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W D Rawlinson

Publications and source records attributed to W D Rawlinson.

At least 19 recordsLinked to original sources
PubMed2006

Presence of mouse mammary tumour-like virus gene sequences may be associated with morphology of specific human breast cancer.

BACKGROUND: Mouse mammary tumour virus (MMTV) has a proven role in breast carcinogenesis in wild mice and genetically susceptible in-bred mice. MMTV-like env gene sequences, which indicate the presence of a replication-competent MMTV-like virus, have been identified in some human breast cancers, but rarely in normal breast tissues. However, no evidence for a causal role of an MMTV-like virus in human breast cancer has emerged, although there are precedents for associations between specific histological characteristics of human cancers and the presence of oncogenic viruses. AIM: To investigate the possibility of an association between breast cancer and MMTV-like viruses. METHODS: Histological characteristics of invasive ductal human breast cancer specimens were compared with archival MMTV-associated mammary tumours from C3H experimental mice. The presence of MMTV-like env DNA sequences in the human breast cancer specimens was determined by polymerase chain reaction and confirmed by Southern hybridisation. RESULTS: MMTV-like env gene sequences were identified in 22 of 59 (37.3%) human breast cancer specimens. Seventeen of 43 (39.5%) invasive ductal carcinoma breast cancer specimens and 4 of 16 (25%) ductal carcinoma in situ specimens had some histological characteristics, which were similar to MMTV-associated mouse mammary tumours. However, these similarities were not associated with the presence or absence of MMTV-like gene sequences in the human breast tumour specimens. A significant (p = 0.05) correlation was found between the grade of the human breast cancer and similarity to the mouse mammary tumours. The lower the grade, the greater the similarity. CONCLUSION: Some human breast cancer specimens, in which MMTV-like env DNA sequences have been identified, were shown to have histological characteristics (morphology) similar to MMTV-associated mouse mammary tumours. These observations are compatible with, but not conclusive of, an association between the presence of MMTV-like env DNA sequences and some human breast cancers.

Animals↗
PubMed2006

Correlates of placental infection with cytomegalovirus, parvovirus B19 or human herpes virus 7.

Vertical transmission of viruses is an important cause of morbidity in the fetus and neonate. Placental viral infection indicates risk of vertical transmission, but not always transmission to, or disease of the fetus. Specimens from mothers and babies from three groups-two prospective and one retrospective cohort-were tested for pathogens of teratogenic potential using multiplex PCR. Placental infection was present in 13% of the 105 samples collected. Assessment of the prospective cohorts showed cytomegalovirus (CMV) detected in 4% of placentae from unselected women, parvovirus B19 in 1% and Ureaplasma parvum in 1% of placentae. In a retrospective cohort of women at high risk of transmitting congenital infection due to seroconversion during pregnancy, miscarriage or stillbirth, CMV was detected in 64% and human herpes virus type 7 in 9% of placentae. Of 14 PCR-positive placentae, two were associated with the birth of a living symptomatic infant, two with stillbirth, one with miscarriage, and two with elective terminations of pregnancy. Directed laboratory assessment of women at high risk of transmitting congenital infection, on the basis of clinical or laboratory markers, is important for accurate diagnosis of adverse outcomes of pregnancy. However, routine screening for viruses in the placentae from women with a low-risk serological profile for transmitting congenital infection is unlikely to result in significant numbers of additional diagnoses and is confounded by inadequacy of current diagnostic methods. The major pathogen detected in all cases of placental infection associated with fetal death was human CMV.

Adolescent↗
PubMed2005

Murine cytomegalovirus resistant to antivirals has genetic correlates with human cytomegalovirus.

