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Biomedical subjects

S Kim

Publications and source records attributed to S Kim.

At least 217 records · Page 12Linked to original sources
PubMed2001

Correlation of hematopoietic progenitor cell count determined by the SE-automated hematology analyzer with CD34(+) cell count by flow cytometry in leukapheresis products.

The yield of stem cell collection after mobilization is crucial for autologous peripheral blood stem cell (PBSC) transplantation. Quantitative determinations of CD34(+) cells using flow cytometry or stem cell culture have been used, but these methods require much time, technical experience, and expensive reagents. The automated hematology analyzer (Sysmex SE-9000trade mark, TOA, Japan) equipped with the Immature Information (IMI) channel for immature myeloid cells can detect IMI(+) cells within 90 sec. Detection is made possible by the combination of a special reagent system and direct current/radiofrequency biosensors. We studied the relation of IMI(+) cells and variable cell counts with CD34(+) cell yield in autologous stem cell harvest. In a series of 32 patients (median age, 44 years; M:F = 11:21), 184 leukaphereses were performed after mobilization regimens with chemotherapy and G-CSF or G-CSF alone. Full blood cell counts were enumerated on peripheral blood (PB) samples taken prior to each leukapheresis. Mononuclear cell (MNC) and IMI(+) cell counts by automated hematology analyzer and flow cytometry based CD34(+) cell yield were measured on the harvested product. The relationship among PB white blood cells (WBC), PB monocytes, IMI(+) cells, MNC, and CD34(+) cell yield in a single leukapheresis was estimated by Pearson correlation analysis. PB WBC count showed no correlation with CD34(+) cell yield in a single leukapheresis (r = 0.02, P = 0.81). PB monocyte count showed a weak correlation (r = 0.21, P = 0.01) and MNC in harvest also showed a weak correlation (r = 0.36, P = 0.0001) with CD34(+) cell yield. In contrast, CD34(+) cell yield correlated well with IMI(+) cell count (r = 0.68, P = 0.0001), and data could be fitted by a linear regression equation, y = 0.330 + 0.974x. IMI(+) cell assay by the automated hematology analyzer correlated well with the CD34(+) cell yield in a mobilized autologous stem cell harvest. The IMI(+) cell count might be used as a simple and efficient indicator of blood stem cell mobilization and collection.

Adolescent↗
PubMed2001

Advanced hypopharyngeal carcinoma treatment results according to treatment modalities.

BACKGROUND: The purpose of this retrospective study is to compare the treatment results of locally advanced hypopharyngeal carcinoma according to treatment modalities. METHODS: Seventy-three patients with locally advanced hypopharyngeal carcinoma treated at the Department of Therapeutic Radiology, Seoul National University Hospital, between August 1979 and July 1997 were retrospectively analyzed. Twenty-three patients were treated with radiotherapy (RT) alone, 18 patients were treated with surgery and postoperative RT, and 32 patients were treated with neoadjuvant chemotherapy (CTx) and RT. Median follow-up period was 28 months. RESULTS: The overall 5-year survival rates were 15.7% for the RT alone group, 46.8% for surgery and postoperative RT group, and 43.0% for neoadjuvant CTx and RT group. The 5-year disease-free survival rates were 13.9%, 47.4%, and 30.7%, respectively. Surgery and postoperative RT or neoadjuvant CTx and RT showed superiority over RT alone in terms of both overall survival and disease-free survival rates. No significant differences were found in overall and disease-free survival rates between the surgery and postoperative RT group and neoadjuvant CTx and RT group (p =.15, p =.13). In the neoadjuvant CTx and RT group, 12 patients (38%) retained their larynx more than 5 years. CONCLUSION: Neoadjuvant CTx and RT is an effective strategy to achieve organ preservation without compromising the survival of patients with locally advanced hypopharyngeal carcinoma.

Adult↗
PubMed2001

Consecutive carbon-carbon bond formation approach in tandem cyclization reactions.

