Article
Biochemical Research Methods
Maxim A. Volynsky, Oleg Mamontov, Anastasiia Osipchuk, Valery V. Zaytsev, Alexey Y. Sokolov, Alexei A. Kamshilin
Summary: Intraoperative assessment of cerebrovascular reactivity is crucial in neurosurgery. This study proposes the use of imaging photoplethysmography to measure changes in cortical perfusion caused by CO2 inhalation for evaluating the functional reserve of cerebral blood flow. The results reveal that the response to hypercapnia depends strongly on the cranial state. However, regardless of the direction of hemodynamic changes, the ratio of normalized changes in arterial blood pressure and cortical perfusion can serve as an indicator of cerebrovascular functional reserve.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Biochemical Research Methods
Shuqi Zheng, Jerome Mertz
Summary: Laser speckle contrast imaging (LSCI) is a technique for monitoring tissue dynamics. We introduce a model-free method to reconstruct the speckle field decorrelation time, which is applicable to both ergodic and non-ergodic measurements.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Multidisciplinary Sciences
Behnia Rezazadeh Shirazi, Rudy J. Valentine, James A. Lang
Summary: This study investigated the reproducibility and standardization of post-occlusive reactive hyperemia (PORH) using laser speckle contrast imaging (LSCI) technique. Findings suggest that maximal flow and area under the curve standardized to zero perfusion show good reliability, while time to maximal flow (TMF) and hyperemic velocity are not recommended for longitudinal assessment. Alternative kinetic indices such as 1-min AUC and overshoot rate-of-change (ORC) were found to be reliable for assessing the PORH response.
Article
Health Care Sciences & Services
Ani Belcheva, Maria Shindova, Reem Hanna
Summary: This study evaluated the changes in pulpal blood flow during the post-traumatic period of traumatised permanent teeth using laser Doppler flowmetry (LDF), finding that the blood flow in traumatised teeth was significantly higher than in non-traumatised teeth. Therefore, LDF can assist dentists in early and accurate investigation of pulpal blood flow, serving as a useful monitoring tool.
JOURNAL OF PERSONALIZED MEDICINE
(2021)
Article
Medicine, General & Internal
Taipau Chia, Jian-Guo Bau, Guo-Dung Hung, Sz-Huan Tsai, Che-Ming Hu
Summary: This study found that shoulder microcirculation abnormality is associated with severe neck-shoulder pain, and noninvasive LDF can be used to assess it at an early stage.
Article
Dentistry, Oral Surgery & Medicine
Svetlana Antic, Biljana Markovic-Vasiljkovic, Bojan Dzeletovic, Drago B. Jelovac, Jovana Kuzmanovic-Pficer
Summary: This study investigates the dental pulp and gingival blood flow in patients undergoing oropharyngeal radiotherapy (RT) and evaluates the impact of radiation dose on blood flow. The results show that RT causes a significant acute increase in gingival blood flow, followed by a long-term tendency to return to baseline levels. Dental pulp blood flow is differently affected by higher radiation doses. Therefore, protecting teeth near the tumor volume during RT planning is recommended.
JOURNAL OF APPLIED ORAL SCIENCE
(2022)
Article
Multidisciplinary Sciences
Gergely Somogyi, David Hlatky, Tamas Spisak, Zsofia Spisak, Gabriella Nyitrai, Andras Czurko
Summary: This study investigated the effects of scopolamine on brain activity using functional MRI in rats under different drug administration and anesthesia conditions. The results suggest that scopolamine may affect brain activation through central pathways, and its peripheral vascular actions depend on the type of anesthesia or dose.
SCIENTIFIC REPORTS
(2021)
Article
Neurosciences
Justine Robin, Richard Rau, Berkan Lafci, Aileen Schroeter, Michael Reiss, Xose-Luis Dean-Ben, Orcun Goksel, Daniel Razansky
Summary: The study found that fOA and fUS imaging have similar spatial resolution in capturing mouse brain responses to peripheral sensory stimulation, and can provide complementary hemodynamic readouts.
