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Dbf4-dependent kinase promotes cell cycle controlled resection of DNA double-strand breaks and repair by homologous recombination. Nat Commun 2024; 15:2890. [PMID: 38570537 PMCID: PMC10991553 DOI: 10.1038/s41467-024-46951-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 03/13/2024] [Indexed: 04/05/2024] Open
Abstract
DNA double-strand breaks (DSBs) can be repaired by several pathways. In eukaryotes, DSB repair pathway choice occurs at the level of DNA end resection and is controlled by the cell cycle. Upon cell cycle-dependent activation, cyclin-dependent kinases (CDKs) phosphorylate resection proteins and thereby stimulate end resection and repair by homologous recombination (HR). However, inability of CDK phospho-mimetic mutants to bypass this cell cycle regulation, suggests that additional cell cycle regulators may be important. Here, we identify Dbf4-dependent kinase (DDK) as a second major cell cycle regulator of DNA end resection. Using inducible genetic and chemical inhibition of DDK in budding yeast and human cells, we show that end resection and HR require activation by DDK. Mechanistically, DDK phosphorylates at least two resection nucleases in budding yeast: the Mre11 activator Sae2, which promotes resection initiation, as well as the Dna2 nuclease, which promotes resection elongation. Notably, synthetic activation of DDK allows limited resection and HR in G1 cells, suggesting that DDK is a key component of DSB repair pathway selection.
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A SAM-key domain required for enzymatic activity of the Fun30 nucleosome remodeler. Life Sci Alliance 2023; 6:e202201790. [PMID: 37468166 PMCID: PMC10355287 DOI: 10.26508/lsa.202201790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/21/2023] Open
Abstract
Fun30 is the prototype of the Fun30-SMARCAD1-ETL subfamily of nucleosome remodelers involved in DNA repair and gene silencing. These proteins appear to act as single-subunit nucleosome remodelers, but their molecular mechanisms are, at this point, poorly understood. Using multiple sequence alignment and structure prediction, we identify an evolutionarily conserved domain that is modeled to contain a SAM-like fold with one long, protruding helix, which we term SAM-key. Deletion of the SAM-key within budding yeast Fun30 leads to a defect in DNA repair and gene silencing similar to that of the fun30Δ mutant. In vitro, Fun30 protein lacking the SAM-key is able to bind nucleosomes but is deficient in DNA-stimulated ATPase activity and nucleosome sliding and eviction. A structural model based on AlphaFold2 prediction and verified by crosslinking-MS indicates an interaction of the long SAM-key helix with protrusion I, a subdomain located between the two ATPase lobes that is critical for control of enzymatic activity. Mutation of the interaction interface phenocopies the domain deletion with a lack of DNA-stimulated ATPase activation and a nucleosome-remodeling defect, thereby confirming a role of the SAM-key helix in regulating ATPase activity. Our data thereby demonstrate a central role of the SAM-key domain in mediating the activation of Fun30 catalytic activity, thus highlighting the importance of allosteric activation for this class of enzymes.
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DNA Double Strand Break Repair and Its Control by Nucleosome Remodeling. Front Genet 2022; 12:821543. [PMID: 35096025 PMCID: PMC8790285 DOI: 10.3389/fgene.2021.821543] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/23/2021] [Indexed: 12/12/2022] Open
Abstract
DNA double strand breaks (DSBs) are repaired in eukaryotes by one of several cellular mechanisms. The decision-making process controlling DSB repair takes place at the step of DNA end resection, the nucleolytic processing of DNA ends, which generates single-stranded DNA overhangs. Dependent on the length of the overhang, a corresponding DSB repair mechanism is engaged. Interestingly, nucleosomes-the fundamental unit of chromatin-influence the activity of resection nucleases and nucleosome remodelers have emerged as key regulators of DSB repair. Nucleosome remodelers share a common enzymatic mechanism, but for global genome organization specific remodelers have been shown to exert distinct activities. Specifically, different remodelers have been found to slide and evict, position or edit nucleosomes. It is an open question whether the same remodelers exert the same function also in the context of DSBs. Here, we will review recent advances in our understanding of nucleosome remodelers at DSBs: to what extent nucleosome sliding, eviction, positioning and editing can be observed at DSBs and how these activities affect the DSB repair decision.
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Analytical and clinical evaluation of four commercial SARS-CoV-2 serological immunoassays in hospitalized patients and ambulatory individuals. J Virol Methods 2020; 289:114060. [PMID: 33359614 PMCID: PMC7834313 DOI: 10.1016/j.jviromet.2020.114060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/21/2020] [Accepted: 12/21/2020] [Indexed: 12/30/2022]
Abstract
Hospitalized patients seroconverted at ≥ 3 weeks pso. Ambulatory symptomatic individuals seroconverted at 14 days pso. Illness’ severity degree and infection phase impacted the longitudinal Ab changes. Five “severe-to-critically” ill patients have positive Ab levels up to 16 weeks pso. Total Ab immunoassay, compared to IgG, present a better sensitivity and specificity.
Background This study aimed to compare four anti-SARS-CoV-2 immunoassays in populations presenting different clinical severity levels. Methods Three populations were included: “severe-to-critical” ICU-hospitalized patients (n = 18), “mild-to-moderate” hospitalized patients (n = 16) and non-hospitalized symptomatic patients (n = 24). Four commercial immunoassays were analyzed and validated: anti-IgG ARCHITECT® (Abbott), anti-Total antibodies (Ab) VITROS® (Ortho Clinical Diagnostics), anti-IgG NovaLisa® (NovaTec Immundiagnostica) and Healgen® IgM and IgG (Zhejiang Orient Gene Biotech). Sensitivities were evaluated according to days post-symptoms onset (pso). Specificities were evaluated on SARS-CoV-2-negative control sera collected before January 2020. Results A majority of severe-to-critically ill patients showed detectable Ab already at day 14 and sensitivities reached 100 % after 22 days pso. For patients with “mild-to-moderate” illness, sensitivities increased by at least 5-fold from day 0 to day 14 pso. Non-hospitalized symptomatic individuals already seroconverted at day 14 days pso with 100 % sensitivities for Total Ab VITROS®. Specificities were evaluated at 97 % for ARCHITECT® and NovaLisa®, 98 % for VITROS® and at 94 % for Healgen® combined IgM and IgG. Five “severe-to-critically” ill patients presented high positive Ab levels for at least 16 weeks pso. Conclusion The Ab levels and the evaluated sensitivities, representing the true positive rate, increased overtime and were related to the COVID-19 severity. Automated Total Ab immunoassay showed better sensitivities and specificity for immunological surveillance and vaccine evaluation.
