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Biomedical subjects

K A Eaton

Publications and source records attributed to K A Eaton.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of gastritis and gastric epithelial proliferation in Helicobacter heilmannii-infected nude and BALB/c mice.

Gastric mucosal hypertrophy/nodular hyperplasia occurs as a consequence of Helicobacter infection in mice and humans. The pathogenesis of this hyperplastic response is not understood. To determine the role of host cellular immunity in gastric mucosal hypertrophy/hyperplasia, 6-8-week-old female euthymic BALB/c (n = 30) or NIH athymic nude (n = 40) mice were inoculated with H. heilmannii. Equal numbers of uninoculated mice of each strain served as controls. Mice from each group were euthanatized at 0.5, 6, 12, and 18 months postinoculation (PI). Lymphoplasmacytic gastritis and lymphoid follicle development were less severe in nude mice than in euthymic mice at <6 months PI. The prevalence of gastritis at 0.5, 6, 12, and 18 months PI was 0%, 17%, 67%, and 88%, respectively, in infected nude mice and 33%, 83%, 71%, and 100%, respectively, in infected BALB/c mice. CD4+ T cells in infected nude mice were evident at > or =6 months PI but were less numerous than in infected BALB/c mice at comparable time intervals. However, numbers of CD4+ T cells increased substantially throughout the experiment in infected BALB/c mice. The prevalence of nodular mucosal hyperplasia at 0.5, 6, 12, and 18 months PI was 0%, 0%, 33%, and 20%, respectively, in infected nude mice and 0%, 33%, 80%, and 80%, respectively, in infected BALB/c mice. Nodular hyperplasia occurred in association with the appearance of chronic lymphoplasmacytic inflammation and CD4+ T cells at 12 and 18 months PI in nude mice. H. heilmannii-associated gastritis and mucosal remodeling is reduced in immunodeficient mouse strains lacking normal CD4+ T cell numbers as compared with the response in immunocompetent mice. Additionally, CD4 immunocompetence is an integral aspect of the mucosal hypertrophy/nodular hyperplasia in experimental H. heilmannii-associated disease of mice.

Animals↗
PubMed2001

The influence of partial and full-mouth recordings on estimates of prevalence and extent of lifetime cumulative attachment loss: a study in a population of young male military recruits.

BACKGROUND: Previous studies have shown that the use of index teeth may underestimate the prevalence of chronic periodontitis in adults. However, there is little information on the effect of using index teeth to estimate the prevalence of early periodontitis in younger adults and the effect this may have on planning treatment needs and health care resources. The aim of this study was to compare full mouth examination with partial examination using index teeth in a group of young British males. METHODS: One hundred subjects aged between 16 and 20 years (mean 17 years) on entry to the study were examined at baseline, 12 months later, and 30 months later. Lifetime cumulative attachment loss (LCAL) > or =1 mm was measured on the mesio-buccal, disto-buccal, mesio-lingual, and disto-lingual surfaces of all teeth, excluding third molars. All data were entered into a database. The indices used to express LCAL were prevalence, defined as the percentage of subjects with LCAL > or =1 mm, 2 mm, or 3 mm, and extent, defined as the percentage of sites with LCAL > or =1 mm, 2 mm, or 3 mm. Two sets of index teeth were chosen to compare with full mouth recordings, Ramfjord index teeth and the Periodontal Index for Treatment (PIT) teeth. RESULTS: The prevalence of LCAL > or =1 mm was similar (approaching 100%) for the full mouth and both partial mouth recordings. However, as LCAL increased from a minimum of 1 to 3 mm, partial mouth recording resulted in an underestimation of the prevalence of disease. LCAL > or =2 mm was underestimated by up to 22% and LCAL > or =3 mm by up to 36%. The extent of LCAL was less affected by partial mouth recording, in that the percentage of sites with no sign of early attachment loss was underestimated by up to 11%. However, the percentage of sites with LCAL > or =1 mm and 2 mm were overestimated by 11% and, 7% respectively. CONCLUSIONS: These data indicate that the use of index teeth in epidemiological studies which include young adults may result in an underestimation of the prevalence of early periodontitis and an overestimation of the extent.

