Variaciones fenotípicas relacionadas a respuestas hipóxicas entre andinos a distintas altitudes / Phenotypic variations related to hypoxic responses among Andeans at different altitudes

Introducción. La adaptación a grandes altitudes implica cambios evolutivos que conllevan respuestas adaptativas, como a la hipoxia. Los andinos desarrollaron fenotipos eritroides diferentes en relación con otras poblaciones a gran altitud que pueden variar dependiendo la altitud. Objetivo. Determinar las variaciones fenotípicas de hemoglobina (Hb), saturación de oxígeno (SpO2), P50 y lactato en andinos bolivianos con radicatorias entre 400, 4000 y 5000 msnm. Material y métodos. Estudio descriptivo transversal de tipo prospectivo. Se recolectó sangre venosa periférica de andinos bolivianos (n=124) nacidos a 4000 m, pero con radicatoria en altitudes diferentes (400 m, 4000 m, 5000 m), así como de aquellos con eritrocitosis patológicas. Adicionalmente, se recolectó muestras de europeos residentes a 4000 m (n=11). Se realizó estudios de hemograma, oximetría y gasometría. La P50 fue calculada con fórmula de Lichtman. Resultados. Los andinos sanos, comparados entre distintas altitudes, reflejaron aumento de Hb al ser mayor la altitud (p: 0,001), empero disminución de SpO2 (p: 0,001) y P50 (p: 0,001); sin variaciones en lactato. Los europeos a 4000 m, en relación con andinos a la misma altitud, presentaron Hb incrementada (p: 0,01), SpO2 y P50 sin variaciones, pero lactato significativamente aumentado (p: 0,001). Los pacientes con eritrocitosis comparados con sujetos sanos, a 4000 m y 5000 m respectivamente, presentaron Hb aumentada (p: 0,001); SpO2 disminuida (p: 0,001); P50 sin variaciones, pero lactato incrementado (p: 0,01). El lactato elevado en sujetos a 5000 m con eritrocitosis fue llamativo (1,7 mmol/L). Conclusiones. Las variaciones fenotípicas observadas entre andinos en diferentes altitudes constituyen una expresión de una adaptación parcial a la altura.

Introduction. Human adaptation to high altitude involves evolutionary changes leading adaptive responses, such as to hypoxia. Andeans developed different erythroid phenotypes in relation to other populations at high altitude, which can vary depending on the altitude. Objective. To determine the phenotypic variations of hemoglobin (Hb), oxygen saturation (SpO2), P50 and lactate in Bolivian Andeans residing between 400, 4000 or 5000 masl. Material and methods. Prospective cross-sectional descriptive study. Peripheral venous blood from Bolivian Andeans (n=124) born at 4000 m, but residing at different altitudes (400 m, 4000 m, 5000 m), likewise from those with pathological erythrocytosis were collected. Additionally, samples from Europeans residing at 4000 m (n=11) were collected. CBC, oximetry and blood gas studies were performed. P50 was calculated using the Lichtman formula. Results. Healthy Andeans, compared between different altitudes, reflected an increased Hb (p: 0.001), but a decreased SpO2 (p: 0.001) and P50 (p: 0.001) as the altitude was higher; without variations in lactate. Europeans at 4000 m, related to Andeans at the same altitude, presented increased Hb (p: 0.01), SpO2 and P50 without variations, but significantly increased lactate (p: 0.001). Patients with erythrocytosis compared to healthy subjects, at 4000 m and 5000 m respectively, depicted increased Hb (p: 0.001); decreased SpO2 (p: 0.001); P50 without changes, but increased lactate (p: 0.01). Increased lactate in subjects with erythrocytosis at 5000 m was remarkable (1.7 mmol/L). Conclusion. The phenotypic variations observed among Andeans residing at different altitudes constitute an expression of partial adaptation to altitude.

