Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 173
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Circulation ; 148(21): 1691-1704, 2023 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-37850394

RESUMEN

BACKGROUND: Hypercontractility and arrhythmia are key pathophysiologic features of hypertrophic cardiomyopathy (HCM), the most common inherited heart disease. ß-Adrenergic receptor antagonists (ß-blockers) are the first-line therapy for HCM. However, ß-blockers commonly selected for this disease are often poorly tolerated in patients, where heart-rate reduction and noncardiac effects can lead to reduced cardiac output and fatigue. Mavacamten, myosin ATPase inhibitor recently approved by the US Food and Drug Administration, has demonstrated the ability to ameliorate hypercontractility without lowering heart rate, but its benefits are so far limited to patients with left ventricular (LV) outflow tract obstruction, and its effect on arrhythmia is unknown. METHODS: We screened 21 ß-blockers for their impact on myocyte contractility and evaluated the antiarrhythmic properties of the most promising drug in a ventricular myocyte arrhythmia model. We then examined its in vivo effect on LV function by hemodynamic pressure-volume loop analysis. The efficacy of the drug was tested in vitro and in vivo compared with current therapeutic options (metoprolol, verapamil, and mavacamten) for HCM in an established mouse model of HCM (Myh6R403Q/+ and induced pluripotent stem cell (iPSC)-derived cardiomyocytes from patients with HCM (MYH7R403Q/+). RESULTS: We identified that carvedilol, a ß-blocker not commonly used in HCM, suppresses contractile function and arrhythmia by inhibiting RyR2 (ryanodine receptor type 2). Unlike metoprolol (a ß1-blocker), carvedilol markedly reduced LV contractility through RyR2 inhibition, while maintaining stroke volume through α1-adrenergic receptor inhibition in vivo. Clinically available carvedilol is a racemic mixture, and the R-enantiomer, devoid of ß-blocking effect, retains the ability to inhibit both α1-receptor and RyR2, thereby suppressing contractile function and arrhythmias without lowering heart rate and cardiac output. In Myh6R403Q/+ mice, R-carvedilol normalized hyperdynamic contraction, suppressed arrhythmia, and increased cardiac output better than metoprolol, verapamil, and mavacamten. The ability of R-carvedilol to suppress contractile function was well retained in MYH7R403Q/+ iPSC-derived cardiomyocytes. CONCLUSIONS: R-enantiomer carvedilol attenuates hyperdynamic contraction, suppresses arrhythmia, and at the same time, improves cardiac output without lowering heart rate by dual blockade of α1-adrenergic receptor and RyR2 in mouse and human models of HCM. This combination of therapeutic effects is unique among current therapeutic options for HCM and may particularly benefit patients without LV outflow tract obstruction.


Asunto(s)
Cardiomiopatía Hipertrófica , Metoprolol , Humanos , Ratones , Animales , Carvedilol/farmacología , Carvedilol/uso terapéutico , Metoprolol/uso terapéutico , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Arritmias Cardíacas/tratamiento farmacológico , Arritmias Cardíacas/metabolismo , Antagonistas Adrenérgicos beta/farmacología , Antagonistas Adrenérgicos beta/uso terapéutico , Miocitos Cardíacos/metabolismo , Verapamilo/uso terapéutico , Receptores Adrenérgicos/metabolismo
2.
J Am Chem Soc ; 146(29): 20122-20132, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38985988

RESUMEN

Structure-function relationships of supported metal nanoparticle catalysts in the CO-assisted oxidation of ethane to ethanol were investigated. A rutile TiO2-supported Pt nanoparticle catalyst exhibited the highest ethanol production rate and selectivity. During the reaction, sequential changes in the geometric/electronic states and the particle size of the Pt nanoparticles were observed. The comparison of the catalytic performances of model catalysts with controlled metal-support interactions revealed that Pt0 nanoparticles of 2-3 nm with a high fraction of the surface Ptδ+ species are highly active for the oxidation of ethane to ethanol. The coadded CO plays a pivotal role not only in tuning the oxidation state of the surface Pt but also in producing H2O2, which is the true oxidant for the reaction. The supported Pt nanoparticle uses in situ-generated H2O2 to activate ethane, where the C2H5OOH intermediate is formed through a nonradical mechanism and subsequently converted to C2H5OH. This reaction occurs even at 50 °C with an apparent activation energy of 32 kJ mol-1. The present study sheds light on the usefulness of surface-engineered Pt nanoparticles for the low-temperature oxidation of ethane to ethanol.