Human cytomegalovirus (HCMV) resistance to antivirals is a significant clinical problem. Murine cytomegalovirus (MCMV) infection of mice is a well-described animal model for in vivo studies of CMV pathogenesis, although the mechanisms of MCMV antiviral susceptibility need elucidation. Mutants resistant to nucleoside analogues aciclovir, adefovir, cidofovir, ganciclovir, penciclovir and valaciclovir, and the pyrophosphate analogue foscarnet were generated by in vitro passage of MCMV (Smith) in increasing concentrations of antiviral. All MCMV antiviral resistant mutants contained DNA polymerase mutations identical or similar to HCMV DNA polymerase mutations known to confer antiviral resistance. Mapping of the mutations onto an MCMV DNA polymerase three-dimensional model generated using the Thermococcus gorgonarius Tgo polymerase crystal structure showed that the DNA polymerase mutations potentially confer resistance through changes in regions surrounding a catalytic aspartate triad. The ganciclovir-, penciclovir- and valaciclovir-resistant isolates also contained mutations within MCMV M97 identical or similar to recognized GCV-resistant mutations of HCMV UL97 protein kinase, and demonstrated cross-resistance to antivirals of the same class. This strongly suggests that MCMV M97 has a similar role to HCMV UL97 in the phosphorylation of nucleoside analogue antivirals. All MCMV mutants demonstrated replication-impaired phenotypes, with the lowest titre and plaque size observed for isolates containing mutations in both DNA polymerase and M97. These findings indicate DNA polymerase and protein kinase regions of potential importance for antiviral susceptibility and replication. The similarities between MCMV and HCMV mutations that arise under antiviral selective pressure increase the utility of MCMV as a model for in vivo studies of CMV antiviral resistance.

Acyclovir↗
PubMed2005

Development of multiplex PCRs for detection of common viral pathogens and agents of congenital infections.

Potential causes of congenital infection include Toxoplasma gondii and viruses such as cytomegalovirus (CMV), enterovirus, hepatitis C virus, herpes simplex virus types 1 and 2 (HSV-1 and -2), human herpesvirus types 6, 7, and 8, lymphocytic choriomeningitis virus, parvovirus, rubella virus, and varicella-zoster virus. Testing for each of these agents using nucleic acid tests is time consuming and the availability of clinical samples such as amniotic fluid or neonatal blood is often limited. The aim of this study was to develop multiplex PCRs (mPCRs) for detection of DNA and RNA agents in the investigation of congenital infection and an mPCR for the viruses most commonly requested in a diagnostic virology laboratory (CMV, Epstein-Barr virus, enterovirus, HSV-1, HSV-2, and varicella-zoster virus). The assays were assessed using known pathogen-positive tissues (cultures, placentae, plasma, and amniotic fluid) and limits of detection were determined for all the agents studied using serial dilutions of plasmid targets. Nested PCR was performed as the most sensitive assay currently available, and detection of the amplicons using hybridization to labeled probes and enzyme-linked immunosorbent assay detection was incorporated into three of the four assays. This allowed detection of 10 to 10(2) copies of each agent in the samples processed. In several patients, an unexpected infection was diagnosed, including a case of encephalitis where HSV was the initial clinical suspicion but CMV was detected. In the majority of these cases the alternative agent could be confirmed using reference culture, serology, or fluorescence methods and was of relevance to clinical care of the patient. The methods described here provide useful techniques for diagnosing congenital infections and a paradigm for assessment of new multiplex PCRs for use in the diagnostic laboratory.

Amniotic Fluid↗
PubMed2005

Diagnosis of and screening for cytomegalovirus infection in pregnant women.

No single diagnostic test for cytomegalovirus (CMV) infection is currently available for pregnant women at all stages of gestation. Improved accuracy in estimating the timing of primary infections can be used to identify women at higher risk of giving birth to congenitally infected infants. A diagnostic algorithm utilizing immunoglobulin G (IgG), IgM, and IgG avidity was used to prospectively screen serum from 600 pregnant women enrolled from two groups: < or =20 weeks gestation (n = 396) or >20 weeks gestation (n = 204). PCR testing of urine and/or blood was performed on all seropositive women (n = 341). The majority (56.8%) of women were CMV IgG seropositive, with 5.5% being also CMV IgM positive. In the IgM-positive women, 1.2% had a low-avidity IgG, indicating a primary CMV infection and a high risk of intrauterine transmission. Two infants with asymptomatic CMV infection were born of mothers who had seroconverted in the second trimester of pregnancy. Baseline, age-stratified CMV serostatus was established from 1,018 blood donors. Baseline seropositivity from a blood donor population increased with age from 34.9% seroprevalence at less than 20 years of age to 72% seroprevalence at 50 years of age. Women at high risk of intrauterine transmission of CMV were identified at all stages of gestation. Women infected with CMV during late gestation may be more likely to transmit the virus, so failure to detect seroconversions in late gestation may result in failure to detect infected neonates.

Adult↗
PubMed2004

Cytomegalovirus antiviral resistance associated with treatment induced UL97 (protein kinase) and UL54 (DNA polymerase) mutations.

