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AIMS: This open-label, phase I study evaluated the pharmacokinetics and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) for the treatment of chemotherapy-induced neutropenia in children with acute leukaemia. METHODS: PEG-rhG-CSF was administered as a single 100 mcg/kg (3 mg maximum dose) subcutaneous injection at the end of each chemotherapy period when neutropenia occurred. Blood samples were obtained from patients treated with PEG-rhG-CSF. PEG-rhG-CSF serum concentrations were determined by an enzyme-linked immunosorbent assay. Population pharmacokinetic (PPK) analysis was implemented using the nonlinear mixed-effects model. Short-term safety was evaluated through adverse events collection (registered at clinicaltrials.gov identifier: 03844360). RESULTS: A total of 16 acute leukaemia patients (1.8-13.6 years) were included, of whom two (12.5%) had grade 3 neutropenia, six (37.5%) had grade 4 neutropenia, and eight (50.0%) had severe neutropenia. For PPK modelling, 64 PEG-rhG-CSF serum concentrations were obtainable. A one-compartment model with first-order elimination was used for pharmacokinetic data modelling. The current weight was a significant covariate. The median (range) of clearance (CL) and area under the serum concentration-time curve (AUC) were 5.65 (1.49-14.45) mL/h/kg and 16514.75 (6632.45-54423.30) ng·h/mL, respectively. Bone pain, pyrexia, anaphylaxis and nephrotoxicity were not observed. One patient died 13 days after administration, and the objective assessment of causality was that an association with PEG-rhG-CSF was "possible". CONCLUSIONS: The AUC of PEG-rhG-CSF (100 mcg/kg, 3 mg maximum dose) in paediatric patients with acute leukaemia were similar to those of PEG-rhG-CSF (100 mcg/kg) in children with sarcoma. PEG-rhG-CSF is safe, representing an important therapeutic option for chemotherapy-induced neutropenia in paediatric patients with acute leukaemia.
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Leucemia Mieloide Aguda , Neutropenia , Criança , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Neutropenia/induzido quimicamente , Polietilenoglicóis/efeitos adversos , Proteínas RecombinantesRESUMO
AIMS: Recently, letrozole has been used off-label to treat short pubertal boys. The experience on letrozole effectiveness and safety has been obtained primarily from Caucasian children. A simple extrapolation of the data to Chinese paediatric populations is questionable because of the substantial ethnic differences between the two populations. Therefore, the present study aimed to determine the effectiveness and safety of letrozole use in Chinese short pubertal boys as well as to establish an exposure-response relationship. METHODS: Forty-one Chinese boys were included in the study. Patients were given letrozole tablets (2.5 mg) once daily in combination with growth hormone, and follow-up visits were made after 1, 3, 6 and 12 months of treatment. Plasma samples were taken from clinical examinations and analysed using high performance liquid chromatography with fluorescence detection. RESULTS: After 1 year of treatment, 35 (88%) boys showed increased predicted adult heights. However, possible adverse drug reactions were seen in nine boys (22%). Predicted adult heights increased significantly from 168.4 ± 3.7 to 173.0 ± 4.2 cm, while oestrogen levels dropped from 33.2 ± 7.4 to 21.6 ± 7.3 pg/mL. Increments in predicted adult height were significantly correlated with trough letrozole concentrations (r = 0.39, P = .01). CONCLUSION: Letrozole treatment in Chinese pubertal populations should be further optimized, and more personalized therapies should be developed.