3.
J Am Chem Soc ; 146(28): 19599-19608, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38952064

RESUMEN

Crystalline polyethylenes bearing carboxylic acid groups in the main chain were successfully degraded with a Ce catalyst and visible light. The reaction proceeds in a crystalline solid state without swelling in acetonitrile or water at a reaction temperature as low as 60 or 80 °C, employing dioxygen in air as the only stoichiometric reactant with nearly quantitative recovery of carbon atoms. Heterogeneous features of the reaction allowed us to reveal a dynamic morphological change of polymer crystals during the degradation.

4.
Oncology ; 102(2): 114-121, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37699374

RESUMEN

INTRODUCTION: Ovarian metastasis of colorectal cancer is known to have a poor prognosis. This study aimed to elucidate the characteristics of patients who underwent oophorectomy for ovarian metastasis from colorectal cancer. METHODS: This retrospective study included 16 patients who underwent oophorectomy for colorectal cancer metastasis to the ovary from January 2004 to December 2017. Improvement in patient's symptoms and pre- and postoperative changes in various nutritional and inflammatory indicators were assessed. Survival analysis and identification of prognostic factors were conducted with a median follow-up of 40.7 (5-109) months. RESULTS: Of 16 patients, 12 had (75%) synchronous and 4 (25%) had metachronous metastasis. Fourteen patients were symptomatic but symptoms resolved postoperatively. Thirteen patients (81.3%) had ascites and 5 (31.3%) had pleural effusion on preoperative computed tomography that disappeared after surgery in all cases. The median value of prognostic nutritional factor was significantly increased postoperatively (36.0 [preoperatively] vs. 47.5, p < 0.0001). The median (interquartile range) values for lymphocyte-C-reactive protein ratio were 715.2 (110-2,607) preoperatively and 6,095.2 (1,612.3-14,431.8) postoperatively (p = 0.0214). The median survival of the entire cohort was 60.4 months. The 3-year survival rates for R0 + R1 and R2 cases were 83% and 24% (p = 0.018), respectively. Univariate analysis showed that R2 resection and low postoperative lymphocyte-C-reactive protein ratio were associated with poor prognosis. CONCLUSIONS: Oophorectomy for ovarian metastasis from colorectal cancers was safely performed. It improved the patients' symptoms and nutritional status and may result in improved prognosis.


Asunto(s)
Adenocarcinoma , Neoplasias Colorrectales , Neoplasias Ováricas , Femenino , Humanos , Neoplasias Ováricas/cirugía , Estudios Retrospectivos , Proteína C-Reactiva , Estado Nutricional , Neoplasias Colorrectales/patología , Ovariectomía/métodos , Pronóstico , Adenocarcinoma/cirugía , Adenocarcinoma/secundario
5.
Int Immunol ; 35(5): 231-241, 2023 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-36521002

RESUMEN

CD8αα+ intestinal intraepithelial lymphocytes (iIELs) are known for their unique role in keeping the integrity of the intestinal epithelial barrier, but factors affecting the development of these cells have not been thoroughly understood. Here, we found that the transcriptional regulator interferon regulatory factor-2 (IRF-2) plays a cell-intrinsic, indispensable role in establishing iIEL populations. CD8αα+, but not CD8αß+, iIELs bearing TCRαß or TCRγδ were severely reduced in numbers in mice lacking this factor (Irf2-/- mice). Moreover, the majority of residual CD8αα+TCRαß+ iIELs in these mice was immature as judged from their Thy1.2high phenotype and inefficient T-bet expression. Thymic IEL precursors isolated from Irf2-/- mice failed to efficiently generate CD8αα+TCRαß+ and TCRγδ+ IELs upon transfer in vivo and CD8αα+TCRαß+ cells in response to IL-15 in vitro. Double mutant mice lacking both interleukin-15 (IL-15) and IRF-2 showed an even more severe iIEL defect than in mice lacking IL-15 alone. Upon increasing agonistic TCR signal strength through OT-II TCR transgenesis, CD8αα+TCRαß+ iIELs became more abundant but remained immature on the Irf2-/- background. Our current observations, thus, revealed the unique bimodal role that IRF-2 plays in promoting not only generation of IEL progenitors in the thymus but also maturation of iIELs in the periphery in IL-15-dependent and -independent manners.


