162 research outputs found
Studies on the Spherical Bodies Containing Anthocyanins in Plant cells, IV. : A Survey of the Occurrence of Anthocyanoplasts in the Hypocotyls in some Plant Species.
A survey was conducted on the occurrence of anthocyanoplasts using the hypocotyls of 16 families comprising 35 species, of which the names appear in Table 1. The present survey resulted in the discovery that anthocyanoplasts were recognized in the hypocotyls of 21 species. The sizes of the anthocyanoplasts, their shapes and their colors found here closely resembled those in the hypocotyls of radish previously reported on by YASUDA et al. (1985). However, there were some differences between the anthocyanoplasts found here and those of radish. Especially the morning glory hypocotyl data were strikingly different from those obtained from radish, as is shown below. 1. The relationship between the pigment level in the hypocotyls and the frequency with which anthocyanoplasts appear in them. Anthocyanoplast appeared during whole period of pigment formation of morning glory, while in contrast anthocyanoplasts only appeared in the hypocotyls of radish during the first half of pigment formation. 2. The relationship between the numbers of anthocyanoplasts per cell and their diameters The relationship between them was rather complicated, suggesting that fusion of several smaller anthocyanoplasts and the division of larger anthocyanoplasts occurred alternatively during the developmental course of anthocyanoplasts. This differs very markedly from the hypocotyls of radish which showed fusion only in their developmental stages. It was also found that the anthocyanoplasts in the hypocotyls of morning glory have the ability to display light reaction in anthocyanin biosynthesis exactly like the hypocotyls of radish.Article信州大学理学部紀要 27(1): 15-21(1992)departmental bulletin pape
Low-temperature synthesis of crystalline GeSn with high Sn concentration by electron excitation effect
The low-temperature synthesis of high-Sn-concentration GeSn is challenging in realizing flexible thin-film transistors and solar cells. Because of athermal processes, irradiation with energetic particles is anticipated to significantly reduce the processing temperature for device fabrication. Here, we demonstrated that polycrystalline Ge with ~30 at. % Sn can be realized at room temperature by the electron-beam-induced recrystallization of amorphous GeSn. We found that inelastic electronic stopping, the so-called electron excitation effect, plays an important role in the recrystallization of amorphous GeSn
Significance of Smoking as a Postoperative Prognostic Factor in Patients with Non-small Cell Lung Cancer
IntroductionIn this study, we investigated the influence of smoking on the postoperative prognosis in patients with non-small cell lung cancer.MethodsThe subjects consisted of 770 patients who underwent a resection of lung cancer in our department between 1994 and 2005. We compared the clinico-pathological findings between the smoking and never-smoking groups. The pack-year index (PYI) was used as a smoking index.ResultsThe smoking group consisted of 569 patients (74%), and the never-smoking group consisted of 201 patients (26%). The smokers were composed of 492 men and 77 women. Among the adenocarcinoma patients, there were 293 (61%) smokers and 185 (39%) never-smokers. The patients with squamous cell carcinoma included 204 (95%) smokers and 10 (5%) never-smokers. The proportion of patients with stage IA disease was significantly higher in the never-smokers than that of the smokers. The 5-year survival rate after surgery was 66% in the never-smoking group; however, the rates were 56% in patients with a PYI more than or equal to 20, and 55% in those with PYI more than 20. Seventy-nine (13.9%) patients in the smoking group and seven (3.5%) patients in the never-smoking group died of other diseases, with a significant difference (p < 0.01). Of these patients, 44 (56%) and 13 (16%) in the smoking group died of respiratory and cardiovascular disorders, respectively. In our series, excluding those who died of other diseases, there were no significant differences in the postoperative prognosis.ConclusionsIn the smoking group, the prognosis was poorer than that in the never-smoking group. The higher proportion of early stage disease (stage IA) and female gender were major causes of the better prognosis of the never-smokers. Nevertheless, the high pulmonary/cardiovascular complication-related mortality was another cause of the poor prognosis of the smokers with lung cancer
Liquid-mediated crystallization of amorphous GeSn under electron beam irradiation
Crystallization processes of amorphous germanium–tin (GeSn) under low-energy electron-beam irradiation were examined using transmission electron microscopy (TEM). Freestanding amorphous GeSn thin films were irradiated with a 100 keV electron beam at room temperature. The amorphous GeSn was athermally crystallized by electron-beam irradiation, when the electron flux exceeded the critical value. Heterogeneous structures consisting of nano- and micro-crystallites were formed after crystallization of amorphous GeSn with ∼24 at. % Sn in the as-sputtered amorphous state. In situ TEM observations of structural changes under electron-beam irradiation revealed that random nucleation and growth of nanocrystallites occur at the early stage of crystallization, followed by rapid formation of micro-grains surrounding the nanocrystals. It has been suggested that the growth of micro-grains progresses via supercooled liquid Sn at the amorphous/crystalline interface. The resultant GeSn grains with a size of a few micrometers contained ∼15 at. % Sn, much larger than the solubility limit of Sn in Ge (∼1 at. % Sn)
Plasma levels of matrix metalloproteinase‐9 (MMP‐9) are associated with cognitive performance in patients with schizophrenia
Aim: Matrix metalloproteinase‐9 (MMP‐9) has been shown to modulate synaptic plasticity and may contribute to the pathophysiology of schizophrenia. This study investigated the peripheral levels of MMP‐9 and its association with cognitive functions in patients with schizophrenia to see the possible involvement of MMP‐9 in pathophysiology of schizophrenia, especially in cognitive decline.
