Effect of high-concentration hydrogen inhalation on sepsis-associated encephalopathy in mice / 中华麻醉学杂志

Objective:To evaluate the effect of high-concentration hydrogen inhalation on sepsis-associated encephalopathy (SAE) in mice.Methods:Healthy male ICR mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=50 each) using the random number table method: sham operation group (Sham group), SAE group, sham operation plus high-concentration hydrogen group (Sham+ H 2 group), and SAE plus high-concentration hydrogen group (SAE+ H 2 group). SAE model was prepared by cecal ligation and puncture (CLP) in anesthetized animals.At 1 and 6 h after operation, Sham+ H 2 and SAE+ H 2 groups inhaled the mixture of hydrogen and oxygen (67% hydrogen-33% oxygen) for 1 h, and Sham and SAE groups inhaled the mixture of nitrogen and oxygen (67% nitrogen-33% oxygen) for 1 h. The postoperative 7-day survival rate was recorded.Cognitive function was assessed by Y maze test at days 3, 5 and 7 after operation.The mice were sacrificed at 24 h after operation, and hippocampal tissues were obtained for microscopic examination of the pathological changes of neurons in hippocampal CA1 region (with a light microscope) and for determination of normal neuron count, contents of tumor necrosis factor-ɑ (TNF-α) and high mobility group box-1 (HMGB1) (by enzyme-linked immunosorbent assay), mitochondrial membrane potential (MMP) (by fluorescence spectrophotometry) and content of mitochondrial ATP (by fluorescein-fluorescent enzyme luminescence method). Results:Compared with Sham group, the 7-day survival rate after operation, percentage of spontaneous alternation at each time point after operation, and the number of normal neurons were significantly decreased, the contents of TNF-ɑ and HMGB1 were increased, and the contents of ATP and MMP were decreased in SAE and SAE+ H 2 groups ( P<0.05), and no significant change was found in Sham+ H 2 group ( P>0.05). Compared with SAE group, the 7-day survival rate after operation, percentage of spontaneous alternation at each time point after operation, and the number of normal neurons were significantly increased, the contents of TNF-ɑ and HMGB1 were decreased, and the contents of ATP and MMP were increased in SAE+ H 2 group ( P<0.05). Conclusions:High-concentration hydrogen inhalation can reduce SAE, and the mechanism may be related to reduction of hippocampal inflammatory responses and improvement in mitochondrial function in mice.

Phase-rectified signal averaging for the assessment of automatic nervous system activity in surgery during general anesthesia / 临床麻醉学杂志

Objective To observe the feasibility of phase-rectified signal averaging applied for the evaluation of automatic nervous system activity in general anesthesia.Methods Forty-seven fe-males and 63 males aged 18-65 years,ASA falling into category Ⅰ or Ⅱ,scheduled for oral maxillo-facial surgery under general anesthesia were selected.The heart rate variability(HRV)signal was re-corded by Powerlab throughout the operation,and then it was sectioned into three segments with 5 minutes:pre-anesthesia(T0 ),means the waking state before the operation;intra-anesthesia(T1 ),the period of operation in 25-30 min;post-anesthesia(T2 ),the consciousness recovery state in the end of the operation.All indicators of HRV analysis was calculated in the time domain.SpO 2 ,MAP and BIS were recorded synchronously in the three periods.Results Compared with T0 ,DC, RMSSD, SDNN,SD1,SD2,logTP,logLF,logHF were significantly lower at T1 and T2 (P <0.05).In con-trast to T1 ,HR,MAP and BIS were significantly higher at T2 (P <0.05 ),DC,RMSSD,SDNN, SD1,SD2,logTP,logLF,logHF were significantly increased at T2 (P <0.05 ).There was positive relation between DC and RMSSD,SD1,logHF (r =0.905,0.909,0.932,respectively,P <0.01). Conclusion As 5 min-DC could indicate the character of PRSA,especially its specificity in showing vagus nerves activities,it is feasible that DC is used to observe the autonomic nerve activity intra op-eration.

