Respiratory sinus arrhythmia, cardiac vagal tone, and respiration: Within- and between-individual relations

Respiratory sinus arrhythmia (RSA) is frequently employed as an intra- and interindividual index of cardiac parasympathetic tone, although the relationship of RSA to interindividual differences in cardiac vagal tone remains questionable. Our study examined between- and within-subject relations among RSA, cardiac vagal tone, and respiratory parameters. Twenty-nine young adults performed two sessions of tasks under no medication and single and double autonomic blockade (intravenously administered propranolol and atropine). Parasympathetic tone was determined from heart period responses to complete vagal blockade. Results indicated the following. Resting RSA does not accurately predict individual differences in cardiac vagal tone. However, RSA and heart period together do predict such individual differences reasonably well. The relationship between individual variations in RSA and vagal tone is not improved by controlling respiratory parameters. Substantial cardiac vagal activity occurs during inspiration, and intraindividual variations in respiratory measures confound the association between RSA and cardiac vagal tone.     

Power spectrum analysis and heart rate variability in Stage 4 and REM sleep: evidence for state-specific changes in autonomic dominance

The present study investigated autonomic activity during NREM and REM sleep stages and wakefulness by spectral analysis of heart rate variability. The results demonstrated that NREM sleep in humans was characterized by a widely different autonomic activation pattern than REM sleep: high parasympathetic activity was found in NREM, while REM was characterized by attenuated vagal tone, and augmented sympathetic activity. The overall pattern during wakefulness showed an intermediate position between NREM and REM patterns; parasympathetic activity was lower than in NREM and higher than in REM, with an opposite trend for sympathetic activity.     

1%线状透明颤菌面霜在中国女性敏感性皮肤的功效与耐受性评价

目的评价温泉浮游生物纯提取物(pureextractthermalplankton,PETP)即线状透明颤菌(Vitreoscillafiliformis,VF)提取物用于中国女性敏感性皮肤的功效与耐受性。方法经临床检查和乳酸刺激实验筛选出伴有敏感性皮肤的健康女性36例。早晚清洁面部后,均匀涂抹1%VF面霜,每日2次,连续使用3周。分别于实验前后由同一个皮肤科医师观察受试者的皮肤乳酸刺激分数,以及皮肤的临床表现(干燥、红斑、鳞屑、弹性、光滑度)。同时,检测皮肤颜色及皮肤角质层水合度等皮肤生物学参数。结果受试者的乳酸刺激分数显著降低,使用前后差异显著(P<0.0001)。干燥、红斑、鳞屑、光滑度均有不同程度改善。受试者对VF面霜耐受良好。结论伴有敏感性皮肤的中国女性,在皮肤日常护理中,使用含有VF提取物的护肤品有助于改善皮肤的敏感状态和皮肤保健。     

肾移植治疗终末期肾衰竭伴纯红再障临床研究--附2例远期疗效随访报告及文献复习

目的:通过总结2例终末期肾衰竭(ESRD)患者伴纯红再障(pure red cell aplasia,PRCA)的临床资料,介绍该病的诊断与治疗.方法:回顾性总结2例ESRD合并PRCA的诊治并复习相关文献.结果:2例ESRD患者均确诊为肾性贫血常规给予α-促红素(α-rhuEPO)治疗后出现PRCA.2例经肾移植术,随访3年以上,目前病情稳定.结论:使用促红素治疗ESRD所致肾性贫血出现的PRCA,其首选的治疗方法是肾移植.     

