162 results on '"Belkin N"'
Search Results
2. Downwind gas condensate volatiles affect phytoplankton communities
- Author
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Rahav, E., Belkin, N., Velasquez, X., Sisma-Ventura, G., Guy-Haim, T., Paytan, A., and Rubin-Blum, M.
- Published
- 2023
- Full Text
- View/download PDF
3. Iterative Exploration, Design and Evaluation of Support for Query Reformulation in Interactive Information Retrieval.
- Author
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Belkin, N. J., Cool, C., Kelly, D., Lin, S. -J, Park, S. Y., Perez-Carballo, J., and Sikora, C.
- Abstract
Reports on the progressive investigation of techniques for supporting interactive query reformulation in the TREC (Text Retrieval Conference) Interactive Track. Highlights include methods of term suggestion; interface design to support different system functionalities; an overview of each year's TREC investigation; and relevance to the development and evaluation of interactive information retrieval systems. (Author/LRW)
- Published
- 2001
4. A gown is a gown is a gown: or is it?
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Belkin, N. L.
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- 2003
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5. If it is reusable, why not reuse it?
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Belkin, N. L.
- Published
- 2002
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6. Selecting protective apparel for the degree of exposure anticipated
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Belkin, N. L.
- Published
- 2000
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7. ASK for Information Retrieval: Part II. Results of a Design Study.
- Author
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Belkin, N. J.
- Abstract
Reports on methodology and results of design study for an interactive information retrieval system funded by British Library Research and Development Department which will determine structural representations of anomalous states of knowledge (ASKs) underlying information needs. Problem statements, abstracts used, and text analysis are highlighted. References and appendices are provided. (EJS)
- Published
- 1982
8. ASK For Information Retrieval: Part I. Background and Theory.
- Author
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Belkin, N. J.
- Abstract
Discusses background and theory underlying a design study for an interactive information retrieval system funded by the British Library Research and Development Department which will determine structural representations of anomalous states of knowledge (ASKs) underlying information needs. References are cited. (EJS)
- Published
- 1982
9. Strength of toroidal shells and elbows loaded internally under pressure
- Author
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Monoshkov, A. N., Pustin, I. A., Serikov, S. V., Belkin, N. M., and Krasulin, I. D.
- Published
- 1980
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10. Improvement in the calculation of the profile for a horn-shaped core
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Belkin, N. M. and Serikov, S. V.
- Published
- 1978
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11. Efficiency of sharply bent elbows loaded by an internal pressure
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Pustin, I. A., Serikov, S. V., and Belkin, N. M.
- Published
- 1979
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12. M-CSF and GM-CSF Regulation of STAT5 Activation and DNA Binding in Myeloid Cell Differentiation is Disrupted in Nonobese Diabetic Mice.
- Author
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Rumore-Maton, B., Elf, J., Belkin, N., Stutevoss, B., Seydel, F., Garrigan, E., and Litherland, S. A.
- Subjects
CHEMICAL reactions ,BONE marrow cells ,GENETIC regulation ,KILLER cells ,IMMUNE system - Abstract
Defects in macrophage colony-stimulating factor (M-CSF) signaling disrupt myeloid cell differentiation in nonobese diabetic (NOD) mice, blocking myeloid maturation into tolerogenic antigen-presenting cells (APCs). In the absence of M-CSF signaling, NOD myeloid cells have abnormally high granulocyte macrophage colony-stimulating factor (GM-CSF) expression, and as a result, persistent activation of signal transducer/activator of transcription 5 (STAT5). Persistent STAT5 phosphorylation found in NOD macrophages is not affected by inhibiting GM-CSF. However, STAT5 phosphorylation in NOD bone marrow cells is diminished if GM-CSF signaling is blocked. Moreover, if M-CSF signaling is inhibited, GM-CSF stimulation in vitro can promote STAT5 phosphorylation in nonautoimmune C57BL/6 mouse bone marrow cultures to levels seen in the NOD. These findings suggest that excessive GM-CSF production in the NOD bone marrow may interfere with the temporal sequence of GM-CSF and M-CSF signaling needed to mediate normal STAT5 function in myeloid cell differentiation gene regulation. [ABSTRACT FROM AUTHOR]
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- 2008
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13. Relapse in chronic schizophrenics following abrupt withdrawal of tranquillizing medication.
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Prien, R F, Cole, J O, and Belkin, N F
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DRUG therapy for schizophrenia ,CHLORPROMAZINE ,CHRONIC diseases ,CLINICAL trials ,COMPARATIVE studies ,DRUG withdrawal symptoms ,RESEARCH methodology ,MEDICAL cooperation ,PLACEBOS ,PSYCHIATRIC hospitals ,RESEARCH ,TRANQUILIZING drugs ,EVALUATION research ,RANDOMIZED controlled trials - Published
- 1969
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14. Characteristics of a polynomial representation of atmospheric phase distortions.
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Belkin, N. D., Belozerov, A. E., and Matyukhin, V. F.
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- 1985
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15. MicroRNA-181b regulates NF-κB-mediated vascular inflammation.
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Sun X, Icli B, Wara AK, Belkin N, He S, Kobzik L, Hunninghake GM, Vera MP, Blackwell TS, Baron RM, Feinberg MW, MICU Registry, Sun, Xinghui, Icli, Basak, Wara, Akm Khyrul, Belkin, Nathan, He, Shaolin, Kobzik, Lester, Hunninghake, Gary M, and Vera, Miguel Pinilla
- Abstract
EC activation and dysfunction have been linked to a variety of vascular inflammatory disease states. The function of microRNAs (miRNAs) in vascular EC activation and inflammation remains poorly understood. Herein, we report that microRNA-181b (miR-181b) serves as a potent regulator of downstream NF-κB signaling in the vascular endothelium by targeting importin-α3, a protein that is required for nuclear translocation of NF-κB. Overexpression of miR-181b inhibited importin-α3 expression and an enriched set of NF-κB-responsive genes such as adhesion molecules VCAM-1 and E-selectin in ECs in vitro and in vivo. In addition, treatment of mice with proinflammatory stimuli reduced miR-181b expression. Rescue of miR-181b levels by systemic administration of miR-181b "mimics" reduced downstream NF-κB signaling and leukocyte influx in the vascular endothelium and decreased lung injury and mortality in endotoxemic mice. In contrast, miR-181b inhibition exacerbated endotoxin-induced NF-κB activity, leukocyte influx, and lung injury. Finally, we observed that critically ill patients with sepsis had reduced levels of miR-181b compared with control intensive care unit (ICU) subjects. Collectively, these findings demonstrate that miR-181b regulates NF-κB-mediated EC activation and vascular inflammation in response to proinflammatory stimuli and that rescue of miR-181b expression could provide a new target for antiinflammatory therapy and critical illness. [ABSTRACT FROM AUTHOR]
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- 2012
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16. GM-CSF induces STAT5 binding at epigenetic regulatory sites within the Csf2 promoter of non-obese diabetic (NOD) mouse myeloid cells
- Author
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Seydel, F., Garrigan, E., Stutevoss, B., Belkin, N., Makadia, B., Carter, J., Shi, J.-D., Davoodi-Semiromi, A., McDuffie, M., and Litherland, S.A.
- Subjects
- *
GENETICS of diabetes , *GRANULOCYTE-macrophage colony-stimulating factor , *GENE expression , *CELLULAR signal transduction , *PEOPLE with diabetes , *PROTEIN binding , *GENETIC polymorphisms , *LABORATORY mice - Abstract
Abstract: Myeloid cells from non-obese diabetic (NOD) mouse and human type 1 diabetic (T1D) patients overexpress granulocyte–macrophage colony stimulation factor (GM-CSF). This overproduction prolongs the activation of signal transduction and activator of transcription 5 (STAT5) proteins, involved in GM-CSF-induced control of myeloid cell gene expression. We found that GM-CSF can regulate the binding of STAT5 on the promoter of its own gene, Csf2, within regions previously identified as sites of chromatin epigenetic modification important to the regulation of GM-CSF during myeloid differentiation and inflammation. We found multiple sequence polymorphisms within NOD mouse chromosome 11 Idd4.3 diabetes susceptibility region that alter STAT5 GAS binding sequences within the Csf2 promoter. STAT5 binding at these sites in vivo is increased significantly in GM-CSF-stimulated-bone marrow cells and in unactivated, high GM-CSF-producing macrophages from NOD mice as compared to non-autoimmune C57BL/6 mouse myeloid cells. Thus, GM-CSF overproduction by NOD myeloid cells may be perpetuating a positive epigenetic regulatory feedback on its own gene expression through its induction of STAT5 binding to its promoter. These findings suggest that aberrant STAT5 binding at epigenetic regulatory sites may contribute directly to immunopathology through cytokine-induced gene expression dysregulation that can derail myeloid differentiation and increase inflammatory responsiveness. [Copyright &y& Elsevier]
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- 2008
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17. Subclavian to carotid artery bypass for a case of ocular ischemic syndrome.
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Sadri BS, Low DW, Jackson OA, Jackson BM, and Belkin N
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- Humans, Male, Middle Aged, Treatment Outcome, Stents, Carotid Artery, Internal surgery, Carotid Artery, Internal diagnostic imaging, Subclavian Artery surgery, Subclavian Artery diagnostic imaging, Syndrome, Vascular Calcification diagnostic imaging, Vascular Calcification surgery, Vascular Calcification complications, Carotid Stenosis diagnostic imaging, Carotid Stenosis surgery, Carotid Stenosis complications, Ischemia surgery, Ischemia diagnostic imaging, Ischemia etiology, Ischemia physiopathology
- Abstract
Background: Ocular Ischemic Syndrome (OIS) is a rare, vision threatening condition associated with severe carotid artery disease. There are few cases of OIS reported in the literature., Methods: We present the case of a 54-year-old male with history of multiple previous carotid interventions including a right carotid stent, who presented with right-sided OIS., Results: CTA and angiogram showed a severe calcific plaque causing restenosis of the right carotid stent, with a patent right internal carotid artery (ICA) in the very distal neck. The right common carotid artery (CCA) was patent but diseased with ulcerated plaque extending proximally to below the level of the clavicle. The left CCA was chronically occluded from its origin all the way to the bifurcation. Given our patient's surgical history, the imperative to revascularize the ipsilateral carotid, and a diffusely diseased ipsilateral CCA, he was successfully treated with an ipsilateral subclavian to internal carotid bypass., Conclusion: There is paucity of data regarding the best approach for carotid revascularization in OIS. This case report discusses our unique perioperative decision making as well as relevant literature., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2024
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18. Diversity in the utilization of different molecular classes of dissolved organic matter by heterotrophic marine bacteria.