Asunto(s)
Mucosa Intestinal , Linfocitos Intraepiteliales , Ratones , Animales , Antígenos CD8/metabolismo , Mucosa Intestinal/metabolismo , Linfocitos Intraepiteliales/metabolismo , Interleucina-15 , Transducción de Señal , Factor 2 Regulador del Interferón , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Linfocitos T CD8-positivos/metabolismo
6.
J Surg Oncol ; 129(5): 922-929, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38173362

RESUMEN

BACKGROUND AND OBJECTIVES: Robotic distal gastrectomy (RDG) has been widely performed throughout Japan since it became insured in 2018. This study aimed to evaluate the short-term outcomes of RDG and laparoscopic distal gastrectomy (LDG) for gastric cancer using real-world data. METHODS: A total of 4161 patients who underwent LDG (n = 3173) or RDG (n = 988) for gastric cancer between April 2018 and October 2022 were identified through the Japanese Diagnosis Procedure Combination Database, which covers 42 national university hospitals. The primary outcome was postoperative in-hospital mortality rate. The secondary outcomes were postoperative complication rates, time to diet resumption, and postoperative length of stay (LOS). RESULTS: In-hospital mortality and postoperative complication rates in the RDG group were comparable with those in the LDG group (0.1% vs. 0.0%, p = 1.000, and 8.7% vs. 8.2%, p = 0.693, respectively). RDG was associated with a longer duration of anesthesia (325 vs. 262 min, p < 0.001), similar time to diet resumption (3 vs. 3 days, p < 0.001), and shorter postoperative LOS (10 vs. 11 days, p < 0.001) compared with LDG. CONCLUSIONS: RDG was performed safely and provided shorter postoperative LOS, since it became covered by insurance in Japan.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Neoplasias Gástricas , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Japón/epidemiología , Pacientes Internos , Gastrectomía/métodos , Resultado del Tratamiento , Laparoscopía/métodos , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos
7.
Artículo en Inglés | MEDLINE | ID: mdl-39095055

RESUMEN

OBJECTIVES: This study evaluated the feasibility of a model-based iterative reconstruction technique (MBIR) tuned for the myocardium on myocardial computed tomography late enhancement (CT-LE). METHODS: Twenty-eight patients who underwent myocardial CT-LE and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) within 1 year were retrospectively enrolled. Myocardial CT-LE was performed using a 320-row CT with low tube voltage (80 kVp). Myocardial CT-LE images were scanned 7 min after CT angiography (CTA) without additional contrast medium. All myocardial CT-LE images were reconstructed with hybrid iterative reconstruction (HIR), conventional MBIR (MBIR_cardiac), and new MBIR tuned for the myocardium (MBIR_myo). Qualitative (5-grade scale) scores and quantitative parameters (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) were assessed as image quality. The sensitivity, specificity, and accuracy of myocardial CT-LE were evaluated at the segment level using an American Heart Association (AHA) 16-segment model, with LGE-MRI as a reference standard. These results were compared among the different CT image reconstructions. RESULTS: In 28 patients with 448 segments, 160 segments were diagnosed with positive by LGE-MRI. In the qualitative assessment of myocardial CT-LE, the mean image quality scores were 2.9 ± 1.2 for HIR, 3.0 ± 1.1 for MBIR_cardiac, and 4.0 ± 1.0 for MBIR_myo. MBIR_myo showed a significantly higher score than HIR (P < 0.001) and MBIR_cardiac (P = 0.018). In the quantitative image quality assessment of myocardial CT-LE, the median image SNR was 10.3 (9.1-11.1) for HIR, 10.8 (9.8-12.1) for MBIR_cardiac, and 16.8 (15.7-18.4) for MBIR_myo. The median image CNR was 3.7 (3.0-4.6) for HIR, 3.8 (3.2-5.1) for MBIR_cardiac, and 6.4 (5.0-7.7) for MBIR_myo. MBIR_myo significantly improved the SNR and CNR of CT-LE compared to HIR and MBIR_cardiac (P < 0.001). The sensitivity, specificity, and accuracy for the detection of myocardial CT-LE were 70%, 92%, and 84% for HIR; 71%, 92%, and 85% for MBIR_cardiac; and 84%, 92%, and 89% for MBIR_myo, respectively. MBIR_myo showed significantly higher image quality, sensitivity, and accuracy than the others (P < 0.05). CONCLUSIONS: MBIR tuned for myocardium improved image quality and diagnostic performance for myocardial CT-LE assessment.