肾移植术后人类微小病毒B19感染致纯红细胞再生障碍性贫血2例并文献复习

目的探讨肾移植术后人类微小病毒(HPV)B19感染致纯红细胞再生障碍性贫血(纯红再障)的诊断和治疗特点。方法总结南方医科大学南方医院器官移植科收治的2例肾移植术后HPV B19感染致纯红再障的病例,结合文献复习讨论该病的临床特点、诊断方法、治疗过程及预后。结果两例肾移植受者术后早发严重贫血且进行性加重,输血治疗无效。排除导致贫血的其他原因,综合骨髓穿刺活检、荧光聚合酶链反应(PCR)检测HPV DNA等方法诊断为HPV B19感染致纯红再障。经调整免疫抑制方案、静脉注射用免疫球蛋白(IVIG)等治疗后2例患者贫血症状明显改善。结论对于肾移植术后早期不明原因、进行性加重的贫血患者,特别是伴随网织红细胞缺乏者,应考虑HPV B19感染致纯红再障的可能性。骨髓穿刺及荧光PCR检测结果是诊断纯红再障的主要依据,免疫抑制剂减量和应用IVIG治疗是主要治疗措施。经治疗后,患者预后较好,但易复发。     

Investigating functional changes in the brain to intermittently induced auditory illusions and its relevance to chronic tinnitus

Several studies have demonstrated the neural correlates of chronic tinnitus. However, we still do not understand what happens in the acute phase. Past studies have established Zwicker tone (ZT) illusions as a good human model for acute tinnitus. ZT illusions are perceived following the presentation of a notched noise stimulus, that is, broadband noise with a narrow band‐stop filter (notch). In the current study, we compared the neural correlates of the reliable perception of a ZT illusion to that which is not. We observed changes in evoked and total theta power in wide‐spread regions of the brain particularly in the temporal‐parietal junction, pregenual anterior cingulate cortex/ventromedial prefrontal cortex (pgACC/vmPFC), parahippocampus during perception of the ZT illusion. Furthermore, we observe that increased theta power significantly predicts a gradual positive change in the intensity of the ZT illusion. Such changes may suggest a malfunction of the sensory gating system that enables habituation to redundant stimuli and suppresses hyperactivity. It could also suggest a successful retrieval of the memory of the missing frequencies, resulting in their conscious perception indicating the role of higher‐order processing in the mechanism of action of ZT illusions. To establish a more concrete relationship between ZT illusion and chronic tinnitus, future longitudinal studies following up a much larger sample of participants who reliably perceive a ZT illusion to see if they develop tinnitus at a later stage is essential. This could inform us if the ZT illusion may be a precursor to chronic tinnitus.     

听力正常成年人同时多频听觉稳态诱发反应研究

目的　了解正常听力成人同时多频听觉稳态诱发反应的特性。方法　 32名受试者 (6 4耳 ) ,年龄 2 2～ 32岁 ,平均 2 8.3岁 ,男 12名 ,女 2 0名 ,双耳纯音听阈测试各频率听阈在 2 0dB以内。以载波频率为 0 .5、1、2和 4kHz的纯音 ,调制频率分别为 77、85、93和 10 1Hz(左耳 )以及 79、87、95、10 3Hz(右耳 )的调幅声作为测试信号 ,双耳 8个频率同时给声刺激 ,同时自动判定并记录反应。各载波频率的阈值、反应幅度等数据采用SPSS统计软件分析。结果　①同时多频听觉稳态诱发反应阈高于纯音听阈 7～ 19dB。②反应阈经双因素方差分析 (侧别×频率 ) ,左右耳之间无显著性差异 (F =1.94 2 ;μ 1,179;P =0 .16 5 ) ,但各频率之间有显著性差异 (F =31.2 5 4 ;μ 3,179;P =0 .0 0 0 ) ,各频率反应阈均值之间进一步的两两比较显示 0 .5kHz反应阈与其它频率之间存在显著性差异。③以 6 0dBSPL作为分析强度 ,男女受试者在各个频率的反应幅度的差异经双因素方差分析 (性别×频率 )有显著性差异 (F =2 .94 8;μ 3,175 ;P =0 .0 34) ,0 .5kHz反应幅度最低 ,4kHz最高。性别之间有显著性差异 (F =16 .4 90 ;μ 1,175 ;P=0 .0 0 0 ) ,男性反应幅度高于女性。④各频率不同状态下背景噪声的差异经双因素方差分析 ,提示清醒状     

