A community-based epidemiological study of periodontal disease in Keelung, Taiwan: a model from Keelung community-based integrated screening programme (KCIS No. 18)

AIMS

To estimate the prevalence and severity of periodontal disease (PD) in the Taiwanese population aged 35-44 years and to investigate the association between demographic factors and PD.

MATERIALS AND METHODS

Between 2003 and 2005, residents of Keelung of the appropriate age were invited to screening. The community periodontal index (CPI) and loss of attachment (LA) index were used to measure the periodontal status at subject (prevalence) and sextant levels (severity). Basic demographic information was also collected by a questionnaire.

RESULTS

Of 8462 enrollees, 94.8% had some signs of PD, of whom 29.7% had periodontal pockets >3 mm and 35% LA >3 mm. Calculus was the most common problem in terms of both prevalence (49.6%) and severity (affecting an average of 3.0 sextants per person). Risk factors for poor periodontal status (as measured by CPI) were older age (odds ratio, OR: 1.44), male gender (OR: 2.70), low education level (OR: 1.40), and being a manual worker (OR: 1.51). Similar findings were observed for LA.

CONCLUSION

The prevalence of PD in 35-44-year-olds was found to be high in this large community-based study of screening for PD with CPI and LA. Poorer periodontal health was observed in males, the less educated, and manual workers.

Selenium: occurrence in foods and its toxicological significance--a review

The occurrence of selenium (Se) in foods and the toxicological information relevant to it are reviewed. The estimated normal dietary daily intake for man in most parts of the world ranges from 4-35 microgram/person in infants to 60-250 microgram/person in adults. The current use of Se supplementation in animal feeds could elevate the Se content of meats by up to 30%, but this does not lead to a biologically relevant increase in the Se intake of man. Available metabolic data reveal that after ingestion Se is mostly absorbed. Up to 50% is excreted in the urine, and the portion retained in the body accumulates chiefly in the liver and kidneys. Recent epidemiological and animal studies show that Se is not a carcinogen, and in some cases may have anti-cancer properties. Neither the essentiality for man, nor the no-effect level of Se have been established. Human selenosis of food origin has not been reported in the literature, except those documented in the 1930s in the seleniferous areas.

Glucosinolates and their hydrolytic products in intestinal contents, feces, blood, and urine of rats dosed with rapeseed meals

Rapeseed meals were prepared from B. napus rapeseed, either from seed previously heated in boiling water for 10 min or from unheated seed. Rats were dosed by stomach tube with 1 g of each meal and urine was collected for periods of 8,16, 24, and 36 h. Representative rats were sacrificed at these times and total gastrointestinal contents plus feces and total blood were collected. All samples, including the meals, were subjected to analyses for isothiocyanates, nitriles (BCN), and goitrin (OZT), both with and without myrosinase treatment. Significant amounts of glucosinolates were absorbed and excreted intact in the urine. The heated meal yielded more BCN and OZT in the urine than did the raw meal. At 8 h considerable amounts of OZT were found in the blood of rats dosed with heated meal. No free isothiocyanates were found in any of the samples examined. However, following dosing with heated meal, urine treated with myrosinase yielded isothiocyanates equivalent to 40% of their parent glucosinolates present in the meal. Evidence suggests that when heated or raw meals are ingested the main toxic substances formed are BCN and OZT, the former predominating in the case of raw meal and the latter in the case of heated meal.

Cyano compounds and goitrin in rapeseed meal

Raw rapeseed meals of Brassica campestris and cultivar Bronowski were analyzed for cyano compounds and goitrin following autolysis at 37 °C. Urine excreted from 4 to 36 h by rats dosed with the raw or heated meals (dry heat for 15 min at 110 °C) was also examined for these compounds. Unsaturated nitrile level in raw B. campestris meal was about 20 times, and episulfide A and B and goitrin about 10 times that in raw Bronowski meal. Excretion of unsaturated nitrile and goitrin was consistently higher in the urine of rats dosed with heated meals than those dosed with raw meals. Goitrin was excreted more rapidly in the urine than was unsaturated nitrile.

Effect of dietary rapeseed meal on the serum proteins of rats

Two experiments were conducted in which growing male rats were fed three diets containing as protein sources, casein (C), rapeseed meal variety Bronowski (BM), and B. napus meal (NM). In the first experiment the diets were fed to both thyroidectomized rats and to sham-operated rats with thyroid intact. Poorest gains were recorded for rats fed the NM diet irrespective of whether the thyroids were removed or intact, indicating that the toxicity of B. napus meal was not confined to the effect on the thyroid gland. In the second experiment four groups of rats were fed BM diet, NM diet, and C diet. The latter diet was given to both thyroidectomized rats and rats with intact thyroid to provide controls for the study of the effect on the thyroid of the glucosinolate in rapeseed. As in experiment 1, weight gain of rats receiving NM diet was less than that of either of the two groups of rats receiving C diet. After 25 days the serum protein and the thyroxine-binding properties of serum proteins were examined by disc gel electrophoresis. Rats fed NM or C diet (with thyroid removed) showed an altered serum protein pattern as compared to rats fed C or BM diets. The 131I-thyroxine-binding ability of the albumin band was much greater for the serum of rats receiving diets NM and C (with thyroid removed), 37% and 46% versus 22% of the total 131I-thyroxine recovered on the gel.