Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
J Phys Chem B ; 128(1): 20-32, 2024 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-38133567

RESUMEN

Proteins exhibit conformational fluctuations and changes over various time scales, ranging from rapid picosecond-scale local atomic motions to slower microsecond-scale global conformational transformations. In the presence of these intricate fluctuations, chemical reactions occur and functions emerge. These conformational fluctuations of proteins are not merely stochastic random motions but possess distinct spatiotemporal characteristics. Moreover, chemical reactions do not always proceed along a single reaction coordinate in a quasi-equilibrium manner. Therefore, it is essential to understand spatiotemporal conformational fluctuations of proteins and the conformational change processes associated with reactions. In this Perspective, we shed light on the complex dynamics of proteins and their role in enzyme catalysis by presenting recent results regarding dynamic couplings and disorder in the conformational dynamics of proteins and rare but rapid enzymatic reaction events obtained from molecular dynamics simulations.


Asunto(s)
Simulación de Dinámica Molecular , Proteínas , Conformación Proteica , Catálisis
3.
Chemphyschem ; 23(22): e202200109, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-35818319

RESUMEN

In bacteriorhodopsin, representative light-driven proton pump, five proton transfers yield vectorial active proton translocation, resulting in a proton gradient in microbes. Third proton transfer occurs from Asp96 to the Schiff base on the photocycle, which is expected to be a long-range proton transfer via the Grotthuss mechanism through internal water molecules. Here, large-scale quantum molecular dynamics simulations are performed for the third proton transfer, where all the atoms (∼50000 atoms) are treated quantum-mechanically. The simulations demonstrate that two reaction paths exist along the water wire, namely, via hydronium and via hydroxide ions. The free energy analysis confirms that the path via hydroxide ions is considerably favorable and consistent with the observed lifetime of the transient water wire. Therefore, the proposed hydroxide ion mechanism, as in the first proton transfer, is responsible for the third long-range proton transfer.


Asunto(s)
Bacteriorodopsinas , Bacteriorodopsinas/química , Protones , Bombas de Protones , Agua/química
4.
Chem Phys Lett ; 794: 139489, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35221345

RESUMEN

The main protease (Mpro) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) catalyzes the cleavage of polyproteins for viral replication. Here, large-scale quantum molecular dynamics and metadynamics simulations for ligand-free Mpro were performed, where all the atoms were treated quantum-mechanically, focusing on elucidation of the controversial active-site protonation state. The simulations clarified that the interconverting multiple protonation states exist in unliganded Mpro, and the catalytically relevant ion-pair state is more stable than the neutral state, which is consistent with neutron crystallography. The results highlight the importance of the ion-pair state for repurposing or discovering antiviral drugs that target Mpro.

5.
J Phys Chem B ; 125(39): 10947-10963, 2021 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-34582194

RESUMEN

Bacteriorhodopsin (BR) transports a proton from intracellular to extracellular (EC) sites through five proton transfers. The second proton transfer is the release of an excess proton stored in BR into the EC medium, and an atomistic understanding of this whole process has remained unexplored due to its ubiquitous environment. Here, fully quantum mechanical (QM) molecular dynamics (MD) and metadynamics (MTD) simulations for this process were performed at the divide-and-conquer density-functional tight-binding level using realistic models (∼50000 and ∼20000 atoms) based on the time-resolved photointermediate structures from an X-ray free electron laser. Regarding the proton storage process, the QM-MD/MTD simulations confirmed the Glu-shared mechanism, in which an excess proton is stored between Glu194 and Glu204, and clarified that the activation occurs by localizing the proton at Glu204 in the photocycle. Furthermore, the QM-MD/MTD simulations elucidated a release pathway from Glu204 through Ser193 to the EC water molecules and clarified that the proton release starts at ∼250 µs. In the ubiquitous proton diffusion in the EC medium, the transient proton receptors predicted experimentally were assigned to carboxylates in Glu9 and Glu74. Large-scale QM-MD/MTD simulations beyond the conventional sizes, which provided the above findings and confirmations, were possible by adopting our Dcdftbmd program.


