Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.

Pharmacokinetics of collagen dipeptides (Gly-Pro and Pro-Hyp) and tripeptides (Gly-Pro-Hyp) in rats

Although systemic exposure to peptides, such as Gly-Pro-Hyp, Pro-Hyp, and Gly-Pro, has been reported following administration of collagen hydrolysates from fish scale and porcine skin in vivo, the individual peptide pharmacokinetics remain unknown. We administered the three peptides individually to rats via the intravenous (5 mg/kg) and intragastric (100 mg/kg) routes and then monitored systemic exposure and urinary excretion. The peptides in biological samples were analyzed via liquid chromatography/tandem mass spectrometry. Gly-Pro-Hyp tended to exhibit higher first-pass metabolism than Pro-Hyp; the absolute oral bioavailabilities of Gly-Pro-Hyp and Pro-Hyp were 4.4% and 19.3%, respectively. Gly-Pro levels were very low in the systemic circulation. Pro-Hyp biotransformed from Gly-Pro-Hyp behaved similarly to Pro-Hyp alone when administered orally. Flip-flop kinetics (elimination rate ≫ absorption rate) were evident, probably reflecting transporter-mediated slow absorption. A double-peak phenomenon was observed for Gly-Pro-Hyp and Pro-Hyp when administered orally, and 5.9% ± 2.6% and 1.9% ± 0.3% of each dose were excreted in urine after intravenous administration, respectively. Urinary recovery of Gly-Pro was limited to 0.4% ± 0.5% of the intravenous dose. This work represents the first individual pharmacokinetics of Gly-Pro-Hyp, Pro-Hyp, and Gly-Pro in vivo.

Hs27 fibroblast response to contact guidance cues

Contact guidance is the phenomena of how cells respond to the topography of their external environment. The morphological and dynamic cell responses are strongly influenced by topographic features such as lateral and vertical dimensions, namely, ridge and groove widths and groove depth ([Formula: see text], respectively). However, experimental studies that independently quantify the effect of the individual dimensions as well as their coupling on cellular function are still limited. In this work, we perform extensive parametric studies in the dimensional space-well beyond the previously studied range in the literature-to explore topographical effects on morphology and migration of Hs27 fibroblasts via static and dynamic analyses of live cell images. Our static analysis reveals that the [Formula: see text] is most significant, followed by the [Formula: see text]. The fibroblasts appear to be more elongated and aligned in the groove direction as the [Formula: see text] increases, but their trend changes after 725 nm. Interestingly, the cell shape and alignment show a very strong correlation regardless of [Formula: see text]. Our dynamic analysis confirms that directional cell migration is also strongly influenced by the [Formula: see text], while the effect of the [Formula: see text] and [Formula: see text] is statistically insignificant. Directional cell migration, as observed in the static cell behavior, shows the statistically significant transition when the [Formula: see text] is 725 nm, showing the intimate links between cell morphology and migration. We propose possible scenarios to offer mechanistic explanations of the observed cell behavior.

Concurrent Radiation and Immunotherapy Augments Local Immunity and Improves Survival in Aneuploid NSCLC

PURPOSE/OBJECTIVE(S)

Over 500 clinical trials combining radiation (RT) and immune checkpoint blockade (ICB) have been initiated based on preclinical evidence that RT can augment local immunity and improve the efficacy of ICB. However, many recent clinical trials have not found a benefit of combining RT and ICB, raising questions about whether a synergy exists. We examined whether RT and ICB interact to beneficially stimulate the immune response in patients and identified biomarkers of response to RT and ICB.

MATERIALS/METHODS

We performed a molecular analysis of 1,740 patients from 3 cohorts. The COSINR dataset is a randomized clinical trial of 22 non-small cell lung cancer (NSCLC) patients treated with concurrent or sequential SBRT and ipilimumab/nivolumab. Paired pre- and on-treatment biopsies of an irradiated metastasis underwent whole exome sequencing and RNA-seq. On-treatment biopsies were obtained after SBRT and prior to ICB (sequential) or after SBRT and one cycle of ICB (concurrent). The UC cohort consisted of targeted DNA sequencing of 58 NSCLC patients treated with ICB alone, sequential RT+ICB, or concurrent RT+ICB. The MSKCC dataset is a pan-cancer cohort of targeted DNA sequencing of 1,660 patients treated with ICB. Aneuploidy score (AS) was defined as the fraction of chromosome arms with arm-level copy number alterations. Survival analyses utilized the Kaplan-Meier method and multivariable Cox proportional hazards models.

