Biomedical subjects

C J Birch

Publications and source records attributed to C J Birch.

32 records · Page 2Linked to original sources

PubMed1992

Clinical effects and in vitro studies of trifluorothymidine combined with interferon-alpha for treatment of drug-resistant and -sensitive herpes simplex virus infections.

Three AIDS patients with severe cutaneous herpes simplex virus (HSV) infection refractory to therapy with acyclovir and foscarnet (2 patients) were treated with a topical preparation of trifluorothymidine (TFT) and interferon-alpha. Complete healing of lesions occurred in 1 patient; a second had significant regression of the infected area. In the third, the lesion was stabilized twice after application of the preparation and reduced in size after a subsequent treatment. In vitro studies confirmed that isolates from these patients were acyclovir- or acyclovir/foscarnet-resistant. In addition, they revealed strong synergy between TFT and interferon-alpha for these isolates and for strains with wild-type drug sensitivity profiles. Topical TFT/interferon-alpha may be of benefit in the therapy of mucocutaneous HSV infections, especially when they are resistant to treatment with systemic antiviral agents.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Altered sensitivity to antiviral drugs of herpes simplex virus isolates from a patient with the acquired immunodeficiency syndrome.

Acyclovir (ACV)-resistant herpes simplex virus type 2 (HSV-2) was isolated from a patient with acquired immunodeficiency syndrome after long-term but intermittent ACV therapy. These thymidine kinase-defective isolates were sensitive in vitro to foscarnet. While combined therapy with ACV and interferon produced only partial clinical improvement, the in vitro effect of this combination against an ACV-resistant isolate from the patient was strongly synergistic. A short course (10-12 days) of intravenous foscarnet controlled severe ulceration, and clinical improvement lasted 6 months. After recurrence and further courses of foscarnet, however, the patient responded poorly, and subsequent HSV isolates were resistant to both ACV and foscarnet and hypersensitive to aphidicolin.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Feline immunodeficiency virus: prevalence, disease associations and isolation.

Of 467 cat serums tested for antibody to feline immunodeficiency virus (FIV) 120 (26%) were positive. The average age of positive cats was 7.5 years (range 1 to 16 years), and 67% were male. Of 110 serums collected in 1980, 27 (24.5%) were positive. A wide variety of clinical signs including oral cavity disease, anorexia, weight loss, lethargy, depression, fever, respiratory and urinary tract disease, conjunctivitis, abscesses, anaemia and lymphadenopathy were observed in the cats with serum antibody. There was often a history of chronic disease or recurrence of particular or various clinical signs in these cats. FIV was isolated from 4 of 8 FIV antibody positive cats by cocultivation of patient lymphocytes with donor lymphocytes in the presence of interleukin 2.

Animals↗

PubMed1988

Use of serotype-specific monoclonal antibodies to study the epidemiology of rotavirus infection.

The development of an enzyme immunoassay (EIA) capable of serotyping human rotavirus (HRV) in faecal extracts has enabled us to retrospectively study the epidemiology of rotavirus infection in Melbourne. Of 552 stored specimens obtained from individuals with rotavirus-associated gastroenteritis between 1975 and 1986, the serotype could be determined in 62%. Infection was most prevalent in two groups, neonates and children aged between 12 and 24 months. In these groups infection was due to different serotypes, type 1 in older children and an untypable virus in infants. Serotype 1 strains were detected in greater numbers than the other serotypes and circulated in each year of the study. Serotype 2 rotaviruses were associated with a large epidemic in 1978, but have been detected only rarely since.

Age Factors↗

PubMed1988

Synthesis of human rotavirus polypeptides in cell culture.

The replication strategy of a human serotype 1 rotavirus, adapted to rapid growth in CV-1 cells, was investigated. A single cycle growth curve revealed eclipse and latent periods of 3 and 4 hours, respectively. Although the extent of reduction of host cell protein synthesis was directly related to the multiplicity of infection of the virus, incorporation of actinomycin D and excess NaCl into the medium resulted in significant reduction in host cell background and enabled observation of viral polypeptides as early as 2 hours post infection. Five polypeptides were found to be structural components of the virion, and a further eight appeared to be nonstructural proteins or intermediates. Five polypeptides were glycosylated during virus replication, but only one of these, VP7, was a definite structural glycoprotein. Pulse-chase experiments revealed that four low molecular weight polypeptides underwent post-translational modifications.

Animals↗

PubMed1985

Isolation of feline rotaviruses and their relationship to human and simian isolates by electropherotype and serotype.

Rotaviruses were detected by electron microscopy in the faecal specimens of six clinically well cats and virus was subsequently isolated from four of them. Analysis of the RNA of the isolates showed the existence of three electrophoretic types characteristic of the 'long' RNA electrophoretic pattern exhibited by rotaviruses. All feline isolates were neutralized only by antiserum to SA11 rotavirus, indicating that these isolates were serotype 3 rotaviruses. Antiserum prepared against a feline strain neutralized all the feline isolates as well as SA11 but showed no neutralizing activity against human isolates of serotype 1, 2 or 4.

Animals↗

PubMed1984

Influenza in Melbourne, 1982. Epidemiology and virology.