Asunto(s)
Bacteriorodopsinas , Simulación de Dinámica Molecular , Protones , Agua
6.
J Phys Chem B ; 124(39): 8524-8539, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32877195

RESUMEN

Bacteriorhodopsin (BR) is a model protein for light-driven proton pumps, where the vectorial active proton transport results in light-energy conversion. To clarify the microscopic mechanism of primary proton transfer from retinal Schiff base (SB) to Asp85 in BR, herein, we performed quantum-mechanical metadynamics simulations with the isolated BR model (∼3750 atoms). The simulations showed a novel proton transfer mechanism, viz. the hydroxide ion mechanism, in which the deprotonation of specific internal water (Wat452) yields the protonation of Asp85 via Thr89, after which the resulting hydroxide ion accepts the remaining proton from retinal SB. Systematic investigations adopting four sequential snapshots obtained by the time-resolved serial femtosecond crystallography revealed that proton transfer took 2-5.25 µs on the photocycle. The presence of Wat401, which is the main difference between snapshots at 2 and 5.25 µs, is found to be essential in assisting the primary proton transfer. Furthermore, the hydroxide ion mechanism was confirmed by the minimum energy path for the primary proton transfer in BR obtained by the nudged elastic band calculations with the embedded BR model (10,119 atoms), in which BR was embedded within lipid membranes in between water solvents.


Asunto(s)
Bacteriorodopsinas , Hidróxidos , Bombas de Protones , Protones , Bases de Schiff
7.
Angew Chem Int Ed Engl ; 58(24): 8024-8028, 2019 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-30951223

RESUMEN

Alkaline metals are an ideal negative electrode for rechargeable batteries. Forming a fluorine-rich interphase by a fluorinated electrolyte is recognized as key to utilizing lithium metal electrodes, and the same strategy is being applied to sodium metal electrodes. However, their reversible plating/stripping reactions have yet to be achieved. Herein, we report a contrary concept of fluorine-free electrolytes for sodium metal batteries. A sodium tetraphenylborate/monoglyme electrolyte enables reversible sodium plating/stripping at an average Coulombic efficiency of 99.85 % over 300 cycles. Importantly, the interphase is composed mainly of carbon, oxygen, and sodium elements with a negligible presence of fluorine, but it has both high stability and extremely low resistance. This work suggests a new direction for stabilizing sodium metal electrodes via fluorine-free interphases.

8.
J Chem Theory Comput ; 15(3): 1719-1727, 2019 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-30673283

RESUMEN

In this study, the divide-and-conquer (DC) method was extended to time-dependent density functional tight-binding (TDDFTB) theory to enable excited-state calculations of large systems and is denoted by DC-TDDFTB. The efficient diagonalization algorithms of TDDFTB and DC-TDDFTB methods were implemented into our in-house program. Test calculations of polyethylene aldehyde and p-coumaric acid, a pigment in photoactive yellow protein, in water demonstrate the high accuracy and efficiency of the developed DC-TDDFTB method. Furthermore, the (TD)DFTB metadynamics simulations of acridinium in the ground and excited states give reasonable p Ka values compared with the corresponding experimental values.

