摘要:

AbstractSerum anti‐HBc IgM titres were monitored monthly by a semiquantitative method in 14 children with HBeAg positive chronic hepatitis B followed up for 18‐65 months. All patients, but one, were treated with alfa‐interferon (IFN) at different times. On the whole, 12 flare‐up episodes were observed and 7 patients cleared HBV‐DNA and seroconverted to anti‐HBe. Seroconversion occurred only in patients with pretreatment anti‐HBc IgM index greater than 0.15 and serum HBV‐DNA concentration below 100 pg/ml; the pretreatment alanine aminotransferase (ALT) value was not predictive of response. Combining anti‐HBc IgM results and serum HBV‐DNA levels observed during the pre‐IFN period allowed a precise identification of patients who were likely to respond to IFN therapy.Patients who seroconverted to anti‐HBe showed a progressive reduction in serum anti‐HBc IgM titres within 6 months. Interestingly, one child, in whom HBV‐DNA reappeared andwho reconverted to HBeAg 7 months after treatment, showed no anti‐HBc IgM decrease afterthe transient clearance of HBV‐DNA and anti‐HBe seroconversion. Semiquantitative anti‐HBcIgM detection is a useful tool in the decision making process for children with chronic

ISSN:0146-6615    

DOI:10.1002/jmv.1890460302

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

年代:1995

数据来源: WILEY

摘要:

AbstractOut of 64 cases of non‐Hodgkin's lymphomas (NHL), 55 cases of Hodgkin's disease (HD) and 31 cases of multiple sclerosis (MS), 2 NHL, 7 HD and 1 MS cases were found positive by polymerase chain reaction (PCR) for the presence of HHV‐6 sequences in pathologic lymph nodes of the lymphomas and in peripheral blood mononuclear cells (PBMCs) of MS. A further analysis of the PBMCs of the PCR positive cases by standard Southern blot technique revealed only 2 NHL, 3 HD and 1 MS cases as positive, indicating that these six patients have an unusually high viral copy number in the PBMCs. Restriction analysis, carried out using probes representative of differ ent regions of the virus, showed that three cases retain only a deleted portion of the viral genome. In the remaining three cases a complete viral genome was present, containing the right end sequences in which the rep‐like gene, possibly crucial to the viral and cellular life cycle, is lo cated. The analysis by pulsed field gel electrophoresis (PFGE) of the total DNA of the PBMCs obtained directly, without culture from PBMCs of these last three cases (1 NHL, 1 HD, and 1 MS), using the same probes, showed the absence of free viral molecules and the association of viral sequences with high molecular weight DNA. These results are consistent with in vivo integration of the entire virus in the cellular genome. A further study of the same patients with chromo some fluorescence in situ hybridization (FISH) showed in ail the three cases the presence of a specific hybridization site, located at the telomeric extremity of the short arm of chromosome 17 (17p13), suggesting that this location is at least a preferred site of an infrequent, but possi bly biologically important, integration phenomenon. © 1995 Wiley‐L

ISSN:0146-6615    

DOI:10.1002/jmv.1890460303

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

年代:1995

数据来源: WILEY

摘要:

AbstractEpidemiological studies indicate that acquired immunodeficiency syndrome (AIDS)‐associated Kaposi's sarcoma (KS) may be caused by an infectious, preferentially sexually transmitted agent. Infections with human papilloma viruses are common, sexually transmitted diseases occurring frequently in homosexual men, who are also the main risk group of developing KS. In order to evaluate the possible role of HPV in the development of KS, 24 cutaneous AIDS‐associated Kaposi's sarcomas were investigated by the polymerase chain reaction (PCR) and by in situ hybridization for the presence of human papilloma viruses (HPV). HPV DNA sequences were detected in 5 of 24 KS specimens, in 4 of 13 normal skin specimens from AIDS patients withoutKS and in 5 of 14 skin specimens of HIV‐seronegative patients. For the first time, HPV types 6 and 33 were detected by PCR in KS. A higher proportion of HPV types 16/18 was found in AIDS‐associated KS specimens, whereas HPV type 33 was seen more often in normal skin specimens of the control group. Apart from the known HPV types 16/18 described in KS, this study demonstrates also the presence of HPV 6 and 33 in this condition. © 1995 Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890460304

