Influence of Dietary Patterns and Inflammatory Markers on Atherosclerosis Using Ankle Brachial Index as a Surrogate

Objective

To examine the influence of various dietary patterns on ankle-brachial index (ABI) as a surrogate of atherosclerosis, taking into account serum levels of C-reactive protein (CRP) and factors that predispose to inflammation and/or endothelial damage (homocysteine) or may be protective (tryptophan, vitamin D), as well as age, gender, and lifestyle risk factors.

Design

Cross sectional analysis.

Setting

Cohort of 4000 men and women aged 65 years living in the community in Hong Kong SAR China.

Measurements

Interviewer administered questionnaire that includes dietary intake estimation by the food frequency records (from which various dietary patterns can be characterized), socioeconomic status, smoking habit, alcohol consumption, physical activity. Clinical measurements include body weight and height, and ankle-brachial index using hand-held Doppler machine. Laboratory measurements include assays of serum 25 hydroxyvitamin D, CRP, homocysteine, and tryptophan using LC/MC methods.

Results

Compared with the lowest quintile of vitamin D level, higher quintile was associated with lower prevalence of ABI <0.9 in women only after multiple adjustments of covariates. In men the low score group of the vegetables-fruits dietary pattern was associated with increased odds of having ABI<0.9 after adjusting for all covariates (OR=16.51 (95% CI: 2.21, 123.26)). Similar findings apply to the low score group in the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay Diet) pattern (OR=2.6 (95% CI: 1.24, 5.42)). In women, ABI<0.9 was associated with low Dietary Quality Index (DQI) score (OR=2.05 (95% CI: 1.22, 3.43)), and low score group of snacks-drinks-milk products dietary pattern (OR=3.07 (95% CI: 1.05, 9.04)). No association was observed for the Mediterranean Dietary Pattern (MDS), Dietary Approaches to Stop Hypertension (DASH), Okinawan and “meat-fish” dietary patterns in either men or women.

Conclusion

We conclude that any dietary patterns emphasizing fruit and vegetable intake are associated with better vascular health using ABI as an indicator.

     

A mathematical model for post-irradiation hardening of photoactivated composite resins

A generalized mathematical model for the post-irradiation hardness of photoactivated resins is presented. This model describes a ratio of hardness values as a function of time after irradiation. The low error and generalized character of the model indicate similarities in the post-irradiation hardening of adequately irradiated resins. Using a ratio of hardness at the bottom surface to the final hardness of the top surface, an inadequately irradiated resin can be identified by deviation from the generalized model. Such deviations are noted throughout the hardening process and are recommended as a means of readily identifying deficient photoactivation.     

Inhibitory effect of green tea catechins on cysteine proteinases in Porphyromonas gingivalis

The purpose of this study was to examine the effects of catechins and their derivatives on the activities of Arg-gingipain (Rgp) and Lys-gingipain (Kgp) in Porphyromonas gingivalis. Catechin derivatives, which included (-)-epigallocatechin gallate, (-)-epicatechin gallate, (-)-gallocatechin gallate, and (-)-catechin gallate, significantly inhibited the Rgp activity. The 50% inhibitory concentrations (IC50s) of these catechin derivatives for Rgp ranged from 3 to 5 microm. While (-)-epigallocatechin and (-)-gallocatechin moderately inhibited Rgp activity (IC50s, 20 microm), (-) -epicatechin, (+)-catechin, and gallic acid were not effective, with IC50s greater than 300 microm. Further, some of the catechin derivatives tested also inhibited the Kgp activity, though to a lesser extent than inhibition of the Rgp activity. These findings suggest that green tea catechins may have the potential to reduce periodontal breakdown resulting from the potent proteinase activity of P. gingivalis.     

Tooth loss in treated periodontitis patients responsible for their supportive care arrangements

AIM: To identify risk indicators associated with tooth loss and periodontitis in treated patients responsible for arranging supportive periodontal care (SPC). MATERIALS AND METHODS: Ninety-seven Chinese subjects (34-77 years) who showed favourable responses to periodontal therapy provided in a teaching hospital 5-12 years previously were recalled. They were advised to seek regular SPC on discharge. Background information, general health status, smoking, oral hygiene habits, follow-up dental care, tooth loss, and periodontal parameters were investigated. Multiple regression analysis was performed. RESULTS: Two hundred and fifty-six teeth had been lost, 195 because of self-reported periodontal reasons. Up to 26.8% sites were with pockets > or =6 mm. Positive correlations were found between total/periodontal tooth loss and (i) smoking pack-years, (ii) time spent on oral hygiene, (iii) years since therapy's conclusion, (iv) age, and negative correlations with (v) inter-dental brush use, and (vi) education levels. Tooth loss by arch was correlated with wearing of removable partial denture in that arch. Percentage sites with pockets > or =6 mm were significantly negatively correlated with percentage sites without bleeding on probing. CONCLUSIONS: Smokers, more elderly patients, removable partial denture wearers, and patients with lower education levels or not using inter-dental brushes ought to be targeted for clinic-based SPC.     

