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Efficacy and follow-up of anti-VEGF injections in diabetic macular edema in real-life practice at the Dijon university medical centre through the Save Sight Registries. J Fr Ophtalmol 2020; 43:618-625. [PMID: 32473741 DOI: 10.1016/j.jfo.2019.10.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/18/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE To evaluate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections (IVT) in diabetic macular edema (DME) in real-life practice using the Save Sight Registries (SSR). MATERIAL AND METHODS We conducted an observational, single-centre, retrospective study in the department of ophthalmology of the Dijon University Hospital. We included treatment-naive patients who presented with DME between January 2016 and December 2017. Demographic and clinical data, follow-up visits, and treatments administered were entered into the SSR, an international online ophthalmic registry. Primary endpoints were the change in best-corrected visual acuity (BCVA) and central subfield thickness (CST) from baseline to 12 and 24 months. RESULTS Fifty-eight eyes of 43 patients with a mean [standard deviation (SD)] age of 67.1 [9.5] years were included. Forty-one eyes completed 12 months of follow-up, and 17 eyes completed 24 months of follow up. Median [SD] baseline BCVA was 56.1 [22.9] ETDRS letters and the median [95% confidence interval (95% CI)] baseline CST was 447.9 [161.0] micrometers (μm). Median [95% CI] improvement in BCVA from baseline to months 12 and 24 were respectively, +5.6 [+0.5; +10.7] ETDRS letters and +7.7 [-2.8; +18.2] ETDRS letters. The median [95% CI] decrease in CST from baseline to months 12 and 24 were respectively, -110.9 [-154.5; -67.3] μm and -125.5 [-198.0; -53.0] μm. CONCLUSION Our clinical practice can be evaluated easily with the SSR system. In real life, anti-VEGF IVT are an effective treatment for DME, which result in improved BCVA and decreased CST.
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Lipoprotein(A), Oxidized Phospholipids, And Aortic Valve Microcalcification Assessed By 18f-Naf Pet/Ct. Atherosclerosis 2019. [DOI: 10.1016/j.atherosclerosis.2019.06.322] [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: 11/17/2022]
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A new polymer-based approach for in vivo transfection in postnatal brain. J Neurosci Methods 2019; 311:295-306. [PMID: 30408559 DOI: 10.1016/j.jneumeth.2018.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/26/2018] [Accepted: 11/04/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Gene delivery within the central nervous system at postnatal age is one of the most challenging tasks in neuroscience and currently only a few effective methods are available. COMPARISON WITH EXISTING METHODS For postnatal central nervous system cells, viral approaches are commonly used for genetic engineering but they face several biosafety requirements for production and use making them less accessible to the community. Conversely, lipid-based methods are widely used in cell culture but face limitation in vivo mainly due to the inflammatory responses they induce. To this aspect, the use of a transgenic mouse line can represent a credible answer to the community working on rat models still requires an effective and successful solution to circumvent these difficulties. NEW METHOD We describe a new polymer-based gene delivery system allowing persistent and robust in vivo transfection with low DNA amount, reduced inflammation and high diffusion. The expression profile along the brain, the stability, the diffusion of the DNA together with the quantity of cells transfected were evaluated through in vivo approaches. RESULTS With a single low-volume injection, we targeted different cell types within the rat brain. We measured the diffusion rate ranging from 1 to 5 mm based on the injected volume, in the three-dimensions axis. Finally, we modified brain susceptibility to epileptic seizures using a specific knock-down of the neuronal specific potassium-chloride transporter 2. CONCLUSIONS This safe and easy system opens perspectives for non viral gene delivery in the rat brain with perspectives to study brain function in vivo.
