Effect of Mastication Muscle Activity on Prefrontal Cortex NIRS Measurement: A Pilot Study.

Changes in NIRS signals are related to changes in local cerebral blood flow or oxy-Hb concentration. On the other hand, recent studies have revealed the effect of chewing gum on cognitive performance, stress control etc. which accompanied brain activity in the prefrontal cortex (PFC).

Effect of Gum Chewing on PFC Activity During Discomfort Sound Stimulation.

The prefrontal cortex (PFC) is sensitive to the stress exposure and involved in stress coping. And the effects of gum chewing on the stress have been studied using NIRS. However, when measuring NIRS on PFC during gum chewing, blood flows in shallow tissues (scalp, skin, muscle) might be affected.

Relationships Between Gum-Chewing and Stress.

Studies have shown that chewing is thought to affect stress modification in humans. Also, studies in animals have demonstrated that active chewing of a wooden stick during immobilization stress ameliorates the stress-impaired synaptic plasticity and prevents stress-induced noradrenaline release in the amygdala. On the other hand, studies have suggested that the right prefrontal cortex (PFC) dominates the regulation of the stress response system, including the hypothalamic-pituitary-adrenal (HPA) axis.

Influence of Pleasant and Unpleasant Auditory Stimuli on Cerebral Blood Flow and Physiological Changes in Normal Subjects.

The prefrontal cortex (PFC) plays an important role in emotion and emotional regulation. The valence asymmetry hypothesis, proposes that the left/right asymmetry of the PFC activity is correlated with specific emotional responses to stressors. However, this hypothesis still seems to leave room for clarifying neurophysiological mechanisms.

Detection of ROSC in Patients with Cardiac Arrest During Chest Compression Using NIRS: A Pilot Study.

Return of spontaneous circulation (ROSC) during chest compression is generally detected by arterial pulse palpation and end-tidal CO2 monitoring; however, it is necessary to stop chest compression during pulse palpation, and to perform endotracheal intubation for monitoring end-tidal CO2. In the present study, we evaluated whether near-infrared spectroscopy (NIRS) allows the detection of ROSC during chest compression without interruption. We monitored cerebral blood oxygenation in 19 patients with cardiac arrest using NIRS (NIRO-200NX, Hamamatsu Photonics, Japan).

Monitoring of filter patency during carotid artery stenting using near-infrared spectroscopy with high time-resolution.

We aimed to evaluate the usefulness of a newly developed, near-infrared spectroscopy (NIRS) device for monitoring hemodynamic changes during carotid artery stenting (CAS), as a means to detect filter obstruction due to distal embolism. We evaluated 16 patients with internal carotid artery (ICA) stenosis during the CAS procedure, using a NIRS system that can monitor not only changes in oxygenation of hemoglobin (Hb), but also the fluctuation of oxyhemoglobin (oxy-Hb) synchronized with heartbeat. The NIRS system detected a marked decrease of oxy-Hb and an increase of deoxyhemoglobin (deoxy-Hb) during ICA occlusion in patients without anterior cross circulation (ACC).

Effects of enriched environment on hippocampal neuronal cell death and neurogenesis in rat global ischemia.

Enriched environments reportedly show neuroprotective effects. Here, we evaluated the effect of an enriched environment prior to cerebral ischemia on neuronal cell death and neurogenesis in rats. Male SD rats were housed under standard conditions (SC) or in an enriched environment (EE), then subjected to global ischemia.

Correlation between asymmetry of spontaneous oscillation of hemodynamic changes in the prefrontal cortex and anxiety levels: a near-infrared spectroscopy study.

According to the valence asymmetry hypothesis, the left/right asymmetry of prefrontal cortex (PFC) activity is correlated with specific emotional responses to mental stress and personality traits. Here, we evaluated the relation between emotional state and asymmetry in PFC activity at rest by using near-infrared spectroscopy (NIRS). We measured spontaneous oscillation of oxyhemoglobin (oxy-Hb) concentrations in the bilateral PFC at rest in normal adults employing two-channel NIRS.

Acute stress exposure preceding transient global brain ischemia exacerbates the decrease in cortical remodeling potential in the rat retrosplenial cortex.

Doublecortin (DCX)-immunoreactive (-ir) cells are candidates that play key roles in adult cortical remodeling. We have previously reported that DCX-ir cells decrease after stress exposure or global brain ischemia (GBI) in the cingulate cortex (Cg) of rats. Herein, we investigate whether the decrease in DCX-ir cells is exacerbated after GBI due to acute stress exposure preconditioning.

Drastic enhancement of excess electron-transfer efficiency through DNA by inserting consecutive 5-phenylethynyl-2'-deoxyuridines as a modulator.

