摘要:

AbstractFor the past 2 years, a survey network was established for the screening of acyclovir (ACV)‐resistant clinical isolates of herpes simplex virus (HSV). Among 889 strains tested for in vitro ACV sensitivity, 14 HSV‐1 and 6 HSV‐2 were resistant to ACV concentrations exceeding 3 μg/ml. These resistant isolates were most often obtained after prolonged ACV treatment of severely immuno‐compromised patients. For five patients, the emergence of ACV‐resistant virus correlated with treatment failure. In particular, a decrease in the in vitro sensitivity to ACV was observed for eight successive HSV‐1 isolates from one immunodeficient patient undergoing therapy. All ACV‐resistant isolates were studied for their sensitivity to different antiherpetic compounds and showed various cross‐sensitive and ‐resistant patterns. The examination of viral populations by plaque autoradiography procedures frequently revealed their heterogeneity in terms of thymidine kinase (TK) phenotype and allowed the detection of various proportions of TK‐positive (TK+), TK‐deficient (TKD), or TK‐altered (TKA) viruses. Our data underline the importance of monitoring the emergence of drug‐resistant virus during the course of antiviral therapy, and the need for the detection and characterization of TK mutants in clinical specimens. The routine examination of drug sensitivity of HSV isolates provides useful information to clinicians for the management of ACV treatment in the hope of preventing ACV‐resistant mutants from becoming predominan

ISSN:0146-6615    

DOI:10.1002/jmv.1890360102

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

年代:1992

数据来源: WILEY

摘要:

AbstractA case of HTLV‐1 associated tropical spastic paraparesis is described in a Belgian nun who had been working as a midwife in Central Africa. Occupational exposure was the only risk factor identified. Among 2,482 Belgian expatriates in tropical countries, 92% of whom had resided in sub‐Saharan Africa for an average of 15.5 years, only one Belgian‐born man was found seropositive for HTLV‐1. He was married t o an African woman and living in Central Africa for 23 years. The risk of HTLV‐1 infection is low in Belgian expatriates and on its own does not support generalised anti‐HTLV screening in autochthonous Belgian b

ISSN:0146-6615    

DOI:10.1002/jmv.1890360103

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

年代:1992

数据来源: WILEY

摘要:

AbstractBecause of widely differing reports on the significance of IgM anti‐HBc in chronic hepatitis B virus (HBV) infection, paired sera and liver biopsies from 49 patients with chronic HBV infection were analysed for serum IgM anti‐HBc, HBsAg titre, HBeAgianti‐HBe, HBV DNA, serum aspartate transaminase, intrahepatic HBcAg expression, and liver histology. High levels of IgM anti‐HBc, i n the diagnostic range of acute hepatitis B (>1.2), were detected in seven patients (14.3%) and a total of 34 patients (69.6%) had an index of more than 0.2. No correlation was found between IgM anti‐HBc and the serum markers of active viral replication or HBsAg titre but it correlated significantly with intrahepatic expression of cytoplasmic HBcAg (r2= 0.165,P=0.002). IgM anti‐HBc also correlated with active liver histology (P= 0.015) but there was a considerable overlap of the IgM anti‐HBc index values between the various disease groups, indicating a poor specificity. Serial assessment of IgM anti‐HBc in eight patients treated with interferon‐α (four responders) showed an increase in IgM anti‐HBc in three out of four patients corresponding to the e‐seroconversion period followed by a drop in IgM anti‐HBc levels. However, an increase in IgM anti‐HBc was also seen in one non‐responder, indicating that this feature is not unique to interferon‐α responders. These data indicate that serum IgM anti‐HBc cannot be used alone as a certain diagnostic measure of HBV replication nor in

ISSN:0146-6615    

DOI:10.1002/jmv.1890360104

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

年代:1992

数据来源: WILEY

摘要:

AbstractUsing a double polymerase chain reaction a method was devised for detecting and subtyping hepatitis B virus DNA in serum samples. Primers from the S‐gene were selected from the sequence analyses of five HBV HBsAg subtypes, to amplify HBV DNA and subtype for y specific DNA. Thirty‐eight samples were subtyped fordandydeterminants by radioimmunoprecipitation assay (RIPA) and the polymerase chain reaction (PCR). Subtyping by PCR and RIPA was in agreement in 100°/o of subtype y samples and 83.3% of subtyped, giving an overall correlation of 92.1%. As a third comparison, 12 amplified samples were digested by the restriction enzymeSau3A, which differentiates between subtypesyandd. The digest results agreed with PCR in 83.3% of the samples. In addition, we compared our standard phenol/chloroform extraction against a rapid one step method. The phenol/chloroform stage was found to be essential for the removal of nucleases and polymerase inhibitors present in

ISSN:0146-6615    

DOI:10.1002/jmv.1890360105

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

年代:1992

数据来源: WILEY

摘要:

AbstractIn a prospective study of posttransfusion hepatitis, 14 patients who were diagnosed with post‐transfusion hepatitis C were enrolled randomly for the study of hepatitis C virus (HCV) RNA in saliva. Saliva and serum samples were collected on the same day. Spouses of 11 married patients were also tested for anti‐C100 and HCV RNA. Paired serum and saliva samples were tested for HCV RNA by a nested polymerase chain reaction (PCR). Two primer pairs specific for the non‐coding region of HCV were used for the PCR and a oligonucleotide sequence between the primers was used as the probe for Southern hybridization. Six patients were positive for HCV RNA by first round PCR amplification and an additional four patients were detected after second round PCR. All patients were negative for HCV RNA in saliva after first round PCR, while seven were positive after second round PCR amplification. All seven patients were positive for HCV RNA in paired serum samples. HCV RNA was detectable in saliva from 1 week to 38 months after the onset of hepatitis. All spouses were negative for anti‐100 and HCV RNA. We conclude that HCV RNA is present in the saliva of approximately half of patients with acute and chronic hepatitis C, and the presence of HCV RNA correlates with HCV viremia. The efficiency of HCV transmission is low among

ISSN:0146-6615    

DOI:10.1002/jmv.1890360106

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

年代:1992

数据来源: WILEY

摘要:

AbstractIn contrast to lymphocytic choriomeningitis virus, another arenavirus, Junin virus (JV), the etiologic agent of Argentine hemorrhagic fever, when inoculated into suckling mice, induces lethal meningoencephalitis characterized by a delayed‐type hypersensitivity (DTH)‐like immune response. However, the adult BALB/c mouse is resistant to infection and no DTH reaction can be seen. This different viral sensitivity may be related t o the development of an antigen non‐specific DTH‐suppressor cell pathway at work in the adult mouse. When the resistant mice are treated with cyclophosphamide (Cy) (50 mg/kg each dose) given at days −1,+1,+4 (zero: infection day), animals become susceptible and develop DTH reaction in brain that leads to death. We analyze the influence of the timing of Cy administration on the suppressor system developing after infection. It was found that Cy depletes the previously described JV‐induced suppressor populations (Tsv) but a new suppressor cell (Tsv*) is disclosed bearing the Thy 1+Ly1+2−phenotype which is unable to depress DTH in Cy‐treated animals. With only two doses of Cy corresponding to days −1 and + 1, the target of Tsv*cells is depleted but the third dose is still required to achieve full depletion of Tsv cells which are able to employ the Cy‐resistant antigen‐specific suppressor cells as targets. Since the Cy treatment is able t o deplete the Tsv population together with the target of Tsv*cells, animals became unable to regulate lethal DTH reaction. Thus, a cellular explanation for an empirically established Cy schedule able to abrogate the adult mouse resista

