scholarly journals Noninvasive in vivo monitoring of methemoglobin formation and reduction with broadband diffuse optical spectroscopy

2006 ◽  
Vol 100 (2) ◽  
pp. 615-622 ◽  
Author(s):  
Jangwoen Lee ◽  
Naglaa El-Abaddi ◽  
Andrew Duke ◽  
Albert E. Cerussi ◽  
Matthew Brenner ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Spectroscopy ◽  
Near Infrared ◽  
Ex Vivo ◽  
Rabbit Model ◽  
Nir Spectroscopy ◽  
Blood Chemistry ◽  
Diffuse Optical Spectroscopy ◽  
Methemoglobin Formation

We present noninvasive, quantitative in vivo measurements of methemoglobin formation and reduction in a rabbit model using broadband diffuse optical spectroscopy (DOS). Broadband DOS combines multifrequency frequency-domain photon migration (FDPM) with time-independent near infrared (NIR) spectroscopy to quantitatively measure bulk tissue absorption and scattering spectra between 600 nm and 1,000 nm. Tissue concentrations (denoted by brackets) of methemoglobin ([MetHb]), deoxyhemoglobin ([Hb-R]), and oxyhemoglobin ([HbO2]) were determined from absorption spectra acquired in “real time” during nitrite infusions in nine pathogen-free New Zealand White rabbits. As little as 30 nM [MetHb] changes were detected for levels of [MetHb] that ranged from 0.80 to 5.72 μM, representing 2.2 to 14.9% of the total hemoglobin content (%MetHb). These values agreed well with on-site ex vivo cooximetry data ( r2 = 0.902, P < 0.0001, n = 4). The reduction of MetHb to functional hemoglobins was also carried out with intravenous injections of methylene blue (MB). As little as 10 nM changes in [MB] were detectable at levels of up to 150 nM in tissue. Our results demonstrate, for the first time, the ability of broadband DOS to noninvasively quantify real-time changes in [MetHb] and four additional chromophore concentrations ([Hb-R], [HbO2], [H2O], and [MB]) despite significant overlapping spectral features. These techniques are expected to be useful in evaluating dynamics of drug delivery and therapeutic efficacy in blood chemistry, human, and preclinical animal models.

scholarly journals Real-Time Optical Monitoring of Endotracheal Tube Displacement

Biosensors ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 174
Author(s):  
Ramzan Ullah ◽  
Karl Doerfer ◽  
Pawjai Khampang ◽  
Faraneh Fathi ◽  
Wenzhou Hong ◽  
...  
Keyword(s):  
Endotracheal Tube ◽  
Real Time ◽  
Near Infrared ◽  
Ex Vivo ◽  
Light Emitting Diode ◽  
Clinical Care ◽  
Cost Effective ◽  
Infrared Light ◽  
In Vivo Experiments

Proper ventilation of a patient with an endotracheal tube (ETT) requires proper placement of the ETT. We present a sensitive, noninvasive, operator-free, and cost-effective optical sensor, called Opt-ETT, for the real-time assessment of ETT placement and alerting of the clinical care team should the ETT become displaced. The Opt-ETT uses a side-firing optical fiber, a near-infrared light-emitting diode, two photodetectors with an integrated amplifier, an Arduino board, and a computer loaded with a custom LabVIEW program to monitor the position of the endotracheal tube inside the windpipe. The Opt-ETT generates a visual and audible warning if the tube moves over a distance set by the operator. Displacement prediction is made using a second-order polynomial fit to the voltages measured from each detector. The system is tested on ex vivo porcine tissues, and the accuracy is determined to be better than 1.0 mm. In vivo experiments with a pig are conducted to test the performance and usability of the system.

Real-Time In Vivo Characterization of Primary Liver Tumors With Diffuse Optical Spectroscopy During Percutaneous Needle Interventions

2015 ◽  
Vol 50 (7) ◽  
pp. 443-448 ◽  
Author(s):  
Rami Nachabé ◽  
Benno H.W. Hendriks ◽  
Ross Schierling ◽  
Jasmine Hales ◽  
Judy M. Racadio ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Spectroscopy ◽  
Liver Tumors ◽  
Diffuse Optical Spectroscopy ◽  
Primary Liver Tumors ◽  
In Vivo Characterization ◽  
Needle Interventions

scholarly journals Noninvasive In Vivo Monitoring of Cyanide Toxicity and Treatment Using Diffuse Optical Spectroscopy in a Rabbit Model

2009 ◽  
Vol 174 (6) ◽  
pp. 615-621 ◽  
Author(s):  
Jangwoen Lee ◽  
Kelly A. Keuter ◽  
Jae Kim ◽  
Andrew Tran ◽  
Amit Uppal ◽  
...  
Keyword(s):  
Optical Spectroscopy ◽  
Rabbit Model ◽  
Diffuse Optical Spectroscopy ◽  
Cyanide Toxicity ◽  
In Vivo Monitoring

scholarly journals Special Issue on New Horizons in Time Domain Diffuse Optical Spectroscopy and Imaging

2020 ◽  
Vol 10 (8) ◽  
pp. 2752
Author(s):  
Yoko Hoshi
Keyword(s):  
Infrared Spectroscopy ◽  
Optical Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Time Domain ◽  
Near Infrared ◽  
Special Issue ◽  
Diffuse Optical Spectroscopy ◽  
New Horizons

In 1977, Jöbsis first described the in vivo application of near-infrared spectroscopy (NIRS) [...]

