Crossover from negative to positive shear rate dependence in granular friction

We conduct an experiment on the frictional properties of granular matter over a wide range of shear rate that covers both the quasistatic and the inertial regimes. We show that the friction coefficient exhibits negative shear-rate dependence in the quasistatic regime, whereas the shear-rate dependence is positive in the inertial regime. This crossover from negative to positive shear-rate dependence occurs at a critical inertial number. This is explained in terms of the competition between two physical processes, namely frictional healing and anelasticity. We also find that the result does not depend on the shape of the grains and that the behavior in the inertial regime is quantitatively the same as that in numerical simulations.Comment: 4 page

Transplantation of genetically marked cardiac muscle cells

AbstractWe examined the possibility that cardiomyocytes could be genetically marked or modified before being grafted to the heart under conditions applicable to the clinical setting. We used a replication-defective recombinant adenovirus carrying the β-galactosidase reporter gene, and delivered it to cultured murine fetal cardiac myocytes. Virtually all fetal cardiomyocytes in a primary culture expressed β-galactosidase 24 hours after recombinant adenovirus infection. These cells were transplanted to the hearts of syngenic adult recipient mice. Expression of the β-galactosidase gene in the grafted cells was demonstrated by staining with 5-bromo-4-chloro-3-indoyl-β-d-galactosidase, resulting in a blue color at the histochemical level and an electron-dense deposit on transmission electron microscopic analysis. Gene expression was recognized from 7 days to 12 weeks after transplantation. Implanted cardiomyocytes aligned themselves along the layers of the host myocardium. Formation of gap junctions was demonstrated by transmission electron microscopy. Neither inflammation nor fibrous scar tissue was detectable by histologic analysis. This study demonstrates that ex vivo gene transfer to the heart by means of the adenoviral vector is possible. (J Thorac Cardiovasc Surg 1997;113:10-8

Knowledge, attitude, and practice (KAP) of HIV prevention and HIV infection risks among Congolese refugees in Tanzania

Little is known about HIV infection risks and risk behaviours of refugees living in resource-scarce post-emergency phase camps in Africa. Our study at Nyarugusu Camp in Tanzania, covering systematically selected refugees (n=1140) and refugees living with HIV/AIDS (PLWHA) (n=182), revealed that the level of HIV risk of systematically selected refugees increased after displacement, particularly regarding the number having transactional sex for money or gifts, while radio broadcast messages are perceived to promote a base of risk awareness within the refugee community. While condoms are yet to be widely used in the camp, some refugees having transactional sex tended to undertake their own health initiatives such as using a condom, under the influence of peer refugee health workers, particularly health information team (HIT) members. Nevertheless, PLWHA were less faithful to one partner and had more non-regular sexual partners than the HIV-negative group. Our study revealed that community-based outreach by refugee health workers is conducive to risk behaviour prevention in the post-emergency camp setting. It is recommended to increase the optimal use of “radio broadcast messages” and “HIT,” which can act as agents to reach out to wider populations, and to strengthen the focus on safer sex education for PLWHA; the aim being to achieve dual risk reduction for both refugees living with and without HIV/AIDS

Regional Morphogenesis in the Hypothalamus: A BMP-Tbx2 Pathway Coordinates Fate and Proliferation through Shh Downregulation

SummaryA central challenge in embryonic development is to understand how growth and pattern are coordinated to direct emerging new territories during morphogenesis. Here, we report on a signaling cascade that links cell proliferation and fate, promoting formation of a distinct progenitor domain within the developing chick hypothalamus. We show that the downregulation of Shh in floor plate-like cells in the forebrain governs their progression to a distinctive, proliferating hypothalamic progenitor domain. Shh downregulation occurs via a local BMP-Tbx2 pathway, Tbx2 acting to repress Shh expression. We show in vivo and in vitro that forced maintenance of Shh in hypothalamic progenitors prevents their normal morphogenesis, leading to maintenance of the Shh receptor, ptc, and preventing progression to an Emx2+-proliferative progenitor state. Our data identify a molecular pathway for the downregulation of Shh via a BMP-Tbx2 pathway and provide a mechanism for expansion of a discrete progenitor domain within the developing forebrain

Evidence for the Involvement of a Src-Related Tyrosine Kinase inXenopusEgg Activation

AbstractRecently, we have purified a Src-related tyrosine kinase, namedXenopustyrosine kinase (Xyk), from oocytes ofXenopus laevisand found that the enzyme is activated within 1 min following fertilization [Satoet al.(1996)J. Biol. Chem.271, 13250–13257]. A concomitant translocation of a part of the activated enzyme from the membrane fraction to the cytosolic fraction was also observed. In the present study, we show that parthenogenetic egg activation by a synthetic RGDS peptide [Y. Iwao and T. Fujimura, T. (1996)Dev. Biol.177, 558–567], an integrin-interacting peptide, but not by electrical shock or the calcium ionophore A23187 causes the kinase activation, tyrosine phosphorylation, and translocation of Xyk. A synthetic tyrosine kinase-specific inhibitor peptide was employed to analyze the importance of the Xyk activity in egg activation. We found that the peptide inhibits the kinase activity of purified Xyk at IC50of 8 μM. Further, egg activation induced by sperm or RGDS peptide but not by A23187 was inhibited by microinjection of the peptide. In the peptide-microinjected eggs, penetration of the sperm nucleus into the egg cytoplasm and meiotic resumption in the egg were blocked. Indirect immunofluorescence study demonstrates that Xyk is exclusively localized to the cortex ofXenopuseggs, indicating that Xyk can function in close proximity to the sperm–egg or RGDS peptide–egg interaction site. Taken together, these data suggest that the tyrosine kinase Xyk plays an important role in the early events ofXenopusegg activation in a manner independent or upstream of calcium signaling