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Givati S, Forchielli E, Aharonovich D, Barak N, Weissberg O, Belkin N, Rahav E, Segrè D, and Sher D
- Subjects
- Mediterranean Sea, Microbiota, Amino Acids metabolism, Organic Chemicals metabolism, Seawater microbiology, Heterotrophic Processes, Bacteria classification, Bacteria metabolism, Bacteria genetics, Bacteria isolation & purification
- Abstract
Heterotrophic marine bacteria utilize and recycle dissolved organic matter (DOM), impacting biogeochemical cycles. It is currently unclear to what extent distinct DOM components can be used by different heterotrophic clades. Here, we ask how a natural microbial community from the Eastern Mediterranean Sea (EMS) responds to different molecular classes of DOM (peptides, amino acids, amino sugars, disaccharides, monosaccharides, and organic acids) comprising much of the biomass of living organisms. Bulk bacterial activity increased after 24 h for all treatments relative to the control, while glucose and ATP uptake decreased or remained unchanged. Moreover, while the per-cell uptake rate of glucose and ATP decreased, that of Leucin significantly increased for amino acids, reflecting their importance as common metabolic currencies in the marine environment. Pseudoalteromonadaceae dominated the peptides treatment, while different Vibrionaceae strains became dominant in response to amino acids and amino sugars. Marinomonadaceae grew well on organic acids, and Alteromonadaseae on disaccharides. A comparison with a recent laboratory-based study reveals similar peptide preferences for Pseudoalteromonadaceae , while Alteromonadaceae , for example, grew well in the lab on many substrates but dominated in seawater samples only when disaccharides were added. We further demonstrate a potential correlation between the genetic capacity for degrading amino sugars and the dominance of specific clades in these treatments. These results highlight the diversity in DOM utilization among heterotrophic bacteria and complexities in the response of natural communities., Importance: A major goal of microbial ecology is to predict the dynamics of natural communities based on the identity of the organisms, their physiological traits, and their genomes. Our results show that several clades of heterotrophic bacteria each grow in response to one or more specific classes of organic matter. For some clades, but not others, growth in a complex community is similar to that of isolated strains in laboratory monoculture. Additionally, by measuring how the entire community responds to various classes of organic matter, we show that these results are ecologically relevant, and propose that some of these resources are utilized through common uptake pathways. Tracing the path between different resources to the specific microbes that utilize them, and identifying commonalities and differences between different natural communities and between them and lab cultures, is an important step toward understanding microbial community dynamics and predicting how communities will respond to perturbations., Competing Interests: The authors declare no conflict of interest.
- Published
- 2024
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19. Active microbial communities facilitate carbon turnover in brine pools found in the deep Southeastern Mediterranean Sea.
- Author
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Rubin-Blum M, Makovsky Y, Rahav E, Belkin N, Antler G, Sisma-Ventura G, and Herut B
- Subjects
- Mediterranean Sea, Carbon metabolism, Salts, Methane metabolism, Archaea genetics, Archaea metabolism, Seawater microbiology, Bacteria metabolism, Bacteria genetics, Bacteria classification, Microbiota
- Abstract
Discharge of gas-rich brines fuels productive chemosynthetic ecosystems in the deep sea. In these salty, methanic and sulfidic brines, microbial communities adapt to specific niches along the physicochemical gradients. However, the molecular mechanisms that underpin these adaptations are not fully known. Using metagenomics, we investigated the dense (∼10
6 cell ml-1 ) microbial communities that occupy small deep-sea brine pools found in the Southeastern Mediterranean Sea (1150 m water depth, ∼22 °C, ∼60 PSU salinity, sulfide, methane, ammonia reaching millimolar levels, and oxygen usually depleted), reaching high productivity rates of 685 μg C L-1 d-1 ex-situ. We curated 266 metagenome-assembled genomes of bacteria and archaea from the several pools and adjacent sediment-water interface, highlighting the dominance of a single Sulfurimonas, which likely fuels its autotrophy using sulfide oxidation or inorganic sulfur disproportionation. This lineage may be dominant in its niche due to genome streamlining, limiting its metabolic repertoire, particularly by using a single variant of sulfide: quinone oxidoreductase. These primary producers co-exist with ANME-2c archaea that catalyze the anaerobic oxidation of methane. Other lineages can degrade the necromass aerobically (Halomonas and Alcanivorax), or anaerobically through fermentation of macromolecules (e.g., Caldatribacteriota, Bipolaricaulia, Chloroflexota, etc). These low-abundance organisms likely support the autotrophs, providing energy-rich H2, and vital organics such as vitamin B12., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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20. The Framing Effect of Digital Textual Messages on Uptake Rates of Medical Checkups: Field Study.
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Maltz A, Rashkovich S, Sarid A, Cohen Y, Landau T, Saifer E, Amorai Belkin N, and Alcalay T
- Subjects
- Humans, Health Facilities, Internet, Middle Aged, Aged, Aortic Aneurysm, Abdominal, Papillomavirus Infections, Text Messaging
- Abstract
Background: Health care authorities often use text messages to enhance compliance with medical recommendations. The effectiveness of different message framings has been studied extensively over the past 3 decades. Recently, health care providers have begun using digital media platforms to disseminate health-related messages., Objective: This study aimed to examine the effectiveness of some of the most widely used message framings on the uptake rates of medical checkups., Methods: This study used a large-scale digital outreach campaign conducted by Maccabi Healthcare Services (MHS) during 2020-2021, involving a total of 113,048 participants. MHS members aged 50-74 years were invited to take their recommended medical actions from the following list: human papillomavirus (HPV), mammography, abdominal aortic aneurysm, fecal occult blood test (FOBT), and pneumococcal vaccination. Each member was randomly assigned to receive 1 of 6 message framings: control (neutrally framed; n=20,959, 18.5%), gains (benefits of compliance; n=20,393, 18%), losses (negative consequences of noncompliance; n=15,165, 13.4%), recommendation (a recommendation by an authoritative figure, in this context by a physician; n=20,584, 18.2%), implementation intentions (linking potential outcomes to future reactions; n=20,701, 18.3%), and empowerment (emphasizing personal responsibility for maintaining good health; n=15,246, 13.5%). The time frames for measuring a successful intervention were 14 days for scheduling screenings (ie, HPV, mammography, or abdominal aortic aneurysm), 30 days for performing the FOBT, and 60 days for receiving pneumococcal vaccination. We also examined the effectiveness of media channels (text message or email) on uptake rates and whether the subject-line length is correlated with message-opening rates., Results: No significant effect of message framing on uptake rates of medical checkups was observed. The rates of appointments for screening ranged from 12.9% to 14.1% across treatments. Based on a chi-square test, there was no evidence to reject the null hypothesis that these compliance rates are independent of the treatments (P=.35). The uptake rates for the FOBT and pneumococcal vaccination ranged from 23.3% to 23.8% across treatments, and we could not reject the hypothesis that they are independent of the treatments (P=.88). We also found that emails are more effective than text messages (P<.001) and that the subject-line length is negatively correlated with message-opening rates., Conclusions: No evidence was found for an effect of the 5 message framings on uptake rates of medical checkups. To enhance compliance rates, public health officials may consider alternative framings. Furthermore, media channels and the subject-line length should be given careful consideration in the planning stages of health care campaigns., Trial Registration: AEA RCT Registry AEARCTR-0006317; https://www.socialscienceregistry.org/trials/6317/history/201365., (©Amnon Maltz, Stella Rashkovich, Adi Sarid, Yafit Cohen, Tamar Landau, Elina Saifer, Neta Amorai Belkin, Tamar Alcalay. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 06.03.2024.)
- Published
- 2024
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21. Shared ancestry of algal symbiosis and chloroplast sequestration in foraminifera.
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Pinko D, Abramovich S, Rahav E, Belkin N, Rubin-Blum M, Kucera M, Morard R, Holzmann M, and Abdu U
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- Phylogeny, Chloroplasts genetics, Symbiosis genetics, Foraminifera genetics
- Abstract
Foraminifera are unicellular organisms that established the most diverse algal symbioses in the marine realm. Endosymbiosis repeatedly evolved in several lineages, while some engaged in the sequestration of chloroplasts, known as kleptoplasty. So far, kleptoplasty has been documented exclusively in the rotaliid clade. Here, we report the discovery of kleptoplasty in the species Hauerina diversa that belongs to the miliolid clade. The existence of kleptoplasty in the two main clades suggests that it is more widespread than previously documented. We observed chloroplasts in clustered structures within the foraminiferal cytoplasm and confirmed their functionality. Phylogenetic analysis of 18 S ribosomal RNA gene sequences showed that H. diversa branches next to symbiont-bearing Alveolinidae. This finding represents evidence of of a relationship between kleptoplastic and symbiotic foraminifera.. Analysis of ribosomal genes and metagenomics revealed that alveolinid symbionts and kleptoplasts belong to the same clade, which suggests a common ancestry.
- Published
- 2023
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22. Socioeconomic characteristics of those with peripheral artery disease in the chronic renal insufficiency cohort.
