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Biomedical subjects

N Booth

Publications and source records attributed to N Booth.

At least 19 recordsLinked to original sources
PubMed2006

Opacity measurements of a hot iron plasma using an x-ray laser.

The temporal evolution of the opacity of an iron plasma at high temperature (30-350 eV) and high density (0.001-0.2 g cm-3) has been measured using a nickel-like silver x-ray laser at 13.9 nm. The hot dense iron plasma was created in a thin (50 nm) iron layer buried 80 nm below the surface in a plastic target that was heated using a separate 80 ps pulse of 6-9 J, focused to a 100 microm diameter spot. The experimental opacities are compared with opacities evaluated from plasma conditions predicted using a fluid and atomic physics code.

Journal Article↗
PubMed2001

Evaluation of estrogenic activity of plant extracts for the potential treatment of menopausal symptoms.

Eight botanical preparations that are commonly used for the treatment of menopausal symptoms were tested for estrogenic activity. Methanol extracts of red clover (Trifolium pratense L.), chasteberry (Vitex agnus-castus L.), and hops (Humulus lupulus L.) showed significant competitive binding to estrogen receptors alpha (ER alpha) and beta (ER beta). With cultured Ishikawa (endometrial) cells, red clover and hops exhibited estrogenic activity as indicated by induction of alkaline phosphatase (AP) activity and up-regulation of progesterone receptor (PR) mRNA. Chasteberry also stimulated PR expression, but no induction of AP activity was observed. In S30 breast cancer cells, pS2 (presenelin-2), another estrogen-inducible gene, was up-regulated in the presence of red clover, hops, and chasteberry. Interestingly, extracts of Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) induced pS2 mRNA expression in S30 cells, but no significant ER binding affinity, AP induction, or PR expression was noted in Ishikawa cells. Dong quai [Angelica sinensis (Oliv.) Diels] and licorice (Glycyrrhiza glabra L.) showed only weak ER binding and PR and pS2 mRNA induction. Black cohosh [Cimicifuga racemosa (L.) Nutt.] showed no activity in any of the above in vitro assays. Bioassay-guided isolation utilizing ER competitive binding as a monitor and screening using ultrafiltration LC-MS revealed that genistein was the most active component of red clover. Consistent with this observation, genistein was found to be the most effective of four red clover isoflavones tested in the above in vitro assays. Therefore, estrogenic components of plant extracts can be identified using assays for estrogenic activity along with screening and identification of the active components using ultrafiltration LC-MS. These data suggest a potential use for some dietary supplements, ingested by human beings, in the treatment of menopausal symptoms.

Binding, Competitive↗
PubMed2000

Attenuation and immunogenicity of a Brucella abortus htrA cycL double mutant in cattle.

PHE1 is a htrA cycL double gene deletion mutant of virulent Brucella abortus strain 2308 (S2308) which has previously been evaluated in the murine and caprine models of bovine brucellosis. This report describes the results of studies conducted with this mutant in the natural bovine host. Six sexually mature, non-gravid heifers were inoculated via the conjunctival sac with 1 x 10(10) colony forming units (CFU) of either the parental S2308 or the htrA cycL gene deletion mutant, PHE1. At 4, 7 and 11 days post-inoculation, PHE1 was found to colonize the bovine host at lower levels than S2308. In a second experiment, eight heifers in mid-gestation were infected with 1 x 10(7) CFU of either strain via the conjunctival sac. The virulent S2308 caused abortions or weak calves in 4/4 cows, while all four cows infected with PHE1 had healthy calves. Furthermore, PHE1 exhibited decreased resistance to killing by cultured bovine neutrophils and macrophages compared to the parental strain. These studies demonstrate that the B. abortus htrA cycL gene deletion mutant PHE1 is highly attenuated in the bovine host when compared to the virulent parental S2308.

Animals↗
PubMed2000

Suicide in the farming community: methods used and contact with health services.

