Biomedical subjects

J G Steele

Publications and source records attributed to J G Steele.

At least 19 recordsLinked to original sources

PubMed2001

The impact of oral health on people in the UK in 1998.

Knowledge of the extent of dental disease gives a clinical indication of the experience of dental problems but it does not necessarily reflect the problems that people experience as a result of their dentition. It is becoming increasingly appreciated that the way a disease affects people's lives is just as important as epidemiological measures of its prevalence or incidence. The 1998 Adult Dental Health survey is the first of the decennial series of UK adult dental health surveys to use and report a measure of the self-perceived impact on people of the dental and periodontal diseases and other oral conditions. Over half (51%) of dentate adults said they had been affected in some way by their oral health, and in 8% of cases the impact was sufficient to have reduced their quality of life.

Adult↗

PubMed2001

Dental restorations in adults in the UK in 1998 and implications for the future.

People in their late fifties in the UK today can expect to live another 20 years and most want to maintain a functional and aesthetically acceptable dentition. However, 50% of the teeth of dentate adults aged 45 years and over are filled and crowned. The challenges for the dental profession in addressing these aspirations are discussed.

Adolescent↗

PubMed2001

Stimulation of epithelial tissue migration by certain porous topographies is independent of fluid flux.

A surface with columnar pores 0.1 or 0.4 microm in diameter is shown to have a novel effect on the migration of corneal epithelial tissue sheets; migration is stimulated in a nondirectional manner with respect to migration over a planar, nonporous surface (Dalton, Evans, McFarland, and Steele, J Biomed Mater Res 1999;45:384-394; Steele, Johnson, McLean, Beumer, and Griesser, J Biomed Mater Res 2000;50:475-482). By blind-ending the pores, we show that this increase in tissue migration is not dependent on fluid flux through the pores and so appears to occur as a result of surface topography. From transmission electron micrographs, the migrating tissue appears to form either close contacts or focal adhesions at the edge of some pore channels; we speculate that this may provide a fulcrum for the enhanced migration. Scanning electron micrographs suggest that within tissue that migrates over the surfaces that contain blind-ended pores, the cells are more extensively spread than those in tissue migrating on a planar surface. The migration of disaggregated epithelial cells is enhanced on surfaces that contain 0.1- or 0.4-microm-diameter pores (compared with a planar surface), and this is similarly independent of fluid flux.

Animals↗

PubMed2001

Modulation of epithelial tissue and cell migration by microgrooves.

We used a polystyrene substratum to study the response of migrating epithelium to 1- or 5-microm depth microgrooves with groove/ridge widths of 1, 2, 5, or 10 microm. The migration of a tissue sheet was enhanced along the microgrooves, while migration across the microgrooves was inhibited. Changing the depth of the microgrooves had a greater effect on migration than alteration of the groove/ridge width. The migration of epithelial cells from a confluent monolayer culture followed a similar pattern to that of intact epithelial tissue. Cellular extensions generally followed the microgroove direction by tracking along the top of the ridges or following the ridge walls, as revealed by scanning electron microscopy. Actin filaments within the basal cell layer of the tissue were aligned with the microgrooves, unlike filaments in the superficial layers that did not appear to be affected by the presence of underlying microgrooves. The basal cell layer of the tissue conformed to the contours of the microgroove following migration. However, the ultrastructure of the tissue above the ridges resembled that of tissue on a flat surface. We concluded that surface microgrooves have the potential to direct the migration of immediately adjacent epithelial tissue, the effect of which is to guide epithelial tissue on the surface of implanted biomaterials.

Actin Cytoskeleton↗

PubMed2001

Prevalence of impacts of dental and oral disorders and their effects on eating among older people; a national survey in Great Britain.

