A new concept of the contraction–extension property of the left ventricular myocardium

ObjectivesUsing newly developed ultrasonic technology, we attempted to disclose the characteristics of the left ventricular (LV) contraction–extension (C–E) property, which has an important relationship to LV function.MethodsStrain rate (SR) distribution within the posterior wall and interventricular septum was microscopically measured with a high accuracy of 821 μm in spatial resolution by using the phase difference tracking method. The subjects were 10 healthy men (aged 30–50 years).ResultsThe time course of the SR distribution disclosed the characteristic C–E property, i.e. the contraction started from the apex and propagated toward the base on one hand, and from the epicardial side toward the endocardial side on the other hand. Therefore, the contraction of one area and the extension of another area simultaneously appeared through nearly the whole cardiac cycle, with the contracting part positively extending the latter part and vice versa. The time course of these propagations gave rise to the peristalsis and the bellows action of the LV wall, and both contributed to effective LV function.The LV contraction started coinciding in time with the P wave of the electrocardiogram, and the cardiac cycle was composed of 4 phases, including 2 types of transitional phase, as well as the ejection phase and slow filling phase. The sum of the measurement time duration of either the contraction or the extension process occupied nearly equal duration in normal conditions.ConclusionThe newly developed ultrasonic technology revealed that the SR distribution was important in evaluating the C–E property of the LV myocardium. The harmonious succession of the 4 cardiac phases newly identified seemed to be helpful in understanding the mechanism to keep long-lasting pump function of the LV.     

食管裂孔疝患者食管蠕动功能的变化

目的探讨食管裂孔疝患者食管蠕动功能的改变在胃食管反流中的意义。方法选择32例有胃食管反流症状患者(单纯食管裂孔疝10例、食管裂孔疝合并食管炎12例、单纯食管炎10例)和9例无反流症状的对照组,分别测定其下食管括约肌(LES)压力、食管的蠕动波幅、蠕动时限、蠕动速度,并经内镜对患者食管炎的程度进行分级。结果裂孔疝合并食管炎组、单纯食管炎组其LES压力较对照组均降低,单纯裂孔疝组LES压力较对照组降低,但无统计学差异。食管近端及远端的蠕动波幅食管裂孔疝组最高,达(51.3±5.4)mmHg和(83.6±8.3)mmHg,食管炎组最低;食管近远端的蠕动时限各组间无统计学差异;而食管远端的蠕动速度裂孔疝组也最高,食管炎组低于对照组。结论食管裂孔疝患者食管蠕动功能在胃食管反流、粘膜损伤的发生发展中起着重要的作用。     

Histologic and Manometric Studies on the Esophagus Following Endoscopic Sclerotherapy

Objective The aim of this work was to study the histologic and manometric changes in the distal esophagus beyond 2 years following endoscopic sclerotherapy (EST) and/or surgical intervention, and to try to understand the etiological factors associated with these changes. Patients and interventions Forty patients, with an average age of 61.5 years, were studied for 2–12 years following sclerotherapy and/or surgical intervention. The causes of liver disease were alcoholic cirrhosis (78.6%), primary biliary cirrhosis (14.3%), and chronic aggressive hepatitis (7.1%). A predominant number of cases (65%) had a mesocaval interposition shunt due to the failure of EST, 32.5% EST alone, and 2.5% esophageal devascularization. All patients had esophageal manometry following mucosal biopsies taken in duplicate endoscopically from three levels of the distal esophagus. Results In the EST and shunt groups, 88.5% had manometric abnormalities, esophagitis, and chronic inflammatory changes. In the EST group, all but two patients had manometric abnormalities and chronic inflammatory changes. Analysis of the patient groups on the basis of the number of EST sessions and the amount of sclerosant injected showed that both histologic changes and dysmotility were more profound in those treated over five times with EST. The differences were significant. Conclusion It appears that EST causes persistent manometric abnormalities and chronic inflammatory changes in the distal esophagus, the severity of which seems to vary directly with the frequency of sclerotherapy and not amount of sclerosant injected.     

