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Biomedical subjects

H D Glenwright

Publications and source records attributed to H D Glenwright.

At least 19 recordsLinked to original sources
PubMed1996

Chemiluminescent assay of alkaline phosphatase in human gingival crevicular fluid: investigations with an experimental gingivitis model and studies on the source of the enzyme within crevicular fluid.

The purpose of this study was to investigate how levels of gingival crevicular fluid (GCF) alkaline phosphatase (ALP) change in relation to levels of plaque and gingival inflammation in 20 adults during a 21 day period of experimental gingivitis. The source of ALP within GCF was also investigated using a repeat sampling protocol; by determining enzyme levels derived from 30 putative periodontal pathogenic and non-pathogenic species; and by examining inhibition profiles from a variety of host and bacterial ALP isoenzymes. Total 30-s GCF ALP levels increased significantly (p < 0.002) during experimental gingivitis and preceded an increase in gingival index (GI) by approximately 7 days. Enzyme levels correlated with GCF volume (R = 0.7; p < 0.0001), but repeat sampling indicated that entry of ALP into the gingival crevice was independent of the rate of fluid flow. Only 5 of the bacterial species investigated produced clearly detectable levels of ALP in culture supernatants, these were P. gingivalis (381), P. intermedia (581), P. nigrescens (8944), Dentin P. gingivalis (TW 471: clinical isolate) and C. ochracea (25). Levamisole inhibition and studies on suspensions of washed plaque demonstrated that host-derived ALP contributed to > 80% of the enzyme in GCF. We conclude that elevated 30-s GCF ALP levels measured using the chemiluminescent assay reported, are detectable before increases in gingival indices and appear to be a better marker of gingival inflammation than ALP concentrations. The major source of ALP within GCF is host derived and in early inflammatory disease is likely to be of polymophonuclear leukocyte origin.

Adult↗
PubMed1995

Calibration and reliability of the Periotron 6000 for individual gingival crevicular fluid samples.

The Periotron 6000 fluid analyser has become widely used as a diagnostic tool for a variety of oral diseases and recent work has questioned its reliability. This paper investigates for the first time, the detailed calibration curves of 2 Periotron 6000 machines across a range of 23 different fluid volumes. Within and between machine reliability is analyzed and the shape of the calibration line determined. The measurement errors incurred by using a single fluid sample, as opposed to mean values of triplicate samples are also determined. We conclude that there are 3 sections to the calibration line, 2 linear and a quadrilateral zone, and that 2 separate regression equations should be used; from 0-0.1 microliter and from 0.1-1.0 microliter. Within machine calibration errors were only 3.2 +/- 7.5%, but values for volumes below 0.2 microliter were as high as 18.7%. Using a single fluid sample rather than mean values of multiple samples, incurred a further 4 +/- 4% error, which was as high as 7% for volumes lower than 0.12 microliter. Whilst significant differences in volume reading existed between different machines (p < 0.0004) and between the same volumes of different fluids (p < 0.00001), individual Periotron calibrations were extremely reproducible and reliable. We conclude that the Periotron 6000 is a reliable and convenient instrument for measuring fluid volumes greater than 0.2 microliter. For volumes lower than 0.2 microliter errors in measurement may be too high for some investigations, but this is likely to be due to problems with evaporation and with measurement technique, rather than errors directly due to the Periotron itself. Finally, for optimum accuracy, the digital display should be re-set to zero after each sample is measured.

Blood↗
PubMed1994

Site-specific alkaline phosphatase levels in gingival crevicular fluid in health and gingivitis: cross-sectional studies.