OBJECTIVE: The objective was to assess the prevalence, in a British population aged 65 years and older, of oral health related impacts and the effects they had on the quality of daily life and in particular on eating. METHODS: 753 free living and 202 institutionalised subjects aged 65 years and over, participating in the oral health survey of the British National Diet and Nutrition Survey (NDNS), had a dental examination and interview. Data on the impact of dental and oral disorders on the activities of daily living based upon the modified Oral Impacts on Daily Performance (OIDP) indicator were collected. RESULTS: 17% of the free living edentate participants reported that their mouth affected their pattern of daily living on a regular basis. Oral impacts levels were lowest in dentate subjects with the greatest number of teeth. For the dentate, the most common oral impacts were on eating and speaking. Impacts relating to emotional stability, sleeping, relaxing, carrying out physical activity and social contact were very infrequent, but were severe when they did occur. Among those with an impact on eating, 25% said it was severe and 42% had the impact nearly every day or in a spell of 3 or more months. Oral impacts were more prevalent among the institution sample, particularly the dentate. The impacts were associated with the inability or difficulty to eat a range of 16 common foods. CONCLUSION: This survey has shown that the oral status of older people fairly frequently affects the quality of life of older people, and in particular, the ability to eat several common types of foods.

Aged↗

PubMed2001

The relationship among dental status, nutrient intake, and nutritional status in older people.

Dental health status may influence nutrition. The objective of this part of the National Diet and Nutrition Survey was to assess if there is a relationship between dental status in people 65 years and older and intake of certain nutrients and any link between dental status and blood-derived values of key nutrients. Random national samples of independently living subjects and those living in institutions had dental examinations, interviews, four-day food diaries, and blood and urine analyzed. In the sample living independently, intakes of most nutrients were lower in edentate than dentate subjects. Intake of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C was significantly lower in edentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly of non-starch polysaccharide. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and plasma retinol were the only analytes significantly associated with dental status.

Aged↗

PubMed2001

The influence of stromal contraction in a wound model system on corneal epithelial stratification.

PURPOSE: The healing process of some corneal wounds involves closure by stromal contraction and the renewal of the stratified epithelium. In wound gape injury such stromal contraction occurs with epithelial stratification. In previous in vitro studies of noncontracted and contracted corneal fibroblast-seeded collagen gels (FSCGs) it was shown that initiation of wound contraction by the myofibroblast phenotype (present within the wounded stroma) was dependent on vitronectin and/or fibronectin. This study considers one aspect of the epithelial-stromal interaction that occurs during wounding. The stratification of corneal epithelial cells on noncontracted and contracted corneal FSCGs was compared. METHODS: Dissociated bovine corneal epithelial cells were seeded on noncontracted and contracted corneal FSCGs, and these assemblies were cultured for 7 days. The epithelium that formed was evaluated using laser confocal microscopy and immunohistochemical markers directed against cytokeratin 3, desmoplakin I and II, integrin alpha-6 subunit, laminin, and collagen VII. The characteristics of the epithelium were compared with stromal carriers comprised of dissociated bovine corneal epithelial cells seeded on intact stroma and basement membrane (stromal carrier biopsies). RESULTS: The stratified epithelium that developed on contracted corneal fibroblast-seeded collagen gels was similar to that formed on stromal carriers, whereas nonstratified epithelium formed on noncontracted FSCGs. CONCLUSIONS: These studies showed that the contracted state of fibroblast-seeded gels enhanced the development of well-organized, stratified corneal epithelium.

Animals↗

PubMed2000

Total tooth loss in the United Kingdom in 1998 and implications for the future.

The 1998 Adult Dental Health Survey, published this year, showed that the number of people without teeth should fall over the next three decades, to only 4% of the UK population. Patterns of tooth loss and retention are also changing. This article, the first of a series on the interpretation of the Adult Dental Health Survey, discusses the implications of these trends for dentistry.

Adolescent↗

PubMed2000

Peptoid-containing collagen mimetics with cell binding activity.

