Search PubMed⌕ Search

Biomedical subjects

A B Wade

Publications and source records attributed to A B Wade.

At least 19 recordsLinked to original sources
PubMed1998

Effect of transforming growth factor-beta1 on parathyroid hormone-related protein secretion and mRNA expression by normal human keratinocytes in vitro.

Parathyroid hormone-related protein (PTHrP) is produced by a wide range of neoplastic and normal cells, including keratinocytes where it may regulate growth and differentiation. Transforming growth factor-beta (TGF-beta) is a growth factor produced by many cells, including keratinocytes where it regulates epidermal homeostasis. TGF-beta has been reported to be cosecreted with PTHrP in some neoplasms and to stimulate PTHrP production by neoplastic keratinocytes. However, the effects of TGF-beta on PTHrP production by normal keratinocytes are not well characterized. In this study, we investigated the effects of endogenous and exogenous TGF-beta on PTHrP production by normal human foreskin keratinocytes. PTHrP secretion, mRNA expression, and mRNA transcription in vitro were determined by N-terminal radioimmunoassay, ribonuclease protection assay, and transient transfections. PTHrP production and secretion of latent TGF-beta activity were greatest in proliferating keratinocytes prior to and at confluence of monolayer cultures. TGF-beta1 increased PTHrP mRNA expression by normal keratinocytes in a dose-dependent manner with maximal stimulation at 6-1 2 h after treatment. In addition, keratinocytes treated with a monoclonal anti-TGF-beta antibody expressed decreased levels of PTHrP mRNA. The increased levels of PTHrP mRNA following TGF-beta1 treatment were owing, at least partly, to an increase in PTHrP mRNA stability. TGF-beta1 failed to activate transcription of the luciferase reporter gene driven by either the human or mouse PTHrP promoters. In conclusion, TGF-beta1 functions as a paracrine or autocrine regulator of PTHrP production in normal human keratinocytes, and this may play a role in the regulation of keratinocyte proliferation or differentiation.

Animals↗
PubMed1991

Augmentation of superoxide dismutase and catalase activity in alveolar type II cells.

This study tested whether adducts formed by covalent linkage of superoxide dismutase (SOD) or catalase to polyethylene glycol (PEG) could augment SOD and catalase activity in alveolar type II cells and document enhanced resistance to oxidant damage. Alveolar type II cells were isolated from adult, pathogen-free rats. Antioxidant enzymes were added to the medium of cell cultures in various concentrations for periods up to 48 h. Incubation with 500 to 3,000 U of PEG-SOD or 10,000 to 40,000 U of PEG-catalase/10(6) cells produced a dose-response-related increase in intracellular enzyme activity in comparison with controls (untreated or treated with SOD or catalase, inactivated PEG-SOD or PEG-catalase, or PEG alone). Uptake was maximal during the first 4 h. Using fluorescent label (fluorescein isothiocyanate) bound to PEG-catalase, we found intracellular localization of the labeled enzyme. Exposure to H2O2 led to reduced cytotoxicity in cells pretreated with PEG-catalase than in controls. We conclude that supplementation with PEG-SOD or PEG-catalase enhanced the activity of these enzymes in alveolar type II cells and increased their resistance to oxidant stress.

Animals↗
PubMed1986

Toothbrush age and wear as it relates to plaque control.

An investigation was conducted to test the hypothesis that age and wear of toothbrushes do not affect plaque removal. 40 preclinical dental students between the ages of 19 and 26 years were assigned randomly to 2 groups. 1 group of 19 subjects used a toothbrush for 10 weeks while the 21 subjects in the other group were given new toothbrushes every 2 weeks for 10 weeks. A baseline of zero plaque and calculus was obtained on the first visit. On subsequent visits, 2 weeks apart, the gingival status of each group was evaluated using the gingival index, and plaque levels were scored using the patient hygiene performance index. The brushing surface area of the toothbrushes was measured with a caliper as well as being graded subjectively according to their condition (good, fair or poor). Results were statistically analysed at the end of the 10-week period. It was found that after 10 weeks, the subjects using the same toothbrush for the whole period had significantly more plaque than those who replaced their brushes every 2 weeks. As brushes deteriorated, they became less effective. No differences in gingival state were detected. There was appreciable variation in toothbrush wear among subjects, some reducing their brush to a poor state in 2 weeks whereas with others the brush was rated as "good" after 10 weeks.

Adult↗
PubMed1985

A comparative study of effectiveness in plaque removal by Super Floss and waxed dental floss.

The effectiveness of Super Floss and waxed dental floss as proximal surface cleansing agents was compared in 34 subjects. Each subject used 1 agent twice daily for 2 weeks followed by the other agent used with the same frequency and for the same period. The order in which the agents were used was selected at random. Plaque was stained by erythrosin, and a plaque index of Wolffe used. Super Floss was found to be superior to waxed dental floss in removing proximal plaque, but neither was 100% effective. Some plaque was present in 49.9% of the proximal surfaces when Super Floss had been used and on 54.7% when the waxed dental floss had been used. Both agents cleaned distal surfaces better than mesial surfaces, proximal surfaces of anterior teeth more effectively than those of posterior teeth, the coronal half of the proximal surfaces better than the apical half and the facial half more efficiently than the lingual half. No differences were found between maxillary teeth and mandibular teeth. Subjects used more lengths of Super Floss than of waxed dental floss, indicating its relative 'brittleness'. However, the majority of subjects preferred Super Floss, mainly because it was thicker and felt more abrasive.