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0123 Cortisol, Sleep And Heart Rate Variability In Resting Neurotypical And Autistic Adults. Sleep 2018. [DOI: 10.1093/sleep/zsy061.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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1166 POOR SLEEP IS ASSOCIATED WITH MORNING HIGH SYMPATHETIC ACTIVITY AND LOW PARASYMPATHETIC ACTIVITY IN RESTING NEUROTYPICAL AND AUTISTIC ADULTS. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.1165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Morphology-induced phonon spectra of CdSe/CdS nanoplatelets: core/shell vs. core-crown. NANOSCALE 2016; 8:17204-17212. [PMID: 27722399 DOI: 10.1039/c6nr06949e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recently developed two-dimensional colloidal semiconductor nanocrystals, or nanoplatelets (NPLs), extend the palette of solution-processable free-standing 2D nanomaterials of high performance. Growing CdSe and CdS parts subsequently in either side-by-side or stacked manner results in core-crown or core/shell structures, respectively. Both kinds of heterogeneous NPLs find efficient applications and represent interesting materials to study the electronic and lattice excitations and interaction between them under strong one-directional confinement. Here, we investigated by Raman and infrared spectroscopy the phonon spectra and electron-phonon coupling in CdSe/CdS core/shell and core-crown NPLs. A number of distinct spectral features of the two NPL morphologies are observed, which are further modified by tuning the laser excitation energy Eexc between in- and off-resonant conditions. The general difference is the larger number of phonon modes in core/shell NPLs and their spectral shifts with increasing shell thickness, as well as with Eexc. This behaviour is explained by strong mutual influence of the core and shell and formation of combined phonon modes. In the core-crown structure, the CdSe and CdS modes preserve more independent behaviour with only interface modes forming the phonon overtones with phonons of the core.
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EFS Centre-Atlantique donor's biobank: Ten years of samples usage. Transfus Clin Biol 2015; 23:95-7. [PMID: 26711889 DOI: 10.1016/j.tracli.2015.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/02/2015] [Indexed: 11/18/2022]
Abstract
INTRODUCTION The French Establishment of Blood Centre Atlantique (EFSCA) is one of the French regional blood transfusion centers. Donor's biobank is a mandatory activity leading to the storage of biological samples taken from the blood donor. Samples of each blood donation are preserved for a 5-year period at Châteauroux in the form of two straws of 500microliters stored in liquid nitrogen. The aim of this study was to analyze the samples usage by studying quantitative, qualitative and economic criteria. MATERIAL AND METHOD We analyzed all the requests of stored blood samples from 2005 to 2014. They were coming either from the blood donor qualification laboratory (BDQL), in order to perform complementary tests, or from hemovigilance inquiry. RESULTS Among the blood donation samples, 2,144,636 (whole blood, plasma or platelets apheresis) were preserved during these ten years. During this period, 548 (0.025%) requests for samples were received; 78% were in relation with a request of the BDQL and 22% in relation with a request of hemovigilance. For the straws, the mean exit delay with regard to the blood donation date was 11.5 months (2-55). The cost of samples exit includes only working hours of a laboratory technician. On average, the annual working time dedicated to this activity was 23h. Also, the average price for one-year issuing activity was 620.31 euros. CONCLUSION In our study, the donor's biobank was little used. The part of hemovigilance was weak but essential for the blood safety.
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555 18F-FDG PET/CT as a new imaging modality for diagnosis of cardiac device infections (PET-ID). Can J Cardiol 2011. [DOI: 10.1016/j.cjca.2011.07.459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Synthesis of novel amphiphilic di-block and multiarmed star-shaped copolymers based on polyisobutylene and poly(ethylene oxide). ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19971220157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bioinformatic Analysis Of Epithelial Cell Gene Expression In Chronic Rhinosinusitis Identifies Constitutive Differences Between CRSwNP And CRSsNP. J Allergy Clin Immunol 2011. [DOI: 10.1016/j.jaci.2010.12.1070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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344 Chirurgie de la cataracte sous anesthésie topique par Oxybuprocaïne 0,4 % collyre : étude prospective de faisabilité ; à propos de 1 600 cas. J Fr Ophtalmol 2007. [DOI: 10.1016/s0181-5512(07)80156-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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554 Mélanocytome et baisse brutale d’acuité visuelle : à propos d’un cas de neuropathie optique ischémique antérieure aiguë (NOIAA). J Fr Ophtalmol 2005. [DOI: 10.1016/s0181-5512(05)73673-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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[Endocarditis due to Bacteroides fragilis revealed by portal thrombosis: a case report]. Rev Med Interne 2005; 25:473-5. [PMID: 15158322 DOI: 10.1016/j.revmed.2004.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Accepted: 01/26/2004] [Indexed: 11/30/2022]
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Abdominal skin temperature variation in healthy broiler chickens as determined by thermography. Poult Sci 2003; 82:846-9. [PMID: 12762409 DOI: 10.1093/ps/82.5.846] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abdominal skin temperature of healthy broiler chickens was determined by thermography to estimate the normal range of between- and within-bird temperature variation. Effects of potential confounding factors, such as bird's contention duration, abdominal side, age, and time of day, were also estimated. Mean skin temperature was estimated from thermogram pictures by computer image analysis of a predetermined abdominal area. Results demonstrated that skin temperature was not significantly affected by contention duration. However, skin temperature was higher on the right abdominal side in younger birds and at 1200 h. Between- and within-bird variation in healthy birds was small (< 0.5 degrees C) when age, abdominal side, and time of day were taken into account. This work suggests that skin temperature measurement using thermography can be adapted for the study of skin temperature in broiler chickens.