Preparation of a novel double polymerized of red blood cell substitute and preliminary observation of its curative effect / 中国输血杂志

【Objective】 To study the red blood cell substitute preparation method of glutaraldehyde(GDA) and Bis(3, 5-dibromosalicyl) fumarate(DBBF) double polymerized, and also observe its curative effect. 【Methods】 The affecting factors of the crosslink of DBBF and human placental hemoglobin(Hb) were selected, including solution pH, inositol hexaphosphoric acid concentration, and molar ratios of DBBF/Hb. The changes of P50, Hill Co and methemoglobin(MetHb) content during the preparation process were studied and the molar ratio of GDA to DBBF-Hb were determined. The final product was obtained through the steps of ultrafiltration, filtration, and deoxygenation, etc., and the final product was subjected to a study on the curative effect of anti-hemorrhagic shock in rats. 【Results】 Under the condition of pH 8.0, the concentration of inositol hexaphosphoric acid was 10mM/L, the molar ratio of DBBF/hemoglobin was 6∶1, the content of dimer was(22.67±3.28)%, the content of tetramer was (74.64±7.05)%, and its P50 was (25.25±2.31) mmHg. As the molar ratio of DBBF/Hb increased, P50 and MetHb content would gradually increase, while the Hill Co will gradually decrease. The molar ratio of GDA and DBBF-Hb was 7∶1, the content of dimer was (8.23±0.79)%, the content of tetramer was (27.87±3.63)%, the content of super-macromolecule was (1.05±0.31)%. As the molar ratio of GDA and DBBF/Hb increased, MetHb content would increase, while the P50 and Hill Co would gradually decrease. The 24h survival rate of the product in rats with hemorrhagic shock was 83.33%(10/12), which was significantly higher than that in the negative control group[41.67%(5/12)], while similar with the positive control group [91.67%(11/12)]. 【Conclusion】 The red blood cell substitutes with GDA and DBBF double polymerized can effectively reduce the dimer content, which is more conducive to industrial production, and has a positive effect on the treatment of hemorrhagic shock.

Research progress and future of red blood cell substitutes / 中国输血杂志

This paper briefly reviewed blood substitutes, focusing on the background, history of research and development(R&D), types, functions, characteristics, the indications that will be mainly targeted in clinical, and their special status and role in the future, especially in the rescue of war/trauma patients using hemoglobin-based oxygen carriers(HBOCs). Additionally, the authors put forward unique insights and suggestions on some key concepts and R&D bottlenecks in the development of HBOCs through combining the authors′ own R&D experience for decades with efforts and lessons given by many scholars in this field at home and abroad, hoping to provide some new inspirations and ideas for colleagues to innovate and develop blood substitutes to benefit the clinical as soon as possible.

Study of P50 sensory gating deficit in schizophrenic patients with violent and aggressive behaviors / 四川精神卫生

ObjectiveTo assess the specificity of P50 auditory-evoked potential in schizophrenic patients with violent and aggressive behaviors， so as to provide objective biological markers for predicting violent behaviors of schizophrenic patients. MethodsA total of135 schizophrenic patients who met the diagnostic criteria of the International Classification of Diseases， tenth edition （ICD-10） were divided into aggressive group （n=70） and non-aggressive group （n=65） according to the assessment results of the Modified Overt Aggression Scale （MOAS）， meantime， another 60 healthy individuals matched for age and gender were set as healthy group. Then the P50 auditory-evoked potentials of all selected individuals were measured using EP/EMG system （MEB-9200， Nihon Kohden， Japan）. ResultsAmp S2 of the aggressive group was significantly higher than those of the non-aggressive group and healthy control group， with statistical differences ［（9.86±6.04）μV vs. （7.06±3.88）μV， P=0.004； （9.86±6.04）μV vs. （7.82±3.87）μV， P=0.031］. The proportion of S2/S1 ratio ≥0.5 was 72.88%， 43.86% and 30.00% in aggressive group， non-aggressive group and healthy group， which was the highest in aggressive group， with statistical differences （P<0.01）. The amplitude difference of P50 （S1-S2） of the aggressive group was lower than those of the non-aggressive group and the healthy control group， the differences were of statistical significance ［（4.35±9.39）μV vs.（9.89±8.48）μV， P=0.001； （4.35±9.39）μV vs.（13.42±9.81）μV， P<0.01］. ConclusionThe violent and aggressive behaviors in schizophrenic patients may be related to the sensory gating deficit.