Adult↗
PubMed1980

The role of visual feedback by a disclosing agent in plaque control.

The common prescription of disclosing agents for home use assumes a relationship between visual feedback from stained plaque and subsequent oral hygiene behaviour. A study of double crossover design showed that there was no significant difference in the improvement in plaque control between the group which received only individual oral hygiene education and another group which had the same oral hygiene education supplemented by the home use of a disclosing agent for 2 weeks. On receiving oral hygiene reinforcement and discontinuing use of the disclosing agent, there was a further significant improvement in plaque control after another 2 weeks. This again suggests that visual feedback from the disclosing agent did not play a critical role in patient motivation. It appears that oral hygiene education is still fundamental to the whole concept of prevention. The prescription of a disclosing agent for home use should not be considered mandatory. Thorough and repeated oral hygiene education seems to be the most important feature in patient motivation.

Adolescent↗
PubMed1978

A comparison of the scalloped and linear incisions as used in the reverse bevel technique.

Using a split-mouth technique in 20 patients, a comparison was made of the linear and scalloped incisions as used in the reverse bevel technique. Forty full thickness periodontal flap procedures were evaluated. The PlI and GI were recorded and gingival fluid collected at operation and at weeks 1, 2, 3, 4 and 12 after operation. Pocket depths and attachment levels were noted and gingival contour assessed, using the Contour Index, pre-operatively and 12 weeks after operation. Pain experience during the first week after operation was evaluated. No significant changes in PlI occurred throughout the study. The GI and gingival fluid flow showed comparable trends. More inflammation was present after the linear incision during the first 2 weeks after operation. Clinically, satisfactory results were achieved for both scalloped and linear incision procedures as shown by the improvement in gingival contour, reduction in pocket depth, slight gain in attachment, lack of gingivitis and low plaque scores.

Epithelial Attachment↗
PubMed1977

The relative effectiveness of plaque removal by the Proxabrush and rubber cone stimulator.

The effectiveness of two agents in plaque removal from the proximal surfaces of teeth was studied in 30 subjects with large interproximal spaces. The Proxabrush was more effective than the rubber cone stimulator in its ability to remove proximal plaque, but neither achieved complete removal. Both agents cleaned incisor teeth better than posterior teeth, mesial surfaces better than distal surfaces, facial halves better than lingual halves and coronal halves better than apical halves of proximal surfaces. No differences in gingival health were detected. A majority of the patients preferred the Proxabrush.

Adult↗
PubMed1977

Plaque removal by the Bass and Roll brushing techniques.

The effectiveness of plaque removal using two brushes with the Bass technique and two with the Roll method was compared in a group of 38 junior dental students using a crossover experimental design. The Bass technique was superior to the Roll method in cleaning the tooth tissue adjacent to the gingival tissue on the lingual and facial aspects, but no significant differences were found in the overall effectiveness. Cleaning of all tooth surfaces was at an unacceptable level and it is concluded that efficient tooth cleaning is not achieved by detailed instruction at a single visit including a demonstration of competence by the subject and the issue of written instructions. Repetition of the instruction within 3 weeks did not achieve a higher standard of plaque removal.

Dental Plaque↗
PubMed1977

Importance of filament diameter when using bass brushing technique.

A comparative study using a crossover experimental construction was made of the effectiveness of brushes containing 6/10 nylon filaments of 0.132 mm mean diameter using a Bass technique with those containing filaments of the same type of nylon but 0.280 mm diameter. Each type of brush was used for a 2-week period. Even though the finer filament brushes contained more than three times as many filaments, they were inferior in cleaning achievement to the brushes with the broader filaments. The difference was particularly marked on the facial aspect, but was largely nullified lingually. The effectiveness of the Bass technique in the gingival zone demonstrated in a previous investigation when brushes containing filaments of 0.18 and 0.20 mm were used, was not found in this investigation. It is concluded that filament diameter is critical in achieving effective cleaning using the Bass technique.

Dental Plaque↗
PubMed1976

Use of food colourants as plaque disclosing agents.

The effectiveness of plaque disclosure by several liquid food colourants and disclosing agents was compared in a group of eight subjects. The subjects refrained from all forms of oral hygiene for a 48-hour period prior to rinsing with 5 ml of each dye in turn at weekly intervals. Kodachrome film records were taken and projected for the assessment at weekly intervals. Kodachrome film records were taken and projected for the assessment of plaque staining efficacy by a panel of 38 assessors. Acceptability with respect to taste, extent and duration of mucosal staining and any side effects was also evaluated. The food colourants were as effective as the disclosing agents. Ability to stain plaque appears to be related not only to the constituents of each dye, but also to their concentrations and relative proportions. Other desirable properties of an ideal disclosing agent tended to be fulfilled to a level equivalent to, or better than, that reached by the proprietery disclosing agents. Difficulty in obtaining proprietary disclosing agents should not act as a handicap to achieving better levels of oral cleanliness as inexpensive food colourants of equal effectiveness to the best proprietary agent are readily available.

Coloring Agents↗