Long-term depression of a sympathetic ganglionic response to opioids by prolonged synaptic activity and by phorbol esters

We studied the effect of the adenylate cyclase activator forskolin, of protein kinase C-activating phorbol esters and of prolonged preganglionic input activation on the inhibitory response of the perfused superior cervical ganglion of the cat to exogenous met-enkephalin (Met-ENK). Met-ENK inhibited, in a concentration-dependent manner, the postganglionic compound action potential evoked by cervical sympathetic trunk stimulation. The inhibition was reversible, was blocked by naloxone as well as by pertussis toxin and showed no homologous desensitization in the concentration range 0.01–10 μM. Pretreatment of the ganglion with 4β-phorbol 12,13-dibutyrate or 4β-phorbol 12,13-diacetate depressed the Met-ENK response for several hours, while pretreatment with forskolin had no effect. This action of phorbol esters was prevented by the protein kinase inhibitor H-7 but not by the calmodulin antagonist W-7 or the protein kinase A inhibitor HA 1004 and was calcium-dependent. Recovery of the response from the depression produced by phorbol esters was not affected by a protein synthesis inhibitor. A 40 Hz 20 min stimulus train to the cervical sympathetic trunk mimicked the effect of phorbol esters, depressing for several hours the inhibition produced by Met-ENK. Stimulus trains of duration shorter than 5 min or frequency lower than 5 Hz were ineffective. This effect of prolonged preganglionic stimulation occurred even when the stimulus train was delivered during complete block of nicotinic and muscarinic ganglionic transmission but was lost when the stimulus train was delivered during perfusion with calcium-free Krebs. The protein kinase inhibitor H-7 prevented the depression of the Met-ENK response by the train, while W-7 and HA 1004 had no effect. These findings suggest that, in the superior cervical ganglion of the cat, a kinase, activated by phorbol esters and inhibited by H-7, exerts a long-term control of the ganglion cell responsiveness to opiate receptor activation. A similar mechanism can be synaptically activated by a non-cholinergic transmitter, released by the preganglionic axons during prolonged, high frequency, activity.     

Optimization of pulse train presaturation for CEST imaging in clinical scanners

Chemical exchange saturation transfer (CEST) imaging depends on the performance of radiofrequency saturation during the experiment. Scanner specifications, in particular limited pulse width and duty‐cycle, and specific absorption rate guidelines restrict the full exploitation of CEST effects in clinical MR systems. The purpose of this study was to optimize techniques for effective pulse train presaturation for CEST imaging in a whole‐body MR scanner. Theoretical analysis and simulations of the spectral properties of radiofrequency pulse trains demonstrated the significance of pulse width τ_P and interpulse delay τ_D for effective and selective labeling of a chemically exchanging proton pool. CEST experiments with model solutions, e.g., creatine dissolved in water, showed best performance of pulse trains with τ_P = τ_D = 100 msec, regarding minimum direct water saturation in z‐spectra and distinct magnetization transfer ratio asymmetry that can be determined quantitatively. Saturation efficiency of trains of Gaussian‐shaped radiofrequency pulses using this timing was evaluated in MR imagers with field strengths of 1.5, 3, and 7 T. The proposed saturation pulse train does not require hardware modifications, offers low specific absorption rate, and can be used in a standard clinical setup. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.     

加快寄防人才培养促进寄防事业发展

针对寄生虫病防治及人才队伍的现状,提出了加强专业教育、搞好在岗培训、提倡以老带新和鼓励在职自学等措施来加快寄防人才培养,促进寄防事业的发展。     

石家庄铁路客运段动车、城际乘务员自测健康状况及影响因素分析

目的了解铁路动车和城际列车职工自测健康状况及不同性别、年龄、教育程度和婚姻状况对自测健康状况的影响。方法于2011年10月,采用自测评定量表和整群抽样方法,对动车队138人和城际队174人进行现场问卷调查和测试。结果不同车型的量表总分及三个子量表得分均有统计学意义(P<0.05),总分及各子量表得分均以动车乘务员最高;同年龄的量表总分及三个子量表得分差异均有统计学意义(P<0.05),量表总分及生理健康子量表、心理健康子量表得分以17～年龄组最高,社会健康子量表得分以30～岁年龄组最高。不同教育程度量表总分及三个子量表得分为大学组与中专、中技组,差异有统计学意义(P<0.05),总分和各子量表得分以大学组乘务员最高。不同婚姻状况的量表总分及三个子量表得分均有统计学意义(P<0.05),总分及各子量表得分均以未婚乘务员最高。结论动车乘务员自测健康状况较好,并且不同性别、年龄、教育程度及婚姻状况的乘务员自测健康状况也不同。     

择时针刺治疗乳腺增生症的思路与方法

通过详细介绍月经周期中的择时治疗及纳甲法、纳子法的开穴原理,探讨择时针刺治疗乳腺增生症的思路与方法,从而指导乳腺增生症的临床针刺治疗.     

