Tomohiro Masuda

Publications (27)59.87 Total impact

• Article: Superiority of Experts Over Novices in Trueness and Precision of Concentration Estimation of Sodium Chloride Solutions.

  Tomohiro Masuda, Yuji Wada, Masako Okamoto, Yasushi Kyutoku, Yui Yamaguchi, Atsushi Kimura, Tatsu Kobayakawa, Takayuki Kawai, Ippeita Dan, Fumiyo Hayakawa
  [show abstract] [hide abstract]
  ABSTRACT: Several studies have reported that experts outperform novices in specific domains. However, the superiority of experts in accuracy, taking both trueness and precision into consideration, has not yet been explored. Here, we examined differences between expert and novice performances by evaluating the accuracy of their estimations of physical concentrations of sodium chloride in solutions while employing a visual analog scale. In Experiment 1, 14 experts and 13 novices tasted 6 concentrations of the solutions until they had learned their intensities. Subsequently, they repeatedly rated the concentration of 3 other solutions in random order. Although we did not find a difference between the performances of the 2 groups in trueness (difference between rating and correct concentration), the precision (consistency of ratings for each participant) of experts was higher than that of novices. In Experiment 2, 13 experts who had participated in Experiment 1 and 10 experts and 12 novices who had not participated in Experiment 1 rated the salt concentration in sodium chloride/sucrose mixtures in the same way as in Experiment 1. Both trueness and precision of performance were higher in both expert groups than in the novice group. By introducing precision and trueness parameters, we succeeded in quantifying the estimations of experts and novices in rating the concentration of solutions, revealing experts' superiority even for a task they had not been trained for.
  Chemical Senses 01/2013; · 2.60 Impact Factor
• Article: Glossiness and Perishable Food Quality: Visual Freshness Judgment of Fish Eyes Based on Luminance Distribution.

  Takuma Murakoshi, Tomohiro Masuda, Ken Utsumi, Kazuo Tsubota, Yuji Wada
  [show abstract] [hide abstract]
  ABSTRACT: Previous studies have reported the effects of statistics of luminance distribution on visual freshness perception using pictures which included the degradation process of food samples. However, these studies did not examine the effect of individual differences between the same kinds of food. Here we elucidate whether luminance distribution would continue to have a significant effect on visual freshness perception even if visual stimuli included individual differences in addition to the degradation process of foods. We took pictures of the degradation of three fishes over 3.29 hours in a controlled environment, then cropped square patches of their eyes from the original images as visual stimuli. Eleven participants performed paired comparison tests judging the visual freshness of the fish eyes at three points of degradation. Perceived freshness scores (PFS) were calculated using the Bradley-Terry Model for each image. The ANOVA revealed that the PFS for each fish decreased as the degradation time increased; however, the differences in the PFS between individual fish was larger for the shorter degradation time, and smaller for the longer degradation time. A multiple linear regression analysis was conducted in order to determine the relative importance of the statistics of luminance distribution of the stimulus images in predicting PFS. The results show that standard deviation and skewness in luminance distribution have a significant influence on PFS. These results show that even if foodstuffs contain individual differences, visual freshness perception and changes in luminance distribution correlate with degradation time.
  PLoS ONE 01/2013; 8(3):e58994. · 4.09 Impact Factor
• Article: Dish influences implicit gender-based food stereotypes among young Japanese adults.

  Atsushi Kimura, Yuji Wada, Akio Asakawa, Tomohiro Masuda, Sho-ichi Goto, Ippeita Dan, Takashi Oka
  [show abstract] [hide abstract]
  ABSTRACT: The present study explored whether the gender impression of a dish affects the gender stereotypes of foods. We assessed gender stereotypes of food among young Japanese adults using a semantic priming task. As prime stimuli, we took pictures of food in combination with a dish. We used feminine- and masculine-evaluated foods and dishes in order to create four different combinations of food and dishes. In the semantic priming task, we primed the participants (n=58) with the pictures of food-dish combinations and immediately after the priming, we presented them with forenames as target stimuli and let them decide whether the forename given was feminine or masculine. By so doing, we estimated the semantic association between the food-dish combinations with gender. The results demonstrate that gender impressions of dishes affect gender stereotypes toward foods. The feminine-evaluated dish exhibited a facilitation of the femininity and an inhibition of the masculinity of foods. Similarly, the masculine-evaluated dish exhibited a facilitation of the masculinity and an inhibition of the femininity of foods. These results suggest that gender-based stereotypical attitudes toward food pictures are determined by the combination of gender impressions for both the food itself and its dish.
  Appetite 02/2012; 58(3):940-5. · 2.59 Impact Factor
• Article: Infant visual preference for fruit enhanced by congruent in-season odor.