Assessment of the Effect of Pain on Autonomic Nervous System in Human Body Using Heart Rate Variability Analysis / 生物医学工程学杂志

The purpose of this study is to discuss the feasibility of establishing capsaicin pain model and the possibility to evaluate different degrees of pain by the heart rate variability (HRV). It also aims to investigate the changes of autonomic nervous activity of volunteers during the process of pain caused by capsaicin. A total of 30 volunteers were selected, who were physically and mentally healthy, into the study. To assess the effects of capsaicin on the healthy volunteers, we recorded the Visual Analogue Scale (VAS) scores after the capsaicin stimulus. Additionally, the electrocardiogram signals and HRV analysis index before and after stimulating were also recorded, respectively. More specifically, the HRV analysis indexes included the time domain index, the frequency domain index, and the nonlinear analysis index. The results demonstrated that the activity of the autonomic nerves was enhanced in the process of capsaicin stimulus, especially for the sympathetic nerve, which exhibited a significantly differences in HRV. In conclusion, the degree of pain can be reflected by the HRV. It is feasible to establish a capsaicin pain model. And in further experiments, HRV analysis could be used as a reference index for quantitative evaluation of pain.

Experimental research on heart rate variability analysis with application of acquisition system of R peak of electrocardiosignal based on sound card / 生物医学工程学杂志

This study designed an audio signal acquisition system to achieve real-time detection of R peak for heart rate variability (HRV) analysis, substituting ECG-specific data acquisition board with sound card. It is proved that the R peak with low frequency can be gathered by sound card. The comparison with PowerLab signal acquisition system has shown that the acquisition system of R peak could accurately detect the R peak. The R peak detected by sound card and PowerLab signal acquisition system completely overlap each other, while RR intervals has no difference. The HRV analysis was accurate and reliable with the RR interval from sound card. This low cost, high performance, strong compatibility and easy upgraded acquisition system of R peak compared with the traditional data acquisition board has the value of practical uses and might have broad applications in the future.

Application of 5-second heart rate variability parameter based on poincare plot in real-time monitoring of the autonomic nervous system activity / 生物医学工程学杂志

This study designed one index of HRV from Poincaré plot named 5SSD1 by the present authors, which can describe the characteristics of the heart rate dynamics with 5-second data. We also investigated the feasibility of its clinical application in real-time monitoring of the activity of autonomic nervous system. We studied 20 patients scheduled for oral maxillofacial surgery. ECG recording was obtained when kept awake and anesthetic states, respectively. We calculated the correlation coefficients between the 5SSD1 and the other quantitative indicators, such as 5-minute HRV in the time domain, the frequency domain, and the Poincaré plot families. The correlation between 5SSD1 and indicators, such as rMSSD, HF and SD1 of 5-minute HRV was significantly high, with r=0.995, 0.895, 0.996, respectively, at P<0.01 for all. However, the correlation between 5SSD1 and the other indicators of 5-minute HRV was relatively poor. It was proved that 5SSD1 could be used to assess the activities of the autonomic nervous system in real-time, and the stable and reliable results might play more roles in the clinical applications.

Distraction osteogenesis for correction of cleft palate in rhesus-histological and fluorescent labeling study / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of new bone formation in the distraction osteogenesis (DO) for correction of cleft palate (CP) in rhesus.</p><p><b>METHODS</b>CP was created by operation in 23 rhesus. The CP was corrected with DO in 21 animals as experimental group. The distraction rate was 0.8 mm per day, two times a day. The bone fragments were fixed after cleft closure, every 3 animals were sacrificed to get specimen after 1, 2, 4, 6, 8, 12, 24 weeks of fixation. 6 days before sacrifice, tetracycline was administrated for labeling (30 mg/kg).</p><p><b>RESULTS</b>The hard and soft tissue def of fixation. At the same time, the bone volume and calcification between the distraction gap increased. The cleft in the control group could not b ect was successfully closed with DO by intramembrane osteogenesis. The new formed bone was remodeling and became maturation during the period e corrected spontaneously.</p><p><b>CONCLUSIONS</b>The DO can successfully correct both the soft and hard tissue defect in CP by intramembrane osteogenesis. The fixation is important for remodeling and maturation of the new formed bone.</p>