CircHMGCS1 Activates the NF-κB Signaling Pathway and Promotes Proliferation and Invasion in Cervical Cancer Cells / 中国生物化学与分子生物学报

Circular RNAs play an important role in tumorigenesis. In this study, we explored the role of aberrant expression of circHMGCS1 in cervical cancer cells with TNF-α treatment. RT-qPCR assays showed that circHMGCS1 was highly expressed after TNF-α treatment. And then we investigated the cyclization and stabilization of circHMGCS1 by RNase R and half-life analysis. We further revealed that overexpression of circHMGCS1 promoted the malignancy of cervical cancer cells and the expression of the epithelial-mesenchymal transition (EMT) markers by Transwell analysis, MTT, clone formation and Western blotting. Furthermore, we found that circHMGCS1 activated the NF-κB signaling pathway. Altogether, this study provides an experimental basis for elucidating the role of circHMGCS1 in cervical cancer cells, and provides a potential biomarker for the diagnosis and treatment of cervical cancer.

The therapeutic effect of salidroside on rats with permanent cerebral ischemia through regulating PDK/Akt signaling pathway / 中国药理学通报

Aim To investigate the neuroprotective effect and mechanism of salidroside (Sal) on rats with permanent middle cerebral artery occlusion model (pMCAO) by regulating the PI3 K/AKT signaling pathway. Methods A total of 80 healthy adult SPF male SD rats were randomly divided into sham operation group (sham group), model group (pMCAO group), drug administration group (pMCAO + Sal group) and inhibitor group (pMCAO + Sal + YL group). After the pMCAO model rats were prepared by the line bolt method, salidroside (50 mg · kg

Auditory Evoked Potentials P50: Pure-tones vs Clicks. There is a Similar Supression?

Objective:Clinical application of middle-latency auditor evoked potential (MLAEPs) has been increasing, highlighting the importance of understanding the nature of P50,a componentof middle-latency auditory evoked potential. We manipulated stimulus frequency bands in auditory stimuli in order to investigate the nature of P50 in human auditory evoked potentials.Methods:Two paradigms have been used to obtain P50: one is a conditioning /testing paradigm in which paired of pure tone (1000Hz) are delivered, and the other was presented paired of clicks, both with an intensity of 60 dB sound pressure level above the auditory threshold. A total of 30 healthy volunteers were recruited for this study among Center of genetic engineering (fifteen man and fifteen women, mean age of 36,5). All without consumption of caffeine, cigarettes and drugs. Results:No statistically significant differences occurred between the P50 amplitudes and latencies for the pure tone and those for the clicks.Conclusions:Ourpresent results indicate that P50 in humans may reflect a feed-forward mechanism of the brain where a preceding stimulus drives sensory gating mechanisms in preparation for a second stimulus, but the contained frequency doesn't influence on the P50. Both types (tones or clicks) can be used in the exploration of patient with this evoked potential

Effect of Yanghe decoction serum on the proliferation of breast cancer stem cells / 国际中医中药杂志

Objective To investigate the effect of Yanghe decoction serum on the proliferation of breast cancer stem cells HMLER90hi and its mechanism. Methods Twenty female Sprague-Dawley rats were randomly divided into low,medium and high dose groups containing drug serum and control group, in order to prepare the Yanghe decoction serum and blank serum. After 24 hours of drug intervention,the effects of each group on the proliferation of HMLER90hi cells at 24 h,48 h,and 72 h were detected by MTT assay. The expression of EphA4 and p50 mRNA in each group were detected by real-time fluorescence quantitative PCR. Results Compared with the blank control group,the cell proliferation activity of each dose group of Yanghe decoction significantly decreased at 24 h (0.818 ± 0.061, 0.706 ± 0.073, 0.587 ± 0.052 vs. 0.928 ± 0.075), 48h (0.760 ± 0.047, 0.638 ± 0.056, 0.510 ± 0.059 vs. 0.973 ± 0.095), and 72 h (0.672 ± 0.102, 0.508 ± 0.092, 0.448 ± 0.048vs.1.023 ± 0.099) (P<0.05 orP<0.01), respectively. After 24 h of drug intervention, compared with the control group, the expression of EphA4 mRNA (0.54 ± 0.07, 0.54 ± 0.07, 0.33 ± 0.04 vs.0.68 ± 0.09) significantly decreased, and p50 mRNA (0.69 ± 0.10, 0.54 ± 0.08, 0.41 ± 0.06vs. 0.85 ± 0.13) significantly decreased in each dose group of Yanghe decoction (P<0.05 orP<0.01).ConclusionsTheYanghe decoction can inhibit the proliferation of breast cancer stem cell HMLER90hi,and its mechanism may be related to its inhibition of the conduction of the juxtacrine pathway of monocyte macrophage.

