Biomedical subjects

Eun Ha Lee

Publications and source records attributed to Eun Ha Lee.

11 recordsLinked to original sources

PubMed2006

Effect of coping on endocrinoimmune functions in different stress situations.

The objective of this study was to examine the effects of coping strategies on the endocrine and immune functions in different stress situations. Thirty-eight medical students were enrolled in this study. Cell-mediated immune function was measured using the lymphocyte proliferative response to phytohemagglutinin (PHA) and interleukin-2 (IL-2) production during the nonexamination period and during the preexamination period. Endocrine functions were assessed by measuring the plasma levels of norepinephrine, adrenocorticotropic hormone (ACTH) and cortisol. The Global Assessment of Recent Stress (GARS) scale, the Stress Response Inventory, the anxiety, depression, and somatization subscales of the Symptom Checklist-90-revised, the Way of Coping-revised, the Toronto Alexithymia Scale and the Anger Expression Scale were used as psychometric measures. The subjects with higher levels of total GARS scores showed significantly higher IL-2 production during the nonexam period than those with lower levels of total GARS scores. During the same period, IL-2 production in the less positive reappraisal group was significantly higher than in the more positive reappraisal group. Lymphocyte proliferation in the group seeking less social support was also significantly higher than in the group seeking more social support. However, no significant association was found between the coping strategies and each of the hormone levels. These results suggest that positive reappraisal and seeking social support can be associated with the alteration of immune function during a chronic stress period. In particular, positive reappraisal is likely to reverse the stress-induced immune responses. This study did not find that neuroendocrine function such as the sympathetic-adrenal medullary axis or the hypothalamic-pituitary-adrenal axis is playing a mediating role in the relationship between coping and immunity.

Adaptation, Psychological↗

PubMed2005

Predictive validity of driving-simulator assessments following traumatic brain injury: a preliminary study.

OBJECTIVE: To evaluate whether driving simulator and road test evaluations can predict long-term driving performance, we conducted a prospective study on 11 patients with moderate to severe traumatic brain injury. Sixteen healthy subjects were also tested to provide normative values on the simulator at baseline. METHOD: At their initial evaluation (time-1), subjects' driving skills were measured during a 30-minute simulator trial using an automated 12-measure Simulator Performance Index (SPI), while a trained observer also rated their performance using a Driving Performance Inventory (DPI). In addition, patients were evaluated on the road by a certified driving evaluator. Ten months later (time-2), family members observed patients driving for at least 3 hours over 4 weeks and rated their driving performance using the DPI. RESULTS: At time-1, patients were significantly impaired on automated SPI measures of driving skill, including: speed and steering control, accidents, and vigilance to a divided-attention task. These simulator indices significantly predicted the following aspects of observed driving performance at time-2: handling of automobile controls, regulation of vehicle speed and direction, higher-order judgment and self-control, as well as a trend-level association with car accidents. Automated measures of simulator skill (SPI) were more sensitive and accurate than observational measures of simulator skill (DPI) in predicting actual driving performance. To our surprise, the road test results at time-1 showed no significant relation to driving performance at time-2. CONCLUSION: Simulator-based assessment of patients with brain injuries can provide ecologically valid measures that, in some cases, may be more sensitive than a traditional road test as predictors of long-term driving performance in the community.

Adolescent↗

PubMed2004

Mutation analysis of the MCM gene in Korean patients with MMA.

Methylmalonic acidemia (MMA) is an autosomal recessive inborn error of metabolism caused by inadequate function of methylmalonyl-CoA mutase. We studied five Korean patients diagnosed with mut MMA, here, we report five new missense mutations (G94E, R369C, S344Y, N189K, and T230I) and a previously reported mutation (R369H) that, this is the first time this mutation has been identified in Korean individuals. Genetic heterogeneity in mut MMA is high. The R369H mutation has been identified in America and Japan. To date, more than 55 different mutations have been identified in mut MMA. A majority of mutations is novel with only three (G717V, E117X, and N219Y) being reported more frequently, the G717V mutation was found in Africa-Americans and Ghanaian. The E117X mutation has been found in Japan. The N219Y mutation has been found in Caucasians and Arab. The R369H mutation is the first mutation identified in three nations (Korea, Japan, and America).

