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Kwang-Soo Lee

Publications and source records attributed to Kwang-Soo Lee.

At least 19 recordsLinked to original sources
PubMed2007

Fluoroscopic computer-assisted pedicle screw placement through a mature fusion mass: an assessment of 24 consecutive cases with independent analysis of computed tomography and clinical data.

STUDY DESIGN: Observational matched cohort study with computed tomography (CT) analysis of pedicle screw placement. OBJECTIVE: Assess the clinical accuracy of computer-assisted fluoroscopy for the placement of thoracolumbar pedicle screws through a mature posterolateral fusion mass. SUMMARY OF BACKGROUND DATA: Pedicle screw placement through an amorphous posterolateral fusion mass intuitively carries a higher risk of pedicle wall violation. METHODS: Postoperative CT scans of 102 pedicle screws placed through a mature posterolateral fusion mass (n = 10 [T10-T12]; n = 92 [L1-S1]) were independently assessed and compared with a matched control (nonobscured anatomy) group. All screws were placed before any decompression using the FluoroNav system. RESULTS: In the fusion mass group, overall 81.4% of screws were completely within the pedicle. Seven medial and 12 lateral pedicle breaches occurred. Relative to the total number of screws, pedicle breaches were graded II (<2 mm) in 13.5%, III (2-4 mm) in 2.9%, and IV (>4 mm) in 2.0% of screws. The number and direction of pedicle breaches were not significantly different when compared with the control group. There were no clinically significant screw misplacements in either group. CONCLUSIONS: The use of computer-assisted fluoroscopy is safe and effective for the placement of thoracolumbar (T10-S1) pedicle screws through a posterolateral fusion mass without performing laminoforaminotomies.

Adult↗
PubMed2006

Early pathological changes in the cerebellum of patients with pure cerebellar syndrome demonstrated by diffusion-tensor imaging.

We evaluated the early pathological changes in patients with sporadic cerebellar ataxia by measuring fractional anisotropy (FA) values in diffusion tensor MRIs (DTI). FA and apparent diffusion coefficient (ADC) values were compared in the brain stem and cerebellum of 5 patients with idiopathic cerebellar ataxia-C and 7 age-matched controls. Patients with sporadic cerebellar ataxia had decreased FA values in the bilateral cerebellar peduncle and cerebellar hemisphere, but normal FA values in the basis pontes. Assuming that the loss in FA parallels neuronal changes, our results suggest that the derangement and altered fiber integrity of the cerebellum are present regardless of the presence of morphological alterations on conventional MRI. Therefore, DTI may be superior to conventional MRI in the evaluation of early pathological changes in patients with sporadic cerebellar ataxia.

Adult↗
PubMed2006

Do health behaviors moderate the effect of socioeconomic status on metabolic syndrome?

PURPOSE: The purpose of this study is to determine whether the effect of socioeconomic factors on metabolic syndrome is influenced by such covariates as health behavior and psychosocial factors. METHODS: This study used data collected from 4400 households during the 2001 Korea National Health and Nutrition Examination Survey. A stratified multistage probability sampling method was applied and the final sample included 6601 subjects older than 20 years who had completed necessary health examinations. RESULTS: The prevalence of metabolic syndrome in Koreans was 25.5% (95% confidence interval [CI], 23.8-27.2) for men and 28.7% (95% CI, 27.2-30.2) for women. Analysis of moderator effects showed that interactions between education and smoking or exercise status and between income and alcohol or smoking status were significant. The significance of the interaction terms indicates that health behavior and psychosocial factors modified the relationship between socioeconomic factors and metabolic syndrome. CONCLUSIONS: Results of this study provide evidence that such behaviors as smoking, drinking alcohol, and insufficient exercise contribute to the incidence of metabolic syndrome. Changes to higher socioeconomic status may not reduce the odds of metabolic syndrome unless behavior also is adapted.

Adult↗
PubMed2006

Pisa syndrome as a motor complication of Parkinson's disease.

We describe two elderly patients with a convincing clinical diagnosis of Parkinson's disease (PD) who developed axial end-of-dose/off dystonia, also referred to as Pisa syndrome (PS). The worsening of symptoms in the "off" period, and a favorable response of the dystonia to an increase of levodopa suggests that PS in our patients may be primarily related to a manifestation of motor fluctuations in PD.

Aged↗
PubMed2006

Identification of DNA copy-number aberrations by array-comparative genomic hybridization in patients with schizophrenia.