Improvement and Anti-inflammation Mechanism of Shenfu Injection on Lung Tissue in Endotoxin Shock Model Rats / 中国药房

OBJECTIVE： To study the improvement and anti-inflammation mechanism of Shenfu injection on lung tissue of endotoxin shock model rats. METHODS： Totally 48 rats were randomized into control group，model group，dexamethasone group （positive control，1 mg/kg） and Shenfu injection low-dose，medium-dose and high-dose groups （5，10，15 mL/kg），with 8 rats in each group. Except for normal group， other groups were given intraperitoneal injection of lipopolysaccharide （LPS） to induce endotoxin shock model. After modeling， each group was given relevant medicine once intraperitoneally. 24 h after medication， HE staining was used to observe pathological changes of lung tissue in rats and pathological scoring was conducted. RT-PCR was used to determine mRNA levels of P65 and P50 proteins related to NF-κB signaling pathway. Western blot assay was used to determine the expression levels of P65 and P50 proteins in lung tissue， and the expression levels of P65 protein in nucleus and cytoplasm of lung tissue were also determined. The level of TNF-α in plasma in rats were determined by ELISA. RESULTS： Compared with control group， alveolar septum became thicker， obvious vascular engorgement was found， and a large number of neutrophils infiltrated the interstitium in model group. Histopathological score， mRNA and protein expression levels of P65 and P50 in lung tissues were increased significantly （P＜0.01 or P＜0.001）； the protein expression of levels P65 in nucleus and cytoplasm and level of TNF-α in plasma were increased significantly （P＜0.001）. Compared with model group， alveolar structure of rats in dexamethasone group and Shenfu injection medium-dose and high-dose groups was complete， no obvious bleeding was observed， and the degree of inflammatory cell infiltration was improved significantly. Histopathological score， mRNA and protein expression levels of P65 and P50 in lung tissue and level of TNF-α in plasma were decreased significantly （P＜0.05 or P＜0.01 or P＜0.001）. The protein expression level of P65 in nucleus and cytoplasm of lung tissue were decreased significantly in dexamethasone group and Shenfu injection low-dose and medium-dose groups were decreased significantly （P＜0.05 or P＜0.01 or P＜0.001）. CONCLUSIONS： Shenfu injection can decrease mRNA and protein expression levels of P65 and P50 in lung tissue， level of TNF-α in plasma， and protect lung tissue of endotoxin shock rats.

Effect of sodium carboxymethyl starch on erythrocyte rheology and oxygen carrying function / 国际药学研究杂志

Objective: To investigate the physicochemical properties of sodium carboxymethyl starch(CMS) and its effect on erythrocyte rheology and oxygen carrying function. Methods According to the requirements of Chinese Pharmacopoeia,the physicochemical properties were determined for CMS120,CMS380 and hydroxyethyl starch 130 (HES130),including pH value,osmotic pressure molar concentration and viscosity. Normal saline,CMS120,CMS380 and HES130 were mixed with whole blood(7:3,V/V),respectively,and the experimental groups were set as whole blood group,whole blood+normal saline(NSB)group,whole blood+CMS120(CMS120B)group,whole blood+CMS380 (CMS380B)group,and whole blood+HES130(HES130B)group. The colloid osmotic pressure,blood viscosity,eryth- rocyte deformation and aggregation,and the partial pressure of oxygen when blood oxygen saturation was 50%(P50)val- ue were measured for each of these groups. Results: The osmotic pressure molar concentration and the viscosity of CMS120 and CMS380 were both significantly higher than those of HES130(all P<0.05)as indicated by the determina- tion of physicochemical properties. Compared with the whole blood group,the colloid osmotic pressure was significantly increased in the CMS380B and CMS120B groups(P<0.05),which was also significantly higher than that in the HES130B group(P<0.05). At low shear rate(10/s),compared with the whole blood group,the whole blood and the plasma vis- cosities were significantly increased in the NSB,CMS380B and CMS120B groups(all P<0.05),but the whole blood viscosity was significantly decreased in the HES130B group(P<0.05). Under the conditions of shear rate 10/s,50/s and 150/s,compared with the HBS130B group,the whole blood and the plasma viscosities were both significantly in- creased in the CMS120B and CMS380 groups(all P<0.05). At the effect of high shear rate,both the CMS380 and HES130 groups showed a tendency to promote erythrocyte deformation,and the CMS120B and CMS380B groups promot- ed erythrocyte aggregation,while the HES130B group inhibited erythrocyte aggregation amplitude(P<0.05). The P50 value was significantly higher in the CMS380B group than in the HES130B group(P<0.05). Conclusion: CMS130 and CMS380 could improve the rheological properties of erythrocytes and CMS380 could also promote the oxygen release of erythrocytes.

