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Biomedical subjects

R Wilson

Publications and source records attributed to R Wilson.

At least 325 records · Page 18Linked to original sources
PubMed1995

Contribution of pancreatic hormone responses to the elevation in carbohydrate metabolism with reduced PaO2.

Reduced O2 availability, as might occur under some physiological and pathological conditions, stimulates insulin and glucagon release and increases glucose fluxes and muscle carbohydrate metabolism. The aim of this study was to determine the role of reduced PO2, independent of changes in glucagon and insulin. In six dogs, in paired studies separated by 2 wk, glucagon and insulin levels were fixed throughout by infusion of somatostatin with basal intraportal glucagon and insulin replacement. A control period was followed by 90 min of breathing 21% (NO) or 8% (LO) O2. Isotopic and arteriovenous methods were used to assess carbohydrate metabolism. Measured variables were constant over time in NO. Arterial PO2 (Pao2) was approximately 100 mmHg in NO and approximately 30 mmHg in LO, resulting in a 50% fall in O2 content. Insulin, glucagon, and catecholamine levels were similar in NO and LO. Cortisol was significantly increased in LO. Arterial glucose was unchanged in both groups. In the last 45 min of the experimental period in LO, 1) glucose production (14 +/- 1 to 18 +/- 1 mumol.kg-1.min-1), glucose disappearance (15 +/- 1 to 17 +/- 1 mumol.kg-1.min-1), and net hepatic glucose output (11 +/- 1 to 15 +/- 1 mumol.kg-1.min-1) rose, 2) limb pyruvate oxidation (11 +/- 2 to 24 +/- 5 mumol/min) and estimated glycogenolysis (9 +/- 3 to 42 +/- 9 mumol/min) increased, 3) percentages of CO2 from limb pyruvate and glucose increased, and percentage of lactate from blood glucose decreased, and 4) arterial blood lactate was approximately 100% more, although net limb and hepatic lactate balances were unaltered, which suggests that neither liver nor muscle is the source of increased blood lactate. Comparison of these results with our previous study [Zinker et al. Am. J. Physiol. 266 (Endocrinol. Metab. 29): E921-E929, 1994] shows that the response to reduced PaO2, although present, is reduced when glucagon and insulin levels are fixed at basal. The majority of stimulation of glucose production by decreased PaO2 is still present when pancreatic hormones are clamped at basal, while the response by the hindlimb tissues is greatly reduced.

Animals↗
PubMed1995

Ciliary disorientation in patients with chronic upper respiratory tract inflammation.

Random ciliary orientation was recently described as a possible variant of primary ciliary dyskinesia (PCD). The cilia have normal ultrastructure and nearly normal ciliary beat frequency (CBF) but lack efficacy because the beat direction is disoriented. However, delayed mucociliary clearance (MCC), transitory changes in ultrastructure, and slowed CBF can all occur in the presence of inflammation. This study investigated groups of patients with upper respiratory tract inflammation caused by infection to assess whether ciliary disorientation was present and its relation to MCC. The study population consisted of 10 healthy nonatopic nonsmoking volunteers, 15 patients with idiopathic bronchiectasis and chronic mucopurulent sinusitis, 12 patients with cystic fibrosis, and two patients with the clinical features of PCD but normal CBF and ciliary ulstrastructure. Ciliary disorientation was significantly (p < 0.05) increased in the three patient groups compared with the volunteers, being greatest in the two patients with the clinical features of PCD and in bronchiectasis patients with P. aeruginosa, and was positively correlated (r = 0.9) with MCC but not with CBF. Treatment of one patient with antibiotics and topical corticosteroids for a prolonged period resulted in ciliary disorientation returning to normal. Ciliary disorientation may therefore occur secondary to inflammation caused by infection, and the study suggests that ciliary disorientation rather than ultrastructural abnormalities or slow CBF results in delayed MCC.

Biopsy↗
PubMed1995

The ciliary transportability of sputum is slow on the mucus-depleted bovine trachea.