  Yuji Wada, Yuna Inada, Jiale Yang, Satomi Kunieda, Tomohiro Masuda, Atsushi Kimura, So Kanazawa, Masami K Yamaguchi
  [show abstract] [hide abstract]
  ABSTRACT: We explored the ability of infants to recognize the smell of daily foods, including strawberries and tomatoes, by using a preferential-looking-technique. Experiment 1 was conducted while strawberries were in season (from March to June) in order to enhance the frequency of participant exposure to strawberries outside of the laboratory. Thirty-seven infants aged 6-8 months were tested with a stimulus composed of a pair of photos of strawberries and tomatoes placed side by side and accompanied by a strawberry odor, a tomato odor, or no odors. Infants showed a preference for the strawberry picture when they smelled the congruent odor, but no such preference for the tomato picture. These results suggest that even young infants can recognize olfactory-visual congruency. We conducted Experiment 2 while strawberries were out of season (from July to September) to reduce participant exposure to strawberries in their daily life. Twenty-six infants aged 6-8 months were tested with a stimulus composed of a pair of photos of strawberries and tomatoes placed side by side and accompanied by a strawberry odor, or no odors. In Experiment 2, the olfactory-visual binding effect disappeared. This implies that visual-olfactory binding is triggered by an observer's experience.
  Appetite 02/2012; 58(3):1070-5. · 2.59 Impact Factor
• Article: Luminance distribution modifies the perceived freshness of strawberries.

  Carlos Arce-Lopera, Tomohiro Masuda, Atsushi Kimura, Yuji Wada, Katsunori Okajima
  [show abstract] [hide abstract]
  ABSTRACT: Material perception studies focus on the analysis of visual cues that may underlie the ability to distinguish between the different properties of an object. Herein, we investigated the effects of luminance distribution on the perceived freshness of a strawberry independent from its colour information. We took photographs of the degradation of a strawberry over 169 hours in a controlled environment, then presented cropped square patches of the original images to subjects who then rated the perceived freshness using a visual analogue scale. Freshness ratings were significantly highly correlated with statistical measures of the luminance and colour channels. To clarify which of these visual cues affects freshness perception, we created artificial images by modifying only the luminance distribution and keeping the colour information unchanged. The modification of luminance resulted in a highly correlated change in freshness perception, suggesting that luminance visual cues are essential to the freshness perception of strawberries. Finally, by eliminating the colour information from the images, we examined the contribution of luminance distribution independent of colour information and found that luminance information suffices for accurate estimation of strawberry freshness.
  i-Perception. 01/2012; 3(5):338-55.
• Article: Hardness perceptions of the visual penetrating motion influenced by velocity change1

  TOMOHIRO MASUDA, ATSUSHI KIMURA, SHO-ICHI GOTO, YUJI WADA
  [show abstract] [hide abstract]
  ABSTRACT: Humans perceive the various physical properties of objects based on visual motion. We examined the influence of prepenetration and penetration velocity changes (deceleration, constant velocity, and acceleration) and average velocity during penetration on visual hardness judgments of virtual objects. Eleven participants judged the surface and internal hardness of penetrated objects using an analog scale. They were asked to judge the relative hardness of the penetrated objects compared with a standard pattern with no changes in velocity. The results showed that perceived surface hardness was greater when the penetrating object decelerated during prepenetration or accelerated during penetration, and internal hardness was less when the velocity changed from constant velocity during prepenetration to deceleration during penetration, or when the average velocity was higher during penetration than prepenetration. These results suggest that visual hardness perception is influenced by velocity changes and average velocity during penetration. Furthermore, our findings imply that prepenetration velocity change, which is not directly related to actual penetration in a natural environment, is also related to the perception of physical properties of the visual motion.
  Japanese Psychological Research 10/2011; 53(4):440 - 447. · 0.33 Impact Factor
• Article: Molecular cloning, molecular evolution and gene expression of cDNAs encoding thyrotropin-releasing hormone receptor subtypes in a teleost, the sockeye salmon (Oncorhynchus nerka).

