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1.
Cell ; 183(6): 1714-1731.e10, 2020 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-33275901

RESUMEN

Targeted protein degradation (TPD) refers to the use of small molecules to induce ubiquitin-dependent degradation of proteins. TPD is of interest in drug development, as it can address previously inaccessible targets. However, degrader discovery and optimization remains an inefficient process due to a lack of understanding of the relative importance of the key molecular events required to induce target degradation. Here, we use chemo-proteomics to annotate the degradable kinome. Our expansive dataset provides chemical leads for ∼200 kinases and demonstrates that the current practice of starting from the highest potency binder is an ineffective method for discovering active compounds. We develop multitargeted degraders to answer fundamental questions about the ubiquitin proteasome system, uncovering that kinase degradation is p97 dependent. This work will not only fuel kinase degrader discovery, but also provides a blueprint for evaluating targeted degradation across entire gene families to accelerate understanding of TPD beyond the kinome.


Asunto(s)
Proteínas Quinasas/metabolismo , Proteolisis , Proteoma/metabolismo , Adulto , Línea Celular , Bases de Datos de Proteínas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas Quinasas/genética , Proteómica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Adulto Joven
2.
Nature ; 631(8019): 134-141, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38867047

RESUMEN

Mosaic loss of the X chromosome (mLOX) is the most common clonal somatic alteration in leukocytes of female individuals1,2, but little is known about its genetic determinants or phenotypic consequences. Here, to address this, we used data from 883,574 female participants across 8 biobanks; 12% of participants exhibited detectable mLOX in approximately 2% of leukocytes. Female participants with mLOX had an increased risk of myeloid and lymphoid leukaemias. Genetic analyses identified 56 common variants associated with mLOX, implicating genes with roles in chromosomal missegregation, cancer predisposition and autoimmune diseases. Exome-sequence analyses identified rare missense variants in FBXO10 that confer a twofold increased risk of mLOX. Only a small fraction of associations was shared with mosaic Y chromosome loss, suggesting that distinct biological processes drive formation and clonal expansion of sex chromosome missegregation. Allelic shift analyses identified X chromosome alleles that are preferentially retained in mLOX, demonstrating variation at many loci under cellular selection. A polygenic score including 44 allelic shift loci correctly inferred the retained X chromosomes in 80.7% of mLOX cases in the top decile. Our results support a model in which germline variants predispose female individuals to acquiring mLOX, with the allelic content of the X chromosome possibly shaping the magnitude of clonal expansion.


Asunto(s)
Alelos , Cromosomas Humanos X , Mosaicismo , Humanos , Femenino , Cromosomas Humanos X/genética , Proteínas F-Box/genética , Cromosomas Humanos Y/genética , Predisposición Genética a la Enfermedad/genética , Deleción Cromosómica , Herencia Multifactorial/genética , Leucocitos/metabolismo , Mutación Missense/genética , Exoma/genética
3.
Nature ; 608(7921): 168-173, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35896748

RESUMEN

Multiple studies have established associations between human gut bacteria and host physiology, but determining the molecular mechanisms underlying these associations has been challenging1-3. Akkermansia muciniphila has been robustly associated with positive systemic effects on host metabolism, favourable outcomes to checkpoint blockade in cancer immunotherapy and homeostatic immunity4-7. Here we report the identification of a lipid from A. muciniphila's cell membrane that recapitulates the immunomodulatory activity of A. muciniphila in cell-based assays8. The isolated immunogen, a diacyl phosphatidylethanolamine with two branched chains (a15:0-i15:0 PE), was characterized through both spectroscopic analysis and chemical synthesis. The immunogenic activity of a15:0-i15:0 PE has a highly restricted structure-activity relationship, and its immune signalling requires an unexpected toll-like receptor TLR2-TLR1 heterodimer9,10. Certain features of the phospholipid's activity are worth noting: it is significantly less potent than known natural and synthetic TLR2 agonists; it preferentially induces some inflammatory cytokines but not others; and, at low doses (1% of EC50) it resets activation thresholds and responses for immune signalling. Identifying both the molecule and an equipotent synthetic analogue, its non-canonical TLR2-TLR1 signalling pathway, its immunomodulatory selectivity and its low-dose immunoregulatory effects provide a molecular mechanism for a model of A. muciniphila's ability to set immunological tone and its varied roles in health and disease.


