摘要:

AbstractThe relative frequency and distribution of the VP4 (P) genotypes of 227 human rotavirus field strains were investigated in South Africa. The stool samples were collected between 1984‐1993 from infants and young children with diarrhea at Ga‐Rankuwa Hospital, Pretoria, South Africa. The RNA was extracted from stools, heat denatured, and dot blotted onto nylon membranes. The blots were hybridized to PCR‐gener‐ated,32P radio‐labelled VP4‐specific probes (corresponding to the hyperdivergent region of the VP4 gene) of the following human rotavirus VP4 genotypes: P4, P6, P8, P9, P10, and P12. Of the 157 rotavirus strains typed by the probes, the P8 genotype was identified most frequently in 63.7% (n=100) of the samples. The P4 and P6 genotypes were detected less frequently in 22.3% (n=35) and 8.3% (n=13) of the samples, respectively. Five cases of dual infection between P8 and P4 genotypes occurred, indicating the potential for reassortment between members of different rotavirus genogroups. The P9 genotype could not be confirmed in 3 cases (1.9%), while the PI0 genotype was not observed at all, indicating the scarcity or absence of these VP4 genotypes in this region. Interestingly, we identified the newly‐described PI2 VP4 genotype in 6 cases (3.8%), suggesting a wide geographical distribution. Furthermore, several samples with sufficient RNA by gel electrophoresis remained untyped by the probes used in this study, and may represent putative “new” human VP4 genotype(S). © 19

ISSN:0146-6615    

DOI:10.1002/jmv.1890470102

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe aim of this study was to examine the efficacy of semi‐quantitative polymerase chain reaction (PCR) testing in cervical smears as an adjunct to cytological surveillance in a cohort of women with mild or moderate dyskaryosis. The study population comprised a group of 62 women who underwent twelve months of cytological and col‐poscopic surveillance as part of a larger randomised prospective study of women with mild and moderate dyskaryosis. Semi‐quantitative PCR for HPV‐16 DNA was carried out on the initial and twelve month study smears before a large loop excision of the transformation zone (LLETZ) was carried out. Smears from a control population which comprised 167 women without a history of abnormal cervical cytology who were attending family planning and general practitioner clinics for routine cervical smears were tested similarly.The presence of high or intermediate levels of HPV‐16 DNA on both the initial and twelve month study smear was positively associated with the identification of cervical intraepithelial neoplasia (CIN) grades II or III in the LLETZ specimen (P=0.01). While the combination of HPV‐16 DNA testing with cytology on a repeat cervical smear improved the selection of women with underlying CIN II/III, there was still a false negative rate of 53%. Twenty‐nine women had ‘low risk’ levels of HPV‐16 DNA and mild dyskaryosis or less on both repeat smears indicating suitability for surveillance, but in fact 34% of them had CIN II/III.This study supports the finding reported previously of an association between high and intermediate levels of HPV‐16 DNA and CIN II/III. This suggests that semi‐quantitative PCR may be a useful adjunct to cytology for selecting those women with mildly abnormal smears who would benefit most from colposcopy. A significant fluctuation in the levels of HPV‐16 DNA was not detected when repeated smears were studied, suggesting that serial estimations of HPV‐16 levels would add little to cytological examination for the subsequent surveillance of women considered to be at low risk of CIN II/

ISSN:0146-6615    

DOI:10.1002/jmv.1890470103

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

年代:1995

数据来源: WILEY

摘要:

AbstractSix hundred intravenous drug users (IVDUs) and two hundred North Africans were screened for human T‐cell leukemia virus (HTLV) antibodies using several serological methods. Eighteen of the eighty‐two HTLV‐seropositive individuals were also tested by the polymerase chain reac‐ tion‐DNA enzyme immunoassay (PCR‐DEIA), a non‐isotopic method of immunoenzymatic detection of the amplified DNA. Of these eighteen subjects, eight IVDUs were found to be HTLV‐II‐positive by the PCR‐DEIA, whereas all of the eighteen subjects were negative for HTLV‐I. Western blot (WB) confirmed six of the eight HTLV‐positive subjects, while the results of the remaining two were indeterminate. The results confirmed the PCR‐DEIA as a rapid and an efficient method of discriminating between HTLV‐I and HTLV‐II infection, whereas serological tests, including the WB, have limitations in terms of specificity and sensitivity. Moreover, this study showed a higher frequency of HTLV seroreactivity in the Italian IVDU population than in previous studies and confirmed that HTLV‐II is more frequent than HTLV‐I in this p

