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Sleep apnea syndrome (SAS) often accompanies alterations in heart rate variability (HRV). The severity of SAS is sometimes evaluated using the oxygen desaturation index (ODI). We hypothesized that effects of the autonomic nervous system could be involved in the coordination between HRV and physical acceleration during free movement in patients with SAS. Among 33 women aged 60 years or older, 19 had a high ODI (>5). Their HRV and physical acceleration were simultaneously obtained every minute for 24 hours. The low frequency/high frequency (LF/HF) ratio and the high frequency in normalized units (HFnu) were used as HRV indices. Low levels of %Lag0, defined as the percentage of the lag = 0 min in 1 h, indicated coordination between physical acceleration and HRV. Nineteen participants were divided into group A (high %Lag0 before sleep [n = 9]) or group B (low %Lag0 [n = 10]). In group B participants with a high ODI and low %Lag0 in the hour after waking, HFnu was significantly increased compared to that in group A participants with high ODI and high %Lag0 in the hour after waking (p less then 0.05). These results suggest that close associations between high ODI and discoordination between HRV and physical acceleration may be due to higher parasympathetic nervous system activity after waking.Autonomic disorders such as orthostatic hypotension often become a problem during the early mobilization of poststroke patients. We reported that the prefrontal cortex (PFC) oxyhemoglobin changes at rest are often on the right, and a positive correlation was observed between the left and right activity balance and the change in oxy-Hb. In this study, we focused on the asymmetrical changes associated with the standing load from rest. We assessed the left-right asymmetry of the PFC oxyhemoglobin changes at rest and standing load by calculating the Laterality Index at Rest (LIR) and laterality index during activity (LIA); positive values indicate the right-dominant activity, while negative values indicate left-dominant activity. As for left-right asymmetry LIA, the active dominant PFC was reversed in five patients. It should be noted that in almost all of the 13 cases, the active PFC and the lesion side matched. The detailed mechanism of overactivity up to the prefrontal cortex on the lesion side is unknown, but it may be a recovery mechanism that elicits plasticity in the brain network.

In modern society, we are increasingly exposed to numerous sources of blue light, including screens (e.g., TVs, computers, laptops, smartphones, tablets) and light from fluorescent and LED lamps. Due to this wide range of applications, the effects of blue light exposure (BLE) on the human physiology need to be thoroughly studied.

To investigate the impact of long-term BLE on frontal and occipital human cerebral hemodynamics and oxygenation using functional near-infrared spectroscopy (fNIRS) neuroimaging.

32 healthy right-handed subjects (20 females, 12 males; age 23.8±2.2years) were exposed to blue LED light for 15minutes. Before (baseline, 8min) and after (recovery, 10min) the BLE, subjects were in darkness. We measured the concentration changes of oxyhemoglobin ([O

Hb]) and deoxyhemoglobin ([HHb]) at the prefrontal cortex (PFC) and visual cortex (VC) by fNIRS during the experiment. Subjects were then classified into different groups based on their hemodynamic response pattern of [O

Hb] at the PFC an to their magnitudes and shapes, and (iii) can be classified into eight groups. We conclude that blue light affects humans differently. It is essential to consider this when assessing the impact of the BLE on society.Normal brain function requires an integrated, simultaneous communication between brain regions in a coordinated manner. In our studies on cortical spreading depolarization (CSD) induced electrically in the rat brain while recording electrocorticography (ECoG) and delta wave activity, we found for the first time that CSD suppressed delta wave activity, which began even before the CSD was fully developed. We pursued this observation to determine whether repeated CSD suppressed delta wave activity in rats. CSD was produced by electrical stimulation of the neocortex while recording the development of CSD and changes in the coupling of low-frequency band cross coupling to four typical physiological neuronal activity frequency bands, i.e., 5-7 Hz, 8-12 Hz, 13-30 Hz, and 30-80 Hz. Band-pass filters were applied to achieve the corresponding physiological band signals. Besides the cross-frequency coupling (CFC) analysis, the distribution of delta wave density in time domain was analyzed. We calculated the delta wave density per 30 seconds but represent the density as frequency per minute. A Generalized Linear Models (GLM) was used to carry out the CFC analysis in Matlab. Because delta waves dominated the ECoG recorded, we modeled the higher-frequency amplitude envelope as a function of low-frequency phase using a spline basis. Besides the CFC analysis, we also characterized the distribution of the delta wave density in time domain. Four CFC, Theta, Alpha, Beta, and Gamma were at very small values after CSD, and after about 8 minutes, the CFC recovered to the pre-CSD level. CFC were seen to decrease before a CSD occurred at the higher-frequency bands and tended to decrease quickly. Whether the attenuated CFC by CSD has long-term consequences remains to be determined. Future studies will explore the impact of cortical CSD on CFC with deeper brain structures, including the thalamus and the caudate putamen.This is the first multimodal study of cerebral tissue metabolism and perfusion post-hypoxic-ischaemic (HI) brain injury using broadband near-infrared spectroscopy (bNIRS), diffuse correlation spectroscopy (DCS), positron emission tomography (PET) and magnetic resonance spectroscopy (MRS). In seven piglet preclinical models of neonatal HI, we measured cerebral tissue saturation (StO2), cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2), changes in the mitochondrial oxidation state of cytochrome c oxidase (oxCCO), cerebral glucose metabolism (CMRglc) and tissue biochemistry (Lac+Thr/tNAA). At baseline, the parameters measured in the piglets that experience HI (not controls) were 64 ± 6% StO2, 35 ± 11 ml/100 g/min CBF and 2.0 ± 0.4 μmol/100 g/min CMRO2. After HI, the parameters measured were 68 ± 6% StO2, 35 ± 6 ml/100 g/min CBF, 1.3 ± 0.1 μmol/100 g/min CMRO2, 0.4 ± 0.2 Lac+Thr/tNAA and 9.5 ± 2.0 CMRglc. This study demonstrates the capacity of a multimodal set-up to interrogate the pathophysiology of HIE using a combination of optical methods, MRS, and PET.The blood-brain barrier (BBB) poses a significant challenge for drug delivery to the brain. The limitations of our knowledge about the nature of BBB explain the slow progress in the therapy of brain diseases and absence of methods for drug delivery to the brain in clinical practice. Here, we show that the BBB opens for high-molecular-weight compounds after exposure to loud sound (100 dB 370 Hz) in rats. The role of stress induced by loud sound and the systemic and molecular mechanisms behind it are discussed in the framework of the BBB. This opens an informative platform for novel fundamental knowledge about the nature of BBB and for the development of a noninvasive brain drug delivery technology.Oxygen supply to tissues can be seriously impacted during wound healing. In particular, edema can increase the distance between capillaries, thus decreasing oxygen supply to cells. Thus, the detection of edema, preferably at the preclinical stage, is of great importance. However, there is no reference standard for a cross-sectional, objective measurement of edema. Multispectral imaging can be such adjuvant technology to elucidate the impact of edema on oxygen transport to tissues. The purpose of the current study is to assess the feasibility of multispectral imaging for visualization of water content in surface tissues.

