Biomedical subjects

T S Kim

Publications and source records attributed to T S Kim.

At least 109 records · Page 6Linked to original sources

PubMed2000

Digital chest radiography with a selenium-based flat-panel detector versus a storage phosphor system: comparison of soft-copy images.

OBJECTIVE: We compared the soft-copy images produced by a digital chest radiography system that uses a flat-panel X-ray detector based on amorphous selenium with images produced by a storage phosphor radiography system for the visualization of anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists and two residents analyzed 46 pairs of posteroanterior chest radiographs on high-resolution video monitors (2560 x 2048 x 8 bits). In each pair, one radiograph was obtained with a storage phosphor radiography system, and the other radiograph was obtained with a selenium-based flat-panel detector radiography system. Each pair of radiographs was obtained at the same exposure settings. The interpreter rated the visibility and radiographic quality of 11 different anatomic regions. Each pair of images was ranked on a five-point scale (1 = prefer image A, 3 = no preference, 5 = prefer image B) for preference of technique. Statistical significance of preference was determined using the Wilcoxon's signed rank test. RESULTS: The interpreters had a statistically significant preference for the selenium-based radiography system in six (unobscured lung, hilum, rib, minor fissure, heart border, and overall appearance) of 11 anatomic regions (p<0.001) and for the storage phosphor system in two regions (proximal airway and thoracic spine) (p<0.05). Chest radiologists strongly preferred selenium-based images in eight regions, and they did not prefer storage phosphor images in any region. CONCLUSION: The soft-copy images produced by the selenium-based radiography system were perceived as equal or superior to those produced by the storage phosphor system in most but not all anatomic regions.

Adult↗

PubMed2000

A case of epidermoid cyst of the intrapancreatic accessory spleen.

A 54-year-old woman presented with a huge palpable mass on left upper quadrant of the abdomen. After preoperative work-up, a cystic disease of pancreatic tail or accessory spleen was initially suspected. We performed exploratory laparotomy and resected both the spleen and a 15 x 11 cm-sized huge cystic mass containing a part of solid component which extended continuously to the pancreatic tail. The solid component, comprising the upper portion of the resected cyst, was reddish brown and granular like as normal splenic tissue. The inner surface of the cyst was smooth and was filled with yellowish white material. Histologic examination showed an epidermoid cyst originating in the accessory spleen of the pancreatic tail lacking hair or skin appendages.

Epidermal Cyst↗

PubMed2000

Muscle fiber type disproportion with an autosomal dominant inheritance.

Congenital muscle fiber type disproportion (CFTD) has been described as a form of congenital myopathy characterized by the smallness and marked predominance of type 1 fibers in a muscle biopsy. Clinical manifestations include hypotonia, nonprogressive muscle weakness, joint contractures, and skeletal deformities. However, it has also been noted that the same pathologic alterations appeared in clinically diverse conditions. Recently, we experienced a family, a mother and two children, in which a muscle biopsy showed the mother to have muscle fiber type disproportion. This case was unusual in that there was a significant progression of weakness, an absence of neonatal hypotonia, and other commonly associated musculo-skeletal deformities. In this report, we describe the clinicopathologic features of the family with a brief review about muscle fiber type disproportion.

Adult↗

PubMed2000

Diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread.

A case of diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread is presented. The patient, an 18-year-old girl, was admitted due to progressive weakness and paresthesia of both legs, following rapid neuropsychiatric deterioration. An initial magnetic resonance imaging (MRI) study of the T-spine showed diffuse high signal intensities from T9 to T12 spinal cords on a T2 sagittal image and diffuse cord bulging at T1WI. This suggested an inflammatory lesion such as tuberculosis or fungal meningoencephalitis. A limited autopsy was performed. A microscopic examination revealed multifocal GFAP-positive astrocytic proliferations that were low grade astrocytoma in the cerebral leptomeninges, parietal, occipital and temporal lobes and anaplastic astrocytoma in the spinal cord and spinal leptomeninges. The high proliferative indices of the spinal lesion and aneuploidy correspond to a diagnosis of malignant astrocytoma and a rapid fatal clinical course.

Adolescent↗

PubMed2000

Identification and partial characterization of lacticin BH5, a bacteriocin produced by Lactococcus lactis BH5 isolated from Kimchi.

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer that has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by API test. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the nonpathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by L. lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against nonpathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely destroyed by protease XIV. The inhibitory activities of lacticin BH5 were detected during treatments up to 100 degrees C for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. It demonstrated a typical bactericidal mode of inhibition against M. flavus ATCC 10240. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3 to 3.5 kDa, by the direct detection of bactericidal activity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Bacterial Proteins↗

PubMed2000

[The life of Dr. John William Heron, the second superintendent of Chejungwon].