Farmers have a high rate of suicide (1% of suicides in England and Wales). This study sought to test whether farmers would be less likely to have been in contact with primary or mental health services before death due to their reluctance to seek help. The study also sought to identify other characteristics that differentiated suicide among male farmers from other professional groups. A retrospective case-control design was used comparing male farmers with an age and sex matched control group. Cases were all members of the farming community within the Exeter Health District on whom suicide or open verdict had been recorded between 1979 and 1994. 63 Cases were identified and entered into the study. Controls were non-farmers with the same verdict who were matched for age (5 year age bands) sex and social class. Farmers were significantly more likely to use firearms to kill themselves (42% of farmers v 11% controls). They were less likely to use a car exhaust or to die by poisoning (9% farmers v 50% controls). Farmers were significantly less likely to leave a suicide note (21% farmers v 41% controls). There was no significant difference between farmers and controls for numbers in contact with their general practitioner or mental health services in the 3 months before death. There may be some differences in help seeking behaviour between farmers and the general population as over 30% of farmers presented with exclusively physical symptoms. General practitioners should consider depressive and suicidal intention in farmers presenting with physical problems. When depression is diagnosed consideration should be given to the temporary removal of firearms as the high rate of suicide in the farming community may be strongly influenced by access to means.

Agriculture↗
PubMed2000

Sex and relationships following childbirth: a first report from general practice of 131 couples.

Changes in a couple's sexual relationship following childbirth may be more significant than previous studies have suggested. Around 50% of first-time parents in this study described their sex life as 'poor' or 'not very good' eight months after the birth of their baby, and one in five said that they would like help for this. First-time parents rating their general relationship as 'poor' or 'not very good' rose from 1% before pregnancy to 20% eight months after childbirth. Changes in the general relationship and the quality of sex life were associated in these couples.

Coitus↗
PubMed2000

Using scenarios in chronic disease management guidelines for primary care.

The Prodigy system is a guideline-based decision-support system designed to assist general practitioners in England choose the appropriate therapeutic action for their patients. As part of the system, we developed a novel model for encoding clinical guidelines for managing patients with chronic diseases such as asthma and hypertension. The model structures a guideline as a set of choices to be made by the clinician. It models patient scenarios which drive decision making and are used to synchronize the management of a patient with guideline recommendations. The model is robust with respect to available input data and leaves the control of decision-making to the clinician. We have built execution engines to verify the computability of the model. We intend to test the model integrated in up to 200 live systems from at least four system vendors in English General practice.

Angina Pectoris↗
PubMed1999

The PRODIGY project--the iterative development of the release one model.

We summarise the findings of the first two research phases of the PRODIGY project and describe the guidance model for Release One of the ensuing nationally available system. This model was a result of the iterative design process of the PRODIGY research project, which took place between 1995 and 1998 in up to 183 general practices in the England. Release One of PRODIGY is now being rolled out to all (27,000) General Practitioners in England during 1999-2000.

Attitude to Computers↗
PubMed1999

The TextBase project--implementation of a base level message supporting electronic patient record transfer in English general practice.

The TextBase project is a laboratory experiment to assess the feasibility of a common exchange format for sending a transcription of the contents of the Electronic Patient Record (EPR) between different general practices, when patients move from one practice to another in the NHS in England. The project was managed using a partnership arrangement between the four EPR systems vendors who agreed to collaborate and the project team. It lasted one year and consisted of an iterative design process followed by creation of message generation and reading modules within the collaborating EPR systems according to a software requirement specification created by the project team. The paper describes the creation of a common record display format, the implementation of transfer using a floppy disk in the lab, and considers the further barriers before a national implementation might be achieved.

Family Practice↗
PubMed1998

Plasminogen activator in acute myeloid leukaemic marrows: u-PA in contrast to t-PA in normal marrow.

Leukaemic and normal bone marrow samples were compared in terms of their content of the fibrinolytic agents, tissue plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and their inhibitors. plasminogen activator inhibitors 1 and 2 (PAI-1 and PAI-2). Normal marrow contained t-PA as the principal plasminogen activator, whereas in leukaemic marrow samples u-PA was the predominant activator. Both normal and leukaemic marrows contained PAI-1 in similar amounts, but whereas normal marrow contained significant amounts of PAI-2 the leukaemic marrows contained very little. Plasminogen activators were present in uncomplexed, active forms and plasmin-alpha2-antiplasmin complexes were generated locally more prominently in leukaemic marrows. u-PA associated with blast cells may contribute to the severe forms of haemorrhage sometimes occurring in myeloid types of leukaemia.

Acute Disease↗
PubMed1995

A critique of 'at risk' pressure sore assessment tools.

