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S J Lee

Publications and source records attributed to S J Lee.

At least 55 records · Page 3Linked to original sources
PubMed2005

Bupivacaine induces apoptosis via ROS in the Schwann cell line.

Local anesthetics have been generally accepted as being safe. However, recent clinical trials and basic studies have provided strong evidence for the neurotoxicity of local anesthetics, especially through apoptosis. We hypothesized that local anesthetics cause neural complications through Schwann cell apoptosis. Among local anesthetics tested on the Schwann cell line, RT4-D6P2T, bupivacaine significantly induced cell death, measured by the methyl tetrazolium (MTT) assay, in a dose- (LD50 = 476 microM) and time-dependent manner. The bupivacaine-induced generation of reactive oxygen species (ROS), which was initiated within 5 hrs and preceded the activation of caspase-3 and poly ADP-ribose polymerase (PARP) degradation, was suggested to trigger apoptosis, exhibited by Hoechst 33258 nuclear staining and DNA fragmentation. Furthermore, concomitant block of ROS by anti-oxidants significantly inhibited bupivacaine-induced apoptosis. Among the local anesthetics for peripheral neural blocks, bupivacaine induced apoptosis in the Schwann cell line, which may be associated with ROS production.

Analysis of Variance↗
PubMed2004

Normal rainbow trout serum (RTS)-resistant variants of the infectious pancreatic necrosis virus (IPNV)-Jasper differ with respect to inhibition by RTS, serotype and cDNA sequence.

In order to determine if the infectious pancreatic necrosis virus isolate IPNV-Jasper (Ja-ATCC) is homogeneous or heterogeneous with respect to inhibition by normal rainbow trout serum (RTS), 50 clones were tested for sensitivity to RTS. The initial isolate was very sensitive to RTS, losing from 10(4) to 10(8) 50 % tissue culture infection dose (TCID50) ml(-1) with a 1:100 dilution of RTS. The sensitivity of the clones ranged from highly sensitive to completely resistant (0 to 10(8) TCID50 ml(-1) reduction). Eight percent of clones (4/50) were very sensitive to RTS (Ja-S) and 84% of clones (42/50) showed a mid-range of sensitivity to RTS. The final 8 % of clones (4/50) were resistant to RTS (Ja-R). Enzyme immunodot assay revealed that Ja-S clones showed a monoclonal reaction identical to the parents, Ja-ATCC; however, Ja-R clones differed by several epitopes from the parental strain. Analysis of Ja-S and Ja-R revealed that there were significant differences in their nucleic acid sequences for the capsid protein VP2. These 2 strains shared 80.7 and 86.5% identity in nucleic acid and in amino acid sequences, respectively. Ja-S had 99.7 and 91.0 % identity in nucleic acid sequences, and 99.5 and 95.9 % in amino acid sequences with Ja-ATCC and Jasper-Dobos (Ja-D), respectively, while Ja-R showed 80.6 and 79.8 % identity in nucleic acid sequences and 86.5 and 87.0 % in amino acid sequences with Ja-ATCC and Ja-D, respectively. In conclusion, the Ja-ATCC population was heterogeneous in terms of RTS sensitivity, serotype and cDNA sequences from the VP2 coding region.

Amino Acid Sequence↗
PubMed2004

Construction of a BAC library of Korean ginseng and initial analysis of BAC-end sequences.

We estimated the genome size of Korean ginseng (Panax ginseng C.A. Meyer), a medicinal herb, constructed a HindIII BAC library, and analyzed BAC-end sequences to provide an initial characterization of the library. The 1C nuclear DNA content of Korean ginseng was estimated to be 3.33 pg (3.12 x 10(3) Mb). The BAC library consists of 106,368 clones with an average size of 98.61 kb, amounting to 3.34 genome equivalents. Sequencing of 2167 BAC clones generated 2492 BAC-end sequences with an average length of 400 bp. Analysis using BLAST and motif searches revealed that 10.2%, 20.9% and 3.8% of the BAC-end sequences contained protein-coding regions, transposable elements and microsatellites, respectively. A comparison of the functional categories represented by the protein-coding regions found in BAC-end sequences with those of Arabidopsis revealed that proteins pertaining to energy metabolism, subcellular localization, cofactor requirement and transport facilitation were more highly represented in the P. ginseng sample. In addition, a sequence encoding a glucosyltransferase-like protein implicated in the ginsenoside biosynthesis pathway was also found. The majority of the transposable element sequences found belonged to the gypsy type (67.6%), followed by copia (11.7%) and LINE (8.0%) retrotransposons, whereas DNA transposons accounted for only 2.1% of the total in our sequence sample. Higher levels of transposable elements than protein-coding regions suggest that mobile elements have played an important role in the evolution of the genome of Korean ginseng, and contributed significantly to its complexity. We also identified 103 microsatellites with 3-38 repeats in their motifs. The BAC library and BAC-end sequences will serve as a useful resource for physical mapping, positional cloning and genome sequencing of P. ginseng.

