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Biomedical subjects

C K Chung

Publications and source records attributed to C K Chung.

At least 37 records · Page 2Linked to original sources
PubMed2000

The lateralizing and surgical prognostic value of a single 2-hour EEG in mesial TLE.

We investigated 109 patients who received anterior temporal lobectomy for intractable mTLE by post-operative follow-up for at least 11/2 years. We reviewed pre-operative 2-hour interictal EEGs, counted interictal epileptiform discharges (IEDs), and compared the lateralization of IEDs with the side of surgery and surgical outcome. Twenty of 22 patients who had no spikes and 44 of 51 who had unitemporal spikes became seizure free after surgical resection. The correct lateralization of the epileptogenic side was possible in 90. 9% of the patients with unitemporal IEDs. In 12 seizure-free patients of 15 patients with less than 70% predominance of IED in one temporal lobe, the positive predictive value of the lateralization was 41.7%. In 16 seizure-free patients of 21 with more than 70% preponderance of IED in one lobe, the positive predictive value was 81.3%. Surgical outcome of patients with unitemporal and bitemporal IEDs were not significantly different. Interictal scalp EEG can be used as a lateralizing tool in mTLE when the temporal IEDs appear with more than 70% preponderance in one side. Although the presence of bitemporal IEDs often causes confusion in terms of the correct lateralization, it does not affect the surgical outcome.

Adult↗
PubMed2000

The clinical usefulness of ictal surface EEG in neocortical epilepsy.

PURPOSE: Localizable scalp EEGs, during ictal episodes, appear to be rare in neocortical epileptic syndromes. However, studies based on large numbers of patients are also rare. This study aims to identify the characteristic patterns of variable neocortical epilepsies and to evaluate their clinical usefulness in the localization of epileptogenic focuses. METHODS: We retrospectively assessed 394 noninvasive ictal recordings from 86 patients who subsequently underwent invasive study and resective surgery. Ictal EEGs were recorded using a video-EEG monitoring system with electrodes placed according to the International 10-20 system, with additional anterior temporal electrodes. The ictal recordings were analyzed according to localizing accuracy and frequency characteristics. The durations of discrete or regional ictal rhythms were also measured. RESULTS: The percentage of discrete or regional EEGs was 23% in frontal lobe epilepsy, 52% in lateral temporal lobe epilepsy, 70% in occipital lobe epilepsy, and 10% in parietal lobe epilepsy. In order of frequency, the localizable ictal rhythms were theta, beta, alpha, delta, and rhythmic spike-and-wave. The duration of discrete or regional ictal rhythms was significantly shorter in frontal lobe epilepsy and parietal lobe epilepsy than in other epilepsies. Ictal beta activity was the most common rhythm in discrete-patterned EEGs. Structural lesions found on MRI did not significantly affect the localization of epileptogenic focuses in the patients. The type of seizure was not related to the degree of localization, with the exception of simple partial seizure. CONCLUSIONS: Ictal surface EEG was clinically helpful in the localization of epileptogenic focuses in at least some neocortical epileptic syndromes.

Adult↗
PubMed2000

Protein kinase C independent activation of inducible nitric oxide synthase by tumor necrosis factor-alpha in TM4 Sertoli cells.

To investigate the nitric oxide (NO) production and its signalling mechanism in TM4 Sertoli cells, the cells were treated with recombinant tumor necrosis factor-alpha (rTNF-alpha), recombinant interleukin-1 alpha (rIL-1alpha), or lipopolysaccharide (LPS), either alone or in combination with recombinant interferon-gamma (rIFN-gamma), and NO production was measured by using the Griess method. TM4 Sertoli cells produced a small amount of NO upon treatment with rIFN-gamma. The effect of rIFN-gamma was drastically increased by cotreatment with rTNF-alpha in a dose-dependent manner. However, combination of rIL-1alpha or LPS with rIFN-gamma did not synergize to activate cells. RIFN-gamma in combination with rTNF-alpha showed marked increase of the expression of iNOS protein. Protein kinase C inhibitors did not inhibit the production of NO induced by rIFN-gamma plus rTNF-alpha. These results suggest that the role of TNF-alpha is to provide TM4 Sertoli cells with the active cofactor for NO production and TNF-alpha-induced signaling for induction of NO synthesis is not dependent on protein kinase C activation.

Animals↗
PubMed2000

Intradural extramedullary tuberculoma of the spinal cord: a case report.

Intradural extramedullary (IDEM) tuberculoma of the spinal cord is uncommon entity and moreover, few reports have been documented on concurrent IDEM and intracranial tuberculomas. Authors report a case of IDEM spinal tuberculoma having intracranial lesion simultaneously. A 49-year-old woman suffered from paraparesis and urinary incontinence while being given medical treatment for tuberculous meningitis. Magnetic resonance imaging (MRI) revealed an IDEM mass lesion between the T1 and T2 spinal levels, and multiple intracranial tuberculous granulomas. Surgical resection of the IDEM tuberculoma followed by anti-tuberculous medication resulted in good outcome.

