应变应变率成像技术的临床应用

应变应变率成像是新近发展起来的一种无创性定量评价心肌功能的超声技术。与组织多普勒相比,应变应变率成像具有不受心脏平移和周围心肌牵拉影响的优点。这样在定量检测急慢性心肌缺血导致的局部心肌功能异常方面,应变应变率成像比组织多普勒更加准确客观。同时,应变应变率成像的时间分辨率和空间分辨率大大提高,可以明确心肌收缩过程及心肌运动的协调性。随着应变应变率成像技术的不断成熟进步,临床心血管病的各个方面都会用到应变应变率成技术,进一步丰富临床诊断信息。     

Induction of Intestinal Tumors and Lymphomas in C57BL/6N Mice by a Food-borne Carcinogen, 2-Amino-l-methyl-6-phenylimidazo[4,5-b]pyridine

2-Amino-l-methyl-6-phenylimidazo[4,5- b ]pyridine (PhIP) is the most abundant heterocyclic amine contained in cooked meat and fish. Although PhIP has been demonstrated to induce various types of tumors in rats, lymphomas predominated in mice using the CDF1 strain. To investigate the carcinogenic activity of PhIP on other organs in mice with a different genetic background, PhIP was administered to C57BL/6N mice. After a 40-week administration of 300 ppm of PhIP in a high-fat diet followed by continuous feeding with a high fat diet, C57BL/6N mice developed adenomas and adenocarcinomas in the small intestine, the incidences being 52% in males and 68% in females at weeks 95 and 70, respectively. Lymphomas of B-cell origin also developed in both sexes as frequently as in the CDF1 strain, incidences being 48% in males and 32% in females. Although the incidence in PhIP-treated female mice did not differ from that in the control mice, lymphomas developed significantly earlier in the PhIP-treated mice. The present study demonstrated that the intestinal tract is another potential target of PhIP-induced carcinogenesis in mice, and that the carcinogenic activity of PhIP could be affected by the genetic background of the animals.     

应变率显像评价冠心病患者的左室心肌功能

目的:应用应变率成像(SRI)技术评价冠心病患者的左室功能,探讨SRI评价左室功能的临床价值。方法:正常组30例,冠心病组30例,取心尖四腔、心尖两腔、心尖左室长轴切面的心肌应变率曲线,测定左室各室壁的收缩期、舒张早期、舒张晚期的峰值应变率(SRS、SRE、SRA),统计两组左室各壁出现的收缩后缩短(PSS)的节段数;定量检测各节段收缩-舒张转换时间(TCEC),比较各组左室壁各节段TCEC的差异。结果:冠心病组的SRS、SRE、SRA明显降低(P<0.05),PSS的检出率明显增多(P<0.05),与非缺血节段比较,缺血节段TCEC延长(P<0.05)。结论:应变率成像(SRI)技术为定量、准确评价冠心病左室心肌功能提供了新的方法。     

Drug induced hypothermia in adult and senescent rats

Temperature regulation was evaluated in senescent (34-40 month old) and adult (8-9 month old) female Iva:WIWU and Emd:Wi-AF/Han rats. Injection of 1.5 mg/kg BW apomorphine HCl or 1.0 mg/kg BW oxotremorine sesquifumarate produced comparable maximal hypothermic responses in adult and senescent rats. However, the latency to reach maximal hypothermia after oxotremorine (but not apomorphine) was longer in senescent than in adult rats of both strains.     

Role of stimulus locale on strain differences in active avoidance after scopolamine of D-amphetamine treatment.

Three strains of mice were trained in a shuttle avoidance task following treatment with scopolamine (2.0 mg/kg) or d-amphetamine (3.0 mg/kg). When required to run towards light (CS) to avoid shock, A/J mice acquired the response more readily than DBA/2J or C57BL/6J mice. However, when required to run away from the light, the strain differences were eliminated. Under both testing conditions scopolamine and d-amphetamine augmented the performance of A/J mice, but had no effect of even disrupted performance of C57BL/6J. In DBA/2J mice d-amphetamine augmented performance only in the toward condition. Results were interpreted to support the hypothesis that scopolamine and d-amphetamine improve performance by response-disinhibition and response excitation, respectively. The presence of associative difficulties limit the effects of these agents.     

A minicomputer approach to consultation-liaison data basing: Pedagog-Admin-CLINFO

Minicomputer systems have been designed for researchers who have no prior computer experience and, therefore, require no computer training, that is, programming knowledge. Such systems allow immediate access to the data, their retrieval, reduction, and analysis, and the retention of direct control over the data base by the researcher. In addition, CLINFO offers a wide range of calculations and statistical procedures. The three-dimensional, time-oriented data-base format of CLINFO allows for a longitudinal study of a particular variable, and its repeated measure over time in the same patient. This system has been adapted for use in the consultation-liaison setting to provide pedagogic, research, and administrative functions from a field-tested data base.     

