Biomedical subjects

D S Lee

Publications and source records attributed to D S Lee.

At least 37 records · Page 2Linked to original sources

PubMed2004

Case of living donor liver transplantation in a patient with biliary atresia combined with situs inversus.

Until recently, situs inversus was considered to be an absolute contraindication for liver transplantation. However, recent reports have suggested that situs inversus should not be considered a contraindication. This study presents a successful living donor liver transplantation performed in a 4-month-old male infant with biliary atresia and situs inversus. The surgical findings revealed abdominal situs inversus with polysplenia and an absent retrohepatic inferior vena cava and intestinal malrotation.

Adult↗

PubMed2004

Polymerase chain reaction for the diagnosis of human polyomavirus-associated nephropathy in renal transplant recipients.

Human polyomavirus type BK may be related to interstitial nephropathy or renal-allograft dysfunction. Patients with nephropathy due to infection with human polyomavirus may be identified early using the polymerase chain reaction(PCR). We attempted to evaluate whether the positive response in the PCR test of BK virus DNA in the plasma of renal transplant recipients affects the function of the renal allograft. Seventy-seven patients were prospectively analyzed according to the operative sex, age, sources of allograft, serum creatinine levels during PCR test for BK virus, postoperative type of immunosuppressant, and presence of graft rejection. Two groups were distinguished according to the PCR result for BK virus: group 1 (n = 12) positive PCR reaction and group 2 (n = 65) negative reaction. The mean follow-up was 32.6 weeks. The incidence of positive PCR tests for BK virus replication after renal transplantation was 15.6%. Decoy cells in the urine were detected in 20.7%. The incidence of BK virus nephropathy was 1.3%. The mean serum creatinine levels of group 1 and 2 at the time of the PCR tests were 1.34 and 1.22, respectively. The rejection rates in group 1 and 2 were 8% and 4.5%, respectively (P > .05). We consider that a PCR assay to detect BK virus in renal recipients blood may be useful to identify patients at risk for nephropathy. It may serve as a noninvasive indicator of BK virus replication, although this study is limited by the short follow-up and small numbers.

Adolescent↗

PubMed2004

Changes in expression of T-cell activation-related molecules and cytokines during tolerance induction in an allogeneic skin transplantation murine model.

Bone marrow transplantation after treatment with busulfan and costimulatory blockade with monoclonal antibodies (mAb) cytotoxic T lymphocyte antigen 4 (CTLA4)-Ig and anti-CD154 mAb or two-signal blockade using anti-CD45RB and anti-CD154 mAb are nonmyeloablative treatment regimens for allogeneic transplantation. There may be differences in the mechanisms of donor cell engraftment and reactive cell deletion by which these regimens induce donor-specific tolerance. Therefore, this study was performed to investigate changes in T cells and cytokines during tolerance induction toward allogeneic skin grafts. BALB/c and C57BL/6 mice were used as donors and recipients, respectively. Skin and bone marrow transplantations were performed and busulfan was administered. Three groups were treated with mAb as follows: group 1, anti-CD154 mAb; group 2, anti-CD154 plus anti-CD45RB mAb; and group 3, anti-CD154 mAb plus CTLA4-Ig. The proportions of CD4+ or CD8+ T cells and the expression of CD45RB isoforms on splenocytes were measured using flow cytometry and the production of cytokines by CD4+ T cells using enzyme-linked immunosorbent assay. Group 2 showed a significant reduction in the proportions of CD8+ T cells and CD45RB high isoforms compared with groups 1 and 3. The levels of interleukin (IL)-2 and IL-4 in group 2 were lower and higher than those of groups 1 and 3, respectively. In conclusion, the combined use of anti-CD154 and anti-CD45RB mAb decreases the CD8+ T-cell population and the expression of CD45RB, resulting in a Th2 cytokine profile, which may be a characteristic mechanism leading to donor cell engraftment and reactive cell deletion for donor-specific tolerance.