- Author
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Stoecker JB, Cohen JB, Belkin N, Chen JC, Townsend RR, Xie D, Feldman HI, and Wang GJ
- Subjects
- Adult, Humans, Male, Female, Middle Aged, Cohort Studies, Prospective Studies, Risk Factors, Ankle Brachial Index adverse effects, Socioeconomic Factors, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Peripheral Arterial Disease diagnosis, Peripheral Arterial Disease epidemiology, Peripheral Arterial Disease therapy, Renal Insufficiency, Chronic diagnosis, Renal Insufficiency, Chronic epidemiology, Renal Insufficiency, Chronic therapy
- Abstract
Background: The association between socioeconomic factors and peripheral arterial disease (PAD) has not been as well characterized as other cardiovascular conditions. We sought to define how annual income and education level are associated with PAD in a well-characterized diverse set of adults with chronic kidney disease (CKD)., Methods: The Chronic Renal Insufficiency Cohort Study (CRIC) is a multi-center, prospective cohort study designed to examine risk factors for progression of CKD and cardiovascular disease. Demographic, income, and education-level data, as well as clinical data including ankle-brachial index (ABI) were collected at baseline. Annual income was categorized as < $25,000, $25,000-50,000, $50,000-100,000, or above $100,000; educational level was categorized as some high school, high school graduate, some college, or college graduate. Participants with missing income data or incompressible ABI (>1.4) were excluded from initial analysis. Logistic regression was used to estimate the association of income and/or education level with PAD, defined as an enrollment ABI of <0.90, history of PAD, or history of PAD intervention., Results: A total of 4122 were included, mean age of participants was 59.5 years, 56% were male, and 44% were Black. There were 763 CRIC participants with PAD at study enrollment (18.5%). In the final multivariable logistic regression model, Black race (OR = 1.3, 95% CI 1.1-1.6, p = 0.004) and level of annual household income remained independently associated with PAD at the time of enrollment (income <$25,000 OR = 1.9, 95% CI 1.3-2.8, p < 0.001; income $25,000-50,000 OR = 1.6, 95% CI 1.1-2.3, p = 0.011; income $50,000-100,000 OR = 1.2, 95% CI 0.9-1.8, p = 0.246), relative to a baseline annual income of >$100,000 (overall p -value <0.001). Decreasing level of educational attainment was not independently associated with increased PAD at enrollment, but lower level of educational attainment was associated with increased PAD when income data was not adjusted for ( p = 0.001). Interestingly, Black race (OR = 0.7, 95% CI 0.6-0.8, p < 0.001), female gender (OR = 0.8, 95% CI 0.7-0.9, p = 0.007), and income <$25,000 (OR = 0.7, 95% CI 0.5-0.9, p = 0.008) were significantly associated with decreased statin use even after controlling for cardiovascular conditions., Conclusions: In this prospectively followed CKD cohort, lower annual household income and Black race were significantly associated with increased PAD at study enrollment. In contrast, educational level was not associated with PAD when adjusted for patient income data. Black race, female gender, and low income were independently associated with decreased statin use, populations which could be targets of future public health programs.
- Published
- 2023
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23. The Differential Impact of Medicaid Expansion on Disparities in Outcomes Following Peripheral Vascular Intervention.
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Ramadan OI, Santos T, Stoecker JB, Belkin N, Jackson BM, Schneider DB, Rice J, and Wang GJ
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- Adult, United States, Humans, Aged, Retrospective Studies, Treatment Outcome, Risk Factors, Time Factors, Insurance Coverage, Healthcare Disparities, Medicaid, Peripheral Arterial Disease diagnosis, Peripheral Arterial Disease surgery
- Abstract
Background: Peripheral artery disease (PAD) disproportionately affects nonwhite, Hispanic/Latino, and low socioeconomic status patients, who are less likely to have insurance and routine healthcare visits. Medicaid expansion (ME) has improved insurance rates and access to care, potentially benefitting these patients. We sought to assess the impact of ME on disparities in outcomes after peripheral vascular intervention (PVI) for PAD., Methods: A retrospective analysis of prospectively-collected Vascular Quality Initiative PVI procedures between 2011 and 2019 was conducted. The sample was restricted to first-record procedures in adults under the age 65 in states that expanded Medicaid on January 1, 2014 (ME group) or had not expanded before January 1, 2019 (non-expansion [NE] group). ME and NE groups were compared between pre-expansion (2011-2013) and post-expansion (2014- 2019) time periods to assess baseline demographic and operative differences. We used difference-in-differences multivariable logistic regression adjusted for patient factors and clinical center and year fixed effects. Our primary outcome was 1-year major amputation. Secondary outcomes included trends in presentation, 30-day mortality, 1-year mortality, and 1-year primary and secondary patency. Outcomes were stratified by race and ethnicity., Results: We examined 34,313 PVI procedures, including 20,378 with follow-up data. Rates of Medicaid insurance increased post-expansion in ME and NE states (ME 16.7% to 23.0%, P < 0.001; NE 10.0% to 11.9%, P = 0.013) while rates of self-pay decreased in ME states only (ME 4.6% to 1.8%, P < 0.001; NE 8.1% to 8.4%, P = 0.620). Adjusted difference-in-differences analysis revealed lower odds of urgent/emergent PVI among all patients and all nonwhite patients in ME states post-expansion compared to NE states (all: odds ratio [OR] 0.53 [95% confidence interval 0.33-0.87], P = 0.011; nonwhite: OR 0.41 [0.19-0.88], P = 0.023). No differences were observed for 1-year major amputation (OR 0.70 [0.43-1.14], P = 0.152), primary patency (OR 0.93 [0.63-1.38], P = 0.726), or secondary patency (OR 1.29 [0.69-2.41], P = 0.431). Odds of 1-year mortality were higher in ME states post-expansion compared to NE states (OR 2.50 [1.07-5.87], P = 0.035), although 30-day mortality was not different (OR 2.04 [0.60-6.90], P = 0.253). Notably, odds of 1-year major amputation among Hispanic/Latino patients decreased in ME states post-expansion compared to NE states (OR 0.11 [0.01-0.86], P = 0.036)., Conclusions: ME was associated with lower odds of 1-year major amputation among Hispanic/Latino patients who underwent PVI for PAD. ME was also associated with lower odds of urgent/emergent procedures among patients overall and nonwhite patients specifically. However, 1-year mortality increased in the overall cohort. Further study is needed to corroborate our findings that ME may have benefits for certain underserved populations with PAD., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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24. Discharge of Polyphosphonate-Based Antiscalants via Desalination Brine: Impact on Seabed Nutrient Flux and Microbial Activity.
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Sisma-Ventura G, Belkin N, Rubin-Blum M, Jacobson Y, Hauzer H, Bar-Zeev E, and Rahav E
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- Nutrients, Organophosphorus Compounds, Salts, Seawater, Water
- Abstract
Desalination brine is a hypersaline byproduct that contains various operational chemicals such as polyphosphonate-based antiscalants. Brine often sinks and flows over the seabed by density currents; therefore, it may affect sediment-water nutrient fluxes and thus microbial activity. We quantified these parameters in brine plumes around two large-scale desalination facilities located in the P-limited Southeastern Mediterranean Sea. The benthic nutrient fluxes and microbial activity were determined using ex-situ core benthocosms, to which we added brine from the dispersion area in excess salinities of ∼3% and 5% above natural levels. A higher influx of dissolved organic phosphorus (∼6-fold) and an efflux of dissolved organic carbon (∼1.7-fold) were measured in the brine-amended cores relative to the controls. This was accompanied by increased oxygen consumption (15%) and increased microbial activity (∼1.5-6.5-fold). Field observations support the results from experimental manipulations, yielding ∼4.5-fold higher microbial activity rates around the brine plume compared to uninfluenced locations. Our results imply that desalination brine can alter sedimentary processes affecting benthic nutrients inventories. Moreover, we show that brine acts as a vector of anthropogenic P, stimulating microbial activity in the sediment-water interface.
- Published
- 2022
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25. Jellyfish swarm impair the pretreatment efficiency and membrane performance of seawater reverse osmosis desalination.
- Author
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Rahav E, Belkin N, Nnebuo O, Sisma-Ventura G, Guy-Haim T, Sharon-Gojman R, Geisler E, and Bar-Zeev E
- Subjects
- Filtration, Membranes, Artificial, Osmosis, Seawater, Water Purification methods
- Abstract
Circumstantial evidence has suggested that jellyfish swarms impair the operation of seawater reverse osmosis desalination facilities. However, only limited information is currently available on the pretreatment efficiency of jellyfish and their effects on reverse osmosis (RO) membrane performance. Here, we have comprehensively tested the pretreatment efficiency of a dual-media gravity filter and cartridge micro-filtration following the addition of jellyfish into the feedwater. Concurrently, the fouling propensity and performance of the RO membranes were examined. We show that jellyfish demise resulted in seawater eutrophication that triggered a significant increase in bacterial biomass (∼50-fold), activity (∼7-fold), and release of transparent exopolymer particles (∼5-fold), peaking three days after the addition of jellyfish into the feedwater. In parallel, a significant reduction in permeate water flux was recorded (∼10%) while trans-membrane pressure sharply increased (15%), reaching the operation pressure limit of our system (75 bar) after five days. At the conclusion of the experiments, the membrane surface was heavily covered by large chunks of organic-rich material and multilayered biofilms. Our results provide a holistic view on the operational challenges of seawater reverse osmosis (SWRO) desalination triggered by jellyfish swarms in coastal areas. Following the above, it can be inferred that freshwater production will likely be halted three days after drawing the jellyfish into the pretreatment system. Outcomes from these results may lead to the development of science-based operational protocols to cope with growing occurrence of jellyfish swarms around the intake of SWRO desalination facilities worldwide., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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26. A miRNA cassette reprograms smooth muscle cells into endothelial cells.
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McCoy MG, Pérez-Cremades D, Belkin N, Peng W, Zhang B, Chen J, Sachan M, Wara AKMK, Zhuang R, Cheng HS, and Feinberg MW
- Subjects
- Animals, Cell Differentiation, Endothelial Cells metabolism, Gene Expression Profiling, Humans, Mice, Myocytes, Smooth Muscle metabolism, MicroRNAs metabolism
- Abstract
Cellular reprogramming through targeting microRNAs (miRNAs) holds promise for regenerative therapy due to their profound regulatory effects in proliferation, differentiation, and function. We hypothesized that transdifferentiation of vascular smooth muscle cells (SMCs) into endothelial cells (ECs) using a miRNA cassette may provide a novel approach for use in vascular disease states associated with endothelial injury or dysfunction. miRNA profiling of SMCs and ECs and iterative combinatorial miRNA transfections of human coronary SMCs revealed a 4-miRNA cassette consisting of miR-143-3p and miR-145-5p inhibitors and miR-146a-5p and miR-181b-5p mimics that efficiently produced induced endothelial cells (iECs). Transcriptome profiling, protein expression, and functional studies demonstrated that iECs exhibit high similarity to ECs. Injected iECs restored blood flow recovery even faster than conventional ECs in a murine hindlimb ischemia model. This study demonstrates that a 4-miRNA cassette is sufficient to reprogram SMCs into ECs and shows promise as a novel regenerative strategy for endothelial repair., (© 2022 Federation of American Societies for Experimental Biology.)
- Published
- 2022
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27. Diversity, activity, and abundance of benthic microbes in the Southeastern Mediterranean Sea.
