimental infection of marmosets, hepatitis a virus (hav) was isolated from clams collected from the market and the sea bed during the epidemic. a dose-response curve correlating the quantity of clams consumed to the attack rate of hepatitis a was well documented. the occurrence of the epidemic was associated with a good harvest of clams ... | 1992 | 1335663 |
| hepatitis a as an occupational hazard. | few studies have been carried out to evaluate the role of hepatitis a virus (hav) as an occupational hazard. our analysis of data on occupational diseases in germany showed that hepatitis a ranks as third among infectious occupational diseases. morbidity based on the frequency of compensation (15.2%) was in the same range as that observed for hepatitis b (19.7%). in another study, data were collected on anti-hav prevalence among 2293 hospital workers in southwest germany. anti-hav prevalence of ... | 1992 | 1335666 |
| who should receive hepatitis a vaccine? considerations for the development of an immunization strategy. | the availability of efficacious hepatitis a vaccines should greatly facilitate the prevention of hepatitis a virus (hav) infection. groups at high risk of hav infection have been identified from epidemiological studies and include both children and adults. while certain high-risk adults, such as travellers, could be a convenient target for vaccination, selective immunization of high-risk adults would not be expected to lower the overall rates of infection in most countries. because a significant ... | 1992 | 1335667 |
| cost-effectiveness analysis of hepatitis a prevention in travellers. | the advent of new vaccines and the changing epidemiology of hepatitis a call for an update of the economic evaluation of costs and benefits associated with the various alternative preventative strategies. a decision-tree-based model has been developed which enables the calculation of expected costs and expected numbers of hepatitis a virus hav infections based on different intervention strategies. the model is sufficiently generic to allow for the evaluation of both population-wide strategies an ... | 1992 | 1335668 |
| perspectives on the control of hepatitis a by vaccination. | the availability of an inactivated hepatitis a virus (hav) vaccine, and the development of live attenuated virus vaccines against hepatitis represent great advances in the effort to control an important cause of viral hepatitis. there are a number of ways hepatitis a vaccines could be used, depending on the epidemiology of hav infection in the country concerned, the cost of the product, the duration of protection that the vaccine affords and its effectiveness for postexposure prophylaxis. expert ... | 1992 | 1335670 |
| [antibody titers against the hepatitis a virus in a healthy population from an urban health area]. | to assess the level of immunity in a healthy population to the hepatitis a virus (hav), according to age groups and in an urban health area. | 1992 | 1339210 |
| the seroepidemiology of hepatitis a and b in a japanese town. | sera collected from 1,118 healthy children and adults aged between four years and 90 years during the period 1989 to 1990, were tested for serological markers of hepatitis a virus (hav) [antibody to hav (anti-hav)] and hepatitis b virus (hbv) [hepatitis b surface antigen (hbsag) and antibody to hepatitis b surface antigen (anti-hbsab)]. the overall prevalence rates of anti-hav, hbsag, and anti-hbv were 20.2%, 0.36%, and 5.1%, respectively. no body was found to be positive for anti-hav below 30 y ... | 1992 | 1339221 |
| primary isolation of a brazilian strain of hepatitis a virus (haf-203) and growth in a primate cell line (frhk-4). | 1. although hepatitis a is endemic in brazil, this is the first report describing the isolation of a brazilian strain of hepatitis a virus (hav). 2. fecal specimens obtained from patients in the acute phase of hepatitis a were inoculated into fetal rhesus kidney cell cultures (frhk-4). only one inoculum, denoted haf-203, could be propagated serially. both cell lysates and tissue culture fluids of infected cells were used as inocula and evaluated for viral antigen and rna content by enzyme immuno ... | 1992 | 1342600 |
| reactogenicity and immunogenicity of inactivated hepatitis a vaccines. | two inactivated hepatitis a virus (hav) candidate vaccine strain were tested, derived from strains clf and hm175. neither vaccine increased liver enzymes levels and reactogenicity was similar to that observed with other alum-absorbed products. antibody responses were dose-dependent and protection against hav can be presumed to last for at least three years. all persons receiving 720 elisa units (el.u) of the clf vaccine seroconverted after one dose. for the hm175 vaccine, anti-hav persisted unti ... | 1992 | 1362031 |
