• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.34-45
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• 1998

We provide the reader with a brief introduction to the neurobiology of neuropeptides. Several comprehensive reviews of the distribution and neurochemical, neurophysiological, neuropharmacological and behavioral effects of the major neuropeptides have recently appeared. In reviews of the large number of neuropeptides in brain and their occurance in brain regions thought to be involved in the pathogenesis of major psychiatric disorders, investigators have sought to determine whether alternations in neuropeptide systems are associated with schizophrenia, mood disorders, anxiety disorders, alcoholism and neurodegenerative disease. There is no longer any doubt that neuropeptide-containing neurons are altered in several neuropsychiatric disorders. One of the factors that has hindered neuropeptide research to a considerable extent is the lack of pharmacological agents that specifically alter the synaptic availability of neuropeptides. With the exception of naloxone and naltrexone, the opiate-receptor antagonists, there are few available neuropeptide- receptor antagonists. Two independent classes of neuropeptide-receptor antagonists has been expected to be clinically useful. Naltrexone, a potent ${\mu}$-receptor antagonist, has been used successfully to reduce the need for alcohol consumption. And cholecycstokinin antagonists are now in development as a new class of anxiolytics, which would be expected to be free from tolerance and physical dependence and lack of sedation. In this review, we deal with these two kinds of neuropeptide system, the opioid system and cholesystokinins in the brain. The role of opioid systems in the reinforcement after alcohol consumtion and that of cholesystokinins in the pathogenesis of anxiety will be discussed briefly. As we know, the future for neuropeptides in psychiatry remains bright indeed.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.171-181
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• 2007

Objective: The present study was aimed at an analytical formulation of the micro-implant related torque as a function of implant size, i.e. the diameter and length, screw size, and the bony resistance at the implant to bone interface. Methods: The resistance at the implant to cancellous bone interface $(S_{can})$ was assumed to be in the range of 1.0-2.5 MPa. Micro-implant model of Absoanchor (Dentos Inc. Daegu, Korea) was used in the course of the analysis. Results: The results showed that the torque was a strong function of diameter, length, and the screw height. As the diameter increased and as the screw size decreased, the torque index decreased. However the strength index was a different function of the implant and bone factors. The whole Absoanchor implant models were within the safe region when the resistance at the implant/cancellous bone $(=S_{can})$ was 1.0 or less. Conclusion: For bone with $S_{can}$ of 1.5 MPa, the cervical diameter should be greater than 1.5 mm if micro-implant models of 12 mm long are to be placed. For $S_{can}$ of 2.0 MPa, micro-implant models of larger cervical diameter than 1.5 mm were found to be safe only if the endosseous length was less than 8 mm.