Adolescent↗
PubMed2000

A survey of undergraduate orthodontic education in 23 European countries.

This paper reports on a survey of teaching contents and time allocation within the undergraduate orthodontic curriculum in European countries in 1997, and on whether or not these countries set a formal undergraduate examination in orthodontics. A questionnaire and an explanatory letter were mailed to all members of the EURO-QUAL BIOMED II project. Answers were validated during a meeting of project participants and by fax when necessary. Completed questionnaires, which were subsequently validated, were returned by orthodontists from 23 countries. They indicated that orthodontics was taught in all undergraduate curriculums of the countries surveyed. The number of hours in the undergraduate curriculum devoted to orthodontics was reported as varying from 135 to 500 hours with a mean of 245 hours. The time reported as allocated to theory, clinical practice, laboratory work, diagnosis, and treatment planning varied widely. In general, clinical practice and theory were reported as being allocated most curriculum hours, whilst diagnosis, laboratory work, and treatment planing were reported as receiving relatively less time. Removable appliances were reported to be taught in 22 of the 23 countries, functional appliances in 21 countries and fixed appliances in 17 countries. An undergraduate examination in orthodontics was reported by 20 countries. It was concluded that orthodontics occupies a small proportion of the undergraduate curriculum in dentistry in most countries, the emphasis is on theory and clinical work, and that removable appliances, functional appliances, and certain aspects of fixed appliances are taught in the majority of countries that responded to the questionnaire

Curriculum↗
PubMed2000

A survey of postgraduate (specialist) orthodontic education in 23 European countries.

This paper reports on a survey of the duration, funding, and assessment of postgraduate specialist orthodontic training, the requirement for postgraduate training prior to entering specialist orthodontic training and registration of specialist orthodontists in Europe. A questionnaire and explanatory letter were mailed to all members of the EURO-QUAL BIOMED II project. Answers were validated during a meeting of project participants and by fax, when necessary. Completed questionnaires which were subsequently validated, were returned by orthodontists from 23 countries. The results indicated that a period of postgraduate training, prior to entering specialist orthodontic training was required in 12 of the responding countries. Specialist orthodontic training was reported as lasting 2 years in three countries, 3 years in 17, and for 4 years in three. Part-time training was reported as a possibility in four countries. In 21 of the 23 countries specialist training was reported to take place in full or part within universities, with some training taking place in government clinics in four countries. In five countries some or all training was reported to take place in specialist practices. Training was said to be funded solely or partially by governments in 15 of the 23 countries, to be solely self-funded in five countries, and partly or solely funded by universities in six countries. A final examination at the end of specialist training was reported to be held in 21 of the 23 countries. The nature of this examination varied widely and there was no such examination in two countries. Twelve of the 23 countries reported that they had a specialist register for orthodontics; 11 that they had no register. In none of the countries surveyed was there a requirement for those on a register to undergo periodic reassessment of competence once they are on the register. It was concluded that there was wide diversity in all aspects of specialist orthodontic training and registration within the countries surveyed.

Credentialing↗
PubMed2000

A survey of perceived problems in orthodontic education in 23 European countries.