Collagen mimetic peptides containing the peptoid residue Nleu (Goodman Bhumralkar, Jefferson, Kwak, Locardi. Biopolymers 1998;47:127-142) were tested for interactions with epithelial cells and fibroblasts. Molecules containing the sequence Gly-Pro-Nleu with a minimum of nine repeats showed cell binding activity. The activity of these molecules appeared to be conformationally sensitive, with the triple-helical form being preferred. When immobilized on a surface, the (Gly-Pro-Nleu)(10)-Gly-Pro-NH(2) sequence stimulated the attachment and growth of corneal epithelial cells and fibroblasts and the migration of epithelial tissue. The peptide sequence KDGEA inhibited cell attachment to the (Gly-Pro-Nleu)(10)-Gly-Pro-NH(2) sequence, suggesting that cell binding to this collagen mimetic involves the alpha2beta1 heterodimer integrin receptor. Interestingly, peptides containing the sequence (GlyNleu-Pro-)(10)-NH(2) did not have cell binding activity. The discovery that triple-helical peptides containing the Gly-Pro-Nleu sequences interact with cells opens up new opportunities in the design of collagen mimetic biomaterials.

Amino Acid Sequence↗

PubMed2000

Effect of porosity and surface hydrophilicity on migration of epithelial tissue over synthetic polymer.

The relative effects of porosity and surface chemistry on the migration of epithelial tissue over the surface of a polymer were determined in vitro. These studies compared nonporous polymers with those having 0.1-microm diameter track-etched pores and were conducted on polycarbonate and polyester. Epithelial tissue migration over the polymer surface was stimulated by the presence of these pores. The surface chemistries of the polymers were modified by deposition of various polymer films using radio frequency gas deposition, giving a range of surfaces that varied in air:water sessile contact angle (SCA) of between 26 and 100 degrees. Tissue migration on the nonporous surfaces was affected by the surface chemistry, being generally linear as a function of the SCA and higher on hydrophilic than on hydrophobic surfaces but reduced if the hydrophilic surface had a mobile chemistry. The effects of the 0.1-microm diameter pores and the surface hydrophilicity were additive with the maximal level of epithelial tissue migration occurring on a porous, hydrophilic polymer surface.

Animals↗

PubMed2000

Protein adsorption and cell attachment to patterned surfaces.

To better understand the events involved in the generation of defined tissue architectures on biomaterials, we have examined the mechanism of attachment of human bone-derived cells (HBDC) to surfaces with patterned surface chemistry in vitro. Photolithography was used to generate alternating domains of N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (EDS) and dimethyldichlorosilane (DMS). At 90 min after seeding, HBDC were localized preferentially to the EDS regions of the pattern. Using sera specifically depleted of adhesive glycoproteins, this spatial organization was found to be mediated by adsorption of vitronectin (Vn) from serum onto the EDS domains. In contrast, fibronectin (Fn) was unable to adsorb in the face of competition from other serum components. These results were confirmed by immunostaining, which also revealed that both Vn and Fn were able to adsorb to EDS and DMS regions when coated from pure solution, i.e., in the absence of competition. In this situation, each protein was able to mediate cell adhesion across a range of surface densities. Cell spreading was constrained on the EDS domains, as indicated by cell morphology and the lack of integrin receptor clustering and focal adhesion formation. This spatial constraint may have implications for the subsequent expression of differentiated function.

Animals↗

PubMed2000

Using partial recording to assess tooth wear in older adults.

OBJECTIVES: To establish whether partial recording can be used for the measurement and reporting of tooth wear data in samples of adult populations, whilst maintaining the usefulness of the index. METHODS: Using whole mouth coronal tooth wear data from a large random population sample of 1200 dentate older adults in England, several different partial recording systems were investigated to establish which teeth would maintain a high level of sensitivity for the most economic use of codes and index teeth. Tooth wear data were recorded on a surface-by-surface basis on all teeth in the sample using the tooth wear index. RESULTS: Five different partial mouth recording systems were assessed, including half-mouth scoring, assessment of just upper or just lower anterior teeth, assessment of all anterior teeth and use of six index teeth. The 12 anterior teeth were the ones most often affected by moderate or severe wear, and when all 12 teeth were used as the index teeth few wear cases were missed, and all the most extensive and severe cases of coronal wear were classified as having some wear. A limited index of only six anterior teeth (three uppers and three lowers) was almost as sensitive, but allowed less flexibility when reporting the extent of coronal wear. Other systems for partial recording were less sensitive. CONCLUSIONS: Partial recording using six or 12 anterior teeth is appropriate for measuring and reporting tooth wear data in large population surveys.