The effects of p-chlorophenylalanine on morphine analgesia,tolerance and dependence development in two strains of rats

The effects of p-chlorophenylalanine (p-CPA; 100 mg/kg/day for 3 days) on morphine analgesia and the development of tolerance and physical dependence were investigated in Sprague-Dawley (SD) and Fisher (F) strains of albino rats. Using a modified flinch-jump method to detect changes in reactivity to electric footshock, F strain rats were more reactive to the footshock than SD rats, but showed less relative increase in threshold (analgesia) than SD rats following various doses of morphine. Pretreatment with p-CPA attenuated significantly morphine analgesia in SD, but not F rats. In animals implanted subcutaneously with morphine pellets, p-CPA appeared to delay the development of tolerance to morphine in both strains of rats. Hyperalgesia and loss of body weight resulted from administration of naloxone to pellet-implanted rats and p-CPA pretreatment lessened these withdrawal effects significantly in SD rats only. These results emphasize the importance of strain differences in the study of morphine analgesia and development of tolerance and dependence. Assuming differences in the function of the serotonergic inhibitory system in the two strains of rats, these data provide general support for the involvement of brain 5-HT mechanisms in modulating, if not mediating the effects of morphine.     

The use of sudden darkness in mice: a behavioural and pharmacological approach

Sudden darkness is a non-invasive behavioural analysis tool which increases motor activity and decreases anxiety in rats. It has been shown in previous studies that in rats, dark test conditions can also modify behavioural responses to drugs acting on the dopaminergic system. The increasing use of transgenic mice in behavioural research has raised interest in developing new tests for phenotyping mice. Hence, the aim of the present study was to adapt the sudden darkness paradigm for mice. In the first part of this study, effects of sudden darkness on the performance of mice in the elevated plus maze test were evaluated. Both genders of two mouse strains (Swiss and Balb/c) were tested either in high light intensity conditions or were exposed to sudden darkness. In the second part, responses to the 5-HT_1A receptor agonist 8-OH-DPAT (0.5 and 1.0 mg/kg) and 5-HT_2C receptor agonist mCPP (1.0 and 2.0 mg/kg) were investigated in male Swiss mice. Sudden darkness induced a clear anxiolytic effect in male and female Swiss mice. In Balb/c mice, anxiety-related behaviour was only decreased in females, whereas in males the anxiety state remained unchanged. An increase in motor activity was only observed in male Swiss mice; in the other groups, sudden darkness did not affect locomotion. Depending on the light conditions used, the behavioural response to receptor agonists was more evident: 8-OH-DPAT (1.0 mg/kg) only significantly decreased the anxiety state when mice were tested under high levels of illumination, whereas the anxiogenic effect of mCPP (1.0 and 2.0 mg/kg) was only evident in the dark. This study suggests that the sudden darkness paradigm is also a useful tool for the analysis of mice and can be used to modulate the anxiety level without administering drugs. Depending on the mouse strain tested, the same effects on anxiety and motor activity were observed as have been shown for rats.     

Forced swimming test in mice: a review of antidepressant activity

Rationale Among all animal models, the forced swimming test (FST) remains one of the most used tools for screening antidepressants.Objective This paper reviews some of the main aspects of the FST in mice. Most of the sensitivity and variability factors that were assessed on the FST are summarized.Mechanisms We have summarized data found in the literature of antidepressant effects on the FST in mice. From this data set, we have extrapolated information on baseline levels of strain, and sensitivity against antidepressants.Results We have shown that many parameters have to be considered in this test to gain good reliability. Moreover, there was a fundamental inter-strain difference of response in the FST.Conclusions The FST is a good screening tool with good reliability and predictive validity. Strain is one of the most important parameters to consider. Swiss and NMRI mice can be used to discriminate the mechanisms of action of drugs. CD-1 seems to be the most useful strain for screening purposes, but this needs to be confirmed with some spontaneous locomotor activity studies.Electronic Supplementary Material Supplementary material is available for this article at .     

The role of hippocampal cholinergic mechanisms in the aquisition of a barpress response.

The role of hippocampal cholinergic mechanisms in learning a bar-press response reinforced with food was investigated. Firstly, an interstrain comparison showed that mice having a low choline acetyltransferase activity in the dorsal hippocampus were quicker to associate the barpress with reinforcement. Secondly, when the activity of this enzyme was reduced by a subseizure electrical stimulation of the hippocampus learning was accelerated. It is suggested that acetylcholine availability at the hippocampal synapses slowed the apparition of these learned responses.