bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibody‐Mediated enhancement of BK virus infection in human monocytes and a human macrophage‐like cell line
Authors: Traavik T. , Uhlin‐Hansen L. , Flægstad T. , Christie K. E. 
Published: March 2007

AbstractWe have monitored BK virus (BKV) antigen expression and multiplication in human monocytes and in a human macrophage (Mo)‐like cell line (U937) in the presence or absence of dilution series of human or rabbit anti‐BKV antisera.After infection with BKV alone, restricted expression (structural antigens and T‐antigen) and multiplication was recorded in monocytes from some donors, while in U937 cells and monocytes from other donors, no signs of viral activity were detected. Monocyte cultures established from the same donor at different times demonstrated antigen expression/multiplication on two occasions but not on the third.A pronounced enhancement of BKV expression/multiplication in human monocytes and multiplication in U937 cells was seen with some dilutions of all antisera (human and rabbit) used. The pattern of enhancement and the dilution resulting in maximum viral activity was constant and seemed to be determined by the serum, but the exact level of enhancement for a given serum differed considerably in monocytes from different donors and seemed to be determined by the cells. In the latter respect, monocytes taken from the same donor some weeks apart showed variations at the same level, as did cells from different donors. PMA (phorbol‐12‐myristate‐13‐acetate) stimulation of monocytes and U937 cells resulted in stronger antibody enhancement in terms of infectivity, without affecting the number of monocytes showing antigen expression. No expression/multiplication of BKV was detected in the murine Mo‐like cell line P338 DI.
Recombination in tissue culture between varicella‐zoster virus strains
Authors: Dohner Dennis E. , Adams Susan G. , Gelb Lawrence D. 
Published: March 2007

AbstractSeveral clinical varicella‐zoster virus isolates obtained during testing of a live varicella vaccine had DNA restriction fragment patterns resembling neither vaccine nor wild‐type virus [Gelb et al., J Infect. Dis. 155, 633–640, 1987]. One explanation for these isolates was recombination in vivo. To determine if such recombination is likely, two strains of varicella‐zoster virus, distinguishable by restriction endonuclease fragment size differences (wild‐type strain EF and the OKA vaccine strain), were grown together in tissue culture. After three passages, the mixed infection virus was plaque‐purified. DNA from about 13% of the plaque‐purified isolates had one or more BglI fragments found in neither parental virus. Hybridization studies showed that isolates containing one of the new BglI fragments were recombinants of the two parental strains. The BglI restriction fragment pattern of these recombinants resembled those of the unusual varicella isolates from individuals either vaccinated with the live attenuated OKA varicella vaccine and later exposed to natural varicella, or simultaneously exposed to both a recent recipient of the vaccine and natural varicella.
Complement‐mediated cytolytic activity associated with cytomegalovirus complement‐fixing IgM antibody
Authors: Booth J. C. , Mohammed H. S. 
Published: March 2007

AbstractCytomegalovirus‐specific complement‐fixing IgM (CMV CF‐IgM) antibody was detected in 12/84 (14.3 percent) sera containing CMV‐specific IgM. Higher titres were obtained by using a purified antigen preparation containing enveloped virus particles and membrane fragments when compared with a crude extract of infected cells, suggesting that the CF component of CMV IgM reacts predominantly with antigens on the surface of the infected cells. This also accounts for its complement‐mediated cytolytic activity. Neither CMV‐specific non‐complement‐fixing IgM nor CMV‐specific IgG demonstrates cytolytic activity.
Enhancement of hepatitis A propagation in tissue culture with 5,6‐dichloro‐1‐β‐D‐ribofuranosylbenzimidazole
Authors: Widell Anders , Hansson Bengt Göran , Nordenfelt Erik , Öberg Bo 
Published: March 2007

AbstractThe adenosine analog 5,6‐dichloro‐1‐β‐D‐ribofuranosylbenzimidazole (DRB) was found to increase the production of hepatitis A (HAV) antigen in two monkey kidney cell lines (Frhk‐4 and Vero cells). DRB, a known inhibitor of the synthesis of messenger RNA, caused moderate changes in cell morphology. However, Frhk‐4 cells could be maintained for several weeks at 80 μM of DRB, the concentration that caused maximal enhancement on HAV. DRB should be present from about the time of virus inoculation and its strongest effect was seen at low multiplicities of infection. Using radioimmunofocus assay it could be shown that DRB increased the amount of infectious virus. DRB treatment was applied in primary isolation of HAV from feces. In nine of ten strains HAV antigen expression was strongly increased and in six of the ten strains infectivity of harvested material increased by one 10log or more. DRB thus seems to be a useful enhancer of HAV growth in tissue culture.
Occurrence of cytomegalovirus hepatitis in liver transplant patients
Authors: Bronsther Oscar , Makowka Leonard , Jaffe Ronald , Demetris A. Jake , Breinig Mary Kay , Ho Monto , Esquivel Carlos O. , Gordon Robert D. , Iwatsuki Shunzaburo , Tzakis Andreas , Marsh James W. , Mazzaferro Vincenzo , Van Thiel David , Starzl Thomas E. 
Published: March 2007

