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Does vaginal bacterial colonization contribute to preterm birth in women with asymptomatic shortened cervix? Arch Gynecol Obstet 2024:10.1007/s00404-024-07397-2. [PMID: 38578544 DOI: 10.1007/s00404-024-07397-2] [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: 07/30/2023] [Accepted: 01/22/2024] [Indexed: 04/06/2024]
Abstract
PURPOSE The aim of this study is to describe the typical microbial spectrum and the influence of distinct vaginal infections on preterm birth in pregnancies affected by cervical incompetence. METHODS 327 patients were admitted because of asymptomatic shortening of the cervix in the second and third trimester of pregnancy. Clinical data such as age, cervical length, gestational age at admission and at delivery and vaginal microbiologic findings were collected and analyzed. RESULTS The spectrum of germs in the vagina revealed seven different distinct species; the most common bacteria were Ureaplasma spp. and E. coli. In 327 included patients, 217 revealed a bacterial colonization, 110 did not. Most common bacteria in women with preterm birth before 34 weeks were Ureaplasma spp., while E. coli was most common in women undergoing preterm birth after 34 weeks. Nevertheless, the rates of occurrence of these bacterial taxa were not significantly different between who underwent preterm birth to those who did not. CONCLUSIONS This study gives an overview over the vaginal bacterial colonization in pregnant women with cervical incompetence. The clinical relevance of vaginal bacterial colonization remains unclear.
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Effect of SGLT2 inhibition on coronary microvascular function in patients with type 2 diabetes. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.2651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Treatment with sodium-glucose cotransporter 2 (SGLT2) inhibitor reduces risk of cardiovascular death and heart failure but the underlying mechanisms remain poorly understood. It has been suggested that a shift in fuel source in the myocardium from glucose and free fatty acids to the more energy efficient ketogenesis reduces oxidative stress involved in coronary microvascular damage, leading to improved coronary microvascular function.
Purpose
To test the hypothesis that treatment with the SGLT2 inhibitor empagliflozin improves non-endothelial dependent coronary microvascular function.
Methods
We included 26 patients with type 2 diabetes in a double blinded, placebo-controlled cross-over study. Participants were treated with empagliflozin 25 mg and placebo for 12 weeks, interrupted by 2 weeks wash-out period. The primary outcome was change in coronary microvascular function, assessed as coronary flow velocity reserve (CFVR) and measured with transthoracic doppler echocardiography. Secondary endpoints were change in echocardiographic parameters of cardiac systolic function and 184 cardiovascular protein biomarkers.
Results
Nineteen patients completed both study periods according to protocol. There was a significant weight loss and reduction in Hba1c after empagliflozin treatment (table). We found no improvement in CFVR and parameters of cardiac systolic function. We observed a general tendency of reduction in level of cardiovascular biomarkers after empagliflozin treatment (figure) with significant difference between empagliflozin and placebo for 27 proteins, including IL18, ST2, YKL40, ACE2 and leptin.
Conclusions
Despite a significant weight loss and reduction in Hba1c after empagliflozin treatment, we found no effect on non-endothelial dependent coronary microvascular function in patients with type 2 diabetes mellitus. Improvement in multiple biomarkers may indicate underlying mechanisms but need confirmation in larger studies.
Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): The Danish Council for Independent Research Table 1. Change in outcome parametersFigure 1. Change in biomarker levels
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Underpotential deposition of lead on quasi-spherical and faceted gold nanoparticles. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Investigation of the diversity of effector genes in the banana pathogen, Fusarium oxysporum f. sp. cubense, reveals evidence of horizontal gene transfer. MOLECULAR PLANT PATHOLOGY 2018; 19:1155-1171. [PMID: 28802020 PMCID: PMC6638072 DOI: 10.1111/mpp.12594] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 05/03/2023]
Abstract
It is hypothesized that the virulence of phytopathogenic fungi is mediated through the secretion of small effector proteins that interfere with the defence responses of the host plant. In Fusarium oxysporum, one family of effectors, the Secreted In Xylem (SIX) genes, has been identified. We sought to characterize the diversity and evolution of the SIX genes in the banana-infecting lineages of F. oxysporum f. sp. cubense (Foc). Whole-genome sequencing data were generated for the 23 genetic lineages of Foc, which were subsequently queried for the 14 known SIX genes (SIX1-SIX14). The sequences of the identified SIX genes were confirmed in a larger collection of Foc isolates. Genealogies were generated for each of the SIX genes identified in Foc to further investigate the evolution of the SIX genes in Foc. Within Foc, variation of the SIX gene profile, including the presence of specific SIX homologues, correlated with the pathogenic race structure of Foc. Furthermore, the topologies of the SIX gene trees were discordant with the topology of an infraspecies phylogeny inferred from EF-1α/RPB1/RPB2 (translation elongation factor-1α/RNA polymerase II subunit I/RNA polymerase II subunit II). A series of topological constraint models provided strong evidence for the horizontal transmission of SIX genes in Foc. The horizontal inheritance of pathogenicity genes in Foc counters previous assumptions that convergent evolution has driven the polyphyletic phylogeny of Foc. This work has significant implications for the management of Foc, including the improvement of diagnostics and breeding programmes.
