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.

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.

Use of the laser speckle flowgraphy in posterior fundus circulation research

Objective To review articles aiming to present an overview of the principles, progress, uses and limitations of laser speckle flowgraphy （LSFG） in posterior fundus circulation research. Data sources The data used in this review was obtained mainly from the studies reported in PubMed using the key terms ＂laser speckle＂, ＂ocular blood flowmetry＂ and ＂retinal imaging＂. Study selection Relevant literatures on studies of LSFG were selected. Results LSFG is a unique, noninvasive imaging instrument to quantitatively visualize posterior fundus circulation in vivo This review delineates the LSFG principles and development, demonstrates its extensive applicability for measurement of retina, choroid and optic nerve head circulation, compares it with other retinal imaging technologies and discusses unresolved issues. Conclusions LSFG is a noninvasive, two-dimensional objective diagnostic technique that has become a powerful method for the clinical and scientific assessment of posterior fundus circulation. Further studies may help to develop a more comprehensive evidence-based measurement and facilitate the correlation with other methods for chorioretinal circulation assessment.