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Estatura , Uso Off-Label , Adulto , Criança , China , Humanos , Letrozol , Masculino , Nitrilas/efeitos adversosRESUMO
AIMS: Chinese children are more susceptible to the development of thiopurine-induced leukopenia compared with Caucasian populations. The aim of our study was to establish a 6-mercaptopurine (6-MP) dose-concentration-response relationship through exploration of pharmacogenetic factors involved in the thiopurine-induced toxicities in Chinese paediatric patients afflicted by acute lymphoblastic leukaemia (ALL). METHODS: Blood samples were obtained from ALL children treated with 6-MP. We determined the metabolite steady-state concentrations of 6-MP in red blood cells (RBCs) by using high-performance liquid chromatography. Pharmacogenetic analysis was carried out on patients' genomic DNA using the MassArray genotyping platform. RESULTS: Sixty children afflicted by ALL who received 6-MP treatment were enrolled in this study. The median concentration of 6-thioguanine in patients afflicted by leukopenia was 235.83 pmol/8 × 108 RBCs, which was significantly higher than for patients unafflicted by leukopenia (178.90 pmol/8 × 108 RBCs; P = 0.029). We determined the population special target 6-thioguanine threshold to have equalled 197.50 pmol/8 × 108 RBCs to predict leukopenia risk in Chinese paediatric patients afflicted by ALL. Among 36 candidate single nucleotide polymorphisms, our results indicated that NUDT15 (rs116855232) and IMPDH1 (rs2278293) were correlated with a 5.50-fold and 5.80-fold higher risk of leukopenia, respectively. MTHFR rs1801133 variants were found to have had a 4.46-fold significantly higher risk of hepatotoxicity vs wild-type genotype. CONCLUSION: Our findings support the idea that predetermination of genotypes and monitoring of thiopurine metabolism for Chinese paediatric patients afflicted by ALL is necessary to effectively predict the efficacy of treatments and to minimize the adverse effects of 6-MP maintenance therapy.
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Mercaptopurina , Leucemia-Linfoma Linfoblástico de Células Precursoras , Antimetabólitos Antineoplásicos/uso terapêutico , Criança , China , Feminino , Humanos , Masculino , Mercaptopurina/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , TioguaninaRESUMO
First dose prediction is challenging in neonates. Our objective in this proof-of-concept study was to perform a pharmacokinetic (PK) bridging study from juvenile mice to neonates for drugs metabolized by CYP3A. We selected midazolam and clindamycin as model drugs. We developed juvenile mice population PK models using NONMEM. The PK parameters of these two drugs in juvenile mice were used to bridge PK parameters in neonates using different correction methods. The bridging results were evaluated by the fold-error of 0.5- to 1.5-fold. Simple allometry with and without a correction factor for maximum lifespan potential could be used for a bridging of clearance (CL) and volume of distribution (Vd), respectively, from juvenile mice to neonates. Simulation results demonstrated that for midazolam, 100% of clinical studies for which both the predictive CL and Vd were within 0.5- to 1.5-fold of the observed. For clindamycin, 75% and 100% of clinical studies for which the predictive CL and Vd were within 0.5- to 1.5-fold of the observed. A PK bridging of drugs metabolized by CYP3A is feasible from juvenile mice to neonates. It could be a complement to the ADE and PBPK models to support the first dose in neonates.
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Simulação por Computador , Citocromo P-450 CYP3A/metabolismo , Animais , Clindamicina/farmacocinética , Camundongos , Midazolam/farmacocinética , Modelos BiológicosRESUMO
Continuous 6-mercaptopurine (6-MP) dose titration is necessary because of its narrow therapeutic index and frequently encountered dose-limiting hematopoietic toxicity. However, evidence-based guidelines for gene-based 6-MP dosing have not been established for Chinese children with acute lymphoblastic leukemia (ALL). This multicenter, randomized, open-label, active-controlled clinical trial randomly assigned Chinese children with low- or intermediate-risk ALL in a 1:1 ratio to receive TPMT-NUDT15 gene-based dosing of 6-MP (N = 44, 10 to 50 mg/m2 /day) or standard dosing (N = 44, 50 mg/m2 /day) during maintenance therapy. The primary end point was the incidence of 6-MP myelosuppression in both groups. Secondary end points included frequencies of 6-MP hepatotoxicity, duration of myelosuppression and leukopenia, event-free survival, and steady-state concentrations of active metabolites (6-thioguaninenucleotides and 6-methylmercaptopurine nucleotides) in erythrocytes. A 2.2-fold decrease in myelosuppression, the primary end point, was observed in the gene-based-dose group using ~ 50% of the standard initial 6-MP dose (odds ratio, 0.26, 95% confidence interval, 0.11 to 0.64, P = 0.003). Patients in the gene-based-dose group had a significantly lower risk of developing thiopurine-induced myelosuppression and leukopenia (P = 0.015 and P = 0.022, respectively). No significant differences were observed in the secondary end points of the incidence of hepatotoxicity and steady-state concentrations of active metabolites in erythrocytes between the two groups. TPMT- and NUDT15-based dosing of 6-MP will significantly contribute toward further reducing the incidence of leukopenia in Chinese children with ALL. This trial is registered at www.clinicaltrial.gov as #NCT04228393.
