效度概念新认识

本文主要讨论了效度概念的演变和存在的问题、效度概念新认识及如何寻找效度三个问题。效度概念的发展从内容效度、预测效度、构想效度和同时效度并存发展到现在由构想效度涵盖了其它所有效度。但一直以来,把效度概念作为一个法理学网络来理解,造成了我们对效度概念理解的很多误区。事实上效度概念是一种本体论的观点,重视现实参照并依据因果关系。我们应该通过建立一个理论假设、形成一个测验和确定测量的属性来寻找效度。     

Quantitative trait locus mapping: fishing strategy or replicable results?

Genomewide scan, as shown by recently published linkage studies on the behavior of mice or in psychiatry, provides evidence for replicated quantitative trait loci (QTL). Several studies of Alzheimer's disease have demonstrated the promise of moving from clinical diagnoses to biological signs for psychiatric investigations. Empirical studies also demonstrate that genetic background, differences in environment, epistatic effects, and definition of the phenotype (including psychiatric diagnosis) all actively contribute to limit the duplication of QTL.     

Serotonin antagonists and vascular protection

Summary There is very suggestive evidence for a role of serotonin release from platelets in the mechanisms for platelet aggregation, arterial thrombosis, and arterial spasm. These effects are mediated via the 5HT₂ receptor and are specifically antagonized by ketanserin. The recently published PACK study was a randomized controlled trial of the effects of ketanserin in patients with intermittent claudication. The purpose of the trial was to discover whether ketanserin treatment would reduce the incidence of atherosclerotic complications such as myocardial infarction or stroke. An unexpected adverse interaction between ketanserin and potassium-losing diuretics was observed, causing an excess of deaths in the group taking this combination of drugs. The intention-to-treat analysis showed no overall difference between ketanserin and placebo in terms of cardiovascular complications. Withdrawal of patients taking potassium-losing diuretics left insufficient numbers of patients in the study to answer the original question. However, the on-treatment analysis excluding those taking the combination suggested strongly, although did not prove, that ketanserin reduced thrombotic episodes by about 25%. It is concluded that the risks of interactions between many drugs and potassium-losing diuretics make the use of the latter undesirable. Further studies on ketanserin, possibly combined with thromboxane A₂ inhibitors, seem highly desirable.     

Behavioural analysis of the anorectic effects of fluoxetine and fenfluramine

Two sets of experiments were carried out to compare the effects of fenfluramine and fluoxetine on consummatory and operant behaviour. In food-deprived rats allowed access to a 35% sucrose solution, an initial period of sucrose consumption was followed by a short period of grooming and exploratory behaviour, later superceded by resting. This behavioural satiety sequence was advanced by fluoxetine, but disrupted bydl-fenfluramine, which suppressed post-prandial resting, even at sub-anorectic doses. Fluoxetine also elicited resting behaviour following water drinking. However, this did not appear to be a non-specific sedative effect, since fluoxetine increased post-prandial grooming. In rats performing on random interval schedules of food reinforcement, fluoxetine caused proportionally greater decreases in responding on a reinforcement-lean schedule (RI-300s), as compared to a reinforcement-rich schedule (RI-7.5s); this effect is similar to that of a reduction in level of food deprivation. By contrast, fenfluramine reduced responding equally on both schedules. In both paradigms, the effects of fluoxetine were compatible with an increase in postprandial satiety, but the effects of fenfluramine were not.     

2型糖尿病心血管病变的QT离散度分析

目的　探讨 2型糖尿病心血管病变的QT离散度变化的意义。方法　分析 40例 2型糖尿病心血管病变者体表 12导联同步心电图 ,并与 42例 2型糖尿病无心血管病变及 42例正常人作对照。结果　糖尿病心血管病变组QTd及QTcd均显著高于其余两组 (P <0 .0 1)。以QTd >46ms为异常 ,则诊断糖尿病心血管病变的敏感性、特异性及准确性分别为 82 .5 %、85 .7%及 84.1%。以QTcd >5 2ms判为异常 ,则诊断敏感性、特异性及准确性分别为 85 .0 %、83.3 %、84.1%。结论　QTd及QTcd延长可作为临床诊断 2型糖尿病患者伴心血管病变的一项指标。     

京剧嗓音的声学分析及音域特征

目的　从声学角度客观地检测京剧的嗓音特征 ,为京剧演唱者嗓音的训练和保护提供参考。方法　对 73名 1 6～ 5 7岁不同行当的专业京剧演员或学员 ,利用Dr Speech计算机频谱分析系统对元音 /a/、/i/歌唱舒适音和唱段进行声学参数的检测和分析。结果　各行当元音 /a/、/i/歌唱舒适音的基频 (fundamentalfrequency,F0 )分别是 :丑角 (2 72 6± 42 0 )Hz( x±s ,下同 )、(30 4 2± 2 2 1 )Hz;小生 (499 3± 34 0 )Hz,(485 4± 1 8 7)Hz;老生 (335 6± 6 0 0 )Hz,(31 7 9± 45 1 )Hz ;花脸 (31 9 0±6 1 3)Hz,(34 0 1± 6 8 8)Hz;老旦 (42 7 6± 47 2 )Hz,(437 7± 45 8)Hz ;花旦 (5 35 8± 48 8)Hz,(5 6 1 6± 2 9 2 )Hz ;青衣 (5 48 0± 6 9 5 )Hz,(5 43 5± 79 3)Hz;其它声学参数 :频率微扰 (pitchperiodperturbation,或Jitter)、振幅微扰 (amplitudeperturbation ,或Shimmer)和声门噪声能量 (也称标准化噪声能量级 ,normalizednoiseenergy ,NNE)均在软件提供的正常值范围内 ;京剧演员歌唱音域的跨度为 1 7～ 2 8个八度 ,最低音和多数最高音均比西洋唱法的高音声部相应的值高。结论　京剧嗓音有着独特的声学特征 ;结果对其嗓音的训练和保护有一定的临床参考     

多普勒组织显像评价高血压病心房内传导间期变化与房性心律失常的关系

目的　应用多普勒组织显像评价高血压病心房内传导间期变化与房性心律失常的关系 ;方法　利用超声多普勒组织显像法测量了 2 0例高血压病心房内传导间期与正常人对比分析 ;结果　高血压病心房内传导间期存在异常 ,心房内传导间期与左房内径大小无相关 (r =0 1,P >0 2 5 ) ,与左室舒张功能指标E A比值中度相关 (r=0 5 7,0 0 1

0 2 5 ) ;结论　高血压病房性心律失常与心房内传导异常及左室舒张功能有关 ,多普勒组织显像法是一种较好的测量高血压病心房内传导间期的方法     

急性心肌梗死早期QT间期JT间期离散度与近期严重心律失常的关系

目的 :探讨AMI早期QT间期离散度、JT间期离散度与严重心律失常的关系。方法 :测定 46例AMI患者心梗发生后第 3d的QT间期离散度 (QTd)和JT间期离度 (JTd)。并与30例正常人的对照组比较。结果 :AMI组QTd、JTd、QTcd较对照组显著增大 (P <0 0 1 )。住院期间严重室性心律失常发生组 (1 8例 )的QTd、JTd、QTcd较无严重室性心律失常组 (2 8例 )明显增大 (P <0 0 1 ) ,且发生室颤的 9例患者QTd、JTd、QTcd比无室颤的明显增大 (P <0 0 1 )。结论 :早期测定AMI患者QTd、JTd、QTcd对患者近期严重室性心律失常的发生有预测意义     

Comparison of the acute cardiotoxicity of the antimalarial drug halofantrine in vitro and in vivo in anaesthetized guinea-pigs

1. Several unrelated drugs have pro-arrhythmic activity associated with an ability to prolong the QT interval of the ECG. The aim of this work was to examine the effects of the antimalarial drug halofantrine in vivo and in vitro.
2. In anaesthetized guinea-pigs consecutive bolus doses of halofantrine (0.3, 1, 3, 10 and 30 mg kg⁻¹, i.v.) at 25 min intervals caused dose-dependent prolongation of the rate corrected QTc interval and bradycardia. The change in heart rate became significant after administration of 10 mg kg⁻¹ halofantrine (−23±9 beats min⁻¹) whereas the increase in QTc was significant with only 1 mg kg⁻¹ halofantrine (22±10 ms). It was only with the highest dose of halofantrine that the PR interval was increased (from 52±3 to 67±4 ms) and second degree atrioventricular (AV) block (type 1 Mobitz) occurred in all animals. No changes were observed in any parameters in a separate group of guinea-pigs which received vehicle (dimethylacetamide 60% propylene glycol 40%) at equivalent time points.
3. The blood concentrations of halofantrine ranged from 0.26±0.17 μM after administration of 0.3 mg kg⁻¹ to 2.79±0.87 μM after 30 mg kg⁻¹, i.v. There was a significant correlation between the blood concentrations of halofantrine and the changes in QTc interval.
4. In guinea-pig left papillary muscles the effective refractory period was increased significantly 60 min after addition of halofantrine; from 161±4 to 173±6 ms with 10 μM, 156±8 to 174±6 ms with 30 μM and 165±6 to 179±5 ms with 100 μM halofantrine. However, the vehicle (0.1% Tween 80 in DMSO; final concentration of vehicle in Krebs, 1%) also increased the effective refractory period from 164±5 to 173±6 ms. Similar results were obtained in right ventricular strips but left atrial effective refractory periods were not altered by either the vehicle or halofantrine.
5. The results of these experiments suggest that any direct effects that halofantrine may have had on the effective refractory period of cardiac muscle cannot be separated from those of the vehicle. The prolongation of QTc and consistent observation of AV block with halofantrine in anaesthetized guinea-pigs suggest that in vivo models may be more useful for further studies investigating the mechanisms underlying the cardiotoxicity of halofantrine.