The purpose of this paper is to overview the life of John W. Heron, M. D. who was the first appointed medical missionary to Korea by the Presbyterian Church USA. Although he was a competent doctor as well as a devoted missionary, he is not well-known yet, because he died early after 5 years' service in Korea. Dr. Heron was born in Derbyshire, England on June 15, 1856. His father, Rev. E. S. Heron, was a Scotch Minister of Congregational Church. His family emigrated to America in 1870 when he was fourteen years old and settled in Knoxville, Tennessee. In 1881, he was admitted to the University of Tennessee Medical School and graduated with highest honors in 1883. After training in New York University Hospital, he refused the offer of professorship from the University of Tennessee to become a medical missionary to Korea. He arrived in Seoul on June 21, 1885 and began to work in Royal Government Hospital, Chejungwon, the predecessor of Severance Hospital. In 1887, he became the superintendent of the Hospital following Dr. Horace N. Allen. He also worked for the Royal family and sometimes traveled to the rural areas to care for the patients. He started Chejungwon Church which later became Namdaemoon Presbyterian Church. In 1887, Dr. Heron worked as a member of the Bible translation committee and in 1889, he was elected as the chairman of the Public Committee of the Presbyterian Churches. In 1890, he established 'The Korean Religious Tract Society (Chosunsyungkyoseohoi) with Underwood and Ohlinger. The society published and replenished Christian books, periodical magazines and booklets. In the Summer of 1890, Dr. Heron did his best to take care of the sick suffering from an epidemic dysentery and himself got infected because of the terrible overwork. He passed away on July 26th, 1890. On his deathbed, he told his soldier and native friends around him as follow: "Jesus loves you. He gave His life for you. Stand by Him!" The martyrdom of Dr. Heron should be remembered in the Korean history of mission, because he was the first victim among the foreign missionaries who had lived and worked in Seoul for Korean mission. Dr. Heron's mind of love, service and devotion should be remembered by the medical doctors working today in caring for the patients suffering from physical and spiritual illnesses.

History, 19th Century↗

PubMed1999

Inhibition of interleukin-12 production in lipopolysaccharide-activated macrophages by curcumin.

Pharmacological control of interleukin-12 production may be a key therapeutic strategy for modulating immunological diseases dominated by type-1 cytokine responses. In this study we investigated the effects of curcumin (1,7-bis[4-hydroxy-3-methoxyphenyl]-1, 6-heptadiene-3,5-dione) on the production of interleukin-12 from mouse macrophages stimulated with lipopolysaccharide. Curcumin potently inhibited the production of interleukin-12 in a dose-dependent manner. The effect of curcumin on interleukin-12 p40 promoter activation was analyzed by transfecting RAW264.7 monocytic cells with p40 promoter/reporter constructs. The repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor kappaB (p40-kappaB). Furthermore, activation of macrophages by lipopolysaccharide resulted in markedly enhanced binding activity to the kappaB site, which significantly decreased upon addition of curcumin. These results suggest that curcumin-induced inhibition of interleukin-12 production in macrophages may explain some of the biological effects of curcumin including its anti-inflammatory activity.

Animals↗

PubMed1999

Chloromethyl ketones inhibit interleukin-12 production in mouse macrophages stimulated with lipopolysaccharide.

Interleukin-12 (IL-12) plays a pivotal role in the development of T-helper type 1 (Th1) immune response, which may be involved in the pathogenesis of chronic inflammatory autoimmune disorders. In this study, we investigated the effects of N-alpha-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK), serine protease inhibitors, on the production of IL-12 from macrophages stimulated with lipopolysaccharide (LPS). TPCK and TLCK potently inhibited this LPS-induced IL-12 production in a dose-dependent manner. The effect of TPCK and TLCK on the IL-12 p40 promoter activation was analyzed by transfecting monocytic RAW264.7 cells with p40 promoter-reporter constructs. The repressive effect maps to a region in the p40 promoter containing a binding site for NFkappaB (p40-kappaB). A linker scan mutant of the p40-kappaB site abrogates the inhibitory effect on the p40 promoter, confirming the functional relevance of the NFkappaB site. Our results show that TPCK and TLCK inhibit NFkappaB-mediated IL-12 production in macrophages. reserved.