HCMV-related illness due to infections with antiviral resistant virus was verified by phenotypic and genotypic assays in 17% (8/47) of high-risk immunocompromised Australian patients. Selective PCR-sequencing of UL97 (protein kinase; PK) and UL54 (DNA polymerase; DNApol) regions important for antiviral sensitivity, identified the majority (6/8) of resistant strains through detection of mutations known to confer antiviral resistance. Additionally, eight UL54 (DNApol) mutations (N408K, T691S, A692V, S695T, L737M, A834P, V955I, and A972V) of unknown phenotype were identified in six specimens from patients with clinical evidence of antiviral resistant infections. One isolate was resistant to ganciclovir (GCV) and another resistant to PFA on phenotypic testing where mutations in UL97 (PK) or UL54 (DNApol) were not detected, suggesting a loss of correlation between phenotype and genotype. Selective PCR-sequencing of UL97 (PK) and UL54 (DNApol) provided rapid and comprehensive results, but missed some resistance detected by phenotypic assays. A combination of phenotypic and genotypic assays is recommended for complete analysis of CMV antiviral resistance, as well as further definition of the clinical relationship between novel UL54 (DNApol) mutations and antiviral resistance.

Amino Acid Substitution↗
PubMed2004

BK viral infection in an Australian pediatric renal transplant population.

BK virus (BKV) is recognized as a significant cause of renal allograft dysfunction in adults, and there is growing awareness of its importance in the pediatric population. Eighteen pediatric renal transplant recipients and 18 age-matched controls were prospectively studied. Anti-BKV immunoglobulin G (IgG) and IgM titres were assayed in all subjects at entry to the study. Polymerase chain reaction (PCR) for BKV DNA was performed on urine and serum at entry, and prospectively tested again at 4, 8 and 12 months. Mean age +/- s.d. of transplant recipients and controls was 14.6 +/- 3.3 and 13.9 +/- 0.33 yr respectively [not significant (NS)]. Transplant patients were studied at a mean time of 5.6 +/- 4.2 yr post-transplant. 56% of transplant patients and 39% of controls were seropositive (+ve BKV IgG) (NS). Plasma BKV PCR was positive in one transplant patient (who also had positive urine PCR) and in none of the controls. The prevalence of positive urine PCR in transplant patients was greater than in controls (33% vs. 0%, p = 0.02). Positive urine BKV PCR was more commonly found in patients treated with mycophenolate than azathioprine (p = 0.04). We conclude that the prevalence of BKV seropositivity and viral activation in this Australian pediatric renal transplant population is similar to that reported in adult and pediatric populations in other countries. BK viruria was more common in children with greater immunosuppression, suggesting that this group is at higher risk of BKV induced nephropathy.

Adolescent↗
PubMed2003

Survival after pulmonary edema due to enterovirus 71 encephalitis.

BACKGROUND: A distinctive pattern of enterovirus 71 (EV71) infection, characterized by fever, exanthem, acute pulmonary edema (PE), brainstem encephalitis, and flaccid paresis, affects infants and young children. Most die rapidly owing to respiratory failure and fulminant PE. METHOD: The authors report short- and long-term outcome of six survivors of the acute illness. RESULTS: In the context of acute PE and widespread weakness, recognition of the underlying neurologic disorder was facilitated by the distinctive pattern of MRI signal abnormalities in posterior pons and medulla. EV71-specific PCR of clinical samples helped confirm the diagnosis. Acute PE was managed with mechanical ventilation, afterload reduction, and inotrope support, and resolved completely over days. One patient with minimal neurologic recovery died 9 weeks after disease onset. The other patients have residual neurologic dysfunction, varying from subtle monoparesis to severe bulbar dysfunction, central and peripheral respiratory failure, and flaccid quadriparesis. Faster neurologic recovery was associated with less long-term deficit. Long-term outcome was similar in patients treated with and without pleconaril or IV immunoglobulin. Three long-term survivors treated with IV corticosteroids had less severe long-term neurologic disability than two not treated with steroids. CONCLUSION: Acute pulmonary edema and encephalomyelitis occurs with EV71 infection in infants. Long-term neurologic outcome varied from minor, focal weakness to profound, global motor dysfunction with respiratory failure.

Acute Disease↗
PubMed2001

Antiviral agents for influenza, hepatitis C and herpesvirus, enterovirus and rhinovirus infections.

