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Biomedical subjects

D Attwood

Publications and source records attributed to D Attwood.

At least 19 recordsLinked to original sources
PubMed1992

Pitted enamel hypoplasia in tuberous sclerosis.

Thirty patients with tuberous sclerosis (from 29 different families) were examined for evidence of macroscopically visible pitted enamel hypoplasia. Of 23 patients with permanent teeth, 11 (48%) showed multiple enamel pits (mean 4.6 pits, range 3-9), but none were seen in six patients with deciduous teeth. Five of 563 controls (0.88%) had similar pitted enamel hypoplasia. Simple dental examination may be a useful adjunct in the assessment of patients with permanent teeth when a diagnosis of tuberous sclerosis is being considered, but is less likely to be helpful in the pre-school child.

Adolescent↗
PubMed1992

Antitumor effect of pluronic F-127 gel containing mitomycin C on sarcoma-180 ascites tumor in mice.

Pluronic F-127 (PLF-127) gels were evaluated as a sustained-release vehicle for intraperitoneal administration of mitomycin C (MMC) in order to enhance the therapeutic effects of MMC against a Sarcoma-180 ascites tumor in mice. Tumor cell injections were made on day 0 and injections of MMC in 25% (w/w) PLF-127 on day 1, both intraperitoneally. A prolongation of the life span of tumor-bearing mice following injection of therapeutic PLF-127 was noted, and PLF-127 containing MMC was therapeutically more active than free drug. The high chemotherapeutic efficiency of MMC in PLF-127 was striking at high doses, which would be toxic in the case of the drug alone. PLF-127 gels exhibit reverse thermal behavior and are fluid at refrigerator temperature, but are soft gels at body temperature. The in vitro release experiments indicated that Pluronic gel might serve as a rate-controlling barrier and be useful as a vehicle for sustained-release preparations of MMC to be administered intraperitoneally. These results suggest that sustained-release occurs in the peritoneum and that effective drug concentrations can be maintained by the preparation.

Animals↗
PubMed1991

A report on the feasibility of establishing a paediatric emergency dental service at Glasgow Dental Hospital.

A six-month pilot emergency service for children was established at Glasgow Dental Hospital to provide care for patients in pain, offer preventive advice and ensure ongoing dental care. The service was staffed by experienced community dental officers. In the main study period 2965 patients were seen. The majority (54 per cent) were referred from general dental practitioners; however, 27 per cent came directly to the hospital without seeking dental advice in their locality. The most common problems were toothache (55 per cent), occasional pain (28 per cent) and swelling (14 per cent). Eighty per cent of the patients were directed to oral surgery for extractions under general anaesthesia and six per cent for extractions under local anaesthesia. Dental caries still causes pain and distress to a large number of Glasgow school children. Clearly water fluoridation would greatly improve dental health and in so doing reduce the proportion of children requiring extractions under a general anaesthetic. The emergency service is currently being reorganised so as to place more emphasis on following up those patients who do not have a dentist, or who presented for care without a referral letter.

Adolescent↗
PubMed1991

A review of referral patterns to paediatric dental consultant clinics.

A retrospective survey of 317 child patients referred to consultant paediatric dental clinics at Glasgow Dental Hospital over a 12-month period is reported. It was found that although there was a wide range of reasons for referral the most frequent problem was the management of the patient. As a result of this finding, the dental hospital is currently establishing a clinic specifically for patients with a fear of dental treatment.

Adolescent↗
PubMed1991

Dental health in schoolchildren 5 years after water fluoridation ceased in south-west Scotland.

A follow-up study of the dental health of children resident in two towns in south-west Scotland, one of which had fluoridated water until 1983, was carried out at the end of 1988. Comparison with an identical 1980 study allowed trends in the prevalence of caries to be examined. In 1988, the mean, decayed, missing and filled deciduous teeth (dmft) score for 5-year-old children in Stranraer, the formerly fluoridated town, was 3.08, 24 per cent worse than the score of 2.48 reported in 1980. In Annan, mean dmft for 5-year-old children was 3.18 in 1988, 27 per cent lower than the 1980 dmft score of 4.38. The difference in caries prevalence between the two towns in 1988 was a non-significant 3.1 per cent compared with the 44 per cent difference found in 1980. Similar trends in caries prevalence were also found in 10-year-old children with mean DMFT scores of 2.28 in Stranraer and 2.56 in Annan in 1988, a 10.9 per cent difference compared with the 50 per cent difference reported in 1980. The Stranraer DMFT score was 37.4 per cent higher than the DMFT of 1.66 recorded in 1980, while in Annan, the mean DMFT of 2.56 was 23.6 per cent lower than the 1980 score of 3.35. The comparison confirms a trend to lower caries levels in Annan children in line with the general trend in caries prevalence in much of western Europe. However, despite the almost universal use of fluoride toothpaste, caries prevalence in Stranraer children has increased since fluoridation ceased to almost parity with children in the non-fluoridated area. This study shows that there is still a benefit to be gained in terms of lower caries rates by implementing water fluoridation despite the general decline in dental caries.

