老年高血压病患者大动脉扩张性的临床研究

目的 探讨老年高血压病患者大动脉扩张性的改变及其相关因素。方法 应用脉搏波传导速度(PWV)自动测量系统测定颈动脉-股动脉PWV作为反映大动脉扩张性的参数。对118例老年高血压病患者进行了PWV检测,其中男87例,女31例,年龄64-83岁,平均(67.12±10.26)岁。结果 118例老年高血压病患者的研究结果显示PWV随年龄的增大而增加(P<0 001)。多元逐步回归分析结果表明年龄、收缩压与反映大动脉扩张性的PWV关系密切(P<0.001)。结论 老年高血压病导致大动脉扩张性降低,年龄、收缩压与患者大动脉扩张性密切相关。     

不同水平脉压差变异率指导肺切除术中液体管理的随机对照研究

目的评价以不同阈值脉压差变异率(PPV)为目标导向液体治疗(GDFT)对胸腔镜肺切除患者术后早期康复的影响。方法选择2017年8月至2018年11月在安徽医科大学第二附属医院择期行胸腔镜肺实质切除患者171例,采用随机数字表法分为标准血流动力学管理组(C组) 57例、低PPV组(G_1组) 57例及高PPV组(G_2组) 57例。C组根据中心静脉压(CVP)、心率(HR)、尿量指导输液; G_1组以低PPV(3%≤PPV≤6%)为目标指导输液; G_2组以高PPV(10%≤PPV≤13%)为目标指导输液。比较3组患者各时间点血流动力学、液体出入量、术后1周肺部并发症(PPCs)、术后肺功能、住院时间等差异。结果 3组患者HR在不同时间点有随时间变化的趋势,时间效应有统计学意义(P <0. 05),分组效应及交互效应无统计学意义(P> 0. 05)。3组患者的平均动脉压(MAP)在不同时间点有随时间及分组变化的趋势,时间效应及分组效应有统计学意义(P <0. 05),交互效应无统计学意义(P> 0. 05),G_1组、G_2组术中各时间点MAP值较C组更稳定。3组患者的乳酸值(Lac)在不同时间点有随时间及分组变化的趋势,时间效应、分组效应及交互效应有统计学意义(P <0. 05),G_1组术中各时间点Lac值更稳定,优于C组、G_2组。3组患者的氧合指数(PaO_2/FiO_2)在不同时间点有随时间及分组变化的趋势,时间效应及分组效应有统计学意义(P <0. 05),交互效应无统计学意义(P> 0. 05),G_1组、G_2组术中各时间点PaO_2/FiO_2值更稳定,优于C组。3组患者的动脉血二氧化碳分压(PaCO_2)在不同时间点有随分组变化的趋势,分组效应有统计学意义(P <0. 05),时间效应及交互效应无统计学意义(P> 0. 05),G_1组、G_2组术中各时间点PaCO_2更稳定,优于C组。C组、G_1组、G_2组患者术后1周术后肺部并发症(PPCs)发生率分别为35. 09%、14. 04%和28. 07%,3组患者PPCs发生率的差异有统计学意义(χ~2=6. 855,P=0. 032)。C组、G_1组、G_2组住院时间分别为(14. 56±5. 52) d、(11. 42±3. 83) d、(12. 91±3. 77) d,G_1组患者住院时间与C组、G_2组患者相比明显缩短(P<0. 05)。结论胸腔镜下肺切除术中运用GDFT时,以低PPV为目标的液体输注方案为好,能够改善氧合,降低PPCs发生率、缩短住院时间,有利于预后。     

Distal Convoluted Tubule

The distal convoluted tubule is the nephron segment that lies immediately downstream of the macula densa. Although short in length, the distal convoluted tubule plays a critical role in sodium, potassium, and divalent cation homeostasis. Recent genetic and physiologic studies have greatly expanded our understanding of how the distal convoluted tubule regulates these processes at the molecular level. This article provides an update on the distal convoluted tubule, highlighting concepts and pathophysiology relevant to clinical practice.     

Differential Processing of Neuropeptides Influences Drosophila Heart Rate

Peptides that play critical physiological roles are often encoded in precursors that contain several structurally-related gene products. Differential processing of a precursor by cell-specific processing enzymes can yield multiple messengers with diverse distributions and activities. We have reported the isolation of SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide from adult Drosophila melanogaster. The peptides are encoded in the FMRFamide gene and have a common C-terminal FMRFamide but different N-terminal extensions. In order to investigate the processing of the FMRFamide polypeptide protein precursor, we generated antisera to distinguish among the structurally-related neuropeptides. Utilizing a triple-label immunofluorescent protocol, we mapped the distribution of the peptides. Each peptide has a unique, non-overlapping cellular expression pattern in neural tissue suggesting that the precursor is differentially processed. In order to identify a biological activity of the peptides, we established an in vivo heart rate assay. SDNFMRFamide decreases heart rate but DPKQDFMRFamide and TPAEDFMRFamide do not, indicating that the N-terminal residues are critical for this activity. SDNFMRFamide immunoreactivity is present in the aorta, implying that SDNFMRFamide acts locally to affect heart rate; DPKQDFMRFamide and TPAEDFMRFamide antisera do not stain cardiac tissue. Our data support the conclusion that Drosophila contains cell-specific proteolytic enzymes to differentially process a polypeptide protein precursor resulting in unique expression patterns of structurally-related, yet functionally distinct neuropeptides.     