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Endocardite à Bacteroides fragilis : Une observation. Rev Med Interne 2002. [DOI: 10.1016/s0248-8663(02)80611-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Structure-based chimeric enzymes as an alternative to directed enzyme evolution: phytase as a test case. J Biotechnol 2001; 85:15-24. [PMID: 11164958 DOI: 10.1016/s0168-1656(00)00373-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Thermostability is a key feature for commercially attractive variants of the fungal enzyme phytase. In an initial set of experiments, we restored ionic interactions and hydrogen bonds on the surface of Aspergillus terreus phytase, which are present in the homologous but more thermostable enzyme from A. niger. Since these mutations turned out to be neutral, we replaced-in the same region and based on the crystal structure of A. niger phytase-entire secondary structure elements. The replacement of one alpha-helix on the surface of A. terreus phytase by the corresponding stretch of A. niger phytase resulted in an enzyme with improved thermostability and unaltered enzymatic activity. Surprisingly, the thermostability of this hybrid protein was very similar to that of A. niger phytase, although the fusion protein contained only a 31 amino acid stretch of the more stable parent enzyme. This report provides evidence that structure-based chimeric enzymes can be used to exploit the evolutionary information within a sequence alignment. We propose this method as an alternative to directed enzyme evolution if due to expression constraints the screening of large mutant populations is not feasible.
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Cellulitis in broiler chickens: a one-year retrospective study in four Québec abattoirs. Avian Dis 2001; 45:191-4. [PMID: 11332482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A 1-yr retrospective study was undertaken to verify whether the prevalence of cellulitis in broiler chicken flocks was associated 1) with sex and average body weight controlling for the time of year and 2) with some other condemnation causes such as air-sacculitis, ascites, cyanosis, emaciation, valgus varus deformity, peritonitis, and total condemnation rate controlling for sex, average body weight, and time of year. Data were collected from four Québec abattoirs between October 1992 and September 1993. Data from 2452 unisex male and female broiler flocks were compiled and analyzed with univariate and multivariate models. The prevalence of cellulitis among flocks was 42.2 per 10,000 birds slaughtered. Cellulitis was associated with sex and increased with time of year (P < 0.0001). The prevalence was higher in male (mean +/- SD, 50.7+/-24.3; median, 31.8) than in female flocks (mean +/- SD, 34.2+/-15.6; median, 20.0) but showed no relationship with average body weight. Associations between condemnation causes and cellulitis were relatively weak; increases in the prevalence of cellulitis correlated with increases in total condemnation rate (r2 = 0.19), ascites (r2 = 0.09), airsacculitis (r2 = 0.0), cyanosis (r2 = 0.04), peritonitis (r2 = 0.03), emaciation (r2 = 0.02), and valgus varus deformity (r2 = 0.02). These results suggest that flock sex is a potential correlate of cellulitis prevalence in broiler chickens. Associations between the prevalence of cellulitis and other diseases observed at the abattoir were not very strong. However, it appears here that general disease status of Québec broiler flocks is a better indicator of cellulitis occurrence than the main diseases considered individually.
