Effect of ultrasound exposure on sonicated microbubbles stability

The study of intlavenous myocedal coneest echocedo~ (IVMCE) is a hot topic in the Pursuit ofcoronap healt disease, and much achievement has beenmade in ash ultheound etwpment development and cont. .[if ~t agent improvement. Most colltrsst opllts such asMiunex, Ophson etc. are pIDduced by sonication, andcan be used as echogenic bacers of blood flow in WMCE.SOme studies have suggested, however, that the ndcrobubbles exposed to ultrasound are Open to mpture[']. Ihan effort to detendne the o…     

4-硒硫酸酯多糖的体内抗瘤作用

目的　观察 4-硒硫酸酯多糖 (Se-carra)的体内抗瘤作用。方法　于小鼠右腋皮下接种瘤细胞 2 4h后开始给药 ,连续 10天 ,观察其抑瘤率 ;小鼠腹腔接种肿瘤细胞前或接种后连续给药 10天 ,观察动物的生存时间。结果　 4-硒硫酸酯多糖能明显抑制肿瘤细胞的生长 ,延长小鼠的生存期。结论　 4-硒硫酸酯多糖体内给药有良好的抗瘤效果 ,值得进一步研究。     

超声照射对声振微泡稳定性的影响

目的与方法造影剂微泡浓度、大小是影响心肌声学显影最重要因素。本研究采用２×２×４析因分析法分析不同超声照射条件对造影剂微泡浓度及直径的影响,即声波频率、能量以及照射时间对微泡浓度、大小的单独及交互作用。为临床行静脉心肌声学造影检查时选择适宜的超声照射条件提供参考。结果能量越大、照射时间越长,微泡破坏越多,平均直径越小：照射频率对微泡浓度影响不大,但影响微泡大小,频率越高,微泡越小。结论为减少超声照射对微泡的破坏,提高心肌声学造影效果,应尽可能选用低能量、低频率超声波,并减少不必要的照射时间。     

Anticoagulation after valve replacement: a multicenter retrospective study

Anticoagulant therapy after cardiac valve replacement was evaluated retrospectively in 1,200 patients attending 8 cardiac surgery clinics in the Tokyo area as part of the Tokyo Area Study on Anticoagulation After Cardiac Valve Replacement Using PT-INR (TAS). A prospective trial is also in progress and will be reported later. The prothrombin time international normalized ratio (PT-INR) was determined at the time of thromboembolic and bleeding complications in 1,200 patients. During the 5 year study period, thromboembolisms occurred in 21 patients, and bleeding complications occurred in 15 patients. In 71% of patients with thromboembolism and 47% of those with bleeding complications, the PT-INR was within the range of 1.6 to 2.8, which is the accepted therapeutic range in Japan. Therefore, the correct PT-INR therapeutic range for Japanese patients with mechanical heart valves needs to be reexamined, and data from the prospective TAS trial that is currently underway will be used for this purpose.     

D—二聚体测定在换瓣病人抗凝治疗效果评价中的意义

为探讨Ｄ－二聚体（Ｄ－Ｄ）测定在换瓣病人抗凝治疗效果评价中的意义,用一期法和ＥＬＩＳＡ快速法分别测定了６６例服用华法令的换瓣病人血浆凝血酶原时间（ｔｐ）和Ｄ－Ｄ的含量。初步结果表明：Ｄ－Ｄ与ｔｐ测定值是基本符合的;在ｔｐ测定低于正常值的６例中,Ｄ－Ｄ测定仅２例阳性;在Ｄ－Ｄ测定高于正常值（即发生血栓）的３例中,ｔｐ测定仅２例低于正常值。提示ｔｐ作为换瓣病人抗凝治疗的唯一指标似存在局限性,同时测定ｔｐ和Ｄ－Ｄ可防止临床误诊;建议对换瓣病人进行药量调整时,有必要作Ｄ－Ｄ检测     

