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Biomedical subjects

B K Cho

Publications and source records attributed to B K Cho.

At least 37 records · Page 2Linked to original sources
PubMed2001

Intractable epilepsy associated with brain tumors in children: surgical modality and outcome.

OBJECTS: The aim of this study was to evaluate the role of surgical modality in children with brain tumors and intractable epilepsy. METHODS: Twenty-three patients who were treated for brain tumors and intractable epilepsy between January 1985 and March 1998 were retrospectively reviewed. The most common tumors were dysembryoplastic neuroepithelial tumors (n=9), oligodendrogliomas (n=6), and gangliogliomas (n=5). Six patients exhibited cortical dysplasia. The mean duration of follow-up was 43.4 months (range 12 to 125 months). Seizure outcome was more favorable (Engel's classes I and II) in patients with a complete resection of tumor (14/14 vs 6/9 for incomplete resection; P<0.05). There was no significant difference in seizure outcome between lesionectomy (n=13) and epilepsy surgery (n=10). The likelihood of requiring postoperative antiepileptic drugs was not influenced by the extent of resection or type of surgery. CONCLUSIONS: On the basis of this study, we conclude that the complete resection of these tumors can be an appropriate initial treatment for children with brain tumors who experience intractable epilepsy.

Adolescent↗
PubMed2001

Radical excision of pediatric craniopharyngioma: recurrence pattern and prognostic factors.

The purpose of our study was to investigate the pattern of recurrence and the prognostic factors for recurrence of pediatric craniopharyngiomas after radical excision. A series of 36 patients with craniopharyngiomas (21 boys and 15 girls; age range 1-15 years; mean 7.3 years) were reviewed. All patients had undergone radical excision without radiotherapy. The mean follow-up period was 52 months (range 1-149 months). Tumors recurred in 14 patients within 83 months (mean 31.4 months). The overall 5-year recurrence-free survival rate was 55%. Regular neuroimaging follow-up detected tumor recurrence while the lesions were still small before symptoms developed (P<0.05). At the first surgical procedure, the optic nerve/chiasm (n=23) was the most common adhesion site. The most frequent sites of recurrence were the optic nerve/chiasm (n=6) and the pituitary fossa (n=6). Tumor location was the single significant clinical predictor of recurrence. The 5-year recurrence-free survival rate was 39% for those who had an intrasellar tumor component and 81% for those who did not (P<0.05). The Ki-67 labeling indices (LIs) of primary tumors did not have prognostic value for recurrence. Recurrent tumors tended to have higher Ki-67 LIs than their primary counterparts. On the basis of this study, we concluded that craniopharyngiomas with intrasellar components should be followed cautiously and the necessity for regular follow-up should be emphasized, even when the tumor is "totally" resected.

Adolescent↗
PubMed2001

External compression of bronchus by aneurysm from divided major aortopulmonary collateral artery after unifocalization.

The right ventricle to pulmonary artery connection with an extracardiac conduit, left pulmonary artery reconstruction, ligation of patent ductus arteriosus, and take-down of right Blalock--Taussig shunt were performed on a 1-year-8-month-old boy who had pulmonary atresia, ventricular septal defect, patent ductus arteriosus, and major aortopulmonary collateral arteries. He previously underwent the unifocalization and right modified Blalock--Taussig shunt at 9 months of age. He repeatedly had a difficulty in weaning from the mechanical ventilator. After removing the aneurysm from the divided major aortopulmonary collateral artery that compressed the left main bronchus externally, it was possible to wean him from the mechanical ventilator.

Aortic Aneurysm↗
PubMed2001

Biological behavior and tumorigenesis of subependymal giant cell astrocytomas.

In spite of the benign nature of subependymal giant cell astrocytomas (SEGAs), some show massive hemorrhage, rapid growth, and tumor recurrence. This led us to investigate the biological behavior, cell dynamics, and tumorigenesis of SEGAs. All patients (4 men and 3 women; age range, 6-27 years; mean, 13.6 years) had features of tuberous sclerosis complex and obstructive hydrocephalus. One patient had intratumoral bleeding. In two patients, sequential neuroimaging showed a subependymal nodule growing to become a SEGA. All underwent surgical resection without radiation therapy. One tumor recurred and was treated surgically. There were no postoperative deaths. The presence of cytologic atypia, mitoses and vascular proliferation had no implication in terms of the clinical course. MIB-1 labeling indices were low (mean, 0.9), indicating low proliferative potential. Unexpectedly, bcl-2 staining was sparse and bax staining predominated in majority of cases. However, the mean value of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling index was low. Immunohistochemically, tumors were positive for both glial and neuronal markers. In the majority of our cases, the expression of p53 was low. Only one tumor was focally positive for tuberin. SEGAs have low proliferative potential and apoptotic activity, and exhibit features of mixed glial-neuronal differentiation. In contrast to p53, tuberin is suggested to be the tumor suppressor in this tumor.

