Clinical Significance of Gray to White Matter Ratio after Cardiopulmonary Resuscitation in Children.

Cardiopulmonary resuscitation (CPR) successfully restores systemic circulation approximately 50% of the time; however, many successfully restored patients have severe neurologic damage. In adults, the gray matter to white matter attenuation ratio (GWR) in brain computed tomography (CT) correlates with the neurologic outcome. However, in children, the clinical significance of GWR still remains unclear. The aim of this study was to evaluate the clinical characteristics of children who underwent CPR for cardiac arrest according to the survival and to demonstrate the differentiation of grey/white matter by Hounsfield units of brain CT and to characterize the attenuations of grey and white matters. METHODS: This is a retrospective single-center study. We enrolled those who underwent brain CT within 24 h after return of spontaneous circulation (ROSC) from January 2005 to June 2018. Brain CTs were taken within 24 h of ROSC. We measured the attenuation of grey and white matter in Hounsfield units and calculated GWR. They were compared with healthy controls. Patients were analyzed as follows: survivors vs. non-survivors and better neurologic outcome vs. worse neurologic outcome. RESULTS: Among 100 pediatric patients who had CPR, 56 met inclusion criteria. There were 24 patients who survived and 32 non-survivors. Our study revealed that the incidence of seizure, duration of CPR, and instances of hypothermia were significantly different between survivors and non-survivors. In both survivors and non-survivors, the attenuation of the caudate nucleus, putamen, GWR-basal ganglia, and average GWR were significantly different from controls. In regression analyses, the medial cortex and average GWR were the significant variables to predict survival, and the receiver operating curves revealed areas under curve of 0.733 and 0.666, respectively. Also, the medial cortex 1 was the only variable that predicted the neurologic outcome. CONCLUSIONS: There was some predictive survival value of GWR and medial cortex at the centrum semiovale level in early brain CT within 24 h after cardiac arrest. Although we could not find the predictive value of GWR in the neurologic outcome of pediatric patients, we found that the absolute attenuation of the medial cortex was low in patients with worse neurologic outcomes. Further prospective, multicenter studies are needed to determine the predictive value of GWR and the medial cortex.

Influenza-associated Neurologic Complications in Hospitalized Pediatric Patients: A Multicenter Retrospective Study in Republic of Korea.

BACKGROUND: The rates of influenza-associated neurologic complications are variable among studies, and a difference has been observed between the Western and Asian countries. The study aims to evaluate the frequency and characteristics of influenza-associated neurologic complications. METHODS: We performed a retrospective review of hospitalized cases of influenza infection from October 2010 to April 2017 from 3 referral hospitals. RESULTS: A total of 1988 influenza cases were identified. Influenza-associated neurologic complications were 161 cases (8.1%); influenza virus A was detected in 113 (70.2%) cases, B in 47 (29.2%) cases and both A and B in 1 case (0.6%). Twenty-four patients (15%) had underlying neurologic diseases. The most common diagnosis was a simple febrile convulsion (44%), followed by complex febrile convulsion (29%), fever-provoked seizure under pre-existing neurologic disease or afebrile seizure (14%), encephalopathy/encephalitis (8%) and meningitis (5%). Most of the patients fully recovered (96%). Three patients (1.9%) died of myocarditis (n = 1), encephalopathy (n = 1), and simultaneous encephalitis and myocarditis (n = 1). Pre-existing neurologic disease, age groups of 6 months to 6 years and 6-12 years were a risk factor of influenza-associated neurologic complications with an adjusted odds ratio of 5.41 (95% confidence interval [CI] 3.23-9.06, P < 0.001), 12.99 (95% CI 1.77-95.19, P = 0.01) and 8.54 (95% CI 1.14-64.79, P = 0.04), respectively. There was no association between neuropsychiatric adverse events and oseltamivir prescription (P = 0.17). CONCLUSIONS: Influenza-associated neurologic complications are not uncommon, and most patients fully recovered. The frequency of influenza-associated neurologic complications in Korean children was not significantly different from that of children in Western countries.

Incidence and characteristics of norovirus-associated benign convulsions with mild gastroenteritis, in comparison with rotavirus ones.