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Long-Term Stability of Lorazepam in Sodium Chloride 0.9% Stored at Different Temperatures in Different Containers. Hosp Pharm 2020; 55:188-192. [PMID: 32508356 DOI: 10.1177/0018578719836649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Objective: Infusion containing lorazepam is used by geriatric department to limit anxiety disorders in the elderly. Currently, these infusions are prepared according to demand by the nursing staff, but the preparation in advance in a centralized service could improve quality of preparation and time management. The aim of this study was to investigate the long-term stability of this infusion in polypropylene syringes stored at 5 ± 3°C. Then, results obtained were compared with stability data of lorazepam in syringes stored at room temperature, glass bottles at 5 ± 3°C, and glass bottles at room temperature. Method: Eight syringes and 6 bottles of infusion were prepared by diluting 1 mL lorazepam 4 mg in 23 mL of NaCl 0.9% under aseptic conditions. Five syringes and 3 bottles were stored at 5 ± 3°C and 3 syringes and 3 bottles were stored at room temperature for 30 days. During the storage period, particle appearance or color change were periodically checked by visual and microscope inspection. Turbidity was assessed by measurements of optical density (OD) at 3 wavelengths (350 nm, 410 nm, 550 nm). The stability of pH was also evaluated. The lorazepam concentrations were measured at each time point by high-performance liquid chromatography with ultraviolet detector at 220 nm. Results: Solutions were physically unstable in syringes at 5 ± 3°C after 4 days: crystals and a drop of OD at 350 nm were observed. However, pH was stable. After 2 days, solutions were considered as chemically unstable because a loss of lorazepam concentration higher than 10% was noticed: the lower 1-sided confidence limit at 95% was below 90% of the initial concentration. To assess temperature and polypropylene influence, results were compared with those obtained for syringes at room temperature and bottles at 5 ± 3°C and room temperature. Precipitation, drop of OD at 350 nm, and chemical instability were observed in all conditions. Conclusion: Solutions of lorazepam were unstable after 2 days in syringes at 5 ± 3°C. Preparation in advance appears, therefore, not possible for the clinical use. Storage conditions (temperature and form) do not improve the stability.
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An advanced cell cycle tag toolbox reveals principles underlying temporal control of structure-selective nucleases. eLife 2020; 9:e52459. [PMID: 32352375 PMCID: PMC7220381 DOI: 10.7554/elife.52459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 04/29/2020] [Indexed: 12/26/2022] Open
Abstract
Cell cycle tags allow to restrict target protein expression to specific cell cycle phases. Here, we present an advanced toolbox of cell cycle tag constructs in budding yeast with defined and compatible peak expression that allow comparison of protein functionality at different cell cycle phases. We apply this technology to the question of how and when Mus81-Mms4 and Yen1 nucleases act on DNA replication or recombination structures. Restriction of Mus81-Mms4 to M phase but not S phase allows a wildtype response to various forms of replication perturbation and DNA damage in S phase, suggesting it acts as a post-replicative resolvase. Moreover, we use cell cycle tags to reinstall cell cycle control to a deregulated version of Yen1, showing that its premature activation interferes with the response to perturbed replication. Curbing resolvase activity and establishing a hierarchy of resolution mechanisms are therefore the principal reasons underlying resolvase cell cycle regulation.
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Dormant origins and fork protection mechanisms rescue sister forks arrested by transcription. Nucleic Acids Res 2019; 46:1227-1239. [PMID: 29059325 PMCID: PMC5815123 DOI: 10.1093/nar/gkx945] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/03/2017] [Indexed: 12/18/2022] Open
Abstract
The yeast RNA/DNA helicase Sen1, Senataxin in human, preserves the integrity of replication forks encountering transcription by removing RNA-DNA hybrids. Here we show that, in sen1 mutants, when a replication fork clashes head-on with transcription is arrested and, as a consequence, the progression of the sister fork moving in the opposite direction within the same replicon is also impaired. Therefore, sister forks remain coupled when one of the two forks is arrested by transcription, a fate different from that experienced by forks encountering Double Strand Breaks. We also show that dormant origins of replication are activated to ensure DNA synthesis in the proximity to the forks arrested by transcription. Dormant origin firing is not inhibited by the replication checkpoint, rather dormant origins are fired if they cannot be timely inactivated by passive replication. In sen1 mutants, the Mre11 and Mrc1–Ctf4 complexes protect the forks arrested by transcription from processing mediated by the Exo1 nuclease. Thus, a harmless head-on replication-transcription clash resolution requires the fine-tuning of origin firing and coordination among Sen1, Exo1, Mre11 and Mrc1–Ctf4 complexes.
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Right time, right place-DNA damage and DNA replication checkpoints collectively safeguard S phase. EMBO J 2018; 37:embj.2018100681. [PMID: 30287420 DOI: 10.15252/embj.2018100681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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P5547Effect of transradial access for coronary angiography on vascular function of brachial arteries. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
During the years 1970–1978, 213,575 women living in the Florence District had at least one cytologic smear. The overall incidence ratios were: dysplasia 1.09 ±, carcinoma «in situ » 1.25 ±, invasive carcinoma 1.01 ±. Age of the women attending the service, and incidence ratios according to age groups are examined. Incidence ratios in women who had previous negative smears are calculated; these values seem to fit well with a «false negative model». These results are compared with those reported by other authors, and indications for a new kind of program are suggested.
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Does an interaction exist between ketamine hydrochloride and Becton Dickinson syringes? Eur J Hosp Pharm 2016; 24:230-234. [PMID: 31156944 DOI: 10.1136/ejhpharm-2016-001045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/29/2016] [Accepted: 09/19/2016] [Indexed: 11/03/2022] Open
Abstract
Introduction An international alert from Becton Dickinson (BD) has noted the possibility of interaction between several molecules and some syringes. The Centralized IntraVenous Additives Service of the institution was using 3 mL BD syringes to store ketamine HCl. This study evaluated the interaction between ketamine and these syringes. Method A batch of BD syringes produced in Europe and left in quarantine from the day of the international alert has been tested at 22, 29, 36, 43 and 50 days of storage at room temperature. At each time, the pH of the solutions was measured. The solutions were inspected visually and by microscope, and spectrophotometric measurements were performed. The concentrations were measured by a validated ultra-high-performance liquid chromatography-diode array detector. Results Neither physical change nor pH modification was observed during the study. According to a lower limit of the 95% unilateral CI on the mean >90% of the theoretical concentration, the solutions remain stable for at least 50 days. Conclusion In our study conditions, ketamine can be stored for at least 50 days without risk of sorption with syringes.
