bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in frequency of natural reinfection with influenza A viruses
Authors: Frank Arthur L. , Taber Larry H. 
Published: March 2007

AbstractTo investigate the frequency of natural reinfection with influenza A viruses, 55 children followed from birth along with the 44 other children and 85 adults in their families were observed for varying periods between 1975 and 1981 in the Houston Family Study. Persons infected in 1976 or early 1977 with influenza A subtype H3N2 experienced a high rate of reinfection during the 1977–78 season (63% in one group of young children) and additional reinfections in 1980–81. Persons in whom H3N2 infection was first observed in 1977–78 had little or no reinfection in 1980–81; one reinfection was observed in 1980–81 among 19 young children at risk. Only one reinfection with influenza A subtype H1N1 was observed following introduction of the virus in early 1978 despite exposure in 1978–80 and a substantial outbreak in 1980–81. Statistically significant protection from reinfection in young children followed from birth was not noted for the 1977–78 H3N2 outbreak but was present in 1979–81 for both H3N2 and H1N1 viruses. Reasons for variations in reinfection suggested by this data include (1) socioeconomic and other factors influencing intensity of exposure, (2) age at primary infection, (3) varying degrees of antigenic difference between sequential variants of a major subtype, and (4) unrecognized immunogenicity or virulence differences between subtypes and variants.
Attenuated marmoset herpesvirus isolated from recombinants of virulent marmoset herpesvirus and hybrid plasmids
Authors: Kit Saul , Qavi Hamida , Dubbs Del Rose , Otsuka Haruki 
Published: March 2007

AbstractMarmoset herpesvirus (MarHV) deletion mutants in the thymidine kinase (TK) gene were isolated after infection of OMK cells with TK+ MarHV DNA and the hybrid plasmid, pMAR401, which lacks a 2.6‐kb KpnI‐M fragment in the coding region of the MarHV TK gene. After plaque purification in TK− HeLa(BU25) cells, the DNA's from five recombinant araT‐resistant MarHV clones were analyzed with restriction nucleases to verify that the 2.6‐kb KpnI‐M fragment (and a 0.9‐kb Bg1II‐Q fragment) were deleted from the viral DNA's. Molecular hybridization experiments using 32P‐labeled pMAR4 probes and viral DNA fragments also showed that the recombinant viral DNA's lacked the KpnI‐M and Bg1II‐Q fragments, that BamHI‐I of parental virus was shortened, and that three new HindIII fragments replaced the parental virus HindIII‐G fragment. The recombinants did not induce TK activity in LM (TK−) cells. To study the relative virulence of the recombinants, 3‐week‐old Swiss mice were injected intracerebrally (Ic) or subcutaneously (Sc) in the sacro‐lumbar region with either parental or recombinant viruses. The LD50 for the parental virus was 3 p.f.u. (Ic) and 7,600 p.f.u. (Sc). The recombinant viruses were significantly less virulent than TK+ MarHV after Ic inoculation (LD50 of 62,000 and 32,000 p.f.u., respectively, for viruses 5D‐6B and 5D‐4B) and gave no fatalities after Sc inoculation. Mice surviving TK− MarHV infections were protected from challenge with TK+ parental MarHV. Recombinant TK− MarHV's may be useful as vectors for the expression of foreign genes in animal cells and as the starting material for the design of vaccines.
Detection of a human rotavirus strain different from types 1 and 2—A new subgroup? epidemiology of subgroups in a swedish and an ethiopian community
Authors: Tufvesson B. 
Published: March 2007

AbstractA possible new subgroup of human rotavirus was found by crossed immunoelectrophoresis and enzyme‐linked immunosorbent assay. The epidemiology of the established subgroups 1 and 2 and this new variant was studied in two different communities. Of 398 rotavirus isolates from Malmö, Sweden, 26.8% were of type 1, 71.7% of type 2, and 1.5% of the new variant. Corresponding figures for 384 samples from Addis Ababa, Ethiopia, were 33.1% type 1 and 66.9% type 2. A total of 87% of the Swedish and 79% of the Ethiopian rotavirus‐positive samples could be classified. The yearly distribution of the subgroups was stable and similar in Sweden and Ethiopia. The new variant could only be found in one outbreak during 1979. Among children with sequential infections eight of ten primary infections were type 1, and no one shed the same type of rotavirus twice.
Inhibition by acyclovir of herpes simplex virus type 2 morphologically transformed cell growth in tissue culture and tumor‐bearing animals
Authors: Kucera Louis S. , Furman Phillip A. , Elion Gertrude B. 
Published: March 2007

