Biomedical subjects

K Cho

Publications and source records attributed to K Cho.

At least 73 records · Page 4Linked to original sources

PubMed1999

[Myocardial distribution of iodine-123-iodophenyl-9-methyl-pentadecanoic acid (9MPA) in patients with acute myocardial infarction: comparison with regional wall motion obtained from technetium-99m-sestamibi gated SPECT].

123I-iodophenyl-9-methyl-pentadecanoic acid (9MPA) is a modified long-chain (15 carbons) fatty acid with a methyl branch on its 9 carbon location. Myocardial SPECT images (two sets, 10 min each) were obtained starting 10 min (early phase) and 50 min (delay phase) after the injection of 160 MBq 123I-9MPA at rest in 10 patients with acute myocardial infarction. The segmental myocardial uptake (% uptake) and clearance (% washout) from early to delay image were calculated by the SPECT data. ECG-gated myocardial SPECT with 99mTc-sestamibi was also performed and segmental left ventricular (LV) wall motion was evaluated using QGS (quantitative gated SPECT) program. The % uptake of LV segments with hypokinetic or akinetic wall motion were significantly lower than those with normokinesis (p < 0.01) for both early and delay phases. The % washout of hypokinetic segments were significantly lower than those of normokinetic regions (p < 0.01), while the % washout of akinetic segments were significantly higher than those of severely hypokinetic segments (p < 0.05). Thus, 123I-9MPA myocardial distribution and clearance thought to be associated with left ventricular regional wall motion.

Fatty Acids↗

PubMed1999

[Assessment of left ventricular contraction abnormalities with myocardial infarction using gated technetium-99m sestamibi SPECT: comparison of wall thickening and regional ejection fraction analysis for the detection of coronary artery stenosis].

ECG-gated myocardial Technetium-99m sestamibi SPECT is a useful technique to measure myocardial perfusion and function simultaneously. In this study, wall thickening (WT) and regional ejection fraction (rEF) using ECG-gated SPECT have been studied to determine which parameter would be more sensitive to detect coronary artery stenosis in patients with acute myocardial infarction (AMI). Forty-five patients (36 men, 9 women, mean age 63 +/- 9 years old) with AMI were examined. CAG was performed for all patients. ECG-gated SPECT was performed 60 min after the intravenous injection of 555 MBq 99mTc-sestamibi at rest. Commercially available software (QGS) was used to produce WT and rEF polar maps from acquired SPECT data. The WT and rEF polar maps were evaluated visually and quantitatively. WT indicated higher sensitivity (80.3% vs. 59.1%, p < 0.05) and accuracy (86.7% vs. 74.8%, p < 0.05) than rEF for detecting overall coronary artery stenosis on visual interpretation. On quantitative analysis, WT had higher specificity (91.3% vs. 75.4%, p < 0.05) and accuracy (85.9% vs. 72.6%, p < 0.05) than rEF for detecting overall coronary artery stenosis, and showed a higher specificity (93.8% vs. 59.4%, p < 0.01) and accuracy (88.9% vs. 62.2%, p < 0.01) for detecting LCX stenosis. Moreover, sensitivity of WT for detecting coronary artery stenosis without infarction was higher than that of rEF significantly in quantitative analysis (75.0% vs. 31.3%, p < 0.05). These results suggested that WT was superior to rEF for detecting the coronary artery stenosis in patients with and without myocardial infarction. We concluded that WT is more sensitive indicator to determine localization of regional left ventricular dysfunction in AMI than rEF.

Aged↗

PubMed1999

[Disseminated histoplasmosis caused by Histoplasma capsulatum with cerebral involvement occurring 13 years after the primary infection].

A 49-year-old man with disseminated histoplasmosis (pulmonary and central nervous system involvement) successfully treated with ketoconazole and fluconazole combination is reported. Histoplasma capsulatum infection of the central nervous system is extremely rare in France partly because the organism is not endemic. Oral treatment with newer triazoles may be useful for central nervous system histoplasmosis, but additional information is needed to establish their effectiveness.

Antifungal Agents↗

PubMed1998

Rapid data acquisition protocol in ECG-gated myocardial perfusion SPECT with Tc-99m-tetrofosmin.

