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Biomedical subjects

A Walker

Publications and source records attributed to A Walker.

At least 55 records · Page 3Linked to original sources
PubMed2002

Randomised trial of endoscopy with testing for Helicobacter pylori compared with non-invasive H pylori testing alone in the management of dyspepsia.

OBJECTIVE: To compare the efficacy of non-invasive testing for Helicobacter pylori with that of endoscopy (plus H pylori testing) in the management of patients referred for endoscopic investigation of upper gastrointestinal symptoms. DESIGN: Randomised controlled trial with follow up at 12 months. SETTING: Hospital gastroenterology unit. PARTICIPANTS: 708 patients aged under 55 referred for endoscopic investigation of dyspepsia, randomised to non-invasive breath test for H pylori or endoscopy plus H pylori testing. MAIN OUTCOME MEASURE: Glasgow dyspepsia severity score at one year. Use of medical resources, patient oriented outcomes, and safety were also assessed. RESULTS: In 586 patients followed up at 12 months the mean change in dyspepsia score was 4.8 in the non-invasive H pylori test group and 4.6 in the endoscopy group (95% confidence interval for difference -0.7 to 0.5, P=0.69). Only 8.2% of patients followed up who were randomised to breath test alone were referred for subsequent endoscopy. The use of non-endoscopic resources was similar in the two groups. Reassurance value, concern about missed pathology, overall patient satisfaction, and quality of life were similar in the two groups. The patients found the non-invasive breath test procedure less uncomfortable and distressing than endoscopy with or without sedation. No potentially serious pathology requiring treatment other than eradication of H pylori was missed. CONCLUSION: In this patient group, non-invasive testing for H pylori is as effective and safe as endoscopy and less uncomfortable and distressing for the patient. Non-invasive H pylori testing should be the preferred mode of investigation.

Adolescent↗
PubMed2002

The politics of intergenerational relations.

The main purpose of this article is to emphasise the critical role of politics and political ideology in determining the nature of intergenerational relations. This is not the only source of influence on intergenerational relations but it has been under-emphasised in scientific inquiry. Social policies embodying political ideology have an impact at both micro and macro levels. The article summarises the ethical basis of generational solidarity, the nature of the social contract, the changes taking place in relations between the generations and the recent impact of political ideology on the social contract. The main point of reference is the UK.

Aged↗
PubMed2002

Randomized clinical trial of no wound drains and early discharge in the treatment of women with breast cancer.

BACKGROUND: Women undergoing surgery for primary breast cancer routinely have suction drains inserted deep to the wounds, which are removed approximately 6-8 days after operation, requiring a period of stay of that duration in hospital. The aim of this study was to perform a prospective randomized clinical trial to evaluate a new surgical technique of suturing flaps without wound drainage, combined with early discharge, in women undergoing surgery for breast cancer. METHODS: A total of 375 patients undergoing surgery for breast cancer were randomized to conventional surgery or suturing of flaps with no drain. The main outcome measures were length of hospital stay, surgical morbidity, psychological morbidity and health economics. RESULTS: Suturing of flaps and avoiding wound drainage in women undergoing surgery for breast cancer resulted in a significantly shorter hospital stay. Adopting this surgical technique with early discharge did not lead to any difference in surgical or psychological morbidity. Health economic benefits to the National Health Service resulted from saved bed days with no impact on community costs. CONCLUSION: Wound drainage following surgery for breast cancer can be avoided, thereby facilitating early discharge with no associated increase in surgical or psychological morbidity.

Bed Occupancy↗
PubMed2002

An economic analysis of specialist heart failure nurse management in the UK; can we afford not to implement it?

