Laterality and coherence analysis of Laser Doppler Flowmetry signals in bilateral Nèi guān(内关 PC 6):a potential non-invasive method to assess microcirculatory changes of people in different ages

Objective To investigate lateralization and Coherence analysis of blood perfusion in bilateral Neiguan （内关 PC 6） in different ages. Methods Healthy volunteers （n=30） were placed in a temperature-controlled room as a resting state for 40 min. Then the blood perfusion of bilateral PC 6 were carried out using PeriFlux System 5000 for 25 minutes. Mean blood flux of every 5 minutes was calculated. Then the participants were divided into groups of young （n=18） and the old （n=12） as the boundary of 40 years, the asymmetry index and coherence value of bilateral PC 6 were analyzed in different group. Results The mean blood flow of the right PC 6 was significantly higher than the left PC 6 in three different epochs, the mean blood flow of right PC 6 vs left PC 6 is 9.74±3.36 vs 6.73±2.22 （t=5.9, P〈0.001）, 9.83±3.63 vs 6.99±2.37 （t=5.11, P〈0.001） and 9.69±3.40 vs 6.77±2.32 （t=5.99, P〈0.001）, respectively. Although the asymmetry index is higher in old group than in young group, there is no statistically significant age-related differences. Coherence analysis suggest that there is significant difference in frequency value corresponding to peak crest between young and old group. Conclusion The blood perfusion in right PC 6 is higher than left PC 6. Coherence analysis of laser Doppler flowmetry signals in bilateral PC 6 might provide a potential non-invasive method to assess microcirculatory changes in different ages.

Dynamic Non-Invasive Detection of NADH Based on Blood Flow-Mediated Skin Fluorescence (FMSF) Method

Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in important biochemical reactions in human metabolism, including participation in energy production by mitochondria. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. In this paper, a non-invasive dynamic monitoring system based on blood flow-mediated skin fluorescence (FMSF) technology is developed to monitor the NADH fluorescence intensity of skin tissue during the process of blocking reactive hyperemia. Simultaneously, laser speckle contrast imaging (LSCI) and laser Doppler flowmetry (LDF) were used to observe blood flow, blood oxygen saturation (SOt2) and relative amount of hemoglobin (rHb) during the measurement process, which helped to explore NADH dynamics relevant physiological changes. A variety of parameters have been derived to describe NADH fluorescence curve based on the FMSF device. The experimental results are conducive to understanding the NADH measurement and the physiological processes related to it, which help FMSF to be a great avenue for in vivo physiological, clinical and pharmacological research on mitochondrial metabolism.

Detection of angiospastic disorders in the microcirculatory bed using laser diagnostics technologies

The evaluation of the microcirculatory bed functional state and the identification of angiospastic disorders with related complications,when the pathological changes are reversible,have an important role in medical practice.The aim of this study was to evaluate the possibility of using optical noninvasive methods and the cold pressor test to solve this problem.A total of 33 patients with rheumatological diseases and 32 healthy volunteers were included in the study.Laser Doppler flowmetry,tissue reflectance oximetry and pulse oximetry were used as optical noninvasive methods.The parameters were recorded before,immediately after and 20 min after the cold pressor test.Based on the measured parameters,the complex parameters of the microcirculatory bed were calculated.A detailed statistical analysis of the parameter changes for each individual in the two groups displayed diverse microcirculatory bed parameter responses upon cold exposure,with differing recovery of parameters after CPT.New diagnostic criteria were proposed for the identification of angiospastic disorders.According to the proposed criteria,27 people of the volunteers group were confirmed to not display any disorders.In the patient group,however,18 people were observed to have a relatively normal functional state of the microcirculatory bed,while 15 people were observed to have a possible tendency to angiospasm.To highlight the diferences between a relatively normal state and presence of angiospastic disorders,statistical analysis of experimental data was carried out,which revealed significant differences.Further analysis of data with angiospastic disorders identified a relationship between their diagnoses and the results of labo-ratory studies.Thus,the evaluation of combined noninvasive optical diagnostic method use,the cold pressor test and proposed diagnostic criteria showed a positive result.This approach can be used to detect the presence of possible angiospastic disorders and related complications,as well as mi-crocirculatory bed disorders against the background of other diseases.

