Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure

Cury JA, do Amaral RC, Tenuta LMA, Del Bel Cury AA, Tabchoury CPM. Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure. Eur J Oral Sci 2010; 118: 370–375. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Because low‐fluoride toothpaste (500 p.p.m. F) has not clearly been shown to be effective for controlling caries in caries‐active children, this experimental in situ study was conducted to evaluate whether its effect, when compared with a conventional toothpaste (1,000–1,500 p.p.m. F), would depend on the cariogenic challenge. During four phases of 14 d each, 14 volunteers used 500 or 1,100 p.p.m. F toothpaste and wore palatal appliances containing deciduous enamel slabs, on which biofilm was accumulated and exposed to 20% sucrose solution at frequencies increasing from two to eight times per day. The F concentration was determined in the biofilm formed, and enamel demineralization was assessed by surface hardness loss (%SHL) and integrated area of hardness × lesion depth (ΔS). The F uptake by enamel was also determined. Fluoride in biofilm fluid and solids was statistically higher when conventional F toothpaste was used. The toothpastes did not differ statistically in terms of %SHL, ΔS, and F in enamel, but only the conventional F toothpaste significantly reduced caries‐lesion progression according to the frequency of sucrose exposure. The findings suggest that the high‐F availability in biofilm, resulting from the use of conventional toothpaste compared with low‐F toothpaste, may be important for reducing caries‐lesion progression in conjunction with a high frequency of sucrose exposure.     

Development and assessment of a verbal response scale for the Patient-Specific Functional Scale (PSFS) in a low-literacy,non-western population

Quality of Life Research - The Patient-Specific Functional Scale (PSFS) is a routinely used measure of physical function with a 0–10 response scale. We aimed to develop verbal response...     

Survival of patients with malignant biliary stricture based on endoscopic brushing and on bilirubinemia

BACKGROUND: Pancreatic cancer and cholangiocarcinoma are the main causes of malignant biliary stricture. Both types of cancers have dismal survival rates, and treatment has little or no effect on prolonging the patients lives. Prognostic definition at initial endoscopic retrograde cholangiopancreatography is important to choose the most suitable management. AIM: To analyse endoscopic brushing and bilirubinemia importance in determination of the survival of patients with malignant biliary stricture. METHODS: Patients with biliary strictures diagnosed during endoscopic retrograde cholangiopancreatography were submitted to double brushing cytology. Serum samples were taken from all patients for bilirubinemia assay. Patients were followed to determine the final diagnosis and survival rates. RESULTS: A total of 50 patients with biliary stricture underwent endoscopic retrograde cholangiopancreatography (40 ultimately found to have a final diagnosis of malignant disease). Hyperbilirubinemia or cytology brushing positive for malignancy was related to a shorter survival rate. CONCLUSION: This research data demonstrate the possibility of determining the prognosis of patients with malignant biliary stricture using endoscopic brushing results and bilirubinemia levels.     

血管内皮细胞生长因子受体KDR基因靶向RNA干扰质粒的构建

目的:应用RNA干扰技术设计构建针对血管内皮细胞生长因子受体KDR的小干扰RNA,并观察脂质体转染肺癌细胞A549后的干扰效果。方法:实验于2005-03/2006-01在沈阳医学院生物化学及分子生物学教研室完成。①设计针对KDR编码区有短发夹结构的3条mRNA序列,经退火成互补双链,克隆到pGCsi.H1/neo/GFP载体中构建3个重组质粒,分别命名为KDR-siRNA1、KDR-siRNA2和KDR-siRNA3。②设立5组:小干扰RNA组,分别转染KDR-siRNA1、KDR-siRNA2和KDR-siRNA3;阳性对照组,转染pGCsi.H1/neo/siGFP,该质粒载体中的插入序列为针对绿色荧光蛋白的小干扰RNA,不干扰待研究的内源性基因;阴性对照组,转染pGCsi.H1/neo/GFP/NON,该载体为不干扰任何内源性基因的小干扰RNA;空白对照组,转染pGCsi.H1/neo/GFP空载体;正常对照组,不进行任何转染。③对重组质粒进行酶切鉴定、DNA测序分析;脂质体法转染质粒至肺癌A549细胞株后,实时定量PCR检测KDRmRNA的水平变化;细胞计数法绘制细胞生长曲线。结果:①小干扰RNA表达载体的鉴定:KDR-siRNA1、KDR-siRNA2和KDR-siRNA3表达载体用限制性内切酶NdeⅠ和SmaⅠ进行单酶切后,均产生约713bp、5480bp和2403bp、3790bp两个片段,与预期结果相同。测序结果与设计的编码相应短发夹状KDR-小干扰RNA的寡核苷酸序列一致,证明KDR-小干扰RNA真核表达载体构建成功。②KDR-小干扰RNA对A549细胞中KDRmRNA水平的影响:与阳性对照组、阴性对照组、空白对照组和正常对照组的A549细胞相比,KDR-siRNA1,2,3表达载体转染后的A549细胞KDR基因表达水平均明显受到抑制,抑制率分别为64%、81%和72%,其中以KDR-siRNA2抑制作用最为明显。③KDR-小干扰RNA对A549细胞生长的影响:阳性对照组、阴性对照组、空白对照组、正常对照组的A549细胞生长趋势较为一致,且生长速度均明显高于转染3种KDR-小干扰RNA表达载体的A549细胞,从接种第2天开始差异有显著性意义(t=15.29～17.65,P均<0.01)。结论:血管内皮细胞生长因子受体KDR靶向RNA干扰重组质粒构建成功,该载体能有效抑制肺癌A549细胞KDR基因表达与细胞增殖。