Temporal variation in growth of yellowfin tuna (Thunnus albacares) larvae in the Panama Bight, 1990

Tuna larvae (at flexion, postflexion, and transformation stages) were collected by dip net and light traps at night in the northwestern Panama Bight during the season of reduced upwelling (June−September) of 1990, 1991, 1992, and 1997. The larvae were identified as yellowfin tuna (Thunnus albacares) by mtDNA analysis. Ichthyoplankton data from bongo and Tucker trawl tows were used to examine the potential prey abundance in relation to the mean size-at-age and growth rates of the yellowfin tuna larvae and their otoliths. The most rapid growth rates occurred during June 1990 when plankton volumes were at their highest levels. The lowest plankton volumes coincided with the lowest growth rates and mean sizes-at-age during the August−September 1991 period. High densities of larval fish were prevalent in the ichthyoplankton tows during the 1991 period; therefore intra- and interspecific competition for limited food resources may have been the cause of slower growth (density-dependent growth) in yellowfin tuna larvae The highest mean seasurface temperature and the lowest mean wind stress occurred during an El Niño-Southern Oscillation (ENSO) event during the 1997 period. There appeared to be no clear association between these environmental factors and larval growth rates, but the higher temperatures may have caused an increase in the short-term growth of otoliths in rela

Investigation of the mechanisms of acute lung injury, using an isolated perfused mouse lung

Acute lung injury (ALI) is a severe inflammatory lung disease with high mortality. Previous studies revealed several important concepts in ALI, including cellular interaction between lung-marginated leukocytes and pulmonary endothelium, and decompartmentalisation of soluble mediators. However, there are inherent limitations within both in vivo and in vitro models to identify the detailed mechanism underlying these concepts. In this PhD project, we attempted to address these unanswered questions, using an in situ isolated perfused mouse lung (IPL). Specifically, we aimed to 1) develop, characterise, and optimise the mouse IPL model; 2) investigate soluble and cellular aspects of two models of ALI that are particularly amenable to study using the IPL, namely ventilator-induced lung injury (VILI) and ischaemia-reperfusion injury. From a physiological viewpoint, VILI consists of 2 primary components, high-stretch and atelectasis. Modelling atelectasis-related injury in vivo is difficult due to negative pleural pressure. We took advantage of the zero pleural pressure of open-chest IPL system to develop an atelectasis-related VILI model. Comparison of this ‘atelectrauma’ and a high-stretch ‘volutrauma’ model demonstrated that both cause lung oedema and pulmonary inflammation, but the inflammatory impact was different between them. Volutrauma, but not atelectrauma, facilitated systemic cytokine release, in which lung-marginated monocytes seem to play an important role. This finding in the VILI model drove us to further investigate the role of these monocytes in an ischaemia-reperfusion model, which is clinically highly relevant and simulates a lung transplantation setting. Our results suggested that lung-marginated monocytes may also contribute to develop ischaemia-reperfusion injury, potentially involving TNF upregulation. Through this PhD project, we have successfully developed a technically very challenging mouse IPL model. We utilised the unique features of the IPL to develop experimental models that we believe will be strong tools to fill the gap between in vivo physiological significance and in vitro mechanistic understanding

網膜電図の新電位(暗所閾値電位,STR)の発生機構の基礎的研究およびその臨床応用

金沢大学医学部研究課題/領域番号:01771400, 研究期間(年度):1989出典：研究課題「網膜電図の新電位(暗所閾値電位,STR)の発生機構の基礎的研究およびその臨床応用」課題番号01771400（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-01771400/）を加工して作

原発性黄斑部変性症の臨床電気生理学的検査法の開発とその臨床応用

金沢大学医学部研究課題/領域番号59771244, 研究期間(年度):1984出典：研究課題「原発性黄斑部変性症の臨床電気生理学的検査法の開発とその臨床応用」課題番号59771244（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-59771244/）を加工して作

