Effects of Clinical Experience and Explorer Type on Judged Crown Margin Acceptability

Purpose: This study was undertaken to simultaneously compare instrumentation type and operator characteristics in judgments of clinical acceptability of crowns exhibiting a controlled range of marginal gaps. The research was conducted in a laboratory setting and generalizability analysis was used as a statistical technique to identify the sources contributing to variation in the judgment outcome. Materials and Methods: A crown was seated on an ivorine tooth in a device that permitted continuous adjustment in intervals of 25 μm to produce known marginal gaps ranging from zero to 250 μm. Forty‐nine students and six faculty members used five types of explorers each to determine, by tactile examination, the point on the controlled increasing marginal gap where they would no longer regard the gap as clinically acceptable. Results: There were no differences across type of explorer. Operators with clinical experience had a threshold that rejected crowns at a smaller gap than did those operators without clinical experience (p= 0.007). Faculty members maintained a higher individual degree of consistency in their personal judgments than did students (p= 0.02); however, the inter‐operator consistency was significantly lower for faculty members than for students (p < 0.05). Conclusions: Differences among operators in a simulation of the decision regarding gaps in crowns accounted for 63% of the variance; type of explorer used in assisting this decision accounted for about half as much variance. Faculty members making such judgments exhibited high intra‐operator consistency but significantly lower inter‐operator consistency than did students. The study suggests that the internal standards dentists use for clinical decision making deserves further study as they may be as significant as the equipment used.     

Arterial internal elastic lamina holes: relationship to function?

Internal elastic lamina (IEL) hole (fenestration) characteristics and myoendothelial gap junction (MEGJ) density were examined in selected resistance and conduit arteries of normal and diseased rat and mouse models, using conventional, ultrastructural and confocal microscopy methods. Selected vessels were those commonly used in functional studies: thoracic aorta, proximal and distal mesenteric, caudal, saphenous, middle‐cerebral and caudal cerebellar artery. Rat and mouse strains and treatment groups examined were Dahl, Sprague Dawley, Wistar Kyoto, Wistar, spontaneously hypertensive (SHR), deoxycorticosterone (DOC) treated rat; and apolipoprotein E knockout, C57/BL6 and BALB/c mice. Vessel size (as IEL circumference), IEL hole and MEGJ density were quantified. In mesenteric arteries, the width of IEL holes and the percent of IEL occupied by holes were also determined. IEL hole density varied significantly within and between mesenteric artery beds, even among normotensive rat strains. Among the hypertensive rats (SHR and DOC), hole density in some vessels was higher in the normotensives than in the hypertensives within each strain, whereas in Dahl rats, hole density was similar between hypertensives and normotensives. Hole density was not correlated with the formation of intimal lesions in superior mesenteric artery. There was no positive general correlation between IEL hole and MEGJ density in resistance and conduit vessels. However, there was a positive correlation between the size of some resistance arteries and MEGJ density, although such a relationship did not hold for conduit vessels or during development, and there was no such relationship between vessel size and IEL hole density. Whilst IEL holes are obviously required for MEGJ communication, their presence is not an indication of contact‐mediated communication, but rather may be related to the presence of sites for the low resistance passage of diffusion‐mediated release of vasoactive endothelial and smooth muscle substances.     

Endocrinology of bone mineralization: An update

Throughout the world, millions of people suffer from fragilizing osteopathies such as osteomalacia and osteoporosis. Osteomalacia is a rare disorder, corresponding to mineralization abnormalities in adult bone, as opposed to rickets in children. Renal phosphate loss and hypophosphatasia are the main causes of vitamin-resistant osteomalacia. Diagnosis is based on clinical history, phosphocalcic metabolism assessment and, if necessary, molecular characterization, and must be rapid in order to initiate the most appropriate treatment and consider new treatments such as burosumab if necessary. Osteoporosis is characterized by reduced bone mass and strength, which increases the risk of fragility fracture. Fracture-related burden is expected to increase over the coming decades linked to the aging of population and a treatment gap. In order to reduce this treatment gap, it is important to develop two strategies: improvement of screening and of treatment. Systematic screening using the FRAX® fracture risk assessment tool could be useful to increase anti-osteoporosis medical treatment and reduce fracture rates. The question of treatment sequencing in osteoporosis is another challenge, notably after denosumab cessation, complicated by a decrease in bone mineral density and increased risk of fracture. New treatments are also available, including romosozumab, a humanized monoclonal antibody, which promotes bone formation and inhibits bone resorption by inhibiting sclerostin. Romosozumab is approved in several countries, including France, for treating severe osteoporosis in postmenopausal women at high risk of fracture and free of cardiovascular comorbidity. Endocrinologists need to be aware of these fragilizing osteopathies in order to improve both diagnosis and treatment.     