This paper reports on a survey of perceived problems in the provision of orthodontic education at the stages of undergraduate, postgraduate, and continuing professional education (CPE) in 23 European countries in 1997. A questionnaire, together with an explanatory letter, was mailed to all members of the EUROQUAL II BIOMED project. Answers were validated during a meeting of project participants and by further correspondence, when necessary. The topics covered in the questionnaire were adequacy of funding, numbers of orthodontic teachers, availability of equipment, regulations, training centres, numbers of orthodontists, availability of books, journals, and information technology. Completed questionnaires were returned by orthodontists from all 23 countries. Respondents from seven countries did not answer all questions. Respondents reported a perceived almost universal lack of adequate funding for postgraduate orthodontic training (from 18 out of 20 countries) and, to a lesser extent, at undergraduate (13 out of 20 countries) and CPE levels (17 out of 21 countries). Respondents from 12 of the 20 countries reported adequate numbers of qualified teachers at undergraduate level, but only seven out of 18 at postgraduate level and eight out of 19 for CPE. Lack of suitable equipment was reported as a more frequent problem by central and eastern European countries (six out of 20 countries at undergraduate level, eight out of 20 countries at postgraduate level, and 12 out of 19 at CPE level). Too few or too many regulations were only perceived to be a problem by the respondent from one country out of 19 at undergraduate level, by seven out of 19 at postgraduate level, and by eight out of 16 at CPE level). Lack of training centres was more frequently reported as a problem by respondents from central and eastern European countries, but was generally not perceived as a problem by respondents from west European countries. Respondents from seven countries reported a lack of training centres for CPE. Respondents from six countries reported that they perceived there to be too many orthodontists at postgraduate level, from seven countries that there were an appropriate number, and from seven that there were too few. A lack of books, journals, and information technology was reported to be a problem by respondents from four out of 19 countries at undergraduate level, eight out of 20 at postgraduate level, and 10 out of 20 at CPE level. At both undergraduate and postgraduate level, the majority of respondents from central and eastern European countries reported problems with books, journals, and information technology. The results of the survey confirmed many anecdotal impressions and provided an extremely useful background against which to formulate quality guidelines for orthodontic education in Europe.

Dental Equipment↗
PubMed2000

Suggested guidelines for the provision and assessment of orthodontic education in Europe. A report from the Professional Development Group of the EURO-QUAL BIOMED II Project.

The suggested guidelines for the provision and assessment of Orthodontic education in Europe, which are introduced, set out, and discussed in this paper, resulted from the work of the Professional Development Group (PDG) of the EURO-QUAL BIOMED II project. They were published in the final report of the project, after comments had been received from a range of national and European bodies and societies, including the British and the European Orthodontic Societies, Royal Colleges, and the General Dental Council.

Curriculum↗
PubMed2000

'Flexispira rappini' strains represent at least 10 Helicobacter taxa.

'Flexispira rappini' is a provisional name given to gram-negative, microaerophilic, motile, spindle-shaped micro-organisms with spiral periplasmic fibres and bipolar tufts of sheathed flagella. Several investigators, including Kirkbride, Romero, and Archer isolated strains possessing this morphology. Previously, the phylogenetic position of three 'Flexispira rappini' strains was determined by 165 rRNA sequencing, which indicated that flexispira were members of the genus Helicobacter. As more organisms with 'F. rappini' morphology were isolated, it became apparent that there were multiple Helicobacter taxa with this distinctive morphology. The purpose of this study was to examine a collection of 36 'F. rappini' strains from diverse habitats by using 165 rRNA sequence analysis. The strains fell into 10 taxa, each possibly representing a novel Helicobacter species. Two of these flexispira taxa were previously named, by us, Helicobacter bilis and Helicobacter trogontum. Currently, none of the flexispira taxa contains enough phenotypically and genotypically characterized strains to be formally named 'Helicobacter rappinii'.

Animals↗
PubMed2000

Switching of flagellar motility in Helicobacter pylori by reversible length variation of a short homopolymeric sequence repeat in fliP, a gene encoding a basal body protein.

The genome of Helicobacter pylori contains numerous simple nucleotide repeats that have been proposed to have regulatory functions and to compensate for the conspicuous dearth of master regulatory pathways in this highly host-adapted bacterium. H. pylori strain 26695, whose genomic sequence was determined by The Institute for Genomic Research (TIGR), contains a repeat of nine cytidines in the fliP flagellar basal body gene that splits the open reading frame in two parts. In this work, we demonstrate that the 26695(C9) strain with a split fliP gene as sequenced by TIGR was nonflagellated and nonmotile. In contrast, earlier isolates of strain 26695 selected by positive motility testing as well as pig-passaged derivatives of 26695 were all flagellated and highly motile. All of these motile strains had a C(8) repeat and consequently a contiguous fliP reading frame. By screening approximately 50,000 colonies of 26695(C9) for motility in soft agar, a motile revertant with a C(8) repeat could be isolated, proving that the described switch is reversible. The fliP genes of 20 motile clinical H. pylori isolates from different geographic regions possessed intact fliP genes with repeats of eight cytidines or the sequence CCCCACCC in its place. Isogenic fliP mutants of a motile, C(8) repeat isolate of strain 26695 were constructed by allelic exchange mutagenesis and found to be defective in flagellum biogenesis. Mutants produced only small amounts of flagellins, while the transcription of flagellin genes appeared unchanged. These results strongly suggest a unique mechanism regulating motility in H. pylori which relies on slipped-strand mispairing-mediated mutagenesis of fliP.