- Author
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Rubin-Blum M, Sisma-Ventura G, Yudkovski Y, Belkin N, Kanari M, Herut B, and Rahav E
- Subjects
- Geologic Sediments microbiology, Mediterranean Sea, RNA, Ribosomal, 16S genetics, Archaea genetics, Bacteria genetics
- Abstract
Benthic microbes are key organisms in the oligotrophic Southeastern Mediterranean Sea (SEMS), yet their abundance, activity, and diversity in this rapidly changing basin are not fully understood. We investigated the prokaryotic and microfungal communities throughout years 2018-2020 at 27 stations (6-1900 m water depths, down to 20 cm below the sediment surface), in two transects with distinct downslope transport regimes, and along the eutrophic coastline. We estimated microbial abundance with flow cytometry, secondary production as leucine assimilation, and sequenced marker genes (the 16S rRNA and internal transcribed spacer) to assess diversity indices. The highest abundance (0.21 × 108 cells gr-1 sediment) was estimated at slope stations where we assumed substantial transport rates and found an accumulation of organic carbon. Secondary production was the highest nearshore (12 ± 4 ng C gr-1 h-1), and markedly declined offshore (0.5 ± 0.9 ng C gr-1 h-1). Populations of archaea (dominant Nitrososphaeria and Nanoarchaeia) and diverse bacteria were stable over three years, and taxonomic composition was dictated mainly by depth gradients. Saprotrophic and pathotrophic microfungi Ascomycota (70% ± 23%) and Basidiomycota (16% ± 18%) were prevalent, whereas parasitic chytrids were abundant nearshore. Our results highlight the role of downslope transport, which enriched the typical deep-sea communities with anaerobic lineages, in shaping microbial populations near the continental slope., (© The Author(s) 2022. Published by Oxford University Press on behalf of FEMS.)
- Published
- 2022
- Full Text
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28. The Association Between Socioeconomic Factors and Incident Peripheral Artery Disease in the Chronic Renal Insufficiency Cohort (CRIC).
- Author
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Stoecker JB, Cohen JB, Belkin N, Chen JC, Townsend RR, Xie D, Feldman HI, and Wang GJ
- Subjects
- Adult, Black or African American, Aged, Ankle Brachial Index, Female, Humans, Incidence, Income, Male, Middle Aged, Peripheral Arterial Disease epidemiology, Prospective Studies, Risk Factors, Sex Factors, Peripheral Arterial Disease etiology, Renal Insufficiency, Chronic complications, Socioeconomic Factors
- Abstract
Background: The association between socioeconomic factors and development of peripheral artery disease (PAD) has not been as well characterized compared to other cardiovascular diseases. We sought to define how annual income, sex, race, and education level are associated with newly diagnosed PAD in a well-characterized, diverse set of adults with CKD., Methods: The Chronic Renal Insufficiency Cohort Study (CRIC) is a multicenter, prospective cohort study designed to examine risk factors for progression of CKD and cardiovascular disease. Demographic and clinical data including ankle brachial index (ABI) and interventions were collected at baseline, as well as yearly during follow-up visits. Annual income was categorized as: <$25,000, $25,000-50,000, $50,000-100,000, or above $100,000. We excluded those with pre-existing PAD, defined as enrollment ABI of <0.9 or >1.4, or missing income data. Cox proportional hazards regression was used to estimate the risk for incident PAD during CRIC enrollment, defined as a drop in ABI to <0.90 or a confirmed PAD intervention, including revascularization or amputation., Results: A total of 3,313 patients met inclusion criteria, the mean age was 58.7 years, 56% were male, and 42% were Black. Over a median follow-up of 10.1 years, 639 participants (19%) were newly diagnosed with PAD. After adjusting for cardiovascular risk factors, all lower levels of annual household income were associated with increased incidence of PAD (income <$25,000 HR 1.7, 95% CI 1.1-2.4, P = 0.008; income $25,000-50,000 HR 1.5, 95% CI 1.1-2.3, P = 0.009; income $50,000-100,000 HR 1.6, 95% CI 1.2-2.4, P = 0.004), relative to a baseline annual income of >$100,000 (overall P-value = 0.02). In the multivariable model, there was no association between education level and PAD incidence (P = 0.80). Black race (HR 1.2, 95% CI 1.0-1.5, P = 0.023) and female sex (HR 1.7, 95% CI 1.4-2.0, P < 0.001) were independently associated with PAD incidence. Multiple imputation analysis provided similar results., Conclusions: In the CRIC, a multi-center cohort of prospectively followed CKD patients undergoing yearly CVD surveillance, lower annual household income, female sex, and Black race were significantly associated with the PAD incidence. In contrast, level of education was not independently associated with incident PAD., (Copyright © 2021. Published by Elsevier Inc.)
- Published
- 2022
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29. Impacts of sewage outbursts on seawater reverse osmosis desalination.
- Author
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Bar-Zeev E, Belkin N, Speter A, Reich T, Geisler E, and Rahav E
- Subjects
- Membranes, Artificial, Osmosis, Seawater, Sewage, Water Purification
- Abstract
Sewage outbursts affect coastal environments as seawater is enriched with nutrients, organic matter and microbes, thus can potentially impair seawater reverse osmosis (SWRO) desalination. In this study, we evaluated how municipal sewage outbursts affect SWRO desalination in a pilot-scale system. To this end, feedwater characteristics (i.e., coastal water), the removal efficiency of organic foulants by a dual-media gravity filter, and cartridge micro-filtration were determined daily for 12 days. Permeate water flux was maintained constant during the study, while trans-membrane pressure (TMP) was automatically adjusted and continuously monitored. The results indicate that sewage outbursts caused an immediate (∼1 d) buildup of phyto/bacterioplankton biomass (up to 10-fold), and enhanced activity (maximal 30-fold) followed by an increase in transparent exopolymer particle (TEP) concentrations. After sewage addition, algal biomass was significantly removed by the pretreatment system (72-90%), while a considerable fraction of the bacterial biomass (42-65%) and TEP (53-65%) passed these procedures. The result was a negative impact on the desalination performance reflected by a significant increase (> 10%) in RO-TMP 7.5 d after the sewage addition. Our results indicate on a direct link between sewage outbursts, pretreatment efficiency, and SWRO desalination. Nevertheless, these findings can lead to new avenues for the development of science-based operational protocols to minimize the deleterious effects of abrupt sewage outbursts on SWRO desalination., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
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30. Dust-borne microbes affect Ulva ohnoi's growth and physiological state.
- Author
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Krupnik N, Asis DT, Belkin N, Rubin-Blum M, Israel Á, Paytan A, Meiri D, Herut B, and Rahav E
- Subjects
- Dust, Ecosystem, Mediterranean Sea, Seaweed, Ulva
- Abstract
The marine macroalgae Ulva sp. is considered an ecosystem engineer in rocky shores of temperate waters worldwide. Ulva sp. harbors a rich diversity of associated microbial epibionts, which are known to affect the algae's typical morphological development and 'health'. We examined the interaction between airborne microbes derived from atmospheric aerosols and Ulva ohnoi growth and physiological state. Specifically, we measured U. ohnoi growth rates and photosynthetic efficiency (Fv/Fm), alongside its microbial epibionts abundance, activity and diversity following dust (containing nutrients and airborne microorganisms) or UV-treated dust (only nutrients) amendments to filtered seawater. Parallel incubations with epibionts-free U. ohnoi (treated with antibiotics that removed the algae epibionts) were also tested to specifically examine if dust-borne microbes can replenish the epibiont community of U. ohnoi. We show that viable airborne microbes can restore U. ohnoi natural microbial epibionts communities, thereby keeping the seaweed alive and 'healthy'. These results suggest that microbes delivered through atmospheric aerosols can affect epiphyte biodiversity in marine flora, especially in areas subjected to high annual atmospheric dust deposition such as the Mediterranean Sea., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS.)
- Published
- 2021
- Full Text
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31. Effects of dual antiplatelet therapy on graft patency after lower extremity bypass.
- Author
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Belkin N, Stoecker JB, Jackson BM, Damrauer SM, Glaser J, Kalapatapu V, Golden MA, and Wang GJ
- Subjects
- Aged, Aged, 80 and over, Blood Vessel Prosthesis Implantation adverse effects, Databases, Factual, Female, Graft Occlusion, Vascular diagnostic imaging, Graft Occlusion, Vascular etiology, Graft Occlusion, Vascular physiopathology, Humans, Male, Middle Aged, Peripheral Arterial Disease diagnostic imaging, Peripheral Arterial Disease physiopathology, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Dual Anti-Platelet Therapy adverse effects, Graft Occlusion, Vascular prevention & control, Lower Extremity blood supply, Peripheral Arterial Disease therapy, Vascular Patency drug effects
- Abstract
Objective: Current guidelines recommend single-agent antiplatelet therapy for patients with symptomatic peripheral artery disease and consideration of dual antiplatelet therapy (DAPT) after surgical revascularization. The objective of this study was both to explore prescribing patterns of single antiplatelet therapy vs DAPT after lower extremity bypass surgery and to investigate the effects of antiplatelet therapy on bypass graft patency., Methods: A retrospective analysis of prospectively collected nonemergent infrainguinal lower extremity bypass operations entered in the national Vascular Quality Initiative (2003-2018) with captured long-term follow-up was performed. Patients discharged on aspirin monotherapy or DAPT were identified. Linear regression investigated temporal trends in antiplatelet use. Multivariable Cox regression investigated predictors of primary, primary assisted, and secondary patency., Results: Of the 13,020 patients investigated, 52.2% were discharged on aspirin monotherapy and 47.8% on DAPT. The proportion of patients discharged on DAPT increased from 10.6% in 2003 to 60.6% in 2018 (P < .001). The DAPT cohort was younger, had higher rates of medical (hypertension, diabetes, congestive heart failure, chronic obstructive pulmonary disease) and atherosclerotic (coronary artery disease, prior coronary artery bypass graft or percutaneous coronary intervention, prior lower extremity intervention) comorbidities, and had higher risk bypass procedures (more distal targets, prior inflow bypass procedure, prosthetic conduit use). Multivariable Cox regression analysis did not show any difference between the DAPT and aspirin cohorts in primary patency (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.88-1.10; P = .78), primary assisted patency (HR, 0.93; 95% CI, 0.80-1.07; P = .30), or secondary patency (HR, 0.88; 95% CI, 0.74-1.06; P = .18). On subgroup analysis based on bypass conduit, DAPT was found to have a protective effect on patency only in the prosthetic bypass cohort (primary patency: HR, 0.81 [95% CI, 0.66-1.00; P = .05]; primary assisted patency: HR, 0.74 [95% CI, 0.58-0.94; P = .01]; and secondary patency: HR, 0.60 [95% CI, 0.44-0.82; P < .001]). No patency differences were observed on adjusted subgroup analysis for the other bypass conduits., Conclusions: A significant and increasing proportion of patients are discharged on DAPT after lower extremity bypass revascularization. These patients represent a higher risk cohort with more medical comorbidities and higher risk bypass features. After controlling for these differences, DAPT therapy had no beneficial effect on overall bypass graft patency or major adverse limb events. However, on subgroup analysis, DAPT was associated with improved bypass graft patency in patients receiving prosthetic bypass conduits. Further study is warranted to investigate optimal duration of DAPT therapy and its possible bleeding complications in prosthetic bypass patients., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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32. The use of intravascular ultrasound in the treatment of type B aortic dissection with thoracic endovascular aneurysm repair is associated with improved long-term survival.