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Poster session 3The imaging examinationP646Simulator-based testing of skill in transthoracic echoP647Clinical and echocardiographic characteristics of isolated left ventricular non-compactionP648Appropriate use criteria of transthoracic echocardiography and its clinical impact in an aged populationAnatomy and physiology of the heart and great vesselsP649Prevalence and determinants of exercise oscillatory ventilation in the EUROEX trial populationAssessment of diameters, volumes and massP650Left atrial remodeling after percutaneous left atrial appendage closureP651Global atrial performance with tyrosine kinase inhibitors in metastatic renal cell carcinomaP652Early right ventricular response to cardiac resynchronization therapy: impact on clinical outcomesP653Parameters of speckle-tracking echocardiography and biomechanical values of a dilative ascending aortaAssessments of haemodynamicsP654Right atrial hemodynamics in infants and children: observations from 3-dimensional echocardiography derived right atrial volumesAssessment of systolic functionP655One-point carotid wave intensity predicts cardiac mortality in patients with congestive heart failure and reduced ejection fractionP656Persistence of cardiac remodeling in adolescents with previous fetal growth restrictionP6572D speckle tracking-derived left ventricle global longitudinal strain and left ventricular dysfunction stages: a useful discriminator in moderate-to-severe aortic regurgitationP658Global longitudinal strain and strain rate in type two diabetes patients with chronic heart failure: relevance to circulating osteoprotegerinP659Analysis of left ventricular function in patients before and after surgical and interventional mitral valve therapyP660Left ventricular end-diastolic volume is complementary with global longitudinal strain for the prediction of left ventricular ejection fraction in echocardiographic daily practiceP661Left ventricular assist device, right ventricle function, and selection bias: the light side of the moonP662Assessment of right ventricular function in patients with anterior ST elevation myocardial infarction; a 2-d speckle tracking studyP663Right ventricular systolic function assessment in sickle cell anaemia using echocardiographyAssessment of diastolic functionP664Prognostic value of transthoracic cardiopulmonary ultrasound in cardiac surgery intensive care unitP665Comparative efficacy of renin-angiotensin system modulators on prognosis, right heart and left atrial parameters in patients with chronic heart failure and preserved left ventricular systolic functionP666Left atrial volume index is the most significant diastolic functional parameter of hemodynamic burden as measured by NT-proBNP in acute myocardial infarctionP667Preventive echocardiographic screening. preliminary dataP668Assessment of the atrial electromechanical delay and the mechanical functions of the left atrium in patients with diabetes mellitus type IIschemic heart diseaseP669Coronary flow velocity reserve by echocardiography as a measure of microvascular function: feasibility, reproducibility and agreement with PET in overweight patients with coronary artery diseaseP670Influence of cardiovascular risk in the occurrence of events in patients with negative stress echocardiographyP671Prevalence of transmural myocardial infarction and viable myocardium in chronic total occlusion (CTO) patientsP672The impact of the interleukin 6 receptor antagonist tocilizumab on mircovascular dysfunction after non st elevation myocardial infarction assessed by coronary flow reserve from a randomized studyP673Impact of manual thrombus aspiration on left ventricular remodeling: the echocardiographic substudy of the randomized Physiologic Assessment of Thrombus Aspirtion in patients with ST-segment ElevatioP674Acute heart failure in STEMI patients treated with primary percutaneous coronary intervention is related to transmural circumferential myocardial strainP675Long-term prognostic value of infarct size as assessed by cardiac magnetic resonance imaging after a first st-segment elevation myocardial infarctionHeart valve DiseasesP676Prognostic value of LV global longitudinal strain in aortic stenosis with preserved LV ejection fractionP677Importance of longitudinal dyssynchrony in low flow low gradient severe aortic stenosis patients undergoing dobutamine stress echocardiography. a multicenter study (on behalf of the HAVEC group)P678Predictive value of left ventricular longitudinal strain by 2D Speckle Tracking echocardiography, in asymptomatic patients with severe aortic stenosis and preserved ejection fractionP679Clinical and echocardiographic characteristics of the flow-gradient patterns in patients with severe aortic stenosis and preserved left ventricular ejection fractionP6802D and 3D speckle tracking assessment of left ventricular function in severe aortic stenosis, a step further from biplane ejection fractionP681Functional evaluation in aortic stenosis: determinant of exercise capacityP682Left ventricular mechanics: novel tools to evaluate left ventricular function in patients with primary mitral regurgitationP683Plasma B-type natriuretic peptide level in patients with isolated rheumatic mitral stenosisP684Quantitative assessment of severity in aortic regurgitation and the influence of elastic proprieties of thoracic aortaP685Characterization of chronic aortic and mitral regurgitation using cardiovascular magnetic resonanceP686Functional mitral regurgitation: a warning sign of underlying left ventricular systolic dysfunction in heart failure with preserved ejection fraction.P687Secondary mitral valve tenting in primary degenerative prolapse quantified by three-dimensional echocardiography predicts regurgitation recurrence after mitral valve repairP688Advanced heart failure with reduced ejection fraction and severe mitral insufficiency compensate with a higher oxygen peripheral extraction to a reduced cardiac output vs oxygen uptake response to maxP689Predictors of acute procedural success after percutaneous mitraclip implantation in patients with moderate-to-severe or severe mitral regurgitation and reduced ejection fractionP690The value of transvalvular gradients obtained by transthoracic echocardiography in estimation of severe paravalvular leakage in patients with mitral prosthetic valvesP691Characteristics of infective endocarditis in a non tertiary hospitalP692Infective endocarditis: predictors of severity in a 3-year retrospective analysisP693New echocardiographic predictors of early recurrent mitral functional regurgitation after mitraclip implantationP694Transesophageal echocardiography can be reliably used for the allocation of patients with severe aortic stenosis for tras-catheter aortic valve implantationP695Annular sizing for transcatheter aortic valve selection. A comparison between computed tomography and 3D echocardiographyP696Association between aortic dilatation, mitral valve prolapse and atrial septal aneurysm: first descriptive study.CardiomyopathiesP698Cardiac resynchronization therapy by multipoint pacing improves the acute response of left ventricular mechanics and fluid dynamics: a three-dimensional and particle image velocimetry echo studyP699Long-term natural history of right ventricular function in dilated cardiomyopathy: innocent bystander or leading actor?P700Right to left ventricular interdependence at rest and during exercise assessed by the ratio between pulmonary systolic to diastolic time in heart failure reduced ejection fractionP701Exercise strain imaging demonstrates impaired right ventricular contractile reserve in patients with hypertrophic cardiomyopathyP702Prevalence of overt left ventricular dysfunction (burn-out phase) in a portuguese population of hypertrophic cardiomyopathy, a multicentre studyP703Systolic and diastolic myocardial mechanics in hypertrophic cardiomyopathy and their link to the extent of hypertrophy, replacement fibrosis and interstitial fibrosisP704Multimodality imaging and genotype-phenotype associations in a cohort of patients with hypertrophic cardiomyopathy studied by next generation sequencing and cardiac magnetic resonanceP705Sudden cardiac death risk assessment in apical hypertrophic cardiomyopathy: do we need to add MRI to the equation?P706Prognostic value of left ventricular ejection fraction, proBNP, exercise capacity, and NYHA functional class in patients with left ventricular non-compaction cardiomyopathyP707The anti-hypertrophic microRNAs miR-1, miR-133a and miR-26b and their relationship to left ventricular hypertrophy in patients