BACKGROUND AND PURPOSE: Rotavirus was detected in 40-50% of patients with benign convulsions with mild gastroenteritis (CwG) before the rotavirus vaccine was introduced in late 2000. However, the rate of rotavirus positivity has decreased since 2010 while the prevalence of norovirus has gradually increased. We investigated the incidence of norovirus-associated CwG during a recent 3-year period and additionally compared the characteristics of norovirus-associated CwG with those of rotavirus-associated CwG. METHODS: The medical records of CwG patients admitted to our hospital between March 2014 and February 2017 were reviewed, including the results of stool virus tests. For comparing norovirus- and rotavirus-associated CwG, data obtained between March 2005 and February 2014 that included sufficient numbers of patients with rotavirus-associated CwG were additionally reviewed. Data were collected on clinical characteristics (age, sex, seasonal distribution, enteric symptoms, and the interval to seizure onset), seizure characteristics (frequency, duration, type, and electroencephalographic findings), and laboratory findings. RESULTS: CwG was diagnosed in 42 patients during the 3-year study period. Stool viruses were checked in 40 (95.2%) patients and were detected in 32 (80.0%) patients. Norovirus genogroup II was detected in 27 (67.5%) of the 40 patients, rotavirus was detected in 3 patients, and adenovirus was detected in 2 patients. In total, 140 CwG patients were enrolled between March 2005 and February 2017. The patients with norovirus-associated CwG (N = 44) and rotavirus-associated CwG (N = 26) were aged 18.66 ±â€¯5.57 and 19.31 ±â€¯7.37 months (mean ±â€¯standard deviation), respectively (P > 0.05). Norovirus-associated CwG was less prevalent than rotavirus-associated CwG during spring (13.6% vs. 34.6%, P = 0.04), while the prevalence of both types of CwG peaked during winter (63.6% and 46.2%, respectively). Vomiting was more prevalent in norovirus- than rotavirus-associated CwG (97.7% vs. 80.8%, P = 0.02) and the interval between enteric symptom onset and seizure onset was shorter in norovirus-associated CwG (2.00 ±â€¯1.06 vs. 2.58 ±â€¯1.21 days, P = 0.04). Most cases in both groups had seizures that lasted for less than 5 min (95.5% vs. 92.3%). Clustered seizures seemed to occur more frequently in the norovirus group (79.5% vs. 57.7%), although with borderline significance (P = 0.05). Posterior slowing was observed more frequently in norovirus-associated CwG (34.9% vs. 11.5%, P = 0.03). CONCLUSION: The most common viral pathogen of CwG was norovirus during the analyzed 3-year period, with an incidence of 67.5%. In comparison with rotavirus-associated CwG, norovirus-associated CwG was less frequent during spring, more frequently seen with vomiting, had a shorter interval from enteric symptom onset to seizure onset, and more frequently showed posterior slowing in electroencephalography.

A Mild Form of COG5 Defect Showing Early-Childhood-Onset Friedreich's-Ataxia-Like Phenotypes with Isolated Cerebellar Atrophy.

Progressive cerebellar ataxias are rare diseases during childhood, especially under 6 years of age. In a single family, three affected siblings exhibited Friedreich's-ataxia-like phenotypes before 2 years of age. They had progressive cerebellar atrophy, intellectual disability, and scoliosis. Although their phenotypes were similar to those observed in patients with autosomal recessive cerebellar ataxias, other phenotypes (e.g., seizure, movement disorders, ophthalmologic disturbance, cardiomyopathy, and cutaneous disorders) were not noted in this family. Whole-exome sequencing of the family members revealed one potential heterozygous mutation (c.1209delG, NM_181733.2; p.Met403IlefsX3, NP_859422.2) of the gene encoding conserved oligomeric Golgi complex subunit 5 (COG5). The heterozygous deletion at the fifth base in exon 12 of COG5 caused a frameshift and premature stop. Western blotting of COG5 proteins in the skin tissues from an affected proband showed a significantly decreased level of full length COG5 and smaller, aberrant COG5 proteins. We reported a milder form of COG5 defect showing Friedreich's-ataxia-like phenotypes without hypotonia, microcephaly, and short stature that were observed in most patients with COG5 defect.

A novel PIGA mutation in a family with X-linked, early-onset epileptic encephalopathy.