- Author
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Belkin N, Jackson BM, Foley PJ, Damrauer SM, Kalapatapu V, Golden MA, Fairman RM, and Wang GJ
- Subjects
- Aortic Dissection diagnostic imaging, Aortic Dissection mortality, Aortic Aneurysm, Thoracic diagnostic imaging, Aortic Aneurysm, Thoracic mortality, Databases, Factual, Female, Humans, Male, Middle Aged, Postoperative Complications mortality, Postoperative Complications therapy, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Aortic Dissection surgery, Aortic Aneurysm, Thoracic surgery, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation mortality, Endovascular Procedures adverse effects, Endovascular Procedures mortality, Ultrasonography, Interventional adverse effects, Ultrasonography, Interventional mortality
- Abstract
Objective: Intravascular ultrasound (IVUS) examination is an integral technique used for treating type B aortic dissection (TBAD) because it verifies true lumen access. The purpose of this study was to evaluate the use of IVUS, to determine factors associated with IVUS use, and to investigate the potential survival benefit associated with IVUS in the treatment of TBAD., Methods: A retrospective review of TEVARs performed for TBAD in the national Vascular Quality Initiative was performed from January 2010 to August 2018. Data collected included demographics, intraoperative and postoperative variables, and long-term mortality. Multivariable logistic regression evaluated variables associated with IVUS the use and mortality, and Cox regression was performed for adjusted survival analysis., Results: In this study of 2686 patients, the average age was 60.4 years, 69.3% were male, and IVUS examination was used in 74.6% of cases. IVUS patients were younger (60.0 years vs 61.7 years; P = .004), more often male (72.1% vs 61.3%; P < .001), exhibited less coronary disease, but had higher preoperative creatinine (1.27 ± 0.89 mg/dL vs 1.14 ± 0.68 mg/dL; P < .001) and were more often treated in the acute setting (55.2% vs 49.7%; P = .03). Interestingly, there were no differences in contrast use (117.4 ± 77.6 mL vs 123.0 ± 81.90.1 mL; P = .11) or fluoroscopy time (20.3 ± 16.5 minutes vs 19.0 ± 22.1 minutes; P = .10). However, IVUS cases had a greater number of devices implanted (1.84 vs 1.65; P < .001), higher rates of Zone 0 to 2 proximal seal (43.9% vs 30.7%; P < .001), higher rates of distal seal zones beyond the diaphragm (53.9% vs 37.4%; P = .001), and larger proximal and distal graft diameters, with no differences in postoperative renal function. IVUS patients notably also had higher rates of follow-up imaging (61.3% vs 54.8%; P = .003), larger maximum aortic diameters at follow-up, and more reinterventions over time. The number of aortic devices (odds ratio [OR] 1.56; 95% confidence interval [CI], 1.24-1.97; P < .001), malperfusion indication (OR, 1.68; 95% CI, 1.17-2.42; P = .005) and distal seal zone beyond the diaphragm (OR, 1.64; 95% CI, 1.30-2.07; P < .001) were independently associated with IVUS use, whereas female gender showed a trend towards less IVUS use (OR, 0.79; 95% CI, 0.62-1.01; P = .063). Even after controlling for age, preoperative comorbidities, and postoperative complications like spinal cord ischemia, IVUS was associated with a 61% decrease in the odds of mortality (OR, 0.39; 95% CI, 0.20-0.78; P = .008), with a clear survival advantage shown in adjusted survival curves., Conclusions: IVUS examination was used in the majority of TBAD, although not universally. IVUS examination was used more often in acute TBAD and more complex aortic repairs, and was independently associated with improved long-term survival. Further study is needed to understand these patterns., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2020
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33. Phytoplankton response to N-rich well amelioration brines: A mesocosm study from the southeastern Mediterranean Sea.
- Author
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Raveh O, Angel DL, Astrahan P, Belkin N, Bar-Zeev E, and Rahav E
- Subjects
- Biodiversity, Biomass, Chlorophyll A metabolism, Cyanobacteria physiology, Ecosystem, Eukaryota physiology, Eutrophication, Mediterranean Sea, Phytoplankton genetics, RNA, Ribosomal, 18S, Seasons, Nitrogen metabolism, Phytoplankton physiology, Seawater chemistry
- Abstract
Human-induced eutrophication of coastal water may be a major threat to aquatic life. Here, we investigated the effects of N-rich well amelioration brines (WAB) on coastal phytoplankton population's habitat in the surface oligotrophic waters of the southeastern Mediterranean Sea (SEM). To this end, we added WAB (2 concentrations) to mesocosms (1-m
3 bags) to surface SEM water during summer and winter, where changes in phytoplankton biomass, activity and diversity was monitored daily for 8 days. Our results demonstrate that WAB addition triggered a phytoplankton bloom, resulting in elevated algal biomass (maximal +780%), increased primary production rates (maximal +675%) and a decrease in eukaryotic algal α-diversity (ca. -20%). Among the species that bloomed following WAB amendments, we found the potentially toxic dinoflagellate Karlodinium venificum. This study adds valuable perspective to the effect of nutrients discharged into nutrient limited SEM coastal waters, and in particular of N-derived WAB., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
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34. Trends in inferior vena cava filter placement and retrieval at a tertiary care institution.
- Author
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Belkin N, Jackson BM, Foley PJ, Damrauer SM, Kalapatapu V, Golden MA, Fairman RM, and Wang GJ
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Philadelphia, Prosthesis Implantation adverse effects, Registries, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Device Removal trends, Practice Patterns, Physicians' trends, Prosthesis Implantation instrumentation, Prosthesis Implantation trends, Tertiary Care Centers trends, Vena Cava Filters trends
- Abstract
Objective: The aim of this study was to examine practice patterns of inferior vena cava (IVC) filter insertion and retrieval at a tertiary care institution., Methods: A retrospective review of all IVC filter procedures performed at the University of Pennsylvania and entered into the Penn cohort of the Vascular Quality Initiative registry between January 2013 and September 2017 was performed. Data collected included demographics, venous thromboembolism risk factors, indications for filter placement, and presence and timing of retrieval. Trend analysis and multivariable logistic regression were performed to evaluate factors associated with failure to retrieve the filter., Results: During the study period, 627 IVC filters were inserted. The mean age was 52.8 ± 16.9 years, and 49.3% were male; 39.2% were placed for a major indication, whereas 58.1% were placed for prophylaxis. There was a significant decline in overall frequency of filter placement during the period observed, with a 33% decrease from 2015 to 2016 and a 26% decrease from 2016 to 2017 (P < .001), with an overall retrieval rate of 44.9%. In contrast, there was a corresponding increase in filter retrieval, with a 20% increase in 2015 and a 68% increase in 2016 (P = .02). In evaluating trends separated by indication, there was a significant decline in prophylactic filter placement (P < .001) and a trend toward an increase in retrieval of prophylactic filters (P = .09). Whereas there was not a significant change in number of filter insertions for major indication (P = .06), filter retrievals for major indication filters increased (P = .01). Multivariable regression analysis revealed that longer time to follow-up (odds ratio [OR], 1.08; P < .001) and discharge to rehabilitation facility (OR, 6.14; P < .001) were predictive of failure to retrieve the filter. In contrast, filter placement at a later date within our study period (OR, 0.90; P < .001) and prophylactic indication for filter placement (OR, 0.36; P < .001) were protective from filter nonretrieval., Conclusions: These results show both a decline in overall IVC filter placement and an increase in overall IVC filter retrieval at our institution. These trends are predominantly due to a decrease in prophylactic filter placement as well as an overall increase in filter retrieval. Further study should be dedicated to increasing the retrieval rate in this population of patients., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
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35. Length of Stay after Thoracic Endovascular Aortic Repair Depends on Indication and Acuity.
