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Biomedical subjects

I S Choi

Publications and source records attributed to I S Choi.

At least 73 records · Page 4Linked to original sources
PubMed1999

Delayed movement disorders after carbon monoxide poisoning.

Of 242 patients with carbon monoxide (CO) poisoning examined between 1986 and 1996, delayed movement disorders were diagnosed in 32 (13. 2%). There were 15 men and 17 women. Ages at insult ranged from 9 to 69 years (mean 45.3 years). Of the 32 patients with delayed movement disorders, 23 (71.9%) had parkinsonism, 5 dystonia, 3 chorea and 1 myoclonus. All were associated with delayed CO encephalopathy. The median latency between CO poisoning and the onset of movement disorders was 4 weeks for parkinsonism, 51 weeks for dystonia, 4 weeks for chorea and 8 weeks for myoclonus. The latency of dystonia onset after CO poisoning was longer than that of other types of movement disorders. The CT findings in delayed movement disorders after CO poisoning were variable, and there was no correlation between the sites of imaging and the development of movement disorders. Abnormal dyskinesias disappeared within 8 weeks, and patients recovered from parkinsonism within 6 months. In conclusion, delayed movement disorders after CO poisoning are not rare, and usually appear as a part of delayed CO encephalopathy. The prognosis is good.

Adolescent↗
PubMed1999

Primary and elective stenting of unprotected isolated left main coronary ostial stenosis in acute coronary syndrome.

Direct surgical angioplasty or coronary artery bypass graft has been done in patients who have left main coronary ostial stenosis. Recent reports have demonstrated that stenting of unprotected left main coronary artery stenosis has been attempted as an alternative to bypass surgery in selected patients with normal LV function. We report two patients with isolated left main coronary ostial stenosis who are undergoing primary and elective stenting, respectively. Major cardiac events did not occur during a 3-month follow-up. This study suggests that stenting of isolated left main coronary ostial stenosis in acute coronary syndrome is feasible and results in excellent outcomes.

Acute Disease↗
PubMed1998

Isolation and characterization of hrp1+, a new member of the SNF2/SWI2 gene family from the fission yeast Schizosaccharomyces pombe.

The SNF2/SWI2 ATPase/helicase family comprises proteins from a variety of species, which serve a number of functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Several proteins with unknown functions are also included in this family. The number of genes that belong to this family is rapidly expanding, which makes it easier to analyze the common biological functions of the family members. This study was designed to clone the SNF2/SWI2 helicase-related genes from the fission yeast Schizosaccharomyces pombe in the hope that this would help to elucidate the common functions of the proteins in this family. The hrp1+ (helicase-related gene from S. pombe) gene was initially cloned by PCR amplification using degenerate primers based on conserved SNF2 motifs within the ERCC6 gene, which encodes a protein involved in DNA excision repair. The hrp1+ ORF codes for an 1373-amino acid polypeptide with a molecular mass of 159 kDa. Like other SNF2/SWI2 family proteins, the deduced amino acid sequence of Hrp1 contains DNA-dependent ATPase/7 helicase domains, as well as a chromodomain and a DNA-binding domain. This configuration is similar to that of mCHD1 (mouse chromo-ATPase/helicase-DNA-binding protein 1), suggesting that Hrp1 is a S. pombe homolog of mCHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. Northern blot analysis showed that the hrp1+ gene produces a 4.6-kb transcript, which reaches its maximal level just before the cells enter the exponential growth phase, and then decreases gradually. DNA-damaging agents, such as MMS, MNNG and UV, decrease the rate of transcription of hrp1+. Deletion of the hrp1+ gene resulted in accelerated cell growth. On the other hand, overexpression of Hrp1 caused a reduction in growth rate. These results indicate that hrp1+ may act as a negative regulator of cellular growth.

Adenosine Triphosphatases↗
PubMed1998

Recurrent restenosis following stent and rotational atherectomy of coronary artery stenosis in Takayasu's arteritis.

We report a patient with Takayasu's arteritis who had recurrent restenosis following intracoronary bifurcation stenting of proximal left anterior descending and first diagonal arteries, and rotational atherectomy for in-stent restenosis. After all, the patient underwent coronary artery bypass grafts (CABG) and has remained asymptomatic during 3 months without damaging myocardium. We suggest that endoluminal stenting or rotational atherectomy may be an alternative treatment for the patients with coronary artery stenosis due to active Takayasu's arteritis as a therapy to postpone CABG.

Adult↗
PubMed1998

Idiopathic hypertrophic pachymeningeal lesions: correlation between clinical patterns and neuroimaging characteristics.

