scholarly journals Monitoring the skin NADH changes during ischaemia and reperfusion in humans

2020 ◽  
Vol 89 (1) ◽  
pp. e405
Author(s):  
Jan Nizinski ◽  
Lukasz Kamieniarz ◽  
Piotr Filberek ◽  
Greta Sibrecht ◽  
Przemysław Guzik
Keyword(s):  
Optical Properties ◽  
Nicotinamide Adenine Dinucleotide ◽  
Energy Production ◽  
Reduced Form ◽  
Human Metabolism ◽  
Dynamic Changes ◽  
Non Invasive ◽  
Ischaemia And Reperfusion ◽  
Invasive Method ◽  
Skin Fluorescence

Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in many important biochemical reactions in human metabolism, including participation in energy production by mitochondria. Flow Mediated Skin Fluorescence (FMSF) is a non-invasive method to study dynamic changes in the content of the reduced form of NADH by measuring the optical properties of NADH related to the emission of the autofluorescent light (460 nm) after an earlier excitation by ultraviolet light. This review summarises the available studies using this method to describe its potential and limitations.

scholarly journals Biochemical Methanol Gas Sensor (MeOH Bio-Sniffer) for Non-Invasive Assessment of Intestinal Flora from Breath Methanol

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4897
Author(s):  
Koji Toma ◽  
Kanako Iwasaki ◽  
Geng Zhang ◽  
Kenta Iitani ◽  
Takahiro Arakawa ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gas Sensor ◽  
Nicotinamide Adenine Dinucleotide ◽  
Dynamic Range ◽  
Intestinal Flora ◽  
Alcohol Oxidase ◽  
Cascade Reaction ◽  
Reduced Form ◽  
Exhaled Breath ◽  
Non Invasive

Methanol (MeOH) in exhaled breath has potential for non-invasive assessment of intestinal flora. In this study, we have developed a biochemical gas sensor (bio-sniffer) for MeOH in the gas phase using fluorometry and a cascade reaction with two enzymes, alcohol oxidase (AOD) and formaldehyde dehydrogenase (FALDH). In the cascade reaction, oxidation of MeOH was initially catalyzed by AOD to produce formaldehyde, and then this formaldehyde was successively oxidized via FALDH catalysis together with reduction of oxidized form of β-nicotinamide adenine dinucleotide (NAD+). As a result of the cascade reaction, reduced form of NAD (NADH) was produced, and MeOH vapor was measured by detecting autofluorescence of NADH. In the development of the MeOH bio-sniffer, three conditions were optimized: selecting a suitable FALDH for better discrimination of MeOH from ethanol in the cascade reaction; buffer pH that maximizes the cascade reaction; and materials and methods to prevent leaking of NAD+ solution from an AOD-FALDH membrane. The dynamic range of the constructed MeOH bio-sniffer was 0.32–20 ppm, which encompassed the MeOH concentration in exhaled breath of healthy people. The measurement of exhaled breath of a healthy subject showed a similar sensorgram to the standard MeOH vapor. These results suggest that the MeOH bio-sniffer exploiting the cascade reaction will become a powerful tool for the non-invasive intestinal flora testing.

scholarly journals The influence of the optical properties on the determination of capillary diameters

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Moritz Späth ◽  
Maximilian Rohde ◽  
Dongqin Ni ◽  
Ferdinand Knieling ◽  
Florian Stelzle ◽  
...  
Keyword(s):  
Optical Properties ◽  
Absolute Quantification ◽  
The State ◽  
Capillary Diameter ◽  
Non Invasive ◽  
Wide Range ◽  
All Optical ◽  
Invasive Method ◽  
Diffuse Reflectance Imaging

AbstractVarious clinically applicable scores and indices are available to help identify the state of a microcirculatory disorder in a patient. Several of these methods, however, leave room for interpretation and only provide clues for diagnosis. Thus, a measurement method that allows a reliable detection of impending or manifest circulatory malfunctions would be of great value. In this context, the optical and non-invasive method of shifted position-diffuse reflectance imaging (SP-DRI) was developed. It allows to determine the capillary diameter and thus to assess the state of the microcirculation. The aim of the present study is to investigate how the quantification of capillary diameters by SP-DRI behaves in different individuals, i.e. for a wide range of optical properties. For this, within Monte-Carlo simulations all optical properties (seven skin layers, hemoglobin) were randomly varied following a Gaussian distribution. An important finding from the present investigation is that SP-DRI works when the optical properties are chosen randomly. Furthermore, it is shown that appropriate data analysis allows calibration-free absolute quantification of the capillary diameter across individuals using SP-DRI. This underpins the potential of SP-DRI to serve as an early alert system for the onset of microcirculatory associated diseases.

scholarly journals Polarimetric interferometry to objectively evaluate the optical properties of corneal stroma

