Inhibition of enamel demineralization by buffering effect of S‐PRG filler‐containing dental sealant

The buffering capacity and inhibitory effects on enamel demineralization of two commercially available dental sealants were evaluated in this study. The effects of filler particles were also examined. Disks of enamel and cured sealant materials of BeautiSealant (silica or S‐PRG filler) or Teethmate F‐1 were incubated in lactic acid solutions (pH 4.0) for 1–6 d. The pH changes and amounts of ions released in the solutions were assessed, and enamel surfaces were observed using a scanning electron microscope. The pH of the solution with BeautiSealant (S‐PRG filler) was neutralized from pH 4.0 to pH 6.1 (after incubation for 1 d) and from pH 4.0 to pH 6.7 (after incubation for 6 d). In addition, no release of calcium ions was detected and the enamel surface was morphologically intact in scanning electron microscopy images. However, the pH of the solution with Teethmate F‐1 remained below pH 4.0 during incubation from days 1 to 6. Calcium release was increased in solutions up to and after 6 d of incubation. Scanning electron microscopy images showed that the structures of hydroxyapatite rods were exposed at the specimen surfaces as a result of demineralization. Ions released from S‐PRG filler‐containing dental sealant rapidly buffered the lactic acid solution and inhibited enamel demineralization.     

LC-MS/MS测定人血浆中对乙酰氨基酚及其人体药动学和生物等效性研究

目的 建立一种快速、灵敏的高效液相色谱-串联质谱（HPLC-MS/MS）方法以测定人血浆中对乙酰氨基酚浓度,并应用于两种对乙酰氨基酚制剂的人体药代动力学和生物等效性研究。方法 以替硝唑为内标,200μL血浆样品经5倍于其体积的乙酸乙酯液液萃取,再经Waters XBridge? C18柱等度洗脱分离后导入串联质谱,以正离子多反应监测模式进行定量分析,对乙酰氨基酚和内标的选择性反应离子对分别是m/z 152→110和248→121。方法经验证后应用于19名健康受试者单剂量空腹口服两种对乙酰氨基酚制剂500mg后药代动力学和生物等效性的研究。结果 血浆中对乙酰氨基酚在0.1～8.0 μg·mL-1范围内线性良好（r2 > 0.99）,最低检测限为 0.1 μg·mL-1,提取回收率为91.0%～98.7%,日内和日间准确度分别为98.8%～111.3% （精密度：CV ? 9.03%）和94.9%～102.6% （精密度：CV ? 10.68%）。生物等效性试验中,受试制剂与参比制剂的主要药代动力学参数Cmax、AUC0-t和AUC0-∞ 几何均值比的90%置信区间分别为83.50%～105.79%,94.25%～101.54%和93.24%～101.02%,均落在生物等效可接受标准80.00%～125.00%范围内。结论 所建立测定人血浆中对乙酰氨基酚浓度的HPLC-MS/MS法具有快速灵敏、回收率高、选择性好的特点,适用于对乙酰氨基酚片人体药代动力学和生物等效性研究。受试制剂与参比制剂在人体内吸收速度和程度相似,两种制剂生物等效。     

Biliary adenofibroma with ominous features of imminent malignant changes

Biliary adenofibroma (BAF) is a rare, benign liver tumor. Herein, we report a case of BAF with histological features of imminent malignant changes. Ultrasound and CT revealed a solid 2.5-cm mass in the right liver lobe. The patient was asymptomatic and had no past medical history including liver disease. A general examination that included the abdomen and the laboratory data were normal. Because of the increase of its size, this tumor was surgically resected. Grossly, a 3.5-cm nodular mass abutted on the hepatic capsule was found, and its cut surface showed a well-circumscribed, whitish, and firm lesion that showed microcystic changes in the periphery and solid changes in the central parts. Histologically, the tumor showed a proliferation of tubulocystic structures embedded in a fibrous stroma. Microcysts were prevalent in the periphery, while tubular components with abundant fibrous stroma were in the central parts. The tubules were variably dilated and branched. This case closely resembled the previously reported cases of BAF, except that there were complicated papillary projections with fine fibrovascular cores in some of the microcysts and that the epithelial component in papillary projections showed dysplastic changes and increased cellular proliferative activities, implicating ominous features of imminent malignant changes. These dysplastic and papillary changes may be an intermediate lesion leading to malignancy, which have occasionally been reported in BAF.     

The administration of pitavastatin augments creatinine clearance associated with reduction in oxidative stress parameters: acute and early effects

Background

Chronic kidney disease (CKD) is a serious health problem worldwide. Therapies that can halt the progression of CKD are limited, and the identification of new strategies for CKD treatment is therefore important. Pitavastatin, one of the newest statins introduced to the market, has been shown to exhibit some beneficial effects on renal and endothelial function.

Method

We enrolled 12 healthy volunteers for our study. With or without pitavastatin administration, creatinine clearance (Ccr), urinary albumin excretion, lipid status, and oxidative stress markers were evaluated in acute and early phases after administration of the drug.

Results

A single pitavastatin administration increased Ccr and reduced oxidative stress parameters, such as 8-OHdG levels and isoprostane production, within 6 h, without altering lipid status in healthy participants. A two-week treatment with pitavastatin lowered total and LDL cholesterol and triglycerides but not HDL cholesterol at 7 and 14 days. This change in lipid profile is associated with enhanced Ccr and the suppression of oxidative stress parameters. Urinary albumin excretion was reduced after either acute or chronic administration of pitavastatin, although this effect was not yet significant.

Conclusion

We found that pitavastatin augmented Ccr and reduced oxidative stress parameters in healthy subjects. These data suggest that pitavastatin affects renal outcomes in both lipid status-dependent and -independent manners. These observations suggest that pitavastatin treatment could be beneficial for CKD patients.