Chromosomal abnormalities are implicated as important markers for the pathogenesis in patients with schizophrenia. In this study, with using bacterial artificial chromosome (BAC) array-based comparative genomic hybridization (CGH), we analyzed DNA copy-number changes among 30 patients with schizophrenia. The most frequent changes were partial gain of Xq23 (52%) and loss of 3q13.12 (32%). Other frequent gains were found in: 1p, 6q, 10p, 11p, 11q, 14p, and 15q regions, and frequent losses were found in: 2p, 9q, 10q, 14q, 20q, and 22q regions. The set of abnormal regions was confirmed by real-time PCR (9q12, 9q34.2, 11p15.4, 14q32.33, 15q15.1, 22q11.21, and Xq23). All real-time PCR results were consistent with the array-CGH results. Therefore, it is suggested that array-CGH and real-time PCR analysis could be used as powerful tools in screening for schizophrenia-related genes. Our results might be useful for further exploration of candidate genomic regions in the pathogenesis of schizophrenia.

Adult↗
PubMed2006

Successful stem cell therapy using umbilical cord blood-derived multipotent stem cells for Buerger's disease and ischemic limb disease animal model.

Buerger's disease, also known as thromboangiitis obliterans, is a nonatherosclerotic, inflammatory, vasoocclusive disease. It is characterized pathologically as a panangiitis of medium and small blood vessels, including both arteries and adjacent veins, especially the distal extremities (the feet and the hands). There is no curative medication or surgery for this disease. In the present study, we transplanted human leukocyte antigen-matched human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) into four men with Buerger's disease who had already received medical treatment and surgical therapies. After the stem cell transplantation, ischemic rest pain suddenly disappeared from their affected extremities. The necrotic skin lesions were healed within 4 weeks. In the follow-up angiography, digital capillaries were increased in number and size. In addition, vascular resistance in the affected extremities, compared with the preoperative examination, was markedly decreased due to improvement of the peripheral circulation. Because an animal model of Buerger's disease is absent and also to understand human results, we transplanted human UCB-derived MSCs to athymic nude mice with hind limb ischemia by femoral artery ligation. Up to 60% of the hind limbs were salvaged in the femoral artery-ligated animals. By in situ hybridization, the human UCB-derived MSCs were detected in the arterial walls of the ischemic hind limb in the treated group. Therefore, it is suggested that human UCB-derived MSC transplantation may be a new and useful therapeutic armament for Buerger's disease and similar ischemic diseases.

Adult↗
PubMed2006

Mutational spectrum of type I collagen genes in Korean patients with osteogenesis imperfecta.

Mutations in the type I collagen genes COL1A1 and COL1A2 are responsible for the dominantly inherited connective tissue disorder osteogenesis imperfecta (OI). The severity of OI is diverse, ranging from perinatal lethality to a very mild phenotype that is characterized by normal stature and the absence of deformities. Although there have been several studies on the mutational spectra of COL1A1 and/or COL1A2 in Western populations, very few cases have been reported from Asia. In this study, we investigated 67 unrelated Korean probands with OI and used nucleotide sequence analysis to detect COL1A1 and COL1A2 mutations. Thirty-five different mutations were identified in the two genes, including 24 novel mutations. Among the 35 kinds of detected mutations, 15 were glycine substitutions (seven in COL1A1 and eight in COL1A2), one was a nonsense mutation, four were frameshift mutations in COL1A1, three were in-frame duplications in COL1A2, and 12 were splice site mutations (seven in COL1A1 and five in COL1A2). Until now, mutations in the COL1A1 and COL1A2 genes known to cause OI were unique and rarely repeated in other families. Interestingly, the c.982G>A (p.Gly328Ser) mutation in COL1A2 was found recurrently and was the causative mutation in five independent OI probands. Haplotype analysis of the COL1A2 gene revealed that four probands from five independent OI probands with c.982G>A (p.Gly328Ser) had a common haplotype. Our clinical data showed the heterogeneity even within a specific genotype, which suggested the complex expression of this disease.

Adolescent↗
PubMed2006

Disappearance of essential tremor after frontal cortical infarct.

We present a patient with essential tremor who spontaneously improved after a sensorimotor stroke related to a small cortical infarct near by the left precentral region of the brain. This finding supports the presence of cortical or transcortical motor loops that are likely involved in essential tremor and suggests a possible link with the cerebellar-thalamic-cortical pathway.