Using a recently developed chemiluminescent assay enabling alkaline phosphatase (ALP) quantification in nanolitre volumes of gingival crevicular fluid (GCF), we have investigated GCF ALP levels in health and in the presence of gingivitis. In gingival health, there was a site-specific pattern of ALP concentration with higher enzyme concentrations around the upper and lower anterior teeth. Furthermore, clinically normal sites that had been subjected to different levels of plaque control produced significantly different ALP levels, (p < 0.03). This indicates that biochemical components of GCF may be used to measure subclinical inflammatory status. The ratio of GCF to serum ALP varied from 6:1 to 11:1, suggesting that a major source of the enzyme is through local production. The main cross-sectional study of 30 patients with gingivitis (276 sites) demonstrated that total GCF ALP levels, collected over a 30-s sampling time were higher for a gingival index of 1 than of 0 (p < 0.014). There was no significant relationship between total GCF ALP and plaque levels of the enzyme, and analysis of plaque within the study group demonstrated very low levels of ALP, indicating that the enzyme is likely to be largely derived from the periodontal tissues. The ratio of GCF ALP levels to those of saliva within individuals was 530:1, thereby eliminating saliva contamination as a risk, when total GCF ALP is being measured.

Adult↗
PubMed1993

A new ultrasensitive chemiluminescent assay for the site-specific quantification of alkaline phosphatase in gingival crevicular fluid.

The search for markers of periodontal disease activity and progression has accelerated over the last decade, in an effort to replace existing subjective clinical measures of periodontal health status. Research is being aimed at establishing more objective and quantitative methodology, capable of rapid diagnosis prior to the appearance of clinical signs of destructive disease. Such tests need to be sensitive enough to evaluate individual periodontal sites in health as well as disease states. We report the development of a new chemiluminescent assay for the enzyme alkaline phosphatase, that is capable of quantifying the enzyme in sub-microliter volumes of gingival crevicular fluid and serum. The technique will measure alkaline phosphatase (ALP) whilst immobilised on paper strips, without the need for an elution stage. It is simple, versatile and amenable to chair-side use. We discuss in detail the assay procedure and have examined levels of ALP in 11 adult volunteers with clinically healthy periodontal tissues. The mean ALP concentration was 2135 IU/L for GCF and 183 IU/L for serum, a 12-fold difference. There also appeared to be an "oral pattern" of enzyme distribution in healthy periodontal sites, with levels being higher in the anterior region of the mouth and highest in the lower anterior region.

Adamantane↗
PubMed1992

Clinical effects of pulsed oral irrigation with 0.2% chlorhexidine digluconate in patients with adult periodontitis.

The aim of this study was to investigate the effects of using 0.2% Chlorhexidine digluconate in an pulsated jet irrigator by patients as part of their daily dental home-care measures. After initial assessment, 16 patients diagnosed as having adult periodontitis received scaling and polishing together with advice on the subgingival use of a pulsated jet oral irrigator with which they were supplied. 8 patients having 293 active sites with probing depths equal to or in excess of 4 mm used 0.2% chlorhexidine digluconate (CHX) in the oral irrigator, 2 x daily for 56 days. The other group of 8 patients with 253 active sites over 4 mm used a placebo as the irrigating solution. A modified dichotomous plaque index (MPI), gingival bleeding index (GBI) and probing pocket depths (PPD) were assessed on days 0, 28 and 56. Within-group comparisons showed that the CHX regime reduced MPI, GBI and PPD significantly but that the placebo group (PG) only achieved a significant reduction in the PPD. Between-group comparisons showed that the use of 0.2% CHX as an irrigant was significantly more effective than the placebo solution at reducing all the clinical parameters studied. The patients found the oral irrigator easy and pleasant to use, although all the CHX group developed staining to a varying extent. This double blind study demonstrated that 0.2% CHX used 2 x daily in an oral irrigator was effective at reducing plaque deposition, periodontal inflammation and probing pocket depths. The effects of using lower concentrations of chlorhexidine digluconate in this regime need to be investigated.

Adult↗
PubMed1992

Hypophosphatasia: a family study involving a case diagnosed from gingival crevicular fluid.

