Three-dimensional observation and analysis of remineralization in dentinal caries lesions

The remineralization mechanism in dental caries lesions is not completely understood. This study reports on ultrastructural and chemical changes observed within arrested caries lesions. Carious human teeth were observed using scanning electron microscopy (SEM) and focused-ion-beam (FIB)-SEM. The crystals detected in the caries lesions were characterized by transmission electron microscopy (TEM), along with chemical element mapping using energy-dispersive spectroscopy (EDS)-STEM. FIB-SEM 3D reconstructions revealed a severely damaged dentin surface abundantly covered by bacteria. Although the dentin tubules were clogged up to a depth of 100 mu m, bacterial invasion into dentin tubules was not observed. TEM crystal analysis and EDS-STEM revealed the presence of Ca and P, as well as of Mg within the HAp crystals deposited inside the dentin tubules. It was concluded that extensive remineralization with deposition of Mg-HAp crystals had occurred in dentin tubules of caries-arrested dentin. Understanding the natural remineralization process is thought to be helpful for developing clinical biomimetic remineralization protocols

Multiparametric analysis for pharynx SCC

Purpose : To predict local control / failure by a multiparametric approach using magnetic resonance (MR)-derived tumor morphological and functional parameters in pharynx squamous cell carcinoma (SCC) patients. Materials and Methods : Twenty-eight patients with oropharyngeal and hypopharyngeal SCCs were included in this study. Quantitative morphological parameters and intratumoral characteristics on T2-weighted images, tumor blood flow from pseudo-continuous arterial spin labeling, and tumor diffusion parameters of three diffusion models from multi-b-value diffusion-weighted imaging as well as patients’ characteristics were analyzed. The patients were divided into local control / failure groups. Univariate and multiparametric analysis were performed for the patient group division. Results : The value of morphological parameter of ‘sphericity’ and intratumoral characteristic of ‘homogeneity’ was revealed respectively significant for the prediction of the local control status in univariate analysis. Higher diagnostic performance was obtained with the sensitivity of 0.8, specificity of 0.75, positive predictive value of 0.89, negative predictive value of 0.6 and accuracy of 0.79 by multiparametric diagnostic model compared to results in the univariate analysis. Conclusion : A multiparametric analysis with MR-derived quantitative parameters may be useful to predict local control in pharynx SCC patients

Alisol B, a triterpene from Alismatis rhizoma (dried rhizome of Alisma orientale), inhibits melanin production in murine B16 melanoma cells

To develop new whitening agents from natural products, we screened 80 compounds derived from crude drugs in Kampo medicine in a melanin synthesis inhibition assay using murine B16 melanoma cells. The screen revealed that treatment with alisol B, a triterpene from Alismatis rhizoma, significantly decreased both melanin content and cellular tyrosinase activity in B16 cells. However, alisol B did not directly inhibit mushroom tyrosinase activity in vitro. Therefore, we investigated the mechanism underlying the inhibitory effect of alisol B on melanogenesis. Alisol B suppressed mRNA induction of tyrosinase and its transcription factor, microphthalmia-associated transcription factor (MITF). Furthermore, alisol B reduced the phosphorylation of CREB and maintained the activation of ERK1/2. These results suggest that the reduction in melanin production by alisol B is due to the downregulation of MITF through the suppression of CREB and activation of ERK, and that alisol B may be useful as a new whitening agent

Influence of Thermodynamic Effect on Blade Load in a Cavitating Inducer

Distribution of the blade load is one of the design parameters for a cavitating inducer. For experimental investigation of the thermodynamic effect on the blade load, we conducted experiments in both cold water and liquid nitrogen. The thermodynamic effect on cavitation notably appears in this cryogenic fluid although it can be disregarded in cold water. In these experiments, the pressure rise along the blade tip was measured. In water, the pressure increased almost linearly from the leading edge to the trailing edge at higher cavitation number. After that, with a decrease of cavitation number, pressure rise occurred only near the trailing edge. On the other hand, in liquid nitrogen, the pressure distribution was similar to that in water at a higher cavitation number, even if the cavitation number as a cavitation parameter decreased. Because the cavitation growth is suppressed by the thermodynamic effect, the distribution of the blade load does not change even at lower cavitation number. By contrast, the pressure distribution in liquid nitrogen has the same tendency as that in water if the cavity length at the blade tip is taken as a cavitation indication. From these results, it was found that the shift of the blade load to the trailing edge depended on the increase of cavity length, and that the distribution of blade load was indicated only by the cavity length independent of the thermodynamic effect

Case report on a coronary artery bypass graft for a patient with antiphospholipid antibody syndrome associated with systemic lupus erythematosus

　Antiphospholipid antibody syndrome (APS) is an immune disease in which antiphospholipid antibodies cause hypercoagulability and thromboembolic complications. We experienced APS cases associated with systemic lupus erythematosus with three-vessel lesions of the coronary artery. After a below knee amputation on a 60-year-old woman with APS, she complained of chest pain at rest. An electrocardiogram showed an ST depression and a coronary angiography showed complicated three-vessel disease, as a result she was referred to the cardiac surgery department. A coronary artery bypass with arterial grafts was performed along with postoperative anticoagulant and antiplatelet therapy, and the short-term graft patency was good. Case reports of coronary artery bypass grafts for secondary APS are rare, so we report here on our case and our strategy to treat thromboembolic complications

