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Biomedical subjects

Y J Lee

Publications and source records attributed to Y J Lee.

At least 37 records · Page 2Linked to original sources
PubMed2005

Feasibility study of nitrogen removal with the mecellulose wasted liquor as an external carbon source in the two-stage denitrification process.

The utilization of mecellulose wasted liquor (MWL) as an external carbon source was investigated to find an alternative for methanol in the two-stage denitrification pilot process. The pilot plant was supplied with the raw water from the J-Municipal Sewage Treatment Plant (J-MSTP) in Korea. The raw water of J-Municipal Sewage Treatment Plant contains low and high concentration of biodegradable organics and nitrogen source, respectively, due to the inflow of industrial wastewater and landfill leachate. Methanol was fed to provide external carbon source for high concentration of nitrogen source removal by denitrification in this J-Municipal Sewage Treatment Plant, and thus this study was performed to test effects to the effluent quality and efficiencies of nitrogen source removal with an alternative carbon source for the cost reduction. The 6.5mg 1(-1) and 5.7mg l(-1) of total nitrogen (TN) concentration in the effluent were achieved with mecellulose and methanol, whereas mecellulose and methanol were fed to give the same ratio of gCODgNO,-N(-1), respectively. The 60% of COD in mecellulose wasted liquor was used as a carbon source for denitrification and the stable denitrification rate was earned when one half of the required total carbon source for denitrification was fed to pre-anoxic tank in the pilot plant. The required gCODgNO,-N(-1) ratio with mecellulose wasted liquor was 1.4 times higher than with methanol. Mecellulose wasted liquor is feasible to be used as external carbon source for organic loading, nitrogen and phosphorus removal. If mecellulose wasted liquor is considered as an alternative external carbon source to substitute methanol 26-28m3 mecellulose wasted liquor per 1 m3 methanol will be required. However, to meet with the effluent standard (10 mg BOD l(-1)) for J-Municipal Sewage Treatment Plant, the feed concentration of mecellulose wasted liquor should be recommended to be lower than 200 mgl(-1).

Carbon↗
PubMed2005

Molecular cloning and characterization of bovine PRKAG3 gene: structure, expression and single nucleotide polymorphism detection.

The protein kinase adenosine monophosphate-activated gamma3-subunit (PRKAG3) gene encodes a muscle-specific isoform of the regulatory gamma-subunit of adenosine monophosphate-activated protein kinase, which plays a key role in regulating energy homeostasis in eucaryotes. It is well known that mutations in the PRKAG3 gene affect high glycogen content in the porcine skeletal muscle and, consequently, meat quality. The genomic structure and sequence of the bovine PRKAG3 were analysed from a Korean cattle BAC clone. The bovine PRKAG3 gene comprises 13 exons and spans approximately 6.8 kb on BTA2. From 5' and 3'-rapid amplification of cDNA ends experiments, the full-length cDNA of bovine PRKAG3 has been identified, encoding a deduced protein of 465 amino acids. Two splice isoforms, generated by the alternative splicing of exon 2, were also identified. Northern blot analysis demonstrated that, similar to other species, the bovine PRKAG3 transcript was only expressed in skeletal muscle. Seven single nucleotide polymorphisms, including two previously identified variants, were detected in four Bos taurus cattle breeds. The bovine PRKAG3 gene described in this study may be involved in muscle-related genetic diseases or meat quality traits in cattle.

Amino Acid Sequence↗
PubMed2005

MHC class I chain-related gene A (MICA) polymorphism and the different histological types of cervical cancer.