Asunto(s)
Akkermansia , Homeostasis , Inmunidad , Fosfatidiletanolaminas , Akkermansia/química , Akkermansia/citología , Akkermansia/inmunología , Membrana Celular/química , Membrana Celular/inmunología , Citocinas/inmunología , Homeostasis/inmunología , Humanos , Mediadores de Inflamación/síntesis química , Mediadores de Inflamación/química , Mediadores de Inflamación/inmunología , Fosfatidiletanolaminas/síntesis química , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/inmunología , Relación Estructura-Actividad , Receptor Toll-Like 1/inmunología , Receptor Toll-Like 2/agonistas , Receptor Toll-Like 2/inmunología
4.
Mol Biol Evol ; 40(10)2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37903429

RESUMEN

Natural selection signatures across Japanese subpopulations are under-explored. Here we conducted genome-wide selection scans with 622,926 single nucleotide polymorphisms for 20,366 Japanese individuals, who were recruited from the main-islands of Japanese Archipelago (Hondo) and the Ryukyu Archipelago (Ryukyu), representing two major Japanese subpopulations. The integrated haplotype score (iHS) analysis identified several signals in one or both subpopulations. We found a novel candidate locus at IKZF2, especially in Ryukyu. Significant signals were observed in the major histocompatibility complex region in both subpopulations. The lead variants differed and demonstrated substantial allele frequency differences between Hondo and Ryukyu. The lead variant in Hondo tags HLA-A*33:03-C*14:03-B*44:03-DRB1*13:02-DQB1*06:04-DPB1*04:01, a haplotype specific to Japanese and Korean. While in Ryukyu, the lead variant tags DRB1*15:01-DQB1*06:02, which had been recognized as a genetic risk factor for narcolepsy. In contrast, it is reported to confer protective effects against type 1 diabetes and human T lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis. The FastSMC analysis identified 8 loci potentially affected by selection within the past 20-150 generations, including 2 novel candidate loci. The analysis also showed differences in selection patterns of ALDH2 between Hondo and Ryukyu, a gene recognized to be specifically targeted by selection in East Asian. In summary, our study provided insights into the selection signatures within the Japanese and nominated potential sources of selection pressure.


Asunto(s)
Pueblos del Este de Asia , Selección Genética , Humanos , Aldehído Deshidrogenasa Mitocondrial/genética , Alelos , Pueblo Asiatico/genética , Frecuencia de los Genes , Haplotipos , Polimorfismo de Nucleótido Simple , Selección Genética/genética , Japón
5.
J Virol ; 97(3): e0176322, 2023 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-36995092

RESUMEN

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi sarcoma (KS), the plasmablastic form of multicentric Castleman's disease, and primary effusion lymphoma. In sub-Saharan Africa, KS is the most common HIV-related malignancy and one of the most common childhood cancers. Immunosuppressed patients, including HIV-infected patients, are more prone to KSHV-associated disease. KSHV encodes a viral protein kinase (vPK) that is expressed from ORF36. KSHV vPK contributes to the optimal production of infectious viral progeny and upregulation of protein synthesis. To elucidate the interactions of vPK with cellular proteins in KSHV-infected cells, we used a bottom-up proteomics approach and identified host protein ubiquitin-specific peptidase 9X-linked (USP9X) as a potential interactor of vPK. Subsequently, we validated this interaction using a co-immunoprecipitation assay. We report that both the ubiquitin-like and the catalytic domains of USP9X are important for association with vPK. To uncover the biological relevance of the USP9X/vPK interaction, we investigated whether the knockdown of USP9X would modulate viral reactivation. Our data suggest that depletion of USP9X inhibits both viral reactivation and the production of infectious virions. Understanding how USP9X influences the reactivation of KSHV will provide insights into how cellular deubiquitinases regulate viral kinase activity and how viruses co-opt cellular deubiquitinases to propagate infection. Hence, characterizing the roles of USP9X and vPK during KSHV infection constitutes a first step toward identifying a potentially critical interaction that could be targeted by future therapeutics. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi sarcoma (KS), the plasmablastic form of multicentric Castleman's disease, and primary effusion lymphoma. In sub-Saharan Africa, KS is the most common HIV-related malignancy. KSHV encodes a viral protein kinase (vPK) that aids viral replication. To elucidate the interactions of vPK with cellular proteins in KSHV-infected cells, we used an affinity purification approach and identified host protein ubiquitin-specific peptidase 9X-linked (USP9X) as a potential interactor of vPK. Depletion of USP9X inhibits both viral reactivation and the production of infectious virions. Overall, our data suggest a proviral role for USP9X.