Animals↗

PubMed1999

Fetal mouse selenophosphate synthetase 2 (SPS2): biological activities of mutant forms in Escherichia coli.

A novel gene, sps2, detected in mouse embryo at the early stages of development has been identified as an analog of the E. coli selenophosphate synthetase gene. Unlike the E. coli enzyme, the presence of selenocysteine in the mouse enzyme is indicated by a TGA codon in the open reading frame of the cDNA. Using an N-FLAG monoclonal antibody, it was shown that the full length N-FLAG-sps2 gene product was expressed in COS-7 cells. To investigate the biological activity of the sps2 gene product in vivo, the mutated sps2 gene, which contains cysteine in the place of the TGA encoded selenocysteine in the wild type, was expressed in the E. coli selD deficient mutant, MB08. Like the E. coli wild type selD gene, the mutant sps2 gene complemented the selD mutation. However, replacement of Cys with either Ala, Ser, or Thr resulted in a loss of ability to complement the selD mutation. The SPS2-CYS protein expressed in E. coli was purified and its catalytic activity was determined. The Km value for ATP was 0.75 mM and Vmax was 9.23 nmole/min/mg protein. These results confirm that the mouse embryonic sps2 gene encodes an eukaryotic selenophosphate synthetase, and that availability of selenophosphate as a selenium donor compound is widespread.

Adenosine Triphosphate↗

PubMed1999

Antigen-specific cytotoxicity and cell number of adoptively transferred T cells are efficiently maintained in vivo by re-stimulation with an antigen/interleukin-2 fusion protein.

In order to maintain in vivo anti-tumor efficacy of antigen (Ag)-specific T cells in adoptive immunotherapy for a prolonged period, we constructed a fusion protein (OVA/IL-2) containing ovalbumin (OVA) as a model tumor Ag, co-valently linked to murine interleukin-2 (IL-2). The OVA/IL-2 protein produced in a baculovirus expression system displayed potent IL-2 bio-activity. Immunization with the OVA/IL-2 protein after adoptive transfer of OVA-specific T cells maintained the OVA-specific cytotoxicity and cell number of adoptively transferred T cells long term in vivo, while a simple mixture of recombinant OVA (rOVA) and rIL-2 did not. The response was dependent on the injection doses and times of the OVA/IL-2 protein. Furthermore, weekly re-stimulation of adoptively transferred OVA-specific T cells with the OVA/IL-2 protein cured 70% of tumor-bearing mice. In contrast, re-stimulation with a mixture of rOVA and rIL-2 could not significantly prolong the survival period of tumor-bearing mice. These studies suggest that the co-valent linkage between IL-2 and antigen confines the effect of IL-2 to antigen-specific T cells, leading to efficient maintenance of the anti-tumor activity of adoptively transferred T cells.

Animals↗

PubMed1999

Spectral indices of cardiac autonomic function in obstructive sleep apnea.

Spectral analysis of heart rate variability (HRV) is useful as a noninvasive means of assessing autonomic function in patients with obstructive sleep apnea (OSA). However, standard spectral measures, such as the ratio of low-frequency to high-frequency power (LHR) and normalized high-frequency power (NHFP), can be confounded by the abnormal breathing patterns that occur during sleep. To circumvent this limitation, we employed an autoregressive modeling approach to partition the RR time-series into a component that is correlated with respiration and a respiration-independent component. From these components, we derived two new spectral indices: the modified LHR (MLHR) and the average gain relating respiration to RR changes (GRSA). Six normals and seven OSA patients were studied in relaxed wakefulness and stage 2 sleep; during sleep, the OSA patients were studied without and with continuous positive airway pressure (CPAP) therapy. All four spectral indices showed significant differences between OSA patients and normals in both wakefulness and sleep, although the changes in MLHR and GRSA were substantially larger and less variable: MLHR (p < 0.0003) and GRSA (p < 0.0001) vs. LHR (p < 0.005) and NHFP (p < 0.004). However, in the OSA subjects, LHR and NHFP were unchanged by CPAP. By contrast, CPAP produced a highly significant increase in GRSA (p < 0.0004), as well as a decrease in MLHR (p < 0.03). Thus, by compensating for the effects of breathing pattern differences, MLHR and GRSA unmasked the effects of CPAP therapy, which has been shown in previous studies to reduce sympathetic activity and increase vagal cardiac modulation.

Adult↗

PubMed1999

Retinoids inhibit interleukin-12 production in macrophages through physical associations of retinoid X receptor and NFkappaB.