Animals↗

PubMed2004

Effect of panel-reactive antibody positivity on graft rejection before or after kidney transplantation.

INTRODUCTION: Because it is well known that kidney transplant recipients with preformed lymphocytotoxic antibodies against HLA antigens have increased graft rejection rates, a serological crossmatch is routinely performed before kidney transplantation. But, the presence of these antibodies is not routinely monitored after transplantation. We investigated the panel-reactive antibody (PRA) response to know whether variations before or after kidney transplantation were associated with graft rejection. METHODS: We prospectively analyzed sera from 350 renal allograft recipients from September 1998 to March 2003. Pretransplantation and posttransplantation sera at 3 or 5 weeks postoperatively were tested in PRA. Recipients were stratified into 3 groups according to their PRA levels group I, PRA = 0; group II, PRA = less than 50%, and group III, PRA = more than 50%. RESULTS: The total graft rejection rate among 350 recipients was 9.4% (n = 33). Twenty-four pretransplantation PRA-positive recipients had a graft rejection rate of 20.8% (n = 5), compared with an 8.6% (n = 28) rate among 326 pretransplantation PRA-negative recipients. Six of 24 posttransplantation PRA-positive recipients (25%) experienced a graft rejection versus 27 (8.3%) of 326 posttransplantation PRA-negative subjects. Among the pretransplantation PRA stratae, the rejection rate in group III was 25% (1 of 4) versus 20% (4 of 20) in group II and 8.6% (28 of 326) in group I (P < .05). According to the postransplantation PRA level, 37.5% (3 of 8) in group III versus 18.8% (3 of 16) in group II and 8.3% (27 of 326) in group I (P < .05) had a graft rejection. CONCLUSION: Our study suggests that the PRA response pretransplantation and in the early posttransplantation period correlates with the kidney allograft rejection rate.

Adolescent↗

PubMed2004

Posttransplantation lymphoproliferative disorder in pediatric liver transplantation.

INTRODUCTION: The aim of this study was to evaluate the clinical features of risk factors for posttransplantation lymphoproliferative disorder (PTLD) in pediatric liver transplantation. MATERIALS AND METHODS: Between June 1996 and June 2002, among 41 pediatric patients who underwent liver transplantation, 7 died in the postoperative period. Thirty-five patients, including 1 patient who died of PTLD, were reviewed. Based on the serology results, patients were divided into a high-risk group (EBV-naive recipients of EBV-positive grafts) and a low-risk group (patients other than those in the high-risk group). RESULTS: Five of 41 patients (12.2%) developed PTLD. All of them belonged to the high-risk group. The incidence of PTLD in the high-risk group was 31.3% (5 of 16). The mean duration between operation and diagnosis for PTLD was 9.8 months. Primary EBV infection developed at a median of 6 months after transplantation. Three of 5 patients developed rejection before the diagnosis of PTLD. One patient was diagnosed with laryngeal and gastrointestinal PTLD, whereas the other 4 had gastrointestinal PTLD. They experienced the following symptoms and signs: anemia (100%), hypoalbuminemia (100%), fever (80%), diarrhea (80%), gastrointestinal bleeding (80%), and anorexia (60%). CONCLUSION: The common features of PTLD development were as follows: (1) EBV-positive donors placed into EBV-naive recipients, (2) primary EBV infection approximately 6 months after transplantation, (3) young age, 1 year old at operation, and (4) requirement for intensive posttransplantation immunosuppression.

Child↗

PubMed2004

Prevention of de novo hepatitis B infection from HbcAb-positive donors in living donor liver transplantation.

