单纯收缩期高血压病人年龄与血管内皮功能对大动脉僵硬度的影响

目的探讨单纯收缩期高血压(ISH)患者大动脉僵硬度与年龄、血管内皮功能之间的关系。方法对老年单纯收缩期高血压病人71例,进行大动脉僵硬度(主动脉脉搏波传导速度,baPWV)和内皮依赖性血管舒张功能(FMD)检测。同期年龄配对的健康老年人30例和健康中年人50例作为对照组。结果老年单纯收缩期高血压组、老年健康组、中年健康组 baPWV 依次减慢[老年 ISH:(2459.2±436.8)比老年健康:(2097.2±315.7)比中年健康:(1619.7±214.2)cm/s,P<0.01或<0.05),而 FMD 则依次增大(老年 ISH:6.2±2.2比老年健康:9.8±2.5比中年健康:14.4±1.9,P<0.05或<0.01)。在老年单纯收缩期高血压组中,baPWV 与 FMD呈显著性负相关、与收缩压(SBP)、脉压(PP)呈显著性正相关。多元逐步回归分析证明:年龄、FMD、SBP、PP 是大动脉僵硬度的危险因素。结论在老年单纯收缩期高血压病人中增龄与 FMD 失调明显增加了大动脉僵硬度,因此,在控制 ISH 的同时,改善 FMD 可以降低大动脉僵硬度,从而进一步降低心血管事件的风险。     

右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响

目的　探讨右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响及其机制。方法　对比分析左冠状动脉狭窄患者在合并与不合并右冠状动脉病变时的左心室射血分数。结果　与相应部位单纯左冠状动脉狭窄患者相比 ,合并右冠状动脉病变患者左心室射血分数均呈不同程度地下降 ,其中在左前降支、左前降支 +左回旋支狭窄基础上合并右冠状动脉病变时左心室射血分数下降有统计学意义 (P <0 .0 5或 0 .0 1) ,左主干合并右冠状动脉狭窄患者下降幅度最大 ,但无统计学意义。结论　右冠状动脉病变可在单纯左冠状动脉狭窄的基础上使左心室收缩功能进一步恶化 ;当左冠状动脉狭窄部位为左前降支、左主干或左前降支 +左回旋支时 ,对左心室收缩功能影响更为严重     

Haloperidol affects coupling between QT and RR intervals in guinea pig isolated heart

Prolonged QT interval is an independent risk factor for development of ventricular arrhythmias. Haloperidol is one of the drugs inducing QT prolongation. Previous studies showed that haloperidol affects not only QT duration but also heart rate (RR interval). The present work focused on relationship between QT and RR and its changes under acute and chronic haloperidol administration. The study included 14 male guinea pigs divided into control and haloperidol-treated group. After 21-days administration of haloperidol or vehiculum, electrograms in isolated hearts were recorded. QT/RR and dQT/dRR coupling were calculated. Chronic haloperidol administration significantly decreases the coupling between QT and RR. Acute haloperidol exposure significantly decreases the dQT/dRR coupling in both treated and untreated guinea pig hearts. Flatter QT/RR relationship reveals a lack of QT adaptation to increased heart rate. It should be emphasized that in such situation ECG recording will not show significant QT prolongation evaluated according to clinical rules. However, if QT interval does not adapt to increased heart rate sufficiently, the risk of ventricular arrhythmias may be increased despite practically normal QT interval length. The results are supported by findings in biochemical analyses, which proved eligibility of the used model.     