Into 25 patients with heart disorders, 99mTc-tetrofosmin 555-740 MBq was injected intravenously at rest. After 40 minutes, ECG-gated myocardial perfusion SPECT was performed with a two detector gamma camera VERTEX (ADAC), setting up two detectors to form a 90-degree angle. Sixteen frames per R-R interval were acquired during a 180 degree rotation from the RAO 45 degrees to the LPO 45 degrees. A pair of data sets with standard (SDA) and rapid data acquisition (RDA) protocols was collected. In an SDA protocol, SPECT imaging was performed for 50 sec per step in 5 degree angular steps (total acquisition time; 15 minutes). An RDA protocol was conducted with 12 sec per step, 6 degree angular steps (acquisition time, 3 minutes). LVEF (%) and LVEDV (ml) quantitated automatically with a QGS program showed excellent correlations between two protocols with correlation coefficients of 0.980 (p < 0.01) and 0.983 (p < 0.01), respectively. Subsequently visual assessment of regional wall motion based on a four-point grading system was carried out with a 3-D cine LV display. High complete agreement was gained with 158 (90.3%) out of total 175 segments, so that assessment of the global and regional LV function with the RDA protocol demonstrated high reliability and feasibility.

Electrocardiography↗

PubMed1998

Cloning and mapping of cat (Felis catus) immunoglobulin and T-cell receptor genes.

Molecular cloning and chromosomal mapping of the cat immunoglobulin (Ig) and T-cell receptor (TcR) genes were carried out to provide basic information for genetic analysis of immunologic diseases including leukemias and lymphomas in cats. We cloned two Ig constant genes, IGHM and IGHG and three TcR constant genes, TRAC, TRGC, and TRDC, by polymerase chain reaction (PCR) amplification of cDNA from cat peripheral blood mononuclear cells. For chromosomal mapping of the Ig and TcR loci including the IGK, IGL, and TRB on the cat genome, we performed PCR screening of DNAs from 37 cat x rodent somatic cell hybrids by using specific primers for the given genes. Consequently, three loci for IGH, TRA, and TRD, and two loci for TRB and TRG were found to be syntenic and assigned to cat chromosomes (FCA) B3 and A2, respectively. Further, IGK and IGL loci were mapped on FCA A3 and D3, respectively. These findings support the notion that the genetic linkages between the Ig and TcR genes are extensively conserved between humans and cats.

Amino Acid Sequence↗

PubMed1998

Effects of neonatal hypoxia on the medulla-spinal cord descending neurons.

Hypoxic changes in the medulla-spinal cord descending neurons were studied morphologically using a retrograde neurotracer, choleratoxin B subunit (CTb). On postnatal day 7, Sprague-Dawley rats were subjected to a hypoxic load of 8% oxygen for 5 hours. In the rats that survived, CTb was injected into the lumbar enlargement at postnatal day 26, and they were killed at postnatal day 28 for histologic analysis. Retrograde transported CTb was visualized by immunohistochemistry. The results were compared with those obtained from control rats. In the control rats, CTb-positive cells were observed in the nucleus reticularis gigantocellularis, nucleus reticularis magnocellularis, nucleus raphe magnus, nucleus raphe obscurus, and nucleus raphe pallidus. In the hypoxic rats, although CTb-positive cells were detected in the same areas as the control rats, there was a noteworthy decrease in the number of CTb-positive cells in all areas, and there were many cells with hypoxic degeneration. In all of the nuclei a marked decrease in the number of CTb-positive cells was observed. Because medulla-spinal cord descending neurons have important roles in the regulation of postural muscle tone, these results may account for the pathophysiology of abnormal muscle tonus accompanying hypoxic brain damage.

Animals↗

PubMed1998

Coarctation of the aorta presenting in a 79-year-old male.

We present a case of coarctation of the aorta with a post-stenotic aneurysm in a 79-year-old male patient. Diagnostic studies included computed tomographic angiogram, magnetic resonance angiogram and digital subtraction angiogram. Our patient underwent operative therapy that resulted in improvement of his hypertension and cardiac function.

Age Factors↗

PubMed1998

The discrepancy between 99Tcm-ECD dynamic and static SPET images in patients with ischaemic lesions corresponds to reduced vasoreactivity to acetazolamide.

