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Biomedical subjects

R Wilson

Publications and source records attributed to R Wilson.

At least 55 records · Page 3Linked to original sources
PubMed2001

The clinical and microbiological effects of a novel acidified sodium chlorite mouthrinse on oral bacterial mucosal infections.

Acidified sodium chlorite mouthrinses have been shown to have equivalent anti-plaque activity to those containing chlorhexidine, the current 'gold standard'. In this study, sodium chlorite mouthrinses (ASC) acidified with either malic or gluconic acids were compared to each other and with a chlorhexidine rinse and sterile water for their effect on salivary bacterial counts. Sixteen subjects participated in the study, which had a cross-over Latin square design. In a second study, a sodium chlorite/gluconic acid rinse was compared with chlorhexidine for its clinical and microbiological effects in 36 patients with oral mucosal infections. The sodium chlorite rinses acidified with malic and gluconic acids and the chlorhexidine rinse caused significant reductions in salivary bacterial counts up to 7 h after a single rinse compared with water. There were no significant differences between the three active treatments. In the mucosal infection study, there was a significant reduction in erythema in the chlorhexidine group compared with the ASC group. Patients who received the ASC rinse reported significantly less discomfort following treatment than those receiving the chlorhexidine rinse. Staphylococcus aureus counts were significantly reduced in the group who received the sodium chlorite rinse. There were no other significant differences between the treatments. ASC appears to be an effective alternative to chlorhexidine mouthrinse.

Adult↗
PubMed2001

Bottlenecks, drift and differentiation: the population structure and demographic history of sika deer (Cervus nippon) in the Japanese archipelago.

We assessed genetic differentiation and diversity in 14 populations of sika deer (Cervus nippon) from Japan and four populations of sika deer introduced to the UK, using nine microsatellite loci. We observed extreme levels of differentiation and significant differences in diversity between populations. Our results do not support morphological subspecies designations, but are consistent with previous mitochondrial DNA analyses which suggest the existence of two genetically distinct lineages of sika deer in Japan. The source of sika introduced to the UK was identified as Kyushu. The underlying structure of Japanese populations probably derives from drift in separate glacial refugia and male dispersal limited by distance. This structure has been perturbed by bottlenecks and habitat fragmentation, resulting from human activity from the mid-nineteenth century. Most current genetic differentiation and differences in diversity among populations probably result from recent drift. Coalescent model analysis suggests sika on each of the main Japanese islands have experienced different recent population histories. Hokkaido, which has large areas of continuous habitat, has maintained high levels of gene flow. In Honshu the population is highly fragmented and is likely to have been evolving by drift alone. In Kyushu there has been a balance between gene flow and drift but all the populations have experienced high levels of drift. Habitat fragment size was not significantly associated with genetic diversity in populations but there was a significant correlation between habitat fragment size and effective population size.

Alleles↗
PubMed2001

The filamentous type III secretion translocon of enteropathogenic Escherichia coli.

Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system (TTSS) to inject effector proteins into the plasma membrane and cytosol of infected cells. To translocate proteins, EPEC, like Salmonella and Shigella, is believed to assemble a macromolecular complex (type III secreton) that spans both bacterial membranes and has a short needle-like projection. However, there is a special interest in studying the EPEC TTSS owing to the fact that one of the secreted proteins, EspA, is assembled into a unique filamentous structure also required for protein translocation. In this report we present electron micrographs of EspA filaments which reveal a regular segmented substructure. Recently we have shown that deletion of the putative structural needle protein, EscF, abolished protein secretion and formation of EspA filaments. Moreover, we demonstrated that EspA can bind directly to EscF, suggesting that EspA filaments are physically linked to the EPEC needle complex. In this paper we provide direct evidence for the association between an EPEC bacterial membrane needle complex and EspA filaments, defining a new class of filamentous TTSS.

Bacterial Proteins↗
PubMed2001

End-stage renal disease: factors affecting referral decisions by family physicians in Canada, the United States, and Britain.

The objective of this study is to determine how patient age, sex, creatinine level, and comorbidity affect referral decisions for the treatment of end-stage renal disease (ESRD) and whether these decisions are affected by physician characteristics in three countries: Canada, the United States, and Britain. A vignette-based questionnaire was mailed to a random sample of family physicians in Ontario, Canada (1,818 physicians); all family physicians in the state of New York (1,814 physicians); and a sample of general practitioners from the south of England (2,228 physicians) in 1996. Physicians were presented with clinical scenarios involving a patient with varying degrees of renal insufficiency and a complicating comorbidity, including angina, diabetes, cancer, mental illness, or socioeconomic circumstances. They were asked to indicate the likelihood of referral. Half the physicians received a questionnaire describing a male patient, and half, a female patient. Mean creatinine levels at which physicians would refer were 260 micromol/L for British physicians, 297 micromol/L for Canadian physicians, and 340 micromol/L for American physicians. No difference in referral rates was found based on the sex of the patient or physician. Sixty-five percent of American and Canadian physicians would refer regardless of patient age, but only 49% of British physicians would do so. Family physicians in the United States, Canada, and Britain function as gatekeepers for patients with ESRD. They are less likely to refer based on increasing severity of comorbid conditions. They also discriminate based on age, but not sex.

