Search PubMed⌕ Search

Biomedical subjects

J M Watson

Publications and source records attributed to J M Watson.

At least 127 records · Page 7Linked to original sources
PubMed1994

Cloning and characterization of the platypus mitochondrial genome.

The vertebrate mitochondrial genome is highly conserved in size and gene content. Among the chordates there appears to be one basic gene arrangement, but rearrangements in the mitochondrial gene order of the avian lineages have indicated that the mitochondrial genome may be more variable than once thought. Different gene orders in marsupials and eutherian mammals leave the ancestral mammalian order in some doubt. We have investigated the mitochondrial gene order in the platypus (Ornithorhynchus anatinus), a representative of the third major group of mammals, to determine which mitochondrial gene arrangement is ancestral in mammals. We have found that the platypus mtDNA conforms to the basic chordate gene arrangement, common to fish, amphibians, and eutherian mammals, indicating that this arrangement was the original mammalian arrangement, and that the unusual rearrangements observed in the avians and marsupials are probably lineage-specific.

Animals↗
PubMed1994

Cytokine-induced modulation of tumor suppressor gene expression in ovarian cancer cells: up-regulation of p53 gene expression and induction of apoptosis by tumor necrosis factor-alpha.

OBJECTIVE: Our purpose was to determine the effect of tumor necrosis factor-alpha on anti-oncogene expression and to investigate the relationship between the up-regulation of the p53 tumor suppressor gene and tumor necrosis factor-alpha-mediated apoptosis in epithelial ovarian cancer cell lines. STUDY DESIGN: By means of Northern blot techniques p53 messenger ribonucleic acid expression was assayed in ovarian cancer cells. Tumor cells explanted from patients into Balb/c nude mice were exposed to supernatants from activated monocytes, activated T cells, or the recombinant cytokines interleukin-6 and tumor necrosis factor-alpha. Time- and dose-dependence of p53 up-regulation was measured. Induction of programmed cell death (apoptosis) by tumor necrosis factor-alpha was quantitated by means of a deoxyribonucleic acid fragmentation assay. RESULTS: Detectable levels of messenger ribonucleic acid for p53 were seen in ovarian cancer cells. Tumor necrosis factor-alpha induced a significant up-regulation of p53 messenger ribonucleic acid levels in ovarian cancer cells grown in nude mice and in vitro, whereas interleukin-6 did not. The maximum level of induction was 8 hours, and the up-regulation of p53 was dose dependent. In addition, tumor necrosis factor-alpha induced a dose-dependent increase in deoxyribonucleic acid fragmentation. CONCLUSION: Tumor necrosis factor-alpha induced up-regulation of p53 tumor suppressor gene expression in epithelial ovarian cancer cell lines, together with the induction of cell death by apoptosis.

Apoptosis↗
PubMed1994

Nosocomial Legionnaires' disease in England and Wales, 1980-92.

Two hundred and eighteen nosocomial cases of Legionnaires' disease with 68 deaths were reported to the National Surveillance Scheme for Legionnaires Disease between 1980 and 1992, representing 15% of the reported infections acquired in England and Wales. Twenty-two nosocomial outbreaks accounted for 135 (62%) of these cases, the remainder occurring as single cases either in hospitals where other single cases or outbreaks had been reported in different years or as 'sporadic' cases in hospitals from which no other cases were reported. A clinical history prior to onset of Legionnaires' disease was available for 124 patients, 61 of whom had undergone recent transplant therapy or were immunosuppressed for other reasons. Sixty cases (27%) were diagnosed by culture of the organism and isolates from 56 patients were typed; 25 (42%) were non L. pneumophila serogroup 1 infections. Methods for prevention and control of nosocomial outbreaks are discussed, in particular the susceptibility to Legionnaires' disease of certain groups of hospital patients.

Adolescent↗
PubMed1994

Piccadilly Circus legionnaires' disease outbreak.

