ハナゴウナ科およびトウガタガイ科腹足類における寄生戦略の進化と形態多様化

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 小島 茂明, 東京大学教授 加瀬 友喜, 東京大学准教授 上島 励, 東京大学准教授 佐々木 猛智, 東京大学准教授 狩野 泰則University of Tokyo(東京大学

Comprehensive behavioral phenotyping of calpastatin-knockout mice

<p>Abstract</p> <p>Background</p> <p>Calpastatin is an endogenous inhibitor of calpain, intracellular calcium-activated protease. It has been suggested to be involved in molecular mechanisms of long-term plasticity and excitotoxic pathways. However, functions of calpastatin in vivo are still largely unknown. To examine the physiological roles of calpastatin, we subjected calpastatin-knockout mice to a comprehensive behavioral test battery.</p> <p>Results</p> <p>Calpastatin-knockout mice showed decreased locomotor activity under stressful environments, and decreased acoustic startle response, but we observed no significant change in hippocampus-dependent memory function.</p> <p>Conclusion</p> <p>These results suggest that calpastatin is likely to be more closely associated with affective rather than cognitive aspects of brain function.</p

Endoscopy-assisted transoral resection of a parapharyngeal space schwannoma without mandibular dissection

副咽頭間隙腫瘍切除術では，下顎離断により良好な視野を得られるが，その手術侵襲は大きい．本論文では佐藤式彎曲型喉頭鏡，nerve integrity monitoring（NIM）， narrow-band imaging（NBI）などの手術支援器具を用いて，頸部高位に存在する巨大交感神経鞘腫に対して下顎離断を行うことなくtransorally using video-laryngoscopic surgery（TOVS）により経口腔的切除し得た一例を報告する

Approach for growth of high-quality and large protein crystals

Three crystallization methods, including crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study, crystallization has been further evaluated in the presence of a semi-solid agarose gel by crystallizing additional proteins. A novel crystallization method combining TSSG and the large-scale hanging-drop method has also been developed

Narrow band imaging accentuates differences in contrast between cartilage and perichondrium in the elevation of the muco-perichondrium flap during septoplasty and open septorhinoplasty

鼻中隔矯正術において区別が難しい軟骨と軟骨膜を白色光（White light; WL）と狭帯域光観察（Narrow band imaging; NBI）で観察した．軟骨と軟骨膜の間の輝度の差はWLよりNBIで有意に大きかった．得られた画像を赤・緑・青に分光すると，赤では有意に輝度の差がみられた．以上からNBIを用いると軟骨と軟骨膜の間のコントラストが強調されることが示された．また，このコントラストの強調はNBIの赤色の処理によることが示された

Low-temperature Synthesis of FeTe0.5Se0.5 Polycrystals with a High Transport Critical Current Density

We have prepared high-quality polycrystalline FeTe0.5Se0.5 at temperature as low as 550{\deg}C. The transport critical current density evaluated by the current-voltage characteristics is over 700 A/cm2 at 4.2 K under zero field, which is several times larger than FeTe0.5Se0.5 superconducting wires. The critical current density estimated from magneto-optical images of flux penetration is also similar to this value. The upper critical field of the polycrystalline FeTe0.5Se0.5 at T = 0 K estimated by Werthamer-Helfand-Hohenberg theory is 585 kOe, which is comparable to that of single crystals. This study gives some insight into how to improve the performance of FeTe0.5Se0.5 superconducting wires.Comment: 12 pages, 6 figure