Asunto(s)
Herpesvirus Humano 8 , Sarcoma de Kaposi , Ubiquitina Tiolesterasa , Niño , Humanos , Enzimas Desubicuitinizantes , Herpesvirus Humano 8/fisiología , Infecciones por VIH/complicaciones , Linfoma de Efusión Primaria , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Sarcoma de Kaposi/metabolismo , Sarcoma de Kaposi/patología , Sarcoma de Kaposi/virología , Ubiquitina Tiolesterasa/genética , Proteínas Virales/genética
6.
Magn Reson Med ; 91(3): 1030-1042, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38013217

RESUMEN

PURPOSE: This study aimed to quantify T 2 * $$ {T}_2^{\ast } $$ for hyperpolarized [1-13 C]pyruvate and metabolites in the healthy human brain and renal cell carcinoma (RCC) patients at 3 T. METHODS: Dynamic T 2 * $$ {T}_2^{\ast } $$ values were measured with a metabolite-specific multi-echo spiral sequence. The dynamic T 2 * $$ {T}_2^{\ast } $$ of [1-13 C]pyruvate, [1-13 C]lactate, and 13 C-bicarbonate was estimated in regions of interest in the whole brain, sinus vein, gray matter, and white matter in healthy volunteers, as well as in kidney tumors and the contralateral healthy kidneys in a separate group of RCC patients. T 2 * $$ {T}_2^{\ast } $$ was fit using a mono-exponential function; and metabolism was quantified using pyruvate-to-lactate conversion rate maps and lactate-to-pyruvate ratio maps, which were compared with and without an estimated T 2 * $$ {T}_2^{\ast } $$ correction. RESULTS: The T 2 * $$ {T}_2^{\ast } $$ of pyruvate was shown to vary during the acquisition, whereas the T 2 * $$ {T}_2^{\ast } $$ of lactate and bicarbonate were relatively constant through time and across the organs studied. The T 2 * $$ {T}_2^{\ast } $$ of lactate was similar in gray matter (29.75 ± 1.04 ms), white matter (32.89 ± 0.9 ms), healthy kidney (34.61 ± 4.07 ms), and kidney tumor (33.01 ± 2.31 ms); and the T 2 * $$ {T}_2^{\ast } $$ of bicarbonate was different between whole-brain (108.17 ± 14.05 ms) and healthy kidney (58.45 ± 6.63 ms). The T 2 * $$ {T}_2^{\ast } $$ of pyruvate had similar trends in both brain and RCC studies, reducing from 75.56 ± 2.23 ms to 22.24 ± 1.24 ms in the brain and reducing from 122.72 ± 9.86 ms to 57.38 ± 7.65 ms in the kidneys. CONCLUSION: Multi-echo dynamic imaging can quantify T 2 * $$ {T}_2^{\ast } $$ and metabolism in a single integrated acquisition. Clear differences were observed in the T 2 * $$ {T}_2^{\ast } $$ of metabolites and in their behavior throughout the timecourse.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Humanos , Ácido Pirúvico/metabolismo , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/metabolismo , Carcinoma de Células Renales/patología , Bicarbonatos/metabolismo , Imagen por Resonancia Magnética/métodos , Encéfalo/metabolismo , Riñón/diagnóstico por imagen , Riñón/metabolismo , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Lactatos/metabolismo , Isótopos de Carbono/metabolismo
7.
Magn Reson Med ; 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38775035

RESUMEN

PURPOSE: Metabolite-specific balanced SSFP (MS-bSSFP) sequences are increasingly used in hyperpolarized [1-13C]Pyruvate (HP 13C) MRI studies as they improve SNR by refocusing the magnetization each TR. Currently, pharmacokinetic models used to fit conversion rate constants, kPL and kPB, and rate constant maps do not account for differences in the signal evolution of MS-bSSFP acquisitions. METHODS: In this work, a flexible MS-bSSFP model was built that can be used to fit conversion rate constants for these experiments. The model was validated in vivo using paired animal (healthy rat kidneys n = 8, transgenic adenocarcinoma of the mouse prostate n = 3) and human renal cell carcinoma (n = 3) datasets. Gradient echo (GRE) acquisitions were used with a previous GRE model to compare to the results of the proposed GRE-bSSFP model. RESULTS: Within simulations, the proposed GRE-bSSFP model fits the simulated data well, whereas a GRE model shows bias because of model mismatch. For the in vivo datasets, the estimated conversion rate constants using the proposed GRE-bSSFP model are consistent with a previous GRE model. Jointly fitting the lactate T2 with kPL resulted in less precise kPL estimates. CONCLUSION: The proposed GRE-bSSFP model provides a method to estimate conversion rate constants, kPL and kPB, for MS-bSSFP HP 13C experiments. This model may also be modified and used for other applications, for example, estimating rate constants with other hyperpolarized reagents or multi-echo bSSFP.

