The use of stereoscopic images has been spreading rapidly. Nowadays, stereoscopic movies are nothing new to people. Stereoscopic systems date back to 280 A.D. when Euclid first recognized the concept of depth perception by humans. Despite the increase in the production of three-dimensional (3D) display products and many studies on stereoscopic vision, the effect of stereoscopic vision on the human body has been insufficiently understood. However, symptoms such as eye fatigue and 3D sickness have been the concerns when viewing 3D films for a prolonged period of time; therefore, it is important to consider the safety of viewing virtual 3D contents as a contribution to society. It is generally explained to the public that accommodation and convergence are mismatched during stereoscopic vision and that this is the main reason for the visual fatigue and visually induced motion sickness (VIMS) during 3D viewing. We have devised a method to simultaneously measure lens accommodation and convergence. We used this simultaneous measurement device to characterize 3D vision. Fixation distance was compared between accommodation and convergence during the viewing of 3D films with repeated measurements. Time courses of these fixation distances and their distributions were compared in subjects who viewed 2D and 3D video clips. The results indicated that after 90 s of continuously viewing 3D images, the accommodative power does not correspond to the distance of convergence. In this paper, remarks on methods to measure the severity of motion sickness induced by viewing 3D films are also given. From the epidemiological viewpoint, it is useful to obtain novel knowledge for reduction and/or prevention of VIMS. We should accumulate empirical data on motion sickness, which may contribute to the development of relevant fields in science and technology.

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Objectives: Recent advances in three-dimensional (3D) display technology have contributed significantly to society, particularly in the increasing use of stereoscopic characters. For example, 3D text information is utilized in digital signage. However, research on 3D characters is limited and discussion on the safety and comfort of 3D technology is lacking. According to the 3D Consortium Safety Guidelines in Japan, a comfortable visual parallax with 3D images is less than ±1.0°. However, 3D text must be shown in front of its associated content in order for it to be displayed simultaneously with that content. Methods: We carried out an experiments to verify the permissive limits of cognition in subjects regarding the parallax of 3D images. In the experiment, 94 subjects aged 18 to 81 viewed a 3D flat Maltess cross image having no depth and projected outward from a screen at a large parallax of 1.0° to 6.0°. Results: Eighty-six percent of the subjects recognized the 3D flat image even when it protruded at a 2.0° parallax. These subjects viewed the image comfortably and without visual problems. Conclusions: This study concludes that people can cognitively recognize a 3D telop at a 2.0° parallax without feeling fatigued.

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Objectives: We aimed to investigate the effect of stereoscopic viewing and the degree of awareness of motion sickness on posture by measuring body sway during motion movie viewing. Methods: Nineteen students (12 men and 7 women; age range, 21–24 years) participated in this study. The movie, which showed several balls randomly positioned, was projected on a white wall 2 m in front of the subjects through a two-dimensional (2-D)/three-dimensional (3-D) convertible projector. To measure body sway during movie viewing, the subjects stood statically erect on a Wii balance board, with the toe opening at 18 degrees. The study protocol was as follows: The subjects watched (1) a nonmoving movie for 1 minute as the pretest and then (2) a round-trip sinusoidally moving-in-depth-direction movie for 3 minutes. (3) The initial static movie was shown again for 1 minute. Steps (2) and (3) were treated as one trial, after which two trials (2-D and 3-D movies) were performed in a random sequence. Results: In this study, we found that posture changed according to the motion in the movie and that the longer the viewing time, the higher the synchronization accuracy. These tendencies depended on the level of awareness of motion sickness or the 3-D movie viewed. Conclusions: The mechanism of postural change in movie viewing was not vection but self-defense to resolve sensory conflict between visual information (spatial swing) and equilibrium sense (motionlessness).

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Objectives: Owing to the recent rapid advancements in image processing and three-dimensional (3-D) technologies, stereoscopic images can now be viewed on television as well as in theaters and on gaming consoles among others. However, with these advancements, there have also been reports on motion sickness and asthenopia induced by viewing stereoscopic films. Human equilibrium function deteriorates when viewing stereoscopic films, which may lead to motion sickness; however, the exact cause of such motion sickness remains unknown. Therefore, as part of hygiene research that contributes to society, it is important to consider the safety of viewing virtual 3D contents. Methods: In this study, we investigated the effects of viewing 2-D/3-D video clips on the human body by stabilometry, electrogastrography (EGG), and subjective assessments. Seven subjects aged 22 to 24 viewed 2-D/3-D video clips for 60 min. Results: A comparison of time series data obtained at rest shows a significant change in the EGG patterns 20 min after the start of viewing the video clips. Furthermore, sway values while viewing the 3-D video clips were considerably higher than those while viewing the 2-D video clips 60 min after the start of viewing. Conclusions: These findings show that the autonomic nervous system is affected first by long-term viewing of stereoscopic films, and the equilibrium function deteriorates gradually over the course of the exposure.

