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Article Citation - WoS: 357Citation - Scopus: 374A New Artificial Urine Protocol To Better Imitate Human Urine(Nature Portfolio, 2019) Sarigul, Neslihan; Korkmaz, Filiz; Kurultak, IlhanArtificial urine has many advantages over human urine for research and educational purposes. By closely mimicking healthy individuals' urine, it may also be important in discovering novel biomarkers. However, up until now, there has not been any specific protocol to prove the similarity in terms of the chemical composition at the molecular level. In this study, a new artificial urine protocol is established to mimics the urine of healthy individuals. The multi-purpose artificial urine (MP-AU) presented here is compared with two other protocols most cited in literature. Furthermore, these three protocols are also compared with samples from 28 healthy young individuals. To do so, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is used, according to which MP-AU shows a significantly close similarity with human urine. In formulating MP-AU, the infrared spectra of nine compounds is provided, making possible the band assignment of some absorption bands to certain compounds. Given its properties, the MP-AU protocol introduced here is both economical and practical, making it useful when designing comparative-controlled experiments.Article Citation - WoS: 9Citation - Scopus: 9Urinalysis of Individuals With Renal Hyperfiltration Using Atr-Ftir Spectroscopy(Nature Portfolio, 2022) Kurultak, Ilhan; Sarigul, Neslihan; Kodal, Nil Su; Korkmaz, FilizAbnormal increased glomerular filtration rate (GFR), otherwise known as renal hyperfiltration (RHf), is associated with an increased risk of chronic kidney disease and cardiovascular mortality. Although it is not considered as a disease alone in medicine today, early detection of RHf is essential to reducing risk in a timely manner. However, detecting RHf is a challenge since it does not have a practical biochemical marker that can be followed or quantified. In this study, we tested the ability of ATR-FTIR spectroscopy to distinguish 17 individuals with RHf (hyperfiltraters; RHf (+)), from 20 who have normal GFR (normofiltraters; RHf(-)), using urine samples. Spectra collected from hyperfiltraters were significantly different from the control group at positions 1621, 1390, 1346, 933 and 783/cm. Intensity changes at these positions could be followed directly from the absorbance spectra without the need for pre-processing. They were tentatively attributed to urea, citrate, creatinine, phosphate groups, and uric acid, respectively. Using principal component analysis (PCA), major peaks of the second derivative forms for the classification of two groups were determined. Peaks at 1540, 1492, 1390, 1200, 1000 and 840/cm were significantly different between the two groups. Statistical analysis showed that the spectra of normofiltraters are similar; however, those of hyperfiltraters show diversity at multiple positions that can be observed both from the absorbance spectra and the second derivative profiles. This observation implies that RHf can simultaneously affect the excretion of many substances, and that a spectroscopic analysis of urine can be used as a rapid and non-invasive pre-screening tool.Editorial Citation - WoS: 1Citation - Scopus: 1Commentary on "spectral Characterization of the Binding and Conformational Changes of Serum Albumins Upon Interaction With an Anticancer Drug, Anastrozole"(Pergamon-elsevier Science Ltd, 2015) Korkmaz, FilizThe manuscript by R. Punith and J. Seetharamappa (http://dx.doi.org/10.1016/j.saa.201202.038) presents the interaction between serum albumin from human (HAS) and from bovine (BSA) with a drug called Anastrozole (AZ). The drug is on the market for treating patients with breast cancer after surgery and for metastasis in women. The study utilizes various spectroscopic techniques such as; fluorescence, synchronous fluorescence, 3D fluorescence measurements, FTIR, CD and UV. Although there are some relatively minor comments on the paper, the main point that needs to be reviewed by the authors is the result of FTIR measurements. Based on the data provided in the text (there is no figure), the protein sample is not in its native state, which makes the data inconvenient to be used in drawing conclusions. Authors are kindly requested to take another look at the FUR experiments. (C) 2014 Elsevier B.V. All rights reserved.Article Citation - WoS: 17Citation - Scopus: 18in Situ Opening/Closing of Ompg From e. coli and the Splitting of Β-Sheet Signals in Atr-Ftir Spectroscopy(Pergamon-elsevier Science Ltd, 2012) Korkmaz, Filiz; Koester, Stefan; Yildiz, Oezkan; Maentele, Werner; Mäntele, Werner; Köster, StefanThe pH dependent opening and closure of Escherichia coli OmpG is driven by the formation and breaking of hydrogen bridges in beta-strands S11-S13. We have investigated the in situ secondary structural changes of OmpG with ATR-FTIR difference spectroscopy in order to detect the signals associated with the newly established interactions. Curve-fitting of OmpG in two pH conditions revealed the splitting and shifting of beta-sheet signals upon opening of the channel. Besides secondary structure changes, there are also amino acid side chain signals that play active role in opening/closing of the channel. An interaction among positively charged arginines and negatively charged aspartic and glutamic acid residues is suggested upon closure of the channel while this interaction is abolished when the channel opens at higher pH. (C) 2012 Elsevier B.V. All rights reserved.Article Author Correction: Using Urine Ftir Spectra To Screen Autism Spectrum Disorder(Nature Portfolio, 2024) Sarigul, Neslihan; Bozatli, Leyla; Kurultak, Ilhan; Korkmaz, Filiz[No Abstract Available]Article Citation - WoS: 7Citation - Scopus: 6Using urine FTIR spectra to screen autism spectrum disorder(Nature Portfolio, 2023) Sarigul, Neslihan; Bozatli, Leyla; Kurultak, Ilhan; Korkmaz, FilizAutism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder caused by multiple factors, lacking clear biomarkers. Diagnosing ASD still relies on behavioural and developmental signs and usually requires lengthy observation periods, all of which are demanding for both clinicians and parents. Although many studies have revealed valuable knowledge in this field, no clearly defined, practical, and widely acceptable diagnostic tool exists. In this study, 26 children with ASD (ASD+), aged 3-5 years, and 26 sex and age-matched controls are studied to investigate the diagnostic potential of the Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The urine FTIR spectrum results show a downward trend in the 3000-2600/cm region for ASD+ children when compared to the typically developing (TD) children of the same age. The average area of this region is 25% less in ASD+ level 3 children, 29% less in ASD+ level 2 children, and 16% less in ASD+ level 1 children compared to that of the TD children. Principal component analysis was applied to the two groups using the entire spectrum window and five peaks were identified for further analysis. The correlation between the peaks and natural urine components is validated by artificial urine solutions. Less-than-normal levels of uric acid, phosphate groups, and ammonium (NH4+) can be listed as probable causes. This study shows that ATR-FTIR can serve as a practical and non-invasive method to screen ASD using the high-frequency region of the urine spectrum.