with essential hypertensionP708Prevalence of left ventricular systolic dysfunction in a portuguese population of left ventricular non-compaction cardiomyopathy, a multicentre studyP709Assessment of systolic and diastolic features in light chain amyloidosis: an echocardiographic and cardiac magnetic resonance studyP710Morbid obesity-associated hypertension identifies bariatric surgery best responders: Clinical and echocardiographic follow up studyP711Echocardiographic markera for overhydration in patients under haemodialysisP712Gender aspects of right ventricular size and function in clinically stable heart transplant patientsP713Evidence of cardiac stem cells from the left ventricular apical tip in patients undergone LVAD implant: a comparative strain-ultrastructural studySystemic diseases and other conditionsP714Speckle tracking assessment of right ventricular function is superior for differentiation of pressure versus volume overloaded right ventricleP715Prognostic value of pulmonary arterial pressure: analysis in a large dataset of timely matched non-invasive and invasive assessmentsP716Effect of the glucagon-like peptide-1 analogue liraglutide on left ventricular diastolic and systolic function in patients with type 2 diabetes: a randomised, single-blinded, crossover pilot studyP717Tissue doppler evaluation of left ventricular functions, left atrial mechanical functions and atrial electromechanical delay in juvenile idiopathic arthritisP718Echocardiographic detection of subclinical left ventricular dysfunction in patients with rheumatoid arthritisP719Left ventricular strain values are unaffected by intense training: a longitudinal, speckle-tracking studyP720Diastolic left ventricular function in autosomal dominant polycystic kidney disease: a matched-cohort, speckle-tracking echocardiographic studyP721Relationship between adiponectin level and left ventricular mass and functionP722Left atrial function is impaired in patients with multiple sclerosisMasses, tumors and sources of embolismP723Paradoxical embolization to the brain in patients with acute pulmonary embolism and confirmed patent foramen ovale with bidirectional shunt, results of prospective monitoringP724Following the European Society of Cardiology proposed echocardiographic algorithm in elective patients with clinical suspicion of infective endocarditis: diagnostic yield and prognostic implicationsP725Metastatic cardiac18F-FDG uptake in patients with malignancy: comparison with echocardiographic findingsDiseases of the aortaP726Echocardiographic measurements of aortic pulse wave velocity correlate well with invasive methodP727Assessment of increase in aortic and carotid intimal medial thickness in adolescent type 1 diabetic patientsStress echocardiographyP728Determinants and prognostic significance of heart rate variability in renal transplant candidates undergoing dobutamine stress echocardiographyP729Pattern of cardiac output vs O2 uptake ratio during maximal exercise in heart failure with reduced ejection fraction: pathophysiological insightsP730Prognostic value and predictive factors of cardiac events in patients with normal exercise echocardiographyP731Right ventricular mechanics during exercise echocardiography: normal values, feasibility and reproducibility of conventional and new right ventricular function parametersP732The added value of exercise-echo in heart failure patients: assessing dynamic changes in extravascular lung waterP733Applicability of appropriate use criteria of exercise stress echocardiography in real-life practice: what have we improved with new documents?Transesophageal echocardiographyP7343D-TEE guidance in percutaneous mitral valve interventions correcting mitral regurgitationContrast echocardiographyP735Pulmonary transit time by contrast enhanced ultrasound as parameter for cardiac performance: a comparison with magnetic resonance imaging and NT-ProBNPReal-time three-dimensional TEEP736Optimal parameter selection for anisotropic diffusion denoising filters applied to aortic valve 4d echocardiographsP737Left ventricle systolic function in non-alcoholic cirrhotic candidates for liver transplantation: a three-dimensional speckle-tracking echocardiography studyTissue Doppler and speckle trackingP738Optimizing speckle tracking echocardiography strain measurements in infants: an in-vitro phantom studyP739Usefulness of vascular mechanics in aortic degenerative valve disease to estimate prognosis: a two dimensional speckle tracking studyP740Vascular mechanics in aortic degenerative valve disease: a two dimensional speckle-tracking echocardiography studyP741Statins and vascular load in aortic valve disease patients, a speckle tracking echocardiography studyP742Is Left Bundle Branch Block only an electrocardiographic abnormality? Study of LV function by 2D speckle tracking in patients with normal ejection fractionP743Dominant inheritance of global longitudinal strain in a population of healthy and hypertensive twinsP744Mechanical differences of left atria in paroxysmal atrial fibrillation: A speckle-tracking study.P745Different distribution of myocardial deformation between hypertrophic cardiomyopathy and aortic stenosisP746Left atrial mechanics in patients with chronic renal failure. Incremental value for atrial fibrillation predictionP747Subclinical myocardial dysfunction in cancer patients: is there a direct effect of tumour growth?P748The abnormal global longitudinal strain predicts significant circumflex artery disease in low risk acute coronary syndromeP7493D-Speckle tracking echocardiography for assessing ventricular funcion and infarct size in young patients after acute coronary syndromeP750Evaluation of left ventricular dyssynchrony by echocardiograhy in patients with type 2 diabetes mellitus without clinically evident cardiac diseaseP751Differences in myocardial function between peritoneal dialysis and hemodialysis patients: insights from speckle tracking echoP752Appraisal of left atrium changes in hypertensive heart disease: insights from a speckle tracking studyP753Left ventricular rotational behavior in hypertensive patients: Two dimensional speckle tracking imaging studyComputed Tomography & Nuclear CardiologyP754Effectiveness of adaptive statistical iterative reconstruction of 64-slice dual-energy ct pulmonary angiography in the patients with reduced iodine load: comparison with standard ct pulmonary angiograP755Clinical prediction model to inconclusive result assessed by coronary computed tomography angiography. Eur Heart J Cardiovasc Imaging 2015. [DOI: 10.1093/ehjci/jev277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Severe hypoglycaemia during treatment with sulphonylureas in patients with type 2 diabetes in the Capital Region of Denmark. Diabetes Res Clin Pract 2015; 110:202-7. [PMID: 26515912 DOI: 10.1016/j.diabres.2015.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 08/19/2015] [Accepted: 09/03/2015] [Indexed: 12/31/2022]
Abstract
AIMS Sulphonylureas (SU) are currently recommended as a well-established second line treatment in guidelines for type 2 diabetes (T2DM). In the Capital Region of Denmark 16,865 patients were given SU as part of their treatment of T2DM in 2010-2011. To what extent SU are associated with hospitalizations due to severe hypoglycaemic episodes, defined as episodes with a need for external assistance, was investigated. The prevalence and characteristics of these patients and potential risk factors were studied. METHODS ICD-10 diagnosis codes were used to identify patients hospitalized due to hypoglycaemia and T2DM for a period of 2 years (2010-2011). Inclusion criteria were T2DM, hospitalization due to hypoglycaemia and treatment with SU as monotherapy or in combination with other glucose-lowering drugs except insulin treatment. RESULTS We identified 161 patients fulfilling the inclusion criteria. Their mean age was 76 (53-97) years and 54% were males. Sixty percent of the patients had diabetic complications, including 19% with diabetic nephropathy. The major reason for severe hypoglycaemia was an unchanged dose of SU despite of a significant decline in food intake (45%). In 22% of the patients more than one reason was listed, most commonly a concomitant infection associated with decreased food intake and unchanged dose of SU. CONCLUSION The incidence of hospital admission-requiring severe hypoglycaemia in patients treated with SU was 0.48 episodes per 100 patient-years of SU-treated patients. It was mainly older patients with diminished food intake, excessive alcohol use or other medications, concomitant infection, and with diabetic complications.