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Worldwide, lifestyle-related diseases such as type 2 diabetes and cardiovascular diseases are presently the leading causes of death and disability, and their incidences tend to increase. A lifestyle-related disease has been considered mainly to be induced by specific disease susceptibility genes and lifestyle after birth. However, the steep increase in the incidences of lifestyle-related diseases is difficult to be explained only by specific genes. Presently, a new theory has been proposed. Epidemiological and animal studies have disclosed the intimate links between malnutrition in the developmental stage and lifestyle-related chronic diseases. Such studies provide the foundation and framework for a new life science, that is, the theory of developmental origins of health and diseases (DOHaD). Although much research has been carried out to elucidate the putative concepts and mechanisms that relate specific exposures in early life to the risk of chronic diseases, a complete picture still remains obscure. Historically, the world has experienced severe famines, for example, the Dutch Winter Famine, the Chinese Great Leap Forward Famine, the Leningrad Siege and the Biafran Famine. These famines showed that malnutrition in utero poses higher risks of lifestyle-related diseases. The main research point has been focused on periconceptional and perinatal undernutrition and specific nutrient deficiencies. However, presently, the number of people who are overweight and obese has been increasing. Therefore, perinatal overnutrition and specific nutrient excesses should also be examined. In addition, psychological stress, environmental chemicals and artificial reproductive techniques are other important research fields in DOHaD.

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Japan has the highest proportion of low-birth-weight infants among OECD countries for over 20 years. In 2011, the proportion of low-birth-weight infants in Japan was 9.6%, whereas the mean proportion in OECD countries was only 6.8%. In particular, young Japanese women’s strong desire to be thin has been pointed out as the underlying cause. Indeed, the frequencies of unhealthy thinness among third-year female junior and senior high school Japanese students have been increasing since the start of “Healthy Parents and Children 21”, and both groups have reached about 20%. The hypothesis of the fetal origins of adult disease (Barker’s theory) was proposed by Professor David J. Barker of Southampton University, who had conducted descriptive epidemiological studies in England and Wales and birth cohort studies in Hertfordshire, for example. In early 21st century, it became the wider theory known as the “Developmental Origins of Health and Disease (DOHaD)”, which was composed of developmental plasticity and the mismatch concept. Birth cohort studies are believed to be suitable for epidemiological studies to demonstrate the DOHaD theory. These studies and their collaborations are very popular in European countries, whereas such collaborations lagged behind in Japan. Recently, a new paradigm, “preemptive medicine”, has been proposed in Japan. The importance of interdisciplinary studies focusing on fetal and childhood periods was also recommended as a political strategy. We just expect the realization of nationwide large-scale interdisciplinary research projects based on DOHaD and preemptive medicine and the establishment of a central research institute of these studies.

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We studied the characteristics of psychiatric social workers (PSWs) and present research on job-related stress among them; we also provide insights into the future of such research. In recent years, studies on job-related stress among PSWs have been gaining interest. In particular, stress associated with the repeated revisions of related laws has increased. Subsequently, it was found that occupational stress in PSWs differs qualitatively and quantitatively depending on educational history, years of experience, and service department. However, no scale captures the specific characteristics of job-related stress among PSWs. Moreover, the development of a mental health care program for PSWs seems difficult. To develop a mental health care program that caters specifically to this group, future research should focus on developing a scale that determines the specific characteristics of job-related stress among PSWs, which should be evaluated on the basis of each PSW’s educational history, years of experience, and service department.

