Hemoglobin Oxygenation State Research Articles

Carboxylated nanodiamond and re‐oxygenation process of gamma irradiated red blood cells

Nanodiamonds (NDs) possess exceptional physical, chemical, and biological properties, which make them suitable for potential biomedical applications. They are biocompatible and their usefulness as effective Raman/fluorescence probes for labeling as well as for drug delivery has been demonstrated. Related to their biocompatibility, the interaction between NDs and red blood cells (RBCs) is of great interest. In this work, the influence of carboxylated NDs (cNDs) in the re‐oxygenation capability of both γ‐irradiated and stored RBCs was studied. The standard 25 Gy γ dose recommended to prevent transfusion associated graft‐versus‐host disease was used. A 5‐day maximum storage time was used to evaluate the “storage lesion”. The hemoglobin (Hb) oxygenation state was assessed by Raman microspectroscopy and the morphologic changes on cells were tracked by optical imaging. Our results show that irradiated RBCs have a better re‐oxygenation capability and morphological recovery when they are in presence of cNDs.

Abstract 388: Morphological assessment of tumor-associated vessels: Automated image processing of whole tumor sections in invasive breast cancer.

Abstract Clinical benefit of anti-angiogenic therapies in different cancers is a result of normalizing the tumor vasculature by these agents. However, tumor vascular imaging modalities in human cancers are in their early evaluating phases. Photoacoustic mammography (PAM) is a newly introduced technique which can image the hemoglobin distribution and oxygenation state inside breast tissue with high spatial resolution. We have previously presented the oxygenation data of our first study in breast cancers by PAM in European Congress of Radiology (ECR) 2011. Here we report the morphological assessment of tumor-associated vessels in 81 histological sections of 20 invasive breast carcinomas. The histological slides were scanned with the magnification of 200 after CD31 immunohistochemical staining. For automated CD31 analysis, 105 jpeg files were extracted from each virtual slide and were changed to binary images with Image Pro-Plus 7.0 software. The optimal hue, saturation and intensity (HSI) of stained structures was selected for each virtual slide. Each binary file was divided into 16 squares of 0.84mm x 0.84 mm size. Total number, area and length of stained structures were calculated in each square. Patients’ age ranged from 36 to 84 years.19 cases were invasive ductal carcinomas and 1 case was invasive lobular carcinoma. Nine cases were luminal A, 9 cases luminal B and 2 cases were HER-2 subtype. For Ki67 scoring ndex,5 cases had <5%, 9 cases between 5-20% and 6 cases had more than 20%. There was a wide heterogeneity among total of 2.95 x10 6 analyzed tumor-associated vessels in 81 histological sections. Table-1 shows the characteristics and distribution pattern. Total number of vessels/mm2 of breast tissue Total area of vessels (μm2)/mm2 of breast tissue Total perimeter of vessels (μm)/mm2 of breast tissue Perimeter/vessel (μm) Area/vessel (μm2) Min 4.6 218.4 65.5 17.8 37.7 Max 87 4369.8 1274.5 45.4 139.3 Average (+SD) 30.7 (+19) 1573.9 (+1060.8) 448.3 (+286.7) 28.9 (+ 4.2) 71.6 (+ 17.9) Additional analysis of shape and pericyte coverage in these vessels is on its way. In conjunction with oxygenation data obtained by PAM,this can be used as a tumor vessel normalization assessment tool which can be used as a biomarker in anti-angiogenic treatments in breast cancers. Citation Format: Elham Fakhrejahani, Yasufumi Asao, Iku Yamaga, Masae Torii, Masahiro Takada, Toshiyuki Kitai, Tomoharu Sugie, Masakazu Toi. Morphological assessment of tumor-associated vessels: Automated image processing of whole tumor sections in invasive breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 388. doi:10.1158/1538-7445.AM2013-388

