Factors related to number of present teeth in Korean elderly adults aged 55-84 years.

OBJECTIVES: The aim of this study was to determine the associations between the number of present teeth (NT) and socio-economic, demographic and oral health behavioural factors among Korean adults aged 55-84 years. METHODS: The total subjects comprised 3767 individuals who were examined and who answered the questions on socio-economic status and oral health behaviour from the fourth Korean National Health and Nutrition Examination Survey conducted from 2007 to 2009. The dependent variable was NT, with binary status divided by the median. Socio-economic and demographic factors included gender, educational level, parent's educational levels, region of residence, household income, type of health insurance and mother's economic activity. Oral health behaviours were as follows: daily toothbrushing frequency, smoking status, recent dental visit and illegal dental treatment. Multivariate logistic regression models were applied to explain the associations between NT and other variables. RESULTS: In a model adjusted by socio-economic, demographic and oral health behavioural variables, subjects who lived in urban areas were more likely to have larger NT compared to those in suburban areas (OR: 1.22, P = 0.025). Males were more likely to have larger NT (OR: 1.90, P < 0.001), and daily toothbrushing frequency was associated with NT (OR = 1.25, P = 0.023). Non-smokers (OR: 2.44, P < 0.001) and past smokers (OR: 1.70, P < 0.001) were more likely to have lager NT compared to current smokers. Subjects without illegal dental treatments were more likely to have lager NT compared to those with illegal dental treatments (OR = 2.21, P < 0.001). CONCLUSIONS: Interventions aiming to preserve present teeth in elderly adults should consider socio-economic, demographic and oral health behavioural factors.

Percutaneous placement of a constrained stent for the treatment of dialysis associated arteriovenous graft steal syndrome.

Though rare, dialysis associated steal syndrome (DASS) can cause debilitating symptoms. Surgical revision of the dialysis access is typically required. We describe a percutaneous technique to alleviate steal syndrome utilizing a constrained stent within an arteriovenous graft. A brief review of the incidence, pathophysiology, and standard treatment of DASS is also provided.

Enhancement of biliary excretion of aflatoxin B(1) and suppression of hepatic ornithine decarboxylase activity by 2-(allylthio)pyrazine in rats.

2-(Allylthio)pyrazine (2-AP), a synthetic pyrazine derivative with an allylsulfur moiety, has protective effects against chemically-induced hepatic toxicity. Previous studies have shown that 2-AP significantly reduces the formation of preneoplastic foci in rats exposed to aflatoxin B(1) (AFB(1)). The present study was designed to determine whether 2-AP could increase the biliary excretion of metabolites of AFB(1) in rats treated with this carcinogen and whether the agent could alter the activity of ornithine decarboxylase (ODC), which is considered to be associated with tumor promotion. Rats were pretreated with 2-AP (p.o.) at a daily dose of 50 mg/kg for 5 consecutive days. AFB(1) (5 mg/kg) was administered intraperitoneally 2 h after the last dose of 2-AP. Amounts of principal AFB(1) metabolites, AFB(1)-glutathione and a glucuronide conjugate secreted in bile juice was increased by 56 and 50%, respectively, after the 2-AP treatment. Levels of radiolabelled AFB(1) covalently bound to calf thymus DNA catalyzed by microsomes obtained from 2-AP-treated rats (10 and 50 mg/kg, for 5 days) were reduced by 47 to 66%. ODC activity in AFB(1)-treated rats was determined by the three-step medium-term hepatocarcinogenesis assay. Rats were treated with 2-AP at the daily doses of 10, 25 and 50 mg/kg for 16 consecutive days. During this period, four repeated doses of AFB(1) (1.0 mg/kg) were given to the animals. Rats were then subjected to two-third partial hepatectomy, followed by administration of phenobarbital. 2-AP inhibited AFB(1)-induced ODC activity by 40 to 66%, as determined at the 44th day. Inhibition of AFB(1)-induced ODC activity by 2-AP in conjunction with acceleration of AFB(1) elimination through metabolic conjugation may contribute to its chemopreventive effects against this carcinogen.

2-(Allylthio)pyrazine inhibition of aflatoxin B1-induced hepatocarcinogenesis in rats.

2-(Allylthio)pyrazine (2-AP), a synthetic pyrazine derivative with an allylsulfur moiety, has hepatoprotective effects against toxicants. Effect of 2-AP on hepatic tumorigenesis in association with glutathione S-transferase (GST) induction was examined in rats exposed to aflatoxin B1 (AFB1). Both AFB1-DNA adduct formation in the liver and urinary elimination of 8,9-dihydro-8-(N7-guanyl)-9-hydroxy-aflatoxin B1 (AFB1-N7-guanine) adduct were also determined. Male Sprague Dawley rats were treated with 2-AP at the daily oral doses of 10, 25 and 50 mg/kg for 16 consecutive days, during which four repeated doses of AFB1 (1.0 mg/kg) were given to the animals. Rats were then subjected to two-thirds of hepatectomy, followed by administration of phenobarbital (PB). Focal areas of hepatocellular alteration were identified after 44 days and preneoplastic foci expressing the placental form of glutathione S-transferase P (GST-P) were quantified by immunostaining of liver sections. 2-AP reduced the volume of liver occupied by GST-P foci by 65-96%. Under these experimental conditions, 2-AP treatment resulted in significant elevations in GST activity in the liver. Levels of radiolabeled AFB1 covalently bound to hepatic DNA, RNA and proteins were significantly reduced in rats treated with 2-AP for 5 days. 2-AP pretreatment also caused a 45% reduction in the urinary elimination of AFB1-N7-guanine adduct over the 24-h postdosing period. The present findings demonstrated that 2-AP exhibited protective effects against AFB1-induced hepatocarcinogenesis in rats with a marked decrease in the level of AFB1-DNA adduct. Reduction of hepatic DNA adducts might result from elevations of activity of GST, which catalyzes detoxification of the carcinogen.

2-(allylthio)pyrazine inhibition of aflatoxin B1-induced hepatotoxicity in rats: inhibition of cytochrome P450 2B- and 3A2-mediated bioactivation.

2-(Allylthio)pyrazine (2-AP), a synthetic organosulfur compound, exhibits hepatoprotective and chemopreventive effects. The effects of 2-AP on aflatoxin B1 (AFB1)-induced hepatotoxicity was studied in rats. 2-AP treatment substantially reduced AFB1-induced toxicity, as evidenced by reduction in the mortality rate of animals as well as decreases in serum alanine aminotransferase and sorbitol dehydrogenase activities. AFB -induced lipid peroxidation was also significantly reduced in rats by 2-AP treatment. Studies were extended to determine whether 2-AP was active in inhibiting cytochrome P450-mediated metabolic activation of AFB1. Covalent binding of AFB1 to calf thymus DNA in the presence of S-9 fraction was inhibited by 2-AP in vitro. Hepatic microsomal pentoxyresorufin-O-depentylase and ethoxyresorufin-O-deethylase activities were also potently inhibited by 2-AP. These results demonstrated that 2-AP was effective in protecting the liver against AFB1-induced toxicity and the mechanism of chemoprotection by 2-AP might involve inhibition of the P450 2B- and 3A2-mediated metabolism of AFB1.