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[Influence of biotic and abiotic factors on the morphology and reproduction of Suaeda maritima on a salt marsh]. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 2000; 323:905-11. [PMID: 11098406 DOI: 10.1016/s0764-4469(00)01233-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this study was to estimate the influence of biotic and abiotic factors on Suaeda maritima reproduction on a salt marsh. Individuals of Suaeda maritima were submitted in natural conditions to four series of densities (100, 1,000, 4,000 and 8,000 plants/m2). When density increases, individuals tend to be less or non-branched, while individual biomass decreases. Consequently, individual seed production decreases as density increases. Despite morphological modifications, Suaeda maritima present density-dependent mortality. For a unit area, total biomass and seed production are higher at intermediate density (1,000 plants/m2). Environmental factors could interfere with self-thinning. They seem to limit the effect of competition on mortality and to have an influence on individual and total seed production. This experiment stressed the importance of a biotic factor such as intra-specific competition, which occurs at the same time as abiotic factors, in Suaeda maritima dynamics in the field.
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Optimization of the catalytic properties of Aspergillus fumigatus phytase based on the three-dimensional structure. Protein Sci 2000; 9:1304-11. [PMID: 10933495 PMCID: PMC2144679 DOI: 10.1110/ps.9.7.1304] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Previously, we determined the DNA and amino acid sequences as well as biochemical and biophysical properties of a series of fungal phytases. The amino acid sequences displayed 49-68% identity between species, and the catalytic properties differed widely in terms of specific activity, substrate specificity, and pH optima. With the ultimate goal to combine the most favorable properties of all phytases in a single protein, we attempted, in the present investigation, to increase the specific activity of Aspergillus fumigatus phytase. The crystal structure of Aspergillus niger NRRL 3135 phytase known at 2.5 A resolution served to specify all active site residues. A multiple amino acid sequence alignment was then used to identify nonconserved active site residues that might correlate with a given favorable property of interest. Using this approach, Gln27 of A. fumigatus phytase (amino acid numbering according to A. niger phytase) was identified as likely to be involved in substrate binding and/or release and, possibly, to be responsible for the considerably lower specific activity (26.5 vs. 196 U x [mg protein](-1) at pH 5.0) of A. fumigatus phytase when compared to Aspergillus terreus phytase, which has a Leu at the equivalent position. Site-directed mutagenesis of Gln27 of A. fumigatus phytase to Leu in fact increased the specific activity to 92.1 U x (mg protein)(-1), and this and other mutations at position 27 yielded an interesting array of pH activity profiles and substrate specificities. Analysis of computer models of enzyme-substrate complexes suggested that Gln27 of wild-type A. fumigatus phytase forms a hydrogen bond with the 6-phosphate group of myo-inositol hexakisphosphate, which is weakened or lost with the amino acid substitutions tested. If this hydrogen bond were indeed responsible for the differences in specific activity, this would suggest product release as the rate-limiting step of the A. fumigatus wild-type phytase reaction.
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Parallel gene expression monitoring using oligonucleotide probe arrays of multiple transcripts with an animal model of focal ischemia. J Cereb Blood Flow Metab 2000; 20:1045-55. [PMID: 10908038 DOI: 10.1097/00004647-200007000-00004] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
High density oligonucleotide arrays offer tremendous potential to study gene changes occurring in disease states. The authors described the first case of using a custom designed high density oligonucleotide probe array containing 750 genes to monitor the changes in mRNA transcript levels occurring after focal ischemia for a period of 3 hours. Permanent middle cerebral artery occlusion in the rat resulted in neuronal degeneration in the dorsolateral cortex and striatum over a time course of 24 hours. Comparing the changes in hybridization levels in the frontal and parietal cortices and the striatum, between the ipsilateral and contralateral sides of the brain using the probe arrays resulted in the up-regulation of 24 genes, which showed greater than a twofold change. Very few genes were found to be downregulated after the ischemic insult. Many of the immediate early genes (IEGs) such as c-fos, NGFI-A, NGFI-C, and Krox-20 were found to be robustly upregulated in the three different regions studied. Other genes that were up-regulated in perifocal regions included Arc, Inhibin-beta-A, and the phosphatases MKP-1 and MKP-3. The hybridization signal intensity from the probe arrays enabled quantification of many genes relative to one another, and robust changes in expression were obtained with very little interanimal variability. Furthermore, the authors were able to validate the increased expression of NGFI-C and Arc using in situ hybridization. This represented the first example of using high density oligonucleotide probe arrays in studying the expression of many genes in parallel and in discrete brain regions after focal ischemia.