8.
Magn Reson Med ; 92(2): 702-714, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38525680

RESUMEN

PURPOSE: This study aimed to develop a new high-resolution MRI sequence for the imaging of the ultra-short transverse relaxation time (uT2) components in the brain, while simultaneously providing proton density (PD) contrast for reference and quantification. THEORY: The sequence combines low flip angle balanced SSFP (bSSFP) and UTE techniques, together with a 3D dual-echo rosette k-space trajectory for readout. METHODS: The expected image contrast was evaluated by simulations. A study cohort of six healthy volunteers and eight multiple sclerosis (MS) patients was recruited to test the proposed sequence. Subtraction between two TEs was performed to extract uT2 signals. In addition, conventional longitudinal relaxation time (T1) weighted, T2-weighted, and PD-weighted MRI sequences were also acquired for comparison. RESULTS: Typical PD-contrast was found in the second TE images, while uT2 signals were selectively captured in the first TE images. The subtraction images presented signals primarily originating from uT2 components, but only if the first TE is short enough. Lesions in the MS subjects showed hyperintense signals in the second TE images but were hypointense signals in the subtraction images. The lesions had significantly lower signal intensity in subtraction images than normal white matter (WM), which indicated a reduction of uT2 components likely associated with myelin. CONCLUSION: 3D isotropic sub-millimeter (0.94 mm) spatial resolution images were acquired with the novel bSSFP UTE sequence within 3 min. It provided easy extraction of uT2 signals and PD-contrast for reference within a single acquisition.


Asunto(s)
Encéfalo , Imagenología Tridimensional , Imagen por Resonancia Magnética , Esclerosis Múltiple , Humanos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Esclerosis Múltiple/diagnóstico por imagen , Adulto , Masculino , Femenino , Algoritmos , Persona de Mediana Edad , Procesamiento de Imagen Asistido por Computador/métodos , Interpretación de Imagen Asistida por Computador/métodos , Voluntarios Sanos , Simulación por Computador
9.
Phys Chem Chem Phys ; 26(23): 16477-16487, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38656815

RESUMEN

In this work we develop a new scheme to construct a diabatic potential energy matrix (DPEM). We propose a diabatization method which is based on integrating the diabatic potential gradient difference to diabatize adiabatic ab initio energies. This method is capable of performing high-precision adiabatic-to-diabatic transformations, with a unique advantage in effectively handling the significant fluctuations in derivative-couplings caused by conical intersection (CI) seams. The above scheme is applied to the DPEM construction of the Na(3p) + H2 → NaH + H reaction. The fitting data including adiabatic energies, energy gradients and derivative-couplings obtained from a previous benchmark DPEM are diabatized and fitted using a general neural network fitting procedure to generate the DPEM. The produced DPEM can effectively describe nonadiabatic processes involving different electronic states. We further perform quantum dynamical calculations on the new DPEM and the previous benchmark DPEM, and the obtained results demonstrate the effectiveness of our scheme.

10.
Cardiol Young ; 34(1): 201-204, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37990583

RESUMEN

Danon disease is a rare X-linked disorder caused by deficiency of the lysosome-associated membrane protein-2. We report a case of hypertrophic obstructive cardiomyopathy secondary to a novel mutation in the lysosome-associated membrane protein-2 gene in a 10-year-old male adolescent. We performed a modified extended Morrow procedure to minimise the risk of death and improve the patient's quality of life. The patient did not have exertional dyspnoea, and auscultation did not reveal a cardiac murmur at 1-year follow-up.


