The Versatility of Framework Regions of Chicken V(H) and V(L) to Mutations

To identify the interchangeability of V(H) and V(L) framework region (FR) residues, we artificially introduced random mutations at all residue positions in a chicken monoclonal antibody, which has only one functional V(H) and Vλ gene. When we classified the amino acids into 5 groups by their physicochemical properties, all FR residues could be replaced by another group except L23 (C), H36 (W), H86 (D), H104 (G), and H106 (G). Eighty-two (50.9%), 48 (29.8%), 17 (10.6%), and 9 FR residues (5.6%) could be replaced by 4, 3, 2, and 1 group(s), individually, without significant loss of reactivity. We also confirmed a similar level of versatility with 2 different chicken antibodies. This high level of versatility on FR residues has not been predicted because it has not been observed in the 150 chicken antibodies that we previously generated or in the 1,269 naïve chicken V(H) sequences publically available. In conclusion, chicken antibody FR residues are highly interchangeable and this property can be applied for improving the physicochemical property of antibody including thermal stability, solubility and viscosity.

CTLA4-CD28 chimera gene modification of T cells enhances the therapeutic efficacy of donor lymphocyte infusion for hematological malignancy

Donor lymphocyte infusion (DLI) followed by hematopoietic stem cell transplantation has served as an effective prevention/treatment modality against the relapse of some hematologic tumors, such as chronic myeloid leukemia (CML). However, the therapeutic efficacies of DLI for other types of leukemia, including acute lymphocytic leukemia (ALL), have been limited thus far. Therefore, we examined whether increasing the reactivity of donor T cells by gene modification could enhance the therapeutic efficacy of DLI in a murine model of ALL. When a CTLA4-CD28 chimera gene (CTC28) in which the intracellular signaling domain of CTLA4 was replaced with the CD28 signaling domain was introduced into CD4 and CD8 T cells in DLI, the graft-versus-tumor (GVT) effect was significantly increased. This effect was correlated with an increased expansion of donor CD8 T cells in vivo, and the depletion of CD8 T cells abolished this effect. The CD8 T cell expansion and the enhanced GVT effect were dependent on the transduction of both CD4 and CD8 T cells with CTC28, which emphasizes the role of dual modification in this therapeutic effect. The CTC28-transduced T cells that expanded in vivo also exhibited enhanced functionality. Although the potentiation of the GVT effect mediated by the CTC28 gene modification of T cells was accompanied by an increase of graft-versus-host disease (GVHD), the GVHD was not lethal and was mitigated by treatment with IL-10 gene-modified third-party mesenchymal stem cells. Thus, the combined genetic modification of CD4 and CD8 donor T cells with CTC28 could be a promising strategy for enhancing the therapeutic efficacy of DLI.

Paraplegia following cervical epidural catheterization using loss of resistance technique with air: a case report / 대한마취과학회지

We report a case of paraplegia without neurologic deficit of upper extremities following cervical epidural catheterization using air during the loss of resistance technique. A 41-year-old woman diagnosed with complex regional pain syndrome had upper and lower extremity pain. A thoracic epidural lead was inserted for a trial spinal cord stimulation for treating lower extremity pain and cervical epidural catheterization was performed for treating upper extremity pain. Rapidly progressive paraplegia developed six hours after cervical epidural catheterization. Spine CT revealed air entrapment in multiple thoracic intervertebral foraminal spaces and surrounding epidural space without obvious spinal cord compression before the decompressive operation, which disappeared one day after the decompressive operation. Her paraplegia symptoms were normalized immediately after the operation. The presumed cause of paraplegia was transient interruption of blood supply to the spinal cord through the segmental radiculomedullary arteries feeding the spinal cord at the thoracic level of the intervertebral foramen caused by the air.

Enhanced Anti-tumor Reactivity of Cytotoxic T Lymphocytes Expressing PD-1 Decoy

Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN-γ secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy.

Clinical Applications of Neurofeedback Treatment for Insomnia / 수면정신생리

Since the pharmacological treatment of insomnia has the potential risk for dependence and various side effects, nonpharmacological intervention for insomnia is very important in clinical practice. The neurophysiological characteristics and recent researches using quantitative EEG of insomnia suggest the insomnia as a state of CNS(central nervous system) hyperarousal. Insomnia should not be restricted to subjective sleep complaints alone because it appears to be a 24-hour disorder including daytime fatigue and decreased quality of life. The neurofeedback treatment is a self-regulation method based on the paradigm of operant conditioning. The goal of this treatment modality is to normalize the functioning of the brain by inhibiting and/or reinforcing specific frequency bands of brain waves. Therefore, the neurofeedback treatment on the basis of thalamocortical mechanisms which play an important role in sleep and arousal might be a useful treatment modality for the insomnia in the future. In this paper the authors suggest the clinical applications of neurofeedback for the treatment of insomnia and further clinical researches about its therapeutic effects in insomnia.