The conventional tandem cyclization reactions involve the formation of alternating carbon-carbon bonds, whereas the newly developed cyclization reactions involve the formation of consecutive carbon-carbon bonds, in which N-aziridinylimines have been utilized as geminal radical acceptor and donor equivalents in a single operation. This unprecedented tandem cyclization approach becomes feasible by the successful generation of 5- and 6-membered ring radicals by radical cyclizations of N-aziridinylimines. The same notion can be applied to the anionic cyclizations of N-aziridinylimines, thereby allowing anionic consecutive carbon-carbon bond formation. This approach has great synthetic potential, particularly for the construction of quaternary carbon centers, and it provides highly efficient routes for the synthesis of natural products.

Aziridines↗
PubMed2001

Msx1 gene overexpression induces G1 phase cell arrest in human ovarian cancer cell line OVCAR3.

Recent evidence suggested an involvement of homeobox genes in tumorigenesis. Here we investigated whether one of homeobox-containing genes, Msx1, might be involved in the regulation of cell proliferation and cell cycle using Msx1 overexpressing human ovarian cancer cell line, OVCAR3. Overexpression of Msx1 in OVCAR3 cells inhibited cell proliferation by markedly increasing the length of the G1 phase of the cell cycle over control cells. Consistent with this result, dramatic suppression of cyclins D1, D3, E, cyclin-dependent kinase 4, c-Jun, and Rb was observed. Elevated expression of genes involved in the growth arrest and apoptosis (GADD153 and apoptotic cystein protease MCH4) and suppression of proliferation associated protein gene (PAG) in Msx1-overexpressing cells by cDNA expression array analysis provide further evidence for a potential repressor function of Msx1 in cell cycle progression.

Cell Division↗
PubMed2001

The effects of scrambling on Spanish and Korean agrammatic interpretation: why linear models fail and structural models survive.

Several models of comprehension deficits in agrammatic aphasia rely heavily on linear considerations in the assignment of thematic roles to structural positions (e.g., the Trace-Deletion Hypothesis, the Mapping Hypothesis, and the Argument-Linking Hypothesis). These accounts predict that constructions in languages with rules that affect syntactic structure but preserve relative linear order should be unimpaired. Other models [e.g., the Double-Dependency Hypothesis, (DDH)] do not resort to linearity but are purely structural in conception and therefore should be immune to word-order effects. We tested linear and nonlinear accounts with scrambling structures in Korean and topicalization structures in Spanish. The results are very clear. The (nonlinear) DDH is entirely compatible with the evidence, but the linear accounts are not.

Adult↗
PubMed2001

Human choroid plexus growth factors: What are the implications for CSF dynamics in Alzheimer's disease?

The choroid plexus plays a key role in supporting neuronal function by secreting cerebrospinal fluid (CSF) and may be involved in the regulation of various soluble factors. Because the choroid plexus is involved in growth factor secretion as well as CSF dynamics, it is important to understand how growth factors in CSF interact with the brain parenchyma as well as with cells in direct contact with the flowing CSF, i.e., choroid plexus and arachnoid villi. While the existence of growth factors in the choroid plexus has been documented in several animal models, the presence and distribution of growth factors in the human choroid plexus has not been extensively examined. This study describes the general distribution and possible functions of a number of key proteins in the human choroid plexus and arachnoid villi, including basic fibroblast growth factor, FGF receptor, and vascular endothelial growth factor. FGF and VEGF could both be readily demonstrated in choroid plexus epithelial cells. The presence of FGF and VEGF within the choroid plexus was also confirmed by ELISA analysis. Since Alzheimer's disease (AD) is known to be associated with a number of growth factor abnormalities, we examined the choroid plexus and arachnoid villi from AD patients. Immunohistochemical studies revealed the presence of FGF and VEGF within the AD choroid plexus and an increased density of FGFr in both the choroid plexus and the arachnoid villi of AD patients. No qualitative changes in the distribution of FGF and VEGF were observed in the AD choroid plexus. The appearance of FGFr in AD arachnoid was associated with robust amyloid and vimentin immunoreactivity. These findings confirm the presence of FGF and VEGF within the normal and AD choroid plexus and suggest that the alteration of growth factors and their receptors may contribute to the pathogenesis of the hydrocephalus ex vacuo that is characteristically seen in AD.