Electroencephalography and Schizophrenia / 신경정신의학

Electroencephalography (EEG) and event-related potentials (ERPs) are useful measures of information processing that are believed to reflect the cognitive processing of the brain. Recently, these electrophysiological markers have been studied repeatedly to examine patients with schizophrenia. Among the ERPs components, P50, P300, mismatch negativity, loudness dependence of auditory evoked potentials, and 40 Hz auditory steady state response are meaningful neurophysiological markers of schizophrenia. The employment of novel ERP paradigms designed to carefully characterize the early spectrum of perceptual and cognitive information processing allows investigators to identify the neurophysiological basis of cognitive dysfunction in schizophrenia and examine the associated clinical and functional impairments. Lately, functional neural networks using resting state EEG have been studied extensively in patients with schizophrenia. In this article, qEEG, several ERP components, and functional neural networks that were considered useful neurophysiological markers of schizophrenia are reviewed and their clinical implications are discussed.

Event-Related Potentials in Major Depressive Disorder / 신경정신의학

Many event-related potentials (ERPs) studies have been performed in major depressive disorder. ERPs include P50, N170, loudness dependence of auditory evoked potentials (LDAEP), P300, and mismatch negativity (MMN). These ERPs have good time-resolution as noninvasive methods, so they can be used easily in clinical practice and research. For example, ERPs can be used to differentiate patients from healthy people, as well as for assessing the subtype and severity, investigating the psychopathology, and predicting the treatment response in mental disorders. This review focuses on P50, N170, LDAEP, P300, and MMN in major depressive disorders.

Usefulness of P(50,std) for the Diagnostic Work-up of Patients with Erythrocytosis

High oxygen-affinity hemoglobin (Hb) variants and a 2,3-diphosphoglycerate (2,3-DPG) deficiency could cause congenital (familial) erythrocytosis. High oxygen-affinity Hb variants and a 2,3-DPG deficiency might result in low tissue oxygen tension left-shifted oxygen dissociation curves and reduction in the standard P₅₀ value (P(50,std), oxygen tension at which haemoglobin is 50% saturated). Hence, the P(50,std) value is considered while formulating diagnostic strategies for erythrocytosis. In this study, we established a reference range for P(50,std) using an International Federation of Clinical Chemistry and Laboratory Medicine-approved equation (Hill's equation) for individual single venous/arterial blood samples. Blood gas analysis results of 243 samples with oxygen saturation ranging from 40%–90% (Hb < 16 mg/dL) were selected. The reference range of P(50,std) was in the 2.5th–97.5th percentile, and was 25.9–27.3 mm Hg. Hill's equation is a simple approved method for evaluating the P(50,std) values. Only a single sample of venous or arterial blood and a blood gas analyser are required to obtain the P(50,std). Our study provides a useful tool for the diagnostic work-up of patients with erythrocytosis.

Effect of Oxygen Inhalation on Auditory Sensory Gating P50 / 中国康复理论与实践

@#Objective To explore the effect of oxygen inhalation on auditory sensory gating P50 in healthy human brain. Methods 28 healthy male academician right-handed were included. They were divided into control group (n=12) and experiment group (n=16) according to the random numerical table, and blinded about groups. The subjects inhaled pure oxygen in the experiment group, and air in the control group through a mask for 60 min. The electroencephalograph was recorded while an auditory paired-click sensory gating test was conducted during 4 study periods: before inhalation (pre0), inhale for 20 min (Oxy20) and 50 min (Oxy50), and 30 min after inhalation (post30). The latency and amplitude (S1-S2) of auditory sensory gating P50 were calculated. Results The latencies of P50 from S1 were stable in each group (P>0.7), and the latency of Oxy50 was shorter in the experiment group than in the control group (P<0.05). The latencies from S2 were stable in each group (P>0.30), and there was no significant difference between groups in all the time points (P>0.05). The amplitudes of (S1-S2) of P50 were stable in the control group (P=0.70), and was higher on Oxy20 (P=0.04) and Oxy50 (P=0.02) than post30 in the experiment group. There was no difference between the groups in all the time points (P>0.05). Conclusion Oxygen inhalation may be helpful to shorten the active time to stimulate, and trend to enhancing the amplitude of P50.