8.
J Synchrotron Radiat ; 30(Pt 2): 368-378, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36891850

RESUMEN

X-ray fluorescence holography (XFH) is a powerful atomic resolution technique capable of directly imaging the local atomic structure around atoms of a target element within a material. Although it is theoretically possible to use XFH to study the local structures of metal clusters in large protein crystals, the experiment has proven difficult to perform, especially on radiation-sensitive proteins. Here, the development of serial X-ray fluorescence holography to allow the direct recording of hologram patterns before the onset of radiation damage is reported. By combining a 2D hybrid detector and the serial data collection used in serial protein crystallography, the X-ray fluorescence hologram can be directly recorded in a fraction of the measurement time needed for conventional XFH measurements. This approach was demonstrated by obtaining the Mn Kα hologram pattern from the protein crystal Photosystem II without any X-ray-induced reduction of the Mn clusters. Furthermore, a method to interpret the fluorescence patterns as real-space projections of the atoms surrounding the Mn emitters has been developed, where the surrounding atoms produce large dark dips along the emitter-scatterer bond directions. This new technique paves the way for future experiments on protein crystals that aim to clarify the local atomic structures of their functional metal clusters, and for other related XFH experiments such as valence-selective XFH or time-resolved XFH.


Asunto(s)
Holografía , Rayos X , Holografía/métodos , Fluorescencia , Proteínas , Radiografía , Cristalografía por Rayos X
9.
Anal Biochem ; 678: 115272, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37541642

RESUMEN

This study sought to develop a specific and sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for pharmacokinetic studies of dasatinib, a tyrosine kinase inhibitor. Anti-dasatinib antibodies were obtained from mice or rabbits by using two partial structures of dasatinib as haptens: 2-amino-N-(2-chloro-6-methylphenyl)-thiazole-5-carboxamide and 2-{4-(2-hydroxyethyl)-1-piperazinyl}-isonicotinic acid. The best combination of two antibodies for sandwich ELISA of dasatinib was determined using four anti-dasatinib antibodies derived from mice and rabbits. Using two dasatinib-specific rabbit antibodies, we successfully developed an ultra-specific and highly sensitive sandwich ELISA that is hardly affected by the main metabolite of dasatinib. The sandwich ELISA showed a linear detection range from 320 pg/mL to 1000 ng/mL. Serum dasatinib concentrations lower than 320 pg/mL were reproducibly measurable using the sandwich ELISA. The ELISA was specific to dasatinib and there were no cross-reactivities with the major metabolites 4'-hydroxy dasatinib and dasatinib carboxylic acid. The developed sandwich ELISA will be a valuable tool for pharmacokinetic studies of dasatinib. Furthermore, this study revealed that rabbit antibodies can sandwich drug molecules of a smaller size than mouse antibodies in sandwich ELISA.


Asunto(s)
Dasatinib , Inhibidores de Proteínas Quinasas , Animales , Ratones , Conejos , Anticuerpos , Ensayo de Inmunoadsorción Enzimática
10.
Int J Mol Sci ; 24(22)2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-38003303

RESUMEN

In our preliminary experiment, peritoneal sclerosis likely induced by peritoneal dialysis was unexpectedly observed in the livers of rats given bleomycin and lansoprazole. We examined whether this peritoneal thickening around the liver was time-dependently induced by administration of both drugs. Male Wistar rats were injected with bleomycin and/or lansoprazole for 2 or 4 weeks. The 3YB-1 cell line derived from rat fibroblasts was treated by bleomycin and/or lansoprazole for 24 h. The administration of both drugs together, but not individually, thickened the peritoneal tissue around the liver. There was accumulation of collagen fibers, macrophages, and eosinophils under mesothelial cells. Expressions of Col1a1, Mcp1 and Mcp3 genes were increased in the peritoneal tissue around the liver and in 3YB-1 cells by the administration of both drugs together, and Opn genes had increased expressions in this tissue and 3YB-1 cells. Mesothelial cells indicated immunoreactivity against both cytokeratin, a mesothelial cell marker, and αSMA, a fibroblast marker, around the livers of rats given both drugs. Administration of both drugs induced the migration of macrophages and eosinophils and induced fibrosis associated with the possible activation of fibroblasts and the possible promotion of the mesothelial-mesenchymal transition. This might become a novel model of peritoneal sclerosis for peritoneal dialysis.