We evaluated 99Tcm-N,N'-(1,2-ethylenediyl)bis-L-cysteine diethyl ester (99Tcm-ECD) dynamic and static SPET (single photon emission tomographic) images to examine 99Tcm-ECD kinetics under ischaemic cerebrovascular conditions. In 20 patients who showed arterial occlusion on magnetic resonance angiography, dynamic (0-10 min) and static (15-35 min) SPET images were acquired after the intravenous administration of 99Tcm-ECD. Thirteen of the patients had focal perfusion deficits that were more evident on the dynamic than on the static images; the other seven showed no such discrepancy. In those patients with a mismatch between the dynamic and static images, the extent corresponded to reduced vaso-reactivity to acetazolamide. Based on quantitative analysis of the ratio of tracer uptake in affected to that in unaffected areas, the patients with discrepant findings showed significantly different ratios on the dynamic and static images, whereas those with no such mismatch did not. Our results suggest that dynamic 99Tcm-ECD images provide circulatory information and that static images reflect a filling-in phenomenon of ECD metabolites in ischaemic lesions. 99Tcm-ECD dynamic and static SPET images offer an alternative method of detecting mild perfusion deficits without the need for acetazolamide challenge.

Acetazolamide↗

PubMed1998

Genetic analysis of 13 families with X-linked chronic granulomatous disease reveals a low proportion of sporadic patients and a high proportion of sporadic carriers.

X-linked chronic granulomatous disease (X-CGD) is the most common type of CGD, whose responsible gene has been identified and termed as CYBB, according to the gp91-phox, a subunit of cytochrome b558. Although approximately 200 different mutations of the gp91-phox gene have been reported, no precise study of the proportion of sporadic cases in X-CGD, based on molecular genetic analysis, has been reported. We made a genetic analysis of six newly identified X-CGD patients together with that of eight previously reported X-CGD patients. The mutations newly detected were three missense mutations, two splice mutations, and one insertion of 2 bases. All of the mutations were novel. Twelve mothers (two of them came from the same family) and four maternal grandmothers from 13 different X-CGD families were available for further genetic studies. It was revealed that a proportion of sporadic patients was low and that of sporadic carriers was high. These results suggest that the mutation for the disease originates mainly from male gametes.

Alternative Splicing↗

PubMed1998

Antimorphic goosecoids.

goosecoid (gsc) is a homeobox gene expressed in the Spemann organizer that has been implicated in vertebrate axis formation. Here antimorphic gscs are described. One antimorphic gsc (MTgsc) was fortuitously created by adding 5 myc epitopes to the N terminus of gsc. The other antimorph (VP16gsc) contains the transcriptional activation domain of VP16. mRNA injection of either antimorph inhibits dorsal gastrulation movements and leads to embryos with severe axial defects. They upregulate ventral gene expression in the dorsal marginal zone and inhibit dorsal mesoderm differentiation. Like the VP16 domain, the N-terminal myc tags act by converting wild-type gsc from a transcriptional repressor into an activator. However, unlike MTgsc, VP16gsc is able at low dose to uncouple head from trunk formation, indicating that different antimorphs may elicit distinct phenotypes. The experiments reveal that gsc and/or gsc-related genes function in axis formation and gastrulation. Moreover, this work warns against using myc tags indiscriminately for labeling DNA-binding proteins.

Animals↗

PubMed1998

Quantitative kinetic analysis of blood vessels in the outer membranes of chronic subdural hematomas.

Dynamic biologic modeling was used to calculate the transfer rate constant for gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) and capillary permeability in the outer membrane of chronic subdural hematomas and effusions. Following intravenous Gd-DTPA injection, Gd concentrations in the subdural fluid and in timed arterial blood samples were measured by ion-coupled plasma emission spectrometry in 53 chronic subdural hematomas and 18 chronic subdural effusions. The capillary surface area in outer membrane was assessed morphometrically. Transfer rate constants for subdural hematomas and subdural effusions were 12.4 +/- 1.0 and 20.6 +/- 1.7 (x 10(-4)min-1, respectively. Capillary permeabilities for subdural hematomas and subdural effusions were 16 +/- 1.2 and 19 +/- 3.7 ml.min-1(mm2/mm3)-1, respectively. The capillary surface areas for subdural hematomas and subdural effusions were 48 +/- 3 and 77 +/- 10 mm2/mm3, respectively. The high degree of infiltration of Gd into subdural effusions reflects the high capillary surface area in the outer membrane rather than greater permeability of individual capillaries. The value of transfer rate constant was correlated inversely with the duration of the chronic subdural fluid collection. Immature outer membrane has a high transfer rate constant which allows extravasation of plasma components into the subdural space, resulting in increasing volume of the subdural effusion. Delayed magnetic resonance imaging following Gd administration may be clinically useful for estimating the age of chronic subdural fluid accumulations.