Photoacoustic mammography: initial clinical results

Photoacoustic tomography can image the hemoglobin distribution and oxygenation state inside tissue with high spatial resolution. The purpose of this study is to investigate its clinical usefulness for diagnosis of breast cancer and evaluation of therapeutic response in relation to other diagnostic modalities. Using a prototype machine for photoacoustic mammography (PAM), 27 breast tumor lesions, including 21 invasive breast cancer (IBC), five ductal carcinoma in situ (DCIS), and one phyllodes tumor, were measured. Nine out of twenty-one IBC patients had received primary systemic therapy (PST). Eight out of twelve IBC without PST were visible. Notably, detection was possible in all five cases with DCIS, whereas it was not in one case with phyllodes tumor. Seven out of nine IBC with PST were assigned as visible in spite of decreased size of tumor after PST. The mean value of hemoglobin saturation in the visible lesions was 78.6 %, and hemoglobin concentration was 207 μM. The tumor images of PAM were comparable to those of magnetic resonance imaging (MRI). It is suggested that PAM can image tumor vascularity and oxygenation, which may be useful for diagnosis and characterization of breast cancer.

Effect of mastication on the autonomic nervous system in the human eye

To evaluate the effect of mastication on the autonomic nervous system in the human eye, we investigated pupil diameter and accommodation during the change in fixation from a distant to a near object by using a new dioptric accommodometer and infrared pupillography. The hemoglobin oxygenation state in the ciliary muscle before and after a gum-chewing task was measured by visible spectroscopy. The measurements were performed on 10 healthy volunteers ranging in age from 18 to 24 years. The hemoglobin oxygenation state value in each individual before the gum-chewing task (used as the standard) was set equal to 100%.

FT‐IR studies of sickle hemoglobin interaction with phosphatidylserine

The interaction of dilauroylphosphatidylserine (DLPS) vesicles with both normal human hemoglobin (HbA) and hemoglobin from patients with sickle cell disease (HbS) has been investigated with FTIR spectroscopy. Changes in the conformational order of the phospholipid chains were directly monitored via the acyl chain CH2 symmetric stretching mode frequencies. The hemoglobin oxygenation state was simultaneously monitored via the S−H stretching contour. The current study reveals that under oxygenated conditions, DLPS shows little interaction with either HbA or HbS. In contrast, deoxyHbS interacted with DLPS by abolishing the gel−liquid crystal phase transition.

Relationship between the gene expression of c-fos and degree of hypoxia in rat brain, as revealed by near-infrared spectroscopy.

Hypoxic induction of c-fos was studied in rat brains as a function of the cerebral oxygenation state using near-infrared spectroscopy by which the hemoglobin oxygenation state and redox state of mitochondrial cytochrome oxidase can be monitored noninvasively. Following reoxygenation after hypoxia, the expression of c-fos and MAP2 mRNAs was determined by reverse transcription-coupled PCR. The expression of MAP2 remained unchanged throughout all conditions from 21 to 8% FiO2. Under the mildly hypoxic conditions, c-fos mRNA was not induced. Hemoglobin was partially deoxygenated but cytochrome oxidase remained fully oxidized. Severe hypoxia, where cytochrome oxidase was reduced, caused a significant induction of c-fos mRNA. At this stage, the oxygen concentration in cerebral tissue fell to lower than 10(-7) M. These data suggest that the decline in oxidative phosphorylation might be a trigger for the induction of c-fos mRNA.

Changes of cerebral blood volume in frontal region during mirror drawing task measured by two channel NIRS in schizophrenics

Near-infrared spectroscopy (NIRS) is a non-invasive measurement of brain function with indices of real-time simultaneous monitoring of hemoglobin oxygenation state of blood near the cortical surface. Frontal lobe dysfunction in schizophrenic patients has been reported by many researchers. We investigated the frontal lobe function in schizophrenia during a Mirror Drawing Task (MDT). A total of 15 schizophrenic patients and 15 controls were examined. All subjects and controls were right-handed. Two 1-channel NIRS systems were used. A light-guide and detector were placed on each side of the frontal region. Oxy-hemoglobin, deoxy-hemoglobin and total hemoglobin were measured approximately each second. A MDT was performed three times. t-Values were calculated by a paired t-test between the average concentration of oxy-hemoglobin for one minute before MDT and each sampling point during MDT. The grand averages of the concentration of oxy-hemoglobin in controls increased in the bilateral frontal regions during the second and third trials; there was no change in the schizophrenic patients. These findings should support the “hypofrontality” hypothesis concerning schizophrenic patients. It is considered that NIRS is useful and an “easy to use” tool to study the brain dysfunction in various mental disorders.