| hepatitis c core antibody detection in acute hepatitis and cirrhosis patients from tunisia. | the detection of anti-hepatitis c virus (hcv) core antibodies is an important addition to hcv antibody testing. in this study it appears to be more specific than the first generation hcv tests and in combination with the detection of anti-c33c antibodies, it is possibly more sensitive. in tunisia hepatitis c virus is implicated by the presence of anti-core antibodies in only 8% of the adult cases of acute hepatitis as opposed to 60% for hepatitis b virus (hbv) and 4% for hepatitis a virus (hav). ... | 1992 | 1383914 |
| enteric non-a, non-b hepatitis: epidemics, animal transmission, and hepatitis e virus detection by the polymerase chain reaction. | we studied epidemics of viral hepatitis occurring at three different places in india. one was a combined epidemic due to hepatitis e virus (hev) and hepatitis a virus (hav) infections. in this epidemic, hav affected children below 10 years of age, whereas hev infected the young adult population. hev was transmitted to rhesus monkeys (macaca mulata) and confirmed by the polymerase chain reaction (pcr) on bile from the animals. fecal material from acutely infected patients in one of the epidemics ... | 1992 | 1402825 |
| mutations within the 5' nontranslated region of hepatitis a virus rna which enhance replication in bs-c-1 cells. | passage of human hepatitis a virus (hav) in cell culture results in attenuation of the virus as well as progressive increases in the efficiency of virus replication in cell culture. because the presence of identical mutations within the 5' nontranslated regions (5'ntrs) of several independently isolated cell culture-adapted hav variants suggests that the 5'ntr may play a role in determining this change in virus host range, we constructed chimeric infectious cdna clones in which portions of the 5 ... | 1992 | 1404601 |
| [complement c3 and c4 levels in serum from acute viral hepatitis]. | serial measurements of c3 and c4 complement components were performed in 50 patients with acute, uncomplicated viral hepatitis, in the beginning of the symptoms and in the peaks of serum transaminases. there were 17 patients diagnosed as having hepatitis a virus (hav) infection and 33 patients diagnosed as having hepatitis b virus (hbv) infection. there were 4 women and 46 men with a mean age of 22.1 years. in the sera of 50 healthy control subjects serum c3 and c4 complement components measured ... | 1992 | 1435361 |
| immune pathogenesis of hepatitis a. | in an effort to elucidate the mechanism of liver damage resulting from hepatitis a virus (hav) infection, we have studied infected skin fibroblasts and autologous lymphocytes from hav patients. we report here that hla-restricted virus-specific t cells play an essential role in hav-related hepatocellular injury. | 1992 | 1450708 |
| relapsing hepatitis a in saimiri monkeys experimentally reinfected with a wild type hepatitis a virus (hav). | saimiri monkeys were inoculated three times with hepatitis a virus and observed in a follow-up study for sixteen months. the monkeys developed recurrent hepatitis involving liver damage and cycles of hav antigen shedding in stools. the relapses were presumably due to immune response effects. | 1992 | 1450724 |
| nosography and immunopathogenesis of viral hepatitis. | five viruses are responsible for the vast majority of cases of viral related hepatitis. they have been named hepatitis a virus (hav), hepatitis b virus (hbv), hepatitis c virus (hcv), hepatitis d virus (hdv), hepatitis e virus (hev). the more recent literature concerning the viral structure, the epidemiology, the serological identification, the clinical course and the prevention of each type of hepatitis is reviewed. hbv is not directly cytopathic. hepatitis is a consequence of the destruction o ... | 1992 | 1501725 |
| hepatitis a virus 3c proteinase substrate specificity. | hepatitis a virus (hav) 3c proteinase is responsible for processing the viral precursor polyprotein into mature proteins. the substrate specificity of recombinant hepatitis a 3c proteinase was investigated using a series of synthetic peptides representing putative polyprotein junction sequences. two peptides, corresponding to the viral polyprotein 2b/2c and 2c/3a junctions, were determined to be cleaved most efficiently by the viral 3c proteinase. the kcat/km values determined for the hydrolysis ... | 1992 | 1510973 |
| sociodemographic factors and the declining prevalence of anti-hepatitis a antibodies in young adults in israel: implications for the new hepatitis a vaccines. | in order to examine changes in the epidemiology of hepatitis a virus (hav) infection in israel during the past decade, a sero-epidemiological study was carried out in 1989 in a random sample of 1153 members of the permanent army, aged 21-30 years. of the males 59.2%, and 54.3% of the females were anti-hav antibody positive (p = 0.22). at all ages, the highest prevalence was in those of north african origin, followed by those of asian, native israeli and western origin. there was a marked decline ... | 1992 | 1544745 |