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe use of an enzyme immunoassay (EIA) employing a baculovirus‐expressed recombinant human calicivirus (Mexico virus, MxV) for the detection of IgG‐specific antibodies is described. MxV appeared to be related antigenically to a strain of small round structured virus, SRSV/UK4/Leeds/91, which had previously been shown by solid phase immune electron microscopy (SPIEM) to be related to Snow Mountain agent (SMA). One other outbreak which occurred in San Anita, USA in 1980 and was due to consumption of contaminated water was caused by a virus antigenically related to MxV.Volunteers and patients who developed significant IgG responses to rMxV showed anamnestic IgG responses (2 to 4‐fold) in the recombinant Norwalk virus (rNV) IgG assay. Patients and volunteers who were known to have been infected with several other strains of calicivirus/small round spherical viruses (SRSV) including NV and SRSV UK3 showed no significant antibody response to rMxV in the EIA. A seroepidemiological survey of sera from 338 children in London showed that infection with MxV occurred earlier in life than NV. Primary infections with MxV were common after the age of 6 months. Over 70% of children had evidence of infection by the age of 2 years, whereas only 12% of these children had been infected with NV. High concentrations of maternal antibody were present during the first month of life which was detected in 96% of the neonates. The results suggest that the high sensitivity of the EIA may be detecting maternal antibody throughout the first 8 months of life. © 1995 Wiley‐L

ISSN:0146-6615    

DOI:10.1002/jmv.1890460305

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe nucleotide sequences of the precore/core and X open reading frames (ORFs) of hepatitis B virus (HBV) were studied in four subjects who were serologically negative for anti‐hepatitis B core antibody. These subjects were positive for serum hepatitis B surface antigen and were considered to be asymptomatic HBV carriers. Sequencing of the precore/core ORF revealed precore wild type and 3 to 8 nucleotide substitutions (replacing 0 to 2 amino acids) in the core region compared with the sequence of subtypeadr. These substitutions were not considered to have changed the epitope of the core antigen, resulting in the absence of anti‐HBc as determined by a conventional diagnostic kit. The X ORF showed 1 to 5 nucleotide substitutions (replacing 1 to 3 amino acids) and the structure of the X protein and the core promoter/enhancer II complex appeared to be conserved. These findings strongly suggest that the absence of serum anti‐HBc is not due to mutation of the HBV DNA but to an aberrant immune reaction of the host to HBV. © 1995 Wiley‐L

ISSN:0146-6615    

DOI:10.1002/jmv.1890460306

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe presence of hepatitis B virus (HBV) DNA in extrahepatic tissues has been well documented. Whether HBV DNA can persist in extrahepatic tissues for long periods of time in the absence of replication in the liver has not been determined previously. Recently, two patients with end‐stage liver disease secondary to chronic active HBV were treated with baboon liver xenotransplants as these animals are felt to be resistant to HBV infection. Multiple tissues from these two patients were examined for HBV DNA using polymerase chain reaction (PCR). HBV DNA was not detectable in four of five samples of the liver xenografts. A positive signal was observed in a single assay for one sample, but this sample was not positive in subsequent assays. HBV DNA was detected in peripheral blood lymphocytes, spleen, kidney, bone marrow, pancreas, lymph node, heart and small intestine. The level of HBV DNA in these tissues was too low for the detection of HBV DNA replicative intermediates by Southern hybridization; thus, it could not be determined whether the HBV DNA in these tissues represented actively replicating HBV in extrahepatic sites, integrated HBV sequences, HBV in infiltrating lymphocytes, or deposition of HBV immune complexes originating from the plasma. However, it is clear from this study that HBV DNA persisted in multiple tissues for 70 days after replication in the liver had ceased or at least was below the level of detection by PCR. © 1995 Wiley‐Liss,

ISSN:0146-6615    

DOI:10.1002/jmv.1890460307

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

年代:1995

数据来源: WILEY

摘要:

AbstractStrong evidence has implicated human papillomaviruses (HPV) in the pathogenesis of anogenital cancers and a number of other mucosal and cutaneous lesions. Data concerning the involvement of HPV in esophageal cancers are controversial. Different investigators have detected HPV types (mainly types 16 and 18) in biopsy specimens of esophageal cancers. A study was undertaken to determine whether responses to chemotherapy of advanced squamous cell carcinomas could be correlated with the HPV status. Polymerase chain reaction (PCR) amplification was used for the detection of HPV DNA in biopsies of esophageal squamous cell carcinomas treated with either surgical resection alone (n = 42) or chemotherapy followed by surgical resection (n = 21). Different general and consensus PCR primer sets, which allow the detection of most of the known as well as a number of not yet characterized HPV types, were used. HPV DNA was not detected in any of the 61 esophageal squamous cell carcinomas, suggesting that HPV infections are not likely to play a major role in the etiology of this neoplasm. © 1995 Wiley‐Liss, I