Chromosomes, Artificial, Bacterial↗
PubMed2004

Micro total analysis system (micro-TAS) in biotechnology.

Nanobiotechnology raises fascinating possibilities for new analytical assays in various fields such as bioelectronic assembly, biomechanics and sampling techniques, as well as in chips or micromachined devices. Recently, nanotechnology has greatly impacted biotechnological research with its potential applications in smart devices that can operate at the level of molecular manipulation. Micro total analysis system (micro-TAS) offers the potential for highly efficient, simultaneous analysis of a large number of biologically important molecules in genomic, proteomic and metabolic studies. This review aims to describe the present state-of-the-art of microsystems for use in biotechnological research, medicine and diagnostics.

Biosensing Techniques↗
PubMed2004

Changes in the local morphology of the rectus abdominis muscle following the DIEP flap: an ultrasonographic study.

This study was undertaken to assess the changes in the local morphology of the rectus abdominis muscle following intramuscular dissection of the deep inferior epigastric artery perforators after harvesting of the deep inferior epigastric perforator (DIEP) flap. While the DIEP provides the well-known advantage of use of the lower abdominal tissue with preservation of the integrity of the abdominal wall musculature, postoperative problems such as abdominal asymmetry, bulges and reduced flexion capacity have been found. These changes may be due to rectus abdominis muscle damage from ischemia or denervation. We used ultrasonography to assess the changes in rectus abdominis muscle thickness and contractility, preoperatively, 1-month and 1-year postoperatively. The study group consisted of 17 rectus abdominis muscles in 14 patients subjected to intramuscular dissection of perforators. The control group consisted of 11 intact rectus abdominis muscles in 11 patients who had undergone unilateral DIEP flap elevation, the dissected muscles being part of the study group. We found that the resting muscle thickness in the study group was, significantly increased at 1-month postoperatively, resolving by 1-year follow-up. As these changes were not seen in the control group, the increased muscle thickness is attributed to postoperative oedema that resolves with time. All muscles in the study and control groups retained contractility showing no evidence of muscle denervation. Our date demonstrates that intramuscular dissection of perforator vessels in the DIEP flap leads to minimal changes in the local morphology and contractility of the rectus abdominis muscle.

Adult↗
PubMed2004

Estrogen induces phosphorylation of cyclic AMP response element binding (pCREB) in primary hippocampal cells in a time-dependent manner.

Using hippocampal primary cell cultures at 14 days in vitro (div), we have investigated actions of 17-beta estradiol (E; 10 nM) on the phosphorylation of CREB and on signaling pathways that regulate CREB phosphorylation. After demonstrating that 14 div is optimal for these studies, we examined the time course of E induction of CREB phosphorylation (pCREB) at serine residue 133. The induction of pCREB occurs as early as 1 h following E treatment, presumably via a mechanism involving an E-stimulated signal transduction system, which is sustained for at least 24 h but inhibited by 48 h. The early activity may represent an initial signal required for events leading to phosphorylation of CREB while the sustained signal may lead to CREB-mediated gene expression for cell survival and synapse formation. Furthermore, we examined the pathways for E action preceding pCREB induction by blocking three major kinases (protein kinase; mitogen activated protein kinase, MAPK; and calcium-calmodulin kinase II, CaMKII) upstream of pCREB. We found that E stimulates each pathway at 24 h and that phosphorylation of CREB is dependent on both MAPK and CaMK activities, but less dependent on the Akt pathway. Because CREB has been linked to E induction of excitatory spine synapses, we used a spine marker, spinophilin, to establish E effects on spine formation. Spinophilin expression was up-regulated in response to E and this effect was blocked by an inhibitor of (CaMKII). These studies demonstrate the central role played by CaMKII pathway in the actions of E on both transcriptional regulation and structural reorganization in neurons.

Animals↗
PubMed2004

Estradiol affects spinophilin protein differently in gonadectomized males and females.

