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Biomedical subjects

R Elson

Publications and source records attributed to R Elson.

18 recordsLinked to original sources
PubMed2006

Publication bias in foodborne outbreaks of infectious intestinal disease and its implications for evidence-based food policy. England and Wales 1992-2003.

Systematic national surveillance of outbreaks of infectious intestinal disease (IID) was introduced in England and Wales in 1992 to provide comprehensive information on causative organisms, sources or vehicles of infection and modes of transmission. We compared information from this system with that published in the peer-reviewed literature between 1 January 1992 and 31 January 2003 to assess the potential effect of publication bias on food-safety policy. During the study period 1763 foodborne outbreaks of IID were reported to national surveillance. Fifty-five were published in the peer-reviewed literature. The peer-reviewed literature overestimated the impacts of milk/milk products, miscellaneous foods (e.g. sandwiches) and desserts and underestimated those of poultry, fish and shellfish, red meat/meat products and eggs/egg products. Without systematic surveillance, knowledge of causative organisms, sources or vehicles of infection and modes of transmission, as gleaned from the peer-reviewed literature, would potentially distort food-safety policy.

Animals↗
PubMed2006

Prevalence of Listeria monocytogenes and other Listeria species in butter from United Kingdom production, retail, and catering premises.

Two recent listeriosis outbreaks involving butter prompted this first cross-sectional study on the prevalence, levels, and types of Listeria species in 3229 samples of butter from production, retail, and catering premises in the United Kingdom during May and June 2004. When the criteria of the Microbiological Guidelines were used, 99.4% of samples were found to be of satisfactory microbiological quality, 0.5% were of acceptable quality, and 0.1% were of unsatisfactory quality as a result of high levels (>100 CFU/g) of Listeria spp. The butter samples with Listeria spp. present at more than 100 CFU/g were negative for L. monocytogenes. L. monocytogenes was detected in 0.4% (n=13) of samples, all at levels of less than 10 CFU/g, and were therefore of acceptable quality. Butter was contaminated more frequently with Listeria spp., including L. monocytogenes, when packed in plastic tubs, when in pack sizes of 500 g or less, when stored or displayed above 8 degrees C, when a hazard analysis system was not in place, and when the manager had received no food hygiene training. This study demonstrates that although butter is regarded as a low-risk product, it may provide an environment for the persistence and growth of Listeria spp., including L. monocytogenes. The control of L. monocytogenes in food processing and supply systems is critical in order to minimize the potential for this bacterium to be present in foods at the point of consumption at levels hazardous to health.

Butter↗
PubMed2005

Salmonella and raw shell eggs: results of a cross-sectional study of contamination rates and egg safety practices in the United Kingdom catering sector in 2003.

This study was prompted by epidemiological investigations of the unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in catering premises in England and Wales during 2002. The aims of the study, performed between April and May 2003, were to establish the rate of Salmonella contamination in raw shell eggs from catering premises, investigate any correlation between the origin and type of eggs and the presence of particular serotypes or phage types (PTs) of Salmonella, and examine the use of raw shell eggs in catering premises in the United Kingdom. A total of 34,116 eggs (5,686 pooled samples of six eggs) were collected from 2,104 catering premises, most of which were eggs produced in the United Kingdom (88%). Salmonella was isolated from 17 pools (0.3%) of eggs. Of these, 15 were Salmonella Enteritidis, which were further characterized to PTs as follows: PT6 (0.1%), PT4 (0.07%), PT12 (0.04%), PT1 (0.04%), and PT14b (0.02%). Salmonella Livingstone and Salmonella Typhimurium definitive type 7 resistant to ampicillin, streptomycin, sulfonamides, and tetracycline were also isolated. The Salmonella contamination rate of eggs produced in the United Kingdom appears to have decreased significantly since 1995 and 1996. This trend is reflected in the decrease of Salmonella Enteritidis and, in particular, Salmonella Enteritidis PT4. The impact of the United Kingdom Food Standards Agency's advice on the use of eggs, issued in January 2003, is discussed.

Animals↗
PubMed2004

Microbiological examination of ready-to-eat cold sliced meats and pâté from catering and retail premises in the UK.

