4种机用镍钛器械在模拟弯曲根管内成形能力的实验研究

 目的    比较4种不同机用镍钛器械预备树脂模拟弯曲根管的成形能力，为临床应用提供实验依据。方法    将40个单弯树脂模拟根管随机分为4组，每组10个，分别为ProTaper Universal组、iRaCe组、Reciproc Blue组和HyFlex EDM组，采用4种不同机用镍钛器械进行根管预备，并记录各组预备时间。使用单反相机采集各组预备前后根管的形态照片，采用Adobe Photoshop CS5软件进行图像重叠，使用Image Pro Plus6.0软件测量10个观测点的根管内、外侧壁树脂去除量并计算器械的中心定位能力，采用SPSS 17.0软件对数据进行统计学分析。结果    iRaCe组预备时间最短，预备效率最高（P < 0.05）。在根尖区，iRaCe组的中心定位能力最好；在弯曲点附近，iRaCe组和HyFlex EDM组的中心定位能力较好，相对优于ProTaper Universal组和Reciproc Blue组；在弯曲点冠方，iRaCe组、Reciproc Blue组、HyFlex EDM组的中心定位能力均显著优于ProTaper Universal组（P < 0.05）。结论　4种机用镍钛器械均可较好地保持原始根管的走向，无明显的偏移及台阶等出现。与ProTaper Universal相比，iRaCe、Reciproc Blue和HyFlex EDM镍钛器械对弯曲根管表现出更加出色的成形能力，更适合用于弯曲根管的预备。     

In vivo evaluation of an oral health toothpaste with 0.1% vitamin E acetate and 0.5% sunflower oil (with vitamin F)

Objectives : To measure the delivery of active ingredients of a new oral health toothpaste with zinc citrate trihydrate/triclosan and containing α‐tocopherol acetate (vitamin E) and sunflower oil (vitamin F) and compare its anti‐plaque/anti‐ginigvitis efficacy to that of a clinically proven control toothpaste. Methods : The new toothpaste contained 0.1% vitamin E acetate (α‐tocopherol acetate) and 0.5% sunflower oil as a source for vitamin F (linoleic acid). It also included an anti‐caries agent (0.32% sodium fluoride) and a proven gum‐health active system (0.3% triclosan and 0.75% zinc citrate trihydrate). Three studies were carried out. In study 1 (n=45) the bio‐availability of zinc and triclosan was measured in plaque 12h after brushing with the test toothpaste. In study 2 (n=93) the effect of the test toothpaste on plaque and gingival condition was investigated over three weeks in a randomised, parallel, double‐blind, controlled design. The control toothpaste was a fluoride toothpaste containing 0.3% triclosan. Healthy adult volunteers with GI>1.0 were enrolled and given a full mouth scale and polish. Plaque levels (Modified Quigley and Hein Index) and gingival condition (Gingival Index) were assessed at baseline and after three weeks. Study 3 (n=93) lasted for nine weeks. Subjects did not receive a full mouth scale and polish at baseline but the study was otherwise identical to study 2. Results : In study 1, no triclosan was detected in baseline plaque samples; mean triclosan concentration in plaque 12h after last brushing with the test toothpaste was 5.78μg/g (std=4.74); the mean zinc concentration rose from 15.2μg/g zinc ion in baseline plaque samples to 84.3μg/g zinc ion (p>0.0001) in samples taken 12h after brushing. In study 2, mean plaque and gingival indices were significantly reduced in both test and control group after three weeks compared to baseline; there was no significant difference between the test and control group after three weeks. In study 3, mean plaque and gingival indices were significantly reduced in both test and control group after three and nine weeks compared to baseline; there was no significant difference between the test and control group after three and nine weeks. Conclusion : The delivery of zinc and triclosan from a new oral health toothpaste containing zinc citrate trihydrate and triclosan was unaffected by the addition of α‐tocopherol acetate (vitamin E) and sunflower oil (vitamin F). The new toothpaste was effective in reducing plaque levels and improving gingival conditions to the same degree as a clinically proven positive control. Regular oral hygiene with this toothpaste is therefore beneficial for maintaining healthy and strong gums.     

