Recently, the prevalence of non-alcoholic steatohepatitis (NASH) is increasing in Japan. NASH increases the risk of liver related death, cardiovascular event and liver cancer. Liver biopsy is needed to diagnose the disease, however, new diagnostic methods were required, because the biopsy is an invasive procedure. In this review, the author will discuss the studies of the optical diagnosis of fatty liver disease, and introduce our applied research of diffuse reflectance spectroscopy for in vivo mice liver.

The aim of the present study was to perform a comparative evaluation of the cost-effectiveness of health insurance-approved additional treatments to the standard Stupp regimen for newly diagnosed glioblastoma. According to the clinical symptoms and disease progression of patients with newly diagnosed glioblastoma, a Markov model was constructed to estimate the quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). Utility parameters were obtained from the data of published phase II or III clinical studies. Additional intraoperative treatment using carmustine wafers and photodynamic therapy (PDT) increased overall costs by 1,035,000 yen and 1,212,290 yen, with a gain in 0.221 and 0.552 QALYs, resulting in ICERs of 4,683,258 yen/QALY and 2,196,178 yen/QALY, respectively. Furthermore, additional postoperative adjuvant treatment using Bevacizumab and Tumor-treating field increased overall costs by 4,719,942 yen and 9,000,000 yen, with a gain in 0.14 and 0.257 QALYs, resulting in ICERs of 33,713,971 yen/QALY and 35,019,455 yen/QALY, respectively. These data suggested that the additional intraoperative PDT was the most cost-effective treatment for patients with newly diagnosed glioblastoma in the context of an ICER of 5,000,000 yen/QALY willingness-to-pay threshold. The main limitation of this study was that the additional costs required for the adverse events that may occur as a result of these treatments were not evaluated, and these should be evaluated in the future using real-world diagnosis procedure combination (DPC) data. In summary, we showed that additional intraoperative PDT is an extremely low-cost and high-quality treatment option for the patients with newly diagnosed glioblastoma, using medico-economical evaluation.

Since lasers were first used for cavity preparation in 1964 by Goldman et al., there have been several reports of their application to clinical dentistry. They are widely used for incising oral soft tissue, hemostasis, coagulation, and evaporation in oral and periodontal surgery, and have recently been reported a new finding about the caries treatment. We report that the possibility of the caries diagnosis, caries prevention, selective removal of the caries with the light.

Er:YAG and Er,Cr:YSGG lasers, among various dental lasers, have been widely used in various dental treatments, including tooth cutting. Our department researched the application of various dental lasers in restoration from approximately 20 years ago and recently identified the Er,Cr:YSGG laser, which can efficiently cut teeth. Additionally, we have studied the improvement in tooth surface adhesion prepared using this laser, correlation between irradiation condition and efficacy of cutting, dental pulp response to tooth cutting, and so on. In this review, I primarily discuss the dental pulp response to tooth cutting with dental lasers as well as the response to laser irradiation of the exposed pulp.

The microcirculatory system of the dental pulp plays an essential role in the maintenance of homeostasis. Transmitted-light plethysmography (TLP) is a non-invasive and objective diagnostic method for detecting blood circulation in the dental pulp, and has been clinically used as a pulp vitality test in pediatric and special-needs dentistry. As the dental pulp is encased in mineralized tissues, LED light sources with shorter wavelengths at visible regions are suitable for detecting minute blood flow changes due to high absorbance by hemoglobin. This review summarizes the role of blood flow measurements using the TLP method for the diagnosis of dental pulp, and findings relevant to microcirculation in the developmental stages of young permanent teeth.

Apical periodontitis is defined as an inflammatory disease due to intracanal pathogens, and root canal irrigation is one of the critical treatment procedures to facilitate the elimination of intracanal pathogens that are left in the uninstrumented area. Although laser-activated irrigation (LAI) using an Er:YAG laser has been reported as a superior root canal cleaning method which generates shockwave, cavitation and acoustic streaming, there have been concerns about the uncertainties of the optimum setting for cleaning and the risk of irrigant extrusion from the apical foramen. In this article, we review the findings of previously published studies on the cleaning efficacy and safety of LAI using an Er:YAG laser and also introduce our current studies.

GaAlAs diode laser (810 nm) is known to induce mineralized tissue formation in dentin/pulp complex, and thus may contribute to the improvement in the predictability of vital pulp therapy. The mineralized tissue formation may involve the reparative process that takes place after injury of the dental pulp, whereas the detailed mechnisms remain to be elucidated. Thus, the authors examined the dynamics of cells expressing an odontoblast differentiation marker (heat-shock protein 25) and analyzed the expression of non-collagenous matrix proteins in diode laser-irradiated rat molars. The purpose of this paper is to review our experimental findings and discuss mechanisms behind the diode laser-induced mineralized tissue formation in dentin/pulp complex.

Metronomic photodynamic therapy (mPDT) initiates cancer cell death by intermittent continuous irradiation with low power light for extended durations (several days). We developed a wireless powered, fully implantable LED device capable of transmitting significant anti-tumor effects of mPDT. Considering application to clinical practice, repeated intravenous administration of photosensitizers for mPDT may increase the patient’s burden. Therefore, in this study, 5-aminolevulinic acid (ALA) was selected to be administered orally as a photosensitizer, and studied the anti-tumor effects of mPDT. In the mice intradermal tumor model, with orally administered ALA (200 mg/kg daily for five days), the tumor in each mouse was irradiated (8 h/day for five days) using a wirelessly powered implantable green LED device (532 nm, 0.05 mW). Tumor growth in mPDT-treated mice was suppressed by about half compared to untreated mice. Results proved mPDT using the wirelessly powered implantable LED device with orally administered ALA displayed significant anti-tumor effects. This treatment regimen could reduce the burden of photosensitizer administration for a patient.