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Coronary endarterectomy: an old technique and new controversies. Adv Cardiol 2015; 36:34-40. [PMID: 3266433 DOI: 10.1159/000415612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Rapid amelioration of respiratory parameters in severely obese patients after percutaneous dilatational tracheotomy. Crit Care 2015. [PMCID: PMC4471178 DOI: 10.1186/cc14298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Genetic diversity between individuals can be tracked and monitored using a range of molecular markers. These markers can detect variation ranging in scale from a single base pair up to duplications and translocations of entire chromosomal regions. The genotyping of individuals allows the detection of this variation and it has been successfully applied in plant science for many years. The increasing amounts of sequence data able to be generated using next-generation sequencing (NGS) technologies have produced a vast expansion in the rate of discovery of polymorphisms, with single nucleotide polymorphisms (SNPs) predominating as the marker of choice. This increase in polymorphic marker resources through efficient discovery, coupled with the utility of SNPs, has enabled the shift to high-throughput genotyping assays and these methods are reviewed and discussed here, alongside the recent innovations allowing increased throughput.
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Identification and characterization of more than 4 million intervarietal SNPs across the group 7 chromosomes of bread wheat. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:97-104. [PMID: 25147022 DOI: 10.1111/pbi.12240] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 07/07/2014] [Accepted: 07/13/2014] [Indexed: 05/19/2023]
Abstract
Despite being a major international crop, our understanding of the wheat genome is relatively poor due to its large size and complexity. To gain a greater understanding of wheat genome diversity, we have identified single nucleotide polymorphisms between 16 Australian bread wheat varieties. Whole-genome shotgun Illumina paired read sequence data were mapped to the draft assemblies of chromosomes 7A, 7B and 7D to identify more than 4 million intervarietal SNPs. SNP density varied between the three genomes, with much greater density observed on the A and B genomes than the D genome. This variation may be a result of substantial gene flow from the tetraploid Triticum turgidum, which possesses A and B genomes, during early co-cultivation of tetraploid and hexaploid wheat. In addition, we examined SNP density variation along the chromosome syntenic builds and identified genes in low-density regions which may have been selected during domestication and breeding. This study highlights the impact of evolution and breeding on the bread wheat genome and provides a substantial resource for trait association and crop improvement. All SNP data are publically available on a generic genome browser GBrowse at www.wheatgenome.info.
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Next-generation genome sequencing can be used to rapidly characterise sequences flanking T-DNA insertions in random insertional mutants of Leptosphaeria maculans. Fungal Biol Biotechnol 2014; 1:10. [PMID: 28955452 PMCID: PMC5611616 DOI: 10.1186/s40694-014-0010-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/14/2014] [Indexed: 12/05/2022] Open
Abstract
Background Banks of mutants with random insertions of T-DNA from Agrobacterium tumefaciens are often used in forward genetics approaches to identify phenotypes of interest. Upon identification of mutants of interest, the flanking sequences of the inserted T-DNA must be identified so that the mutated gene can be characterised. However, for many fungi, this task is not trivial as widely used PCR-based methods such as thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) are not successful. Findings Next-generation Illumina sequencing was used to locate T-DNA insertion sites in four mutants of Leptosphaeria maculans, a fungal plant pathogen. Sequence reads of up to 150 bp and coverage ranging from 6 to 24 times, were sufficient for identification of insertion sites in all mutants. All T-DNA border sequences were truncated to different extents. Additionally, next-generation sequencing revealed chromosomal rearrangements associated with the insertion in one of the mutants. Conclusions Next-generation sequencing is a cost-effective and rapid method of identifying sites of T-DNA insertions, and associated genomic rearrangements in Leptosphaeria maculans and potentially in other fungal species.
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Gene loss in the fungal canola pathogen Leptosphaeria maculans. Funct Integr Genomics 2014; 15:189-96. [PMID: 25421464 DOI: 10.1007/s10142-014-0412-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/29/2014] [Accepted: 11/04/2014] [Indexed: 12/31/2022]
Abstract
Recent comparisons of the increasing number of genome sequences have revealed that variation in gene content is considerably more prevalent than previously thought. This variation is likely to have a pronounced effect on phenotypic diversity and represents a crucial target for the assessment of genomic diversity. Leptosphaeria maculans, a causative agent of phoma stem canker, is the most devastating fungal pathogen of Brassica napus (oilseed rape/canola). A number of L. maculans genes are known to be present in some isolates but lost in the others. We analyse gene content variation within three L. maculans isolates using a hybrid mapping and genome assembly approach and identify genes which are present in one of the isolates but missing in the others. In total, 57 genes are shown to be missing in at least one isolate. The genes encode proteins involved in a range of processes including oxidative processes, DNA maintenance, cell signalling and sexual reproduction. The results demonstrate the effectiveness of the method and provide new insight into genomic diversity in L. maculans.
