Functional near infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) both measure the hemodynamic response, and so both imaging modalities are expected to have a strong correspondence in regions of cortex adjacent to the scalp. To assess whether fNIRS can be used clinically in a manner similar to fMRI, 22 healthy adult participants underwent same-day fMRI and whole-head fNIRS testing while they performed separate motor (finger tapping) and visual (flashing checkerboard) tasks. Analyses were conducted within and across subjects for each imaging approach, and regions of significant task-related activity were compared on the cortical surface.
View Article and Find Full Text PDFBackground: Changes in cerebral blood flow in response to neuronal activation can be measured by time-dependent fluctuations in hemoglobin species within the brain; this is the basis of functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS). There is a clinical need for portable neural imaging systems, such as fNIRS, to accommodate patients who are unable to tolerate an MR environment.
Objective: Our objective was to compare task-related full-head fNIRS and fMRI signals across cortical regions.
Photobiomodul Photomed Laser Surg
July 2021
To study the effects of 670 and 830 nm irradiation on oxygen consumption by cytochrome c oxidase (CCO) in a Clark electrode type reaction chamber. To explore the effect of irradiation on the nitric oxide (NO) donor-induced inhibition of oxygen consumption. Most theories of photobiomodulation (PBM) involve the enzyme CCO as a cellular target for red-to-near infrared light (R-NIR) irradiation.
View Article and Find Full Text PDFSimilar to functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS) detects the changes of hemoglobin species inside the brain, but via differences in optical absorption. Within the near-infrared spectrum, light can penetrate biological tissues and be absorbed by chromophores, such as oxyhemoglobin and deoxyhemoglobin. What makes fNIRS more advantageous is its portability and potential for long-term monitoring.
View Article and Find Full Text PDFPhotobiomodul Photomed Laser Surg
July 2020
The underlying mechanisms of photobiomodulation (PBM) remain elusive. The most attractive hypotheses revolve around the role of cytochrome c oxidase (CCO) and cellular energetics. No reliable demonstration of any PBM-related light-induced mechanistic effect on CCO has been reported.
View Article and Find Full Text PDFIn a previous study on chromate toxicity, an increase in the 2Fe2S electron paramagnetic resonance (EPR) signal from mitochondria was found upon addition of chromate to human bronchial epithelial cells and bovine airway tissue ex vivo. This study was undertaken to show that a chromate-induced increase in the 2Fe2S EPR signal is a general phenomenon that can be used as a low-temperature EPR method to determine the maximum concentration of 2Fe2S centers in mitochondria. First, the low-temperature EPR method to determine the concentration of 2Fe2S clusters in cells and tissues is fully developed for other cells and tissues.
View Article and Find Full Text PDFPostural orthostatic tachycardia syndrome (POTS) is a disabling condition characterized by orthostatic intolerance with tachycardia in the absence of drop-in blood pressure. A custom-built near-infrared spectroscopy device (NIRS) is applied to monitor the muscle oxygenation, noninvasively in patients undergoing incremental head-up tilt table (HUT). Subjects (6 POTS patients and 6 healthy controls) underwent 30 mins of 70°on a HUT.
View Article and Find Full Text PDFObjective: Evaluate the effect of near-infrared light (NIR) on immediate production of ATP by osteoblasts and fibroblasts , and the healing process of rat femur fractures with intramedullary fixation.
Background: NIR is one potential treatment option for complications of fracture healing, which has shown to stimulate cellular proliferation and to enhance the healing process.
Methods: Cell culture - MC3T3-E1 and 3T3-A31 cells were subjected to NIR at 660 nm, 830 nm, or both combined.
Photomed Laser Surg
December 2016
Objective: Our primary hypothesis was that red-to-near infrared (R-NIR) irradiation would have an effect on the kinetics parameters of the reaction of cytochrome c with isolated cytochrome c oxidase (CCO), and that the magnitude and direction of these changes could be interpreted in the context of the reaction schemes proposed by other authors. New values for the milimolar extinction coefficients of cytochrome c were also determined.
Background Data: Definitive answers to the fundamental processes involved in red-to-near infrared photobiomodulation (R-NIR-PBM) have not been obtained.
This paper reports the findings from a pilot study of four patients with medically refractory epilepsy undergoing pre-surgical evaluation with ages ranging from 5 to 17 years. Video electroencephalography recordings and data from a near infrared spectroscopy cerebral/somatic oximeter were gathered and related to electrographic seizure onset and offset as determined by a paediatric epileptologist. All four patients showed haemodynamic changes associated with epileptiform activities.
View Article and Find Full Text PDFPurpose: To determine whether hyperbaric oxygen (HBO2) therapy should be used for the treatment of autism spectrum disorders (ASD).
Methods: A literature search was performed on PubMed, Cochrane Library and DynaMed for studies evaluating the use of HBO2 for ASD treatment. The studies were then reviewed for the highest quality evidence.
Photodiagnosis Photodyn Ther
September 2015
Introduction: What is the current status of photodynamic therapy (PDT) with regard to treating malignant brain tumors? Despite several decades of effort, PDT has yet to achieve standard of care.
Purpose: The questions we wish to answer are: where are we clinically with PDT, why is it not standard of care, and what is being done in clinical trials to get us there.