AbstractRat embryo fibroblasts (REF) morphologically transformed by herpes simplex virus type 2 (HSV‐2) and tumor‐derived cells were tested for ability to grow in the presence of 9‐(2‐hydroxyethoxymethyl) guanine (acyclovir). Results indicated that the effective dose of acyclovir (ACV) required to inhibit HSV‐2‐transformed and tumor‐derived cell growth by 50% (ED50) compared to mock‐treated control cells averaged 15 to 75 μg/ml. In contrast, the ED50 of acyclovir was more than 250 μg/ml for nontransformed REF, retrovirus‐transformed rat cells, and human HEp‐2 cells. HSV‐2‐transformed and tumor‐derived cells after both low (less than 30) and high (greater than 30) serial passages expressed detectable levels of the virus‐coded thymidine kinase (TK) measured in cell extracts by serum neutralization assay. HSV‐2‐transformed or tumor‐derived cells converted two‐ to ten‐fold more acyclovir to phosphorylated forms than nontransformed REF cells. Preliminary data showed that the drug inhibited tumor development in newborn syngeneic rats inoculated with HSV‐2‐transformed cells. The inhibitory activity of acyclovir and presence of low levels of HSV‐2 TK activity appeared to correlate.
Disseminated neonatal echovirus 11 disease following antenatal maternal infection with a virus‐positive cervix and virus‐negative gastrointestinal tract
Authors: Reyes Milagros P. , Ostrea Enrique M. , Roskamp Jacqueline , Lerner A. Martin 
Published: March 2007

AbstractAn infant girl was born apparently well one week after her mother had had a mild illness with chills, fever, and diarrhea. On the third day of life, the infant became ill and died four days later with necrotizing hepatitis. On the same day, echovirus type 11 was recovered from the throat, rectum, and buffy coat of the infant and from the cervix of the mother. At this time, the mother had an IgM neutralizing antibody titer to echovirus type 11 of 1:128, but no IgG antibodies. The infant had no echovirus type 11 antibodies. The virus was also isolated from the baby's liver and adrenal at autopsy. These findings raise the possibility of enterovirus infection at delivery from a contaminated cervix.
Hepatitis A and hepatitis B virus infection in children and adolescents in North‐East Italy
Authors: Chiaramonte M. , Floreani A. , Silvan C. , Zampieri L. , Trivello R. , Renzulli G. , Moschen M. , Naccarato R. 
Published: March 2007

AbstractThe sera of 722 children and adolescents without overt liver disease were tested for hepatitis B surface antigen (HBsAg), antiHBs and anti‐hepatitis B core antiHBc; 658 of the sera were also tested for anti‐hepatitis A virus anti‐HAV. Except for the “passive” antibody peak observed in babies, the anti‐HAV age‐specific prevalence was negligible until the age of 3; it then increased, reaching 35% by the age of 15. Serological evidence of HBV was present in 16% of the subjects: this prevalence was almost constant at all ages. The HBsAg carrier rate was highest in children under 5 years of age (7.6%) and decreased with age. However, only one HBsAg carrier was under 1 year of age. Anti‐HBs age‐specific prevalence increased progressively from 2.7% to 11.4%. Anti‐HBc alone was present in 4.1% of the subjects. No significant sex differences were found in the prevalence of HBV serum markers or in the HBsAg carrier rate. Neither HAV nor HBV infection was significantly influenced by place of residence or socioeconomic status. It is concluded that in this area both HAV and HBV are endemic, but while HAV is mainly acquired at school, most of HBV infections occur within the household. The results suggest that not only perinatal transmission, but also intrafamilial horizontal infection, plays a role in HBV spread among infants.
Measles virus‐specific IgM antibodies in sera from patients with chronic active hepatitis
Authors: Christie K. E. , Haukenes G. 
Published: March 2007

AbstractThe occurrence of measles virus‐specific IgM antibodies in sera from patients with chronic active hepatitis not caused by Hepatitis B virus was examined by a specific enzyme‐linked immunosorbent assay (ELISA). Using whole serum, specific IgM antibodies were detected in 12 of 23 sera from patients with hepatitis B surface antigen (HBsAg)‐negative chronic active hepatitis. In nine of these sera the finding of specific IgM antibodies was verified by separation of IgM by density gradient centrifugation and examination of the fractions by ELISA.Most of the sera from the patients with measles virus‐specific IgM antibodies had an elevated level of specific IgG antibodies compared to the level of IgG found in control sera.The significance of these findings in view of a possible persistent measles virus antigen production in patients with chronic active hepatitis is discussed.
Mixed infection with human cytomegalovirus and human polyomavirus (BKV)
Authors: Goldstein Simoy C. , Tralka Tommie S. , Rabson Alan S. 
Published: March 2007