Hepatitis B virus (HBV) prophylaxis is necessary to prevent de novo hepatitis B infection from HbcAb-positive donors. However, which protocol is more effective is somewhat controversial. Also, it is uncertain whether it is necessary to administer HBV prophylaxis for HbsAb-positive recipients. This study attempted to determine whether it is necessary to administer HBV prophylaxis for HbsAb-positive patients and to evaluate the efficacy of an HBIG monotherapy protocol. From May 1996 to July 2001, among 128 donors examined for HbcAb, 58 donors (45.3%) were HbcAb-positive. Eighteen HbcAb-positive grafts were transplanted to HbsAg-negative recipients. The 4 patients who died of unrelated causes were excluded from this study. Of 14 study cases, 12 recipients were HbsAb-positive, and 2 were HbsAb-naive. Prior to late 1998, we used HBV vaccination only for de novo infection prophylaxis. However, starting from December 1998, HBIG was administered from the time of the liver transplantation regardless of HBsAb positivity. The overall rate of de novo HBV infections from HbcAb-positive donors was 21.4% (3 of 14). All 3 recipients without HBIG prophylaxis presented with de novo HBV infections. Two were HbsAb-positive preoperatively. No de novo HBV infections occurred among recipients with HBIG prophylaxis. Therefore, it is essential to administer HBV prophylaxis even for vaccinated HbsAb-positive patients. HBIG monotherapy is effective to prevent de novo hepatitis B infections from HbcAb-positive donors in living donor liver transplantation.

Child↗

PubMed2004

Can we expand the Milan criteria for hepatocellular carcinoma in living donor liver transplantation?

INTRODUCTION: The Milan criteria, namely, tumors 5 cm or less in diameter in patients with single hepatocellular carcinoma (HCC), no more than 3 tumor nodules, and each 3 cm or less in diameter in patients with multiple tumors, are accepted for cadaveric liver allocation. However, in living donor liver transplantation (LDLT), graft donation may only depend on the donor's intention. The aim of this study was to elucidate the feasibility of Milan criteria in LDLT. MATERIALS AND METHODS: From January 2001 to December 2002, 46 cases of liver transplantation (LT) for HCC included 5 hospital mortalities and 3 cadaveric transplantations, all of which were excluded. We classified the patients into Group I cases that met the Milan criteria and Group II cases that did not meet the Milan criteria. The analyses examined tumor-related risk factors affecting recurrence and survival, such as tumor size, number of tumor nodules, and presence of microvascular and macrovascular invasion. RESULTS: Twenty-one cases belonged to Group I and 17 to Group II. There was no significant difference in the recurrence or survival rates between Groups I and II. The risk factors affecting recurrence were macrovascular invasion and tumor size (5 cm). The number of tumor nodules and microvascular invasion did not appear to affect recurrence. The risk factor affecting survival was macrovascular invasion. CONCLUSION: We suggest that in selected cases the Milan criteria could be extended to increase the number of tumor nodules as long as the HCC were small and did not macrovascular invasion.

Cadaver↗

PubMed2004

Small-for-size graft in adult living-donor liver transplantation.

In the era of living donor liver transplantation (LDLT), graft size is related to recipient prognosis. This study was performed to compare the clinical outcomes according to the graft-to-recipient weight ratio (GRWR) in adult LDLT. Seventy-nine adult patients who had undergone LDLT between June 1997 and June 2002 were retrospectively analyzed. The patients were divided into two groups according to the GRWR (group I, GRWR < 0.8%, n = 11; group II, GRWR > or = 0.8%, n = 68). The mean follow-up period was 19.4 (range 1 to 48) months. The recipients were 62 men (78.5%) and 17 women (21.5%) of mean age 45.2 (range 18 to 63) years. The overall patient survival rates were 74.7% at 1 year and 70.7% at 2 years. The patient survival rate in group I was 54.6% at 1 year and 40.9% at 2 years, whereas that in group II was 77.9% at 1 year and 75.3% at 2 years, showing a significant difference (P = .03). There were no significant differences in postoperative total bilirubin, transaminase enzyme level, prothrombin time (INR), portal vein flow on Doppler sonography, amount of ascites through the drain, complications, or acute rejection rates between the two groups. In conclusion, the minimum acceptable graft size in an adult-to-adult LDLT is GRWR of 0.8%. This study suggests that careful postoperative management and/or technical modifications during surgery are necessary, because small-for-size grafts (GRWR < 0.8%) result in lower patient survival rates.

