氯沙坦联合依那普利对高血压心肌肥厚患者左室舒张功能的影响

目的 观察氯沙坦联合依那普利对高血压心肌肥厚患者左心室舒张功能的影响.方法 采用自身对照设计,36例坚持随访均患者给予氯沙坦50mg/次,每天一次;依那普利10mg/次～20mg/次,每天一次,随访24周,期间比较血压的变化;治疗前后作超声心动图检查,比较心肌厚度及左室舒张功能的改变.结果 与治疗前相比,患者左室后壁舒张末期厚度(LVPWT)、室间隔舒张末期厚度(IVST)、均明显下降(P<0.01);反映左室舒张功能的A/E值亦较治疗前下降(P<0.05);收缩压与舒张压均明显降低(P<0.01). 结论 氯沙坦与依那普利联合用药能有效地控制血压、逆转左室肥厚、改善左心室舒张功能.     

Determinants of the white-coat effect in normotensives and never-treated mild hypertensives

The prognostic significance of the white-coat effect (WCE) is unclear. Knowledge of the predictors of the WCE may help illuminate the clinical significance of this phenomenon. The purpose of this study was to (i) compare characteristics of subjects demonstrating a WCE, those not demonstrating a WCE, and those demonstrating a reverse WCE and (ii) determine clinical features that may influence the size of the WCE. Forty-one subjects with normotension or mild hypertension who had never been treated with antihypertensive medications were recruited for the study. All subjects underwent a battery of anthropometrical measurements and clinic blood pressure (BP) measurements. To calculate arterial compliance, impedance cardiography was used to measure resting stroke volume in each subject. All subjects performed a laboratory mental stress protocol to determine the size of the BP reactivity. Ambulatory blood pressure (ABP) profiles were studied in each subject with the use of an oscillometric ABP recorder. White-coat effect was determined by subtracting the awake period of the ambulatory systolic blood pressure (SBP) from the clinical SBP. Subjects were grouped according to the size of their WCE. Those who showed a WCE of 5 mmHg and above were assigned to the WCE group; those who showed a WCE of between -5 and 5 mmHg were assigned to the no white coat effect (NWCE) group; those who exhibited a WCE of -5 mmHg and lower were assigned to the reverse white-coat effect (RWCE) group. Subjects with a positive WCE had significantly higher body mass index (BMI) than those without a WCE and those with a RWCE. The WCE group had significantly higher clinic SBP and heart rate (HR) than the RWCE group. Arterial compliance was significantly lower in the WCE group as compared to the NWCE group and the RWCE group. The three groups had comparable ABP profiles. In terms of BP variability, the increase in SBP in response to mental stress did not differ among the three study groups nor did the 24-hour and awake BP variability. For the sample as a whole, clinic HR and clinic-ambulatory SBP difference were higher and arterial compliance were lower in women than in men. Furthermore, clinic SBP significantly correlated with the systolic WCE (r = 0.40, P = 0.009). When men and women were analyzed separately, the correlation between clinic SBP and the systolic WCE was significant in women (r = 0.63, P = 0.001) but not in men (P = 0.95). Multiple linear regression showed that sex (P = 0.013) and clinical SBP (P = 0.003) were the only two variables that significantly influenced the systolic WCE. These two variables together accounted for 29% of the variation in the systolic WCE. In conclusion sex and clinic BP are two major determinants of the WCE. The results of this study indicate that WCE is not related to higher stress reactivity or higher BP variability.     

局部亚低温对大鼠脑缺血-再灌注后的神经保护作用

目的探讨脑局部亚低温对脑缺血-再灌注大鼠模型的神经保护作用及其机制。方法健康雄性SD大鼠96只,随机将大鼠分为亚低温组和正常温度组,每组48只。每组中12只用于脑梗死体积的测定;36只用于DNA单链损伤的测定。每组再分为假手术组,缺血3h再灌注0.5、2、8、24、72h亚组,每个亚组6只大鼠。采用线栓法制作大鼠脑缺血-再灌注模型。使用冰帽控制基底核区温度在32～34℃,同时使用电热毯维持肛温在36.5～37.5℃。应用2,3,5-氯化三苯基四氮唑(TTC)染色测定脑梗死体积;观察再灌注72h两组大鼠存活率;行DNA多聚酶Ⅰ介导的生物素偶联腺嘌呤脱氧核苷酸的缺口平移标记(PANT)染色,检测DNA单链损伤。结果①生理学指标:亚低温组及正常温度组血糖、血压及血气差异无统计学意义。②72h生存率:亚低温组再灌注72h大鼠的生存率为92%,正常温度组为58%(χ2=6.75,P=0.027)。③梗死体积:亚低温组总的脑梗死体积,脑皮质、基底核区梗死体积分别为(61±28)、(20±17)、(42±14)mm3;正常温度组为(240±55)、(163±41)、(77±17)mm3,两组比较,总的脑梗死体积(P<0.05),皮质、基底核区脑梗死体积,差异均有统计学意义(P<0.01)。④DNA氧化损伤:PANT染色阳性细胞数于再灌注0.5h开始出现,亚低温组和正常体温组分别为(20±7)、(44±4)个/高倍视野(P<0.05);24h达高峰,亚低温组和正常体温组分别为(44±9)、(133±12)个/高倍视野(P<0.01)。亚低温可以减轻所有时间点的PANT染色阳性细胞数。结论局部亚低温可降低大鼠缺血-再灌注脑损伤,其机制可能与减轻缺血后DNA氧化损伤有关。     

亚低温对局灶性脑缺血治疗时间窗的实验研究进展

脑血管病是严重威胁人类生命健康的临床常见病，而缺血性脑血管病占其中的70％，大脑中动脉阻塞（MCAO）是临床上常见的局灶性脑缺血性疾病。目前，对于急性MCAO的治疗已经由单纯的药物治疗发展成为神经介入和（或）药物联合治疗。由于急性脑缺血再通后可以级联一系列再灌注损伤，因此，进行MCAO的动物实验研究具有现实的临床意义。什么时间内实施亚低温治疗才能起到最大限度的神经保护作用，这涉及到亚低温治疗的时间窗问题。作者对亚低温局灶性脑缺血治疗时间窗的实验研究及临床应用前景综述如下。     

脑温对大脑灶性脑缺血再灌注损伤的影响

目的 研究预高温和缺血时轻度高温、亚低温对脑缺血再灌注损伤组织脂质过氧化和缺血脑组织病变的影响。方法 75只Wistar大鼠按不同脑温和缺血条件被随机分为生化组（5组，n=7)和病理组（5组，n=8),采用Nagasawa脑缺血模型，观察脑缺血再灌注损伤组织超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH－Px)、还原型谷胱甘肽（GSH）、丙二醛（MDA）及缺血脑组织病理变化。结果 轻度高温加重常温脑缺血组织SOD、GSH的降低和MDA的增高，使GSH－Px呈降低趋势，而亚低温相反；预高温对常温脑缺血各项指标影响不显。轻度高温组脑缺血病理损伤最重，亚低温和预高温有改善脑缺血损伤的作用。结论 高温加重而亚低温抑制脑血损伤，分别与其增加或减少内源性抗氧化酶消耗、降低或增强缺血脑组织清除氧自由基的能力有关；预高温对缺血脑组织有保护作用，未能肯定此作用与内源性抗氧化酶消耗减少和缺血脑组织清除氧自由基的能力增强有关。     

脑温对大鼠灶性脑缺血再灌注损伤的影响

目的　研究预高温和缺血时轻度高温、亚低温对脑缺血再灌注损伤组织脂质过氧化和缺血脑组织病变的影响。方法　 75只Wistar大鼠按不同脑温和缺血条件被随机分为生化组 (5组 ,n=7) 和病理组 (5组 ,n=8) ,采用Nagasawa脑缺血模型 ,观察脑缺血再灌注损伤组织超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH Px)、还原型谷胱甘肽 (GSH)、丙二醛 (MDA)及缺血脑组织病理变化。结果　轻度高温加重常温脑缺血组织SOD、GSH的降低和MDA的增高 ,使GSH Px呈降低趋势 ,而亚低温相反 ;预高温对常温脑缺血各项指标影响不显著。轻度高温组脑缺血病理损伤最重 ,亚低温和预高温有改善脑缺血损伤的作用。结论　高温加重而亚低温抑制脑缺血损伤 ,分别与其增加或减少内源性抗氧化酶消耗、降低或增强缺血脑组织清除氧自由基的能力有关 ;预高温对缺血脑组织有保护作用 ,未能肯定此作用与内源性抗氧化酶消耗减少和缺血脑组织清除氧自由基的能力增强有关     