A gap in formal long-term care use related to characteristics of caregivers and households,under the public universal system in Japan: 2001–2010

We investigated whether the universal provision of long-term care (LTC) under Japan's public system has equalized its use across households with different socio-economic characteristics, with a special focus on the gender and marital status of primary caregivers, and income. We used repeated cross-sectional data from national household surveys (2001, 2004, 2007, and 2010) and conducted multiple logistic regression analyses to obtain odds ratios of caregiver and household characteristics for service use, adjusting for recipients’ characteristics. The results showed that the patterns of service use have been consistently determined by caregivers’ gender and marital status over the period despite demographic changes among caregivers. The gap in service use first narrowed, then widened again across income levels after the global economic recession. The results indicate that the traditional gender-bound norms and capacity constraints on households’ informal care provision remained influential on decisions over service use, even after the universal provision of formal care. To improve equality of service utilization, the universal LTC system needs to meet diversifying needs of caregivers/recipients and their households, by overcoming barriers related to gender norms and economic disparity.     

Up-regulation of connexin45 in heart failure

INTRODUCTION: Heart failure is associated with reduced expression of the major gap junction protein connexin43 (Cx43), which may contribute to arrhythmias and sudden cardiac death in this patient population. Other cardiac connexins may be altered as well. Because connexin45 (Cx45) has been shown to colocalize with Cx43, we determined whether the number, size, or distribution of Cx45 gap junctions is altered in the failing heart. METHODS AND RESULTS: Cx45 expression levels were measured by immunoblotting and quantitative immunostaining in failing and control human left ventricles. Total Cx45 protein was significantly (P = 0.021) up-regulated 1.8-fold in failing hearts. Cx45 immunohistochemical signal was increased by 80% (P = 0.005) due to a 3.5-fold increase in the number of gap junctions containing Cx45. Cx45 mRNA was not altered in failing hearts, suggesting reduced degradation of Cx45 protein in the failing heart. Cx43 signal, on the other hand, was reduced by 49% in failing hearts. Double-label experiments demonstrated colocalization of Cx45 and Cx43 in the same gap junctions. CONCLUSION: Cx45 is markedly enhanced in the failing heart. Up-regulation of Cx45 in conjunction with down-regulation of Cx43 could result in abnormal impulse propagation and generation of ventricular arrhythmias, thereby predisposing patients in heart failure to sudden cardiac death.     

常规QA设备对脊柱转移瘤SRS/SBRT计划的验证及存在问题探讨

目的:对比aSi-1200 EPID与Octavius 1500电离室矩阵在6 MV非均整脊柱转移瘤计划验证中的应用,探讨可能存在的问题。方法:23例计划在全局归一方式下以不同标准和阈值行2D γ通过率（GPR）评估,将治疗计划系统（TPS）中患者数据导入Verisoft软件重建剂量。引入不同类型和量值的误差:MLC的透射率（TF）和剂量叶片间隙（DLG）、治疗等中心和MU误差,使用GPR方法量化Octavius 1500识别这些误差的灵敏度,并通过评估靶区和危及器官（OARs）剂量学指标变化研究TF和DLG误差的临床意义。结果:与Octavius 1500矩阵相比,EPID方式在同一标准不同阈值下GPR均值更大数据离散程度更小,重建与计算的剂量体积直方图分析表明临床靶区和计划靶区Dmin、Dmax和Dmean的百分剂量偏差（DD%）较大,其中临床靶区最大DD%值为50.00%、11.31%和-8.71%,计划靶区最大DD%值为-25.86%、9.31%和-8.22%。治疗等中心和+3%、+5%的MU误差都被检测到,所有标准均未检测到TF误差,+0.3 mm的DLG误差只被2%/3 mm的标准检测到。TF值增大0.023 6％模型误差和DLG增加0.3 mm模型误差均导致靶区和OARs的剂量增加,其中OARs剂量增加较明显,尤其健侧肺的V20分别增加9.80%和8.85%,脊髓D0.1 cc均增加5.35%。结论:使用GPR方法识别引入误差的MLC模型可靠性不够,提示鉴别TPS问题的根源需要更有效的独立质量保证方法以确保通过TPS计算得出的陡峭剂量梯度的可信度。剂量验证系统软件算法的独立验证研究是有必要的,以确定算法局限性导致的重建剂量不确定性范围。