This paper critiques pressure sore risk assessment tools. No attempt is made to describe individual tools in detail as this literature is available elsewhere. The economic case for risk assessment is presented along with the criteria for an effective risk assessment instrument. Reliability and validity studies are reviewed in relation to three risk assessment tools: Norton, Waterlow and Braden. Finally a number of issues related to threshold scores, research design and the need to view pressure sores as a clinical problem rather than a nursing problem are discussed.

Humans↗
PubMed1994

What are the Read Codes?

The Read Codes were initially developed by a general practitioner, Dr James Read from Loughborough, in the early 1980s and rapidly gained acceptance by general practitioners as a popular and useful mechanism for storing structured information about patients in individual, patient-based records, which were beginning to become popular in a few general practices at the time. This short article aims to explain the past and future development of the coding system in the National Health Service as a whole.

Abstracting and Indexing↗
PubMed1991

A pilot study of the efficacy and safety of bolus administration of alteplase in acute myocardial infarction.

OBJECTIVE: To examine the efficacy, safety, and the pharmacokinetic profile of a bolus dose administration regimen of alteplase in the treatment of acute myocardial infarction. DESIGN: An open pilot study. SETTING: District general hospital. PATIENTS: 33 suitable consecutive patients presenting within six hours of the onset of symptoms who satisfied the electrocardiographic criteria for acute myocardial infarction. INTERVENTIONS: Two intravenous boluses of 35 mg alteplase, 30 minutes apart. MAIN OUTCOME MEASURES: Angiographic coronary patency at 90 minutes and 24 hours. Plasma alteplase concentration-time profile and pharmacokinetic analysis. RESULTS: Coronary patency at 90 minutes: 26 of 30 arteries (87%, 95% confidence interval (CI) 74-99%). Coronary patency at 24 hours: 24 of 29 arteries (83%, CI 69-97%). Mean (SD) plasma tissue plasminogen activator (t-PA) concentration reached 4434.8 (2117.8) and 4233.3 (2217.5) ng/ml within 10 minutes of each bolus and fell to 425.8 (288.3) ng/ml between boluses. The estimated peak concentrations at two minutes after boluses were 12,389 (8580) ng/ml and 10,811 (6802) ng/ml. The derived pharmacokinetic variables were volume of distribution 3.11 (1.89) 1, clearance 21.3 (9.3) 1/h, half life 5.9 (1.7) minutes. CONCLUSIONS: This simple administration regimen achieved brief, high concentrations of plasma t-PA that were well tolerated. The regimen was associated with a high coronary patency rate at 90 minutes that was well maintained at 24 hours.

Adult↗
PubMed1990

Occupational asthma caused by latex in a surgical glove manufacturing plant.

A 33-year-old latex glove inspector was diagnosed as having occupational asthma on the basis of peak flow and methacholine-responsiveness changes related to workplace exposure. She had latex sensitivity by skin prick testing. This finding led to a survey of her workplace. Of the 81 workers, 84% completed a questionnaire to assess work-related respiratory symptoms, 79% underwent skin prick testing to latex and six other workplace chemicals, and 62% performed workshift spirometry. Seven workers had spirometric changes consistent with asthma, of whom five had greater than or equal to 15% fall in FEV1 during the workshift. Six of these workers underwent methacholine-challenge testing, and three were found to have a significant improvement in responsiveness to methacholine away from work, suggestive of occupational asthma. Two of these workers had positive skin test responses to latex. Including the index case, 6% of workers who had pulmonary function testing had findings of latex-related occupational asthma. Skin test responses to latex occurred in 11% of workers tested. Our findings suggest that latex should be considered among the causes of occupational asthma.

Adult↗
PubMed1984

Respiratory variables and exposure-effect relationships in isocyanate-exposed workers.

Respiratory variables in 95 isocyanate workers and 37 control workers were compared. The exposed workers had a slightly higher frequency of cough and shortness of breath than the controls and a significantly lower frequency of family history of asthma, hay fever, and bronchitis. The isocyanate workers had slightly lower baseline lung function than the control workers but demonstrated significantly larger declines in their pulmonary function over the work shift. Both groups showed some intraday and intraweek variation in lung function. The changes in lung function over the work shift varied with different job categories, the largest changes occurring in finishing-area workers. A gradation of response was observed when exposure was categorized as nil, low, or high, but no exposure-effect relationships could be demonstrated by regression analysis of either area or personal results.

Adult↗