Brain↗
PubMed2000

MR imaging features of clear-cell meningioma with diffuse leptomeningeal seeding.

Clear-cell meningioma is a rare disease entity showing a more aggressive nature, clinically, than those of other subtypes of meningioma. It occurs in younger persons and commonly in the spinal canal. The recurrence rate has been reported to be as high as 60%. We present a case of clear-cell meningioma in a 17-year-old man in whom initial MR imaging showed localized leptomeningeal enhancement that had progressed into the entire subarachnoid space after surgical resection of the primary tumor.

Adolescent↗
PubMed2000

Combined anomaly of intramedullary arteriovenous malformation and lipomyelomeningocele.

We report a rare situation in which a lipomyelomeningocele and an intramedullary arteriovenous malformation (AVM) occurred together at the T11-L1 level in a 44-year-old man. MR images showed a hypervascular lesion intradurally and a fatty component extradurally. Spinal angiography revealed this lesion to be an intramedullary AVM with multiple feeding arteries from the right T12 and left T10 intercostal artery and the left L1 lumbar artery, drained by tortuous, dilated, perimedullary veins.

Adult↗
PubMed1999

The nitric oxide-producing activities of Scutellaria baicalensis.

Scutellaria baicalensis (SB) has antibacterial and antiviral activities. Nitric oxide (NO) as a potent macrophage-derived effector molecule against a variety of bacteria, viruses and tumors has received increasing attention. The objective of this study was to determine the effect of SB on the production of NO. Stimulation of mouse peritoneal macrophages with SB after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in the increased NO production. SB had no effect on NO production by itself. When SB was used in combination with rIFN-gamma, there was a marked cooperative induction of NO production in a dose-dependent manner. The optimal effect of SB on NO production was shown 6 h after treatment with rIFN-gamma. NO production by SB was inhibited by N(G)-monomethyl-L-arginine. The increased production of NO from rIFN-(gamma) plus SB-stimulated cells was decreased by the treatment of protein kinase C inhibitor such as staurosporin. In addition, synergy between rIFN-gamma and SB was mainly dependent on SB-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of SB were endotoxin free. These results suggest that the capacity of SB to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of SB-induced TNF-gamma secretion.

Animals↗
PubMed1999

Activation of inducible nitric oxide synthase by Taraxacum officinale in mouse peritoneal macrophages.

The objective of the current study was to determine the effect of Taraxacum officinale (TO) on the production of nitric oxide (NO). Stimulation of mouse peritoneal macrophages with TO after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in increased NO synthesis. TO had no effect on NO synthesis by itself. When TO was used in combination with rIFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of TO on NO synthesis was shown 6 h after treatment with rIFN-gamma. This increase in NO synthesis was manifested as an increased amount of inducible NO synthase (iNOS) protein. NO production was inhibited by N(G)-monomethyl-L-arginine. The increased production of NO from rIFN-gamma plus TO-stimulated cells was decreased by treatment with a protein kinase C inhibitor such as staurosporin. In addition, synergy between rIFN-gamma and TO was mainly dependent on TO-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of TO were endotoxin free. These results suggest that the capacity of TO to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of TO-induced TNF-alpha secretion.

Animals↗
PubMed1999

Production of nitric oxide in mouse peritoneal macrophages after priming with interferon-gamma by the stem of Sinomenium acutum.

The present study demonstrates that the aqueous extract of Sinomenium acutum stem (SSAE) produces nitric oxide (NO) upon treatment with recombinant interferon gamma (rIFN-gamma) in mouse peritoneal macrophages. Apparently SSAE has no effect on NO production by itself. This production is dependent on L-arginine and can be inhibited by the L-arginine analogue N(G)-monomethyl-L-arginine. The increased production of NO from rIFN-gamma plus SSAE-stimulated cells was decreased by the treatment of protein kinase C inhibitor. Tumor necrosis factor-alpha (TNF-alpha) has been shown to stimulate the oxidative metabolism of L-arginine to produce NO. Mouse peritoneal macrophages secrete high levels of TNF-alpha after incubation with rIFN-gamma plus SSAE. In addition, SSAE-induced NO production is progressively inhibited by anti-murine TNF-alpha neutralizing antibody. These results show that the capacity of SSAE to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of SSAE-induced TNF-alpha secretion.

Animals↗
PubMed1999

Comparison of localizing values of various diagnostic tests in non-lesional medial temporal lobe epilepsy.