Asunto(s)
Cardiomiopatía Hipertrófica , Enfermedad por Depósito de Glucógeno de Tipo IIb , Masculino , Adolescente , Humanos , Niño , Enfermedad por Depósito de Glucógeno de Tipo IIb/complicaciones , Enfermedad por Depósito de Glucógeno de Tipo IIb/diagnóstico , Enfermedad por Depósito de Glucógeno de Tipo IIb/genética , Calidad de Vida , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/genética
11.
Nano Lett ; 23(24): 11793-11801, 2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38055779

RESUMEN

The chiral nature of active matter plays an important role in the dynamics of active matter interacting with chiral structures. Skyrmions are chiral objects, and their interactions with chiral nanostructures can lead to intriguing phenomena. Here, we explore the random-walk dynamics of a thermally activated chiral skyrmion interacting with a chiral flower-like obstacle in a ferromagnetic layer, which could create topology-dependent outcomes. It is a spontaneous mesoscopic order-from-disorder phenomenon driven by the thermal fluctuations and topological nature of skyrmions that exists only in ferromagnetic and ferrimagnetic systems. The interactions between the skyrmions and chiral flowers at finite temperatures can be utilized to control the skyrmion position and distribution without applying any external driving force or temperature gradient. The phenomenon that thermally activated skyrmions are dynamically coupled to chiral flowers may provide a new way to design topological sorting devices.

12.
Matern Child Nutr ; 20(3): e13653, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38624183

RESUMEN

Maternal anaemia is a major public health problem. Developing maternal anaemia prevention and control policies is an important prerequisite for carrying out evidence-based interventions. This article reviews maternal anaemia prevention and control policies in China, identifies gaps, and provides references for other countries. We examined policies concerning maternal nutrition and other related literature in China, identified through key databases and government websites, and conducted a narrative review of the relevant documentations guided by the Smith Policy-Implementing-Process framework. A total of 65 articles and documents were identified for analysis. We found that Chinese government has committed to reducing maternal anaemia at the policy level, with established objectives and a clear time frame. However, most of policies were not accompanied by operational guidelines, standardized interventions, and vigorous monitoring and evaluation mechanisms, and 85% of the policies don't have quantifiable objectives on anaemia. Maternal anaemia prevention and control services offered in clinical settings were primarily nutrition education and anaemia screening. Population-based interventions such as iron fortification have yet to be scaled up. Furthermore, medical insurance schemes in some regions do not cover anaemia prevention and treatment, and in other regions that offer coverage, the reimbursement rate is low. The number and capacity of health professionals is also limited. Policy changes should focus on the integration of evidence-based interventions into routine antenatal care services and public health service packages, standardization of dosages and provision of iron supplementation, streamline of reimbursement for outpatient expenses, and capacity building of health professionals.


Asunto(s)
Anemia , Política de Salud , Humanos , Femenino , China , Embarazo , Anemia/prevención & control , Política de Salud/legislación & jurisprudencia , Atención Prenatal , Fenómenos Fisiologicos Nutricionales Maternos , Política Nutricional/legislación & jurisprudencia , Anemia Ferropénica/prevención & control , Complicaciones Hematológicas del Embarazo/prevención & control
13.
J Antimicrob Chemother ; 78(4): 991-999, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-36775998

RESUMEN

BACKGROUND: Nacubactam, a new ß-lactamase inhibitor with antibacterial activity, is being developed as a single drug to be co-administered with cefepime or aztreonam. However, determining pharmacokinetics/pharmacodynamics (PK/PD) parameters in ß-lactam/ß-lactamase inhibitor combinations remains challenging. We aimed to establish a practical PK/PD analysis method for aztreonam/nacubactam that incorporates instantaneous MIC (MICi). METHODS: Based on chequerboard MIC measurements, MICi of aztreonam against carbapenemase-producing Klebsiella pneumoniae in the presence of nacubactam was simulated. RESULTS: The mean change in the bacterial count of thigh-infected mice in an in vivo PD study was plotted based on %fT>MICi and analysed using the inhibitory effect sigmoid Imax model. fT>MICi calculated from the PK experiments showed a high correlation with the in vivo bactericidal effect, suggesting that fT>MICi is the optimal PK/PD parameter for aztreonam/nacubactam. The target values of fT>MICi achieving growth inhibition, 1 log10 kill and 2 log10 kill, were 22, 38% and 75%, respectively. CONCLUSIONS: The PK/PD analysis method proposed in this study is promising for determining practical PK/PD parameters in combination therapy. In addition, this is the first report of aztreonam/nacubactam showing a potent in vivo therapeutic effect against NDM-producing K. pneumoniae.


