208 research outputs found
Pathophysiology of placentation abnormalities in pregnancy-induced hypertension
During embryogenesis and development, the fetus obtains oxygen and nutrients from the mother through placental microcirculation. The placenta is a distinctive organ that develops and differentiates per se, and that organizes fetal growth and maternal condition in the entire course of gestation. Several life-threatening diseases during pregnancy, such as pregnancy-induced hypertension (PIH) and eclampsia, are closely associated with placental dysfunction. Genetic susceptibilities and poor placentation have been investigated intensively to understand the pathophysiology of PIH. It is currently thought that “poor placentation hypothesis”, in which extravillous trophoblasts fail to invade sufficiently the placental bed, explains in part maternal predisposition to this disease. Cumulative studies have suggested that hypoxic micromilieu of fetoplacental site, shear stress of uteroplacental blood flow, and aberrantly secreted proinflammatory substances into maternal circulation synergistically contribute to the progression of PIH. For example, soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble form of CD105 are elevated in circulation of PIH mothers. However, it remains to be poorly understood the pathological events in the placenta during the last half of gestation as maternal systemic disorders get worse. For better understanding and effective therapeutic approaches to PIH, it is important to clarify pathological course of PIH-associated changes in the placenta. In this review, current understanding of placental development and the pathophysiology of PIH placenta are summarized. In addition, recent findings of vasoactive signalings in PIH and rodent PIH models are discussed
Fundamental studies on the reproductive strategies of Quercus serrata - Pollination patterns in different flowering heights -
コナラは花の形質から風媒花とされているが、近年訪花昆虫が確認されており、その送粉様式は未解明である。そこで、送粉様式を解明するにあたり、次のような仮説を立てた。樹冠上部では、風媒の割合が下部より高く、下部では、虫媒の割合が上部より高いというものである。また、昆虫の訪花頻度は花のディスプレイサイズに影響を受けるため、コナラの花序数や花序長も考慮する必要がある。したがって、着花高度の違いによる送粉者の貢献度、着花高度と送粉者の違いによる結実への影響、着花高度と花のディスプレイサイズが訪花昆虫に与える影響を明らかにすることによってコナラの送粉様式を解明し、繁殖戦略を明らかにすることを目的とした。樹冠下部では、訪花昆虫を制限すると結実率が低下した。種子サイズは上部の方が大きかったが、ばらつきは上部と下部で変わらなかった。また、着花高度別の訪花昆虫については、下部の方が上部より個体数も種類も多かった。さらに、訪花昆虫は風速が一定以上に大きくなると訪花しなくなり、上部では訪花頻度が低下することが分かった。花のディスプレイサイズについては、上部の方が単位面積あたりの花序数が多いが花序は短く、下部では花序が長いものが多かった。昆虫の訪花頻度は風速だけでなく、花のディスプレイサイズにも影響を受け、それが花序数であるか花序長であるかは種によって異なった。以上のことから、送粉者である風と昆虫に対する依存度が着花高度によって異なることが示唆された。
An analysis of pressure pattern in severe Typhoon Bart hitting the Japanese Islands in 1999 and a comparison of the gradient wind with the observed surface wind
Aggressive natural killer cell leukemia: Therapeutic potential of l-asparaginase and allogeneic hematopoietic stem cell transplantation
We conducted a retrospective JapanKorea multicenter study to better elucidate the clinicopathologic features and therapeutic modalities for aggressive natural killer cell leukemia (ANKL). A total of 34 patients were analyzed. The median age of the patients was 40 years. Among the patients in the study, four had a history of EpsteinBarr virus-related disorders. Three types of ANKL cells were categorized according to their morphological features. Leukemic cells were below 20% in both peripheral blood and bone marrow of 11 patients. The clinical characteristics and prognoses of these 11 patients did not differ significantly from those of the others. As an initial therapy, l-asparaginase chemotherapy resulted in a better response. A total of six patients received allogeneic hematopoietic stem cell transplantation (HSCT) and two received autologous HSCT, with all in non-complete remission (CR). After HSCT, four with allogeneic and one with autologous HSCT reached CR. Median survival of all patients was 51 days. Median survival for the patients with and without HSCT were 266 and 36 days, respectively. A total of two patients with allogeneic HSCT were alive and in CR. All patients without HSCT died of ANKL. The use of l-asparaginase was indicated as a factor for longer survival (HR 0.33, 95% confidence interval; 0.130.83, P = 0.02). Early diagnosis of ANKL, l-asparaginase-based chemotherapy and allogeneic HSCT might lead to improved patient outcomes.ArticleCANCER SCIENCE. 103(6):1079-1083 (2012)journal articl
Essential roles of DC-derived IL-15 as a mediator of inflammatory responses in vivo
Interleukin (IL)-15 is expressed in a variety of inflammatory diseases. However, the contribution of dendritic cell (DC)–derived IL-15 to the development of diseases is uncertain. Using established models of Propionibacterium acnes (P. acnes)– and zymosan-induced liver inflammation, we observed granuloma formation in the livers of wild-type (WT) and RAG-2−/− mice but not in those of IL-15−/− mice. We demonstrate that this is likely caused by an impaired sequential induction of IL-12, IFN-γ, and chemokines necessary for monocyte migration. Likewise, lethal endotoxin shock was not induced in P. acnes– and zymosan-primed IL-15−/− mice or in WT mice treated with a new IL-15–neutralizing antibody. In both systems, proinflammatory cytokine production was impaired. Surprisingly, neither granuloma formation, lethal endotoxin shock, nor IL-15 production was induced in mice deficient for DCs, and adoptive transfer of WT but not IL-15−/− DCs restored the disease development in IL-15−/− mice. Collectively, these data indicate the importance of DC-derived IL-15 as a mediator of inflammatory responses in vivo