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População do Leste Asiático , Mercaptopurina , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Antimetabólitos Antineoplásicos/efeitos adversos , Doenças da Medula Óssea , Doença Hepática Induzida por Substâncias e Drogas , China/epidemiologia , Leucopenia/induzido quimicamente , Leucopenia/epidemiologia , Mercaptopurina/efeitos adversos , Metiltransferases , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/etnologiaRESUMO
OBJECTIVE: Immune monotherapy as second-line treatment confers only modest survival benefit on non-small cell lung cancer (NSCLC) patients with no mutated driver genes, necessitating combination treatment strategies. This phase Ib trial investigated the efficacy and safety of anti-PD-L1 antibody TQB2450 plus antiangiogenic drug anlotinib for NSCLC. MATERIALS AND METHODS: Pretreated stage IIIB or IV NSCLC patients with wild-type EGFR/ALK and minimally one measurable lesion were randomized 1:1:1 to receive TQB2450 1200 mg plus placebo, or TQB2450 1200 mg plus anlotinib 10 or 12 mg. The primary outcome was progression-free survival (PFS) and the secondary outcomes included objective response rate (ORR). RESULTS: Thirty-three patients received TQB2450 plus placebo and 34 patients each received TQB2450 plus anlotinib 10 mg and 12 mg. At the data cutoff, the median PFS was 8.7 months (95% CI 6.1-17.1) in the TQB2450 plus anlotinib group and 2.8 months (95% CI 1.4-4.7) in the TQB2450 only group. The ORR reached 30.9% (95% CI 20.2%-43.3%) in the TQB2450 plus anlotinib group and was 3.0% (95% CI 0.1%-15.8%) in the TQB2450 only group. In patients with PD-L1 ≥ 1%, the ORR was 50.0% (95% CI 33.4%-66.6%) for TQB2450 plus anlotinib and 5.3% (95% CI 0.1%-26.0%) for TQB2450 plus placebo. No new safety signals were observed. CONCLUSION: Anlotinib plus TQB2450 demonstrated promising antitumor activities in advanced NSCLC patients without EGFR and ALK alterations and the toxicities were overall manageable. The study findings support the continued development of TQB2450 plus anlotinib for advanced NSCLC patients without driver gene alterations.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Anticorpos Monoclonais , Inibidores de Checkpoint Imunológico , Receptores ErbB , Receptores Proteína Tirosina QuinasesRESUMO
Non-small-cell lung cancer (NSCLC) is one of the most serious cancers. The circular RNA_0078767 (circ_0078767) expression was decreased in NSCLC tissues. However, the molecular mechanism of circ_0078767 remains unknown. The expression of circ_0078767, microRNA-665 (miR-665), and glutathione peroxidase 3 (GPX3) was detected by quantitative real-time fluorescence polymerase chain reaction (qRT-PCR). Cell proliferation, migration, and invasion were detected by colony formation assay and transwell assay, respectively. The lactate production and glucose consumption were tested by glycolysis. Western blot examined the protein levels of hexokinase-2 (HK2), matrix metalloproteinase-9 (MMP9), and GPX3 cells. Circinteractome predicted the relationship between miR-665 and circ_0078767 or GPX3 and was verified by dual luciferase reporter assays. The xenotransplantation model was established to study the role of circ_0078767 in vivo. The expression of circ_0078767 and GPX3 was decreased in NSCLC tissues, while the expression of miR-665 was increased. Circ_0078767 can sponge miR-665, and GPX3 is the target of miR-665. In vitro complement experiments showed that knockdown of circ_0078767 significantly promoted malignant behavior of NSCLC, while cotransfection of miR-665 inhibitor partially reduced this change. In addition, the GPX3 overexpression decreased the promoting effects of miR-665 upregulation on proliferation, migration, and invasion of NSCLC cells. Mechanically, circ_0078767 regulates the GPX3 expression in NSCLC cells by spongy miR-665. In addition, in vivo studies have shown that downregulation of circ_0078767 promotes tumor growth. Circ_0078767 silencing promotes proliferation, migration, invasion, and glycolysis of NSCLC cells by regulating the miR-665/GPX3 axis, suggesting that circ_0078767/miR-665/GPX3 axis may be a potential regulatory mechanism for the treatment of NSCLC.
