| a simplified multiwell plate assay for the measurement of hepatitis a virus infectivity. | a standardized multiwell plate assay (mwpa) was developed to provide a simple in situ measurement of hepatitis a virus (hav) infectivity titers. following attachment (4 h, 35 degrees c) of serial 10-fold dilutions of hav strain cr326 f (variant f') to confluent mrc-5 monolayers in 24-well plates, cultures were overlaid with maintenance medium and incubated for 35 days at 35 degrees c with weekly medium replacement. cells were fixed with 90% acetone and hav antigen was quantitated by reaction wit ... | 1991 | 1659431 |
| hepatitis a virus attachment to cultured cell lines. | identification of a hepatitis a virus (hav) receptor is important for understanding hav tissue tropism and replication sites and in the design of vaccines and antiviral therapy. the attachment of hav to cultured cell lines was evaluated: calcium-dependent specific attachment of four hav strains to permissive cells occurred, whereas binding to nonpermissive cells did not. investigation of hav antigenic variant strains (neutralization escape mutants) demonstrated identical attachment properties wi ... | 1991 | 1659597 |
| concentration and detection of hepatitis a virus and rotavirus from shellfish by hybridization tests. | a modified polyethylene glycol precipitation method for concentration of virus followed by a new method to recover nucleic acid was used to detect hepatitis a virus (hav) and rotavirus (sa11) in shellfish (oysters and hard-shell clams) by hybridization tests. infectious virus, seeded into relatively large quantities of shellfish, was recovered consistently, with greater than 90% efficiency as measured by either in situ hybridization (hav) or plaque assay (rotavirus sa11). viral nucleic acid for ... | 1991 | 1660697 |
| a rapid method for determination of endoproteinase substrate specificity: specificity of the 3c proteinase from hepatitis a virus. | the preferred amino acid residues at the p'1 and p'2 positions of peptide substrates of the 3c proteinase from hepatitis a virus (hav-3c) have been determined by a rapid screening method. the enzyme was presented with two separate mixtures of n-terminal acetylated peptides, which were identical in sequence except for the amino acids at the p'1 or p'2 positions, where a set of 15 or 16 amino acids was introduced. enzyme-catalyzed hydrolysis of the peptide mixtures generated free amino termini, wh ... | 1991 | 1662396 |
| prevalence of antibodies against hepatitis a virus, hepatitis b virus, and treponema pallidum in mauritius. | a seroepidemiological study on the prevalence of antibodies against hepatitis a virus (hav), hepatitis b virus (hbv) and treponema pallidum was conducted in various groups of the population of the state of mauritus (islands of mauritus and rodrigues). 618 sera were tested. the overall prevalence of anti-hav was 86.1% and yielded and age-dependent increase. serological evidence for acute or chronic hbv infection was found in 3.8%; 4.5% were positive for anti-hbc alone, and in 12.6% past hbv infec ... | 1991 | 1662829 |
| immunogenicity trial of inactivated hepatitis a virus vaccine in human volunteers. | an inactivated hepatitis a virus (hav) vaccine was tested on a group of human adult volunteers. the vaccine was administered subcutaneously, and a control group received a placebo (aluminium hydroxide). the vaccine was found to be relatively well tolerated and non-reactogenic, and levels of anti-hav were comparable to those in other studies. | 1991 | 1663301 |
| occurrence of faecal bacteria, salmonella and antigens associated with hepatitis a virus in shellfish. | an investigation was carried out over a one year period to examine jointly the occurrence of faecal bacteria, salmonella and the presence of antigens associated with the hepatitis a virus (hav) in oysters (crassostrea gigas), mussels (mytilus edulis, mytilus galloprovincialis) and cockles (cerastoderma edule), taken from 8 shellfish farming areas or natural beds along the french coast. for the faecal coliforms (fc) and faecal streptococci (fs), statistical analysis of the 176 samples examined sh ... | 1991 | 1663750 |
| [the use of lanthanide immunofluorescence analysis for demonstrating the antigen of viral hepatitis a]. | the study dealt with the development of an express method for detection of hepatitis a virus (hav) antigen employing lantanides, especially europium. the new time-resolved fluoroimmunoassay (trfia), alongside with a significant shortening of the time for reaction, was also 8 times as sensitive as the analogous enzyme immunoassay. the trfia may be used effectively both for control of the antigen amplification in hav-infected cell culture and for early diagnosis of acute forms of viral hepatitis a ... | 1991 | 1664554 |
| antiviral activity of carrageenan on hepatitis a virus replication in cell culture. | sulphated polysaccharides such as iota-, lambda- and kappa-carrageenans showed a potent inhibitory effect on the replication of hepatitis a virus (hav) in the human hepatoma cell line plc/prf/5. no cytotoxic effects were detected with concentrations of carrageenans up to 200 micrograms/ml. the selectivity indices of these substances, calculated as the ratio of the dose that reduced the number of viable cells to 50% (cd50) to the effective dose that inhibited 50% of viral antigen expression (ed50 ... | 1991 | 1665574 |
| genetic variability within the 5' nontranslated region of hepatitis a virus rna. implications for secondary structure and function. | the rna genome of hepatitis a virus (hav) contains a lengthy and relatively well conserved 5' nontranslated region (5'ntr). in other picornaviruses, the 5'ntr has been shown to have important functions related to the initiation of viral translation and replication of viral rna, functions which are critically dependent on both primary and secondary rna structure. we have utilized a phylogenetic approach to construct a model of the secondary structure of the hav 5'ntr. by comparing the nucleotide ... | 1991 | 1668324 |
| identification of hepatitis a virus as a trigger for autoimmune chronic hepatitis type 1 in susceptible individuals. | to identify factors contributing to the pathogenesis of autoimmune chronic active hepatitis (cah) healthy relatives of 13 patients with the disorder were followed prospectively for 4 years. 58 relatives were monitored for various serological markers and for t-lymphocyte migration inhibitory activity every 2 months. 3 cases of subclinical acute hepatitis a occurred during the study. in 2 of the 3 subjects, before hepatitis a virus (hav) infection, there was a defect in suppressor-inducer t lympho ... | 1991 | 1673738 |
| hepatitis a virus infection in taipei city in 1989. | to evaluate the current status of hepatitis a virus (hav) infection, a seroepidemiologic study to detect the prevalence of antibodies against hav (anti-hav) has conducted in taipei city, from march to july, 1989. serum specimens were collected from 602 male and 503 female apparently healthy children age 12 and under. the prevalence rate of anti-hav was 27.5% in infants, and decreased to nearly 0% in preschool and early school children up to 10 years old. compared to a previous study in the same ... | 1991 | 1678406 |
| monoclonal antibodies against an immunodominant and neutralizing epitope on hepatitis a virus antigen. | two monoclonal antibodies (813 and 10.09) were raised against hepatitis a virus (hav). they recognize an immunodominant epitope and a neutralizing site on hav. | 1990 | 1696807 |