RESULTS

In the COSINR trial, SBRT+ICB increased, whereas SBRT alone decreased, expression of effector T cell IFN-gamma and adaptive immune signatures (P<0.05). Established biomarkers of ICB response, including IFN-gamma signature, tumor mutational burden (TMB), PD-L1 expression, and neoantigen burden were not associated with survival (P>0.05). However, patients whose tumors exhibited high (≥median) but not low, AS had improved survival when treated with concurrent vs. sequential SBRT+ICB (1-year overall survival [OS] 100% vs. 17%, P = 0.025). Our findings were corroborated in the UC cohort: high AS tumors treated with RT + ICB had superior 1-year OS compared to those treated with ICB alone (59% vs. 31%, P = 0.021). Among those who received RT + ICB, concurrent treatment improved OS relative to sequential (1-year OS 76% vs. 38%). RT did not improve OS in patients with low (

CONCLUSION

Our findings distinguish the genomic and transcriptomic effects of RT versus RT+ICB and challenge the prevailing paradigm that local ablative RT positively stimulates the immune response. We propose the use of tumor aneuploidy as a biomarker in personalizing treatment approaches for patients with various cancers.

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Apoptosis of Kinetin Riboside in Colorectal Cancer Cells Occurs by Promoting β-Catenin Degradation

Kinetin riboside is a naturally produced cytokinin that displays strong antiproliferative activity in various human cancer cells. However, the mechanism of chemoprevention in colorectal cancer cells has not been elucidated. We used a cell-based reporter system to identify kinetin riboside as an antagonist of the Wnt/β-catenin pathway, which is aberrantly upregulated in colorectal cancer. Kinetin riboside suppressed β-catenin response transcription (CRT) by accelerating the degradation of intracellular β-catenin via a proteasomal degradation pathway. Pharmacological inhibition of glycogen synthase kinase-3β did not affect CRT downregulation. Kinetin riboside decreased the intracellular β-catenin levels in colorectal cancer cells with mutations in adenomatous polyposis coli (APC) and β-catenin. Consistently, kinetin riboside repressed expression of c-Myc and cyclin D1, β-catenin/T-cell factor (TCF)-dependent genes, and inhibited the proliferation of colorectal cancer cells. In addition, kinetin riboside stimulated apoptosis, as measured by an increase in annexin V-FITC-stained cells. These findings suggest that kinetin riboside exerts its anti-cancer activity by promoting β-catenin degradation and has significant potential as a chemopreventive agent for colorectal cancer cells.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

A, Barbano A, Barwick SW, Bastian B, Basu V, Baur S, Bay R, Beatty JJ, Becker KH, Becker Tjus J, Bellenghi C, BenZvi S, Berley D, Bernardini E, Besson DZ, Binder G, Bindig D, Blaufuss E, Blot S, Boddenberg M, Bontempo F, Borowka J, Böser S, Botner O, Böttcher J, Bourbeau E, Bradascio F, Braun J, Brinson B, Bron S, Brostean-Kaiser J, Browne S, Burgman A, Burley RT, Busse RS, Campana MA, Carnie-Bronca EG, Chen C, Chen Z, Chirkin D, Choi K, Clark BA, Clark K, Classen L, Coleman A, Collin GH, Conrad JM, Coppin P, Correa P, Cowen DF, Cross R, Dappen C, Dave P, De Clercq C, DeLaunay JJ, Delgado López D, Dembinski H, Deoskar K, Desai A, Desiati P, de Vries KD, de Wasseige G, de With M, DeYoung T, Diaz A, Díaz-Vélez JC, Dittmer M, Dujmovic H, Dunkman M, DuVernois MA, Dvorak E, Ehrhardt T, Eller P, Engel R, Erpenbeck H, Evans J, Evenson PA, Fan KL, Fazely AR, Fedynitch A, Feigl N, Fiedlschuster S, Fienberg AT, Filimonov K, Finley C, Fischer L, Fox D, Franckowiak A, Friedman E, Fritz A, Fürst P, Gaisser TK, Gallagher J, Ganster E, Garcia A, Garrappa S, Gerhardt L, Ghadimi A, Glaser C, Glauch T, Glüsenkamp T, Goldschmidt A, Gonzalez JG, Goswami S, Grant D, Grégoire T, Griswold S, Günther C, Gutjahr P, Haack C, Hallgren A, Halliday R, Halve L, Halzen F, Ha Minh M, Hanson K, Hardin J, Harnisch AA, Haungs A, Hebecker D, Helbing K, Henningsen F, Hettinger EC, Hickford S, Hignight J, Hill C, Hill GC, Hoffman KD, Hoffmann R, Hokanson-Fasig B, Hoshina K, Huang F, Huber M, Huber T, Hultqvist K, Hünnefeld M, Hussain R, Hymon K, In S, Iovine N, Ishihara A, Jansson M, Japaridze GS, Jeong M, Jin M, Jones BJP, Kang D, Kang W, Kang X, Kappes A, Kappesser D, Kardum L, Karg T, Karl M, Karle A, Katz U, Kauer M, Kellermann M, Kelley JL, Kheirandish A, Kin K, Kintscher T, Kiryluk J, Klein SR, Koirala R, Kolanoski H, Kontrimas T, Köpke L, Kopper C, Kopper S, Koskinen DJ, Koundal P, Kovacevich M, Kowalski M, Kozynets T, Kun E, Kurahashi N, Lad N, Lagunas Gualda C, Lanfranchi JL, Larson MJ, Lauber F, Lazar JP, Lee JW, Leonard K, Leszczyńska A, Li Y, Lincetto M, Liu QR, Liubarska M, Lohfink E, Lozano Mariscal CJ, Lu L, Lucarelli F, Ludwig A, Luszczak W, Lyu Y, Ma WY, Madsen J, Mahn KBM, Makino Y, Mancina S, Mariş IC, Martinez-Soler I, Maruyama R, Mase K, McElroy T, McNally F, Mead JV, Meagher K, Mechbal S, Medina A, Meier M, Meighen-Berger S, Micallef J, Mockler D, Montaruli T, Moore RW, Morse R, Moulai M, Naab R, Nagai R, Nahnhauer R, Naumann U, Necker J, Nguyen LV, Niederhausen H, Nisa MU, Nowicki SC, Nygren D, Obertacke Pollmann A, Oehler M, Oeyen B, Olivas A, O’Sullivan E, Pandya H, Pankova DV, Park N, Parker GK, Paudel EN, Paul L, Pérez de los Heros C, Peters L, Peterson J, Philippen S, Pieper S, Pittermann M, Pizzuto A, Plum M, Popovych Y, Porcelli A, Prado Rodriguez M, Price PB, Pries B, Przybylski GT, Raab C, Rack-Helleis J, Raissi A, Rameez M, Rawlins K, Rea IC, Rehman A, Reichherzer P, Reimann R, Renzi G, Resconi E, Reusch S, Rhode W, Richman M, Riedel B, Roberts EJ, Robertson S, Roellinghoff G, Rongen M, Rott C, Ruhe T, Ryckbosch D, Rysewyk Cantu D, Safa I, Saffer J, Sanchez Herrera SE, Sandrock A, Sandroos J, Santander M, Sarkar S, Sarkar S, Satalecka K, Schaufel M, Schieler H, Schindler S, Schmidt T, Schneider A, Schneider J, Schröder FG, Schumacher L, Schwefer G, Sclafani S, Seckel D, Seunarine S, Sharma A, Shefali S, Silva M, Skrzypek B, Smithers B, Snihur R, Soedingrekso J, Soldin D, Spannfellner C, Spiczak GM, Spiering C, Stachurska J, Stamatikos M, Stanev T, Stein R, Stettner J, Steuer A, Stezelberger T, Stokstad R, Stürwald T, Stuttard T, Sullivan GW, Taboada I, Ter-Antonyan S, Tilav S, Tischbein F, Tollefson K, Tönnis C, Toscano S, Tosi D, Trettin A, Tselengidou M, Tung CF, Turcati A, Turcotte R, Turley CF, Twagirayezu JP, Ty B, Unland Elorrieta MA, Valtonen-Mattila N, Vandenbroucke J, van Eijndhoven N, Vannerom D, van Santen J, Verpoest S, Walck C, Watson TB, Weaver C, Weigel P, Weindl A, Weiss MJ, Weldert J, Wendt C, Werthebach J, Weyrauch M, Whitehorn N, Wiebusch CH, Williams DR, Wolf M, Woschnagg K, Wrede G, Wulff J, Xu XW, Yanez JP, Yoshida S, Yu S, Yuan T, Zhang Z, Zhelnin P. Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Bioavailability of xanthorrhizol following oral administration of a supercritical extract of Java turmeric