Near-Infrared Optical Imaging by Time-Resolved Spectroscopy.

Near-infrared spectroscopy (NIRS) measures changes in the hemoglobin oxygenation state in the human brain. NIRS has recently started to be used for neuroimaging as well as for clinical monitoring. CW-type NIRS instruments have high temporal resolution and allow prolonged-time and continuous measurements, but they do not provide absolute values of changes in hemoglobin concentrations. In contrast, time-resolved spectroscopy (TRS), which uses short-pulse laser diodes as light sources, makes quantification possible. Quantification is necessary for imaging of brain activity. Recently, a 64-channel time-resolved optical tomographical imaging system (optical CT) and a single-channel TRS instrument have been developed. By the use of this optical CT or combining the single-channel TRS instrument with the multichannel CW-type NIRS instrument, we can obtain topographical images. NIRS is completely noninvasive and does not require strict motion restriction during measurements, unlike PET and fMRI. NIRS will provide a new direction for functional mapping studies.

Influence of mastication on the amount of hemoglobin in human brain tissue

The purpose of this study was to investigate the influence of mastication on the amount of hemoglobin in human brain tissue. Nine healthy volunteers (6 males and 3 females) participated in this study. They underwent two tasks: 1) at rest, 2) gum-chewing. In seven of the nine (4 males and 3 females), experimental occlusal interference was applied to the first molar of the mandibule on the habitual masticatory side. They underwent the gum-chewing task. To evaluate the amount of hemoglobin, both the hemoglobin oxygenation state and blood volume during gum-chewing were measured in the frontal region, using near-infrared spectroscopy. The amount of total-hemoglobin (blood volume) and oxyhemoglobin of subjects significantly increased during gum-chewing (p < 0.01). When the subjects finished gum-chewing, both levels returned to the original levels. When experimental occlusal interference was imposed on the subject, the amount of them significantly decreased compared with subjects without experimental occlusal interference (p < 0.05). The results suggested that increases of cerebral blood flow in the frontal region were not due to the mandibular movement, and that human brain activity caused by mastication was not only in the cortical masticatory area but also in the frontal region.

C-fos expression and redox state of cytochrome oxidase of rat brain in hypoxia.

Hypoxic induction of c-fos was studied in rat brains as a function of the cerebral oxygenation state using near-infrared spectroscopy by which the hemoglobin oxygenation state and redox state of mitochondrial cytochrome oxidase could be monitored noninvasively. Following reoxygenation after hypoxia, the expression of c-fos and MAP2 mRNAs was followed by reverse transcription-coupled PCR. The expression of MAP2 remained unchanged throughout all the conditions from 21 to 8% FiO2. Under mildly hypoxia conditions, c-fos mRNA was not induced. Hemoglobin was partially deoxygenated but cytochrome oxidase remained fully oxidized. Severe hypoxia, where cytochrome oxidase was reduced, caused a significant induction of c-fos mRNA At this stage, the oxygen concentration in cerebral tissue fell to < 10(-7) M. These data suggest that the decline in oxidative phosphorylation might be a trigger for the induction of c-fos mRNA.

Oxygen dependency of cerebral oxidative phosphorylation in newborn piglets.

Changes in hemoglobin oxygenation and oxidation state of the CuA centre of cytochrome oxidase were measured with full spectral near infrared spectroscopy simultaneously with phosphorus metabolites using nuclear magnetic resonance 31P spectroscopy at high time resolution (10 seconds) during transient anoxia (FiO2 = 0.0 for 105 seconds) in the newborn piglet brain. During the onset of anoxia, there was no change in either phosphocreatine (PCr) concentration or the oxidation state of the CuA centre of cytochrome oxidase until there was a substantial fall in cerebral hemoglobin oxygenation, at which point the CuA centre reduced simultaneously with the decline in PCr. At a later time during the anoxia, intracellular pH decreased rapidly, consistent with a fall in cerebral metabolic rate for O2 and reduced flux through the tricarboxylic acid cycle. The simultaneous reduction of CuA and decline in PCr can be explained in terms of the effects of the falling mitochondrial electrochemical potential. From these observations, it is concluded that, at normoxia, oxidative phosphorylation and the oxidation state of the components of the electron transport chain are independent of cerebral oxygenation and that the reduction in the CuA signal occurs when oxygen tension limits the capacity of oxidative phosphorylation to maintain the phosphorylation potential.