AIMS: To establish the microbiological quality of cold ready-to-eat sliced meats and pâté from catering and retail premises, and investigate links hypothesized between foodborne Campylobacter infection and the consumption of cold sliced meats. METHODS AND RESULTS: A total of 4078 cold meat and pâté samples were collected and examined according to a standardized protocol. Comparison with published microbiological guidelines revealed that most ready-to-eat meat and pâté samples (75%) were of satisfactory/acceptable microbiological quality and 25% were of unsatisfactory/unacceptable quality. Two cold meat samples (<1%) were of unacceptable microbiological quality because of the presence of Campylobacter jejuni in 25 g and Listeria monocytogenes at 3.4 x 104 CFU g-1. CONCLUSIONS: Acceptable microbiological quality was associated with premises where the management was trained in food hygiene and those that had hazard analysis in place. Poor microbiological quality was associated with storage above 8 degrees C, presliced meats, infrequent cleaning of slicing equipment and poor control of practices that may lead to cross contamination. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides important information about the microbiological quality of cold ready-to-eat meats and pâté. It also assists caterers, retailers, enforcement officers and policy makers to understand how different food safety practices affect microbiological quality.

Campylobacter jejuni↗
PubMed2002

Surveillance of foodborne outbreaks of infectious intestinal disease in England and Wales 1992-1999: contributing to evidence-based food policy?

Between 1992 and 1999, a total of 1426 general outbreaks of infectious intestinal disease reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC) were described as foodborne. Where the evidence base to support the conclusions drawn was provided (66.3% of outbreaks) a combination of microbiological and analytical evidence was reported in 4% of outbreaks (60/1426); microbiological evidence alone in 10% of outbreaks (149/1426); analytical evidence alone in 23% of outbreaks (322/1426); microbiological evidence in combination with descriptive epidemiology in 3% of outbreaks (46/1426) and descriptive epidemiology alone in 26% of outbreaks (365/1426). Information supplied to CDSC by local investigators appears to be of varying quality and depth and may be influenced by the individual characteristics of outbreaks such as size and duration, outbreak setting, causative organism, vehicles of infection and time of year. These findings have implications for the use of these surveillance data in developing evidence-based food policy.

Communicable Diseases↗
PubMed1998

Basic principles for generating motor output in the stomatogastric ganglion.

The lobster stomatogastric ganglion contains 30 neurons and when modulated can produce two distinct rhythmic motor patterns--the gastric mill and the pyloric. The complete neural circuitry underlying both patterns is well known. Without modulatory input no patterns are produced, and the neurons fire tonically or are silent. When neuromodulators are released into the ganglion from specific neurons or are delivered as hormones, the properties of the neurons and synapses change dramatically and modulator-specific gastric mill and pyloric patterns are produced. In general the rhythmicity derives from the induced burstiness of the neurons, and the pattern from the strengths of the electrical and chemical synapses. The organized activity can be traced to a marked reduction of chaotic activity in individual neurons when they shift from the unmodulated to the modulated state.

Animals↗
PubMed1998

Information technology and the clinical curriculum: some predictions and their implications for the class of 2003.

Information technology, medical knowledge, and medical practice are on a collision course. The consequences of the impact will change the way physicians work, the way medical knowledge is processed, packaged, and distributed, and the way patients obtain medical care and information. Today's educators need to design an information technology curriculum to prepare students for this emerging world of practice. Computer labs, based on today's complex and unreliable desktop systems, are not the answer. What is needed by students who entered medical school in 1997-98 is an informatics curriculum that is based on the real-world requirements of 2003 and beyond. The authors draw upon academic studies and their own clinical and industry experiences to outline some predictable elements of what lies ahead. Their predictions--ubiquitous, simple network computing and "power tools" for managing medical knowledge--have implications for how schools cover such educational topics as patient confidentiality, systems thinking and error management, and knowledge resource evaluation.

Computer Communication Networks↗
PubMed1997

Managing and communicating information in a new era.

BACKGROUND AND OBJECTIVES: Academic and community-based family physician faculty must be adept at using technology as an information management tool and a vehicle for written communication. Today's family physicians must apply communication and technology skills in the traditional areas of research and education and in the ever-changing world of managed care, which in turn influences research and education. Written communication and computer competencies are interconnected by the need to collect, manage, and share information. While technology is changing the way family physicians practice, teach, and conduct research, the written word remains one of the most important means for communicating that information to others. This article summarizes the literature on competencies needed, methods used to prepare faculty, evidence of effectiveness of the methods, and recommendations for faculty development activities specific to communication of the written word, emphasizing information technology. We highlight gaps in that literature and offer a revised set of competencies for managing and communicating information in the context of a managed care environment.

Computer Literacy↗
PubMed1994

One-stage exchange in the treatment of the infected total hip arthroplasty.