Nine patients with intracranial pachymeningeal thickening and enhancement on magnetic resonance imaging (MRI) completed a short-term clinical and MRI follow-up study. Based on clinical pictures, 4 of them were found to have spontaneous intracranial hypotension (SIH) and the remaining 5 had idiopathic intracranial pachymeningitis (IIP). Both groups were compared regarding their clinical and MRI characteristics. In 4 patients with SIH, gadolinium-enhanced T1-weighted images (WI) showed a diffuse and even enhancement of the entire intracranial and spinal dura mater. These thickened dura was slightly hyperintense on T2-WI. They had a favorable prognosis. In 2 patients with IIP, MRI demonstrated a relatively focal and even thickening and enhancement of the intracranial dura which was slightly hyperintense with a central hypointense area on T2-WI. These patients showed a very favorable course with or without steroid pulse therapy. In the remaining 3 patients with IIP, MRI depicted a focal, uneven enhancement of the intracranial dura which was relatively hypointense on T2-WI. Two of them with prolonged symptoms had a remitting and relapsing course, and 1 had a favorable outcome. In spite of current limitations in identifying the underlying causes of idiopathic pachymeningeal abnormalities, MRI can characterize the different patterns of pachymeningeal thickening. These findings may also correlate with the clinical picture and may be useful in predicting the response to treatment and prognosis.

Adult↗
PubMed1998

Molecular analysis of prion protein gene (PRNP) in Korean patients with Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD), a relatively uncommon human dementia, is caused by an unconventional slow infectious agent. Several cases of CJD, clinically or histopathologically diagnosed, have been reported in Korea. In order to confirm the diagnosis of CJD and also differential diagnosis of sporadic and familial types of CJD in Korea, we studied two patients who had symptoms of CJD. The histopathological and immunohistochemical studies showed spongiform neurodegeneration and expression of abnormal isoform of prion protein (PrPSc) in astrocytes. Thus, these two patients were diagnosed CJD. To investigate whether these patients were sporadic or familial type of CJD, the molecular analyses of the prion protein gene (PRNP) were done by restriction fragment length polymorphism (RFLP) and DNA sequencing. In the cases of a healthy Korean and two CJD patients, no point mutation was detected in the known hot spots (178, 180, 200, 210, and 232) and they exhibited wild type PRNP sequences. We concluded that both patients have a sporadic type of CJD, but not familial type.

Base Sequence↗
PubMed1998

Clinical and electrophysiological characteristics in Korean patients with WPW syndrome.

This study was designed to investigate the clinical and electrophysiologic characteristics of WPW syndromes in Korea. A total of 400 symptomatic WPW syndrome patients were consecutively recruited. The most common documented symptomatic tachyarrhythmia was orthodromic atrioventricar reentrant tachycardia (75.3%), followed by atrial fibrillation (31.3%), and antidromic atrioventricular reentrant tachycardia (6.2%). There was a higher incidence of multiple bypass tract in patients with antidromic tachycardia than in those with orthodromic tachycardia (30.4 vs 4.3%, P < 0.001). The inducibility of tachyarrhythmia with electrophysiologic study in this study population was 95.8%. The most frequent location of the accessory pathway was the left free wall (48.0%), followed by the right free wall (29.1%), posterior septum (17.5%) and anterior septum (3.5%). These results indicated that 1) clinical and electrophysiological characteristics of Korean patients with WPW syndrome were similar to those of western countries and 2) the electrophysiologic study was important in the evaluation of patients with WPW syndrome.

Adolescent↗
PubMed1997

Osseous craniofacial arteriovenous malformations in the pediatric population.

Osseous craniofacial arteriovenous malformations are rare and challenging entities. A 20-year retrospective review at our institutions identified 47 cases of craniofacial arteriovenous malformations, 3 of which were in children with extensive osseous facial structure involvement. Diagnostic evaluation included computed tomography, magnetic resonance imaging, and angiography. A 3-stage treatment protocol employed both transarterial embolization and direct intralesional puncture embolization followed by complete surgical resection. Mean intraperative blood loss was limited to 1000 mL. There were no complications during therapy. All 3 patients are without recurrence at 2- to 4-year follow-up. Osseous craniofacial arteriovenous malformations should be approached with multimodality therapy, incorporating interventional neuroradiologic and surgical management. Using the outlined protocol, these lesions can be treated safely and effectively.

Adolescent↗
PubMed1997

Patients in poor neurological condition after subarachnoid hemorrhage: early management and long-term outcome.