Although xanthorrhizol, a sesquiterpenoid oil obtained from the rhizome of Curcuma xanthorrhiza Roxb., known as Java turmeric, has many pharmacological effects, its pharmacokinetics remain unclear. Therefore, we investigated the pharmacokinetics of xanthorrhizol in mice and rats. Xanthorrhizol was administered intravenously and orally to mice, while xanthorrhizol and a Java turmeric supercritical extract were administered orally to rats. The terminal half-life (t1/2), clearance, and absolute bioavailability (BA) of xanthorrhizol in mice were almost 8 h, 6.5 L/h/kg, and 10.2%, respectively. In comparison, the clearance of xanthorrhizol was 3-fold higher in rats than mice. The absolute BAs of xanthorrhizol in rats were 12.9% and 13.4% after oral administration of xanthorrhizol and a supercritical extract, respectively. Our results regarding the pharmacokinetics of xanthorrhizol could guide the conversion of intravenous and oral doses, and help identify the optimal maintenance doses of xanthorrhizol and the extract for desirable pharmacodynamic effects.

Quantitative determination of ICG-001 in rat plasma using HPLC-MS/MS: A pharmacokinetic study

Although ICG-001, chemically synthesised from a bicyclic β-turn peptidomimetic template, represents various pharmacological activities, no validated determination methods in biological samples have been reported. This study was designed to establish a quantitative determination method for ICG-001 in rat plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) to validate the analytical method, including stability, and to characterise its pharmacokinetic behaviour in rats. After simple protein precipitation with acetonitrile, ICG-001 was eluted on a reversed-phase column using a mobile phase of water and acetonitrile (3:7 v/v, including 0.1% formic acid). The protonated precursor ion [M+H]⁺ and the major fragment ion were confirmed at m/z 549.2 and 141.4, respectively, for ICG-001. ICG-001 was stable under bench and storage conditions. The analytical method met the criteria for Food and Drug Administration-validated bioanalytical methods, and was successfully applied to a pharmacokinetic study for the first time following subcutaneous and intravenous administration.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Nonalcoholic steatohepatitis in hepatocarcinoma: new insights about its prognostic role in patients treated with lenvatinib

BACKGROUND

Hepatocellular carcinoma (HCC) treatment remains a big challenge in the field of oncology. The liver disease (viral or not viral) underlying HCC turned out to be crucial in determining the biologic behavior of the tumor, including its response to treatment. The aim of this analysis was to investigate the role of the etiology of the underlying liver disease in survival outcomes.

PATIENTS AND METHODS

We conducted a multicenter retrospective study on a large cohort of patients treated with lenvatinib as first-line therapy for advanced HCC from both Eastern and Western institutions. Univariate and multivariate analyses were performed.