| prophylactic treatment regimens for the prevention of hepatitis a. current concepts. | hepatitis a virus (hav) occurs worldwide. in developing countries the virus is endemic, with the majority of the population being exposed to it in childhood, when the infection usually causes, at the most, a mild anicteric illness. in developed countries the majority of hav infections occur at a later age, often in adults, especially those with a history of recent travel to developing countries. in adults, hav infection usually causes a symptomatic icteric illness. in addition to community sanit ... | 1991 | 1715265 |
| [synthesis and immunochemical properties of oligopeptides--fragments of capsid proteins of the hepatitis a virus]. | the hepatitis a virus (hav) capsid protein vp1, vp2 and vp3 are exposed at the virion surface and should therefore contain antigenic determinants. algorithms for hydrophilicity, antigenicity and flexibility were used to predict probable antigenic sites. synthesis of 7- to 23-membered overlapping peptides from seven sites, viz., 1-11, 1-17, 2-33, 11-25, 73-82, 76-86, 98-109, 98-112, 102-107, 102-108, 108-127, 113-123, 118-140, 276-298 from vp1, 42-62 from vp2, 76-85 from vp3, and 1-23 from vp4, w ... | 1991 | 1724368 |
| changing epidemiology of hepatitis a virus (hav) infection: a comparative seroepidemiological study (1979 vs 1989) in north-east italy. | a comparative seroepidemiological study (1979 vs 1989) on hav infection, was carried out in children and adolescents from north-east italy. anti-hav was tested in 850 subjects 6 to 8 years of age and the results were compared to those observed in 1979, in 462 subjects of the same age range and from the same geographical area. overall anti-hav prevalence was 1.9% (ranging from 0.5 to 5.2) in 1989 vs 32.5% (ranging from 7.8 to 70.7) in 1979. this dramatic decline of hav infection in children and a ... | 1991 | 1742523 |
| epidemiologic patterns of wild-type hepatitis a virus determined by genetic variation. | hepatitis a virus (hav) isolates from different parts of the world are a single serotype. however, genetic analysis of the vp1 genome region of published hav sequences suggested that distinct genotypes of hav could be defined based upon the geographic source of the original isolates. to circumvent the process of cell culture adaptation or animal passage, a 247-bp segment within the vp1 genome region of wild-type hav was amplified by reverse transcription followed by polymerase chain reaction amp ... | 1991 | 1846392 |
| rapid completion of the replication cycle of hepatitis a virus subsequent to reversal of guanidine inhibition. | the single-cycle replication kinetics of hepatitis a virus (hav: hm175 p39) in bs-c-1 cells were examined by rna hybridization and vp1 immunoblot assays. viral products accumulated after 4 days of lag phase and reached a plateau by 12 days postinfection. defective, subgenomic rnas were not detected by northern blot analysis of cytoplasmic extracts from infected cells or purified virions. replication of this hav strain was markedly inhibited by 2 mm guanidine. neither the virion itself nor the ad ... | 1991 | 1846497 |
| a simple antigen-reduction assay for the measurement of neutralizing antibodies to hepatitis a virus. | a simplified hepatitis a virus (hav) antigen-reduction neutralization assay (havarna) was developed to permit the measurement of biologically active antibodies in recipients of candidate hav vaccines. degrees of neutralization were measured from the reduction in the amount of hav antigen synthesized by 7-10 days after infection of mrc-5 (fetal human diploid lung) cell cultures. sera producing a greater than or equal to 50% reduction in viral infectivity were scored as neutralizing. the assay was ... | 1991 | 1847404 |
| safety and immunogenicity of a live attenuated hepatitis a virus vaccine in seronegative volunteers. | seronegative adults were enrolled in a dose-escalating study of a live attenuated hepatitis a virus (hav) vaccine that was prepared from the f' variant of hav strain cr326f. they were injected subcutaneously with 10(4.1), 10(5.2), 10(6.1), or 10(7.3) tcid 50 of hav vaccine (n = 40) or with placebo (n = 12) and were followed for 6 months. none of the vaccine recipients developed significant systemic reactions or aminotransferase elevations. hav was not isolated in cell culture from any postvaccin ... | 1991 | 1849160 |
| detection of hepatitis a virus and other enteroviruses in water by ssrna probes. | sensitive and specific methods are needed to detect hepatitis a virus (hav) and other human enteroviruses in environmental samples such as drinking water and foods. clones of cdna encoding the 5'-most 1 kb of the hav and coxsackievirus b3 (cb3) genomes were subcloned into t7/sp6 rna transcription vectors. in vitro transcribed rna from the t7 promoter detected their respective hav or cb3 genomic rna. conversely, sp6 transcripts detected viral negative-stranded rna but not the genome. when both ss ... | 1991 | 1849914 |
| the 5'-terminal nucleotides of hepatitis a virus rna, but not poliovirus rna, are required for infectivity. | a series of plasmids containing hepatitis a virus (hav) cdna was constructed such that positive-strand hav rna could be transcribed with t7 rna polymerase. the plasmids differed in the number of 5'-terminal nucleotides representing the junctions between vectors and hav sequences that were present in the transcripts. when these transcripts were used to transfect cultured bs-c-1 cells, it was found that only those transcripts that contained all of the 5'-terminal hav nucleotides, in addition to on ... | 1991 | 1850050 |
| translation of hepatitis a virus rna in vitro: aberrant internal initiations influenced by 5' noncoding region. | hepatitis a virus (hav) rnas were translated in vitro in rabbit reticulocyte lysates. the pattern of proteins synthesized from full-length hav rna was highly complex, consisting of a continuous spectrum of polypeptides ranging from less than 20,000 to greater than 200,000 da. the pattern was not significantly altered by varying incubation times, ion, or other reaction parameters, or by the addition of hela or bs-c-1 cell extracts to the translation reactions. plasmids engineered with mutations i ... | 1991 | 1850924 |
| [a comparative study of the sensitivity and specific activity of an immunoenzyme test system for determining class-m antibodies to the hepatitis a virus]. | the diagnostic value of the first experimental production batches of assay kit "diagn-a-hep", produced at the institute of poliomyelitis and viral encephalitides (ussr acad. med. sci.) and intended for the determination of igm to hepatitis a virus (hav) in the enzyme immunoassay (eia), has been studied in comparison with that of the internationally known and widely approved commercial eia system "havab-meia" for the determination of antibodies to hav (the product of abbott, usa). the study has r ... | 1991 | 1882626 |
| treatment of fulminant viral hepatic failure with prostaglandin e. a preliminary report. | the effect of prostaglandins (pg) in patients with fulminant and subfulminant viral hepatitis was studied. seventeen patients presented with fhf secondary to hepatitis a (n = 3), hepatitis b (n = 6) and non-a, non-b (nanb) hepatitis (n = 8). fourteen of the 17 patients had stage iii or iv hepatic encephalopathy (he). at presentation, the mean ast was 1844 +/- 1246 units/liter, bilirubin 232 +/- 135 mumol/liter, pt 34 +/- 18 and ptt 73 +/- 26 sec, and coagulation factors v and vii were 8 +/- 4 an ... | 1991 | 1903342 |