Age Distribution↗

PubMed2000

Impact of treatment provision on the epidemiological recording of root caries.

The estimation of root caries prevalence and the identification of risk factors for decay depend upon the successful identification of carious lesions in epidemiological studies. Root surface restorations can either be placed to manage decay or cervical wear/sensitivity. The handling of data for restorations during epidemiological surveys is critical to the accurate assessment of caries prevalence. The objective of this study was to determine the relative frequency of dentists' placing root surface restorations according to their reason for placement. Data for 696 restorations were recorded from 35 dentists. Forty-five % of restorations were placed because of decay compared with 55% for cervical wear/sensitivity. There were no significant differences in proportion of placement of restoration with age of the patient or between regular and irregular attenders of different ages. Using these data a correction factor was developed for inclusion in the Root Caries Index (RCI) to make allowance for the proportion of restorations placed because of wear/sensitivity. When this correction factor was introduced into an existing data-set for root caries, the RCI was reduced for all groups. This reduction was greatest in regular attenders. When these data were analysed without making allowance for treatment effects, there was a significant difference in RCI between regular and irregular attenders. When the correction factor was applied to these data, this difference was eliminated.

Adult↗

PubMed2000

Use of rubber dam and irrigant selection in UK general dental practice.

AIM: To evaluate factors which influence rubber dam use and irrigant selection in UK National Health Service (NHS) endodontics. METHODOLOGY: A postal survey was conducted amongst two age cohorts of dentists, representing all of the 1970-73 (older) and 1990-93 (younger) graduates of two northern English dental schools (n = 643). Key and supplementary questions were posed on levels of rubber dam use, irrigant selection, and factors influencing practice in NHS endodontics. After manual checking, validated (dual) entry of responses was made to a flat ASCII data file before analysis with SPSS software. The threshold for statistical significance was set at the 95% probability level. RESULTS: Eighty-five per cent of the valid sample responded to the questionnaire. Regardless of age and qualifying school, less than one-fifth of dentists always or frequently used rubber dam, whilst 60% never used it. Qualifying school had a significant influence on rubber dam use, whilst age had a variable influence. Major disincentives to the use of rubber dam included the perception that patients do not like it, that the NHS fee was inadequate to justify its use, that it took too long to apply, and that dentists had received inadequate training. Frequent users of rubber dam were significantly less likely to cite these disincentives than nonusers. Overall, local anaesthetic solution was the most common endodontic irrigant. Irrigant choice was strongly linked to rubber dam use, and to graduation cohort. Seventy-one per cent of rubber dam users irrigated with sodium hypochlorite, compared with only 38% of nonusers. This pattern was reversed for local anaesthetic irrigation. Younger graduates were significantly more likely to irrigate with local anaesthetic solution than their older counterparts, and the younger graduates of one school showed a highly significant increase in the use of chlorhexidine. CONCLUSIONS: 1) The majority of UK Health Service dentists never use rubber dam isolation in endodontic treatment. 2) Qualifying school has a significant impact on rubber dam use, and irrigant selection. 3) Use of rubber dam has a significant association with irrigant choice in endodontics.

Age Factors↗

PubMed2000

Oral health and nutrition in older people.

The theoretical link between foods choice and masticatory efficiency has long been established. Recent evidence has confirmed this association, demonstrating a progressive alteration in food choice with decreasing numbers of teeth, with the greatest effect being among those who are edentulous. This altered food selection results in significant differences in the hematological status for some key nutrients in the one study in which this association was investigated. This paper summarizes some of the literature relevant to diet as a risk factor for systemic disease and identifies areas where altered food choice as a consequence of reduced masticatory efficiency might be placing individuals at increased risk of life-threatening conditions, such as atherosclerosis and cancer.