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Arctic sea ice retreat is linked to extrapolar thermal energy import, while the potential impact of pan-Arctic river heat discharge on sea-ice loss has been unresolved. We reconstructed the Holocene history of Arctic sea ice and Russian pan-Arctic river heat discharge, combining ice-rafted debris records and sedimentation rates from the East Siberian Arctic Shelf with a compilation of published paleoclimate and observational data. In the mid-Holocene, the early summer (June-July) solar insolation was higher than that during the late Holocene, which led to a larger heat discharge of the Russian pan-Arctic rivers and contributed to more Arctic sea ice retreat. This intensified decline of early-summer sea ice accelerated the melting of sea ice throughout the summertime by lowering regional albedos. Our findings highlight the important impact of the larger heat discharge of pan-Arctic rivers, which can reinforce Arctic sea-ice loss in the summer in the context of global warming.
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BACKGROUND: Dasatinib, an orally administered Src-family kinase inhibitor, is combined with the standard chemotherapeutic regimen to enhance antineoplastic activity against core-binding factor acute myeloid leukemia (CBF-AML) in adults; however, limited data are available for use in children. In the present study, we studied the pharmacokinetics and safety of dasatinib in children. METHODS: Dasatinib (60 or 80 mg/m2 once daily) was administered to 20 children with CBF-AML. Blood samples were collected and drug concentrations were quantified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Population pharmacokinetic analysis and Monte-Carlo simulations were performed using NONMEM software, and safety analyses were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.0 (NCT03844360). RESULTS: Twenty pediatric patients (3.3-14.4 years of age) were included, and a total of 40 dasatinib concentrations were available for population pharmacokinetic analysis. The mean (standard deviation) of the estimated area under the concentration-time curve extrapolated to steady state (AUCss) of dasatinib 60 and 80 mg/m2 was 366.1 (146.6) ng·h/mL and 425.3 (150.7) ng·h/mL, respectively. The majority of adverse events were grade 1/2 in severity, including thrombocytopenia, rash, and pain in the extremities. The estimated cumulative incidence of complete remission and complete molecular response were 95.0% and 75.5%, respectively. CONCLUSIONS: The population pharmacokinetics of orally administered dasatinib were evaluated in pediatric CBF-AML patients. The AUCss of dasatinib (80 mg/m2) in CBF-AML pediatric patients was similar to those of dasatinib (100 mg) in adult patients. Dasatinib is well-tolerated in pediatric patients with CBF-AML.
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Leucemia Mieloide Aguda , Espectrometria de Massas em Tandem , Adulto , Criança , China , Fatores de Ligação ao Core , Dasatinibe/efeitos adversos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversosRESUMO
Methane is supersaturated in surface seawater and shallow coastal waters dominate global ocean methane emissions to the atmosphere. Aerobic methane oxidation (MOx) can reduce atmospheric evasion, but the magnitude and control of MOx remain poorly understood. Here we investigate methane sources and fates in the East China Sea and map global MOx rates in shallow waters by training machine-learning models. We show methane is produced during methylphosphonate decomposition under phosphate-limiting conditions and sedimentary release is also source of methane. High MOx rates observed in these productive coastal waters are correlated with methanotrophic activity and biomass. By merging the measured MOx rates with methane concentrations and other variables from a global database, we predict MOx rates and estimate that half of methane, amounting to 1.8 ± 2.7 Tg, is consumed annually in near-shore waters (<50 m), suggesting that aerobic methanotrophy is an important sink that significantly constrains global methane emissions.