9.
J Neurosurg ; : 1-8, 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29932376

RESUMEN

OBJECTIVEEncephalo-myo-synangiosis (EMS) is an effective revascularization procedure for the treatment of moyamoya disease (MMD). However, the temporalis muscle used for EMS sometimes swells and causes ischemic complications by compressing the underlying brain. This study aimed to elucidate the effect of sagittal splitting (SS) of the muscle for prevention of ischemic complications and its impact on the postoperative development of collateral vessels.METHODSIn this historical case-control study, we analyzed 60 hemispheres in adult patients with MMD who underwent EMS using the temporalis muscle from December 1998 to November 2017. The muscle was divided anteroposteriorly by coronal splitting, and the anterior, posterior, or both parts of the muscle were used for EMS in 17, 4, and 39 hemispheres, respectively. In cases performed after 2006, the muscle was halved by SS, and the medial half was used for EMS to reduce the muscle volume (n = 47). The degree of postoperative muscle swelling was evaluated by measuring the maximum thickness of the muscle on CT scans obtained 3 to 7 days after surgery. The collateral developments of the anterior deep temporal artery (aDTA), posterior deep temporal artery (pDTA), and middle temporal artery (MTA) were assessed using digital subtraction angiography and MR angiography performed 6 months or more after surgery.RESULTSSS significantly reduced the temporalis muscle thickness from 12.1 ± 5.0 mm to 7.1 ± 3.0 mm (p < 0.01). Neurological deterioration due to the swollen temporalis muscle developed in 4 of the 13 hemispheres without SS (cerebral infarction in 1, reversible neurological deficit in 2, and convulsion in 1) but in none with SS. There were no significant differences in the postoperative collateral developments of the aDTA, pDTA, and MTA between hemispheres with and without SS. The MTA more frequently developed in hemispheres with EMS in which the posterior part of the muscle was used (30/37) than those in which this part was not used (4/16) (p < 0.01).CONCLUSIONSSS of the temporalis muscle might prevent neurological deterioration caused by the swollen temporalis muscle by reducing its volume without inhibiting the development of the collateral vessels.

10.
Neurology ; 90(13): e1143-e1149, 2018 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-29490916

RESUMEN

OBJECTIVES: This cross-sectional survey explored the characteristics and outcomes of direct oral anticoagulant (DOAC)-associated nontraumatic intracerebral hemorrhages (ICHs) by analyzing a large nationwide Japanese discharge database. METHODS: We analyzed data from 2,245 patients who experienced ICHs while taking anticoagulants (DOAC: 227; warfarin: 2,018) and were urgently hospitalized at 621 institutions in Japan between April 2010 and March 2015. We compared the DOAC- and warfarin-treated patients based on their backgrounds, ICH severities, antiplatelet therapies at admission, hematoma removal surgeries, reversal agents, mortality rates, and modified Rankin Scale scores at discharge. RESULTS: DOAC-associated ICHs were less likely to cause moderately or severely impaired consciousness (DOAC-associated ICHs: 31.3%; warfarin-associated ICHs: 39.4%; p = 0.002) or require surgical removal (DOAC-associated ICHs: 5.3%; warfarin-associated ICHs: 9.9%; p = 0.024) in the univariate analysis. Propensity score analysis revealed that patients with DOAC-associated ICHs also exhibited lower mortality rates within 1 day (odds ratio [OR] 4.96, p = 0.005), within 7 days (OR 2.29, p = 0.037), and during hospitalization (OR 1.96, p = 0.039). CONCLUSIONS: This nationwide study revealed that DOAC-treated patients had less severe ICHs and lower mortality rates than did warfarin-treated patients, probably due to milder hemorrhages at admission and lower hematoma expansion frequencies.


Asunto(s)
Anticoagulantes/efectos adversos , Hemorragia Cerebral/epidemiología , Warfarina/efectos adversos , Administración Oral , Anciano , Anticoagulantes/uso terapéutico , Hemorragia Cerebral/terapia , Comorbilidad , Estudios Transversales , Femenino , Humanos , Masculino , Inhibidores de Agregación Plaquetaria/uso terapéutico , Puntaje de Propensión , Índice de Severidad de la Enfermedad , Warfarina/uso terapéutico
11.
J Neurosurg ; 128(5): 1318-1326, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28548595

