摘要:

AbstractA strain of hepatitis E virus (HEV), the 87A strain isolated in 2BS cells from the feces of a patient with hepatitis E, has been reported previously. In this study, the 87A strain was propagated in A549 cells, and the marked cytopathic effect (CPE) appeared in the infected monolayer cells. The size of this virus is about 30 nm in diameter. Furthermore, HEV‐RNAfrom the supernatants of the virus of different passages was detected by polymerase chain reaction (PCR) amplification using ET1 .1 HEV primers. A band of HEV for 239 bp from PCR products was revealed by electro‐phoresis. PCR products of the fourth passage were sequenced. These results show that the 87A virus replicates in the A549 cell line. © Wiley‐Lis

ISSN:0146-6615    

DOI:10.1002/jmv.1890470402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe isolation and identification of the 87A strain of hepatitis E virus (HEV) by means of cell culture have been described previously. This paper reports the nucleotide sequence of a portion of this HEV strain. The RNA extracted from the supernatants of the different passages of the 87A strain cultured in the A549 cell line was reverse‐transcribed (RT) to cDNA, and then the polymerase chain reaction (PCR) amplification was carried out using the primers of HEV ET1.l region. The PCR products from 1) the supernatant of the infected cells at the fourth passage, 2) the virus concentrated by polyethylene glycol (PEG) precipitation at the tenth passage, and 3) the virus purified by a sucrose gradient at the tenth pas sage were sequenced. In addition, three other PCR products obtained from sera of acute hepa titis E patients in Beijing (B‐9) and Guangzhou (G‐9 and G‐20) were also sequenced. The nucle otide sequences of the above four strains of HEV (located in the genome from positions 4545–4754) were compared to those of some reported HEV strains. The nucleotide sequences of the B‐9 strain and the 87A strain were similar to the Burmese strain and may belong to the same branch of HEV. The nucleotide sequences of the G‐9 strain and the G‐20 strain were a novel and unique branch. The Chinese HEV strains are multiplex and variable in gene structure. ©

ISSN:0146-6615    

DOI:10.1002/jmv.1890470403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTwo‐hundred Mexican children monitored from birth to 2 years of age in a cohort study of diarrhea were tested for Norwalk virus (NV) and Nor‐walk‐related virus infection. Blood was collected quarterly and tested by an enzyme immunoassay (EIA) using the recombinant NV (rNV) particles as antigen. Stool was collected weekly and tested by an EIA using hyperimmune antisera from animals immunized with rNV and a reverse transcription‐polymerase chain reaction (RT‐PCR) with primers in the RNA polymerase region of NV. A high prevalence of serum antibody to NV (85% at age 2 years) was found by the antibody EIA. In 54 stool specimens selected from children who developed a high titer of serum antibody to rNV, none was positive for NV by the antigen EIA, but 6 yielded products by the RT‐ PCR. One stool specimen (MX virus) yielded a 3.3 kb RT‐PCR product from the 3′ end of the viral genome. The MX virus cDNA has a genomic organization like other caliciviruses. Sequence comparison showed that MX virus shares 80% nucleic acid and 91% amino acid sequence identity with Snow Mountain agent (SMA), but only 62% and 60% identity, respectively, with NV in the RNA polymerase region, suggesting that MX virus is a SMA‐like virus.

ISSN:0146-6615    

DOI:10.1002/jmv.1890470404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractChildren with malignancy are immunosup‐pressed and susceptible to serious infections with herpesviruses. The majority of children on chemotherapy for malignancy are seropositive for human herpesvirus‐6 (HHV‐6), and although HHV‐6 has been demonstrated to be a pathogen in severely immunocompromised patients, whether this is the case for paediatric oncology patients is unknown.HHV‐6 is secreted in saliva and in this study samples were examined prospectively for HHV‐6 DNA in healthy children and those with malignancy. In a nested polymerase chain reaction (PCR), a 287 bp outer fragment and 163 inner fragment of HHV‐6 DNA were amplified. The resulting amplimer contained a Hind III restriction site present only in “B” type HHV‐6 and this was used to identify the type of HHV‐6 amplified. In saliva from healthy control children, 74% (28/38) of samples were HHV‐6 DNA‐positive in either the supernate, pellet or both. In the patients, 58% (45/77) of all samples were HHV‐6 DNA‐positive. When sequential samples from twelve patients were examined the children appeared to fall into two groups: those who were frequently HHV‐6 DNA‐positive (60% of samples or more) and those who were rarely HHV‐6 DNA‐positive (33% of samples or less) (P<0.0001). The only apparent difference between these two groups was that the less frequently HHV‐6‐positive group was more often febrile and unwell with neutro‐paenia. Hind III digestion demonstrated all the positive samples to be “6” type HHV‐6. Possible explanations for this difference in HHV‐6 secretion between