The effect of rate stress on the auditory brainstem response in autism: A preliminary report

Abstract

Efforts to correlate peripheral neurophysiologic function with perceptional deficits seen in autistic disorder (AD) have resulted in mixed findings, reflecting the high degree of heterogeneity observed in these individuals. We used the auditory brainstem response to study the effect of stress (high click presentation rate) on the auditory system in 20 children with AD (7–13 years) and 20 age-matched typically developing (TD) children. We report latency prolongations in children with AD vs. TD at waves I, III, and V that differed by ear of presentation: overall, left ear showed significant prolongations by group while right ear did not. The ‘stressed’ condition produced prolongations for both groups at each wave. At wave V, children with AD showed significant prolongations vs. TD, particularly for the right ear. For children with AD, wave V latency prolongations corresponded to language outcome as measured by VIQ, with longer prolongations associating with lower VIQ. Preliminary results provide evidence for reduced synaptic efficiency in auditory pathways in children with AD, which may form the neural bases for sensory reactivity and language impairment.

Sumario

Los esfuerzos para correlacionar la función neurofisiológica periférica con los déficits de percepción que se observan en el trastorno autístico (AD) han producido hallazgos mixtos que reflejan el alto grado de heterogeneidad que se aprecia en estos individuos. Usamos la respuesta auditiva de tallo cerebral para estudiar el efecto de tasas elevadas de presentación de clicks al sistema auditivo de 20 niños con AD (7-13 años) y de otros 20, pareados en edad, con desarrollo típico (TD). Reportamos latencias prolongadas en niños con AD vs. TD en las ondas I, III y V que difirieron según el oído estimulado. Globalmente, el oído izquierdo mostró prolongaciones significativas por grupo, mientras que no fue así con el oído derecho. La condición de “alta estimulación” produjo prolongaciones en ambos grupos y con cada una de las ondas. En la onda V, los niños con AD mostraron prolongaciones significativas vs. los niños TD, particularmente con el oído derecho. En niños con AD, las prolongaciones de latencia de la onda V, correspondieron a resultados lingüísticos medidos con VIQ, con prolongaciones aun mayores que se asociaron con niveles VIQ más bajos. Los resultados preliminares proporcionan evidencias de eficiencia sináptica reducida en las vías auditivas de niños con AD, que pueden ser el fundamento neural de la reactividad sensorial y de los impedimentos del lenguaje.     

Distortion Product Otoacoustic Emissions: A Normative Study

Distortion product otoacoustic emissions (DPOAEs) were quite recently introduced as a new objective auditory screening technique, having a unique potential because of their ability to analyze the micromechanical functions of the cochlea in a frequency-specific way. In 1992, Kemp and Bray released the commercially available Oto-dynamics Analyzer IL092, which enabled investigators and audiological centres to perform DPOAE measurements in different populations, but without any relationship to normative data. The purpose of this study was to describe the normative aspects of 2fl-f2 DPOAEs obtained with the IL092 from 101 normal ears of 101 healthy young adults. The DPOAEs were obtained automatically by means of two data-collection protocols on the IL092 in the form of DP-gram and DP-growth functions. These data were statistically processed to form a normative database which has the potential of serving as a basis for further research aimed at determining the utility of DPOAE testing in evaluating ear pathology     

Neurophysiological adaptations to spaceflight and simulated microgravity

Changes in physiological functions after spaceflight and simulated spaceflight involve several mechanisms. Microgravity is one of them and it can be partially reproduced with models, such as head down bed rest (HDBR). Yet, only a few studies have investigated in detail the complexity of neurophysiological systems and their integration to maintain homeostasis. Central nervous system changes have been studied both in their structural and functional component with advanced techniques, such as functional magnetic resonance (fMRI), showing the main involvement of the cerebellum, cortical sensorimotor, and somatosensory areas, as well as vestibular-related pathways. Analysis of electroencephalography (EEG) led to contrasting results, mainly due to the different factors affecting brain activity. The study of corticospinal excitability may enable a deeper understanding of countermeasures' effect, since greater excitability has been shown being correlated with better preservation of functions. Less is known about somatosensory evoked potentials and peripheral nerve function, yet they may be involved in a homeostatic mechanism fundamental to thermoregulation. Extending the knowledge of such alterations during simulated microgravity may be useful not only for space exploration, but for its application in clinical conditions and for life on Earth, as well.