磁共振电影成像技术观察子宫收缩的研究进展

子宫固有收缩对精子的运输、受精卵的着床以及月经血的排出起着重要作用。尽管子宫的收缩与各种生理及病理状态的关系复杂,但磁共振电影成像技术能够直接显示这些生理及病理状态下的子宫收缩情况,是评价两者关系的有效工具。本文就磁共振电影成像技术对各种状态下子宫收缩的研究进展作一综述。     

经口内镜下肌切开术对Ⅱ型贲门失弛症食管动力学影响

目的 应用高分辨率食管测压(HRM)探讨经口内镜下肌切开术(POEM)对Ⅱ型贲门失弛症(AC)病人的食管动力学影响,评估POEM治疗Ⅱ型AC的近期疗效。方法 选取2015年6月至2017年6月在安徽医科大学附属安庆医院经食管钡餐造影及胃镜检查确诊为AC病人连续入组,并进行HRM,根据2014年芝加哥分类标准选取Ⅱ型AC病人20例,其中12例入组行POEM手术。所有入组者分别于术前及术后1个月行HRM检查,比较手术前后食管动力学指标的变化。结果 12例Ⅱ型AC病人POEM术治疗前后临床症状评分系统(Eckardt评分)差异有统计学意义(t＝4.325,P＜0.001);所有入组者食管下括约肌松弛参数及食管体部蠕动性参数均有明显改善,食管下括约肌静息压(LESP)术前(37.5±18.6)mmHg(1 mmHg＝0.133 kPa)高于术后(16.4±6.4)mmHg (t＝3.935,P＜0.001);4 s完整松弛压力(4 s IRP)术前(31.4±14.8)mmHg与术后(11.5±6.5)mmHg比较,差异有统计学意义(t＝5.815,P＜0.001);食管下括约肌松弛率(LESRR)术前(23.1±18.6)%与术后(45.6±21.7)%比较,差异有统计学意义(t＝-5.482,P＜0.05)。12例病人术前食管运动以无传导性同步收缩波为主,术后有2例病人出现食管近端蠕动波,但仍达不到正常水平;其余10例在压力测定中同步收缩及无效吞咽显著减少,但食管体部均无完整的蠕动性收缩波。结论 POEM能有效改善Ⅱ型AC病人的LES松弛障碍和降低LESP,但对恢复食管体部蠕动功能有限,近期效果显著,远期疗效及并发症有待进一步随访研究。     

Colonic Transit Time After Spinal Cord Injury: Any Clinical Significance?

Abstract

Background: Both bowel dysfunction and increases in colonic transit time (CTT) are frequently observed in individuals with spinal cord injury; however, it is unknown whether there is an association between chronic intestinal problems and changes in CTTs. The current study investigates a possible relationship between the main intestinal symptoms of SCI patients and CTT values.

Methods: The following clinical variables and symptoms were investigated and collected in 30 individuals with SCI: total time for bowel care, abdominal pain, abdominal gas, success of rectal emptying, fecal incontinence, and decrease in quality of life. Total and segmental CTTs (right colon, left colon, and rectosigmoid colon) were assessed using radiopaque markers. The effects of the sociodemographic variables and the clinical symptoms on the different CTTs (total and segmental) were analyzed.

Results: The assessed clinical conditions were observed in the following percentages of subjects: abdominal gas symptoms (70%), fecal incontinence (56%), abdominal pain (63%), total time for bowel care > 1 hour (11%), difficult rectal emptying (66%), and decrease in quality of life (36%). We also observed an increase in total CTT in 47% of subjects; increases in segmental CTT were found in the right colon in 23%, in the left colon (60%), and in the rectosigmoid segment (23%). Statistical analyses failed to show a significant difference in mean CTT values between the group of symptomatic patients (1 or more symptoms) and the group of asymptomatic patients. No significant difference could be detected in the incidence of each intestinal symptom between the group of participants with normal CTT values and those with abnormal CTT values. For each of the clinical data assessed separately, a significantly longer CTT (left colon) was associated with the lack of abdominal pain (P < .03) and the presence of fecal incontinence (P < .01 ); successful rectal emptying was associated with significantly shorter total (P < .02) and segmental CTTs for the left colon (P < .01 J and rectosigmoid colon (P < .05).