Early-onset epileptic encephalopathies (EOEEs) are severe and intractable infantile-onset epilepsies with progressive intellectual disability and other associated neurologic comorbidities. Whole-exome sequencing (WES) was recently used to determine the causative gene mutations in individuals with unclassified EOEEs. The present study used WES to determine the causative variant in a family with X-linked, EOEE. One potential variant (c. 427A>G, NM_002641.3; p.Lys143Glu, NP_002632.1) of the gene encoding phosphatidylinositol glycan biosynthesis class A protein (PIGA; PIGA) was found, which was verified by Sanger sequencing. The functional effect of this PIGA mutation was assessed by the surface expression levels of glycosylphosphatidylinositol-anchored proteins on blood cells: CD16 on red blood cells was significantly decreased in the proband (by 11.0%) and his mother (by 15.6%). This is the second report of a less-severe form of PIGA deficiency.

The relationship between medical students' epistemological beliefs and achievement on a clinical performance examination.

PURPOSE: This study was to explore the relationship between clinical performance examination (CPX) achievement and epistemological beliefs to investigate the potentials of epistemological beliefs in ill-structured medical problem solving tasks. METHODS: We administered the epistemological beliefs questionnaire (EBQ) to fourth-year medical students and correlated the results with their CPX scores. The EBQ comprised 61 items reflecting five belief systems: certainty of knowledge, source of knowledge, rigidity of learning, ability to learn, and speed of knowledge acquisition. The CPX included scores for history taking, physical examination, and patient-physician interaction. RESULTS: The higher epistemological beliefs group obtained significantly higher scores on the CPX with regard to history taking and patient-physician interaction. The epistemological beliefs scores on certainty of knowledge and source of knowledge were significantly positively correlated with patient-physician interaction. The epistemological beliefs scores for ability to learn were significantly positively correlated with those for history taking, physical examination, and patient-physician interaction. CONCLUSION: Students with more sophisticated and advanced epistemological beliefs stances used more comprehensive and varied approaches in the patient-physician interaction. Therefore, educational efforts that encourage discussions pertaining to epistemological views should be considered to improve clinical reasoning and problem-solving competence in the clinic setting.

Familial pachygyria in both genders related to a DCX mutation.

Doublecortin (DCX) and tubulin play critical roles in neuronal migration. DCX mutations usually cause anterior dominant lissencephaly in males and subcortical band heterotopia (SBH) in females. We used whole-exome sequencing to investigate causative gene variants in a large family with late-childhood-onset focal epilepsy and anterior dominant pachygyria without SBH in both genders. Two potential variants were found for the genes encoding DCX and beta tubulin isotype 1 (TUBB1). The novel DCX mutation (p.D90G, NP_000546.2) appeared to be a major causative variant, whereas the novel mutation of TUBB1 (p.R62fsX, NP_110400.1) was found only in patients with more-severe intellectual disability after gender matching. We report an unusual DCX-related disorder exhibiting familial pachygyria without SBH in both genders.

Incidence of benign convulsions with mild gastroenteritis after introduction of rotavirus vaccine.

BACKGROUND AND PURPOSE: Rotavirus was the most common virus in benign convulsions with mild gastroenteritis (CwG), with an incidence of 40-50%. As rotavirus gastroenteritis has decreased since introduction of rotavirus vaccine, we investigated the incidence of CwG and rotavirus positivity after introduction of the vaccine. METHODS: We retrospectively reviewed the medical records of 987 patients aged between 3months and 3years who were admitted to the Chonnam National University Hospital between March 2005 and February 2014 due to their first seizures and enrolled 102 patients with CwG. The incidences of CwG among seizure patients and stool rotavirus positivity in CwG patients were compared between two periods: period I (March 2005-February 2010) and period II (March 2010-February 2014). Other viruses in stools were also reviewed. RESULTS: The incidence of CwG were 8.47% (45 among 531 patients) in period I and 12.50% (57 among 456 patients) in period II (P=0.018). Stool rotavirus was checked in 85.29% (87 patients): 82.22% (37 patients) in period I and 87.72% (50 patients) in period II (P=0.166). The positivity of rotavirus was 40.54% (15 patients) in period I and 16.00% (8 patients) in period II (P=0.01). In the patients without rotavirus gastroenteritis, 30 patients were test for other viruses. Norovirus was the most common (56.67%, 17 patients) and was more frequent in period II than I (71.43% versus 22.22%, P=0.018). CONCLUSION: After introduction of rotavirus vaccine, rotavirus-associated CwG has decreased but the incidence of CwG has increased due to an increase of norovirus.

Characteristics of brain magnetic resonance images at symptom onset in children with moyamoya disease.

