Effect of peripherally administered lipopolysaccharide (LPS) on GTP cyclohydrolase I, tetrahydrobiopterin and norepinephrine in the locus coeruleus in mice

Lipopolysaccharide (LPS), an endotoxin released from the outer membranes of Gram-negative bacteria, triggers cells to synthesize and release inflammatory cytokines that may progress to septic shock in vivo. We found that LPS enhances tetrahydrobiopterin (BH4) biosynthesis by inducing the biosynthetic enzyme GTP cyclohydrolase I (GCH) in vitro in the mouse neuroblastoma cell line N1E-115. Furthermore, we observed that gene expression of GCH in the locus coeruleus (LC) in mice was enhanced by peripheral administration of LPS, resulting in increased concentrations of BH4, and norepinephrine, and its metabolite 4-hydroxy-3-methoxyphenylglycol (MHPG). These results suggest that tyrosine hydroxylase (TH) activity is increased by increased content of BH4 due to enhanced mRNA expression of GCH in the LC resulting in the increase in norepinephrine in the LC during endotoxemia. LPS in blood may act as a stressor to increase norepinephrine biosynthesis in the mouse LC.     

Change of a frame of reference with velocity in visual motion perception

The present study examined how a frame of reference was affected by velocity. This question was examined with respect to a system consisting of two points: one moved rectilinearly with constant velocity, and the other moved on a track in the shape of a cycloid (defined as the movement of two points—one on the hub and the other on the rim of a rolling wheel). The results indicated that (1) a frame of reference in which the centroid of the total picture was stationary was chosen mainly in a low-velocity range (0.1–0.7 deg/sec), (2) a frame of reference in which a picture point moved rectilinearly was chosen mainly in a medium-velocity range (0.8–40.0 deg/sec), and (3) an absolute coordinate system was chosen mainly in a high-velocity range (>40.0 deg/sec). The current evidence and other findings seem to be consistent with the idea that groups of neurons related to the three frames of reference are independent of one another, that the velocity ranges of the groups of neurons roughly overlapped each other, and that the most salient frame of reference is chosen (i.e., exclusion principle in choice of a frame of reference).     

Pure feedback effects in absolute identification

To reveal the pure effects of trial-by-trial feedback on judgmental accuracy and sequential dependencies independent of global anchoring effects and other influences, we presented subjects with sequences consisting alternately (within an experimental session) of short runs of trials with feedback (feedback sequences) and without feedback (no-feedback sequences). In Experiments 1 and 2 (absolute identification of sound intensity and sound frequency, respectively), judgmental accuracy was the same in the feedback and the no-feedback sequences, contrary to previous results. Also, in the feedback sequences, the dependency of the current response on the immediately preceding stimulus was larger than that in the no-feedback sequences, while the dependency on the previous response was larger in the no-feedback sequences. In Experiment 3 (absolute identification of sound frequency), we attempted to separate the effects of the number of response categories on sequential dependencies from the effects of the number of stimuli. The results showed that the number of response categories had a larger effect than the number of stimuli on most aspects of performance, but that both affected sequential dependencies. These results are generally consistent with a theory of absolute identification in which feedback affects judgmental accuracy by improving long-term memory for judgmental anchors, while feedback affects sequential dependencies by altering response biases.     

Nitroglycerin relieves emotional stress-induced stomach ulcers in rats

It is known that nitroglycerin (GTN) can be converted to form a nitric oxide (NO) molecule which is a highly reactive and unstable free radical species. NO is known to have many beneficial effects such as relaxing blood vessels, promoting digestive activity, and regulating blood pressure. The first experiment established an additional effect of NO, that GTN can help prevent emotionally-induced stomach stress ulcers in rats. In Experiment 2, we sought to estimate the quantity of nitrogen oxides in serum produced by GTN that is administered subcutaneously to rats. The results indicated that rats administered GTN increased significantly the amount of serum NO₂ and NO₃, relative to values for a control group. Since amounts of NO₂ and NO₃ reflect amount of NO, the administration of GTN significantly increased amount of NO. An implication of this research is that chemicals such as GTN may be used in therapy with humans for the prevention of some kinds of ulcers. Furthermore, while NO is commonly recognized as a pollutant, it has a number of beneficial effects on the body, e. g., it may slow the aging process, contribute to therapy for improtency, and facilitate memory processes.     

医疗纠纷处理中若干伦理问题的思考

医疗纠纷的增势和处理难已成为众所周知的事实。但是,在医疗纠纷处理中存在着医患关系的信任性、医疗事故鉴定的公正性和经济裣的合理笥是思考的伦理问题。只要医患双方、乃至社会对诸如医疗行为是否等同于一般的服务行为、病人权益是否等同于消费者权益、医疗事故鉴定是不是医医相护、经济裣能不能实行等价赔偿原则、医疗差错要不要给予经济补偿等有效为统一的认识,就会有利于医疗纠纷的处理,有利于维护医患双方的合法权益,有利