The effect of medroxyprogesterone acetate on estrogen-dependent risks and benefits – an attempt to interpret the Women's Health Initiative results

The results of the two arms of the Women's Health Initiative (WHI) study allow a comparative assessment of the contribution of the progestogen component to the changes in risk of cardiovascular disease and cancer during treatment of postmenopausal women with conjugated equine estrogens and medroxyprogesterone acetate (CEE/MPA). However, the high proportion of older and overweight or obese women compromises any conclusions, since we estimate that 50% of the women would have the metabolic syndrome. In overweight postmenopausal women with hyperinsulinemia, the risk of breast cancer is elevated and cannot be increased further by hormone replacement therapy (HRT). Therefore, the non-significant, but consistent reduction in breast cancer risk during treatment with CEE alone might be based on an improvement of hyperinsulinemia. The 24% increase in breast cancer risk in the CEE/MPA group can be regarded as an artifact due to very low numbers of breast cancer diagnoses in the placebo group of women who had received HRT prior to the WHI study. The elevated risk of venous thromboembolism and the transient increase in the risk of coronary heart disease (CHD) during treatment with CEE/MPA but not CEE alone suggests a direct effect of MPA on the vessel wall. MPA has been demonstrated to upregulate the thrombin receptor, the thrombin-induced production of tissue factor and procoagulatory activity in the vessel wall owing to its glucocorticoid activity. In contrast, CEE alone reduced non-significantly the risk of CHD in women aged 50–59 years, suggesting that primary prevention is possible if estrogen replacement therapy is initiated early. As clinical studies on the effect of different progestogens combined with estrogens are scarce, a possible superiority of progestogens other than MPA remains to be proven.     

Effect of ethinylestradiol/cyproterone acetate on endothelial function in young non-obese women with polycystic ovary syndrome: a pilot study

Background.?Combined oral contraceptives are used in polycystic ovary syndrome (PCOS) women for the treatment of hyperandrogenism and menstrual cycle disturbances.

Aim.?To assess the effect of ethinylestradiol and cyproterone acetate (EE/CA) on endothelial function in young, non-obese PCOS women in a pilot study.

Methods.?Thirteen young, non-obese PCOS women (20.9?±?3.7 years, 23.0?±?4.0?kg/m²) received 35?mcg EE & 2?mg CA for 6 months. Fourteen age- and body mass index (BMI)-matched healthy women served as controls. Endothelial function assessed by brachial artery flow-mediated dilation (FMD), indices of hyperandrogenism, and insulin resistance were studied at baseline and 6-month follow-up.

Results.?FMD was impaired in PCOS compared to control women (4.67?±?2.38% vs. 10.12?±?3.19%, p?<?0.001), but increased significantly following EE/CA (9.99?±?2.11%, p?<?0.001 vs. baseline), reaching normal values (p?=?NS vs. controls). EE/CA also significantly decreased hyperandrogenism indices and increased total and HDL cholesterol and triglycerides (p?<?0.05 vs. baseline). The only independent predictor of treatment-induced FMD improvement in PCOS women was the decrease in free androgen index.

Conclusions.?Treatment with combination of estrogens and antiandrogens reverses endothelial dysfunction in young, non-obese PCOS women mainly via improving hyperandrogenism. Further research is needed to investigate whether this treatment may also reduce cardiovascular risk in these women.     

Assessment of mammographic density in postmenopausal women during long term hormone replacement therapy

Abstract

Objective: To assess long-term effects of different hormone replacement therapy (HRT) regimens on mammographic density.

Methods: One hundred sixty-five postmenopausal women were treated with the same HRT during 5 years: 38 received transdermal estradiol, 78 cyclic combined therapy and 49 continuous combined therapy. Mammograms were obtained at baseline, at 1-year and 5-year treatment. Breast density changes were categorized as slight focal increased density, considerable focal increased density, slight diffuse increased density and considerable diffuse increased density.

