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Biomedical subjects

P G Baker

Publications and source records attributed to P G Baker.

At least 19 recordsLinked to original sources
PubMed1999

An ontology for bioinformatics applications.

MOTIVATION: An ontology of biological terminology provides a model of biological concepts that can be used to form a semantic framework for many data storage, retrieval and analysis tasks. Such a semantic framework could be used to underpin a range of important bioinformatics tasks, such as the querying of heterogeneous bioinformatics sources or the systematic annotation of experimental results. RESULTS: This paper provides an overview of an ontology [the Transparent Access to Multiple Biological Information Sources (TAMBIS) ontology or TaO] that describes a wide range of bioinformatics concepts. The present paper describes the mechanisms used for delivering the ontology and discusses the ontology's design and organization, which are crucial for maintaining the coherence of a large collection of concepts and their relationships. AVAILABILITY: The TAMBIS system, which uses a subset of the TaO described here, is accessible over the Web via http://img.cs.man.ac.uk/tambis (although in the first instance, we will use a password mechanism to limit the load on our server). The complete model is also available on the Web at the above URL.

Animals↗
PubMed1998

Recent developments in biological sequence databases.

Biological sequence databases are currently being re-engineered to make them more efficient and easier to use. This re-engineering is also providing an infrastructure to make it easier to interrogate and integrate data from different sources. The net result of this effort should be a great improvement in the power and availability of bioinformatics resources to the general biology community.

Databases, Factual↗
PubMed1998

TAMBIS--Transparent Access to Multiple Bioinformatics Information Sources.

The TAMBIS project aims to provide transparent access to disparate biological databases and analysis tools, enabling users to utilize a wide range of resources with the minimum of effort. A prototype system has been developed that includes a knowledge base of biological terminology (the biological Concept Model), a model of the underlying data sources (the Source Model) and a 'knowledge-driven' user interface. Biological concepts are captured in the knowledge base using a description logic called GRAIL. The Concept Model provides the user with the concepts necessary to construct a wide range of multiple-source queries, and the user interface provides a flexible means of constructing and manipulating those queries. The Source Model provides a description of the underlying sources and mappings between terms used in the sources and terms in the biological Concept Model. The Concept Model and Source Model provide a level of indirection that shields the user from source details, providing a high level of source transparency. Source independent, declarative queries formed from terms in the Concept Model are transformed into a set of source dependent, executable procedures. Query formulation, translation and execution is demonstrated using a working example.

Artificial Intelligence↗
PubMed1996

Final results of the Royal College of Radiologists' trial comparing two different radiotherapy schedules in the treatment of cerebral metastases.

Between February 1990 and February 1993, 25 centres in the UK recruited 544 patients into a prospective randomized trial comparing two whole-brain radiotherapy regimens (30 Gy in ten fractions over 2 weeks versus 12 Gy in two fractions on consecutive days) for the treatment of patients with symptomatic cerebral metastases. Of these patients 533 were eligible for analysis: 270 assigned to the two-fraction arm and 263 to the ten-fraction arm. The two groups were well balanced with respect to patient characteristics. Median survival was 77 days with two fractions (95% CI 68-89) and 84 days for the longer schedule (95% CI 67-102). Analysis of the survival curves showed a marginal advantage for ten fractions (P = 0.04). Performance status (P = 0.0001), site of primary tumour (P = 0.006), dose of dexamethasone (P = 0.004), age (P = 0.04) and randomization treatment (P = 0.03) were independant factors associated with survival. The classification of patients into good or poor risk groups based on these factors, excluding treatment, showed highly significant differences in survival (P < 0.0001). Predictive models suggested that any benefit attributable to the longer radiotherapy schedule was confined to those in a good prognostic group (these patients formed 22% of the study population). Radiation related side effects, other than alopecia, were seen in 12% of patients receiving two fractions and 8% of those given ten fractions. The short survival of many patients hampered the assessment of response, but overall responses were seen in 39% of those given two fractions and 44% of patients receiving ten fractions. These results suggest that any increase in survival due to longer radiotherapy treatment is confined to good prognosis patients, but, for the majority, there is no advantage and the value of radiotherapy for these patients relates purely to the possibility of control or relief of distressing symptoms.

Brain Neoplasms↗
PubMed1994

Steroid receptors, pS2 and cathepsin D in early clinically node-negative breast cancer.

