299,923 research outputs found
Ha-Dibbur Ha-Ivri
No full textHebrew Speech, a manual for beginners for the study of Hebrew according to the Natural Method). Author: M. Krinsky. Illustrator: H. Goldberg. Publisher: Ha-Or Publishing. . 146 pp. 254 b/w ills. (+1 color chart) + cover b/w ill. primer.Digital imagedigitize
Puromycin aminonucleoside triggers apoptosis in podocytes by inducing endoplasmic reticulum stress
No full textBackground: Puromycin aminonucleoside (PAN) is a known podocytotoxin. PAN-induced nephrosis is a widely used animal model for studying human idiopathic nephrotic syndrome. Abnormal protein accumulation associated with podocyte-specific endoplasmic reticulum (ER) stress damages cells structurally and functionally, which in turn induces apoptosis and severe proteinuria. In the present study, we investigated the effect of PAN on ER stress and apoptosis in podocytes in vitro. Methods: Mouse podocytes were cultured and treated with various concentrations of PAN. ER stress markers were then evaluated by western blotting, and apoptosis was evaluated by fluorescence-activated cell sorting (FACS) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. Results: PAN treatment increased ER stress markers such as activating transcription factor (ATF) 6α and caspase-12 in a dose-dependent manner at 12 and 24 hours, respectively. These markers were reduced by chemical chaperones, such as sodium 4-phenylbutyric acid and tauroursodeoxycholic acid. PAN treatment also increased 78 kD glucose-regulated protein (GRP78)/binding immunoglobulin protein (BiP) at the earlier stage of 12 hours. PAN significantly induced podocyte apoptosis in concentration- and time-dependent manners, as seen using FACS and TUNEL assays. This result was improved by Nox4 siRNA, ATF6 siRNA, and chemical chaperones. LY294002, a PI3-kinase inhibitor, significantly boosted ER stress and apoptosis. PAN-induced ER stress increased oxidative stress and subsequently induced apoptosis, and could be mitigated by inhibition of PI3-kinase signaling. Conclusion: Our findings suggest that PAN induces ER stress in podocytes mainly through the GRP78/BiP, ATF6α, and caspase-12 pathways, which trigger apoptosis via induction of oxidative stress. This stress is mitigated by inhibiting PI3-kinase signaling
Use of axial tomography to follow temporal changes of benthic communities in an unstable sedimentary environment (Baie des Ha! Ha!, Saguenay Fjord)
No full textIn the upper layer of the sediment column, organic matter recycling is greatly influenced by bioturbation. However, there are many physical changes in the nature of the sediment that may disturb benthic communities and create a biogeochemical imbalance. Following a very heavy rainfall between 26 and 29 July 1996, an intense flash flood in the Saguenay Fjord caused discharges of 6 million cubic metres of sediments into Baie des Ha! Ha!. Unstable sediment deposits located at the top of the delta of the Rivie`re des Ha! Ha! were sporadically exported to the deep basin. After this physical disturbance, meiobenthic and macrobenthic organisms progressively re-colonised the sediment column. To determine the impacts of such sedimentary depositions on benthic fauna, two stations, one at the head and one at the mouth of the Baie des Ha! Ha!, have been monitored since 1996. During this survey, we developed a new method for the quantification of biogenic structures using computer axial tomography (CAT-Scan). Benthic fauna analysis showed that the two stations were characterised by different temporal changes in the benthic dynamics according to their geographic location. Using CAT-Scan analysis of sediment cores, we were able to characterise the stability of the sediment column for the two stations in 1999 and 2000. Scan results suggest that colonisation processes were closely linked with the stability of the sediment column. Erosion and redeposition of surficial sediments caused a succession in the formation of biogenic structures. These variations were characterised for the first time using CAT-Scan, which is a nondestructive, rapid, and precise method. Tomographic analysis showed the importance of the production and destruction rates of biogenic structures and the sedimentation rate for the preservation of burrows and potentially reactive components. This study finally demonstrated that each erosional event could be followed by a rapid formation of biogenic structures, allowing the re-oxidation of old deposits
Yesode ḥokhmat ha-ṭevaʻ ha-kelalit : ṿe-gam yediʻot ḥaroshet ha-maʻaśeh ṿi-yediʻot madaʻim shonim /
No full textVols 2-4 have title: Otsar ha-ḥokhmah ṿeha-madaʻ, kolel yesode ḥokhmat ha-ṭevaʻ ha-kelalit. Published by ha-Almanah ṿeha-aḥim Rom.1. Sefer ha-menuḥah ṿeha-tenuʻah -- 2. Sefer ha-Harkavah ṿeha-hafradah -- 3. Sefer Toldot ha-esh ṿeha-mayim -- [4] Sefer Even ha-shoʾevet.Mode of access: Internet
Redox-sensitivity and site-specificity of S- and N- denitrosation in proteins
No full textBackground
S-nitrosation – the formation of S-nitrosothiols (RSNOs) at cysteine residues in proteins – is a posttranslational modification involved in signal transduction and nitric oxide (NO) transport. Recent studies would also suggest the formation of N-nitrosamines (RNNOs) in proteins in vivo, although their biological significance remains obscure. In this study, we characterized a redox-based mechanism by which N-nitroso-tryptophan residues in proteins may be denitrosated.