Self-Contained Induction of Neurons from Human Embryonic Stem Cells

BACKGROUND: Neurons and glial cells can be efficiently induced from mouse embryonic stem (ES) cells in a conditioned medium collected from rat primary-cultured astrocytes (P-ACM). However, the use of rodent primary cells for clinical applications may be hampered by limited supply and risk of contamination with xeno-proteins. METHODOLOGY/PRINCIPAL FINDINGS: We have developed an alternative method for unimpeded production of human neurons under xeno-free conditions. Initially, neural stem cells in sphere-like clusters were induced from human ES (hES) cells after being cultured in P-ACM under free-floating conditions. The resultant neural stem cells could circumferentially proliferate under subsequent adhesive culture, and selectively differentiate into neurons or astrocytes by changing the medium to P-ACM or G5, respectively. These hES cell-derived neurons and astrocytes could procure functions similar to those of primary cells. Interestingly, a conditioned medium obtained from the hES cell-derived astrocytes (ES-ACM) could successfully be used to substitute P-ACM for induction of neurons. Neurons made by this method could survive in mice brain after xeno-transplantation. CONCLUSION/SIGNIFICANCE: By inducing astrocytes from hES cells in a chemically defined medium, we could produce human neurons without the use of P-ACM. This self-serving method provides an unlimited source of human neural cells and may facilitate clinical applications of hES cells for neurological diseases

Effects of a high-sodium diet on renal tubule Ca2+ transporter and claudin expression in Wistar-Kyoto rats

Background: Urinary Ca^{2+} excretion increases with dietary NaCl. NaCl-induced calciuria may be associated with hypertension, urinary stone formation and osteoporosis, but its mechanism and long-term effects are not fully understood. This study examined alterations in the expressions of renal Ca^{2+} transporters, channels and claudins upon salt loading to better understand the mechanism of salt-induced urinary Ca^{2+} loss. Methods: Eight-week old Wistar-Kyoto rats were fed either 0.3% or 8% NaCl diet for 8 weeks. Renal cortical expressions of Na+/Ca2+ exchanger 1 (NCX1), Ca^{2+} pump (PCMA1b), Ca^{2+} channel (TRPV5), calbindin-D28k, and claudins (CLDN-2, -7, -8, -16 and −19) were analyzed by quantitative PCR, western blot and/or immunohistochemistry. Results: Fractional excretion of Ca^{2+} increased 6.0 fold with high-salt diet. Renal cortical claudin-2 protein decreased by approximately 20% with decreased immunological staining on tissue sections. Claudin-16 and −19 expressions were not altered. Renal cortical TRPV5, calbindin-D28k and NCX1 expressions increased 1.6, 1.5 and 1.2 fold, respectively. Conclusions: Chronic high-salt diet decreased claudin-2 protein and increased renal TRPV5, calbindin-D28k, and NCX1. Salt loading is known to reduce the proximal tubular reabsorption of both Na+ and Ca^{2+}. The reduction in claudin-2 protein expression may be partly responsible for the reduced Ca^{2+} reabsorption in this segment. The concerted upregulation of more distal Ca^{2+}-transporting molecules may be a physiological response to curtail the loss of Ca^{2+}, although the magnitude of compensation does not seem adequate to bring the urinary Ca^{2+} excretion down to that of the normal-diet group

Long-term results of modified bentall procedures: 18-year experience of the flanged technique

Objectives: To evaluate the early and late outcomes of the modified Bentall procedure with the flanged technique. Methods: We reviewed the medical records of 63 patients who had undergone root replacement by the modified Bentall procedure at our institute between January 2001 and December 2018. In most cases, we adopted a composite graft constructed with a mechanical valve or bioprosthesis and a Dacron graft by the flanged technique. Since 2011, we have used Valsalva grafts. Results: Mean age 57 ± 16 years, range 16-80, male 43 cases. The mean follow-up was 75 ± 56 months (range 0-216). Through April 1, 2020, we could follow up on 61 cases (97%) within a six-month period. Hospital mortality was 7.9% (4.8% in elective cases). In late follow-up, eight deaths were observed. In the bio-Bentall group (n=26), no deaths or major adverse valve-related events (MARVEs) occurred. In the mechanical Bentall group (n=37), seven cases of MARVEs, including two cerebral hemorrhages and one cerebral embolism, were observed. All patients were free from MARVEs at 5 years post procedure in the bio-Bentall group, and 93.8% and 76.8% were event-free at 5 years and 10 years, respectively, in the mechanical Bentall group. Conclusions: The 18-year results of the modified Bentall procedure were acceptable, providing excellent outcomes in the bio-Bentall group. The flanged technique enabled the use of a larger prosthesis, which may have resulted in good durability with the bio-Bentall procedure