Child↗
PubMed1990

Dental health of 12-year-old children in Athens.

A 10% sample (684) of boys and girls in the final year of state primary schools in three different areas of the city of Athens were examined. Their mean age was 11 yr 7 months and a mean DMFT of 2.41 was found. The majority of children claimed to be regular dental attenders. When the dental data from the three different socio-economic areas of the city were analysed independently, differences in the caries experience were noted. This investigation has reported lower DMFT scores than other Greek studies.

Analysis of Variance↗
PubMed1990

The effect of solubilized water on the size and shape of lecithin micelles in an apolar solvent.

The changes in the size and shape of the micelles of soya lecithin in trichlorotrifluoroethane following the solubilization of increasing quantities of water have been examined by dynamic and static light scattering and viscometric techniques. Micelles in systems with water/lecithin molar ratios. R. of less than 2.6 were oblate and exhibited no significant changes in asymmetry or aggregation number with changes in the amount of solubilized water. Spherical micelles were evident in systems with R = 2.6 whereas prolate micelles were present in solutions of higher water content (3.5 less than or equal to R less than or equal to 5.2). An increase of R in these systems caused a decrease in the axial ratio and an increase in the aggregation number of the micelle.

Chlorofluorocarbons, Ethane↗
PubMed1990

Effect of structural variations of non-ionic surfactants on surface properties: surfactants with semi-polar hydrophobes.

The surface properties of a series of non-ionic surfactants in which a polar group (either an ether or a keto group) has been introduced into a hydrocarbon chain of octadecylpolyoxyethylene glycol monoether (C18E17-19) have been investigated. Surface tension measurements indicated that the critical micelle concentrations for these semi-polar surfactants in aqueous solution were all significantly higher than those of C18E22, the corresponding unsubstituted octadecylpolyoxyethylene glycol monoether. The minimum areas per molecule of the semi-polar surfactants in the surface monolayer were all larger than the area obtained for C18E22, from which it was concluded that the hydrophobe, and not the polyoxyethylene chain was the main determinant of surface area.

Micelles↗
PubMed1990

A comparison of the dental health of 5-year-old children from Glasgow, Scotland, in 1984 and 1987.

In 1984, Greater Glasgow Health Board commissioned a study of 5-year-old children to provide information for the planning of dental services. The study revealed high levels of caries prevalence in these children. As a preventive dental care programme has been introduced for pre-school children, a new investigation was undertaken in 1987 to assess whether there had been any improvement in caries prevalence in 5-year-olds. The study also compared caries prevalence in children from good and deprived socio-economic areas. Comparison of mean scores for all children in 1984 and 1987 showed reductions in dmft components with a 17% fall in mean dmft. However, when examined by socioeconomic group, significant differences in caries levels were noted. While there has been an improvement in dental health in 5-year-old children, the dental health divide between children from good and deprived areas has widened over time.

Child, Preschool↗
PubMed1990

Comparison of the dental health of 12-year-old schoolchildren living in Athens and Glasgow.

In 1987 studies of the dental health of 12-year-old children in Athens and Glasgow were linked to allow comparison. Standardized examiners used the same methodology and criteria in the two studies and the data were also analysed by socio-economic background. Mean DMFT in Glasgow was 2.91, compared with a mean of 4.71 in a 1984 study. Mean DMFT for Athens 12-year olds was 2.41, in 1987, showing that irrespective of social background, they had reached the WHO Global Goal of 3.0. In Glasgow, 12-year olds from the deprived areas still fell far short of this target. As Greece's new National Health Service begins, a plea is made for the commissioning of National Dental Surveys, to assist monitoring and planning.

Child↗
PubMed1990

A three year follow up study of the dental health of 12- and 15-year-old schoolchildren in Glasgow.

