摘要:

AbstractA study evaluating the risk of a commercial factor VIII (FVIII) concentrate's transmitting the human immunodeficiency virus (HIV) was carried out on hemophiliacs, by using multiple serological markers and the polymerase chain reaction (PCR). Twenty‐nine hemophiliacs, negative for HIV antibodies, were treated for 18 months with a concentrate that had been inactivated by solvent‐detergent. HIV‐1 antibodies and antigen were assayed during the follow‐up period. At the end of the study, all patients were also tested by the HIV 1+2 combined antibody assay; Western blot (WB) antibody analysis; and in eight cases, by an HIV‐1 PCR technique. Patients received a yearly median FVIII dose of 35,330 IU (range 3,300‐306,000); the median number of lots given to each patient was 6 (1‐45). During the follow‐up period and at the end of the study, HIV‐1 antibodies and antigen were not detected in any of the subjects. The HIV 1+2 combined assay and WB analysis carried out only at the end of the study were negative. HIV‐1 PCR was negative in all the tested patients. This study has shown that this solvent‐detergent‐treated FVIII concentra

ISSN:0146-6615    

DOI:10.1002/jmv.1890360202

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe prevalence of cytomegalovirus (CMV) antibody was studied in 966 children in 1984 and 927 children in 1989. The overall prevalence rate of CMV antibody was 59% for children in 1984 and 46% for children in 1989 (P<0.05). In both study years, the prevalence rate of CMV antibody was about 70% in infants under 6 months of age, declined to a trough between the ages of 6 and 12 months, and then increased to 40‐50% between 1 and 4 years of age. The rate of CMV antibody for children above 4 years in 1984 increased steadily with age and reached 82% by 12 years. In contrast, the prevalence rate in 1989 remained at the level of 40‐5070 from age 4 to 10 years. It was followed by a sharp increase after 10 years of age and reached 84% at 12 years old. The seropositive rate in each of the 5‐, 6‐, 8‐, 9‐, and 10‐year‐old groups was higher in 1984 than that in 1989. These observations indicated that the prevalence rate of CMV antibody is decreasing in children. This change may be related to various socioeconomic factors, especially the less crowded family conditions

ISSN:0146-6615    

DOI:10.1002/jmv.1890360203

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

年代:1992

数据来源: WILEY

摘要:

AbstractMultiple mutations in the reverse transcriptase (RT) gene were observed in a drug‐resistant isolate of human immunodeficiency virus type 1 (HIVI) from an individual having prolonged (<2 years) zidovudine (AZT) therapy. The virus replicated in PBMC′s in the presence of very high concentrations of AZT (1 25 μM). Drug‐sensitive strains were curtailed by 0.01 μM AZT.Eleven defined mutations were observed as compared with published sequences of RT for eight strains of HIVI. Eight of these mutations were found in the domain involved in nucleotide recognition and enzyme function. Only one of the mutations, giving a Thr—Tyr change at amino acid 215, matched those previously ascribed (67,70, 215, and 219) to the generation of high‐level resistance to AZT. Therefore additional amino acid changes may have significance in the emergence of super‐resi

ISSN:0146-6615    

DOI:10.1002/jmv.1890360204

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

年代:1992

数据来源: WILEY

摘要:

AbstractHepatitis E virus (HEV), a positive‐strand RNA agent, has been associated with enterically transmitted non‐A, non‐B hepatitis in Asia, Africa, and Mexico. To evaluate the role of HEV in an outbreak of hepatitis in Pakistan, we used immune electron microscopy to detect 1) antibody to HEV, for evidence of infection, and 2) virus, to determine the pattern of HEV excretion. Paired sera from 2 patients were assayed for antibody by using reference HEV: one seroconverted, an atypical finding for HEV infections; the other had high levels of anti‐HEV in both sera. Virus particles with the size (29 × 31 nm) and morphology of HEV were detected in feces from 10 of 85 patients and serologically identified as HEV by using reference antibodies from an HEV‐infected chimpanzee. One of these HEV‐containing specimens was collected 9 days before the onset of jaundice; it was among feces from 38 outpatients with nonspecific symptoms and biochemical hepatitis, 12 of whom subsequently developed jaundice. The other 9 feces with HEV were among 36 collected within 7 days of the onset of acute icteric hepatitis; all 11 feces from days 8 to 15 were negative for HEV. Fecal concentrations of HEV appeared t o be lower than those of many enteric viruses: only one specimen contained as many as 5 particles per EM grid square. It is concluded that HEV was etiologically associated with the epidemic and was predominantly excreted at very low levels during the first week