| immunoglobulin prophylaxis for hepatitis a. | studies conducted over the past 45 years have shown that immunoglobulin (ig) prevents 80%-90% of cases of hepatitis a when administered before exposure or shortly thereafter. protection is short lived and requires early diagnosis and timely administration of ig to contacts. inactivated and attenuated hepatitis a virus (hav) vaccines have recently been developed and should be available for clinical use within the next few years. evaluation of antibodies to hav in ig and in ig recipients provides ... | 1992 | 1554845 |
| age-specific prevalence of hepatitis a virus infection among teenagers in sardinia. | in 1989, the prevalence of antibodies to hepatitis a virus (anti-hav) in a sample of 1350 sardinian teenagers aged 14 to 19 years was estimated by elisa method. the overall anti-hav prevalence was 20%; it increased from 12.3% among 14-16 year old subjects to 27.4% in subjects aged 17-19 years (p less than 0.01). a slight female preponderance was observed (22.1% versus 17.9) but no statistically significant difference was attained. compared with the corresponding figure (71.6% of prevalence rate) ... | 1991 | 1648657 |
| effect of relative humidity and air temperature on survival of hepatitis a virus on environmental surfaces. | stainless steel disks (diameter, 1 cm) were contaminated with fecally suspended hepatitis a virus (hav; strain hm-175) and held at low (25% +/- 5%), medium (55% +/- 5%), high (80% +/- 5%), or ultrahigh (95% +/- 5%) relative humidity (rh) at an air temperature of 5,20, or 35 degrees c. hav survival was inversely proportional to the level of rh and temperature, and the half-lives of the virus ranged from greater than 7 days at the low rh and 5 degrees c to about 2 h at the ultrahigh rh and 35 degr ... | 1991 | 1649579 |
| parameters influencing the attachment of hepatitis a virus to a variety of continuous cell lines. | we have investigated the interactions of purified radiolabelled hepatitis a virus (hav) with a variety of continuous cell lines. virus labelled either in vitro with radiolabelled iodine or in vivo with radiolabelled uridine bound to cells with similar efficiency. attachment to bs-c-1 cells was calcium ion-dependent and this correlated with infectivity assay results. the cell tropism of hav attachment was examined using cell suspensions and confluent cell monolayers at both 4 degrees c and 37 deg ... | 1991 | 1649900 |
| simian hepatitis a virus (hav) strain agm-27: comparison of genome structure and growth in cell culture with other hav strains. | fragments of cdna representing greater than 99% of the entire genome of wild-type hepatitis a virus (hav) strain agm-27, isolated from an african green monkey, were obtained by the polymerase chain reaction and sequenced. comparison with other hav isolates revealed differences in the predicted amino acid sequence in functionally critical parts of the genome. comparison of the biological properties of agm-27 with those of human wild-type and cell culture-adapted hm-175 strains revealed that agm-2 ... | 1991 | 1649901 |
| sequence analysis of a new hepatitis a virus naturally infecting cynomolgus macaques (macaca fascicularis). | a new isolate of hepatitis a virus (hav), cy-145, was isolated from stool specimens obtained from cynomolgus macaques naturally infected with this agent. sequence analysis of the capsid region of the genome indicated that this virus differed from other sequenced hav strains by about 20% at the nucleotide level and 7% at the amino acid level. two amino acid residues (residues 70 of vp3 and 102 of vp1), previously identified as constituting an immunodominant site and conserved in all sequenced hav ... | 1991 | 1649902 |
| adsorption-elution with negatively and positively-charged glass powder for the concentration of hepatitis a virus from water. | two methods based on virus adsorption and elution from glass powder were developed for the concentration of hepatitis a virus (hav) from large volumes of water. the cytopathogenic phm-175 strain of hav was used to test these procedures in tap water, fresh water, sea water and raw sewage. hav was quantitated by a plaque assay in the frhk-4 cell line. hav was concentrated by glass powder adsorption-elution from 20-liter samples with satisfactory efficiencies in all types of water: 100% for tap wat ... | 1991 | 1650787 |
| hepatitis a outbreak in a neonatal intensive care unit: risk factors for transmission and evidence of prolonged viral excretion among preterm infants. | an outbreak of hepatitis a virus (hav) infection in a neonatal intensive care unit (nicu) provided the opportunity to examine the duration of hav excretion in infants and the mechanisms by which hav epidemics are propagated in nicus. the outbreak affected 13 nicu infants (20%), 22 nicu nurses (24%), 8 other staff caring for nicu infants, and 4 household contacts; 2 seropositive infants (primary cases) received blood transfusions from a donor with hav infection. risk factors for infection among n ... | 1991 | 1651359 |