Alzheimer Disease↗
PubMed2001

Angiotensin blockade inhibits increased JNKs, AP-1 and NF- kappa B DNA-binding activities in myocardial infarcted rats.

Inhibition of the renin-angiotensin system has been shown to prevent left ventricular remodeling after myocardial infarction. However, the effect of angiotensin on the signal transduction pathway of left ventricular remodeling after myocardial infarction is as yet unknown. The purpose of this study was to measure myocardial MAPKs and AP-1, NF- kappa B, and Sp-1 DNA-binding activities after myocardial infarction. Moreover, we evaluated the effects of angiotensin converting enzyme (ACE) inhibitor and angiotensin receptor blocker (ARB) on signal transduction pathway. Myocardial infarction was produced by ligation of the coronary artery in Wistar rats. Temocapril (ACE inhibitor) (3 and 30 mg/kg/day) and candesartan cilexitil (ARB) (1 and 10 mg/kg/day) were orally administered once a day. After ligation of the left descending coronary artery, JNKs (p46JNK and p55JNK) increased to 2.0- (P<0.01) and 2.8-fold (P<0.01) at 7 days, respectively. ERKs (p44ERK and p42ERK) and p38 activities did not increase significantly. AP-1 and NF- kappa B binding activities increased at 5 days, reached their peak 2.2- and 2.0-fold at 7 days. Sp-1 did not change. ACE inhibitor and ARB inhibited JNKs, NF- kappa B and AP-1 activities. Increased JNKs, AP-1, NF- kappa B, and Sp-1 DNA-binding activities were suppressed by both drugs in the infarcted region. Doppler-echocardiography showed that ACE inhibitor and ARB prevented the dilatation of left ventricular cavity at 14 days and improved diastolic filling pattern. JNKs, AP-1 and NF- kappa B activation in myocardial infarcted rats could be responsible for left ventricular remodeling after myocardial infarction and angiotensin may be related to the activation of these signals.

Angiotensin Receptor Antagonists↗
PubMed2001

Induction of quinone reductase activity by stilbene analogs in mouse Hepa 1c1c7 cells.

Based on the potential cancer chemopreventive activity of resveratrol, a trihydroxystilbene with the induction of quinone reductase activity, this study was designed to determine if stilbene-related compounds were inducers of phase II detoxifying metabolic enzyme quinone reductase (QR) in the mouse hepatoma Hepa 1c1c7 cells. Among the thirteen compounds tested, several compounds including 3,4,5,3',5'-pentamethoxy-trans-stilbene were found to potentially induce QR activity in this cell line. In addition, substitution with 3-thiofurane ring instead of phenyl ring in the stilbene skeleton also exhibited potential induction of QR activity. This result will give primary information to design the potential inducers of QR activity in the stilbene analogs.

Animals↗
PubMed2001

Resveratrol analog, 3,5,2',4'-tetramethoxy-trans-stilbene, potentiates the inhibition of cell growth and induces apoptosis in human cancer cells.

Resveratrol, a trihydroxystilbene found in grapes and several plants, has been shown to be active in inhibiting multistage carcinogenic process. Using resveratrol as the prototype, we synthesized several analogs and evaluated their growth inhibitory effect using cultured human cancer cells. In the present report we show that one of the resveratrol analogs, 3, 5,2',4'-tetramethoxy-trans-stilbene, potentiated the inhibition of cancer cell growth. Prompted by the strong growth inhibitory activity of the compound (IC50; 0.8 microg/ml) compared to resveratrol (IC50; 18.7 microg/ml) in cultured human colon cancer cells (Col2), we performed an action mechanism study using the compound. The compound induced the accumulation of cellular DNA contents in the sub-G0 phase DNA contents of the cell cycle by in a time-dependent manner. The morphological changes were also consistent with an apoptotic process. This result indicated that the compound induced apoptosis of cancer cells, and may be a candidate for use in the development of potential cancer chemotherapeutic or cancer chemopreventive agents.

Anticarcinogenic Agents↗
PubMed2001

Synergetic analysis of spatio-temporal EEG patterns: Alzheimer's disease.

