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L C Archard

Publications and source records attributed to L C Archard.

At least 37 records · Page 2Linked to original sources
PubMed1997

Coxsackievirus B3-induced myocarditis. Characterization of stable attenuated variants that protect against infection with the cardiovirulent wild-type strain.

Coxsackievirus B3 (CVB3) is the enterovirus most frequently involved in human myocarditis or dilated cardiomyopathy. Attenuated variants were derived from a cardiovirulent CVB3 reactivated from a sequenced, full-length cDNA clone. The prophylactic potential of these variants was assessed in SWR/Ola (H-2q) mice. Animals immunized with attenuated variants of CVB3 were protected from myocarditis when challenged subsequently with the cardiovirulent wild-type virus. In contrast to nonimmunized controls, the wild-type virus was not isolated from myocardium of protected mice, nor was viral RNA detected in myocardium by reverse transcription nested polymerase chain reaction. Specific antibody to CVB3 was demonstrated by virus neutralization assay and by indirect immunofluorescence. The attenuated phenotype of one variant, p14V-1, remained stable throughout 20 consecutive passages in SWR mice and induced a markedly lower level of autoantibody against mouse cardiac myosin heavy chain than the cardiovirulent wild type. These data demonstrate that attenuated strains protect against CVB3-induced myocarditis in mice, that the attenuated phenotype is stable, and that they do not persist in myocardium nor induce a significant level of anti-heart anti-body against myosin heavy chain. These attenuants may be the basis of a live vaccine against CVB3 in the prevention of enteroviral heart muscle disease.

Animals↗
PubMed1996

Enterovirus persistence and myocardial damage detected by 111In-monoclonal antimyosin antibodies in patients with dilated cardiomyopathy.

BACKGROUND: Patients with dilated cardiomyopathy in whom enteroviruses in the myocardium are detected are more likely to die than those in whom no viruses have been demonstrated. The presence of enterovirus RNA in the myocardium at endomyocardial biopsy has been shown to be the strongest predictor of reduced survival. These results raise the question as to whether persistent virus might be responsible for continuing myocardial damage. Detection of myocardial cell damage is assessed using 111Indium-labelled monoclonal antimyosin antibodies. The present study was undertaken to address the question of whether the presence of myocardial cell damage by such antibodies in patients with dilated cardiomyopathy can be correlated with enterovirus persistence. PATIENTS AND METHODS: A series of 19 consecutive patients diagnosed as having chronic dilated cardiomyopathy who were referred for evaluation for heart transplantation were studied with 111Indium labelled monoclonal antimyosin antibodies. These patients and 10 controls were screened for enterovirus RNA sequences in endomyocardial biopsy tissue by hybridization with an enterovirus group-specific cDNA probe. RESULTS: Antimyosin uptake, indicative of myocardial cell damage, was observed in 16 of 19 patients (84%), with dilated cardiomyopathy, and enterovirus RNA sequences were detected in endomyocardial biopsies from four of these 16 patients (25%), but not in myocardium from the remaining three patients with a negative antimyosin scan, nor from any of 10 controls. CONCLUSIONS: Although these data do not establish a causal relationship between virus persistence in the myocardium and myocardial damage, the results obtained in the preliminary study support the hypothesis that enterovirus persistence is associated with continuing myocardial damage in patients with dilated cardiomyopathy.

Adult↗
PubMed1996

Similarity in genome organization between Molluscum contagiosum virus (MCV) and vaccinia virus (VV): identification of MCV homologues of the VV genes for protein kinase 2, structural protein VP8, RNA polymerase 35 kDa subunit and 3beta-hydroxysteroid dehydrogenase.