Article
Cardiac & Cardiovascular Systems
Rachel J. Skow, R. Matthew Brothers, Jurgen A. H. R. Claassen, Trevor A. Day, Caroline A. Rickards, Jonathan D. Smirl, Patrice Brassard
Summary: This article presents recommended terminology for reporting cerebral hemodynamic data and discusses the current use and misuse of terminology in the field. It provides guidelines for researchers in the study of cerebral hemodynamics.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2022)
Article
Engineering, Biomedical
Evgeny Zherebtsov, Igor Kozlov, Viktor Dremin, Alexander Bykov, Andrey Dunaev, Igor Meglinski
Summary: Nowadays, photonics-based techniques are extensively used in various applications such as functional clinical diagnosis and progress monitoring in treatment. In this study, a new signal processing approach for the decomposition of Laser Doppler Flowmetry (LDF) power spectra in terms of blood flow distribution was introduced. The approach showed great potential in improving the diagnostic accuracy of microvascular changes in patients with Diabetes Mellitus type 2 and age-specific changes.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2023)
Article
Psychology, Biological
Katrina N. Bouchard, Caroline F. Pukall
Summary: This study investigated the measurement properties of laser Doppler flowmetry and examined the time course of genital response using flowmetry. The results showed that laser Doppler flowmetry is a valid, reliable, and sensitive measure of women's genital response. It is capable of detecting increases in genital blood flow elicited by sexual stimuli and exhibits good convergent validity with genital response assessed via laser Doppler imaging and self-reported sexual arousal.
Article
Multidisciplinary Sciences
M. Provansal, G. Labernede, C. Joffrois, A. Rizkallah, R. Goulet, M. Valet, W. Deschamps, U. Ferrari, A. Chaffiol, D. Dalkara, J. A. Sahel, M. Tanter, S. Picaud, G. Gauvain, F. Arcizet
Summary: This study demonstrates the detection of deep optogenetic activations in anesthetized rats' V1 using fUS imaging. The optogenetic specificity of these activations and their neuronal origin were confirmed through electrophysiological recordings. Furthermore, it was shown that the optogenetic response initiated in V1 spreads to downstream (LGN) and upstream (V2) visual areas.
SCIENTIFIC REPORTS
(2021)
Review
Physiology
Lana Kralj, Helena Lenasi
Summary: Laser Doppler flowmetry (LDF) is widely regarded as the gold standard for non-invasive assessment of skin microvascular function. Spectral analysis, particularly wavelet analysis (WA), can provide both time and frequency localization of the LD microcirculatory signals, allowing for a more comprehensive analysis of the signals' properties. However, there is a need for analytical standardization and improvements in WA to accurately evaluate microcirculatory signals and enhance prognosis of diseases with microvascular dysfunction.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Physiology
Masayo Koide, Hannah R. Ferris, Mark T. Nelson, George C. Wellman
Summary: Subarachnoid hemorrhage (SAH) is a common form of hemorrhagic stroke with high mortality and severe disability rates. Recent studies suggest that delayed cerebral ischemia (DCI) in SAH is related to disturbances in cerebral circulation, particularly involving cerebral autoregulation malfunction. The study quantitatively examines the impact of SAH on cerebral autoregulation and provides evidence of decreased cerebral blood flow and impaired autoregulation range in SAH animals. This novel methodology could lead to future studies on therapeutic strategies targeting impaired cerebral autoregulation in cardiovascular and cerebrovascular disorders.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Muhammad Asfandyar Awan, Moaaz Ahmed, Bo Wang
Summary: This article presents a compact blood flow measurement system based on the Doppler effect and photocurrent sensing technique, which can be used for wearable health monitoring. The system allows continuous monitoring of blood flow in patients with peripheral artery disease (PAD) without involving a physician. It offers a small size, high accuracy, and low cost, and does not require the use of optical filters or fibers.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Analytical
Dessislava Lazarova, Severina Semkova, Genoveva Zlateva, Higashi Tatsuya, Ichio Aoki, Rumiana Bakalova
Summary: Total redox capacity (TRC) and oxidative stress (OxiStress) are commonly analyzed parameters in life science, and the development of highly sensitive molecular probes and analytical methods for detecting these parameters is a rapidly growing sector of the BioTech R&D industry. This study focused on developing quantum sensors for tracking TRC and/or OxiStress in living biological objects using advanced imaging techniques, and successfully applied the sensors for cellular analysis in vitro and noninvasive imaging in vivo.
ANALYTICAL CHEMISTRY
(2021)
Article
Neurosciences
Lin Cai, Tomonori Nitta, Sho Yokota, Takayuki Obata, Eiji Okada, Hiroshi Kawaguchi
Summary: The study introduced a sensitivity-based matching method for fNIRS to consider the impact of light scattering on the scalp-cortex correlation, showing its superiority over conventional geometrical matching methods. The method allows for precise evaluation of cortical activity that may be overlooked by traditional approaches, making it a promising tool for fNIRS probe arrangement design and data interpretation.