OBJECTIVES: To clarify the characteristics of brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) at symptom onset in patients with childhood moyamoya disease (MD) according to developmental stage. METHODS: In 26 childhood MD patients who underwent brain MRI and MRA within 3 months from symptom onset, MRA scores and grades and MRI findings from symptomatic hemispheres were summarized according to developmental stage: infancy (0-1 years, three patients), toddlerhood/preschool age (2-5 years, nine patients), school age (6-10 years, seven patients), and adolescence (11-18 years, seven patients). RESULTS: Mean MRA score was 5.6, which was higher in adolescents (6.9). The most common MRA grade was grade 3, particularly in those under 10 years. Acute ischemic infarction presented in 17 patients (65%), was more common in patients below 5 years (83%) and was mainly in a gyral pattern (47%). Most hemorrhagic infarctions occurred in adolescents. Moyamoya vessels in the Sylvian valleys were apparent in 22 patients (85%), which were the most sensitive non-ischemic findings on T2 weighted images. The signal void in the distal internal carotid artery was diminished in 73% and apparent signal voids in basal ganglia were seen in three patients. The ivy sign was positive in 81% on fluid attenuated inversion recovery images and 69% on contrast-enhanced T1-weighted images in 21 and 16 patients, respectively. CONCLUSIONS: Brain MRIs and MRAs at symptom onset in childhood MD have characteristic findings, which differ in different developmental stage.

Mentoring experience and its effects on medical interns.

INTRODUCTION: Effective mentoring helps interns in the early stages of their medical career to reach personal and professional goals. This study investigated the mentoring experience of Korean interns during medical internship and evaluated mentoring effects to facilitate the development of future mentoring programmes. METHODS: Participants were interns being trained at Chonnam National University Hospital, South Korea, in 2011. Interns were asked to complete a questionnaire about their mentoring experiences and job satisfaction. RESULTS: A total of 61 medical interns participated in the study, giving a response rate of 70.1%. Among these interns, 26 (42.6%) had mentoring experiences, with an average of 2.3 ± 1.9 mentors per mentee. Mentees usually discussed career planning and concerns regarding their personal and social lives with their mentors. Perceived quality of the mentor was significantly more important for male mentees than for female mentees. Female interns without a mentor made significantly less effort to seek a mentor than their male counterparts. Having and not having a mentor resulted in significant differences in the interns' job satisfaction. CONCLUSION: Fewer than half of the medical interns had mentoring experiences. Results suggest that the mentoring relationship may be less satisfying and more challenging for female interns. Effective mentoring may not only help interns plan their medical career, but also increase job satisfaction. Mentoring programmes during medical internship should be expanded and supported, as it is the initial step in a medical career.

Early clinical characteristics according to developmental stage in children with definite moyamoya disease.

The objective is to clarify the early clinical characteristics in childhood moyamoya disease (MD). Epidemiologic characteristics, symptoms and diagnostic rates were assessed in 64 children (0-18 years) with definite MD according to developmental stage: infancy (5; 0-1 years); toddlerhood/preschool age (22; 2-5 years); school age (29; 6-10 years); and adolescence (8; 11-18 years). The median ages at onset was 6.25 years and the female to male ratio was 1.9 (~2.5 in toddlerhood/preschool age and in adolescence, P=0.71). Previous headache was observed in 23% (14/64): frequently in school age (38%, P=0.02) and within 6 months before main symptoms (6/11). As an initial symptom, weakness was observed in 78% (50/64) mainly as transient ischemic attack (TIA, 61%) in limbs (90%) and unilaterally (82%). TIA was less frequent in infancy (40%, P=0.04). Seizure was observed in 27% (17/64): frequently in infancy (100%, P<0.01), as the focal type (71%), and in the right extremity (3:1). Isolated seizures without other symptoms was frequent in children ~5 years (P<0.01). Severe headache associated with MD was observed in 14% (9/64). Provoking events were positive in 42% (27/64): in school age, frequently during eating (28%); and in toddlerhood/preschool age, during crying (27%). The diagnostic rates at 3 and 12 months from symptom-onset were 39% (80% during infancy vs. 28% in school age, P=0.14) and 67%, respectively. Symptomatic progression at diagnosis was observed in 38% (24/64). Initial clinical characteristics in childhood definite MD differed according to developmental stage and from at diagnosis.

Advance organizers in a gross anatomy dissection course and their effects on academic achievement.