  Yuichi Saito, Miyuki Mekuchi, Noriaki Kobayashi, Makoto Kimura, Yasuhiro Aoki, Tomohiro Masuda, Teruo Azuma, Motohiro Fukami, Masayuki Iigo, Tadashi Yanagisawa
  [show abstract] [hide abstract]
  ABSTRACT: Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a teleost, the sockeye salmon (Oncorhynchus nerka). Four different TRHR cDNAs were cloned and named TRHR1, TRHR2a, TRHR2b and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. Important residues for TRH binding were conserved in deduced amino acid sequences of the three TRHR subtypes except for the TRHR2b. Seven transmembrane domains were predicted for TRHR1, TRHR2a and TRHR3 proteins but only five for TRHR2b which appears to be truncated. In silico database analysis identified putative TRHR sequences including invertebrate TRHR and reptilian, avian and mammalian TRHR3. Phylogenetic analyses predicted the molecular evolution of TRHR in vertebrates: from the common ancestral TRHR (i.e. invertebrate TRHR), the TRHR2 subtype diverged first and then TRHR1 and TRHR3 diverged. Reverse transcription-polymerase chain reaction analyses revealed TRHR1 transcripts in the brain (hypothalamus), retina, pituitary gland and large intestine; TRHR2a in the brain (telencephalon and hypothalamus); and TRHR3 in the brain (olfactory bulbs) and retina.
  General and Comparative Endocrinology 07/2011; 174(2):80-8. · 3.27 Impact Factor
• Article: Effects of environmental context on temporal perception bias in apparent motion.

  Tomohiro Masuda, Atsushi Kimura, Ippeita Dan, Yuji Wada
  [show abstract] [hide abstract]
  ABSTRACT: We investigated whether the directional effect on the kappa effect can be attributed to the directional anisotropy of retinotopical space or to the representation of forces provided by environmental contexts (e.g., gravity) in an observed event. We examined whether different contexts with similar directional changes (straight vs. reversed motion) influence the kappa effect in four experiments. The object's motion appeared to depict only forces under the natural laws of physics on a slope (Experiment 1) or on a horizontal plane (Experiment 2) in virtual 3D space. In Experiments 3 and 4, the motion appeared to be subjected to external or self-driving forces additionally influenced by internal forces on a slope (Experiment 3) or a horizontal plane (Experiment 4). The results demonstrated that the directional effect on the kappa effect was observed only in Experiment 1, and not in Experiments 2 and 3, while the kappa effect was preserved. Furthermore, not even the kappa effect was observed in the reversed motion of Experiment 4. The results of the present study suggest that the determining factor of direction in the kappa effect is not a simple anisotropy, but rather the context of observed events.
  Vision research 06/2011; 51(15):1728-40. · 2.29 Impact Factor
• Article: Conjoint analysis on the purchase intent for traditional fermented soy product (natto) among Japanese housewives.

  Atsushi Kimura, Shigetaka Kuwazawa, Yuji Wada, Yasushi Kyutoku, Masako Okamoto, Yui Yamaguchi, Tomohiro Masuda, Ippeita Dan
  [show abstract] [hide abstract]
  ABSTRACT: The effect of sensory and extrinsic attributes on consumer intentions to purchase the Japanese traditional fermented soybean product natto was evaluated using conjoint analysis. Six attributes with 2 levels each were chosen and manipulated: price (high compared with low), the country of origin of the soybeans (domestic compared with imported), stickiness (strong compared with moderate), smell (rich compared with moderate), attached seasonings (attached compared with no attached seasonings), and the environmental friendliness of the packaging (high compared with low). A fractional factorial design was applied and 8 hypothetical product labels were produced. A sample of 479 Japanese housewives ranked these product labels based on their purchase intentions. Overall purchase intention was affected by country of origin, attached seasonings, and price; those attributes accounted for 81.0%, while the sensory attributes of the product accounted for 19.0% of purchase intents. In order to estimate market segments for the natto products based on consumer preference, a cluster analysis was performed. It identified 4 segments of consumers: 1 oriented to attached seasonings, another conscious of the price, and the other 2 oriented to origins. The behavioral and demographic characteristics of the respondents had a limited influence on segment membership. PRACTICAL APPLICATION:  This research was conducted to understand how consumers valuate various sensory and nonsensory product attributes based on their assessment of the overall product in the case of Japanese fermented soy product (natto). The data of this research would be of great importance both in understanding consumer behavior and in designing strategies for product development.
  Journal of Food Science 04/2011; 76(3):S217-24. · 1.66 Impact Factor
• Article: A case of fulminant peritonitis caused by Streptococcus mitis in a patient on peritoneal dialysis.

