Visualisation of phenotypically mixed HIV-1 and HTLV-I virus particles by electron microscopy.

Virions produced after HIV-1 infection of HTLV-I transformed cells have an expanded tropism that has been attributed to the presence of HTLV-I glycoproteins in the envelope. This report now directly identifies these phenotypically mixed virions by immunogold labelling electron microscopy. Furthermore we estimate there are 2% of these in cell-free supernatant, which represents up to 1 x 10(7) particles/ml from an in vitro infection.

A compilation of cellular transcription factor interactions with the HIV-1 LTR promoter.

The human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) represents a model promoter system and the identification and characterisation of cellular proteins that interact with this region has provided a basic understanding about both general eukaryotic and HIV-1 proviral transcriptional regulation. To date a large number of sequence-specific DNA-protein interactions have been described for the HIV-1 LTR. The aim of this report is to provide a comprehensive, updated listing of these HIV-1 LTR interactions.

The explosive human immunodeficiency virus type 1 epidemic among injecting drug users of Kathmandu, Nepal, is caused by a subtype C virus of restricted genetic diversity.

An explosive epidemic of human immunodeficiency virus type 1 (HIV-1) has been documented among the injecting drug user population of Kathmandu, Nepal, whose seropositivity rate has risen from 0 to 40% between 1995 and 1997. By using Catrimox to preserve whole-blood RNA at ambient temperature for transportation, HIV-1 envelope V3-V4 sequences were obtained from 36 patients in this group. Analysis of the sequences indicated a homogenous epidemic of subtype C virus, with at least two independent introductions of the virus into the population.

Genetically identical primate modelling systems for HIV vaccines.

There is an urgent need for a safe and effective vaccine to prevent human immunodeficiency virus (HIV) infection. Several HIV vaccine candidates have shown promise, but many concerns regarding the safety and efficacy of current vaccines remain. A major hindrance in HIV vaccine development is a poor understanding of precisely what functions HIV vaccines are required to perform in order to protect humans from HIV-1.

Can HIV infection be prevented with a vaccine?

The global human immunodeficiency virus type 1 (HIV-1) epidemic is devastating many communities and a well tolerated and effective vaccine is urgently required. Several lines of evident suggest that vaccine-induced protective immunity can be achieved. This evidence includes individuals shown to have natural immunity, and the partially effective immune responses that are generated during natural infection.

Identification of a new recipient in the Sydney Blood Bank Cohort: a long-term HIV type 1-infected seroindeterminate individual.

We have reported previously a cohort of long-term survivors of HIV-1 infection, known as the Sydney Blood Bank Cohort, who received HIV-1-positive blood from a common infected donor. A new recipient, C135, has been identified. This recipient became infected after receiving blood donated during the presumed time of seroconversion of the donor in February 1981.

Expression and characterisation of the ovine respiratory syncytial virus (ORSV) G protein for use as a diagnostic reagent.

Respiratory syncytial virus (RSV) causes severe lower respiratory tract infection in children and calves. Antibodies to ovine RSV (ORSV) are common in sheep, but the clinical disease is not well defined. There is no report of ORSV infection in Australian sheep although respiratory distress syndrome has been described.

The impact of diagnosis of hepatitis C virus on quality of life.

The aim of this study was to examine the effects of diagnosis of hepatitis C virus (HCV) infection on quality of life in a cohort admitted to Fairfield Infectious Diseases Hospital with acute hepatitis from 1971 to 1975. Sera stored from the original admission were tested for antibody to HCV. Systematic approaches were used to locate anti-HCV-positive individuals and outcomes assessed by the Short Form 36 (SF-36) scale and a study-specific questionnaire as well as clinical review.

Tuberculosis infection and homelessness in Melbourne, Australia, 1995-1996.

Objective: To describe tuberculosis infection among persons experiencing homelessness in inner Melbourne, Australia.

Design: Homeless people were surveyed during late 1995 and early 1996. In stage one of the study 284 homeless people from crisis and long-term accommodation sites were recruited by means of stratified, systematic, random sampling.

At-birth immunisation against hepatitis B using a novel pre-filled immunisation device stored outside the cold chain.

