Biomedical subjects

Sung Soo Kim

Publications and source records attributed to Sung Soo Kim.

At least 19 recordsLinked to original sources

PubMed2026

Respiratory pandemic risk in the Anthropocene: A One Health framework and GISRS+ agenda.

Recent epidemics and pandemics caused by respiratory viruses, alongside the animal panzootic spread of highly pathogenic avian influenza A(H5Nx), have become a structural feature of the Anthropocene, yet responses remain largely reactive. This review integrates findings from WHO's Global Influenza Surveillance and Response System (GISRS) and related surveillance data (2000-2024), epidemiological studies of influenza A virus, SARS-CoV, MERS-CoV, SARS-CoV-2, and H5Nx, and One Health literature. We examine major groups of respiratory viruses and identify mismatches between risk and surveillance by focusing on spillover potential from animal hosts, human-to-human transmission and its controllability, and Anthropocene characteristics that increase epidemic risk. The analysis indicated that SARS-related coronaviruses and influenza A viruses, particularly H5Nx, are among the leading candidates based on currently available evidence because they have large reservoirs in animal hosts and spillover to humans is highly probable. The previous presymptomatic spread of SARS-CoV-2 and recent mammalian adaptation in H5N1 clade 2.3.4.4b highlight limitations of the traditional symptom-based and pathogen-specific surveillance system. Spillover events tend to occur in tropical and subtropical regions in low- and middle-income countries, but most genomic surveillance is in high-income countries. We propose interventions that address the upstream, midstream, downstream processes of epidemics. Upstream interventions are primary prevention measures related to land use, livestock, wildlife, and urban environments; midstream interventions are GISRS+-based pathogen-agnostic genomic and metagenomic early warning systems triggered by One Health; and downstream interventions include vaccines, antivirals, non-pharmaceutical interventions, and engineering with equity-centred global governance and sustainable financing.

Anthropocene↗

PubMed2006

Inhibition of AMP-activated protein kinase suppresses IL-2 expression through down-regulation of NF-AT and AP-1 activation in Jurkat T cells.

AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis and its activation during T cell receptor stimulation has recently been reported. In this study, we examined the role of AMPK in interleukin (IL)-2 production in T cells. Inhibition of AMPK by compound C, a specific inhibitor of AMPK or small interfering RNA of AMPKalpha1 suppressed IL-2 production in Jurkat T cells and peripheral blood lymphocytes stimulated with PMA plus ionomycin (PMA/Io) or with monoclonal anti-CD3 plus anti-CD28. We then showed that AMPK inhibition reduced PMA/Io-induced IL-2 mRNA expression and IL-2 promoter activation. Moreover, inhibition of AMPK suppressed transcriptional activation of NF-AT and AP-1, but not NF-kappaB, in PMA/Io-activated Jurkat cells. Finally, we found that compound C inhibited PMA/Io-induced phosphorylation of p38, JNK, and GSK-3beta but not of ERK. These results suggest that AMPK mediates IL-2 production by regulating NF-AT and AP-1activation during T cell stimulation.

AMP-Activated Protein Kinases↗

PubMed2006

Indenone derivatives: a novel template for peroxisome proliferator-activated receptor gamma (PPARgamma) agonists.

Agonists of peroxisome proliferator-activated receptor gamma (PPAR gamma) are of interest as a treatment for diabetes, which prompted the identification of a new class of non-TZD PPAR gamma agonist. Moreover, compound 14c has displayed the most active agonistic activity with an EC50 value of 50 nM, in addition to exhibiting a new binding mode in the X-ray cocrystal structure.