Acidosis↗

PubMed2004

Electrophysiologic abnormalities of auditory and visual information processing in patients with traumatic brain injury.

OBJECTIVE: Through both auditory and visual modalities, we sought to explore the efficacy of event-related potentials in detecting residual cognitive impairments in patients with traumatic brain injury (TBI). DESIGN: Control subjects and TBI patients with favorable recovery were recruited. Pure tone and primary color discrimination tasks were utilized to elicit auditory and visual event-related potentials, respectively. All subjects were instructed to push a response button when they detected the target stimuli. Both behavioral and electrophysiologic responses were obtained simultaneously. We analyzed the event-related potential waveforms and examined the differences in amplitude, latency, behavioral reaction time, and response accuracy. RESULTS: A total of 11 TBI patients and 11 control subjects were tested. Results showed that (1) TBI patients had significantly lower P300 amplitude in both auditory (11.2 vs. 22. 7 microV) and visual (11.6 vs. 20.9 microV) domains, (2) TBI patients had significantly longer P300 latency in both auditory (355 vs. 294 msecs) and visual (376 vs. 341 msecs) modalities, and (3) although there was no significant difference in response accuracy (97.7%vs. 100%), reaction time for both auditory and visual tasks were significantly longer in TBI patients (auditory, 404 vs. 277 msecs; visual, 397 vs. 346 msecs). CONCLUSION: Although TBI patients with good recovery showed similar response accuracy when compared with control subjects, they demonstrated significantly poorer performance in both electrophysiologic and behavioral responses. Diminished amplitudes and prolonged latencies in P300 responses indicate impaired organization and categorization of incoming sensory information; prolonged behavioral reaction times suggest slowing in the response execution process. Clinical and theoretical implications and goals for continued research are discussed.

Adult↗

PubMed2004

Brainstem auditory-evoked potentials as an objective tool for evaluating hearing dysfunction in traumatic brain injury.

Because of the violent nature of traumatic brain injury, traumatic brain injury patients are susceptible to various types of trauma involving the auditory system. We report a case of a 55-yr-old man who presented with communication problems after traumatic brain injury. Initial results from behavioral audiometry and Weber/Rinne tests were not reliable because of poor cooperation. He was transferred to our service for inpatient rehabilitation, where review of the initial head computed tomographic scan showed only left temporal bone fracture. Brainstem auditory-evoked potential was then performed to evaluate his hearing function. The results showed bilateral absence of auditory-evoked responses, which strongly suggested bilateral deafness. This finding led to a follow-up computed tomographic scan, with focus on bilateral temporal bones. A subtle transverse fracture of the right temporal bone was then detected, in addition to the left temporal bone fracture previously identified. Like children with hearing impairment, traumatic brain injury patients may not be able to verbalize their auditory deficits in a timely manner. If hearing loss is suspected in a patient who is unable to participate in traditional behavioral audiometric testing, brainstem auditory-evoked potential may be an option for evaluating hearing dysfunction.

Brain Injuries↗

PubMed2003

Hypothalamic-pituitary-adrenal reactivity in boys with attention deficit hyperactivity disorder.

The hypothesis 'whether subjects with attention-deficit/ hyperactivity disorder (ADHD), who showed under-reactivity of the hypothalamic-pituitary-adrenal (HPA) axis to stress, would make more commission errors in attention tasks', was examined. Forty-three boys, with ADHD, who visited the psychiatric outpatient clinic, at Kangbuk Samsung Hospital, were the subjects of this study. Both pre- and post-test morning saliva samples were collected from the patients at the Korean Educational Development Institute-Wechsler Intelligence Scale for Children (KEDI-WISC), and Tests of Variables of Attention (T.O.V.A.) performed. The Standard scores of the T.O.V.A were compared between the patients with decreases, or increases, in the salivary cortisol levels after the test. Decreases, or increases in the salivary cortisol levels after the test were shown in 28 and 15 patients, respectively. The patients with decreased cortisol levels after the test tended to make more commission errors in compared with those with increased cortisol levels. The patients with the decreased cortisol levels after test had more omission errors in the first quarter of the test, and more commission errors in the second half of the test compared to those with the increased cotisol levels. Subjects who show decreased salivary cortisol levels after stress make more commission errors in attention tests. This suggests that the blunted HPA axis response to stress is related to the impulsivity in patients with ADHD.