We report management and outcome data on 118 patients that presented to our emergency room over a 4 year interval (1990-1994) in poor neurological condition after subarachnoid hemorrhage. All patients were treated following a strict protocol. After initial evaluation, patients underwent a head computerized tomography (CT) scan to try to understand the mechanism of coma. If CT did not show destruction of vital brain areas, a ventriculostomy was inserted and ICP measured. If ICP was less than 20 mm Hg, or if standard treatment of increased ICP was able to lower the ICP to a value less than 20 mmHg, patients were evaluated with cerebral angiogram to determine the location of the ruptured aneurysm. The lesion was then treated by craniotomy for aneurysm clipping or endovascular obliteration. Postoperative monitoring for vasospasm with clinical exam and transcranial doppler studies was performed routinely. If vasospasm developed, this was managed aggressively with hypertensive, hypervolemic and hemodilutional therapy and, at times, endovascular treatment with angioplasty or papaverine. Outcome was measured at 1 year or more after treatment. Among patients who met criteria for aneurysm treatment, 47% had excellent or good neurologic outcome. There was a 30% mortality rate in these patients. In patients with high ICP, poor brainstem function or destruction of vital brain areas on CT, comfort measures only were offered and almost all died. It is concluded that an approach of early aneurysm obliteration and aggressive medical and endovascular management of vasospasm is warranted in patients in poor neurological conditions after subarachnoid hemorrhage.

Adult↗
PubMed1997

Treatment of dissecting basilar artery aneurysm by flow reversal.

Dissecting aneurysm of the basilar artery is a rare but increasingly recognized entity, with a frequently fatal or morbid outcome. Unlike the well established proximal occlusion and trapping approaches to vertebral artery dissections, surgical intervention for basilar lesions has been limited to wrapping techniques for arterial wall reinforcement. We report a case of midbasilar dissecting aneurysm successfully treated by clipping the proximal basilar artery below the level of the anterior inferior cerebellar arteries, allowing retrograde flow via the posterior communicating arteries to provide continued basilar perfusion. With the growing recognition of basilar dissection and pseudoaneurysm formation there is a need for improved therapeutic options. We suggest that definitive treatment can be achieved using the principle of proximal occlusion and flow reversal, and review the pertinent literature on basilar artery dissection.

Aortic Dissection↗
PubMed1996

Identification of the DNA damage-responsive elements of the rhp51+ gene, a recA and RAD51 homolog from the fission yeast Schizosaccharomyces pombe.

The Schizosaccharomyces pombe rhp51+ gene encodes a recombinational repair protein that shares significant sequence identities with the bacterial RecA and the Saccharomyces cerevisiae RAD51 protein. Levels of rhp51+ mRNA increase following several types of DNA damage or inhibition of DNA synthesis. An rhp51::ura4 fusion gene was used to identify the cis-acting promoter elements involved in regulating rhp51+ expression in response to DNA damage. Two elements, designated DRE1 and DRE2 (for damage-responsive element), match a decamer consensus URS (upstream repressing sequence) found in the promoters of many other DNA repair and metabolism genes from S. cerevisiae. However, our results show that DRE1 and DRE2 each function as a UAS (upstream activating sequence) rather than a URS and are also required for DNA-damage inducibility of the gene. A 20-bp fragment located downstream of both DRE1 and DRE2 is responsible for URS function. The DRE1 and DRE2 elements cross-competed for binding to two proteins of 45 and 59 kDa. DNase I footprint analysis suggests that DRE1 and DRE2 bind to the same DNA-binding proteins. These results suggest that the DRE-binding proteins may play an important role in the DNA-damage inducibility of rhp51+ expression.

Base Sequence↗
PubMed1996

Regional subacute cranial neuropathies following internal carotid cisplatin infusion.

The inferolateral trunk arises from the internal carotid artery at C-4 and provides vascular supply to cranial nerves III to VI. We report a patient who developed neuropathies of cranial nerves III, V1-3, and VI, 48 hours after infusion of cisplatin into the right internal carotid artery for an anaplastic oligoastrocytoma. The clinical and radiographic findings implicated direct toxicity to nerves in the distribution of the inferolateral trunk. We found additional cases by review of published brain tumor chemotherapy trials, thus identifying a novel, toxic neurovascular mechanism for injury to cranial nerves III to VI.

Adult↗
PubMed1996

Guglielmi coils.

Explore the source record for details and available documents.

Adult↗
PubMed1996

Paroxysmal kinesigenic choreoathetosis.