Animals↗

PubMed2006

Differential anti-proliferative actions of peroxisome proliferator-activated receptor-gamma agonists in MCF-7 breast cancer cells.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) activation has been a new approach to cancer therapy. In the present study, we investigated the effects of two structurally different PPARgamma agonists, rosiglitazone and KR-62980 on MCF-7 breast cancer cells. Both agonists inhibited the cell proliferation and colony formation via apoptosis. PTEN expression was increased with decreased Akt phosphorylation by the agonists, whereas agonists actions were abolished in PTEN knockdown cells, indicating the critical role of PTEN in the anti-proliferative effects of PPARgamma activation. Rosiglitazone induced the MCF-7 cell differentiation but KR-62980 did not alter the differentiation pattern with little effects on the lipid accumulation and the expression of lipogenesis markers. These results suggest that PPARgamma activation may result in the inhibition of cell proliferation and/or induction of cell differentiation depending on the type of PPARgamma agonists, and that KR-62980 may be useful in breast cancer therapy by inducing apoptosis.

Apoptosis↗

PubMed2006

Small molecule-based reversible reprogramming of cellular lifespan.

Most somatic cells encounter an inevitable destiny, senescence. Little progress has been made in identifying small molecules that extend the finite lifespan of normal human cells. Here we show that the intrinsic 'senescence clock' can be reset in a reversible manner by selective modulation of the ataxia telangiectasia-mutated (ATM) protein and ATM- and Rad3-related (ATR) protein with a small molecule, CGK733. This compound was identified by a high-throughput phenotypic screen with automated imaging. Employing a magnetic nanoprobe technology, magnetism-based interaction capture (MAGIC), we identified ATM as the molecular target of CGK733 from a genome-wide screen. CGK733 inhibits ATM and ATR kinase activities and blocks their checkpoint signaling pathways with great selectivity. Consistently, siRNA-mediated knockdown of ATM and ATR induced the proliferation of senescent cells, although with lesser efficiency than CGK733. These results might reflect the specific targeting of the kinase activities of ATM and ATR by CGK733 without affecting any other domains required for cell proliferation.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2006

KR-62980: a novel peroxisome proliferator-activated receptor gamma agonist with weak adipogenic effects.

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) is the target for the anti-diabetic drugs including thiazolidinediones. We report here the identification and characterization of a novel PPARgamma agonist KR-62980. KR-62980 acted as a selective PPARgamma agonist in transactivation assay with an EC50 of 15 nM. In fully differentiated 3T3-L1 adipocytes, KR-62980 induced [3H]-deoxyglucose uptake in a concentration-dependent manner in the presence of insulin. KR-62980 was weakly adipogenic with little induction of aP2 mRNA, and was able to antagonize the adipogenic effects of rosiglitazone in C3H10T1/2 cells. In vivo pharmacokinetic profile of KR-62980 revealed that the compound exhibited good oral bioavailability of 65% with a terminal elimination half-life of 2.5 h in the rat. Treatment of high fat diet-induced C57BL/6J mice with KR-62980 for 14 days reduced plasma glucose levels with little side effects with regard to weight gain, cardiac hypertrophy and hepatotoxicity. These results suggest that KR-62980 acts as a selective PPARgamma modulator with anti-hyperglycemic activity, and that the mechanism of actions of KR-62980 appears to be different from that of rosiglitazone with improved side effect profiles.

3T3-L1 Cells↗

PubMed2006

Synthesis and biological evaluation of rhodanine derivatives as PRL-3 inhibitors.

A series of rhodanine derivatives was synthesized and evaluated for their ability to inhibit PRL-3. Benzylidene rhodanine derivative showed good biological activity, while compound 5e was the most active in this series exhibiting an IC50 value of 0.9 microM in vitro and showed a reduced invasion in cell-based assay.

Aldehydes↗

PubMed2006

Effects of ginsenosides and their metabolites on voltage-dependent Ca(2+) channel subtypes.