Asunto(s)
Fibrosis Peritoneal , Ratas , Masculino , Animales , Fibrosis Peritoneal/inducido químicamente , Fibrosis Peritoneal/genética , Bleomicina/efectos adversos , Ratas Wistar , Lansoprazol/efectos adversos , Lansoprazol/metabolismo , Células Epiteliales/metabolismo , Peritoneo/patología
11.
Int J Cancer ; 150(7): 1184-1197, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-34913485

RESUMEN

Adult T-cell leukemia-lymphoma (ATL) is an aggressive neoplasm derived from T-cells transformed by human T-cell lymphotropic virus-1 (HTLV-1). Recently, we reported that regional DNA hypermethylation in HTLV-1-infected T-cells reflects the disease status of ATL and the anti-ATL effects of DNA demethylating agents, including azacitidine (AZA), decitabine (DAC) and a new DAC prodrug, OR-2100 (OR21), which we developed. Here, to better understand the mechanisms underlying drug resistance, we generated AZA-, DAC- and OR21-resistant (AZA-R, DAC-R and OR21-R, respectively) cells from the ATL cell line TL-Om1 and the HTLV-1-infected cell line MT-2 via long-term drug exposure. The efficacy of OR21 was almost the same as that of DAC, indicating that the pharmacodynamics of OR21 were due to release of DAC from OR21. Resistant cells did not show cellular responses observed in parental cells induced by treatment with drugs, including growth suppression, depletion of DNA methyltransferase DNMT1 and DNA hypomethylation. We also found that reduced expression of deoxycytidine kinase (DCK) correlated with lower susceptibility to DAC/OR21 and that reduced expression of uridine cytidine kinase2 (UCK2) correlated with reduced susceptibility to AZA. DCK and UCK2 catalyze phosphorylation of DAC and AZA, respectively; reconstitution of expression reversed the resistant phenotypes. A large homozygous deletion in DCK and a homozygous splice donor site mutation in UCK2 were identified in DAC-R TL-Om1 and AZA-R TL-Om1, respectively. Both genomic mutations might lead to loss of protein expression. Thus, inactivation of UCK2 and DCK might be a putative cause of phenotypes that are resistant to AZA and DAC/OR21, respectively.


Asunto(s)
Antineoplásicos/uso terapéutico , Metilación de ADN/efectos de los fármacos , Desoxicitidina Quinasa/fisiología , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Pirimidinas/metabolismo , Uridina Quinasa/fisiología , Azacitidina/uso terapéutico , Línea Celular Tumoral , Decitabina/uso terapéutico , Resistencia a Antineoplásicos , Humanos , Leucemia-Linfoma de Células T del Adulto/metabolismo , Piridinas/uso terapéutico
12.
Biochem Biophys Res Commun ; 618: 93-99, 2022 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-35716601

RESUMEN

Interaction among various adaptive, circulating cells and tissue-resident cells including innate lymphocytes during the establishment and maintenance of the barrier-tissue immune system has only recently started to be explored. Here, we show that the cellular crosstalk with circulating T cells and other resident cells regulated the population size of type 2 innate lymphoid cells (ILC2s) in the small intestine lamina propria. Rag1-/- mice had excessive numbers of both ILC2s and ILC3s, and such an over-expansion was corrected by establishing parabiosis with wild type mice or by adoptively transferring wild type CD4+ T cells. In contrast, anti-CD3 antibody-mediated T cell depletion in wild type mice increased ILC2 but not ILC3 numbers. Unconventional CD4-CD8- αß T and γδ T cells could also restrict ILC2 expansion as the numbers of ILC2s were not altered even in mice treated with anti-CD4/anti-CD8 antibodies. ILC3 restriction seemed to be through the control of proliferation, but that for ILC2s did not. In addition, elevation in ILC2 numbers seen in mice lacking the transcription factors RORγt and STAT6 was found to be T cell-independent. Our current findings altogether uncovered the homeostatic 'quota' restriction imposed on intestinal ILC2s in the steady state by resident non-T cells via RORγt- and STAT6-dependent mechanisms as well as by conventional and nonconventional T cells.