We presented two kinds of advance organizers (AOs), video clips and prosection, for a gross anatomy dissection course and compared their effects on academic achievement and student perception of the learning experience. In total, 141 students at Chonnam National University Medical School were randomly assigned to two groups: Group 1 (n = 70) was provided with video clips AO, whereas Group 2 (n = 71) was provided with prosection AO, the use of cadaveric specimens dissected by the course instructor. Student self-assessment scores regarding the learning objectives of upper limb anatomy improved significantly in both groups. Academic achievement scores in Group 2 were significantly higher than those in Group 1, although the self-assessment scores were not significantly different between the groups. Additionally, students in Group 2 responded significantly more positively to the statements about perception of the learning experience such as helping them understand the course content and concepts, decreasing anxiety about the dissection course, and participating actively in the dissection. It would seem that the application of prosection as an AO improved academic achievement and increased student engagement and satisfaction. This study will contribute to designing effective AOs and developing a teaching and learning strategy for a gross anatomy dissection course.

Medical residents' job satisfaction and their related factors.

PURPOSE: This study was conducted to investigate medical residents' job satisfaction and their related factors to improve the quality of residency program. METHODS: The study subjects were 159 medical residents being trained at Chonnam National University Hospital, South Korea, in 2011. The participants were asked to complete a short form Minnesota satisfaction questionnaire (MSQ). RESULTS: The mean score for 20 items on the short form MSQ varied between 2.91 and 3.64 on a 5-point Likert scale. The assessment of related factors with job satisfaction revealed that medical residents had higher levels for job satisfaction, particularly those who were women (beta=0.200, p=0.022), and those who had mentorship experience (beta=0.219, p=0.008). CONCLUSION: This study results indicate that we should expand and support the mentorship program during medical residency to promote job satisfaction.

Prevalence of primary immunodeficiency in Korea.

This study represents the first epidemiological study based on the national registry of primary immunodeficiencies (PID) in Korea. Patient data were collected from 23 major hospitals. A total of 152 patients with PID (under 19 yr of age), who were observed from 2001 to 2005, have been entered in this registry. The period prevalence of PID in Korea in 2005 is 11.25 per million children. The following frequencies were found: antibody deficiencies, 53.3% (n = 81), phagocytic disorders, 28.9% (n = 44); combined immunodeficiencies, 13.2% (n = 20); and T cell deficiencies, 4.6% (n = 7). Congenital agammaglobulinemia (n = 21) and selective IgA deficiency (n = 21) were the most frequently reported antibody deficiency. Other reported deficiencies were common variable immunodeficiencies (n = 16), X-linked agammaglobulinemia (n = 15), IgG subclass deficiency (n = 4). Phagocytic disorder was mostly chronic granulomatous disease. A small number of patients with Wiskott-Aldrich syndrome, hyper-IgE syndrome, and severe combined immunodeficiency were also registered. Overall, the most common first manifestation was pneumonia. This study provides data that permit a more accurate estimation PID patients in Korea.

Neurologic adverse events following influenza A (H1N1) vaccinations in children.

BACKGROUND: Since the monovalent pandemic influenza A (H1N1) vaccine was recommended worldwide in October 2009, there has been a shortage of pediatric clinical data for post-vaccine neurologic adverse events (NAE), including Guillain-Barré syndrome. We reviewed pediatric NAE data following H1N1 vaccinations and for patients with peripheral neuropathy, we followed their progress. METHODS: In our single-center study, we retrospectively reviewed 14 cases of children who visited the Division of Pediatric Neurology in the Department of Pediatrics of Chonnam National University Hospital due to NAE following monovalent influenza A (H1N1) vaccination between November 2009 and March 2010. RESULTS: Clinical diagnoses for major NAE included: polyneuropathy in the extremities (11/14, 78.6%), sensory mononeuropathy with numbness in the left fibula area (1/14, 7.1%), Bell's palsy (1/14, 7.1%) and recent-onset acute headache only (1/14, 7.1%). Therefore, most patients were diagnosed as having peripheral neuropathy (13/14, 92.9%), and two met the Brighton Collaboration Guillain-Barré syndrome definition criteria for level 3 (the lowest level of diagnostic certainty). CONCLUSIONS: Post-vaccine NAE were mainly motor weakness due to polyneuropathy, which had a good prognosis of complete improvement within a few months without sequelae.

Mutation Screening of the γ-Aminobutyric Acid Type-A Receptor Subunit γ2 Gene in Korean Patients with Childhood Absence Epilepsy.