In previous reports we demonstrated that ginsenosides, active ingredients of Panax ginseng, affect some subsets of voltage-dependent Ca(2+) channels in neuronal cells expressed in Xenopus laevis oocytes. However, the major component(s) of ginseng that affect cloned Ca(2+) channel subtypes such as alpha(1C) (L)-, alpha(1B) (N)-, alpha(1A) (P/Q)-, a1E (R)- and a1G (T) have not been identified. Here, we used the two-microelectrode volt-age clamp technique to characterize the effects of ginsenosides and ginsenoside metabolites on Ba(2+) currents (IBa) in Xenopus oocytes expressing five different Ca(2+) channel subtypes. Exposure to ginseng total saponins (GTS) induced voltage-dependent, dose-dependent and reversible inhibition of the five channel subtypes, with particularly strong inhibition of the a1G-type. Of the various ginsenosides, Rb(1), Rc, Re, Rf, Rg(1), Rg(3), and Rh(2), ginsenoside Rg(3) also inhibited all five channel subtypes and ginsenoside Rh(2) had most effect on the a1C- and a1E-type Ca(2+) channels. Compound K (CK), a protopanaxadiol ginsenoside metabolite, strongly inhibited only the a(1G)-type of Ca(2+) channel, whereas M4, a protopanaxatriol ginsenoside metabolite, had almost no effect on any of the channels. Rg(3), Rh(2), and CK shifted the steady-state activation curves but not the inactivation curves in the depolarizing direction in the alpha(1B)- and alpha(1A)-types. These results reveal that Rg(3), Rh(2) and CK are the major inhibitors of Ca(2+) channels in Panax ginseng, and that they show some Ca(2+) channel selectivity.

Animals↗

PubMed2006

Potent inhibitory effects of resveratrol derivatives on progression of prostate cancer cells.

Resveratrol has been identified as a potent anticancer agent in a variety of studies. In this study, several resveratrol derivatives were synthesized and investigated in the search for an anticancer agent with higher efficacy than resveratrol. During our examination of cancer cell lines, compounds C, F, and G evidenced higher inhibitory activity than resveratrol with regard to the growth of PC-3 and LNCaP human prostate cancer cells. Moreover, four derivatives of resveratrol evidenced potent growth inhibitory activity (IC50 0.01-0.04 microM) in LNCaP cells. The levels of activity in these derivatives were 25-100 times stronger than that associated with resveratrol (IC50 1.0 microM). Our results suggested that compounds C, D, F, and G might function as anticancer agents on prostate tumors. This study also contains a discussion regarding the structure-activity relationships of several resveratrol derivatives.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Immunoglobulin can be functionally regulated by protein carboxylmethylation in Fc region.

Protein carboxylmethylation methylates the free carboxyl groups in various substrate proteins by protein carboxyl O-methyltransferase (PCMT) and is one of the post-translational modifications. There have been many studies on protein carboxylmethylation. However, the precise functional role in mammalian systems is unclear. In this study, immunoglobulin, a specific form of gamma-globulin, which is a well-known substrate for PCMT, was chosen to investigate the regulatory roles of protein carboxylmethylation in the immune system. It was found that the anti-BSA antibody could be carboxylmethylated via spleen PCMT to a level similar to gamma-globulin. This carboxylmethylation increased the hydrophobicity of the anti-BSA antibody up to 11.4%, and enhanced the antigen-binding activity of this antibody up to 24.6%. In particular, the Fc region showed a higher methyl accepting capacity with 80% of the whole structure level. According to the amino acid sequence alignment, indeed, 7 aspartic acids and 5 glutamic acids, as potential carboxylmethylation sites, were found to be conserved in the Fc portion in the human, mouse and rabbit. The carboxylmethylation of the anti-BSA antibody was reversibly demethylated under a higher pH and long incubation time. Therefore, these results suggest that protein carboxylmethylation may reversibly regulate the antibody-mediated immunological events via the Fc region.

Amino Acid Sequence↗

PubMed2006

Central obesity as a risk factor for prostatic hyperplasia.