Advances in antiviral therapy have involved both development of new, effective drugs and modification of pre-existing drugs or regimens to increase effectiveness. New agents against influenza virus are the neuraminidase inhibitors zanamivir and oseltamivir, which target specific viral processes and have minimal side effects. New agents for herpesviruses (famciclovir, valaciclovir, valganciclovir) have greater oral bioavailability, allowing less frequent dosing, but mechanisms of action are similar to older agents (aciclovir, ganciclovir). Pleconaril has some activity against enteroviruses and is available for compassionate use in meningitis; it also shows some efficacy against rhinoviruses in ongoing trials, but is not available for routine clinical use. Hepatitis C treatment efficacy has improved dramatically with the introduction of combination interferon-ribavirin therapy, with sustained-response rates up to 60%.

Antiviral Agents↗
PubMed2001

Hepatitis and death following vaccination with 17D-204 yellow fever vaccine.

We describe a man vaccinated with the 17D204 strain of yellow fever virus, who subsequently died of yellow fever. Sequencing of the NS5-39 untranslated region showed that the virus isolated from the patient was identical to the vaccine strain of the same batch, and different from wild-type virus. Both viruses contained a mutation, although the association of this mutation with virulence is unknown. Severe, rapidly progressive, and ultimately fatal disease can follow use of the 17D204 vaccine strain. There is need for renewed discussion as to the safety of the vaccine and the indications for its use.

Adverse Drug Reaction Reporting Systems↗
PubMed2001

Congenital and perinatal infections with cytomegalovirus.

Congenital cytomegalovirus (CMV) infections remain the leading viral cause of congenital malformations in the developed world. Despite advances in our knowledge, the epidemiology and natural history of congenital CMV infection are still poorly understood, particularly in Australia. Congenital CMV causes illness ranging from no clinical disease (asymptomatic, but infected) through to prematurity, encephalitis, deafness and haematological disorders and death. Perinatal CMV acquisition usually results in less severe illness including asymptomatic infection, acute infection with hepatitis, fever, and pneumonitis. CMV infects only humans, and in vitro and in vivo models for intrauterine infection are required in order to test new treatments, and better describe the pathogenesis of congenital CMV. Using new knowledge of the epidemiology and natural history of CMV, treatment regimens during late pregnancy are currently undergoing clinical trial although no definitive recommendations are available.

Amniocentesis↗
PubMed2001

Integrons and gene cassettes in the enterobacteriaceae.

Integrons were detected in 59 of 120 (49%) urinary isolates of Enterobacteriaceae by PCR using degenerate primers targeted to conserved regions of class 1, 2, and 3 integrase genes. PCR sequencing analysis of the cassette arrays revealed a predominance of cassettes that confer resistance to the aminoglycosides and trimethoprim.

Aminoglycosides↗
PubMed2001

Diagnosis of enteric pathogens in children with gastroenteritis.

The aim of this study was to determine the isolation trends of common and emerging pathogens in children over a 12-month period. The study group included 412 children under 6 years with diarrhoea who were either hospitalised, or seen in the outpatients department of The Sydney Children's Hospital. Pathogens were detected in 137 (33%) samples, with rotavirus most common (40%), followed by adenovirus (26%), astrovirus (12%), Campylobacter jejuni (12%), Salmonella spp. (10%) and Giardia lamblia (< 1 %). Giardia-specific antigen (GSA) was detected in 11 of 382 (3%) using an enzyme immunoassay (EIA), and this included four samples in which cysts of G. lamblia were detected by microscopy. Using electron microscopy (EM), viruses were detected in 29 of 120 (24%) samples from hospitalised children and 53 of 171 (31%) outpatients (P = 0.23). Amongst this subset, Norwalk-like viruses (NLVs) were detected by RT-PCR in 10 samples including six of 14 with small round viruses, one of seven with small viral-like particles (SVLPs), and three of 126 EM-negative samples. Lactoferrin, detected by EIA, was 59% more likely to be positive in samples infected with salmonella/campylobacter than in samples in which bacterial pathogens were not isolated. As an indicator for infection with these bacterial agents, the assay showed a sensitivity and specificity of 95 and 40.3%, respectively. A routine microbiological analysis of stools from children of this age group should include a screen for foodborne bacterial agents and rotavirus. Tests for adenovirus, astrovirus and NLVs should be secondary. The cost-effectiveness of including the EIAs for lactoferrin and G. lamblia in the routine testing protocol needs to be evaluated.

Animals↗
PubMed2001

Influenza outbreak in a correctional facility.