| detection of anti-hepatitis c virus antibody in fulminant hepatic failure. | serial serum samples obtained from 27 patients with fulminant hepatic failure (fhf) in a variety of etiology were tested for anti-hepatitis c virus antibody (anti-hcv) with uses of two different assay systems. the incidence of anti-hcv in patients with fhf due to hepatitis b (ortho test system; 7/11, 63.6%: abbott test system; 9/11, 81.8%) was found to be significantly higher than that in acute hbv hepatitis (ortho test system; 0/17, 0%) (p less than 0.001). in particular, all 3 post-transfusion ... | 1991 | 1909270 |
| hepatitis a and b infections in transfusion-dependent thalassaemia from endemic areas. | the aim of this study was to determine the prevalence of previous hepatitis a virus (hav) and b virus (hbv) infection which is in 64 transfusion-dependent (td) patients with thalassaemia including 26 patients who were transfused before blood donors were screened for hbv. serial blood samples taken from these 64 patients and 10 non-td beta-thalassaemia intermedia patients during a 3 year period, were tested for antibody to hav (anti-hav), hepatitis b surface antigen (hbsag), antibody to hbsag (an ... | 1991 | 1958422 |
| [safety observation of attenuated live hepatitis b vaccine (h2 strain) in humans]. | 3089 healthy persons, aged 4 to 27 years, have been inoculated in 3 batches with attenuated live hepatitis a vaccine (h2 strain) since may, 1987. each subject received 10(8.5) tcid dosage subcutaneously in the upper arm. none of the recipients developed any local or systemic reaction during a 42-day followup after vaccination. the serum enzyme activities, including sgpt/alt and ldh5, were within normal range during the 4th to 16th weeks of serial tests after inoculation. the study of hepatitis a ... | 1990 | 1963372 |
| [the modelling of hepatitis a and of enterally transmitted non-a, non-b hepatitis (hepatitis e) in saguinus mystax tamarins]. | a comparative study of hepatitis infection caused by human hepatitis a virus (ms-1 strain), simian hepatitis a virus (agm-27 strain), and enterically transmitted non-a, non-b hepatitis virus (tashkent-1435 strain) was carried out. susceptibility of tamarins to the agm-27 and tashkent-1435 as well as to ms-1 strain was demonstrated. all the strains induced an acute infection characterized by serum alanine aminotransferase (alt) elevation, virus excretion and antibody response. certain differences ... | 1990 | 1967121 |
| dissociation of alanine aminotransferase values in acute hepatitis a patients with and without past experience to the hepatitis b virus. | serological markers and peak serum alanine aminotransferase (alt) values of 140 in-patients with acute hepatitis, either type a (n = 90), or type b (n = 50) were prospectively assessed. in 23 out of the 90 patients with acute hepatitis a, evidence of previous experience with hepatitis b virus (hbv) was found, whereas 35 out of the 50 patients with acute hepatitis b had past contact with hepatitis a virus (hav). the mean peak alt values [s.d.] were significantly higher in hepatitis a patients wit ... | 1991 | 2019305 |
| an outbreak of acute hepatitis a infection in rural saudi arabia. | in areas of hyperendemicity of hepatitis a virus (hav) infection, acquisition of immunity occurs relatively early in life. in such populations epidemic outbreaks are rare. a recent hav infection outbreak occurred in the al-dahnah district in saudi arabia. in thirty day period, 23 children and adolescents were diagnosed by clinical examination. 19 of these were positive for igm anti-hav. concomitant acute infections with the epstein bar virus (ebv) was documented in 4 of these patients. a limited ... | 1990 | 2075630 |
| correlation of hepatitis b surface antigen clearance with the route of hepatitis b virus infection. | we studied 563 consecutive adults with acute hepatitis b hospitalized from may 1981 to may 1983 and their habitual heterosexual partners. radio-immunoassays for the detection of serological markers of hepatitis a virus (hav) and hepatitis b virus (hbv) and enzyme-immunoassay for the detection of igm antibody to hepatitis b core antigen (igm anti-hbc) were used. of the 563 patients, 503 (89.7%) were hepatitis b surface antigen (hbsag) positive and 60 (10.7%) were hbsag negative on admission. abse ... | 1990 | 2103406 |
| anti-hepatitis c virus antibody prevails in fulminant hepatic failure. | serial serum samples obtained from 27 patients with fulminant hepatic failure (fhf) in a variety of etiology were tested for anti-hepatitis c virus antibody (anti-hcv). seven out of 10 patients (70%) with fhf due to hepatitis b virus (hbv) infection were positive for anti-hcv, showing a significantly higher rate than that in acute hbv hepatitis (0/17, 0%): in particular, all 3 post-transfusion hbv-fhf cases were found to be positive for the antibody. the incidence of anti-hcv in sporadic non-a n ... | 1990 | 2106465 |
| hepatitis c virus infection in individuals with or without human immunodeficiency virus type 1 infection. | serum specimens from 111 human immunodeficiency virus type 1 (hiv-1) infected and 183 hiv-1 seronegative patients were analysed for antibodies to hepatitis c virus (hcv), hepatitis b virus (hbv) and hepatitis a virus (hav) by enzyme linked immunoassay (elisa) and radioimmunoassay. anti-hcv and anti-hbv antibodies were found in the vast majority (89 and 83%, respectively) of intravenous drug addicts (ivda), independent of the type of drug abuse or whether the patients were hiv-1 infected or not. ... | 1990 | 2127586 |
| 19s and 7-8s forms of igm antibody to hepatitis b core antigen in acute icteric hepatitis superimposed on hepatitis b surface antigen carriage. | the 19s and 7-8s forms of igm antibody to hepatitis b core antigen (igm anti-hbc) were separated by rate-zonal centrifugation from the serum of 20 greek hepatitis b surface antigen (hbsag) carriers with a superimposed acute icteric hepatitis positive for igm anti-hbc by a radioimmunoassay. serological markers of hepatitis a virus (hav), hepatitis b virus (hbv) and hepatitis d virus (hdv) infections were detected with radioimmunoassays and serum hbv dna was detected with molecular hybridization t ... | 1990 | 2127587 |
| incidence of different types of viral hepatitis in delhi, uttar pradesh and rajasthan areas. | a total of 428 sera samples from patients of acute sporadic viral hepatitis collected from delhi (172), uttar pradesh (192) and rajasthan (64) were tested for hepatitis a virus (hav) and hepatitis b virus (hbv) markers. non a non b was diagnosed by exclusion. the prevalence of hav, hbv and non a non b in such cases was almost comparable at three places. the prevalence of hav ranged between 15.7 and 20.3 per cent, hbv between 41.3 and 51.6 per cent while non a non b ranged between 28.1 and 43 per ... | 1990 | 2129122 |
| persistence of hepatitis a virus in fulminant hepatitis and after liver transplantation. | a peroxidase-labelled, specific mouse monoclonal antibody to hepatitis a virus (hav) and an in situ hybridization technique (streptavidin-biotin-horseradish peroxidase reaction) with an hav-specific cdna probe (recombinant plasmid pawha comprising 1.8 kb of the hav-specific cdna, located toward the 3' end of the genome) were used to detect hav in liver tissues in two patients with fulminant viral hepatitis type a treated by liver transplantation after a protracted (day 40: case 1) and relapsing ... | 1990 | 2156006 |