Lipopolysaccharide (LPS) increases the production of interleukin-12 (IL-12) from mouse macrophages via a kappaB site within the IL-12 p40 promoter. In this study, we found that retinoids inhibit this LPS-stimulated production of IL-12 in a dose-dependent manner. The NFkappaB components p50 and p65 bound retinoid X receptor (RXR) in a ligand-independent manner in vitro, and the interaction interfaces involved the p50 residues 1-245, the p65 residues 194-441, and the N-terminal A/B/C domains of RXR. Activation of macrophages by LPS resulted in markedly enhanced binding activities to the kappaB site, which significantly decreased upon addition of retinoids, as demonstrated by the electrophoretic mobility shift assays. In cotransfections of CV-1 and HeLa cells, RXR also inhibited the NFkappaB transactivation in a ligand-dependent manner, whereas a mutant RXR lacking the AF2 transactivation domain, which serves as ligand-dependent binding sites for transcription integrators SRC-1 and p300, was without any effect. In addition, coexpression of increasing amounts of SRC-1 or p300 relieved the retinoid-mediated inhibition of the NFkappaB transactivation. From these results, we propose that retinoid-mediated suppression of the IL-12 production from LPS-activated macrophages may involve both inhibition of the NFkappaB-DNA interactions and competitive recruitment of transcription integrators between NFkappaB and RXR.

Animals↗

PubMed1999

mRNA expression of glomerular basement membrane proteins and TGF-beta1 in human membranous nephropathy.

Immunogold densities for the 'classical' and 'novel' alpha chains of type IV collagen, laminin, and fibronectin are increased in the spikes in human membranous nephropathy (MN). To investigate the molecular mechanisms which underlie these changes in glomerular basement membrane (GBM) components, alpha1(IV) collagen, alpha4(IV) collagen, S-laminin, fibronectin, transforming growth factor (TGF)-beta1 and TGF-beta2 mRNA expression was examined in 12 renal biopsy specimens with MN and six renal biopsies with no detectable abnormality by RNA in situ hybridization. In controls, there were relatively low signals of alpha1(IV) collagen, alpha4(IV) collagen, S-laminin, and TGF-beta1 mRNAs, but there were no fibronectin or TGF-beta2 transcripts in glomerular cells. In MN, the number of alpha4(IV) collagen, alpha1(IV) collagen, S-laminin or TGF-beta1 mRNA-expressing cells per glomerular cross-section was significantly larger than in controls (p< 0.05), and fibronectin mRNA was occasionally expressed in glomerular visceral epithelial cells (GECs). No message for TGF-beta2 was seen in MN. The number of TGF-beta1 mRNA-expressing cells per glomerular cross-section significantly correlated with that of alpha1(IV) mRNA-expressing cells (p< 0.01). The MN patients with positivie signal for fibronectin mRNA exhibited more severe GBM thickening than those without (p< 0.05). These results indicate that the increased presence of GBM proteins in spikes of MN is associated with enhanced mRNA expression of these proteins. They also suggest that subepithelial deposits in MN stimulate GECs to produce TGF-beta1, which in turn could mediate the expression of GBM protein genes by GECs.

Adolescent↗

PubMed1999

Studies on the synthesis and in vitro antitumor activity of the isoquinolone derivatives.

3-Arylisoquinolin-1(2H)-ones (2) are possible bioisosteres of the 5-[4'-(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,1-a]iso quinoline (1) which is in clinical evaluation for the treatment of cancer. Structure-activity relationship studies of 3-arylisoquinolin-1(2H)-ones (2) led to the synthesis of 3-arylquinolin-2(1H)-ones (3). A number of 3-phenyl substituted quinolin-2(1H)-ones were synthesized and tested for their in vitro antitumor activity against four different human tumor cell lines and 3-phenyl-N-benzyl-3,4-dihydroquinolin-2(1H)-one (12) showed the most potent activity.

Antineoplastic Agents↗

PubMed1999

Anterior cervical spinal epidural abscess in an infant.

Spinal epidural abscess (SEA) is rare in children, especially in newborns and infants, groups in which only very few cases have been reported. Because of the nonspecificity of presenting symptoms in children the diagnosis may be delayed, resulting in major permanent neurological deficits. In this paper, we report a case of cervical SEA in a 6-week-old infant who initially presented with fever and developed quadriparesis 19 days prior to admission. After emergency anterior decompression of the abscess the neurological function was improved immediately. Five months after surgery the neurological status was normal, an MR study showing disappearance of the epidural abscess and spinal cord indentation, and progressive fusion of the C3, C4 and C5 vertebral bodies. Anterior decompression without bone graft can provide an excellent prognosis in case of an anterior cervical SEA in infants.

