Biomedical subjects

K Cho

Publications and source records attributed to K Cho.

At least 91 records · Page 5Linked to original sources

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↗

PubMed1997

Improvement of hypertonus after treatment for sleep disturbances in three patients with severe brain damage.

Treatment for sleep disturbance was given to three patients with severe brain damage (a 14-year-old boy, an 8-year-old girl and a 9-year-old boy), and changes in their muscle tone were estimated using F-wave analysis. In all patients, F-wave analysis was performed in the ulnar nerve before and 2 weeks after treatment with flunitrazepam or melatonin. From 16 recordings of F-waves, the mean amplitude and latency, the ratio of F-wave amplitude to M-wave amplitude (F/M ratio), the mean F-wave conduction velocity and the F-wave occurrence were evaluated. All patients showed at least one significant decrement of mean F-wave amplitude, the F-wave occurrence and mean F/M ratio, which suggests a reduction in muscle tone after treatment for sleep disturbance. It is concluded that treatment for sleep disturbance occurring in brain damage is important in view of the improvement of increased muscle tone.

Adolescent↗

PubMed1997

Cloning and characterization of rhesus cytomegalovirus glycoprotein B.

Rhesus cytomegalovirus (RhCMV) infection of rhesus macaques is an important model to investigate critical issues of cytomegalovirus biology. To better understand host immunological responses to viral glycoproteins, the glycoprotein B (gB) gene of RhCMV was molecularly cloned, sequenced and characterized. Transcription analysis revealed that RhCMV gB was transcribed as a late gene. The RhCMV gB gene encoded a predicted protein of 854 amino acids that was 60% identical/75% similar to the human CMV (HCMV) gB protein. The region of HCMV gB proposed to be responsible for virus binding to host cells, fusion and cell-to-cell spread was the most highly conserved region with RhCMV gB (74% identity/85% similarity). Conserved elements included 11 of 12 cysteine residues, 14 of 16 potential N-linked glycosylation sites and cross-reactive epitopes. Metabolic labelling experiments demonstrated that RhCMV gB was proteolytically processed similarly to HCMV gB. These results are critical for investigating virus-host relationships in CMV-infected primates.

Amino Acid Sequence↗

PubMed1997

Pyruvate dehydrogenase complex deficiency with multiple minor anomalies.

Pyruvate dehydrogenase complex (PDHC) deficiency is known to cause congenital lactic acidosis. The case of a 9-month-old female infant with PDHC deficiency caused by a mutation in exon 11 of the pyruvate dehydrogenase (PDH) E1 alpha gene is described. Her facial features were as follows: frontal bossing, upslanting palpebral fissures, a short upturned nose, a long philtrum and low set ears. These anomalies are characteristic not only of a malformation syndrome or chromosomal aberration, but also of PDHC deficiency. Because PDHC deficiency requires early treatment, metabolic disorders should be kept in mind in a patient with dysmorphic features. Further, she had multiple minor anomalies including bilateral inguinal herniae, an umbilical hernia and small hands and feet, which have not been described in previous reports.

Abnormalities, Multiple↗

PubMed1997

Transcriptional regulation and locations of Agrobacterium tumefaciens genes required for complete catabolism of octopine.

By screening for octopine-inducible gene expression, we previously identified all the genes required for utilization of octopine as a source of carbon, nitrogen, and energy. They are (i) octopine oxidase, which converts octopine to arginine and pyruvate and is encoded by the ooxAB operon, (ii) arginase, which converts arginine to ornithine and urea and is encoded by arcA, (iii) ornithine cyclodeaminase, which converts ornithine to proline and ammonia and is encoded by the homologous arcB and ocd genes, and (iv) proline dehydrogenase, which converts proline to glutamate and is encoded by putA. Here we describe the regulation and localization of each of these genes. The ooxA-ooxB-ocd operon was previously shown to reside on the Ti plasmid and to be directly inducible by octopine. The arcAB operon is directly inducible by arginine, while it is induced by octopine only in strains that can convert octopine to arginine. Ornithine may also be a direct inducer of arcAB. putA is directly inducible by proline, while induction by octopine and by arginine (and probably by ornithine) requires their conversion to proline. Genetic studies indicate that arcAB and putA are localized on a conjugal genetic element. This element can be transferred to other Agrobacterium tumefaciens strains by a mechanism that does not require recA-dependent homologous recombination. Transfer of this genetic element from A. tumefaciens R10 requires at least one tra gene found on its Ti plasmid, indicating that this element is not self-transmissible but is mobilizable by the Ti plasmid. The DNA containing the arcAB and putA genes comigrates with a 243-kb linear molecular weight standard on field inversion electrophoretic gels.

Agrobacterium tumefaciens↗

PubMed1997

The value of emergency CT studies in spontaneous rupture of hepatocellular carcinoma. Analysis for tumor protrusion and hemorrhagic ascites.

CT characteristics of spontaneous rupture of HCC (n = 13) were reviewed retrospectively, and the value of emergency CT studies in this disease was evaluated. Especially, tumor protrusion ratio (TPR) and ascitic CT numbers were measured to for comparison with the data for unruptured HCCs and ordinary (e.g. non hemorrhagic) ascites (n = 13). As a result, except for diffuse type HCCs, the TPR was significantly higher than for the unruptured HCCs. Nine cases had intraperitoneal HDAs, and the laterality of the HDAs corresponded with that of the ruptured tumors in 8 cases. Also, the ascitic CT numbers apart from the HDA were still higher than the ordinary ascites. Therefore, a high TPR, HDAs adjacent to the tumor, and elevated ascitic CT numbers are important CT manifestations indicating HCC rupture. Diffuse HCCs, however, require careful clinical evaluation.