Attention↗

PubMed2003

Neuroprotective effects of antioxidative flavonoids, quercetin, (+)-dihydroquercetin and quercetin 3-methyl ether, isolated from Opuntia ficus-indica var. saboten.

The flavonoids quercetin, (+)-dihydroquercetin, and quercetin 3-methyl ether were isolated from the ethyl acetate fractions of the fruits and stems of Opuntia ficus-indica var. saboten. In the present study, we evaluated their protective effects against oxidative neuronal injuries induced in primary cultured rat cortical cells and their antioxidant activities by using three different cell-free bioassays. Quercetin was found to inhibit H(2)O(2)- or xanthine (X)/xanthine oxidase (XO)-induced oxidative neuronal cell injury, with an estimated IC(50) of 4-5 micro g/ml. However, it was no more protective at concentrations of 30 micro g/ml and above. (+)-Dihydroquercetin concentration-dependently inhibited oxidative neuronal injuries, but it was less potent than quercetin. On the other hand, quercetin 3-methyl ether potently and dramatically inhibited H(2)O(2)- and X/XO-induced neuronal injuries, with IC(50) values of 0.6 and 0.7 micro g/ml, respectively. All three principles markedly inhibited lipid peroxidation and scavenged 1,1-diphenyl-2-picrylhydrazyl free radicals. In addition, quercetin and quercetin 3-methyl ether were shown to inhibit XO activity in vitro, with respective IC(50) values of 10.67 and 42.01 micro g/ml. These results indicate that quercetin, (+)-dihydroquercetin, and quercetin 3-methyl ether are the active antioxidant principles in the fruits and stems of Opuntia ficus-indica var. saboten exhibiting neuroprotective actions against the oxidative injuries induced in cortical cell cultures. Furthermore, quercetin 3-methyl ether appears to be the most potent neuroprotectant of the three flavonoids isolated from this plant.

Animals↗

PubMed2003

Constituents of the stems and fruits of Opuntia ficus-indica var. saboten.

From the stems and fruits of Opuntia ficus-indica var. saboten, eight flavonoids, kaempferol (1), quercetin (2), kaempferol 3-methyl ether (3), quercetin 3-methyl ether (4), narcissin (5), (+)-dihydrokaempferol (aromadendrin, 6), (+)-dihydroquercetin (taxifolin, 7), eriodictyol (8), and two terpenoids, (6S,9S)-3-oxo-alpha-ionol-beta-D-glucopyranoside (9) and corchoionoside C (10) were isolated and identified by means of chemical and spectroscopic. Among these isolates, compounds 3-5 and 8-10 were reported for the first time from the stems and fruits of O. ficus-indica var. saboten.

Fruit↗

PubMed2003

Use of somatosensory-evoked potentials and cognitive event-related potentials in predicting outcomes of patients with severe traumatic brain injury.