| the hepatitis a virus polyprotein expressed by a recombinant vaccinia virus undergoes proteolytic processing and assembly into viruslike particles. | hepatitis a virus (hav) contains a single-stranded, plus-sense rna genome with a single long open reading frame encoding a polyprotein of approximately 250 kda. viral structural proteins are generated by posttranslational proteolytic processing of this polyprotein. we constructed recombinant vaccinia viruses which expressed the hav polyprotein (rv-orf) and the p1 structural region (rv-p1). rv-orf-infected cell lysates demonstrated that the polyprotein was cleaved into immunoreactive 29- and 33-k ... | 1991 | 1651421 |
| characterization of hepatitis a virus capsid proteins with antisera raised to recombinant antigens. | the capsid proteins of hepatitis a virus (hav) were expressed as fusion proteins of beta-galactosidase in e. coli using the expression vector lambda gt11. four fusion proteins were stably expressed and used to immunize rabbits to obtain mono-specific antisera. the antisera were unable to neutralize viral infectivity or react with hav by radioimmunoassay. three of the antisera were able to recognize hav antigens in infected bs-c-1 cells by immunofluorescence and denatured capsid proteins by immun ... | 1991 | 1651950 |
| large-scale purification of inactivated hepatitis a virus by centrifugation in non-ionic gradients. | formalin-inactivated hepatitis a virus (hav) can be purified for vaccine preparation by centrifugation in renografin-76 (diatrizoate meglumine and diatrizoate sodium) gradients. both continuous-flow rate-zonal and isopycnic methods were used for the separation of a major antigen component from minor antigen and host protein. the major antigen component, which appeared to contain complete virions by electron microscopy, could be recovered from gradients and accounted for approximately one third o ... | 1991 | 1651954 |
| [the chronic course of spontaneous and experimental hepatitis a in rhesus monkeys with viral persistence]. | the prolonged (up to 2 years) complex observation of 11 rhesus macaques (macaca mulatta) with spontaneous hepatitis a and 14 rhesus macaques with experimental hepatitis a developing after their intravenous and/or oral infection with human hepatitis a virus (hav). both natural and experimental infection took a chronic course (15-18 months). in 13 monkeys showing morphological changes in the liver during the whole period of the disease elevated enzyme levels in the blood and virus shedding in fece ... | 1991 | 1653510 |
| identification and characterization of incomplete hepatitis a virus particles. | the range of hepatitis a virus (hav) particles generated during persistent infection of different cell lines was studied. buoyant density and sedimentation analyses of cell extracts revealed a uniform profile of particles in all cell lines analysed except for bs-c-1 cells. the virion itself usually represented less than 50% of the total mass of virus antigen. a major portion of the antigen was associated with non-infectious, empty particles, which banded at 1.305 g/ml and 1.20 g/ml cscl, and sed ... | 1991 | 1654375 |
| a recombinant vaccinia virus expressing hepatitis a virus structural polypeptides: characterization and demonstration of protective immunogenicity. | a recombinant vaccinia virus containing most of the p1 region of hepatitis a virus (hav) was constructed. cell lysates of cultures infected with the virus contained hav proteins detectable by radioimmunoassay. western blot analysis revealed the presence of a single protein of mr 60k to 62k, bearing epitopes from structural polypeptides vp4, -3 and -2, and the n terminus of vp1. the size of the protein suggests that at least some of the vaccinia virus thymidine kinase is also expressed. inoculati ... | 1991 | 1654376 |
| the 5' nontranslated region of hepatitis a virus rna: secondary structure and elements required for translation in vitro. | although the lengthy 5' nontranslated regions (5'ntrs) of other picornaviral rnas form highly ordered structures with important functions in viral translation, little is known about the 5'ntr of hepatitis a virus (hav). we determined the nearly complete 5'ntr nucleotide sequences of two genetically divergent hav strains (pa21 and cf53) and included these data in a comparative phylogenetic analysis of the hav 5'ntr. we identified covariant nucleotide substitutions predictive of conserved secondar ... | 1991 | 1656072 |
| detection of hepatitis a virus proteins in infected bs-c-1 cells. | hepatitis a virus (hav) is distinguished from other picornaviruses by its tropism for the liver in infected hosts, a nonlytic infection in hepatocytes, and a slow and nonlytic growth cycle in cultured cells. although the genome structure and organization of hav appear to be similar to those of the other picornaviruses, the viral proteins synthesized in infected cells have not been previously characterized. we have utilized specific antisera raised in rabbits to recombinant hav proteins expressed ... | 1991 | 1656592 |