Cervical cancer has been one of the most important gynecologic cancer in Taiwan with incidence of 24/100,000 and mortality of 8.7/100,000 annually. About 70-80% are squamous cell carcinoma; the remainder are composed of various types of adenocarcinoma, adenosquamous carcinoma and undifferentiated carcinoma. The Major Histocompatibility Complex (MHC) class I chain-related gene A (MICA) is expressed by keratinocytes and epithelial cells and interacts with gamma-delta T cells. Although MICA was not associated with cervical cancer in the study of Northern Sweden, there are no further studies about the association of MICA polymorphism and the different histological types of cervical cancer. We analyzed the MICA polymorphism in 110 cervical cancer cases (88 squamous cell carcinoma, 12 adenocarcinoma and 10 adenosquamous carcinoma) and 82 randomly selected unrelated controls from 1994 to 2000 in the Mackay Memorial Hospital, Taipei, Taiwan. DNA was extracted part from leukocytes of peripheral blood, part from tumor tissue and 5 polymorphic microsatellite alleles (A4,A5,A5.1,A6,A9) of MICA were identified by a polymerase chain reaction-based (PCR) technique using ABI Prism 377-18 DNA sequencer (Applied Biosystems, Foster City, CA, USA). The phenotypes, alleles and genotypes of MICA gene were calculated. There was no association with cervical cancer patients and non-cervical cancer patients (p=0.337, 0.356 and 0.414). After dividing the cervical cancer patients into 3 major histological types (squamous cell carcinoma, adenocarcinoma and adenosquamous carcinoma), the result was still the same (p=0.598, 0.172 and 0.617) in our study. We found no association between MICA gene polymorphism and cervical cancer in Taiwan. Different histological types of cervical cancer also have no significant correlation with MICA gene polymorphism. It demonstrates that polymorphism of MICA gene bears no relation to cervical cancer and the different histological types of cervical cancer in Taiwan. We need further studies for identifying the factors causing the differentiation of cancer cells of the uterine cervix.

Adenocarcinoma↗
PubMed2004

Osteopenia in men with mild and severe ankylosing spondylitis.

We investigated the frequency and distribution of osteopenia according to the clinical severity in ankylosing spondylitis (AS). Bone mass was measured in men with mild (n = 45) and severe AS (n = 31) with dual-energy X-ray absorptiometry (DEXA). Definition of clinical severity was based on the Schober's test. Osteopenia was commonly detected (48% in mild AS and 39% severe AS) and, in mild disease, more frequently observed at the lumbar spine than any of the proximal femur sites. In severe AS, however, the frequency of osteopenia at the femoral neck and Ward's triangle was as high as at the lumbar spine. Both bone mineral density and T-scores in severe disease were lower than in mild disease at the femur neck, Ward's triangle, and total proximal femur, but not in the lumbar spine. The progression of osteopenia may be reflected more reliably at proximal femur sites than at the lumbar spine.

Absorptiometry, Photon↗
PubMed2004

Clinical features of adult-onset ankylosing spondylitis in Korean patients: patients with peripheral joint disease (PJD) have less severe spinal disease course than those without PJD.

OBJECTIVE: We investigated the clinical features of Korean patients with adult-onset ankylosing spondylitis (AAS) and examined the differences between AAS patients with and without peripheral joint disease (PJD). METHODS: We studied 67 consecutive patients with primary AAS who visited the rheumatology clinic of a tertiary referral hospital. All patients experienced joint symptoms after the age of 15 and fulfilled the modified New York criteria for ankylosing spondylitis. Hips and shoulders were not considered as peripheral joints. RESULTS: The male-to-female ratio was 8.6:1.0. Mean age at disease onset was 22.3 +/- 5.5 (mean +/- s.d.) yr and disease duration was 10.8 +/- 8.0 yr. Spinal symptoms were the first manifestations in 80.6% of patients. During the disease course, hip, shoulder and peripheral joint involvement were found in about 60% of patients. In patients with PJD, the most commonly affected joints were the knees and ankles. The pattern of PJD, in most cases, was asymmetrical and mono/oligoarticular. AAS patients with PJD had fewer spinal symptoms than those without PJD as a presenting feature (71.8 vs 92.9%, P = 0.035). The modified Schober test showed greater increments in patients with PJD (4.9 +/- 2.4 vs 3.0 +/- 2.4 cm, P = 0.002). Forced vital capacity was better in patients with PJD (79.0 +/- 11.4 vs 70.8 +/- 15.5% of predicted value, P = 0.016). Totally ankylosed sacroiliitis, spinal squaring and syndesmophytes on radiographs were less common in the patients with PJD than in those without PJD (33.3 vs 64.2%, P = 0.012; 20.5 vs 67.9%, P = 0.000; and 38.5 vs 71.4%, P = 0.008, respectively). CONCLUSION: Peripheral joints as well as shoulder and hip joints were more frequently involved during the disease course in Korean AAS patients compared with earlier reports in Caucasians. The general joint involvement pattern of PJD was similar to patterns reported previously. Our data suggest that, clinically and radiographically, AAS patients with PJD have a less severe spinal disease course than those without PJD.