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Robust Replication Control Is Generated by Temporal Gaps between Licensing and Firing Phases and Depends on Degradation of Firing Factor Sld2. Cell Rep 2016; 17:556-569. [DOI: 10.1016/j.celrep.2016.09.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 08/10/2016] [Accepted: 09/02/2016] [Indexed: 10/20/2022] Open
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Long-term stability of dexamethasone and alizapride or ondansetron in sodium chloride 0.9% polyolefin bag at 5±3°C. ANNALES PHARMACEUTIQUES FRANÇAISES 2016; 75:30-39. [PMID: 27634586 DOI: 10.1016/j.pharma.2016.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/28/2016] [Accepted: 08/09/2016] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The aim of the study was to investigate the long-term stability of dexamethasone 10mg associated with alizapride 100mg or ondansetron 8mg in 100mL of 0.9% sodium chloride solution stored at 5±3°C. METHOD Solutions of 0.9% sodium chloride 100mL in polyolefin bags (n=5) containing approximately dexamethasone (DEX) 10mg associated with alizapride (ALI) 100mg or ondansetron (OND) 8mg were prepared under aseptic conditions and stored about 30 days at 5±3°C. ALI, DEX and OND concentrations were measured by high-performance liquid chromatography (HPLC). Optic density measurement at different wavelengths, pH measurement and optic microscope observations were performed periodically during the storage. A forced degradation test with HCL 5M and NaOH 5M before and after heating at 100°C was also performed. Solutions were considered stable if the 95% one-sided lower confidence limit of the concentration remains superior to 90% of the initial concentration or 95% of the initial concentration when any signs of physical instability exist as recently recommend. RESULTS The calibration was linear over the following range from 20 to 1.25mg/100mL for DEX, from 200 to 12.5mg/100mL for ALI and from 20 to 1.25mg/100mL for OND with a calculated correlation coefficient (r2) of 0.998, 0.999 and 0.999, respectively. The inter- and intra-assay precision was below 10% for both mixtures. All formulations were physically stable during the storage. The lower confidence limit of the concentration for these solutions remains superior to 90% of the initial concentration at this date as recommended by the Food and Drug Administration (FDA) until 30 days. CONCLUSION The HPLC method is specific and reproducible and can easily be adopted for monitoring the quality control in the production of DEX-ALI and DEX-OND bags. Solutions of DEX-ALI and DEX-OND were physically and chemically stable for 30 days in polyolefin bags stored at 5±3°C and could therefore be prepared in advance.
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Long-term stability of ketamine hydrochloride 50mg/ml injection in 3ml syringes. ANNALES PHARMACEUTIQUES FRANÇAISES 2016; 74:283-7. [DOI: 10.1016/j.pharma.2016.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/10/2016] [Accepted: 03/16/2016] [Indexed: 10/21/2022]
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PP-017 The physical stability of injectable drugs must be proved to ensure patient safety. Eur J Hosp Pharm 2016. [DOI: 10.1136/ejhpharm-2016-000875.456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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PP-016 Long term stability of a generic product of piperacilline/tazobactam in glucose 5% infusion polyolefin bags at 5°c ± 3°c after microwave freeze–thaw treatment. Eur J Hosp Pharm 2016. [DOI: 10.1136/ejhpharm-2016-000875.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Microwave freeze-thaw technique of injectable drugs. A review from 1980 to 2014. ANNALES PHARMACEUTIQUES FRANÇAISES 2015; 73:436-41. [DOI: 10.1016/j.pharma.2015.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/20/2015] [Accepted: 04/22/2015] [Indexed: 11/17/2022]
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[The long-term chemical stability of injectable drugs reconstituted in Hospital Pharmacy]. JOURNAL DE PHARMACIE DE BELGIQUE 2015:36-44. [PMID: 26513834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND Other injectable preparations than parenteral nutrition admixture and injectable cytotoxic drugs could be prepared by Centralised IntraVenous Admixture Service (CIVAS) if the Long-term stability of the drugs is known. However, this information is not always available. PURPOSE To develop a program of chemical drug stability analysis in collaboration between Hospital Pharmacy, Medical Laboratory and Scientific Support Unit to determine the long-term stability of largely used injectable anti-infectious and non-anti-infectious drugs. MATERIAL AND METHODS After a setup of the High Performance Liquid Chromatography (HPLCI method, 28 drugs were reconstituted in laminar air flow hood, 17 of them stored directly at 5 +/- 3 degrees C and 19 stored in the freezer at -20 degrees C, thawed by microwave following a standardised procedure and stored at 5 +/- 3 degrees C before use. Concentration stability was evaluated by regression analysis. RESULTS For each drug, long-term stability has varied from 11 days to 180 days. The freeze-thaw treatment by microwave may enhance the stability (from 30 to 120 days) and allow batch-scale production of intravenous drugs, less expensive in term of manpower and sterile device than a drug reconstitution at the ward. The results were published by 55 posters in international congress and by 36 publications in national and international pharmaceutical journals. CONCLUSIONS Our findings contribute to enhance the scale of drugs that may be take on by a CIVAS.
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303 Smoking cessation help should be available at CF reference centres – a Belgian national survey of smoking in patients with cystic fibrosis. J Cyst Fibros 2015. [DOI: 10.1016/s1569-1993(15)30477-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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[Physical compatibility of a mixture of alizapride and dexamethasone in flexible infusion bags of 100 ml of 0.9% NaCl]. JOURNAL DE PHARMACIE DE BELGIQUE 2015:38-39. [PMID: 26466508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Replication and transcription on a collision course: eukaryotic regulation mechanisms and implications for DNA stability. Front Genet 2015; 6:166. [PMID: 25972894 PMCID: PMC4412130 DOI: 10.3389/fgene.2015.00166] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/12/2015] [Indexed: 12/20/2022] Open
Abstract
DNA replication and transcription are vital cellular processes during which the genetic information is copied into complementary DNA and RNA molecules. Highly complex machineries required for DNA and RNA synthesis compete for the same DNA template, therefore being on a collision course. Unscheduled replication–transcription clashes alter the gene transcription program and generate replication stress, reducing fork speed. Molecular pathways and mechanisms that minimize the conflict between replication and transcription have been extensively characterized in prokaryotic cells and recently identified also in eukaryotes. A pathological outcome of replication–transcription collisions is the formation of stable RNA:DNA hybrids in molecular structures called R-loops. Growing evidence suggests that R-loop accumulation promotes both genetic and epigenetic instability, thus severely affecting genome functionality. In the present review, we summarize the current knowledge related to replication and transcription conflicts in eukaryotes, their consequences on genome stability and the pathways involved in their resolution. These findings are relevant to clarify the molecular basis of cancer and neurodegenerative diseases.