A preliminary report on patient acceptance of a novel intra-oral lubricating device for the management of radiotherapy-related xerostomia

Management of radiotherapy-related xerostomia is difficult. Saliva substitutes are helpful but the effects are short-lived. The purpose of the study was to develop a prototype intra-oral lubricating device for the management of radiotherapy-related xerostomia and to evaluate patient acceptance. An intra-oral lubricating device was fabricated that incorporated a reservoir in the palatal vault and permitted slow release of saliva substitute by the patient. Preliminary clinical testing was done in five patients with radiotherapy-related xerostomia. A measure incorporating seven questions was used to explore patient acceptance. The device was simple to fabricate using materials available in a technical laboratory. All patients were able to wear the device for at least 4 h per day throughout the test period. The device was considered easy to use and clean. Some impairment of speech and chewing was noted although this appeared to be related to the bulkiness of the reservoir. General oral comfort was improved due to the lubricating effect. The bulk of the reservoir was reduced as a consequence of patient feedback. The design addressed key problems associated with previous lubricating systems. Patient reports on oral functioning with the device in situ provided pivotal information on the devices utility.     

Validation of a Chinese version of the dental anxiety inventory

OBJECTIVES: To translate the English version of Dental Anxiety Inventory (DAxI) and its short-form (SDAxI) and to validate their use in Hong Kong Chinese. METHODS: The DAxI and SDAxI were translated into Chinese. A total of 500 adults (18-64 years) were interviewed, the Chinese DAxI, Symptom Checklist 90 (SCL-90), Depression Anxiety Stress Scales (DASS) and State-Trait Anxiety Inventory (STAI) were completed. Based on their initial DAxI scores, 135 interviewees were invited to attend a dental examination 1 month later. Then, the subjects completed the DAxI again, together with Beck Anxiety Inventory (BAI) which measured the state anxiety level of the participants. Two months after the initial interview, all 500 subjects were asked to complete the DAxI again. Another 300 adults were recruited and interviewed for the SDAxI validation. RESULTS: Cronbach's alpha of the Chinese DAxI and SDAxI were 0.77 and 0.80 and the test-retest correlation coefficients were 0.90 and 0.84, respectively. High correlation between BAI and DAxI scores and its stability over time supported construct validity of the Chinese DAxI. Small positive correlations between the DAxI and other subscales of the SCL-90, DASS and STAI supported discriminant validity of the instrument. The SDAxI demonstrated comparable validity and reliability with DAxI. CONCLUSION: The translated Chinese DAxI demonstrated good validity and reliability. It is available for use in dental anxiety research in adult Chinese. In situations where a short-form is desirable, the Chinese SDAxI is a simple, valid, reliable and interpretable scale for measuring dental anxiety in both research and dental practice.     

Oral colonisation by aerobic and facultatively anaerobic Gram-negative rods and yeast in Tibetans living in Lhasa

Sample groups of children (n=50) and adults (n=38) were selected from pools of 207 children, (11-13-year olds from two primary schools) and 94 adults (25-44-year olds from four governmental agencies) who were the subjects of an oral health survey among Tibetans living in Lhasa, Tibet Autonomous Region. Mean ages of the study groups of children (38% females) and adults (61% females) were 11.6+/-0.9 and 37.1+/-6.1 years, respectively. All had lived in Tibet since birth. Oral rinse samples were selective cultured to isolate, quantify and speciate aerobic and facultatively anaerobic Gram-negative rods (using the API 20E kit) and yeasts (using API 20C AUX and API ZYM kits). For children, the isolation rates for oral coliform bacteria and yeasts were 84 and 14%, respectively, for adults, the respective rates were 26 and 40%. The corresponding quantities of coliforms/yeasts for children and adults were 0.4+/-1.6 x 10(3)c.f.u./15.8+/-72.3 and 0.2+/-0.6 x 10(3)c.f.u./57.2+/-137.5c.f.u. per millilitre oral rinse, respectively. Aerobic and facultatively anaerobic Gram-negative rods and Stenotrophomonas maltophilia, a free-living saprophytic and ubiquitous bacterial species of wide geographic distribution, were significantly more frequently recovered from the children's oral rinses. The isolation rates of facultatively anaerobic Gram-negative rods in adults and yeasts in both groups were similar to those found in similar cohorts from southern China in earlier studies. Randomly amplified polymeric DNA analysis showed that the S. maltophilia spp. isolated from children were of several different clonal types and were school specific. This study shows that the colonisation rate of facultatively anaerobic Gram-negative rods in adults and yeasts in both groups are similar to those in populations living at lower altitudes, the native young, urban Tibetans appear to exhibit a high oral carriage rate of S. maltophilia spp.     

The correlation between neovascularization and bone formation in the condyle during forward mandibular positioning

The aim of the present study was to investigate the temporal pattern of expression of VEGF (Vascular Endothelial Growth Factor) and new bone formation in the condyle during forward mandibular positioning. The importance of vascularization during endochondral ossification was investigated during natural growth of the condyle and compared to that after forward mandibular positioning. The goal was to further our understanding of the cellular responses during functional appliance therapy with a view to extending the experiment into maturity. One hundred and fifty 35 days old Sprague-Dawley rats, 100 fitted with a bite-jumping appliance and 50 untreated, were divided into 10 groups. One group was sacrificed on each of experimental days 3, 7, 14, 21, 30, 33, 37, 44, 51 and 60 respectively. Sagittal sections were cut and stained with VEGF antibodies and Periodic acid and Schiff's reagent (PAS). Each section was quantitatively analyzed with a computer assisted analyzing program and the temporal sequence of expression of VEGF and new bone formation during natural growth and after mandibular forward positioning was compared. There was significant increase in both vascularization and mandibular bone growth upon forward mandibular positioning and the highest amount of both were expressed in the posterior region of the condyle. The highest acceleration of vascularization preceded that of new bone formation. Thus, forward mandibular positioning was found to solicit a sequence of cellular events leading to increased vascularization and subsequently new bone formation resulting in enhanced condylar growth.