Conclusions: Besides an association between shorter CTT and successful rectal emptying, there was little relationship between CTTs and intestinal symptoms in this study of patients with SCI.     

Axial force measurement for esophageal function testing

The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the ＂golden standard＂ for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force （force in radial direction） whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal （axial） direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method.     

Antagonism by methylxanthines of purine nucleotide- and dipyridamole-induced inhibition of peristaltic activity of the guinea pig ileum

The effect of the methylxanthines (aminophylline, AMI and theophylline, THEO) on the responses to the purine pig ileum has been studied. ATP, ADP and adenosine produced concentration-dependent inhibition of peristaltic activity in non-treated, reserpine- or 6-hydroxydopamine-pretreated preparations; the relative potencies in descending order were ATP ? ADP > adenosine. This inhibition of peristaltic activity by the purine nucleotides was antagonized by low concentrations of the methylxanthines and this effect was reversible at all concentrations tested. The antagonism by THEO (5.0 μM) appeared competitive in nature. In contrast, peristaltic acdtivity inhibited by noradrenaline, isoprenaline, periarterial nerve stimulation (PNS) or papaverine was unaffected by the presence of the methylxanthines. Dipyridamole (5–10 μM) produced and inhibition in the late phase of the peristaltic activity, while lower concentrations (0.5–1.3 μM) potentiated the inhibitory response to ATP, ADP and adenosine without influencing the responses to noradrenaline, isoprenaline, PNS or papaverine. The methylxanthines selectively antagonized the inhivitory effects of dipyridamole alone or in combination with the purine nucleotides.It is proposed, that AMI and THEO exert a selective action on a specific ATP-receptor and that THEO may be a competitive antagonist of the purine nucleotides on peristaltic activity of the guinea pig ileum. Since 100-fold greater concentrations of AMI ot THEO are required to inhibit this preparation by inhibition of phosphodiesterase, it is highly unlikely that the inhibition of peristalsis by dipyridamole and the subsequent blockade by low concentrations of the methylxanthines involves the 3′, 5′-cyclic AMP pathway. Furthermore, the parallelism observed, between the effect of the methylxanthines on the inhibitory responses obtained with dipyridamole nad the effect of ATP, ADP and adenosine, supports the hypothesis that non-adrenergic, non-cholinergic inhibitory neurons releasing a purine nucleaotide as the neurotransmitter contribute to the descending inhibition observed during peristalsis.     

米索前列醇对剖宫产术后产妇肠蠕动的影响

目的 探讨米索前列醇对剖宫产术后产妇肠蠕动的影响.方法 随机选100例行子宫下段剖宫产术的产妇,观察组50例术后常规米索前列醇直肠给药,余50例产妇作空白对照.分别比较两组产妇肛门排气时间、泌乳时间、产后出血量.结果 观察组产妇肛门排气及泌乳时间明显缩短(均P＜0.05),产后出血量减少(P＜0.05).结论 剖宫产术后应用米索前列醇可促进产妇肠蠕动,有效恢复体力.     