Clinical Applications of Neurofeedback Treatment for Insomnia / 수면정신생리

Since the pharmacological treatment of insomnia has the potential risk for dependence and various side effects, nonpharmacological intervention for insomnia is very important in clinical practice. The neurophysiological characteristics and recent researches using quantitative EEG of insomnia suggest the insomnia as a state of CNS(central nervous system) hyperarousal. Insomnia should not be restricted to subjective sleep complaints alone because it appears to be a 24-hour disorder including daytime fatigue and decreased quality of life. The neurofeedback treatment is a self-regulation method based on the paradigm of operant conditioning. The goal of this treatment modality is to normalize the functioning of the brain by inhibiting and/or reinforcing specific frequency bands of brain waves. Therefore, the neurofeedback treatment on the basis of thalamocortical mechanisms which play an important role in sleep and arousal might be a useful treatment modality for the insomnia in the future. In this paper the authors suggest the clinical applications of neurofeedback for the treatment of insomnia and further clinical researches about its therapeutic effects in insomnia.

Neurofeedback Treatment of Panic Disorder

BACKGROUND: It is reported that many types of psychiatric disorders, including anxiety disorder, are related with abnormal brain wave activity, and neurofeedback is associated with clinical improvement in generalized anxiety, OCD, phobic disorder, and PTSD. But in panic disorder, previous studies with neurofeedback are very lacking. Therefore, in this study, the author applied neurofeedback to patients with panic disorder, refractory to cognitive-behavioral therapy and medication. METHODS: From March 2 to May 15 in 2005, six patients with a panic disorder had received 20 sessions of neurofeedback training. The author evaluated the treatment effect by using the alteration of K-APPQ score, the frequency of panic attack, medication and individual handicap. RESULTS: All 6 patients completed 20 sessions of neurofeedback training. At the end, the score of total APPQ, agoraphobia, and interoceptive fear was decreased (P= 0.028) and the frequency of panic attack, medication, and individual handicap was also decreased. CONCLUSION: Neurofeedback training was successful in reducing panic symptom severity, frequency and individual handicap. A controlled study on a larger population is strongly recommended.

The Predictive Factors of Treatment Effects in Children with Attention Deficit Hyperactivity Disorder / 대한정신약물학회지

This study examined 60 children with ADHD through K-ABC, ADDES-HV, ADD-H comprehensive teacher's rating scale (ACTeRS), CAP, SNAP, Academic Performance rating scale, K-PIC, CPT and WCST in order to estimate the effects of methylphenidate, and find out various factors which can influence on treatment responses and predictive factors of treatment. Boys showed better improvement in impulsiveness of behavior symptoms than girls, but girls showed better improvement in trials to completed the first category in WCST. In the aspect of age, the lower graders (age 7-9) showed improvement in sequential processing ability of intelligence but the higher graders (age 10-12) showed deterioration. In the aspect of sub-categories of ADHD, children with mixed type who had been worse in attention deficit and behavior symptoms in pretreatment state, showed significantly higher improvement than children with predominantly inattentive type in every scopes of behavior symptom check list. And in clusters of K-PIC, after treatments the group those who had have more anxiety or depression showed better improvement in omission error in CPT. In the aspect of intelligence level, children with average intelligence showed better improvement in impulsiveness and impulse control than the rests. In the aspect of executive functions, the less omission errors in CPT one made, the better improvement in attention and academic ability he showed. And the less perseverative response in WCST one had, the better improvement in hyperactivity he showed however his simultaneous processing abilities were deteriorated. With these results, this study confirms that methylphenidate is effective in behavior symptoms, academic performance, intelligence and various performance abilities of children with ADHD including attention and response control. In the cases of the children with severe ADHD symptoms, especially behavioral disinhibition and the children with mixed type of ADHD, it is considered useful to predict the results of treatments.