AbstractMixed infection, the infection of a single cell by two distinguishable viruses, has been demonstrated electron microscopically in human embryo lung (HEL) and human embryo kidney (HEK) cells infected with human cytomegalovirus (HCMV) and human polyomavirus (BKV). There was no evidence of enhancement of HCMV by BKV in either cell system; however, in HEL cells under certain conditions, HCMV enhanced the growth rate of BKV. Since both BKV and HCMV are often found in the urine of immunosuppressed patients, the enhancement of BKV by HCMV may be of clinical significance.
Detection of varicella‐zoster virus by dot‐blot hybridization using a molecularly cloned viral DNA probe
Authors: Seidlin Mindell , Takiff Howard E. , Smith Holly A. , Hay John , Straus Stephen E. 
Published: March 2007

AbstractVaricella‐Zoster Virus (VZV) infection can be definitively diagnosed by isolation of virus in cell culture, a process that usually takes 7–14 days. In order to facilitate the more rapid detection of this virus, we developed a technique for hybridization of DNA from clinical specimens using an in vitro‐labeled mixture of cloned fragments of VZV DNA as a probe. The assay can be completed in 36–48 hr and can be successfully carried out in the range of 10 pg to 10 ng of viral DNA. In analyses of 38 specimens from patients with a clinical diagnosis of VZV infection, the results of viral isolation and this assay were highly concordant. The sensitivity of standard cell culture for detection of VZV was 58%, whereas the sensitivity of the assay was 76%, not significantly different (P = 0.14). The specificity of cell culture was 100%, whereas that of the assay was 94% (P = 0.49). The technique appears to be sensitive, specific, and useful for analyses of tissues and body fluids.
The behaviour of recent isolates of human respiratory coronavirus in vitro and in volunteers: Evidence of heterogeneity among 229E‐related strains
Authors: Reed Sylvia E. 
Published: March 2007

AbstractStrains of human coronavirus (HCV) isolated between 1974 and 1976 have been studied in vitro and in volunteers. All strains caused colds in volunteers, and those cultivable in tissue culture (TC) produced significantly more coryza and less sore throat than strains growing only in organ culture (OC). The TC strains were serologically related to 229E, but these isolates produced colds with a frequency and severity that contrasted with the effects of 229E itself. Tests on volunteers' preinfection sera showed that the prevalence of antibody to 229E had increased during the period 1961–1979 and that during 1977–1979 only 11% of subjects had no neutralising antibody against 229E. Susceptibility to the 229E‐related isolates PR and TO was associated with low preinfection serum neutralising antibody against the homologous virus, and paired sera frequently showed fourfold or greater antibody rises, most commonly against the homologous strain. Volunteers infected with TO were immune when reinoculated with the same strain approximately 1 year later, but other similar volunteers were at least partly susceptible to infection with a heterologous 229E‐related virus after similar time intervals. Although the strains of HCV that were grown in tissue culture were all related to the prototype 229E, they appeared not to be identical with it, and this heterogeneity is probably a significant factor in the epidemiology of HCV infections.
Hemagglutination by human rotavirus strains
Authors: Kitaoka Setsuko , Suzuki Hiroshi , Numazaki Toshio , Sato Tetsuo , Konno Tasuke , Ebina Takusaburo , Ishida Nakao , Nakagomi Osamu , Nakagomi Toyoko 
Published: March 2007

AbstractHuman rotavirus isolates, KUN, MO, and Wa strains were found to agglutinate erythrocytes of the day‐old chicken and adult goose, optimally at pH 6.6. Only those fractions containing double‐shelled rotavirus particles isolated by isopycnic centrifugation in cesium chloride had hemagglutinating activity. Trypsin treatment decreased the hemagglutination titer of human rotavirus strains and conversely increased their infectivity. Hemagglutination inhibition tests with antisera against type‐specific antigens demonstrable by neutralization showed no type specificity.
Evaluation of cold‐adapted adn temperature‐sensitive mutants of parainfluenza virus type 3 in weanling hamsters
Authors: Crookshanks Frances K. , Belshe Robert B. 
Published: March 2007