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Preparation and Spectroscopic Characterization of Cyclopenta[1,2-a : 3,4,5-b′c′]dicoronene. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znb-1992-0917] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The non-alternant hydrocarbon cyclopenta[1,2-a : 3,4,5-b′c′]dicoronene (3) has been prepared by aluminium chloride catalyzed dimerization of coronene (1). The UV/VIS absorption spectrum, fluorescence spectrum and fluorescence quantum yield of 3 is reported and compared with that of the alternant isomer benzo[1,2,3-bc:4,5,6-b′c′]dicoronene (2). Relationships observed in the UV/VIS absorption spectra of alternant and non-alternant polycyclic aromatic hydrocarbons and preliminary theoretical investigations (PMO calculations) on two model systems (C, E) are also reported.
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Abstract
Am N -(9-phenanthryl)-carbazol (II) und dem Maleinsäureanhydrid-Addukt III des Anthraceno- 2′.3′:2.3-carbazols wird intramolekulare Triplettenergieübertragung beobachtet (Donator: Carbazol- Kern: Akzeptor: Phenanthren- bzw. Naphthalin-Kern). - N-(α-Naphthyl)-carbazol (I) und II zeigen ein für diese Stoffklasse in bezug auf Lösungsmittel- und Temperaturabhängigkeit ungewöhnliches Fluoreszenzverhalten.
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Abstract
Abstract
Fluorescence quenching of 22 polycyclic aromatic hydrocarbons by nitromethane in toluene and acetonitrile solutions has been studied. Contrary to Sawicki’s observations that the fluorescence of hydrocarbons with the fluoranthene skeleton is not quenched that of 11.12-and 3.4-benzofluor-anthene and fluoranthene itself is quenched. These compounds have a high energy of the fluorescence transition. The fluorescence quenching of the compounds investigated follows a dynamic quenching mechanism. The bimolecular rate constant of fluorescence quenching increases exponentially with the energy of the fluorescing state of alternant hydrocarbons.
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The Intra-annular Internal Heavy-atom Effect on the Fluorescence and Phosphorescence Properties of Oxygen, Sulphur or Selenium Containing Heterocyclic Systems Related to Dibenzo [b,n] perylene. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1989-1113] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Fluorescence and phosphorescence properties of dibenzo [2,3:10,11] perylo [1,12-bcd] furan (1), dibenzo [2,3:10,11] perylo [1,12-bcd] thiophene (2), and dibenzo [2,3:10,11 ] perylo [1,12-bcd] selenophene (3) have been studied. Fluorescence quantum yields as well as phosphorescence lifetimes correlate linearly with
where ck are the Hückel AO coefficients in the HOMO of the parent carbocyclic system dibenzo [b, n] perylene (4) on carbon centres k to which the hetero-atom is bound, and ζ is the spin-orbit coupling constant of the heavy-atom present. The half-value concentration of fluorescence quenching (quencher: methyl iodide) of 1 - 3 increases with increasing strength of the internal heavy-atom effect present
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Abstract
Abstract
The recently introduced approach of S, T isomers [1] has been applied to aza-benzenes and aza-perylenes. Ab initio and HMO calculations as well as experimental results clearly show that the S.T approach is a suitable means to derive definite predictions concerning the MO patterns and HOMO energies of structurally related aza-arenes.
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Abstract
Abstract
Two temperature-dependent bands on the short wavelengths side of the phosphorescence spectrum of coronene in a perhydro-coronene matrix are identified as hot bands (from higher vibrational levels of the triplet state T1) by measurement of lifetimes and activation energies.
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Photoluminescence of [22]Paracyclophane and p-Xylene in the Presence of Silver Ions. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1984-1019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Phosphorescence spectra and phosphorescence lifetimes of [22]paracyclophane (I) and p-xylene have been measured in ethanol glass at 77 K in the presence of silver Perchlorate at various concentrations. From the results it is concluded that the ground state complex formed with AgClO4 is much more stable in the case of the cyclophane than with p-xylene. The results would indicate that under the conditions used [22]paracyclophane forms a 1:1 complex with AgClO4 with the silver ion being located within the cyclophane cage. Fluorescence quenching measurements in fluid solution at room temperature using ethyl bromide and AgClO4 as quenchers support this assumption.
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Photochemisches Verhalten und spektroskopische Eigenschaften von Anilino-naphthalinen. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1976-0818] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
From the fluorescence and phosphorescence spectra of several aromatic amines it is concluded that the conjugation between nitrogen and aryl groups in the excited state is restricted. With this result a sterical explanation for the lack of the expected photochemical carbazole ring closure of 1-and 2-anilino naphthalene is given.
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Abstract
Abstract
Absorption spectra in liquid solution, fluorescence and phosphorescence spectra, phosphores-cence quantum yields, phosphorescence to fluorescence quantum yield ratios, and phosphorescence decay times of 9 chloro substituted biphenyls dissolved in low temperature EPA glass were in-vestigated. The emission spectra of sterically unhindered systems are structured and significantly Stokes-shifted. Ortho substitution shifts the conjugation band in absorption as well as the un-structured fluorescence and phosphorescence bands to shorter wave lengths presumably by pre-venting the system from attaining a planar excited state. Chloro substitution which increases the rate constant of phosphorescence in the order meta < para < ortho, is nearly additive for multiple substituted systems and is correlated to the MO coefficients at the chloro substituted position in the absence of steric hindrance
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Fluoreszenzlöschung alternierender und nicht-alternierender polycyclischer aromatischer Kohlenwasserstoffe durch Nitroverbindungen / Fluorescence Quenching of Alternant and Non-alternant Polycyclic Hydrocarbons by Nitro Compounds. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1977-1235] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Fluorescence Quenching of Alternant and Non-alternant Polycyclic Hydrocarbons by Nitro Compounds Fluorescence quenching of polycyclic aromatic hydro carbons by nitromethane or nitrobenzene in fluid solutions is due to an electron transfer mechanism. The non diffusion controlled rate constant of quenching is very much greater for alternant than for non-alternant hydrocarbons with equal singlet excitation energy. This is explained by the known more positive reduction potential of non-alternant compared to alternant hydrocarbons.