AbstractThe differential diagnosis of liver dysfunction after orthotopic liver transplantation can be difficult. Cytomegalovirus (CMV) hepatitis is one possibility. This report reviews our experience with 17 cases of pathologically proven CMV hepatitis following liver transplantation and demonstrates the need for percutaneous liver biopsies to establish the diagnosis. There were seven pediatric patients (ages 2–11 years, five males, two females) and ten adult patients (ages 17–53 years, eight males, two females). The most common symptoms were prolonged fever (15 patients, with a mean duration of 22 ± 5.5 days), elevation in total bilirubin (14 patients), and elevation in liver enzymes (15 patients); all symptoms were also found in rejection. Leukopenia and thrombocytopenia, reported to frequently occur with CMV infection, were found in only three and five patients, respectively.Twelve patients with the above symptoms underwent percutaneous biopsy on one or more occasions to differentiate CMV hepatitis from rejection. The diagnosis was made at retransplantation in five patients. CMV hepatitis followed treatment for acute rejection in 14 patients and occurred without additional immunosuppression in three patients. All patients were maintained on cyclosporine and prednisone. Acute rejection episodes were treated with a 5‐day tapering dose of steroids (17 courses in 12 patients), OKT3 monoclonal antibody [Ortho (4 patients)] antithymocyte globulin [Upjohn (2 patients)], and azathioprine (1 patient).CMV was isolated from urine (nine patients), blood (nine patients), throat (seven patients), lungs (two patients), and other organs (two patients). CMV was cultured from the liver biopsy specimens in five of the seven attempts in pediatric patients. When the diangosis was confirmed in the absence of rejection, immunosuppression was routinely lowered. When rejection occurred concomitantly with CMV hepatitis, therapy had to be individualized. Retrospectively, three patients treated for rejection were noted at retransplantation to have only CMV hepatitis, and all three paients died.A high index of suspicion and the judicioususe of liver bopsies is essential in order to differentiate CMV hepatitis from other causes of posttransplant liver dysfunction.
Prevalence of genital HPV infections in a regularly screened population in the netherlands in relation to cervical cytology
Authors: Melchers Willem J. G. , Herbrink Paul , Quint Wim G. V. , Walboomers Jan M. M. , Meijer Chris J. L. M. , Lindeman Jan 
Published: March 2007

AbstractTo determine the prevalence of human papilloma virus (HPV) genotypes in relation to cervical cytology, 1,290 cervical samples from a regularly screened population of 30‐55‐year‐old women were investigated. Gynaecological specimens, obtained from the cervix, were cytologically classified and screened for the presence of HPVs 6/11 and 16/18 using dot‐spot DNA hybridisation. Of the cervical samples containing unequivocally normal cells, 21 of 1,271 (1.6%) were found positive for HPV, and of the cervical samples containing cells with mild dysplasia, 6 of 14 (43%) were found positive for HPV. All five samples containing cells consistent with severe dysplasia or carcinoma in situ were found positive for HPV. Approximately 50% of the HPV positive samples contained HPV 16 and/or HPV 18 DNA.
Systemic lymphoproliferative responses to rotavirus
Authors: Totterdell B. M. , Banatvala J. E. , Chrystie I. L. , Ball G. , Cubitt W. D. 
Published: March 2007

AbstractIn comparison with healthy adults, elderly patients and patients who had received renal transplants had significantly lower lymphoproliferative responses to rotavirus (P = 0.04, P = 0.002, respectively) and phytohaemagglutinin (P = 0.001). However, following acute rotavirus infection, elderly persons mounted good lymphoproliferative and specific antibody responses to rotavirus. No lymphoproliferative response or specific antibody to rotavirus was detected in a child with cartilage hair hypoplasia. In cord blood samples, specific antibodies were detected in the absence of a lymphoproliferative response to rotavirus. Increases in lymphoproliferative responses as well as specific antibodies were not detected in immune adult recipients of a human rotavirus vaccine (RIT 4375), but a recipient of a bovine vaccine (RIT 4237) had an increase in lymphoproliferative response to rotavirus between 13 and 28 days postvaccination. Stimulation indices for both rotavirus and phytohaemagglutinin within the vaccine groups were comparable to the healthy laboratory personnel group.
History of recurrent mucocutaneous herpes correlates with relatively low interferon production by herpes simplex virus‐exposed cultured monocytes
Authors: Linnavuori Kimmo H. 
Published: March 2007

