高效液相梯度洗脱法测定血清中氢化可的松和可的松的含量

目的　测定血清中氢化可的松和可的松的比值以反映人体肝脏 1 1 β -羟类固醇脱氢酶的活性 ,为其研究提供一个有效的分析手段。方法　HPLC -UV法 ,梯度洗脱 ,内标定量。结果　血清中氢化可的松在 50～ 2 0 0μg·L-1 、可的松在 1 0～ 50 μg·L-1 范围内其线性回归方程分别为Y =- 0 .42 5 +0 .0 1 0X、Y =- 0 .1 63 +0 .0 50X ,相对回收率分别为 (1 0 2 .5± 3 .6) %、(97.6± 6 .0 ) %。 82名健康志愿者血中氢化可的松和可的松的浓度分别为 (1 32 .2± 44 .5) μg·L-1 和 (1 9.7± 5 .0 ) μg·L-1 ,其比值为 6 .89± 2 .2 6。结论　本法操作简便、灵敏可靠 ,符合人体血样糖皮质激素测定的要求     

Evaluation of dietetic activity analysis (DAA)—a system for data collection in clinical dietetics

A system of data collection and analysis based on patient visits was evaluated over a four-week period in five districts and a six-month period in one district by twenty-five dietitians. Each patient visit was analysed by diagnosis (the problem), by diet (the treatment) and by nutritional care level (the action). The system was seen to encourage self analysis by dietitians and proved a useful educational tool in addition to providing dietetic managers with data on clinical dietetic activity. It was considered successful and well accepted in four of the six districts.     

自动化分析仪同时测定血清12项生化指标的正常值

本文将生化自动分析仪应用于健康检诊中,就其中1089名健康者的血清进行12项生化指标的检测,并对测得的结果进行分析整理,确定国人的正常值范围。同时又对自动分析仪的质量管理进行了探讨。     

介入法和无创法评价急性心肌梗死溶栓后心肌再灌注的一致性研究

目的 探讨急性心肌梗死（AMI）溶栓治疗后无创法评价心肌再灌注的可行性。方法选择AMI溶栓治疗后行冠状动脉造影的患者，溶栓后90min血浆肌红蛋白（Mb）浓度与溶栓前血浆Mb浓度比值≥2．4或心电图ST段回落≥50％定义为成功再灌注（阳性）。上述两项指标均阳性为完全再灌注，仅一项阳性为部分再灌注，两项均阴性为无再灌注。再根据冠状动脉造影结果将患者分为完全再灌注（TIMI3级）、部分再灌注（TIMI2级）、无再灌注（TIMI0～1级）。对无创法和介入法进行一致性检验。共入选45例患者。结果无创法和介入法评价心肌再灌注经一致性检验，符合率为84．4％，Kappa=0．75（P〈0．01）。结论．心电图ST段回落和血浆Mb浓度变化两项指标合用可提高评价心肌再灌注准确性，和介入法有很高的符合率，简便易行，且结果可靠。     

Left ventricle haemodynamics and vaso-active hormones during graded supine exercise in healthy male subjects

Left ventricle systolic and diastolic functional parameters were measured by gated equilibrium radionuclide cardiography in 12 healthy men (age 33–51 years) at rest and during graded supine exercise. The leftventricle end-diastolic volume showed an initial small (11%) increase during low submaximal exercise [from mean 163 (SD 40) at rest to mean 181 (SD 48) ml], while left ventricle end-systolic volume decreased successively [from mean 59 (SD 19) to mean 39 (SD 21) ml] with increasing exercise. Stroke volume was therefore elevated at all exercise levels compared with rest [mean 104 (SD 23) ml], and the peak value [mean 128 (SD 33) ml] was found at the lowest exercise level, contributing 40% to the initial increase in cardiac output. Cardiac output increased from mean 6.2 (SD 1.4) at rest to mean 20.2 (SD 5.0) 1 · min^–1 at maximum. Left ventricle peak ejection and peak filling rates increased from mean 449 (SD 89) and mean 442 (SD 85) ml · s^–1 at rest to mean 996 (SD 227) and mean 1255 (SD 333) ml · s^–1, respectively, at maximum. The myocardium oxygen consumption, assumed to be proportional to the sum of the stroke work and the potential energy, increased fourfold, but absolute values were twice as high as expected, indicating that extrapolation from data obtained in dog hearts (as we have done) cannot be directly applied to humans. Selected vaso-active hormones were measured at all exercise intensities. Noradrenaline (NA), adrenaline (A) and angiotensin II (AII) concentrations showed a very pronounced increase at maximal exercise compared with the preceding lower intensites, while atrial natriuretic factor (ANF) and cyclic guanosinemonophosphate (cGMP) concentrations showed a more continuous increase, and dopamine (DA) remained almost unchanged. This speaks in favour of a crucial role for NA, A and AII in preserving blood pressure at maximum exercise, while DA probably has no importance for the cardiovascular homeostasis during exercise. Increases in concentrations of ANF and cGMP were highly correlated (r = 0.86). Our data supported the opinion that there is a cardiac limitation to maximal performance connected to the cardiac pumping capacity.     

Road traffic noise around schools: a risk for pupil's performance?

Summary Noise levels around educational centres can negatively affect the performance of both teachers and pupils. Two public schools in Valencia, Spain, were selected for study. One of these schools was exposed to excessively high road traffic noise levels while the other was located in a relatively quiet area. The socioeconomic level of those attending the schools was very similar. A set of external and internal noise measurements were carried out, along with two different attention tests among the children. Test results were consistently better (both for tests and for children from different classrooms in each school) in the quiet school. Exposure to high traffic noise levels in the noisy school over the whole school year is a plausible determinant of these results.     

Facilitation of stimulus detection performance of rats with d-amphetamine: a function of dose and level of training

 Conditions under which amphetamine may facilitate stimulus detection task choice performance in rats were investigated. Rats (n=15) were trained in a two-choice, light-detection task to three successively more stringent criterion levels of task training (minimal, intermediate, and extended) and then tested after administration of saline, 0.25, 0.50, and 0.75 mg/kg d-amphetamine (AMP). For each training level, baseline levels of choice accuracy were maintained at approximately 82% by manipulating the animals’ cue duration. No aspect of performance was enhanced by any dose of AMP after minimal criteria training, and there was a dose-dependent decrease in the number of trials completed. After the intermediate level of training, the 0.25 mg/kg dose of AMP reliably increased choice accuracy, there was no reliable change in choice reaction time, and there was a dose-dependent decrease in the number of trials completed. After the extended training, the 0.25 mg/kg dose of AMP reliably increased choice response accuracy, the 0.25 and 0.50 mg/kg doses of AMP reliably decreased choice reaction time, and there was no reliable change in the number of trials completed at any dose of AMP. These results support the contention that psychostimulants can facilitate the choice performance of rats in stimulus detection tasks if an appropriately low dose is used and the animal’s behavior is strongly controlled by the stimulus-reinforcement contingencies of the task. Received: 24 September 1997 / Final version: 9 May 1998     

ROBUST GUARANTEED COST CONTROL OF UNCERTAIN NON-LINEAR ROBOTIC SYSTEM USING MIXED MINIMUM TIME AND QUADRATIC PERFORMANCE INDEX

To provide better transient performance in controlling robots, a mixed minimum time and quadratic performance index is used. For known and uncertain revolute robot manipulators a conventional optimal control and a robust guaranteed cost control are proposed respectively. Asymptotic stability is also discussed based on the Lyapunov direct method. The proposed robust control is continuous and requires no knowledge of the uncertain system except for bounding functions.     

Short and long term effects of exercise training on the tonic autonomic modulation of heart rate variability after myocardial infarction

We studied the effects of cardiac rehabilitation on the sympathovagalcontrol of heart rate variability in 30 patients after a first,uncomplicated myocardial infarction. Twenty-two patients completed8 weeks of endurance training (trained), while eight decidednot to engage in the rehabilitation programme for logisticalreasons, and were taken as untrained controls. Age, site ofinfarction, ejection fraction, ventricular diameter and stresstest duration were similar in the two groups at baseline. Heartrate variability was evaluated 4 weeks after infarction beforestarting rehabilitation, and repeated 8 weeks and one year laterin both trained and untrained patients. Measures of heart ratevariability, obtained from both time- and frequency- domainanalysis of a 15 min ECG recording in resting conditions, wereas follows: mean RR interval and its standard deviation (RRSD),the mean square successive differences (MSSD), the percent ofRR intervals differing >50 ms from the preceding RR (pNTN50),the low and high frequency components of the autoregressivepower spectrum of the RR intervals and their ratio (LF/HF).At baseline, heart rate variability was similar in trained anduntrained patients. In the short term (8 weeks after infarction),training increased RRSD by 25% (P<0·01), MSSD by 69%(P<0·01), pNN50 by 120% (P<0·01), and reducedLF/HF ratio by 30% (P<0·01). The effects persistedafter one year in trained patients. In untrained patients, theautonomic control of heart rate variability did not change 8weeks after myocardial infarction and was only slightly modifiedby time. Thus, exercise training, performed for 8 weeks aftera myocardial infarction, modifies the sympathovagal controlof heart rate variability toward a persistent increase in parasympathetictone, known to be associated with a better prognosis. This maypartly account for the favourable outcome of patients who undergorehabilitation.