144 research outputs found

    The relative frequency, clinical and laboratory findings of adult glomerulonephritidies in Tehran

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    Background: Renal diseases information is population-based and has great geographic variability. Due to the lack of national renal data registry system, there is no information on the prevalence rate, and clinical and laboratory features of various glomerulonephritidies (GNs) in Iran. Methods: In a retrospective cross sectional study, we analyzed 462 adult renal biopsies in Hashemi Nejad hospital, Tehran, Iran. We determined the prevalence rate and the frequency of different clinical and laboratory findings in patients with different GNs. We also compared our results with the reports from other countries. Results: There were 267(57.8) males and 195(42.2) females. The mean age (± SD) was 33.6 ± 15.7 (range, 13-75) years old. After exclusion of 55 biopsies with pathologies other than GNs and in the remaining 407 biopsies, membranous glomerulopathy (MGN) was the most common GN (23.6), followed by IgAN (13.5), membranoproliferative GN (11.5), systemic lupus nephritis (10.6), focal segmental glomerulosclerosis (10.3), and minimal change disease (9.8). These 6 GNs comprised the majority (79.4) of all GNs. Conclusion: MGN is the most common form of GN, followed by IgAN, MPGN, SLE-GN, FSGS and MCD in adult patients in our study. The multi-center studies with a larger sample size are needed for more comprehensive data in Iranian population

    Attitude of Iranian Nephrologists Toward Living Unrelated Kidney Donation

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    Living unrelated kidney donation (LURD) is increasing worldwide due to the shortage of cadaveric kidneys. In our country an LURD program has been practiced since 1988. This study sought to evaluate the attitude of Iranian nephrologists towards various aspects of the program. Questionnaires including 20 queries were sent to nephrologists. Among 100 randomly selected nephrologists, 50 completed and returned the questionnaires. Forty six (92) and 45 (90) believed that LURD has potential minor short- and long-term complications, respectively. Forty two percent assumed renal failure was a potential complication. Ninety two percent used to inform donors about the complications, all verbally. Thirty four percent and 72 assumed inhalational opium addiction and heroin addiction were contraindications to LURD, respectively. Twenty eight percent and 68 believed that the amount of recipients' gift and the governmental award are not sufficient, respectively. Thirty two percent believed that all compensation should be paid by the government. Sixty six percent believed that donors should be given social advantages, and 26 believed that they should not, in order to not enhance persuasion of nonaltruistic donation. Eighty eight percent claimed that donor follow-up is not regularly done and should be organized. Finally, 30 agreed and 19 disagreed with LURD. We conclude that despite the success of our LURD program in elimination of the transplant waiting list, most Iranian nephrologists believe that there should be some revisions. Verbal information about complications may not be sufficient to help the donors to make a correct decision. We should reconsider the method and amount of financial compensation and organize a regular follow-up program. © 2007 Elsevier Inc. All rights reserved

    Nucleocytoplasmic transport: a thermodynamic mechanism

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    The nuclear pore supports molecular communication between cytoplasm and nucleus in eukaryotic cells. Selective transport of proteins is mediated by soluble receptors, whose regulation by the small GTPase Ran leads to cargo accumulation in, or depletion from the nucleus, i.e., nuclear import or nuclear export. We consider the operation of this transport system by a combined analytical and experimental approach. Provocative predictions of a simple model were tested using cell-free nuclei reconstituted in Xenopus egg extract, a system well suited to quantitative studies. We found that accumulation capacity is limited, so that introduction of one import cargo leads to egress of another. Clearly, the pore per se does not determine transport directionality. Moreover, different cargo reach a similar ratio of nuclear to cytoplasmic concentration in steady-state. The model shows that this ratio should in fact be independent of the receptor-cargo affinity, though kinetics may be strongly influenced. Numerical conservation of the system components highlights a conflict between the observations and the popular concept of transport cycles. We suggest that chemical partitioning provides a framework to understand the capacity to generate concentration gradients by equilibration of the receptor-cargo intermediary.Comment: in press at HFSP Journal, vol 3 16 text pages, 1 table, 4 figures, plus Supplementary Material include

