Singlet oxygen induced advanced glycation end-product photobleaching of in vivo human fingertip autofluorescence

Deng, Bin; Simental, Anabel; Lutz, Patrick; Shaheen, George; Chaiken, J.

doi:10.1117/12.914050

Cited by 4 publications

(6 citation statements)

References 11 publications

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“…10 Once fully bleached, the tissue remains bleached for at least 5 h in actual live tissue, without additional exposure to the laser. 14,15 This qualitative behavior of the probing/algorithm applied to spinal cord is essentially identical to that when applied to skin and despite the fact that we calibrated the algorithm in use against capillary blood Hct variation in skin, the same set of parameters a to f for Eq. (5) produces acceptable variation for image formation.…”

Section: Line Scansmentioning

confidence: 80%

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In vivo, noncontact, real-time, PV[O]H imaging of the immediate local physiological response to spinal cord injury in a rat model

et al. 2019

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We report a small exploratory study of a methodology for real-time imaging of chemical and physical changes in spinal cords in the immediate aftermath of a localized contusive injury. One hundred separate experiments involving scanning NIR images, one-dimensional, two-dimensional (2-D), and point measurements, obtained in vivo, within a 3 × 7 mm field, on spinal cords surgically exposed between T9 and T10 revealed differences between injured and healthy cords. The collected raw data, i.e., elastic and inelastic emission from the laser probed tissues, combined via the PV[O]H algorithm, allow construction of five images over the first 5 h post injury. Within the larger study, a total of 13 rats were studied using 2-D images, i.e., injured and control. A single 830-nm laser (100-μm diameter round spot) was spatially line-scanned across the cord to reveal photobleaching effects and surface profiles possibly locating a near surface longitudinal artery/vein. In separate experiments, the laser was scanned in two dimensions across the exposed cord surface relative to the injury in a specific pattern to avoid uneven photobleaching of the imaged tissue. The 2-D scanning produced elastic and inelastic emission that allowed construction of PV[O]H images that had good fidelity with the visually observed surfaces and separate line scans and suggested differences between the volume fractions of fluid and turbidity of injured and healthy cord tissue.

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Section: Line Scansmentioning

confidence: 80%

“…Chemical information can often be inferred from fluorescence measurements utilizing endogenous or exogenous fluorophores. 14,15 PV[O]H can be used to produce images based on perfusion, Hct, fluorescence, or Raman spectra thereby potentially providing a new noncontact imaging modality not currently met by any other modality.…”

Section: Pv[o]hmentioning

confidence: 99%

In vivo, noncontact, real-time, PV[O]H imaging of the immediate local physiological response to spinal cord injury in a rat model

et al. 2019

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“…The largest known source of error for this probe is systematic. Whenever there is slight movement of the probe aperture with respect to the skin surface, the probing light reaches unbleached skin causing an apparent decrease in the hematocrit, and then an increase as the skin bleaches 26 , typically reaching the same previously established equilibrium bleached level in <20 seconds. Figure 3 shows the results of 6 separate experiments executed over a 3 month period involving a single, healthy male test subject aged 60.…”