ISSN:0146-6615    

DOI:10.1002/jmv.1890470405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractBefore completion of polarization, Madin‐Darby canine kidney (MDCK) cells showed high infectivity and progeny production of herpes simplex virus type 1 infection. After polarization or formation of tight junctions, the infectivity and virus replication in MDCK cells was restricted significantly. The disruption of tight junctions by depletion of Ca2+resulted in increasing virus infectivity and productivity. Mechanical disruption of tight junctions by scratching the cell monolayers with injection needle allowed markedly the replication of HSV‐I in the cells aligned along the injured area. In polarized MDCK cells the progeny were released preferentially from the apical surface of the cells. These data suggest that because polarized MDCK cells mimic the epithelial cell layers, this cell line is helpful for determining the factors which regulate viral transmission in the human body. © Wiley‐Lis

ISSN:0146-6615    

DOI:10.1002/jmv.1890470406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe diagnosis of human immunodeficiency virus (HIV) infection in children born to HIV‐infected mothers is complicated by the presence of passively acquired maternal antibodies, and exclusion of infection in these infants remains problematic. The use of genome detection by polymerase chain reaction (PCR) amplification and the quantification of anti‐HIV‐I antibodies were examined as methods for early diagnosis. Blood samples were taken from 84 non‐breastfed infants of HIV‐infected mothers in five Italian and Spanish centres, a subgroup of children enrolled in the European Collaborative Study (ECS) for whom clinical and immunological information has been documented from birth. Whole blood was added to glycigel cryopreservative, stored, and tested in the United Kingdom by a nested PCR method. Antibody to HIV‐1 was detected and quantified by titration using a gelatin particle agglutination test. PCR sensitivity and specificity were assessed. Twenty‐one of the 84 children tested were infected. The estimated PCR sensitivity ranged from 0% (95% CI 0–26%) on day 1, 57% (19–85) on day 7, to 63% (33–92) on day 30. The negative predictive value of PCR ranged from 85% (83–88) on day 0 to 98% (94–100) at 3 months of age. On average, the level of maternal antibody halved every 33 days (31–36.5) in uninfected children. Between 6 and 9 months of age, increases in antibody titres in infected children were not more informative than absolute levels. These findings suggest that antibody measurement may supplement genomic diagnosis and that this collection method provides an alternative to the use of dried blood

ISSN:0146-6615    

DOI:10.1002/jmv.1890470407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe incidence of perinatal transmission of hepatitis B virus (HBV) depends on the HBeAg/anti‐HBe status of the mother. While children of HBeAg‐positive mothers have a 90% probability of acquiring a chronic hepatitis B virus carrier state, babies of anti‐HBe‐positive mothers are more likely to develop fulminant hepatitis within the first 3 to 4 months of life. There is evidence that precore (pre‐C) mutations of the HBV can be associated with fulminant hepatitis. The pre‐C region was therefore examined in sera from nine infants with fulminant hepatitis after vertical transmission, one HBeAg‐positive and seven anti‐HBe‐positive mothers by polymerase chain reaction (PCR) and direct sequence analysis. In five mother/infant pairs the virus populations were characterized in addition by analysing clones of the amplified products. All mothers were infected with two or four variants of HBV with mutations at different positions of the preC genome including position 1896, which results in a stop codon. While the precore stop codon was detected in a portion of the virus populations of the HBeAg‐positive and of four anti‐HBe‐positive mothers the dominating viral strain was represented by the wild type virus in three. In contrast, the virus populations of all babies showed the 1896 precore variant as the prevalent virus strain during the phase of active disease. In the surviving baby only wild type sequences were detected after recovery. Subtypeaywwas found in all mothers and infants andadw2was present in three mothers and in the surviving child.The findings suggest that all mothers carried a wild type HBV population with a certain number of different HBV variants. After transmission of the mixed virus population a selection process was started in the baby. The association of subtypeaywwith the precore mutations and with the fatal outcome of the hepatitis B might be the result of a directed selection of this variant with a particular advantage in the viral life c

ISSN:0146-6615    

DOI:10.1002/jmv.1890470408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractEarly and specific recognition of varicella zoster virus (VZV) infection is of vital concern in immunocompromised patients. The aim of this study was to compare the diagnostic accuracy of histochemical and immunohistochemical identification of the VZV ORF63 encoded protein (IE63) and of the VZV late protein gE on smears and formalin‐fixed paraffin‐embedded skin sections taken from lesions clinically diagnosed as varicella (n = 15) and herpes zoster (n = 51).Microscopic examinations of Tzanck smears and skin sections yielded a diagnostic accuracy of Herpesviridae infections in 66.7% (10/15) and 92.3% (12/13) of varicella, and 74.4% (29/39) and 87.8% (43/49) of herpes zoster, respectively. Immunohistochemistry applied to varicella provided a type‐specific virus diagnostic accuracy of 86.7% (13/15; IE63) and 100% (15/15; gE) on smears, and of 92.3% for both VZV proteins on skin sections. In herpes zoster, the diagnostic accuracy of immunohistochemistry reached 92.3% (36/39; IE63) and 94.9% (37/39; gE) on smears, and 91.7% (44/48; IE63) and 91.8% (45/49; gE) on skin sections.These findings indicate that the immunohistochemical detection of IE63 and gE on both smears and skin sections yields a higher specificity and sensitivity than standard microscopic assessments. © Wiley‐L

ISSN:0146-6615    

DOI:10.1002/jmv.1890470409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractAn unusual rotavirus strain, MG6, was isolated from a 16‐month‐old child admitted to hospital with acute gastroenteritis. The virus could not be serotyped (G‐typed) by enzyme immunoassay using standard reagents specific for common serotypes of human Group A rotaviruses. Nucleotide sequencing of cDNA derived from the gene encoding the outer capsid protein, VP7, and deduction of the VP7 amino acid sequence indicated that this strain belonged to serotype G6, a serotype normally associated with viruses causing disease in cattle. This was confirmed by polymerase chain reaction typing and enzyme immunoassay using a G6‐specific monoclonal antibody. The VP4 genotype of MG6 was determined by hybridization of its VP4 cDNA to genomic RNA isolated from standard strains of defined P‐types. This analysis, confirmed by deduced amino acid sequence analysis, classified MG6 into the novel genotype P13. MG6, therefore, is related to the previously described G6P13 human strain PA169, isolated in Italy. The emergence of strain MG6, the first human G6 rotavirus identified in Australia, provides further evidence of reassortment between human and animal rotaviruses. © Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890470410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractVascular endothelial cells (EC) play a key role in viral tropism in vivo. Since conflicting reports have been published on the capability of HIV to infect EC in vitro, we analyzed some factors potentially capable of influencing the susceptibility of human umbilical vein endothelial cells (HU‐VEC) to HIV‐1. Both primary cultures and differentiated immortalized HUVEC lines were used. HUVEC were negative for the expression of CD4, but weakly CD26‐ and galactosylceramide‐positive. Although binding of HIV to EC was substantial, the virus was apparently incapable of replicating in nonproliferating cultures. In resting cultures, the content of cell‐associated HIV disappeared 4–6 days after infection without production of p24 and infectious progency. In contrast, infection of proliferating EC cultures led to the transient release of p24 and infectious virus (102.5‐103.5 SFU/ml) peaking 2–6 days postinfection. Antibody neutralization of cytokines that may be produced by EC (IL1, IL6, IL8, TNF, IFN‐β) failed to modify virus adsorption and replication, whereas treatment with IL1‐β plus TNF‐α stimulated both virus binding and virus release. As seen by gag polymerase chain reaction (PCR) the viral genome persisted up to 15 days in untreated EC cultures, but over 20 days in cultures exposed to IL1‐β plus TNF‐α. This study shows that: (a) CD4‐negative HUVEC are capable of binding substantial amounts of HIV‐1; (b) binding is enhanced by proinflammatory cytokines; (c) the establishement of productive infection is favored by cell proliferation; and (d) exposure to IL1‐β plus TNF‐α enhan

ISSN:0146-6615    

DOI:10.1002/jmv.1890470411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY