Impact and Predictors of Noncircular Left Ventricular Outflow Tract Shapes on Estimating Aortic Stenosis Severity by Means of Continuity Equations

Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm²) was underestimated by the standard method (1.05 ± 0.47 cm²; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index.     

Predictors of gastric emptying in Parkinson''s disease

Predictors of gastric emptying (GE) in patients with idiopathic Parkinson's disease (PD) of a solid and liquid meal are not well defined. For measurement of GE 80 patients with PD were randomly assigned to receive either a solid meal (250 kcal) containing 13C-octanoate (n = 40) or a liquid meal (315 kcal) with 13C-acetate (n = 40). All patient groups were off medication affecting motility and were matched for age, gender, body mass index, disease duration and severity, using Unified Parkinson's Disease Rating Scale (UPDRS). Gastric emptying was compared with a healthy control group (n = 40). Multiple regression analysis was used to determine predictors of gastric emptying. Exactly 88% and 38% of PD patients had delayed GE of solids and liquids respectively. Solid and liquid emptying was similar in women and men. There were no differences in GE in PD patients < 65 years of age when compared with patients > or = 65 years. Multiple regression analysis showed that motor handicaps such as rigour and action tremor are independent predictors of solid GE (r = 0.68, P < 0.001). The severity of motor impairment, but not any other neurological symptom, as assessed by UPDRS is associated with gastroparesis in PD and solid emptying is more likely to be delayed.     

European Committee on Antimicrobial Susceptibility Testing (EUCAST) Technical Notes on antimicrobial susceptibility testing

The main objectives of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are to harmonise breakpoints for antimicrobial agents in Europe, and to act as the breakpoint committee for the European Medicines Agency (EMEA) during the registration of new antimicrobial agents. Detailed EUCAST procedures for harmonising and setting breakpoints for antimicrobial agents are available on the EUCAST website. Beginning with the current issue, a series of EUCAST Technical Notes will be published in CMI, based on the rationale documents produced by EUCAST for each of the antimicrobial agents studied, with the aim of highlighting important background information underlying decisions on breakpoints made by EUCAST.     

COPD机械通气病人下呼吸道感染致病菌分布特点

①目的 探讨慢性阻塞性肺病(COPD)病人机械通气后下呼吸道感染致病菌的特点。②方法 取32例COPD并发呼吸衰竭行机械通气病人下呼吸道分泌物做痰细菌学培养，同时做药物敏感试验。③结果 32例病人共分离出菌株76株，阳性率71．7％，其中混合感染10例次。其中革兰阴性杆菌(GNB)58株，占76．3％；阳性球菌10株，占13．2％；真菌8株，占10．5％。常见致病菌以铜绿假单胞菌、鲍曼不动杆菌和肺炎杆菌为主，GNB中铜绿假单胞菌和不动杆菌的耐药率高。④结论 COPD应用机械通气病人下呼吸道感染以革兰阴性杆菌为主，耐药性高。     

茶色素对冠心病及高血压病病人血小板功能的影响

目的：探索茶色素对冠心病、高血压病病人血小板功能的影响。方法：冠心病病人３６例（男性２１例，女性１５例；年龄６４±ｓ４ａ）；高血压病病人３０例（男性１８例，女性１２例；年龄５８±８ａ）。采用茶色素２５０ｍｇ，ｐｏ，ｔｉｄ，３０ｄ为一个疗程。结果：治疗后ＴＸＢ２下降，６－ｋｅｔｏ－ＰＧＰ１α上升，ＴＸＢ２／６－ｋｅｔｏ－ＰＧＦ１α比值下降（Ｐ＜０．０１或Ｐ＜０．０５），ＧＭＰ－１４０下降（Ｐ＜０．０５），ＰａｇＴ，ＰａｄＴ下降（Ｐ＜０．０５）。结论：茶色素具有降低血小板表面活性作用，抑制血小板聚集和粘附，抗血栓形成，改善微循环，对冠心病和高血压病病人起到积极的防治作用。     

An alternative method for significance testing of waveform difference potentials

Guthrie and Buchwald (1991) proposed an ad hoc procedure for assessing the statistical significance of waveform difference potentials that may arise in a variety of psychophysiology research contexts. In our paper, an alternative method is presented and demonstrated that has fewer underlying assumptions than does the Guthrie-Buchwald test and may, therefore, produce better results in some situations. In particular, the test proposed here (a) is distribution free, (b) requires no assumption of an underlying correlation structure (e.g., first-order autoregressive), (c) requires no estimate of the population autocorrelation coefficient, (d) is exact, (e) produces p values for any number of subjects and time points, and (f) is highly intuitive as well as theoretically justifiable. This procedure may be used to carry out multiple comparisons with exact specification or experimentwise error, however, this test is based on permutation principles and may require large amounts of computer time for its implementation.     