AbstractMonocytes separated from blood specimens of healthy voluntary blood donors were infected with herpes simplex virus (HSV) 1 or 2. The amount of interferon produced by the HSV‐exposed monocytes was found to be donor‐specific and was similar whether tested with HSV 1 or HSV 2. The interferon levels in repeated blood specimens from a given donor were relatively stable within an observation period of a few months. The survey was expanded by testing 27 persons with history of recurrent herpes disease and 16 control persons without such history. HSV‐exposed monocytes of the controls produced significantly higher amounts of interferon than those of the patients with lesions of recurrent herpes (mean levels 145 and 58 IU/ml, respectively; P < 0.05). A correlation was also found between the antibody status of the cell donor and the capability of the monocytes to produce interferon when infected with HSV 1 or HSV 2: the interferon responses of monocytes of seronegative cell donors were significantly higher than those of cultures from donors with complement fixing antibodies against HSV (P < 0.01).
Isolation and characterization of a variant of human papillomavirus type 11 from a nasal inverting (schneiderian) papilloma
Authors: Pater Alan , Gardner Humphrey , Respler Don S. , Jahn Anthony , Pater Mary M. 
Published: March 2007

AbstractWe have previously reported the presence of a variant of human papillomavirus (HPV) type 11 in a nasal inverting papilloma [Respler et al., 1987]. In the present study, we have cloned molecularly the DNA of this variant at its unique restriction enzyme Bam HI site into lambda BF101 phage. Restriction enzyme mapping and DNA sequencing revealed that the genome of this virus contained an extra 531 base pair (bp) which was the repeat of most of the noncoding region (ncr) of HPV 11. Insertion of ranscriptional control elements, including the repeated sequence, in front of the chloramphenicol acetyltransferase (CAT) gene resulted in a 5‐ to 30‐fold increase in expression in transfected cells, as compared to the constructs containing a single ncr of HPV 11. This increased expression was due to enhanced levels of CAT RNA the synthesis of which is initiated by the viral promoter element.
Lack of reverse transcriptase activity in serum in sporadic post‐transfusional and presumed epidemic or water‐borne forms of severe non‐A, non‐B hepatitis
Authors: Brahm Javier , McClure Myra O. , Sommerfelt Maja A. , Exley Mark A. , Weiss Robin A. , Fagan Elizabeth A. , Williams Roger 
Published: March 2007

AbstractReverse transcriptase (RT) activity was not detected in any serum sample taken from 22 patients with mainly severe non‐A, non‐B hepatitis (NANBH), using two assays selected to cover the range of known human and animal retroviruses. The study included patients with fulminant and sub‐acute hepatic failure, which was attributed to sporadic, post‐transfusional, and presumed epidemic or water‐borne epidemiological forms of NANBH. Although we cannot exclude the possibility that some of the agents implicated in NANBH are retroviruses, our negative findings suggest that other agents may be involved at least in the severe forms of NANBH.
Recombinant vaccinia virus expressing epstein‐barr virus glycoprotein gp340 protects cottontop tamarins against EB virus‐induced malignant lymphomas
Authors: Morgan A. J. , Mackett M. , Finerty S. , Arrand J. R. , Scullion F. T. , Epstein M. A. 
Published: March 2007

AbstractA strong association exists between Epstein‐Barr (EB) virus and two human cancers, endemic Burkitt's lymphoma and nasopharyngeal carcinoma. In addition, the virus causes infectious mononucleosis [reviewed in Epstein and Achong, 1979, 1986] and more recently has been implicated in lymphomas arising in immunosuppressed individuals [Cleary et al., 1986]. The possibility of preventing or influencing the course of these diseases by vaccination has been advocated for a number of years [Epstein, 1976]. especially in the case of undifferentiated nasopharyngeal carcinoma, which is the most common tumour of men in southern China and is prevalent in other specific regions; it therefore represents a major world cancer problem [Shanmugaratnam, 1971]. Two vaccinia virus strains were employed to make recombinants expressing the gene coding for the EB virus envelope glycoprotein, gp340, and were used to vaccinate cottontop tamarins. Protection against EB‐virus‐induced lymphoma was obtained in animals immunized with the laboratory (WR) strain recombinant but not with those recombinants derived from the vaccine (Wyeth) strain. Circulating antibodies to EB virus gp340 were not detected in any of the immunized animals.
Use of polyclonal and monoclonal antibodies and analysis of viral RNA in the detection of unusual group A human rotaviruses
Authors: Aboudy Yair , Shif Ilan , Zilberstein Ilana , Gotlieb‐Stematsky Tamar 
Published: March 2007