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Metano , Água do Mar , Oxirredução , Atmosfera , DifusãoRESUMO
OBJECTIVE: To assess the efficacy and toxicity of the kangai injection combination of fludarabine (Flud), cytosine arabinoside (Ara-C), and granulocyte colony-stimulating factor (G-CSF) (FLAG) in refractory/relapsed acute leukemia (AL) patients. METHOD: From 2004 to 2010 in our hospital, the 49 cases of refractory/relapsed acute luekemia were randomly divided into treatment group (28 cases) and control group (21 cases). The control group were treated by kangai injection plus FLAG regimen, and the control group were treated by FLAG regimen. RESULT: The remission rate of treatment and total effective rate treatment group were 57.1% (16/28) and 71.4% (21/28), the control group were 52.3% (11/21) and 61.9% (13/21), there were no significant differences in the two groups. Duration of neutrophils less than 0.5 x 10(9)/L in treatment group was (14 +/- 6) day, control group was (23 +/- 3) day, Duration of platelet less than 25 x 10(9)/L in treatment group was (17 +/- 6) day, control group was (31 +/- 2) day, treatment group of III-IV degree of infection was 6.9% (1/28) and control group was 23.8% (5/21) between the two groups were significantly different (P < 0.05). treatment group of III- IV degree of gastrointestinal; toxicity was 10.7% (3/28) and control group was 28. 5% (6/ 21). CONCLUSION: Kangai injection plus FLAG regimen could increase the remission rate, shorten the period of bone marrow suppression, significantly reduced the incidence and degree of infection, play a important role in attenuated efficiency.
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Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , Leucemia/tratamento farmacológico , Doença Aguda , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Citarabina/administração & dosagem , Citarabina/efeitos adversos , Medicamentos de Ervas Chinesas/efeitos adversos , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Vidarabina/administração & dosagem , Vidarabina/efeitos adversos , Vidarabina/análogos & derivadosRESUMO
Dimethylated sulfur compounds play an important role in global sulfur cycle. We investigated the seasonality of dimethylsulfoniopropionate (DMSP), dimethylsulfoxide (DMSO), dimethylsulfide (DMS) and associated processes in two north China marginal seas during 2014 and 2016. High concentrations of DMS, DMSP and DMSO occurred in summer/spring, while the lowest were observed in winter. This clear seasonality was primarily driven by biomass abundance and phytoplankton communities, reflected in chlorophyll a concentrations and the composition/ratios of diatoms and dinoflagellates. The spring maximum was attributed to the annual occurrence of algal bloom. The sea-to-air fluxes of DMS also varied largely between seasons, with an average of 8.84, 11.87, 10.50 and 2.14 µmol m-2 day-1 in spring, summer, autumn and winter, respectively. Given the seasonal uncertainty of sea-to-air flux, the seasonality or situations where specific blooms occur regularly should be considered for accurate estimation of annual global DMS emission.
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Água do Mar , Compostos de Enxofre , China , Clorofila A , Oceanos e Mares , Fitoplâncton , Estações do AnoRESUMO
The spatial distributions, fluxes, and environmental effects of non-methane hydrocarbons (NMHCs) were investigated in the Yellow Sea (YS) and the East China Sea (ECS) in spring. The average concentrations of ethane, propane, i-/n-butane, ethylene, propylene and isoprene in the seawater were 18.1 ± 6.4, 15.4 ± 4.7, 6.8 ± 2.9, 6.4 ± 3.2, 67.1 ± 26.7, 20.5 ± 8.7 and 17.1 ± 11.1 pmol L-1, respectively. The alkenes in the surface seawater were more abundant than their saturated homologs and NMHCs concentrations (with the exception of isoprene) decreased with carbon number. The spatial variations of isoprene were consistent with the distributions of chlorophyll a (Chl-a) and Chaetoceros, Skeletonema, Nitzschia mainly contributed to the production of isoprene, while the others' distributions might be related to their photochemical production. Observations in atmospheric NMHCs indicated alkanes in the marine atmosphere decreased from inshore to offshore due to influence of the continental emissions, while alkenes were largely derived from the oceanic source. In addition, no apparent diurnal discrepancy of atmospheric NMHCs (except for isoprene) were found between daytime and night. As the main sink of NMHCs in seawater, the average sea-to-air fluxes of ethane, propane, i-/n-butane, ethylene and propylene were 31.70, 29.75, 18.49, 15.89, 239.6, 67.94 and 52.41 nmol m-2 d-1, respectively. The average annual emissions of isoprene accounted for 0.1-1.3% of the global ocean emissions, which indicated that the coastal and shelf areas might be significant sources of isoprene. Furthermore, this study represents the first effort to estimate the environmental effects caused by NMHCs over the YS and the ECS and the results demonstrated contributions of alkanes to ozone and secondary organic aerosol (SOA) formation were lower than those of the alkenes and the largest contributor was isoprene.