One-stage exchange for deep infection of a joint arthroplasty has a valuable place in our range of techniques but should be utilized with great care. Bacteriological facilities must be of an especially high quality. If the operator lacks experience, it is wise to revert to a more conventional two-stage procedure. I believe that for one-stage exchange, heavily antibiotic-loaded acrylic cement should be used. In this account, results from my hospital show that useful survival can be achieved as well as an acceptable rate of control of the infection.

Anti-Bacterial Agents↗
PubMed1986

A modification of Charnley low-friction arthroplasty. Representative ten-year follow-up results of the St. Georg prosthesis.

From the stimulus offered by John Charnley in 1962, Hans Wilhelm Buchholz developed the St. Georg hip implant in Hamburg. The design differed from that of Charnley notably in the size of the femoral head. The results of early operations performed in Hamburg are confined largely to the most cogent form of failure, mechanical loosening of one or both components. Four representative years (1968-1971) were selected for this purpose, and survival curves were constructed for 1971 patients of different age and preoperative diagnosis. In conventional terms, the rate of mechanical loosening for the femoral component is 1.9%, for the acetabular component 2.4%, and for both components 7.5% for a ten or more year follow-up period. The principle annunciated by Charnley suggesting that total joint arthroplasty be performed in large units or special hospitals is strongly recommended.

Adolescent↗
PubMedDate not supplied

Reliable circuits from irregular neurons: a dynamical approach to understanding central pattern generators.

Central pattern generating neurons from the lobster stomatogastric ganglion were analyzed using new nonlinear methods. The LP neuron was found to have only four or five degrees of freedom in the isolated condition and displayed chaotic behavior. We show that this chaotic behavior could be regularized by periodic pulses of negative current injected into the neuron or by coupling it to another neuron via inhibitory connections. We used both a modified Hindmarsh-Rose model to simulate the neurons behavior phenomenologically and a more realistic conductance-based model so that the modeling could be linked to the experimental observations. Both models were able to capture the dynamics of the neuron behavior better than previous models. We used the Hindmarsh-Rose model as the basis for building electronic neurons which could then be integrated into the biological circuitry. Such neurons were able to rescue patterns which had been disabled by removing key biological neurons from the circuit.

Animals↗
PubMedDate not supplied

Quantitation of comparative thrombogenicity of dog, pig, and human platelets in a hemodialyzer.

Comparative platelet thrombogenicity was quantified with In111 labeled platelets. The platelets collected from the blood of Beagle dogs, Yorkshire pigs, and human volunteers were labeled with detergent free In111 tropolone, and sham hemodialysis (SHD) was performed with a hollow fiber dialyzer in a flow loop at 37 degrees C, with flow rates of 7, 150, and 270 ml/min. After SHD, hemodialyzer radioactivity was measured with an ionization chamber, gamma counter, and it was imaged with a gamma camera. The mean values of hemodialyzer-adherent platelet radioactivity were calculated. Canine platelets are more thrombogenic than porcine and human platelets. Quantitation of comparative thrombogenicity with In111 platelets may provide an estimation of prosthesis induced thrombogenicity of human platelets from animal studies.

Animals↗
PubMedDate not supplied

In vitro and in vivo evaluation of the comparative thrombogenicity of cellulose acetate hemodialyzers with radiolabeled platelets.

Platelet consumption and platelet kinetics during hemodialysis were quantified in Yorkshire pigs with In-111 labeled platelets. Six anesthetized pigs (20-25 kg) were hemodialyzed at 150 ml/min for 3 hr. All pigs were injected with autologous In-111 labeled platelets (300-420 microCi) 24 hr before dialysis and were systemically heparinized (ACT > 400 sec) before cannulation. Hemodialysis was instituted with a Drake-Willock hemodialysis machine and a hollow fiber dialyzer (Cobe4, 0.6 m2). In vitro sham dialysis was carried out at 150 ml/min for 3 hr with six more dialyzers in a flow-loop with the blood reservoir maintained at 37 degrees C. In vitro thrombogenicity over-estimates (10-fold) in vivo values. In both systems, platelet deposition on dialyzers reached a steady state, suggesting a constant rate of thrombus formation and embolization in the hollow fiber system. The relative thrombus distribution after 3 hr of dialysis was similar in both systems, with adherent thrombi in the entry and exit ports and highest numbers in the midsection of the hemodialyzer. Biodistribution after 3 hr of dialysis indicated that thrombosis of the hemodialyzer and arterial and venous traps as well as embolization reduced the platelet pool in the blood and increased platelet emboli in lung, brain, kidneys, and skeletal muscle, as measured by the In-111 labeled platelets.

Animals↗