ISSN:0146-6615    

DOI:10.1002/jmv.1890360107

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe relationship between serum immunoglobulins and the severity and risk of Respiratory Syncytial Virus (RSV) infection in the institutionalized elderly was prospectively assessed during the winter of 1989‐1990 at a 591 bed nursing home. Forty RSV infections were identified out of 149 respiratory illnesses by isolation of the virus or by a ≥fold rise in RSV‐specific IgG by EIA. Acute serum RSV IgG levels were similar in those with RSV infection and those with non‐RSV illness. Additionally, among the RSV‐in‐fected elderly there was no correlation between severity of clinical symptoms and level of acute IgG titers by EIA or virus neutralization. The results of this study suggest that humoral immunity does not play a major role in reducing the risk of infection nor modulating the clinical severity of illness in elderly persons with RSV

ISSN:0146-6615    

DOI:10.1002/jmv.1890360108

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

年代:1992

数据来源: WILEY

摘要:

AbstractSyncytium formation, the characteristic cytopathic effect (CPE) of the human immunodeficiency virus (HIV) and cell fusion by Sendai virus, is accelerated by increasing the ambient temperature to values at which normal metabolic activity is inhibited. Uninfected C8166, CEM, and H9 cells were absorbed at 4°C onto monolayers of H9 cells chronically infected with HIV and incubated subsequently at either 37°C or 45°C. Similarly chick and human erythrocytes and Hela cells were agglutinated with Sendai virus at 4°C before incubation at temperatures of up to 50°C. With both viruses the rate of cell fusion was directly related to temperature. Since membrane fluidity is dependent on the phase‐transition temperature points of the membrane lipids it is proposed that sufficient membrane fluidity is essential for cell fusion to occur. The implication of these observations on the cytopathology of HIV is dis

ISSN:0146-6615    

DOI:10.1002/jmv.1890360109

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

年代:1992

数据来源: WILEY

摘要:

AbstractThirty‐nine children without previous cytomegalovirus (CMV) infection received blood transfusion in the National Taiwan University Hospital. The overall transfusion‐acquired CMV infection rate was 36% (14/39). Donor CMV seropositive rate was 70%. None of the nine children who had received seronegative blood became infected, in contrast to 14 of the 21 children (67%) who had received seropositive blood (P= 0.002). Another significant risk factor associated with CMV infection was the use of fresh blood: 13 of 15 (87%) with fresh seropositive blood were infected, in contrast to one of six (17%) with “old” seropositive blood (P= 0.01). Most of the fresh blood was used within 24 hours. This blood processing method was shown to account for the extremely high rate of CMV infection in those who had received fresh seropositive blood. The results indicated that the incidence of CMV infection can be reduced by avoiding the use of fresh blood, especially blood less than 24 hours old. For such a population in Taiwan with high prevalence of positive CMV antibody, this approach was more applicable than screening donor blood for CMV a

ISSN:0146-6615    

DOI:10.1002/jmv.1890360110

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

年代:1992

数据来源: WILEY

摘要:

AbstractAn archival survey of 98 cervical cancer specimens dating from the 1920s to the 1980s was undertaken to determine whether changes had occurred in the prevalence of human papillomavirus (HPV) DNA. HPV DNA was detected in paraffin sections of cancers fixed in 10% formalin by in situ hybridisation (ISH) using HPV 6, 11, 16, and 18 32P‐labelled DNA probes under conditions of high stringency; and by the polymerase chain reaction (PCR) using 20‐mer oligonucleotide primers to amplify 109 bases of the E6 region of HPV 16. In 30 instances results obtained from Southern blot hybridisations which had been carried out on specimens of fresh tissue from the same cancers collected during the 1980s were available for comparison. The rates of HPV DNA detection in cervical cancers ranged from 83% (by Southern or PCR) and 70% (by ISH) on specimens from the 1980s, to 50% and 63% (by ISH and PCR, respectively) on specimens from the 1920s. HPV 16 was by far the most common type, being identified by Southern or ISH i n approximately 92% of HPV DNA‐ positive specimens. No significant change in the prevalence of HPV DNA, or of HPV types, in cervical cancers was found over the 65 year period exa

ISSN:0146-6615    

DOI:10.1002/jmv.1890360111

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

年代:1992

数据来源: WILEY