Mucus retention in the lungs is a feature of several chest diseases. It is unclear to what extent suboptimal mucus transportability is responsible for the poor clearance of lung secretions. We described a new model, the mucus-depleted bovine trachea, for measurement of the ciliary transportability of respiratory mucus. Mucus depletion was demonstrated microscopically and functionally, and it was accomplished by simple physical means without impairing ciliary action. Control mucus from the tracheas of humans and animals was transported rapidly on this system. However, sputum from 54 patients with bronchiectasis was transported slowly, at a mean of 15% of the rate of control mucus. There was no correlation between sputum transportability and either purulence or the presence of Pseudomonas aeruginosa. This work suggests that there is a serious defect in the ciliary transportability of sputum that is unrelated to the presence of infection. The model should allow in vitro assessment of agents designed to aid mucociliary clearance.

Animals↗
PubMed1995

Reliability of stomach temperature changes in determining feeding characteristics of seabirds

We examined the accuracy of stomach temperature archival units (STAUs), which are typically used to determine feeding activity in marine endotherms, with regard to determination of the time of prey ingestion as well as the number of prey items ingested and their masses. Units were deployed in nine species of free-living seabirds, where feeding conditions were uncontrolled, eight species of captive seabirds, where feeding conditions could be partially controlled, and in laboratory stomach simulations, where variables could be strictly controlled. The quality of data obtained on the timing of feeding, the mass ingested and the number of prey items ingested was subject to two main sources of error (i) those induced by changes in animal activity and (ii) those resulting from the physical form of the STAUs themselves. Animal activity factors considered important included the following: variability in (a) body temperature, (b) stomach blood perfusion, (c) consistency of stomach contents and (d) stomach churning and changes in body orientation. The physical form (size and buoyancy) of the STAU affected the location of the unit within the stomach, and thus the likelihood that ingested prey comes into contact with the sensor. The timing of prey ingestion can generally be determined accurately; however, considerable errors in mass estimates can occur if data acquired using STAUs are not critically assessed. An understanding of these sources of errors will allow researchers to construct STAUs appropriate to the species being studied and to analyze data critically so that errors are reduced.

Journal Article↗
PubMed1995

Current prescribing in primary care in the UK. Effects of the indicative prescribing scheme and GP fundholding.

The costs of drugs prescribed in primary care in the UK continue to rise despite a variety of government initiatives. Two of the major initiatives are considered here in detail: the Indicative Prescribing Scheme (IPS), and general practitioner (GP) fundholding, both of which began in 1991. Other more recent initiatives are also described, including the selected list, the Pharmaceutical Pricing Regulatory Scheme and the move to relicense drugs for nonprescription sale. The IPS has generally failed to control the rise in drug costs because of unrealistic targets, organisational difficulties (including the lack of adequate data to set budgets properly) and because there was neither incentive nor penalty to encourage compliance on the part of the GP. The IPS stresses cost containment, and makes little allowance for the consideration of quality of appropriateness of prescribing. Despite this disappointment, the IPS is continuing, and the future of the scheme is discussed here. GP fundholding, in contrast, has reduced the rate of rise of drug costs in participating GP practices, although it has not actually reduced drug costs. There have been a number of studies of this model, which are discussed here. The clear financial incentive to fundholders encourages them to restrain drug costs. Attempts to extend similar incentives to nonfundholding GPs are also described. Although there is a commitment on the part of the government to encourage and make use of data about economic evaluations of drug therapy and other medical interventions, so far the emphasis has been exclusively on cost containment. In this paper, we consider possible mechanisms by which this might be improved.

Cost-Benefit Analysis↗
PubMed1995

Health practices and mental health revisited.

The relationships of seven health practices with a measure of mental well-being were explored in a sample of 490 university students. Mental well-being was associated with moderate exercise and regular sleep.

Adolescent↗
PubMed1995

LPNs and delegating.

Explore the source record for details and available documents.

Delivery of Health Care↗
PubMed1995

Interaction of fimbriated and nonfimbriated strains of unencapsulated Haemophilus influenzae with human respiratory tract mucus in vitro.