Molluscum contagiosum virus (MCV) and vaccinia virus (VV) are serologically unrelated poxviruses with a disparate genome composition (MCV, 66% G+C; VV, 33% G+C). Molecular studies of MCV have been hindered by the inability to propagate the virus in cells cultured in vitro. We sequenced 7765 bp of MCV DNA cloned from four widely spaced regions throughout the MCV genome and identified a total of 11 potential open reading frames (ORF), designated CX1-11. These include MCV homologues of the VV genes encoding protein kinase 2, structural protein VP8, RNA polymerase 35 kDa subunit and 3beta-hydroxysteroid dehydrogenase. The position and orientation of the MCV ORFs was collinear to the VV genome, with the exception of the region around ORF CX11 which is inverted in the MCV genome.

3-Hydroxysteroid Dehydrogenases↗
PubMed1996

Enterovirus infection of the central nervous system of humans: lack of association with chronic neurological disease.

We have searched, using a sensitive nested-PCR, for enterovirus RNA in cerebrospinal fluid and post mortem central nervous system (CNS) tissue from patients with previous poliomyelitis with or without late functional deterioration, patients with motor neuron disease (MND), and control patients with other neurological disease or without neurological disease. Enterovirus RNA was detected in patients with previous poliomyelitis and MND, but also in control patients with and without neurological disease. Our results do not provide any evidence that such enterovirus infection is related to late functional deterioration in patients with previous poliomyelitis, which could be attributed to other medical conditions in most instances, and do not support the hypothesis that MND is associated with enterovirus infection of the CNS. Nucleotide sequence analysis of enterovirus RNA sequences detected indicated that enteroviruses detected were of the non-polio type.

Adult↗
PubMed1995

Conserved gene sequences for species identification: PCR analysis of the 3' UTR of the SON gene distinguishes human and other mammalian DNAs.

In this paper we show that the polymerase chain reaction (PCR) can be used on regions of highly conserved genes, such as the 3' untranslated region (3' UTR) of the SON gene, to identify the mammalian origin of a sample. Using this test, we have been able to distinguish human, monkey, cat, dog, mouse and hamster DNAs. We have also determined the DNA sequence of these different PCR products, which can be used to reinforce species identification. The advantages of this test are that: (i) no prior information is required on the possible species origin of a sample, (ii) the reaction produces a single PCR product which varies in size according to the species of origin, making the test simple to interpret, and (iii) the target region of DNA amplified in these experiments is small and can easily be sequenced and sized using automated techniques. This small size has enabled us to successfully amplify this product from DNA extracted from compromised material (human bone samples) and so demonstrate that the test is valuable for the characterisation of remains in which DNA is degraded.

Animals↗
PubMed1995

A single amino acid substitution in the capsid protein VP1 of coxsackievirus B3 (CVB3) alters plaque phenotype in Vero cells but not cardiovirulence in a mouse model.

We previously described a large plaque attenuant (p14V-1) derived from a cardiovirulent Coxsackievirus B3 (CVB3) and showed that there were no major determinants of either attenuation or plaque phenotype in the 5' nontranslated region (5'NTR). Part of the region encoding the last 124 amino acids of VP3 and the first 106 amino acids of VP1 of the attenuant was then sequenced and compared to the wild-type. Three nucleotide changes were found in the VP1 coding region: a silent single base change at nucleotide position 2467 (C to U) and a double-base change at position 2690-1 (AA to GT), which leads to a change from lysine to serine at amino acid position 80. This mutation maps to the begining of B-C loop of the three-dimensional structure of VP1 of CVB3, where a distinct surface projection is formed. Two infectious chimeric cDNA clones were constructed, based on a cardiovirulent cDNA construct. In one construct, the 5'NTR and the VP3-VP1 region were from p14V-1 and in the other, only the VP3-VP1 region was from this attenuant. Both chimeric viruses produced large plaques on Vero cell monolayers, similar to p14V-1 but larger than the prototypic cardiovirulent virus. In vivo experiments showed that both chimeric viruses induced myocarditis in a murine model, similar to wild-type virus. We conclude that mutation serine-80 in capsid protein VP1 of p14V-1 is a determinant of the large plaque phenotype but is not responsible for attenuation.

Amino Acid Sequence↗
PubMed1995

Detection of Coxsackievirus B3 RNA in mouse myocarditis by nested polymerase chain reaction.