Adult↗

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

The number of CD8+ T cells and NKT cells increases in the aqueous humor of patients with Behçet's uveitis.

To determine whether there are differences in the immunopathogenesis of different endogenous uveitis syndromes, the phenotypic characteristics of immune cells were analysed among patients with endogenous uveitis. The aetiology of the uveitis included idiopathic recurrent acute anterior uveitis (18 patients), idiopathic intermediate uveitis (13 patients), Behçet's uveitis (17 patients), Vogt-Koyanagi-Harada syndrome (7 patients), and so on. Flow cytometric analysis was performed using immune cells of the aqueous humor and the peripheral blood during the active phase of intraocular inflammation, and monoclonal antibodies to CD3, CD4, CD8, CD14, CD19, CD56, TCR gammadelta, pan TCR alphabeta and Valpha24. CD8+ T cells were predominant in the aqueous humor of the patients with Behçet's uveitis, whereas CD4+ T cells were mainly found in the aqueous humor of patients other than those with Behçet's uveitis. The number of NKT (CD3+CD56+) cells was significantly higher both in the aqueous humor and the peripheral blood of the patients with Behçet's uveitis compared with the other groups (P < 0.05). CD8+CD56+ cells were the predominant subtype of the increased NKT cells in patients with Behçet's uveitis. In addition, intraocular infiltration of CD14+ cells significantly differed among the uveitis patients (P < 0.05). These results suggest that the immunopathogenesis of endogenous uveitis can vary between syndromes, and that CD8+CD56+ NKT cells may play an important role in the immunopathogenesis of Behçet's uveitis.

Adolescent↗

PubMed2004

Optimal but robust N and P removal in Sbrs: a model-based systematic study of operation scenarios.

A systematic approach to determine the optimal operation strategy for nitrogen (N) and phosphorus (P) removal of sequencing batch reactors (SBRs) has been developed and applied successfully to a lab-scale SBR. The methodology developed is based on using a grid of possible scenarios to simulate the effect of the key degrees of freedom in the SBR system. The grid of scenarios is simulated using a calibrated ASM2dN model developed and calibrated in a previous study. Effluent quality in combination with a robustness index for each of the scenarios is used to select the best scenario. With the best scenario, it is possible to improve/increase the current performance of the SBR system by around 54% and 74% for N and P removal respectively.

Bioreactors↗

PubMed2003

Intracranial ictal onset zone in nonlesional lateral temporal lobe epilepsy on scalp ictal EEG.

OBJECTIVE: To determine the ictal focus and the role of seizure characteristics, fluorodeoxyglucose (FDG) PET, and subtraction ictal SPECT in patients diagnosed as having nonlesional lateral temporal lobe epilepsy by long-term scalp video-EEG monitoring. METHODS: The authors studied 33 consecutive patients with nonlesional neocortical epilepsy who had a scalp ictal onset zone localized in the temporal lobe and good surgical outcome after focal neocortical resection. All patients were evaluated using intracranial recordings prior to resection. Semiology, FDG-PET, and ictal-interictal subtraction SPECT were used to verify the diagnostic role of these methods in the localization of epileptic foci. RESULTS: The ictal onset zones, confirmed by intracranial study, were the lateral temporal (22 patients), parietal (5), frontal (3), temporoparietal (2), and occipital (1) areas. FDG-PET analyzed by statistical parametric mapping correctly localized the epileptogenic lobe in 18 of 33 patients and subtraction ictal SPECT correctly localized it in 13 of 25 patients. However, in patients with extratemporal ictal onset zones, FDG-PET and ictal SPECT in combination correctly localized the epileptogenic lobe in only 3 of 11 cases. CONCLUSIONS: An extratemporal ictal onset zone was encountered in patients with nonlesional lateral temporal lobe seizures based on scalp video-EEG monitoring. FDG-PET and subtraction SPECT had localizing value in no more than half of patients.