Aged↗

PubMed1998

Pathologic characteristics of primary cutaneous T-cell lymphoma in Korea.

Cutaneous T-cell lymphomas (CTCL) represent a heterogeneous group of peripheral T-cell lymphomas arising in the skin and show considerable variations in clinicopathological features. This study was designed to examine viral genomes and cellular proliferation markers in CTCLs arising in Korea. On the basis of their morphologic characteristics and immunophenotypes, 43 cases of primary CTCL were classified, and evaluated for association with either HTLV-I or EBV, p53 protein immunoreactivity and Ki-67 labeling index (LI). EBV was demonstrated in 15 cases (35%) either by EBER in-situ hybridization or PCR; particularly high rates were exhibited by angiocentric T-cell lymphomas. PCR was used to detect HTLV-I proviral DNA, but none was found. The p53 expression rate was higher in large cell lesions, but the Ki-67 LI failed to show any significant differences among the different types. We therefore concluded that in Korea, HTLV-I is less frequently associated with CTCL than in other endemic countries. EBV was found particularly in angiocentric lesions, regardless of cell size or degree of pleomorphism. Because of its high positive rates in high grade lesions, the p53 expression showed positive correlation with histologic grade; however, the Ki-67 labeling index did not correlate with the histologic grade in CTCL.

Adolescent↗

PubMed1998

Long-term effects of zonisamide in the treatment of epilepsy in children with intellectual disability.

Zonisamide is a new drug with broad-spectrum antiepileptic activity against partial as well as generalized seizures. The purpose of the present study was to compare the long-term efficacy of zonisamide in the treatment of epilepsy in children with intellectual disability (ID) with those with normal intelligence (NI). One hundred and thirty children (74 ID, 56 NI) were included in the study. Fifteen of the subjects were eliminated from the study because of adverse effects or aggravation of seizures. The remaining 115 children (66 ID, 49 NI) were followed up for more than one year. Twenty-eight children (6 ID, 22 NI) were in zonisamide monotherapy. The mean numbers of different antiepileptic drugs were 4.5 and 3 for the ID and NI groups, respectively. The overall improvement rates, defined as a >50% reduction in the number of seizures, were 41% (ID) and 67% (NI) (P<0.01). Side-effects were observed in 27% and 30% of subjects in the ID and NI groups, respectively. However, in the monotherapy group, side-effects were observed in 50% (ID) and in 27% (NI). In conclusion, the effectiveness of zonisamide was weaker in children with ID than those with NI. This is in agreement with the known phenomenon that epileptic children with ID are likely have more intractable seizures than those with NI.

Adolescent↗

PubMed1998

[99mTc-tetrofosmin exercise leg perfusion scintigraphy in arteriosclerosis obliterans (ASO)--assessment of leg ischemia using two phase data acquisition].

Twenty-one patients with arteriosclerosis obliterans (ASO) were studied with 99mTc-tetrofosmin exercise leg perfusion scintigraphy using the delayed administration method. In this method, tracer was injected 4 minutes after termination of symptom-limited repetitive climbing of a stair to validate prolonged vasodilatation in an ischemic lower limb after exercise. Visual and quantitative analyses were performed to evaluate a diseased leg using dynamic and static images. On a posterior whole body image, all cases except one showed decreased foot uptake in the affected side (affected normal ratio; ANR = 0.82 +/- 0.14). On dynamic images, 9 cases showed transient hyper-accumulation (blush phenomenon) only in the thigh of the affected side suggesting that this valuable finding may be a useful diagnostic sign to distinguish a diseased leg. Sensitivity and positive predictive value were 71.4% and 93.8% to detect a diseased leg based on more than one finding of non-visualization of ilio-femoral artery, muscle-soft tissue blush, and early venous return in a dynamic study. Moreover, a low uptake of ANR of below 0.90 in the foot in the static study gave an improved sensitivity of 85.7%. The transit time of the diseased legs (12.0 +/- 3.1 sec.) which was determined as the interval between the time of arterial and venous peak counts was significantly shorter than that of normal legs (17.3 +/- 4.5 sec.; p < 0.0001, paired t-test). The cases with blush phenomenon showed significantly higher thigh ANR (1.04 +/- 0.11) than those without (0.94 +/- 0.08; p < 0.05, unpaired t-test). These results could reflect prolongation of a hypervascular state after exercise in a diseased leg which sometimes induced blush phenomenon at arterial phase and high leg uptake at static phase. This scintigraphy is useful for the detection of a diseased leg as well as for grasping changes of vascular regulation after stress in patients with ASO.