ISSN:0146-6615    

DOI:10.1002/jmv.1890460308

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

年代:1995

数据来源: WILEY

摘要:

AbstractHuman monocyte‐derived cytotoxic factors (CF) induced by dengue virus were studied. Using several human leukemia cell lines as precursors, the biological activities of CF in conditioned medium from dengue virus‐infected monocytes were demonstrated through the measurement of tumor cell growth inhibition. The conditioned medium from dengue virus infected monocytes suppressed significantly growth of CEM, HL60, K562, and U937 cells. In the presence of 10% conditioned medium (v/v) from dengue virus infected monocytes, DNA synthesis of U937 cells, as measured by [3H]thymidine incorporation, decreased by 99% in contrast to their synthesis in conditioned medium from noninfected control monocytes, which did not have any suppressive effect. Partial characterization of CF showed that it is a proteinase‐K‐sensitive and heat‐labile protein with a molecular mass over 100 kDa. Employing a flow cytometric analysis of the cell cycle, it was found that U937 cells, treated either with conditioned medium from dengue virus infected monocytes or with CF, but not treated with conditioned medium from noninfected monocytes, showed cell‐cycle arrest in G1 phase by 48 hr. This suppressive effect of CF on U937 growth was dose‐ and time‐dependent. These results suggest that dengue virus‐infected monocytes may produce CF to target myeloid cells, resulting in the hematological changes observed in patients with dengue fever. © 19

ISSN:0146-6615    

DOI:10.1002/jmv.1890460309

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

年代:1995

数据来源: WILEY

摘要:

AbstractInbred rabbits of B/Jas strain were found to be highly susceptible to herpes simplex virus type 1 encephalitis, following i.v. injection of the virus, while Chbb:HM strain rabbits were not susceptible. The susceptibility trait seemed to be inherited recessively, involving multiple genes, because (B/Jas x Chbb:HM)Fl hybrids were as resistant as Chbb:HM rabbits, and because more than 90% of backcrosses of (B/Jas x Chbb: HM)FI to B/Jas were resistant to viral inoculation. The encephalitis in B/Jas rabbits resembled human herpes simplex encephalitis, in that the temporal lobe as well as the brain stem were affected preferentially, leading to the development of various types of seizures, such as circling, loss of balance leading to a fall, and tonic and clonic convulsions. The disease could be diagnosed by magnetic resonance imaging (MRI) analysis before onset of seizures, and diseased rabbits showed a marked lymphopenia at onset of seizures. © 1995 Wiley‐Liss, I

ISSN:0146-6615    

DOI:10.1002/jmv.1890460310

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn interferon treatment of chronic hepatitis C patients, the biochemical and virological responses mostly parallel each other. However, some patients who show persistent ALT normalization display continued viremia after cessation of therapy. High‐density hepatitis C virus (HCV) particles, which are immune complex forms, are reported to be less infectious both in vitro and in vivo. To assess whether high‐density HCV contributes to the response discrepancies and to clarify the association with patient outcome, sera were examined from chronic hepatitis C patients who were treated with interferon‐α. This study included 10 sustained responders with viremia (SR + ve), 5 SR without viremia, 3 transient responders (TR), and 3 nonresponders (NR). The SR + ve patients were defined as those with continued ALT normalization and serum HCV‐RNA positivity at 24 weeks after therapy completion. Serum samples obtained before and 24 weeks after therapy were ultracentrifuged on 35% sucrose. The ratio between high‐density and low density HCV was determined by quantification of HCV‐RNA titers in the bottom and top fractions by competitive reverse transcription and by the polymerase chain reaction, and expressed as the bottom/top (B/T) ratio. The B/T ratios before therapy were 1:l in all groups of patients, and 1:l after therapy in TR and NR groups. Five out of 6 SR + ve patients who showed 1:1 ratio after the apy relapsed within 1 year. In contrast, all SR + ve patients whose ratios were 10‐100:1 continued to show ALT normalization. These findings demonstrate that patients who have high‐density HCV dominance after therapy show persistent ALT normalization despite viremia, which can be explained by predominance of the neutralized immune complex. © 199

ISSN:0146-6615    

DOI:10.1002/jmv.1890460311

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

年代:1995

数据来源: WILEY