RESUMEN

OBJECTIVE Although heterogeneity in patient outcomes following subarachnoid hemorrhage (SAH) has been observed across different centers, the relative merits of clipping and coiling for SAH remain unknown. The authors sought to compare the patient outcomes between these therapeutic modalities using a large nationwide discharge database encompassing hospitals with different comprehensive stroke center (CSC) capabilities. METHODS They analyzed data from 5214 patients with SAH (clipping 3624, coiling 1590) who had been urgently hospitalized at 393 institutions in Japan in the period from April 2012 to March 2013. In-hospital mortality, modified Rankin Scale (mRS) score, cerebral infarction, complications, hospital length of stay, and medical costs were compared between the clipping and coiling groups after adjustment for patient-level and hospital-level characteristics by using mixed-model analysis. RESULTS Patients who had undergone coiling had significantly higher in-hospital mortality (12.4% vs 8.7%, OR 1.3) and a shorter median hospital stay (32.0 vs 37.0 days, p < 0.001) than those who had undergone clipping. The respective proportions of patients discharged with mRS scores of 3-6 (46.4% and 42.9%) and median medical costs (thousands US$, 35.7 and 36.7) were not significantly different between the groups. These results remained robust after further adjustment for CSC capabilities as a hospital-related covariate. CONCLUSIONS Despite the increasing use of coiling, clipping remains the mainstay treatment for SAH. Regardless of CSC capabilities, clipping was associated with reduced in-hospital mortality, similar unfavorable functional outcomes and medical costs, and a longer hospital stay as compared with coiling in 2012 in Japan. Further study is required to determine the influence of unmeasured confounders.


Asunto(s)
Hemorragia Subaracnoidea/terapia , Estudios de Cohortes , Comorbilidad , Estudios Transversales , Femenino , Costos de la Atención en Salud , Mortalidad Hospitalaria , Humanos , Japón , Tiempo de Internación , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Hemorragia Subaracnoidea/economía , Hemorragia Subaracnoidea/epidemiología , Resultado del Tratamiento
12.
Stroke ; 48(6): 1665-1667, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28446622

RESUMEN

BACKGROUND AND PURPOSE: Venous oxygen saturation (SO2) is measured in medical fields to assess tissue circulation insufficiency. This study aimed to elucidate the use of a cortical venous redness measurement to evaluate hemodynamic changes during revascularization surgery for patients with moyamoya disease. METHODS: In this retrospective case-series analysis, we first quantitatively measured and correlated SO2 and R intensity of 24-bit color digital red-green-blue pictures of blood samples from 3 volunteers. Subsequently, based on intraoperative digital pictures of 29 patients with moyamoya disease, we measured the R intensities of a cortical vein near the anastomosis site before and after anastomosis. Cerebral blood flow (CBF) at the site was measured using a single-photon emission computed tomography before and 1 to 3 days after surgery. Venous R intensity and CBF were measured twice by 4 raters, and their correlations were examined using generalized linear mixed effect model and linear regression analysis. RESULTS: A strong linear correlation was found between blood R intensity and its SO2 (coefficients, 0.522; 95% confidence interval, 0.364-0.680, using generalized linear mixed effect model). Venous R intensity before the anastomosis was not correlated with preoperative CBF (coefficients, 0.000352; 95% confidence interval, -0.000369 to 0.00107, by generalized linear mixed effect); however, the increases in venous R intensity after anastomosis were correlated with postoperative increases in CBF (R2, 0.367; 95% confidence interval, 0.116-0.618 to 0.548; 95% confidence interval, 0.331-0.764, by linear regression analysis). CONCLUSIONS: Cortical venous redness represented impaired CBF and could be a useful parameter for assessing hemodynamic changes during revascularization surgery.