Adult↗

PubMed2003

Developmental hemispheric asymmetry of interregional metabolic correlation of the auditory cortex in deaf subjects.

The functional connectivity of the auditory cortex might be altered in deaf subjects due to the loss of auditory input. We studied the developmental changes of functional connectivity of the primary auditory cortex (A1) in deaf children, deaf adults, and normal hearing adults by examining interregional metabolic correlation with (18)F-FDG PET. The mean activity of FDG uptake in the cytoarchitectonically defined A1 region served as a covariate in the interregional and interhemispheric correlation analysis. A1 metabolic rate was correlated with that of the ipsilateral superior temporal lobe in both normal and deaf subjects. This correlated area was larger in deaf children than in deaf or normal hearing adults. Concerning the functional connectivity of A1, a hemispheric asymmetry was found in that the extent of interregional correlation was clearly larger in the right than in the left hemisphere. This asymmetry was particularly pronounced in the younger deaf children. Both extent and asymmetry of the functional connectivity of A1 subsided with age. Contrary to this, a correlation between the left and the right primary auditory cortices was absent in younger deaf children but became apparent as they grew older.

Adolescent↗

PubMed2003

Brain glucose metabolic changes associated with neuropsychological improvements after 4 months of treatment in patients with obsessive-compulsive disorder.

OBJECTIVE: The study was designed to elucidate regional brain metabolic changes according to a treatment and their relationship with neuropsychological performance changes in obsessive-compulsive disorder (OCD). METHOD: Cerebral glucose metabolic rates were repeatedly measured before and after treatment in 10 patients with OCD using [18F]-2-fluoro-deoxyglucose positron emission tomography (PET). They were compared on a voxel-basis, and the correlations were counted between the regional metabolic changes and the degree to improvement on the neuropsychological assessments. RESULTS: After treatment, the patients showed significant (P < 0.005, two-tailed) regional metabolic changes in multiple brain areas involving frontal-subcortical circuits and parietal-cerebellar networks. Especially, the metabolic changes of the putamen, the cerebellum, and the hippocampus were significantly correlated with the improvement of the immediate- and delayed-recall scores of the Rey-Osterrieth Complex Figure Test (RCFT). CONCLUSION: These results suggest a possibility that metabolic changes of frontal-subcortical and parietal-cerebellar circuit changes may underlie cognitive improvements in patients with OCD.

Adult↗

PubMed2003

A double-blind, randomised- placebo, controlled, parallel group, multicentre, flexible-dose escalation study to assess the efficacy and safety of sildenafil administered as required to male outpatients with erectile dysfunction in Korea.

The efficacy and safety of sildenafil was evaluated in a randomiSed, double-blind, placebo-controlled, flexible-dose study in Korean men aged 28-78 y with erectile dysfunction (ED) of broad-spectrum aetiology and more than 6 months duration. A total of 133 patients were randomised at six centres in Korea to receive either sildenafil (50 mg initially, increased if necessary to l00 mg or decreased to 25 mg depending on efficacy and tolerance) (n=66) or matching placebo (n=67) taken on an 'as needed' basis l h prior to anticipated sexual activity for a period of 8 weeks. At the end of this time, the primary efficacy variables relating to the achievement and maintenance of erections sufficient for sexual intercourse, and the secondary efficacy variables, which included: (1) the five separate domains of sexual functioning of the International Index of Erectile Function (IIEF) scale, (2) the percentage of successful intercourse attempts, and (3) a global assessment of erections, were all statistically significantly improved by sildenafil in comparison with placebo (P&<0.0001). Treatment-related adverse events occurred in 56.1% of patients receiving sildenafil and 20.9% receiving placebo. The most common adverse events with sildenafil were vasodilatation (flushing), headache and abnormalities in colour vision (31.8, 22.7 and 6.1% of patients, respectively), and most were mild in nature. The efficacy and safety of sildenafil in this population of Korean men appears similar to that reported in other studies in western populations.

