Visualization of the composition of the urinary fluorescent metabolome. Why is it important to consider initial urine concentration?

Urine is a highly complex fluorescent system, the fluorescence of which can be affected by many factors, including the often-ignored initial urine concentration in comprehensive fluorescent urine analysis. In this study, a total urine fluorescent metabolome profile (uTFMP) was created as a three-dimensional fluorescence profile of serial synchronous spectra of urine diluted by geometric progression. uTFMP was generated using software designed for this purpose after recalculating the 3D data concerning the initial urine concentration. It can be presented as a contour map (top view) or as a more illustrative and straightforward simple curve, thus usable in various medicinal applications.

Derivative Three-Dimensional Synchronous Fluorescence Analysis of Tear Fluid and Their Processing for the Diagnosis of Glaucoma.

BACKGROUND: Sensitive and rapid diagnosis of the early stages of glaucoma from tear fluid is a great challenge for researchers. METHODS: Tear fluid was analyzed using three-dimensional synchronous fluorescence spectroscopy (3D-SFS). Our previously published results briefly describe the main methods which applied the second derivative to a selected synchronous spectrum Δλ = 110 nm in distinguishing between healthy subjects (CTRL) and patients with glaucoma (POAG). RESULTS: In this paper, a novel strategy was used to evaluate three-dimensional spectra from the tear fluid database of our patients. A series of synchronous excitation spectra were processed as a front view and presented as a single curve showcasing the overall fluorescence profile of the tear fluid. The second derivative spectrum provides two parameters that can enhance the distinction between CTRL and POAG tear fluid. CONCLUSIONS: Combining different types of 3D-SFS data can offer interesting and useful diagnostic tools and it can be used as input for machine learning and process automation.

Tear fluid biomarkers in major depressive disorder: Potential of spectral methods in biomarker discovery.

Spectroscopic methods represent a group of analytical methods that demonstrate high potential in providing clinically relevant diagnostic information, such as biochemical, functional or structural changes of macromolecular complexes that might occur due to pathological processes or therapeutic intervention. Although application of these methods in the field of psychiatric research is still relatively recent, the preliminary results show that they have the capacity to detect subtle neurobiological abnormalities in major depressive disorder (MDD). Methods of mass spectrometry (MALDI-TOF MS), zymography, synchronous fluorescence spectroscopy (SFS), circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) were used to analyze the human tear fluid of subjects with MDD. Using MALDI-TOF MS, two diagnostically significant peaks (3747 and 16 411 m/z) were identified with an AUC value of 0.89 and 0.92 in tear fluid of subjects with MDD vs controls, respectively. We also identified various forms of matrix metalloproteinase 9 in subjects with MDD using zymography and synchronous fluorescence spectra (SFS) showed a significant increase in fluorescence intensity at 280 nm. CD spectra were redshifted in tear fluid of subjects with MDD vs healthy controls. FTIR spectroscopy showed changes in the positions of peaks for amide A, I, II in tear fluid of subjects with MDD vs controls. Moreover, atomic force microscopy (AFM) showed different pattern in the crystal structures of tear fluid components in subjects with MDD. SFS, CD, FTIR spectroscopy, AFM and MALDI-TOF MS confirmed, that the human tear fluid proteome could be helpful in discriminating between the group of subjects with MDD and healthy controls. These preliminary findings suggest that spectral methods could represent a useful tool in clinical psychiatry, especially in establishing differential diagnosis, monitoring illness progression and the effect of psychiatric treatment.

Development of novel parameter for monitoring of malignant melanoma progression.

OBJECTIVE: Increasing HIFs in malignant melanoma, the highly aggressive skin tumour, results in the stimulation of invasiveness. Increased HIF-1α fallouts in inhibition of the activity of some mitochondrial enzymes and leads to preference of cytosol energetic metabolism. Increase of aerobic glycolysis is reflected in an increase of free NADH (Warburg effect) and develops the malignant melanoma.Our goal was to find a link between hypoxia, or hypoxia mimicking factors and the stage of malignant melanoma. Furthermore, we focused on the finding of the experimental parameter which could monitor melanoma patients. PATIENTS AND METHODS: We targeted HIF-1α gene expression and VDR rs2107301 gene polymorphism by PCR analysis. We detected the level of NADH in blood plasma by fluorescence spectroscopy (excitation and emission spectra). RESULTS: Analysis of the obtained data from patient samples has shown an increase in HIF-1α which correlates with the disease stage. Investigation VDR rs2107301 polymorphism of patient samples does not show any significant changes in single nucleotide polymorphism, and the low vitamin D level in blood is not a result of VDR mutation in mitochondria. NADH levels vary under hypoxic and pseudohypoxic conditions and refer to the cancer stage. CONCLUSIONS: The apparent mismatch between HIF-1α expression and NADH fluorescence has become the basis for the design of an algorithm for monitoring malignant melanoma based on the sensing of NADH fluorescence and the determination of HIF-1α.

Detection of FLT3 Mutations in Patients from Eastern Slovakia.