A spatio-temporal analysis has been employed on EEG signals recorded in groups of patients with Alzheimer's disease (AD). The so-called Karhunen-Loeve analysis method was applied to four groups of subjects: 12 patients who were diagnosed as having severe AD, 8 mild AD patients, 10 vascular dementia patients, and 10 normal aged controls, to obtain the spatio-temporal eigenpatterns. The local difference of the global EEG pattern in mild AD patients from that of normal controls was expanded to the frontal regions in the case of severe AD. The analysis showed significant bilateral temporal functioning differences and inter-hemispheric connection difficulty, along with remarkable intra-hemispheric correlation in severe AD patients. Compared to the normal controls, severe AD patients' brains exhibit only weak local connections and correlations, resulting into limited harmonious inter-hemispheric information processing. The results from the spatio-temporal EEG study of AD patients can be considered to be due to a change in the relative activity of the brain corresponding to the pathologic variation in AD, and the results are in accordance with reported clinical studies.

Alzheimer Disease↗
PubMed2001

The IsdA gene is necessary for sexual development inhibition by a salt in Aspergillus nidulans.

Using one of 17 expressed sequence tags (ESTs) previously identified as specific to the late sexual developmental (LSD) stage of Aspergillus nidulans, a gene for the subject EST was isolated. The determined DNA sequences revealed an open reading frame encoding a 356 amino acid polypeptide which does not share a sequence similarity to previously identified genes or proteins. The isolated gene was named lsdA (late sexual development), since it was expressed abundantly at the LSD stage. The lsdA gene expression began earlier than at the LSD stage. Disruption of the lsdA gene in the veA+ background strongly induced sexual development under conditions where sexual development in wild-type strains is almost completely inhibited. In contrast, in the veA1 background, an lsdA null mutant failed to show any phenotypic difference in sexual development under the various conditions tested. These results indicate that the lsdA gene may be responsible for inhibiting the sexual development of veA+ strains by a high concentration of a salt.

Amino Acid Sequence↗
PubMed2001

Biological monitoring of workers exposed to ethylbenzene and co-exposed to xylene.

OBJECTIVE: Ethylbenzene is an important constituent of widely used solvent mixtures in industry. The objective of the present study was to provide information about biological monitoring of occupational exposure to ethylbenzene, and to review the biological limit values corresponding to the threshold limit value of ethylbenzene. METHODS: A total of 20 male workers who had been exposed to a mixture of ethylbenzene and xylene, through painting and solvent mixing with commercial xylene in a metal industry, were recruited into this study. Environmental and biological monitoring were performed during an entire week. The urinary metabolites monitored were mandelic acid for ethylbenzene and methylhippuric acid for xylene. Correlations were analyzed between urinary metabolites and environmental exposure for ethylbenzene and xylene. The interaction effects of a binary exposure to ethylbenzene and xylene were also investigated using a physiologically based pharmacokinetic (PBPK) model. RESULTS: The average environmental concentration of organic solvents was 12.77 ppm for xylene, and 3.42 ppm for ethylbenzene. A significant correlation (R2 = 0.503) was found between environmental xylene and urinary methylhippuric acid. Urinary level of methylhippuric acid corresponding to 100 ppm of xylene was 1.96 g/g creatinine in the worker study, whereas it was calculated as 1.55 g/g creatinine by the PBPK model. Urinary level of mandelic acid corresponding to 100 ppm of ethylbenzene was found to be 0.7 g/g creatinine. PBPK results showed that the metabolism of ethylbenzene was highly depressed by co-exposure to high concentrations of xylene leading to a non-linear behavior. CONCLUSIONS: At low exposures, both methylhippuric acid and mandelic acid can be used as indicators of commercial xylene exposures. However at higher concentrations mandelic acid cannot be recommended as a biological indicator due to the saturation of mandelic acid produced by the co-exposure to xylene.

Benzene Derivatives↗
PubMed2001

Japanese generalised osteoarthritis was associated with HLA class I--a study of HLA-A, B, Cw, DQ, DR in 72 patients.