Evaluation of changes in the haemoglobin of skin and muscle tissue of the calf, as induced by topical application of a nonivamide/nicoboxil cream

2014 ◽  
Vol 92 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Jan M. Warnecke ◽  
Thomas Wendt ◽  
Stefan Winkler ◽  
Matthias Schak ◽  
Thorsten Schiffer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Optical Spectroscopy ◽  
Topical Application ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Topical Administration ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen

Topical agents like nonivamide and nicoboxil induce hyperaemisation and increase cutaneous blood flow and temperature. This study aimed to determine the effects of a nonivamide–nicoboxil cream on haemodynamics in the skin and calf muscle, via optical spectroscopy, discriminating between the changes for skin and muscle. Optical spectroscopy was applied in the visible (VIS) and near-infrared (NIR) wavelength range. The study determined the effect of the cream on changes in oxygenated (ΔoxyHb) and deoxygenated (ΔdeoxyHb) haemoglobin in skin and muscle, as well as on tissue oxygen saturation (SO2) in the skin of 14 healthy subjects. The left and right calves of the subjects were either treated with nonivamide–nicoboxil cream or were sham-administered. NIR spectroscopy allows noninvasive in-vivo examination of the oxygenation of human skeletal muscle. Topical administration of the nonivamide–nicoboxil cream significantly increased the concentration of oxygenated haemoglobin and tissue oxygen saturation in the skin, as well as the concentration of oxygenated haemoglobin in the muscle of the treated legs after 15 min, but with stronger and faster effects in the skin. The topical application of the nonivamide–nicoboxil cream increased blood flow in (smaller vessels of) the skin and muscle tissues.

scholarly journals Glycan-Based Near-infrared Fluorescent (NIRF) Imaging of Gastrointestinal Tumors: a Preclinical Proof-of-Concept In Vivo Study

2020 ◽  
Vol 22 (6) ◽  
pp. 1511-1522 ◽  
Author(s):  
Ruben D. Houvast ◽  
Victor M. Baart ◽  
Shadhvi S. Bhairosingh ◽  
Robert A. Cordfunke ◽  
Jia Xin Chua ◽  
...  
Keyword(s):  
Real Time ◽  
Cell Lines ◽  
Cancer Cell ◽  
Near Infrared ◽  
Ex Vivo ◽  
Gastrointestinal Tumors ◽  
Proof Of Concept ◽  
Nirf Imaging ◽  
Ht 29

Abstract Purpose Aberrantly expressed glycans in cancer are of particular interest for tumor targeting. This proof-of-concept in vivo study aims to validate the use of aberrant Lewis glycans as target for antibody-based, real-time imaging of gastrointestinal cancers. Procedures Immunohistochemical (IHC) staining with monoclonal antibody FG88.2, targeting Lewisa/c/x, was performed on gastrointestinal tumors and their healthy counterparts. Then, FG88.2 and its chimeric human/mouse variant CH88.2 were conjugated with near-infrared fluorescent (NIRF) IRDye 800CW for real-time imaging. Specific binding was evaluated in vitro on human gastrointestinal cancer cell lines with cell-based plate assays, flow cytometry, and immune-fluorescence microscopy. Subsequently, mice bearing human colon and pancreatic subcutaneous tumors were imaged in vivo after intravenous administration of 1 nmol (150 μg) CH88.2-800CW with the clinical Artemis NIRF imaging system using the Pearl Trilogy small animal imager as reference. One week post-injection of the tracer, tumors and organs were resected and tracer uptake was analyzed ex vivo. Results IHC analysis showed strong FG88.2 staining on colonic, gastric, and pancreatic tumors, while staining on their normal tissue counterparts was limited. Next, human cancer cell lines HT-29 (colon) and BxPC-3 and PANC-1 (both pancreatic) were identified as respectively high, moderate, and low Lewisa/c/x-expressing. Using the clinical NIRF camera system for tumor-bearing mice, a mean tumor-to-background ratio (TBR) of 2.2 ± 0.3 (Pearl: 3.1 ± 0.8) was observed in the HT-29 tumors and a TBR of 1.8 ± 0.3 (Pearl: 1.9 ± 0.5) was achieved in the moderate expression BxPC-3 model. In both models, tumors could be adequately localized and delineated by NIRF for up to 1 week. Ex vivo analysis confirmed full tumor penetration of the tracer and low fluorescence signals in other organs. Conclusions Using a novel chimeric Lewisa/c/x-targeting tracer in combination with a clinical NIRF imager, we demonstrate the potential of targeting Lewis glycans for fluorescence-guided surgery of gastrointestinal tumors.

scholarly journals Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  
Keyword(s):  
Real Time ◽  
Rational Design ◽  
Near Infrared ◽  
Fluorescent Proteins ◽  
Covalent Bond ◽  
Binding Pocket ◽  
Tissue Imaging ◽  
Covalent Attachment ◽  
Time Resolved

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.

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