Cocaine's effects on speech sound identification and reaction times in baboons

The effects of cocaine on speech sound discriminations was examined to determine whether cocaine's previously demonstrated effect in reducing speech sound discriminability was dependent upon either the type of stimuli employed (simple tones versus complex speech) or the procedure (stimulus detection versus stimulus discrimination). Because of demonstrated similarities in the way that baboons and humans discriminate speech, and in the way the CNS is thought to encode and process speech sounds in these two species, baboons were trained to perform a choice procedure to identify the occurrence of different synthetic vowel sounds (/a/, /æ/, //, /U/, and /љ/). Animals held down a lever and released the lever only when one of four target vowels sounded, and not when a fifth, standard vowel sounded. Acute IM administration of cocaine (0.0032–1.0 mg/kg) produced dose-dependent decreases in vowel discriminability that were mostly due to elevations in false alarms (i.e., releases to the standard vowel) following cocaine. Cocaine also shortened reaction times to the stimuli in two of three baboons, but to a much lesser extent than observed previously. These results suggest that cocaine may interfere with the ability of the CNS to process the acoustic cues in speech sounds, and that the effects of cocaine on reaction times may depend upon the complexity of the reaction time procedure employed.     

How do normal subjects learn a simple adaptative task: How and why do paranoid schizophrenic patients fail?

Summary The authors studied the behavior of normal subjects and paranoid schizophrenic patients in a simple problem-solving situation. The schizophrenics were divided into two sample groups, one of individuals under treatment and the other of individuals not under treatment.The learning process involved in this problem-solving situation is very similar to an instrumental conditioning, and can be understood by means of the following assumptions: (1) the subjects use decision functions in reacting to the stimuli, although they may be not fully aware of this; (2) learning is the result of successive transformations of these decisions in the course of time; (3) the changes have specific probabilities and are related to (a) those responses which are made to the latest stimuli, and (b) a differential probability for decision functions which were effective, or only interrupted painful reinforcement, or were completely ineffective.In schizophrenics further factors of importance were (1) an inertia factor and (2) the rigidly continued use of unsuccessful or only partially successful decision criteria.The authors used a systems theory based on Galois field theory and a calculus of operators specifying three groups of subjects. A computer program based on these hypotheses was tested in a simulation experiment.The statistical evaluation of the results showed a congruence between the theoretical approach and the experimental data.This work was carried out with financial support from the Institute de Alta Cultura, Lisbon, between 1970 and 1974     

Application of Akaike's information criterion (AIC) in the evaluation of linear pharmacokinetic equations

According to linear pharmacokinetics, the time course of plasma concentration of a drug, C_p,is expressed by a sum of exponential functions, C_p= _i=1 ⁿ a_i .This article describes a statistical technique to estimate the number of exponential terms, n,for the time course of drug by the application of Akaike's information criterion (AIC). Plasma concentrations of ethoxybenzamide, sulfisoxazole, bishydroxycoumarin, and diazepam measured following bolus intravenous injection were used as clinical examples for this method. Selection of models is compared between the AIC method and an Ftest method at significance levels of 5% and 1%.     

Molecular Motion of Drugs in Hydrocolloids Measured by Electron Paramagnetic Resonance

The effects of a polymer, the Li-salt copolymer of methyl-methacrylic acid, and its methyl ester on the motion of drug molecules in hydrocolloids were studied. The investigation was carried out by means of electron paramagnetic resonance (EPR) using the model nitroxide tempol, and the spin-labeled drugs lidocaine (si-lid) and dexamethasone (sl-dex). Synthesis of sl-dex was performed. Spin-labeled molecules dissolved in hydrocolloids undergo a fast reorientation motion. The decreasing order of rotational correlation times () —sl-dex > si-lid > tempol—suggests that the size and the shape of the molecules strongly affect their motion. The inhibition of motion of larger molecules depends also on their flexibility. The values indicate proportionality of the microviscosity of hydrocolloids to the polymer concentration. Rotational motion is dependent on the local environment conditioned by the free spaces between polymer molecules.