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Synthesis and characterization of poly(copolyethers-block-polyamides) II. Characterization and properties of the multiblock copolymers. POLYMER 2000. [DOI: 10.1016/s0032-3861(99)00526-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The wild-type phytases from the Aspergillus niger strains NRRL 3135 and T213 display a three-fold difference in specific activity (103 versus 32 U/mg protein), despite only 12 amino acid differences that are distributed all over the sequence of the protein. Of the 12 divergent positions, three are located in or close to the substrate binding site. Site-directed mutagenesis of these residues in A. niger T213 phytase showed that the R297Q mutation (R in T213, Q in NRRL 3135) fully accounts for the differences in catalytic properties observed. Molecular modelling revealed that R297 may directly interact with a phosphate group of phytic acid. The fact that this presumed ionic interaction - causing stronger binding of substrates and products - correlates with a lower specific activity indicates that product (myo-inositol pentakisphosphate) release is the rate-limiting step of the reaction.
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Abstract
PURPOSE Sauna bathing is a popular recreational activity that is generally considered to be safe. However, there have been case reports of adverse cardiac events. We sought to determine whether sauna use caused myocardial ischemia in patients with coronary artery disease. METHODS Sixteen patients with proven coronary artery disease were submitted to three conditions (rest, exercise, and sauna bathing) with continuous electrocardiographic (ECG) monitoring and regular blood pressure measurements. During each condition, patients were injected with Tc-99 sestamibi followed by nuclear scintigraphic imaging. Perfusion defect scores were calculated in 15 patients. RESULTS Sauna bathing was well tolerated. There was a mean (+/- SD) increase in heart rate of 32% +/- 20% in the sauna (resting mean heart rate = 60 +/- 9 beats per minute vs sauna mean heart rate = 79 +/- 11 beats per minute, P <0.001) and a 13% +/- 6% drop in systolic blood pressure (resting mean systolic blood pressure = 142 +/- 14 mm Hg vs sauna mean systolic blood pressure = 123 +/- 15 mm Hg, P <0.001). There were no arrhythmias or ECG changes in the sauna. Compared with rest, there was significant ischemia during sauna bathing (average perfusion defect score at rest = -0.44 vs average sauna score = -0.93, P <0.001). The perfusion defect score in the sauna was worse than the resting score in 14 of the 15 patients. Sauna-associated perfusion defect scores were highly correlated with exercise-induced scores (R2 = 0.65, P <0.001). CONCLUSION In patients with stable coronary artery disease, sauna use is clinically well tolerated but is associated with scintigraphically demonstrated myocardial ischemia.
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Biophysical characterization of fungal phytases (myo-inositol hexakisphosphate phosphohydrolases): molecular size, glycosylation pattern, and engineering of proteolytic resistance. Appl Environ Microbiol 1999; 65:359-66. [PMID: 9925554 PMCID: PMC91033 DOI: 10.1128/aem.65.2.359-366.1999] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phytases (myo-inositol hexakisphosphate phosphohydrolases) are found naturally in plants and microorganisms, particularly fungi. Interest in these enzymes has been stimulated by the fact that phytase supplements increase the availability of phosphorus in pig and poultry feed and thereby reduce environmental pollution due to excess phosphate excretion in areas where there is intensive livestock production. The wild-type phytases from six different fungi, Aspergillus niger, Aspergillus terreus, Aspergillus fumigatus, Emericella nidulans, Myceliophthora thermophila, and Talaromyces thermophilus, were overexpressed in either filamentous fungi or yeasts and purified, and their biophysical properties were compared with those of a phytase from Escherichia coli. All of the phytases examined are monomeric proteins. While E. coli phytase is a nonglycosylated enzyme, the glycosylation patterns of the fungal phytases proved to be highly variable, differing for individual phytases, for a given phytase produced in different expression systems, and for individual batches of a given phytase produced in a particular expression system. Whereas the extents of glycosylation were moderate when the fungal phytases were expressed in filamentous fungi, they were excessive when the phytases were expressed in yeasts. However, the different extents of glycosylation had no effect on the specific activity, the thermostability, or the refolding properties of individual phytases. When expressed in A. niger, several fungal phytases were susceptible to limited proteolysis by proteases present in the culture supernatant. N-terminal sequencing of the fragments revealed that cleavage invariably occurred at exposed loops on the surface of the molecule. Site-directed mutagenesis of A. fumigatus and E. nidulans phytases at the cleavage sites yielded mutants that were considerably more resistant to proteolytic attack. Therefore, engineering of exposed surface loops may be a strategy for improving phytase stability during feed processing and in the digestive tract.