Cerebral Infarction↗
PubMed2006

Cardiac [123I]metaiodobenzylguanidine scintigraphy for vascular Parkinsonism.

The purpose of our study was to prospectively evaluate cardiac [(123)I]metaiodobenzylguanidine (MIBG) uptake in patients with cerebrovascular disease (CVD) who develop clinical symptoms of vascular Parkinsonism (VP). A total of 19 consecutive patients who developed Parkinsonism during the course of their CVD were enrolled in the study; 16 age-matched subjects, and 30 patients with Parkinson's disease (PD) were also evaluated with cardiac MIBG uptake. MIBG uptake was assessed using the ratio of the heart to the upper mediastinum (H/M) according to planar scintigraphic data. The mean H/M ratio was significantly higher in patients with VP than in those with PD (2.28 +/- 0.41 vs. 1.27 +/- 0.13; P < 0.001). MIBG uptake did not differ between VP and controls (2.46 +/- 0.33; P > 0.05). Our findings suggest that myocardial postganglionic sympathetic dysfunction found in PD is absent in most patients with VP. MIBG single photon emission computed tomography imaging may be useful to help distinguish between PD and VP patients in clinical practice.

3-Iodobenzylguanidine↗
PubMed2006

[Does a higher coronary artery bypass graft surgery volume always have a low in-hospital mortality rate in Korea?].

OBJECTIVES: To propose a risk-adjustment model with using insurance claims data and to analyze whether or not the outcomes of non-emergent and isolated coronary artery bypass graft surgery (CABG) differed between the low- and high-volume hospitals for the patients who are at different levels of surgical risk. METHODS: This is a cross-sectional study that used the 2002 data of the national health insurance claims. The study data set included the patient level data as well as all the ICD-10 diagnosis and procedure codes that were recorded in the claims. The patient's biological, admission and comorbidity information were used in the risk-adjustment model. The risk factors were adjusted with the logistic regression model. The subjects were classified into five groups based on the predicted surgical risk: minimal (<0.5%), low (0.5% to 2%), moderate (2% to 5%), high (5% to 20%), and severe (=20%). The differences between the low- and high-volume hospitals were assessed in each of the five risk groups. RESULTS: The final risk-adjustment model consisted of ten risk factors and these factors were found to have statistically significant effects on patient mortality. The C-statistic (0.83) and Hosmer-Lemeshow test (x2=6.92, p=0.55) showed that the model's performance was good. A total of 30 low-volume hospitals (971 patients) and 4 high-volume hospitals (1,087 patients) were identified. Significant differences for the in-hospital mortality were found between the low- and high-volume hospitals for the high (21.6% vs. 7.2%, p=0.00) and severe (44.4% vs. 11.8%, p=0.00) risk patient groups. CONCLUSIONS: Good model performance showed that insurance claims data can be used for comparing hospital mortality after adjusting for the patients' risk. Negative correlation was existed between surgery volume and in-hospital mortality. However, only patients in high and severe risk groups had such a relationship.

Aged↗
PubMed2005

Structural and functional analyses of mutations of the human phenylalanine hydroxylase gene.

BACKGROUND: Phenylketonuria (PKU) is an inborn error of metabolism that results from a deficiency of phenylalanine hydroxylase (PAH). We demonstrated PAH mutational spectrum from patients with PKU, including 10 novel and 3 tetrahydrobiopterin (BH(4))-responsive mutations. In this study, 11 PAH missense mutations, including 6 novel mutations (P69S, G103S, L293M, G332V, S391I, A447P) found in our previous study, 2 mutations common in east Asian patients with PKU (R243Q, R413P), and 3 tetrahydrobiopterin (BH(4))-responsive mutations (R53H, R241C, R408Q) have been functionally and structurally analyzed. METHODS: A transient protein overexpression system and an in vitro BH(4)-responsiveness study were used. The effects of PAH missense mutations on the PAH protein structure were also analyzed. To determine the conservation of 12 mutated residues, PAH was aligned using BLAST against full genomic sequences of 221 different species. Model structures of PAH protein and the composite tetramer were constructed using the software program, SHEBA. RESULTS: No PAH activity was detected for some mutants. However, the residual activities associated with other mutants ranged over a wide spectrum. The missense mutations responsive to BH(4) were not highly conserved throughout the 43 species in the multiple sequence alignment that encode PAH. The composite model structure of PAH revealed that dimer stability was reduced in the BH(4)-responsive mutants, whereas tetramer stability remained normal. CONCLUSION: This expression study analyzed PAH mutations and model structures of mutant PAH proteins are proposed. Correlation between the proposed mutant PAH structures and functions are suggested.