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Über die Löschung von „Twisted Intramolecular Charge Transfer" (TICT)-Fluoreszenzen durch äußere Schweratom-Störer. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1984-0108] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The quenching by methyl iodide and ethyl bromide of the TICT fluorescence of N-(p-cyanophenyl)- carbazole (II) and N-(l-naphthyl)-carbazole (III) has been studied in solvents of different polarity. It is found that the heavy atom induced bimolecular fluorescence quenching increases with increasing energy of the TICT fluorescence transition, contrary to the energy-gaprule, and that TICT states are much less readily quenched than locally excited (LE) states. These results are explained by assuming a very small S-T energy gap for TICT states and a solvent polarity dependent distribution function for the intramolecular twist angle.
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Löschung der Perylen-Fluoreszenz durch Schweratom-induzierte intermolekulare Singlett Triplett-Energieübertragung. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1974-1028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The fluorescence of perylene is quenched by bromonaphthalene but not by bromo-benzene. This is explained with the assumption of an intermolecular energy transfer from the fluorescing state S1 of perylene to the lowest triplet state T1 of the halogen-naphthalene.
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Die Bedeutung von Donor-Acceptor-Wechselwirkungen im äußeren Schweratom-Effekt von AgNO3 auf das Lumineszenzverhalten von Aza-aromaten und Carbazolen / The Significance of Donor-Acceptor Interactions in the External Heavy Atom Effect of AgNO3 on the Luminescence Behaviour of Aza-aromatic Systems and Carbazoles. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1978-0821] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The transition probabilities of spin-forbidden processes become much more enhanced in the case of aza-aromatic systems than for structurally related aromatic hydrocarbons when AgNO3 is used as an external heavy atom perturber. This is explained with the strong electron donor properties of aza-aromatic systems thus causing strong interaction between the π-electronic system and the perturber. Since carbazoles are weaker electron donors than aza-aromatic systems, the enhancement of the phosphorescence/fluorescence quantum yield ratio by AgNO3 is lower than for aza-aromatic systems. The different behaviour of aza-aromatic systems and aromatic hydrocarbons in the heavy atom experiment with AgNO3 can find applications in fluorescence analysis.
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Abstract
Abstract
Some general aspects of the concept of molecular topology are delt with. The role of the separability of topological and non-topological factors that determine molecular properties, as well as the "holistic" behaviour of certain classes of compounds are discussed. A suggestion regarding a deeper understanding of the role of molecular topology is made
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On the Phosphorescence of Benzologues of Furan , Thiophene , Selenophene , and Tellurophene . A Systematic Study of the Intra -annular Internal Heavy-atom Effect. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1989-0306] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Phosphorescence in ethanol and n-pentane at 77 K of the benzologues 1-8 of furan, thiophene, selenophene and tellurophene has been investigated. The rate constants of both the radiative (kPT) and non-radiative (kGT) deactivation of the lowest triplet state correlate linearly with
where ck denotes the Hückel AO coefficients in the HOMO of the carbon atoms bound to the hetero-atom and ζ is the spin-orbit coupling constant of the hetero-atom present. - The linear correlation observed between kPT and kGT is an example for the Orlandi-Siebrand rule. - The influence of an external heavy-atom perturber (methyl iodide) on phosphorescence lifetimes and the vibrational structure of phosphorescence spectra is the more efficient the less efficient is the internal perturbation caused by the intra-annular heavy-atom.
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Eine PMO-theoretische Untersuchung der benzogenen Diels-Alder-Reaktion polycyclischer aromatischer Kohlenwasserstoffe / APMO-theoretical Treatment of the Benzogenic Diels-Alder Reaction of Polycyclic Arom atic Hydrocarbons. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1978-1123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Experimental reaction rates of the benzogenic Diels- Alder reaction of polycyclic aromatic hydrocarbons with maleic anhydride are correlated with the corresponding bislocalization energies calculated by the PMO method. The observed relations between the localization energies of the reacting centres and the topology of the hydrocarbons can be qualitatively understood on the basis of Clar’s π-sextet model of polycyclic systems and Polansky’s pars orbital method.
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Note on the Influence of External Heavy-Atom Perturbers on the Phosphorescence Spectrum of Triphenylene. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1984-1123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Spectral changes in symmetry-forbidden phosphorescence spectra observed in the presence of external heavyatom perturbers may have quite different causes depending on the chemical nature of the perturber. This is exemplified using triphenylene as the phosphorescent compound and methyl iodide and silver Perchlorate respectively as the perturber. Intensification of the 0-0 band of the symmetry-forbidden phosphorescence spectrum of triphenylene by silver Perchlorate is assumed to result from symmetry-reduction of the hydrocarbon by ground-state complex formation with silver Perchlorate.
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Notizen: E-Typ-verzögerte Fluoreszenz von 1,1′-Dicoronyl in einer Kunststoffmatrix / E-type Delayed Fluorescence of 1,1′-dycoronyl in a Plastic Matrix. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1975-0833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
E-type delayed fluorescence of 1,1′-dicoronyl (III) has been established by measurement of luminescence lifetimes and activation energy.
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On the Role of Microcrystal Formation in Intermolecular Triplet-Triplet Energy Transfer in Rigid Glasses. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1983-1017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The intermolecular triplet-triplet energy transfer system benzophenone (donor)/naphthalene (acceptor) was studied in various rigid glasses at 77 K. It is shown that energy transfer is much more efficient if the donor is present in the form of microcrystals than in the case where both donor and acceptor compound are in true solution.