Signaling pathways regulating autophagy after cerebral ischemia / 国际脑血管病杂志

A lot of evidence shows that autophagy is involved in the occurrence and development of cerebral ischemia - reperfusion. Autophagy and its related signal transduction pathways may be an effective therapeutic target for ischemic brain injury. This article reviews related signal transduction pathways of autophagy regulation after cerebral ischemia.

Correlation between cognitive function and P50 sensory gating in patients with drug-na¨ive first-episode schizophrenia / 中国心理卫生杂志

Objective:To explore the relation of cognitive function correlates to P50 sensory gating in patients with schizophrenia.Methods:Totally 106 patients with drug-na¨ive first-episode schizophrenia and 86 healthy con-trol subjects matched for age,sex and education were recruited.All patients met the Diagnostic and Statistical Man-ual of Mental Disorders,Fourth Edition (DSM-IV)criteria for schizophrenia.Their cognitive function were assessed with the MATRICS Consensus Cognitive Battery (MCCB).The P50 auditory gating potential were recorded in all subjects using conditioning-testing stimulus paradigm and stimulus train paradigm.The P50 components were meas-ured in S1 S2 latency,S1 S2 amplitude and P50 suppression ratios.Results:Compared with the controls subjects, the patients with schizophrenia had significantly longer S1[60.8 ±7.8)ms vs.(56.3 ±7.0)ms,P 0.05).No significant correlation was found between P50 gating measures (P50 ratio and P50 ampli-tude difference)and neuropsychological measures in MCCB scores (Ps >0.05).Conclusion:There may be no as-sociation between P50 deficits and cognitive measures in patients with drug-na¨ive first-episode schizophrenia.

Effect of Oxygen Inhalation on Auditory Sensory Gating P50 / 中国康复理论与实践

Objective To explore the effect of oxygen inhalation on auditory sensory gating P50 in healthy human brain. Methods 28 healthy male academician right-handed were included. They were divided into control group (n=12) and experiment group (n=16) according to the random numerical table, and blinded about groups. The subjects inhaled pure oxygen in the experiment group, and air in the control group through a mask for 60 min. The electroencephalograph was recorded while an auditory paired-click sensory gating test was conducted during 4 study periods:before inhalation (pre0), inhale for 20 min (Oxy20) and 50 min (Oxy50), and 30 min after inhalation (post30). The la-tency and amplitude (S1-S2) of auditory sensory gating P50 were calculated. Results The latencies of P50 from S1 were stable in each group (P>0.7), and the latency of Oxy50 was shorter in the experiment group than in the control group (P0.30), and there was no significant difference between groups in all the time points (P>0.05). The amplitudes of (S1-S2) of P50 were stable in the control group (P=0.70), and was higher on Oxy20 (P=0.04) and Oxy50 (P=0.02) than post30 in the experi-ment group. There was no difference between the groups in all the time points (P>0.05). Conclusion Oxygen inhalation may be helpful to shorten the active time to stimulate, and trend to enhancing the amplitude of P50.

Effect of Oxygen Inhalation on Auditory Sensory Gating P50 / 中国康复理论与实践

@#Objective To explore the effect of oxygen inhalation on auditory sensory gating P50 in healthy human brain. Methods 28 healthy male academician right-handed were included. They were divided into control group (n=12) and experiment group (n=16) according to the random numerical table, and blinded about groups. The subjects inhaled pure oxygen in the experiment group, and air in the control group through a mask for 60 min. The electroencephalograph was recorded while an auditory paired-click sensory gating test was conducted during 4 study periods: before inhalation (pre0), inhale for 20 min (Oxy20) and 50 min (Oxy50), and 30 min after inhalation (post30). The latency and amplitude (S1-S2) of auditory sensory gating P50 were calculated. Results The latencies of P50 from S1 were stable in each group (P>0.7), and the latency of Oxy50 was shorter in the experiment group than in the control group (P<0.05). The latencies from S2 were stable in each group (P>0.30), and there was no significant difference between groups in all the time points (P>0.05). The amplitudes of (S1-S2) of P50 were stable in the control group (P=0.70), and was higher on Oxy20 (P=0.04) and Oxy50 (P=0.02) than post30 in the experiment group. There was no difference between the groups in all the time points (P>0.05). Conclusion Oxygen inhalation may be helpful to shorten the active time to stimulate, and trend to enhancing the amplitude of P50.

