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The enjoyment of tastes should be one of the greatest pleasures in life. Without the sense of taste, one cannot enjoy one's food. The result would then be poor appetite, eating less and weight loss. As the elderly population in Japan increases, the number of patients suffering from taste disorder has also increased. While changes in the ability to distinguish tastes are partly associated with advancing age, they occur moreover in response to secondary influences, such as the side effects of drugs, or the effects of some diseases including periodontal disease/oral infections, nervous disorders, nutritional impairment, and endocrine disorders. Some drugs affect sensitivity to taste by directly stimulating the taste receptors, not only altering the normal transmission process and cellular functions, but also altering the salivary flow. The reduction of salivary flow strongly correlates with a decline in taste perception. In cases of taste disorder, early detection and treatment are important because the appreciation of taste is vital for overall health and long life.

Patients with dry mouth are increasing in Japan due to the country's super-aging society and stressful modern society. Dry mouth affects quality of life, including difficulty with speech or swallowing, and also causes aspiration pneumonia and, respiratory infection. Moreover, dry mouth closely relates to taste dysfunction, resulting in malnutrition, a common risk of nursing care in the elderly. Against these backgrounds, dry mouth has recently been a target of social concern. Drugs for dry mouth such as M3, a muscarinic agonist, have been widely used: however, these drugs have serious side effects, such as vomiting, sweating and/or digestive disorders. We examined the gustatory-salivary reflex to explore a remedy for dry mouth. We have demonstrated that umami stimulation increases saliva from both minor- and major salivary-glands, and that the effect is longer-lasting than with the other four basic tastes. Stimulating the umami response could therefore be a safe and useful remedy for dry mouth.

Rhythm control therapy improves the quality of life in properly selected patients with atrial fibrillation (AF). Sodium channel blockers are recommended as a first-line therapy for lone paroxysmal AF. Pilsicainide, a pure sodium channel blocker is the most frequently used drug in Japan. In addition to amiodarone, several reports performed in Japan described defibrillating effect of bepridil. These two drugs are considered as first choice for rhythm control treatment to lone persistent AF. Since sodium channel blockers increase mortality in patients with reduced cardiac function, amiodarone or bepridil are recommended for rhythm control in AF accompanied with structural heart disease. However, sufficient treatment for underlying heart disease is required prior to administration of antiarrhythmic drugs.

Quality assurance and quality control of delivered dose are important in proton therapy. The delivered proton dose is controlled using a dose monitor system which consists of two ionization chambers filled with free air. Response of the monitor for the delivered dose changes under the influence of temperature and pressure of surrounding air. In the dose monitor system at the National Cancer Center Hospital East, the monitor is near an X-tray tube which operates at a high temperature and is frequently used in every patient setup. Therefore the response of the dose monitor changes a lot with the temperature of the X-ray tube. In this report, temperature and pressure influence on the dose monitor was investigated in detail. Furthermore, a new method was presented to correct the monitor response using the real-time data of temperature and pressure at any time for each patient. This method improved the accuracy of delivered dose from 1% to 0.5%.

It is very important for proton therapy to make and carry out a quality assurance (QA) program. Operators and medical personnel have to avoid any trouble during treatment and provide patients with high quality and reliable treatment. A proton therapy machine consists of an accelerator, gantry and various beam modifying devices. Although QA for proton therapy is complicated and difficult, we tried to realize daily QA for proton therapy. Two main purposes in daily QA are stable operation of the accelerator and reliable control of the irradiation system. In order to determine the daily QA issues, past problems were considered. We made a daily QA program and used it for one year. In this paper, we show the daily QA program and report our results. The daily QA was clearly effective for stable operation of the accelerator and for controlling quality of the irradiation system.

Clinical and electrocochleographic studies of low tone familial deafness were carried out in 19 patients of 10 families. These hearing impairments were characterized by an upward-sloping pure tone audiogram with 50dB to 60dB hearing threshold below 2000Hz and with normal or near-normal hearing threshold above this frequency. The type of inheritance in these families showed autosomal dominant mode and no associated malformation. In 7 patients, hearing tests were repeated, it was observed that hearing threshold was not elevated. The short increment sensitivity index (SISI) tests were positive suggesting a hair cell lesion in tested 7 patients. The caloric tests were normal in tested 3 patients. No abnormal internal ear configuration was found in both X-ray and high-resolution computed tomography. Twelve patients with these familial low tone deafness (FLTD), 19 patients with Ménière's disease, and 9 patients with low tone sudden deafness (LTSD) were studied using the transtympanic electrode technique of electrocochleography. All patients of FLTD showed normal negative summating potential (-SP) amplitude, and the cochlear microphonics (CM) showed a nearly same detection threshold as hearing level of the pure tone audiogram at 1 kHz and 0.5 kHz. The evidence suggested that the hearing impairment resulted from a localized abnormality of the cochlear apex, and without endolymphatic hydrops. On the other hand, patients with Ménière's disease and LTSD showed a high -SP amplitude and a satisfactory detection threshold of CM compared with hearing level of the pure tone audiogram. These findings suggest that both Ménière's disease and LTSD relate to endolymphatic hydrops.