| protracted alanine aminotransferase levels in tamarins infected with hepatitis a virus. | eighteen red-bellied tamarins (saguinus labiatus), experimentally infected with hepatitis a virus (hav), were followed for up to 1.5 years after initial challenge. half of these animals developed protracted alanine aminotransferase (alt) abnormalities, which lasted for between 23 and 55 weeks post-challenge. igm anti-hav was detected intermittently during the early phase of their relapsing hepatitis and never after return of alt levels to normal. the possibility that these findings may be relate ... | 1990 | 2156008 |
| construction of recombinant dna molecules by the use of a single stranded dna generated by the polymerase chain reaction: its application to chimeric hepatitis a virus/poliovirus subgenomic cdna. | in order to study the importance of vp4 in picornavirus replication and translation, we replaced the hepatitis a virus (hav) vp4 with the poliovirus (pv1) vp4. using a modification of oligonucleotide site directed mutagenesis and the polymerase chain reaction (pcr), we created a subgenomic cdna chimera of hepatitis a virus in which the precise sequences coding for hav vp4 capsid protein were replaced by the sequences coding for the poliovirus vp4 capsid protein. the method involved the use of pc ... | 1990 | 2156236 |
| recovery of hepatitis a virus from a water supply responsible for a common source outbreak of hepatitis a. | an outbreak of hepatitis a occurred in a north georgia trailer park served by a private well. of 18 residents who were serosusceptible to hepatitis a virus (hav), 16 (89%) developed hepatitis a. well water samples were collected 3 months after illness onset in the index case and 28 days after illness onset in the last trailer park resident. hepatitis a virus antigen (havag) was detected in the samples by enzyme immunoassay from three of the five cell lines following two 30-day passages and from ... | 1990 | 2156462 |
| simultaneous vaccination for hepatitis a and b. | seronegative volunteers (15) were vaccinated at three 1-month intervals with a combined hepatitis a and b vaccine. the vaccine contained a killed hepatitis a vaccine made from hepatitis a virus (hav) propagated in diploid human fibroblast cell cultures and hepatitis b surface antigen (hbsag) produced in yeast. after only one injection, all volunteers developed neutralizing antibodies for hav with antibody titers comparable to those found after gamma globulin administration. compared with the ant ... | 1990 | 2157770 |
| disappearance of igm antibodies to hepatitis a virus after an acute infection in children and adolescents. | the kinetics of igm antibodies to hepatitis a virus (hav) following an acute infection, were studied in 17 children. antibodies disappeared in two patterns, one group at 113 +/- 18 days after the acute infection in the children, and the second group at 283 +/- 90 days. the same two patterns of kinetics were seen in adults. we conclude that igm anti-hav antibodies can be found in the sera of children for over 6 months after the acute infection, as was observed in adults. | 1990 | 2157834 |
| molecular epidemiology of human hepatitis a virus defined by an antigen-capture polymerase chain reaction method. | we describe an immunoaffinity-linked nucleic acid amplification system (antigen-capture/polymerase chain reaction, or ac/pcr) for detection of viruses in clinical specimens and its application to the study of the molecular epidemiology of a picornavirus, hepatitis a virus (hav). immunoaffinity capture of virus, synthesis of viral cdna, and amplification of cdna by a polymerase chain reaction (pcr) were carried out sequentially in a single reaction vessel. this approach simplified sample preparat ... | 1990 | 2158093 |
| subclinical infection with hepatitis a in peace corps volunteers following immune globulin prophylaxis. | a study was undertaken to determine the incidence of subclinical infection in peace corps volunteers (pcvs) maintained on a routine prophylactic immune globulin (ig) regimen. serum markers to hepatitis a virus (hav) were detected in 172 of 1,508 (11.4%) single serum samples from a cross-sectional sample of pcvs. of those tested prior to service, 15/298 (5%) were seropositive for hav. those tested at 1-12 months showed 48/417 (11.3%) seropositivity, while 72/529 (13.6%) of those with greater than ... | 1990 | 2160196 |
| characterization by t1-oligonucleotide fingerprinting of three strains of human hepatitis a virus isolated in italy. | three human hepatitis a virus strains, all of them isolated in italy but one acquired abroad, were analyzed by t1-rnaase oligonucleotide mapping and by monoclonal antibody neutralization. the variation among their genomes according to t1-maps was calculated to be about 9%, thus confirming the poor genomic variation assessed by nucleotide sequencing (1-10%). however t1-maps of these italian isolates were different from those reported in the literature (weitz and siegl, 1985). neutralization by mo ... | 1990 | 2160891 |
| immunofluorescence and immunoperoxidase assays for the titration of infectious hepatitis a virus (hav). | immunofluorescence (ifa) and immunoperoxidase (ipa) assays were developed for the titration of infectious hepatitis a virus. both of these methods were found to be simple, rapid and quantitatively reproducible. the immunoperoxidase technique could be the method of choice for the assay of hav in cell culture. | 1990 | 2164520 |
| preparation of noninfectious hepatitis a virus hemagglutinin for detecting hemagglutination inhibition antibodies. | hepatitis a virus (hav) harvested from infected mrc-5 cells can hemagglutinate various species of erythrocytes at acid ph (eckels et al., 1989). further studies revealed that the majority of the hemagglutinin (ha) in mrc-5 and bs-c-1 cells was cell-associated. a simplified procedure for preparing hav-ha consisted of collecting infected cells in phosphate-buffered saline followed by three cycles of freeze-thawing and sonication. the fluids were clarified and stored at 4 degrees c. the analysis of ... | 1990 | 2166750 |
| inhibition of hepatitis a virus replication in vitro by antiviral compounds. | forty antiviral compounds were screened for inhibitory effect on hepatitis a virus (hav) antigen expression in the human hepatoma cell line plc/prf/5. ribavirin, amantadine, glycyrrhizin, and pyrazofurin were selected in this screening test and were studied further. the selectivity indices of these four compounds, calculated as the ratio of 50% cytotoxic dose (determined by the trypan blue exclusion and by inhibition of [3h] leucine incorporation) to the 50% effective dose (determined by the vir ... | 1990 | 2167349 |
| inhibitory effects of atropine, protamine, and their combination on hepatitis a virus replication in plc/prf/5 cells. | atropine, protamine, and the combination of these drugs were tested for their effects on hepatitis a virus (hav) replication in cell culture. plc/prf/5 hepatoma cells were treated simultaneously with nontoxic concentrations of these drugs and inoculated with hav strain cf 53 at several multiplicities of infection. the yields of infectious hav after 4 and 15 days were markedly reduced by each drug, especially at the lowest multiplicity of infection. the activities of each drug were irreversible. ... | 1990 | 2168143 |