  Masashi Mizuno, Yasuhiko Ito, Tomohiro Masuda, Susumu Toda, Hideki Hiramatsu, Yasuhiro Suzuki, Takenori Ozaki, Yoshinari Yasuda, Isao Ito, Naotake Tsuboi, Waichi Sato, Shoichi Maruyama, Enyu Imai, Seiichi Matsuo
  [show abstract] [hide abstract]
  ABSTRACT: A 54-year-old woman on peritoneal dialysis (PD) was hospitalized with peritonitis with a high body temperature, abdominal pain and cloudy peritoneal fluid. She progressively fell into septic-like shock within only 6 hours after onset. The causative bacteria were Streptococcus mitis (S. mitis), part of the normal flora of oral cavity, intestine, female genial tract and upper respiratory tract. S. mitis shows pathogenicity for diseases such as endocarditis, brain abscesses and sepsis in children with malignancy or transplantation. However, S. mitis rarely shows severe pathogenic responses in adults. We report herein a case of fulminant peritonitis caused by S. mitis in an adult PD patient.
  Internal Medicine 01/2011; 50(5):471-4. · 0.94 Impact Factor
• Article: Molecular cloning, gene structure, molecular evolution and expression analyses of thyrotropin-releasing hormone receptors from medaka (Oryzias latipes).

  Miyuki Mekuchi, Yuichi Saito, Yasuhiro Aoki, Tomohiro Masuda, Masayuki Iigo, Tadashi Yanagisawa
  [show abstract] [hide abstract]
  ABSTRACT: Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a model teleost fish, medaka (Oryzias latipes). Four subtypes of TRHR were cloned and named them as TRHR1a, TRHR1b, TRHR2 and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. TRHR1a, TRHR1b, TRHR2, and TRHR3 of medaka encode 416, 398, 451, and 386 amino acid residues, respectively. Comparison of cDNA sequences of medaka TRHR subtypes with respective genomic DNA sequences revealed gene structures: TRHR1a, TRHR1b and TRHR3genes consist of two exons while the TRH2 gene consists of five exons. Molecular phylogenetic analyses depicted the molecular evolution of TRHR in vertebrates: From the ancestral molecule, TRHR2 diverged first and then TRHR1 and TRHR3. Reverse transcription-polymerase chain reaction analyses revealed the sites of TRHR expression: Expression of TRHR1, TRHR1b and TRHR2 subtypes has been confirmed in the brain, pineal organ, retina and pituitary gland. In addition, TRHR1b is expressed in spleen, digestive tract and skin, and TRHR2 in testis, ovary and gill. TRHR3 is widely expressed in various tissues. These results indicate that in medaka, TRH might exert multiple functions mediated by different TRHR subtypes expressed in each tissue.
  General and Comparative Endocrinology 10/2010; 170(2):374-80. · 3.27 Impact Factor
• Source

  Available from: ku.ac.th

  Article: Interactive effects of carbon footprint information and its accessibility on value and subjective qualities of food products.