The effect of diet on simvastatin and losartan enhancement of endothelial function

Patients with hypertension take antihypertensive agents and cholesterol-lowering drugs; however, few studies describe the effects of the interaction of antihypertensive agents with statins. Therefore, the purpose of this study was to characterize the effects of losartan, simvastatin, and their combination on the progression of hypertension in the spontaneously hypertensive rats (SHRs). Also, we determined whether diet influenced the drug responses. Rats were fed three different diets - low-salt (LS), high-salt (HS), and lipid-rich (LR) - and treated with either no drug (control), losartan (LOS, 10 mg/kg/day), simvastatin (SIM, 2 mg/kg/day) or LOS combined with SIM for four weeks. After four weeks on the diets, systolic blood pressure rose in all groups and remained elevated. Treatment with LOS alone or in combination with SIM reduced BP in the rats fed the LS and HS diet, respectively. Furthermore, LOS alone increased NO in the LS and LR groups; however, LOS combined with SIM completely abolished this rise in NO in LS group. Plasma PGI2 and TXA2 levels were increased in the presence of SIM alone; however LOS combined with SIM completely blocked SIM-induced increases in PGI2 and TXA2. Kidney levels of angiotensin II were higher in the LS group and significantly increased in the HS group following treatment with LOS alone. However, kidney aldosterone levels were significantly reduced in the presence of LOS in the HS group. Total cholesterol, LDL cholesterol, and triglycerides were significantly higher in the LR group. Together, these data suggest a contribution of endogenous NO and PGs in the antihypertensive effect of LOS and SIM that may be affected by the type of diet.     

早期肠内营养支持对急性期卒中患者免疫功能的影响

目的探讨早期肠内营养支持对急性期卒中患者免疫功能的影响。方法选择卒中急性期伴吞咽障碍患者49例,随机分为研究组24例和对照组25例,于入院后72 h内分别给予鼻饲肠内营养支持和普通鼻饲饮食。两组患者分别于入院第1、7及21天测定总淋巴细胞计数(TLC)、免疫球蛋白A(IgA)、G(IgG)、M(IgM)及补体C3、C4含量。并观察营养指标的变化以及感染并发症的发生率。结果21 d后研究组TLC[(2.1±0.4)×109/L]、IgA[(2.7±0.5)g/L]、IgG[(11.1±2.2)g/L]、IgM[(1.7±0.7)g/L]和补体C3[(1.2±0.2)g/L]水平显著高于对照组TLC[(1.7±0.4)×109/L,P<0.05]、IgA[(2.0±0.4)g/L,P<0.01]、IgG[(8.9±2.5)g/L,P<0.01]、IgM[(1.3±0.6)g/L,P<0.05]和补体C3[(1.0±0.3)g/L,P<0.01]。研究组感染并发症发生率(29.2%)显著低于对照组(60.0%,P<0.05)。研究组的营养指标亦显著优于对照组。结论早期肠内营养支持可改善急性期卒中患者机体的免疫功能,降低感染并发症的发生率。     

脑卒中早期认知功能与BEAM、CT改变关系分析

急性脑血管病 (ＡＣＶＤ)患者认知障碍 (ＣＤ)是血管性痴呆 (ＶＤ)的早期阶段 ,其临床表现隐匿 ,如及早接受治疗 ,可延缓病情进展。本研究收集 1996 - 0 8～ 1998- 12医院住院的ＡＣＶＤ患者 ,了解ＡＣＶＤ患者早期认知障碍与脑电地形图 (ＢＥＡＭ )、ＣＴ改变的关系。1　资料与方法1 1　一般资料　所有患者均为首次发病 7ｄ以内ＡＣＶＤ住院患者 ,经ＣＴ或ＭＲＩ证实 ,发病前无明显认知及心理异常 ,排除受教育年限 1年以下及发病后有明显失语、意识障碍而不能配合量表检查者。共 84例 ,男性 5 8例 ,女性2 6例 ,平均年龄 (6 7 8± 8 6 )岁。…     