Adult↗

PubMed2003

On-line monitoring equipment for wastewater treatment processes: state of the art.

A (non-exhaustive) survey of new and existing technologies for the monitoring of wastewater treatment plants is presented. Emphasis is given to the way these sensors can provide insight in the ongoing (bio-) processes. Three different uses for sensors can be found: for monitoring (operator support), in automatic control systems and as tools for plant auditing/optimization/modelling by consultants. From this, sensors have been classified in two basic types: (i) reliable, simple and low maintenance sensors for day-to-day monitoring and control and (ii) advanced, higher maintenance sensors that are used in auditing, model calibration and optimisation. The paper is organized according to the typical unit processes of biological wastewater treatment systems: anaerobic digestion, activated sludge, nutrient removal and sedimentation. Attention is drawn to a number of practical problems associated with the use of sophisticated sensors in the harsh (dirty) conditions of wastewater treatment processes. The use of autocalibration and built-in sensor checks, cleaning systems and reliable sample preparation units is illustrated. The paper ends with a discussion of the applicability of the different sensors.

Automation↗

PubMed2002

Hepatitis B and C virus prevalence in a rural area of South Korea: the role of acupuncture.

A cross-sectional study evaluated the prevalence of and the risk factors for hepatitis C and B viruses among 700 adults above the age of 40 years in a rural area of South Korea. Seropositivity for hepatitis C virus antibody (11.0%, 95% confidence interval: 8.7-13.6) was higher than that for hepatitis B surface antigen (4.4%, 95% confidence interval: 3.0-6.2). Anti-hepatitis C virus seropositivity was associated with a history of repeated acupuncture (odds ratio=2.1, 95% confidence interval: 1.1-4.0), and blood transfusion (odds ratio=5.5, 95% confidence interval: 1.6-19.3) before 1992 when hepatitis C virus screening in blood donors became mandatory. Hepatitis C virus 2a was the most prevalent genotype, followed by 1b. Hepatitis C virus risk attributable to acupuncture was 38% (9% for men and 55% for women). Safer acupuncture practice has become a priority for hepatitis C virus prevention in South Korea.

Acupuncture Therapy↗

PubMed2002

Dopamine transporter density is decreased in parkinsonian patients with a history of manganese exposure: what does it mean?

Manganese (Mn) exposure can cause parkinsonism. Pathological changes occur mostly in the pallidum and striatum. Two patients with a long history of occupational Mn exposure presented with Mn-induced parkinsonism. In one patient, magnetic resonance imaging (MRI) showed findings consistent with Mn exposure, and Mn concentration was increased in the blood and urine. However, this patient's clinical features were typical of idiopathic Parkinson disease (PD). Previous pathological and positron emission tomography studies indicate that striatal dopamine transporter density is normal in Mn-induced parkinsonism, whereas it is decreased in PD. Therefore, we performed [(123)I]-(1r)-2 beta-carboxymethoxy-3beta-(4-iodophenyl)tropane ([(123)I]-beta-CIT) single-photon emission computed tomography. Severe reduction of striatal beta-CIT binding was indicated, which is consistent with PD. We propose three interpretations: (1) the patients have PD, and Mn exposure is incidental; (2) Mn induces selective degeneration of presynaptic dopaminergic nerve terminals, thereby causing parkinsonism; or (3) Mn exposure acts as a risk of PD in these patients. Our results and careful review of previous studies indicate that the axiom that Mn causes parkinsonism by pallidal lesion may be over-simplified; Mn exposure and parkinsonism may be more complex than previously thought. Further studies are required to elucidate the relationship between Mn and various forms of parkinsonism.

Causality↗