Effect of Oxygen Inhalation on Auditory Sensory Gating P50 / 中国康复理论与实践

@#Objective To explore the effect of oxygen inhalation on auditory sensory gating P50 in healthy human brain. Methods 28 healthy male academician right-handed were included. They were divided into control group (n=12) and experiment group (n=16) according to the random numerical table, and blinded about groups. The subjects inhaled pure oxygen in the experiment group, and air in the control group through a mask for 60 min. The electroencephalograph was recorded while an auditory paired-click sensory gating test was conducted during 4 study periods: before inhalation (pre0), inhale for 20 min (Oxy20) and 50 min (Oxy50), and 30 min after inhalation (post30). The latency and amplitude (S1-S2) of auditory sensory gating P50 were calculated. Results The latencies of P50 from S1 were stable in each group (P>0.7), and the latency of Oxy50 was shorter in the experiment group than in the control group (P<0.05). The latencies from S2 were stable in each group (P>0.30), and there was no significant difference between groups in all the time points (P>0.05). The amplitudes of (S1-S2) of P50 were stable in the control group (P=0.70), and was higher on Oxy20 (P=0.04) and Oxy50 (P=0.02) than post30 in the experiment group. There was no difference between the groups in all the time points (P>0.05). Conclusion Oxygen inhalation may be helpful to shorten the active time to stimulate, and trend to enhancing the amplitude of P50.

The Meaning of P50 Suppression: Interaction of Gamma and Alpha Waves

OBJECTIVES: Sensory gating dysfunctions in patients with schizophrenia and bipolar disorder have been investigated through two similar methods ; P50 suppression and prepulse inhibition paradigms. However, recent studies have demonstrated that the two measures are not correlated but rather constitute as distinct neural processes. Recent studies adopting spectral frequency analysis suggest that P50 suppression reflects the interaction between gamma and other frequency bands. The aim of the present study is to investigate which frequency component shows more significant interaction with gamma band. METHODS: A total of 108 mood disorder patients and 36 normal subjects were included in the study. The P50 responses to conditioning and test stimuli with an intra-pair interval of 500 msec were measured in the study population. According to P50 ratio (amplitude to the test stimulus/amplitude to the conditioning stimulus), the subjects with P50 ratio less than 0.2 were defined as suppressed group (SG) ; non-suppressed group (NSG) consisted of P50 ratio more than 0.8. Thirty-five and 25 subjects were included in SG and NSG, respectively. Point-to-point correlation coefficients (PPCCs) of both groups were calculated between two time-windows : the first window (S1) was defined as the time-window of one hundred millisecond after the conditioning auditory stimulus and the second window (S2) was defined as the time-window of 100 msec after the test auditory stimulus. Spectral frequency analysis was performed to investigate which frequency band results in the difference of PPCC between SG and NSG. RESULTS: Significant reduction of PPCC between S1 and S2 was observed in the SG (Pearson's r = 0.24), compared to PPCC of the NSG (r = 0.58, p < 0.05). In spectral frequency analysis, gamma band showed "phase-reset" and similar responses after the two auditory stimuli in suppressed and non-suppressed group. However in the case of alpha band, comparison showed significantly low PPCC in SG (r = -0.14) compared to NSG (r = 0.36, p < 0.05). This may be reflecting "phase-out" of alpha band against gamma band at approximately 50 msecs after the test stimulus in the SG. CONCLUSIONS: Our study suggests that normal P50 suppression is caused by phase-out of alpha band against gamma band after the second auditory stimulus. Thus it is demonstrated that normal sensory gating process is constituted with attenuated alpha power, superimposed on consistent gamma response. Implications of preserved gamma and decreased alpha band in sensory gating function are discussed.