Adult↗
PubMed2001

Contact dermatitis in Korean dental technicians.

The high risk of occupational contact dermatitis in dental personnel are well accepted throughout the world. There are few reports concerning occupational skin disease in dental personnel in Korea. The purposes of this study were to investigate the frequency, characteristics and causative factors of contact dermatitis in Korean dental technicians. Recording of personal history, physical examination and patch tests with the Korean standard series and dental screening series were performed in 49 dental technicians. Most of the subjects were exposed to a variety of compounds, including acrylics, metals, plaster, alginate, etc. 22 (44.9%) subjects had contact dermatitis, present or past, and the site involved was the hand in all 22. The most common clinical feature of hand dermatitis was itching (77.3%); scaling, fissuring and erythema were other common clinical features. Metals, including potassium dichromate (24.5%), nickel sulfate (18.4%), mercury ammonium chloride (16.3%), cobalt chloride (12.2%) and palladium chloride (10.2%), showed high positive rates in patch test results of 49 dental technicians. 7 positive reactions to the various acrylics were found in 3 subjects. In our study, the frequency and clinical features of the contact dermatitis showed a similarity to other reports, though the patch test results were somewhat different; a higher patch-positive reaction to metals and a relatively lower patch-positive reaction to acrylics than the patch test results reported in Europe.

Adult↗
PubMed2001

Antibacterial effect of antibiotic solution on cellular viability in canine veins.

Pretreatment of tissue by using antibiotics is a critical step to prevent microbial contamination before venous transplantation. In this study, the optimal time and temperature of antibiotic solution treatment for maintaining cellular viability with antibacterial effect were investigated. The antibiotic-nutrient solutions were composed of cefoxitin, lincomycin, vancomycin, and polymyxin B in RPMI-1640 medium. After various antibiotic solution treatment times (4, 8, and 12 h) and temperatures (4, 25, and 37 degrees C), the viabilities of cells dissociated from veins (jugular vein, femoral vein, superior vena cava, and inferior vena cava) were determined. Double staining by Griffonia simplicifolia agglutins-fluorescein isothiocyanate (GS1-FITC) and propidium iodide was used. To measure the antibacterial effect of the antibiotic solution, canine veins were artificially infected by 3 kinds of bacteria (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) and were treated by antibiotic solutions as viability test conditions. After the treatment with the antibiotic solution, the tissue was minced, and the homogenized tissue fraction was cultured on standard method agar. The colony that seemed to be resistant to the antibiotic solution was counted. At 37 and 25 degrees C, the viability of whole cells decreased significantly Asymptotic Significance 2-tailed (Asymp.Sig 2-tailed) < 0.05 after 4 h of antibiotic solution treatment, whereas at 4 degrees C it began to reduce significantly after 8 h of treatment. By antibiotic solution treatment at all 3 temperatures for 4 h, no significant difference in viability of the endothelial cells and whole cells was observed. To maintain the donor vein's cellular viability until transplantation, antibiotic solution treatment for 4 h at 4 degrees C is assumed to be appropriate.

Animals↗
PubMed2001

Hemifacial seizure of cerebellar ganglioglioma origin: seizure control by tumor resection.

The cerebellum is known to have an inhibitory effect on seizures. Nevertheless, cerebellar dysplastic lesions can be epileptogenic. A 4-month-old infant had paroxysmal facial contractions; tachypnea and nystagmoid eyeball and tremulous movements were occasionally combined. These evolved to stereotypic clinical patterns and frequencies, which increased despite administration of antiepileptic drugs (AEDs). Magnetic resonance imaging (MRI) demonstrated a mass arising from the superior cerebellar peduncle, although video-scalp EEG monitoring revealed no abnormal findings. Positron emission tomography with [(18)F]fluorodeoxyglucose revealed focal hypermetabolism in the same area identified by MRI. A depth electrode implanted in the mass revealed focal spike-and-wave discharges. The lesion was partly removed; pathologic diagnosis was ganglioglioma. Because of incomplete seizure control and residual tumor visible on MRI, a second operation was performed. After complete excision of the tumor, the patient became seizure free without AEDs. This case confirms the presence of seizure originating from the cerebellum and emphasizes the need for the complete removal of an epileptogenic lesion.