We evaluated the immunogenicity of hepatitis B (HB) vaccine in UniJect, a pre-filled, non-reusable injection device, stored at tropical temperatures for up to one month and used to give the first dose of HB vaccine to newborns. Infants in Tabanan district, Bali, Indonesia, were given their first dose of HB vaccine with UniJect stored out of the cold chain, UniJect stored in the cold chain; or standard syringe, needle and multidose vial stored in the cold chain. Subsequent doses were given by usual means and blood samples drawn 4-6 weeks after the third dose.

Sequence variation within the capsid protein of Australian isolates of feline calicivirus.

The capsid protein of Australian feline calicivirus (FCV) isolates is demonstrably different from the prototype strain F9. Five Australian isolates of FCV, dating from 1970 to 1989, were analysed by western blotting and immunoprecipitation. Varying reactivity to a panel of F9 specific monoclonal antibodies (MAbs) was observed.

Serological evidence for swine hepatitis E virus infection in Australian pig herds.

Hepatitis E virus (HEV) is an enterically transmitted human pathogen, with some similarities to caliciviruses. A variant of HEV was recently identified in pigs in the USA, infecting almost 100% of animals in commercial herds. Phylogenetic analysis suggests that this is a true 'swine HEV' distinct from the human virus, but the swine virus may also infect man.

ELISA for IgG-class antibody to hepatitis E virus based on a highly conserved, conformational epitope expressed in Escherichia coli.

In assays based on most recombinant hepatitis E virus (HEV) antigens, the IgG antibody responses to HEV are observed commonly to wane or disappear after the acute phase of infection. Such IgG assays have therefore been used for the diagnosis of acute HEV infection, but they have limited usefulness in seroepidemiological studies. Using western immunoblotting, it was shown previously that the open reading frame (ORF) 2.

Immunisation strategies for viral diseases in developing countries.

In just under a quarter of a century, the Expanded Programme on Immunisation has been associated with an increase in infant immunisation coverage from around 5% to 80%, and the prevention of at least 3 million deaths annually, at very low cost. The global target of poliomyelitis eradication by the year 2000 appears feasible. Measles is the next likely target for eradication via immunisation, through 'catch-up', 'keep up' and 'follow-up' strategies which have proven highly effective in the Americas.

Examination of potential inhibitors of hepatitis A virus uncoating.

Hepatitis A virus (HAV) replication in BS-C-1 cells was studied in the presence of ten potential uncoating inhibitors. Strong inhibition of HAV replication was only observed in the presence of the phenothiazine compound chlorpromazine and the lysosomotropic agent chloroquine, but not by other lysosomotropic agents. Chlorpromazine and chloroquine were found to prevent virus uncoating.

Assessment of long-term outcomes of hepatitis C virus infection in a cohort of patients with acute hepatitis in 1971-1975: results of a pilot study.

Background: To examine the long-term effects of hepatitis C virus (HCV) infection in a cohort of patients admitted to Fairfield Hospital with hepatitis from 1971 to 1975. The availability of stored sera from this time enabled testing to identify those who were anti-HCV positive on admission.

Methods: Sixteen per cent (n = 230) of the cohort tested positive for HCV antibody (anti-HCV).

Does HIV cause depletion of CD4+ T cells in vivo by the induction of apoptosis?

The central pathogenic feature of AIDS is the dramatic loss of CD4+ lymphocytes. Despite more than a decade of intense research, the exact mechanism by which HIV causes this is still not understood. A major model for T cell depletion, proposed originally by Ameison and Capron in a report published in 1991, is that HIV sensitizes CD4+ T cells for activation-induced apoptosis.

Respiratory syncytial virus G glycoprotein expressed using the Semliki Forest virus replicon is biologically active.

The respiratory syncytial virus (RSV) G glycoprotein mediates attachment of RSV to cells via an unknown receptor. To study G glycoprotein function we have cloned two variants of the RSV G gene into a Semliki Forest virus (SFV) expression vector, a full length (rG) and soluble (srG) G glycoprotein variant. By immunofluorescence microscopy, rG was found to be predominantly membrane associated, while srG was mostly cytoplasmic.

Hepatitis A vaccination of child care workers in Victoria: are recommendations being implemented?

This study examined the self-reported hepatitis A and B immunisation status of child care workers, the level of awareness among child care workers of the NHMRC recommendation for immunisation against hep. A and centre practices. A confidential mail survey was conducted in June 1996 with workers and co-ordinators from 113 randomly selected child care centres.