Normal phosphorylation of duck hepatitis B virus L protein is dispensable for infectivity.

A fraction of the large surface protein (L) of duck hepatitis B virus (DHBV) is phosphorylated at serine or threonine residues (E. Grgacic & D. Anderson, Journal of Virology 68, 7344-7350, 1994).

Enhanced T-cell immunogenicity and protective efficacy of a human immunodeficiency virus type 1 vaccine regimen consisting of consecutive priming with DNA and boosting with recombinant fowlpox virus.

The induction of human immunodeficiency virus (HIV)-specific T-cell responses is widely seen as critical to the development of effective immunity to HIV type 1 (HIV-1). Plasmid DNA and recombinant fowlpox virus (rFPV) vaccines are among the most promising safe HIV-1 vaccine candidates. However, the immunity induced by either vaccine alone may be insufficient to provide durable protection against HIV-1 infection.

The prevalence of hepatitis C in patients admitted with acute hepatitis to Fairfield Infectious Diseases Hospital, 1971-1975.

Objective: To identify and determine trends in the prevalence of hepatitis C virus (HCV) antibody in stored sera from 1971 to 1975 and to determine associations with HCV seropositivity, including markers for other hepatitis infections and possible routes of transmission.

Design: A retrospective cross-sectional study.

Patients And Setting: 1511 adults admitted to Fairfield Infectious Diseases Hospital, Victoria, with a clinical and biochemical diagnosis of hepatitis between 1 January 1971 and 31 December 1975.

Coresistance to zidovudine and foscarnet is associated with multiple mutations in the human immunodeficiency virus type 1 reverse transcriptase.

Human immunodeficiency virus type 1 (HIV-1) isolates obtained from a patient with AIDS were assessed for coresistance to foscarnet and zidovudine. An HIV-1 strain (AP20) coresistant to foscarnet and zidovudine was isolated after 20 months of continuous combination therapy. The reverse transcriptase (RT) gene of AP20 had 41 substitutions which were different from the HXB2-D sequence and 9 that were different from the sequence of its foscarnet-sensitive, zidovudine-resistant progenitor virus (AP6).

Juvenile offenders and hepatitis B: risk, vaccine uptake and vaccination status.

Objective: To determine the hepatitis B vaccination status of juvenile offenders in a custodial setting, their perceived risk of hepatitis B infection, and factors influencing vaccine uptake.

Design: 130 males aged 14-17 years resident at the Melbourne Juvenile Justice Centre for at least one week between mid-January and mid-December 1996 were invited to participate; 90 (69%) completed a doctor-administered questionnaire, and blood for serological testing was obtained from 83 of these participants.

Main Outcome Measures: Whether hepatitis B vaccine had been offered; whether hepatitis B vaccine had been given; the presence of antibodies to hepatitis B and C; risk factors and self-perceived risk of hepatitis B.

Immunogenicity and reactogenicity of a combined hepatitis A-hepatitis B vaccine in adolescents.

Objective: To evaluate the immunogenicity and reactogenicity of two lots of a combined hepatitis A-hepatitis B vaccine (HAV, HBV) in healthy 15 to 18 year olds.

Design: This was a double-blind, randomized clinical study. Vaccine was administered into the deltoid at 0, 1, and 6 months.

Serostatus for vaccine-preventable diseases in residents at Melbourne Juvenile Justice Centre.

There are concerns in Australia about inadequate rates of childhood immunisation, an important preventive measure to reduce infectious diseases. The population passing through the Melbourne Juvenile Justice Centre (MJJC) comes from a background at high risk for inadequate immunisation and outbreaks can occur in residential institutions. MJJC residents were invited to participate in a study by completing a medical officer-administered risk behaviour questionnaire and/or giving a blood sample.

A methodology for sampling and accessing homeless individuals in Melbourne, 1995-96.

A methodology for sampling homeless populations in inner Melbourne was developed to study their health status and prevalence of tuberculosis. This paper describes the design, development and implementation of the project. The results of health status and tuberculosis analysis are published elsewhere.

HIV positive tests at Coronial Services in Victoria 1989-1996: lessons for HIV surveillance.

Results of routine testing at other sites can supplement surveillance of the HIV epidemic in Australia which is largely based upon voluntary testing. Since 1989, systematic onsite HIV testing has been undertaken on all bodies taken to the Victorian Institute of Forensic Medicine (VIFM). Information was collected on all cases of HIV infection detected at VIFM between 1989 and 1996, and matched to surveillance databases.

Specificity of binding of HIV-1 anti-p24 antibodies to CD4+ lymphocytes from HIV-infected subjects.

The clinical utility of a flow cytometric assay (FCA) for intracellular HIV p24 antigen was evaluated in a group of HIV-1-infected subjects. A previously described method, p24-FCA (1), was modified to minimize nonspecific staining and to include irrelevant isotype-matched control antibodies. Blood mononuclear cells from 32 HIV-1 seropositive subjects and 14 HIV-1 seronegative controls were examined.

Restricted HIV-1 infection of human astrocytes: potential role of nef in the regulation of virus replication.

A small percentage of astrocytes are consistently infected in vivo by HIV-1 and may contribute to neuropathogenesis despite a non-productive infection. Overexpression of the nef gene product has been associated with their infection both in vivo and in vitro. We examined the role of the nef gene during HIV replication in astrocytes (U251MG cells) following transfection with pNL4-3 proviral plasmid or isogenic strains containing a deletion or point mutation in the nef gene (pNL4-3deltaNef; pNL4-3-nef-stop).

Impaired fitness of foscarnet-resistant strains of human immunodeficiency virus type 1.