2018 ◽  
Vol 2 (2) ◽  
pp. 36-41
Author(s):  
Eugenio Lipari ◽  
Alessandra Sborgia ◽  
Mario Nubile ◽  
Leonardo Mastropasqua ◽  
Giovanni Alessio
Keyword(s):  
Optical Properties ◽  
Early Stage ◽  
Corneal Stroma ◽  
Collagen Fibrils ◽  
New Method ◽  
Strong Impact ◽  
Corneal Disease ◽  
Non Invasive ◽  
Invasive Method ◽  
Corneal Collagen

A new non-invasive method, based on the interferometric analysis of diff ractive and polarizing effects related to the birefringent properties of corneal collagen fibrils, has been developed to objectively evaluate the optical properties of the stroma. The new method shows a relevant impact on corneal surgeries specifically for lamellar transplantation where, due to the polarizing properties of the stroma, the alignment between collagen fibrils of donor corneas with patient collagen fibril orientation has shown an improvement of visual acuity postoperatively. Further studies on the regularity of the corneal isogyre pattern are showing this new method has a strong impact in early-stage diagnosis of corneal disease.

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

2001 ◽  
Vol 12 (1) ◽  
pp. 8-14
Author(s):  
Gertraud Teuchert-Noodt ◽  
Ralf R. Dawirs
Keyword(s):  
Prefrontal Cortex ◽  
Mental Disorders ◽  
Dentate Gyrus ◽  
Cognitive Functions ◽  
Experimental Approach ◽  
Regulatory Mechanisms ◽  
Hippocampal Dentate Gyrus ◽  
Non Invasive ◽  
Invasive Method ◽  
Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

scholarly journals Creating enzymes and self-sufficient cells for biosynthesis of the non-natural cofactor nicotinamide cytosine dinucleotide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xueying Wang ◽  
Yanbin Feng ◽  
Xiaojia Guo ◽  
Qian Wang ◽  
Siyang Ning ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Escherichia Coli ◽  
Nicotinamide Adenine Dinucleotide ◽  
Chemical Biology ◽  
Reduced Form ◽  
Redox Transformations ◽  
Nicotinamide Mononucleotide ◽  
Self Sufficiency ◽  
Binding Pockets ◽  
Pathway Regulation

AbstractNicotinamide adenine dinucleotide (NAD) and its reduced form are indispensable cofactors in life. Diverse NAD mimics have been developed for applications in chemical and biological sciences. Nicotinamide cytosine dinucleotide (NCD) has emerged as a non-natural cofactor to mediate redox transformations, while cells are fed with chemically synthesized NCD. Here, we create NCD synthetase (NcdS) by reprograming the substrate binding pockets of nicotinic acid mononucleotide (NaMN) adenylyltransferase to favor cytidine triphosphate and nicotinamide mononucleotide over their regular substrates ATP and NaMN, respectively. Overexpression of NcdS alone in the model host Escherichia coli facilitated intracellular production of NCD, and higher NCD levels up to 5.0 mM were achieved upon further pathway regulation. Finally, the non-natural cofactor self-sufficiency was confirmed by mediating an NCD-linked metabolic circuit to convert L-malate into D-lactate. NcdS together with NCD-linked enzymes offer unique tools and opportunities for intriguing studies in chemical biology and synthetic biology.

scholarly journals Asymmetric TCD Findings in Malignant MCA Infarction, Resolution after Decompressive Hemicraniectomy: A Case Report

2020 ◽  
Vol 12 (Suppl. 1) ◽  
pp. 127-136
Author(s):  
Hazel Gaile  Barrozo ◽  
Maria Anna De Guzman ◽  
Jose  Navarro ◽  
Narayanaswamy Venketasubramanian
Keyword(s):  
Pressure Effects ◽  
Mean Flow ◽  
Brain Swelling ◽  
Decompressive Hemicraniectomy ◽  
Non Invasive ◽  
Invasive Method ◽  
Malignant Mca Infarction ◽  
Subsequent Rise ◽  
Very High ◽  
Hemispheric Infarct

Transcranial Doppler (TCD) is a non-invasive method for assessing cerebral hemodynamics in the acute phase of stroke. We report a case of a 33-year-old man who presented with a massive left hemispheric infarct developing into “malignant” MCA infarction. TCD was utilized to monitor intracranial hemodynamics while the clinical and neuroimaging findings were used to help us in the decision to proceed with decompressive craniectomy (DC). Pre-operatively, there was reduced mean flow velocities (MFV) of the middle cerebral artery (MCA) with increasing pulsatility index (PI) ipsilateral to the infarct. The subsequent but smaller rise in the PI in the contralateral MCA was suggestive of very high intracranial pressure (ICP) from massive brain swelling. Serial TCD examinations post-operatively showed normalization of the PI, and subsequent rise in the left MCA MFV. Clinical improvement was also noted as the TCD findings improved. The asymmetry in TCD findings can be attributed to occlusion of the MCA with subsequent spontaneous recanalisation, occlusion of the MCA with subsequent recanalisation due to the DC, or initial occlusion and subsequent pressure effects on the arterioles of the MCA due to the “malignant” edema of that hemisphere that was relieved by DC. This case illustrates the value of TCD as a useful modality in monitoring intracranial hemodynamics in acute stroke.

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