Hearing impairment in Parkinson's disease: Expanding the nonmotor phenotype

The objective of this study was to evaluate hearing impairment in patients affected by Parkinson's disease compared with hearing scores observed in normal age‐ and sex‐matched controls. One hundred eighteen consecutive patients with a clinical diagnosis of Parkinson's disease were screened. Severity of motor symptoms and staging were measured with the Unified Parkinson's Disease Rating Scale (section III) and the Hoehn and Yahr scale. Audiometric evaluation consisted of a comprehensive audiologic case history and questionnaire, visual otoscopic examination, acoustic immittance measures (tympanogram and acoustic reflexes), pure tone audiometry, and measurement of brain stem auditory‐evoked potentials. Healthy age‐ and sex‐matched subjects were selected as the control group. One hundred six of 118 patients were enrolled. Pure tone audiometry revealed age‐dependent high‐frequency hearing loss in patients with Parkinson's disease compared with both normative values and values for healthy age‐ and sex‐matched controls (75/106 [71%], χ² = 5.959, P = .02; 92/106 [86.8%] vs 60/106 [56.6%], χ² = 23.804, P < .001, respectively). Pure tone audiometry scores correlated with Hoehn and Yahr scale scores (P < .05). Brain stem auditory‐evoked potentials were normal in all patients. Our patients with Parkinson's disease showed age‐dependent peripheral, unilateral, or bilateral hearing impairment. Whether these auditory deficits are intrinsic to Parkinson's disease or secondary to a more complex impaired processing of sensorial inputs occurring over the course of illness remains to be determined. Because α‐synuclein is located predominately in the efferent neuronal system within the inner ear, it could affect susceptibility to noise‐induced hearing loss or presbycusis. It is feasible that the natural aging process combined with neurodegenerative changes intrinsic to Parkinson's disease might interfere with cochlear transduction mechanisms, thus anticipating presbycusis. © 2012 Movement Disorder Society     

Effects of muscarinic receptor stimulation and nitric oxide synthase inhibition on gastric tone and gastric myoelectrical activity in canines

Aims:  This study was designed to assess whether the muscarinic receptor stimulation and nitric oxide synthase inhibition were equally effective on gastric fundic tone or gastric myoelectrical activity (GMA) in canines, and the correlation between gastric fundic tone and GMA.
Methods:  Gastric fundic tone and GMA were recorded on seven dogs implanted with serosal electrodes and a gastric cannula.
Results:  Bethanechol and L-nitro-N-arginine (L-NNA) significantly increased gastric fundic tone; gastric volume was decreased with bethanechol or L-NNA ( P  < 0.05). Increased spike activities were observed after both bethanechol and L-NNA. The percentage of slow waves superimposed with spikes was increased with bethanechol ( P  < 0.001) and L-NNA ( P  < 0.05). There was a significant reduction in dominant frequency (DF) ( P  < 0.05), dominant power (DP) ( P  < 0.05) and percentage of normal slow waves (%N) ( P  < 0.05) with bethanechol, while no significant change was observed with L-NNA. The variation of gastric tone was not correlated with parameters of GMA.
Conclusions:  Muscarinic receptor stimulation and nitric oxide synthase inhibition have similar effects on gastric tone and gastric spike activities, but different effects on gastric slow waves. Gastric fundic tone does not correlate with gastric slow waves.     

Aortic dissection as a possible cause of pure transient global amnesia: a case report and literature review

A 55-year-old man suddenly developed anterograde and retrograde amnesia. His colleagues witnessed the onset of the episode and reported that 2 h before the onset of the amnesic attack the patient transiently became pale. Physical examination was unremarkable and neurological examination revealed no focal neurological sign although a laboratory investigation revealed leukocytosis. Pure transient global amnesia (TGA) was diagnosed. The anterograde amnesia resolved 20 h after onset, but the causes of his transient paleness precedent to TGA and leukocytosis were unclear. Thirty-four hours after onset, the patient complained of sudden back pain and radiological studies revealed aortic dissection (AD; Stanford type B). We emphasize AD as a rare cause of pure TGA, because TGA in itself often has a benign natural history, but AD can be life-threatening if undiagnosed. The precedent pain, transient systemic symptoms, and leukocytosis can be red flags suggesting AD as an etiology of TGA.