Asunto(s)
Inmunidad Innata , Linfocitos , Animales , Proliferación Celular , Citocinas , Intestino Delgado , Pulmón , Ratones , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares , Linfocitos T
13.
J Am Chem Soc ; 143(29): 10853-10859, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-34197100

RESUMEN

In recent years, London dispersion interactions, which are the attractive component of the van der Waals potential, have been found to play an important role in controlling the regio- and/or stereoselectivity of various reactions. Particularly, the dispersion interactions between substrates and catalysts (or ligands) are dominant in various selective catalyzes. In contrast, repulsive steric interactions, rather than the attractive dispersion interactions, between bulky substituents are predominant in most of the noncatalytic reactions. Herein, we demonstrate the first example of London dispersion-controlled noncatalytic (2 + 2) cyclodimerization of substituted benzynes to selectively afford proximal biphenylenes in high yields and regioselectivities, depending on the extent of dispersion interactions in the substituents. This method can be applied for the synthesis of novel helical biphenylenes, which would be fascinating for chemists as these compounds are potential skeletons for ligands, catalysts, and medicines.

14.
Nat Mater ; 19(5): 508-511, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31988514

RESUMEN

The diffusion of defects in crystalline materials1 controls macroscopic behaviour of a wide range of processes, including alloying, precipitation, phase transformation and creep2. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is dominated by de-trapping processes. It is generally believed that de-trapping occurs only by thermal activation. Here, we report the direct observation of the quantum de-trapping of defects below around one-third of the Debye temperature. We successfully monitored the de-trapping and migration of self-interstitial atom clusters, strongly trapped by impurity atoms in tungsten, by triggering de-trapping out of equilibrium at cryogenic temperatures, using high-energy electron irradiation and in situ transmission electron microscopy. The quantum-assisted de-trapping leads to low-temperature diffusion rates orders of magnitude higher than a naive classical estimate suggests. Our analysis shows that this phenomenon is generic to any crystalline material.

15.
Hepatology ; 71(5): 1609-1625, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31529722

RESUMEN

BACKGROUND AND AIMS: Dysfunctional hepatic lipid metabolism is a cause of nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disorder worldwide, and is closely associated with insulin resistance and type 2 diabetes. ELOVL fatty acid elongase 6 (Elovl6) is responsible for converting C16 saturated and monounsaturated fatty acids (FAs) into C18 species. We have previously shown that Elovl6 contributes to obesity-induced insulin resistance by modifying hepatic C16/C18-related FA composition. APPROACH AND RESULTS: To define the precise molecular mechanism by which hepatic Elovl6 affects energy homeostasis and metabolic disease, we generated liver-specific Elovl6 knockout (LKO) mice. Unexpectedly, LKO mice were not protected from high-fat diet-induced insulin resistance. Instead, LKO mice exhibited higher insulin sensitivity than controls when consuming a high-sucrose diet (HSD), which induces lipogenesis. Hepatic patatin-like phospholipase domain-containing protein 3 (Pnpla3) expression was down-regulated in LKO mice, and adenoviral Pnpla3 restoration reversed the enhancement in insulin sensitivity in HSD-fed LKO mice. Lipidomic analyses showed that the hepatic ceramide(d18:1/18:0) content was lower in LKO mice, which may explain the effect on insulin sensitivity. Ceramide(d18:1/18:0) enhances protein phosphatase 2A (PP2A) activity by interfering with the binding of PP2A to inhibitor 2 of PP2A, leading to Akt dephosphorylation. Its production involves the formation of an Elovl6-ceramide synthase 4 (CerS4) complex in the endoplasmic reticulum and a Pnpla3-CerS4 complex on lipid droplets. Consistent with this, liver-specific Elovl6 deletion in ob/ob mice reduced both hepatic ceramide(d18:1/18:0) and PP2A activity and ameliorated insulin resistance. CONCLUSIONS: Our study demonstrates the key role of hepatic Elovl6 in the regulation of the acyl-chain composition of ceramide and that C18:0-ceramide is a potent regulator of hepatic insulin signaling linked to Pnpla3-mediated NAFLD.