Differential reversal of drug-induced small bowel paralysis by cerulein and neostigmine

Objective: Cerulein and neostigmine are prokinetic drugs whose potency and effective dose range are barely known. The aim of this study was to assess their benefit for normal and compromised peristalsis. Design: In vitro, isolated segments of guinea pig small intestine. Setting: University laboratory. Interventions: Small bowel segments were mounted in tissue baths and luminally perfused with Tyrode solution. Test drugs (prokinetic: cerulein, neostigmine; inhibitory: atropine, hexamethonium, epinephrine, sufentanil) were added to the tissue bath. Measurements and results: Peristalsis was quantified via changes in the peristaltic pressure threshold. One-way and two-way analysis of variance (ANOVA) were used for statistical analysis. Cerulein (0.03–100 nM) stimulated normal peristalsis in a concentration-dependent manner and reversed paralysis of peristalsis induced by all inhibitory test drugs to a similar extent. The properistaltic effect of neostigmine was limited to a narrow concentration range (0.03–0.1 µM), whereas concentrations >0.3 µM inhibited peristalsis. Neostigmine more effectively counteracted blockage of peristalsis caused by atropine than that caused by hexamethonium. The inhibitory effects of epinephrine and sufentanil on peristalsis were reversed only at the concentration range of 0.1–0.3 µM neostigmine. Conclusions: Cerulein stimulates normal peristalsis in vitro at a wide concentration range and reverses blockage of peristalsis caused by drugs with a site of action either on the enteric nervous system or intestinal smooth muscle. Neostigmines prokinetic effect, to the contrary, is limited to a small concentration range and best seen when peristalsis is depressed by blockage of cholinergic muscle activation.     

促使剖宫产术后早进食早泌乳的护理研究

目的：为解决剖宫产术后产妇早进食，早泌乳，满足母乳喂养的需要。方法：采用剖宫产术后６ｈ给予口服果导，７ｈ给予流汁饮食，术后１２ｈ进半流质为实验给；并设术后６ｈ给予流汁饮食为对照组１；设术后肛门排气后再进食为对照组２，注意观察各组肠蠕动及泌乳民政部的比较。结果：口服果导组肛门排气时间明显缩短，泌乳时间提前，泌乳量均较对照组明显增加。经统计学自理有显著性差异。结论剖宫产术后适当刺激肠蠕动，对恢复产妇饮     

MR电影对正常小肠运动功能定量评估的应用价值

目的探讨MR电影技术定量评估正常小肠运动功能的可行性。材料与方法运用美国GE公司MR Discovery 750HD 3.0 T扫描仪,采用32通道Body线圈,对2012年10月至2014年3月间44名肠道志愿者进行MR口服造影扫描,在不憋气状态下进行时间为2 min的MR电影序列扫描。将采集的电影图像传送至ADW 4.5工作站,并对每帧图像中左上腹及右下腹两段肠管的肠腔管径进行测量。通过绘制时间-肠腔管径曲线进一步对每段肠管的最大肠腔管径,收缩频率、收缩周期以及间歇期进行测定。结果所有志愿者均完成了检查。一共对86段充盈良好的小肠肠管进行了定量分析。所有肠段均存在间歇期。左上腹及右下腹两段肠管间的最大肠腔管径、收缩频率、收缩周期和间歇期分别为（17.66±2.27）mm、（8.64±0.69）s、（3.03±0.61）min、（54.19±15.10）s和（17.42±1.87）mm、（8.75±0.77）s、（3.86±0.54）min、（47.47±15.82）s。两段肠管间的收缩频率以及间歇期存在统计学差异（P〈0.01）。结论 MR电影能够对正常小肠的蠕动功能状况进行定量评估。理论上在了解正常小肠运动特征的基础上,可以运用MR电影这项无创的检查方法对器质性以及功能性小肠疾病患者异常的小肠运动状况进行进一步的研究。     