  Atsushi Kimura, Yuji Wada, Akiko Kamada, Tomohiro Masuda, Masako Okamoto, Sho-ichi Goto, Daisuke Tsuzuki, Dongsheng Cai, Takashi Oka, Ippeita Dan
  [show abstract] [hide abstract]
  ABSTRACT: We aimed to explore the interactive effects of the accessibility of information and the degree of carbon footprint score on consumers' value judgments of food products. Participants (n=151, undergraduate students in Japan) rated their maximum willingness to pay (WTP) for four food products varying in information accessibility (active-search or read-only conditions) and in carbon footprint values (low, middle, high, or non-display) provided. We also assessed further effects of information accessibly and carbon footprint value on other product attributes utilizing the subjective estimation of taste, quality, healthiness, and environmental friendliness. Results of the experiment demonstrated an interactive effect of information accessibility and the degree of carbon emission on consumer valuation of carbon footprint-labeled food. The carbon footprint value had a stronger impact on participants' WTP in the active-search condition than in the read-only condition. Similar to WTP, the results of the subjective ratings for product qualities also exhibited an interactive effect of the two factors on the rating of environmental friendliness for products. These results imply that the perceived environmental friendliness inferable from a carbon footprint label contributes to creating value for a food product.
  Appetite 10/2010; 55(2):271-8. · 2.59 Impact Factor
• Source

  Available from: psu.edu

  Article: Influence of luminance distribution on the appetizingly fresh appearance of cabbage.

  Yuji Wada, Carlos Arce-Lopera, Tomohiro Masuda, Atsushi Kimura, Ippeita Dan, Sho-ichi Goto, Daisuke Tsuzuki, Katsunori Okajima
  [show abstract] [hide abstract]
  ABSTRACT: We investigated the effect that the parameters of luminance distribution in fresh food have on our visual perception of its freshness. We took pictures of the degradation over 32 h in freshness of a cabbage. We used original images, which were patches of the pictures taken at different sampling hours, and artificially generated pictures, called "matched images," created by fitting the luminance histogram shape of the original image (taken at the 1st hour) to those at various freshness stages using a luminance histogram-matching algorithm. Nine participants rated the perceived freshness of the original and the matched images on a scale of degradation. As a result, we found that the participants could quantitatively estimate the degradation in freshness of the cabbage simply by looking at the presented images. Some parameters of the luminance histograms monotonically change with decreasing freshness, indicating that the freshness of cabbage can be estimated using these parameters. However, the freshness ratings for the matched images after the 8th hour of degradation had lower modification than those for the respective original images. These results suggest that the luminance distribution in the vegetable texture partly contributes to visual freshness perception but other variables, such as spatial patterns, might also be important for estimating visual freshness.
  Appetite 04/2010; 54(2):363-8. · 2.59 Impact Factor
• Article: Acute kidney injury presenting a feature of leukemic infiltration during therapy for chronic myelogenous leukemia.

  Yukio Yuzawa, Waichi Sato, Tomohiro Masuda, Yuzuru Hamada, Miho Tatematsu, Yoshinari Yasuda, Takenori Ozaki, Isao Ito, Masashi Mizuno, Shoichi Maruyama, Yasuhiko Ito, Seiichi Matsuo
  [show abstract] [hide abstract]
  ABSTRACT: Chronic myelogenous leukemia (CML) is a myeloproliferative disease that originates in abnormal pluripotent bone marrow stem cells and it is consistently associated with the Philadelphia chromosome and/or BCR/ ABL fusion gene. Renal infiltration of leukemic cells is relatively rare in CML and is associated with renal impairment. We describe a patient who developed acute renal failure by tubulointerstitial nephropathy during treatment with imatinib mesylate for CML. The acute kidney injury was subsequently found to be due to direct leukemic infiltration. Treatment with hydroxycarbamide and prednisolone resulted in stabilization of the renal function for approximately 4 months. Leukemic infiltration into the kidney should always be considered when a patient with CML presents with renal impairment, regardless of the clinical stage, as the renal failure often responds well to chemotherapy.
  Internal Medicine 01/2010; 49(12):1139-42. · 0.94 Impact Factor
• Article: Infants' recognition of objects using canonical color.