5-(Phenylethynyl)-2'-deoxyuridine ((Ph)U) was consecutively incorporated into oligodeoxynucleotides as an electron transport modulator for regulating DNA-mediated excess electron transfer (EET). Upon photoexcitation of the ethynylpyrene chromophore, extremely high EET efficiencies through DNA containing consecutive (Ph)Us were observed using 5-bromouracil as a distal electron trap.

Photo-switching of vinylpyrene-substituted 2'-deoxyguanosine and its application.

We synthesized C8-vinylpyrene-substituted 2'-deoxyguanosine (VPy)G and studied the photoinduced reversible E-Z isomerization. When E-isomer was irradiated with visible light (>420 nm), E- to Z-isomerization took place very rapidly, while upon irradiation with UV-light ( approximately 365 nm), Z-isomer was converted to E-isomer. When Z-isomer was illuminated with 365- 400 nm light, no fluorescence was observed, while E-isomer showed a very strong fluorescence emission, indicating that (VPy)G could be a useful fluorescence switching molecule.

Design of extremely facile 3'- and 5'- ends free molecular beacons using C8 alkylamino substituted 2'-deoxyguanosine.

A novel fluorescent oligonucleotide probe containing pyrene-labeled C8 alkylamino-substituted 2'-deoxyguanosine and a practically useful 3'- and 5'- ends-free self-quenched molecular beacons (MB) were designed. A unique MB detectable by pyrene excimer fluorescence was also demonstrated.

Design of an ultimate quencher free molecular beacon containing pyrrolocytidine-guanine base pair.

A novel quencher free molecular beacon was designed in which fluorophore-labelled pyrrolocytidine was placed away from the stem terminal. This new type of MB was used for the detection of a target DNA with an excellent efficiency.

Design of an efficient self-quenched molecular beacon for SNPs genotyping.

Quencher free molecular beacon with an excellent signal to noise ratio was designed and used for SNPs genotyping.

Fluorometric sensing of conformational switching of DNA; the use of fluorescence labeled C8-alkylamino substituted 2'-deoxyguanosine.

C8-alkylamino substituted 2'-deoxyguanosine was incorporated into a DNA sequence and then labeled with pyrene. The conformational change from B- to Z-form was monitored using CD and fluorescence spectroscopy for both labeled and unlabeled ODNs.

Synthesis of C8-alkylamino substituted 2'-deoxyguanosine.

Synthesis of C8-alkynyl- and alkylamino substituted 2'-deoxyguanosine is described. Protected alkynylamines are coupled with 8-bromo-2'-deoxyguanosine by a Pd(0)-mediate Sonogashira coupling protocol. Hydrogenation of alkynyl derivatives over 10% Pd/C under atmospheric pressure gave 8-alkylamino guanosine derivatives in nearly quantitative yields.

Mouse zona pellucida dynamically changes its elasticity during oocyte maturation, fertilization and early embryo development.

A change in the elasticity of mouse zona pellucida was quantitatively evaluated during oocyte maturation, fertilization and early embryo development. Young's modulus of zona pellucida of germinal vesicle (GV), metaphase-II (MII), pronuclear (PN), 2cell, 4cell, 8cell, morulae (M) and early blastocyst (EB) stages was measured using a micro tactile sensor (MTS) and a chamber exclusively designed for the measurement. The MTS has very high sensitivity and a deformation of only 5 microm was sufficient to calculate the Young's modulus and the oocyte/embryo maintained its original spherical shape during the measurement.

Synthesis of perylene-labeled base-discriminating fluorescent (BDF) nucleoside and its fluorescence properties.

We have synthesized perylene labeled BDF probe and its photophysical properties were explored. Perylene labeled oligonucleotide probe is capable of detecting cytosine from its target mismatch sequence by enhancement of fluorescence intensity.

Design of base-discriminating fluorescent (BDF) nucleobase for SNP typing.

We have devised novel pyrene-labeled BDF nucleosides, (Py)U, (Py)C, (Py)deazaA, and (Py)A. BDF probes containing these fluorescent nucleosides selectively emit fluorescence only when the base opposite the BDF base is a target base. Oligonucleotides containing these BDF nucleosides act as effective reporter probes for homogeneous SNP typing of DNA samples.

Intelligent fluorescent nucleoside in sensing cytosine base: importance of hydrophobic nature of perylene fluorophore.

Fluorescence response upon hybridization of perylene labeled oligonucleotide probes depends on the microenvironment experienced by the perylene fluorophore. In mismatched duplex ((Per)U-C), enhanced fluorescence was observed while in matched duplex ((Per)U-A) fluorescence intensity decreased considerably. This observation will be a promising research effort in giving rise to a new powerful tool in detection of SNP.

Base-discriminating fluorescent (BDF) nucleoside: distinction of thymine by fluorescence quenching.

A novel fluorescence BDF probe containing pyrene-labeled 7-deaza-2[prime or minute]-deoxyadenosine has been developed for the detection of thymine base on a target DNA.