The Characteristics of Executive Dysfunctions and Changes after Mehylphenidate Treatment in ADHD Children / 대한정신약물학회지

The characteristics and changes after methylphenidate treatment of executive functions were conducted. Forty elementary school children, over 85 in intelligence quotient, were selected as experimental group. They are diagnosed to have Attention Deficit Hyperactivity Disorder (ADHD). 40 normal control group were also selected. For comparing of executive functions, ADHD subjects were tested executive functions before and 4 weeks after methylphenidate. Normal control group were also tested. Several behavioral checklists were used, and Kaufman Assessment Battery for Children, Conners Continuous Performance Test, Stop Signal Task, Trail-Making Test (patr B), and Maze test were used. The executive functions and intelligence of ADHD were generally lower than normal control group. On CPT, ADHD showed significantly lower performances in commissions, hit reaction time standard errors, variability of standard errors, and attentiveness. On SST, ADHD presented significantly lower performance in probability of inhibit, stop signal reaction time, Z Score of relative finishing time, Mean delay time on each block, and primary standard deviation. On WCST, ADHD had meaningfully lower performance in total corrects, total errors, nonperseverative errors, completed category, and trials to 1st category completed. After medication, intelligence was not changed, but simultaneous processing ability was improved significantly. And the behavioral problems were improved, but still had differences comparing to control. Commission of Conners' CPT, all aspects of SST and total corrects of WCST were improved.

A Study on Reliability and Validity of the Korean Version of Spiritual Well Being Scale / 신경정신의학

OBJECTIVES: The study is to test reliability and validity of the Korean version of spiritual well being scale which is devised by Paloutzian and Ellison. METHODS: The spiritual well being scale was translated into Korean by two psychiatrist and 131 Christians rated the Korean version of spiritual well being scale. For test-retest reliability, 80 telephone counsellor trainee rated it again after one week interval and statistical analysis was done with the collected data. RESULT: Correlation coefficients were regarded to have good test-retest reliability. Cronbach alpha value of total score, and religious well being subscale and existential well being subscale were significantly high. Among demographic factors, health(healthier) factors, is related with significantly high score of spiritual well-being scale(SWS). Period(over 30year) of christianity showed significant discriminative score of SWS. Factor analysis for validity showed 5 subgroups which were correlated with religious well-being scale(RWS) and existential well-being scale(EWS). 1st subgroup of RWS is related with educational factor, 2nd subgroup of RWS is related with health foactor, 3rd subgroup of RWS is related with personal relationship with God especially, 4th subgroup of EWS is related with health factor and 5th subgroup of EWS is related with reality oriented view. CONCLULSION: The Korean version of SWS which is consisted of RWS and EWS was proved to be a reliable and valid instrument of assessment of spirituality.

The Effect of Imipramine and Desmopressin for the Treatment of Enuresis in Attention Deficit Hyperactivity Disorder Children

PURPOSE: Attention Deficit Hyperactivity Disorder(ADHD) is one of the most common childhood psychiatric diseases and nocturnal enuresis is also a common involuntary disorder, whose symptoms can appear more than 2-3 times per month even after the age of 5. The incidence of nocturnal enuresis is believed to be increasing in ADHD patients. This study investigates the effectiveness of desmopressin and imipramine in the treatment of nocturnal enuresis as well as on ADHD. METHODS: ADHD children of over five years of age displaying nocturnal enuresis were divided into three groups : Group 1, the placebo group; Group 2, the imipramine group; and Group 3, the desmopressin group. They were given their respective treatment agents for 12 weeks and were asked to record their daily urination routine. Their progress was observed two and four weeks after treatment and psychiatric evaluation was performed two weeks after treatment. RESULTS: One week after the start of treatment, the frequency of enuresis in group 3 dropped markedly, showing a much faster treatment response than group 2. Although group 1 showed no significant change in the ADHD index after treatment, groups 2 and 3 showed better ADHD conditions along with enuresis. CONCLUSION: The ADHD scale improved in the two groups whose nocturnal enuresis was successfully treated with imipramine and desmopressin in our study. This may provide evidence for the possibility of one common factor in the cause of ADHD and nocturnal enuresis. More studies on this possibility are required.