Results: Mammographic density increased in 7.9% of women receiving estrogen alone versus 25.2% of women receiving combined therapy (p?<?0.022) during 1 year, and in 7.9% of women versus 28.3% of women (p?<?0.009) after 5 years of therapy, respectively. There were significant statistical differences in women treated with estrogen alone versus those treated with combined HRT after 1 and 5 years. After 5 years of HRT, breast density increased 21.8% in women receiving cyclic combined therapy versus 38.8% in those under continuous combined therapy (p?<?0.039).

Conclusion: An increase in breast density is significantly more frequent in women receiving combined estrogen-progestin therapy than in women receiving estrogen alone. There are differences between cyclic and continuous combined therapy at 5 years of treatment.     

Are contact allergens stable in patch test preparations? Investigation of the degradation of d-limonene hydroperoxides in petrolatum

Several of the products formed after oxidation of d-limonene exhibit strong contact allergenic properties. Some, e.g., the hydroperoxides, are unstable compounds. In this study, we have examined whether the limonene hydroperoxides are chemically stable in white petrolatum used for patch testing. We found that the stability of the hydroperoxides was strongly dependent on whether or not the petrolatum was stabilized with alpha-tocopheryl acetate. In the presence of this antioxidant, the hydroperoxides were degraded to a greater extent. The hydroperoxides were shown to be directly reduced to the corresponding alcohols by this agent. On the other hand, the compounds where shown to be stable in non-stabilized petrolatum throughout clinical patch testing for a period of 6 weeks, provided that the preparations were stored in a refrigerator when not used. Thus, it is recommended that vehicles without alpha-tocopheryl acetate are used when peroxy or hydroperoxy compounds are patch tested or used in sensitization experiments. However, it is important to limit the storage time so that optimal conditions are at hand. A fast method was developed to enable isolation and quantification of the hydroperoxides in white petrolatum. This analytical method may also be applicable to other compositions of patch test preparations.     

Influence of cyproterone acetate and estradiol on cell kinetics in the sebaceous gland of the golden hamster ear

Summary The cell kinetics of the sebaceous gland of the hamster ear were analysed in untreated animals, in animals treated with cyproterone acetate, and in animals treated with estradiol. Both active substances lead to a reduction in the size of the sebaceous gland (measurement with the integration plate), to a reduction of mitoses (colcemide method), to a reduction in the ³H-thymidine labelling index, to a prolongation of the S-phase (double labelling technique with ³H-thymidine which remain in contact with the basal lamina of the sebaceous gland 6 days after application of the isotope. The results indicate that, like cyproterone acetate, estradiol reduces the effect of androgens on cell kinetics in the sebaceous gland under the test conditions chosen, even if in an entirely different way.Dedicated to Prof. Dr. W. Schneider on the occasion of his 70th birthday     

Orale Kontrazeptiva und Acne vulgaris

Ohne Zusammenfassung

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局部注射平阳霉素和确炎舒松A治疗小儿皮肤血管瘤的比较研究

目的 :　探讨和比较平阳霉素和确炎舒松A治疗小儿皮肤血管瘤的疗效。方法 :　 2 80例皮肤血管瘤患儿随机分为平阳霉素治疗组 (10 4例 )和确炎舒松A治疗组 (176例 ) ,平阳霉素组采用平阳霉素瘤体内注射 ,浓度为 2～ 3.2mg ml ;确炎舒松A组采用确炎舒松A瘤体内注射 ,浓度为 8mg ml。每 2周重复注射一次 ,总疗程 3～ 10次。结果 :　平阳霉素组 10 4例患儿中 ,治愈 89例 (治愈率 85 .6 % )和有效 15例 (14 .4 % ) ,确炎舒松A组 176例血管瘤患儿中 ,治愈 86例 (4 8.9% )和有效 75例 (4 2 .6 % )。两组比较差异有统计学意义 (P <0 .0 0 1)。结论 :　平阳霉素瘤体内注射治疗小儿皮肤血管瘤安全有效 ,其疗效优于确炎舒松A。