Publications by authors named "Sang K Kim"

During the COVID-19 pandemic, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) has been recognized as the most reliable diagnostic tool. However, there is a need to develop multiplexed assays capable of analyzing multiple genes simultaneously to expand its application. To address this, a multiplexed RT-qPCR using a double emulsion (DE)-based carrier and a polymer microparticle reactor, termed primer-incorporated network tailored with Taqman probe (TaqPIN) is developed.

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: Perillyl alcohol (POH), a monoterpene natural product derived from the essential oils of plants such as perilla (), is currently in phase I and II clinical trials as a chemotherapeutic agent. In this study, we investigated the effect of POH on cytochrome P450 (CYP) activity for evaluating POH-drug interaction potential. : The investigation was conducted using pooled human liver microsomes (HLMs), recombinant CYP3A4 (rCYP3A4) enzymes, and human pluripotent stem cell-derived hepatic organoids (hHOs) employing liquid chromatography-tandem mass spectrometry.

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Despite its profound significance, the molecular structural changes near the transition state, driven by the vibronic coupling, have remained largely unexplored, leaving a crucial aspect of chemical reactions shrouded in uncertainty. Herein, the dynamical behavior of the reactive flux on the verge of chemical bond breakage was revealed through the spectroscopic characterization of a large amplitude vibrational motion. Highly excited internal rotor states of S methylamine (CHND) report on the structural change as the molecule approaches the transition state, indicating that the quasi-free internal rotation is strongly coupled to the reaction coordinate as their energies near the maximum of the reaction barrier for the N-D chemical bond predissociation.

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New approach methods (NAMs) are required to predict human toxicity effectively, particularly due to limitations in conducting in vivo studies. While NAMs have been established for various industries, such as cosmetics, pesticides, and drugs, their applications in natural products (NPs) are lacking. NPs' complexity (multiple ingredients and structural differences from synthetic compounds) complicates NAM development.

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A photodetachment and photoelectron spectroscopic study by employing a cryogenically cooled ion trap combined with a velocity-map imaging setup has been carried out to unravel the vibrational structures and autodetachment dynamics of the dipole-bound states (DBSs) of -, -, and -methylphenolate anions (-, -, and -CHPhO). The electron binding energy of the DBS increases monotonically with the increase of the neutral dipole moment to give respective values of 66 ± 15, 123 ± 18, or 154 ± 14 cm for the -, -, or -isomer. The different electron-donating effects of the methyl moieties in the three geometrically different isomers seem to be reflected in the experiment.

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The S state relaxation dynamics of chlorobenzene (CB), 3-chlorophenol (3-CP), 3-CP·HO, and 2-chlorophenol·HO (2-CP·HO) have been investigated by means of picosecond time-resolved pump-probe spectroscopy in a state-specific manner. For CB, the S state relaxes via the S-S internal conversion in the low internal energy region (<2000 cm), whereas the direct C-Cl bond dissociation channel mediated by the upper-lying repulsive πσ* state is opened to give the rather sharp increase of the S relaxation rate in the high internal energy region (>2000 cm). A similar dynamic feature has been observed for 3-CP in terms of the lifetime behavior with an increase in the S internal energy, suggesting that the H atom tunneling dissociation reaction from OH might contribute less compared to the internal conversion, although it is not clear at the present time whether or not the sharp increase of the S relaxation rate in the high internal energy region of 3-CP (>1500 cm) is entirely due to that of the internal conversion.

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Introduction: Abnormalities in the hippocampus have been extensively reported in schizophrenia research. However, inconsistent findings exist, and how structural and functional abnormalities of the hippocampus are associated with clinical symptoms in schizophrenia, especially concerning clozapine treatment, remains uncertain.

Methods: We recruited 52 patients with schizophrenia, each with an illness duration of at least 5 years, and categorized them based on clozapine treatment.

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Article Synopsis
  • Erastin, a drug that induces ferroptosis, has limitations such as poor effectiveness and toxicity, which led to the development of ECINs, a new nanomedicine that enhances tumor targeting and reduces side effects.
  • ECINs are created using chondroitin sulfate A derivatives and indocyanine green, providing sustained release and stability while significantly improving erastin delivery to tumors and minimizing harm to other organs.
  • In studies, ECINs not only arrested cancer cell growth but also effectively shrank tumors when combined with laser treatment, indicating a promising new method for liver cancer therapy targeting CD44-overexpressing tumors.
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The Ames test is used worldwide to initially screen the mutagenic potential of new chemicals. In the standard Ames test, S. typhimurium strains (TA100, TA98, TA1535, and TA1537) and Escherichia coli (WP2uvrA) are treated with substances with/without cytochrome P450s (CYPs)-induced rat S9 fractions for identifying mutagens and pro-mutagens.

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Donepezil and tadalafil, commonly prescribed among older persons to treat dementia and erectile dysfunction, respectively, are primarily metabolized by cytochrome P450 (CYP) 3A4. However, the drug-drug interactions (DDIs) of these drugs are unknown. Therefore, this study evaluated the CYP-mediated metabolic interaction between donepezil and tadalafil using pooled human liver microsomes (HLMs) to predict their DDI potential.

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Background: Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) catalyzes the sulfation of glucuronic acid residues in heparan sulfate proteoglycans, enabling these proteoglycans to interact with numerous ligands within tumor microenvironments. However, the prognostic role of HS2ST1 expression in cancer remains unclear.