AbstractCold‐adapted (ca) and temperature‐sensitive (ts) mutants of parainfluenza virus 3 were produced by serially passaging wild type (wt) parainfluenza virus 3 at 20°C 45 times. Previously, plaque‐purified viruses (clones) were selected from the wt parent and from cold passage levels 7, 12, 18, and 45 and characterized in vitro. In the present study, we evaluated at least one mutant from each cold passage level for attenuation in hamsters. Four of the five mutants tested were ts and ca (one each from cold passage levels 7, 12, 18, and 45) and one was ca but not ts (from cold passage 18). Groups of hamsters were inoculated intranasally with either parent wt or mutant virus. Four or five hamsters from each group were sacrificed prior to inoculation and daily on the first, second, third, fourth, and sixth or seventh day postinoculation and the amount of virus in nasal turbinates and lungs was quantitated. The quantity of virus recovered from the hamsters and the parainfluenza virus 3 antibody titers were inversely related to the cold passage level. Two of the mutants did not replicate in hamsters. Cold adaptation of parainfluenza virus 3 resulted in progressive attenuation of the virus in weanling hamsters. These highly attenuated mutants are suitable for evaluation in children as live virus vaccines.
Absence of IgG Fc receptors on varicella‐zoster virus‐infected cells
Authors: Ishak Ricardo , Andiman Warren A. , Tucker Grace 
Published: March 2007

AbstractHerpesvirus‐infected cells usually express receptors for the Fc portion of immunoglobulin G. Varicella‐zoster virus has so far been the sole exception in the family. Both immunehemadsorption and immunofluorescence techniques failed to detect the expression of such receptors. This observation excludes the possibility of false‐positive results in serological tests for antibodies to this virus. It is possible that the function of these receptors early in infection is not needed in the subsequent reactivation(s) of the virus. No variation has been shown to occur with different isolates.
Altered hemolysis in single radial hemolysis from a single serum sample as an indicator of recent primary rubella virus infection
Authors: Hedman Klaus , Räihä Kirsti , Meurman Olli , Vaheri Antti 
Published: March 2007

AbstractThe quality of hemolysis in the single radial hemolysis (SRH) test was observed to be altered in a small proportion (5.7%) of Sera (N = 9628) studied for rubella antibodies. Three different types of altered hemolysis were identified. Two of these types, the “soft margin” (SM) or the “soft zone” (SZ), occurred singly or in combination in 97% of paired sera (N = 321) taken 3–30 days after primary rubella infection (diagnostic seroconversion). For comparison, diagnostic inercases of rubella antibodies (N = 77), including both primary and reinfections, contained these types of altered hemolysis in 80% of the cases. Of the remaining 20% of the samples (N = 15) rubella antibodies of IgM class were looked for in seven cases but not found. After primary rubella, SZ was always present in the first serum sample and disappeared rapidly within 20 days while SM persisted longer. The predictive value of the different types of hemolysis was estimated from 96 primary sera, which had altered hemolysis. In this material, SZ was followed by a diagnostic increase of antibodies in 87% of the cases; the prognostic value of the SM was significant but lower. These data show that the appearance of SM or SZ in a single serum sample is a useful marker of recent primary rubella. On the other hand, a normal hemolysis in SRH can be used to exclude recent primary rubella, but not reinfection, with a high degree of probability.
Immune responses to live attenuated and inactivated mumps virus vaccines in seronegative and seropositive young adult males
Authors: Ilonen J. , Salmi A. , Tuokko H. , Herva E. , Penttinen K. 
Published: March 2007

AbstractLive attenuated mumps virus vaccine and Formalin‐inactivated mumps vaccine were compared for their ability to induce antibody responses and cell‐mediated immune responses as measured by a lymphocyte blast transformation test (LBT). The subjects studied were conscripts of the Finnish Defense Forces. In seronegative subjects antibody levels induced by attenuated virus were more variable than those induced by inactivated virus, including one failure with the live vaccine out of a total of nine subjects. IgM antibody class response was seen only in four of nine subjects vaccinated with live virus—in those subjects with the highest post vaccination antibody levels and strongest LBT responses. Increases of antibody levels in originally seropositive subjects were higher in subjects vaccinated with inactivated virus. Cell‐mediated immunity induced by both vaccines was relatively poor when measured by the LBT test. At a time of 6–8 months after vaccination, LBT responses in originally seronegative subjects were not observed.
Age‐specific prevalence and significance of hepatitis B e antigen and antibody in chronic hepatitis B virus infection in taiwan: A comparison among asymptomatic carriers, Chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma
Authors: Liaw Yun‐Fan , Chu Chia‐Ming , Lin Deng‐Yn , Sheen I‐Shyan , Yang Chaur‐Young , Huang Miau‐Ju 
Published: March 2007