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Long-term stability of acyclovir in 0.9% NaCl infusion polyolefin bags at 5±3°C after freeze-thaw treatment: A generic product versus the brand name. ANNALES PHARMACEUTIQUES FRANÇAISES 2015; 73:108-13. [DOI: 10.1016/j.pharma.2014.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 10/24/2022]
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PP-006 Microwave freeze-thaw treatment of injectable drugs: a review of the literature from 1980 to 2014. Eur J Hosp Pharm 2015. [DOI: 10.1136/ejhpharm-2015-000639.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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[Physical compatibility of a mixture of alizapride and clorazepate in flexible infusion bags of 100 ml of 5% glucose]. JOURNAL DE PHARMACIE DE BELGIQUE 2014:38-39. [PMID: 25226762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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Abstract
High anion gap metabolic acidosis due to pyroglutamic acid (5-oxoproline) is a rare complication of acetaminophen treatment (which depletes glutathione stores) and is often associated with clinically moderate to severe encephalopathy. Acquired 5-oxoprolinase deficiency (penicillins) or the presence of other risk factors of glutathione depletion such as malnutrition or sepsis seems to be necessary for symptoms development. We report the case of a 55-year-old women who developed a symptomatic overproduction of 5-oxoproline during flucloxacillin treatment for severe sepsis while receiving acetaminophen for fever control. Hemodialysis accelerated the clearance of the accumulated organic acid, and was followed by a sustained clinical improvement.
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Long-term stability of morphine hydrochloride in 0.9% NaCl infusion polyolefin bags after freeze-thaw treatment and in polypropylene syringes at 5 degrees C + 3 degrees C. INTERNATIONAL JOURNAL OF PHARMACEUTICAL COMPOUNDING 2014; 18:78-82. [PMID: 24881344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aim of this study was to investigate the long-term stability of morphine hydrochloride in 0.9% NaCI infusion polyolefin bags and polypropylene syringes after storage at 5 degrees C + 3 degrees C and to evaluate the influence of initial freezing and microwave thawing on this stability. Ten polyolefin bags and five polypropylene syringes containing 100 mL of 1 mg/mL of morphine hydrochloride solution in 0.9% NaCI were prepared under aseptic conditions. Five polyolefin bags were frozen at -20 degrees C for 90 days before storage. Immediately after the preparation and after thawing, 2 mL of each bag were withdrawn for the initial concentration measurements. All polyolefin bags and polypropylene syringes were then refrigerated at 5 degrees C + 3 degrees C for 58 days during which the morphine concentrations were measured periodically by high-performance liquid chromatography using a reversed-phase column, naloxone as internal standard, a mobile phase consisting of 5% acetonitrile and 95% of KH2PO4 buffer (pH 3.50), and detection with diode array detector at 254 nm. Visual and microscopic observations and spectrophotometric and pH measurements were also performed. Solutions were considered stable if the concentration remained superior to 90% of the initial concentration. The degradation products peaks were not quantitatively significant and were resolved from the native drug. Polyolefin bag and polypropylene syringe solutions were stable when stored at 5 degrees C + 3 degrees C during these 58 days. No color change or precipitation in the solutions was observed. The physical stability was confirmed by visual, microscopic, and spectrophotometric inspection. There was no significant change in pH during storage. Freezing and microwave thawing didn't influence the infusion stability. Morphine hydrochloride infusions may be prepared in advance by centralized intravenous additive service, frozen in polyolefin bags, and microwave thawed before storage under refrigeration until 58 days either in polyolefin bags or polypropylene syringes. Such treatment could improve safety and management.
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TCH-036 Results of a Systematic Long-Term Stability Study For Ready-To-Use Injectable Drugs Produced by a Centralized Intravenous Admixture Service. Eur J Hosp Pharm 2013. [DOI: 10.1136/ejhpharm-2013-000276.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Microwave freeze-thaw treatment of dose-banded cytotoxics injectable drugs: A review of the literature from 1980 to 2011. ANNALES PHARMACEUTIQUES FRANÇAISES 2012; 70:227-35. [DOI: 10.1016/j.pharma.2012.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/19/2012] [Accepted: 04/26/2012] [Indexed: 11/30/2022]
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Long-term stability of morphine HCl in 0.9% NaCl infusion. Eur J Hosp Pharm 2012. [DOI: 10.1136/ejhpharm-2012-000074.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Long-term stability of temocillin in dextrose 5% and in sodium chloride 0.9% polyolefin bags at 5±3°C after freeze-thaw treatment. ANNALES PHARMACEUTIQUES FRANÇAISES 2011; 69:296-301. [DOI: 10.1016/j.pharma.2011.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 09/20/2011] [Accepted: 09/22/2011] [Indexed: 11/29/2022]
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Physico-chemical analysis of several injectable drug in ready-to-use infusion after microwave freeze-thaw treatment and final storage at 5±3̊C. ANNALES PHARMACEUTIQUES FRANÇAISES 2011; 69:270-6. [DOI: 10.1016/j.pharma.2011.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/02/2011] [Accepted: 08/04/2011] [Indexed: 11/28/2022]
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Long-term stability of the hydrochlorides of tramadol and alizapride in dextrose 5% polyolefin bag at 5+/-3 degrees C. ANNALES PHARMACEUTIQUES FRANÇAISES 2010; 68:157-62. [PMID: 20569772 DOI: 10.1016/j.pharma.2010.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/23/2010] [Accepted: 03/27/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To investigate the stability of tramadol hydrochloride 100mg associated with alizapride 50mg in 100ml of 5% dextrose solution stored at 5+/-3 degrees C. METHODS Solutions of 5% dextrose 100ml in polyolefin bags (n=5) containing approximately tramadol hydrochloride 100mg associated with alizapride 50mg were prepared under aseptic conditions and stored about 32 days at 5+/-3 degrees C. The tramadol hydrochloride and alizapride concentrations were measured by high-performance liquid chromatography (HPLC). Visual inspection was performed and pH was measured periodically during the storage. Stability of the solutions was defined as the common regression line 95% lower confidence limit of the concentration remaining superior to 90% of the initial concentration as recommended by the Food and Drug Administration (FDA). RESULTS No color change or precipitation in the solutions was observed. Tramadol hydrochloride 100mg associated with alizapride 50mg in 100ml of 5% dextrose infusions was stable when stored at 5+/-3 degrees C during 32 days. Throughout this period, the lower confidence limit of the estimated regression line of concentration-time profile remained above 90% of the initial concentration. There was no significant change in pH during storage. CONCLUSION Under the conditions of this study, tramadol hydrochloride 100mg associated with alizapride 50mg in 100ml of 5% dextrose infusions stored up to 32 days at 5+/-3 degrees C remain stable and may be prepared in advance by a Centralized Intravenous Additive Service (CIVAS) to improve safety and management.
