In order to explore the effect of forest bathing on human immune function, we investigated natural killer (NK) activity; the number of NK cells, and perforin, granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields. Twelve healthy male subjects, age 37-55 years, were selected with informed consent from three large companies in Tokyo, Japan. The subjects experienced a three-day/two-night trip in three different forest fields. On the first day, subjects walked for two hours in the afternoon in a forest field; and on the second day, they walked for two hours in the morning and afternoon, respectively, in two different forest fields. Blood was sampled on the second and third days, and NK activity; proportions of NK, T cells, granulysin, perforin, and granzymes A/B-expressing cells in PBL were measured. Similar measurements were made before the trip on a normal working day as the control. Almost all of the subjects (11/12) showed higher NK activity after the trip (about 50 percent increased) compared with before. There are significant differences both before and after the trip and between days 1 and 2 in NK activity. The forest bathing trip also significantly increased the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells. Taken together, these findings indicate that a forest bathing trip can increase NK activity, and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins.

We previously reported that a forest bathing trip enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes. In the present study, we investigated how long the increased NK activity lasts and compared the effect of a forest bathing trip on NK activity with a trip to places in a city without forests. Twelve healthy male subjects, age 35-56 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields and to a city, in which activity levels during both trips were matched. On day 1, subjects walked for two hours in the afternoon in a forest field; and on day 2, they walked for two hours in the morning and afternoon, respectively, in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood samples and completing the questionnaire. Blood and urine were sampled on the second and third days during the trips, and on days 7 and 30 after the trip, and NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trips on a normal working day as the control. Phytoncide concentrations in forest and city air were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzyme A/B-expressing cells and significantly decreased the concentration of adrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. In contrast, a city tourist visit did not increase NK activity, numbers of NK cells, nor the expression of selected intracellular anti-cancer proteins, and did not decrease the concentration of adrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air, but almost not in city air. These findings indicate that a forest bathing trip increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone may partially contribute to the increased NK activity.

Smoking displays the greatest impact on periodontitis among lifestyle-related factors. Both smoking and obesity are independent risk indicators for periodontitis; moreover, these parameters exhibit a dose-response relationship with respect to periodontitis risk.

The lentiviral vector system based on human immunodeficiency virus type 1 (HIV-1) is used extensively in gene therapy trials of neurological and neurodegenerative diseases. Retrograde axonal transport of viral vectors offers a great advantage to the delivery of genes into neuronal cell bodies that are situated in regions distant from the injection site. Pseudotyping of HIV-1-based vectors with selective variants of rabies virus glycoprotein (RV-G) increases gene transfer via retrograde transport into the central nervous system. Because large-scale application for gene therapy trials requires high titer stocks of the vector, pseudotyping of a lentiviral vector that produces more efficient retrograde transport is needed. In the present study, we developed a novel vector system for highly efficient retrograde gene transfer by pseudotyping an HIV-1 vector with a fusion envelope glycoprotein (termed FuG-B) in which the cytoplasmic domain of RV-G was substituted by the corresponding part of vesicular stomatitis virus glycoprotein. The FuG-B pseudotype shifted the transducing property of the lentiviral vector and enhanced the retrograde transport-mediated gene transfer into different brain regions innervating the striatum with greater efficiency than that of the RV-G pseudotype in mice. In addition, injection of the FuG-B-pseudotyped vector into monkey striatum (caudate and putamen) allowed for highly efficient gene delivery into the nigrostriatal dopamine system, which is a major target for gene therapy of Parkinson's disease. Our strategy provides a powerful tool for the treatment of certain neurological and neurodegenerative diseases by promoting retrograde gene delivery via a lentiviral vector.

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This study investigated the associations between the intensity of mobile phone use and health-related lifestyle. For 275 university students, we evaluated health-related lifestyle using the Health Practice Index (HPI; Hagihara & Morimoto, 1991; Kusaka, Kondou, & Morimoto, 1992) and analyzed responses to a questionnaire (MPDQ; Toda, Monden, Kubo, & Morimoto, 2004) designed, with a self-rating scale, to gauge mobile phone dependence. For males, there was a significant relationship between smoking habits and mobile phone dependence. We also found that male respondents with low HPI scores were significantly higher for mobile phone dependence. These findings suggest that, particularly for males, the intensity of mobile phone use may be related to healthy lifestyle.

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Passage of the mouse-adapted rabies virus strain CVS-24 (where CVS is challenge virus standard) in BHK cells results in the rapid selection of a dominant variant designated CVS-B2c that differs genotypically and phenotypically from the dominant variant CVS-N2c present in mouse-brain-or neuroblastoma-cell-passaged CVS-24. The glycoprotein of CVSB2c has 10 amino acid substitutions compared with that of CVS-N2c. Because CVS-B2c can be reproducibly selected in BHK cells, it is likely to be a conserved minor subpopulation of CVS-24. CVS-N2c is more neurotropic in vitro and in vivo than CVS-B2c, which replicates more readily in nonneuronal cells in vitro and in vivo. These characteristics appear to be relevant to the pathogenicity of the two variants. CVS-N2c is more pathogenic for adult mice than CVS-B2c. In contrast, CVS-B2c is more pathogenic for neonatal mice. These differences in pathogenicity are reflected in the selection pattern when mixtures of CVS-N2c and CVS-B2c were used to infect neonatal and adult mice. Although CVS-N2c was highly selected in adult mice, no selection for either variant was seen in neonates, suggesting that certain aspects of development, such as maturation of the nervous and immune systems, may contribute to the selection process. We speculate that the existence of different variants within a rabies virus strain may facilitate the virus in overcoming barriers to its spread, both within the host and between species.By far the predominant target of rabies virus infection in vivo is the neuron (1). Nevertheless, it has been shown that rabies virus can infect myocytes before the virus infection reaches neurons in the spinal cord or dorsal root ganglia (1, 2). In addition, high titers of rabies virus can be produced in mucogenic acinary cells of the salivary glands during the final phase of infection. In vitro experimentation has shown that street rabies virus can infect macrophages (3) and fixed rabies virus strains can infect murine lymphocytes and human lymphoblast T cells (4). However, it is not clear whether virus replication in nonneuronal tissue, with the exception of the salivary glands, actually represents an integral part of the pathogenesis of rabies nor it is known whether a single virus population or different subpopulations of a particular strain are responsible for the infection of neuronal and nonneuronal cells. In this context, it has been shown, in mice persistently infected with lymphocytic choriomeningitis virus (LCMV), that different variants of the same LCMV strain are associated with infection of neuronal cells, liver cells, or spleen cells (5, 6). Because of the high mutation rates resulting from the lack of proofreading by RNA polymerases RNA virus strains exist as quasispecies (7). It has been demonstrated that in a constant environment quasispecies contain a stable dominant virus species within a pool of viruses with related but often extremely heterogeneous genomes (7-9). Such complexity endows RNA viruses with an enormous capacity to adapt to changing host...