Asunto(s)
Corteza Cerebral/diagnóstico por imagen , Revascularización Cerebral/métodos , Venas Cerebrales/diagnóstico por imagen , Circulación Cerebrovascular , Enfermedad de Moyamoya/diagnóstico por imagen , Oxígeno/metabolismo , Tomografía Computarizada de Emisión de Fotón Único/métodos , Adolescente , Adulto , Anciano , Color , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Moyamoya/cirugía , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía Computarizada de Emisión de Fotón Único/normas , Adulto Joven
13.
BMC Neurol ; 17(1): 46, 2017 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-28241749

RESUMEN

BACKGROUND: Although the Brain Attack Coalition recommended establishing centers of comprehensive care for stroke and cerebrovascular disease patients, a scoring system for such centers was lacking. We created and validated a comprehensive stroke center (CSC) score, adapted to Japanese circumstances. METHODS: Of the selected 1369 certified training institutions in Japan, 749 completed an acute stroke care capabilities survey. Hospital performance was determined using a 25-item score, evaluating 5 subcategories: personnel, diagnostic techniques, specific expertise, infrastructure, and education. Consistency and validity were examined using correlation coefficients and factorial analysis. RESULTS: The CSC score (median, 14; interquartile range, 11-18) varied according to hospital volume. The five subcategories showed moderate consistency (Cronbach's α = 0.765). A strong correlation existed between types of available personnel and specific expertise. Using the 2011 Japanese Diagnosis Procedure Combination database for patients hospitalized with stroke, four constructs were identified by factorial analysis (neurovascular surgery and intervention, vascular neurology, diagnostic neuroradiology, and neurocritical care and rehabilitation) that affected in-hospital mortality from ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. The total CSC score was related to in-hospital mortality from ischemic stroke (odds ratio [OR], 0.973; 95% confidence interval [CI], 0.958-0.989), intracerebral hemorrhage (OR, 0.970; 95% CI, 0.950-0.990), and subarachnoid hemorrhage (OR, 0.951; 95% CI, 0.925-0.977), with varying contributions from the four constructs. CONCLUSIONS: The CSC score is a valid measure for assessing CSC capabilities, based on the availability of neurovascular surgery and intervention, vascular neurology, diagnostic neuroradiology, and critical care and rehabilitation services.


Asunto(s)
Hemorragia Cerebral/terapia , Hospitales/normas , Accidente Cerebrovascular/terapia , Hemorragia Subaracnoidea/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/terapia , Hemorragia Cerebral/mortalidad , Trastornos Cerebrovasculares/terapia , Bases de Datos Factuales , Femenino , Mortalidad Hospitalaria , Humanos , Japón , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/diagnóstico , Hemorragia Subaracnoidea/mortalidad , Adulto Joven
14.
Contrib Nephrol ; 189: 246-251, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27951575

RESUMEN

BACKGROUNDS: Vascular access (VA) stenosis increases the risk of VA obstruction due to the gradual progress of intimal thickening. Therefore, we should try to detect VA stenosis early. However, we do not have a cutoff for when a difference between prescribed Kt/V and delivered Kt/V reflects a clinical issue. Thus, we have devised a new index, the 'clearance gap' (CL-Gap), which quantifies the difference between the effective clearance (eCL) of a hemodialysis (HD) patient and the theoretical clearance (tCL) of a dialyzer to detect a decrease in dialysis efficiency due to VA dysfunction. SUMMARY: We propose a qualitative technique of analyzing dialysis (the CL-Gap method) concerning Kt/V by estimating the eCL based on the delivered Kt/V and the difference with the tCL based on the dialyzer. When VA recirculation and blood removal failure occurs, the eCL decreases, and it is expected that the CL-Gap increases. On the contrary, if uniform internal removal occurs, the eCL rises when we overestimate the delivered Kt/V and the CL-Gap is expected to decrease. However, we cannot judge whether a high CL-Gap indicates VA dysfunction immediately because it is necessary to consider not only VA dysfunction, but also the effect of other factors on the CL-Gap. Key Messages: We believe that it is important to think about VA function in a qualitative manner when managing the dose using the CL-Gap to achieve better dialysis treatment.