Amino Acid Sequence↗
PubMed2005

Association of vitamin D receptor gene polymorphism and Parkinson's disease in Koreans.

1alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3), which is the biologically active form of vitamin D, has anti-inflammatory effects and can prevent experimental Parkinson's disease (PD). 1,25(OH)2D3 exerts most of its actions only after it binds to its specific nuclear receptors. Eighty-five Korean patients with PD and 231 unrelated healthy individuals were evaluated to determine if vitamin D receptor gene (VDRG) BsmI polymorphisms were markers for the susceptibility to PD in Korean patients. Each polymorphism was detected using polymerase chain reaction (PCR)-based restriction analysis. In addition, the relationship between the BsmI polymorphisms and the clinical manifestations of PD was evaluated. Overexpression of the b allele (91.2 vs. 85.7%; p=0.069) and homozygote bb (84.7 vs. 72.7%; p=0.043) was found in the PD patients compared with the controls. These results show for the first time an association between PD and a VDRG polymorphism, which might be involved in the pathogenesis of PD, or in the linkage disequilibrium of the VDRG to another pathogenic gene locus.

Aged↗
PubMed2005

[Impact of risk adjustment with insurance claims data on cesarean delivery rates of healthcare organizations in Korea].

OBJECTIVES: To propose a risk-adjustment model from insurance claims data, and analyze the changes in cesarean section rates of healthcare organizations after adjusting for risk distribution. METHODS: The study sample included delivery claims data from January to September, 2003. A risk-adjustment model was built using the 1st quarter data, and the 2nd and 3rd quarter data were used for a validation test. Patients' risk factors were adjusted using a logistic regression analysis. The c-statistic and Hosmer-Lemeshow test were used to evaluate the performance of the risk-adjustment model. Crude, predicted and risk-adjusted rates were calculated, and compared to analyze the effects of the adjustment. RESULTS: Nine risk factors (malpresentation, eclampsia, malignancy, multiple pregnancies, problems in the placenta, previous Cesarean section, older mothers, bleeding and diabetes) were included in the final risk-adjustment model, and were found to have statistically significant effects on the mode of delivery. The c-statistic (0.78) and Hosmer-Lemeshow test (chi2=0.60, p=0.439) indicated a good model performance. After applying the 2nd and 3rd quarter data to the model, there were no differences in the c-statistic and Hosmer-Lemeshow chi2. Also, risk factor adjustment led to changes in the ranking of hospital Cesarean section rates, especially in tertiary and general hospitals. CONCLUSION: This study showed a model performance, using medical record abstracted data, was comparable to the results of previous studies. Insurance claims data can be used for identifying areas where risk factors should be adjusted. The changes in the ranking of hospital Cesarean section rates implied that crude rates can mislead people and therefore, the risk should be adjusted before the rates are released to the public. The proposed risk-adjustment model can be applied for the fair comparisons of the rates between hospitals.

Cesarean Section↗
PubMed2004

The molecular basis of phenylketonuria in Koreans.

Phenylketonuria (PKU) is an inborn error of metabolism that results from a deficiency of phenylalanine hydroxylase (PAH). We characterized the PAH mutations of 79 independent Korean patients with PKU or hyperphenylalaninemia. PAH nucleotide sequence analysis revealed 39 different mutations, including ten novel mutations. The novel mutations consisted of nine missense mutations (P69S, G103S, N207D, T278S, P281A, L293M, G332V, S391I, and A447P) and a novel splice site variant (IVS10-3C>G). R243Q, IVS4-1G>A, and E6-96A>G were the most prevalent mutations, as they accounted for 32% of the total mutant alleles in this study. Although some common characteristics of allele frequency and distribution were identified among oriental populations, several distinctive characteristics were revealed in Korean patients. Although the R413P allele is the most prevalent form (30.5%) in Japanese, we detected it in only five chromosomes from 158 independent chromosomes (3.2%). The A259T allele, which has not yet been found in oriental populations, was frequently found in this study. We also observed that tetrahydrobiopterin (BH4) responsiveness was associated with specific genotypes (R53H, R241C, and R408Q), suggesting there are some correlations between phenotype and genotype.

DNA Mutational Analysis↗