bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection and characterization of hepatitis B virus DNA in serum of HBe antigen‐negative HBsAg carriers
Authors: Tur‐Kaspa Ran , Keshet Eli , Eliakim Marcel , Shouval Daniel 
Published: March 2007

AbstractSera from 153 Israeli patients in various stages of hepatitis B virus (HBV) infection with undetectable hepatitis Be antigen (HBeAg) were studied for the presence of HBV DNA in the serum by molecular hybridization. HBV DNA was detected in 10 patients: 3 with acute hepatitis, 4 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 1 with chronic active hepatitis, 1 with cirrhosis, and 1 with mixed cryoglobulinemia. HBV DNA was detected in 7 of 10 HBeAg‐positive control samples tested. Hybridization analysis was used for quantitative comparison of HBV DNA levels in serum. HBV DNA levels, found in HBeAg‐negative patients sometimes exceeded the levels found in HBeAg‐positive patients. Restriction enzyme analysis of serum HBV DNA from four HBeAg‐negative samples gave undistinguishable digestion patterns as compared to 3 HbeAg‐positive samples. However, heterogeneity in HBV DNA restriction fragments was detected among HBV genomes in sera of HBeAg‐positive samples. These data demonstrate that HBV DNA may be present in the serum at various stages of HBV infection, regardless of HBeAg detection. Failure to detect HBeAg in these patients does not necessarily reflect low serum levels of viral particles, or the occurrence of HBV genome variants.
Genome variants of adenovirus 41 (subgroup G) from children with diarrhoea in South Africa
Authors: Kidd A. H. 
Published: March 2007

AbstractFifteen strains of faecal adenovirus from 3 continents (4 from Europe, 4 from Canada, and 7 from South Africa) were typed as Ad41a by restriction enzyme analysis of the DNA using Sma I. The DNA of the strains was further compared by digestion with 9 other restriction enzymes. All strains had the same cleavage sites for enzymes Bam HI, Bgl I, Sst I, Pvu II, and Xho I, indicating a close relationship. The Canadian and European strains also had the same cleavage sites for Hind III, Eco RI, Bst EII, and Kpn I, within the limits of resolution of the technique. Only one of the 7 South African strains had a combination of restriction sites identical to the European and Canadian strains, whereas Hind III, Eco RI, Bst EII, and Kpn I digests of the other 6 South African Ad41 DNAs showed the existence of 4 other genome types of Ad41. All 15 Ad41a strains studied were easily distinguished from Ad40 strains using any of the 10 restriction enzymes.
Dynamics of viral growth, viral enzymatic activity, and antigenicity in murine lungs during the course of influenza pneumonia
Authors: Astry Calvin L. , Yolken Robert H. , Jakab George J. 
Published: March 2007

AbstractMice were infected by aerosol inhalation with influenza A/PR8/34 virus, and the kinetics of infection were monitored by the measurement of infectious virus, viral neuraminidase activity, and viral antigen as detected by enzyme immunoassay. Pulmonary levels of neuraminidase activity closely paralleled the infectious titers quantitated by standard egg inoculation techniques. Both viral neuraminidase activity and viral antigen increased in a dose‐dependent manner during the early stages of the viral infection. After day 5, however, viral neuraminidase activity precipitously declined, whereas viral antigen levels remained elevated at high concentration for up to 60 days. Immunosuppressive treatment with cyclophosphamide resulted in the prolonged maintenance of peak virus titers without any additional increases in viral antigen. Previously infected mice were resistant to reinfection with homologous virus as evidenced by the lack of detectable viral neuraminidase activity and the lack of generation of additional viral antigen. These data define the temporal relationship between levels of infectious virus, neuraminidase activity, and viral antigen in an experimental model of influenza virus infection.
Immune response of adults to sequential influenza vaccination
Authors: Powers Robert D. , Hayden Frederick G. , Samuelson Joel , Gwaltney Jack M. 
Published: March 2007

AbstractAnnual immunization against influenza is recommended for numerous individuals, but the antibody response to sequential vaccination has not been well characterized. Levels of hemagglutination‐inhibition antibody were measured in adults given either two or three doses of trivalent influenza vaccine at six‐month intervals. A significant rise in the number of individuals with antibody titers of ≥40 was seen for all three antigens only after initial vaccination. Repeated vaccination was necessary to maintain adequate antibody levels only to the A/Brazil (H1N1) antigen; it did not significantly affect the proportions of individuals with protective levels of antibody to either the A/Bangkok (H3N2) or the B/Singapore 222/79 antigens. These findings do not support the current recommendation for annual immunization when the vaccine formulation has not changed.
Antibody responses to mumps virus proteins in natural mumps infection and after vaccination with live and inactivated mumps virus vaccines
Authors: Julkunen Ilkka , Väänänen Pertti , Penttinen Kari 
Published: March 2007