Asunto(s)
Ceramidas/metabolismo , Elongasas de Ácidos Grasos/fisiología , Resistencia a la Insulina/genética , Hígado/enzimología , Animales , Ceramidas/química , Sacarosa en la Dieta/administración & dosificación , Regulación hacia Abajo , Elongasas de Ácidos Grasos/genética , Ratones , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Fosfolipasas A2 Calcio-Independiente/metabolismo , Proteína Fosfatasa 2/metabolismo , Esfingosina N-Aciltransferasa/metabolismo
16.
Oncology ; 99(10): 632-640, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34280933

RESUMEN

INTRODUCTION: Patients with unresectable or recurrent gastric cancer who have an objective response (OR) to nivolumab monotherapy are expected to have a good long-term prognosis. However, the OR rate for nivolumab treatment is low at 11%, and there is a need for biomarkers to predict the treatment response. This study aimed to analyze the significance of systemic inflammation-related variables and clinicopathologic characteristics as predictive markers of response to nivolumab monotherapy in patients with advanced gastric cancer. METHODS: In this retrospective cohort study, we enrolled 71 consecutive patients who received nivolumab monotherapy for unresectable or recurrent gastric cancer. Receiver operating characteristic curve analysis was performed to determine the cutoff values of systemic inflammation-related variables, predictors of treatment response, and other prognostic factors related to nivolumab therapy. We focused on systemic inflammation-related variables measured before nivolumab induction and 2 weeks after its first administration and performed multivariate analysis to assess whether they could be used as prognostic factors. RESULTS: Multivariate analysis revealed that a lymphocyte-to-monocyte ratio (LMR) of ≤3.28 after 2 weeks of initial nivolumab treatment (2wLMR) is a statistically significant predictor of treatment response (p = 0.012). The progression-free survival (PFS) rate of patients with liver metastasis was significantly worse than that of the other patients (1-year PFS: 0.0 vs. 24.4%, respectively; p = 0.005). The overall survival (OS) of patients with a low 2wLMR was significantly longer than that in patients with a high 2wLMR (1-year OS: 37.4 vs. 18.9%, respectively; p = 0.022). CONCLUSIONS: Thus, the 2wLMR could be a useful biomarker to predict response to nivolumab treatment and the prognosis of unresectable and recurrent gastric cancer.


Asunto(s)
Linfocitos/patología , Neutrófilos/patología , Neoplasias Gástricas/sangre , Neoplasias Gástricas/tratamiento farmacológico , Adulto , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Nivolumab , Pronóstico , Estudios Retrospectivos , Neoplasias Gástricas/patología
17.
Biol Pharm Bull ; 44(10): 1565-1570, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34602567

RESUMEN

Sunitinib is an oral multi-targeted tyrosine kinase inhibitor approved for treating metastatic renal cell carcinoma. This study reports a specific and sensitive competitive enzyme-linked immunosorbent assay (ELISA) for the pharmacokinetic evaluation of sunitinib. Anti-sunitinib serum was obtained from mice by using N-(2-(diethylamino)ethyl)-5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxamide (DFPC) as a hapten, which has the same substructure as sunitinib, in order to avoid the effects of structural changes in the geometrical isomers of sunitinib. Enzyme labeling of sunitinib with horseradish peroxidase was similarly performed using DFPC. Serum sunitinib concentrations below the limit of quantification of 0.52 ng/mL were reproducibly measurable. This ELISA was specific for sunitinib (Z- and E-isomers) and showed very low cross-reactivity (0.094%) with its major metabolite, N-desethyl sunitinib. Its analytical applicability was demonstrated by a kinetic study with human liver microsomes. In addition, the levels of sunitinib measured by ELISA in a kinetic study with human liver microsomes were comparable with those measured by HPLC, and there was a strong correlation between the values determined by both methods (y = 1.065x - 51.2, R2 = 0.9804). The developed ELISA provides for the specific and sensitive quantification of sunitinib without the influence of its major metabolite or light-induced geometric isomers. This ELISA will be a valuable tool in pharmacokinetic studies of sunitinib.


Asunto(s)
Monitoreo de Drogas/métodos , Sunitinib/análisis , Animales , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Isomerismo , Luz/efectos adversos , Límite de Detección , Ratones , Microsomas Hepáticos , Modelos Animales , Sunitinib/química , Sunitinib/farmacocinética , Sunitinib/efectos de la radiación
18.
Int Heart J ; 62(1): 50-56, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33518666