Estrogen (E) treatment of ovariectomized animals increases dendritic spines and/or synaptic protein expression in the hippocampus of female rats [J Neurosci 12 (1992) 2549; Endocrinology 142 (2001) 1284; Endocrinol Rev 20 (1999) 279; Annu Rev Pharmacol Toxicol 41 (2001) 569], mice [Proc Natl Acad Sci USA 101 (2004) 2185], rhesus monkeys [Proc Natl Acad Sci USA 98 (2001) 8071; Endocrinology 144 (2003) 4734; J Comp Neurol 465 (2003) 540] and hippocampal cells in vitro [J Neurosci 16 (1996) 4059; Neuroscience 124 (2004) 549]. The role of E in hippocampal synaptic structural plasticity in males is less well understood. In the present study, we have used a recently developed technique to count spinophilin immunogold-reactive (Ir) puncta as well as in situ hybridization to compare E effects on spinophilin-Ir and mRNA in gonadectomized female and male rats 48 h after E treatment. Spinophilin is an established spine marker, which interacts with several proteins (including actin and protein phosphatase 1) that are highly enriched in spines [Proc Natl Acad Sci USA 94 (1997) 9956; Proc Natl Acad Sci USA 97 (2000) 9287]. We report that E exerts sex-specific effects on dendritic spinophilin-labeled spines in the CA1 region: E treatment significantly increased spinophilin-Ir puncta, indicative of spines, in females, but led to a decrease in males. Furthermore, while hippocampal spinophilin mRNA changes could have occurred earlier, spinophilin mRNA levels were unchanged after 48 h of E in both males and females. This suggests the possibility that E regulates spinophilin protein expression and or stability within dendrites via post-transcriptional mechanisms.

Animals↗
PubMed2004

Glycoprotein isolated from Solanum nigrum L. inhibits the DNA-binding activities of NF-kappaB and AP-1, and increases the production of nitric oxide in TPA-stimulated MCF-7 cells.

Solanum nigrum L. (SNL) has been used in traditional folk medicine to treat numerous cancers. We isolated a glycoprotein (150 kDa) from SNL and tested its effect on the modulation of transcriptional factors (NF-kappa B and AP-1) and iNO production in TPA induced-MCF-7 cells, which are part of the human breast cancer cell line, without estrogen receptors. However, the mechanism of SNL glycoprotein in pharmacological and biochemical actions in cancer cells has not been studied. To test the effect of SNL glycoprotein on the DNA-binding activities of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1), and nitric oxide (NO) production, these experiments were carried out using electrophoretic mobility shift assays (EMSA), western blot analysis, and the Griess method. Results in this experiment showed that SNL glycoprotein inhibits 12-O-Tetra decanoylphorbol-13-acetate (TPA; 100 nM)-induced DNA-binding activities of NF-kappaB and AP-1, and enhances NO production in MCF-7 cells. That is, our results indicated that SNL glycoprotein has the capacity to modulate the TPA-induced DNA-binding activities of transcription factors and NO production, which play a critical role with respect to cytotoxicity in MCF-7 cells. Therefore, SNL glycoprotein might be one of the agents that blocks TPA-mediated signal responses in tumor cells.

Breast Neoplasms↗
PubMed2004

Partial CD8+ T-cell depletion of allogeneic peripheral blood stem cell transplantation is insufficient to prevent graft-versus-host disease.

Prior studies suggest that depletion of CD8+ T cells from donor bone marrow or donor lymphocyte infusions can reduce graft-versus-host disease (GVHD) without compromising graft-versus-leukemia. We explored CD8 depletion in patients undergoing matched related donor (MRD, n=25) and unrelated donor (URD, n=16) peripheral blood stem cell transplantation following myeloablative conditioning with cyclophosphamide (60 mg/kg/day i.v. x 2) and total body irradiation (200 cGy x 7 fractions). Ex vivo incubation of mobilized donor peripheral blood cells with anti-CD8 antibody coated high-density microparticles removed 99% of CD8+ cells. The median number of CD8+ cells infused was 3.9 x 10(5) cells/kg (2.2 x 10(5) in MRD, and 8.1 x 10(5) in URD patients). Post transplant immune suppression included tacrolimus in the MRD cohort, and tacrolimus plus mini-methotrexate (5 mg/m2 days +1, 3, 6, 11) in the URD cohort. All 41 patients engrafted. Grade 2-4 acute GVHD incidence was 61% (44% MRD, 88% URD). Chronic GVHD incidence was 50% (48% MRD, 55% URD). Relapse incidence was 4.9%. Estimated event-free and overall survival rates were 65 and 63%, respectively, at 1 year and 56 and 57%, respectively, at 2 years. There was no correlation between CD8+ number and GVHD or survival. A 2-log depletion of CD8+ cells from PBSC is insufficient to prevent GVHD.