Asunto(s)
Aztreonam , Inhibidores de beta-Lactamasas , Animales , Ratones , Aztreonam/farmacología , Inhibidores de beta-Lactamasas/farmacología , Klebsiella pneumoniae , Antibacterianos/farmacología , beta-Lactamasas/farmacología , Compuestos de Azabiciclo/farmacología , Pruebas de Sensibilidad Microbiana
14.
Phys Rev Lett ; 130(10): 106701, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36962022

RESUMEN

We propose a skyrmion-based universal quantum computer. Skyrmions have the helicity degree of freedom in frustrated magnets, where twofold degenerated Bloch-type skyrmions are energetically favored by the magnetic dipole-dipole interaction. We construct a qubit based on them. A skyrmion must become a quantum-mechanical object when its size is of the order of nanometers. It is shown that the universal quantum computation is possible based on nanoscale skyrmions in a magnetic bilayer system. The one-qubit quantum gates are materialized by controlling the electric field and the spin current. The two-qubit gate is materialized with the use of the Ising-type exchange coupling. The merit of the present mechanism is that external magnetic field is not necessary. Our results may open a possible way toward universal quantum computation based on nanoscale topological spin textures.

15.
Pharm Res ; 40(1): 187-196, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36329373

RESUMEN

PURPOSE: Vancomycin-resistant enterococci (VRE) have recently become a major cause of nosocomial infections and a global public health concern. Tedizolid exhibits powerful antibacterial activity against VRE in vitro, but its pharmacokinetic/pharmacodynamic (PK/PD) parameters remain unclear. Therefore, we aimed to determine the PK/PD indices of tedizolid action on VRE and the mechanisms underlying the PK/PD indices differences of tedizolid against VRE and methicillin-resistant Staphylococcus aureus (MRSA). METHODS: Optimal PK/PD target values of tedizolid were determined in vitro, based on time-kill curves and post-antibiotic effects (PAEs), and in vivo, using mouse models of thigh infection with VRE and MRSA strains. RESULTS: The tedizolid bactericidal activity on VRE and MRSA was time-dependent. Correlations were closest between fAUC24/MIC and the tedizolid PK/PD index against MRSA and VRE. To achieve 1 log10 kill tedizolid fAUC24/MIC in neutropenic mouse models of thigh infection with VRE and MRSA should be 14.2 and 138.5, respectively. The PAEs of tedizolid against VRE and MRSA were 2.39 and 0.99 h, respectively. CONCLUSION: Tedizolid showed bactericidal effects against VRE even in neutropenic mice unlike MRSA, which could be attributed to its longer PAE against VRE. Hence, we hypothesize that tedizolid treatment against VRE infections is promising for achieving therapeutic success in clinical.


Asunto(s)
Infecciones por Bacterias Grampositivas , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Enterococos Resistentes a la Vancomicina , Animales , Ratones , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología
16.
Pharm Res ; 40(7): 1789-1797, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37253866

RESUMEN

PURPOSE: Cefditoren, the active form of cefditoren pivoxil, is an oral cephalosporin antimicrobial drug. Although cefditoren exhibits high antimicrobial activity against Streptococcus pneumoniae, its pharmacokinetics/pharmacodynamics (PK/PD) characteristics remain unknown. This study aimed to determine its PK/PD parameter with target values for cefditoren against S. pneumoniae in S. pneumoniae lung-infected mice and to simulate MIC range of S. pneumoniae that can be expected to be treated at approved cefditoren doses in human using population pharmacokinetic (PPK) data from patients. METHODS: Susceptibility testing and time-kill assays against S. pneumoniae ATCC® 49619 were performed for in vitro PD evaluation. Based on the results of a PK study in healthy mice and PD studies in S. pneumoniae lung-infected mice, optimal PK/PD parameters were determined using the correlation curve between the PK/PD parameters and lung bacterial count changes. The target value was calculated to achieve a 2 log10 reduction in the lung bacterial counts. RESULTS: In vitro PD evaluation showed that cefditoren had a potent antimicrobial effect against S. pneumoniae in a time-dependent manner at concentrations above the MIC. In PK/PD analyses, both fAUC24/MIC and fCmax/MIC were well correlated with bactericidal efficacy, achieving 2 log10-kill with fAUC24/MIC ≥ 63 and fCmax/MIC ≥ 16. CONCLUSIONS: Cefditoren pivoxil has good therapeutic efficacy against acute pneumonia caused by S. pneumoniae with a MIC ≤ 0.031-0.063 mg/L at approved doses in adults and children.