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Identifying genetic diversity of avirulence genes in Leptosphaeria maculans using whole genome sequencing. Funct Integr Genomics 2013; 13:295-308. [PMID: 23793572 DOI: 10.1007/s10142-013-0324-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/07/2013] [Accepted: 05/12/2013] [Indexed: 12/18/2022]
Abstract
Next generation sequencing technology allows rapid re-sequencing of individuals, as well as the discovery of single nucleotide polymorphisms (SNPs), for genomic diversity and evolutionary analyses. By sequencing two isolates of the fungal plant pathogen Leptosphaeria maculans, the causal agent of blackleg disease in Brassica crops, we have generated a resource of over 76 million sequence reads aligned to the reference genome. We identified over 21,000 SNPs with an overall SNP frequency of one SNP every 2,065 bp. Sequence validation of a selection of these SNPs in additional isolates collected throughout Australia indicates a high degree of polymorphism in the Australian population. In preliminary phylogenetic analysis, isolates from Western Australia clustered together and those collected from Brassica juncea stubble were identical. These SNPs provide a novel marker resource to study the genetic diversity of this pathogen. We demonstrate that re-sequencing provides a method of validating previously characterised SNPs and analysing differences in important genes, such as the disease related avirulence genes of L. maculans. Understanding the genetic characteristics of this devastating pathogen is vital in developing long-term solutions to managing blackleg disease in Brassica crops.
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Single nucleotide polymorphism discovery from wheat next-generation sequence data. PLANT BIOTECHNOLOGY JOURNAL 2012; 10:743-9. [PMID: 22748104 DOI: 10.1111/j.1467-7652.2012.00718.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Single nucleotide polymorphisms (SNPs) are the most abundant type of molecular genetic marker and can be used for producing high-resolution genetic maps, marker-trait association studies and marker-assisted breeding. Large polyploid genomes such as wheat present a challenge for SNP discovery because of the potential presence of multiple homoeologs for each gene. AutoSNPdb has been successfully applied to identify SNPs from Sanger sequence data for several species, including barley, rice and Brassica, but the volume of data required to accurately call SNPs in the complex genome of wheat has prevented its application to this important crop. DNA sequencing technology has been revolutionized by the introduction of next-generation sequencing, and it is now possible to generate several million sequence reads in a timely and cost-effective manner. We have produced wheat transcriptome sequence data using 454 sequencing technology and applied this for SNP discovery using a modified autoSNPdb method, which integrates SNP and gene annotation information with a graphical viewer. A total of 4,694,141 sequence reads from three bread wheat varieties were assembled to identify a total of 38 928 candidate SNPs. Each SNP is within an assembly complete with annotation, enabling the selection of polymorphism within genes of interest.
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Gewinnung von Kupfer aus metallurgischen Schlacken. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201000115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Quantenchemische und photophysikalische Untersuchungen zum Termschema von Acenchinonen. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19770810713] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Retinopathia traumatica nach Thoraxkompression bei Verkehrsunfall. Klin Monbl Augenheilkd 2009. [DOI: 10.1055/s-0029-1242968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bluttraumatisierung in Oxygenatoren unter standardisierten Bedingungen am Beispiel eines Bubble-Oxygenators. BIOMED ENG-BIOMED TE 2009. [DOI: 10.1515/bmte.1978.23.s1.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Four weeks of near-normalization of blood glucose has no effect on postprandial GLP-1 and GIP secretion, but augments pancreatic B-cell responsiveness to a meal in patients with Type 2 diabetes. Diabet Med 2008; 25:1268-75. [PMID: 19046215 DOI: 10.1111/j.1464-5491.2008.02579.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of the present study was to investigate whether 4 weeks of near-normalization of blood glucose (BG) improves incretin hormone secretion and pancreatic B-cell function during a mixed meal. RESEARCH DESIGN AND METHODS Nine patients with Type 2 diabetes in poor glycaemic control [glycated haemoglobin (HbA(1c)) 8.0 +/- 0.4%] were investigated before and after 4 weeks of near-normalization of BG (mean BG 6.4 +/- 0.3 mmol/l) using insulin treatment. HbA(1c) after insulin treatment was 6.6 +/- 0.3%. For comparison, nine healthy control subjects were also studied. Postprandial glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) incremental responses were assessed during a mixed meal test. Fasting and postprandial pancreatic B-cell function was determined from calculations of insulin secretion rates in relation to plasma glucose. RESULTS There was no difference in IAUC(totalGLP-1) or in IAUC(totalGIP) between the two experimental days. B-cell sensitivity to glucose (insulinogenic index) did not differ before and after insulin treatment in the fasting state (0.21 +/- 0.17 vs. 0.25 +/- 0.10 pmol kg(-1) min(-1)/mmol l(-1)), but improved significantly during the first 30 min after start of the meal (0.28 +/- 0.07 vs. 0.46 +/- 0.06 pmol kg(-1) min(-1)/mmol l(-1)) and during the following 4 h (0.34 +/- 0.09 vs. 0.56 +/- 0.07 pmol kg(-1) min(-1)/ mmol l(-1)). The B-cell responsiveness to changes in plasma glucose, expressed as the slope of the linear relationship between the insulin secretion rate and the concomitant plasma glucose increased from 0.59 +/- 0.16 to 0.94 +/- 0.13 pmol kg(-1) min(-1)/ mmol l(-1) (P < 0.07). CONCLUSIONS Four weeks of near-normalization of BG had no effect on postprandial secretion of incretin hormones. Nevertheless, several parameters of meal-induced insulin secretion improved after insulin treatment.