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Gene cloning, purification, and characterization of a heat-stable phytase from the fungus Aspergillus fumigatus. Appl Environ Microbiol 1997; 63:1696-700. [PMID: 9143104 PMCID: PMC168464 DOI: 10.1128/aem.63.5.1696-1700.1997] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The finding of heat-stable enzymes or the engineering of moderately thermostable enzymes into more stable ones by random or site-directed mutagenesis has become a main priority of modern biotechnology. We report here for the first time a heat-stable phytase able to withstand temperatures up to 100 degrees C over a period of 20 min, with a loss of only 10% of the initial enzymatic activity. The gene (phyA) encoding this heat-stable enzyme has been cloned from Aspergillus fumigatus and overexpressed in Aspergillus niger. The enzyme showed high activity with 4-nitrophenyl phosphate at a pH range of 3 to 5 and with phytic acid at a pH range of 2.5 to 7.5.
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Isolation and characterization of the carotenoid biosynthesis genes of Flavobacterium sp. strain R1534. Gene X 1997; 185:35-41. [PMID: 9034310 DOI: 10.1016/s0378-1119(96)00624-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The Gram-negative bacterium Flavobacterium sp. strain R1534 is a natural producer of zeaxanthin. A 14 kb genomic DNA fragment of this organism has been cloned and a 5.1 kb piece containing the carotenoid biosynthesis genes sequenced. The carotenoid biosynthesis cluster consists of five genes arranged in at least two operons. The five genes are necessary and sufficient for the synthesis of zeaxanthin. The encoded proteins have significant homology to the crtE, crtB, crtY, crtI and crtZ gene products of other carotenogenic organisms. Biochemical assignment of the individual gene products was done by HPLC analysis of the carotenoid accumulation in Escherichia coli host strains transformed with plasmids carrying deletions of the Flavobacterium sp. strain R1534 carotenoid biosynthesis cluster.
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Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry of synthetic polyesters. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0168-1176(95)04159-i] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Effects of a low-doses treatment with cuprum on neostigmine digestive action in female mice. Drug Dev Res 1991. [DOI: 10.1002/ddr.430240304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Conversion-electron Mössbauer spectroscopy studies in amorphous Tb-Fe films. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:11931-11933. [PMID: 9946106 DOI: 10.1103/physrevb.38.11931] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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The limited photochemical activity of solid aggregated forms of bovine rhodopsin. Biochem Cell Biol 1988; 66:161-6. [PMID: 3382541 DOI: 10.1139/o88-022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The visual pigment rhodopsin has been purified and depleted of detergent. Under these conditions, the pigment strongly aggregates. When dried, a significant fraction of these aggregates appear insensitive to light. We have characterized them by means of absorption and photoacoustic spectroscopies and we find that their photochemical behavior is best explained by a limited activity that does not reach photointermediates beyond the lumirhodopsin step in the bleaching sequence of rhodopsin. We interpret this result as an indication of a significant conformational change of the protein during the transition from lumi- to meta-rhodopsin.
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Structural study of telechelic oligoisobutylenes in relation with the experimental conditions of their synthesis. Eur Polym J 1986. [DOI: 10.1016/0014-3057(86)90065-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Synthesis of mono and difunctional oligoisobutylenes—IV. Modification of α,ω-dichlorooligoisobutylene by reaction with maleic anhydride. Preliminary study on block polycondensation. Eur Polym J 1984. [DOI: 10.1016/0014-3057(84)90049-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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34
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[Adolescence and sexuality : the stakes in prevention.]. SANTE MENTALE AU QUEBEC 1984; 9:64-73. [PMID: 17093819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Studies of adolescent girls underline the limits of clinical services in the prevention of undesired pregnancies. This article concerns a study carried out at the St-Denis Youth Clinic with the aim of collecting data to permit the development of adequate preventive measures in work with the adolescent population. The author deals with factors linked to the development of the adolescent personality and presents two theories explaining preventive behaviour. She gives an account of evaluations of current practices in Quebec in relation to sexuality and contraception, and suggests avenues to pursue at different levels of prevention.
