Detection of early metabolic alterations in the ocular fundus of diabetic patients by time-resolved autofluorescence of endogenous fluorophores

2011 ◽  
Author(s):  
D. Schweitzer ◽  
M. Klemm ◽  
S. Quick ◽  
L. Deutsch ◽  
S. Jentsch ◽  
...  
Keyword(s):  
Diabetic Patients ◽  
Time Resolved ◽  
Ocular Fundus ◽  
Metabolic Alterations ◽  
Endogenous Fluorophores

scholarly journals Development, Characterization, and Application of a Versatile Single Particle Detection Apparatus for Time-Integrated and Time-Resolved Fluorescence Measurements—Part II: Experimental Evaluation

2009 ◽  
Vol 2009 ◽  
pp. 1-14
Author(s):  
Xihong Wu ◽  
J. A. Merten ◽  
N. Omenetto ◽  
B. W. Smith ◽  
J. D. Winefordner
Keyword(s):  
Single Particle ◽  
Narrow Beam ◽  
Time Resolved Fluorescence ◽  
Particle Detection ◽  
Time Resolved ◽  
Endogenous Fluorophores ◽  
Fluorescence Measurements ◽  
On Line ◽  
Single Particle Detection ◽  
Speed Mode

This paper describes the experimental realization and characterization of a versatile single particle detection apparatus. The system utilizes a novel particle beam inlet that can serve as either an on-line particle concentrator (i.e., all diameters confined in a narrow beam) or as a segregator (i.e., selected diameters confined in a narrow beam) and can be operated in a high-speed mode as well as in a low-speed mode, thus allowing different interaction times between the particles and the laser beam. An aerodynamic sizing technique has been incorporated into the system to provide rapid, real-time, and high-resolution sizing. Parameters such as transmission efficiency and size-segregation efficiency have been measured. The performance of the instrument has been demonstrated by on-line detection of spectrally resolved and time resolved fluorescence detection from airborne dye-doped particles and aerosolized endogenous fluorophores found in biological agents.

Evaluation of time-resolved autofluorescence images of the ocular fundus

2003 ◽  
Author(s):  
Dietrich Schweitzer ◽  
Martin Hammer ◽  
Frank Schweitzer ◽  
Stefan Schenke ◽  
Elizabeth R. Gaillard
Keyword(s):  
Time Resolved ◽  
Ocular Fundus

scholarly journals Cortisol-related metabolic alterations assessed by mass spectrometry assay in patients with Cushing's syndrome

2017 ◽  
Vol 177 (2) ◽  
pp. 227-237 ◽  
Author(s):  
Guido Di Dalmazi ◽  
Marcus Quinkler ◽  
Timo Deutschbein ◽  
Cornelia Prehn ◽  
Nada Rayes ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cushing’S Syndrome ◽  
Cushing's Syndrome ◽  
Diabetic Patients ◽  
Contributing Factors ◽  
Metabolic Disturbances ◽  
Cross Sectional ◽  
Metabolic Alterations ◽  
Metabolomic Profiling ◽  
Metabolic Inflexibility

Objective Endogenous hypercortisolism is a chronic condition associated with severe metabolic disturbances and cardiovascular sequela. The aim of this study was to characterize metabolic alterations in patients with different degrees of hypercortisolism by mass-spectrometry-based targeted plasma metabolomic profiling and correlate the metabolomic profile with clinical and hormonal data. Design Cross-sectional study. Methods Subjects (n = 149) were classified according to clinical and hormonal characteristics: Cushing’s syndrome (n = 46), adrenocortical adenomas with autonomous cortisol secretion (n = 31) or without hypercortisolism (n = 27). Subjects with suspicion of hypercortisolism, but normal hormonal/imaging testing, served as controls (n = 42). Clinical and hormonal data were retrieved for all patients and targeted metabolomic profiling was performed. Results Patients with hypercortisolism showed lower levels of short-/medium-chain acylcarnitines and branched-chain and aromatic amino acids, but higher polyamines levels, in comparison to controls. These alterations were confirmed after excluding diabetic patients. Regression models showed significant correlation between cortisol after dexamethasone suppression test (DST) and 31 metabolites, independently of confounding/contributing factors. Among those, histidine and spermidine were also significantly associated with catabolic signs and symptoms of hypercortisolism. According to an discriminant analysis, the panel of metabolites was able to correctly classify subjects into the main diagnostic categories and to distinguish between subjects with/without altered post-DST cortisol and with/without diabetes in >80% of the cases. Conclusions Metabolomic profiling revealed alterations of intermediate metabolism independently associated with the severity of hypercortisolism, consistent with disturbed protein synthesis/catabolism and incomplete β-oxidation, providing evidence for the occurrence of metabolic inflexibility in hypercortisolism.