Adolescent↗
PubMed2004

Observation of large CP violation and evidence for direct CP violation in B0-->pi(+)pi(-) decays.

We report the first observation of CP violation in B0-->pi(+)pi(-) decays based on 152x10(6) gamma (4S)-->BB decays collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We reconstruct a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two B meson decay points, we obtain A(pipi)=+0.58+/-0.15(stat)+/-0.07(syst) and S(pipi)=-1.00+/-0.21(stat)+/-0.07(syst). We rule out the CP-conserving case, A(pipi)=S(pipi)=0, at a level of 5.2 standard deviations. We also find evidence for direct CP violation with a significance at or greater than 3.2 standard deviations for any S(pipi) value.

Journal Article↗
PubMed2004

Interaction of silicon dangling bonds with insulating surfaces.

We use first principles density functional theory calculations to study the interaction of a model dangling bond silicon tip with the surfaces of CaF2, Al2O3, TiO2, and MgO. In each case the strongest interaction is with the highest anions in the surface. We show that this is due to the onset of chemical bonding with the surface anions, which can be controlled by an electric field across the system. Combining our results and previous studies on semiconductor surfaces suggests that using dangling bond Si tips can provide immediate identification of surface species in atomically resolved noncontact atomic force microscopy and facilitate selective measurements of short-range interactions with surface sites.

Journal Article↗
PubMed2004

Expression of osteoclast differentiation factor and osteoclastogenesis inhibitory factor in rat osteoporosis induced by immunosuppressant FK506.

Immunosuppressant drugs are currently required by transplant recipients for the remainder of their lives, despite the many adverse effects associated with these therapies. Acute osteoporosis is one such effect, and a reproducible osteoporosis model has been established through the administration of the immunosuppressant drug FK506 in rats. The cause of this osteoporosis has been shown to be abnormal osteoclast proliferation, altering the process of bone remodeling. However, the reasons why FK506 induces osteoclast proliferation and whether this process is mediated by cytokine changes or an increase in bone resorption factors have been unclear. An investigation was therefore conducted focusing on the recent discoveries of osteoclast differentiation factor (ODF) and osteoclastogenesis inhibitory factor (OCIF). These factors led to elucidation of the osteoclast differentiation-maturation mechanism. An osteoporosis model was produced in rats utilizing intramuscular FK506 injection (1 mg/kg) for 28 consecutive days. Trabecular bone resorption was observed inferior to enchondral ossification in the FK506 group, and tartrate resistant acid phosphatase (TRAP) staining revealed a clear increase in osteoclasts at the site of enchondral ossification, relative to the control group. Real-time PCR and in situ hybridization (ISH) demonstrated minimal differences in OCIF expression between control and the treatment groups. However, Real-time PCR revealed clearly increased ODF expression in the treatment group. ODF expression was also shown to be increased in the treatment group using ISH. This was histologically consistent with a region of osteoclast proliferation inferior to enchondral ossification. The results of this study support the hypothesis that FK506-mediated osteoporosis occurs by action of the drug on osteoclasts, promoting expression of ODF messenger ribonucleic acid (mRNA) and thus prompting osteoclast differentiation and maturation.

Animals↗
PubMed2004

Intraoperative assessment of hepatic venous congestion with direct clamping of the hepatic vein trunk for living donor liver transplantation.