The skin (hand and forearm) of healthy volunteers was imaged using the Multi-Spectral Imaging Device (MSID). MSID is a multispectral imaging system for visualization of tissue chromophores in surface tissues. It uses a 12-bit scientific-grade NIR-enhanced monochrome camera and ten wavelength light source (600-1000 nm range) to visualize the distribution of oxy- and deoxyhemoglobins, methemoglobin, water, and melanin. The imaging distance is 30 cm and the field of view 7×7 cm.

Water content was extracted using various subsets of two and three wavelengths. To mimic the use of a consumer-grade camera, four least significant bits for each pixel value of a 12-bit image were discarded during preprocessing. Eight-bit results were compared with 12-bit results.

Rough numerical calculations and initial experiments show feasibility of water content imaging in the skin using 970 nm band illumination and 12- and 8-bit cameras.

Rough numerical calculations and initial experiments show feasibility of water content imaging in the skin using 970 nm band illumination and 12- and 8-bit cameras.In radiotherapy, hypoxia is a known negative factor, occurring especially in solid malignant tumours. Nitroimidazole-based positron emission tomography (PET) tracers, due to their selective binding to hypoxic cells, could be used as surrogates to image and quantify the underlying oxygen distributions in tissues. The spatial resolution of a clinical PET image, however, is much larger than the cellular spatial scale where hypoxia occurs. A question therefore arises regarding the possibility of quantifying different hypoxia levels based on PET images, and the aim of the present study is the prescription of corresponding therapeutic doses and its exploration.A tumour oxygenation model was created consisting of two concentric spheres with different oxygen partial pressure (pO2) distributions. selleck products In order to mimic a PET image of the simulated tumour, given the relation between uptake and pO2, fundamental effects that limit spatial resolution in a PET imaging system were considered the uptake distribution was processed with a Gaussian 3D filter, and a re-binning to reach a typical PET image voxel size was performed. Prescription doses to overcome tumour hypoxia and predicted tumour control probability (TCP) were calculated based on the processed images for several fractionation schemes. Knowing the underlying oxygenation at microscopic scale, the actual TCP expected after the delivery of the calculated prescription doses was evaluated. Results are presented for three different dose painting strategies by numbers, by contours and by using a voxel grouping-based approach.The differences between predicted TCP and evaluated TCP indicate that careful consideration must be taken on the dose prescription strategy and the selection of the number of fractions, depending on the severity of hypoxia.Epithelial-mesenchymal transition (EMT), which is involved in metastasis formation, requires reprogramming of gene expression mediated by key EMT transcription factors. However, signals from the cellular microenvironment, including hypoxia, can also modulate the process of EMT. Hypoxia is often associated with a reduction in the extracellular pH of the tumor microenvironment (acidosis). Whether acidosis alone has an impact on the expression of the EMT markers E-cadherin, N-cadherin, and vimentin was studied in NCI-H358 lung cancer cells. Reducing extracellular pH decreased E-cadherin mRNA, while vimentin and N-cadherin mRNA were doubled. However, at the protein level, E-cadherin and N-cadherin were both reduced, and only vimentin was upregulated. E-cadherin and N-cadherin expression at the cell surface, which is the relevant parameter for cell-cell and cell-matrix interaction, decreased too. The reduction of cell surface proteins was due to diminished protein expression and not changes in cellular localization, since localization of EMT markers in general was not affected by acidosis.