RESULTS

Among the 1232 lenvatinib-treated HCC patients, 453 (36.8%) were hepatitis C virus positive, 268 hepatitis B virus positive (21.8%), 236 nonalcoholic steatohepatitis (NASH) correlate (19.2%) and 275 had other etiologies (22.3%). The median progression-free survival (mPFS) was 6.2 months [95% confidence interval (CI) 5.9-6.7 months] and the median overall survival (mOS) was 15.8 months (95% CI 14.9-17.2 months). In the univariate analysis for OS NASH-HCC was associated with longer mOS [22.2 versus 15.1 months; hazard ratio (HR) 0.69; 95% CI 0.56-0.85; P = 0.0006]. In the univariate analysis for PFS NASH-HCC was associated with longer mPFS (7.5 versus 6.5 months; HR 0.84; 95% CI 0.71-0.99; P = 0.0436). The multivariate analysis confirmed NASH-HCC (HR 0.64; 95% CI 0.48-0.86; P = 0.0028) as an independent prognostic factor for OS, along with albumin-bilirubin (ALBI) grade, extrahepatic spread, neutrophil-to-lymphocyte ratio, portal vein thrombosis, Eastern Cooperative Oncology Group (ECOG) performance status and alpha-fetoprotein. An interaction test was performed between sorafenib and lenvatinib cohorts and the results highlighted the positive predictive role of NASH in favor of the lenvatinib arm (P = 0.0047).

CONCLUSION

NASH has been identified as an independent prognostic factor in a large cohort of patients with advanced HCC treated with lenvatinib, thereby suggesting the role of the etiology in the selection of patients for tyrosine kinase treatment. If validated, this result could provide new insights useful to improve the management of these patients.

Absolute oral and subcutaneous bioavailability of ortho-topolin riboside in mice

Among essential phytohormones playing a pivotal role in regulating growth and development, ortho-topolin riboside (oTR) exerts the most substantial anti-tumor potency in various cancer cell lines. This study was designed to establish a quantitative determination method for oTR in mouse plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), to validate the analytical method including stability, and to characterise its pharmacokinetic behaviour in mice. After simple protein precipitation with acetonitrile including kinetin riboside (internal standard), oTR was eluted on a reversed-phase column using a mobile phase of water and acetonitrile (3:7 v/v, including 0.1% formic acid). The protonated precursor ion [M+H]⁺ and major fragment ion were confirmed at m/z 374.06 and 241.99 for oTR, and 348.23 and 216.06 for the IS, respectively. oTR was stable under bench and storage conditions. The analytical method met the criteria of FDA-validated bioanalytical methods and was successfully applied to a pharmacokinetic study for the first time following oral, subcutaneous, and intravenous administrations. While oTR was merely absorbed by an oral route, 90% of the absolute subcutaneous bioavailability was observed.

Protein microbeadification to achieve highly concentrated protein formulation with reversible properties and in vivo pharmacokinetics after reconstitution

A protein precipitation technique was optimized to produce biophysically stable 'protein microbeads', applicable to highly concentrated protein formulation. Initially, production of BSA microbeads was performed using rapid dehydration by vortexing in organic solvents followed by cold ethanol treatment and a vacuum drying. Out of four solvents, n-octanol produced the most reversible microbeads upon reconstitution. A Shirasu porous glass (SPG) membrane emulsification technique was utilized to enhance the size distribution and manufacturing process of the protein microbeads with a marketized human IgG solution. Process variants such as dehydration time, temperature, excipients, drying conditions, and initial protein concentration were evaluated in terms of the quality of IgG microbeads and their reversibility. The hydrophobized SPG membrane produced a narrow size distribution of the microbeads, which were further enhanced by shorter dehydration time, low temperature, minimized the residual solvents, lower initial protein concentration, and addition of trehalose to the IgG solution. Final reversibility of the IgG microbeads with trehalose was over 99% at both low and high protein concentrations. Moreover, the formulation was highly stable under repeated mechanical shocks and at an elevated temperature compared to its liquid state. Its in vivo pharmacokinetic profiles in rats were consistent before and after the 'microbeadification'.