Methodology/Principal Findings
The denitrosation of N-acetyl-nitroso Trp (NANT) by glutathione (GSH) required molecular oxygen and was inhibited by superoxide dismutase (SOD). Transnitrosation to form S-nitrosoglutathione (GSNO) was observed only in the absence of oxygen or presence of SOD. Protein denitrosation by GSH was studied using a set of mutant recombinant human serum albumin (HSA). Trp-214 and Cys-37 were the only two residues nitrosated by NO under aerobic conditions. Nitroso-Trp-214 in HSA was insensitive to denitrosation by GSH or ascorbate while denitrosation at Cys-37 was evident in the presence of GSH but not ascorbate. GSH-dependent denitrosation of Trp-214 was restored in a peptide fragment of helix II containing Trp-214. Finally, incubation of cell lysates with NANT revealed a pattern of protein nitrosation distinct from that observed with GSNO.
Conclusions
We propose that the denitrosation of nitrosated Trp by GSH occurs through homolytic cleavage of nitroso Trp to NO and a Trp aminyl radical, driven by the formation of superoxide derived from the oxidation of GSH to GSSG. Overall, the accessibility of Trp residues to redox-active biomolecules determines the stability of protein-associated nitroso species such that in the case of HSA, N-nitroso-Trp-214 is insensitive to denitrosation by low-molecular-weight antioxidants. Moreover, RNNOs can generate free NO and transfer their NO moiety in an oxygen-dependent fashion, albeit site-specificities appear to differ markedly from that of RSNOs
On the lifts of F(2K S; S)structure satisfying F2KS FS 0; (F 6 0; K 1 1; S 1 1) on cotangent and tangent bundle
No full textThis paper consists of two main sections. In the first part, we find the integrability conditions bycalculating Nijenhuis tensors of the horizontal lifts of F(2K S; S)structure Satisfying F2KS FS 0. Later, we get the results of Tachibana operators applied to vector and covector fieldsaccording to the horizontal lifts of F(2K S; S)structure in cotangent bundle T(Mn). Finally,we have studied the purity conditions of Sasakian metric with respect to the horizontal lifts of thestructure. In the second part, all results obtained in the first section were obtained according to thecomplete and horizontal lifts of F(2K S; S)structure in tangent bundle T(Mn)
Milhemet ha-niglah veha-nistar be-safrutenu : mi-yemot ʻolam u-shenot dor va-dor ʻad ha-yom ha-zeh /
No full textRomanized record."Nidpas be-Ner ha-maʻaravi, shanah 2."Mode of access: Internet
Author Ha Jin at Kalamazoo College
No full textPhotographer unknown.Author Ha Jin's book "Waiting" was selected for the 2002 Summer Common Reading program at Kalamazoo College. The author visited campus that year as part of the program
Classification and phylogenetic analysis of Acetobacter sp. HA by 5 S ribosomal RNA sequencing
No full textThe strain Acetobacter sp. HA was isolated from Korean traditional fermented vinegar and defined as a new acidophilic Acetobacter species [Chun, H. S.，and Kim, S. J. (1993) J. MicrobioL Biotech, 5, 108-114]. Ribosomal 5 S RNA was isolated from Acetobacter sp. HA and sequenced by the direct chemical methods. Acetobacter sp. HA contained RNAs belonging to the 121 nucleotide type. The sequence of the cytoplasmic 5 S rRNA from Acetobacter sp. HA was compared to the known 5 S rRNA sequences of 11 strains of the genus Acetobacter and two strains of the Gluconobacter. Based on KnUC values, the Acetobacter sp. HA was phyloge-netically closer to Acetobacter aceti than to any other strains of Acetobacter or Gluconobacter,open
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