川芎嗪对离体豚鼠气道平滑肌的效应及机制研究

目的：探讨川芎嗪( ligustrazine,LIG)对离体豚鼠气道平滑肌( airway smooth muscle,ASM)的效应及机制。方法取正常豚鼠支气管,制作成气管螺旋条,随机分成LIG组、LIG+普萘洛尔组、LIG+阿托品组、LIG+硝苯地平组、LIG+格列苯脲组、对照组。分别观察ASM在静息张力下以及组胺所致的高张力下,各组不同LIG浓度对ASM的效应并比较各组间ASM舒张率。结果(1) LIG对离体豚鼠ASM静息张力以及组胺所致的高张力均具有舒张作用。(2)离体豚鼠ASM在静息张力下,与LIG组比较,LIG+普萘洛尔组在LIG浓度10-7~10-6．5 mol/L时,舒张作用明显受到拮抗( P <0．05)。 LIG +阿托品组、LIG+格列苯脲组在LIG浓度10-7．5~10-3 mol/L时,舒张作用没有明显差别(P>0．05)。 LIG+硝苯地平组在LIG浓度10-6~10-4 mol/L时,舒张作用明显加强( P<0．05)。(3)离体豚鼠ASM在组胺所致的高张力下,与LIG组比较,LIG+普萘洛尔组在LIG浓度10-6.5~10-5 mol/L时,舒张作用明显受到拮抗( P<0．05);LIG+阿托品组、LIG+格列苯脲组在LIG浓度10-8~10-3 mol/L时,舒张作用没有明显差别( P>0．05);LIG+硝苯地平组在LIG浓度10-6.5~10-5 mol/L时,舒张作用明显加强(P<0．05)。结论 LIG可对离体豚鼠ASM静息张力以及组胺所致的高张力产生明显的舒张作用,其效应的产生可能与竞争性激动β2受体以及抑制Ca2+内流有关,这为临床应用川芎嗪治疗支气管哮喘提供了理论依据。     

Mechanical intestinal obstruction due to isolated diffuse venous malformations in the gastrointestinal tract: A case report and review of literature

BACKGROUND Isolated gastrointestinal venous malformations(GIVMs)are extremely rare congenital developmental abnormalities of the venous vasculature.Because of their asymptomatic nature,the diagnosis is often quite challenging.However,as symptomatic GIVMs have nonspecific clinical manifestations,misdiagnosis is very common.Here,we report a case of isolated diffuse GIVMs inducing mechanical intestinal obstruction.A literature review was also conducted to summarize clinical features,diagnostic points,treatment selections and differential diagnosis in order that doctors may have a comprehensive understanding of this disease.CASE SUMMARY A 50-year-old man presented with recurrent painless gastrointestinal bleeding for two months and failure to pass flatus and defecate with nausea and vomiting for ten days.Digital rectal examination found bright red blood and soft nodular masses 3 cm above the anal verge.Computed tomography showed that part of the descending colon and rectosigmoid colon was thickened with phleboliths in the intestinal wall.Colonoscopy exhibited bluish and reddish multinodular submucosal masses and flat submucosal serpentine vessels.Endoscopic ultrasonography showed anechoic cystic spaces within intestinal wall.The lesions were initially thought to be isolated VMs involving part of the descending colon and rectosigmoid colon.Laparoscopic subtotal proctocolectomy,pullthrough transection and coloanal anastomosis and ileostomy were performed.Histopathology revealed intact mucosa and dilated,thin-walled blood vessels in the submucosa,muscularis,and serosa involving the entire colorectum.The patient recovered with complete symptomatic relief during the 52-mo follow-up period.CONCLUSION The diagnosis of isolated GIVMs is challenging.The information presented here is significant for the diagnosis and management of symptoms.     

Comparison of vasoconstrictor actions of norepinephrine and potassium chloride before and after damage of endothelium by saponin

Summary Using isolated and perfused mesenteric arterial preparations of dogs, vasoconstrictor responses to intraluminal norepinephrine and potassium chloride were investigated in the presence and absence of the endothelium. Intraluminal administration of saponin readily removed the endothelium. Saponin (1–3 mg) caused an increase in perfusion pressure, and then approximately 20 min later perfusion pressure became stable at a somewhat higher level than that of the control. A larger dose of saponin (10 mg) caused a tremendous but temporary increase of perfusion pressure. KCl-induced vasoconstriction was significantly enhanced by pretreatment with 0.3, 1, and 3 mg saponin, but norepinephrine-induced constriction was not modified significantly. Moreover, it was demonstrated that diltiazem, a potent Ca antagonist, inhibited the KCl-induced vasoconstriction more readily in the absence than in the presence of the endothelium.     

