Publications by authors named "Se Chang Yoon"

Obsessive-compulsive symptoms (OCS) commonly occur in the course of schizophrenia. The aim of this study was to investigate the rate of obsessive-compulsive disorder (OCD) in patients with chronic schizophrenia and evaluate lifetime correlates of the comorbidity. Subjects were clinically stable patients with chronic schizophrenia (n = 320).

View Article and Find Full Text PDF

BACKGROUND The aim of this study was to investigate the detailed motives, concerns, and psychological defensiveness of living liver donor candidates in a Korean population. MATERIAL AND METHODS We analyzed data of 102 donor candidates obtained from routine psychosocial evaluation for living donor liver transplantation (LDLT) using descriptive methods. Donor candidates completed 2 questionnaires regarding their motivations and concerns, as well as a validity scale, the K scale from the Minnesota Multiphasic Personality Inventory-2.

View Article and Find Full Text PDF

Objective: Chromosome 22q11 has been implicated as a susceptibility locus of schizophrenia. It also contains various candidate genes for which evidence of association with schizophrenia has been reported. To determine whether genetic variations in chromosome 22q11 are associated with schizophrenia in Koreans, we performed a linkage analysis and case-control association study.

View Article and Find Full Text PDF

Antidepressants are known to have no significant ability to cause addiction. However, a recent study showed many individuals with mood disorders self-medicated with antidepressants to relieve symptoms. We report here a male physician, diagnosed five years ago with major depressive disorder, with insomnia, anxiousness, and chest heaviness.

View Article and Find Full Text PDF

Objective: We evaluated cell viability and proliferation activity of peripheral lymphocytes as potential models of neuronal death in Alzheimer's disease (AD).

Methods: We analyzed the cell viability and proliferation activity of phytohemagglutinin (PHA)-activated lymphocytes from 68 AD patients and 33 normal controls. The cellular measures were made at baseline (0 hr), 24 hrs, 48 hrs, 72 hrs, and 96 hrs after PHA stimulation.

View Article and Find Full Text PDF

Objectives: Studies have shown that patients with congenital facial anomalies are vulnerable to depression. In addition, concealment of facial anomalies in an effort to mask handicaps is common, and these patients also often have difficulties with interpersonal relationships and in social situations. Despite this, no previous study has investigated the association between concealment of facial anomalies and depression, and a patient's quality of life.

View Article and Find Full Text PDF

Objective: This paper aims to examine the association between painful physical symptoms (PPS) and major depressive disorder (MDD) in a naturalistic clinical practice setting within a Korean population.

Methods: Patients with acute MDD that joined a multicountry, observational, three-month study in six Asian countries and regions were classified as PPS+ (mean score >/=2) and PPS- (mean score <2) using the modified Somatic Symptom Inventory. In this analysis, we report the results from the Korean subset, where depression severity was assessed using the Clinical Global Impression of Severity (CGI-S) scale and 17-item Hamilton Depression Rating Scale (HAMD(17)).

View Article and Find Full Text PDF

The purpose of the present study was to identify the factor structure of neurocognitive tests used on schizophrenia patients by using the confirmative factor analysis, and to assess the factor score differences of schizophrenia patients and healthy controls. Comprehensive neurocognitive tests were administered to stabilized schizophrenia patients (N=114) and healthy controls (N=120). In the results of factor analyses on patients, the multifactorial-6-factor model, which included the speed of processing, working memory, verbal learning and memory, visual learning and memory, attention/vigilance, and reasoning/problem solving as suggested by the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS), showed the better goodness of fit than any of the other models tested.

View Article and Find Full Text PDF

Even though a large body of data suggests the presence of various types of cognitive deficits in the unaffected relatives of schizophrenia patients, more study is needed to clarify the comparative sensitivities of specific cognitive measures for relative-control differences. In this study, the authors compared the cognitive profiles of unaffected siblings of schizophrenia patients and those of patients and normal controls, and attempted to identify cognitive markers that might be associated with genetic liability to schizophrenia. Eighty-eight clinically stable schizophrenia patients, 44 healthy patient siblings, and 100 normal controls were evaluated using comprehensive neuropsychological tests.

View Article and Find Full Text PDF

In experimental animals, including rats, MK-801 produces characteristic behavioural changes that model schizophrenia. It has been hypothesized that these changes accompany long-term synaptic changes, which require protein neosynthesis. We observed the effect of MK-801 on the "mammalian target of rapamycin" (mTOR)/70-kDa ribosomal protein S6 kinase (p70S6K) pathway that regulates protein synthesis in the rat frontal cortex.