The major features of the outbreaks of influenza A and B, which occurred in Melbourne during the winter of 1982, are described. Diagnoses of influenza A or influenza B were established in 310 patients by virus isolation, immunofluorescence, and serological tests. Immunofluorescence was found to be a valuable, rapid, but considerably less sensitive, test than virus isolation, and serodiagnosis was the test of choice either when patients did not present or when specimens were not collected until late in the illness. The results of haemagglutination-inhibition tests performed with a panel of monoclonal antibodies suggest that at least two recognizably different strains of influenza A and influenza B were circulating in the community.

Adolescent↗

PubMed1983

Replication of human rotavirus in cell culture.

Nine strains of human rotavirus were adapted to growth in CV-1 and/or MA-104 cells following pretreatment of virus with trypsin, incorporation of trypsin into culture medium, and use of roller cultures. Immunofluorescence was the most reliable method for the detection of virus replication, although characteristic cytopathic effects were produced sporadically by most isolates. Virus could be readily detected in supernatant fluids of cell cultures and in cell sections by electron microscopy.

Animals↗

PubMed1982

Human rotavirus infection in Efate, Vanuatu.

Serum and fecal samples collected from children with gastroenteritis and healthy children and adults living in Efate, Vanuatu (formerly the New Hebrides), were tested for the presence of human rotavirus antigen or antibody by electron microscopy and enzyme-linked immunosorbent assay. Virtually every subject was found to have detectable levels of antibody and age-specific studies showed that primary infections occur early in life. Human rotavirus was demonstrated to be the cause of an outbreak of gastroenteritis among children which occurred between August and September 1980, although it had not been detected in the population in the preceding 13 months. Epidemics of human rotavirus-associated gastroenteritis appear to occur every 2nd year in this population.

Adolescent↗

PubMed1982

Coronavirus-like particles and other agents in the faeces of children in Efate, Vanuatu.

Between June 1979 and July 1980, faecal specimens were collected from 100 children in Efate, Vanuatu, and examined for the presence of virus-like particles by direct negative staining electron microscopy. Of the children, 40 were hospital patients 22 of whom had gastroenteritis and 18 had other illnesses. The remaining 60 children were apparently healthy controls. Coronavirus-like particles were the most common agents encountered and were detected in approximately 20% of all three groups of children. Particles with the morphological features of calicivirus, astrovirus, adenovirus and parvovirus were also detected.

Adenovirus Infections, Human↗

PubMed1979

Comparison of passive haemagglutination and haemagglutination-inhibition techniques for detection of antibodies to rubella virus.

Because of the technical problems and length of time involved in the satisfactory performance of the haemagglutination-inhibition test for detection of rubella-specific antibodies, a commercially available passive haemagglutination (PHA) kit utilising rubella antigen-sensitised human erythrocytes was tested for its suitability for use in diagnostic laboratories. The immune response to acute rubella infections as measured by PHA was considerably delayed compared to the response measured by haemagglutination-inhitition. Titres of rubella-specific antibody only became comparable six months after the infection. The commercially available PHA kits is a useful addition to diagnostic laboratories for the determination of immune status and, in conjunction with the haemagglutination-inhibition test, can be an indicator of recent rubella infection.

Antibodies, Viral↗

PubMed1979

Comparison of electron microscopy, enzyme-linked immunosorbent assay, solid-phase radioimmunoassay, and indirect immunofluorescence for detection of human rotavirus antigen in faeces.

Four techniques were compared for their practicability, speed, and sensitivity for the detection of human rotavirus. Radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) were found to be the most sensitive means of identifying rotavirus, and, once processed, up to 40 specimens could be examined daily. Electron microscopy, although less sensitive than these techniques, had the advantage of being able to detect other viral agents present in faecal extracts. Indirect immunofluorescence failed to detect rotavirus as often as the other three methods. In laboratories where routine examination of faecal specimens from patients with gastroenteritis is required, ELISA and RIA are useful alternatives to electron microscopy.

Adolescent↗

PubMed1977

A study of the prevalence of rotavirus infection in children with gastroenteritis admitted to an infectious diseases hospital.

In a 12 month survey of infants and children with gastroenteritis admitted to Fairfield Hospital, Melbourne, rotavirus was found in approximately 42% of patients. This virus was detected more often during the winter months, particularly in children aged between 12 months and 3 years. Detection of rotavirus by electron microscopy was found to be more sensitive than by counterimmunoelectrophoresis. Routine bacterial and viral studies revealed that bacterial pathogens and common enteric viruses were associated with relatively few cases of gastroenteritis. There is little doubt that rotavirus is the most important aetiological agent of acute gastroenteritis in yvirus is the most important aetiological agent of acute gastroenteritis in young children in Melbourne.

Age Factors↗

PubMed1974

Enterovirus type 71 infection in Melbourne.

Between November 1972 and May 1973, 60 strains of a new enterovirus were isolated from 49 patients investigated at Fairfield Hospital for Communicable Diseases, Melbourne. Of these patients 39 were admitted to hospital with aseptic meningitis (which was accompanied by a rash in 6), 5 others had rash alone, 4 had acute respiratory tract infections, and 1 had infective polyneuritis. A representative strain from this outbreak had the physicochemical properties of an enterovirus but could not be identified with antisera prepared against the prototype polio, coxsackie, and echo viruses. Studies, performed in association with the WHO Collaborating Centre for Virus Reference and Research, Houston, TX, USA, showed the outbreak to be due to enterovirus 71. Most of the epidemic strains required sodium deoxycholate treatment before neutralization could be demonstrated.

Adolescent↗