BACKGROUND: A majority of cases of viral myocarditis are associated with group B Coxsackieviruses (CVB) and the persistence of these viruses in the myocardium is associated with the progression of acute myocarditis to chronic dilated cardiomyopathy. A highly sensitive nested polymerase chain reaction (NPCR) is required to study the mechanisms of viral persistence in the myocardium. OBJECTIVES: To develop an enterovirus group-specific NPCR system, to compare it to the reverse-transcription PCR (RT-PCR) plus Southern hybridisation and to investigate the dynamics of viral RNA in a murine model of myocarditis induced by CVB3. STUDY DESIGN: Primers corresponding to the conserved sequences in the 5'-nontranslated region of enteroviruses were designed to ensure a broad specificity. The specificity of PCR products was confirmed by Southern hybridisation. The sensitivity of RT-PCR or NPCR was assessed using reconstructed infected muscle samples. The myocardial samples of the SWR murine model of CVB3-myocarditis were collected from day 1 to 30 after infection. The presence of viral RNA was detected by the RT-PCR or NPCR and infectious virus was isolated by cell culture. RESULTS: Both RT-PCR and NPCR could detect all 11 representative enteroviruses. The NPCR could detect as few as 0.01 plaque forming unit of virus, 100 times more sensitive than the RT-PCR. Virus was isolated from the myocardium in acute phase, but was no longer recoverable after 9 days. Viral RNA was detected by the NPCR technique throughout the studied period. CONCLUSIONS: An enterovirus group-specific NPCR system was developed and was much more sensitive than the RT-PCR technique. It can replace the Southern hybridisation of RT-PCR products. The presence of viral RNA in the myocardium after acute phase indicates a possibility of CVB3 shifting to persistent infection in the SWR mice.

Journal Article↗
PubMed1995

A new group (type 3) of Mycobacterium celatum isolated from AIDS patients in the London area.

We describe a new group (type 3) of the recently proposed species Mycobacterium celatum isolated from eight patients with AIDS in London, England. Sequences of genes coding for 16S rRNA (EMBL accession no. Z46664) showed a divergence of 17 bases from M. celatum type 2 reference isolates and a divergence of 7 bases from M. celatum type 1 reference isolates. A reference strain is available (NCTC 12882).

Acquired Immunodeficiency Syndrome↗
PubMed1995

Rapid identification of mycobacteria from AIDS patients by capillary electrophoretic profiling of amplified SOD gene.

Aim-Rapid differentiation of mycobacterial species at the genomic level.Methods-The manganese superoxide dismutase (SOD) gene (464 bp) and 16SrRNA (353 bp) from 104 isolates (18 species) of mycobacteria were amplified using polymerase chain reaction (PCR). Products were sequenced and a phenogram of SOD sequences derived. PCR products of SOD gene were digested with HaeIII, and restriction fragment profiles visualised using capillary electrophoresis.Results-Novel SOD sequences were found for M szulgai, M marinum, M phlei, M smegmatis, M chelonei, M paratuberculosis, M malmoense, M intracellulare serotype 7, M intracellulare serotype 18, and M celatum types 1, 2, and 3. Phylogenetic analysis indicated that 18 of 19 species studied had 8-29% interspecies and <6% intraspecies sequence diversity in the SOD gene. No consistent differences were detected between AIDS and non-AIDS isolates. M paratuberculosis showed a unique SOD sequence with a 1.1% (SD 0.5%) diversity from M avium. Capillary electrophoresis profiles were able to differentiate 16 of 18 species within 24 hours.Conclusions-A phenogram of SOD sequences clearly delineated all mycobacterial species and showed two distinct clusters, fast growing species, and the M avium complex (MAC). Within the MAC, M avium (five types), M intracellulare (five types), M scrofulaceum (two types), and M paratuberculosis (one type) could be demonstrated. Phylogenetic diversity of M celatum from MAC, previously suggested by 16SrRNA data, was confirmed. This simple and rapid method for DNA extraction, in conjunction with capillary electrophoresis of SOD restriction fragments, allows rapid identification of mycobacterial isolates.

