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Single-photon emission computed tomography of spontaneous liver metastasis from orthotopically implanted human colon cancer cell line stably expressing human sodium/iodide symporter reporter gene
Masayuki Inubushi, Yong-Nan Jin, Chika Murai, Hironobu Hata, Yoshimasa Kitagawa, Tsuneo Saga
EJNMMI Research , 2012, DOI: 10.1186/2191-219x-2-46
Abstract: A recombinant plasmid containing a constitutively driven NIS gene (pcDNA3-NIS) was transfected into the human colon cancer cell line HCT116, and stable cell lines were established. The stable cells were subcutaneously injected into the nude mice. When the diameter reached 10？mm, the xenografts were excised, cut into small fragments, and orthotopically implanted into the cecal walls of another nude mice. 99mTcO4？ SPECT/CT imaging was initiated 8？weeks later and repeated every 1 to 2？weeks.The production and function of NIS protein was confirmed in vitro by Western blotting and 99mTcO4？ uptake assay. On SPECT/CT imaging, focal 99mTcO4？ uptake was detected in the liver. Necropsy revealed local growth of the orthotopic colon xenografts with extensive invasion, microscopic serosal metastasis, and metastatic foci in the corresponding hepatic regions showing focal 99mTcO4？ uptake. Immunohistochemistry revealed high levels of NIS expression in cells forming liver tumor, indicating that the liver tumor cells originated from the orthotopic colon xenografts.The present proof-of-concept study provided a rationale for employing a radionuclide reporter gene for the specific visualization of spontaneous liver metastasis in living mice. This unique animal model of clinically relevant and externally detectable liver metastasis will be a powerful tool for investigating tumor biology and developing novel therapies for cancer metastasis.Research using animal models that represent all processes of metastasis formation is essential. However, the currently used rodent tumor models, such as the subcutaneous (ectopic) tumor graft models in nude mice, do not sufficiently represent clinical cancer, particularly with regard to metastasis formation, since the subcutaneous micro-environment for visceral tumors is considerably different from their original environment [1,2]. Experimental liver metastasis can be induced by intrasplenic [3] or direct intraportal [4] injection of cancer cells in the
Customers’ Responses to Employee Extra Attention  [PDF]
Yoshimasa Kageyama, Albert Barreda
Open Journal of Business and Management (OJBM) , 2019, DOI: 10.4236/ojbm.2019.71004
Abstract:
Focusing on positive service experiences, this study examined the relation-ships among employee extra attention, customers delight, and customer re-purchase intentions. The target sample that had a positive interaction with an employee in the recent six months was invited to participate in the survey. The data analysis was performed in two steps: 1) Confirmatory Factor Analysis (CFA) and 2) Structural Equation Modeling (SEM). The results suggested that employees’ extra attention affects customer delight. Subsequently, customer delight has a positive relationship with customer repurchase intentions. Furthermore, employee extra attention has a positive relationship with customer repurchase intentions. The finding of the study provides valuable implications for research and the industry regarding generating favorable customer repurchase intentions in positive service experiences.
Evaluation of an oral moisture-checking device for screening dry mouth  [PDF]
Yosuke Fukushima, Tetsuya Yoda, Shoichiro Kokabu, Ryuichiro Araki, Tsubasa Murata, Yoshimasa Kitagawa, Ken Omura, Shuji Toya, Kayoko Ito, Saori Funayama, Hiroshi Iwabuchi, Kazuhiro Asano, Yutaka Imai, Akihide Negishi, Satoshi Yokoo, Goichi Matsumoto, Eiro Kubota, Hideki Watanabe, Mikio Kusama, Kojiro Onizawa, Takuya Goto, Seiji Nakamura, Ryuichi Nakazawa, Kiyoshi Harada, Takashi Fujibayashi
Open Journal of Stomatology (OJST) , 2013, DOI: 10.4236/ojst.2013.38073
Abstract:

Objective: This multicenter clinical study was to assess the clinical usability of an oral moisture-checking device in detecting the dry mouth patients and evaluating the optimal measurement site. Materials and Methods: The study group comprised 250 patients with dry mouth and 241 healthy volunteer subjects at 13 medical centers. This device was used to measure the moisture degrees of the lingual mucosa and the buccal mucosa. Subjective oral dryness, objective oral dryness, and saliva flow rates were also compared between the two groups. For statistical analysis, receiver-operating characteristic analysis was performed to calculate the area under the curve (AUC). Results: The moisture degree of the lingual mucosa was significantly lower in the dry mouth group (27.2 ± 4.9) than that in the healthy group (29.5 ± 3.1, AUC = 0.653). When a lingual mucosa moisture degree of 31.0 or higher was defined as normal, less than 27.0 as dry mouth, and 27.0 to less than 31.0 as borderline zone of dry mouth, both the sensitivity and the specificity for the diagnosis of dry mouth were close to 80%. Conclusion: These results suggest that the oral moisture-checking device is a usable screening device for dry mouth.