Aged↗

PubMed2000

Vitronectin or fibronectin is required for corneal fibroblast-seeded collagen gel contraction.

PURPOSE: The wound healing process in the corneal stroma involves the activation of corneal keratocytes and the expression of associated phenotypes (fibroblasts and myofibroblasts). One of these phenotypes, the myofibroblasts, synthesizes alpha-smooth muscle actin in order to affect wound closure by contracting the surrounding matrix. Excessive contraction results in the formation of unresolvable scars that are undesirable in the corneal stroma. The authors tested the effect of vitronectin and fibronectin on the contraction process associated with corneal wound healing. METHODS: Collagen gels were prepared and were exposed to different treatments of fetal calf serum (FCS). The FCS used was either depleted of fibronectin and vitronectin or contained a known concentration of fibronectin, vitronectin, or both at 50 microg/ml. Contraction was measured using image analysis and cross sections of contracted gels were examined for alpha-smooth muscle actin expression using laser confocal microscopy. RESULTS: Fibroblasts seeded in collagen gels paralleled the morphologic characteristics and cell distribution of keratocytes in unwounded cornea. Matrix contraction was dependent on the presence of fibronectin and/or vitronectin where myofibroblasts were present. The cell-mediated contraction process was maximal at 0.5 x 10(5) fibroblasts/ml. CONCLUSIONS: These studies showed that vitronectin or fibronectin is required for the myofibroblast-associated contraction to occur in this in vitro model of stromal wound healing. This model system shows a distinct potential for further studies relating to the corneal wound healing process.

Actins↗

PubMed2000

Epithelialization of a synthetic polymer in the feline cornea: a preliminary study.

PURPOSE: This study examined the potential of a synthetic polymer to support stable epithelial growth when implanted in the feline cornea. METHODS: A perfluoropolyether-based polymer was cast into lenticules that were coated with collagen I and implanted in four feline corneas. Epithelial growth onto the lenticules was monitored clinically for 6 weeks, after which time the animals were killed, and three corneas were evaluated histologically. Immunohistochemistry was used to identify proteins associated with the formation of a basement membrane (laminin) and adhesion complexes (bullous pemphigoid antigen and collagen VII). Electron microscopy was used to examine the tissue-polymer interface for evidence of the assembly of these adhesive structures. RESULTS: Postoperative epithelial growth began on days 2 to 3, and lenticules were fully epithelialized by days 5 to 9. Lenticules were clinically well tolerated and histology showed epithelium consisting of multiple layers adherent to the lenticule's surface. Laminin, bullous pemphigoid antigen and collagen VII were identified at the tissue-polymer interface using immunohistochemistry. Ultrastructural examination showed evidence of assembly of these proteins into a recognizable basement membrane and hemidesmosomal plaques. CONCLUSIONS: A perfluoropolyether-based polymer coated with collagen I was implanted in the feline cornea and supported epithelial growth that showed signs of persistent adhesion, both clinically and histologically. This polymer shows potential for ophthalmic applications that require sustained epithelialization.

Animals↗

PubMed1999

Measuring oral health: does your treatment really make a difference.

An understanding of a broader concept of health is increasingly important for all health professionals, including dentists, and has recently been incorporated as a key principle in the Government White Paper, The New NHS. This aims to deliver a dependable, high quality, egalitarian health service. In the past, performance measurements in the UK have often relied simply on those areas which are most easily quantified. For example, within the hospital service, performance was measured in terms of the cost and the number of finished consultant episodes, from which the 'purchaser efficiency index' was calculated. This tended to produce a driving force rewarding those doing more rather than those doing more better. It is analogous to the system which has been the backbone of NHS dental practice for many years, 'fee per item of service', where throughout is rewarded rather than outcome. However, the White Paper has signalled a move away from simply counting activity. From April 1999 within the hospital service the purchaser efficiency index has been replaced with more rounded measures, reflecting the changing concepts of health, in a new broader performance framework to determine what really counts for patients. It will focus on measuring health improvement, fairer access, better quality and outcome, including the views of patients.

Dental Care↗