Amino Acid Sequence↗
PubMed2000

A survey of continuing professional education for orthodontists in 23 European countries.

This paper reports on a survey of the organization, forms and methods of funding continuing professional education (CPE) for those providing orthodontics in 23 European countries in 1997. A postal questionnaire was sent to all members of the EURO-QUAL II BIOMED project, who came from 28 countries, together with an explanatory letter. Answers were validated during a meeting of project participants and by further correspondence, when necessary. Completed questionnaires, which were subsequently validated, were returned by orthodontists from 23 countries and indicated that orthodontic CPE took place in 22 of the 23 countries surveyed. A number of different bodies were reported as organizing orthodontic CPE. This task was most frequently performed by orthodontic societies (in 22 out of 23 countries), but a number of other bodies were also involved. Practical technique courses were reported as taking place in 20 countries. Other frequently occurring forms of orthodontic CPE were lectures (in 18 countries) and study groups (in 15 countries). Orthodontists were reported as financing their CPE in 22 countries; others, who contributed to some or all of the costs, were the Government (in six countries), employers (in four countries), universities (in four countries), and a dental company (in one country). It was concluded that some orthodontic CPE took place in the vast majority of the countries surveyed, and was invariably organized by and paid for, wholly or in part by orthodontists themselves.

Curriculum↗
PubMed2000

A survey of the delegation of orthodontic tasks and the training of chairside support staff in 22 European countries.

This paper reports on a survey which was undertaken to investigate the delegation of orthodontic tasks and the training of chairside support staff in Europe. Two questionnaires were posted to all members of the EURO-QUAL BIOMED II project together with an explanatory letter. The first dealt with the delegation of nine clinical tasks during orthodontic treatment. The second with the types of chairside assistant employed in each country and the training that they are given. Completed questionnaires, which were subsequently validated, were returned by orthodontists from 22 countries. They indicated that there was no delegation of clinical tasks in six of the 22 countries and delegation of all nine tasks in five countries. The most commonly delegated tasks were taking radiographs (in 14 of the 22 countries) and taking impressions (in 13 of the 22 countries). The least commonly delegated tasks were cementing bands (in five of the 22 countries) and trying on bands (in six of the 22 countries). Seven of the 22 countries provided chairside assistants with training in some clinical orthodontic tasks. Eighteen of the 22 countries provided general training for chairside assistants and offered a qualification for chairside assistants. Four of these 18 countries reported that they only employed qualified chairside assistants. Of the four countries which reported that they did not provide a qualification for chairside assistants, two indicated that they employed chairside assistants with no formal training and two that they did not employ chairside assistants. It was concluded that there were wide variations within Europe as far as the training and employment of chairside assistants, with or without formal qualifications, and in the delegation of clinical orthodontic tasks to auxiliaries was concerned.

Cementation↗
PubMed2000

The impact of the electronic media on primary dental care in the 21st century.

This paper attempts to predict how electronic media will impact on primary dental care in the twenty-first century. The predictions for the next 10 years are based on developments currently in train or on the premise that equipment and techniques, which have been recently introduced and are at present used by relatively few, will be used by many by 2010. During this decade, the impact of electronic media is considered in the areas of patient support, diagnosis, treatment planning, provision of treatment and its maintenance, quality control and practice management. The paper then speculates briefly about how dentists in primary dental care might practise in the year 2100. It concludes that although electronic media are likely to play an increasingly important role, a clinician's skills, knowledge and ability to communicate with patients will remain the keys to successful practice for the foreseeable future.

Comprehensive Dental Care↗
PubMed1999

Appraisal of a standardised periodontal referral proforma.