Cerebellar Neoplasms↗
PubMed2001

Left atrial appendage stenosis.

We describe an unusual case with an anatomic narrowing at the opening of the left atrial appendage demonstrated by two-dimensional color Doppler and continuous-wave Doppler transesophageal echocardiography.

Atrial Appendage↗
PubMed2001

A two-year longitudinal study of dental caries in permanent first molars of Korean elementary schoolchildren.

OBJECTIVE: This longitudinal study investigated dental caries increment in permanent first molars of Korean elementary schoolchildren. METHODS: A convenience sample of 722 children aged 7-9 years attending one urban elementary school was examined at baseline, with follow-up examinations at one and two years. Coronal surfaces of permanent first molars were scored with regard to caries experience and sealant status. RESULTS: Among sound occlusal surfaces at baseline, 21 percent of upper and 25 percent of lower surfaces developed caries during the two-year interval. In teeth that erupted between baseline and the first follow-up exam, over 10 percent of occlusal surfaces developed caries. Pit and fissure caries accounted for 93 percent of all new carious surfaces, while sealants had been placed on 16 percent of occlusal surfaces during the study. CONCLUSIONS: Recognizing the limitations of this convenience sample, dental sealants should be used more widely in this Korean population, and should be applied soon after tooth eruption.

Child↗
PubMed2001

Pathogenesis of lumbosacral lipoma: a test of the "premature dysjunction" theory.

Premature separation of the neuroectoderm from the ipsilateral surface ectoderm allowing mesenchymal tissue to invade into the central canal, or "premature dysjunction" theory, was proposed for the pathogenesis of dorsal type lumbosacral lipoma. To test this theory, the unilateral neural fold was incised using Hamburger and Hamilton stage 12 or 13 chick embryos. Among 35 embryos evaluated, 15 showed abnormal findings, and of these one showed findings which suggested lumbosacral lipoma: a back lump, blending of the neuroepithelium and mesenchyme through indistinct basement membrane and vertebral body abnormalities. The other 14 embryos showed abnormalities including blunt tails, open neural tube defects, incomplete closure of the dorsal neuroepithelium with intact skin, skin dimples, disorganized gray matter, scoliosis, ectopic neuroepithelium and an accessory spinal cord. The results revealed that the incision of the unilateral neural fold in the early chick embryo may produce a lesion suggestive of lumbosacral lipoma, a finding which supports the premature dysjunction theory. This method needs further refinement to overcome technical difficulties, high mortality, and a low yield before being adopted as an experimental model for lumbosacral lipoma.

Animals↗
PubMed2001

Epidemiologic and clinical survey of Behcet's disease in Korea: the first multicenter study.

The prevalence of Behcet's disease is the highest in the East Asian and the Mediterranean countries. Behcet's disease is also distributed in the Asian countries, but the nationwide survey has not been performed in Korea yet. The Korean Study Group for Behcet's Disease, founded in 1999, conducted a multicenter, retrospective survey on epidemiologic and clinical features of the patients with Behcet's disease from 20 hospitals around the nation from 1997 to 1999. Of 3,497 patients, 1,527 were classified into complete or incomplete type of Behcet's disease according to the revised Shimizu's classification. The sex ratio was 1:1.75 with the female predominance. Geographical distribution showed the highest frequency in Seoul (38.5%). Clinically, 98.8% had oral ulcers, 83.2% had genital ulcers, 84.3% had skin lesions and 50.9% had ocular lesions. As for the minor clinical manifestations, articular symptoms were the most frequent. The pathergy test showed positive in 15.4% of patients and revealed a higher positive rate in males (20.2%) than in females (12.7%). In conclusion, we performed the first multicenter study on Behcet's disease in Korea and revealed the female predominance, higher frequency of ocular lesions, and lower positivity of pathergy test in the patients.

Adolescent↗
PubMed2001

The detection of p53 gene mutation using a microdissection technique in primary intracranial germ cell tumors.