AIMS: Hospital activity represents the major component of health care expenditure related to heart failure. This study evaluated the economic impact of applying specialist nurse management programmes that limit heart failure-related hospital readmissions within a whole population. METHODS: Using a reliable and validated estimate of the current level and cost of heart failure-related hospital activity in the U.K., we determined the thresholds at which the actual cost of establishing and applying a national service based on three different models of specialist nurse management would be equal to the 'cost' of bed utilization associated with preventable hospital readmissions in the year 2000. The three models of care examined were home-based, clinic-based or a combination of home plus clinic-based, post-discharge follow-up. The potential impact of this service was based on a U.K.-wide caseload of 122,000 patients discharged to home with a discharge diagnosis of congestive heart failure in that year. RESULTS: Based on heart failure-specific patterns of hospital activity, we estimate that 47,000 of these 122,000 patients would normally accumulate a total of 594000 days of associated hospital stay from 49,000 readmissions (for any reason) within 1 year of hospital discharge. The cost of these admissions to the National Health Service was calculated at 166.2 million pounds sterling. Taking into account other costs associated with such hospital activity (e.g. general practice and hospital outpatient visits) each 10% reduction in recurrent bed utilization would be associated with 18.0 million ponds sterling in cost savings. Alternatively, the cost of applying a U.K.-wide programme of home-, clinic- or home plus clinic-based follow-up was calculated to be 69.4 pounds sterling, 73.1 pounds sterling and 72.5 million pounds sterling per annum, respectively. The relative thresholds at which generated 'cost-savings' would equal the cost of applying these programmes of care would therefore be a 38.5%, 40.6% and 40.3% reduction in recurrent bed utilization, respectively. If, as expected, a home-based programme of specialist nurse management reduced recurrent bed utilization by 50% or more, annual savings equivalent to 169,000 pounds sterling per 1000 patients treated would be generated. CONCLUSIONS: This is the first study to examine the economic consequences of applying a specialist nurse-mediated, post-discharge management service for heart failure within a whole population. Our findings suggest that such a service will not only improve quality of life and reduce readmissions in patients with congestive heart failure, but also reduce costs and improve the efficiency of the health care system in doing so.

Community Health Nursing↗
PubMed2002

Mometasone furoate is a less specific glucocorticoid than fluticasone propionate.

Fluticasone propionate (FP) and mometasone furoate (MF) are potent synthetic corticosteroids that are widely used as anti-inflammatory agents to treat respiratory diseases. As part of the assessment of the potential for side-effects associated with their use, their activities, not only at the glucocorticoid receptor (GR) but also at the other members of the steroid nuclear receptor family, have been compared. Cell-based functional systems were established to measure different aspects of GR function, as well as the activity at all the other steroid nuclear receptors. The effects of MF and FP on the GR were potent and indistinguishable. Neither corticosteroid showed any activity at the oestrogen receptor, while both were weak antagonists of the androgen receptor. FP was a relatively weak agonist of the progesterone receptor but MF was a very potent agonist of the progesterone receptor, giving activity at similar concentrations to those that stimulate the GR (concentration generating 50% maximal effect (EC50)=50 pM). Moreover, while FP was a weak antagonist of the mineralocorticoid receptor (concentration generating 50% maximal inhibitory effect=80 nM), MF displayed potent partial agonist activity (EC50=3 nM, 30%). Mometasone furoate is considerably less specific for the glucocorticoid receptor than fluticasone propionate, showing significant activity at other nuclear steroid receptors.

Androstadienes↗
PubMed2001

Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins.

A modern human-like sequence of dental development, as a proxy for the pace of life history, is regarded as one of the diagnostic hallmarks of our own genus Homo. Brain size, age at first reproduction, lifespan and other life-history traits correlate tightly with dental development. Here we report differences in enamel growth that show the earliest fossils attributed to Homo do not resemble modern humans in their development. We used daily incremental markings in enamel to calculate rates of enamel formation in 13 fossil hominins and identified differences in this key determinant of tooth formation time. Neither australopiths nor fossils currently attributed to early Homo shared the slow trajectory of enamel growth typical of modern humans; rather, both resembled modern and fossil African apes. We then reconstructed tooth formation times in australopiths, in the approximately 1.5-Myr-old Homo erectus skeleton from Nariokotome, Kenya, and in another Homo erectus specimen, Sangiran S7-37 from Java. These times were shorter than those in modern humans. It therefore seems likely that truly modern dental development emerged relatively late in human evolution.