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Effect of freezing, long-term storage and microwave thawing on the stability of a mixture of diclofenac and sodium bicarbonate in glucose 5% polyolefin Bags. ANNALES PHARMACEUTIQUES FRANÇAISES 2009; 67:427-32. [DOI: 10.1016/j.pharma.2009.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/03/2009] [Accepted: 09/07/2009] [Indexed: 11/24/2022]
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Effect of freeze-thawing on the long-term stability of calcium levofolinate in 5% dextrose stored on polyolefin infusion bags. J Clin Pharm Ther 2009; 34:423-8. [DOI: 10.1111/j.1365-2710.2009.01043.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Long-term stability of tramadol hydrochloride and droperidol mixture in 5% dextrose infusion polyolefin bags at 5+/-3 degrees C. ANNALES PHARMACEUTIQUES FRANÇAISES 2009; 67:272-7. [PMID: 19596101 DOI: 10.1016/j.pharma.2009.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 02/26/2009] [Accepted: 03/03/2009] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate the stability of tramadol hydrochloride 100mg associated with droperidol 2.5mg in 100ml of 5% dextrose solution stored at 5+/-3 degrees C. METHODS Solutions of 5% dextrose 100ml in polyolefin bags (n=5) containing approximately tramadol hydrochloride 100mg associated with droperidol 2.5mg were prepared under aseptic conditions and stored about 32 days at 5+/-3 degrees C. The tramadol hydrochloride and droperidol concentrations were measured by high performance liquid chromatography (HPLC). Visual inspection was performed and pH was measured periodically during the storage. Stability of the solutions was defined as the common regression line 95% lower confidence limit of the concentration remaining superior to 90% of the initial concentration as recommended by the Food and Drug Administration (FDA). RESULTS No colour change or precipitation in the solutions was observed. Tramadol hydrochloride 100mg associated with droperidol 2.5mg in 100 ml of 5% dextrose infusions was stable when stored at 5+/-3 degrees C during 32 days. Throughout this period, the lower confidence limit of the estimated regression line of concentration-time profile remained above 90% of the initial concentration. There was no significant change in pH during storage. CONCLUSION Under the conditions of this study, tramadol hydrochloride 100mg associated with droperidol 2.5mg in 100 ml of 5% dextrose infusions stored up to 32 days at 5+/-3 degrees C remain stable and may be prepared in advance by CIVAS to improve safety and management.
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[Tobacco use treatment]. JOURNAL DE PHARMACIE DE BELGIQUE 2006; 61:26-9. [PMID: 16669344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
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Lipids in ischemic stroke subtypes. Acta Neurol Belg 2004; 104:13-9. [PMID: 15143957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
In secondary prevention, reduction of the risk of recurrent ischemic stroke might be expected with statins if a correlation can be established between hyperlipidemia and ischemic stroke or some specific ischemic stroke/TIA subtypes. However, such correlation remains controversial, and more particularly with the etiologic stroke/TIA subtypes. Few studies have evaluated the plasma lipid profile in different ischemic stroke subtypes, and notably in lacunar infarctions and cardioembolic strokes. The objectives of this case-control study was to determine (1) which cholesterol fractions is associated with large vessel disease (LVD), small vessel disease (SVD), and cardioembolic disease (CED); (2) whether hypertriglyceridemia is related more to any particular stroke subtype; and (3) whether the lipid profile is different between LVD and SVD which are both responsible for atherothrombotic cerebral ischemia. From a cohort of 485 patients, were selected 240 consecutive cases with ischemic stroke (n = 182) or transient ischemic attack (n = 58) due to a single etiology. The levels of total cholesterol (total-C), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), and triglycerides (TG) were measured in 61 patients with LVD, in 65 with SVD, and in 114 with CED, and compared with age- and sex-matched control subjects. Additional analysis was performed to compare the lipid profile between LVD and SVD after adjustment for other risk factors. Compared to controls, the total-C level was significantly higher in patients with SVD (p = 0.005) and LVD (p = 0.018). A significant increase in the LDL-C level (p < 0.004) and a significant decrease in the HDL-C level (p = 0.001) were only observed in the LVD patients. The three stroke subtypes showed higher TG levels than the controls (CED, p = 0.037; SVD, p < 0.001; LVD, p = 0.014). The plasma lipid profile was similar in the SVD and LVD subtypes except for HDL-C, which was significantly lower in LVD than in SVD (p = 0.047). Logistic regression adjusted for confounders showed that decreased HDL-C (p = 0.020), and smoking (p = 0.019) were significant discriminative factors for LVD vs. SVD. In conclusion, this controlled study shows that hypertriglyceridemia is commonly found in patients with ischemic cerebrovascular disease whatever the etiologic subtype, whereas hypercholesterolemia is related more to SVD and LVD. In addition to hypertension and diabetes, hypercholesterolemia may also be involved in the etiology of SVD and differs from LVD by a lower decrease in HDL-C.
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Clinical impact (cost-effectiveness) of qualifying atypical squamous cells of undeterminate significance (ASCUS) in cases favoring a reactive or dysplastic process. Diagn Cytopathol 2003; 29:4-7. [PMID: 12827706 DOI: 10.1002/dc.10317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The cost-effectiveness of qualifying ASCUS cases into two different subcategories, favoring a reactive (ASCUS-R) or dysplastic process (ASCUS-S), was evaluated at the Centro per lo Studio e la Prevenzione Oncologica of Florence in a prospective study. The study determined the positive predictive value (PPV) for histologically confirmed cervical intraepithelial neoplasia grade 2 (CIN2) or more (CIN>) severe lesion of the two ASCUS subgroups. ASCUS-S had a PPV (10.78%) comparable to low-grade squamous intraepithelial lesions (LSIL) (11.40%). For ASCUS-R cases, the recommendation of 6-mo repeat cytology prompting colposcopy in cases of persistent ASCUS or more severe cytology was also effective, as it selected a subgroup with a relatively high PPV (10.34%). The cost-effectiveness of a protocol based on ASCUS qualification was compared with two other possible options for nonqualified ASCUS cases: immediate colposcopy and colposcopy in persistent ASCUS at 6-mo repeat cytology. The detection rate of CIN2> was substantially higher using ASCUS qualification (35.9 vs 14.8 or 17.1). The cost per ASCUS subject was euro 24.99, 27.11, or 25.14 and that per CIN2> detected was euro 697, 1,831 or 1,470 for the three options, respectively. The evidence that ASCUS detection option implies a higher detection rate of CIN2> and subsequently a lower cost per CIN2> detection must be considered with caution and deserves confirmation by other comparative studies.
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Abstract
The clinical value of biochemical analysis of sperm is still unclear. In this study, we evaluated the potential of several biochemical markers in the seminal plasma (zinc, citrate, acid phosphatase, fructose and neutral alpha-glucosidase) as a screening method in male infertility investigation.