ISSN:0146-6615    

DOI:10.1002/jmv.1890470104

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe polymerase chain reaction (PCR) was used to investigate the presence of positive and negative hepatitis C virus (HCV) RNA strands in serumand peripheral blood mononuclear cells (PBMC) of 20 patients with histologically proven HCV‐ related chronic liver disease. All patients completed a course of interferon (IFN) treatment (6 MU of IFN‐α2b three times a week for 24 weeks) and were followed‐up for 12 months after treatment was discontinued. Pre‐treatment, end‐treatment and 6‐month follow‐up serum and PBMC samples were examined. At enrollment, the positive strand of HCV‐RNA was detected in serum of 18 patients (90%), the negative strand in none. Positive‐stranded HCV‐RNA was detected in PBMC of 15 patients (75%), 13 of whom also had detectable levels of negative‐stranded HCV‐RNA in PBMC. By the end of the treatment, 12 patients (60%) were responders. The pre‐treatment HCV infection of PBMC, indicated by the presence of both RNA strands, was found in 8 (66.7%) responders compared to 5 (62.5%) non‐responders (P=n.s.). End‐treatment loss of PMBC HCV‐RNA correlated significantly with the response since it occurred in all responders compared to 2 non‐responders (P=0.02). However, end‐treatment‐negative serum and PBMC HCV‐RNA did not predict the occurrence of a sustained response, which was observed at month 12 in 5 of 12 responders (P= n.s.). On the other hand, the persistent absence of HCV RNA in serum and PBMC at the end of the 6‐month follow‐up was significantly associated with the occurrence of a sustained

ISSN:0146-6615    

DOI:10.1002/jmv.1890470105

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe polymerase chain reaction (PCR) was used to amplify a 149 base‐pair region of the cytomegalovirus (CMV) genome and a 551 base‐pair region of the HIV‐1 proviral long terminal repeat (LTR) present in DNA extracted from post‐mor‐tem tissue. Multiple tissues (n=116) obtained from 16 patients which were subjected to PCR were also subjected to cell culture and histo‐pathological analyses. One hundred and seven samples (92%) contained CMV DNA and 66/116 (57%) contained HIV proviral DNA at a level of ≥10 genomes. Both viruses were detected in 60/116 (51.7%) of samples, with co‐infection most frequent in the lung (69%). Cell culture for CMV detected 9.3% of the PCR‐positive samples, whilst histology identified CMV inclusions in 15.9% of samples, all of which were CMV PCR‐positive. CMV was most frequently detected in adrenal and lung tissues by histology. These results show that co‐infection with CMV and HIV is a common occurrence in organs from AIDS patients and provide further evidence for a role of cytomegalovirus in the pathogenesis of AIDS.

ISSN:0146-6615    

DOI:10.1002/jmv.1890470106

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

年代:1995

数据来源: WILEY

摘要:

AbstractEnteroviruses cause significant illness in man but viral diagnosis is problematic. Enterovirus specific IgM tests have been developed but due to the difficulties of obtaining reliable control sera the interpretation of assay data remains mainly arbitrary and empirical. The present study was undertaken to assess the reliability of such assays by comparing two tests performed independently in two different laboratories: a μ‐capture radioimmunoassay (MACRIA) which utilizes35S‐labelled Coxsackie virus antigens and an enzyme immunoassay (EIA). A feature of the MACRIA was that sera were tested in one large batch whereas the EIA was in routine use in a reference laboratory. The MACRIA was easy to perform but more suitable for research investigations than routine diagnostic use. Similar results were detected in the majority of sera tested in the two assays with 85% concordance achieved on testing 120 sera. Of the 18 discrepant results, 11 were positive by EIA only and 7 by MACRIA only. 89‐95% concordance was obtained on testing sera against individual Coxsackie B1‐5 serotypes, moreover 52% of the serapositive in MACRIA were reactive against only one viral antigen and the results on certain of the more strongly reactive sera suggested the existence of a measure of type specificity in the MACRIA test. Qualitative differences between the two tests highlighted problems of interpretation in the absence of a gold standard and cautioned against sole reliance on serology for diagnosis of enteroviral infections. © 1995 Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890470107

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

年代:1995

数据来源: WILEY

摘要:

AbstractTwo rapid genotyping methods for hepatitis C virus (HCV), the line probe assay (Inno‐LiPA) and the subtype‐specific core amplification system [Okamoto et al., (1992b)Journal of General Virology73:673‐679], were applied to 58 HCV isolates which were typed as type 1 (n=37) and type 2 (n=21) by sequence analysis of the 5′ untranslated region (5′UTR). The line probe assay targets the 5′UTR and recognized 12 subtype 1a, 25 subtype 1b, 18 subtype 2a, 2 subtype 2b and 1 subtype 2d in accordance with sequence analysis of this region. Subtype‐specific core amplification revealed 7 discrepancies among the 37 type 1 isolates when compared to LiPA. A different subtype was observed in 3 isolates (la versus 1b), 2 isolates remained untyped and 2 isolates showed a coinfection of subtype la and 1b. The first 5 discrepancies were confirmed by sequence analysis of the core region whereas the coinfection could not be confirmed. Of the 21 type 2 isolates only one could be typed by subtype‐specific core amplification. HCV RNA was detected in all 21 cases after the general first round of polymerase chain reaction (PCR). Direct sequencing of the core region indicated sequence variation as a source of failure.It is concluded that LiPA results are conclusive for typing of HCV. However, LiPA is hampered occasionally for subtyping by lack of subtype specific sequence variation in 5′UTR. Subtyping results by subtype‐specific core amplification were accurate. However, it seems that this assay is not suitable for the identification of genotype 2 isolates that circulate in patients living in Western Europe. ©