BACKGROUND: The study investigated FLT3 gene mutations in patients from eastern Slovakia using a simple molecular method. PATIENTS AND METHODS: We analyzed 141 patients with primary acute myeloid leukemia (AML) and 8 patients with AML that developed from myelodysplastic syndrome (MDS) who were aged 19-81 years. DNA isolated from peripheral blood and/or bone marrow was analyzed by PCR. FLT3 internal tandem duplication (FLT3-ITD) was detected by amplification of exons 14 and 15. Point mutations in the FLT3 tyrosine kinase domain (FLT3-TKD) were detected by digesting the PCR product of exon 20 with the restriction endonuclease EcoRV. Fragments were separated electrophoretically. PCR products of the positive samples were also analyzed using a microchip device (Bioanalyzer 2100). RESULTS: LT3-ITD and point mutations in the FLT-TKD were detected in 19 and 8% of patients, resp. Two patients (1%) harbored both types of mutations. Patients with and without FLT3 mutations were called FLT+ and FLT-, resp. Most FLT3+ patients had no chromosomal aberrations (59%) or harbored the t (15; 17) translocation in PML-RARA (15%). The mortality rate was 33% among FLT3+ patients and 10% among FLT3-patients. Among FLT3+ patients, the mortality rates of patients with FLT3-ITD and point mutations of the FLT-TKD were almost the same. A 77-year-old female patient with both FLT3-ITD and a point mutation in the FLT3-TKD was in remission. The eight patients who developed AML from MDS were assessed separately. Of these, three patients were FLT3+; two patients displayed FLT3-ITD, and one patient harbored a point mutation in the FLT3-TKD. No other genetic aberrations were detected. FLT3+ patients lived for longer than FLT3-patients. These analyses of FLT3 gene mutations in patients from eastern Slovakia are consistent with published data from other databases. CONCLUSION: The applied PCR method is reliable, relatively fast, and affordable, and can be used for routine monitoring of FLT3 gene mutations. FLT3 mutations can be verified using a microchip as an alternative to capillary electrophoresis. Key words: acute myelogenous leukemia - DNA - PCR - mutation - FLT3-ITD - FLT3-TKD The study was supported by the European Regional Development grant OPVaV-2009/2.2/05- -SORO (ITMS code: 26220220143). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical paper Submitted: 19. 10. 2017 Accepted: 15. 2. 2018.

A novel way to monitor urine concentration: fluorescent concentration matrices.

BACKGROUND: The amount of water found in urine is important diagnostic information; nevertheless it is not yet directly determined. Indirectly, the water content in urine is expressed by its density (specific gravity). However, without the diuresis value it is not possible to determine whether the increase in density of urine is due to a decrease in water secretion or an increase in the concentration of secreted substances. This problem can be solved by the use of fluorescent concentration 3D-matrices which characterise urine concentration through the pφ (or -logφ) value of the first fluorescence centre. MATERIALS AND METHODS: The urine fluorescent concentration 3D-matrix was created by the alignment of the synchronous spectra of the dilution series of urine starting from undiluted (pφ = 0) to 1000-fold diluted urine (pφ = 3). RESULTS: Using the fluorescence concentration 3D-matrix analysis of the urine samples from healthy individuals, a reference range was established for the value pφ, determining the normal, concentrated or diluted type of urine. The diagnostic potential of this approach was tested on urine samples from two patients with a chronic glomerulonephritis. CONCLUSION: The pφ value of the urine fluorescence concentration 3D-matrix analysis determines whether the urine sample falls within the normal, concentrated or diluted type of urine. This parameter can be directly utilised in sportsmen's hydration state monitoring, as well as in the diagnosis and treatment of serious diseases. An important advantage of this novel diagnostic approach is that a 12/24 h urine collection is not required, which predetermines it for use especially within paediatrics.

In vivo monitoring the changes of interstitial pH and FAD/NADH ratio by fluorescence spectroscopy in healing skin wounds.

The aim of our study was to evaluate the changes of interstitial pH and flavin adenine dinucleotide (FAD)/reduced nicotinamide adenine dinucleotide (NADH) ratio in healing skin wounds using fluorescence spectroscopy in Sprague Dawley rats. In the experiment, excisional and incisional models of wound healing were used. The florescein as the pH-sensitive probe using excitation spectra (lambda(Em) = 535 nm) was used for the measurement of pH changes, and synchronous fluorescence spectra (Deltalambda = 60 nm) for the monitoring of FAD/NADH ratio changes were measured from the surfaces of healing wounds. Increase of interstitial pH and FAD/NADH ratio was recorded during the time interval from the 15th to the 65th minute after surgery. The decrease of pH between the 48th and the 72nd hour after surgery as well as the increase of FAD/NADH ratio between the 72nd and the 96th hour of wound healing were recorded. The results indicate that the use of fluorescence spectroscopy may be considered as a valuable tool for noninvasive in vivo monitoring of selected redox parameters in the early phases of wound healing.

Diagnostic monitoring of urine by means of synchronous fluorescence spectrum.

A novel approach to clinical-biochemical analysis of urine is presented in this work. Urine composition is defined graphically as a record of synchronous fluorescence spectra (SFS). The graphical standard has been made from SFS of urine samples from healthy children. Simple comparison of a standard record with that of an analyzed urine sample will immediately reveal changes in its composition. Reproducibility of the graphical definition is very high and it maintains its characteristic shape during repeated measurements over a span of 2 years. It is possible to elaborate patients' own standard for those with chronic illness. It differs from a normal course but it is characteristic for a given patient and it enables the clinician to monitor changes or the outcome of therapy at regular medical examinations. Application of this method for monitoring of urine composition for selected cases is a new alternative with several advantages. Analysis without any added reagents very quickly detects some illnesses near onset when they may be clinically asymptomatic and classical screening methods show negative results. Computerization of spectral measuring and filing the results enables to give a likely diagnosis or a deviation from standard. This method can also serve a doctor-clinician either to confirm or to exclude a concrete diagnosis.