AIM: The primary objective was to assess the standard of new-patient referral communications to the Periodontology Department of a teaching hospital and evaluate any differences in referral quality between referrals that used a standardised proforma and conventional letters. Secondary objectives were to evaluate the potential influence on referral performance of age, postgraduate qualifications and country of qualification of the referring practitioners. DESIGN: A retrospective analysis of a randomised sample of all referral letters and proformae received during a nine-month period. SETTING: Letters and referral proformae received by the Periodontal Department of the teaching hospital between 1 January and 30 September 1995 were surveyed. METHODS: An objective Categorisation System for Periodontal Referral Quality (CSPRQ) was devised and tested for inter- and intra-examiner reproducibility. The referral communications in the random sample were then categorised for quality. The year, country of qualification (UK or non-UK) and possession or otherwise of postgraduate qualifications for each of the referring dentists was ascertained from the Dentists' Register. A Standard Normal Deviants (SND), or Z-test was applied to the resulting data. OUTCOME MEASURES: Acceptability or unacceptability of referral letters and proformae, related to the age (assessed by year of qualification), country of qualification and possession or otherwise of postgraduate qualifications. RESULTS: A random sample of 378 referral communications (from a total of 2663) was analysed. Sixty-three of the random sample were referral proformae. The use of the referral proforma was associated with a highly significantly better (P < 0.01) referral performance, than the use of referral letters. There was a trend for referrals from the small numbers of practitioners who were Fellows in Dental Surgery or Masters of Science to be better than those from other practitioners. There was also a trend for use of the referral proforma to enhance the referral performance of practitioners who had been qualified for more than 20 years. Use of the referral proforma highly significantly (P < 0.01) improved the quality of referrals from non-UK qualified practitioners. CONCLUSIONS: In this study, the quality of periodontal referrals was associated for the better with the use of a referral proforma.

Dental Clinics↗
PubMed1999

flaA mRNA transcription level correlates with Helicobacter pylori colonisation efficiency in gnotobiotic piglets.

In-vivo passage of the gastric pathogen Helicobacter pylori in gnotobiotic piglets results in a greater colonisation efficiency in subsequent infections. The rate of colonisation steadily increases with the number of passages. To determine if this increased efficiency is related to the level of expression of flaA, a gene which encodes the major subunit of flagella, this study evaluated the level of flaA expression at five points during serial in-vivo passage of strain 26695. Semi-quantitative reverse transcriptase polymerase chain reaction and Northern dot-blot analysis of flaA mRNA levels (expressed as a ratio to the level of ureA mRNA) revealed a positive correlation between flaA expression and colonisation efficiency; flaA mRNA levels increased incrementally with in-vivo passage as did colonisation rates. Immunoblots of outer-membrane vesicles from pig-passaged and laboratory-passaged strains also demonstrated marked differences in the amount of flagellin present in poor and efficient colonisers.

Animals↗
PubMed1999

Murine splenocytes induce severe gastritis and delayed-type hypersensitivity and suppress bacterial colonization in Helicobacter pylori-infected SCID mice.

The goal of this study was to evaluate the role of host immunity in gastritis and epithelial damage due to Helicobacter pylori. Splenocytes from H. pylori-infected and uninfected C57BL/6 mice were adoptively transferred to H. pylori-infected and uninfected severe combined immunodeficient (SCID) mice. Transfer was verified by flow cytometry, and all mice were evaluated for the presence of delayed-type hypersensitivity (DTH) by footpad inoculation with sterile H. pylori sonicate and for humoral immunity by enzyme-linked immunosorbent assay. The severity of gastritis and gastric epithelial damage was quantified histologically, epithelial proliferation was determined by proliferating cell nuclear antigen staining, and colonization was quantified by culture. C57BL/6 mice, but not nonrecipient SCID mice, developed moderate gastritis in response to H. pylori. In contrast, recipient SCID mice developed severe gastritis involving 50 to 100% of the gastric mucosa and strong DTH responses not present in C57BL/6 mice. DTH, but not serum anti-H. pylori immunoglobulin G, correlated with adoptive transfer, gastritis, and bacterial clearance. Severe gastritis, but not bacterial colonization, was associated with epithelial metaplasia, erosions, and an elevated labeling index. This study demonstrates that (i) adaptive immunity is essential for development of gastritis due to H. pylori in mice, (ii) T-cell-enriched lymphocytes in SCID mice induce DTH and gastritis, which is more severe than donor gastritis, and (iii) the host inflammatory response, not direct bacterial contact, causes epithelial damage. The greater severity of gastritis in recipient SCID mice than in donor C57BL/6 mice suggests that gastritis is due to specific T-cell subsets and/or the absence of regulatory cell subsets in the transferred splenocytes.