BACKGROUND: An outbreak of legionnaires' disease occurred in central London in January and February 1989. An Infection Control Committee was established to investigate the outbreak and institute control measures. The objective of this paper is to describe the investigation and control of the outbreak. METHODS: An epidemiological survey and case-control study were carried out. The subjects were cases of community acquired pneumonia associated with central London with onset of illness in January and February 1989. RESULTS: Thirty-three confirmed cases, including five deaths, and ten suspected cases, including three deaths, were identified with dates of onset from 1 January to 11 February. A clustering of visits by cases to the vicinity of Piccadilly Circus was noted, and a case-control study demonstrated a strong association between illness and visits to this area in the two weeks before onset of symptoms. The causative organism, Legionella pneumophila serogroup 1, was isolated from six patients. Legionella pneumophila of the same serogroup was isolated from water samples from five wet cooling systems (cooling towers) in the area under investigation, but in only two systems was the organism indistinguishable by subtyping from the patients' strains. Many of the cooling towers examined were inadequately maintained, including one of the two above a building adjacent to Piccadilly Circus from which a strain indistinguishable from the outbreak strain was isolated. All cooling towers in the area were shut down until inspected, and only allowed to restart after appropriate maintenance had been instigated. CONCLUSIONS: This outbreak showed the continuing risk of legionnaires' disease posed by wet cooling systems, including cooling towers, and highlighted the need to assess this risk so that appropriate maintenance is carried out. Regulations have recently been introduced, under the Health and Safety at Work Act, requiring notification of all wet cooling systems to the local authority to facilitate the investigation of outbreaks of legionnaires' disease.

Adolescent↗
PubMed1993

Drug resistance in initial isolates of Mycobacterium tuberculosis in England and Wales, 1982-1991.

A total of 1833 out of over 16,000 'initial' isolates of Mycobacterium tuberculosis, submitted by hospital laboratories to the PHLS Regional Tuberculosis Centres in England and Wales between 1982 and 1991, were resistant to one or more first line anti-tuberculosis drugs. Isoniazid resistance was found in 6.1% of these strains, half of which were resistant to isoniazid alone. Resistance to isoniazid and rifampicin, with or without resistance to other drugs, was found in 0.6% of isolates. The proportion of initial isolates resistant to one or more drugs was 9.8%. It ranged from 8.0% to 10.9% between 1982 and 1990, and increased to 14.2% in 1991. The incidence of multiple drug resistance remained very low throughout the period. However, in the light of the problems with tuberculosis and drug resistance emerging elsewhere in the world, vigilance is essential, and enhanced surveillance is being planned in England and Wales.

Adolescent↗
PubMed1993

Legionnaires' disease surveillance: England and Wales, 1992.

One hundred and forty-seven cases of legionnaires' disease, 25 of whom died, were reported in England and Wales in 1992. Six outbreaks were recognised: two in hospitals, three in the community and one associated with a private house. Travel-associated legionnaires' disease accounted for 45% of the total cases for 1992. The highest number of travel cases were associated with Spain, but the annual rate of infection per million visitors to Spain has declined, compared with emerging tourist centres such as Turkey where the rate remains high. Immunosuppressed patients continue to be a susceptible group for nosocomial legionellosis.

Adolescent↗
PubMed1993

Sequences homologous to the human X- and Y-borne zinc finger protein genes (ZFX/Y) are autosomal in monotreme mammals.

The human zinc finger protein genes (ZFX/Y) were identified as a result of a systematic search for the testis-determining factor gene on the human Y chromosome. Although they play no direct role in sex determination, they are of particular interest because they are highly conserved among mammals, birds, and amphibians and because, in eutherian mammals at least, they have active alleles on both the X and the Y chromosomes outside the pseudoautosomal region. We used in situ hybridization to localize the homologues of the zinc finger protein gene to chromosome 1 of the Australian echidna and to an equivalent position on chromosomes 1 and 2 of the platypus. The localization to platypus chromosome 1 was confirmed by Southern analysis of a Chinese hamster x platypus cell hybrid retaining most of platypus chromosome 1. This localization is consistent with the cytological homology of chromosome 1 between the two species. The zinc finger protein gene homologues were localized to regions of platypus chromosomes 1 and 2 that included a number of other genes situated near ZFX on the short arm of the human X chromosome. These results support the hypothesis that many of the genes located on the short arm of the human X were originally autosomal and have been translocated to the X chromosome since the eutherian-metatherian divergence.