- Author
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Belkin N, Jackson BM, Foley PJ, Damrauer SM, Kalapatapu V, Golden MA, Fairman RM, Kelz RR, and Wang GJ
- Subjects
- Aged, Aged, 80 and over, Aortic Dissection diagnostic imaging, Aorta, Thoracic diagnostic imaging, Aortic Aneurysm, Thoracic diagnostic imaging, Databases, Factual, Female, Health Status, Humans, Male, Middle Aged, Quality Indicators, Health Care, Retrospective Studies, Risk Factors, Time Factors, Treatment Outcome, United States, Aortic Dissection surgery, Aorta, Thoracic surgery, Aortic Aneurysm, Thoracic surgery, Blood Vessel Prosthesis Implantation adverse effects, Endovascular Procedures adverse effects, Length of Stay, Patient Acuity
- Abstract
Background: Length of stay (LOS) is a commonly used metric to optimize value in medical care. Although pathways have been developed for some procedures in vascular surgery to reduce LOS, they do not yet exist for thoracic endovascular aortic repair (TEVAR). The purpose of this study is to identify and define the risk factors for prolonged LOS in patients undergoing TEVAR to facilitate pathway development., Methods: We included TEVAR patients in the National Surgical Quality Improvement Program database from 2005 to 2015. Prolonged LOS was defined as LOS > 75th percentile of the overall cohort (11 days). Because initial analysis revealed the distinct clinical differences between dissection and aneurysm patients, further analysis was stratified by aortic pathology. Student's t-test and Chi-square tests were used to compare demographic and perioperative variables between dissection and aneurysm patients, respectively. Multivariable logistic regression was used to evaluate the predictors for prolonged LOS., Results: A total of 3,021 patients underwent TEVAR, with 858 patients (28.4%) undergoing TEVAR for dissection and 2,163 (71.6%) undergoing TEVAR for aneurysm. An initial analysis with logistic regression identified dissection indication (odds ratio [OR], 2.87; 95% confidence interval [CI], 1.1-7.3) as an independent predictor of prolonged LOS. Further analysis for prolonged LOS was subsequently performed separating dissection and aneurysm patients. Aneurysm patients were older (71.2 ± 11.7 vs. 63.1 ± 13.6 years, P < 0.001), more often Caucasian (76.8% vs. 61.8%, P < 0.001), and had more medical comorbidities (chronic obstructive pulmonary disease, cardiac history, diabetes, peripheral vascular disease, transient ischemic attack [TIA], P < 0.001). In contrast, dissection patients had higher American Society of Anesthesiology (ASA) classification score (58.5% had >3 ASA vs. 45.5%, P < 0.001), longer hospitalizations (10.2 ± 9.3 vs. 8.5 ± 10.4 days, P < 0.001), were more likely to have been transferred from another hospital or emergency room (58.4% vs. 48.3%, P < 0.001), and were more often emergent (32.4% vs. 15.4%, P < 0.001). In dissection patients, ASA classification score (OR, 1.49; 95% CI, 1.1-2.1) and dialysis (OR, 1.98; 95% CI, 1.0-3.9) were independent predictors for prolonged LOS. In aneurysm patients, dependent functional status (OR, 2.03; 95% CI, 1.4-2.8), diabetes (OR, 1.75; 95% CI, 1.1-2.8), cardiac history (OR, 1.37; 95% CI, 1.0-1.9), emergency status (OR, 1.98; 95% CI, 1.4-2.8), and dialysis (OR, 2.08; 95% CI, 1.2-3.7) predicted prolonged LOS. Postoperative complications including stroke/TIA; failure to wean from ventilator, sepsis, and pneumonia; and need for reoperation similarly increased LOS in both dissection and aneurysm patients., Conclusions: Dissection and aneurysm patients undergoing TEVAR are comprised of different patient populations, with dissection patients more often enduring prolonged hospitalizations. In contrast, TEVAR performed for nonemergent aneurysm repair had the shortest LOS. These data support the development of separate pathways defined by indication and acuity for patients undergoing TEVAR., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2019
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36. Benefit from decline: the primary transcriptome of Alteromonas macleodii str. Te101 during Trichodesmium demise.
- Author
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Hou S, López-Pérez M, Pfreundt U, Belkin N, Stüber K, Huettel B, Reinhardt R, Berman-Frank I, Rodriguez-Valera F, and Hess WR
- Subjects
- Alteromonas growth & development, Alteromonas metabolism, Bacterial Proteins genetics, Microbial Interactions, RNA, Small Untranslated metabolism, Salinity, Transcription Initiation Site, Trichodesmium genetics, Alteromonas genetics, Transcriptome, Trichodesmium growth & development
- Abstract
Interactions between co-existing microorganisms deeply affect the physiology of the involved organisms and, ultimately, the function of the ecosystem as a whole. Copiotrophic Alteromonas are marine gammaproteobacteria that thrive during the late stages of phytoplankton blooms in the marine environment and in laboratory co-cultures with cyanobacteria such as Trichodesmium. The response of this heterotroph to the sometimes rapid and transient changes in nutrient supply when the phototroph crashes is not well understood. Here, we isolated and sequenced the strain Alteromonas macleodii str. Te101 from a laboratory culture of Trichodesmium erythraeum IMS101, yielding a chromosome of 4.63 Mb and a single plasmid of 237 kb. Increasing salinities to ≥43 ppt inhibited the growth of Trichodesmium but stimulated growth of the associated Alteromonas. We characterized the transcriptomic responses of both microorganisms and identified the complement of active transcriptional start sites in Alteromonas at single-nucleotide resolution. In replicate cultures, a similar set of genes became activated in Alteromonas when growth rates of Trichodesmium declined and mortality was high. The parallel activation of fliA, rpoS and of flagellar assembly and growth-related genes indicated that Alteromonas might have increased cell motility, growth, and multiple biosynthetic activities. Genes with the highest expression in the data set were three small RNAs (Aln1a-c) that were identified as analogs of the small RNAs CsrB-C in E. coli or RsmX-Z in pathogenic bacteria. Together with the carbon storage protein A (CsrA) homolog Te101_05290, these RNAs likely control the expression of numerous genes in responding to changes in the environment.
- Published
- 2018
- Full Text
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37. Peripheral Arterial Disease Genetics: Progress to Date and Challenges Ahead.
- Author
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Belkin N and Damrauer SM
- Subjects
- Evidence-Based Medicine, Gene Expression Profiling, Gene-Environment Interaction, Humans, Peripheral Arterial Disease epidemiology, Peripheral Arterial Disease physiopathology, Polymorphism, Single Nucleotide, Epistasis, Genetic, Genetic Predisposition to Disease, Genome-Wide Association Study, Peripheral Arterial Disease genetics
- Abstract
Purpose of Review: In this paper, we review the progress made thus far in research related to the genetics of peripheral arterial disease (PAD) by detailing efforts to date in heritability, linkage analyses, and candidate gene studies. We further summarize more contemporary genome-wide association studies (GWAS) and epigenetic studies of PAD. Finally, we review current challenges and future avenues of advanced research in PAD genetics including whole genome sequencing studies., Recent Findings: Studies have estimated the heritability of PAD to be moderate, though the contribution to this heritability that is independent of traditional cardiovascular risk factors remains unclear. Recent efforts have identified SNPs associated with PAD in GWAS analyses, but these have yet to be replicated in independent studies. Much remains to be discovered in the field of PAD genetics. An improved understanding of the genetic foundation for PAD will allow for earlier diagnosis of disease and a more complete pathophysiological understanding of the mechanisms of the disease leading to novel therapeutic interventions. Future avenues for success will likely arise from very large-scale GWAS, whole genome sequencing, and epigenetic studies involving very well-characterized cohorts.
- Published
- 2017
- Full Text
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38. Morbidity Associated with Diverting Loop Ileostomies: Weighing Diversion in Rectosigmoid Resection.
- Author
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Belkin N, Bordeianou LG, Shellito PC, and Hawkins AT
- Subjects
- Female, Humans, Male, Middle Aged, Morbidity, Prospective Studies, Colorectal Neoplasms surgery, Ileostomy adverse effects, Ileostomy methods, Postoperative Complications epidemiology, Postoperative Complications etiology, Rectal Neoplasms surgery, Sigmoid Neoplasms surgery
- Abstract
Anterior resection with primary anastomosis is the procedure of choice for patients with rectosigmoid cancers with good sphincter function. Surgeons may perform an associated diverting loop ileostomy (DLI) to minimize the likelihood and/or the severity of an anastomotic leak. To examine the morbidity of DLIs, we performed a review of a prospectively maintained database. Participants included all patients at the Massachusetts General Hospital who underwent anterior resection from January 2013 to July 2015 for rectosigmoid cancers and who subsequently underwent adjuvant chemotherapy. The primary outcome was time to start of adjuvant chemotherapy. Secondary outcomes included length of hospitalization, perioperative complications, and 60-day postoperative complications. Inclusion criteria were met in 57 patients and DLI was performed in 21 (37%). The DLI group had higher estimated blood loss (431.7 vs 192.1 mL, P = 0.03) and a longer operation time (3.7 vs 2.3 hours, P = 0.0007). The DLI group took over a week longer to start adjuvant chemotherapy than the non-DLI group (median time to chemo: 43 vs 34 days, P = 0.002). Postoperatively, DLI was associated with a longer hospitalization (6.7 vs 3.1 days, P = 0.0003), more perioperative complications (57.1% vs 13.9%, P = 0.0006), and more 60-day readmissions or emergency department visits (38.1% vs 5.6%, P = 0.002). Ostomies are associated with appreciable morbidity. In turn, they do not eliminate postoperative complications. Surgeons should closely consider ostomy morbidity in rectosigmoid resection and institute a proactive approach toward identification and prevention of complications.
- Published
- 2017
39. The effect of coagulants and antiscalants discharged with seawater desalination brines on coastal microbial communities: A laboratory and in situ study from the southeastern Mediterranean.
- Author
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Belkin N, Rahav E, Elifantz H, Kress N, and Berman-Frank I
- Subjects
- Food Chain, Seasons, Salinity, Seawater chemistry
- Abstract
Desalination outflows frequently discharge brine containing coagulants and antiscalants (e.g. Iron-hydroxides and polyphosphonates) to the coastal environment. Here we examined changes in composition and productivity of natural microbial coastal communities in experimental mesocosms treated with either iron-hydroxide (Fe), polyphosphonate (Pn), or a combination of high salinities with both chemicals (All). Within 2 h of addition Fe already altered the microbial community composition, enhanced the bacterial production (BP) and cell specific production (BP/BA), and decreased primary production. Addition of Pn, relieved phosphorus stress as demonstrated by the immediate (within 2 h) and significant reduction in the ecto-enzyme alkaline phosphatase activity (APA). Synergistic effects were observed in the All treatment, reflected by increased production of both primary and bacterial producers as P-stress was relieved. After 10 days of incubation, the microbial community composition changed significantly only in the All treatment. The Fe-only treatment caused a significant decline in autotrophic biomass and in the assimilation number (AN), while in both the Pn and the All treatments the BP/BA increased with the added P. We also examined the microbial community responses in a natural impacted environment at the Ashkelon seawater desalination plant brine discharge site during summer and winter. The community composition differed in elevated-salinity compared with non-impacted stations with higher AN and bacterial efficiencies (BP/BA) measured in summer in the elevated-salinity stations. The seasonal differences in responses may reflect both biotic (i.e. initial community composition) and abiotic factors (currents and residence time of salinity gradients). Our results emphasize that desalination brine discharges that include chemicals such as iron-hydroxide and polyphosphonates can induce physiological and compositional changes in the microbial community. With the expansion of desalination facilities worldwide such shifts in composition and function of the microbial communities may destabilize and change local aquatic food webs and should thus be monitored., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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40. Clinical platform for understanding the relationship between joint contact mechanics and articular cartilage changes after meniscal surgery.