A surgical case of mitral valve replacement for a patient with Fabry disease complicated with hemodialysis

　Fabry disease is a rare genetic disease, and surgical reports for the patients with Fabry disease are also rarer.　A 58-year-old man presented with chest pain. At the age of 40, he commenced dialysis due to chronic renal failure and at the age of 50, he developed shortness of breath on exertion, and echocardiography showed mitral regurgitation and left ventricular hypertrophy. He was then diagnosed with Fabry disease due to decreased alpha-galactosidase activity. This diagnosis led to enzyme replacement therapy (ERT). The ERT was effective as he had not never experienced further exacerbation of congestive heart failure. While the CHF was put under control, his mitral stenosis gradually worsened, and the patient began to have more chest pain and became hypotensive. He then referred to our section for mitral valve replacement. His mitral annulus was severely calcified and we removed mitral annulus calcification (MAC) at minimum so that we could stich needles and implanted mechanical valve. Paroxysmal atrial fibrillation and bradycardia made his hemodynamics unstable against ERT, which also caused low dialysis efficiency. It took longer than usual to wean him off catecholamines. His hemodynamics became more stable and dialysis efficiency generally improved, so he moved from ICU to ward on postoperative day 11. On day 32, he was transferred back to the referring hospital for his rehabilitation.　We have reported a surgical case of Fabry disease, that are not only rare but have high perioperative risk due to Fabry disease’s specific complications

A Case of Anomalous Origin of the Right Coronary Artery from the Left Sinus of Valsalva - Special Reference to PTCA Procedures and Aspirin Effect to Failed PTCA of the Anomalous Coronary Artery -

An unusual case of a 53-year-old male with a right coronary artery originating from the left sinus of Valsalva is presented. Despite acute myocardial infarction due to occlusion of the aberrant right coronary artery (RCA), PTCA was not immediately performed. After 81 mg/day of aspirin had been administered for 1 month, PTCA to the subtotal stenosis of the RCA resulted in failure due to poor deployment of the guiding catheters complicated by withdrawal and uncrossing of a guiding wire. However, complete recanalization occurred after giving the patient 162 mg/day of aspirin for 8 months. Low dose aspirin was effective in recanalizing the subtotal stenosis after failed PTCA

Ultra-high-molecular-weight Polyethylene (UHMWPE) Wing Method for Strong Cranioplasty

We developed a new cranioplasty method that utilizes artificial bone made of ultra-high-molecular-weight polyethylene, with a wedge-shaped edge (UHMWPE Wing). This study shows the methods and data of case series and finite element analyses with the UHMWPE Wing. A circumferential wing was preoperatively designed for a custom-made artificial bone made of UHMWPE to achieve high fixed power and to minimize the usage of cranial implants. Here, we present 4 years of follow-up data and finite element analyses for patients treated with the UHMWPE Wing between February 2015 and February 2019. Eighteen consecutive patients underwent cranioplasty using our UHMWPE Wing design. There were no postoperative adverse events in 17 of the patients for at least 18 months. One case of hydrocephalus experienced screw loosening and graft uplift due to shunt malfunction. Placement of a ventriculo-peritoneal shunt immediately returned the artificial bone to normal position. Finite element analyses revealed that a model using the UHMWPE Wing had the highest withstand load and lowest deformation. This is the first report on the UHMWPE Wing method. This method may enable clinicians to minimize dead space and achieve high strength in cranioplasty

Sandblasting may damage the surface of composite CAD-CAM blocks

　OBJECTIVE:　 CAD-CAM blocks to fabricate semi-direct and indirect restorations are available in different sorts of ceramics as well as composite. In order to bond restorations prepared out of composite blocks into tooth cavities, it is recommended to gently sandblast the surface prior to the application of a primer/adhesive. Today, the effect of sandblasting composite block surfaces has not thoroughly been investigated. In this study, the ultra-structure of composite CAD-CAM blocks was investigated with special attention to the effect of sandblasting on the surface topography and of silanization on the bonding performance. 　METHODS:　 Five different composite CAD-CAM blocks were involved. We correlatively investigated their structural and chemical composition using X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), scanning electron microscopy (SEM) and (scanning) transmission electron microscopy ((S)TEM). The effect of sandblasting was also imaged in cross-section and at the interface with composite cement. Finally, we measured the shear bond strength to the sandblasted block surface with and without silanization. 　RESULTS:　 All composite blocks revealed a different ultra-structure. Sandblasting increased surface roughness and resulted in an irregular surface with some filler exposure. Sandblasting also damaged the surface. When the sandblasted composite blocks were silanized, superior bonding receptiveness in terms of higher bond strength was achieved except for Shofu Block HC. 　SIGNIFICANCE:　 Sandblasting followed by silanization improved the bond strength to composite CAD-CAM blocks. However, sandblasting may also damage the composite CAD-CAM block surface. For the composite CAD-CAM block Shofu Block HC, the damage was so severe that silanization did not improve bond strength