OBJECTIVE: Obesity-related metabolic diseases may influence prostatic hyperplasia. This study examined the impact of obesity on prostate volume in men without overt obesity-related metabolic diseases. RESEARCH METHODS AND PROCEDURES: We recruited 146 men over the age of 40 years who did not have overt obesity-related diseases, such as diabetes, impaired fasting glucose, hypertension, or dyslipidemia. Transrectal ultrasonography was performed on all subjects. The subjects were divided into three groups according to their BMI: normal (18.5 to 22.9 kg/m2), overweight (23 to 24.9 kg/m2), and obese (> or = 25 kg/m2), and two groups according to their waist circumference: normal waist (< or = 90 cm) and central obesity (> 90 cm). The classification of the subgroups was based on the Asia-Pacific criteria of obesity. We compared the prostate volume among subgroups and assessed factors related to prostatic hyperplasia. RESULTS: Mean prostate volume was 18.8 +/- 5.0, 21.8 +/- 7.2, and 21.8 +/- 5.6 mL in the normal, overweight, and obese groups, respectively, and was 20.0 +/- 5.9 and 23.7 +/- 5.3 mL in the normal waist and central obesity group, respectively. Prostate volume was significantly greater in the obese group than in the normal group (P = 0.03) and in the central obesity group compared with the normal waist group (P = 0.002). Prostate volume was positively correlated with BMI and waist circumference after adjustment for age. After adjusting for confounding factors, central obesity was an independent factor affecting prostatic hyperplasia, which was defined as a prostate volume > 20 mL (odds ratio = 3.37, p = 0.037). Relative to men with both low BMI (18.5 to 22.9 kg/m2) and normal waist circumference, those with high BMI (> or = 25 kg/m2) and central obesity were at significantly increased risk of prostatic hyperplasia (odds ratio = 4.88, p = 0.008). However, those with high BMI (> or = 25 kg/m2) and normal waist circumference were not at significantly increased risk. DISCUSSION: Prostate volume was greater in the obese and central obesity groups than in the normal group after patients with overt obesity-related metabolic diseases were excluded. Although both BMI and waist circumference were positively correlated with prostate volume, central obesity was the only independent factor affecting prostate hyperplasia. We suggest that central obesity is an important risk factor for prostatic hyperplasia.

Abdominal Fat↗

PubMed2006

Obesity is the only independent factor associated with ultrasound-diagnosed non-alcoholic fatty liver disease: a cross-sectional case-control study.

OBJECTIVE: There is increasing interest in ultrasound-diagnosed non-alcoholic fatty liver disease (NAFLD) in the ambulatory care setting. The aim of this study was to determine the clinical and metabolic features of ultrasound-diagnosed NAFLD. MATERIAL AND METHODS: Fifty ultrasound-diagnosed NAFLD patients who had not consumed alcohol for at least the previous 3 months were matched with 100 controls by age and gender distribution. Clinical, biochemical, and nutritional variables were compared between the ultrasound-diagnosed NAFLD patients and the controls. Conditional logistic regression analyses were used to identify independent factors associated with ultrasound-diagnosed NAFLD. RESULTS: The ultrasound-diagnosed NAFLD patients had higher values on the anthropometric measurements than those of the controls. Aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), uric acid, and gamma-glutamyl transpeptidase levels were higher in the ultrasound-diagnosed NAFLD patients than those in the controls (p<0.001). The ASAT/ALAT ratio of the ultrasound-diagnosed NAFLD patients was lower than that of the controls (p<0.001). Total cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, non-HDL-cholesterol, atherogenic index, fasting glucose, systolic blood pressure (BP), diastolic BP, and pulse pressure were higher in the ultrasound-diagnosed NAFLD patients than in the control subjects, while lipoprotein(a) was lower. There were no significant differences in low-density lipoprotein (LDL)-cholesterol levels or nutritional intake between patients and controls. Abnormal ASAT or ALAT, hypertriglyceridemia, lower HDL-cholesterol levels, silent myocardial ischemic pattern on electrocardiogram (ECG), impaired fasting glucose, and obesity were common among the ultrasound-diagnosed NAFLD patients. The only independent factor associated with ultrasound-diagnosed NAFLD was obesity (p<0.001). CONCLUSIONS: Our data suggest that NAFLD diagnosed by ultrasound is associated with hypertriglyceridemia, impaired fasting glucose, silent myocardial ischemic pattern of ECG, obesity, and abnormal liver tests in adults. Among these factors, obesity was the only independent factor associated with ultrasound-diagnosed NAFLD.