BACKGROUND AND PURPOSE: Since the γ-aminobutyric acid type-A receptor subunit γ2 gene (GABRG2) mutation was discovered in an Australian family with childhood absence epilepsy (CAE) and febrile convulsions, a few screening studies for the GABRG2 mutation have been conducted in sporadic individuals with CAE from other ethnic groups. The aim of this study was to determine whether or not the previously reported genetic mutations and single-nucleotide polymorphisms (SNPs) of GABRG2 can be reproduced in sporadic Korean individuals with CAE, compared to healthy Korean individuals. METHODS: Thirty-five children with CAE in Chonnam National University Hospital and healthy controls (n=207) were enrolled, and the medical records of patients with CAE were reviewed. CAE was diagnosed according to the Classification and Terminology of the International League Against Epilepsy. All nine exons of GABRG2 were directly sequenced. In addition, the two SNPs found in our CAE patients were analyzed: C315T in exon 3 (E3) and C588T in exon 5 (E5). The frequencies of the two SNPs in the CAE patients were compared with data from healthy controls (for E3 and E5) and from previously reported Korean population data (only for E3). RESULTS: No mutation of GABRG2 was found in our CAE patients. In addition, the allele and genotype frequencies of the two polymorphisms did not differ significantly between CAE patients, healthy controls, and the Korean general population (p>0.05). CONCLUSIONS: Our study of sporadic Korean individuals with CAE found no evidence that GABRG2 contributes to the genetic basis of CAE.

Reference values for serum levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in Korean children and adolescents.

OBJECTIVE: Measurements of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are utilized in the diagnostic work-up and clinical management of children with growth disorders. We designed this study to establish the reference values of serum IGF-I and IGFBP-3 levels according to age, sex and pubertal stage in Korean children and adolescents. METHODS: For the study, 1378 healthy Korean children and adolescents aged 0 to 17 years (722 boys, 656 girls) were randomly selected. Blood samples were collected, and the stored sera were assayed for IGF-I and IGFBP-3 using immunoradiometric assay (IRMA, Immunotech). The R 2.8.1 program (Bell Laboratories) was used to generate reference percentile curves for IGF-I and IGFBP-3 according to age, sex, and pubertal stage RESULTS: Serum IGFBP-3 level was higher in girls compared to that in boys of the same ages throughout the pubertal period, whereas IGF-I was only higher for girls younger than 13 years of age. Serum levels of IGF-I and IGFBP-3 increased steadily with age in the prepubertal stage, followed by a progressive decline thereafter. Peak levels of serum IGF-I and IGFBP-3 were observed two years earlier in girls compared to those in boys (13 vs. 15 years of age, respectively). Serum IGF-I and IGFBP-3 concentrations were highest at Tanner stage IV in boys and girls, with a subsequent decline. CONCLUSIONS: Our reference value model based on age, sex, and pubertal stage can improve the diagnostic utility of IGF-1 and IGFBP-3 levels in the evaluation and management of Korean children and adolescents with growth disorders.

Medical students' failure experiences and their related factors.

PURPOSE: A considerable number of medical students drop out due to low academic achievement, and these students have a high probability of repeated failure experiences. This study investigated the personal and academic problems of these students to help develop student support systems. METHODS: First-year (n=146) and second-year (n=119) medical students were asked to complete questionnaires. The questionnaires consisted of personality traits and the students' management of/satisfaction with school life. RESULTS: Students who had already dropped out accounted for 17.4% of the study subjects. The most common reason for dropping out was low academic achievement, and the most difficult part of taking a leave of absence from school was psychological anxiety. The group who dropped out had significantly lower levels of emotional stability, sociability, responsibility, dominance, masculinity, and superiority and more vulnerable mental states compared with those who did not drop out. They also expressed less motivation with regard to medical science and less satisfaction with school life than did the group that did not drop out. Those who dropped out tended not to prepare for exams, and they managed their time ineffectively. They also tried to resolve their difficulties alone and rarely sought help from teachers. CONCLUSION: More intimate student-teacher relationships should be established, and teachers should be encouraged to meet and interact with their students on a regular basis. Additionally, personality inventories should be used to assist in efforts to understand students, especially to identify hidden social and emotional problems.

Stem cell dynamics in an experimental model of stroke.

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin(+) NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin(+) NSCs in the ipsilateral cortex and CC increased at 12 hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.