網膜電図の新電位(暗所閾値電位,STR)の発生機構の基礎的および臨床的研究

金沢大学医学部附属病院前年度に開発した暗所閾値電位(scotopic threshold response,STR)記録システムを用いて1)ウサギおよびカエルにおいてin vivo STRの記録を試み、STRの種差について検討することによりSTRにおけるMuller細胞の関与の可能性を検討した。その結果カエルおよびウサギではSTRに相当する陰性波は観察されなかった。これまでにSTRを持つことが明らかにされているヒトやネコおよびサルと今回検討を行ったウサギおよびカエルとではMuller細胞のK^+透過性分布が異なるとされており、Muller細胞のK^+透過性分布の違いとSTRの有無とが符合することはSTRの発生にMuller細胞が関与していることの傍証となると考えられた。2)ヒトにおいては眼底白点症および無βリポ蛋白血症においてSTRの所見を検討した。眼底白点症は視物質の再生遅延によって暗順応が延長する疾患であるが、今回の検討では本症の3例において充分な暗順応後のSTRは他の網膜電図(electroretinogram,ERG)成分と同様に正常であり、電気生理学的にも充分な暗順応後の網膜機能が正常であることを示した。無βリポ蛋白血症は血清βリポ蛋白の消失を本態とする常染色体劣性遺伝の疾患であり、腸管における脂肪の吸収不全から各種脂容性ビタミンの欠乏症状を呈し眼科的には非定型的網膜色素変性症を合併することで知られている。今回の検討では本症の1例でSTRは観察されず、ERGa波およびb波も高度に減弱していたが、同症例で記録した眼球電位図では異常の程度が原発性網膜色素変性症に比べて軽度であったこととあわせて考えると本症における網膜色素変性症は原発性網膜色素変性症とはその主たる障害の部位が異なる可能性が示唆された。The scotopic threshold response (STR) is a newly investigated component of the electroretinogram. Since the STR reflects post-photoreceptoral processing in the retina at intensities near absolute threshold, the STR would be a useful index to evaluate the rod pathway in the proximal retina. A conventional ERG setup, however, involves difficulties in STR recording. Therefore we constructed a new recording system for the purpose. The characteristics of the apparatus are as follows : 1)A diffusing sphere provides full-field stimuli ranging from a very dim light near absolute threshold to a very bright light. 2)A remote-control system for changing filters is used to avoid breakdown of the dark-adapted status. 3)A software artifact rejection routine is used to exclude response influenced by eye movements and blinks. Using the apparatus we have examined the human STR and generally confirmed the previous findings.Fundus albipunctatus is known as having a prolonged dark adaptation in both rod and cone systems due to a disorder of visual pigment regeneration. We previously reported that the amplitude of the b-wave with a dim light and the early receptor potential with a bright flash recovered slowly along the course of progressive dark adaptation and ended up non-nal after 34 hours of dark adaptation in a case of the disease. The threshold of the b-wave is, however, about 3.5 - 4.0 log higher than the psychophysical threshold. Thus the relationship between psychophysical sensitivity and electrical response below the b-wave threshold has been missing. Since the threshold of the STR is lower than the b-wave threshold, the STR is an appropriate electrical index for evaluating. scotopic activity. In a 7 year-old girl with fundus albipunctatus the characteristics of the STR from the fully dark adapted eye were normal, including the maximum amplitude, waveform, range of stimulus intensity and relationship to rod PII, suggesting a physiological deficit rather than a dystrophic involvement in the disease.Abetalipoproteinemia (Bassen - Komzweig syndrome) is a rare autosomal ressesive disease characterized clinically by acanthocytosis, cerebeller ataxia, fat malabsorption and atypical retinitis pigmentosa. In a patient of the disease, findings of ocular fundus, fluorescein angiography, color vision, visual field and dark adaptation were all compatible to those of typical retinitis pigmentosa sine pigment. ERG and EOG findings recorded from the patient suggested that the main affected site of the disease is different from primary retinitis pigmentosa.The scotopic threshold response (STR) was reported in the cat, sheep monkey and human. The STR has not yet been confirmed in the frog and rabbit. We recorded the ERG intensity series in the frog and rabbit, using dim (-7.7 log) to bright (O log : 280cd/m^2) full field stimli. The threshold of the b-wave in the frog was about -5.7 log intensity. Below the b-wave threshold (at the intensities of -6.3 and -6.7 log), a tiny negative wave (3 - 6[muV) with a long latency (450 msec) seemed to be barely observed indicating that the frog STR is a very tiny tranasient response if present. The threshold of the b-wave in the rabbit was about -5.3 log intensity. Below the b-wave threshold no negative wave was observed in the rabbit. On the hypothesis that membrane potential change of Muller cell in response to extracellular K^+ concentration serves to generate the STR, the differences of the distribution of K^+ conductance of Muller cells among the species may account for the low STR amplitude in the frog and rabbit in comparison with the high STR amplitude in the cat and monkey.研究課題/領域番号:02807162, 研究期間(年度):1990 – 1991出典：研究課題「網膜電図の新電位(暗所閾値電位,STR)の発生機構の基礎的および臨床的研究」課題番号02807162（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-02807162/028071621991kenkyu_seika_hokoku_gaiyo/）を加工して作

網膜疾患とくに黄斑部変性の電気生理学的研究とその臨床応用

金沢大学医学部研究課題/領域番号:56770786, 研究期間(年度):1981出典：「網膜疾患とくに黄斑部変性の電気生理学的研究とその臨床応用」研究成果報告書　課題番号56770786（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-56770786/）を加工して作