Objective: This investigated HS2ST1 expression levels and their prognostic significance in various cancer types, demonstrated the prognostic value of HS2ST1 expression in hepatocellular carcinoma (HCC) patients, and identified molecular signatures associated with HS2ST1 expression.

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State-specific dynamics of the dipole-bound state (DBS) of the cryogenically cooled deprotonated 4,4'-biphenol anion have been investigated by picosecond time-resolved pump-probe spectroscopy. For DBS vibrational states below the electron-detachment threshold, the relaxation rate is slow to give a lifetime (τ) longer than ∼5 ns, and it is attributed to the nonvalence-to-valence orbital transformation. For the DBS resonances above the detachment threshold, however, the lifetime decreases with the activation of autodetachment, whereas the otherwise zeroth DBS modes seem to be randomized by intramolecular vibrational energy redistribution (IVR), as manifested in the biexponential transients.

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We investigated whether radiomics of computed tomography (CT) image data enables the differentiation of bone metastases not visible on CT from unaffected bone, using pathologically confirmed bone metastasis as the reference standard, in patients with gastric cancer. In this retrospective study, 96 patients (mean age, 58.4 ± 13.

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Inhibition of LSD1 was proposed as promising and attractive therapies for treating osteoporosis. Here, we synthesized a series of novel TCP-(MP)-Caffeic acid analogs as potential LSD1 inhibitors to assess their inhibitory effects on osteoclastogenesis by using TRAP-staining assay and try to explore the preliminary SAR. Among them, TCP-MP-CA (11a) demonstrated osteoclastic bone loss both in vitro and in vivo, showing a significant improvement in the in vivo effects compared to the LSD1 inhibitor GSK-LSD1.

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  • The geometry of a molecule significantly affects its chemical reactivity, but studying different molecular isomers is challenging due to their tendency to interconvert.
  • A new crossed-beam experiment was developed to separately analyze the stereoisomers and rotational states of 1,2-dibromoethene while examining their reactions with excited neon atoms.
  • Findings highlighted distinct differences in reactivity based on the isomers and rotational states, emphasizing the crucial roles of molecular shape and motion in chemical reactions.
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  • YAP regulates resistance to targeted cancer treatments, and inhibiting its activity has gained interest in overcoming this resistance.
  • Researchers found that MAP3K3 stabilizes YAP in a way that doesn't involve the Hippo pathway, providing a new target for combatting drug resistance.
  • By depleting MAP3K3, YAP levels dropped significantly in cancer cells, and inhibiting MAP3K3 improved responses to CDK4/6 and BRAF inhibitors, indicating it could be a valuable strategy in cancer therapy.
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Recent development of hepatic organoids (HOs) derived from human pluripotent stem cells (hPSCs) provides an alternative in vitro model that can mimic the human liver detoxification pathway for drug safety assessment. By recapitulating the high level of maturity and drug-metabolizing capacity of the liver in a three-dimensional organoid culture, HOs may allow researchers to assess drug toxicity and metabolism more accurately than animal models or hepatocellular carcinoma cells. Although this promising potential has contributed to the development of various protocols, only a few protocols are available to generate functional HOs with guaranteed CYP450 enzymatic activity, the key feature driving toxic responses during drug metabolism.

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Smoking is a well-established risk factor for various pathologies, including pulmonary diseases, cardiovascular disorders, and cancers. The toxic effects of cigarette smoke (CS) are mediated through multiple pathways and diverse mechanisms. A key pathogenic factor is oxidative stress, primarily induced by excessive formation of reactive oxygen species.

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Despite major advances in therapeutic platforms, most patients with multiple myeloma (MM) eventually relapse and succumb to the disease. Among the novel therapeutic options developed over the past decade, genetically engineered T cells have a great deal of potential. Cellular immunotherapies, including chimeric antigen receptor (CAR) T cells, are rapidly becoming an effective therapeutic modality for MM.

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Yes-associated protein (YAP), an effector molecule of the Hippo signaling pathway, is expressed at high levels in cutaneous melanoma. However, the role of YAP in melanoma progression according to cellular localization is poorly understood. Tissues from 140 patients with invasive melanoma were evaluated by immunohistochemistry.

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In the field of drug discovery, natural products have emerged as therapeutic agents for diseases such as cancer. However, their potential toxicity poses significant obstacles in the developing effective drug candidates. To overcome this limitation, we propose a pathway-screening method based on imaging analysis to evaluate cellular stress caused by natural products.

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The interaction of a resonant light field with a quantum two-level system is of key interest both for fundamental quantum optics and quantum technological applications employing resonant excitation. While emission under resonant continuous-wave excitation has been well studied, the more complex emission spectrum of dynamically dressed states-a quantum two-level system driven by resonant pulsed excitation-has so far been investigated in detail only theoretically. Here, we present the first experimental observation of the complete resonance fluorescence emission spectrum of a single quantum two-level system, in the form of an excitonic transition in a semiconductor quantum dot, driven by finite Gaussian pulses.

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Purpose: The study was to determine the activity and safety of the TGF-β inhibitor vactosertib in combination with imatinib in patients with desmoid tumors.

Patients And Methods: In this investigator-initiated, open-label, multicenter, phase Ib/II trial, patients with desmoid tumors not amenable to locoregional therapies (surgery and/or radiotherapy) or with disease progression following at least one treatment were enrolled. Participants were administered 400 mg imatinib daily in combination with vactosertib (5 days on and 2 days off, twice a day) every 28 days.

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