Methods: We measured the plasma levels of MMP‐9 in 257 healthy controls and 249 patients with schizophrenia, including antipsychotic drug–free patients. We also explored the possible association between plasma MMP‐9 levels and cognitive performance in healthy controls and patients with schizophrenia using the Wechsler Adult Intelligence Scale, Third Edition (WAIS‐ III), the Wechsler Memory Scale‐Revised (WMS‐R), and the Rey Auditory Verbal Learning Test (AVLT).
Results: We found that the plasma levels of MMP‐9 were significantly higher in patients with schizophrenia, including antipsychotic drug–free patients, than in healthy controls. We found a significant negative association between plasma MMP‐9 levels and cognitive performance in controls and patients with schizophrenia.
Conclusion: Together, these convergent data suggest a possible biological mechanism for schizophrenia, whereby increased MMP‐9 levels are associated with cognitive impairment
Plasma Levels of Soluble Tumor Necrosis Factor Receptor 2 (sTNFR2) Are Associated with Hippocampal Volume and Cognitive Performance in Patients with Schizophrenia
Background: An imbalance in the inflammatory tumor necrosis factor system, including soluble tumor necrosis factor receptor 2 (sTNFR2), may contribute to the pathophysiology of schizophrenia.
Methods: We measured the plasma levels of sTNFR2 in 256 healthy controls and 250 patients with schizophrenia including antipsychotic drug-free patients and treatment-resistant patients. We also explored the possible association between plasma sTNFR2 levels and cognitive performance in healthy controls and patients with schizophrenia using the Wechsler Adult Intelligence Scale, Third Edition, the Wechsler Memory Scale-Revised, and the Rey Auditory Verbal Learning Test. An association between plasma sTNFR2 levels and hippocampal volume in controls and patients with schizophrenia was also investigated via MRI.
Results: We found that the plasma levels of sTNFR2 were significantly higher in patients with schizophrenia, including both antipsychotic drug-free patients and treatment-resistant patients. We found a significant negative association between plasma sTNFR2 levels and cognitive performance in controls and patients with schizophrenia. Hippocampal volume was also negatively associated with plasma sTNFR2 levels in patients with schizophrenia.
Conclusion: Together, these convergent data suggest a possible biological mechanism for schizophrenia, whereby increased sTNFR2 levels are associated with a smaller hippocampal volume and cognitive impairment
Transforming somatic mutations of mammalian target of rapamycin kinase in human cancer
Mammalian target of rapamycin (mTOR) is a serine-threonine kinase that acts downstream of the phosphatidylinositol 3-kinase signaling pathway and regulates a wide range of cellular functions including transcription, translation, proliferation, apoptosis, and autophagy. Whereas genetic alterations that result in mTOR activation are frequently present in human cancers, whether the mTOR gene itself becomes an oncogene through somatic mutation has remained unclear. We have now identified a somatic non-synonymous mutation of mTOR that results in a leucine-to-valine substitution at amino acid position 2209 in a specimen of large cell neuroendocrine carcinoma. The mTOR(L2209V) mutant manifested marked transforming potential in a focus formation assay with mouse 3T3 fibroblasts, and it induced the phosphorylation of p70 S6 kinase, S6 ribosomal protein, and eukaryotic translation initiation factor 4E-binding protein 1 in these cells. Examination of additional tumor specimens as well as public and in-house databases of cancer genome mutations identified another 28 independent non-synonymous mutations of mTOR in various cancer types, with 12 of these mutations also showing transforming ability. Most of these oncogenic mutations cluster at the interface between the kinase domain and the FAT (FRAP, ATM, TRRAP) domain in the 3-D structure of mTOR. Transforming mTOR mutants were also found to promote 3T3 cell survival, and their oncogenic activity was sensitive to rapamycin. Our data thus show that mTOR acquires transforming activity through genetic changes in cancer, and they suggest that such tumors may be candidates for molecularly targeted therapy with mTOR inhibitors
Phamacogenomics of Clozapine-Induced Agranulocytosis
Background: Clozapine-induced agranulocytosis (CIA)/clozapine-induced granulocytopenia (CIG) (CIAG) is a life-threatening event for schizophrenic subjects treated with clozapine.