Adult↗

PubMed1997

Thallium-201 single photon emission computed tomography imaging of meningioma cells in hyperostosis.

Hyperostosis is a well-known bony reaction associated with meningioma. However, it is difficult to determine preoperatively whether meningioma cells have invaded the bone, and if so, the extent of tumor invasion. Preoperative thallium-201 chloride single photon emission computed tomography (201Tl SPECT) was performed in four patients with meningioma and hyperostosis. The presence of meningioma cells in bone biopsy specimens was also investigated using standard histological techniques. 201Tl SPECT revealed increased uptake in three of the four patients. Biopsy specimens from these three patients revealed invasion of the bony lesions by meningioma cells in accordance with the 201Tl SPECT findings. 201Tl SPECT found no abnormal uptake in the other patient, in which there was also no histological evidence of tumor invasion of bone. Preoperative 201Tl SPECT can provide information on bone invasion by meningioma, which will facilitate preoperative planning of the extent of bony resection required at meningioma surgery.

Adolescent↗

PubMed1997

Intraventricular, cystic, atypical meningioma.

A 37-year-old male presented with a very rare cystic meningioma in the trigone of the left lateral ventricle. Neurological examination revealed mild conduction aphasia and right hemisensory disturbance. Computed tomography and magnetic resonance imaging showed a solid, enhancing tumor in the left trigone which had multiple cystic components located anteriorly and superiorly. The tumor was totally resected via a parietal, transventricular approach. Histological examination revealed an atypical meningioma with cellular pleomorphism and prominent nucleoli. Both the solid component and the cyst wall consisted of tumor cells.

Adult↗

PubMed1997

CNS innervation of the urinary bladder demonstrated by immunohistochemical study for c-fos and pseudorabies virus.

The aim of the present study is to verify the functional and anatomical neural pathways which innervate the urinary bladder in the central nervous system of the rat. To identify the functional neural pathway, the urinary bladder was stimulated by infusing formalin for 2 h. Then, brain and spinal cord were dissected out and immunohistochemistry was done by using anti-c-fos antibody. Many c-fos immunoreactive (IR) neurons were identified in the telencephalic cortical areas and in several brainstem nuclei, which are known mostly to be related with urinary bladder. In the spinal cord, a number of c-fos IR neurons were found in the lamina I, IIo, dorsal gray commissure, sacral parasympathetic nucleus. To identify the anatomical neural pathway of the urinary bladder, Pseudorabies virus (PRV) was injected into the wall of urinary bladder and was identified with anti-PRV by using immunohistochemistry. Most PRV labeled neurons were found where c-fos IR neurons were identified and few of them were also in the areas where c-fos IR neurons were not found, e.g., prefrontal cortex, agranular insular cortex, and subfornical organ. In the spinal cord, PRV labeled cells were found all over the gray matter. The present study presents morphological evidence demonstrating the supraspinal areas are related with the neural control of the urinary bladder and most functional neural pathway of the urinary bladder is well consistent with the anatomical neural pathway except in some telencephalic cortical areas.

Animals↗

PubMed1997

[Uterine cervical carcinoma after radiotherapy: comparison between MR imaging and histopathological findings].

The findings of MRI and pathologic investigation were correlated in curatively irradiated uterine cervical carcinoma. Four patients having residual carcinoma diagnosed by biopsy underwent hysterectomy. MRI demonstrated the mass lesion in one patient with pathologic confirmation of massive viable cancer cells (case I). Of the other three patients, MRI demonstrated normal configuration of the uterine cervix. Cervical signal intensity, however, varied. Hyperintensity was noted in an area of the posterior wall on T2WI in case 2. The anterior wall of the case 2 and the other two cases showed hypointensity. Cervical specimens with normal intensity showed only a small number of degenerated cancer cells. On the other hand, pathologic examination of the posterior wall of the case 2 revealed both cancer cells with varying degrees of degeneration and necrotic tissues. Degeneration of cancer cells was stronger in the superficial layer than the deeper layer. Fibrosis, hemorrhage, granulation and hyalinization were hypointense on T2WI. T2 elongation reflected not only the residual tumor but the post-irradiation changes. Post-irradiated cervix with normal intensity indicated that only a small number of degenerated cancer cells may persist even if the biopsy was positive. We conclude that MRI is useful in evaluating tumor response to radiotherapy.

Carcinoma, Mucoepidermoid↗

PubMed1997

[The usefulness and the problems of attenuation correction using simultaneous transmission and emission data acquisition method: studies on normal volunteers and phantom].

Attenuation correction using simultaneous transmission data (TCT) and emission data (ECT) acquisition method was applied to 201Tl myocardial SPECT with ten normal adults and the phantom in order to validate the efficacy of attenuation correction using this method. Normal adults study demonstrated improved 201Tl accumulation to the septal wall and the posterior wall of the left ventricle and relative decreased activities in the lateral wall with attenuation correction (p < 0.05: paired t-test). The counts of the posterior wall were however, significantly higher than those of the anterior wall and the lateral wall (p < 0.05: unpaired t-test). Moreover, relative low uptake of the apex was enhanced using attenuation correction. Static phantom studies revealed the self scatter from high 201Tl uptake organs such as the liver and the stomach pushed up the activities in the septal wall and the posterior wall. Cardiac dynamic phantom studies showed partial volume effect due to cardiac motion contributed to under-correction of the apex, which might be overcome using gated SPECT. Although simultaneous TCT and ECT acquisition was conceived of the advantageous method for attenuation correction, miss-correction of the special myocardial segments should be taken into account in assessment of attenuation correction compensated images.

Adult↗