AbstractImmuno‐enzymatic assay employing monoclonal antibodies and viral RNA analysis by gel electrophoresis were used to classify human group A rotaviruses (HRV) into subgroups I and II. Of 249 fecal samples positive for group A rotaviruses, 29 (11%) belonged to subgroup I and 215 (85%) were identified as subgroup II. Two samples (Ro‐302 and Ro‐500) contained mixed infections of the two subgroups. Three isolates belonged to neither one of the two subgroups, but they did not yield enough viral RNA to allow their classification. One subgroup I isolate (Ro‐1845) contained components typical of subgroup II viruses in that it was identical to serotype 3 and yielded RNA with fast‐moving 10th and 11th segments. After growth in culture, the two mixed infections yielded subgroup II viruses, which were identified as serotype 1. The three unclassified isolates grew poorly in culture and could not be further analyzed. The subgroup I isolate (Ro‐1845) grew well in culture and yielded virus similar to the original one.
Nasal‐Secretion leukocyte populations determined by flow cytometry during acute rhinovirus infection
Authors: Levandowski Roland A. , Weaver Carolan W. , Jackson George Gee 
Published: March 2007

AbstractLeukocyte populations in the secretions of volunteers challenged by intranasal inoculation with rhinovirus serotype 25 were evaluated by means of flow cytometry. With the light‐scatter properties of peripheral blood leukocytes as the standard of reference, significant increases (P < 05) of both lymphocytes and phagocytes (polymorphonuclear leukocytes plus monocytes) were detected in the nasal secretions of persons infected by the viral challenge. There was a direct correlation of nasopharyngeal symptom severity with both the percentage of lymphocytes (P < .05) and the percentage of phagocytes (P < .001). Monoclonal antibodies for specific cell‐membrane antigens identified the lymphocytes and phagocytes as leukocytes and also demonstrated the presence of a population of monocytic cells during the phase of maximal symptoms. The panel of monoclonals chosen did not unequivocally identify a lymphocyte population except in the presence of nosebleed. However, the results show that flow cytometry can be used to investigate nasal‐secretion cell populations during the rhinovirus common cold.
Peripheral blood mononuclear cell‐mediated cytolytic activity during cytomegalovirus (CMV) infection of guinea pigs
Authors: Harrison C. J. , Myers M. G. 
Published: March 2007

AbstractInbred Strain‐2 guinea pigs exhibited endogenous peripheral blood mononuclear cell (PBMC)‐mediated cytolytic activity against xenogeneic MA 104 targets and guinea pig cytomegalovirus (gpCMV)‐infected syngeneic and allogeneic targets. This endogenous cytolysis was unaffected by monoclonal T‐cell antibody depletion but was diminished by removal of plastic adherent cells. In nonadherent effector populations, cytolysis was mediated predominately by large granular lymphocytes (LGL).During gpCMV infection, cytolysis of both target types was augmented (MA104 for 3 weeks and gpCMV targets for 10–14 weeks). Augmented cytolysis of gpCMV targets was MHC‐unrestricted and was diminished by removal of plastic adherent cells or monoclonal antibody depletion of T‐cells, being found largely in LGL enriched populations. A role for this augmented activity in limiting gpCMV infection in inbred guinea pigs is suggested by the temporal association of augmented cytolysis of gpCMV targets with the cessation of viremia and clinical recovery.
Contribution of rhinoviruses to respiratory viral infections in childhood: A prospective study in a mainly hospitalized infant population
Authors: Kellner Gabriele , Popow‐Kraupp Therese , Kundi Michael , Binder Christa , Wallner H. , Kunz Christian 
Published: March 2007