Atomic-scale flattening of SiC surfaces by electroless chemical etching in HF solution with Pt catalyst
The authors present a method for flattening SiC surfaces with Pt as a catalyst in HF solution. The mechanism for flattening SiC surfaces is discussed. The flattened 4H-SiC (0001) surface is composed of alternating wide and narrow terraces with single-bilayer-height steps, which are induced by the rate difference of the catalytic reactions between adjacent terraces. Scanning tunneling microscopy images reveal a 1×1 phase on the terraces. The 1×1 phase is composed of coexisting of F- and OH-terminated Si atoms, which originate from the polarization of the underlying Si-C bonds. © 2007 American Institute of Physics.Kenta Arima, Hideyuki Hara, et al. "Atomic-scale flattening of SiC surfaces by electroless chemical etching in HF solution with Pt catalyst", Appl. Phys. Lett. 90(20), 202106 (2007) https://doi.org/10.1063/1.2739084
コウゴウ ヨウシキ ノ チガイ ガ インプラント チリョウ ケッカ ニ オヨボス エイキョウ : ブンケン コウサツ
Occlusion, including the occlusal scheme, occlusal contact, and occlusal force, has been discussed by many researchers. Traditionally, these arguments have been empirical in clinical experience and not based on scientific evidence.
The aim of this study was to analyze the published literature on clinical follow-up studies focusing on the occlusal scheme of implant treatment. Two databases, “PubMed” and “Japana Centra Revuo Medicina” were searched to retrieve research papers on clinical follow-up studies focusing on the occlusal scheme of implant treatment. Twelve papers were selected from the database using the criteria, and were reviewed. Little scientific evidence supports a relationship between the occlusal scheme and the outcome of osseointegrated implant treatment. Within the limitations of the articles, this review indicates that scientific evidence of occlusal scheme of implant treatment is insufficient. Occlusal scheme has little effect on the survival rate of implants and mutually protected occlusion is used in a fixed superstructure and balanced occlusion is used in a removable superstructure
Effects of teaching motor skills to others on the persistence of motor learning
The purpose of this study was to examine the effects of teaching motor skills to others on the survivability of motor learning effects. 20 healthy adults were randomly assigned to two conditions a teaching conditions and reading a magazine condition (control conditions). The number of times of turning was measured before and after each condition. In both conditions, the number of ball rotations and the number of improvements increased 30 minutes after the task was completed compared to before the task. Additionally, the number of improvements in ball rotation was significantly higher in the teaching condition than in the control condition. In the teaching condition, the number of ball turnings significantly increased 30 minutes after the end of the condition compared to before the condition. These results suggested that task for teaching motor skill to others might be useful for improving motor learning
Severe Hypomyelination and Developmental Defects Are Caused in Mice Lacking Protein Arginine Methyltransferase 1 (PRMT1) in the Central Nervous System
Protein arginine methyltransferase 1 (PRMT1) is involved in cell proliferation, DNA damage response, and transcriptional regulation. While PRMT1 is extensively expressed in the central nervous system (CNS) at embryonic and perinatal stages, the physiological role of PRMT1 was poorly understood. Here, to investigate the primary function of PRMT1 in the CNS, we generated CNS-specific PRMT1 knockout mice by Cre-loxP system. These mice exhibited post-natal growth retardation with tremors and most of them died in two weeks after birth. Brain histological analyses revealed the prominent cell reduction in the white matter tracts of the mutant mice. Furthermore, ultrastructural analysis demonstrated that myelin sheath was almost completely ablated in the CNS of these animals. In agreement with hypomyelination, we also observed that most major myelin proteins including MBP, CNPase, and MAG were dramatically decreased, although neuronal and astrocytic markers were preserved in the brain of CNS-specific PRMT1 knockout mice. These animals had reduced number of OLIG2+ oligodendrocyte lineage cells in the white matter. We found that expressions of transcription factors essential for oligodendrocyte specification and further maturation were significantly suppressed in the brain of the mutant mice. Our findings provide evidence that PRMT1 is required for CNS development, especially for oligodendrocyte maturation processes
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