亚低温联合升压对大鼠局灶脑缺血再灌注后血脑屏障、脑组织水含量的影响

目的探讨升压联合亚低温治疗局灶性脑缺血再灌注损伤的可行性及效果。方法取64只大鼠制作局灶性脑缺血再灌注模型,随机分为对照组、升压组、亚低温组及升压联合亚低温治疗组(联合组)。对照组不予处理,后三组分别予升压治疗、亚低温治疗及升压加亚低温联合治疗;观察各组治疗后神经功能缺失评分、血脑屏障破坏情况和脑组织水含量。结果升压组、亚低温组及联合组神经功能缺失评分、Even's蓝染色体积均明显低于对照组(P分别<0.05、<0.01);联合组Even's蓝染色体积小于升压组和亚低温组(P均<0.05),升压组、亚低温组和联合组脑组织水含量均明显低于对照组(P均<0.05)。结论升压和亚低温能明显减轻局灶性脑缺血再灌注后大鼠血脑屏障破坏和脑水肿,联合应用作用更强。     

亚低温对局灶性脑缺血保护作用实验条件的研究进展

目前,已经证实亚低温对脑外伤、脊髓损伤和全脑缺血具有保护作用,其对大脑中动脉阻塞（MCAO）的神经保护作用也受到广泛关注,而实验条件直接影响到实验结果的可信性和科学性.     

原花青素对大鼠局灶性脑缺血的保护作用

目的探讨原花青素对大鼠局灶性脑缺血的保护作用及其机制。方法选用健康SD大鼠30只,随机分为假手术组、缺血对照组和原花青素100mg/kg组、200mg/kg组及400mg/kg组,共5组,每组6只大鼠。进行神经功能评分,并断头取脑,制备脑组织匀浆,检测超氧化物歧化酶(SOD)活性和丙二醛含量。结果原花青素100mg/kg组和200mg/kg组的SOD活性分别为(54.0±2.8)NU/mg和(52.7±2.2)NU/mg,与缺血对照组(46.2±1.8)NU/mg比较差异有显著性(P<0.01);原花青素100mg/kg组和200mg/kg组丙二醛含量分别为(1.15±0.17)μmol/g和(1.17±0.14)μmol/g,与缺血对照组(1.54±0.18)μmol/g比较,差异有显著性(P<0.01)。结论原花青素对局灶缺血性脑损伤具有保护作用,其机制可能与其抗氧化活性和自由基作用有关。     

氯沙坦治疗不同时期慢性肾功能衰竭大鼠的研究

目的　探讨血管紧张素Ⅱ受体拮抗剂氯沙坦对不同时期慢性肾功能衰竭肾小球硬化进程的作用。方法　采用单侧肾摘除加重复静脉注射阿霉素慢性肾功能衰竭大鼠模型 ,将动物分为正常对照组 (N组 )、慢性肾衰疾病组 (D组 )、氯沙坦早期治疗组 (ET组 )及氯沙坦晚期治疗组(LT组 )。检测各组大鼠的血尿素氮 (BUN)、血肌酐 (Scr)、2 4小时尿蛋白排泄率 (TP/2 4h)、平均动脉压 (MAP)以及肾小球平均截面积和平均体积。采用免疫组织化学方法检测肾组织内转化生长因子 β(TGF β)和细胞外基质成分纤维连接蛋白 (FN )的表达。 结果　ET组大鼠BUN、Scr、TP/2 4h、MAP以及肾小球平均截面积和平均体积均显著低于D组和LT组 (P <0 .0 5 ) ,肾组织TGF β和FN表达明显减少 ;LT组各项生化指标水平、MAP、TGF β和FN表达较D组明显下降 (P <0 .0 5 ) ,但程度远不如ET组显著 ;肾小球平均截面积和平均体积虽较D组有所下降 ,但差异无显著性。结论　早期给予氯沙坦治疗能有效抑制TGF β表达 ,延缓慢性肾衰肾小球硬化的进程 ,晚期氯沙坦治疗也能一定程度地改善肾脏组织形态学改变 ,但效果远不如早期治疗     

The effect of potassium and potassium plus magnesium supplementation on ventricular extrasystoles in mild hypertensives treated with hydrochlorothiazide