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Human aldehyde dehydrogenase 2 (ALDH2) is a 56 kDa mitochondrial protein that forms homodimers through hydrogen bonding interactions between the Glu487 and Arg475 residues of two ALDH2 proteins. Two ALDH2 homodimers can interact to form an ALDH2 tetramer. ALDH2 is widely distributed throughout the organs of the body. In addition to its dehydrogenase activity, ALDH2 also exhibits esterase and reductase activities, with the main substrates for these three activities being aldehydes, 4-nitrophenyl acetate and nitroglycerin, respectively. ALDH2 can be readily inhibited by a wide variety of endogenous and exogenous chemicals, but the induction or activation of this enzyme remains unlikely. The polymorphism of ALDH2 to the corresponding ALDH2*2 variant results in a severe deficiency in ALDH2 activity, and this particular polymorphism is prevalent among people of Mongoloid descent. It seems reasonable to expect that people with the ALDH2*2 variant would be more vulnerable to stress and diseases because ALDH2 defends the human body against toxic aldehydes. However, it has been suggested that people with the ALDH2*2 variant are protected by alternative stress-defending systems. The ALDH2*2 variant has been reported to be associated with many different kinds of diseases, although the mechanisms underlying these associations have not yet been elucidated. ALDH2 polymorphism has a significant impact on human health; further studies are therefore required to determine the practical implications of this polymorphism in the fields of preventive and clinical medicine.

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Objectives: The purpose of this study is to clarify whether the explanation received from the guardian at the time of inoculation of a HPV vaccine is related to preventive behaviors against uterine cervical cancer among junior high school girls. The preventive behaviors were set as “wishing to receive the HPV vaccination” and “considering on sexual behaviors (dating, kissing, sexual relations).” Methods: An anonymous self-administered questionnaire survey was performed on 206 second-year junior high school girls who were candidates for the inoculation of the HPV vaccine in the previous year. We considered that a subject received an explanation on HPV vaccination if she received explanations on this topic, such as “an HPV vaccine prevents uterine cancer.” We considered that a subject received an explanation on pubertal events if she received explanations on this topic, such as “the importance of a life.” Including these two variables among the independent variables, multiple logistic regression analysis was performed. Results: The knowledge on uterine cancer was promoted when the subjects received explanations about the HPV vaccination. Many subjects received explanations on pubertal events by receiving explanations on HPV vaccination. The guardian’s explanation about HPV vaccination was one of the factors related to “wishing to receive the HPV vaccination” and “considering on sexual behaviors.” Conclusion: It is important for guardians to explain to their children about HPV vaccination without hesitation at the time of the vaccination.

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Objective: The World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) reported that understanding the use and impact of smokeless tobacco (SLT) products is complicated by product diversity. Many different SLT products with different characteristics are used worldwide. ZERO STYLE STIX^TM (sold by Japan Tobacco Inc.) is a brand of snuff, a type of smokeless tobacco. Our objective was to determine the constituents of the gas from SLT and analyze the ingredients in tobacco fillers. Methods: ZERO STYLE STIX smokeless tobacco was released in the Japanese market in 2010. Nicotine, menthol, and tobacco-specific nitrosamines in the smokeless tobacco fillers were determined by gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). The gaseous compounds were collected by a smoking machine using two smoking protocols, i.e., the ISO and Health Canada Intense methods. Nicotine and menthol in the gas were determined by GC/MS. Results: Nicotine, menthol, and the total tobacco-specific nitrosamines were detected in the tobacco fillers. The level of menthol in the snuff was more than ten times that of nicotine. The determined levels of the two components of the gas from the snuff were higher when using the Health Canada Intense protocol than when using the ISO protocol. In addition, flavors other than menthol were emitted from the smokeless tobacco. Conclusion: The new type of snuff introduced in the Japanese market in 2010 contained added flavors, and was attractive smokeless tobacco. Flavors in tobacco products need to regulate on the basis of FCTC 9 and 10 in JAPAN.