Quality of Life in Women Who Underwent Radical Hysterectomy / 대한산부인과학회잡지

OBJECTIVE: he authors evaluated the quality of life in women who underwent radical hysterectomy. METHODS: he protocol of functional assessment of chronic illness therapy by Cella was used to evaluate the quality of life after radical hysterectomy in 156 women. The data was standardized and scaled 0-100 points by Rasch's assessment model. The statistical analysis was done with ANOVA and post-Hoc test. RESULTS: Those with a lower ECOG performance score, housewives, workers, and those who are married had a higher sense of well-being than those with a higher ECOG performance score or who were jobless or widowed. Women with no family or who are single mothers showed lower emotional well-being (EWB) and Medicare patients had a lower social/family well-being (SFWB) or functional assessment of cancer therapy with general (FACT-G) than those who had medical insurances. The EWB and specific symptoms confined to cervical cancer (CxCs) were found to be higher in women who were diagnosed to be at stage I than those to be at stage II. The physical well-being (PWB) was found to be lower in women when adjunctive chemotherapy or radiation therapy had been performed than only the surgery had been done, and the CxCs was found to be lower in women when radiation therapy had been performed than only the surgery had been done. Conclusions: The results of this study suggest that familial, social condition, clinical stage, and treatment modality affect the quality of life of each patient. In conclusion, our results support the importance of earlier prediction and a proper management plan to improve the quality of life in women who had underwent radical hysterectomy.

The Comparison of Intelligence Efficacy According to Methylphenidate Administration in Attention Deficit Hyperactivity Disorder(ADHD) Patients / 영남의대학술지

BACKGROUND: The causes of ADHD(attention deficit hyperactivity disorder) are various, it is impossible to understand the whole characteristics of ADHD, only with simple intellignece testing scales. We compared cognitive characteristics of ADHD group with normal controls with Korean Kaufman Assessment Battery for Children(K-ABC), It is well known to evaluate neuropsychological and cognitive aspects of the children. MATERIALS AND METHODS: Age and sex matched 40 ADHD patients and 40 normal controls tested with the K-ABC. Each subscales compared between pre-treatment patients and controls, pre-treatment and post-treatment in patient group, post-treatment patients and controls. RESULTS: Significant differences are ovserved in sequential processing, simultaneous processing, cognitive processing and achievement between pre-treatment patients and controls, and in gestalt closure between pre-treatment and post-treatment patients group. But there are no significant differences between pre-treatment patients and controls in gestalt closure and reading/decoding. CONCLUSIONS: Methylphenidate improved the scores of simultaneous scale, which means improvement of executive functions such as divided attention, analysis and organization. Methylphenidate also reduced distractibility.

The Effect of Attention Level of Attention Deficit Hyperactivity Disorder on CPT and WCST / 신경정신의학

OBJECTIVES: The purpose of this study was to investigate the effects of attention level in normal children and Attention Deficit Hyperactivity Disorder(ADHD) children on Continuous Performance Test(CPT) and Wisconsin Card Sorting Test(WCST) performances. METHODS: For this survey, the ADHD children were classified into low, medium, and high attention groups according to the attention level. Normal group of children, chosen for their same attention level as that of high attention level group among ADHD groups, was compared in their CPT and WCST performances with ADHD groups. RESULTS: The findings of the study were as follows. 1) the ADHD groups distinguished by their attention level;in other words, the low, medium, and high attention level groups;showed no differences in CPT performances. This means the unique cognitive deficit of ADHD group is not the character of attention capacity limit. 2) the ADHD group showed lower performances on WCST than the normal group, regardless of attention level. CONCLUSION: ADHD group have a deficit in the ability of regulation strategy, adaptability of attention, and non appropriate response, which are needed for efficient division of prescribed information processing. These results imply that the cognitive deficit of ADHD is a character which shows that the execution deficit, which is a higher cognitive function, is a cognitive deficit of ADHD group, rather than simple attention deficit.

The Comparison of the Executive Functions in Children with Tourette's Disorder with Those with Attention Deficit Hyperactivity Disorder / 신경정신의학