Alanine Transaminase↗

PubMed2006

Problems associated with the 25-gauge transconjunctival sutureless vitrectomy system during and after surgery.

OBJECTIVE: To report the initial experiences with the 25-gauge transconjunctival sutureless vitrectomy (TSV) system, including intraoperative and postoperative problems. METHODS: We retrospectively reviewed the medical records and surgical videotapes of 50 consecutive patients who underwent vitrectomy performed by one surgeon using the TSV system. RESULTS: Intraoperatively, we encountered such problems as difficulty in inserting the microcannula, which led to deformity, instability of the microcannula, self-disconnection of the infusion tip and resultant lens damage, and conversion to 20-gauge conventional vitrectomy. Postoperatively, there were 8 cases with hypotony (IOP < 6 mm Hg) on day 1, 6 cases with elevated IOP, and 3 cases with retinal detachment during follow-up. CONCLUSION: Though certain problems exist during and after surgeries using TSV, this system is both convenient and safe for various vitreoretinal procedures.

Adult↗

PubMed2006

Indocyanine green angiographic features of myopic subfoveal choroidal neovascularization as a prognostic factor after photodynamic therapy.

PURPOSE: To determine the influence of clinical features and Indocyanine green (ICG) angiographic features on the visual outcome of patients with myopic sub-foveal choroidal neovascularization (CNV) who received photodynamic therapy (PDT). METHODS: Thirty-six consecutive patients (39 eyes) with myopic CNV who were followed up for more than one year after PDT were enrolled in this study. Clinical features included age, gender, refractive error, great linear dimension, and subretinal hemorrhage. ICG features included the lesion size, lacquer cracks, hypofluorescence surrounding the CNV (dark rim), peripapillary atrophy size, and visible prominent choroidal veins under the macula. Linear regression analysis was performed using the change in visual acuity (delta logMAR) as the dependent variable and the above factors as independent variables. RESULTS: At one-year follow-up after PDT, a younger age (p = 0.002) and the presence of a dark rim (p = 0.002) were significantly correlated with an improvement of visual acuity (decrement in logMAR) after PDT. Other factors had no significant influence on changes in visual acuity. CONCLUSIONS: Younger patients and patients with a dark rim on ICG angiography had a higher chance of visual improvement after PDT in myopic CNV.

Adult↗

PubMed2006

A novel mutation in the XLRS1 gene in a Korean family with X-linked retinoschisis.

PURPOSE: To report a novel missense mutation in the XLRS1 gene in a Korean family with X-linked retinoschisis. METHODS: Observation case report of a family with a proband with X-linked retinoschisis underwent complete ophthalmologic examination. Genomic DNA was excluded from the family's blood and all exons of the XLRS1 gene were amplified by polymerase chain reaction and analyzed using a direct sequencing method. RESULTS: A novel Leu103Phe missense mutation was identified. CONCLUSIONS: A novel Leu103Phe mutation is an additional missense mutation which is responsible for the pathogenesis of X-linked retinoschisis.

Child↗

PubMed2006

Two cases of uveal effusion syndrome.

PURPOSE: To report a case of uveal effusion syndrome associated with hypotony and a case of uveal effusion syndrome in nanophthalmos. METHODS: The first case was a 25-year-old man who presented with decreased visual acuity in the left eye and hypotony. Fundus examination revealed choroidal effusion and retinal detachment with a thickened eyeball. Partial thickness sclerotomy and sclerectomy were performed. The second case was a 13-year-old boy who had uveal effusion syndrome with a nanophthalmic eye. RESULTS: In the patient with hypotony, intraocular pressure was well maintained following partial thickness sclerotomy and sclerectomy, and choroidal effusion and retinal detachment were reduced. The visual acuity of the nanophthalmic patient was well maintained during a 3-year follow-up period without treatment. CONCLUSIONS: appropriate treatment modalities should be considered depending on the ophthalmic condition of the individual patient.