| [experimental model of hepatitis a in rhesus monkeys (macaca mulatta) infected with human hepatitis a virus]. | the focus of this paper is characterization of hepatitis a experimental model obtained for the first time in rhesus monkeys (m. mulatta) infected with fecal isolate from a patient with hepatitis a (hav-h1). monkeys were susceptible to oral and intravenous routes of hav inoculation. the disease could be reproduced regularly in 4 passages as a result of which hav strain continuously pathogenic for m. mulatta has been established. all 17 infected monkeys developed hepatitis a with characteristic (e ... | 1990 | 2168770 |
| sociodemographic correlates of neutralizing poliovirus and hepatitis a virus antibodies as markers of different modes of acquiring immunity. | the prevalence and sociodemographic correlates of antibodies against poliovirus and hepatitis a virus (hav) were compared in a random sample of 457 military recruits in israel inducted during 1987. lower socioeconomic status (ses) was associated with a higher prevalence of anti-hav antibodies (67.3 vs 32.5 percent), whereas the reverse was true for type 1 poliovirus (78.4 vs 89.5 percent). while the high prevalence of anti-hav antibodies observed in the lower ses groups reflects considerable nat ... | 1990 | 2169209 |
| morphogenesis of hepatitis a virus: isolation and characterization of subviral particles. | the morphogenesis of hepatitis a virus (hav) in bs-c-1 cells was examined by immunoblotting with antisera to capsid proteins and labeling of virus-specific proteins with l-[35s]methionine. antiserum to vp2 detected two virus-specific proteins with apparent molecular masses of 30.6 and 30 kda, representing vp0 and vp2, while antiserum to vp1 detected proteins with molecular masses of 33 and 40 kda, representing vp1 and a virus-specific protein which we designated px, respectively. sedimentation o ... | 1990 | 2170672 |
| [clinical trial of inactivated hepatitis a vaccine]. | a clinical trial was carried out for a lypophilized inactivated hepatitis a vaccine in order to confirm its safety and antibody response. the vaccine used for the study has been developed by denka institute of biological science (lot. d-01), chiba serum institute (lot. c-01) and the chemo-sero-therapeutic research institute (lot. k-02). thirty-six volunteers were selected and employed for the present study from healthy male adults carrying no antibody against hepatitis a virus (hav). they were d ... | 1990 | 2170718 |
| an investigation of hepatitis a virus infected blood products. | hepatitis a virus (hav) infection via the parenteral route is not common. to investigate this further, we obtained the fresh frozen plasma (ffp) component from a unit of whole blood provided by an hav-infected donor and attempted to quantify and characterize the virus in this material. despite repeated efforts at culture and cesium banding, hav was not detected by these methods. however, a hepatitis-a-specific antibody capture assay did demonstrate an occasional hav-like particle upon electron m ... | 1990 | 2172868 |
| high incidence of viral hepatitis among american missionaries in africa. | protestant missionaries (n = 360) serving in sub-saharan africa between 1967-1984 were studied to determine the risk of hepatitis a virus (hav) and hepatitis b virus (hbv) infection. personnel were serologically screened for antibody to both the hepatitis a virus (anti-hav) and the surface antigen to the hepatitis b virus (anti-hbs) prior to departure, periodically during service abroad, and upon completion of their african tour. rates of seroconversion were used as measures of the incidence of ... | 1990 | 2173432 |
| [the sensitivity of rhesus and cynomolgus macaques to the human hepatitis a virus]. | hepatitis a infection characterized by virus excretion in feces, synthesis of specific igm antibody, increased activity of alanine aminotransferase in the blood serum, and a complex of morphological lesions in the liver typical of acute hepatitis was reproduced in m. fascicularis (m. f.) and macaca rhesus (m. r.) using 2 strains of hepatitis a virus (hav) isolated from human patients. the incubation period varying from 9 to 23 (mean 16) days in m. f. and from 12 to 35 (mean 18) days in m. r. in ... | 1990 | 2175064 |
| [the use of a molecular probe containing a specific cdna consisting of bacteriophage m13 for detecting the hepatitis a virus in clinical specimens]. | a probe was constructed containing a fragment of dna replica of hepatitis a virus (hav) rna within bacteriophage m13 single-stranded dna which allowed 10(-12) g of viral rna to be tested. hybridization of 32p-labeled probe with total rna from 559 samples of blood, saliva, and urine from patients with viral hepatitis a revealed the presence of hav rna in 14% of the samples. in the 1st week of the jaundice period hav rna was detected in 40% (15 positive samples out of the 39 tested), in the 2nd we ... | 1990 | 2176421 |
| identification of enterically transmitted hepatitis virus particles by solid phase immune electron microscopy. | small 'featureless' viruses (less than 50 nm) are difficult to identify by routine immune electron microscopy techniques, particularly when they are mixed with debris from stool or cell culture extracts. a combination of conventional immune electron microscopy (iem) and solid phase iem (spiem) methodologies was used to identify hepatitis a virus (hav) in stool and cell culture extracts and non-a non-b hepatitis (hepatitis e) in stool extracts. compared with conventional iem, the modified spiem m ... | 1990 | 2176664 |
| recombinant proteins vp1 and vp3 of hepatitis a virus prime for neutralizing response. | six overlapping genomic regions of capsid proteins vp1 and vp3 of hepatitis a virus (hav) inserted into the expression vectors pbd or pur respectively expressed beta-galactosidase-hav fusion proteins. the recombinant proteins were poorly soluble so they were difficult to detect by human anti-hav sera in radioimmunoassay, but the fusion proteins dissolved in sodium dodecyl sulfate reacted with human and rabbit anti-hav-positive sera in immunoblots. antisera against vp1 and vp3 recombinant protein ... | 1990 | 2176673 |
| [a trial of a cultured inactivated vaccine against hepatitis a on saguinus mystax tamarins]. | an experimental batch of inactivated hepatitis a vaccine was prepared using hepatitis a virus (hav), has-15 strain, adapted to cell culture and purified by ultracentrifugation. the vaccine was tested in tamarins immunized intramuscularly three times one month apart. three tamarins received a vaccine preparation containing 10 ng of immunogen each, three--100 ng each, and three animals were used as controls. the efficacy was judged by the anti-hav antibody response in the vaccinated animals and de ... | 1990 | 2256314 |
| an outbreak of hepatitis a among cancer patients treated with interleukin-2 and lymphokine-activated killer cells. | an outbreak of hepatitis a virus (hav) infection occurred among cancer patients treated with interleukin-2 (il-2) and lymphokine-activated killer (lak) cells between july and september 1986 at six different clinical centers. among 85 patients tested serologically for recent hav infection, 22 (39%) of 56 susceptible patients developed acute hav infection. only exposure to lak cells cultured in medium containing human serum from two specific manufactured pools was associated with hav infection. at ... | 1990 | 2319165 |
| impact of hepatitis a in siena: a "traveller's disease"? | over a period of seven years (from 1980 to 1987) 58 acute viral hepatitis a cases were admitted to the departments for infectious diseases. this number represents 10.76% of all viral hepatitis patients. most of the patients had travelled to foreign countries or to areas in italy with high hepatitis a virus (hav) circulation. an assessment of specific immunization against hav in normal healthy people aged 1-60, performed by elisa, showed a very low number of sero-positive subjects. the disappeara ... | 1990 | 2344870 |
| changing patterns of hepatitis a virus infection in children in palermo, italy. | in 1988 in palermo, italy, the prevalence of antibodies to hepatitis a virus (anti-hav) in a sample of 490 children 6-13 years old was 10.6%; it increased from 6.3% among children 6-10 years old to 14.7% in children 11-13 years old (p less than 0.01). compared with findings from a survey conducted in 1978 in the same area, the results of the present study show a significant (p less than 0.01) reduction in the anti-hav prevalence in both age groups. anti-hav prevalence was inversely related to th ... | 1990 | 2344881 |
| etiological spectrum of acute sporadic viral hepatitis amongst adults in chandigarh. | all 77 hbsag positive and 94 of representative hbsag negative sera derived from 253 adult patients with acute sporadic viral hepatitis during 1987 at chandigarh were tested for serological markers of hepatitis b virus (hbv) and hepatitis a virus (hav) infections. the hbsag positive patients could be classified as acute hepatitis b (64%); chronic hepatitis b with exacerbation, or liver damage by other infectious or noninfectious agent/s over a chronic hbsag carrier state (35%); and coinfection of ... | 1990 | 2345034 |
| [prevalence of hepatitis a markers in families of patients treated at home and in hospitals]. | the data on the time-course examinations of 119 family members of 59 adult patients with hepatitis a (ha) treated at home in moscow and 170 relatives of 82 ha patients admitted to an infectious hospital are presented. the diagnosis for all the patients was verified by the detection in their blood of antibodies to hepatitis a virus (hav) of the igm class. clinical methods of examination were used as well as determinations of anti-hav of the igg and igm classes by enzyme immunoassay. when a case o ... | 1990 | 2363272 |
| [susceptibility of macaca rhesus to infection with hepatitis a virus strains isolated from man and monkeys]. | the results of infection of macaca rhesus monkeys with hepatitis a virus (hav) strains isolated from monkeys and man are presented. after inoculation of monkeys with human nav strains the infection could not be reproduced whereas simian hav strains were found to be pathogenic for m. rhesus monkeys both on experimental inoculation and during natural contacts with infected monkeys in the animal house. | 1990 | 2363273 |
| hepatitis b virus (hbv) markers and hbv-dna in serum and liver tissue of patients with acute exacerbation of chronic type b hepatitis. | we analysed the serum samples and the liver biopsies of six consecutive chronic hbsag/anti-hbe carriers admitted to hospital because of an episode of acute hepatitis. the six patients became positive for igm anti-hbc and negative for hbeag, hepatitis delta virus (hdv) markers, igm anti-hepatitis a virus (hav), anti-cytomegalovirus (cmv) and anti-epstein-barr virus (ebv). two patients showed positivity for hepatitis b virus (hbv)-dna in serum obtained on admission, with no positivity in the subse ... | 1990 | 2365978 |
| genomic heterogeneity among human and nonhuman strains of hepatitis a virus. | cloned cdna probes derived from the p1 and p2 regions of the genome of hm175 virus, a reference strain of human hepatitis a virus (hav), failed to hybridize under standard stringency criteria with rna from pa21 and pa33 viruses, two epizootiologically related hav strains recovered from naturally infected new world owl monkeys. hybridization of these probes to pa21 rna was only evident under reduced stringency conditions. however, cdna representing the 5' nontranslated region of the hm175 genome ... | 1987 | 2433467 |
| inhibition of in vitro hematopoiesis by hepatitis a virus. | inoculation of human bone marrow with hepatitis a virus (hav) resulted in a dose- and duration-of-incubation-dependent suppression of hematopoietic progenitor (cfu-gm, bfu-e, cfu-mix) growth in vitro. monocytic progenitors appeared to be least affected. while hav inactivation by heat or beta-propiolactone and neutralization by specific antibodies completely abrogated hematopoietic inhibition, depletion of adherent bone marrow cells, and enrichment of progenitors did not alter the pattern of supp ... | 1987 | 2443380 |
| [accumulation of the infectious virus and the viral antigen during the multiplication of the hepatitis a virus in an embryonic kidney cell culture of the rhesus macaque (frhk-4)]. | growth characteristics of the has-15 strain of human hepatitis a virus (hav) in rhesus monkey foetal kidney cell line (frhk-4) are described. the conditions optimal for the accumulation of infectious hav and viral antigen (haag) in the infected cells and tissue culture fluids were studied. the production of infectious hav occurred in the first stage while in the second stage predominantly haag was accumulating intracellularly. serological properties of the cultivated hav proved to be very simila ... | 1987 | 2445108 |
| detection of hepatitis a virus by hybridization with single-stranded rna probes. | an improved method of dot-blot hybridization to detect hepatitis a virus (hav) was developed with single-stranded rna (ssrna) probes. radioactive and nonradioactive ssrna probes were generated by in vitro transcription of hav templates inserted into the plasmid pgem-1. 32p-labeled ssrna probes were at least eightfold more sensitive than the 32p-labeled double-stranded cdna counterparts, whereas biotin-labeled ssrna probes showed a sensitivity comparable with that of the 32p-labeled double-strand ... | 1987 | 2447830 |
| [spontaneous hepatitis a with a fatal outcome in rhesus monkeys]. | this is the first report of virologically verified spontaneous hepatitis a in m. rhesus monkeys with severe involvement of the liver leading to the death of the animals. in 21 out of 23 dead monkeys morphological lesions in the liver have been characterized as acute hepatitis. in 6 (26%) animals no other pathological processes were found. in 15 animals hepatitis was combined with other diseases (dysentery, parasitic infestations, coronavirus infection). antigen of hepatitis a virus was detected ... | 1987 | 2451353 |
| [hepatitis-related viral markers in patients under long-term hemodialysis]. | antibody profiles for hepatitis b virus (hbv), hepatitis a virus (hav), cytomegalovirus (cmv), epstein-barr virus (ebv) and human immunodeficiency virus (hiv) were determined on 55 serum samples collected from patients with chronic renal failure who were on long-term haemodialysis for periods ranging from 8 months to 5 years and 3 months. the exposure rates for hbv, hav, cmv, ebv and hiv were 94.5%, 100%, 94.5%, 94.5% and 0% respectively. among the 7 hbsag carriers, 1 and 3 were positive for e a ... | 1987 | 2452721 |
| insertion of short hepatitis virus a amino acid sequences into poliovirus antigenic determinants results in viable progeny. | in an infectious poliovirus cdna construct, the determinant encoding antigenic epitope n-ag1 (in a loop located between two beta-strands in poly-peptide vp1) was altered by site-directed mutagenesis, to be partially similar with the determinants for presumptive epitopes in polypeptides vp1 or vp3 of hepatitis a virus (hav). the modified constructs proved to be infectious. however, another construct, in which the same locus encoded a 'nonsense' and a relatively hydrophobic amino acid sequence, ex ... | 1989 | 2479578 |