View Article and Find Full Text PDF

Repeated administrations of NMDA receptor antagonists induce behavioural changes which resemble the symptoms of schizophrenia in animals. ERK and GSK-3beta associated signalling pathways have been implicated in the pathogenesis of psychosis and in the action mechanisms of various psychotropic agents. Here, we observed the phosphorylations of ERK and GSK-3beta and related molecules in the rat frontal cortex after repeated intraperitoneal injections of MK-801, over periods of 1, 5, and 10 d.

View Article and Find Full Text PDF

The catechol-O-methyl transferase (COMT) gene has been a promising candidate in genetic research on schizophrenia because of its function in dopamine metabolism and its location on chromosome 22q11.2, which may be implicated in both schizophrenia and velocardiofacial syndrome (VCFS). To explore the possible genetic contribution of COMT to the development of schizophrenia, we focused on the subgroup of patients with schizophrenia characterized by minor physical anomalies as a phenotype and the 158 Val/Met polymorphism as a genotype.

View Article and Find Full Text PDF

ERK5-MEF2C has been implicated in many aspects of neuronal survival and neuroprotection. Neurotrophic effects have been considered as one of the mechanisms in therapeutic electroconvulsive shock (ECS). To investigate whether ECS activates ERK5-MEF2C, we examined the phosphorylation of ERK5, along with its downstream molecule MEF2C, after ECS in the rat frontal cortex and hippocampus.

View Article and Find Full Text PDF

GSK-3beta is regarded as playing an important part in the pathogenesis of schizophrenia and the action of psychotomimetic agents. We observed phosphorylation of molecules associated with the GSK-3beta signalling pathway in the rat brain after MK-801 injection, which induces a schizophrenia-like state in humans. Ser9-GSK-3beta phosphorylation was increased after injection of 1 mg/kg MK-801 in the rat frontal cortex but not in the hippocampus or cerebellum.

View Article and Find Full Text PDF

Background: Recent reports indicate that repeated electroconvulsive shock (ECS) induces cortical cell proliferation, suggesting the possibility that ECS may activate cell cycle progression in the rat brain cortex.

Methods: Sprague-Dawley rats (150-200g) were divided into four treatment groups and then given sham treatment or ECS treatment for 1, 5, and 10 days, respectively. The activity of cyclin-dependent kinase 2 (Cdk2), phosphorylation, and total protein amount of cyclin D1, cyclin E, pocket retinoblastoma family of protein (pRB), and E2F1 were analyzed in the rat cerebral cortex.

View Article and Find Full Text PDF

It has been suggested that FAK and PYK2 have differential regulatory pathways and differential functions in the central nervous system. The authors have previously reported that electroconvulsive shock (ECS) activates PYK2 mediated signaling in the rat hippocampus. In the present article, the authors examined the effect of ECS on PYK2 and FAK mediated signaling in the rat cerebral cortex and hippocampus.

View Article and Find Full Text PDF

We investigated the effect of 10 microM clozapine on the activity of glycogen synthase kinase-3beta (GSK-3beta) and its upstream and downstream molecules in SH-SY5Y human neuroblastoma cells. Clozapine activates both Akt- and Dvl-mediated phosphorylation of GSK-3beta through phosphorylation at Ser9, and increased total cellular and intranuclear levels of beta-catenin. Pretreatment with the specific inhibitor of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway, LY294002 (20 microM), prevented the phosphorylation of Akt but did not affect the phosphorylation of GSK-3beta.

View Article and Find Full Text PDF

The analysis of heart rate variability (HRV) has proven to be useful in evaluating the neuroautonomic dysfunctions associated with various clinical conditions. The purpose of this study was to investigate the linear and non-linear dynamic measures of HRV, and to evaluate their relationship with the psychotic symptom severity, in clozapine-treated schizophrenic subjects. Fifty schizophrenic patients treated with clozapine as monotherapy and 50 normal control subjects were evaluated for HRV analysis.

View Article and Find Full Text PDF

Phospholipase Cgamma1 (PLCgamma1) plays an important role in controlling cellular proliferation and differentiation. PLCgamma1 is overexpressed in some tumors, and its overexpression induces solid tumors in nude mice. However, the regulatory mechanisms underlying PLCgamma1-induced cell proliferation are not fully understood.

View Article and Find Full Text PDF

Synopsis of recent research by authors named "Se Chang Yoon"

  • - Se Chang Yoon's research primarily focuses on the intersection of psychiatric disorders, particularly schizophrenia and depression, with various psychosocial and biological factors influencing patient outcomes and treatment efficacy.
  • - Recent studies by Yoon have highlighted comorbid obsessive-compulsive disorder (OCD) in chronic schizophrenia patients, psychosocial factors affecting living liver donors, and associations between painful physical symptoms and major depressive disorder in Korean populations.
  • - Yoon has also engaged in genetic studies examining associations between chromosome variations and schizophrenia, active neurocognitive assessments of unaffected siblings of schizophrenia patients, and explored differential signaling pathways in response to psychotropic interventions.