Asunto(s)
Modelos Teóricos , Dispositivos de Acceso Vascular/normas , Velocidad del Flujo Sanguíneo , Constricción Patológica/diagnóstico , Humanos , Diálisis Renal/métodos
15.
World Neurosurg ; 98: 512-519, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27888077

RESUMEN

OBJECTIVE: Although uncommon, subcortical low-intensity (SCLI) changes on fluid-attenuated inversion recovery images are observed in various diseases, including cerebral ischemia. Here, we aimed to clarify the incidence and clinical implications of SCLI changes after revascularization surgery for moyamoya disease, focusing on the correlation with postoperative transient neurologic events (TNEs). METHODS: In this retrospective case series analysis, we included 10 hemispheres from 9 adults with moyamoya disease who underwent revascularization surgery. Subcortical signal intensity at the 5 gyri around the anastomosis point was quantitatively measured at 1 week and 3 months postoperatively. Changes in cerebral blood flow (CBF) were assessed using single-photon emission computed tomography. RESULTS: Images taken 1 week after surgery showed widespread SCLI changes below the operative fields in all 10 cases, but these changes normalized by 3 months. In addition, the changes in signal intensity at anastomoses negatively correlated with the changes in CBF (R2 = 0.36; P = 0.039). Postoperative TNEs occurred in 6 cases (60%) but were resolved within 17 days after surgery. Postoperative CBF increased in 9 of the 10 cases, with a median of 23%; however, these increases were not associated with the development of TNEs. The SCLI changes at the anastomosis points did not differ by the experience of TNEs. CONCLUSIONS: Early after surgery, SCLI changes are common findings below the operative fields but negatively correlate with increases in CBF. Although no significant association was found between TNEs and the SCLI changes, the synchronized development of these phenomena may suggest a common underlying pathogenesis.


Asunto(s)
Revascularización Cerebral/métodos , Enfermedad de Moyamoya/cirugía , Adolescente , Adulto , Anciano , Infarto Cerebral/etiología , Infarto Cerebral/patología , Medios de Contraste , Femenino , Humanos , Hipoestesia/etiología , Aumento de la Imagen , Ataque Isquémico Transitorio/etiología , Ataque Isquémico Transitorio/patología , Ataque Isquémico Transitorio/cirugía , Angiografía por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedad de Moyamoya/patología , Compuestos Orgánicos , Estudios Retrospectivos , Grado de Desobstrucción Vascular/fisiología , Adulto Joven
16.
J Neurosurg ; 127(5): 1000-1006, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27911235

RESUMEN

OBJECTIVE The neurological prognostic score (NPS) was recently proposed as a means for predicting neurological outcomes, such as the preservation of neurological function and the prevention of neurological death, in brain metastasis patients treated with Gamma Knife radiosurgery (GKRS). NPS consists of 2 groups: Group A patients were expected to have better neurological outcomes, and Group B patients were expected to have poorer outcomes. NPS robustness was tested in various situations. METHODS In total, 3040 patients with brain metastases that were treated with GKRS were analyzed. The cumulative incidence of the loss of neurological function independence (i.e., neurological deterioration) was estimated using competing risk analysis, and NPS was compared between Groups A and B by employing Gray's model. NPS was tested to determine if it can be applied to 5 cancer categories-non-small cell lung cancer, small cell lung cancer, gastrointestinal tract cancer, breast cancer, and other cancers-as well as if it can be incorporated into the 5 major grading systems: recursive partitioning analysis (RPA), score index for stereotactic radiosurgery (SIR), basic score for brain metastases (BSBM), graded prognostic assessment (GPA), and modified-RPA (M-RPA). RESULTS There were 2263 patients in NPS Group A and 777 patients in Group B. Neurological deterioration was observed in 586 patients (19.2%). The cumulative incidences of neurological deterioration were 9.5% versus 21.0%, 14.1% versus 25.4%, and 17.6% versus 27.8% in NPS Groups A and B at 1, 2, and 5 years, respectively. Significant differences were detected between the NPS groups in all cancer categories. There were significant differences between NPS Groups A and B for all classes in terms of the BSBM, GPA, and M-RPA systems, but the differences failed to reach statistical significance in terms of RPA Class I and SIR Class 0 to 3. CONCLUSIONS The NPS was verified as being highly applicable to all cancer categories and almost all classes for the 5 grading systems in terms of neurological function independence. This NPS system appears to be quite robust in various situations for brain metastasis patients treated with GKRS.