The outbreak of influenza in a corrections facility occurred during August 2000. The outbreak progressed following introduction of the disease by a member of the public to the facility. Rapid diagnosis and typing of the influenza isolates was available, although two prisoners required hospital admission due to the severity of complications at the time of diagnosis. The group demonstrated rapid transmission of the virus by the respiratory route and probably by fomites. The identified infecting virus was A/Moscow-like, an H3N2 subtype typically associated with large outbreaks. Prevention of such outbreaks will involve either achieving high rates of vaccination within the risk groups, or rapid (possibly point of care) diagnosis with the institution of antiviral therapy within 48 hours of symptoms. Influenza control within institutions is feasible using such strategies, although it requires considerable planning to have such approaches in place during winter--a time when institutional staff absenteeism is typically high.

Disease Outbreaks↗
PubMed2000

From Bittner to Barr: a viral, diet and hormone breast cancer aetiology hypothesis.

It is hypothesized that the human homologue of the mouse mammary tumour virus (HHMMTV) and other viruses, such as human papillomavirus (HPV) and Epstein-Barr virus (EBV), act as cofactors with diet, oestrogens and other hormones in the initiation and promotion of some types of breast cancer in genetically susceptible women. It is further hypothesized that diet influences the risk of breast cancer, through its influence on oestrogen metabolism and that of other hormones, in combination with genetic and infectious agents.

Breast Neoplasms↗
PubMed2000

Mapping dispersed repetitive loci using semi-specific PCR cloning and somatic cell hybrid mapping.

A simple and effective method based upon semi-specific PCR followed by cloning has been developed. Chromosomal mapping of the generated fragment on a somatic cell hybrid panel identifies the chromosomal position, and yields a unique sequence tag for the site. Using this method, the chromosomal location of one porcine endogenous retrovirus (PERV) was determined. The porcine genomic sequences were first amplified by PCR using a PERV-specific primer and a porcine short interspersed nuclear element (SINE)-specific primer. PCR products were cloned, and those sequences that contained PERV plus flanking regions were selected using a second round of PCR and cloning. Sequences flanking the PERV were determined and a PERV-B was physically mapped on porcine chromosome 17 using a somatic hybrid panel. The general utility of the method was subsequently demonstrated by locating PERVs in the genome of PERV infected human 293 cells. This method obviates the need for individual library construction or linker/adaptor ligation, and can be used to quickly locate individual sites of moderately repeated, dispersed DNA sequences in any genome.

Animals↗
PubMed2000

Transmission of porcine endogenous retroviruses in severe combined immunodeficient mice xenotransplanted with fetal porcine pancreatic cells.

BACKGROUND: Xenotransplantation using pig organs or tissues may alleviate the human donor organ shortage. However, one concern is the potential transmission of pig pathogens to humans, especially pig endogenous retroviruses (PERV), which infect human cell lines in vitro. In this report, the cross-species in vivo transmission of PERV by xenotransplantation was studied using a severe combined immunodeficient (SCID) mouse model. METHODS: Twenty-one SCID mice were transplanted with fetal pig pancreatic cells and left for periods from three to 41 weeks before being killed. DNA and RNA were extracted from liver, spleen, and brain of these mice, and examined for PERV using nested polymerase chain reaction (PCR) and reverse transcriptase-PCR. The pig mitochondrial cytochrome oxidase II subunit gene (COII) was also amplified to monitor the presence of pig cell microchimerism in xenotransplanted tissues, and a housekeeping gene was included to monitor the DNA quality and quantity. RESULTS: Examination of 39 DNA samples from tissues of the 21 xenografted mice identified two mouse tissues (M4-liver and M19-spleen) that were positive for PERV but negative for COII. A total of 23 (59%) of the mouse tissues were positive for both PERV and COII, 6 (16%) were negative for both, and 8 (20%) were positive for COII only. PCR and direct sequencing of the PCR products identified three PERV variants, which were different from the PERV sequence detected by PCR direct sequencing from the pig donor cells. CONCLUSIONS: The PERV+/COII- results from M4-liver and M19-spleen indicated the presence of PERV transmission from pig to mouse tissue. The PERV variants detected in the mouse tissues indicated that different PERVs were transmissible from the pig to mouse tissue during xenotransplantation. The negative reverse transcriptase-PCR results for PERV from three mouse samples including M4-liver and M19-spleen suggest there was no active PERV transcription in the mouse tissues, although this would need to be studied further.

Animals↗