Abscess↗

PubMed1999

Curcumin inhibits Th1 cytokine profile in CD4+ T cells by suppressing interleukin-12 production in macrophages.

1 Interleukin-12 (IL-12) plays a central role in the immune system by driving the immune response towards T helper 1 (Th1) type responses which are characterized by high IFN-gamma and low IL-4 production. In this study we investigated the effects of curcumin, a natural product of plants obtained from Curcuma longa (turmeric), on IL-12 production by mouse splenic macrophages and the subsequent ability of these cells to regulate cytokine production by CD4+ T cells. 2 Pretreatment with curcumin significantly inhibited IL-12 production by macrophages stimulated with either lipopolysaccharide (LPS) or head-killed Listeria monocytogenes (HKL). 3 Curcumin-pretreated macrophages reduced their ability to induce IFN-gamma and increased the ability to induce IL-4 in Ag-primed CD4+ T cells. Addition of recombinant IL-12 to cultures of curcumin-pretreated macrophages and CD4+ T cells restored IFN-gamma production in CD4+ T cells. 4 The in vivo administration of curcumin resulted in the inhibition of IL-12 production by macrophages stimulated in vitro with either LPS or HKL, leading to the inhibition of Th1 cytokine profile (decreased IFN-gamma and increased IL-4 production) in CD4+ T cells. 5 These findings suggest that curcumin may inhibit Th1 cytokine profile in CD4+ T cells by suppressing IL-12 production in macrophages, and points to a possible therapeutic use of curcumin in the Th1-mediated immune diseases.

Animals↗

PubMed1999

Interleukin-12-secreting fibroblasts are more efficient than free recombinant interleukin-12 in inducing the persistent resistance to Mycobacterium avium complex infection.

To determine whether the paracrine secretion of interleukin-12 (IL-12) can efficiently stimulate the resistance to Mycobacterium avium complex (MAC) infection, 3T3 fibroblasts were stably transfected to secrete IL-12 (480 U/106 cells/48 hr) and their effect on MAC infection was investigated in genetically susceptible BALB/c mice, compared with that of free recombinant IL-12 (rIL-12). Injection with IL-12-secreting fibroblasts (3T3-IL-12) during intranasal infection with MAC resulted in a significant decrease in the bacterial load of the lung during the entire 10-week observation period, while rIL-12 reduced the bacterial load initially, at 2 weeks, but not by 10 weeks postinfection. Lung CD4+ T cells in mice injected with the 3T3-IL-12 cells showed a persistent T helper type 1 (Th1) response throughout the 10-week period. Furthermore, immunization with the 3T3-IL-12 cells induced and maintained significantly higher levels of cytotoxic activity and nitric oxide production by lung cells than did rIL-12 immunization. This work suggests that IL-12-secreting fibroblasts may serve as a vehicle for paracrine secretion of IL-12 for immunotherapy of MAC infection.

Animals↗

PubMed1999

Interferon-gamma- and interleukin-4-targeted gene therapy for atopic allergic disease.

Two cytokines, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), which play critical roles in the regulation of serum IgE level by directing the interplay of T helper (Th)1 and Th2 cells, were chosen as targets for gene therapy. Anti-allergic activity was evaluated by determining the serum IgE level, and the functional status of each helper T cell was monitored by the serum concentrations of IgG1 and IgG2a. Experimental animals (BALB/c mice) were divided into four groups: the control group; the ovalbumin (OVA) group; the IFN-gamma group; and the IL-4 group. The control group was injected with saline and the OVA group with OVA-alum. The IFN-gamma and IL-4 groups were treated with OVA-alum plus the cDNAs of mouse IFN-gamma and IL-4 in an expression vector. These treatments were applied intramuscularly on a monthly basis for 4 months. OVA-alum treatment significantly increased the serum IgE and IgG1 concentrations, but did not affect IgG2a. Concomitant treatments with the cDNA of IFN-gamma or IL-4 returned the serum IgE almost to the control level and significantly suppressed the OVA-induced increase of IgG1. IFN-gamma cDNA increased the serum IgG2a but IL-4 cDNA had no affect. These results suggest that IFN-gamma inhibited the OVA-induced IgE production by suppressing the Th2 pathway and by enhancing the Th1 pathway. Administration of IL-4 cDNA suppressed the OVA-induced enhancement of IgE production by inhibiting the Th2 pathway rather than by potentiating it.

Animals↗