AbstractThe age‐specific prevalence of hepatitis B e antigen (HBeAg) and its antibody (anti‐HBe) were studied by radioimmunoassay, and compared in a large series of patients with chronic hepatitis B virus (HBV) infection, including 268 asymptomatic carriers. 389 chronic hepatitis, 114 liver cirrhosis, and 278 hepatocellular carcinoma (HCC). The prevalence of HBeAg/anti‐HBe in asymptomatic carriers and patients with chronic hepatitis correlated closely with age as HBeAg prevalence decreased and anti‐HBe prevalence increased with increasing age (P < 0.0005), and is probably due to high infection rate at young age in Taiwan. The prevalence of HBeAg in patients with both cirrhosis and HCC are much significantly lower and had no correlation with age. Two peaks of age‐specific prevalence of HBeAg and anti‐HBe were observed in patients with HCC, implicating two patterns of HBV infection in these patients. The difference in the prevalence of HBeAg and anti‐HBe might indicate that asymptomatic carriers, chronic hepatitis, liver cirrhosis, and HCC are sequential sequelae of HBV infection.
Cytomegalovirus infection after bone marrow transplantation: Relation of pneumonia to postgrafting immunosuppressive treatment
Authors: Skinhøj P. , Andersen H. Kerzel , Møller J. , Jacobsen N. 
Published: March 2007

AbstractFive fatal cases of CMV associated interstitial pneumonia occurred among 20 patients who had received allogenic bone marrow transplantation for acute leukemia or aplastic anaemia. This outcome was analysed in relation to prospectively obtained data on complement fixing (CF) and IgM anti‐CMV litres and excretion of CMV in urine or pharynx. Altogether 16 patients had primary or reactivated CMV infection. Five of these patients receiving corticosteroids at the time of infection, at a dose of more than 1 mg/kg/day, failed to mount a significant CF antibody response, excreted large amounts of virus, and died from pneumonia, while the remaining 11 infected patients obtained high CF antibody titres and showed no severe symptoms related to CMV infection. IgM antibodies occurred simultaneously with CF anlibodies in most cases of primary and reactivated infection. The results of the study suggest a protective role of the humoral immune response to CMV infection in BMT recipients, and passive immunisalion with CMV hyperimmune globulin should be attempted especially in patienls given additional immunosuppression with high dose corticosteroids.
Production of subgroup‐specific monoclonal antibodies against human rotaviruses and their application to an enzyme‐linked immunosorbent assay for subgroup determination
Authors: Taniguchi Koki , Urasawa Tomoko , Urasawa Shozo , Yasuhara Toshio 
Published: March 2007

AbstractNonneutralizing monoclonal antibodies were prepared against two strains, S2 and YO, of human rotaviruses isolated in cell culture. S2‐37 and YO‐5 antibodies had subgroup I and subgroup II specificities, respectively. The remaining antibodies (S2‐65, YO‐71, YO‐89, and YO‐156) reacted commonly with all the rotaviruses examined. All of the monoclonal antibodies agglutinated exclusively single‐shelled particles and immunoprecipitated 42,000‐dalton protein, a major component of inner capsid.Using the three monoclonal antibodies (S2‐37, YO‐5, and YO‐156), an enzyme‐linked immunosorbent assay was developed for detecting and subgrouping human rotavirus isolates.
Isolation and identification of enteroviruses from faecal samples in a differentiated epithelial cell line (HRT‐18) derived from human rectal carcinoma
Authors: Patel J. R. , Daniel J. , Mathan M. , Mathan V. I. 
Published: March 2007

AbstractA human rectal carcinoma‐derived differentiated epithelial cell line, HRT‐18, was inoculated with faecal samples in an attempt to grow coronavirus‐like particles (CVLP), which are widely prevalent in human stools in southern India. While CVLP did not grow in this cell line, a variety of enteroviruses were isolated from 48 of the 114 stool samples from healthy controls and patients with diarrhoea. The results suggest that human gastrointestinal tumour‐derived differentiated epithelial cells in continuous culture may be useful for the primary isolation of enteroviruses and merit further study.