The effect of Ndrg2 expression on astroglial activation

N-myc downstream-regulated gene 2 (Ndrg2) is a differentiation- and stress-associated molecule predominantly expressed in astrocytes in the central nervous system (CNS). To study the expression and possible role of Ndrg2 in quiescent and activated astrocytes, mice were administrated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine (MPTP), a Parkinson disease (PD)-related neurotoxin which causes both neurodegeneration and glial activation. Immunohistological analysis revealed that Ndrg2 was highly expressed in both types of astrocytes, but less so in astrocytes during the early process of activation. Ndrg2 was also expressed in astrocyte-like cells, but not in neurons, in human brains from PD and Cortico-basal degeneration (CBD) patients. In cultured astrocytes, gene silencing of Ndrg2 significantly enhanced the numbers of 5-bromo-2′-deoxy-uridine (BrdU)-incorporated and proliferating cell nuclear antigen (PCNA)-positive cells, and reduced the length of cell processes and the amount of F-actin. In contrast, adenovirus-mediated overexpression of Ndrg2 significantly reduced the numbers of BrdU-incorporated and PCNA-positive cells, and enhanced the amount of F-actin. Fractionation and immunocytochemical analysis further revealed that Ndrg2 was located in different cellular fractions including the cytosol and cell surface membranes. These results suggest that Ndrg2 may regulate astroglial activation through the suppression of cell proliferation and stabilization of cell morphology. © 2011 Elsevier Ltd. All rights reserved

An Approach to the Theory of Relationships between ""Self"" and ""Other"" in Psychoanalysis

In recent years, problems about relationships between ""Self"" and ""Other"" have been discussed much in the educational theory. In order to find a clue to these problems, we take up some psychoanalytical theories, especially Melanie Klein (1882-1960), Donald Woods Winnicott (1896-1971), Heinz Kohut (1913-1981) and the father of psychoanalysis, Sigmund Freud (1856-1939). This study examines a lot of problems in the theories of relationships between them from the psychoanalytic point of view, and will provide some perspectives for the discussion on this theme

Pancreatic RECK inactivation promotes cancer formation, epithelial-mesenchymal transition, and metastasis

膵癌悪性化の分子機構解明 --RECK発現の低下が膵癌の浸潤・転移を引き起こす--. 京都大学プレスリリース. 2023-09-19.RECK is downregulated in various human cancers; however, how RECK inactivation affects carcinogenesis remains unclear. We addressed this issue in a pancreatic ductal adenocarcinoma (PDAC) mouse model and found that pancreatic Reck deletion dramatically augmented the spontaneous development of PDAC with a mesenchymal phenotype, which was accompanied by increased liver metastases and decreased survival. Lineage tracing revealed that pancreatic Reck deletion induced epithelial-mesenchymal transition (EMT) in PDAC cells, giving rise to inflammatory cancer-associated fibroblast–like cells in mice. Splenic transplantation of Reck-null PDAC cells resulted in numerous liver metastases with a mesenchymal phenotype, whereas reexpression of RECK markedly reduced metastases and changed the PDAC tumor phenotype into an epithelial one. Consistently, low RECK expression correlated with low E-cadherin expression, poor differentiation, metastasis, and poor prognosis in human PDAC. RECK reexpression in the PDAC cells was found to downregulate MMP2 and MMP3, with a concomitant increase in E-cadherin and decrease in EMT-promoting transcription factors. An MMP inhibitor recapitulated the effects of RECK on the expression of E-cadherin and EMT-promoting transcription factors and invasive activity. These results establish the authenticity of RECK as a pancreatic tumor suppressor, provide insights into its underlying mechanisms, and support the idea that RECK could be an important therapeutic effector against human PDAC

Management of Hepatocellular Carcinoma in Japan : JSH Consensus Statements and Recommendations 2021 Update

The Clinical Practice Manual for Hepatocellular Carcinoma was published based on evidence confirmed by the Evidence-based Clinical Practice Guidelines for Hepatocellular Carcinoma along with consensus opinion among a Japan Society of Hepatology (JSH) expert panel on hepatocellular carcinoma (HCC). Since the JSH Clinical Practice Guidelines are based on original articles with extremely high levels of evidence, expert opinions on HCC management in clinical practice or consensus on newly developed treatments are not included. However, the practice manual incorporates the literature based on clinical data, expert opinion, and real-world clinical practice currently conducted in Japan to facilitate its use by clinicians. Alongside each revision of the JSH Guidelines, we issued an update to the manual, with the first edition of the manual published in 2007, the second edition in 2010, the third edition in 2015, and the fourth edition in 2020, which includes the 2017 edition of the JSH Guideline. This article is an excerpt from the fourth edition of the HCC Clinical Practice Manual focusing on pathology, diagnosis, and treatment of HCC. It is designed as a practical manual different from the latest version of the JSH Clinical Practice Guidelines. This practice manual was written by an expert panel from the JSH, with emphasis on the consensus statements and recommendations for the management of HCC proposed by the JSH expert panel. In this article, we included newly developed clinical practices that are relatively common among Japanese experts in this field, although all of their statements are not associated with a high level of evidence, but these practices are likely to be incorporated into guidelines in the future. To write this article, coauthors from different institutions drafted the content and then critically reviewed each other’s work. The revised content was then critically reviewed by the Board of Directors and the Planning and Public Relations Committee of JSH before publication to confirm the consensus statements and recommendations. The consensus statements and recommendations presented in this report represent measures actually being conducted at the highest-level HCC treatment centers in Japan. We hope this article provides insight into the actual situation of HCC practice in Japan, thereby affecting the global practice pattern in the management of HCC