AbstractA prospective study was carried out to investigate the contribution of rhinoviruses to respiratory viral infections in children and to investigate the influence of age, passive smoking, and educational level of the head of the family on the clinical course of viral respiratory disease.Nasopharyngeal aspirates from 519 infants (90.8% inpatients, 9.2 % outpatients) were screened for the presence of rhinoviruses, respiratory syncytial virus (RSV), adenoviruses, parainfluenza virus types 1, 2, 3, influenza virus types A and B, and enteroviruses by tissue culture isolation procedure, enzyme‐linked immunosorbent assay, and/or indirect immunofluorescence method. The total detection rate was 42.4%. The rate decreased with increasing age. Higher detection rates were observed in specimens from children suffering from a more severe respiratory disease, and the highest rate of virus‐positive specimens was found in those aged 0–6 months. Second to RSV (23.1%), rhinoviruses were the most frequently recovered pathogens found in 11.8% of children with acute respiratory tract infections (RTI). In the age group 0–6 months the majority of severe respiratory illnesses was due to RSV. In infants aged 6 months to 1 year a decrease in the number of severe illnesses caused by RSV and an increase in the number of children suffering from a more severe RTI caused by rhinoviruses was found. With the possible exception of one group of children infected with rhinoviruses, a negative effect of passive smoking on the incidence and severity of viral RTI could not be established. A beneficial effect of breast feeding on the severity of viral RTI could not be definitely demonstrated.
Enhancement of class I HLA antigen expression by cytomegalovirus: Role in amplification of virus infection
Authors: Grundy Jane E. , Ayles Helen M. , McKeating Jane A. , Butcher R. G. , Griffiths P. D. , Poulter L. W. 
Published: March 2007

AbstractWe have investigated the effect of cytomegalovirus (CMV) infection on the expression of class I HLA antigens on fibroblasts in vitro. Scanning and integrating microdensitometry was used to quantitate the level of cytoplasmic class I antigen expression, and an antibody binding assay was used to quantitate cell surface expression of class I HLA molecules. CMV infection resulted in a significant increase in the level of cytoplasmic and cell surface class I HLA antigen expression of fibroblast monolayers. The maximal effect was seen at 72 hours postinfection and was observed with both the laboratory strain of CMV, strain AD169, and with CMV purified directly from clinical specimens. Part of the increased HLA expression was mediated by interferon released from infected cells; however, an additional direct effect of the virus itself has not been ruled out. Interferon‐induced increased expression of class I HLA antigens was accompanied by increased binding of CMV to the cells, consistent with our recent demonstration that class I HLA molecules can function as a cellular receptor for CMV.
Placental transfer of IgG subclass‐specific antibodies to varicella‐zoster virus
Authors: Asano Yoshizo , Hiroishi Yuichi , Itakura Naoko , Hirose Shigeyuki , Kajita Yuji , Suga Sadao , Yazaki Takehiko 
Published: March 2007

AbstractCommercially available mouse monoclonal antibodies to human IgG subclasses (IgG 1 to IgG 4) were used in an enzyme‐linked immunosorbent assay to examine the placental transfer of IgG subclass‐specific antibodies to varicella‐zoster virus (VZV). All 46 mothers had total IgG antibody to VZV, and an equal level of antibody was found in the cord blood. All of the mothers had high antibody activities to VZV in IgG 1 and IgG 4 subclasses. The majority of the mothers were negative for IgG 2 and IgG 3 VZV antibodies, and the level of antibody found to be positive was very low. The IgG 1 antibody activity in the cord blood was almost equal to that of the maternal, and significantly higher level of IgG 4 antibody was found in the cord than maternal blood.
Ribavirin effect on experimental Junin virus‐induced encephalitis
Authors: Remesar Mirta C. , Blejer Jorgelina L. , Weissenbacher Mercedes C. , Nejamkis Marta R. 
Published: March 2007

AbstractJunin virus, the etiological agent of Argentine hemorrhagic fever, produces in man a disease mainly characterized by hemorrhagic alterations, commonly accompanied by neurological symptoms, and leading to 10% mortality. Intracerebral inoculation in 10‐day‐old rats or intraperitoneal inoculation in 2‐day‐old rats leads to high mortality due to severe encephalitis. Here, the effect of Ribavirin on these experimental models was tested in order to evaluate the degree of protection achieved against neuropathological manifestations. In intracerebrally infected 10‐day‐old rats the drug was administered 2 hr before virus inoculation. Doses ranged from 30 to 90 mg/kg body weight. Protection reached 40% for the 60 and 90 mg doses. Intraperitoneally infected 2‐day‐old rats received the drug in five 30‐mg daily doses, starting the same day as virus inoculation. Survival was 73%. Viral replication within peritoneal macrophages dropped markedly, leading to much lower CNS viral titres. Together with results reported in primates, our findings support further studies on Ribavirin, with a view to eventual trials in humans.