Evaluation of Oxidative Stress, Antioxidant Power, and Antioxidant Potential of Breastmilk of Breast-Feeding Mothers  [PDF]
Naoko Kuramoto, Mariko Kitagawa
Health (Health) , 2017, DOI: 10.4236/health.2017.98083
Abstract: Purpose: The purpose of this study was to evaluate oxidative stress, antioxidant power, and antioxidant potential of breastmilk of breast-feeding mothers from the early postpartum period to the first 3 months postpartum, and to examine the dynamics and the relationships among them. Method: For 47 pu-erperant women who gave vaginal birth without any pregnancy complications, the oxidative stress levels (d-ROMs levels) and antioxidant power (BAP levels) in the maternal plasma as well as antioxidant potential of breastmilk (BAP levels in breastmilk) were measured 3 times, i.e., in the early puerperium (4 or 5 days after giving birth), one month after giving birth, and 3 months after giving birth. Results: The d-ROMs levels in the maternal plasma were significantly high in the early puerperium (p < 0.001), and decreased gradually in the post-partum period (p < 0.001). On the other hand, BAP levels were significantly low in the early puerperium (p < 0.001), and increased to the almost normal level during one month after giving birth. BAP levels in breastmilk were significantly high in the early puerperium compared with the other periods (p < 0.001), and decreased gradually until 3 months after giving birth (p < 0.001). BAP levels in breastmilk in the early puerperium were higher compared with the maternal BAP levels, and there was a positive correlation between BAP levels in breast-milk and those in the maternal plasma (p < 0.05). Discussion: Regarding the oxidative stress and the antioxidant defense system of breast-feeding mothers, the d-ROMs level was highest and the BAP level was lowest in the early puerperium. The BAP level then showed a clear tendency to recover in the first 3 months after giving birth. Conclusion: When the maternal antioxidant potential remains at a low level after giving birth, careful consideration should be given to the mother’s health and wellbeing because there is a possibility that it might affect the antioxidant potential of breastmilk.
The monetary policy in the Netherlands East Indies under the Japanese administration
Shibata Yoshimasa
Bijdragen tot de Taal-, Land- en Volkenkunde , 1996,
Abstract:
Environmental factors that determine the occurrence and seasonal dynamics of Aphanizomenon flos-aquae
Yoshimasa YAMAMOTO
Journal of Limnology , 2009, DOI: 10.4081/jlimnol.2009.122
Abstract: This study investigated the seasonal dynamics of two populations of Aphanizomenon flos-aquae Ralfs ex Bornet & Flahault var. flos-aquae and four populations of A. flos-aquae var. klebahnii Elenkin in eutrophic water bodies over 1 year from February 2006 to January 2007. The growth of A. flos-aquae var. flos-aquae was promoted at high temperatures even if in one case the biomass development was very low when other co-occurring cyanoprokaryotes (Anabaena spp. and Microcystis spp.) were abundant. In contrast, the highest density of the other population of A. flos-aquae var. flos-aquae was observed in August when the population density of M. aeruginosa (Kützing) Kützing reached an annual peak. A. flos-aquae var. flos-aquae usually bloomed in summer but could also tolerate low temperatures in the winter, and was present in relatively high densities. The populations of A. flos-aquae var. klebahnii observed in this study can be divided into three groups based on preferred temperature; three populations increased in winter, and the other increased in summer. Large biomasses of the low-temperature-adapted A. flos-aquae were observed mainly during winter when population densities of co-occurring cyanoprokaryotes (Anabaena spp., Microcystis spp. and Planktothrix raciborskii (Woloszynska) Anagnostidis & Komárek) were relatively low or almost absent. The increase in or existence of cooccurring cyanoprokaryotes during the summer resulted in a decrease of the A. flos-aquae population density. It was revealed that high temperatures (20-25 °C) are suitable for maintaining A. flos-aquae var. klebahnii strains isolated from the study ponds, implying that low-temperature-adapted A. flos-aquae can grow over a wide range of water temperatures. The high-temperatureadapted A. flos-aquae var. klebahnii co-existed with M. aeruginosa during summer; however, its peak population density was significantly lower than those in previous years when M. aeruginosa was absent. Overall, analytical results imply a possible adverse impact of the existence of other cyanoprokaryotes, such as Anabaena and Microcystis, on both varieties of A. flos-aquae; however, its mechanism remains unknown. Nutrient concentrations and pH had no clear impact on the population density of A. flos-aquae. Based on these observations, progress of eutrophication and absence of other cyanoprokaryotes are likely the key factors determining the future expansion of A. flos-aquae.