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[The St-Denis youth clinic.]. SANTE MENTALE AU QUEBEC 1984; 9:74-82. [PMID: 17093820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Clinique des Jeunes St-Denis was founded in 1977 to provide complete medical and psychosocial services to young clients in matters of sexuality. The work assumed by a multi-disciplinary team has provided its members with an opportunity for growth and allowed them to investigate the different aspects of their work load. The actual clinical needs and the effective treatment are discussed : abortion, incest, sexually transmitted diseases, etc. Groups are formed in order to perceive the adolescent as a whole and not only its sexual dimension ; and a concern for preventive action is always present. A research on these matters has been initiated.
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Synthesis of mono and difunctional oligoisobutylenes—III. Modification of α-chlorooligoisobutylene by reaction with maleic anhydride. Eur Polym J 1984. [DOI: 10.1016/0014-3057(84)90048-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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37
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Amino-acids condensations in the preparation of N alpha-9-fluorenylmethyloxycarbonylamino-acids with 9-fluorenylmethylchloroformate. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:125-8. [PMID: 6885246 DOI: 10.1111/j.1399-3011.1983.tb02076.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Synthesis of N alpha-9-fluorenylmethyloxycarbonyl (Fmoc) amino-acids by reaction of free amino-acids (glycine and alanine) with 9-fluorenylmethylchloroformate leads to formation of small amounts of Fmoc-dipeptide which are difficult to eliminate by crystallization. The alternative way to prepare Fmoc-amino-acids by reacting the Fmoc-chloride first with sodium azide and then with the free amino-acid eliminates this side reaction, at least for glycine and alanine.
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Are interactions with phospholipids responsible for pharmacological activities of cardiotoxins? Mol Cell Biochem 1983; 55:49-64. [PMID: 6353198 DOI: 10.1007/bf00229242] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cardiotoxins are small basic proteins (7 000 daltons) that are found in the venoms of Elapidae snakes. Although they are structurally close to alpha-neurotoxins present in the same secretions, their activity is related to their ability to interact with every cell membrane inducing, near micromolar concentration, the modification of its biological properties and/or physical structure. The mode of action of cardiotoxins, on a molecular level, is still under investigation. However, lipid-protein interactions are more and more involved in their binding to membrane and in their activities. Using new experimental data a better definition of phospholipid-cardiotoxin interaction is arrived at and a tentative molecular explanation of the pharmacological activities of these proteins is presented and discussed.
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Abstract
Four cardiotoxins (CTX I-IV) from Naja mossambica mossambica were compared for their ability to interact with phospholipid vesicles and their capacity to bind erythrocytes. It is concluded that the affinity of the toxins always increases in the order: I approximately equal to II less than III less than IV. The binding is specific for charged lipids even in lipid mixtures. Proteolytic attack of the free and lipid-bound cardiotoxin indicates that at least the first loop Leu1-Thr13 is at the lipid contact. Tryptic and synthetic peptides constitutive of this loop are shown to interact with lipids. Arg5 residue increases the affinity toward the bilayer. The Raman spectra of lipid-bound cardiotoxin indicate a secondary and tertiary structure mainly similar to that of the free toxin. On charged lipids cardiotoxins induce a decrease of the enthalpy and an increase of disorder without change in the transition temperature; at saturating amounts of toxin the transition is abolished. In binary mixtures of phosphatidylcholine and charged lipids the observed effects can be accounted by a phase separation induced by the toxin.
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Binding of 125I-toxin, from the spitting cobra Naja mossambica mossambica, at frog neuromuscular junctions. Toxicon 1978; 16:682-5. [PMID: 725961 DOI: 10.1016/0041-0101(78)90197-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Role de l'eau sur les caracteres morphologiques et la cristallisation du zircon dans les granitoides. ACTA ACUST UNITED AC 1978. [DOI: 10.2113/gssgfbull.s7-xx.5.721] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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