Adult↗
PubMed2004

Decision-making and quality of life in older adults with acute myeloid leukemia or advanced myelodysplastic syndrome.

Older patients with acute myeloid leukemia (AML) and advanced myelodysplastic syndrome (aMDS) must decide between receiving intensive induction chemotherapy (IC) or nonintensive chemotherapy/best supportive care (NIC). Little information exists about what factors influence treatment decisions and what quality of life (QOL) is associated with treatment choices. We prospectively examined 43 patients 60 years or older who were interviewed at diagnosis and periodically over 1 year. IC choice was associated with younger age (66 vs 76 years, P=0.01) and AML diagnosis, but not with performance status, comorbidities, or QOL. In total, 63% of all patients reported not being offered other treatment options despite physician documentation of alternatives. Patient and physician estimates of cure differed significantly: 74% of patients estimated their chance of cure to be 50% or greater, yet for 89% of patients physician estimates of cure were 10% or less. IC patients experienced decreased QOL at 2 weeks, but rebounded to baseline and to NIC levels by 6 weeks. Initial QOL is not associated with treatment choice in older AML and aMDS patients. Regardless of treatment choice, patients report not being offered treatment options and overestimate their chances of cure. In IC patients, QOL decreases during hospitalization but rebounds after discharge.

Acute Disease↗
PubMed2004

Phase II study of theophylline in chronic lymphocytic leukemia: a study of the Eastern Cooperative Oncology Group (E4998).

The Eastern Cooperative Oncology Group (ECOG) performed a phase 2 study in B-cell chronic lymphocytic leukemia (CLL) of oral theophylline, a methylxanthine that inhibits cyclic nucleotide phosphodiesterases, thereby inducing the intracellular accumulation of cyclic adenosine monophosphate (cAMP). In 25 patients with Rai stages 0-I, theophylline, 200 mg given orally every 12 h was well tolerated. There was one complete response after 22.5 months of treatment, which continues at 27+ months, and 18 other patients had stable disease. In vitro exposure of patients' lymphocytes to aminophylline (75-250 microg/ml), the soluble form of theophylline, resulted in dose- and time-dependent induction of apoptosis in 9/20 patients studied. Apoptosis was documented flow-cytometrically by monitoring the expression of bcl-2 and bax, forward light scatter, fluorescence intensity of binding of CD45 antibody, and the binding of annexin. Patients whose leukemic lymphocytes were susceptible to apoptosis induction by aminophylline in vitro experienced a significantly longer progression-free survival than patients whose cells were resistant to the drug in culture (P=0.025). This suggests that in a CLL population treated with theophylline, induction of an apoptotic response to the drug in vitro is prognostic for absence of clinical progression.

Administration, Oral↗
PubMed2004

Temporal differences in relative phasing of gait initiation and first step length in patients with cervical and lumbosacral spinal cord injuries.

STUDY DESIGN: Comparison group design. OBJECTIVE: To compare the temporal distance factors during gait initiation between patients with incomplete cervical spinal cord injury, incomplete lumbosacral spinal lesion, and unimpaired control adults. SETTING: Human performance and movement analysis laboratory, Taiwan. PARTICIPANTS: Five patients with an incomplete cervical spinal cord injury (Group 1), five patients with an incomplete lumbosacral spinal lesion (Group 2) and nine unimpaired control adults (Group 3). METHODS: Subjects underwent a three-dimensional gait analysis. The total gait initiation period, reaction time, each relative phasing of gait initiation and the length of the first step were identified by using the kinematic measurement system. MAIN OUTCOME MEASURES: The total gait initiation period (start of the auditory cue for gait initiation to heel-strike of the first swing leg); each relative phasing of gait initiation indicated that the duration of the preparatory phase (start of auditory cue for gait initiation to heel-off of the first swing leg), the duration of the push-up phase (heel-off to toe-off of the first swing leg), and the duration of the single-stance phase (toe-off to heel-strike of the first swing leg) established by the total gait initiation period; and the length of the first step. RESULTS: The gait initiation period was greater in Groups 1 and 2 than that of Group 3 (P<0.05). Each relative phasing including the duration of the preparatory phase, the push-up phase, and the swing phase relative to the total gait initiation period, did not differ among Groups 1-3 (P>0.05). The length of the first step, measured while the nonpreferred leg stepped first in Groups 1 and 2, was shorter than that of Group 3 (P<0.05). CONCLUSIONS: Patients with incomplete cervical spinal cord injuries or lumbosacral spinal lesions took more time in gait initiation than unimpaired control adults. The first step length also reduced in these patients while the nonpreferred leg stepped first, as compared to unimpaired control adults. The data indicated that centrally programmed gait initiation might be preserved in ASIA-D spinal patients who, in this study, executed gait initiation with varying temporal distance strategies to compensate for peripheral impairments, as compared to unimpaired control adults.