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Poluentes Atmosféricos , Metano , Poluentes Atmosféricos/análise , China , Clorofila A , Monitoramento Ambiental , Hidrocarbonetos/análise , Oceanos e Mares , Estações do AnoRESUMO
PURPOSE: Inflammation has a significant impact on CYP3A activity. We hypothesized that this effect might be age dependent. Our objective was to conduct a population pharmacokinetic study of midazolam in mice at different developmental stages with varying degrees of inflammation to verify our hypothesis. METHODS: Different doses (2 and 5 mg/kg) of lipopolysaccharide (LPS) were used to induce different degrees of systemic inflammation in Swiss mice (postnatal age 9-42 days, n = 220). The CYP3A substrate midazolam was selected as the pharmacological probe to study CYP3A activity. Postnatal age, current body weight, serum amyloid A protein 1 (SAA1) levels and LPS doses were collected as covariates to perform a population pharmacokinetic analysis using NONMEM 7.2. RESULTS: A population pharmacokinetic model of midazolam in juvenile and adult mice was established. Postnatal age and current body weight were the most significant and positive covariates for clearance and volume of distribution. LPS dosage was the most significant and negative covariate for clearance. LPS dosage can significantly reduce the clearance of midazolam by 21.8% and 38.7% with 2 mg/kg and 5 mg/kg, respectively. Moreover, the magnitude of the reduction was higher in mice with advancing postnatal age. CONCLUSION: Both inflammation and ontogeny have an essential role in CYP3A activity in mice. The effect of LPS-induced systemic inflammation on midazolam clearance in mice is dependent on postnatal age.
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One of the fundamental laws in crystallization is translational symmetry, which accounts for the profound shapes observed in natural mineral crystals and snowflakes. Herein, we report on the spontaneous formation of spherical hollow crystals with broken translational symmetry in crystalline molecular bottlebrush (mBB) polymers. The unique structure is named as mBB crystalsome (mBBC), highlighting its similarity to the classical molecular vesicles. Fluorescence resonance energy transfer (FRET) experiments show that the mBBC formation is driven by local chain overcrowding-induced asymmetric lamella bending, which is further confirmed by correlating crystalsome size with crystallization temperature and mBB's side chain grafting density. Our study unravels a new principle of spontaneous translational symmetry breaking, providing a general route towards designing versatile nanostructures.
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Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Irinotecano/uso terapêutico , Docetaxel , Cisplatino/uso terapêutico , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Resultado do Tratamento , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêuticoRESUMO
The present study aimed to evaluate the expression of microRNA (miR)-421 in gastric cancer and to investigate its biological function and underlying mechanism of action in the development of gastric cancer. The expression of miR-421 was measured in 60 pairs of clinically removed gastric cancer tissues and matched adjacent normal gastric tissues by reverse transcription-quantitative polymerase chain reaction. In addition, following transfection with an miR-421 inhibitor to suppress the expression of miR-421, the proliferation, migration and cell cycle distribution of human gastric carcinoma MKN28/MKN74 cells were determined by cell counting, Transwell and flow cytometry assays. The target gene of miR-421 was also predicted using bioinformatic analysis and verified by dual-luciferase reporter gene assay and western blot analysis. Furthermore, overexpression of the miR-421 target protein was induced in MKN28/MKN74 cells to determine its function. It was observed that miR-421 was significantly upregulated in gastric cancer tissues and that the expression of miR-421 was associated with lymph node metastasis and the clinical stage of gastric cancer (all P<0.05). Claudin11 (CLDN11) was predicted and verified as a direct target of miR-421. In vitro experiments demonstrated that inhibition of miR-421 expression suppressed the proliferation and metastasis of MKN28/MKN74 cells and induced G1/S-phase cell cycle arrest (all P<0.05). Analagous results were observed in MKN28/MKN74 cells following overexpression of the CLDN11 protein. Collectively, these data suggest that miR-421 may promote the proliferation, invasion and metastasis of gastric cancer by inhibiting the expression of CLDN11.