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Objective: Some Japanese smokers imported Japanese cigarette brands from other Asian countries for personal use because of the increase in tobacco tax in 2010, which meant that privately importing the cigarettes was cheaper than purchasing them in Japan. We assumed that the health hazards of locally made cigarettes were different from those of privately imported cigarettes, despite the brands being the same. In this study, we carried out a comparative toxicological analysis of domestic and privately imported cigarettes. Methods: Privately imported cigarettes of five brands and domestic cigarettes of the brand named “MILD SEVEN ORIGINAL” were selected for the study. The level of polycyclic aromatic hydrocarbons (PAHs) in mainstream smoke was determined by high-performance liquid chromatography using fluorescence detection. The mutagenicity of mainstream smoke was assessed using the Salmonella typhimurium strains TA100, TA98, and YG1024 with the metabolic activation system (S9mix) by preincubation assay. The levels of heavy metals in cigarette fillers were determined by inductively coupled plasma-mass spectrometry. Results: The level of PAH in the mainstream smoke from the privately imported cigarettes was higher than that in the smoke from the domestic cigarettes. However, the mutagenic activity of the mainstream smoke from the privately imported cigarettes was equivalent to that from the domestic cigarettes. The levels of nickel and cadmium in the fillers of the privately imported cigarettes were higher than those in the domestic cigarettes. Conclusion: The levels of constituents in the fillers and mainstream smoke from the privately imported cigarettes were higher than those in the fillers and mainstream smoke from the domestic cigarettes. The majority of Japanese smokers are unaware of these findings. The guidelines regulating tobacco products recommend that articles 9 and 10 of the World Health Organization (WHO) Framework Convention on Tobacco Control should be fully implemented in Japan.

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The goal of the Japan Environment and Children’s Study (JECS) is to improve the health and welfare of children and to contribute to better risk management of chemical substances in the environment. The study will examine hypotheses related to reproduction, congenital anomalies, neuropsychiatric development, immunity, metabolism and endocrine system. The hypotheses will be tested for indicative outcomes in combination with exposure to chemicals, as well as confounders and modulators, such as chemical, physical, genetic, social and lifestyle-related factors. A total of 100,000 pregnant women associated with the selected study locations were recruited during the first three years starting January 2011. Their children will be followed up until the age of 13 years. The main study (nationwide survey) will include all participants recruited in all regional centres. Substudies will be conducted on randomly selected individuals from among all the participants. In the main and substudies, blood, urine, hair and breast milk samples will be collected from mothers. Blood, hair, and urine samples as well as umbilical cord blood at delivery will be collected from the children. Blood samples will also be collected from fathers. Each specimen will be analysed for specific chemical substances. In addition, genetic background will be evaluated. The collected blood samples for genetic assessments will be stored at the national centre. The detailed assessment procedures will be reviewed for approval by IRBs.

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Multiple chemical sensitivity (MCS) is an acquired chronic disorder characterized by nonspecific symptoms in multiple organ systems associated with exposure to low-level chemicals. Diagnosis of MCS can be difficult because of the inability to assess the causal relationship between exposure and symptoms. No standardized objective measures for the identification of MCS and no precise definition of this disorder have been established. Recent technological advances in mass spectrometry have significantly improved our capacity to obtain more data from each biological sample. Metabolomics comprises the methods and techniques that are used to determine the small-level molecules in biofluids and tissues. The metabolomic profile—the metabolome—has multiple applications in many biological sciences, including the development of new diagnostic tools for medicine. We performed metabolomics to detect the difference between 9 patients with MCS and 9 controls. We identified 183 substances whose levels were beyond the normal detection limit. The most prominent differences included significant increases in the levels of both hexanoic acid and pelargonic acid, and also a significant decrease in the level of acetylcarnitine in patients with MCS. In conclusion, using metabolomics analysis, we uncovered a hitherto unrecognized alteration in the levels of metabolites in MCS. These changes may have important biological implications and may have a significant potential for use as biomarkers.

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Immediately after the official recognition of Minamata disease (1956.5.l) a study group at Kumamoto University suggested that Minamata disease was caused by food poisoning. The next year, this suggestion was accepted by the Ministry of Health and Welfare (MHW). Prior to the decision to apply the Food Sanitation Act (FSA), the local government asked MHW for the application of FSA. Soon after, the chief of the Public Health Bureau replied to the local government that the application of FSA to the Minamata area was impossible. Epidemiological investigations of residents and polluted areas, therefore, were not carried out. Data essential for the screening for exposed residents were unavailable. The criteria for the screening were presented. The Environmental Agency (EA) presented the criteria in the form of notice in 1971, which were revised in 1977. Notwithstanding the clear difference between the original and revised criteria, EA insisted that these two sets of criteria were quite similar. This insistence by EA and the absence of epidemiological data on residents and polluted area resulted in the present confusion about Minamata disease. The application of FSA was stopped by bureaucrats who had no interest in the environmental problems and by several scientists patronized by stakeholders (Chisso, Japanese Association of Chemical Industries, MHW and EA). Stakeholders suppressed science.

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