[Hokkaido igaku zasshi] The Hokkaido journal of medical science
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Hokkaido Igaku Zasshi · May 1993
[Effects of conditioned fear stress on monoaminergic systems in the rat brain].
The effects of conditioned fear stress (CFS), an animal model of anxiety, on brain dopamine (DA) and serotonin (5-HT) metabolism and behavior were investigated in rats. CFS (exposure to an environment paired previously with footshock) after single footshock stress increased plasma corticosterone levels and defecation, and induced freezing behavior. It also increased 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the medial prefrontal cortex (mPFC), paraventricular nucleus of the hypothalamus (PVH) and lateral hypothalamus, increased homovanillic acid (HVA) levels in the mPFC and amygdala, and increased 5-hydroxyindoleacetic acid (5-HIAA) level in the mPFC. ⋯ The 5-HT synthesis inhibitor PCPA failed to change freezing. In conclusion, these results suggest that the anxiolytic effect of ipsapirone results from the activation of postsynaptic 5-HT1A receptors and the facilitation of 5-HT neurotransmission decreases anxiety. This model may be useful for detecting the anxiolytic potential for drugs and examining the relationship of 5-HT to anxiety.
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Hokkaido Igaku Zasshi · Mar 1992
[Continuous Fick cardiac output measurement during inhalation anesthesia].
A computer based system that continuously monitors cardiac output (CO) and the other hemodynamic variables has been developed. Fick CO was calculated every 10 sec on breath by breath basis. The arterio-venous oxygen content difference was measured by a combination of a pulse oximeter and a fiberoptic oximeter. ⋯ The "limits of agreement" (mean difference +/- 2 SD of bias) were within +/- 1.12 l/min, which could be acceptable for clinical settings. When hemodynamic states were abruptly changed by an intravenous administration of isoproterenol, Fick CO reached 90% of EMCO change within 30 sec. The author concludes that this system provides virtually continuous hemodynamic analyses and facilitates more sophisticated circulatory control of the patients within a limited fluctuation.
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Hokkaido Igaku Zasshi · Nov 1991
[Clinical evaluation of arterial tonometry for noninvasive, continuous blood pressure monitoring during anesthesia].
A new continuous, non-invasive arterial blood pressure monitoring system based on arterial tonometry was currently developed. A sensor of this system consists of an array of 15 piezoresistive pressure transducers. An automatic sensor positioning system ensure that at least one of the 15 transducers is positioned on the center of the pneumatically flattened, but not occluded, portion of the artery. ⋯ These results indicate that tonometry provides accurate, reliable and real-time blood pressure measurements together with continuous display of the pressure waveform for wide range of blood pressure. It was concluded that this system may replace the conventional invasive intra-arterial blood pressure monitoring system. This system is especially useful if it is combined with pulse oximetry and capnography.
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Hokkaido Igaku Zasshi · Mar 1990
[Spinal cord evoked potential in experimental spinal cord injury--the changes in spinal cord evoked potential following impact injury, and effect of mannitol administration on acute experimental spinal cord injury].
The authors reported the changes of spinal cord evoked potential following impact injury by the weight dropping technique in untreated and treated animals. The correlation between the change in amplitude of the spinal cord evoked potential after injury and the prognosis for motor recovery of legs was also discussed. (Materials and Methods) The spinal cord of 57 adult dogs was traumatized by the weight dropping technique at the level of Th10. 37 dogs were not treated. The trauma consisted of 300 gm-cm impact injury, 400 gm-cm impact injury and 500 gm-cm impact injury. ⋯ However, the precise prognosis for motor recovery could not be accurately estimated in dogs with recovery of amplitude between 39% and 20%. 3. In mannitol-treated group with intravenous continuous infusion, the recovery of the amplitude was superior to that in untreated group at a significance level of p less than 0.05. However, in the group with intravenous bolus injection of mannitol, the recovery was transient.