    CUL-2<sup>LRR-1</sup> and UBXN-3 drive replisome disassembly during DNA replication termination and mitosis

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    Replisome disassembly is the final step of DNA replication in eukaryotes, involving the ubiquitylation and CDC48-dependent dissolution of the CMG helicase (CDC45-MCM-GINS). Using Caenorhabditis elegans early embryos and Xenopus laevis egg extracts, we show that the E3 ligase CUL-2(LRR-1) associates with the replisome and drives ubiquitylation and disassembly of CMG, together with the CDC-48 cofactors UFD-1 and NPL-4. Removal of CMG from chromatin in frog egg extracts requires CUL2 neddylation, and our data identify chromatin recruitment of CUL2(LRR1) as a key regulated step during DNA replication termination. Interestingly, however, CMG persists on chromatin until prophase in worms that lack CUL-2(LRR-1), but is then removed by a mitotic pathway that requires the CDC-48 cofactor UBXN-3, orthologous to the human tumour suppressor FAF1. Partial inactivation of lrr-1 and ubxn-3 leads to synthetic lethality, suggesting future approaches by which a deeper understanding of CMG disassembly in metazoa could be exploited therapeutically

    Inhibition of autophagy, lysosome and VCP function impairs stress granule assembly

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    Stress granules (SGs) are mRNA-protein aggregates induced during stress, which accumulate in many neurodegenerative diseases. Previously, the autophagy-lysosome pathway and valosin-containing protein (VCP), key players of the protein quality control (PQC), were shown to regulate SG degradation. This is consistent with the idea that PQC may survey and/or assist SG dynamics. However, despite these observations, it is currently unknown whether the PQC actively participates in SG assembly. Here, we describe that inhibition of autophagy, lysosomes and VCP causes defective SG formation after induction. Silencing the VCP co-factors UFD1L and PLAA, which degrade defective ribosomal products (DRIPs) and 60S ribosomes, also impaired SG assembly. Intriguingly, DRIPs and 60S, which are released from disassembling polysomes and are normally excluded from SGs, were significantly retained within SGs in cells with impaired autophagy, lysosome or VCP function. Our results suggest that deregulated autophagy, lysosomal or VCP activities, which occur in several neurodegenerative (VCP-associated) diseases, may alter SG morphology and composition

    International Society of Nephrology Global Kidney Health Atlas: structures, organization, and services for the management of kidney failure in the Middle East

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    Kidney failure is the permanent impairment of kidney function associated with increased morbidity, hospitalization, and requirement for kidney replacement therapy. A total of 11 countries in the Middle East region (84.6) responded to the survey. The prevalence of chronic kidney disease in the region ranged from 5.2 to 10.6, whereas prevalence of treated kidney failure ranged from 152 to 826 per million population. Overall, the incidence of kidney transplantation was highest in Iran (30.9 per million population) and lowest in Oman and the United Arab Emirates (2.2 and 3.0 per million population, respectively). Long-term hemodialysis services were available in all countries, long-term peritoneal dialysis services were available in 9 (69.2) countries, and transplantation services were available in most countries of the region. Public funding covered the costs of nondialysis chronic kidney disease care in two-thirds of countries, and kidney replacement therapy in nearly all countries. More than half of the countries had dialysis registries; however, national noncommunicable disease strategies were lacking in most countries. The Middle East is a region with high burden of kidney disease and needs cost-effective measures through effective health care funding to be available to improve kidney care in the region. Furthermore, well-designed and sustainable health information systems are needed in the region to address current gaps in kidney care in the region. © 2021 International Society of Nephrolog

    Eukaryotic Cells Producing Ribosomes Deficient in Rpl1 Are Hypersensitive to Defects in the Ubiquitin-Proteasome System