Foscarnet (PFA) is a pyrophosphate analogue antiviral active against human immunodeficiency virus (HIV-1) and herpesviruses. Strains of HIV-1 resistant to PFA have mutations in the HIV-1 reverse transcriptase (RT). We examined the influence of PFA resistance mutations, in different genetic backgrounds, on HIV-1 replication competency in both replication kinetics and growth competition assays.

Vietnamese-speaking injecting drug users in Melbourne: the need for harm reduction programs.

While research on aspects of injecting drug use (IDU), including injecting and sexual risks for HIV transmission, has been progressing in 'mainstream' Australian populations, there has been little among non-English speaking background (NESB) communities in Australia, particularly the South-East Asian communities, of which the Vietnamese is the largest. This exploratory study employed and trained peer workers to recruit and interview IDUs of Vietnamese origin in Melbourne on a wide range of subjects related to risks associated with their drug using, as an initial assessment of risk-taking behaviours for blood-borne viruses among Vietnamese-speaking IDUs. A finger-prick blood sample was taken where possible to measure antibody status to HIV, HBV and HCV.

Health indicators and risks among people experiencing homelessness in Melbourne, 1995-1996.

During the study's first stage, 284 homeless people from crisis and long-term accommodation sites were surveyed using stratified, systematic sampling. The second stage involved a survey of a convenience sample of 100 homeless people from squats and the streets. Participants completed a questionnaire, Mantoux testing was performed and blood taken for gamma-interferon assay, liver and renal function tests.

Pathogen interactions with cytokines and host defence: an overview.

This review summarises some of the immune evasion tactics adopted by pathogens. They include the antagonism of immune function through the use of homologues of cytokine receptors, expression of viral proteins which interact with cytokine signal transduction and expression of cytokine mimics and host proteins that influence the Type I or II cytokine responses. Some of the viral defense molecules that interfere with the functions of cytokines include the EBV protein BCRF1 (viral IL-10) which blocks synthesis of cytokines such as IFN-gamma, viral IL-17 and IL-8 receptor encoded by the herpesvirus saimiri genome and chemokine receptor homologues of Epstein-Barr virus, herpesvirus saimiri and cytomegalovirus.

Effect of GM-CSF on HIV-1 replication in monocytes/macrophages in vivo and in vitro: a review.

Cells of macrophage lineage constitute the main cellular target of Human Immunodeficiency Virus type 1 (HIV-1). Replication of HIV-1 in monocyte/macrophages is generally augmented by factors promoting their differentiation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a key regular of the differentiation of cells of macrophage lineage.

Anomalies in Nef expression within the central nervous system of HIV-1 positive individuals/AIDS patients with or without AIDS dementia complex.

In determining levels of expression of HIV-1 Nef protein within the central nervous system (CNS) we assessed antibody responses to the protein both peripherally and in CNS. Antibodies to Nef were not detected within the CNS despite detection of antibodies to both gp41 and Nef in peripheral blood and representative virus isolates derived from CNS and peripheral blood (PB) samples containing full length nef sequence and virus-infected cells expressing Nef protein. We conclude from this that expression of Nef within the CNS is such that little or no antibody production occurs and that these differences indicate that Nef protein may not be directly contributing to the AIDS dementia complex.

HIV-1 DNA and mRNA concentrations are similar in peripheral blood monocytes and alveolar macrophages in HIV-1-infected individuals.

Objective: To determine the relative contribution of alveolar macrophages, peripheral blood monocytes (PBM) and peripheral blood lymphocytes (PBL) from HIV-infected individuals to HIV-1 viral load.

Methods: Alveolar macrophages were obtained by flexible bronchoscopy, and PBM and PBL by venipuncture from HIV-1-infected individuals. Alveolar macrophages and PBM were purified using immunomagnetic bead selection to deplete CD3+ and CD19+ cells from bronchoalveolar lavage and peripheral blood mononuclear cells, respectively.

Documentation of children's vaccination status in child care centres in Victoria.

Objective: To assess the record-keeping of child care centres in Victoria with respect to children's vaccination status.

Methodology: A random sample of 113 centres from a list of over 800 registered Victorian child care centres received a mailed questionnaire on characteristics and policies of the centre, including documentation of attending children's vaccination status.

Results: The response rate was 86.

Serological detection of attenuated HIV-1 variants with nef gene deletions.

Objective: To investigate whether members of a transfusion-linked cohort (the Sydney Bloodbank Cohort) infected with a nef-deleted strain of HIV-1 could be differentiated from individuals infected with wild-type strains of HIV-1 by characterizing the Nef antibody response of cohort members.

Design: Retrospective and prospective analysis of the nef gene sequence and the antibody response to Nef peptides in HIV-infected subjects.

Methods: Plasma was obtained from all individuals of the Sydney cohort, and from a variety of HIV-1-infected and uninfected controls.

Efficacy of fusion peptide homologs in blocking cell lysis and HIV-induced fusion.

Contrary to earlier reports, we have found that tri- and hexapeptides analogous or homologous with segments of the 23-residue N-terminal fusion sequence (FS) of the viral transmembrane glycoprotein gp41 (residues 517-539) did not significantly inhibit HIV-1-induced syncytium formation, using an uninfected cell-infected cell fusion assay. In contrast, we found that the high molecular weight apolipoprotein A-1 and a 23-residue analog of the FS, with the phenylalanine residues at positions 524 and 527 replaced with alanine residues, were effective inhibitors. Although the tripeptides were ineffective as inhibitors of syncytium formation, we found a number of them inhibited red cell lysis induced by the synthetic peptide AVGIGALFLGFLGAAGSTMGARS (based on the HIV-1 gp41 FS).