We devised a hepatic vein clamping method to assess the amount of hepatic venous congestion (HVC) before liver transection. From February 2003 to May 2003, this method was applied to 5 of 58 living donor livers especially to assess donor safety. The left portal vein and proper hepatic artery as well as the middle hepatic vein (MHV)-left hepatic vein (LHV) trunk were clamped simultaneously to assess the HVC in the remnant right lobe before performing extended left lobectomy. As three donors demonstrated the extent of the HVC equivalent to about 40% of the right lobe volume (RLV), their operations proceeded according to the preoperative plan. The territory of HVC after liver transection was the same as that observed with direct clamping of the hepatic vein. However, one donor showed massive HVC more than 50% of RLV and the operative plan was adjusted to harvest only the left lobe without the MHV trunk for donor safety. To assess the HVC in the remnant left lobe, the isolated LHV trunk was occluded after clamping the donor's proper hepatic artery. The whole left lobe except for a small area at the anterior portion of the medial segment became discolored on LHV clamping: the opposite demarcation appeared on MHV clamping. The amount of HVC was so small that we harvested the right lobe with the MHV trunk. All donors and recipients recovered uneventfully. We believe that this direct clamping method makes the assessment of HVC feasible before parenchymal transection of a donor liver.

Adult↗
PubMed2004

Atypical endoscopic features of rectal carcinoids.

BACKGROUND AND STUDY AIMS: It is not normally difficult to diagnose carcinoid tumors (well-differentiated endocrine neoplasms) of the rectum endoscopically, as they usually have a characteristic appearance. However, little is known about the atypical endoscopic findings in some rectal carcinoids and the present study was performed to analyze these. PATIENTS AND METHODS: The endoscopic findings in 67 consecutive patients with rectal carcinoids (37 men, 30 women; age range 23 - 76) were analyzed retrospectively. RESULTS: Tumor size ranged from 2 mm to 30 mm (average 7.4 mm). Of the 67 patients, 52 (78 %) displayed the characteristic endoscopic findings of smooth, round, sessile elevations covered with normal-appearing or yellow-discolored mucosa; in 15 (22 %) there were one or more atypical endoscopic findings. These included a semipedunculated appearance (n = 6), hyperemia (n = 5), a central depression (n = 6), erosion (n = 5), and ulceration (n = 4). Atypical findings were noted in none of 20 carcinoids &lambda< 5 mm in diameter; in six (20 %) of the 30 carcinoids between 5 mm and 9 mm; in six (43 %) of the 14 carcinoids between 10 mm and 19 mm; and in three (100 %) of the three carcinoids >/= 20 mm in diameter ( P < 0.001). Invasion into the muscularis propria or metastasis to the liver or lymph nodes occurred in three of the four patients with ulceration, but it was confirmed in only one of the 63 patients without ulceration ( P < 0.001). CONCLUSIONS: Atypical endoscopic appearances of rectal carcinoids are observed more frequently as the size of the tumor increases and a finding of ulceration may have a prognostic value.

Adult↗
PubMed2004

Amaranth squalene reduces serum and liver lipid levels in rats fed a cholesterol diet.

In this study, the hypocholesterolaemic effect of amaranth grain, oil and squalene are examined. In experiment 1, rats are given a semi-purified diet containing 1% (w/w) cholesterol for four weeks and either amaranth grain (AG; 300 g/kg) or amaranth oil (AO; 90 g/kg) substituted in experimental groups. Both AG and AO lowered serum and hepatic cholesterol and triglyceride levels. Faecal excretion of cholesterol and bile acid in the AO group increased, while AG affected only bile acid excretion. In experiment 2, rats were fed the cholesterol diet for four weeks and injected (i.p.) with saline (control), amaranth squalene (AS) or shark liver squalene (SS, 200 mg/kg) for seven days. The hypolipidaemic effects of AS were evident in both serum and liver. In addition, AS markedly increased faecal excretions of cholesterol and bile acid, and slightly inhibited 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity. In contrast, none of these effects were observed in the SS group. This preliminary study suggests that the cholesterol-lowering effect of AS may be mediated by increased faecal elimination of steroids through interference with cholesterol absorption, and that different sources of squalene (plant versus animal) may affect cholesterol metabolism differently.

Amaranthus↗
PubMed2004

Comparison of [18F]fluorodeoxyglucose uptake with glucose transporter-1 expression and proliferation rate in human glioma and non-small-cell lung cancer.