RESUMEN

Diabetes mellitus (DM) is associated with an increased incidence of cardiovascular events and an elevated prevalence of sarcopenia. However, the relationship between cardiovascular events and sarcopenia in patients with DM remains unclear. This study examined this relationship and investigated the predictors of cardiovascular events in this population.This study enrolled 161 patients with DM and no history of cardiovascular diseases who were admitted to our hospital for the treatment of DM between September 2012 and December 2015. Patients were divided into sarcopenia and non-sarcopenia groups, and were followed until March 2019. The primary endpoint was major adverse cardiovascular events (MACE).The mean age was 65.9 ± 1.8 years old and the mean follow-up period was 4.1 ± 0.8 years. The log-rank test indicated that MACE differed significantly between the two groups (P < 0.0001). Multivariate Cox hazard analysis identified the cardio-ankle vascular index (CAVI) and handgrip strength as independent predictors of MACE (hazard ratio [HR] = 1.18, P = 0.039; and HR = 0.70, P = 0.016, respectively).Handgrip strength is an indicator of sarcopenia in diabetic patients, and together with CAVI it was independently associated with the incidence of MACE. This suggests that the handgrip strength test might be useful in the management of patients with DM at high risk of cardiovascular outcomes.


Asunto(s)
Enfermedades Cardiovasculares/mortalidad , Complicaciones de la Diabetes/mortalidad , Sarcopenia/mortalidad , Anciano , Enfermedades Cardiovasculares/complicaciones , Femenino , Estudios de Seguimiento , Fuerza de la Mano , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Sarcopenia/complicaciones
19.
Molecules ; 26(5)2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33652764

RESUMEN

Infection of hosts by morbilliviruses is facilitated by the interaction between viral hemagglutinin (H-protein) and the signaling lymphocytic activation molecule (SLAM). Recently, the functional importance of the n-terminal region of human SLAM as a measles virus receptor was demonstrated. However, the functional roles of this region in the infection process by other morbilliviruses and host range determination remain unknown, partly because this region is highly flexible, which has hampered accurate structure determination of this region by X-ray crystallography. In this study, we analyzed the interaction between the H-protein from canine distemper virus (CDV-H) and SLAMs by a computational chemistry approach. Molecular dynamics simulations and fragment molecular orbital analysis demonstrated that the unique His28 in the N-terminal region of SLAM from Macaca is a key determinant that enables the formation of a stable interaction with CDV-H, providing a basis for CDV infection in Macaca. The computational chemistry approach presented should enable the determination of molecular interactions involving regions of proteins that are difficult to predict from crystal structures because of their high flexibility.


Asunto(s)
Virus del Moquillo Canino/genética , Moquillo/genética , Enfermedades de los Perros/genética , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/genética , Animales , Química Computacional , Moquillo/virología , Virus del Moquillo Canino/patogenicidad , Enfermedades de los Perros/virología , Perros , Humanos , Macaca/virología , Mutación Puntual/genética , Unión Proteica/genética , Receptores Virales/genética , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/química , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/ultraestructura , Especificidad de la Especie , Linfocitos T/virología
20.
Med Mol Morphol ; 54(3): 227-236, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33864519

RESUMEN

We prepared a polyclonal antibody against a teicoplanin (TEIC)-bovine serum albumin conjugate that was specific to both conjugated and free forms of TEIC. We demonstrated that this antibody could be used to detect the time-dependent localization of TEIC in rat kidneys. Immunohistochemistry revealed immunoreactivity specifically in the microvilli and apical cytoplasm of epithelial cells in proximal tubule segments S1 and S2, 1 h after intravenous TEIC injection, with higher staining intensity in the S2 segments. The epithelial cells of S3 segments showed moderate immunostaining with a few cells exhibiting nuclear staining. Furthermore, we found that the distal tubules and collecting ducts contained both TEIC-positive and -negative cells. TEIC immunoreactivity decreased rapidly over time; only weak staining remained in the S3 segments, distal tubules, and collecting ducts 24 h after administration. No staining was detected 7 days after injection. These results were significantly different from those of our previous study obtained using vancomycin, which showed moderate staining in the proximal tubule segments S1 and S2, distal tubules, and the collecting ducts 8 days after administration. The lower TEIC accumulation in tissues may account for a lower risk of adverse events compared to that using vancomycin.


Asunto(s)
Anticuerpos , Inmunohistoquímica/métodos , Riñón/metabolismo , Teicoplanina/análisis , Teicoplanina/farmacocinética , Animales , Antibacterianos , Inyecciones Intravenosas , Ratas , Teicoplanina/administración & dosificación , Teicoplanina/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA