摘要:

AbstractAnalysis of delta hepatitis virus (HDV) genomic RNA, derived from Greek patients from an area where HDV infection is associated with low pathogenicity, is described. In all isolates sequenced, which included 18/18 HDV cDNA clones derived from 6 different patients, irrespective of pathogenicity, a base change (T→C) was found in position 1014. No significant differences in editing efficiency were found between isolates from inactive and active forms of the disease, although L‐antigen was present in low to undetectable levels in the serum of 5/6 patients. An additional mutation was identified at position 578 (A→G), which reestablishes the canonical base pair G/C with the mutated 1014 when the genome adopts the “rod‐like” conformation. This finding supports the presence of this genome conformation in vivo and the requirement for the Watson‐Crick base pair 10141/578. A mutation, found at amino acid position 170 (serine → asparaginel, appears to segregate with patients with inactive disease. © 1995

ISSN:0146-6615    

DOI:10.1002/jmv.1890470202

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

年代:1995

数据来源: WILEY

摘要:

AbstractTwo synthetic peptides, designated peptides 12G(A) and 12G(B), representing amino acids 174–188 of the G glycoprotein of respiratory syncytial virus (RSV) subgroup A (strain A2) and subgroup B (strain CH18537) were evaluated for their properties as subgroup‐specific antigens for enzyme immunoassay (ELISA). These peptides were used to characterize the immune response of children with naturally occurring RSV infection during six annual epidemics in the Huntington area, West Virginia, USA; viz. 1978–1979, 1979–1980, 198G1981, 1983–1984, 1989–1990, and 1990–1991.The study group comprised 43 paired sera from 42 infants and children, who ranged in age between 1 month and 5.5 years of age (median age 16 months). The inclusion criteria were subgroup identification of RSV, respiratory tract illness requiring admission to hospital, and the availability of paired sera.Five of 30 children with subgroup A and 3 of 13 children with subgroup B infections developed homologous or dual fourfold or greater antibody responses to peptides 12G(A) and 12G(B) during convalescence; six of these eight children also developed antibody rises to whole virus antigens. Twenty children (14 subgroup A and 6 subgroup B) developed such responses in antibody only to whole virus (not to the peptides), and 15 children (11 subgroup A and 4 subgroup B) failed to develop a rise in antibody. Children who developed rises in antibody to the peptides were usually less than 9 months of age, suggesting that a response to peptides was more likely to occur during primary infection. Peptides 12G(A) and 12G(B) of RSV G protein lacked sufficient sensitivity and specificity to serve as antigens for ELISA for characterizing the subgroup‐specific immune responses to RSV infection in infants and children. © 1995

ISSN:0146-6615    

DOI:10.1002/jmv.1890470203

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

年代:1995

数据来源: WILEY

摘要:

AbstractRepeated episodes for enteroviral meningitis occurring within a 1‐month priod in two non‐immunocompromised infant were investigated using molecular techniques to distinguish persistent or recrudescent infection from new infection. Viral RNA from cerebrospinal fluid was amplified by polymerase chanin reaction, cloned, and the nucleic acid sequences determined. This analysis demonstrated that both infants had recurrent episodes of meningitis caused by new infection with a distincy enterovirus strain. The moleular methods that were employed should prove useful in similar clinical settings as well as for the study of enteroviral outbreaks. These cases also illustrate the potential for rapid reinfection of infants with different viruses of the same genus. © 1995 WiIey‐Lis

ISSN:0146-6615    

DOI:10.1002/jmv.1890470204

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe application of C.B‐17 SCID‐Beige mice as an experimental animal system for the acceptance of human leukocyte xenografts, the establishment of functional human immune responses and infection with HIV has been assessed. Reconstitution efficiencies approaching 100% could be obtained by using 2 × l07 human peripheral blood lymphocytes (PBLs). Typical levels of human immunoglobulin in mouse blood reached 120 kg/ml within 2 weeks of reconstitution rising to a maximum in excess of 3 mg/ml by 5 weeks. lmmunohistological examination of lung, spleen, lymph node and thymus tissue, derived from reconstituted mice, with human leukocyte specific monoclonal antibodies revealed the presence of human macrophages (CD68+), T cells (CD43+) and B cells (CD20+). The establishment of a functional immune system was demonstrated by the ability of reconstituted mice to respond to immunisation with KLH. Finally, reconstituted Hu‐PBL‐SCID‐Beige mice were susceptible to infection with HIV‐1 by intra‐peritoneal injection. These results indicate that SCID‐Beige mice are a valuable tool for the generation of human/mouse chimeras and for the establishment of an in vivo HIV infection model. The results are compared with other similar model systems and are discussed in the context of animal models for HIV vaccine studies. © 199

ISSN:0146-6615    

DOI:10.1002/jmv.1890470205

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

年代:1995

数据来源: WILEY

摘要:

AbstractWest African populations are infected with divergent strains of human immunodeficiency virus type 2 (HIV21, some of which are closely related to simian immunodeficiency virus (SIV) and it has been postulated that the HIV2 epidemic might have arisen by cross‐species spread of SIV into the human population in West Africa. To gain some insight into the possible basis for cross protection between these two closely related viruses, the T‐helper responses to 15 synthetic peptides from SIV gag synthetic peptides were investigated in seven HIV2‐infected subjects and in seven healthy controls. Significant reactivity to at least one of the synthetic peptides tested was found in all patients and a statistically significant correlation between CD4+ lymphocyte absolute numbers and the number of reacting peptides was observed. A marginal lymphocyte reactivity was found in two of the healthy controls studied. In conclusion, this preliminary evidence that HIV2‐infected patients exhibit T‐cell responses to SIV gag peptides suggests that both viruses share t‐helper epitopes in the gag viral region and raises the possibility of cross protection between SIV and HIV2 which may be relevant for HIV2 vaccine research based on closely related retroviruses. © 1995 WiI

ISSN:0146-6615    

DOI:10.1002/jmv.1890470206

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe molecular epidemiology of a large, multi‐state outbreak of oyster‐associated gastroenteritis [Kohn et al. (1995):Journal of the American Medical Association 273:466–471. Dowell et al. (1995):Journal of Infectious Diseases 171:1497–1503.] was examined using new methods to detect small round structured viruses (SRSVs) by reverse transcription‐polymerase chain reaction (RT‐PCR) and to characterize strains by Southern hybridization and nucleotide sequencing of 81‐bp of a PCR product amplified from the RNA polymerase gene. Of 37 stool specimens examined from patients in eight clusters of the multi‐state outbreak, 32 (86%) gave RT‐PCR products specific for SRSVs of PI‐A phylogenetic group. Nineteen PCR products from the eight clusters were confirmed to have the identical sequence, indicating that this large outbreak was attributed to a single strain of SRSV. In one of the eight clusters, five (63%) of eight patients had a mixed infection with a second SRSV strain that belonged to P2‐B phylogenetic group. Of 12 specimens from patients in five other outbreaks and one sporadic case which occurred at the same time as the multistate outbreak, 10 (83%) gave products specific for SRSVs representing four phylogenetic groups (PI‐A, PI‐B, P2‐A, and P2‐ B). The sequences of the PI‐A products from two outbreaks and that of the P2‐B product from another outbreak were identical to the P1‐A sequence from the eight clusters and the P2–6 sequence from the one cluster of the multistate outbreak, respectively. These results demonstrate the first application of these methods to enhance our understanding of the molecular epidemiology of SRSVs and provide answers of public health interest that could not have been obtained using classical epidemiologic methods alone. © 1995 Wiley‐Liss, lnc.This article is a US Government work and, as such, is in the publi

ISSN:0146-6615    

DOI:10.1002/jmv.1890470207

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

年代:1995

数据来源: WILEY

摘要:

AbstractHepatitis C virus (HCV) requires reverse transcriptase‐polymerase chain reaction (RT‐PCR) or branched DNA signal amplification assays to be detected in patient samples. Although conventional methods of RNA isolation are employed for samples of serum, plasma, and peripheral blood mononuclear cells (PBMCs), whole blood is generally considered an unsuitable source of RNA because of abundant RNases and poly‐merase inhibitors. Using a cationic surfactant, Catrimox‐14, we adapted a procedure for RNA isolation from whole blood, plasma, and PBMCs that yields RNA template suitable for HCV RT‐PCR. RNA isolation required less than 2 hr, and HCV sequences were easily detected in sample volumes of 50 μl whole blood or plasma, and in less than 1 × l04PBMC. Following the addition of blood to Catrimox, HCV RNA was stable in the mixture when incubated for at least 7 days at room temperature prior to RNA extraction. Comparison of whole blood HCV RNA and plasma HCV RNA from individuals with chronic hepatitis suggests that HCV RNA can be more reliably detected in whole blood. Three of 15 HCV antibody positive patients (20%) had HCV RNA present in whole blood but simultaneously obtained plasma samples were negative. Two of five HCV antibody negative individuals with chronic hepatitis contained HCV RNA in whole blood, yet one of these patient's plasma was negative for viral RNA. The Catrimox‐I4 method of RNA purification is useful for detecting HCV RNA in whole blood and blood subfractions, and provides a practical method of measuring plasma and PBMC HCV RNA from clinical specimens. © 1995 W

ISSN:0146-6615    

DOI:10.1002/jmv.1890470208

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

年代:1995

数据来源: WILEY

摘要:

AbstractEnterovirus71 H (E71 H), an isolate from an adult patient with hand‐foot‐mouth disease (HFMD) in China, was serologically similar to the prototype strain E71 BrCr, which was isolated from a patient with aseptic meningitis. The study further analyzed the similarity of E71 H to E71 BrCr at the 5′‐noncoding region (NCR), a location in genomic RNA that recently was found to be related to neurovirulence in poliovirus and Venezuelan equine encephalitis virus. Using a reverse transcription‐polymerase chain reaction (RT‐PCR) technique and a unique primer pair I, a 397 bp product was detected from E7 I BrCr, Cox A9 (Griggs), Cox A16 (NIH), Cox B1 (HA antigen 201–4681, Cox 65 (wild type), and ECHO 11 (Gregory), butnotfrom E71 H, Cox A24 (Joseph), and ECHO 5 (Noyce). However, all of the viruses generated a 154 bp product using a universal enterovirus primer pair II. Further comparative analysis using primer‐directed sequencing of both the E71 H and E71 BrCr 154 bp products revealed that they differed by 12 bases. The variations between the two viruses were clustered in two loci, one in the region of nucleotides 43–61 with eight variations, and the other in the region of nucleotides 120–133 with three variations. The differences within the 5′‐NCR between the E71 H (HFMD) and the E71 BrCr (aseptic meningitis) viruses might provide a clue to explain why E71 was associated with two different clinical patterns: polio‐like disease in the United States, Australia, and Eastern Europe, HFMD in China, Japan, and Singapor

ISSN:0146-6615    

DOI:10.1002/jmv.1890470209

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

年代:1995

数据来源: WILEY

摘要:

AbstractA mixture of adenoviruses 31 and 49 was isolated from the brain of an AIDS patient with encephalitis. Adenovirus hexon protein was detected in neurons by indirect immunoflourescence. By restriction endonuclease analysis both adenovirus 31 and 49 were shown to be new genotypes. This is the first report of the isolation of a mixture of adenoviruses from adenovirus encephalitis and the first association of adenovirus 49, a new candidate serotype, with encephalitis. © 1995 WiIey‐Liss, I

ISSN:0146-6615    

DOI:10.1002/jmv.1890470210

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn a photodynamic virus inactivation procedure for human fresh frozen plasma the plasma is exposed to visible light in the presence of 1 μM methylene blue. This procedure is known to inactivate HIV‐1 by at least 106.32TCID50/ml within 10 minutes. To elucidate the mechanism of photo‐dynamic inactivation of HIV‐1 by methylene blue/light treatment, reverse transcriptase (RT), the HIV‐1 associated protein p24, and viral RNA were examined. In the dark, methylene blue up to 10 μM has no inhibitory effect on recombinant RT. In the presence of light, recombinant RT inactivation was dependent on illumination time and the concentration of methylene blue. After photoinactivation of the whole virus by methylene blue/light treatment, RT activity was also almost completely inhibited. Simultaneously, it was found by Western blotting that HIV‐1 p24 and gp120 are altered in size, possibly due to protein cross‐linking. In addition, it was shown by poly‐merase chain reaction (PCR) inhibition assay that HIV‐1 inactivation leads to destruction of its RNA. In summary, methylene blue/light treatment acts on HIV‐1 at different target sites: the envelope and core proteins, and the inner core structures RNA and RT. ©

ISSN:0146-6615    

DOI:10.1002/jmv.1890470211

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

年代:1995

数据来源: WILEY