AbstractPaired sera from 20 patients with acute mumps infection, 16 from persons vaccinated with live attenuated mumps virus vaccine, and 12 from persons vaccinated with formalin‐inactivated virus vaccine were studied for mumps antibodies by single radial hemolysis (SRH), hemagglutination inhibition (HI), and by enzyme immunoassays (EIA) specific for whole virus, envelope glycoprotein, and nucleocapsid antibodies. Mumps patients had diagnostic rises in serum mumps antibodies in 90–100% of the cases depending on the method of assay. Vaccination resulted in seroconversion in 75–88% (live vaccine) and in 92% (inactivated vaccine) of the cases as detected by SRH or EIAs, whereas HI detected seroconversion only in 38% and 58% of the cases, respectively.Immunoprecipitation analyses revealed that all sera from mumps patients and nearly all postvaccination sera had antibodies against the main structural proteins of mumps virus. By immunoblotting, antibodies against denatured hemagglutinin‐neuraminidase (HN) and fusion protein (F) were detected in 15–25 % of mumps patients and persons vaccinated with live vaccine, whereas most postvaccination sera from those vaccinated with inactivated vaccine had HN (92%) and F (83%) protein antibodies, suggesting that antibodies against the denatured form of proteins are formed.
Human spumavirus replication in human cells
Authors: Loh Philip C. , Matsuura Faye M. 
Published: March 2007

AbstractIt was previously reported that the replication of the human syncytium‐forming virus (HSFV), a spumavirus, occurred only in fibroblast‐like cell lines (human fetal diploid lung #645 [HFDL]) but not in epithelial‐like lines (recovered amnion) [RA]. Factors that may be involved in such a phenomenon were the subject of this investigation. While both permissive (HFDL) and nonpermissive (RA) cell lines supported the replication of several representative animal viruses and adsorbed HSFV equally well, immunofluorescent staining of HSFV antigens revealed markedly fewer fluorescing cells in nonpermissive cultures. Infectious center assays of infected nonpermissive cells indicated the formation of significantly fewer infectious centers. The rate of DNA synthesis was markedly greater in the permissive cell lines. In addition, in the permissive cell line, the amount of proviral DNA revealed by the Hirt procedure and isopycnic banding in CsCl was significantly increased and was infectious as determined by the calcium phosphate‐DMSO transfection assay. These results indicate that resistance of HSFV infection in nonpermissive cell cultures is probably an intracellular event.
An enzyme‐linked immunosorbent assay (ELISA) for IgG and IgA antibodies to respiratory syncytial virus in low dilutions of secretions of human serum and secretions
Authors: Nandapalan N. , Routledge E. , Toms G. L. 
Published: March 2007

AbstractAn enzyme‐linked immunosorbent assay (ELISA) has been developed for titration of IgG and IgA antibodies to respiratory syncytial (RS) virus in low dilutions of human serum, colostrum, and nasopharyngeal secretions. Previously the sensitivity of RS virus ELISA on such specimens has been limited by nonspecific absorption of antibody, particularly IgA, to crude antigen preparations.For IgG antibody estimation in infant sera, this unwanted binding was reduced to workable levels by increasing the serum, salt, and detergent concentration of the diluent. Residual nonspecific binding of IgA in colostra appeared mainly due to antigen lipids or to lipoproteins. This was markedly reduced by partitioning Triton X‐100‐treated infected cell lysate antigens in Arklone.Using the modified ELISA technique for anti‐RS virus IgA, good correlations were found with unfixed cell membrane immunofluorescence (MIF) for colostra (r = 0.81, P < 0.001) and nasal secretions from adult volunteers. In several samples nonspecific absorption of antibody precluded MIF assay, but did not affect the ELISA. Although there was an overall correlation between ELISA for anti‐RS IgG antibody in sera, the complement fixation test (r = 0.75, P < 0.001), and MIF test (r = 0.82, P < 0.001), the sensitivity of ELISA for antibody responses in convalescent sera of infants from 3 months to 2 years was poor. Conversely, the sensitivity of ELISA for antibody in the sera of older children and for transplacentally acquired antibody in very young infants was higher than that for the other two tests. ELISA was thus less reliable than either CF or MIF for detecting antibody rises in paired infant sera, particularly where maternally acquired antibody remained in the acute serum. The reasons for this apparent disparity are discussed.
Cellular immune response to infection with respiratory syncytial virus and influence of breast‐feeding on the response
Authors: Mito Kazuaki , Chiba Yasuo , Suga Kazuhiro , Nakao Tooru 
Published: March 2007

AbstractVirus‐specific lymphocyte transformation (LTF) activity in vitro was examined in 78 infants with various forms of illness due to respiratory syncytial virus (RSV) infection. In 73 subjects with lower respiratory tract disease, significant LTF activity was often detected within one week after onset of initial symptoms, and responses characteristic for each clinical form were observed in the subsequent rise. Thus, mean activity in subjects with tracheobronchitis increased gradually, with the maximum response being detected at the fourth week after the onset of illness. In subjects with pneumonia the response was rather low during the first week of illness, and then a sharp increase of activity was observed at the second week. Although patients with bronchiolitis elicited similar levels of the activity until the first week, the response was significantly suppressed during the subsequent two weeks. The response at the second week in this group was significantly lower than those of corresponding specimens obtained from patients with pneumonia (p < 0.01) or tracheobronchitis (p < 0.05), suggesting a close association of the responsiveness with underlying mechanisms of bronchiolitis induced by RSV. The present study further indicated a possibility that breast‐feeding of RSV‐infected infants may alter levels of the LTF activity in these subjects.
Local and peripheral cell‐mediated immune response to influenza virus in mice
Authors: Shapira‐Nahor Orit , Zakay‐Rones Zichria 
Published: March 2007

AbstractPresentation of different influenza virus antigens generates different immune responses. Intranasal immunization with either live (VA) or formalin‐inactivated (VF) A/PR/8/34 (HoN1) influenza virus induced local as well as peripheral cell‐mediated immune response (CMI), as evidenced by elevation in 3H‐thymidine incorporation. Cell‐mediated immune response was detected as soon as 24–48 hr following the application of VA and 4–5 days following VF. Cell‐mediated immune response in both instances peaked on the 12th day and disappeared between 16 and 20 days after application.Local CMI response was threefold higher after immunization with VA (SI = 28.6) than with VF (SI = 9.4), while VF induced higher peripheral response (32.0 vs 17.7). The mononuclear cell population in the lungs increased, correlating with a rise in the stimulation index (SI). The percentage of IgA surface‐bearing B lymphocytes was significantly higher following IN administration of VA, but not following VF instillation. This corroborated the finding that VF failed to induce local antibody response in the lungs in spite of its capacity to stimulate humoral antibody and CMI responses.Mice immunized intramuscularly with both viral preparations developed a fair humoral antibody response without detectable CMI (peripheral or local).
Attenuated Junin virus infection in callithrix jacchus
Authors: Avila Dra. M. M. , Frigerio M. J. , Weber E. L. , Rondinone S. , Samoilovich S. R. , Laguens R. P. , de Guerrero L. B. , Weissenbacher M. C. 
Published: March 2007

AbstractTwenty marmosets, male Callithrix jacchus, were used during this study. Fifteen of the marmosets were inoculated with 5,000 TCID50 of the attenuated XJCl3 strain of Junin virus by intramuscular route and five were left as uninoculated controls. Animals were observed for a 420‐day period. In order to carry out virologic, hematologic, serologic, and histologic studies the animals were bled and/or killed at different days post infection(pi).Results obtained showed that the attenuated strain produced an infection with no mortality or signs of illness. There was only a slight loss of weight at 18–40 days pi, which was soon recovered. Viremia was present from day 6 to 22, titers peaking at 4.0 log. Viral spread was limited to the lungs, spleen, lymph nodes, and bone marrow in the animal killed on day 14. No virus was found in the organs of the animal killed on day 23, and neither hematologic alterations nor pathologic lesions were seen in these monkeys except for ganglionar hypertrophy with immunoblast proliferation. Antigen was detected by immunofluorescence (IF) in lymph nodes, spleen, adrenals, lungs and brain.Neutralizing antibodies were detected from the third week onward. Protection conferred by the XJC13 strain proved effective when XJCU–inoculated monkeys were challenged with 1,000 TCID50 of the pathogenic XJ strain at days 60 or 380 pi, while normal controls died.When viral persistence was searched for on days 370, 390, and 420 pi, no infectious virus was detected, but viral antigen was seen in certain organs, which, however, lacked tissue damage.Bearing in mind the main features differentiating the previously tested pathogenic and the attenuated strains, C jacchus may prove a useful model for testing the pathogenicity and efficacy of attenuated vaccines against Argentine hemorrhagic fever (AHF).
Neurotropism of a high‐passage XJ strain of junín virus
Authors: Oubiña José R. , Carballal Guadalupe 
Published: March 2007