In 1984 the Greater Glasgow Health Board commissioned a survey of the dental health of 12- and 15-year-old schoolchildren in Glasgow to aid the planning of dental services. As a number of studies have shown that dental health is improving in Western Europe, a new survey was undertaken in 1987 to assess whether there had been any improvement in the dental health of Glasgow schoolchildren. The 1984 study had also demonstrated a lower level of caries prevalence in good socio-economic areas (SEG1) than in deprived areas (SEG2), therefore the new study was designed to investigate further the effect of the social environment. The sampling frame and methods were similar to the 1984 study. Mean DMFT for 12 year old children was 4.71 in 1984 and 2.91 in 1987, a 38 per cent fall. the 15 year old children had mean DMFT scores of 7.97 and 5.56 respectively, a 30 per cent reduction. Although an improvement in dental health was found in all groups, when the data were divided by socio-economic groups major differences were revealed. The percentage improvements found in SEG1 were up to 3 times larger than those in SEG2. Thus the general improvement in dental health was mainly due to the SEG1 children. There has been an improvement in dental health in Glasgow children over the three-year period, but dental caries is still a major problem in many parts of Glasgow, particularly the deprived areas. Urgent steps need to be taken to implement preventive and health promotion programmes in these areas. The whole of Glasgow would benefit from the introduction of water fluoridation at an early date.

Adolescent↗
PubMed1989

The interior of a whole and unmodified biological object--the zymogen granule--viewed with a high-resolution X-ray microscope.

We report the ability of focused soft X-rays to visualize at spatial resolution well beyond that of the optical microscope (less than 100 nm) the interior of a small, whole biological object without fixation, staining, dehydration or sectioning. Quantitative estimation of its protein content with unique femtogram sensitivity is also reported. The present results represent a significant step towards the goals of natural imaging and chemical mapping of biological structures with soft X-rays.

Animals↗
PubMed1989

Reassessment of the effect of fluoridation on cost of dental treatment among Scottish schoolchildren.

The present study, which is a repeat of a 1980 study, compares the dental treatment needs of 5, 10, and 15-yr-old life-time residents of a fluoridated town (Stranraer) and non-fluoridated town (Annan). Although fluoridation ceased in July 1983, the cost of all dental treatment in 1986 was 57% lower for 5-yr-olds in the fluoride area compared with the non-fluoride one. The corresponding differences in costs for 10- and 15-yr-old groups were 36% and 63%, respectively. Comparison with the 1980 results showed a 21% drop in the cost of all treatment for 5-yr-olds in Annan and a 4% drop in 10-yr-olds. The corresponding comparison for Stranraer 5-yr-olds showed a 43% reduction in the cost of all treatment. The 10-yr-old group in Stranraer showed a 21% increase in the cost of all treatment and a 115% increase in the cost of restorations for caries. The implications of these findings and the possible link with the cessation of water fluoridation are discussed.

Adolescent↗
PubMed1989

Solubilization of indomethacin by polysorbate 80 in mixed water-sorbitol solvents.

The effect of indomethacin on the micellar properties of the non-ionic surfactant, polysorbate 80, in water-sorbitol mixtures containing up to 25% w/v sorbitol has been investigated by light scattering, photon correlation spectroscopy and viscometric techniques. The molecular weight of polysorbate 80 micelles containing solubilized indomethacin increased linearly with increase of sorbitol concentration. Solubilization of indomethacin resulted in an increase of micellar weight due not only to the incorporation of solubilizate but also to an increase in the number of polysorbate molecules per micelle. The micelles in all systems were most satisfactorily represented as oblate ellipsoids, the asymmetry and hydration of which increased with increase of sorbitol concentration. Indomethacin solubilization caused a restructuring of the micelle to produce a more symmetrical micelle of increased hydration.

Indomethacin↗
PubMed1989

Effect of structural variations of non-ionic surfactants on micellar properties and solubilization: surfactants with semi-polar hydrophobes.

Novel non-ionic surfactants have been synthesized in which a polar group (either an ether or a keto group) has been introduced into the hydrocarbon chain of an octadecylpolyoxyethylene glycol monoether (C18En) with an oxyethylene chain length, n, of 17-18 units. Light scattering studies have indicated aggregation numbers for these semi-polar surfactants in aqueous solution of between 55-65% of that of an unsubstituted octadecylpolyoxyethylene glycol monoether, C18E22. The solubilizing capacities of the semi-polar surfactant micelles for test compounds which were mainly solubilized at the polyoxyethylene/core interface were lower than those of C18E22 whilst solubilizates which exhibited a reasonable degree of solubility in both the interface and the micellar core showed an increased solubilization.

Chemical Phenomena↗