Adult↗
PubMed2001

Accuracy of predictions of survival at admission to the intensive care unit.

PURPOSE: The purpose of this study was to compare the accuracy of outcome predictions made on the day of intensive care unit (ICU) admission by critical care physicians, critical care fellows, and primary team physicians. PATIENTS AND METHODS: Fifty-nine consecutive patients admitted to a Medical-Surgical ICU were included in the study. Two ICU attending physicians and two critical care fellows, not involved in medical management, evaluated each new ICU patient at admission and after 48 to 72 hours. Altogether six ICU attendings and six fellows were involved in the study. Each investigator separately assigned probability to each patient of being discharged alive from the ICU and the hospital. On the day of admission the primary service was also asked to estimate the likelihood of successful outcome. All values are expressed in percentiles. Statistical analysis was performed by a logistic regression procedure with a binary outcome. Data are presented as mean +/- SD. RESULTS: Fifty-nine patients were surveyed. Twenty-six (44%) patients died in the ICU, 3 (5%) died in the hospital wards, and 30 (51%) were discharged alive from the hospital. ICU attendings most reliably and accurately estimated patient outcome on admission compared with critical care fellows and primary team physicians. ICU attendings were more consistent than ICU fellows at predicting outcome at 48 and 72 hours. Clinical predictions were better for patients at the extremes of disease severity, and the accuracy of predictions in these patients was highest. Accuracy was diminished in patients with moderate compromise of clinical status. CONCLUSION: ICU attendings predicted most accurately and consistently the final outcome of patients, and ICU fellows estimated outcome more reliably than the primary service. For the most part, the primary service tended to overestimate the probability of favorable outcome of patients for whom ICU admission had been requested. Additionally, clinical accuracy of survival or mortality was best for those patients at the extremes of clinical compromise: this point seems to confirm the validity of using clinical judgement as a guide to restricting ICU resources for those severely compromised or mildly compromised.This study also indicates that predictions of outcome in critically ill patients made within days of admission are statistically valid but not sufficiently reliable to justify irrevocable clinical decisions at present.

Cancer Care Facilities↗
PubMed2001

If the NHS introduced a '50 procedures a year' policy, what proportion of consultant firms would be affected?

BACKGROUND: Governments, insurers, quality assurance agencies and others have used the higher volume = better quality relationship as a basis for health policy. This relationship is probably real enough to justify these policies. However, even if it were not real, there are other reasons why these and other organizations such as the National Health Service (NHS) may favour high-volume providers. This paper attempts to answer the question: 'If, for common elective procedures, the NHS instituted a high-volume purchasing policy that requires consultant firms to perform a minimum of "50 procedures a year", what proportion of consultant firms would be affected?' The aims of this study were to estimate the proportion of NHS consultant firms that perform common elective procedures less than 50 times a year and to estimate the proportion of firms that would have to stop providing these procedures if a '50 procedures a year' purchasing policy were introduced. METHOD: A descriptive analysis was carried out and modelling was performed on data stored in an NHS health episode statistics database of patients treated in West Midlands NHS facilities. For each of 12 common elective procedures we assumed that a volume threshold of at least 50 a year were set, and calculated the proportion of NHS consultant firms undertaking each procedure who performed less than 50 of those procedures each year and the proportion of firms who would have had to stop providing each procedure. RESULTS: All firms performing some procedures, e.g. cataract extraction, did so at least 50 times a year. By contrast, no firm repaired more than 50 recurrent inguinal hernias a year. If a volume threshold of at least 50 procedures a year were set for a basket of 12 common elective procedures, then about 40 per cent of firms would no longer be eligible to provide a procedure. Even if a lower 'one a month' threshold were set, about 20 per cent of firms would still not be eligible to provide that procedure. CONCLUSION: Introduction of a high-volume policy would affect a considerable number of firms, as many NHS consultant firms perform some common elective procedures infrequently. Some consultants would see the introduction of a high-volume policy as an opportunity to further specialize and super-specialize. Others would see it as a policy that restricts them to providing a narrower range of procedures, makes their professional practice less interesting, and reduces their professional autonomy. Postgraduate training institutions need to consider the possibility and implications of high-volume policies, as many junior doctors would probably need to learn to provide a narrower range of skills than at present.

Elective Surgical Procedures↗
PubMed2001

A novel automated injection system for angiography.