  Atsushi Kimura, Yuji Wada, Jiale Yang, Yumiko Otsuka, Ippeita Dan, Tomohiro Masuda, So Kanazawa, Masami K Yamaguchi
  [show abstract] [hide abstract]
  ABSTRACT: We explored infants' ability to recognize the canonical colors of daily objects, including two color-specific objects (human face and fruit) and a non-color-specific object (flower), by using a preferential looking technique. A total of 58 infants between 5 and 8 months of age were tested with a stimulus composed of two color pictures of an object placed side by side: a correctly colored picture (e.g., red strawberry) and an inappropriately colored picture (e.g., green-blue strawberry). The results showed that, overall, the 6- to 8-month-olds showed preference for the correctly colored pictures for color-specific objects, whereas they did not show preference for the correctly colored pictures for the non-color-specific object. The 5-month-olds showed no significant preference for the correctly colored pictures for all object conditions. These findings imply that the recognition of canonical color for objects emerges at 6 months of age.
  Journal of Experimental Child Psychology 12/2009; 105(3):256-63. · 3.12 Impact Factor
• Article: Influences of food-name labels on perceived tastes.

  Masako Okamoto, Yuji Wada, Yui Yamaguchi, Atsushi Kimura, Haruka Dan, Tomohiro Masuda, Archana K Singh, Lester Clowney, Ippeita Dan
  [show abstract] [hide abstract]
  ABSTRACT: We examined whether food identity information presented as name labels would influence perception of basic tastes. To test this hypothesis, we used 10 aqueous taste solutions consisting of 2-3 of the 5 basic tastes in different ratios and presented them with one of these food names: "lemon," "coffee jelly," "caramel candy," and "consomme soup." Forty-six participants tasted samples presented with either food-name labels or random number labels. We found that participants who tasted samples with food-name labels rated tastes with significantly higher liking and familiarity scores than those presented with random numbers, especially when the names and tastes were perceived as being congruent. Though an effect on perceived intensity was not as prominent, we observed cases in which intensity ratings significantly changed. Effects of identity information have been shown in olfaction and flavors. This study demonstrates the first experimental evidence that identity information given as names also influence the perception of unimodal basic tastes.
  Chemical Senses 01/2009; 34(3):187-94. · 2.60 Impact Factor
• Source

  Available from: Takashi Yoshimura

  Article: Molecular evolution of prepro-thyrotropin-releasing hormone in the chicken (Gallus gallus) and its expression in the brain.

  Yasuhiro Aoki, Hiroko Ono, Shinobu Yasuo, Tomohiro Masuda, Takashi Yoshimura, Shizufumi Ebihara, Masayuki Iigo, Tadashi Yanagisawa
  [show abstract] [hide abstract]
  ABSTRACT: A cDNA encoding prepro-thyrotropin-relaesing hormone (ppTRH) in chicken (Gallus gallus) was isolated and the sites of expression in the brain were determined. The chicken ppTRH cDNA encodes 260 amino acids, including four TRH progenitor sequences (-Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg-). It is interesting to note that chicken ppTRH harbors four TRH progenitor-like sequences. According to the hydropathy profile of chicken ppTRH, not only the TRH progenitor sequences but also the TRH progenitor-like sequences are localized in hydrophilic regions. The TRH progenitor-like sequences might be related to structural conservation in the evolution of ppTRH, although they cannot be processed into TRH due to the mutation of several amino acids. According to the alignment of the deduced amino-acid sequences of known vertebrate ppTRHs and the molecular phylogenetic tree we constructed, we speculate on the molecular evolution of ppTRH in vertebrates. In situ hybridization demonstrated experession of the ppTRH gene in the nucleus preopticus periventricularis, nucleus preopticus medialis, regio lateralis hypothalami, paraventricular nucleus, nucleus periventricularis hypothalami, and nucleus ventromedialis hypothalami in the chicken brain.
  ZOOLOGICAL SCIENCE 08/2007; 24(7):686-92. · 0.95 Impact Factor
• Article: Molecular cloning of prepro-thyrotropin-releasing hormone cDNA from medaka (Oryzias latipes).