Asunto(s)
Antiinfecciosos , Neumonía , Infecciones Estafilocócicas , Niño , Humanos , Ratones , Animales , Streptococcus pneumoniae , Infecciones Estafilocócicas/tratamiento farmacológico , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pulmón , Antiinfecciosos/farmacología , Pruebas de Sensibilidad Microbiana
17.
Pharm Res ; 40(10): 2423-2431, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37783926

RESUMEN

PURPOSE: Nacubactam (NAC) is a novel diazabicyclooctane ß-lactamase inhibitor used in combination with cefepime (CFPM). In this study, we aimed to determine the target pharmacokinetics (PK) and pharmacodynamics (PD) values of CFPM/NAC in mice infected with ß-lactamase-producing Enterobacterales, such as the carbapenemase-producing Enterobacterales. METHODS: Three strains of ß-lactamase-producing Enterobacterales, Klebsiella pneumoniae MSC 21444, Escherichia coli MSC 20662, and K. pneumoniae ATCC BAA-1898, were used for checkerboard assays and fractionation studies and dose-range studies. A PK study was performed in neutropenic mice. Additionally, PK/PD analysis was performed based on the instantaneous minimum inhibitory concentration (MICi) concept. RESULTS: Checkerboard measurements revealed that higher NAC concentrations decreased the CFPM MIC in a concentration-dependent manner. In all tested strains, fT > MICi calculated from the PK experiments showed a high correlation with the mean change in the bacterial count of thigh-infected mice in the in vivo PD study, suggesting that fT > MICi is an optimal PK/PD parameter for monitoring the CFPM/NAC combination. The target fT > MICi values for CFPM/NAC to achieve a bacteriostatic effect, 1-log10-kill, and 2-log10-kill values were 30, 49, and 94%, respectively. CONCLUSIONS: Our results indicate that fT > MICi is a PK/PD parameter is suitable for monitoring the CFPM/NAC combination. The minimum target value for achieving a static effect against ß-lactamase-producing Enterobacterales is 30%.


Asunto(s)
Antibacterianos , Klebsiella pneumoniae , Animales , Ratones , Cefepima/farmacología , Antibacterianos/uso terapéutico , Antibacterianos/farmacocinética , beta-Lactamasas , Escherichia coli , Pruebas de Sensibilidad Microbiana
18.
J Cardiovasc Magn Reson ; 25(1): 77, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38093285

RESUMEN

BACKGROUND: The heart has metabolic flexibility, which is influenced by fed/fasting states, and pathologies such as myocardial ischemia and hypertrophic cardiomyopathy (HCM). Hyperpolarized (HP) 13C-pyruvate MRI is a promising new tool for non-invasive quantification of myocardial glycolytic and Krebs cycle flux. However, human studies of HP 13C-MRI have yet to demonstrate regional quantification of metabolism, which is important in regional ischemia and HCM patients with asymmetric septal/apical hypertrophy. METHODS: We developed and applied methods for whole-heart imaging of 13C-pyruvate, 13C-lactate and 13C-bicarbonate, following intravenous administration of [1-13C]-pyruvate. The image acquisition used an autonomous scanning method including bolus tracking, real-time magnetic field calibrations and metabolite-specific imaging. For quantification of metabolism, we evaluated 13C metabolite images, ratio metrics, and pharmacokinetic modeling to provide measurements of myocardial lactate dehydrogenase (LDH) and pyruvate dehydrogenase (PDH) mediated metabolic conversion in 5 healthy volunteers (fasting & 30 min following oral glucose load). RESULTS: We demonstrate whole heart coverage for dynamic measurement of pyruvate-to-lactate conversion via LDH and pyruvate-to-bicarbonate conversion via PDH at a resolution of 6 × 6 × 21 mm3 (13C-pyruvate) and 12 × 12 × 21 mm3 (13C-lactate, 13C-bicarbonate). 13C-pyruvate and 13C-lactate were detected simultaneously in the RV blood pool, immediately after intravenous injection, reflecting LDH activity in blood. In healthy volunteers, myocardial 13C-pyruvate-SNR, 13C-lactate-SNR, 13C-bicarbonate-SNR, 13C-lactate/pyruvate ratio, 13C-pyruvate-to-lactate conversion rate, kPL, and 13C-pyruvate-to-bicarbonate conversion rate, kPB, all had statistically significant increases following oral glucose challenge. kPB, reflecting PDH activity and pyruvate entering the Krebs Cycle, had the highest correlation with blood glucose levels and was statistically significant. CONCLUSIONS: We demonstrate first-in-human regional quantifications of cardiac metabolism by HP 13C-pyruvate MRI that aims to reflect LDH and PDH activity.