Journal Article↗
PubMed1994

Clinical and prognostic significance of detection of enteroviral RNA in the myocardium of patients with myocarditis or dilated cardiomyopathy.

BACKGROUND: Enteroviral RNA sequences have been demonstrated in the myocardium of patients with myocarditis or dilated cardiomyopathy from presentation to end-stage disease. The prognosis of heart muscle disease has not previously been evaluated in relation to the detection of enterovirus in myocardial biopsy tissue. METHODS AND RESULTS: We studied 123 consecutive patients with heart muscle disease prospectively. Multiple endomyocardial biopsy samples taken from all patients during diagnostic cardiac catheterization were classified histologically and were examined for enteroviral RNA by use of an enterovirus group-specific hybridization probe. Three enterovirus-negative patients with cardiac amyloidosis were excluded from subsequent analysis. Enteroviral RNA sequences were detectable in 41 (34%) of the remaining 120 patients (group A), while 79 (66%) had no virus detected (group B). The groups did not differ significantly in age, sex, symptomatic presentation, or hemodynamic characteristics; duration of symptoms was significantly shorter in group A (7.8 +/- 9.6 versus 14.9 +/- 19.0 months, P < .05). At follow-up (mean, 25 months; range, 11 to 50 months), patients from group A had an increased mortality compared with those in group B (25% versus 4%, respectively; P = .02). Mortality was also statistically greater in patients with symptomatic cardiac failure (P = .02), those with elevated left ventricular end-diastolic pressures (P = .03), and those in New York Heart Association functional classes III and IV (P = .05). Multivariate regression analysis, however, showed that only the presence of enterovirus RNA and symptomatic heart failure were of independent prognostic value. CONCLUSIONS: These data demonstrate that the detection of enterovirus RNA in the myocardium of patients with heart muscle disease at the time of initial investigation is associated with an adverse prognosis and that the presence of enterovirus RNA is an independent predictor of clinical outcome.

Adolescent↗
PubMed1994

Dilated cardiomyopathy--new insights into the pathogenesis.

There is increasing evidence for a viral aetiology in many patients with dilated cardiomyopathy, although the term viral heart disease is not currently recognized in the WHO/ISFC classification of the cardiomyopathies. The prognosis of dilated cardiomyopathy remains poor with a high morbidity and mortality. New insights into the pathogenesis of dilated cardiomyopathy and the effect of viruses on its prognosis, offer potential for future treatments to modify the natural history of the disease.

Cardiomyopathy, Dilated↗
PubMed1994

Characterization of a murine model of myocarditis induced by a reactivated coxsackievirus B3.

A transfection-reactivated Coxsackievirus B3 (rCVB3), from a full-length cDNA clone of Nancy strain, has previously been shown to be as cardiovirulent as the wild-type virus. Myocarditis induced by this genetically defined virus was compared in SWR mice with the traditional Balb/c model. SWR mice inoculated with rCVB3 developed more severe myocarditis but less severe pancreatitis than Balb/c mice. In contrast to the poor general health and frequent mortality of Balb/c mice following CVB3 infection, the body weight of SWR mice was not affected by CVB3 inoculation and no mortality occurred at titres of 10(2)-10(7) plaque forming units (PFU). Typical myocarditis developed in SWR mice 7 days post infection. Myocarditic foci consisting of necrotic myocardial fibres and mononuclear cell infiltrates resolved by day 30, similar to that observed in Balb/c. However, SWR mice were more sensitive to rCVB3-induced myocarditis than were Balb/c mice: mild myocarditis was induced (4/4) by as low as 10(2) PFU of the virus (ID50 < 10(1.5) PFU), and more severe myocarditis was seen at higher PFU of virus in a dose-dependent manner. The SWR model was tested with attenuated variants derived from cardiovirulent rCVB3. The ID50 for myocarditis was 10(7) PFU for a large plaque-size attenuant and 10(6) PFU for a minute plaque-size attenuant, indicating loss of cardiovirulence by a factor of more than 10(4)-10(5). rCVB3-induced SWR mouse is a sensitive and reliable model for myocarditis. It is useful in assessing the cardiovirulence of different CVB3 variants and evaluating the efficacies of anti-viral therapies. It will allow follow-up study after high dose infection with cardiovirulent rCVB3.