Adult↗
PubMed2004

Non-adiabatic intramolecular and photodissociation dynamics studied by femtosecond time-resolved photoelectron and coincidence imaging spectroscopy.

Time-resolved photoelectron spectroscopy (TRPES) is emerging as a useful tool for the study of non-adiabatic dynamics in isolated polyatomic molecules and clusters due to its sensitivity to both electronic and vibrational dynamics. A powerful extension of TRPES, coincidence imaging spectroscopy (CIS), based upon femtosecond time-resolved 3D momentum vector imaging of both photoions and photoelectrons in coincidence, is a new technique for the study of complex dissociative processes. Here we show how these spectroscopies can be used to study both non-adiabatic intramolecular and photodissociation dynamics in polyatomic molecules. Intramolecular dynamics in the alpha, beta-enones acrolein, crotonaldehyde and methyl vinyl ketone are studied using both TRPES and laser-induced fluorescence of HCO(X) product yields. The location of the methyl group is seen to have very dramatic effects on the relative electronic relaxation rates and the HCO(X) yield. Applying both TRPES and CIS to the 200 nm and 209 nm photodissociation of the nitric oxide dimer, (NO)2, we observe the fs time-scale evolution of the excited parent neutral via its photoelectron spectrum and the emergence of the NO(A) photofragment including its energy and angular distributions.

Journal Article↗
PubMed2004

Calcium-alginate coated, whey protein-based microspheres: preparation, some properties and opportunities.

An 'all aqueous' encapsulation process followed by a heat treatment was used to prepare calcium-alginate-coated, whey protein-based, water insoluble microspheres containing micronized calcium carbonate as a model core. Results obtained with this process were compared to those obtained with a similar process in which chemical cross-linking was utilized. At an initial core load of 25 or 50% (w/w), core retention ranged from 84.2-95.12% and was not significantly affected by the initial core load or by the cross-linking method. Regardless of the cross-linking method, protein retention during the process was high and ranged from 78.2-87.5%. Outer topography of the microspheres was not influenced by the cross-linking method, however, at a given composition, the inner structure of heat treated microspheres differed from that obtained with chemically-cross-linked microspheres. Swelling properties of denovo microspheres were affected by pH. Results indicated that the micronized calcium carbonate could be used as a porogenic core. Removal of the core, by an acid treatment, allowed preparing microporous delivery devices. In addition to offer opportunities for encapsulation and delivery of crystalline core, the investigated process can provide means to prepare 'ghost' microporous delivery systems that can, in potential, be loaded, following their preparation, with sensitive core materials at conditions that favour the stability and functionality of this core.

Alginates↗
PubMed2004

Using standardised patients in an objective structured clinical examination as a patient safety tool.

Standardised patients (SPs) are a powerful form of simulation that has now become commonplace in training and assessment in medical education throughout the world. Standardised patients are individuals, with or without actual disease, who have been trained to portray a medical case in a consistent manner. They are now the gold standard for measuring the competence of physicians and other health professionals, and the quality of their practice. A common way in which SPs are used in performance assessment has been as part of an objective structured clinical examination (OSCE). The use of an SP based OSCE can be a powerful tool in measuring continued competence in human reliability and skill performance where such skills are a critical attribute to maintaining patient safety. This article will describe how an OSCE could be used as a patient safety tool based on cases derived from actual events related to postdonation information in the blood collection process. The OSCE was developed as a competency examination for health history takers. Postdonation information events in the blood collection process account for the majority of errors reported to the US Food and Drug Administration. SP based assessment is an important patient safety tool that could be applied to a variety of patient safety settings and situations, and should be considered an important weapon in the war on medical error and patient harm.

Clinical Competence↗