Animals↗
PubMed1993

Growth inhibition of ovarian cancer cells induced by antisense IL-6 oligonucleotides.

In previous work, we saw that interleukin-6 (IL-6), a multifunctional cytokine, is produced by epithelial ovarian cancer cells and that ovarian cancer cells express the IL-6 receptor. Here, we examined the possibility that IL-6 acts as an autocrine growth factor for ovarian cancer cells. Inhibition of IL-6 gene expression by exposure to IL-6 antisense oligonucleotides resulted in greatly decreased cellular proliferation. Exposure of ovarian cancer cell lines (CAOV-3, OVCAR-3, and OC-436), to 1-5 microM of a 15-base single-stranded antisense IL-6 oligodeoxynucleotide, specific for a sequence in the second coding exon of the IL-6 gene, resulted in decreased IL-6 production and a > 80-85% inhibition of cellular proliferation. However, the addition of exogenous IL-6 failed to restore the proliferation of the antisense-treated cells. Antibodies to IL-6 did not consistently inhibit cell growth nor did rIL-6 enhance precursor frequency in a limiting dilution analysis. These results suggest that IL-6 does not directly induce the proliferation of ovarian cancer cells although endogenous IL-6 production is needed for optimal cell growth. As the majority of epithelial ovarian cancers produce IL-6, the direct specific inhibition of IL-6 gene expression is of potential therapeutic value.

Base Sequence↗
PubMed1993

Tuberculosis and HIV: estimates of the overlap in England and Wales.

BACKGROUND: A study was designed to determine the extent of the interaction between tuberculosis and human immunodeficiency virus infection in England and Wales. METHODS: Data were obtained from the United Kingdom national AIDS surveillance and the Medical Research Council tuberculosis notification surveys in England and Wales (1983 and 1988). The proportion of patients reported with AIDS known to have had tuberculosis and the proportion of patients notified with tuberculosis known to have HIV infection were estimated. RESULTS: Of the 4360 patients with AIDS reported by 30 June 1991, 200 (4.6%) were in patients reported to have had tuberculosis. Only one of the 3002 patients (0.03%) reported in the 1983 survey of tuberculosis notifications in England and Wales was known to be infected with HIV compared with nine of 2163 patients (0.42%) in the 1988 survey. CONCLUSION: Although the reported number of cases of HIV infection with tuberculosis in this country is increasing it remains small. Complete reporting of cases of AIDS and notification of cases of tuberculosis are essential to enable the two infections to be monitored as the HIV epidemic develops. Special studies, such as those reported here, will need to be undertaken regularly to assess the future extent of the interaction.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Legionnaires' disease surveillance: England and Wales, 1991.

One hundred and eleven cases of legionnaires' disease were reported in England and Wales in 1991, a smaller total than in any year since reporting began in the late 1970s. Four cases were hospital acquired and a further nine may have been associated with a hospital stay. Nosocomial legionellosis remains a cause for concern. Fifty-two cases were associated with travel abroad.

Adolescent↗
PubMed1992

BCG immunisation in England and Wales: a survey of policy and practice in schoolchildren and neonates.

OBJECTIVE: To determine the policy and practice of district health authorities in England and Wales for BCG immunisation in schoolchildren and neonates. DESIGN: Self completion postal questionnaire survey. PARTICIPANTS: District immunisation coordinators. SETTING: 199 district health authorities in England and Wales. RESULTS: Questionnaires were received from 186 districts, a response rate of 94%. Considerable uniformity was observed in many aspects of BCG immunisation policy and practice but some important variations were found. 15 districts no longer carry out a routine schools programme. 148 districts offer BCG to selected groups of neonates and five to all neonates, but 31 districts do not offer BCG to this age group. The recommended action in response to different levels of tuberculin sensitivity in schoolchildren and neonates varied among districts. CONCLUSIONS: Despite the recommendations of the Joint Committee on Vaccination and Immunisation some districts do not offer BCG immunisation to neonates at high risk of tuberculosis and there are important variations in other aspects of BCG policy.

BCG Vaccine↗