| hav recovery from tap water: evaluation of different types of membranes. | a cytopathic strain of hepatitis a virus (hav) has been used to evaluate the absorption-elution of several membranes. filters were obtained from four different manufactures: sartorius, millipore, gelman and cuno. only the electronegative hawp (millipore) and the electropositive (cuno-div.) filters appear to absorb hav with a high efficiency. | 1989 | 2483083 |
| liver-derived cytotoxic t cells in hepatitis a virus infection. | an autologous in vitro model was developed to analyze the immunologic cause of liver tissue injury during hepatitis a virus (hav) infection. human t lymphocytes infiltrating the livers of two patients with acute hav infection were isolated from liver biopsy cores, cloned, and expanded in vitro. procedures using a cell culture system with hav-infected autologous skin fibroblasts demonstrated that 42% and 53% of the liver-infiltrating cd8+ clones were hav-specific and that they kill hav-infected s ... | 1989 | 2503564 |
| etiologic spectrum of acute sporadic viral hepatitis in children in india. | the relative magnitude by hepatitis a virus (hav), hepatitis b virus (hbv) and hepatitis non-a, non-b virus (hnanbv) was determined in 496 children from three different parts of india suffering from acute viral hepatitis by tests for specific igm class anti-hav and anti-hbv antibodies in the serum. hav, hbv and nanb infections accounted for 55.8 per cent, 20.2 per cent and 23.2 per cent of cases respectively. hepatitis a largely (59.5%) affected younger children of 1-5 yr. nearly a third of chil ... | 1989 | 2508281 |
| fulminant viral hepatitis: indian experience. | thirty-six patients with fulminant viral hepatitis were studied. enzyme immunoassay was used to detect the presence of hbsag, igm anti-hbc, and igm anti-hav. non-a, non-b virus was the most common aetiological agent (61.1%) followed by hepatitis b virus (hbv; 30.6%) and hepatitis a virus (8.3%). presence of igm anti-hbc confirmed the diagnosis of hbv infection in three cases who were negative for hbsag. similarly, in one case who was positive for hbsag, absence of igm anti-hbc suggested superinf ... | 1989 | 2518791 |
| effect of cellular function inhibitors on the infection of frp/3 cells by hepatitis a virus. | the effect of some cellular function inhibitors on hepatitis a virus (hav) adsorption and on the successive events of infection in a monkey cell line (frp/3 cells) was investigated. treatments of frp/3 cells with colcemide, vinblastine and cytochalasin d, which affect cytoskeleton organization, indicated that neither microtubules nor microfilaments play an important role in the early events of hav infection. monensin, which acts as an ionophore on intracellular vesicle compartments inhibited hav ... | 1989 | 2535886 |
| primary study of attenuated live hepatitis a vaccine (h2 strain) in humans. | strain h2, an attenuated live hepatitis a virus (hav), was derived from the fecal specimen of a patient with hepatitis a in hangzhou, china. after isolation and passage in a culture of newborn monkey kidney cells, adaptation to grow in human lung diploid cells (kmb17), and serial passage at a low temperature (32 degrees c) in kmb17 cells, this strain became the master seed virus for h2-strain vaccine. twelve human volunteers received the experimental vaccine subcutaneously and were closely obser ... | 1989 | 2538518 |
| variations in genome fragments coding for rna polymerase in human and simian hepatitis a viruses. | the genome of hepatitis a virus (hav) isolated from spontaneously infected african vervet monkey (cercopithecus aethiops) has been cloned and partially sequenced. comparison of genome fragments (1248 and 162 bp) from the 3d (rna polymerase) region with the corresponding parts of human hav genomes revealed a high degree of heterogeneity: there were altogether 257 nucleotide changes leading to 44 substitutions in predicted amino acid sequence, i.e. 89% amino acid identity. this divergence is consi ... | 1989 | 2541023 |
| nucleotide sequence of the vp1 gene from a chinese strain of hepatitis a virus (hav) | | 1989 | 2542903 |
| detection of hepatitis a virus rna and capsid antigen in individual cells. | the replication of hepatitis a virus (hav) rna and the production of hav vp1 protein were examined in cultures of bs-c-1 cells under one-step growth conditions by in situ hybridization and immunofluorescence. individual cells that had undergone active viral rna replication were detectable at 24 h post-infection. during subsequent days, increasing numbers of cells began replicating viral rna, so that by seven days post-infection, all cells had accumulated significant amounts of viral rna. the res ... | 1989 | 2543159 |
| in situ hybridization for quantitative assay of infectious hepatitis a virus. | a method of in situ hybridization using single-stranded rna probes of opposite polarity for quantitative enumeration of hepatitis a virus (hav) in infected cells has been developed. kinetic experiments showed that foci of infected cells appeared as early as day 2 postinfection. the absence of foci in cells examined immediately after virus adsorption indicated that foci detected subsequently were related to viral replication. foci were detected by hybridization with rna probes complementary to ha ... | 1989 | 2545742 |
| hepatitis a virus hemagglutination and a test for hemagglutination inhibition antibodies. | like enteroviruses, hepatitis a virus (hav) hemagglutinated various species of erythrocytes under similar conditions. hav-specific antibodies in both acute- and convalescent-phase sera were found to inhibit hemagglutination. the hav hemagglutination inhibition test can be used for diagnosis, epidemiological surveillance, and vaccine assessment. | 1989 | 2546979 |
| replication kinetics and cytopathic effect of hepatitis a virus. | the replication kinetics and c.p.e. of hepatitis a virus (hav) strain hm-175 were shown to depend upon the passage level of the cell line, and the passage level and method of selection of the virus population. maximum virus production under single-step growth curve conditions occurred as early as 24 to 28 h or as late as 10 days post-infection. although rapid replication of an isolate of hm-715 (phm-175) occurred initially in bs-c-1 cells, its most pronounced c.p.e. was induced in frhk-4 cells. ... | 1989 | 2549182 |
| altered hepatitis a vp1 protein resulting from cell culture propagation of virus. | the published sequence of hepatitis a virus (hav), strain has-15, after 20-30 cell culture passages contains an 18 nucleotide deletion (ovchinnikov et al., 1985) within the vp1 genome region. this results in a significant amino acid difference of the vp1 protein when this strain of hav is compared with other published hav sequences. comparison of the polyacrylamide gel electrophoretic migration of has-15 hav and two other strains of hav revealed that the has-15 vp1 molecule migrated faster than ... | 1989 | 2549747 |
| use of immunogold preembedding technique to detect hepatitis a viral antigen in infected cells. | localization of virus and viral antigen in cell cultures infected with a rapidly replicating isolate of strain hm-175 of hepatitis a virus (hav; phm-175) was accomplished by using immunogold probes. cells infected under one-step growth curve conditions were prefixed with 2% paraformaldehyde and 0.1-0.001% saponin at appropriate times postinfection for detection of maximum virus and viral antigen. an indirect labeling technique was employed using monoclonal antibody to hav followed by 5 nm gold-a ... | 1989 | 2549778 |