OBJECTIVES: This study was performed to verify and compare deterioration of executive functions in the children with Tourette's disorder (TS) with those with Attention Deficit Hyperactivity Disorder (ADHD) and to understand the differentes. METHOD: We administered Kaufman Assessment Battery for Children (K-ABC), Continuous Performance Test (CPT), Wisconsin Card Sorting Test (WCST) on three groups of 18 children each: tow groups of outpatients, one pure TS and one pure ADHD, diagnosed using DSM-IV criteria, and the third, a control group of normal, healthy children who were selected considering age, sex and academic achievement. The children performed all testings without the use of medications RESULTS: In comparisons of CPT perfotmance, the ADHD group showed poor performance with significant difference in commission error, attentiveness and risk taking (p< .05), and the TS group showed significant difference in attentiveness (p< .05) when compared with the control group. There was significant difference between the ADHD group and the TS group in commission error (p< .05). In comparisons of WCST, the ADHD group and the TS group showed significantly poorer performance than the controls in number of trials administered, total number of errors, conceptual level response, number of categories complete, perseverative response and perseverative error (p< .05), but only the ADHD group showed poor performance in perseverative response and perseverative erro r (p< .05). When the results of CPT were analyzed after adjustment for IQ, the ADHD group showed significantly more errors than the TS disorder group in commission error, and only the ADHD group showed significant difference in attentiveness compared with the normal controls (p< .05). In WCST, while these two groups showed significant difference in number of trials administrated, only the ADHD group showed significantly poor performance compared with the normal children group in the 5 sub-categories such as total number of errors, perseverative response, perseverative error, conceptual level response and number of categories complete (p< .05). CONCLUSION: The abnormalities of executive functions appear in both ADHD and Tourette's disorder, but more apparent abnormalities in executive functions were shown in ADHD than in Tourette's disorder. Also the differences of executive functions suggest that these two diseases may have different psychopathophysiology in these dimensions.

Neurobiological Pathophysiology of Attention Deficit Hyperactivity Disorder / 영남의대학술지

BACKGROUND: Models of attention deficit hyperactivity disorder(ADHD) that have proposed a hypodopaminergic state resulting in hypofunction of the prefrontal circuitry have assumed a unitary dopamine system, which largely ignores the distinct functional differences between mesocortical dopamine system and nigrostriatal dopamine system. PURPOSE: The author's goal was to develop a pathophysiological model for ADHD with greater explanotory power than dopaminergic hypofunction hypothesis in prefronal circuitry. MATERIALS AND METHODS: Published clinical findings on ADHD were integrated with data from genetic, pharmacological, neuroimaging studies in human and animals. RESULTS: Molecular genetic studies suggest that three genes may increase the susceptibility to ADHD. The three candidate genes associated with ADHD are each involved in dopaminergic function, and this consistent with the neurobiologic studies implicating catecholamines in the etiology of ADHD. Pharmacological data also provide compelling support for dopamine and noradrenergic hypothesis of ADHD. Neuroimaging studies lend substantial support for the hypothesis that right-sided abnormalities of prefrontal-basal ganglia circuit would be found in ADHD. CONCLUSIONS: The present hypothesis takes advantage of the major differences between the two pertinent dopamine systems. Mesocortical dopamine system, which largely lacks inhibitory autoreceptors, is ideally positioned to regulate cortical inputs, thus improving the signal-to-noise ratio for biologically valued signals. In this circuit, therapeutic doses of stimulants are hypothesized to increase postsynaptic dopamine effects and enhance executive functions. By contrast, symptoms of hyperactivity/impulsivity in ADHD are hypothesized to be associated with relative overactivity of nigrostriatal circuit. This nigrostriatal circuit is tightly regulated by inhibitory autoreceptoors as well as by long distance feedback from the cortex, and slow diffusion of therapeutic doses of stimulant via oral administration is hypothesized to produce a net inhibition of dopaminergic neurotransmission and improves hyperactivity.

The Effects of Methylphenidate on Continuous Performance Test in the Children with Attention Deficit Hyperactivity Disorder / 대한정신약물학회지

This study aims to examine the effect of methylphenidate, which is the most extensively prescribed medicine treating children with Attention Deficit Hyperactivity Disorder (ADHD), on the children's neuropsychiatric functions by comparing the symptomatic differences before and after its medication. MEHTODS: The subjects of this study were 48 children who corresponded to the diagnostic criteria for ADHD of DSM-IV, did not have any problem in vision or hearing, did not have neurologic disorder such as epilepsy and brain damage, and did not have other long term medication. To evaluate the effects of behavioral response and medication, after stopping medication over a week we handed out questionnaires to the parents and conducted CPT to the subjects. A dose of 0.3-0.7 mg/kg (bid or tid) was medicated at 8AM and 1PM everyday. After 4 weeks of medication, the same tests were conducted. RESULTS: Average age of the subjects was 8.88+/-1.55. There were 44 boys (91.7%) and 4 girls (8.3%). Mean intelligence was 96.60+/-18.12 and mental processing was 102.90+/-16.51. On ADDES-HV, after medication attention, impulsivity and hyperactivity were significantly improved (p<0.05). On AcTeRS, after medication attention, impulsivity and social skill were significantly improved (p<0.05). On CAPs, after medication inattention and hyperactivity were significantly improved (p<0.05). On SNAP, after medication inattention impulsivity and hyperactivity were significantly improved (p<0.05). On the academic performance rating scale, after medication total score, learning ability, impulse control and social withdrawal were significantly improved (p<0.05). On performing CPT, after medication commissions error, hit reaction time standard error, variability of standard error and attentiveness were significantly improved (p<0.05). CONCLUSIONS: With these results, we recognized methy-lphenidate is more effective in children's impulsivity and hyperactivity than attention, contrary to the clinical observation.