The present method of performing manual coronary angiography requires repetitive manipulation of a cumbersome stopcock-manifold system and contrast injection by hand syringe. This study reports a novel mechanical contrast injector with automated manifold that provides finger touch operator-controlled contrast injections. The ACIST Injection System components include a software-controlled syringe injector, a disposable automated manifold without stopcocks, a disposable hand controller, and a touch screen control panel. The ACIST system was evaluated in 50 patients undergoing diagnostic coronary angiography (n = 37) or coronary interventions (n = 13). In all cases, the system was easy to use and provided excellent quality images even with four catheters, as well as imaging during stent positioning with 6Fr guides. This mechanical injector facilitates precision operator-controlled angiographic injections, provides superb high quality coronary images even with very small lumen catheters, and expedites ventriculography during angiographic procedures.

Automation↗
PubMed2001

Managed care: a view from Europe.

This article summarizes recent developments in the United Kingdom, the Netherlands, Switzerland, and the new Baltic states that reflect the influence of US managed care concepts and practices. We emphasize (a) developments in restructuring traditional health insurance mechanisms by shifting premium and out-of-pocket burdens to consumers so as to constrain demand and costs and (b) reliance on prospective hospital budgets and case management by primary physicians. Social insurance mechanisms and universal coverage remain national tasks as well as basic components of the social structure of most European countries. Full open-market competition between traditional sick funds and private insurance companies and the introduction of for-profit MCOs beholden to their shareholders appears unlikely on other than an experimental basis. Increased competition between providers may well result from the new right of insurers and payers to contract with medical care providers of their choice. It remains to be shown how far these experiments, which differ substantially between the countries examined, will succeed in their objectives and become permanent features of their national systems.

Cost Control↗
PubMed2001

Efficacy of gemifloxacin in acute exacerbations of chronic bronchitis: a randomised, double-blind comparison with trovafloxacin.

This randomised, double-blind, double-dummy, multinational study compared the efficacy and safety of gemifloxacin with trovafloxacin in the treatment of acute exacerbations of chronic bronchitis. There were 617 patients randomised: 303 to gemifloxacin and 314 to trovafloxacin. Clinical success rates at follow-up (clinical per-protocol population) were 91.5% for gemifloxacin and 87.6% for trovafloxacin. For the intent-to-treat population, the clinical efficacy of gemifloxacin was statistically significantly superior to that of trovafloxacin. In general, the in vitro activity of gemifloxacin against the major respiratory bacterial pathogens was superior to that of other antibiotics tested. Per-patient bacteriological success rates at follow-up (bacteriology per-protocol population) were 86.8% for gemifloxacin and 82.4% for trovafloxacin. Both agents were well tolerated. The clinical and bacteriological efficacy of a once-daily 5-day course of gemifloxacin is at least as good as that of a similar regimen of trovafloxacin in the treatment of acute exacerbations of chronic bronchitis.

Adult↗
PubMed2001

Vitamin E attenuates the injurious effects of bioactive phospholipids on human ciliated epithelium in vitro.

Bioactive phospholipids (PL), particularly lysophosphatidylcholine (LPC), are being increasingly implicated in the pathogenesis of various acute and chronic inflammatory disorders, particularly those of the airways, while there is emerging evidence that vitamin E may function as a natural antagonist of these lipid mediators of inflammation. The aims of this study were to document the effects of vitamin E on the inhibition of ciliary beating and damage to structural integrity of human ciliated epithelium induced by the PL, platelet-activating factor (PAF), lyso-PAF and LPC in vitro in relation to the anti-oxidative and membrane-stabilizing properties of the vitamin. Ciliary beat frequency was measured by a phototransistor technique, and damage to structural integrity assessed by a visual-scoring index, while superoxide production by polymorphonuclear leukocytes and membrane-stabilizing potential were measured using lucigenin-enhanced chemiluminescence and haemolytic procedures, respectively. All three PL caused inhibition of ciliary beating and structural damage to human ciliated epithelium by membrane-directed cytotoxic mechanisms, which were potentiated by human polymorphonuclear leukocytes due to induction of oxidant-mediated injury. Both direct and phagocyte-inflicted epithelial injury was attenuated by vitamin E. In haemolytic and chemiluminescence assays, vitamin E neutralized both the membrane-destabilizing and pro-oxidative actions of all three PL, while spectrophotometric analysis of mixtures of vitamin E with PAF, lyso-PAF and LPC revealed alterations in peak intensity, as well as peak shifts, indicative of physicochemical interactions between the vitamin and the PL. Vitamin E status may be a determinant of susceptibility to phospholipid-mediated airway inflammation and damage.

Cells, Cultured↗
PubMed2001

Primary ciliary dyskinesia syndrome associated with abnormal ciliary orientation in infants.

Primary ciliary dyskinesia (PCD) syndrome associated with abnormal ciliary orientation but with normal ciliary ultrastructure has been described in adults, but there are no normal ranges for orientation in infants, despite the fact that half of all patients with PCD present in the new-born period. Nasal brush biopsies were obtained from eight infants (three males), mean age 13.1 months, range 7-23, in order to determine ciliary orientation. They had no upper or lower airway disease and normal organ arrangement and were undergoing general anaesthesia for other reasons. Two infants with typical PCD syndrome but normal ultrastructure of individual cilia also had orientation studies. In the eight normal subjects, a mean of 254 central pairs was examined, range 82-453. The mean ciliary orientation was 14.9 degrees, range 12.9-17.5. The two infants with PCD syndrome but normal ultrastructure of individual cilia had ciliary orientation of (Case 1) 44.5 degrees (range 10.6-64.5) in 218 central pairs; and on a second occasion, 28.9 degrees, (range 9.0-47.5) in 259 central pairs; for Case 2, 24.4 degrees, (range 13.1-38.4) in 196 central pairs. The normal range for ciliary orientation is similar in infants to that described in other work in adults. The two cases of phenotypic primary ciliary dyskinesia in the presence of normal ciliary ultrastructure but abnormal ciliary orientation in infants supports the contention that measurement of ciliary orientation should be part of the assessment of ciliary structure and function in cases of possible primary ciliary dyskinesia, in particular when the ultrastructure of individual cilia appear to be normal.

Cilia↗
PubMed2001

Bacteria, antibiotics and COPD.

Bacterial infection is one of several important causes of exacerbations of chronic obstructive pulmonary disease (COPD) that may coexist. COPD is a heterogeneous condition and the incidence of bacterial infection is not uniform; mucus hypersecretion may be an important risk factor. The bacteriology of infections varies depending on the severity of the underlying airway disease. There is now a much better understanding of the pathogenesis of bacterial infections of the respiratory mucosa. Lower airway bacterial colonization may be a stimulus for chronic inflammation and may influence the interval between exacerbations. Antibiotic resistance has increased in all the major pathogens. Antibiotics are an important part of the treatment of acute exacerbations of COPD and the decision about whether to give an antibiotic can be made on clinical grounds. It is more difficult to decide, on the available evidence, whether patient characteristics and the risk of antibiotic resistance should influence choice of empiric antibiotic treatment. Most new antibiotics are modifications of existing structures, suggesting that every effort should be made to conserve the sensitivity of current antibiotics by using them appropriately.

Drug Resistance↗
PubMed2001

Age distribution of cancer in mice: the incidence turnover at old age.

We have studied cancer incidence in mice as a function of age in those cohorts where the rodents are allowed to live very close to their full natural lifetime. We find that the incidence rises as a function of age, but then flattens and turns over at an age of about 800 days. This behaviour is similar to that which we observed (Pompei and Wilson, 2001) in the Surveillance, Epidemiology, and End Results (SEER) data where the age distribution of human cancer incidence turns over at about age 80. Although other fits are possible, the three-parameter beta function model fits both the mouse data and the human data well. The beta model implies, and the data do not deny, the interpretation that cancer is not a certainty and mice may also outlive their cancers, although high-dose cohort results suggest cancer might be certain if dose is sufficiently high. Limited data suggest that the cancer age distribution, including the turnover, may be time shifted by dietary restriction.

Age Distribution↗
PubMed2001

Opioids for chronic nonmalignant pain. Attitudes and practices of primary care physicians in the UCSF/Stanford Collaborative Research Network. University of California, San Francisco.

BACKGROUND: We hoped to determine the attitudes and practices of primary care physicians regarding the use of opioids to treat chronic nonmalignant pain (CNMP). We also examined the factors associated with the willingness to prescribe opioids for CNMP. METHODS: A survey was mailed to primary care physicians in the University of California, San Francisco/Stanford Collaborative Research Network. This survey contained questions regarding treatment in response to 3 case vignettes, the use of opioids for CNMP in general, and the demographic characteristics of the physicians. RESULTS: Among 230 physicians surveyed, 161 (70%) responded. Two percent of the respondents were never willing to prescribe schedule III opioids (eg, acetaminophen with codeine) as needed for patients with CNMP that persisted unchanged after exhaustive evaluation and attempts at treatment. Thirty-five percent were never willing to prescribe schedule II opioids (eg, sustained-release morphine) on an around-the-clock schedule for these patients. The most significant predictor of willingness to prescribe opioids for patients with CNMP was a lower level of concern about physical dependence, tolerance, and addiction. CONCLUSIONS: Primary care physicians are willing to prescribe schedule III opioids as needed, but many are unwilling to use schedule II opioids around the clock for CNMP. Individual prescribing practices vary widely among primary care physicians. Concerns about physical dependence, tolerance, and addiction are barriers to the prescription of opioids by primary care physicians for patients with CNMP.

Adolescent↗