ISSN:0146-6615    

DOI:10.1002/jmv.1890360205

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe possibility of obtaining expression of human hepatitis B virus (HBV) genes and production of virus particles in normal liver cells from heterologous species like normal adult rat hepatocytes, by transfecting the complete HBV genome, was investigated. Various techniques for hepatocyte transfection were assayed including the usual calcium‐phosphate coprecipitation technique, the Pasco and Fagan modified calcium‐phosphate procedure, and the lipofection technique. Transfection efficiency was determined by measuring the production of HBV surface antigen under various culture conditions. Transfection was the most efficient when assayed 1 or 2 days after hepatocyte plating at low density. Few variations in the efficiency were observed between the different transfection procedures. We show that under these culture conditions, replication of HBV can be achieved in differentiated adult rat hepatocytes. Synthesis of relaxed circular and single‐stranded DNA forms and of viral transcripts including pregenome RNA occurred in the cells whereas viral antigens and mature and immature viral particles were released into the culture medium. The production of viral proteins was always higher in hepatocytes cocultivated with rat liver epithelial cells and maintained at a low density. In contrast, viral replication was not obtained by transfecting undifferentiated rat liver epithelial cells. These results demonstrate that replication of HBV can occur in hepatocytes from mammalian species non‐closely related to primates and strongly support the idea that attachment of the virus and its penetration into the cells are critical steps in the host‐specificity of the infection process and that hepatic‐specific regulating factors could be essential for viral replication. This model provides a powerful experimental system which is easy to use t o test the role of HBV DNA sequences on normal hepatocyte functional activity, particularly those expected to transactivate cel

ISSN:0146-6615    

DOI:10.1002/jmv.1890360206

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe disease state induced by infection with hepatitis B virus (HBV) is manifest in varying ways characterised by the extent of liver inflammation and damage and viral persistence. In a small percentage of cases, primary infection leads to fulminant hepatitis resulting in severe liver dysfunction with very high mortality. Primary infection is most often resolved by complete clearance of the virus and development of immune memory to counter reinfection, but 5‐10% of infected adults develop chronic infection characterised by the persistence of viral antigens in the serum and accompanied by varying degrees of hepatic injury. This disease state may continue after integration of HBV DNA into the hepatocyte genome from which transcription of viral antigen genes may continue in the absence of virion production. Chronically infected patients are predisposed to developing hepatocellular carcinoma (HCC) [Szmuness, 1978] with more than 100‐fold greater probability than non‐infected individuals [Beasley, et al., 1981]. Hepatitis B constitutes a major worldwide health problem with the number of chronically infected people currently estimated in excess of 250 million.HBV is the prototype member of the family of hepadnaviridae, which includes hepatitis viruses isolated from the woodchuck (WHV) [Summers et al., 1978], ground squirrel (GSHV) [Marion et al., 1980], Pekin duck (DHBV) [Mason et al., 1980], and grey heron (HHV) [Sprengel et al., 1988]. This taxonomy is derived from the relative hepatropism of virus family members, their common virion morphology, genome size, structure and organisation, and common mechanism of genome replication, which proceeds through reverse transcription of an RNA intermediate [Summers and Mason, 1982] in a manner analogous to that of retroviruses. All the viruses exhibit a strict host specificity, the human virus replicating only in man and a small number of higher apes.HBV has a partially double stranded, open‐circular genome of 3.2 kilobases (kb) which contains four open reading frames (ORFs) including theS‐gene encoding the surface antigen and theC‐gene encoding the core antigen (Fig. 1 ). A large ORF encompassing most of the viral genome encodes the viral polymerase while the fourth ORF encodes a protein of 154 amino acid residues which has been termed the X antigen (HBxAg) because the function of this product in the viral lifecycle is still under intensive in

ISSN:0146-6615    

DOI:10.1002/jmv.1890360207

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

年代:1992

数据来源: WILEY

摘要:

AbstractHuman isolates of hepatitis A (HAV) are a single serotype; however, recent genetic surveys using limited nucleotide sequencing have provided evidence that more than one genotype is responsible for HAV infection in different parts of the world (Jansen et al. [1990]: Proc Natl Acad Sci USA 87:2867‐2871; Robertson et al. [1991]J Infect Dis 163:286‐292). One of these genotypes was originally isolated from Panamanian owl monkeys (strain PA21), but has subsequently been found associated with human cases of HAV from Sweden in 1979 (H‐122) and the United States of America in 1976 (GA76). The nucleic acid sequence of the exposed capsid polypeptide region of GA76 differs from other human HAV sequences by approximately 20%, yet differs by only 2.4% when compared with PI sequence of the PA21 strain. The 20% nucleic acid variability between GA76 and other human HAV results in limited amino acid changes (3%), while a comparison with PA21 revealed only four homologous amino acid substitutions within VP2, VP3, and VP1 polypeptides. HAV infected stool specimens from Nepal and northern India during 1989 and 1990 were found to contain virus whose genetic makeup was related t o the PA21 and GA76 isolates. This genotype of HAV appears to be circulating in some parts of the world where HAV is hyperendemic, and is a potential cause of hepatitis A infection within a susceptible popul

ISSN:0146-6615    

DOI:10.1002/jmv.1890360208

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

年代:1992

数据来源: WILEY

摘要:

AbstractHuman parvovirus B19 productively infected erythroid progenitor (EP) cells from umbilical cord blood, in vitro as shown by an increase of viral DNA in supernatant fluid assayed by dot blot hybridization and liquid scintillation counting. Progeny virus was released into the supernatant fluid of CD34+ EP cells which had been purified by immunomagnetic separation. This supernatant fluid was infectious for bone marrow cells. Erythroid bursts infected with virus showed characteristic cytopathic effect by electron microscopy consisting of cytoplasmic vacuolization, marginated chromatin, and nuclear inclusions of lattice or crystalline arrays. Cultures of umbilical cord blood EP cells may be useful for the propagation of parvovirus 619 serological testing reagents and the study of virus‐host cell interaction

ISSN:0146-6615    

DOI:10.1002/jmv.1890360209

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

年代:1992

数据来源: WILEY

摘要:

AbstractHuman papilloma virus type 16 (HPV 16) DNA is found in about 50% of cervical squamous cell carcinomas (SCCs), and this association has raised the possibility of a causal role for HPV 16 in cervical carcinogenesis. We have tested this hypothesis by assaying a series of biopsies (n = 119) ranging from normal mucosa to infiltrating SCC with the PCR‐technique for the presence of HPV 16 DNA. While HPV 16 DNA was detected in 50% of our cases with invasive SCC, the incidence of HPV 16‐positive samples was about 10% in all other biopsies ranging from normal mucosa t o cases of carcinoma in situ. HPV 16 therefore appears to be involved in late tumor promotion but not in early tumor developm

ISSN:0146-6615    

DOI:10.1002/jmv.1890360210

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

年代:1992

数据来源: WILEY

摘要:

AbstractHuman T‐cell leukemia‐lymphoma virus type II (HTLV‐II) has been isolated from patients with hairy cell leukemia (HCL). We previously described a population with longstanding endemic HTLV‐II infection, and showed that there is no increased risk for HCL in the affected groups. We thus have direct evidence that the endemic form(s) of HTLV‐II cause HCL infrequently, if at all. By comparison, there is reason to suspect that the viruses isolated from patients with HCL had an etiologic role in the disease in those patients. One way to reconcile these conflicting observations is to consider that isolates of HTLV‐II might differ in oncogenic potential. To deter mine whether the structure of the putative oncogenic determinant of HTLV‐11,tax2might differ in the new isolates compared to thetaxof the prototype HCL isolate, MO, four new functionaltaxcDNAs were cloned from new isolates. Sequence analysis showed only minor (0.9‐2.0%) amino acid variation compared to the published sequence of MOtax2Some codons were consistently different from published sequences of the MO virus, but in most cases, such variations were also found in each of twotax2clones we isolated from the MO T‐cell line. These variations rendered the new clones more similar to thetax1of the pathogenic virus HTLV‐I. Thus we find no evidence that pathologic determinants of HTLV‐II can be a

ISSN:0146-6615    

DOI:10.1002/jmv.1890360211

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

年代:1992

数据来源: WILEY