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Gastric acidity and duodenogastric reflux during nasojejunal tube feeding in mechanically ventilated patients. Intensive Care Med 1999; 25:574-80. [PMID: 10416908 DOI: 10.1007/s001340050905] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE In order to prevent gastric microbial overgrowth, which may complicate nasogastric feeding, administration of nutrients more distally into the gut has been advocated in intensive care patients, as it offers the advantage of keeping the stomach empty and acid. In this study, we assessed the impact of jejunal feeding upon gastic pH in a group of mechanically ventilated, critically ill patients, with special focus on duodenogastric reflux as a possible cause of gastric alkalinization during jejunal nutrition. DESIGN Prospective experimental study. SETTING Multidisciplinary intensive care unit of a university hospital. PATIENTS AND METHODS Gastric pH was recorded by continuous pHmetry over a 4-h period of fasting followed by a 4-h period of nasojejunal feeding at 100 kcal/h in 21 mechanically ventilated, critically ill patients. To determine the contribution of duodenogastric reflux to modifications of gastric acidity, the diet was traced with [(111)In] DTPA (pentetic acid) in 11 of these 21 patients; gastric contents were aspirated every 30 min, then analysed for measurement of radioactivity, glucose, and bile acid concentration. MEASUREMENTS AND RESULTS Median intragastric pH increased slightly from 1.59 (1.20-2.73; interquartile range) (fasting) to 2.33 (1.65-4.64) (feeding) (p = 0.013), and the length of time that the pH was 4 or above increased from 1 (0-24) to 9 (0-142) min (p = 0.026). The variability of pH values and the number of acute alkalinization episodes did not change between the two phases. In 10 of 11 patients in which the diet was labeled with [(111)In] DTPA, reflux was documented at a given time of the feeding period. Bile acid concentrations in the stomach increased from 392 (61-1076) (fasting) to 1446 (320-2770) micromol/l (feeding) (p = 0.010) and mean glucose concentration increased from 59 (28-95) to 164 (104-449) mg/dl (p = 0.006). CONCLUSION Duodenogastric reflux is common in mechanically ventilated critically ill patients with nasojejunal feeding tubes. It occurs both during fasting and during nasojejunal feeding. During nasojejunal feeding, moderate alkalinization of the gastric contents occurs as a result of bile and nutrient reflux.
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Mechanisms of acute eosinophilic inflammation in a case of acute eosinophilic pneumonia in a 14-year-old girl. Clin Exp Allergy 1998; 28:504-9. [PMID: 9641579 DOI: 10.1046/j.1365-2222.1998.00231.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Acute eosinophilic pneumonia (AEP) is characterized by respiratory distress, eosinophilic infiltration in the lung, acute onset, resolution of symptoms with corticosteroids and the absence of relapse. Studies to identify the pathophysiology of AEP in adults have demonstrated eosinophil activation in the BAL fluid, and the presence of high levels of interleukin 5 (IL-5) in the BAL. OBJECTIVE To investigate the pathophysiology of AEP with pleural effusion in a paediatric patient. METHODS ECP levels in the BALand pleural fluid was determined by radioimmunoassay. IL-5 and GM-CSF concentrations in the BAL and pleural fluid were measured by Elisa. Immunohistochemistry studies performed on open lung biopsy included a specific ICAM-1 immunostaining and a ECP specific immunostaining (EG2+). RESULTS High levels of ECP were found in the BAL (5 microg/L) and pleural fluid (750 microg/L) demonstrating eosinophil activation at these sites. Immunohistochemistry illustrated activated (EG2+) eosinophils in the interalveolar septa and alveolar space and detected increased expression of ICAM-1 on alveolar epithelial cells. High levels of IL-5 were measured in the BAL (1334 pg/mL) and pleural fluid (7014 pg/mL), while elevated concentrations of GM-CSF (150 pg/mL) were found in the BAL. CONCLUSION We conclude that in this paediatric patient with AEP activated eosinophils were present in the BAL fluid, in the interalveolar septa and in the pleural space while increased ICAM-1 expression was detected on alveolar epithelial cells, contributing, at least partly, for their adhesive interactions. IL-5 and GM-CSF are likely important to the massive eosinophil recruitment and activation in the lung, while IL-5 is probably related to eosinophil accumulation and activation in the pleural space. Thus, lung generation of eosinophil-active cytokines is central to the pathophysiology of AEP in paediatric patients.
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Abstract
Octreotide inhibits the secretion of several hormones and exerts vasopressor effects. To clarify the mechanism of atrial natriuretic factor (ANF) secretion and to assess the cardiovascular effects of octreotide in relation to changes in vasoactive peptide secretion, four groups of conscious dogs were studied: group I (n = 11) received saline infusion after placebo, group II (n = 10), the same infusion after octreotide, group III (n = 10), placebo only and group IV (n = 10) octreotide injection only. Saline (10% body wt) was infused over 40 min after subcutaneous injection of placebo or octreotide (1 microgram/kg). Saline produced a rise (p < 0.001) of plasma ANF from 32.4 +/- 4.1 to 59.0 +/- 8.5 pM after placebo and from 35.6 +/- 5.5 to 77.0 +/- 12.6 pM after octreotide. This rise, not significantly different between groups I and II paralleled a 4-5-fold increase (p < 0.005) of right and left atrial pressures. With a higher dose of octreotide (4 micrograms/kg) injected in 4 dogs, plasma ANF increased by 27.5 +/- 5 pM. During hypervolemia, plasma endothelin-1 remained unchanged but plasma angiotensin II and epinephrine decreased (p < 0.05) approximately by 80% without being affected by octreotide. Octreotide did not influence the basal secretion of ANF, endothelin-1, angiotensin II and catecholamines. However, in basal conditions, octreotide injection resulted in a 9% increase (p < 0.005) of left ventricular systolic pressure, unobserved after placebo. Plasma glucose decreased (p < 0.005) in groups receiving octreotide. Thus, octreotide does not impair the stretch-mediated release of ANF which implies a release mechanism independent from somatostatin receptors and consequent changes in intracellular c-AMP. Octreotide has also a pressor effect, unrelated to changes in vasoactive peptide production.