Adolescent↗

PubMed2005

Activation of adenosine A3 receptor suppresses lipopolysaccharide-induced TNF-alpha production through inhibition of PI 3-kinase/Akt and NF-kappaB activation in murine BV2 microglial cells.

Adenosine is an endogenous nucleoside that regulates many processes, including inflammatory responses, through activation of its receptors. Adenosine receptors have been reported to be expressed in microglia, which are major immune cells of brain, yet little is known about the role of adenosine receptors in microglial cytokine production. Thus, we investigated the effect of adenosine and adenosine A3 receptor ligands on LPS-induced tumor necrosis factor (TNF-alpha) production and its molecular mechanism in mouse BV2 microglial cells. Adenosine and Cl-IB-MECA, a specific adenosine A3 receptor agonist, suppressed LPS-induced TNF-alpha protein and mRNA levels. Moreover, MRS1523, a selective A3 receptor antagonist, blocked suppressive effects of both adenosine and Cl-IB-MECA on TNF-alpha. We further examined the effect of adenosine on signaling molecules, such as PI 3-kinase, Akt, p38, ERK1/2, and NF-kappaB, which are involved in the regulation of inflammatory responses. Adenosine inhibited LPS-induced phosphatidylinositol (PI) 3-kinase activation and Akt phosphorylation, whereas it had no effect on the phosphorylation of p38 and ERK1/2. We also found that adenosine as well as Cl-IB-MECA inhibited LPS-induced NF-kappaB DNA binding and luciferase reporter activity. Taken together, these results suggest that adenosine A3 receptor activation suppresses TNF-alpha production by inhibiting PI 3-kinase/Akt and NF-kappaB activation in LPS-treated BV2 microglial cells.

Adenosine↗

PubMed2005

KR-62436, 6-{2-[2-(5-cyano-4,5-dihydropyrazol-1-yl)-2-oxoethylamino]ethylamino}nicotinonitrile, is a novel dipeptidyl peptidase-IV (DPP-IV) inhibitor with anti-hyperglycemic activity.

Dipeptidyl peptidase-IV (DPP-IV) is involved in the inactivation of glucagon-like peptide-1 (GLP-1), a potent insulinotropic peptide. Thus, DPP-IV inhibition can be an effective approach to treat type 2 diabetes mellitus by potentiating insulin secretion. This study describes the biological effects of a new DPP-IV inhibitor, KR-62436 (6-{2-[2-(5-cyano-4,5-dihydropyrazol-1-yl)-2-oxoethylamino]ethylamino}nicotinonitrile) in vitro and in vivo. KR-62436 inhibited rat plasma DPP-IV, porcine kidney DPP-IV as well as human DPP-IV (Caco-2) with IC50 values of 0.78, 0.49, 0.14 microM, respectively. In addition, the compound (10 microM) almost completely inhibited DPP-IV-mediated degradation of GLP-1 in vitro. KR-62436 inhibited the enzyme in a competitive manner, and exhibited selectivity against several proteases including proline-specific proteases. In vivo efficacy of the compound was examined by using normal C57BL/6J mice and ob/ob mice, a type 2 diabetes animal model. Administration of KR-62436 to C57BL/6J mice either orally or subcutaneously resulted in the suppression of plasma DPP-IV activity, increase in intact GLP-1 and insulin levels in plasma. Furthermore, the plasma glucose concentrations during oral glucose tolerance test (OGTT) were reduced upon oral administration of KR-62436. This study demonstrates that KR-62436 could be a good lead compound for further development as a new anti-diabetic agent.

Animals↗