Paroxysmal kinesigenic choreoathetosis (PKC) is characterized by short paroxysms of focal or generalized involuntary movement induced by sudden movements, and is a well-known disease in the neurologic literature, but only 4 cases have been reported in Korea. The purpose of the presentation is to clarify the clinical features of PKC in Korea. We clinically analyzed 20 patients with PKC between 1986 and 1994 at Yongdong Severance Hospital, Yonsei Medical Center, with a minimum of a 1 to 2 year follow-up period. There were 14 men and 6 women. The age at onset of the condition ranged from 8 to 17 years (mean, 13.1 years). Six patients (30%) had a family history of the condition and the mode of inheritance was suggestive of an autosomal recessive pattern. The involuntary movements seemed to be dystonic rather than choreoathetonic upon a mild attack, and the paroxysms were precipitated by sudden movements. The attacks occurred on one or both sides, and were often associated with dysarthria, upward gaze and sensory aura. Consciousness was never lost. Their duration were usually 10 to 30 seconds, and never more than two minutes. All laboratory tests including electroencephalographic and neuroimaging studies showed no abnormality. All patients responded well to diphenylhydantoin. PKC is not rare in Korea and has a benign course.

Adolescent↗
PubMed1996

A comparison of serum CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell lung carcinoma.

To evaluate the usefulness of CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell carcinoma (SQC) of the lung, we tested sera from 124 patients with lung cancers (squamous cell ca 72, adenoca 22, large cell ca 4, small cell ca 18 and undetermined 8) and 78 patients with inflammatory lung diseases (bronchitis 24, bronchiectasis 29, tuberculosis 19 and others 6) using immunoradiometric assay kit for cytokeratin fragment 19 (CYFRA 21-1) and radioimmunoassay kit for SCC Ag. The serum CYFRA 21-1 and SCC Ag were significantly higher in lung cancer patients compared with control subjects. However, the significant difference was restricted only to SQC. In patients with SQC, CYFRA 21-1 and SCC Ag showed significantly higher levels according to the advanced anatomic stages (stage I-IIIa vs. stage IIIb, IV, p < 0.05). There was a good correlation between CYFRA 21-1 and SCC Ag (r = 0.41, p < 0.001). Receiver operating characteristic (ROC) curves were generated from results of both tumor markers and areas under the curves (AUC) were calculated. AUC of CYFRA 21-1 (0.93) were significantly larger than that of SCC Ag (0.77) for the diagnosis of SQC (p < 0.05). Therefore, we conclude that CYFRA 21-1 is superior to SCC Ag in the diagnosis of squamous cell carcinoma of the lung.

Aged↗
PubMed1996

Acute lung injury after phosgene inhalation.

Phosgene (COCl2) is a colorless oxidant gas which is heavier than air and the lethal exposure dose (LC50) in humans is 500 ppm/min. This gas was originally manufactured as an agent for chemical warfare during World War I and there had been a great deal of studies on phosgene poisoning during the early years of industrial use. It is still widely used in the synthesis of chemicals and plastics. In the modern era, however, phosgene poisoning is relatively uncommon except in accidental exposures. In Korea, there has been no report about lung injury from phosgene inhalation. We present a clinical experience with six patients accidentally exposed to phosgene.

Accidents, Occupational↗
PubMed1996

DNA ploidy and proliferative activity in bcl-2 expressed non-small cell lung cancer.

OBJECTIVES: The expressions of bcl-2 have been reported recently in non-small cell lung carcinoma (NSCLC*). As oncogensis is believed to involve a number of genetic alterations, there can be differences in DNA ploidy or proliferative activity even in bcl-2 positive cases according to the superimposed genetic events. SUBJECTS AND METHODS: On the assumption that we might further discern the biologic behavior of bcl-2 positive NSCLC according to the status of DNA ploidy and proliferative activity, we conducted a study for bcl-2 expression with immunohistochemical staining and DNA analysis on 52 surgical specimens of NSCLC. RESULTS: The bcl-2 was positive in 52% (27/52) of specimens, According to the status of bcl-2 expression, there were no significant differences in tumor stages, performance status score and survival time. Among bcl-2 positive NSCLC, aneuploidy and high proliferative activity were noted in 40% and 44%, respectively. In cases with squamous cell carcinoma (SQC**), the proportion of aneuploidy was significantly higher in bcl-2 positive group compared to bcl-2 negative group (p < 0.01), which could not be explained with the sole effect of bcl-2. In bcl-2 positive NSCLC, there was no significant survival difference by the status of DNA analysis results. With a Coxproportional hazard model, only T stage was an independent prognostic factor. CONCLUSION: In bcl-2 expressed NSCLC, proliferative activity and DNA ploidy were not homogeneous, suggesting other genetic alterations. This may explain our results which showed no differences in survival according to the status of the bcl-2 expression.

Adult↗