Adult↗
PubMed2001

Surgical therapy for tremor in multiple sclerosis: an evaluation of outcome measures.

OBJECTIVE: To assess the reliability, validity, and sensitivity of outcome measures that might be used in a clinical trial of surgery for the treatment of severe tremor associated with MS (MS tremor). METHODS: Nine patients with MS tremor were evaluated before and 3 and 12 months after thalamic surgery (six thalamotomy, three deep brain stimulation). A clinical tremor rating scale (CTRS), a novel quantitative movement analysis technique (QMA), and a variety of measures of disability, neurologic impairment, and quality of life was utilized. RESULTS: Both the CTRS and QMA were reliable measures of tremor and both were sensitive to the improvement in tremor following surgery. However, QMA correlated with disability measures and corresponded better to patient and examiner assessment of surgical results. The disability scales used were insensitive to functional improvements that may follow surgery. The box and blocks test clearly separated three patients who had excellent results from three who had poor results. Baseline QMA values predicted improvement on the box and blocks test. CONCLUSIONS: 1) QMA is a reliable, objective and valid measure of MS tremor that could be used in a clinical trial. 2) The box and blocks test can detect the improvement in prehensile function that follows surgery, but standard disability scales are poorly responsive to this change. 3) Preoperative QMA values may predict which patients are most amenable to functional improvement after surgery.

Adult↗
PubMed2001

[How to manage all those ECGs? Experiences with computer-based storage and interpretation of electrocardiograms in the county of Vastmanland].

We describe our experience using a database (Sicare, Siemens Elema) containing 381,000 ECGs covering 90% of all ECGs during 11 years in the county of Västmanland, Sweden, with 260,000 inhabitants. The database expedites rapid recovery of earlier ECGs. For instance, in patients admitted to coronary care with chest pain and ST-elevation, speedy access to an earlier ECG with identical ST-elevation may be crucial for avoiding unnecessary and potentially harmful thrombolysis. The database also enables us to select ECGs with a specific diagnosis, for instance atrial fibrillation. This facilitates characterization and quality control of treatment of atrial fibrillation in a well-defined population.

Archives↗
PubMed2001

Myocardial Akt activation and gender: increased nuclear activity in females versus males.

Cardiovascular disease risk is higher in men than women, but the basis for this discrepancy remains controversial. Estrogenic stimulation of the myocardium or isolated cardiomyocytes has been purported to exert multiple beneficial effects associated with inhibition of maladaptive responses to pathogenic insults. This report describes a significant difference between the sexes in myocardial activation of Akt, a protein kinase that regulates a broad range of physiological responses including metabolism, gene transcription, and cell survival. We find that young women possess higher levels of nuclear-localized phospho-Akt(473) relative to comparably aged men or postmenopausal women. Both localization of phospho-Akt(473) in myocardial nuclei of sexually mature female mice versus males and Akt kinase activity in nuclear extracts of hearts from female mice versus males are elevated. Cytosolic localization of phospho-forkhead, a downstream nuclear target of Akt, is also increased in female relative to male mice, suggesting a potential mechanism for cardioprotective nuclear signaling resulting from Akt activation. Phospho-Akt(473) levels and localization at cardiac nuclei are similarly increased in transgenic mice with myocardium-specific expression of insulin-like growth factor I, a proven stimulus for Akt activation. Phospho-Akt(473) is also localized to the nucleus of cultured cardiomyocytes after exposure to 17beta-estradiol or genistein (a phytoestrogen in soy protein-based diets), and neonatal exposure of litters to genistein elevated nuclear phospho-Akt(473) localization. The activation of Akt in a gender-dependent manner may help explain differences observed in cardiovascular disease risk between the sexes and supports the potential beneficial effects of estrogenic stimulation.

Active Transport, Cell Nucleus↗
PubMed2001

The effect of initial concentration of carbofuran on the development and stability of its enhanced biodegradation in top-soil and sub-soil.