Asunto(s)
Neoplasias Encefálicas/radioterapia , Encéfalo/patología , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Radiocirugia , Anciano , Neoplasias Encefálicas/secundario , Carcinoma de Pulmón de Células no Pequeñas/secundario , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
17.
BMJ Open ; 6(3): e009942, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-27008684

RESUMEN

OBJECTIVES: To elucidate the association between antiplatelet use in patients with non-haemorrhagic moyamoya disease before hospital admission and good functional status on admission in Japan. DESIGN: Retrospective, multicentre, non-randomised, observational study. SETTING: Nationwide registry data in Japan. PARTICIPANTS: A total of 1925 patients with non-haemorrhagic moyamoya disease admitted between 1 April 2012 and 31 March 2014 in Japan. MAIN OUTCOME MEASURE: We performed propensity score-matched analysis to examine the association between prehospital antiplatelet use and no significant disability on hospital admission, as defined by a modified Rankin Scale score of 0 or 1. RESULTS: Propensity-matched patients who received prehospital antiplatelet drugs were associated with a good outcome on hospital admission (OR adjusted for all covariates, 3.82; 95% CI 1.22 to 11.99) compared with those who did not receive antiplatelet drugs prior to hospital admission. CONCLUSIONS: Prehospital antiplatelet use was significantly associated with good functional status on hospital admission among patients with non-haemorrhagic moyamoya disease in Japan. Our results suggest that prehospital antiplatelet use should be considered when evaluating outcomes of patients with non-haemorrhagic moyamoya disease.


Asunto(s)
Hospitalización/estadística & datos numéricos , Enfermedad de Moyamoya/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Adolescente , Adulto , Femenino , Humanos , Japón , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Inhibidores de Agregación Plaquetaria/efectos adversos , Sistema de Registros , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
18.
J Chem Phys ; 142(21): 212404, 2015 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-26049424

RESUMEN

An analytical method based on a three-time correlation function and the corresponding two-dimensional (2D) lifetime spectrum is developed to elucidate the time-dependent couplings between the multi-timescale (i.e., hierarchical) conformational dynamics in heterogeneous systems such as proteins. In analogy with 2D NMR, IR, electronic, and fluorescence spectroscopies, the waiting-time dependence of the off-diagonal peaks in the 2D lifetime spectra can provide a quantitative description of the dynamical correlations between the conformational motions with different lifetimes. The present method is applied to intrinsic conformational changes of substrate-free adenylate kinase (AKE) using long-time coarse-grained molecular dynamics simulations. It is found that the hierarchical conformational dynamics arise from the intra-domain structural transitions among conformational substates of AKE by analyzing the one-time correlation functions and one-dimensional lifetime spectra for the donor-acceptor distances corresponding to single-molecule Förster resonance energy transfer experiments with the use of the principal component analysis. In addition, the complicated waiting-time dependence of the off-diagonal peaks in the 2D lifetime spectra for the donor-acceptor distances is attributed to the fact that the time evolution of the couplings between the conformational dynamics depends upon both the spatial and temporal characters of the system. The present method is expected to shed light on the biological relationship among the structure, dynamics, and function.