| acid stability of hepatitis a virus. | the acid stability of unpurified and highly purified hepatitis a virus (hav) was tested and compared with that of poliovirus type 1, coxsackievirus types a9 and b1 and echovirus type 9. only hav had a high residual infectivity after 2 h of exposure to ph 1 at room temperature, remaining infectious for up to 5 h. at 38 degrees c, ph 1, hav remained infectious for 90 min. highly purified hav was found to be infectious for 8 h at ph 1 and room temperature. this indicates that the increased stabilit ... | 1989 | 2550575 |
| propagation of hepatitis a virus in hybrid cell lines derived from marmoset liver and vero cells. | to establish monkey liver cell lines with a high susceptibility to hepatitis a virus (hav), marmoset (saguinus labiatus) liver cells were fused with vero cells deficient in hypoxanthine-guanine phosphoribosyltransferase and the resulting hybrid cells were selected in hat medium. of four hybrid cell lines obtained (s. 1a/ve-1 to -4), three (s. 1a/ve-1, -3 and -4) were equally susceptible to hav infection. when inoculated with a virus isolated from marmoset liver tissue (10% liver tissue extract) ... | 1989 | 2550576 |
| detection of hepatitis a virus rna in serum from patients with acute hepatitis. | hepatitis a virus (hav) rna was extracted from the sera of patients with acute hepatitis and then detected by molecular hybridization using cloned hav complementary dna (cdna). hav rna was detected in 20 of 85 patients with acute hav infection, mainly during the prodromal stage, or early during the icteric phase of the disease; it was detected as long as 21 days after its initial detection. patients with hav rna in the serum had a significantly higher titer of anti-hav igm. | 1989 | 2550586 |
| membrane lipid components interacting with hepatitis a virus. | the involvement of lipid components in hepatitis a virus (hav) attachment to host cells has been investigated. isolated frp/3 cell membranes and whole lipids, phospholipid and glycolipid fractions extracted from them were able to bind the virus and to prevent infection. treatment of virus with various phospholipids or glycolipids demonstrated the participation of phosphatidylserine, phosphatidylethanolamine and galactose in hav binding. results obtained added further information on the receptor ... | 1989 | 2550740 |
| characterization of a simian hepatitis a virus (hav): antigenic and genetic comparison with human hav. | pa21, a strain of hepatitis a virus (hav) recovered from a naturally infected captive owl monkey, is indistinguishable from human hav in polyclonal radioimmunoassays and cross-neutralization studies. however, cdna-rna hybridization has suggested a significant difference at the genomic level between pa21 and a reference human virus, hm175. further characterization of this unique hav was undertaken in an effort to determine the extent of genetic divergence from human hav and its relation to the co ... | 1989 | 2552172 |
| effect of isoflavans and isoflavenes on the infection of frp/3 cells by hepatitis a virus. | the effect of 6,4'-dichloroflavan and of isoflavan and isoflavene derivatives on hepatitis a virus (hav) infection in a monkey cell line (frp/3 cells) was studied. these compounds were not virucidal and had no measurable effect on the adsorption of virus to the cells at 0 degrees c, whereas they exerted an inhibitory effect on viral antigen synthesis when incubated with the infected cells during hav multiplication. among the substances tested, 6,4'-dichloroflavan and 6,4'-dichloroisoflavan showe ... | 1989 | 2552913 |
| investigation of an outbreak of hepatitis a simplified by salivary antibody testing. | in march 1988 a general practitioner notified two cases of hepatitis a in a private boarding school. epidemiological investigation, including testing for salivary antibodies revealed a further five cases and established immunity to, and recent infection with, hepatitis a virus (hav). the pattern of the outbreak was described. a number of practices which would encourage cross-infection were corrected. normal human immunoglobulin was given to contacts. repeat salivary testing 10 weeks later reveal ... | 1989 | 2553465 |
| attenuation and cell culture adaptation of hepatitis a virus (hav): a genetic analysis with hav cdna. | rna transcripts of hepatitis a virus (hav) hm-175 cdna from attenuated, cell culture-adapted hav were infectious in cell culture. a full-length hav cdna from wild-type hav (propagated in marmosets in vivo) was constructed. chimeric cdnas that contained portions of both wild-type and attenuated genomes were produced. oligonucleotide-directed mutagenesis was used to engineer a point mutation into the vp1 gene of attenuated hav cdna, so that the sequence of this capsid protein would be identical to ... | 1989 | 2555561 |
| detection of defective genomes in hepatitis a virus particles present in clinical specimens. | hepatitis a virus (hav) particles harbouring a physically defective rna genome have been reported to occur in all hav-infected cell culture systems analysed so far. the most prominent defects consist of three distinct overlapping deletions in the region of the hav genome encoding the structural proteins. by probing for the endpoints of these deletions in rna samples using s1 nuclease and exonuclease vii mapping, we obtained suggestive evidence for the existence also of defective genomes in hav p ... | 1989 | 2558163 |
| hepatitis a antibodies: prevalence in saudi arabia. | hepatitis caused by hepatitis a virus (hav) occurs at a variable prevalence in different countries, and the exposure to hav is as high as 100% in some areas. there appears to be a close association between the prevalence of anti-hav and socioeconomic status and age. in this paper, we report the prevalence of antibody to hav (anti-hav) in five regions covering different parts of saudi arabia. the results of this study show that the overall prevalence of anti-hav is 96% and 95.1% in the total male ... | 1989 | 2558227 |
| comparison of ozone inactivation, in flowing water, of hepatitis a virus, poliovirus 1, and indicator organisms. | in steadily flowing water at 20 degrees c and ph 7, five organisms had the following order of resistance to ozone (at constant levels of ozone): poliovirus 1 (pv1) less than escherichia coli less than hepatitis a virus (hav) less than legionella pneumophila serogroup 6 less than bacillus subtilis spores. the tests were repeated at 10 degrees c with hav, pv1, and e. coli. ozone inactivation of hav and e. coli was faster at 10 degrees c than at 20 degrees c. at 20 degrees c, 0.25 to 0.38 mg of o3 ... | 1989 | 2560362 |
| immunogenicity of a killed hepatitis a vaccine in seronegative volunteers. | 32 volunteers who lacked antibody to hepatitis a virus (hav) received, at intervals of one month, three injections of a killed vaccine made from hav propagated in diploid human fibroblast cell cultures. in 16 the vaccine was coupled with aluminium hydroxide as adjuvant. the serconversion rates measured by radioimmunoassay, with and without adjuvant respectively, were 13% and 25% at four weeks, 81% and 89% at eight weeks, and 94% and 100% at twelve weeks. four weeks after the third injection all ... | 1989 | 2565998 |