Ultrastructural and element spectrometric analysis of distraction osteogenesis for reconstruction of cleft palate in rhesus macaque model / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the ultrastructure and Ca/P element spectrometry of distraction osteogenesis (DO) for reconstruction of cleft palate (CP), so as to explore the osteogenesis and remodeling of new bone in situ.</p><p><b>METHODS</b>23 rhesus macaques were operated to establish animal models of CP. 2 monkeys didn't received DO as controls. The other 21 monkeys in experimental group underwent DO to correct both bony and soft tissue defects in palate. The distraction was performed at a rate of 0.8 mm/d, twice a day until the cleft was closed. After fixation for 1, 2, 4, 6, 8, 12, 24 weeks, every 3 animals were sacrificed to get the specimens at the distraction gap. The scanning electron microscopic study and Ca, P elements spectrometric analysis were adopted. There were also two unoperated animals as sham group.</p><p><b>RESULTS</b>After fixation for 1-2 weeks, the distraction gap was full of collagen fibers oriented along vector of distraction. Few trabeculae was seen at the margin area. After fixation for 4-6 weeks, active osteogenesis was presented with new formed bone trabeculae and abundant cellular component. After fixation for 8-12 weeks, the new formed bone became mature and couldn't distinguish from the normal bone. 24 weeks later, the bone between the distraction gap had a similar structure to the normal bone. Elements spectrometric analysis results indicated that in early stage of osteogenesis, the P and S peaks were relatively high while the Ca peak was much lower. During the late stage, the S peak was obviously decreased, and Ca/P ratio increased to normal level as in the empty control group.</p><p><b>CONCLUSIONS</b>The CP can be corrected by DO. The new bone between the distraction gap is formed and remodeled through intramembraneous osteogenesis.</p>

Expression of osteopontin and osteocalcin during distraction osteogenesis on rhesus with cleft palate / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the mechanism of new bone formation and remodeling of distraction osteogenesis (DO) by analysis of the expression of osteopontin (OPN) and osteocalcin (OC).</p><p><b>METHODS</b>Rhesus were operated to reconstruct the animal model of cleft palate (CP). The CP was closed by DO in experimental group(n = 21). After consolidation of 1, 2, 4, 6, 8, 12, 24 weeks, every 3 animals were killed to collect the specimens, respectively. The OPN and OC and their mRNA were detected quantitatively by Real-time RT-PCR and ELISA, respectively. The animals in control group (n = 2) and sham group (n = 2) were used as control.</p><p><b>RESULTS</b>The mRNA expression of OPN increased since 2nd week of consolidation and reached the peak at 4th week (7.59 +/- 0.37). The mRNA expression of OC was up-regulated since 4th week, and reach the peak at 6th week (7.94 +/- 0.31). Then they decreased to about the level in sham group at 24th week (P > 0.05). The OPN and OC were highly expressed during 4 to 6 weeks of consolidation. During 8 to 12 weeks, they decreased like their mRNA expression.</p><p><b>CONCLUSION</b>The intramembraneous new bone formation after DO can reconstruct the bone defect of CP. The new formed bone can be remodeled to be quite normal bone tissue.</p>

Beta -transduction repeat containing protein expressed in tooth germs and ameloblast and odontoblast of different stage of tooth development / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The Sonic hedgehog signalling peptide has been demonstrated to play important roles in the growth and patterning of the tooth development. This study aims on whether the antagonist beta-transduction repeat containing protein of Sonic hedgehog signal transduction expressed in tooth germs ameloblast and odontoblast or not.</p><p><b>METHODS</b>The mouse embryo heads of different developmental stages of E10.5, E13.5, E14.5, E16.5, E18.5 and P0, P3, P6 after birth were acquired fixed with 4% paraformaldehyde for 48 hours, embeded with Paraffin and examined using LsAB (labelled streptavidin-biotin) method to observe the beta-TrCP expression pattern in tooth germs, ameloblast and odontoblast.</p><p><b>RESULTS</b>It was demonstrated that beta-TrCP expressed in oral epithelium, tooth bud, mesenchymal cell cytoplasm of ameloblast and odontoblast of different stage of tooth development.</p><p><b>CONCLUSION</b>beta-TrCP expressed from early stage to later stage of murine tooth development. And these findings provide the evidence of antagonist regulatory pathways for shh in teeth development.</p>