Gastric Mucosal Blood Flow and Acid Secretion in Rats

The relationship between gastric mucosal blood flow (GMBF) and gastric acid secretionwere studied in rats by using secretory stimulant (pentagastrin)and inhibitor(cimetidine). GMBFwas measured by Laser Doppler flowmetry (LDF) and gastric mucosal pH determined by microglasspH electrode. GMBF increased and gastric mucosal pH decreased significantly after intravenous injec-tion of 6μg/kg of pentagastrin; nevertheless GMBF decreased and gastric mucosal pH increasedmarkedly after intravenous administration of 100mg/kg of cimetidine. This indicates that pentagastrincan increase GMBF and gastric acid secretion, and cimetidine can decrease GMBF and gastric acidsecretion in rats, proving the close relationship between GMBF and gastric acid secretion in rats.

Hyaluronidase Proof for Endothelial Glycocalyx as Partaker of Microcirculation Disturbances

Covalent modification of bovine testicular hyaluronidase with chondroitin sulphate led to changes in the pattern of glycation of native and modified enzyme in its reaction with neutral saccharides and N-acetylhexosamines. Thus, mono- and di-saccharides inactivated the native hyaluronidase to a greater extent than the chondroitin sulfate-modified enzyme. N-acetylhexosamine, on the opposite, inactivated the modified hyaluronidase to a greater extent than the native one. These properties made it possible to use native and modified hyaluronidase as an informative research system for in vivo measurement of the predominant type of saccharide agents in the circulation. The proposed approach was experimentally substantiated by obtained results of the study on these interactions of hyaluronidase derivatives with hyaluronan fragments and their mixture. In a model of post-ischemic perfusion of the rat limb, the effect of hyaluronidase derivatives and their components on restoration of the microcirculation were tracked using laser Doppler flowmetry. Native hyaluronidase accelerated the restoration of initial level of microcirculation, but modified enzyme was markedly inhibited by glycocalyx degradation products. N-acetylhexosamine was positioned at the reducing terminal of these products as a natural label for these glycocalyx fragments. These and other data obtained under various experimental conditions supported the participation of endothelial glycocalyx in microcirculation disturbances.

Speed-resolved blood perfusion and oxygen saturation in human skin response to thermal stimulation

The functional status of vessels can be determined by assessing blood perfusion.By integrating diffuse reflectance spectroscopy(DRS)and Laser Doppler Flowmetry(LDF),the speed-resolved blood perfusion and blood oxygen saturation can be measured simultaneously by Enhanced Perfusion and Oxygen Saturation(EPOS).The dataset presented in this descriptor contains EPOS data recorded from a forearm point exposed to different levels of thermal stimulation,the classical LDF at control points,the R-R time series and data regarding the subjects’characteristics.All data were recorded from 60 recruited healthy subjects.Half of the subjects received different levels of thermal stimulation,and half of them were blank controls.We believe that this dataset will lead to the development of local blood perfusion methods that can be used to index vessel function assessments.This publicly available dataset will be beneficial to the microcirculation evaluation.

Changes of Color and Blood Flow of the Tongue in the Mini-swine of Immune Hepatic Injury

Objective:To investigate color and microvascular blood flow of the tongue in the mini-swine with immune hepatic injury. Methods: Six Chinese mini-swine for experimental use, 3 males and 3 females, were randomly divided into two groups, normal group and model group, 3 swine in each group. The swine in the model group was administrated by injection of 5 mg/kg ConA into the vein of auricular back, once every other day, 3 times each week, for 2 weeks in total. The animal in the control group was administrated with equal volume of saline. At 9 o’clock in the morning of the 15th day of the experiment, each swine was anesthetized with intramuscular injection of 9 ml 2.5% pentobarbital sodium and 3 ml Maleate, and then picture of the tongue was taken, microvascular blood flow on the tongue and the liver was detected with a laser Doppler blood flowmeter; Blood was taken from the precaval vein. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST),total bilirubin (Tbil) and total protein (TP) were determined; Pathological changes of the liver and tongue tissues were investigated by means of HE staining; Serum TNF-α content was detected with ELISA assay. Results: In the mini-swine with immune hepatic injury induced by ConA, the tongue color showed cyanotic color, microvascular perfusion in the liver and the tongue, and partial pressure of oxygen in the tongue tissue significantly decreased; and the microcirculatory perfusion of the tongue was significantly correlated with that of the liver and the HIS color spatial value of the tongue; Serum TNF-α content significantly increased. Conclusion: The mini-swine with immune hepatic injury induced by ConA conforms to pathological characteristics of immune hepatic injury. Formation of the cyanotic tongue is related with microcirculatory disturbance of the tongue, which can indirectly reflect hepatic microcirculatory state in the immune hepatic injury.