Using a microdissection technique, the contribution of the p53 mutation to tumorigenesis and prognosis in each histological subtype of the intracranial germ cell tumors (GCTs) was evaluated. Nineteen patients had primary intracranial GCTs, including 4 germinomas (GEs), 4 teratomas (TEs), 1 mixed tumor of GE and TE, and 10 mixed GCTs containing non-germinomatous malignant germ cell tumors (NG-MGCTs). After microdissection of specific subtypes, genomic DNA was screened for mutations in exons 5-8 of the p53 gene, using the dideoxyfingerprinting (ddF) followed by direct DNA sequencing. The direct sequencing revealed a total of six mutations in PCR products derived from the five cases (26%) which showed mobility shifts in ddF. Among the six mutations detected, four were missense mutations and two were silent. Missense mutations of the p53 gene tended to occur more frequently in the NG-MGCT component than in the GE or TE components (3/15 vs. 1/12 vs. 0/13). The incidence of missense mutations was not different between the survivors (3/13) and the deceased (1/6). This study suggests the possible role of the p53 gene in the tumori-genesis of NG-MGCT. However, p53 gene mutation did not correlate with the prognosis of NG-MGCT.

Adult↗
PubMed2001

Long-term results with St. Jude Medical and CarboMedics prosthetic heart valves.

BACKGROUND AND AIM OF THE STUDY: The clinical evaluation and comparison of St. Jude Medical (SJM) and CarboMedics (CM) prosthetic heart valves implanted between 1988 and 1997 is presented. METHODS: In total, 648 SJM valves were implanted in 641 patients, and 601 CM valves in 591 patients. There were 684 mitral valve replacements, 256 aortic valve replacements, 252 mitral and aortic (double) valve replacements, 16 triple valve replacements, and 41 other tricuspid-related valve replacements. Total follow up was 98%. The overall incidence of valve-related events was compared before and after establishment of a 'valve clinic' in 1993. RESULTS: The overall hospital mortality was 3.4%; late mortality was 8.2%. The five- and ten-year survival for all patients was 92.1% and 86.2%, respectively. There were 31 episodes of thromboembolism in 27 patients (including valve thrombosis in three), 21 episodes of bleeding events in 20 patients, and 18 re-replacements of implanted valves. No structural valve deterioration was observed. Freedom from thromboembolism was 97.8% at five years and 96.3% at ten years; freedom from bleeding episodes was 98.1% and 97.6%, respectively. In terms of hospital and late mortality, and incidence of thromboembolism, hemorrhagic episodes and structural valve failure, no statistically significant differences were found between the SJM and CarboMedics patient groups. Freedom from thromboembolism was 96.7% at five years before initiation of an intensive follow up program, and 99.0% thereafter (p = 0.031). In contrast, freedom from bleeding episodes fell from 99.3% to 96.1% during the same time period (p = 0.0004). CONCLUSION: Both the SJM and CM prosthetic heart valves performed well in our study, and no discernible differences in clinical performance of the two valves were detected. The intensive follow up program resulted in a reduced incidence of thromboembolism, but an increased number of bleeding complications. An optimum anticoagulation regimen to manage these two conflicting problems has yet to be elucidated.

Adolescent↗
PubMed2001

Classic Kaposi sarcoma presenting as rapidly growing nodules.

Classic Kaposi sarcoma (KS) is a sporadic disease that usually affects persons older than 50 years, with a distinct male predominance. Although classic KS has a protracted, indolent course, there appears to be a rare disseminated fulminant type. This report describes a case of classic KS, presenting as a very rapid enlargement and dissemination of skin lesions, without evidence of human immunodeficiency virus (HIV) infection or involvement of other internal organs.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Chronological changes of re-closure capacity in surgically induced spinal open neural tube defects of chick embryos.

To investigate the re-closure capacity of surgically induced spinal open neural tube defects (ONTD) and its correlation to the cell proliferation activity in embryonic stages, longitudinal incisions of 3- or 6-somite lengths were made in neural tubes of chick embryos at Hamburger and Hamilton stage 18-19, and the length of the ONTDs was measured on postoperative days 2, 3, 5, 7, and 10. The results demonstrated that re-closure occurred more actively when the incision length was shorter. The chronological changes in the re-closure capacity of the ONTDs paralleled the proliferative activity of the neural tube. We conclude that surgically induced spinal ONTDs may be remodeled in early chick embryos and that manipulation of cell dynamics can enhance the re-closure process in the embryonic spinal cord tissue.

Animals↗