Prediction of Fluoxetine and Norfluoxetine Pharmacokinetic Profiles Using Physiologically Based Pharmacokinetic Modeling

Fluoxetine is a selective serotonin reuptake inhibitor that is metabolized to norfluoxetine by cytochrome P450 (CYP) 2D6, CYP2C19, and CYP3A4. A physiologically based pharmacokinetic model for fluoxetine and norfluoxetine metabolism was developed to predict and investigate changes in concentration-time profiles according to fluoxetine dosage in the Korean population. The model was developed based on the Certara repository model and information gleaned from the literature. Digitally extracted clinical study data were used to develop and verify the model. Simulations for plasma concentrations of fluoxetine and norfluoxetine after a single dose of 60 or 80 mg fluoxetine were made based on 1000 virtual healthy Korean individuals using the SimCYP version 19 simulator. The mean ratios (simulated/observed) after a single administration of 80 mg fluoxetine for maximum plasma concentration, area under the plasma concentration-time curve, and apparent clearance were 1.12, 1.08, and 0.93 for fluoxetine; the ratios of maximum plasma concentration and area under the plasma concentration-time curve were 1.08 and 1.08, respectively, for norfluoxetine, indicating that the simulated concentration-time profiles of fluoxetine and norfluoxetine fitted the observed profiles well. The developed model was used to predict plasma fluoxetine and norfluoxetine concentration-time profiles after repeated administrations of fluoxetine in Korean volunteers. This physiologically based pharmacokinetic model could provide basic understanding of the pharmacokinetic profiles of fluoxetine and its metabolite under various situations.

A sensitive analytical method for the determination of SG-SP1 in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study

SG-SP1, a newly synthesised gallic acid derivative, blocks histamine release by reducing calcium influx in mast cells and inhibits inflammatory cytokine expression. This derivative has promising anti-allergic potential. Our research was designed to establish a quantitative determination method for SG-SP1 in rat plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), to validate the analytical method including stability and to characterise its pharmacokinetic behaviour in rats. After simple protein precipitation with acetonitrile including an internal standard, SG-SP1 was eluted on a reversed-phase column using a mobile phase of water and acetonitrile (2:8 v/v, including 0.1 % formic acid). The protonated precursor ion [M+H]⁺ and major fragment ion were confirmed at m/z 588.2 and 180.1, respectively. The substance was stable under bench and storage conditions. The analytical method met the criteria of FDA-validated bioanalytical methods and was successfully applied to a pharmacokinetic study for the first time. SG-SP1 decayed in a biphasic pattern with terminal half-life of 5.1 h and clearance of about 3.2 L/h/kg. Double peaks were observed following oral administration, and the absolute oral bioavailability was ∼1 %.

The histone deacetylase inhibitor chidamide induces intermittent viraemia in HIV-infected patients on suppressive antiretroviral therapy

OBJECTIVES

To evaluate the safety and efficacy of chidamide to reverse HIV-1 latency in vivo and to compare the effects of four clinically tested histone deacetylase (HDAC) inhibitors on non-histone proteins in vitro.

METHODS

Participants received chidamide orally at 10 mg twice weekly for 4 weeks while maintaining baseline antiretroviral therapy. The primary outcome was plasma viral rebound during chidamide dosing and the secondary outcomes were safety, pharmacokinetic and pharmacodynamic profiles, changes in cell-associated HIV-1 RNA and HIV-1 DNA, and immune parameters. Western blotting was used to compare the in vitro effects of the four HDAC inhibitors on HSP90, NF-κB and AP-1.

RESULTS

Seven aviraemic participants completed eight oral doses of chidamide, and only grade 1 adverse events were observed. Cyclic increases in histone acetylation were also detected. All participants showed robust and repeated plasma viral rebound (peak viraemia 147-3850 copies/mL), as well as increased cell-associated HIV-1 RNA, during chidamide treatment. Furthermore, we identified an enhanced HIV-1-specific cellular immune response and a modest 37.7% (95% CI: 12.7-62.8%, P = 0.028) reduction in cell-associated HIV-1 DNA. Compared with the other three HDAC inhibitors, chidamide had minimal cytotoxicity in vitro at clinically relevant concentrations and showed mechanistically superior effects on non-histone proteins, including HSP90, NF-κB and AP-1.

CONCLUSIONS

Chidamide safely and vigorously disrupts HIV-1 latency in vivo, which makes it a promising latency-reversing agent.