Methods: To examine the genetic factor for CIAG, a genome-wide pharmacogenomic analysis was conducted using 50 subjects with CIAG and 2905 control subjects.
Results: We identified a significant association in the human leukocyte antigen (HLA) region (rs1800625, p = 3.46 × 10−9, odds ratio [OR] = 3.8); therefore, subsequent HLA typing was performed. We detected a significant association of HLA-B*59:01 with CIAG (p = 3.81 × 10−8, OR = 10.7) and confirmed this association by comparing with an independent clozapine-tolerant control group (n = 380, p = 2.97 × 10−5, OR = 6.3). As we observed that the OR of CIA (OR: 9.3~15.8) was approximately double that in CIG (OR: 4.4~7.4), we hypothesized that the CIG subjects were a mixed population of those who potentially would develop CIA and those who would not develop CIA (non-CIA). This hypothesis allowed the proportion of the CIG who were non-CIA to be calculated, enabling us to estimate the positive predictive value of the nonrisk allele on non-CIA in CIG subjects. Assuming this model, we estimated that 1) ~50% of CIG subjects would be non-CIA; and 2) ~60% of the CIG subjects without the risk allele would be non-CIA and therefore not expected to develop CIA.
Conclusions: Our results suggest that HLA-B*59:01 is a risk factor for CIAG in the Japanese population. Furthermore, if our model is true, the results suggest that rechallenging certain CIG subjects with clozapine may not be always contraindicated
The Far-Infrared Surveyor (FIS) for AKARI
The Far-Infrared Surveyor (FIS) is one of two focal plane instruments on the
AKARI satellite. FIS has four photometric bands at 65, 90, 140, and 160 um, and
uses two kinds of array detectors. The FIS arrays and optics are designed to
sweep the sky with high spatial resolution and redundancy. The actual scan
width is more than eight arcmin, and the pixel pitch is matches the diffraction
limit of the telescope. Derived point spread functions (PSFs) from observations
of asteroids are similar to the optical model. Significant excesses, however,
are clearly seen around tails of the PSFs, whose contributions are about 30% of
the total power. All FIS functions are operating well in orbit, and its
performance meets the laboratory characterizations, except for the two longer
wavelength bands, which are not performing as well as characterized.
Furthermore, the FIS has a spectroscopic capability using a Fourier transform
spectrometer (FTS). Because the FTS takes advantage of the optics and detectors
of the photometer, it can simultaneously make a spectral map. This paper
summarizes the in-flight technical and operational performance of the FIS.Comment: 23 pages, 10 figures, and 2 tables. Accepted for publication in the
AKARI special issue of the Publications of the Astronomical Society of Japa
Novel function of HATs and HDACs in homologous recombination through acetylation of human RAD52 at double-strand break sites
The p300 and CBP histone acetyltransferases are recruited to DNA double-strand break (DSB) sites where they induce histone acetylation, thereby influencing the chromatin structure and DNA repair process. Whether p300/CBP at DSB sites also acetylate non-histone proteins, and how their acetylation affects DSB repair, remain unknown. Here we show that p300/CBP acetylate RAD52, a human homologous recombination (HR) DNA repair protein, at DSB sites. Using in vitro acetylated RAD52, we identified 13 potential acetylation sites in RAD52 by a mass spectrometry analysis. An immunofluorescence microscopy analysis revealed that RAD52 acetylation at DSBs sites is counteracted by SIRT2- and SIRT3-mediated deacetylation, and that non-acetylated RAD52 initially accumulates at DSB sites, but dissociates prematurely from them. In the absence of RAD52 acetylation, RAD51, which plays a central role in HR, also dissociates prematurely from DSB sites, and hence HR is impaired. Furthermore, inhibition of ataxia telangiectasia mutated (ATM) protein by siRNA or inhibitor treatment demonstrated that the acetylation of RAD52 at DSB sites is dependent on the ATM protein kinase activity, through the formation of RAD52, p300/CBP, SIRT2, and SIRT3 foci at DSB sites. Our findings clarify the importance of RAD52 acetylation in HR and its underlying mechanism
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