Hypophosphatasia is an inherited disorder characterized by defective mineralization of the skeletal and dental structures of the body and deficient liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. There has been a tremendous advance in our knowledge of this condition over the last decade due to the advent of highly specific DNA probes and novel microanalytic techniques. The purpose of this paper is threefold: to review the dental aspects of current literature about this rare condition; to present a case (and family study) that was diagnosed in a 5-yr-old boy from 0.14 microliters of gingival crevicular fluid, using a new ultrasensitive chemiluminescent assay for the enzyme alkaline phosphatase; and to provide strong evidence for an autosomal dominant mode of inheritance.

Adamantane↗
PubMed1989

The prevention of cross-infection. Progress in the West Midlands.

A questionnaire was sent to a group of general dental practitioners in the West Midlands, one year after they had participated in a previous survey and a year following publication of the British Dental Association's 'Guide to blood-borne viruses and the control of cross-infection in dentistry'. Results show that awareness of the need to safeguard patients and staff from the risks of cross-infection continues to grow and that procedures undertaken to reduce the possibility of cross-infection continue to be improved.

Attitude to Health↗
PubMed1989

The role of medications in dental caries formation: need for sugar-free medication for children.

Most paediatric medicines are prescribed in a liquid form that includes sugar in the formulation. Accumulating evidence, on a clinical and experimental basis, shows a significant association between the intake of sucrose-based medication and an increased incidence of dental caries. Many of the children on long-term medication for chronic medical problems are particularly at risk from the consequences of developing dental caries; dental disease, sepsis or treatment procedures can put the general health or even life of the child at risk. The need to use sucrose in medications should be reassessed; medicines containing sugar should be labelled accordingly; and medical and dental professionals should be aware of potential problems related to sucrose-based medications.

Adolescent↗
PubMed1988

Histiocytosis X: an oral diagnostic problem.

A case of prepubertal periodontitis in a 6 1/2-year-old boy is described. Following failure to respond to conventional treatment including scaling, oral hygiene instruction and tetracycline therapy, a biopsy was performed and root planing carried out. The biopsy revealed histiocytic infiltration and a diagnosis of Histiocytosis X of the Hand-Schüller-Christian type was made. This case emphasises the role of biopsy in establishing a diagnosis in cases of prepubertal periodontitis that do not respond to conventional therapy.

Child↗
PubMed1988

Dark-field microscopy of subgingival plaque microflora in Indian and English subjects.

This present investigation reports on the microbial pattern of subgingival plaque from English and Indian subjects living in the West Midlands of England. Subgingival plaque from healthy and diseased sites was studied using darkfield microscopy. The results indicate that significant differences exist in microbial flora of clinically normal and diseased sites of English as well as Indian subjects. Coccoid cells predominated in healthy sites, with an increase of 21% in the spirochaetes in diseased sites. The ratio of non-motiles to motiles was 1:0.6 in healthy sites, whereas in diseased sites the ratio observed was 1:1.8 in English subjects and 1:3.6 in Indian subjects. Comparison of healthy sites in Indians with healthy sites in English subjects revealed significant differences between numbers of rods (p less than 0.05). Comparing diseased sites of Indians with diseased sites in English subjects revealed significant difference between both cocci (p less than 0.05) and motile rods (p less than 0.01). A positive correlation between chronic inflammatory periodontal disease and spirochaete burden, and a negative one between the disease and coccal burden, was found.

Adult↗
PubMed1984

Relative effectiveness of a rotary and conventional toothbrush in plaque removal.

The ability of a powered rotary toothbrush to remove 3- and 4-day-old microbial plaque deposits was evaluated in 10 young adults with healthy gingivae. Using a split mouth technique and a cross-over experimental design, the powered brush was compared with a conventional hand brush over a 14-day period. Statistical analysis of the results showed no significant differences between either method of brushing when the whole mouth, maxillary or mandibular arches were compared. Further analysis of the proximal scores again showed no significant differences between the powered brush or handbrush. The majority of the subjects preferred the conventional handbrush to the powered brush.

Adult↗