Effect of Repeated Stress on the Antioxidant Activities of Brain / 대한정신약물학회지

OBJECTIVES: Behavioral stress has been suggested as one of important factors which destruct the physiologic antioxidant system. Studies about antioxidant activity changes in brain by repeated stress may be valuable data in the clarification of pathogenesis and development of treatment modalities for the psychologic stress-induced somatic disease. METHODS: We examined, therefore, immobilization stress -induced antioxidant defense chages in the rat brain. Superoxide dismutase, glutathione peroxidase and, glutathione reductase activities were measured in the dissected specimens of the cerebral cortex, hippocampus, striatum, brain stem, cerebellum and hypothalamus of adult male Sprague-Dawley rats subjected to 2 hour immobilization stress for 14 consecutive days. RESULTS: In this study, immobilization inhibited glutathione peroxidase and glutathione reductase activities in striatum and hypothalamus than any other brain regions. CONCLUSION: These results suggest that striatum and hypothalmus are subject to strong pro-oxidant impacts arising at the repeated immobilization stress.

Application of Stop-Signal Task for Evaluation of Children with Attention Deficit Hyperactivity Disorder / 신경정신의학

OBJECTICES AND METHODS: The purpose of this study was to examine availabilities of stop-signal task as a screening test for ADHD and as a research tool. Stop-signal task was applied to 40 ADHD patients and 18 normal children. Followings are the results of this study. RESULTS: There were significant differences between ADHD group and control group in ZRFT, mean delay x block and primary-RT of stop-signal task performance(p<0.05). There was no significant difference in results of continuous performance test. SSRT of stop-signal task had significant correlation with hit reaction time of continuous performance test, and primary-RT and primary-SD with attentiveness and hit reaction time of continuous performance test. There was no significant correlation between scores of ADDES-HV and stop-signal task performance. In change of primary-SD according to intelligence, primary-SD decreased as intelligence increased but made plateau after IQ 110, and in change of SSRT according to age, SSRT decreased as intelligence increased but made plateau after 10 year-old. In discriminant ability, mean delay x block and primary-RT showed highest discriminant ability (each 75%). In addition P-inhibit showed 63.89%, SSRT showed 58%, ZRFT showed 67%, and primary-SD showed 58% in discriminant ability. There was no significant difference in stop-signal task performance between ADHD with hyperactivity and ADHD without hyperactivity. CONCLUSION: In this point of view, stop-signal task was proved to be a useful research tool for attention deficit hyperactivity disorder as well as useful screening test tool.

The Effects of Repeated Stress on the GABAergic Neurotransmission in Rats / 신경정신의학

OBJECTIVES: Changes of GABAergic neurotransmission in response to the application of different types of environmental stress have been the subject of research for over two decades. However, the nature of the changes induced by stress appear to show a dependent phenomena on the type and duration of stressor agent employed. METHODS: For this reason, this study was performed to observe the effects of repeated stress on the radioligands binding to GABA A/benzodiazepine receptors of discrete brain regions. The author also examined the activity of GABA transaminase and the concentration of endogenous GABA. Male Sprague-Dawley rats, weighing 150-200g were forced to suffer an immobilization stress for 2 hours during 14 consecutive days. RESULTS: Repeated immobilization stress decreased the binding of [3H]flunitrazepam on the benzodiazepine receptor in the cortex, hippocampus and hypothalamus. Saturation experiments followed by scatchard analyses of the results showed decreased density of benzodiazepine receptor and the affinity remained unchanged. Repeated immobilization stress did not affect the binding of [3H]muscimol on the GABAA receptor, the activity of GABA transaminase, and the concentration of endogenous GABA in the brain regions. CONCLUSIONS: From these results, it can be concluded that repeated immobilization stress modulated GABAergic neurotransmission via downregulation of the benzodiazepine receptor in the brain.