Contribution of bioturbation by the red swamp crayfish Procambarus clarkii to the recruitment of bloom-forming cyanobacteria from sediment
Yoshimasa YAMAMOTO
Journal of Limnology , 2010, DOI: 10.4081/jlimnol.2010.102
Abstract: The development of cyanobacterial blooms in a small eutrophic pond was monitored along with the potential effect of bioturbation by the red swamp crayfish Procambarus clarkii discussed as well with respect to the recruitment of cyanobacteria from sediment. Cyanobacterial blooms were observed during the early spring and summer. The spring bloom was dominated by Aphanizomenon flos-aquae. Its population density reached the maximum level in late March, thereafter decreasing rapidly and becoming lower than the detection limit from May. When the water temperature exceeded 20 °C in late May, the population density of Microcystis spp. began to increase, and a bloom was formed from July to early August. Anabaena spp. also contributed to the formation of the summer bloom. The population densities of both Microcystis spp. and Anabaena spp. began to decline in mid August. Crayfish were sampled using baited traps from April to November. No sample was obtained in April, whereas crayfish were captured constantly from May to November. They were distributed widely throughout the pond from June, although a large number of crayfish were captured most effectively at a particular point in the pond. The first captures in late May were dominated by males. The sex ratio of the captures was almost 1:1 from June to September, and fell in favor of females from October. The sex ratio reached a minimum (0.2:1) in mid November, when an extremely large number of crayfish were captured at a distinctly warm point. Next, the potential ability of crayfish to promote the recruitment of cyanobacteria from the sediment was examined by performing an incubation experiment. The presence of crayfish in containers of the pond sediment increased the densities of cyanobacteria such as Microcystis spp. and Anabaena spp. However, population densities of cyanobacteria began to decline after the crayfish was removed. Overall, bioturbation by crayfish seemed to be somewhat important in the dynamics of cyanobacterial blooms in the study pond; in addition, their effect varied with sex and season. Males may play an active role in the initiation of the bloom in late spring. Conversely, females may contribute to the extension of bloom in late autumn. Both males and females contribute equally to the maintenance of the bloom from summer to autumn.
Soliton and Periodic solutions of the Short Pulse Model Equation
Yoshimasa Matsuno
Physics , 2009,
Abstract: The short pulse (SP) equation is a novel model equation describing the propagation of ultra-short optical pulses in nonlinear media. This article reviews some recent results about the SP equation. In particular, we focus our attention on its exact solutions. By using a newly developed method of solution, we derive multisoliton solutions as well as 1-and 2-phase periodic solutions and investigate their properties.
The Peakon Limit of the N-Soliton Solution of the Camassa-Holm Equation
Yoshimasa Matsuno
Physics , 2007,
Abstract: We show that the analytic N-soliton solution of the Camassa-Holm (CH) shallow-water model equation converges to the nonanalytic N-peakon solution of the dispersionless CH equation when the dispersion parameter tends to zero. To demonstrate this, we develop a novel limiting procedure and apply it to the parametric representation for the N-soliton solution of the CH equaiton. In the process, we use Jacobi's formula for determinants as well as various identities among the Hankel determinants to facilitate the asymptotic analysis. We also provide a new representation of the N-peakon solution in terms of the Hankel determinants.
Model study of the sign problem in a mean-field approximation
Yoshimasa Hidaka
Physics , 2007,
Abstract: We study the sign problem of the fermion determinant at nonzero baryon chemical potential. For this purpose we apply a simple model derived from Quantum Chromodynamics, in the limit of large chemical potential and mass. For SU(2) color, there is no sign problem and the mean-field approximation is similar to data from the lattice. For SU(3) color the sign problem is unavoidable, even in a mean-field approximation. We apply a phase-reweighting method, combined with the mean-field approximation, to estimate thermodynamic quantities. We also investigate the mean-field free energy using a saddle-point approximation.
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