Peripheral Arteries in Diabetic Patients: Standard Bolus-Chase and Time-resolved MR Angiography

Radiology ◽  
2007 ◽  
Vol 242 (2) ◽  
pp. 610-620 ◽  
Author(s):  
Gustav Andreisek ◽  
Thomas Pfammatter ◽  
Kerstin Goepfert ◽  
Daniel Nanz ◽  
Patrice Hervo ◽  
...  
Keyword(s):  
Mr Angiography ◽  
Diabetic Patients ◽  
Peripheral Arteries ◽  
Time Resolved

scholarly journals Phototherapy of Brain Tumours Using a Fibre Optic Neurosystem

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 462
Author(s):  
Yuliya Maklygina ◽  
Igor Romanishkin ◽  
Aleksej Skobeltsin ◽  
Dina Farrakhova ◽  
Victor Loschenov
Keyword(s):  
Immune System ◽  
Brain Tumour ◽  
Immunocompetent Cells ◽  
Control Technique ◽  
Cellular Composition ◽  
Fibre Optic ◽  
Time Resolved ◽  
Fluorescence Kinetics ◽  
Endogenous Fluorophores ◽  
Kinetics Of

In this work, a new approach was tested to assess the cellular composition of tissues by time-resolved methods of fluorescence analysis of exogenous and endogenous fluorophores. First of all, the differences in fluorescence kinetics of endogenous fluorophores (coenzymes NADH and FAD) in tumour and immunocompetent cells were determined. After that, differences in fluorescence kinetics of photosensitizer 5 ALA-induced protoporphyrin IX were established due to its different metabolism in cells of different phenotypes. Kinetics of photoluminescence of NADH and FAD coenzymes as well as photosensitizer were studied by means of two different methods: time-resolved spectroscopy based on a streak-camera and fibre optic neuroscopy, which served to perform process monitoring and regular fluorescence diagnosis of the probed region. Time-resolved fluorescence microscopy (FLIM) was used as a control technique. Time-resolved spectroscopic fluorescence lifetime analysis was performed on sexually mature female rats induced with glioma C6 brain tumour under in vivo conditions; thus, under conditions where the immune system actively intervenes in the process of oncogenesis. In this regard, the aim of the study was to recognize the cellular composition of the brain tumour tissue, namely the ratio of cancer and immunocompetent cells and their mutual localization. Understanding the role of the immune system thus provides new ways and approaches for further diagnosis and therapy, making tumour-associated immune cells a prime target for modern therapies.

scholarly journals Identification of Metabolic Pathway Dysregulation in Diabetic Retinopathy: A Propensity Score-Matched Metabolomic Study

2021 ◽  
Author(s):  
Chengnan Guo ◽  
Depeng Jiang ◽  
Yixi Xu ◽  
Fang Peng ◽  
Shuzhen Zhao ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Propensity Score ◽  
Metabolic Pathway ◽  
Univariate Analysis ◽  
Support Vector ◽  
Svm Classifier ◽  
Diabetic Patients ◽  
Lasso Regression ◽  
Metabolic Alterations ◽  
Pathway Dysregulation

Abstract Background Diabetic retinopathy (DR) is a major diabetes-related disease linked to metabolism. However, scientifically assessment of serum metabolic alterations in DR is scarce. We aimed to investigate the changes in metabolic coregulation from type 2 diabetic patients (T2DM) to DR and identify corresponding metabolite predictors via a widely targeted metabolomics approach.Methods In this case-control study, we tested 613 serum metabolites in 69 pairs of T2DM with DR (case) and propensity score-matched T2DM without DR (control) utilizing the ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry system. The discrimination capability of differentially expressed metabolites (DEMs) in DR identification was also evaluated using a least absolute shrinkage and selection operator (LASSO) regression-based linear support vector machine (SVM) classifier. Metabolic pathway dysregulation in DR were comprehensively investigated by metabolic pathway analysis, chemical similarity enrichment analysis and MetaMapp approaches.Results A total of 89 DEMs were identified after paired univariate analysis and partial least squares discriminant analysis. The linear-SVM model based on LASSO regression selected DEMs had an excellent discrimination with an area under the ROC curve (AUC) as 0.99 (95% confidence interval: 0.95, 1.00). The biosynthesis of polyunsaturated fatty acids (PUFAs), thiamine metabolism, amino acids (mainly glycine, serine and threonine metabolism), hydroxyeicosatetraenoic acid (HETE), disaccharides, indoles and nucleotides were significantly enriched in DR. Conclusions This study systematically demonstrates that distinct metabolic alterations are linked to DR initiation. n-3 PUFAs, trehalose and vitamin B1 play an important role in inhibiting DR progression.

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