Decreased sensory nerve excitation and bone pain associated with mouse Lewis lung cancer in TRPV1-deficient mice

Bone pain is one of the most common and life-limiting complications of cancer metastasis to bone. Although the mechanism of bone pain still remains poorly understood, bone pain is evoked as a consequence of sensitization and excitation of sensory nerves (SNs) innervating bone by noxious stimuli produced in the microenvironment of bone metastases. We showed that bone is innervated by calcitonin gene-related protein (CGRP)+ SNs extending from dorsal root ganglia (DRG), the cell body of SNs, in mice. Mice intratibially injected with Lewis lung cancer (LLC) cells showed progressive bone pain evaluated by mechanical allodynia and flinching with increased CGRP+ SNs in bone and augmented SN excitation in DRG as indicated by elevated numbers of pERK- and pCREB-immunoreactive neurons. Immunohistochemical examination of LLC-injected bone revealed that the tumor microenvironment is acidic. Bafilomycin A1, a selective inhibitor of H+ secretion from vacuolar proton pump, significantly alleviated bone pain, indicating that the acidic microenvironment contributes to bone pain. We then determined whether the transient receptor potential vanilloid 1 (TRPV1), a major acid-sensing nociceptor predominantly expressed on SNs, plays a role in bone pain by intratibially injecting LLC cells in TRPV1-deficient mice. Bone pain and SN excitation in the DRG and spinal dorsal horn were significantly decreased in TRPV1 −/− mice compared with wild-type mice. Our results suggest that TRPV1 activation on SNs innervating bone by the acidic cancer microenvironment in bone contributes to SN activation and bone pain. Targeting acid-activated TRPV1 is a potential therapeutic approach to cancer-induced bone pain

Structural basis for tropomyosin overlap in thin (actin) filaments and the generation of a molecular swivel by troponin-T

Head-to-tail polymerization of tropomyosin is crucial for its actin binding, function in actin filament assembly, and the regulation of actin-myosin contraction. Here, we describe the 2.1 Å resolution structure of crystals containing overlapping tropomyosin N and C termini (TM-N and TM-C) and the 2.9 Å resolution structure of crystals containing TM-N and TM-C together with a fragment of troponin-T (TnT). At each junction, the N-terminal helices of TM-N were splayed, with only one of them packing against TM-C. In the C-terminal region of TM-C, a crucial water in the coiled-coil core broke the local 2-fold symmetry and helps generate a kink on one helix. In the presence of a TnT fragment, the asymmetry in TM-C facilitates formation of a 4-helix bundle containing two TM-C chains and one chain each of TM-N and TnT. Mutating the residues that generate the asymmetry in TM-C caused a marked decrease in the affinity of troponin for actin-tropomyosin filaments. The highly conserved region of TnT, in which most cardiomyopathy mutations reside, is crucial for interacting with tropomyosin. The structure of the ternary complex also explains why the skeletal- and cardiac-muscle specific C-terminal region is required to bind TnT and why tropomyosin homodimers bind only a single TnT. On actin filaments, the head-to-tail junction can function as a molecular swivel to accommodate irregularities in the coiled-coil path between successive tropomyosins enabling each to interact equivalently with the actin helix

Tumor Induction by Azoxymethane (AOM) and 2-Amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in F344 Rat Gastric Mucosa Featuring Intestinal Metaplasia Caused by X-irradiation

Male F344 5-week-old rats were X-irradiated, and 16 weeks after the first dose. azoxymethane (AOM) was injected or 2-amino-l-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) was given by intragastric intubation. Tumors in the pylorus of the glandular stomach were observed in 4 out of the 29 animals receiving X-rays + AOM and in 4 out of the 25 animals receiving X-rays + PhIP, 12 months after administration. No such lesions were found in the chemical or X-ray alone groups. Intestinal metaplasia and some induced tumors were positive for CDX2. It was concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by colon carcinogens

Construction of Eco-system for NTBFs to Thrive, Grow and Agglomerate (Japanese)

Boston, Massachusetts in the U.S. was able to rejuvenate its economy after WWП through the thrift, growth and agglomeration of MIT-born New Technology-based Firms (NTBFs), which have been categorized as the origin of new venture firms. This paper will explain why some areas like Boston, Silicon Valley, and Austin TX in the U.S. and Cambridge in the UK, were able to construct successful Eco-systems for NTBFs to thrive, grow and agglomerate, while others were unsuccessful, by applying the Eco-system Construction Model deducted from previous studies. Based on the research findings of this paper, we also outline our recommendations for a revision of the U.S. innovation model by clarifying its advantages and disadvantages. The U.S. model was introduced in Japan at the end of the 1990s and prompted a number of new innovation policy projects including the '1000 University Start-up Venture Scheme', the 'Industrial Cluster Project' and the 'Knowledge Cluster Initiative.'