Eleven mild hypertensives with base-line ventricular extrasystoles underwent a 24-week period of treatment with hydrochlorothiazide 50 mg daily. After 8 weeks of treatment either potassium as hydrochloride 1 g twice daily, or a combination of potassium hydrochloride 1 g and magnesium hydroxide 500 mg twice daily was added to the diuretic therapy in a randomised, double-blind, cross-over design. Each treatment period lasted 8 weeks. Supplementation with potassium or potassium plus magnesium resulted in a clear trend for suppression of ventricular ectopic activity. There was no difference in ventricular extrasystoles between the two supplementation groups. Supplementation with potassium plus magnesium but not with potassium only, resulted in a significant rise in serum potassium values (P less than 0.01). Our study suggests that potassium should be supplemented in thiazide-treated hypertensives who are prone to develop ventricular extrasystoles. Addition of magnesium to potassium supplementation does not result in further improvement in ventricular ectopic suppression.     

Circulating reticulated platelets in the early and late phases after ischaemic stroke and transient ischaemic attack

The percentage of reticulated platelets (% RP) could be a useful marker of increased platelet production and/or turnover in patients with increased platelet activation, but few flow cytometric studies have measured the % RP in patients with ischaemic cerebrovascular disease (CVD). Whole blood flow cytometry using thiazole orange was performed to compare the % RP in patients in the early (1-27 d, n = 79) and late phases (79-725 d, n = 70) after ischaemic stroke or transient ischaemic attack (TIA) with controls without CVD (n = 27). The impact of aspirin dose escalation (75-300 mg/d) on the % RP was investigated in 10 patients in the late phase after stroke/TIA. The platelet count and mean platelet volume (MPV) were similar in CVD patients and controls. Compared with controls, the unadjusted % RP was not significantly higher in early or late phase CVD patients (P < or = 0.3). However, having adjusted for age, the % RP was higher in early (P = 0.047) and late phase CVD patients (P = 0.01). There was a positive correlation between % RP and MPV in EDTA- and citrate-anticoagulated blood in both early and late phase CVD patients (P< or = 0.01). The % RP was not significantly influenced by aspirin dose. These data do not convincingly support an excessive stimulus to platelet production in the early or late phases after ischaemic stroke/TIA, but are consistent with the hypothesis that reticulated platelets are larger than more mature 'non-reticulated' platelets in ischaemic CVD.     

Limitations of transoesophageal echocardiography in patients with focal cerebral ischaemic events.

OBJECTIVE--To investigate the detection rate of cardiac sources of embolism by transoesophageal echocardiography in patients with focal cerebral ischaemic events and to relate the echocardiographic findings to other clinical findings. DESIGN--Prospective study with blinded analysis of the echocardiographic data and subsequent comparison with the other clinical findings. SETTING--Regional cardiothoracic unit based in a teaching hospital. PATIENTS--131 consecutive patients with focal ischaemic cerebral events (49 with a transient ischaemic attack, 77 with a cerebrovascular accident, and five with a retinal arterial embolus) referred for echocardiography. INTERVENTIONS--Full M mode, cross sectional, Doppler, and contrast echocardiography by both the precordial and transoesophageal techniques. RESULTS--Precordial echocardiography detected a cardiac abnormality in 72 patients. Transoesophageal echocardiography confirmed all the precordial findings (except left ventricular hypertrophy, which at present cannot be defined with this technique) and detected other abnormalities in a further 20 patients (18 with potential right-to-left shunts and two with valve vegetations). It also showed spontaneous contrast echoes in 27 of 28 patients with a large left atrium and showed atrial thrombus in three. Cardiac abnormalities were clinically detected in 53 patients, all of which were confirmed or documented by echocardiography. In the 78 patients with no clinically detectable cardiac abnormality six had mitral valve prolapse and one had a regional wall motion defect (identified by precordial echocardiography) and 17 had potential right-to-left shunts (11 of which were identified only by transoesophageal echocardiography). CONCLUSIONS--Transoesophageal echocardiography is more sensitive than precordial echocardiography in detecting potential sources of embolism in these patients. However, except for the detection of a potential right-to-left shunt, the yield in patients with no cardiac abnormality is low. Moreover, the abnormalities detected in those with previously detected cardiac disease merely confirm the clinical diagnosis. Patients with left atrial spontaneous contrast echoes may benefit from anticoagulation but this requires further study. Until more data are available on this feature and on the role of potential right-to-left shunts in this population, the contribution of echocardiography, precordial or transoesophageal, remains limited.