Four oestrogen-regulated proteins of reported prognostic value, oestrogen receptor (ER), progesterone receptor (PR), pS2 and cathepsin D (Cat D), have been quantified by immunoassays, and the latter studied by immunohistochemistry (IHC) in primary tumours from clinically node-negative early breast cancer patients, entered into a trial of breast conservation therapy in which all the patients received adjuvant tamoxifen. ER, PR and pS2 significantly co-correlated but none correlated with Cat D. ER, PR and pS2, but not Cat D, were significantly associated with tumour size and grade, although Cat D tended to show an inverse relationship with the latter. Cat D (radioimmunoassay) in pmol/mg significantly correlated with the IHC score for Cat D in carcinoma cells as well as the number of Cat D-expressing macrophages. At a median follow-up of only 16 months, recurrence was significantly more common in patients with tumours having negative status for ER, PR and pS2 but was not associated with Cat D status.

Biomarkers, Tumor↗
PubMed1989

Breast carcinoma cellularity and its relation to oestrogen receptor content.

The cellularity of 104 primary breast carcinomata was determined by semiautomated image analysis to allow the relation between cellularity and oestrogen receptor content values to be assessed. The oestrogen receptor content of tumours detected by a steroid binding assay showed no correlation with cellularity, although a possible weak negative correlation was observed between tumour cellularity and oestrogen receptor content detected by enzyme immunoassay. It is concluded that there is no single direct correlation between tumour cellularity and oestrogen receptor content.

Adult↗
PubMed1984

Selection and training of disabled persons for scuba-diving. Medical and psychological aspects.

Sixteen persons with a wide range of disabilities were subjected to a formal scuba-diver training course, after passing a medical and psychological assessment specific for divers. Subjects with brain damage and with impaired bladder and bowel control were included. The current general guidelines for the medical assessment of non-disabled divers appear to be suitable for disabled persons, but additionally each particular disability demands careful individual assessment. Such assessment requires knowledge of diving and rehabilitative medicine and diving practice. The study supports the argument that scuba-diving may improve the physical self-concept of selected disabled persons. It is stressed that specialized diving supervision is essential for such people.

Adolescent↗
PubMed1984

Treatment of essential hypertension with beta-blocker plus diuretic: a study of 1402 patients treated by general practitioners with acebutolol 200 mg combined with hydrochlorothiazide 12.5 mg ('Secadrex') once daily for 3 months.

One thousand four hundred and two patients with essential hypertension were treated by their general practitioners for 3 months with one tablet daily consisting of 200 mg acebutolol plus 12.5 mg hydrochlorothiazide: 813 were newly diagnosed and 589 were known hypertensives already on treatment. There was no 'wash-out' period before the latter changed to the study treatment. Newly diagnosed hypertensives had an average initial mean arterial pressure (MAP) of 129.9 mm Hg which fell on average by 18.2% during the study: 79% of patients had good results with final MAP levels less than 113 mm Hg (equivalent to e.g., 160/90 mm Hg), and a further 7% also had good results in that MAP fell more than 15%, another 12.5% had moderate results (falls of 5% to 15%): and only 1.5% had poor results (fell less than 5%). Known hypertensives had an average MAP of 127 mm Hg on previous treatment, which fell on average by 15.4% during this study: 70% of patients had good results with final MAP levels less than 113 mm Hg and a further 7% also had good results in that MAP fell more than 15%: 18% had moderate results and 3% poor results. Pulse rate fell by 12.5% in newly diagnosed and 10% in known treated hypertensives. If allowance is made for withdrawals due to side-effects and to the need for more than one tablet of Secadrex daily, then over all 75.7% had a good blood pressure response to study medication, 13.7% a moderate response and 10.7% a poor response. Adverse effects caused the withdrawal of 4% of newly diagnosed and 5% of treated hypertensives, predominantly nausea/vomiting, lassitude/fatigue and malaise.(ABSTRACT TRUNCATED AT 250 WORDS)

Acebutolol↗
PubMed1981

Multi-centre study of acebutolol in hypertensive subjects: results for patients from the 50 to 64-years' old and over 65 years' old age groups.

The results of a multi-centre general practice study on acebutolol in the treatment of hypertension were examined for two age groups of patients, namely those aged from 50 to 64 years and those aged 65 years and over. A total of 1501 patients was studied and followed-up over a period of 3 months. There was a marked reduction in systolic and diastolic blood pressure with treatment and the results, in terms of efficacy and tolerance, were comparable in both age groups. These findings indicate that acebutolol is warranted in the treatment of elderly patients with hypertension.

Acebutolol↗