Though the surgical treatment for medial temporal lobe epilepsy yields a high success rate, more studies are needed in order to determine the most efficacious pre-operative algorithm. The authors studied the relationship between surgical outcome and the localization results of various pre-operative diagnostic tests to assess the predictive value. Seventy-one consecutive patients who had undergone anterior temporal lobectomy with amygdalohippocampectomy with the diagnosis of non-lesional medial temporal lobe epilepsy, who had been followed up more than 24 months, were analyzed retrospectively. Electroencephalogy (EEG), magnetic resonance imaging (MRI), proton emission tomography (PET), single photon emission computed tomography (SPECT), the Wada test, and neuropsychological testing were analyzed. There was no diagnostic test that was found to have a statistically significant relationship between Engel Class I outcome and localization results (P & 0.05). SPECT, neuropsychological testing, and the Wada test all had less predictive values (P < 0.01). EEG and PET had comparable predictive values for Engel Class I with MRI (P & 0.05). No single diagnostic test alone is sufficient to make a diagnosis of non-lesional medial temporal lobe epilepsy. MRI, EEG and PET had comparable predictive values for Engel Class I. SPECT, neuropsychological testing, and the Wada test had less predictive values.

Adolescent↗
PubMed1999

Prognostic factors in anterior temporal lobe resections for mesial temporal lobe epilepsy: multivariate analysis.

PURPOSE: Even though there have been several studies on the prognostic factors of temporal lobe epilepsy (TLE) after lobectomy, no studies have been performed for homogeneous mesial TLE. Furthermore, most studies on the predictors of outcome of epileptic surgery were based on univariate analyses and did not consider modern epileptic surgery investigation modalities such as brain magnetic resonance imaging (MRI) and positron emission tomography (PET). We attempted to identify the prognostic factors in anterior temporal lobectomy (ATL) for mesial TLE with multivariate analysis. METHODS: Ninety-three patients with mesial TLE (54 men and 39 women, mean age at surgery, 28.3 +/- 8.2 years) were included in the study. The primary outcome variable was the status of patients in the second postoperative year, classified as either seizure free (except aura), or not seizure free. Clinical, electroencephalographic, MRI, PET, Wada test, and pathological data were considered. RESULTS: Seventy-eight (84.0%) patients had remission of seizures. With univariate analysis, age at surgery (p < 0.001), epilepsy duration before surgery (p = 0.04), and ipsilateral hippocampal sclerosis on MRI (p = 0.02) were found to be significant. By using multivariate analysis, age at surgery (p = 0.001) and ipsilateral hippocampal sclerosis on MRI (p = 0.03) were found to be the most significant prognostic factors. CONCLUSIONS: Age at surgery and hippocampal sclerosis are independent prognostic factors for ATL in mesial TLE. These findings suggest that mesial TLE may be a progressive disorder, and surgical outcome is better when early ATL is performed.

Adolescent↗
PubMed1999

Thoracic intramedullary schwannoma.

We report a rare case of thoracic intramedullary schwannoma. The patient, a 37-year-old woman, showed no evidence of neurofibromatosis. The possible etiology and treatment of the tumor are discussed and a review of literature is presented.

Adult↗
PubMed1999

Comparison of MR imaging with PET and ictal SPECT in 118 patients with intractable epilepsy.

BACKGROUND AND PURPOSE: MR imaging, PET, and ictal SPECT have been studied extensively as individual techniques in the localization of epileptogenic foci, but only a few comparative studies have been done. We evaluated the concordance rates of ictal video/EEG, MR imaging, PET, and ictal SPECT to compare the sensitivities of these imaging methods in the lateralization of epileptogenic foci. METHODS: The study included 118 consecutive patients who underwent surgery for medically intractable epilepsy and who were followed up for 12 months or more. MR imaging was compared retrospectively with ictal video/EEG, FDG-PET, ictal 99mTc-HMPAO SPECT, and invasive EEG as to their ability to localize the epileptogenic focus; the pathologic findings served as the standard of reference. RESULTS: MR imaging was concordant with video/EEG, PET, and ictal SPECT in 58%, 68%, and 58% of patients, respectively. With the pathologic diagnosis as the standard of reference, MR imaging, PET, and ictal SPECT correctly lateralized the lesion in 72%, 85%, and 73% of patients, respectively. Of the patients with good outcomes, MR imaging, PET, and ictal SPECT were correct in 77%, 86%, and 78%, respectively. In the good outcome group, MR imaging was concordant with PET and ictal SPECT in 73% and 62% of patients, respectively. Of 45 patients who underwent invasive EEG, MR imaging was concordant with the invasive study in 47%; PET in 58%; and ictal SPECT in 56%. Of 26 patients with normal MR findings, PET and ictal SPECT correctly lateralized the lesion in 80% and 55%, respectively. CONCLUSION: Overall concordance among the techniques is approximately two thirds or less in lateralizing epileptogenic foci. PET is the most sensitive, even though it provides a broad approximate nature of the epileptogenic zone, which is not adequate for precise surgical localization of epilepsy. PET and/or ictal SPECT may be used as complementary tools in cases of inconclusive lateralization with ictal video/EEG and MR imaging.