Diagnosis and treatment of thoracic outlet syndrome

Patients who develop symptoms of thoracic outlet syndrome (TOS) have a predisposing anatomic abnormality. In most patients with TOS, the symptoms are caused by entrapment of the brachial plexus and they do not arise from compression of the subclavian artery, as was previously thought. The tests advocated for diagnosing this common syndrome (i.e., evaluating the positional compression of the artery when the arms are raised, the neck is turned, or the shoulders are braced) cannot accurately diagnose this syndrome. There are two reasons for this. The symptoms of TOS are not related to the compression of the artery in the outlet in 98% of patients, and 75% of normal individuals without symptoms show diminished radial pulse on various provocation tests. We employed four timed provocation tests (minute tests) to diagnose TOS: the timed Morley test, timed Wright test, timed Eden test, and elevated arm stress exercise, all of which are very sensitive. In normal individuals without symptoms, 20% experience transitional symptoms such as slight pain and tiredness, on these tests indicating a subclinical state. TOS is treated by keeping the thoracic outlet wide, this being done either conservatively or surgically. In 1993 and 1994, we conservatively treated 418 of 422 patients with TOS by means of active exercise, a brace, and by block therapy. These measures did not reduce the symptoms in 23 of these patients, so surgical treatment was indicated. In the remaining 4 of the 422 patients, conservative treatment was not indicated and surgery was performed directly. All the patients showed significant clinical improvement of varying degree. Presented at the 69th Annual Meeting of the Japanese Orthopaedic Association, Tokyo, April 12, 1996     

测定血清及尿β2微球蛋白评估健康老年人肾功能的价值

测定72例健康老年人（60-84岁）和65例健康青中年人（20-50岁）血清和尿β2微球蛋白（β2m)，发现前血清β2m浓度比后明显增高（p<0.001)；老年组≥70岁尿液β2m浓度也明显增高（p<0.05)。结果表明肾小球滤过率下降随年龄增长而降低，以后再出现肾小管功能减退。本试验较血清尿素氮、肌酐和内生肌酐清除率测定更为敏感。     

XD—1型微电脑程序刺激器在心血管病中的临床应用

本文应用XD—Ⅰ型微电脑程序刺激器检查26例患者,在窦房结功能检查中测定了窦房结恢复时间、窦房传导时间及固有心率;在房室传导功能的估计中测定了文氏点,2∶1阻滞点及房室结的有效不应期;在室上性心动过速中测定了旁路不应期,房室结双通道,折返区及折返性心动过速区;还进行了心脏负荷试验及右束支不应期等方面的测定。并就其方法,判断标准及临床意义等分别作了讨论。     

久泻宁动物毒性试验研究

目的 （1）观察久泻宁一日内小鼠灌胃1～3次后的毒性反应和死亡情况，测定最大耐受量；（2）观察久泻宁给大鼠连续灌胃3个月，对机体产生的毒性反应、严重程度及可逆性，确定无毒剂量。为人拟用量提供参考。方法 （1）久泻宁小鼠灌胃，一日2～3次，观察急性毒性反应．测定最大耐受量；（2）久泻宁高、中、低三个剂量组和一个对照组，大鼠连续灌胃3个月，观察外观行为和体质量变化。试验期结束。每组取1/2动物活杀。检测血常规、血液生化、病理组织；1／2动物停药进行3周的恢复期观察后。同法检测上述指标。结果 久泻宁小鼠灌胃给药的最大耐受药量为750g／kg（含生药）。相当临床日拟用量（2．5g／kg）的300倍；大鼠连续3个月灌胃给药的无毒剂量为125g／kg（含生药）．相当临床拟用量50倍。结论 久泻宁无明显毒性，安全范围大。临床日拟用量2.5g／kg、疗程1个月是安全的。