To clarify the biological significance of [18F]fluorodeoxyglucose (18F-FDG) accumulation in patients with cancer, we assessed the relationships between 18F-FDG uptake and glucose transporter-1 (GLUT-1) expression and proliferation rate in human glioma and lung cancer. We obtained FDG PET images and measured standardized uptake values (SUVs) of primary tumours in 13 patients with brain glioma and 25 patients with non-small-cell lung cancer. After surgery, portions of respected tumours were obtained, and the proliferation rate was measured as proliferation index (per cent of (S+G2+M)/(G0+G1+S+G2+M)) using DNA flow cytometry. The expression of GLUT-1 in a tumour was evaluated by using immunostaining. We classified GLUT-1 expression as grade 0 (no positive cell), grade 1 (< 10% cells positive), grade 2 (11-50% cells positive) and grade 3 (51-100% cells positive). Based on the expression of GLUT-1, cases with grades 0, 1, 2 and 3 showed SUVs of 6.1 +/- 2.8, 5.0 +/- 3.2, 8.3 +/- 3.3 and 10.4 +/- 6.6, respectively (P < 0.05). Non-small-cell lung cancer showed higher FDG uptake (SUV, 8.5 +/- 5.1) and higher GLUT-1 expression (grade, 2.0 +/- 1.0) than did brain glioma (SUV, 4.7 +/- 2.5; grade, 0.8 +/- 0.8). Based on the total number of cases, SUVs did not relate to proliferation index (r = 0.19). In non-small-cell lung cancer, SUVs did not correlate with proliferation index, whereas in glioma, SUVs were strongly related to proliferation index (r = 0.79, P < 0.01). In conclusion, FDG uptake generally correlated with GLUT-1 expression in non-small-cell lung cancer and glioma. In the case of glioma, FDG uptake also indicated increased cellular proliferation, which was not demonstrated in non-small-cell lung cancer.

Biomarkers, Tumor↗
PubMed2004

Identification of two new HLA-DRB1 alleles: HLA-DRB1*1350 and DRB1*140502.

Two new HLA-DRB1 alleles have been found by using high-resolution sequence-based typing. The two sequences have been officially named DRB1*1350 (HWS10001327-AY048687) and DRB1*140502 (HWS10001790-AY129430). DRB1*1350 differs from DRB1*110101 by two amino acids at positions 37 (Y-->N) and 58 (A-->E). This allele may arise from gene conversion between DRB1*110101 and DRB1*130201 or DRB1*030101, which are commonly found in Taiwan populations. The other allele, DRB1*140502, obtained from a patient with rheumatoid arthritis, differs from DRB1*140501 at codon 58 (GCC-->GCT). However, it causes no change in amino acid sequence and would therefore not have direct clinical implications.

Alleles↗
PubMed2004

Transforming growth factor-beta1 polymorphisms in Korean patients with systemic sclerosis.

Transforming growth factor-beta1 (TGF-beta1) plays an important role in the pathogenesis of systemic sclerosis (SSc). To investigate the role of TGF-beta1 gene polymorphisms in SSc, we genotyped six biallelic polymorphic positions (position -988, -800, and -509; and codons 10, 25, and 263) in 61 Korean SSc patients and in 148 healthy controls, using polymerase chain reaction-sequence-specific primers. Genetic polymorphisms were found at position -509 and codon 10 in Koreans. The allele frequencies of C/T at position -509 were 0.59/0.41 in patients and 0.56/0.44 in controls. The allele frequencies of C/T at codon 10 were 0.40/0.60 in patients and 0.50/0.50 in controls. In conclusion, no skewed distribution of TGF-beta1 gene polymorphisms was found in Korean patients with SSc.

Adult↗
PubMed2004

Association of the oestrogen receptor alpha gene polymorphisms with disease onset in systemic lupus erythematosus.