HUMAN BRAIN MAPPING
(2021)
Article
Biochemical Research Methods
Jeff Kershaw, Takayuki Obata
Summary: The OGSE-DWI technique probes tissue microstructure in the frequency domain, but its spectral resolution and range are limited by practical restrictions on gradient oscillation duration and number. The revised framework differs from the conventional description and only allows for indirect information about spectral density.
JOURNAL OF MAGNETIC RESONANCE
(2021)
Article
Pediatrics
Moyoko Tomiyasu, Jun Shibasaki, Hiroshi Kawaguchi, Mikako Enokizono, Katsuaki Toyoshima, Takayuki Obata, Noriko Aida
Summary: In VLBW preterm infants, the concentration of tNAA in specific brain regions showed significant correlations with postmenstrual age, and the slopes of tNAA concentrations were associated with neurodevelopmental outcomes at 3-4 years of age. Slower increase in tNAA brain concentration at term-equivalent age was linked to poorer developmental outcomes, suggesting the importance of monitoring tNAA levels in predicting developmental delays.
PEDIATRIC RESEARCH
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Yoko Ikoma, Hiroyuki Takuwa, Asuka Nishino, Jun Maeda, Kazunori Kawamura, Takayuki Obata, Ming-Rong Zhang, Makoto Higuchi, Tetsuya Suhara
Summary: PET studies using [F-18]altanserin can successfully estimate changes in endogenous serotonin levels by measuring changes in binding potential (BP), which are influenced by the concentration of serotonin and the onset of elevation. This method shows potential for investigating endogenous serotonin levels elevation caused by stimulations.
ANNALS OF NUCLEAR MEDICINE
(2021)
Article
Biochemistry & Molecular Biology
Ken-ichiro Matsumoto, Ikuo Nakanishi, Zhivko Zhelev, Rumiana Bakalova, Ichio Aoki
Summary: The use of nitroxyl radicals based on a cyclic redox mechanism as an index of tissue redox status has significant implications. Recent advances have focused on developing in vivo redox imaging using nitroxyl radicals as redox-sensitive contrast agents. Additionally, the development of nitroxyl radical contrast agents and drugs for theranostics has shown promise.
ANTIOXIDANTS & REDOX SIGNALING
(2022)
Article
Endocrinology & Metabolism
Manabu Kubota, Yasuyuki Kimura, Masafumi Shimojo, Yuhei Takado, Joao M. N. Duarte, Hiroyuki Takuwa, Chie Seki, Hitoshi Shimada, Hitoshi Shinotoh, Keisuke Takahata, Soichiro Kitamura, Sho Moriguchi, Kenji Tagai, Takayuki Obata, Jin Nakahara, Yutaka Tomita, Masaki Tokunaga, Jun Maeda, Kazunori Kawamura, Ming-Rong Zhang, Masanori Ichise, Tetsuya Suhara, Makoto Higuchi
Summary: The study demonstrates that food intake and changes in plasma glucose levels dynamically alter metabotropic glutamate receptor subtype 5 (mGluR5) ligand binding and glutamate levels in the human brain. These findings suggest a mechanistic link between food-associated glucose intake and glutamatergic tones in the brain, which can be accessed in vivo by bimodal PET and MRS techniques in both clinical and non-clinical settings.
JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
(2021)
Article
Multidisciplinary Sciences
Masashi Usumura, Riwa Kishimoto, Koki Ishii, Eika Hotta, Jeff Kershaw, Tatsuya Higashi, Takayuki Obata, Mikio Suga
Summary: The study evaluated the long-term stability of a newly developed PAAm gel viscoelastic phantom for MRE and US SWE. Results showed that the phantom maintained acceptable hardness over time, meeting the criteria for a quality assurance and quality control phantom.
Article
Oncology
Akira Sumiyoshi, Sayaka Shibata, Zhivko Zhelev, Thomas Miller, Dessislava Lazarova, Genoveva Zlateva, Ichio Aoki, Rumiana Bakalova
Summary: The research demonstrates that M/A is a more tolerable pharmacological strategy for selectively targeting glioblastoma, suppressing tumor growth. M/A induces overproduction of mitochondrial superoxide specifically in glioblastoma cells, distinguishing them from normal microglial cells.