Asunto(s)
Bicarbonatos , Ácido Pirúvico , Humanos , Valor Predictivo de las Pruebas , Imagen por Resonancia Magnética/métodos , Glucosa , Ácido Láctico/metabolismo , Isótopos de Carbono
19.
J Infect Chemother ; 29(11): 1088-1090, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37453465

RESUMEN

Tedizolid (TZD) is an oxazolidinone anti-methicillin-resistant Staphylococcus aureus (MRSA) drug. Linezolid (LZD), another oxazolidinone, has been shown to have an anti-inflammatory effect. TZD has been shown to exhibit an anti-inflammatory effect in a murine model of hematogenous pulmonary infection. In this study, we further investigated the anti-inflammatory effect of TZDs using a carrageenan-induced rat footpad edema model. TZD was administered at 0, 10, 20, and 40 mg/kg to the carrageenan-induced rat footpad edema model, and the edema rate was measured over time up to 9 h later. The area under the time curve of the edema rate profile (AUCedema0→9) decreased in a TZD dose-dependent manner. In addition, the correlation between AUCedema0→9 and the area under the time curve of free TZD plasma concentration (fAUCblood) obtained from the pharmacokinetic study of TZD in the carrageenan-induced rat footpad edema model was examined. fAUCblood and AUCedema0→9 showed a good negative correlation. These results indicate that TZD suppresses carrageenan-induced footpad edema and that TZD exerts its anti-inflammatory effects in a plasma concentration-dependent manner.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Oxazolidinonas , Ratas , Ratones , Animales , Antibacterianos/uso terapéutico , Carragenina/farmacología , Oxazolidinonas/uso terapéutico , Oxazolidinonas/farmacocinética , Edema/inducido químicamente , Edema/tratamiento farmacológico , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico
20.
PLoS Genet ; 16(8): e1008915, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32776928

RESUMEN

Sequences homologous to human herpesvirus 6 (HHV-6) are integrated within the nuclear genome of about 1% of humans, but it is not clear how this came about. It is also uncertain whether integrated HHV-6 can reactivate into an infectious virus. HHV-6 integrates into telomeres, and this has recently been associated with polymorphisms affecting MOV10L1. MOV10L1 is located on the subtelomere of chromosome 22q (chr22q) and is required to make PIWI-interacting RNAs (piRNAs). As piRNAs block germline integration of transposons, piRNA-mediated repression of HHV-6 integration has been proposed to explain this association. In vitro, recombination of the HHV-6 genome along its terminal direct repeats (DRs) leads to excision from the telomere and viral reactivation, but the expected "solo-DR scar" has not been described in vivo. Here we screened for integrated HHV-6 in 7,485 Japanese subjects using whole-genome sequencing (WGS). Integrated HHV-6 was associated with polymorphisms on chr22q. However, in contrast to prior work, we find that the reported MOV10L1 polymorphism is physically linked to an ancient endogenous HHV-6A variant integrated into the telomere of chr22q in East Asians. Unexpectedly, an HHV-6B variant has also endogenized in chr22q; two endogenous HHV-6 variants at this locus thus account for 72% of all integrated HHV-6 in Japan. We also report human genomes carrying only one portion of the HHV-6B genome, a solo-DR, supporting in vivo excision and possible viral reactivation. Together these results explain the recently-reported association between integrated HHV-6 and MOV10L1/piRNAs, suggest potential exaptation of HHV-6 in its coevolution with human chr22q, and clarify the evolution and risk of reactivation of the only intact (non-retro)viral genome known to be present in human germlines.


Asunto(s)
Genoma Humano , Herpesvirus Humano 6/genética , Integración Viral , Pueblo Asiatico/genética , Cromosomas Humanos Par 22/genética , Evolución Molecular , Mutación de Línea Germinal , Humanos , Polimorfismo de Nucleótido Simple , ARN Interferente Pequeño/genética
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