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Effect of erythromycin on gastric motility in mechanically ventilated critically ill patients: a double-blind, randomized, placebo-controlled study. Crit Care Med 1995; 23:1356-62. [PMID: 7634805 DOI: 10.1097/00003246-199508000-00008] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To document the action of erythromycin on gastric emptying and motility in mechanically ventilated patients. DESIGN Crossover, double-blind, randomized, placebo-controlled study. SETTING General intensive care unit in a university hospital. PATIENTS Ten patients, mechanically ventilated, in a stable hemodynamic condition. INTERVENTIONS Erythromycin (200 mg i.v. over 30 mins) and placebo were infused at mid-morning, on two consecutive days, in a random order. Pressure changes in the gastric antrum were recorded by means of a multi-lumen manometric tube (perfused catheter technique) over a period of 300 mins, beginning with the institution of the erythromycin or placebo infusion. Gastric emptying was simultaneously assessed by the kinetics of the absorption of acetaminophen delivered into the stomach (1 g with 20 mL of water) immediately before the infusion. MEASUREMENTS AND MAIN RESULTS Motility was quantified by determining the number of contractions, the amplitude of contractions, and the Motility Index (Motility Index = natural logarithm [sum of amplitude x number of contractions] + 1). Comparison between placebo and erythromycin was made for the first hour after the infusion and for the whole recording session. The maximal acetaminophen concentration, the time to reach the peak acetaminophen concentration, and the area under the concentration-time curve at 60 mins were obtained from serial determinations of plasma acetaminophen concentrations. Compared with placebo, the mean number of contractions (104 +/- 34 vs. 5 +/- 8; p = .003), the mean amplitude of contractions (52 +/- 16 vs. 20 +/- 17 mm Hg; p = .005), and the Motility Index (13.06 +/- 0.95 vs. 4.45 +/- 3.54; p = .004) were significantly increased during the first hour after erythromycin infusion compared with placebo. Number of contractions (p = .017) and Motility Index (p < .001) after erythromycin infusion remained significantly higher when values throughout the whole recording session were considered. The following data were noted after erythromycin was infused: a) the time to reach the peak acetaminophen concentration was shorter (32 +/- 8 vs. 171 +/- 93 mins; p = .007); b) the maximal acetaminophen concentration was higher (22.09 +/- 6.23 vs. 5.38 +/- 3.80 micrograms/mL; p = .007); and c) the area under the concentration-time curve at 60 mins increased markedly (730 +/- 269 vs. 72 +/- 42 micrograms/min/mL; p = .002) as compared with placebo. CONCLUSION In mechanically ventilated patients, intravenous erythromycin (200 mg over 30 mins) increases indices of antral motility and accelerates gastric emptying as assessed by the kinetics of acetaminophen absorption.
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Abstract
BACKGROUND Endothelin-1, a vasoconstrictive peptide released by endothelium, may be involved in the pathophysiology of hypertension. The goal of the present study was to evaluate the role of endogenous endothelin-1 in renal hypertension in dogs. The model of hypertension consisted of silk tissue wrapping of the left kidney, which produced hypertension associated with perinephritis after 6 to 8 weeks. METHODS AND RESULTS Thirty-two anesthetized open chest dogs were studied randomly: 8 dogs with perinephritic hypertension received the nonpeptidic ETA-ETB receptor antagonist bosentan (group 1); 8 other hypertensive dogs received the vehicle solution (group 2); 8 healthy dogs received bosentan (group 3); and 8 healthy dogs received the vehicle solution (group 4). Bosentan was injected as an intravenous bolus (3 mg/kg) followed by a 1-hour infusion at a rate of 7 mg.kg-1.h-1. In hypertensive dogs, bosentan produced a similar decrease (P = .0001) of both left ventricular systolic and mean aortic pressures, which averaged 38 mm Hg (-22% and -24%, respectively). These parameters remained unchanged with the vehicle solution. Left ventricular end-diastolic and left atrial pressures also declined significantly with bosentan (P = .0005 and P < .05, respectively). Left ventricular lengths tended to decrease. The other cardiovascular parameters (heart rate, peak [+]dP/dt, time constant of relaxation, and coronary vascular resistance) did not change significantly. In healthy dogs, bosentan decreased mean aortic pressure by 19 mm Hg (P = .004). Vehicle solution had no effect. Plasma endothelin-1 levels, similar under basal conditions in healthy and hypertensive dogs, increased 30-fold with bosentan (P = .0001). CONCLUSIONS Specific endothelin-1 receptor antagonism markedly lowers blood pressure in experimental hypertension but is less effective on blood pressure of healthy animals. This suggests that endothelin-1 plays a role in the pathophysiology of hypertension but contributes to a lesser extent to the maintenance of normal blood pressure. This role of endothelin-1 is unrelated to its plasma levels. The increase of plasma endothelin-1 with bosentan, due either to a displacement of endothelin-1 from its receptor or to a feedback mechanism, does not prevent this blood pressure reduction.
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Progression of left ventricular dysfunction secondary to coronary artery disease, sustained neurohormonal activation and effects of ibopamine therapy during long-term therapy with angiotensin-converting enzyme inhibitor. Am J Cardiol 1994; 73:488-93. [PMID: 7908164 DOI: 10.1016/0002-9149(94)90680-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Left ventricular function and neurohormonal status in patients with heart failure remaining symptomatic during therapy with angiotensin-converting enzyme inhibitors were assessed, and the effects of dopaminergic receptor stimulation in this setting were determined. Neurohormonal and left ventricular function (radionuclide angiography) data were obtained in 19 patients with symptomatic ischemic heart failure. Measurements were repeated after 4 to 6 weeks of therapy with the dopamine agonist ibopamine (100 mg, 3 times/day) or placebo administered in a double-blind, randomized, parallel group design. At baseline, despite therapy with enalapril, the angiotensin II levels (mean 39.4 pg/ml; p < 0.01 vs controls) were significantly increased, as were plasma norepinephrine (497 +/- 240 pg/ml; p < 0.01 vs controls), endothelin-1, atrial natriuretic peptide and arginine vasopressin. Moreover, in comparison with pretreatment values, left ventricular ejection fraction had decreased substantially (-9.1%) in patients with plasma norepinephrine > or = 600 pg/ml, but not in those with lower values of norepinephrine. With ibopamine, plasma norepinephrine decreased from 516 +/- 241 to 391 +/- 208 pg/ml (n = 8; p < 0.025 vs placebo), whereas it increased with placebo. In conclusion, the neurohormonal control provided by an angiotensin-converting enzyme inhibitor is reduced in a large subset of patients during prolonged therapy; ibopamine appears to be a potentially useful drug to improve neurohormonal control in this setting.