Animals↗
PubMed1993

Attenuation of a reactivated cardiovirulent coxsackievirus B3: The 5'-nontranslated region does not contain major attenuation determinants.

To investigate the molecular basis of pathogenicity of Coxsackieviruses, a virus was reactivated by transfection from a full-length cDNA clone derived from cardiovirulent Coxsackievirus B3 (CVB3). The reactivated virus, rCVB3, was passaged serially in human dermatofibroblasts (HDF). No cytopathic effect was observed up to 12 days after inoculation with rCVB3 or early-passage virus, although disintegration of the monolayers was observed with late-passage virus (10th to 14th passages). Approximately 10% of HDF inoculated with rCVB3 were positive for viral antigens by immunofluorescence using enterovirus- or CVB3-specific monoclonal antibodies. These observations, together with the low infectivity titre of rCVB3 in HDF, suggests that HDF initially support only carrier state infection. After the 14th passage, the cardiovirulence of passaged virus (p14V) in mice was attenuated by a factor of > 10(4). Phenotypic changes of plaque size were also noticed in p14V: An attenuated variant (p14V-1) that produced larger plaques than rCVB3 in Vero cells has been plaque purified. The 5'-terminus of the genome of attenuant p14V-1 was amplified by polymerase chain reaction (PCR) and its sequence determined. Only one point mutation was found within the 5'-nontranslated region (5'NTR) at position 690 (A to U) compared to the viral RNA sequence obtained for rCVB3. An intertypic chimeric virus was reactivated from a cDNA clone after replacing the 5'-terminal 891 nucleotides of the wild-type genome with the corresponding region of the attenuant p14V-1. This chimeric virus, CB3/p14V-1/1, produced wild-type plaques in Vero cells and showed cardiovirulence similar to that of rCVB3 in mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Persistence of enterovirus RNA in muscle biopsy samples suggests that some cases of chronic fatigue syndrome result from a previous, inflammatory viral myopathy.

Molecular hybridization using an enterovirus group specific probe detected virus RNA in muscle biopsy samples from 25 of 96 cases of inflammatory muscle disease and similarly from 41 of 158 cases of postviral fatigue syndrome (PFS). Enterovirus RNA was detected in only two of 152 samples of control muscle. The inflammatory myopathy group comprised patients with polymyositis (PM), juvenile dermatomyositis (JDM) or adult dermatomyositis (DM), and all showed the presence of an inflammatory infiltrate and fiber necrosis on histological examination of a muscle biopsy sample. In contrast, muscle samples from the PFS group were histologically normal except for non-specific changes such as occasional single fiber atrophy. By analogy with enteroviral myocarditis, which can progress to a post-inflammatory disease with persistence of virus in myocardium and disposes to the rapid development of dilated cardiomyopathy, we propose that PFS syndrome may be a sequela of a previous inflammatory viral myopathy.

Biopsy↗
PubMed1992

Characterisation by restriction mapping of three subtypes of molluscum contagiosum virus.

DNA from Molluscum contagiosum virus (MCV) isolates was analysed by restriction endonuclease digestion, identifying three virus subtypes. The structural features of MCV DNA are typical of poxviral DNA. Physical maps of cleavage sites for BamHI, CIaI, and HindIII were constructed for single isolates of each subtype. These differ extensively, indicating the independence of the three subtypes. However, they are closely related, as determined by molecular hybridisation and nucleotide sequence analysis, and their genomes are essentially colinear. There is marked geographical variation in the relative incidence of MCV I and II, whilst MCV III is uniformly rare.

Adolescent↗