Aged↗

PubMed1998

[Role of endoscopy for the diagnosis of tuberculosis].

The usefulness of bronchoscopy in diagnosis of pulmonary tuberculosis (PT) has been demonstrated with many workers after 1980's. The indication for bronchoscopy is in patients suspected of having active PT with negative sputum smear and polymerase chain reaction (PCR). The combination of bronchial aspiration, brushing, bronchoalveolar lavage, biopsy and postbronchoscopy sputum give a high yield of early diagnosis, ranging from 40-70% of cases. Furthermore, early diagnostic rate improves by these procedure adding PCR in 85%. The bacteriologic study of pleural effusion in diagnosis of tuberculous pleurisy has shown positive results in less than 30 percent of cases. Although the diagnostic rate improves in 60 percent by blind needle biopsy, the diagnostic accuracy is much greater when the thoracoscopy is used, because the pathologist is provided with multiple, selected biopsy. So not only surgeon but also physician should learn thoracoscopy for the diagnosis of pleural effusion.

Bronchoscopy↗

PubMed1997

Separation of cells at different times within G2 and mitosis by cyclin B1 flow cytometry.

Multivariate flow cytometry using specific cyclin proteins and DNA content can identify cell populations at different points within the cell cycle. Quantification of cyclin B1 and DNA content reveals that cells with high levels of cyclin B1 predominantly have a 4C DNA content and are therefore in G2 or mitosis. We have examined whether separation of cells by levels of cyclin B1 could be used to discriminate cells at discrete times within these phases. Post-replicative cells progressively enter into fractions with higher levels of cyclin B1, indicating that this protein can be used as a marker of time in G2. Furthermore, cells in particular phases of mitosis can be greatly enriched by separation based on cyclin B1 levels. This method can thus be used to isolate cells at specific times within G2 and mitosis, periods of the cell cycle that have been difficult to study by cell fractionation.

Adult↗

PubMed1997

Serial imaging in MELAS.

We report two patients with fatal mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Single-photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine was more sensitive to the lesions than CT or MRI. SPECT showed focal hyperperfusion before or during the stroke and diffuse hypoperfusion of the brain, sparing the basal ganglia in the terminal stages. These findings support the theory that metabolic disturbance in the brain causes the "stroke" in MELAS.

Amphetamines↗

PubMed1997

Placental histology and clinical characteristics of patients with preterm premature rupture of membranes.

OBJECTIVE: To analyze the placental histology in cases of preterm premature rupture of membranes (PROM), classify the cases according to the results of the histologic examination, and determine if these histologic groups have different clinical characteristics and outcomes. METHODS: During a 3-year period, a cohort of 235 women with preterm PROM was studied prospectively. The women were classified according to placental histologic findings, and their prenatal and intrapartum courses and perinatal mortality and morbidity were analyzed and compared. RESULTS: One hundred two placentas (43.4%) exhibited acute inflammatory lesions, 48 (20.4%) had vascular lesions, 48 (20.4%) had both inflammatory and vascular lesions, 31 (13.2%) had no abnormal findings, four (1.7%) had villous edema, and two (0.8%) had chronic villitis. The four largest histologic groups had distinctive characteristics with respect to gestational age at the time of PROM and at delivery, duration of the latency period, and perinatal mortality and morbidity. CONCLUSION: Cases of preterm PROM may be classified according to placental histologic findings, and these groups have different clinical manifestations, prognoses, and outcomes.

Adult↗