AbstractGuinea pig infection with a highly passaged XJ prototype strain of Junín virus by the intramuscular route (IM) was carried out in order to study viral tropism modification in this host. The neurotropism of this strain was demonstrated by viral isolation, meningitis, and by the presence of Junin antigens as shown by immunofluorescence. These events, not previously observed with the same lower‐passaged strain, revealed the appearance of neurotropism after multiple passages in guinea pigs.
Diagnosis of human parvovirus infection by dot‐blot hybridization using cloned viral DNA
Authors: Anderson M. J. , Jones S. E. , Minson A. C. 
Published: March 2007

AbstractThe human parvovirus can be detected in serum by the immunological techniques of immune electron microscopy (IEM), counterimmunoelectrophoresis (CIE), and radioimmunoassay (RIA). A portion of the genome of this virus has been cloned in pAT153 and used as a 32P‐labelled probe in dot‐blot hybridization assays to detect parvovirus DNA in serum specimens. This test proved a highly sensitive means of detecting virus in microlitre volumes of serum, giving positive results for samples containing 0.5 pg viral DNA, equivalent to 104 virus particles. Unlike CIE and RIA the test is not affected by the presence of parvovirus‐specific antibody in serum specimens, and has permitted virus to be detected in specimens obtained up to 11 days after the onset of clinical symptoms of aplastic crisis.
Detection of human parvovirus using a molecularly cloned probe
Authors: Clewley J. P. 
Published: March 2007

AbstractHalf of the genomic DNA of the human parvovirus (B19) was cloned in the plasmid pBR322. The cloned DNA was used as a molecular probe for the detection of parvovirus in serum by means of a dot hybridization test. In an assay of 26 samples, the dot hybridization test was found to be of comparable sensitivity and to be as rapid as radioimmunoassay for viral antigen detection; it is potentially useful as a diagnostic test.
Use of enzyme‐labeled antigen for the detection of immunoglobulin M and A antibody to herpes simplex virus in serum and cerebrospinal fluid
Authors: van Loon A. M. , van der Logt J. T. M. , Heessen F. W. A. , van der Veen J. 
Published: March 2007

AbstractA direct enzyme‐linked immunosorbent assay (ELISA that used peroxidase‐labeled antigen) was developed for detection of IgM and IgA antibody to herpes simplex virus (HSV). The assay uses immuno‐affinity‐purified antihuman IgM or IgA antibody‐coated wells of microtiter plates to separate IgM or IgA from other classes of antibody in serum or cerebrospinal fluid (CSF). The presence of specific IgM or IgA is detected by subsequent, consecutive incubation with peroxidase‐labeled antigen and substrate.HSV antigen was purified by sucrose gradient centrifugation and coupled with peroxidase by the periodate method. By examining sucrose‐gradient‐fractionated sera the assays were shown to be specific for IgM and IgA classes of antibody. None of the sera from patients with Epstein‐Barr virus (n = 20), cytomegalovirus (n = 20), or varicella‐zoster virus (n = 8) infection or with both rheumatoid factor and IgG antibody to HSV (n = 13) reacted positively. Only one out of 78 sera from healthy persons was positive for IgA antibody to HSV, and none for IgM antibody.All 33 patients with HSV infection developed HSV‐IgA, 22 developed HSV‐IgM. Of the 11 patients with primary infection, all had IgM antibody in their first sera and six had IgA antibody. The corresponding figures for the 22 patients with recurrent infection were five and nine. Furthermore, HSV‐IgA antibody was found in serum and CSF of all five patients with HSV encephalitis in the second week after onset of symptoms, indicating the usefulness of the assay as a nonin‐vasive technique for diagnosing HSV encephalitis.
Antibody response to type‐common and type‐unique epitopes of herpes simplex virus polypeptides
Authors: Bernstein David I. , Bryson Yvonne J. , Lovett Michael A. 
Published: March 2007