To investigate the association between generalised osteoarthritis (GOA) and HLA-A, B, Cw, DQ and DR, we typed for HLA in 72 Japanese patients with GOA and compared with those of 1480 normal controls. The antigen frequency of HLA-Cw4 was significantly higher in the GOA group than in the control group. That of B62 was higher, but only uncorrected P values were significant. Those of HLA-Cw1 and Cw10 were significantly lower in the GOA group than in the control group. The antigen frequencies of HLA-DRB1*0101, *0401, *0405, *1001, and *1402, which were reported to be associated with rheumatoid arthritis, in the GOA group were not significantly different from those in the control group. The present study provides evidence of a significant association between Japanese GOA and HLA, which is different from that of Japanese RA. This may suggest that an immunological reaction that is different from RA plays a role in the pathogenesis of GOA.

Aged↗
PubMed2001

Channel catfish follicle-stimulating hormone and luteinizing hormone: complementary DNA cloning and expression during ovulation.

Gonadotropins are important regulators of reproduction. To develop molecular resources for production of recombinant gonadotropins, we have cloned and sequenced complementary DNA encoding the channel catfish (Ictalurus punctatus) follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which encode 132 and 140 amino acid proteins, respectively. The deduced amino acid sequences of the catfish FSH and LH are highly conserved with those cloned from other teleosts. Both the FSH and the LH were highly induced during ovulation after injection of carp pituitary extract. Taken together with our previous findings of enhanced expression of growth hormone and other pituitary hormones, this research suggests that a hormonal cocktail may be needed for more efficient manipulation of catfish reproduction. The availability of the catfish FSH and LH cDNAs provides the opportunity for production of immunologically or biologically active recombinant gonadotropins for the study of catfish reproductive physiology and the manipulation of artificial spawning for aquaculture.

Journal Article↗
PubMed2001

The meaning of health-related quality of life in a Korean sample.

This study describes the impact of diabetes and the meaning of health-related quality of life (HRQOL) for 22 male and female patients in Korea. Open-ended interviews yielded six HRQOL themes: health, overall well-being, harmonious relationships and family responsibilities, a rewarding life, spiritual life, and material support. The physical impact of diabetes included decreased energy, limitations, and physical suffering; while its psychological/spiritual impact extended to general stress, helplessness, fear, depression, anger, and relationship with God. Like Americans, Koreans valued health, psychological well-being and interpersonal support. In addition, the Koreans valued smooth, harmonious interpersonal relationships, overall well-being pertaining to living a comfortable and honorable life.

Adaptation, Psychological↗
PubMed2001

Quality of life for patients with diabetes in Korea--I: the meaning of health-related quality of life.

This study describes the impact of diabetes and the meaning of health-related quality of life (HRQOL) for 22 male and female patients in Korea. Open-ended interviews yielded six HRQOL themes: health, overall well-being, harmonious relationships and family responsibilities, a rewarding life, spiritual life, and material support. The physical impact of diabetes included decreased energy, limitations, and physical suffering; while its psychological/spiritual impact extended to general stress, helplessness, fear, depression, anger, and relationship with God. Like Americans, Koreans valued health, psychological well-being and interpersonal support. In addition, the Koreans valued smooth, harmonious interpersonal relationships, overall well-being pertaining to living a comfortable and honorable life.

Adult↗
PubMed2001

Synthesis and biological activity of 26-norbrassinolide, 26-norcastasterone and 26-nor-6-deoxocastasterone.

26-Norbrassinolide, identified as a metabolite of brassinolide in cultured cells of the liverwort, Marchantia polymorpha, as well as 26-norcastasterone and 26-nor-6-deoxocastasterone were synthesized. Synthesis of these new brassinosteroids was conducted by employing the orthoester Claisen rearrangement and asymmetric dihydroxylation as key reactions. The modified rice lamina inclination test indicated that these three 26-norbrassinosteroids were less active than their corresponding C28 brassinosteroids. Growth-promoting activities were also examined by using the brassinosteroid-deficient, dwarf mutant lkb of garden pea (Pisum sativum L.). In this assay, 26-norbrassinolide was as effective as brassinolide and 26-norcastasterone was more effective than castasterone although 26-nor-6-deoxocastasterone was much less effective than 6-deoxocastasterone. Therefore, removal of C-26 of brassinosteroids does not necessarily reduce the biological activity. The role of C-26 removal in Marchantia cells remains unclear.

Plants↗