Method: Rather than a meta-analysis or comprehensive review, our review focuses on who the major research groups are, what their approaches to the problem are, and how their results compare to standard of care.
It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28 % bacterial growth, while 470-nm blue light alone suppresses up to 92 % methicillin-resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470-nm light (55 J/cm(2)) and HBO will yield 100 % bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3 × 10(6), 5 × 10(6), 7 × 10(6), 8 × 10(6), or 12 × 10(6) CFU/ml and treated each concentration in four groups as follows: (1) control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation.
View Article and Find Full Text PDFIntroduction: A ketogenic diet (KD) may decrease central nervous system oxygen toxicity symptoms in divers, and in view of this implication a feasibility/ toxicity pilot study was performed to demonstrate tolerance of KD while performing normal diving profiles. The exact mechanism of neuroprotection from the KD remains unknown; however, evidence to support the efficacy of the KD in reducing seizures is present in epilepsy and oxygen toxicity studies, and may provide valuable insight in diving activities.
Methods: Three divers (two males and one female ages 32-45 with a history of deep diving and high pO2 exposure) on the KD made dives to varying depths in Hawaii using fully closed-circuit MK-15 and Inspiration rebreathers.
Unlabelled: Abstract Objective: Myocardial reperfusion injury can induce further cardiomyocyte death and contribute to adverse cardiovascular outcomes after myocardial ischemia, cardiac surgery, or circulatory arrest. Exposure to near-infrared (NIR) light at the time of reoxygenation protects neonatal rat cardiomyocytes and HL-1 cells from injury. We hypothesized that application of NIR at 670 nm would protect the heart against ischemia-reperfusion injury.
View Article and Find Full Text PDFThe authors discuss the ever increasing role of biological renewable resources in energy, nutrition, and pharmaceuticals; specifically those potentially available deep within the oceans. They provide a list of products already gleaned from this vastly untapped marine environment; discuss the innovations in technology required to effectively explore and prospect the deeper reaches of the ocean; expose the impressive contribution to the economy; and expound the paramount importance of protecting the oceans to ensure the future. Already many new proteins, enzymes, and pharmaceuticals are being developed from the fauna and flora of the forests and relatively shallow economic zones of the ocean.
View Article and Find Full Text PDFOxygen toxicity seizures are a rare but recognized complication of hyperbaric oxygen (HBO2) therapy. Many patients undergoing HBO2 therapy have medical conditions or are taking medications that could contribute to seizures. Previous literature has not extensively reported on these factors in patients experiencing oxygen toxicity seizures.
View Article and Find Full Text PDFEvaluation of acute ataxia in a child poses a dilemma for the clinician in determining the extent and timing of initial screening tests. This article reviews the evidence concerning the diagnostic yield of commonly ordered tests in evaluating the child with acute ataxia. The literature revealed the following frequencies of laboratory screening abnormalities in children with acute ataxia: CT (∼2.
View Article and Find Full Text PDFJ Natl Compr Canc Netw
October 2012
In the United States, the 5-year survival rate for patients of all ages with all types of brain tumors is approximately 20%, with the scale skewed toward even poorer survival in patients with gliomas. Although surgery and radiotherapy are primary treatment options, surgery is rarely curative and radiotherapy has had little impact on overall survival. Predominantly studied in adults with advanced high-grade gliomas, photodynamic therapy (PDT) represents a paradigmatic shift in the treatment of brain tumors.
View Article and Find Full Text PDFHigh dynamic range optical-to-near-infrared transmission measurements for different parts of human body in the spectral range from 650 to 950 nm have been performed. Experimentally measured spectra are correlated with Monte Carlo simulations using chromaticity coordinates in CIE 1976 L*a*b* color space. Both a qualitative and a quantitative agreement have been found, paving a new way of characterizing human tissues in vivo.
View Article and Find Full Text PDFHydrogen sulfide is an environmental toxicant and gaseous neurotransmitter. It is produced enterically by sulfur-reducing bacteria and invasive pathogens including Streptococcus anginosus group, Salmonella and Citrobacter. We describe putative focal hydrogen sulfide neurotoxicity after Streptococcus constellatus meningitis, treated with adjunctive sodium nitrite and hyperbaric oxygen therapy.
View Article and Find Full Text PDFObjective: The purpose of this was to evaluate the neuroprotective effects of near-infrared (NIR) light using an in-vivo rodent model of traumatic brain injury (TBI), controlled cortical impact (CCI), and to characterize changes at the behavioral and biochemical levels.
Background Data: NIR upregulates mitochondrial function, and decreases oxidative stress. Mitochondrial oxidative stress and apoptosis are important in TBI.
Purpose: The purposes of this paper are to review the best evidence supporting the use of hyperbaric oxygen therapy (HBOT) in delayed radiation injuries in gynecologic malignancies and report the incidence of radiation injuries at two large medical centers in southeastern Wisconsin.
Methods: A literature search was performed on Google Scholar, PubMed, and Ovid for studies evaluating the use of HBOT radiation cystitis, proctitis, and necrosis. The studies were then reviewed for the highest quality evidence using American Academy of Neurology guidelines.