Relationship Between Fluctations in The Cerebral Hemoglobin Oxygenation State and Neuronal Activity During the Resting Period

Relationship Between Fluctations in The Cerebral Hemoglobin Oxygenation State and Neuronal Activity During the Resting Period

Relationship between fluctuations in the cerebral hemoglobin oxygenation state and neuronal activity under resting conditions in man

Simultaneous measurements by near-infrared spectroscopy and electroencephalography were performed during 15-min resting periods in nine healthy adult brains. The peak frequencies of the frontal and occipital rhythms varied with the time course like the hemoglobin oxygenation state. Changes in the amount of oxygenated hemoglobin in the frontal region by more than 50% of the maximum resting variation range were accompanied by changes in peak frequency at the electrode position between two optodes. The results suggest that spontaneous neuronal activity is responsible for fluctuations in the hemoglobin oxygenation state in the resting state.

Near-infrared Spectroscopic Method for Assessing the Tissue Oxygenation State of Living Lung

To quantify changes in tissue oxygenation of pathologic lungs, we applied a novel method using near-infrared spectroscopy (NIRs). In in vitro experiments, we assayed the effect of photon scattering on the absorption spectra of an in vitro system simulating structures of lung, which consists of test tube containing air in hematocrit tubes and red blood cell suspension with various predetermined hemoglobin concentrations. It was determined that photon scattering of the tissue containing air did not affect the absorption in the NIR region. In in vivo experiments, we tested the applicability of the NIRs technique in rat lungs under the following conditions: (1) hypoxic loading; (2) administration of an inhibitor (NaCN) of the mitochondrial respiratory chain; (3) hemorrhagic shock. We found that: (1) Changes in hemoglobin oxygenation state in the lung measured by NIRs depended on inspired oxygen concentrations; (2) NaCN-induced reduction of cytochrome oxidase a,a3 in the lung was observed; and (3) Total hemoglobin levels in the lung decreased after bleeding. Changes in the hemoglobin oxygenation state and cytochrome oxidase redox state in the lung were determined using the least-square-curve fitting for NIR absorption spectra. Our NIRs technique was capable of assessing the hemoglobin oxygenation and cytochrome oxidase redox state in the lung.

Region-dependent asymmetrical or symmetrical variations in the oxygenation and hemodynamics of the brain due to different mental stimuli

The present paper demonstrates region-dependent variations in the oxygenation and hemodynamics of the brain hemispheres due to three different types of mental stimulation. The variations were observed with a four-channel optical imaging system using tissue-transparent near-infrared light and described changes from baseline of both the hemoglobin oxygenation state and blood volume during three kinds of psychological or mental tasks. During the mirror drawing task, a lateralized hemisphere response (the dominant hemisphere response pattern) was observed in 57% of 14 right handed volunteers in the frontal region (Brodmann's area 10), while in the temporal region (area 38), 80% showed the bilateral response pattern. A large majority of the subjects showed the bilateral response pattern in the frontal and temporal regions while calculating. A smaller majority showed this while looking at anatomical charts, though 30% did not show any response at all in the temporal region. This showed that there were region-dependent asymmetrical or symmetrical variations of the oxygen delivery-oxygen utilization relationship due to different types of mental stimuli.

Dynamic multichannel near-infrared optical imaging of human brain activity

The present paper demonstrates functional brain mapping with an optical imaging technique by using tissue-transparent near-infrared light. With a maximal five-channel optical monitoring system, we succeeded in detecting region-specific changes in both the hemoglobin oxygenation state and blood volume during various mental tasks, in addition to visual and auditory stimulation. The time course of increases in blood supply varied with each brain region and depended on the type of internal operations occurring during the mental tasks. Changes in the hemoglobin oxygenation state were also different from region to region. This showed that there were regional variations of the oxygen delivery-oxygen utilization relationship during activation of brain activity. The usefulness of multichannel near-infrared functional imaging was well documented.