Adoptive Transfer↗
PubMed1999

Healthy cats are commonly colonized with "Helicobacter heilmannii" that is associated with minimal gastritis.

Gastric Helicobacter infection in healthy pet cats is not well characterized. We performed endoscopy with gastric biopsy on 15 healthy pet cats that were rigorously screened to exclude underlying or concurrent diseases that might affect Helicobacter colonization. Gastric mucosa biopsy specimens were examined by histology, culture, and PCR for the presence of Helicobacter infection and by histology for the presence of gastritis. Of 15 cats, all but 1 had gastric Helicobacter-like organisms (GHLOs) on examination by light microscopy, and in the one histologically negative cat, GHLOs were detected by PCR. Gastric inflammation was mild or was absent for all cats. No Helicobacter species were identified by culture. Analysis of the 16S rRNA sequence from Helicobacter strains from 10 cats showed that all bacteria were closely related to Helicobacter felis, although there was heterogeneity among the sequences. These results suggest that the gastric mucosa of healthy pet cats is commonly colonized with an uncultivated Helicobacter that is closely related to H. felis, is associated with little or no gastritis, and shows heterogeneity in its 16S rRNA sequence. The epithet "Helicobacter heilmannii" continues to be an appropriate working designation for these bacteria.

Animals↗
PubMed1998

A report of an evaluation of the pilot peer review scheme for general dental practitioners working in the general dental services in England.

OBJECTIVE: To evaluate the pilot peer review scheme for general dental practitioners, working in the general dental services in England. DESIGN: A retrospective analysis of a 50% random sample of end of project résumés. SETTING: The scheme was piloted from August 1991 to April 1996. At the end of each project a résumé was completed. METHODS: The random sample of résumés was subjected to content analysis by three reviewers who had previously undergone consistency training. MAIN OUTCOME MEASURES: The range of topics reviewed, the choice of single or multiple topics, the direct relevance of projects to patient care and the comments of the scheme's participants. RESULTS: 332 résumés were analysed, 89% included positive comments. Overall 42% of projects reviewed single topics, with participants in 4 out of 13 regions favouring this approach. 61% of topics related directly to patient care. CONCLUSIONS: The pilot peer review scheme was enthusiastically welcomed by the participants and achieved its objectives of encouraging initiatives to improve patient services and testing different types of peer review.

Dental Audit↗
PubMed1998

RFLP and RAPD analysis of in vivo genetic interactions between strains of Helicobacter pylori.

BACKGROUND: The nature of the in vivo interactions between co-colonizing strains of Helicobacter pylori has not been well studied. This study was designed to investigate the in vivo interaction between strains of H. pylori using restriction fragment length polymorphism analysis (RFLP) and random amplified polymorphic DNA fingerprinting (RAPD) analysis. MATERIALS AND METHODS: Mice were orally inoculated with either a single strain or a mixture of strains, and killed at various time intervals up to 12 months after inoculation. RESULTS: Inoculum and recovered bacteria were identified by RAPD and RFLP. After 12 months of colonization, bacteria recovered from mice given a single strain were identical to the inoculum. In contrast, bacteria recovered from mice given a mixture of strains developed minor but consistent differences in their RAPD patterns. This variation occurred in spite of the fact that only single strains were recovered from mice given a mixture of strains. CONCLUSION: These findings support the development of genetic heterogeneity of H. pylori during long-term colonization either by genetic drift or by in vivo recombination. Such genomic modification in vivo could explain the naturally occurring heterogeneity of H. pylori.

Animals↗