  Yasuhiro Aoki, Tomohiro Masuda, Masayuki Iigo, Tadashi Yanagisawa
  [show abstract] [hide abstract]
  ABSTRACT: The cDNA encoding prepro-thyrotropin-releasing hormone (ppTRH) in a teleost, medaka (Oryzias latipes) was isolated and characterized. The medaka ppTRH cDNA codes for 270 amino acid residues including eight TRH progenitor sequences (-Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg-). In silico analyses of the medaka genome database predicted that the structure of the medaka ppTRH gene is similar to the ppTRH genes of the other vertebrate species studied to date; consisting of three exons and two introns. Identity of the medaka ppTRH with the other vertebrates is rather low except the sockeye salmon. A molecular phylogenic tree showed that the ppTRH sequences reflected the predicted pattern of species classification. RT-PCR analysis demonstrated ppTRH gene expression in the brain and retina. These results gave some insight into the molecular evolution of ppTRH and physiological functions of TRH in vertebrates.
  General and Comparative Endocrinology 02/2007; 150(2):364-70. · 3.27 Impact Factor
• Article: Molecular analysis of Dec1 and Dec2 in the peripheral circadian clock of zebrafish photosensitive cells.

  Tomotaka Abe, Tomoko Ishikawa, Tomohiro Masuda, Kanta Mizusawa, Toshiro Tsukamoto, Hiroshi Mitani, Tadashi Yanagisawa, Takeshi Todo, Masayuki Iigo
  [show abstract] [hide abstract]
  ABSTRACT: To elucidate the roles of DEC1 and DEC2, basic helix-loop-helix transcription factors, in the circadian clock of photosensitive zebrafish peripheral cells, zebrafish Dec1 and Dec2 (zDec1 and zDec2) were cloned and their functions and expression patterns were examined in BRF41, a zebrafish cell line. zDEC1 and zDEC2 have high sequence similarity to mammalian counterparts and the molecular phylogenetic analysis of the zDEC1 and zDEC2 sequences reflected the predicted pattern of species classification. zDEC1 and zDEC2 inhibited zCLOCK1:zBMAL3 mediated transcription as CRY1a. zDec1 and zDec2 mRNA showed robust circadian oscillation in BRF41 cells. However, zDec1 and zDec2 mRNA was not strongly induced by exposure to light. These results indicate that zDec1 and zDec2 are involved in the circadian clock mechanism in photosensitive zebrafish peripheral cells by suppressing CLOCK/BMAL-induced gene expression and that the feedback loops of zDEC1 and zDEC2 may be interlocked with the PER/CRY core circadian feedback loops.
  Biochemical and Biophysical Research Communications 01/2007; 351(4):1072-7. · 2.48 Impact Factor
• Source

  Available from: Takashi Yoshimura

  Article: Possible involvement of organic anion transporting polypeptide 1c1 in the photoperiodic response of gonads in birds.

  Nobuhiro Nakao, Tsuyoshi Takagi, Masayuki Iigo, Toshiro Tsukamoto, Shinobu Yasuo, Tomohiro Masuda, Tadashi Yanagisawa, Shizufumi Ebihara, Takashi Yoshimura
  [show abstract] [hide abstract]
  ABSTRACT: The photoperiodic response of the gonads requires T3, which is generated photoperiodically from T4 by type 2 iodothyronine deiodinase in the hypothalamus. Although thyroid hormones were long thought to traverse the plasma membrane by passive diffusion due to their lipophilic nature, it is now known that several organic anion transporting polypeptides (Oatp) transport thyroid hormones into target cells. In this study, we have used database searches to isolate DNA sequences encoding members of the chicken Oatp family and constructed a molecular phylogenetic tree. Comprehensive expression analyses using in situ hybridization revealed strong expression of cOatp1c1 and weak expression of cOatp1b1 in the ventro-lateral walls of basal tuberal hypothalamus, whereas expression of four genes (cOatp1a1, cOatp1b1, cOatp1c1, and cOatp3a2) was observed in the choroid plexus. Expression levels of all these genes in both regions were not different between short-day and long-day conditions. Functional expression of cOatp1c1 in Chinese hamster ovary cells revealed that cOatp1c1 is a highly specific transporter for T4 with an apparent Km of 6.8 nm and a Vmax of 1.50 pmol per milligram of protein per minute. These results suggest that cOatp1c1 could be involved in the thyroxine transport necessary for the avian photoperiodic response of the gonads.
  Endocrinology 04/2006; 147(3):1067-73. · 4.46 Impact Factor