AbstractHerpes simplex virus type 1 (HSV1) and type 2 (HSV2) polypeptides with typecommon and type‐unique epitopes were identified using cross‐adsorbed hyperimmune rabbit sera and Western blotting techniques. Twelve HSVl and fourteen HSV2 polypeptides with type‐specific epitopes were identified. Cross‐adsorbed human sera reacted to a subset of the type‐specific epitopes defined by rabbit sera. Human sera with both HSV1‐ and HSV2‐specific antibodies were identified by their reaction to HSV1 ‐type‐specific epitopes after adsorption with HSV2, and HSV2‐type‐specific epitopes after adsorption with HSV1. Mixing experiments demonstrated the sensitivity of this assay for detecting HSV2‐type‐specific anti‐body in the presence of HSV1 antibody. This technique has proven useful in the study of immune response to individual HSV polypeptides during human HSV infections, while the presence of these type‐unique epitopes on HSV polypeptides allows for the detection of type‐specific antibodies in human sera.
Secretion of polyalbumin receptors in vitro
Authors: Gilja Bal K. , Kasambalides Efthimios J. , Bressler Robert S. , Thung Swan N. , Gerber Michael A. 
Published: March 2007

AbstractThe nature of hepatitis B surface antigen (HBsAg)‐associated receptors for polymerized human serum albumin (pHSA‐R) and their relationship to hepatitis B e antigen (HBeAg) and human serum proteins have not been defined. We studied by radioimmunoassay and by electron microscopy HBsAg‐associated pHSA‐R secreted in vitro by a human hepatocellular carcinoma cell line (PLC/PRF/5) and by mouse 3T3 fibroblasts after transfection with cloned hepatitis B virus (HBV) DNA (4.10 cells). PLC/PRF/5 cells expressed only HBsAg, whereas 4.10 cells secreted also HBeAg. There was no significant difference in the production of HBsAg, HBeAg, and pHSA‐R when the cells were cultured in the presence or absence of fetal calf serum. Secretion of pHSA‐R by the two cell lines for a given amount of HBsAg was equal irrespective of the presence or absence of HBeAg. Supernatants from both cell lines grown in serum‐free medium did not contain any Clq or albumin when tested by immunodiffusion. The ability of a transfected mouse cell line to produce HBsAg with pHSA‐R activity strongly suggests that pHSA‐R is coded by the HBV genome and does not depend on the presence of human serum proteins. In addition, our findings fail to demonstrate any correlation between HBeAg production and pHSA‐R.
Incidence of hepatitis A virus (HAV) infection in rural Liberia
Authors: Prince Alfred M. , Brotman Betsy , Richardson Linda , White Tim , Pollock Nancy , Riddle Janet 
Published: March 2007

AbstractTo provide background for future hepatitis A vaccine trials, sera were collected from 0‐ to 4‐year‐old Liberian infants and their mothers on two occasions an average of 14.75 months apart and tested for antibody to hepatitis A virus (anti‐HAV).The prevalence of anti‐HAV rose from 2.5% in infants 0–6 months of age to 70% in children 3–4 years of age and did not differ between male and female infants.The annual incidence of new infections was slightly lower in the first year of life (35%) than in the subsequent 3 years, when it averaged 45%. The presence of HBV infection did not affect the incidence of HAV seroconversion. No clinical hepatitis was recognized in the subjects who seroconverted.Dual hepatitis A and B virus infection were observed; these were all clinically inapparent.The extraordinary incidence of HAV infection documented in the present study offers an opportunity for vaccine efficacy trials requiring minimal numbers of subjects.
Antibody response to Epstein‐Barr‐virus‐specific DNase in 13 patients with nasopharyngeal carcinoma in Taiwan: A retrospective study
Authors: Chen Jen‐Yang , Hwang Lu‐Yu , Yang Czau‐Siung , Beasley R. Palmer , Chien Chia‐Siang 
Published: March 2007

AbstractSerum samples obtained from 13 individuals who were found to have a previous history of or to be suffering from nasopharyngeal carcinoma (NPC) were examined for the presence of antibody to Epstein‐Barr virus (EBV) DNase activity. Significant to high levels of antibody to EBV DNase activity were detected in most serum samples obtained from four patients prior to the diagnosis of NPC. The samples from the other nine patients showed variable levels of antibody. The majority of the samples collected at the remission stage of the disease, especially those from long‐term survivors, contained little or no antibody to the DNase activity. Data presented here suggest that antibody to EBV DNase activity may be a useful marker for the early diagnosis as well as the prognosis of NPC.