The use of acoustic microscopy to study the mechanical properties of glass-ionomer cement.

OBJECTIVES: The aim of the study was to investigate the relationship between microstructure, acoustic and mechanical properties of hardened dental cement samples, prepared with different powder/water ratios. METHODS: Glass-ionomer dental cement samples, prepared with a standard amount of cement powder and different amounts of water have been examined after being hardened. Surface microstructure and ultrasound, longitudinal and shear velocities were obtained with a scanning acoustic microscope. Conditional effective elastic modulus and Poisson's ratio have been calculated using longitudinal and shear sound velocity values. Then on the same samples elastic modulus and microhardness have been determined by standard tests. Additional samples have been used to determine compressive strength. RESULTS: Density; conditionally instantaneous elastic modulus; high-elasticity modulus and compression strength of the samples decrease when large amounts of water were used for their preparation. At the same time porosity and microhardness of the cement matrix increase. Acoustic parameters and parameters of elasticity, calculated on the basis of sound velocity, demonstrated changes, similar to those obtained in standard mechanical tests. SIGNIFICANCE: The established relation between microstructure, acoustic and mechanical parameters demonstrated a high capacity of acoustic microscopy application for non-destructive characterization of dental materials. A particular advantage of the acoustic microscopy is the opportunity to evaluate microstructure and mechanical properties on the same sample.     

Cannabinoid hyperemesis syndrome in two French emergency departments: a prospective cohort

Chronic cannabis use can be associated with uncontrollable vomiting and abdominal pain. Diagnostic criteria for cannabinoid hyperemesis syndrome (CHS) were defined in 2012 by Simonetto et al. The objectives of this study were to describe the prevalence of CHS, the patients' epidemiological characteristics, and to show the difficulties encountered in caring for these patients in emergency departments, the extent of health care and an unsuitable follow‐up in general practices. A prospective cohort of patients with CHS was recruited among a target population of patients leaving the adult emergency services of the Marseille hospitals Nord and La Timone between October 2017 and July 2018, with abdominal pain syndrome of unidentified etiology. Inclusion criteria for the CHS cohort were chronic cannabis use associated with nausea and vomiting. There were 48 patients included in the CHS cohort who took cannabis daily, in a target population of 2 848 patients (i.e. 1.6%). A hot shower was the most effective symptomatic treatment in 54.2% of cases. Patients suffering from CHS spent significantly more hours in emergency departments (11 vs. 6.5), and, on average, visits were more frequent (4.9 vs. 3). 20.3% of them were hospitalized to continue pain medication. Once out of hospital, follow‐up was limited, and weaning off cannabis, the only etiological treatment, was difficult to set up. Informing patients about CHS is essential, and a hot shower could be systematically proposed, thus limiting an unnecessary extent of health care. CHS is genuine, medical staff should be made aware of it in occupational training, and it should be seriously considered in health policies.     

Autophagy is required for CSF-1-induced macrophagic differentiation and acquisition of phagocytic functions

Autophagy is the process by which superfluous or damaged macromolecules or organelles are degraded by the lysosome. Pharmacologic and genetic evidence indicates that autophagy plays pleiotropic functions in cellular homeostasis, development, survival, and differentiation. The differentiation of human blood monocytes into macrophages is a caspase-dependent process when triggered ex vivo by colony stimulating factor-1. We show here, using pharmacologic inhibitors, siRNA approaches, and Atg7-/- mice, that autophagy initiated by ULK1 is required for proper colony stimulating factor-1-driven differentiation of human and murine monocytes. We also unravel a role for autophagy in macrophage acquisition of phagocytic functions. Collectively, these findings highlight an unexpected and essential role of autophagy during monocyte differentiation and acquisition of macrophage functions.     

The development of resistance in different inbred strains of mice to infection with Nematospiroides dubius

Infection by the intestinal nematode parasite Nematospiroides dubius was studied in seven different inbred mouse strains. Although there was some minor variation in the susceptibility of the different strains to a primary infection there were marked differences in their ability to develop resistance to infection following repeated exposure to infective larvae. The strains of mice which developed the best resistance also expelled adult worms arising from the previous infections. The adult worms resulting from a primary infection were slowly eliminated in two inbred strains studied whereas no loss occurred from outbred LACA mice. Although males and females of two strains, C3H/HeJ and CBA/H were equally susceptible to a primary infection, the females developed better resistance than the male mice following two oral administrations of third stage larvae. Infected mice of every strain and both sexes contained high levels of IgG1 in the serum.     

骨骼肌缺血再灌注损伤及发病机制初探

目的：探讨骨骼肌缺血再灌注损伤过程的微循环变化。组织学改变以及多肽含量变化和意义。方法：42只雄性大鼠随机分为留伴行神经组和去伴行神经组,建立标准骨骼肌缺血再灌注模型,采用激光多谱勒及显微放大分析系统,组织学方法以及凝胶电泳方法等观察缺血再灌注损伤变化。结果：缺血再灌注损伤后的骨骼肌微血管管径在20分钟时恢复率基本达到高峰约60％,此后为平台期：90分钟最高峰,为75％,主干血管流速率亦在20分钟基本达到上限,病理检查显示：缺血的骨骼肌纤维呈空泡状,核形态增大,染色加深,红细胞严重聚集,凝胶蛋白电泳提示：缺血骨骼肌中分子量20KD左右的多肽显著增加。结论：骨骼肌缺血再灌注损伤发生后,骨骼肌的微循环发生不同程度的破坏,及因之导致骨骼结构损伤和异常的20KD多肽含量明显增加,以及红细胞凝聚,白细胞的改变,这些共同构成了缺血再灌注损伤机制。