Pharmacological analysis of positive chronotropic and inotropic responses to etilefrine in isolated dog heart preparations

Summary Positive chronotropic and inotropic responses to etilefrine (-[(ethylamino)methyl]-m-hydroxybenzyl alcohol), an orally active cardiovascular agent, were investigated in isolated dog right atrial and left ventricular preparations. Intravenous administration of etilefrine to a support dog increased heart rate and mean systemic blood pressure, and increased sinus rate and atrial contractile force in the isolated right atrium perfused with blood from the support dog. Etilefrine injected intra-arterially to isolated atria and ventricles induced dose-dependent positive chronotropic and inotropic effects. Etilefrine was about 100 times less potent than isoproterenol. The effects of etilefrine in isolated atria were significantly inhibited by treatment with atenolol, but were not significantly inhibited by ICI 118,551. The effects of etilefrine were partially inhibited by imipramine. These results indicate that etilefrine is a highly selective -1 adrenoceptor agonist and suggest a moderate catecholamine-releasing activity by tyramine-like action in the blood-perfused dog heart.     

Sarcoplasmic Reticulum Function in Murine Ventricular Myocytes Overexpressing SR CaATPase

To examine the effects of the overexpression of sarcoplasmic reticulum (SR) CaATPase on function of the SR and Ca²⁺homeostasis, we measured [Ca²⁺]_itransients (fluo-3), and L-type Ca²⁺currents (I_Ca,L), Na/Ca exchanger currents (I_Na/Ca), and SR Ca²⁺content with voltage clamp in ventricular myocytes isolated from wild type (WT) mice and transgenic (SRTG) mice. The amplitude of [Ca²⁺]_itransients was insignificantly increased in SRTG myocytes, while the diastolic [Ca²⁺]_itended to be lower. The initial and terminal declines of [Ca²⁺]_itransients were significantly accelerated in SRTG myocytes, implying a functional upregulation of the SR CaATPase. We examined the functional contribution of only the SR CaATPase to the initial and the terminal phase of the decline of [Ca²⁺]_i, by abruptly inhibiting Na/Ca exchange with a rapid switcher device. The rate of [Ca²⁺] decline mediated by the SR CaATPase was increased by 40% in SRTG compared with WT myocytes. The function of the L-type Ca²⁺channel was unchanged in SRTG myocytes, while INa/Ca density was slightly (10%) decreased. Measured SR Ca²⁺content was significantly increased by 29% in SRTG myocytes. Thus, overexpression of SR CaATPase markedly accelerates the decline of [Ca²⁺]_itransients, and induces an increase in SR Ca²⁺content, with some downregulation of the Na/Ca exchanger.     

Clinical significance of isolated mega cisterna magna

Objective The prevalence and clinical significance of isolated mega cisterna magna in both fetuses and adults is not yet well defined. It is therefore difficult to provide reliable parental counseling in cases of a fetal sonographic diagnosis of this anomaly. The aim of the present study was to, determine the cognitive profile of adults with isolated mega cisterna magna. Methods We reviewed 19,301 consecutive CT/MRI of the brain. Isolated mega cisterna magna was observed in 49 cases. A battery of neuropsychological tests was performed in 18 adults with this anomaly and in 18 controls who had no brain anomaly on CT/MRI. Results Subjects with isolated mega cisterna magna had a lower performance on memory tasks [RAVLT saving score (0.8 ± 0.2 vs. 1.02 ± 0.2, P = 0.003)] and verbal fluency [phonemic fluency (9.4 ± 4.5 vs. 13.6 ± 5.3, P = 0.02), semantic fluency (19.8 ± 5.8 vs. 24.4 ± 7.5, P = 0.05)]. They did not differ from controls in regard to the Raven similarity tests indicating that this brain anomaly is not associated with impairment of general cognitive abilities. Conclusion Adults with isolated mega cisterna have an overall normal cognitive functioning but may score inferior to controls on some parameters of memory and verbal fluency. Although application of adult cases to the fetuses is not well established, this information might be of value in parental counseling in cases of a fetus with this anomaly.