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    It has recently become clear that the misassembly of ribosomes in eukaryotic cells can have deleterious effects that go far beyond a simple shortage of ribosomes. In this work we find that cells deficient in ribosomal protein L1 (Rpl1; Rpl10a in mammals) produce ribosomes lacking Rpl1 that are exported to the cytoplasm and that can be incorporated into polyribosomes. The presence of such defective ribosomes leads to slow growth and appears to render the cells hypersensitive to lesions in the ubiquitin-proteasome system. Several genes that were reasonable candidates for degradation of 60S subunits lacking Rpl1 fail to do so, suggesting that key players in the surveillance of ribosomal subunits remain to be found. Interestingly, in spite of rendering the cells hypersensitive to the proteasome inhibitor MG132, shortage of Rpl1 partially suppresses the stress-invoked temporary repression of ribosome synthesis caused by MG132.United States. National Institutes of Health (GM25532)United States. National Institutes of Health (ARRAGM25532-S1)United States. National Institutes of Health (GM085177)United States. National Institutes of Health (CAI-3330)Natural Sciences and Engineering Research Council of Canada (NSERC

    NeuN/Rbfox3 Nuclear and Cytoplasmic Isoforms Differentially Regulate Alternative Splicing and Nonsense-Mediated Decay of Rbfox2

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    Anti-NeuN (Neuronal Nuclei) is a monoclonal antibody used extensively to specifically detect post-mitotic neurons. Anti-NeuN reactivity is predominantly nuclear; by western it detects multiple bands ranging in molecular weight from 45 kDa to >75 kDa. Expression screening putatively identified R3hdm2 as NeuN; however immunoprecipitation and mass spectrometry of the two major NeuN species at 45–50 kDa identified both as the RNA binding protein Rbfox3 (a member of the Fox family of alternative splicing factors), confirming and extending the identification of the 45 kDa band as Rbfox3 by Kim et al. Mapping of the anti-NeuN reactive epitopes in both R3hdm2 and Rbfox3 reveals a common proline- and glutamine-rich domain that lies at the N-terminus of the Rbfox3 protein. Our data suggests that alternative splicing of the Rbfox3 pre-mRNA itself leads to the production of four protein isoforms that migrate in the 45–50 kDa range, and that one of these splicing choices regulates Rbfox3/NeuN sub-cellular steady-state distribution, through the addition or removal of a short C-terminal extension containing the second half of a bipartite hydrophobic proline-tyrosine nuclear localization signal. Rbfox3 regulates alternative splicing of the Rbfox2 pre-mRNA, producing a message encoding a dominant negative form of the Rbfox2 protein. We show here that nuclear Rbfox3 isoforms can also enhance the inclusion of cryptic exons in the Rbfox2 mRNA, resulting in nonsense-mediated decay of the message, thereby contributing to the negative regulation of Rbfox2 by Rbfox3 through a novel mechanism

    Chemotherapeutic Sensitization of Leptomycin B Resistant Lung Cancer Cells by Pretreatment with Doxorubicin

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    The development of novel targeted therapies has become an important research focus for lung cancer treatment. Our previous study has shown leptomycin B (LMB) significantly inhibited proliferation of lung cancer cells; however, p53 wild type lung cancer cells were resistant to LMB. Therefore, the objective of this study was to develop and evaluate a novel therapeutic strategy to sensitize LMB-resistant lung cancer cells by combining LMB and doxorubicin (DOX). Among the different treatment regimens, pretreatment with DOX (pre-DOX) and subsequent treatment with LMB to A549 cells significantly decreased the 50% inhibitory concentration (IC50) as compared to that of LMB alone (4.4 nM vs. 10.6 nM, P<0.05). Analysis of cell cycle and apoptosis by flow cytometry further confirmed the cytotoxic data. To investigate molecular mechanisms for this drug combination effects, p53 pathways were analyzed by Western blot, and nuclear proteome was evaluated by two dimensional-difference gel electrophoresis (2D-DIGE) and mass spectrometry. In comparison with control groups, the levels of p53, phospho-p53 (ser15), and p21 proteins were significantly increased while phospho-p53 (Thr55) and survivin were significantly decreased after treatments of pre-DOX and LMB (P<0.05). The 2D-DIGE/MS analysis identified that sequestosome 1 (SQSTM1/p62) had a significant increase in pre-DOX and LMB-treated cells (P<0.05). In conclusion, our results suggest that drug-resistant lung cancer cells with p53 wild type could be sensitized to cell death by scheduled combination treatment of DOX and LMB through activating and restoring p53 as well as potentially other signaling pathway(s) involving sequestosome 1
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