Section: Pictures Inmentioning

confidence: 99%

Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

Dent

Deng

Goodisman

et al. 2016

Biophotonics: Photonic Solutions for Better Health Care V

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A new device incorporating a new algorithm and measurement process allows simultaneous noninvasive in vivo monitoring of intravascular plasma volume and red blood cell volume. The purely optical technique involves probing fingertip skin with near infrared laser light and collecting the wavelength shifted light, that is, the inelastic emission (IE) which includes the unresolved Raman and fluorescence, and the un-shifted emission, that is, the elastic emission (EE) which includes both the Rayleigh and Mie scattered light. Our excitation and detection geometry is designed so that from these two simultaneous measurements we can calculate two parameters within the single scattering regime using radiation transfer theory, the intravascular plasma volume fraction and the red blood cell volume fraction. Previously calibrated against a gold standard FDA approved device, 2 hour monitoring sessions on three separate occasions over a three week span for a specific, motionless, and mostly sleeping individual produced 3 records containing a total of 5706 paired measurements of hematocrit and plasma volume. The average over the three runs, relative to the initial plasma volume taken as 100%, of the plasma volume±1 was 97.56±0.55 or 0.56%.For the same three runs, the average relative hematocrit (Hct), referenced to an assumed initial value of 28.35 was 29.37±0.12 or stable to ±0.4%.We observe local deterministic circulation effects apparently associated with the pressure applied by the finger probe as well as longer timescale behavior due to normal ebb and flow of internal fluids due to posture changes and tilt table induced gravity gradients.

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“…Either fluorescence or phosphorescence is usually more intense than any spontaneous Raman scattered emission component. We have previously 23 surveyed various kinds of biological materials that are potential sources of Raman scattering and fluorescence/or phosphorescence under NIR excitation 33 and that display photobleaching as is common for materials in biological media. 34 In vitro spectra of authentic samples of materials and constructs, e.g., tissue phantoms, can provide inferences or support for a hypothetical assignment.…”

Section: Problems In Characterizing and Monitoring Bacterial Culturesmentioning

confidence: 99%

“…While specific assignments are rarely unequivocal it might be useful to discern if there are materials in e.g., LB medium that are either consumed or transformed from an emissive material into a nonemissive material or vice versa. We make this suggestion because of the observation of NIR induced autobleaching 33,34 and also of that inflammation in injured spinal cord tissue in vivo or ex vivo is accompanied by increased autofluorescence. [35][36][37][38][39][40]…”

Section: Problems In Characterizing and Monitoring Bacterial Culturesmentioning

confidence: 99%

Coupled Turbidity and Spectroscopy Problems: A Simple Algorithm for Volumetric Analysis of Optically Thin or Dilute, In Vitro Bacterial Cultures in Various Media

et al. 2020

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An approach binary spectronephelometry (BSN) to perform real-time simultaneous noninvasive in situ physical and chemical analysis of bacterial cultures in fluid media is described. We choose to characterize cultures of Escherichia coli (NC), Pseudomonas aeruginosa (PA), and Shewanella oneidensis (SO) in the specific case of complex media whose Raman spectrum cannot be unambiguously assigned. Nevertheless, organism number density and a measure of the chemical makeup of the fluid medium can be monitored noninvasively, simultaneously, and continuously, despite changing turbidity and medium chemistry. The method involves irradiating a culture in fluid medium in an appropriate vessel (in this case a standard 1 cm cuvette) using a near infrared laser and collecting all the backscattered light from the cuvette, i.e., the Rayleigh–Mie line and the inelastically emitted light which includes unresolved Raman scattered light and fluorescence. Complex “legacy” media contain materials of biological origin whose chemical composition cannot be fully delineated. We independently calibrate this approach to a commonly used reference, optical density at 600 nm (OD600) for characterizing the number density of organisms. We suggest that the total inelastically emitted light could be a measure of the chemical state of a biologically based medium, e.g., lysogeny broth (LB). This approach may be useful in a broad range of basic and applied studies and enterprises that utilize bacterial cultures in any medium or container that permits optical probing in the single scattering limit.

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Singlet oxygen induced advanced glycation end-product photobleaching of in vivo human fingertip autofluorescence

Cited by 4 publications

References 11 publications

In vivo, noncontact, real-time, PV[O]H imaging of the immediate local physiological response to spinal cord injury in a rat model

In vivo, noncontact, real-time, PV[O]H imaging of the immediate local physiological response to spinal cord injury in a rat model

Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

Coupled Turbidity and Spectroscopy Problems: A Simple Algorithm for Volumetric Analysis of Optically Thin or Dilute, In Vitro Bacterial Cultures in Various Media

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