- Author
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Maher SA, Wang H, Koff MF, Belkin N, Potter HG, and Rodeo SA
- Subjects
- Adolescent, Adult, Feasibility Studies, Female, Humans, Male, Outcome Assessment, Health Care methods, Pilot Projects, Young Adult, Cartilage, Articular physiology, Magnetic Resonance Imaging methods, Menisci, Tibial diagnostic imaging, Menisci, Tibial physiology, Menisci, Tibial transplantation
- Abstract
Injury to the meniscus of the knee has been implicated as a significant risk factor for the subsequent development of osteoarthritis, but the mechanisms of joint degeneration are unclear. Our objective was to develop a clinically applicable methodology to evaluate the relationship of joint contact mechanics at the time of surgery to biological changes of articular cartilage as a function of time following surgery. A series of pre-, intra-, and post-operative protocols were developed which utilized electronic sensors for the direct measurement of contact mechanics, and advanced imaging to assess cartilage health. The tests were applied to a pilot cohort of young active patients undergoing meniscus allograft transplantation. Our study demonstrated significant variability across patients in terms of contact area and peak contact stress, both before and after transplantation. Nonetheless, the majority of patients exhibited decreased peak contact stress and increased contact area after graft implantation. MR scans at 3-6 months showed decreased T1ρ values in tibial articular cartilage, suggesting an increase in proteoglycan content or concomitant decrease in water content. Prolongation of T2 values was found primarily within the central, cartilage-cartilage contact region of the tibial plateau suggested disruption of the collagen network. Minimal differences were found in cartilage thickness over the short time frame of this preliminary study. With longer clinical follow-up, our platform of clinical tests can be used to better understand the patient-specific mechanical factors that are related to increased risk of OA after meniscus injury and surgery. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:600-611, 2017., (© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)
- Published
- 2017
- Full Text
- View/download PDF
41. Trimethylated homoserine functions as the major compatible solute in the globally significant oceanic cyanobacterium Trichodesmium.
- Author
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Pade N, Michalik D, Ruth W, Belkin N, Hess WR, Berman-Frank I, and Hagemann M
- Subjects
- Carbon-13 Magnetic Resonance Spectroscopy, Methylation, Proton Magnetic Resonance Spectroscopy, Homoserine analogs & derivatives, Homoserine metabolism, Salt Tolerance, Trichodesmium metabolism
- Abstract
The oceanic N
2 -fixing cyanobacterium Trichodesmium spp. form extensive surface blooms and contribute significantly to marine carbon and nitrogen cycles in the oligotrophic subtropical and tropical oceans. Trichodesmium grows in salinities from 27 to 43 parts per thousand (ppt), yet its salt acclimation strategy remains enigmatic because the genome of Trichodesmium erythraeum strain IMS101 lacks all genes for the biosynthesis of any known compatible solute. Using NMR and liquid chromatography coupled to mass spectroscopy, we identified the main compatible solute in T. erythraeum strain IMS101 as the quaternary ammonium compound N,N,N-trimethyl homoserine (or homoserine betaine) and elucidated its biosynthetic pathway. The identification of this compatible solute explains how Trichodesmium spp. can thrive in the marine system at varying salinities and provides further insight into the diversity of microbial salt acclimation., Competing Interests: The authors declare no conflict of interest.- Published
- 2016
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42. MicroRNA-181b Improves Glucose Homeostasis and Insulin Sensitivity by Regulating Endothelial Function in White Adipose Tissue.
- Author
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Sun X, Lin J, Zhang Y, Kang S, Belkin N, Wara AK, Icli B, Hamburg NM, Li D, and Feinberg MW
- Subjects
- Animals, Cells, Cultured, Diet, High-Fat adverse effects, Human Umbilical Vein Endothelial Cells, Humans, Male, Mice, Mice, Inbred C57BL, Mice, Obese, Adipose Tissue, White metabolism, Blood Glucose metabolism, Endothelial Cells metabolism, Homeostasis physiology, Insulin Resistance physiology, MicroRNAs biosynthesis
- Abstract
Rationale: The pathogenesis of insulin resistance involves dysregulated gene expression and function in multiple cell types, including endothelial cells (ECs). Post-transcriptional mechanisms such as microRNA-mediated regulation of gene expression could affect insulin action by modulating EC function., Objective: To determine whether microRNA-181b (miR-181b) affects the pathogenesis of insulin resistance by regulating EC function in white adipose tissue during obesity., Methods and Results: MiR-181b expression was reduced in adipose tissue ECs of obese mice, and rescue of miR-181b expression improved glucose homeostasis and insulin sensitivity. Systemic intravenous delivery of miR-181b robustly accumulated in adipose tissue ECs, enhanced insulin-mediated Akt phosphorylation at Ser473, and reduced endothelial dysfunction, an effect that shifted macrophage polarization toward an M2 anti-inflammatory phenotype in epididymal white adipose tissue. These effects were associated with increased endothelial nitric oxide synthase and FoxO1 phosphorylation as well as nitric oxide activity in epididymal white adipose tissue. In contrast, miR-181b did not affect insulin-stimulated Akt phosphorylation in liver and skeletal muscle. Bioinformatics and gene profiling approaches revealed that Pleckstrin homology domain leucine-rich repeat protein phosphatase, a phosphatase that dephosphorylates Akt at Ser473, is a novel target of miR-181b. Knockdown of Pleckstrin homology domain leucine-rich repeat protein phosphatase increased Akt phosphorylation at Ser473 in ECs, and phenocopied miR-181b's effects on glucose homeostasis, insulin sensitivity, and inflammation of epididymal white adipose tissue in vivo. Finally, ECs from diabetic subjects exhibited increased Pleckstrin homology domain leucine-rich repeat protein phosphatase expression., Conclusions: Our data underscore the importance of adipose tissue EC function in controlling the development of insulin resistance. Delivery of miR-181b or Pleckstrin homology domain leucine-rich repeat protein phosphatase inhibitors may represent a new therapeutic approach to ameliorate insulin resistance by improving adipose tissue endothelial Akt-endothelial nitric oxide synthase-nitric oxide signaling., (© 2016 American Heart Association, Inc.)
- Published
- 2016
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43. Enhanced salinities, as a proxy of seawater desalination discharges, impact coastal microbial communities of the eastern Mediterranean Sea.
- Author
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Belkin N, Rahav E, Elifantz H, Kress N, and Berman-Frank I
- Subjects
- Bacteria genetics, Base Sequence, Biodiversity, Chlorophyll genetics, Chlorophyll A, DNA, Bacterial genetics, Eukaryota physiology, Food Chain, Mediterranean Sea, Osmolar Concentration, Plankton microbiology, Seasons, Sequence Analysis, DNA, Bacteria metabolism, Microbial Consortia, Plankton metabolism, Salinity, Seawater chemistry, Seawater microbiology, Sodium Chloride metabolism
- Abstract
Seawater desalination plants increase local coastal salinities by discharging concentrated brine back to the sea with ∼ 50% higher than ambient salinities. The impacts of high salinities on microbial coastal populations of the eastern Mediterranean Sea (EMS) were examined in two mesocosm experiments; first, during the mixed-spring and second, during the stratified-summer periods with average salinity of ∼ 39. Ambient salinities were increased by 5% and 15%. Higher salinity (15%) mesocosms induced rapid (within 2 h) declines in both primary productivity (PP) and algal biomass parallel to an increase in bacterial productivity. Subsequently, for the duration of the experiments (11-12 days), both Chlorophyll a and PP rates increased (2 to 5 and 1.5 to 2.5-fold, respectively) relative to unamended controls. The initial assemblages of the ambient microbial populations and intensity of salinity enrichments influenced the community responses. During the mixed-spring experiment, the composition of prokaryotic and eukaryotic populations shifted only slightly, suggesting high functional plasticity of the initial populations. While during the stratified-summer experiment, high salinity changed the composition and reduced the biodiversity of the microbial communities. In an ultra-oligotrophic environment such as the EMS, salinity induced declines in microbial diversity may provide a tipping point destabilizing the local aquatic food web., (© 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.)
- Published
- 2015
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44. The primary transcriptome of the marine diazotroph Trichodesmium erythraeum IMS101.
- Author
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Pfreundt U, Kopf M, Belkin N, Berman-Frank I, and Hess WR
- Subjects
- Aquatic Organisms genetics, Aquatic Organisms metabolism, Bacterial Proteins genetics, Bacterial Proteins metabolism, Base Sequence, Cyanobacteria genetics, Gene Expression Regulation, Bacterial, Genes, Bacterial, Introns, Molecular Sequence Data, Promoter Regions, Genetic, Retroelements, Cyanobacteria metabolism, Transcriptome
- Abstract
Blooms of the dinitrogen-fixing marine cyanobacterium Trichodesmium considerably contribute to new nitrogen inputs into tropical oceans. Intriguingly, only 60% of the Trichodesmium erythraeum IMS101 genome sequence codes for protein, compared with ~85% in other sequenced cyanobacterial genomes. The extensive non-coding genome fraction suggests space for an unusually high number of unidentified, potentially regulatory non-protein-coding RNAs (ncRNAs). To identify the transcribed fraction of the genome, here we present a genome-wide map of transcriptional start sites (TSS) at single nucleotide resolution, revealing the activity of 6,080 promoters. We demonstrate that T. erythraeum has the highest number of actively splicing group II introns and the highest percentage of TSS yielding ncRNAs of any bacterium examined to date. We identified a highly transcribed retroelement that serves as template repeat for the targeted mutation of at least 12 different genes by mutagenic homing. Our findings explain the non-coding portion of the T. erythraeum genome by the transcription of an unusually high number of non-coding transcripts in addition to the known high incidence of transposable elements. We conclude that riboregulation and RNA maturation-dependent processes constitute a major part of the Trichodesmium regulatory apparatus.
- Published
- 2014
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45. Systemic delivery of microRNA-181b inhibits nuclear factor-κB activation, vascular inflammation, and atherosclerosis in apolipoprotein E-deficient mice.