Adherence to mucus may influence bacterial colonization of the respiratory tract. Clinical isolates of nontypable Haemophilus influenzae (NTHi) from the respiratory tract are often fimbriated. We wondered whether fimbriated strains have a different adherence from related nonfimbriated strains. A microtitre plate assay has been developed to study adherence of nontypable H. influenzae to mucus. Wells were coated by incubation either with sol phase of sterile mucoid secretions or with purified preparations of mucins. Two laboratory pairs of fimbriated (F+) and nonfimbriated (F-) nontypable H. influenzae, and six fresh clinical isolates of fimbriated nontypable H. influenzae each with nonfimbriated partners derived by serial passage on agar, were cultured to mid-log phase, washed, and then added to the wells. They were then incubated at 37 degrees C for 30 min before washing to remove unbound bacteria. Adherent bacteria were desorbed by agitation with 0.5% Tween 80 and a viable count performed. The two fimbriated laboratory strains (n = 12 and n = 17), and 5 of the 6 fimbriated clinical isolates were more adherent to sol phase than their respective nonfimbriated partners. Two nonfimbriated clinical isolates were more adherent to plastic than their fimbriated partners. A fimbriated laboratory strain was more adherent than its nonfimbriated partner both to a purified preparation of high molecular mass mucin and to the glycopeptide fraction of the same. We conclude that fimbriated strains of nontypable H. influenzae have increased adherence to sol phase of mucus and purified human respiratory tract mucin. The interactions of fimbriae with mucus are likely to be complex, and may involve both nonspecific and specific interactions.

Bacterial Adhesion↗
PubMed1995

Acute infective exacerbations of chronic bronchitis.

Patients with an acute infective exacerbation of chronic bronchitis (AECB) (n = 471) were enrolled into a computer-based general-practice study to determine whether features of past history, presenting symptoms, or findings on examination were predictive of failure to recover. The median age was 68, 56.3% were male, and 82% were current or ex-smokers. All had daily sputum production and 57.5% had moderate or severe airflow obstruction. During the AECB 11.5% were pyrexial, and 80.7% had abnormal auscultatory findings; about half had moderate to severe increases in dyspnoea and airflow obstruction, and the majority had increases in sputum volume and/or purulence. The median number of AECBs in the previous year was three, and one-third of patients had cardiopulmonary disease. The only factors significantly (p < 0.05) predicting failure to recover from an AECB were historical. Neither clinical features at presentation nor antibiotic treatment affected recovery. Coexistent cardiopulmonary disease was a risk factor for returning with a chest problem and for being referred to hospital. The number of chest infections in the previous 12 months was a risk factor for returning with a chest problem. The higher the number of chest infections, the higher the odds of returning with a chest problem. The best combination predicting return with a chest problem was history of cardiopulmonary disease and more than four previous AECBs in the last 12 months. The sensitivity was 75% and specificity 47%.

Acute Disease↗
PubMed1995

Bronchitis.

Acute bronchitis in previously fit individuals is a common condition that is usually mild and self limiting. Chronic bronchitis remains a common cause of morbidity and mortality, and the cost to the nation due to lost working days and to health services is enormous. Cigarette smoking is the major etiologic factor, although exacerbations may be caused by viruses, environmental pollutants, allergic responses, and bacterial infections. New insights into the underlying basic mechanisms of bronchial inflammation are being made. Antibiotics are commonly used to treat exacerbations, although evidence of efficacy is sometimes lacking. Some patients may be prone to recurrent exacerbations and this influences their chance of recovery. Clinical trials must include an assessment of the severity of the exacerbation, and protocols would be improved by increased definition of the type of patient being enrolled and by inclusion of more detailed measures of benefit. Influenza and pneumococcal vaccination should be encouraged in appropriate patients.

Anti-Bacterial Agents↗
PubMed1994

Differences in the treatment of male and female patients with end-stage renal disease.

OBJECTIVE: To determine whether there is a difference in the allocation of types of dialysis to male and female patients with end-stage renal disease (ESRD). DESIGN: Descriptive study. SETTING: Canada. PATIENTS: All patients registered with the Canadian Organ Replacement Register (CORR) whose treatment began between 1981 and 1991. Data were obtained for 19,732 patients, of whom 18,010 had sufficiently complete data and were being treated with either peritoneal dialysis or hemodialysis 3 months after the diagnosis of ESRD. OUTCOME MEASURES: Proportions of patients receiving peritoneal dialysis and hemodialysis according to sex. RESULTS: Significantly more male (58.1%) than female (50.8%) patients were receiving hemodialysis 3 months after diagnosis (p < 0.00001). Multivariate analysis to control for the possible confounding effects of age, province of treatment, diagnosis, concurrent illness and year of diagnosis did not explain the difference. CONCLUSIONS: In Canada from 1981 to 1991 male patients were more likely than female patients to receive hemodialysis for the treatment of ESRD. Additional research is needed to explain this finding.

Adolescent↗