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Near normalisation of blood glucose improves the potentiating effect of GLP-1 on glucose-induced insulin secretion in patients with type 2 diabetes. Diabetologia 2008; 51:632-40. [PMID: 18292985 DOI: 10.1007/s00125-008-0943-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2007] [Accepted: 11/30/2007] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS The ability of glucagon-like peptide-1 (GLP-1) to enhance beta cell responsiveness to i.v. glucose is impaired in patients with type 2 diabetes mellitus compared with healthy individuals. We investigated whether 4 weeks of near normalisation of blood glucose (BG) improves the potentiation of glucose-stimulated insulin secretion by GLP-1. METHODS Nine obese patients with type 2 diabetes and inadequate glycaemic control (HbA(1c) 8.0+/-0.4%) were investigated before and after 4 weeks of near normalisation of BG using insulin treatment (mean diurnal blood glucose 6.4+/-0.3 mmol/l, HbA(1c) 6.6+/-0.3%). Nine matched healthy participants were also studied. Beta cell function was investigated before and after insulin treatment using stepwise glucose infusions and infusion of saline or GLP-1 (1.0 pmol kg(-1) min(-1)), resulting in supraphysiological total GLP-1 concentrations of approximately 200 pmol/l. The responsiveness to glucose or glucose+GLP-1 was expressed as the slope of the linear regression line relating insulin secretion rate (ISR) and plasma glucose concentration (pmol kg(-1) min(-1) [mmol/l](-1)). RESULTS In the diabetic participants, the slopes during glucose+saline infusion did not differ before and after insulin treatment (0.33+/-0.07 and 0.39+/-0.04, respectively; p=NS). In contrast, near normalisation of blood glucose improved beta cell sensitivity to glucose during glucose+GLP-1 infusion (1.27+/-0.2 before vs 1.73+/-0.31 after; p<0.01). In the healthy participants, the slopes during the glucose+saline and glucose+GLP-1 infusions were 1.01+/-0.14 and 4.79+/-0.53, respectively. CONCLUSIONS/INTERPRETATION A supraphysiological dose of GLP-1 enhances beta cell responses to glucose in patients with type 2 diabetes, and 4 weeks of near normalisation of blood glucose further improves this effect.
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The metabolite generated by dipeptidyl-peptidase 4 metabolism of glucagon-like peptide-1 has no influence on plasma glucose levels in patients with type 2 diabetes. Diabetologia 2006; 49:369-74. [PMID: 16385384 DOI: 10.1007/s00125-005-0098-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Accepted: 08/22/2005] [Indexed: 12/01/2022]
Abstract
AIM/HYPOTHESIS Glucagon-like peptide-1 (GLP-1) is metabolised by the enzyme dipeptidyl-peptidase 4 (DPP-4), generating a metabolite with potential antagonistic properties. This study was conducted to evaluate the effect of that metabolite on plasma glucose levels in patients with type 2 diabetes. MATERIALS AND METHODS The randomised crossover study consisted of five regimens: (1) i.v. infusion of GLP-1 (1.2 pmol kg(-1) min(-1); IV); (2 and 3) s.c. infusion of GLP-1 (2.4 and 9.6 pmol kg(-1) min(-1); LSC, HSC); (4) s.c. infusion of GLP-1 (2.4 pmol kg(-1) min(-1)) in combination with a DPP-4 inhibitor (IB); and (5) s.c. infusion of saline (154 mmol NaCl/l; SAL). Seven patients with type 2 diabetes participated in all protocols. RESULTS Plasma levels of intact GLP-1 increased from 7+/-1 (SAL) to 17+/-3 (LSC), 61+/-7 (IB), 62+/-5 (IV) and 94+/-10 (9.6 s.c.) pmol/l, p<0.0001. Plasma concentrations of the metabolite increased from 1+/-3 (SAL) and 2+/-6 (IB) pmol/l to 42+/-4 (LSC), 64+/-8 (IV) and 327+/-16 (HSC) pmol/l, p<0.0001. Mean plasma glucose levels at 6 h decreased from 12.4+/-1.1 (SAL) mmol/l to 10.4+/-1.1 (LSC), 8.6+/-0.6 (IB), 8.8+/-0.8 (IV) and 9.1+/-0.9 (HSC) mmol/l, p<0.0001. CONCLUSIONS/INTERPRETATION At approximately similar concentrations of intact GLP-1 (IV, IB, HSC), but with widely ranging metabolite concentrations, the effect on plasma glucose levels was equal, indicating that the presence of the metabolite does not antagonise the glucose-lowering effect of GLP-1.
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Merkel-Zellkarzinom der Periorbitalregion. Klin Monbl Augenheilkd 2005. [DOI: 10.1055/s-2005-871586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gesundheitliches Befinden sowie Einstellung zu Studium und Gesundheit von Medizin-, Psychologie-, Musik- und Sportstudenten bei Studienbeginn. PPMP - PSYCHOTHERAPIE · PSYCHOSOMATIK · MEDIZINISCHE PSYCHOLOGIE 2005. [DOI: 10.1055/s-2005-863563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Traumatische Evulsio nervi optici. Klin Monbl Augenheilkd 2004. [DOI: 10.1055/s-2004-828764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
OBJECTIVE The incretin hormone glucagon-like peptide-1 (GLP-1) reduces plasma glucose in type 2 diabetic patients by stimulating insulin secretion and inhibiting glucagon secretion. The biguanide metformin is believed to lower plasma glucose without affecting insulin secretion. We conducted this study to investigate the effect of a combination therapy with GLP-1 and metformin, which could theoretically be additive, in type 2 diabetic patients. RESEARCH DESIGN AND METHODS In a semiblinded randomized crossover study, seven patients received treatment with metformin (1,500 mg daily orally) alternating with GLP-1 (continuous subcutaneous infusion of 2.4 pmol x kg(-1) x min(-1)) alternating with a combination of metformin and GLP-1 for 48 h. Under fixed energy intake, we examined the effects on plasma glucose, insulin, C-peptide, glucagon, and appetite. RESULTS Fasting plasma glucose (day 2) decreased from 13.9 +/- 1 (no treatment) to 11.2 +/- 0.4 (metformin) and 11.5 +/- 0.5 (GLP-1) and further decreased to 9.4 +/- 0.7 (combination therapy) (P = 0.0005, no difference between monotherapy with GLP-1 and metformin). The 24-h mean plasma glucose (day 2) decreased from 11.8 +/- 0.5 (metformin) and 11.7 +/- 0.8 (GLP-1) to 9.8 +/- 0.5 (combination) (P = 0.02, no difference between GLP-1 and metformin). Insulin levels were similar between the three regimens, but glucagon levels were significantly reduced with GLP-1 compared with metformin (P = 0.0003). Combination therapy had no additional effect on appetite scores. CONCLUSIONS Monotherapy with GLP-1 and metformin have equal effects on plasma glucose and additive effects upon combination.
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