- Author
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Sun X, He S, Wara AKM, Icli B, Shvartz E, Tesmenitsky Y, Belkin N, Li D, Blackwell TS, Sukhova GK, Croce K, and Feinberg MW
- Subjects
- Animals, Aorta pathology, Apolipoproteins E genetics, Atherosclerosis etiology, Atherosclerosis metabolism, Atherosclerosis pathology, CD4-Positive T-Lymphocytes metabolism, Diet, High-Fat adverse effects, Human Umbilical Vein Endothelial Cells metabolism, Humans, Inflammation metabolism, Karyopherins genetics, Karyopherins metabolism, Macrophages metabolism, Mice, Mice, Inbred C57BL, MicroRNAs administration & dosage, MicroRNAs blood, MicroRNAs metabolism, NF-kappa B antagonists & inhibitors, Tunica Intima pathology, Aorta metabolism, Atherosclerosis therapy, MicroRNAs therapeutic use, NF-kappa B metabolism, Tunica Intima metabolism
- Abstract
Rationale: Activated nuclear factor (NF)-κB signaling in the vascular endothelium promotes the initiation and progression of atherosclerosis. Targeting endothelial NF-κB may provide a novel strategy to limit chronic inflammation., Objective: To examine the role of microRNA-181b (miR-181b) in endothelial NF-κB signaling and effects on atherosclerosis., Methods and Results: MiR-181b expression was reduced in the aortic intima and plasma in apolipoprotein E-deficient mice fed a high-fat diet. Correspondingly, circulating miR-181b in the plasma was markedly reduced in human subjects with coronary artery disease. Systemic delivery of miR-181b resulted in a 2.3-fold overexpression of miR-181b in the aortic intima of apolipoprotein E-deficient mice and suppressed NF-κB signaling revealed by bioluminescence imaging and reduced target gene expression in the aortic arch in apolipoprotein E-deficient/NF-κB-luciferase transgenic mice. MiR-181b significantly inhibited atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4+ T cells in the vessel wall. Mechanistically, miR-181b inhibited the expression of the target gene importin-α3, an effect that reduced NF-κB nuclear translocation specifically in the vascular endothelium of lesions, whereas surprisingly leukocyte NF-κB signaling was unaffected despite a 7-fold overexpression of miR-181b. Our findings uncover that NF-κB nuclear translocation in leukocytes does not involve importin-α3, but rather importin-α5, which miR-181b does not target, highlighting that inhibition of NF-κB signaling in the endothelium is sufficient to mediate miR-181b's protective effects., Conclusions: Systemic delivery of miR-181b inhibits the activation of NF-κB and atherosclerosis through cell-specific mechanisms in the vascular endothelium. These findings support the rationale that delivery of miR-181b may provide a novel therapeutic approach to treat chronic inflammatory diseases such as atherosclerosis.
- Published
- 2014
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46. Endothelial microRNAs and atherosclerosis.
- Author
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Sun X, Belkin N, and Feinberg MW
- Subjects
- Animals, Atherosclerosis genetics, Endothelium, Vascular metabolism, Humans, MicroRNAs genetics, NF-kappa B metabolism, Signal Transduction, Atherosclerosis metabolism, Endothelial Cells metabolism, Endothelium, Vascular cytology, MicroRNAs metabolism
- Abstract
The vascular endothelium, a thin layer of endothelial cells (ECs) that line the inner surface of blood vessels, is a critical interface between blood and all tissues. EC activation, dysfunction, and vascular inflammation occur when the endothelium is exposed to various insults such as proinflammatory cytokines, oxidative stress, hypertension, hyperglycemia, aging, and shear stress. These insults lead to the pathogenesis of a range of disease states, including atherosclerosis. Several signaling pathways, especially nuclear factor κB mediated signaling, play crucial roles in these pathophysiological processes. Recently, microRNAs (miRNAs) have emerged as important regulators of EC function by fine-tuning gene expression. In this review, we discuss how miRNAs regulate EC function and vascular inflammation in response to a variety of pathophysiologic stimuli. An understanding of the role of miRNAs in EC activation and dysfunction may provide novel targets and therapeutic opportunities for controlling atherosclerosis and other chronic inflammatory disease states.
- Published
- 2013
- Full Text
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47. Dinitrogen fixation in aphotic oxygenated marine environments.
- Author
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Rahav E, Bar-Zeev E, Ohayon S, Elifantz H, Belkin N, Herut B, Mulholland MR, and Berman-Frank I
- Abstract
We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO(-) 3)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L(-1) d(-1) to 0.38 nmol N L(-1) d(-1). N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2-3.5 fold and N2 fixation rates by ~2-fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2-6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP and heterotrophic N2 fixation were carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particle (TEP) concentrations and N2 fixation rates. This suggests that sinking organic material and high carbon (C): nitrogen (N) micro-environments (such as TEP-based aggregates or marine snow) could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75% of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets.
- Published
- 2013
- Full Text
- View/download PDF
48. Bioflocculation: chemical free, pre-treatment technology for the desalination industry.
- Author
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Bar-Zeev E, Belkin N, Liberman B, Berman-Frank I, and Berman T
- Subjects
- Bacteria growth & development, Bacteria ultrastructure, Filtration instrumentation, Flocculation, Metagenome, Microscopy, Electron, Scanning, Particle Size, Pilot Projects, Porosity, Silicon Dioxide, Time Factors, Water Purification instrumentation, Water Quality, Salinity, Water Purification methods
- Abstract
Rapid sand filtration (RSF), proceeded by chemical coagulation and flocculation, is a commonly used, effective pretreatment in the desalination industry. We designed and tested a novel, large pilot-scale, two-stage granular Rapid Bioflocculation Filter (RBF) based on a first-stage Bioflocculator (BF) unit followed by a mixed-media bed filter (MBF). The BF filter bed consisted of an extremely porous volcanic Tuff granular medium which provided an enlarged surface area for microbial development and biofilm proliferation. We compared the efficiency of the pilot RBF to that of a full-scale RSF, operating with upstream chemical coagulation, by measuring the removal from the same untreated seawater feed of key factors related to membrane clogging: SDI, turbidity, chlorophyll a (Chl a) and transparent exopolymer particles (TEP). After 2 weeks of operation, the Tuff grains were colonized extensively by coccoid bacteria that formed biofilm along the entire BF. With bacterial colonization and biofilm development, numerous aggregates of bacteria and some algal cells embedded in an amorphous organic matrix were formed on and within the Tuff grains. By 1-3 months, the biotic diversity within the Tuff filter bed had increased to include filamentous bacteria, cyanobacteria, fungi, protista and even crustaceans and marine worms. During and for ≈ 24 h after each cleaning cycle (carried out every 5 to 7 days by upward flushing with air and water), large numbers of floc-like particles, from ≈ 15 μm to ≈ 2 mm in size were observed in the filtrate of the BF unit. Microscopic examination of these flocs (stained with Alcian Blue and SYTO(R) 9) showed that they were aggregates of many smaller particles with associated bacteria and algae within a polysaccharide gel-like matrix. These biogenic flocs (bioflocs) were observed to form during normal operation of the RBF, accumulating as aggregates of inorganic and organic material on the Tuff surfaces. With each flush cleaning cycle, these bioflocs were released into the BF effluent but were retained by the second phase MBF unit. No flocs were seen in the MBF filtrate. Over a year-long study, both the pilot RBF and the full-scale RSF showed similar filtration efficiencies, measured as the percentage removal of Chl a, TEP, turbidity and SDI from the same seawater feed. These results indicate the potential of the bioflocculation approach with no chemical additives as an alternative to conventional RSF pretreatment for large SWRO facilities., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
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49. Biochemical characterization of P4-ATPase mutations identified in patients with progressive familial intrahepatic cholestasis.
- Author
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Stone A, Chau C, Eaton C, Foran E, Kapur M, Prevatt E, Belkin N, Kerr D, Kohlin T, and Williamson P
- Subjects
- ATP-Binding Cassette Transporters genetics, Amino Acid Sequence, Humans, Kinetics, Molecular Sequence Data, Phenotype, Phospholipids chemistry, Regression Analysis, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism, Sequence Homology, Amino Acid, Substrate Specificity, Adenosine Triphosphatases chemistry, Adenosine Triphosphatases genetics, Cholestasis, Intrahepatic genetics, Mutation
- Abstract
Mutations in the P4-ATPase ATP8B1 cause the inherited liver disease progressive familial intrahepatic cholestasis. Several of these mutations are located in conserved regions of the transmembrane domain associated with substrate binding and transport. Assays for P4-ATPase-mediated transport in living yeast cells were developed and used to characterize the specificity and kinetic parameters of this transport. Progressive familial intrahepatic cholestasis mutations were introduced into the yeast plasma membrane P4-ATPase Dnf2p, and the effect of these mutations on its catalysis of phospholipid transport were determined. The results of these measurements have implications for the basis of the disease and for the mechanism of phospholipid transit through the enzyme during the reaction cycle.
- Published
- 2012
- Full Text
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50. Signal transduction activator of transcription 5 (STAT5) dysfunction in autoimmune monocytes and macrophages.
- Author
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Litherland SA, Xie TX, Grebe KM, Davoodi-Semiromi A, Elf J, Belkin NS, Moldawer LL, and Clare-Salzler MJ
- Subjects
- Adolescent, Adult, Animals, Autoimmune Diseases pathology, Cells, Cultured, Child, Female, Gene Expression Regulation immunology, Humans, Macrophages pathology, Male, Mice, Mice, Inbred NOD, Middle Aged, Monocytes pathology, STAT5 Transcription Factor, Transcriptional Activation, Tumor Suppressor Proteins, Autoimmune Diseases immunology, DNA-Binding Proteins immunology, Macrophages immunology, Milk Proteins immunology, Monocytes immunology, Signal Transduction immunology, Trans-Activators immunology
- Abstract
Autocrine granulocyte macrophage-colony stimulating factor (GM-CSF) sequentially activates intracellular components in monocyte/macrophage production of the pro-inflammatory and immunoregulatory prostanoid, prostaglandin E2 (PGE2). GM-CSF first induces STAT5 signaling protein phosphorylation, then prostaglandin synthase 2 (COX2/PGS2) gene expression, and finally IL-10 production, to downregulate the cascade. Without activation, monocytes of at-risk, type 1 diabetic (T1D), and autoimmune thyroid disease (AITD) humans, and macrophages of nonobese diabetic (NOD) mice have aberrantly high GM-CSF, PGS2, and PGE2 expression, but normal levels of IL-10. After GM-CSF stimulation, repressor STAT5A and B isoforms (80-77kDa) in autoimmune human and NOD monocytes and activator STAT5A (96-94kDa) and B (94-92kDa) isoforms in NOD macrophages stay persistently tyrosine phosphorylated. This STAT5 phosphorylation persisted despite treatment in vitro with IL-10, anti-GM-CSF antibody, or the JAK2/3 inhibitor, AG490. Phosphorylated STAT5 repressor isoforms in autoimmune monocytes had diminished DNA binding capacity on GAS sequences found in the PGS2 gene enhancer. In contrast, STAT5 activator isoforms in NOD macrophages retained their DNA binding capacity on these sites much longer than in healthy control strain macrophages. These findings suggest that STAT5 dysfunction may contribute to dysregulation of GM-CSF signaling and gene activation, including PGS2, in autoimmune monocytes and macrophages.
- Published
- 2005
- Full Text
- View/download PDF
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