OBJECTIVE: This study was performed to evaluate the usefulness of somatosensory-evoked potentials (SEPs) and cognitive event-related potentials (ERPs) in predicting functional outcomes of severe traumatic brain injury patients. DESIGN: Prospective study of 22 patients with severe traumatic brain injury. Demographic information, Glasgow Coma Scale, and electrophysiologic measurements were recorded. Functional outcomes, as quantified by the Glasgow Outcome Scale-Extended, were obtained. RESULTS: Bilateral absence of median nerve SEP was strongly predictive of the worst functional outcome. The specificity and positive predictive value of absent SEP for predicting death or persistent vegetative state at 6 mo after traumatic brain injury were as high as 100%. If the definition of unfavorable outcome was expanded to include Glasgow Outcome Scale-Extended 1-4, absence of ERP was equivalent to the absence of SEP in specificity and positive predictive value. On the other hand, normal ERPs showed higher sensitivity and negative predictive value for prognosticating the best outcomes compared with normal SEPs. If the definition of favorable outcome was expanded to include Glasgow Outcome Scale-Extended 5-8, ERP was still superior to SEP for prognosticating good outcome. Interestingly, the highest sensitivity and negative predictive value for favorable outcomes were associated with the presence of any discernible waveform. CONCLUSIONS: Although median nerve SEP continues to make reliable prediction of ominous outcome in severe traumatic brain injury, the addition of the speech-evoked ERPs may be helpful in predicting favorable outcomes. The strength of the latter test seems to complement the weakness of the former.

Adolescent↗

PubMed2002

Molecular analysis of PCCB gene in Korean patients with propionic acidemia.

Propionic acidemia (PA) is an autosomal recessive inborn error in the catabolism of methionine, isoleucine, threonine, and valine, odd-numbered chain length fatty acids and cholesterol. Clinical symptoms are very heterogeneous and present as a severe neonatal-onset or a late-onset form. It is caused by a deficiency of propionyl-CoA carboxylase (PCC, EC 6.4.1.3), a biotin-dependent enzyme that catalyzes the carboxylation of propionyl-CoA to D-methylmalonyl-CoA. PCC is a heteropolymeric enzyme composed of alpha- and beta-subunits. A greater heterogeneity is observed in the PCCA gene, while for the PCCB gene, a limited number of mutations is responsible for the majority of the alleles characterized in both Caucasian and Oriental populations. We identified eight Korean patients with PA by organic acid analysis confirmed in five patients by the PCC enzyme assay in the lymphoblasts. Two neonatal-onset patients showed undetectable PCC activities while three cases with residual enzyme activities had relatively late manifestations. In the molecular analysis, we identified five novel mutations, Y439C, 1527del3, 1357insT, IVS12-8T-->A, and 31del10, and one known mutation, T428I in PCCB gene. Alleleic frequency of T428I in Korean patients with PA was 56.3% in this study. Two neonatal-onset patients with null enzyme activities were homozygotes with 1527del3 and T428I, respectively. This finding implies that T428I and 1527del3 mutation could be responsible for their severe clinical courses and null enzyme activities. The mRNA of PCCB gene in T428I and 1527del3 homozygotes were normal but in Western blot analysis, the betaPCC-subunit was only absent in 1527del3 homozygote patient suggesting different molecular pathology.

Blotting, Western↗

PubMedDate not supplied

Event-related potential in facial affect recognition: potential clinical utility in patients with traumatic brain injury.

Traumatic brain injury (TBI) frequently leads to deficits in social behavior. Prior research suggests that such deficits may result from impaired perception of basic social cues. However, these social-emotional deficits have not been studied electrophysiologically. We measured the P300 event-related potential (ERP), which has been shown to be a sensitive index of cognitive efficiency, in 13 patients with a history of moderate to severe TBI and in 13 healthy controls. The P300 response was measured during detection of 30 pictures of angry faces (rare target) randomly distributed among 120 neutral faces (frequent nontarget). Compared to control subjects, the TBI group's P300 responses were significantly delayed in latency (p = 0.002) and lower in amplitude (p = 0.003). TBI patients also showed slower reaction times and reduced accuracy when manually signaling their detection of angry faces. Coefficients of variation (CV) for the facial P300 response compared favorably to those of many standard clinical assays, suggesting potential clinical utility. For this study, we demonstrated the feasibility of studying TBI patients' P300 responses during the recognition of facial affect. Compared to controls, TBI patients showed significantly impaired electrophysiological and behavioral responses while attempting to detect affective facial cues. Additional studies are required for clinicians to determine whether this measure is related to patients' psychosocial function in the community.

Affect↗