十二指肠胃反流胃肠动力机制研究

十二指肠胃反流（DGR）是一种常见的生理和病理现象，与许多疾病的发生有关。目前其发生机制尚不明确。目的：探讨DGR发生与胃窦十二指肠消化间期移行性复合运动（MMC）的关系。方法：对20名健康志愿者行24h同步胃内pH监测和胆汁监测，以及夜间长时胃窦十二指肠压力测定。结果：24h同步胃内pH监测和胆汁监测后，20名健康志愿者分为2组：DGR阴性组（D1组）（7名）和DGR阳性组（D2组）（13名）。D1组MMC周期数较D2组显著增加（P〈0．05）；D2组胃窦十二指肠协调收缩较D1组显著减少，十二指肠推进性蠕动减少（P均〈0．05）。D1组十二指肠MMCm相逆蠕动发生率显著低于D2组（P〈0.05）。D2组发生MMCm相逆蠕动前后10min，胃内pH值分别为1.72±0.61和3.70±0.72，差异有统计学意义（P〈0．01）。夜间MMCⅡ相晚期碱反流和胆汁反流的发生率显著高于I相、Ⅱ相早期和Ⅲ相（P均〈0．05）。结论：DGR的发生与胃窦十二指肠MMC周期数、Ⅱ相晚期和Ⅲ相逆蠕动有关。     

Central neural control of esophageal motility: A review

We review recent studies on the central neural control of esophageal motility, emphasizing the anatomy and chemical coding of esophageal pathways in the spinal cord and medulla. Sympathetic innervation of the proximal esophagus is derived primarily from cervical and upper thoracic paravertebral ganglia, whereas that of the lower esophageal sphincter and proximal stomach is derived from the celiac ganglion. In addition to noradrenaline, many sympathetic fibers in the esophagus contain neuropeptide Y (NPY), and both noradrenaline and NPY appear to decrease blood flow and motility. Preganglionic neurons innervating the cervical and upper thoracic ganglia are located at lower cervical and upper thoracic spinal levels. The preganglionic innervation of the celiac ganglion arises from lower thoracic spinal levels. Both acetylcholine (ACh) and enkephalin (ENK) have been localized in sympathetic preganglionic neurons, and it has been suggested that ENK acts to pre-synaptically inhibit ganglionic transmission. Spinal afferents from the esophagus are few, but have been described in lower cervical and thoracic dorsal root ganglia. A significant percentage contain calcitonin gene-related peptide (CGRP) and substance P (SP). The central distribution of spinal afferents, as well as their subsequent processing within the spinal cord, have not been addressed. Medullary afferents arise from the nodose ganglion and terminate peripherally both in myenteric ganglia, where they have been postulated to act as tension receptors, and, to a lesser extent, in more superficial layers. Centrally, these afferents appear to end in a discrete part of the nucleus of the solitary tract (NTS) termed the central subnucleus. The transmitter specificity of the majority of these afferents remains unknown. The central subnucleus, in turn, sends a dense and topographically discrete projection to esophageal motor neurons in the rostral portion of the nucleus ambiguus (NA). Both somatostatin- (SS) and ENK-related peptides have been localized in this pathway. Finally, motor neurons from the rostral NA innervate striated portions of the esophagus. In addition to ACh, these esophageal motor neurons contain CGRP, galanin (GAL), N-acetylaspartylglutamate (NAAG), and brain natriuretic peptide (BNP). The physiological effect of these peptides on esophageal motility remains unclear. Medullary control of smooth muscle portions of the esophagus have not been thoroughly investigated.     

MRI评估胃动力的研究进展

随着生活工作压力的增大,胃动力紊乱的发病率呈逐年增长趋势,而胃动力紊乱的主要原因是功能性消化不良,因此胃动力检测有助于功能性胃肠道疾病的诊断和治疗。近几年,MRI新技术和新软件的研发以及随着其在胃肠道疾病诊断方面研究的快速发展,通过使用组织对比剂可获得胃肠道高分辨率图像。目前,大多数研究是在证实该技术在临床应用中的价值及研发数据处理技术,新软件研发可以克服运动伪影,提高图像质量,便于诊断评价。MRI检查技术具有无创伤、无电离辐射、多平面成像等优势,广泛适用于需要重复检查的患者。但是,目前该技术仍未能在胃肠道动力评价中广泛应用。该文主要对胃动力不同检查技术进行比较及MRI评价胃动力方面研究进展进行阐述。