Dynamic changes in cerebral oxygenation in chemically induced seizures in rats: study by near-infrared spectrophotometry

Using near-infrared spectrophotometry, the redox state of copper in cytochrome oxidase, and the hemoglobin oxygenation state were measured in the rat brain in situ during and after chemically induced seizures. Pentylentetrazol (PTZ) administration caused the partial reduction of cytochrome oxidase in the brain just before the elctroencephalogram (EEG) showed desynchronization, and then blood pressure was elevated concomitantly with an increase in cerebral blood volume. When blood pressure reached a maximum, bursts of spikes appeared on the EEG and cytochrome oxidase was reoxidized to reach the initial oxidation level, giving a rapid, transient reduction of cytochrome oxidase in the preictal period. Hemoglobin was more oxygenated than before the administration throughout the seizure. In the late postictal phase, cytochrome oxidase was partially reduced again, while blood pressure remained high and hemoglobin was more oxygenated than initially. The second administration of PTZ in the late postictal phase induced the same responses as observed after the first administration. By decreasing oxygen concentrations in the inspired gas during the seizure, cytochrome oxidase was more reduced than in the non-epileptic rat, and spike activity was observed until about 85% of cytochrome oxidase was reduced. The transient cerebral hypoxia reflected by the reduction of cytochrome oxidase in the preictal period may be a trigger for an increase in cerebral blood flow rather than the result of a delayed autonomic response. The second reduction of cytochrome oxidase observed in the late postictal phase may be due to a lasting arterio-venous shunt that opens during seizures. These results revive the classical theory that cellular hypoxia is responsible for epileptic brain damage.

Cerebral oxygenation state in chemically-induced seizures in the rat--study by near infrared spectrophotometry.

The hemoglobin oxygenation state and the redox state of Cyt.ox. in the rat brain during and after seizure induced by PTZ were measured by using near-infrared spectrophotometry. PTZ administration caused transient reduction of Cyt.ox. in the brain, which might be a trigger for the increase of CBF during seizure. In postictal phase, although BP remained high, Cyt.ox. was in the certain reduced state, which might be due to A-V shunt. Hypoxic loading during seizure caused more reduction of Cyt.ox. than under non-epileptic conditions, which meant that seizure even under mild hypoxic conditions could cause severe hypoxic brain damage.

Quantitative Analysis of the Hemoglobin Oxygenation State of Rat Brain In Vivo by Picosecond Time-Resolved Spectrophotometry

Through the use of a picosecond laser pulse of near-infrared light at 1,064 nm, the temporal profile of the transmitted light through the anesthetized rat head has been investigated. The light intensity at a certain time after the input pulse was exponentially attenuated by the hemoglobin concentration with hematocrit values from 1.5 to 50%, although the transmitted pulse broadened markedly due to scattering by the cerebral tissue. The optical pathlength, which is required for quantitation of the absolute absorbance change, was directly determined, by the time of flight measurement of the light pulses, as the product of the velocity of light in tissue and time. The mean concentration of hemoglobin in the brain could be determined quantitatively by the use of this pathlength. The oxygen saturation of venous blood determined by our time of flight measurement was very close to that in the internal jugular vein determined directly with a gas analyzer. Thus, the picosecond laser technique is useful for quantifying the blood oxygenation in tissues.

Quantitative analysis of hemoglobin oxygenation state of rat brain in situ by near-infrared spectrophotometry

The light in the near-infrared region (700-900 nm) was illuminated on the rat head, and absorption spectra were measured with the transmitted light under various conditions. The absorbance changes less than 780 nm were attributable to hemoglobin in the brain tissue, whereas those greater than 780 nm were associated with both hemoglobin and cytochrome oxidase. The changes of oxy- and total (oxy- plus deoxy-) hemoglobin content in the rat head could be monitored quantitatively by expressions of delta A700--1.20 delta A730 and delta A700--1.52 delta A730, respectively. The oxyhemoglobin content in the tissue was decreased as the O2 tension in inspired gas was lowered. At 10% O2 approximately 50% of hemoglobin was deoxygenated. The total hemoglobin content was increased under anoxic conditions. Inhalation of 5% CO2 and intravenous injection of a Ca2+ blocker nicardipine increased the O2 saturation of hemoglobin in the brain. These conclusions were confirmed by measuring the difference absorption spectra in the near-infrared region.