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Effects of endothelin-1 at pathophysiologic concentrations on coronary perfusion and mechanical function of normal and postischemic myocardium. J Cardiovasc Pharmacol 1994; 23:212-9. [PMID: 7511749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We assess hemodynamic, vascular, and hormonal effects of endothelin-1 (ET-1) at pathophysiologic levels on normal and ischemic myocardium. Thirty conscious chronically instrumented dogs were studied before, during, and after a 10-min coronary artery occlusion (CAO) performed either during ET-1 infusion (2.5 ng/kg.min, n = 15) or during placebo infusion (n = 15). ET-1 infusion produced an increase in plasma ET-1 (from 1.3 +/- 0.1 to 11.5 +/- 1.1 pM, p < 0.0001) during CAO (pathophysiologic value). Left anterior descending artery (LAD) blood flow (measured by Doppler flow probe) decreased similarly during CAO with ET-1 or placebo (p = 0.0001, NS, ET-1 vs. placebo). Both endocardial and epicardial blood flows in ischemic regions also decreased (p = 0.0001) during CAO but were threefold greater with ET-1 than with placebo (endocardium 42 +/- 7 vs. 14 +/- 2 ml/min/100 g, p = 0.003). No significant difference in myocardial blood flows between groups was observed in control regions. CAO produced increases (p < 0.005) in heart rate (HR), mean aortic pressure (AOP), and ventricular pressures but no change in atrial pressures. The changes in these parameters were comparable in the ET-1 and placebo groups. Despite the greater residual flow during CAO, however, ET-1 decreased the function of the ischemic zone during reperfusion as assessed by systolic shortening (p < 0.05). Atrial natriuretic factor (ANF), unchanged during CAO with placebo, increased from 38.3 +/- 6.1 to 53.3 +/- 10 pM with ET-1 (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
OBJECTIVE To investigate subjects with different types of diabetes mellitus regarding their serum levels of lipoprotein(a). High serum Lp(a) concentration is associated with a high risk of coronary heart disease. Diabetic patients are prone to developing coronary heart disease. RESEARCH DESIGN AND METHODS The subjects were 66 type I diabetic patients, 100 type II diabetic patients treated with diet alone or diet combined with oral hypoglycemic agents, and 46 insulin-requiring type II diabetic patients. Subjects were compared with 142 nondiabetic outpatients. RESULTS Subjects with insulin-requiring type II diabetes mellitus were found to have an increase both in serum Lp(a) concentration and in prevalence of serum Lp(a) concentration > 30 mg/dl compared with the other groups of diabetic patients and nondiabetic control subjects. A nonsignificant increase in the prevalence of coronary heart disease was also found in insulin-requiring type II diabetic patients. The levels of serum concentrations of Lp(a) were not significantly related to the degree of glycemic control, duration of diabetes, presence of macrovascular disease, or intake of female hormone therapy. High levels of Lp(a) in this group of diabetic patients could not be explained by the presence of albuminuria. CONCLUSIONS Insulin-requiring type II diabetic patients have high levels of Lp(a). Chronic hyperinsulinemia might be an eventual causal factor.
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Effect of a motilin receptor agonist infusion on gastric emptying and motility in critically ill patients: A double blind, placebo controlled, cross-over study. Clin Nutr 1993. [DOI: 10.1016/0261-5614(93)90273-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Low-dose endothelin-1 potentiates volume-induced secretion of atrial natriuretic factor. THE AMERICAN JOURNAL OF PHYSIOLOGY 1992; 263:H939-44. [PMID: 1415620 DOI: 10.1152/ajpheart.1992.263.3.h939] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To evaluate the role of calcium in volume-induced secretion of atrial natriuretic factor (ANF), effects of verapamil and endothelin-1 (ET-1), both known to influence free intracellular calcium, were studied during saline infusion in seven conscious instrumented dogs. Fifteen minutes after intravenous injection of placebo or verapamil (0.25 mg/kg) or during continuous ET-1 infusion (at 5 ng.kg-1.min-1), saline (10% body wt) was infused during 40 min. Saline produced a rise (P less than 0.001) of plasma ANF from 28.1 +/- 6.3 to 50.4 +/- 12.9 pM after placebo, from 30.2 +/- 6.1 to 51.1 +/- 8.5 pM after verapamil, and from 31.2 +/- 6.1 to 81.0 +/- 12.9 pM with ET-1. This increase was comparable after placebo and verapamil, but was 80% greater with ET-1 (P less than 0.02). Plasma ET-1, unchanged after placebo, rose (P less than 0.001) from 1.7 +/- 0.5 to 38.3 +/- 9.2 pM with ET-1. In the three experiments, heart rate and left atrial pressure (LAP) increased (P less than 0.001) similarly. The linear relation between ANF and LAP was steeper with ET-1 than with saline or verapamil (both P less than 0.05), indicating that the enhanced ANF secretion with ET-1 was occurring at all levels of LAP. Thus volume-induced secretion of ANF is not suppressed by verapamil, but is directly enhanced by low-dose ET-1, known to activate the phosphoinositide pathway.
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Cardiovascular and endocrine effects of endothelin-1 at pathophysiological and pharmacological plasma concentrations in conscious dogs. Circulation 1991; 84:2476-84. [PMID: 1835679 DOI: 10.1161/01.cir.84.6.2476] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Increased plasma concentrations of endothelin-1, a potent vasoconstrictor produced by the endothelium, have been reported in various pathological conditions. This study was conducted to evaluate effects of endothelin-1 at pathophysiological and pharmacological plasma concentrations. METHODS AND RESULTS Endothelin-1 was infused at increasing doses (2.5, 5, 10, and 20 ng/kg.min for 1 hour each) in nine conscious dogs. During endothelin-1 infusion, plasma endothelin-1 rose from a basal value of 1.8 +/- 0.4 pmol/l to 5.8 +/- 1.1 (pathophysiological), 20.8 +/- 3.9 (pathophysiological), 85.4 +/- 18.9 (pharmacological), and 311.4 +/- 55.7 (pharmacological) pmol/l at each dose, respectively. Heart rate increased at 2.5 ng/kg.min (from 129 +/- 7 to 146 +/- 12 beats/min) but decreased at 20 ng/kg.min (97 +/- 7 beats/min) (p less than 0.001). Such a biphasic response was also observed for peak (+)dP/dt and (dP/dt)/DP40 (p less than 0.005). Left ventricular systolic pressures, mean aortic pressure, and left atrial pressure increased over time (p less than 0.05, p less than 0.005, and p less than 0.001, respectively). The time constant of early isovolumic relaxation rose progressively (p less than 0.001). The percent systolic shortening decreased at 10 and 20 ng/kg.min (p less than 0.005). Pressure-segment length loops showed a reduction in systolic shortening associated with an increase in left ventricular systolic pressure at 20 ng/kg.min. Atrial natriuretic factor rose after 5 ng/kg.min from 28.5 +/- 6.5 to 92.0 +/- 18.2 pmol/l (p less than 0.005). Angiotensin II and catecholamines did not change significantly. Serum urea and creatinine rose progressively (p less than 0.05), whereas glucose decreased (p less than 0.05). The above results differed significantly from measurements obtained in a time-control group of six dogs. CONCLUSIONS A fourfold increase of plasma endothelin-1 obtained after doubling the infusion rate suggests a reduction in endothelin-1 clearance or endothelin-1 endogenous production. The biphasic response of heart rate is consistent with baroreflex-mediated effects resulting from vasodilation at the pathophysiological level and vasoconstriction at the pharmacological level. Hemodynamic data suggest an increase followed by a decrease in contractility at both levels, respectively. Finally, endothelin-1 is a stimulator of atrial natriuretic factor.
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