ISSN:0146-6615    

DOI:10.1002/jmv.1890470108

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

年代:1995

数据来源: WILEY

摘要:

AbstractEach of the four serotypes of dengue viruses is responsible for a spectrum of illnesses that range from nonspecific febrile syndrome with good prognosis to dengue haemorrhagic fever or dengue shock syndrome. Definite diagnosis of dengue is provided by the detection of virus in acute‐phase sera of patients. Virus isolation can be accomplished with mosquito cell lines or mosquito inoculations. However, these methods are time consuming and labour intensive. The reverse‐transcriptase polymerase chain reaction (RT‐PCR) provides a potential means of rapid diagnosis but requires specialised facilities and equipment and is expensive. Therefore a rapid, simple, sensitive, and economical method for direct detection of viral antigens in viraemic sera is needed for clinical and epidemiological investigations. An amplified fluorogenic enzyme‐linked immunosorbent assay (F‐ELISA) is described for the detection and identification of dengue‐3 viruses in serum specimens. This assay utilizes biotinylated mouse IgG antibody directed against dengue antigens captured by anti‐dengue monoclonal antibody coated onto polystyrene microplate wells. lt takes advantage of the high affinity of biotin for the multivalent binding sites of streptavidin‐labelled β‐galactosidase, and combines the amplification effect of biotin‐streptavidin interaction with the high sensitivity of fluorogenic detection methods. Following optimisation of the procedure by reducing nonspecific binding of proteins and enhancing the specific binding of antigens, F‐ELISA was tested on 259 sera submitted routinely to our laboratory for confirmation of dengue diagnosis. The sensitivity of the F‐ELISA was 90%, the specificity was 99% and the agreement rate was 98% between F‐ELISA and virus isolation resul

ISSN:0146-6615    

DOI:10.1002/jmv.1890470109

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

年代:1995

数据来源: WILEY

摘要:

AbstractHuman (HCMV) and guinea pig (gpCMV) cytomegaloviruses share biological similarities and DNA sequence homologies. Therefore, human and guinea pig sera were tested for cross‐reactive antibodies. In eight human sere (four HCMV‐seropositive and four HCMV‐seronegative), low levels of neutralizing activity against gpCMV were not associated with antibodies to HCMV. The convalescent sera of one of three humans infected with either HCMV Towne vaccine or wild‐type HCMV developed a fourfold increase in neutralizing titers to gpCMV after infection, but none of seven guinea pigs immunized with either HCMV Towne or purified HCMV gB developed neutralizing activity against gpCMV. Guinea pigs immunized with gpCMV did not develop antibodies to HCMV or human gB. Neither gpCMV, HCMV Towne stain or purified HCMV gB induced cross‐reactive antibodies against the heterologous virus as detected by enzyme immunoassay. Our results indicate that gpCMV and HCMV share a very limited number, if any, of cross‐reactive neutralizing epitopes. © 1995 Wil

ISSN:0146-6615    

DOI:10.1002/jmv.1890470110

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe antibody prevalence in Sweden to Norwalk virus (NV) was investigated using a baculovirus expressed capsid antigen. One hundred thirty‐two serum samples were examined for IgA, total IgG and IgG subclass antibodies to Norwalk virus. In young children, NV IgG antibody prevalence was higher than the IgA prevalence, whereas no difference was found in individuals older than 21 years. The IgG antibody prevalence was 50% in children below 5 years of age and increased to>8O% in individuals older than 10 years of age. To examine the IgG antibody response in more detail, IgG subclass patterns were characterized. IgG 1 predominated in all age groups. IgG 4, usually detected after repeated exposure to antigen, was the second most prevalent subclass, but was only found in individuals olderthan 21 years of age. IgG 3 subclass antibodies were found in 13% and IgG 2 in 3% of the sera examined. IgG 3 subclass antibodies have been recognized as a marker for recent or ongoing viral infections. © 1995 Wiley‐Liss,

ISSN:0146-6615    

DOI:10.1002/jmv.1890470111

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

年代:1995

数据来源: WILEY