OBJECTIVE: To evaluate the genetic influence of PvuII and XbaI polymorphisms of oestrogen receptor alpha (ORalpha) in patients with systemic lupus erythematosus (SLE) in Korea. METHODS: Genomic DNA from 268 female controls and 137 female SLE patients (41 childhood onset and 96 adult onset) were analysed using PvuII and XbaI restriction fragment length polymorphism. Comparison of the frequencies of alleles and genotypes was made in control and patient groups and in childhood onset and adult onset SLE subgroups. RESULTS: Although the Pp genotype occurred more often in SLE patients than in controls (p(c) = 0.017), ORalpha genotype distributions of adult onset SLE did not differ significantly from controls. The PP, Pp, and xx genotypes occurred less often in childhood onset SLE (p(c) = 0.0045, 0.0498, and 0.0255, respectively) than in controls. Additionally, the PP genotype was less common in childhood onset than in adult onset SLE (p(c) = 0.016). SLE patients with the PP genotypes were older at disease onset than those with the other genotypes (p = 0.001). Patients with the Xx genotype had an earlier onset of SLE than those with the xx genotype (p = 0.025). The frequency of the combined ppXx genotype was greater in childhood onset SLE than in controls (p(c) = 0.0009) or adult onset SLE (p(c) = 0.027). The same trend was supported by subgroup analyses according to age at menarche and logistic multivariate analyses. CONCLUSIONS: ORalpha polymorphisms are significantly associated with the age at disease onset in Koreans with SLE.

Adolescent↗
PubMed2004

Domestic wastewater reclamation by submerged membrane bioreactor with high concentration powdered activated carbon for stream restoration.

This study focuses on the practical application of high concentration powdered activated carbon coupled membrane bio-reactor to domestic wastewater reclamation. The study was conducted in three parts, such as analysis of secondary domestic wastewater effluent, design and operation parameter evaluation and reclaimed water quality estimation for stream restoration. The organic concentration was 25.2-80.2 mgCOD(Cr)/L for the effluent of three domestic wastewater treatment plants. Around 50-75% of the COD was low molecular substances less than 1,000 which were quite biodegradable. The sawdust PAC was estimated to be proper adsorbent for the organics in the secondary effluents. Its Freundlich constant, K value was 5.847 and 1/n, 0.36. Using a system consists of single reactor with high concentration PAC (80 g/L) and submerged hollow fiber MF membrane module with nominal pore size of 0.1 microm, design and operation parameters were obtained, such as HRT of the bioreactor (2.5 hr), PAC concentration (80 g/L), the initial flux (less than 0.5 m/day) and intermittent suction cycle (12 min. suction and 3 min. idling). Organic removal by the system was high enough to produce reclaimed water for urban stream restoration The effluent organic concentration was at the level of 2 mg/L in terms of TOC (around 5 mg/L as COD(Cr)). Substances with molecular weight cut off < 1,000 were removed mostly by adsorption and biodegradation. Those above 1,000 were rejected at PAC cake layer on the membrane and gradually degraded by microorganisms during extended contact.

Bioreactors↗
PubMed2003

Liposome-complexed adenoviral gene transfer in cancer cells expressing various levels of coxsackievirus and adenovirus receptor.

PURPOSE: Loss of coxsackievirus and adenovirus receptor (CAR) is frequently observed in malignant cancer, hampering adenoviral gene therapy approaches. Complexing adenovirus with cationic liposomes can increase adenoviral transgene expression, particularly in cells with CAR-deficiency. We investigated whether other factors such as lipid composition might be involved in determining the efficiency of liposome-complexed adenoviral gene transfer in cancer cells. MATERIAL AND METHODS: Human cancer cell lines with different expression levels of CAR were infected with a GFP transgene. The efficiency of transgene expression was assessed by determining GFP expression using FACS analysis. RESULTS: The efficiency of liposome-complexed adenoviral gene transfer was dependent on the lipid composition constituting liposomes. Polyethylene glycol (PEG)-containing liposomes were most effective in increasing liposome-complexed adenoviral gene transfer. In CAR-deficient cells, use of PEG-containing liposomes enhanced adenoviral gene transfer, whereas in CAR-expressing cells enhancement varied depending on cell type. In some CAR-expressing cells, the effect of liposome complexing was even comparable to that in CAR-deficient cells. Increased adenoviral transgene expression following complexing with PEG-containing liposomes correlated with liposome uptake in cancer cells. CONCLUSIONS: Liposome-complexed adenoviral gene transfer appears to depend on lipid composition and the level of liposome uptake by cancer cells, in addition to CAR levels. Our study suggest that these multiple factors should be considered in designing liposome-complexed adenoviral vectors to improve outcomes of current adenoviral cancer gene therapies.

Adenoviridae↗