ANTICANCER RESEARCH
(2021)
Article
Oncology
Donika Ivanova, Zhivko Zhelev, Genoveva Zlateva, Dessislava Lazarova, Zvezdelina Yaneva, Radmila Panovska, Ichio Aoki, Rumiana Bakalova
Summary: This study analyzed the effects of alpha-tocopheryl succinate (alpha-TS) on the redox-state of leukemia and normal lymphocytes, as well as their sensitivity to anticancer drugs. It found that combination of alpha-TS with certain drugs showed a synergistic cytotoxic effect on leukemia lymphocytes, but had no effect on normal lymphocytes. Therefore, alpha-TS could be a promising adjuvant therapy in second-line anticancer treatment.
ANTICANCER RESEARCH
(2022)
Review
Cell Biology
Zhivko Zhelev, Ichio Aoki, Dessislava Lazarova, Tatyana Vlaykova, Tatsuya Higashi, Rumiana Bakalova
Summary: Cancer metabolism is a fascinating and complex field that involves abnormal activation of various metabolic pathways. Recent studies have found pronounced mitochondrial fatty acid oxidation in many types of cancer cells. This article discusses how this process can escape normal regulation and be overactivated under certain conditions, and proposes a new metabolic pathway called the beta-oxidation shuttle.
OXIDATIVE MEDICINE AND CELLULAR LONGEVITY
(2022)
Article
Oncology
Akira Sumiyoshi, Sayaka Shibata, Zhivko Zhelev, Thomas Miller, Dessislava Lazarova, Ichio Aoki, Takayuki Obata, Tatsuya Higashi, Rumiana Bakalova
Summary: Glioblastoma is characterized by a pronounced redox imbalance due to elevated glycolytic and mitochondrial oxidative metabolism. A pharmacological strategy involving the redox active combination drug menadione/ascorbate effectively targets and treats glioblastoma by suppressing tumor growth and increasing survival without adverse effects on normal cells. The therapy induces selective cytotoxicity in cancer cells, modulates immune response, decreases drug resistance, and potentially sensitizes glioblastoma to conventional chemotherapy.
Article
Oncology
Zhivko Zhelev, Akira Sumiyoshi, Ichio Aoki, Dessislava Lazarova, Tatyana Vlaykova, Tatsuya Higashi, Rumiana Bakalova
Summary: This review presents the concept of the beta-oxidation shuttle in cancer cell metabolism. The beta-oxidation shuttle is a metabolic pathway that arises due to the impaired redox state of cancerous mitochondria, in which it combines with fatty acid synthesis and the mevalonate pathway, leading to biomass accumulation, accelerated oxygen consumption, and proliferation. Studies have found that the beta-oxidation shuttle coexists with abnormally activated fatty acid oxidation and the mevalonate pathway in cancer cells. This new metabolic pathway has significant implications for understanding cancer metabolism and developing anticancer strategies.
Article
Biotechnology & Applied Microbiology
Severina Semkova, Donika Ivanova, Biliana Nikolova, Genoveva Zlateva, Rumiana Bakalova, Zhivko Zhelev, Ichio Aoki
Summary: Oligomycin-A inhibits ATP synthase activity, increasing the cytotoxicity of low/tolerable doses of M/A in leukaemic lymphocytes, while not affecting the effects under high doses of M/A treatment.
BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Takuya Urushihata, Hiroyuki Takuwa, Manami Takahashi, Jeff Kershaw, Yasuhiko Tachibana, Nobuhiro Nitta, Sayaka Shibata, Masato Yasui, Makoto Higuchi, Takayuki Obata
Summary: The study utilized animal models to investigate the effects of aquaporin-4 suppression on ADC values in brain tissue after cerebral infarction. Results showed that aquaporin-4 knockout mice had significantly lower ADC values in ischemic tissue compared to wild-type mice, while exhibiting higher ADC values in the contralateral region. Genotype-dependent differences in ADC were particularly significant in different b-value ranges and diffusion times. Fitting the water-exchange model revealed that aquaporin-4 knockout mice had a longer water-exchange time compared to wild-type mice in the ischemic region. The multi-b-value multi-diffusion-time diffusion-weighted imaging technique may be valuable for the in vivo research and clinical diagnosis of aquaporin-4-related diseases.
EUROPEAN RADIOLOGY EXPERIMENTAL
(2021)