Studies on the mechanism of the action of morphine on the peristalsis of guinea pig ileum in situ

Summary The influence of some drugs on the effect of morphine on the threshold pressure required to elicit peristalsis in the guinea pig ileum in situ was studied, in order to test the hypothesis that this effect of morphine is mediated by catecholamine release.Tachyphylaxis to this effect of morphine was confirmed. Pretreatment with two 8 mg/kg doses of reserpine, 24 and 48 hrs before the experiment, significantly reduced the effect of morphine on the pressure threshold. The i.v. administration of 10 mg/kg dl-Dopa re-established the effect of morphine in reserpinized animals to the level of the untreated controls. Pretreatment with guanethidine (15 mg/kg) decreased and even prevented this effect of morphine. Phentolamine pretreatment (10 mg/kg) also significantly inhibited the effect of morphine. Neither DCI nor propranolol influenced this morphine effect. Pretreatment with reserpine, guanethidine or phentolamine reduced the basic pressure threshold needed to elicit peristalsis.The possibility that the decrease of local circulation induced by hypotension would reduce the local concentration of morphine was rejected because the same doses of guanethidine or phentolamine did not modify the effect of hexamethonium given i.v. in this preparation.All these results support the idea that the effect of morphine on intestinal peristalsis is mediated by a catecholamine acting on -receptors, e. g. norepinephrine.     

In vitro evidence for the participation of intestinal opioids in the control of peristalsis in the guinea pig small intestine

Summary The influence of naloxone on the peristaltic reflex of isolated segments of various parts of the guinea pig small intestine was examined. The narcotic antagonist (–)naloxone (2×10^–7M), but not its stereoisomer (+)naloxone, increased the frequency of peristaltic waves in ileal segments by an average of 12%. In addition, it decreased the length and number of peristalsis-free intervals during periods of elevated intraluminal pressure. Thus, it increased over-all-peristaltic-activity by 25–60%, dependent upon intraluminal pressure.Segments from the duodenum and the proximal or distal jejunum displayed no statistically significant increase of peristalsis after naloxone application.Despite differences in over-all-peristaltic-activity, opiate receptor blockade by naloxone induced changes of a comparable magnitude in preparations from both fetal and adult animals. Neither pregnancy nor enforced prolonged work of the isolated segments enhanced the influence of naloxone relative to normal adult animal preparations.It is concluded that intestinal opioids participate in the control of peristalsis in preparations taken from normal animals rather than being activated only in special in vivo or in vitro circumstances such as pregnancy or fatigue, or at a particular phase of life, for example, during fetal stages.     

GABAA- and GABAB-receptor-mediated modification of intestinal motility

The actions of γ-aminobutyric acid (GABA) and its analogues, 3-amino-1-propanesulphonic acid (3APS) and baclofen, have been investigated using isolated segments of the guinea-pig ileum and distal colon. GABA and 3APS, but not baclofen, induced GABA_A-receptor mediated effects; prompt, dose-dependent contractions of the ileum which were antagonised by bicuculline, picrotoxinin, piretanide, tetramethylenedisulphotetramine, atropine and tetrodotoxin. Baclofen and GABA, but not 3APS, induced a dose-dependent GABA_B-receptor mediated depression of electrically elicited twitch contractions of the ileum, unaffected by the GABA_A-receptor antagonists or by antagonism of adenosine, adrenergic, opiate or nicotinic receptors. In the distal colon, baclofen and GABA caused a bicuculline- and picrotoxinin-intensitive depression of spontaneous cholinergic contractions. Desensitization to GABA and baclofen, and cross-desensitization to both agonists was observed. Combined antagonism of GABA_A-receptors and desensitization to baclofen slowed pellet expulsion to the same extent as GABA desensitization alone, indicating that both GABA_A- and GABA_B-receptor sites are involved in this modification of peristalsis by GABA.