Carbofuran was incubated in top-soil and sub-soil samples from a pesticide-free site at a range of initial concentrations from 0.1 to 10 mg kg-1. Amounts of the incubated soils were removed at intervals over the subsequent 12 months, and the rate of degradation of a second carbofuran dose at 10 mg kg-1 was assessed. An applied concentration as low as 0.1 mg kg-1 to top-soil resulted in more rapid degradation of the fresh addition of carbofuran for at least 12 months. The degree of enhancement was generally more pronounced with the higher initial concentrations. When the same study was conducted in sub-soil samples from the same site, an initial dose of carbofuran at 0.1 mg kg-1 resulted in only small increases in rates of degradation of a second carbofuran dose. However, degradation rates in the sub-soil samples were, in many instances, considerably greater than in the corresponding top-soil samples, irrespective of pre-treatment concentration or pre-incubated period. Initial doses of 0.5 mg kg-1 and higher applied to sub-soil successfully activated the sub-soil microflora. Application of the VARLEACH model to simulate carbofuran movement through the soil profile indicated that approximately 0.01 mg kg-1 of carbofuran may reach a depth of 70 cm 400 days after a standard field application. The results therefore imply that adaptation of the sub-soil microflora (c 1 m depth) by normal field rate applications of carbofuran is unlikely to occur. In experiments to investigate this in soils exposed to carbofuran in the field, there was no apparent relationship between top-soil exposure and degradation rates in the corresponding sub-soils. The results further confirmed that same sub-soil samples have an inherent capacity for rapid biodegradation of carbofuran. The high levels of variability observed between replicates in some of the sub-soil samples were attributed to the uneven distribution of a low population of carbofuran-degrading micro-organisms in sub-surface soil. There was no apparent relationship between soil microbial biomass and degradation rates within or between top-soil and sub-soil samples.

Bacteria↗
PubMed2001

Influence of topsoil tilth and soil moisture status on losses of pesticide to drains from a heavy clay soil.

Twelve lysimeters with a surface area of 0.5 m2 and a length of 60 cm were taken over mole drains from a Denchworth heavy clay soil and divided into two groups with either a standard agricultural tilth or a finer topsoil tilth. The influence of topsoil tilth on leaching of the herbicide isoproturon and a bromide tracer was evaluated over a winter season. The effect of variations in soil moisture status in the immediate topsoil on leaching of isoproturon, chlorotoluron and linuron was investigated in the following winter season. Here, water inputs were controlled such that lysimeters received 50 mm at a maximum intensity of 2 mm h-1 over a 4-week period with herbicides applied on day 15. Three treatments received the water either all prior to application, all after application, or evenly spread over the 4-week period. Leaching losses of the three herbicides were monitored for a subsequently drainage event. Analysis of covariance showed a significant effect of topsoil tilth and total flow on both the maximum concentrations (P = 0.034) and total losses (P = 0.012) of isoproturon in drainflow. Both concentrations and losses were c 35% smaller from lysimeters with the finer tilth. However, generation of the fine tilth in the field was restricted by a wet autumn and this is not considered a reliable management option for reducing pesticide losses from heavy clay soils. In the second experiment, variation in soil moisture content prior to and after application did not have any significant effect (P < 0.05) upon subsequent losses of the three herbicides to drains.

Aluminum Silicates↗
PubMed2001

New hominids from the Lake Turkana Basin, Kenya.

New hominid fossils from the Lake Turkana Basin range in age from ca. 3.35 to ca. 1.0 Ma. Those recovered from sediments stratigraphically just above the Tulu Bor Tuff in the Lomekwi Member of the Nachukui Formation are best attributed to Australopithecus afarensis. This species is rare in Kenya, probably because of the scarcity of sediments deposited during its time span. Younger specimens are referable either to the megadont A. boisei or early Homo. Collectively the new fossils promote further understanding of morphological variation in East African Plio-Pleistocene hominids.

Animals↗