Adolescent↗
PubMed1998

Postnatal expressions of non-phosphorylated and phosphorylated neurofilament proteins in the rat hippocampus and the Timm-stained mossy fiber pathway.

Neurofilament proteins (NFPs), the cytoskeletal proteins that are essential for axogenesis and maintenance of neuron shape in the nervous system, were studied for their spatial distributions at nine postnatal days (PN 3, 5, 7, 10, 14, 17, 21, 28, and 120). Simultaneously non-phosphorylated (SMI-32; 150/200 kDa; Sternberger) and phosphorylated (SMI-31; 200 kDa) NFP immunoreactivity in the entire developing rat hippocampus was studied, quantified, and compared to that of mossy fiber (MF) axons and terminals using Neo-Timm's histochemistry, the most selective, sensitive, and reproducible technique. Differential developmental expressions were observed between the two NFP states. SMI-32 was initially expressed on PN 3 only in the perikarya of pyramidal neurons in CA3. As early as PN 5, SMI-31 appeared in the MF pathway, in parallel to the growth of MF axons. By contrast, SMI-32 did not appear at any age in the MF pathway, including the MF terminal zone of stratum lucidum. At PN 14, the distribution of both NFPs in the MF system (MFs and their target neurons, i.e., CA3/CA4 pyramidal neurons and hilar neurons) was nearly complete; however, the peak densities of SMI-32 and SMI-31 were later at PN 21 and statistically equal to the most adult level (PN 120). The temporal regulation and maximal levels of SMI-32 and SMI-31 expressions on MF target neurons (CA3: SMI-32) and in the MF terminal zone (stratum lucidum: SMI-31) were nearly parallel to the progressive and rapid PN growth of the MF axons and terminals occurring between PN 14 and PN 17, suggesting that the mechanisms for maturation of MF synaptogenesis occur after PN 17.

Animals↗
PubMed1998

The association of cigarette smoking and alcohol consumption with other cardiovascular risk factors in men from Seoul, Korea.

PURPOSE: To explore the effects of cigarette smoking and alcohol consumption on cardiovascular disease risk factors such as hypertension, dyslipidemia, and glucose intolerance in Korean men. METHODS: In this cross-sectional study, we gathered the smoking and drinking history by self-administered questionnaire between June 1994 and May 1995 among 1053 men, age 20-77, who visited a prevention center for a multiphasic health check at St. Mary's Hospital, Seoul. RESULTS: Cigarette smoking had a significant inverse association with systolic and diastolic blood pressure. Adjusted for age, body mass index (BMI), and alcohol consumption, the odds ratio of hypercho-lesterolemia (> or = 240 mg/dl) was 1.30 (95% confidence interval (CI) 1.09-1.55), lower high density lipoprotein (HDL) cholesterol (< 40 mg/dl) was 1.29 (95% CI 1.08-1.54), higher low density lipoprotein (LDL) cholesterol (> or = 160 mg/dl) was 1.30 (95% CI 1.07-1.56), and hypertriglyceridemia (> or = 200 mg/dl) was 1.40 (95% CI 1.16-1.68) among men who smoked 21-30 cigarettes per day compared with nonsmokers. Adjusted for age. BMI, and cigarette smoking in men who consumed 90-179 and 180-269 g/week of alcohol compared with nondrinkers, the odds ratio of hypertension was 1.73 (95% CI 1.01-3.00) and 1.48 (95% CI 1.01-2.17), respectively. Alcohol consumption had a significant protective effect (adjusted odds ratio: 0.60-0.78) against lower HDL cholesterol in all categories > or = 90 g of alcohol per week compared with nondrinkers. The adjusted odds ratio of hypertriglyceridemia was 1.17 (95% CI 1.04-1.31), and glucose intolerance (fasting blood sugar (FBS) > or = 120 mg/dl) was 1.27 (95% CI 1.11-1.14) among those who consumed > or = 360 g/week of alcohol compared with nondrinkers. CONCLUSIONS: In this Korean population study, although alcohol consumption increased HDL cholesterol, which might have a protective effect on coronary heart disease, cigarette smoking was associated with decreased blood pressure, smoking was confirmed to have dyslipidemic effect such as increasing total cholesterol, LDL cholesterol, triglyceride and decreasing HDL cholesterol, and alcohol consumption was confirmed to be associated with hypertension, hypertriglyceridemia, and glucose intolerance as in Caucasian. Further prospective intervention studies are needed for evaluating cardiovascular effects after cessation of smoking and drinking.

Adult↗