NeuroQuest: a comprehensive analysis tool for extracellular neural ensemble recordings

Analyzing the massive amounts of neural data collected using microelectrodes to extract biologically relevant information is a major challenge. Many scientific findings rest on the ability to overcome these challenges and to standardize experimental analysis across labs. This can be facilitated in part through comprehensive, efficient and practical software tools disseminated to the community at large. We have developed a comprehensive, MATLAB-based software package - entitled NeuroQuest - that bundles together a number of advanced neural signal processing algorithms in a user-friendly environment. Results demonstrate the efficiency and reliability of the software compared to other software packages, and versatility over a wide range of experimental conditions.     

Bursting as a source of non‐linear determinism in the firing patterns of nigral dopamine neurons

Nigral dopamine (DA) neurons in vivo exhibit complex firing patterns consisting of tonic single‐spikes and phasic bursts that encode information for certain types of reward‐related learning and behavior. Non‐linear dynamical analysis has previously demonstrated the presence of a non‐linear deterministic structure in complex firing patterns of DA neurons, yet the origin of this non‐linear determinism remains unknown. In this study, we hypothesized that bursting activity is the primary source of non‐linear determinism in the firing patterns of DA neurons. To test this hypothesis, we investigated the dimension complexity of inter‐spike interval data recorded in vivo from bursting and non‐bursting DA neurons in the chloral hydrate‐anesthetized rat substantia nigra. We found that bursting DA neurons exhibited non‐linear determinism in their firing patterns, whereas non‐bursting DA neurons showed truly stochastic firing patterns. Determinism was also detected in the isolated burst and inter‐burst interval data extracted from firing patterns of bursting neurons. Moreover, less bursting DA neurons in halothane‐anesthetized rats exhibited higher dimensional spiking dynamics than do more bursting DA neurons in chloral hydrate‐anesthetized rats. These results strongly indicate that bursting activity is the main source of low‐dimensional, non‐linear determinism in the firing patterns of DA neurons. This finding furthermore suggests that bursts are the likely carriers of meaningful information in the firing activities of DA neurons.     

口腔医学毕业临床技能考核模式的改革与实践

口腔医学是一门实践性很强的经验型学科,口腔医学专业学生不仅要具备扎实的医学理论知识,最重要的是培养临床操作能力。现阶段口腔医学专业的毕业技能考核陈旧、单一,很难对即将毕业的学生进行临床技能的综合评定,随着生活水平的提高和对口腔保健的大量需求,对口腔实用型人才的培养的要求越来越高,为充分体现毕业考试对口腔应用型人才培养的激励作用,培养适合现代医疗水平的高质量口腔医学实用型人才,口腔实践技能的能力要求已成为此口腔医学培养的核心内容,提高口腔临床技能的操作能力,一直是口腔医学教育的难题,目前本校口腔医学院的毕业考试的形式已不符合现代口腔医学培养的目标,本课题将建立以培养目标达成度为导向的口腔医学专业多站式毕业技能考核体系,从考核内容、考核模式、监督机制和效果评价等方面全面改革毕业的形式,探求一个适合现代口腔执业医师要求和能力的考核考试方法,以适应口腔执业医师考试的形式和提高口腔医学专业学生的实践操作技能。     

Cardiovascular reaction to job stress in middle-aged train drivers

In this study, cardiovascular (CV) response to a standard laboratory challenge was compared to 24-hr noninvasive monitoring of heart rate (HR) and blood pressure (BP) in 30 healthy middle-aged train drivers. Laboratory stress test consisted of the orthostatic test, the cold pressor test, the Valsalva maneuver, the Stroop test, and the numerical square. In addition, the participants completed an extensive questionnaire on their health state and family health history, lifestyle, job stress, social and family support, personality characteristics, and health risk behaviors. In waking activities (leisure time, traveling to work, preparations for driving, and an uneventful driving) HR and systolic Wood pressure (SBP), but not diastolic Wood pressure (DBP), were normal (e.g., mean HR = 78.3, SBP = 128.6. and DBP= 92.3 during driving). In occasional stressful work situations, most participants reacted with a considerable rise in SBP and DBP (maximum values 201 for SBP and 126 for DBP). Interindividual differences in maximum BP reactions to emergency stress were predicted reliably by several psychological characteristics and by the CV reactions to the laboratory psychological challenge. The frequency, intensity, and persistence of psychological and physiological reactions to urgent situations appear to be more relevant measures of the health impact of psychological job stress than are the shift average values of physiological stress markers.