Asunto(s)
Adenilato Quinasa/química , Simulación de Dinámica Molecular , Adenilato Quinasa/metabolismo , Espectroscopía de Resonancia Magnética , Conformación Proteica , Espectrometría de Fluorescencia , Espectrofotometría Infrarroja , Factores de Tiempo
19.
J Neurosurg ; 121 Suppl: 35-43, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25434935

RESUMEN

OBJECT: The Basic Score for Brain Metastases (BSBM) proposed by Lorenzoni and colleagues is one of the best grading systems for predicting survival periods after stereotactic radiosurgery (SRS) for brain metastases. However, it includes no brain factors and cannot predict neurological outcomes, such as preservation of neurological function and prevention of neurological death. Herein, the authors propose a modified BSBM, adding 4 brain factors to the original BSBM, enabling prediction of neurological outcomes, as well as of overall survival, in patients undergoing SRS. METHODS: To serve as neurological prognostic scores (NPSs), the authors scored 4 significant brain factors for both preservation of neurological function (qualitative survival) and prevention of neurological death (neurological survival) as 0 or 1 as described in the following: > 10 brain tumors = 0 or ≤ 10 = 1, total tumor volume > 15 cm(3) = 0 or ≤ 15 cm(3) = 1, MRI findings of localized meningeal dissemination (yes = 0 or no = 1), and neurological symptoms (yes = 0 or no = 1). According to the sum of NPSs, patients were classified into 2 subgroups: Subgroup A with a total NPS of 3 or 4 and Subgroup B with an NPS of 0, 1, or 2. The authors defined the modified BSBM according to the NPS subgroup classification applied to the original BSBM groups. The validity of this modified BSBM in 2838 consecutive patients with brain metastases treated with SRS was verified. RESULTS: Patients included 1868 with cancer of the lung (including 1604 with non-small cell lung cancer), 355 of the gastrointestinal tract, 305 of the breast, 176 of the urogenital tract, and 134 with other cancers. Subgroup A had 2089 patients and Subgroup B 749. Median overall survival times were 2.6 months in BSBM 0 (382 patients), 5.7 in BSBM 1 (1143), 11.4 in BSBM 2 (1011) and 21.7 in BSBM 3 (302), and pairwise differences between the BSBM groups were statistically significant (all p < 0.0001). One-year qualitative survival rates were 64.6% (modified BSBM 0A, 204 patients), 45.0% (0B, 178), 82.5% (1A, 825), 63.3% (1B, 318), 86.4% (2A, 792), 73.7% (2B, 219), 91.4% (3A, 268), and 73.5% (3B, 34). One-year neurological survival rates were 82.6% (0A), 52.4% (0B), 90.5% (1A), 78.1% (1B), 91.1% (2A), 83.2% (2B), 93.9% (3A), and 76.3% (3B), where A and B identify the subgroup. Statistically significant differences in both qualitative and neurological survivals between Subgroups A and B were detected in all BSBM groups. CONCLUSIONS: The authors' new index, the modified BSBM, was found to be excellent for predicting neurological outcomes, independently of life expectancy, in SRS-treated patients with brain metastases.


Asunto(s)
Neoplasias Encefálicas , Neoplasias Pulmonares/patología , Radiocirugia/mortalidad , Anciano , Muerte Encefálica , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/cirugía , Neoplasias de la Mama/patología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/secundario , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Femenino , Neoplasias Gastrointestinales/patología , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Clasificación del Tumor , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento , Neoplasias Urogenitales/patología
20.
J Am Heart Assoc ; 3(5): e001059, 2014 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-25336463

RESUMEN

BACKGROUND: Poor outcomes have been reported for stroke patients admitted outside of regular working hours. However, few studies have adjusted for case severity. In this nationwide assessment, we examined relationships between hospital admission time and disabilities at discharge while considering case severity. METHODS AND RESULTS: We analyzed 35 685 acute stroke patients admitted to 262 hospitals between April 2010 and May 2011 for ischemic stroke (IS), intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). The proportion of disabilities/death at discharge as measured by the modified Rankin Scale (mRS) was quantified. We constructed 2 hierarchical logistic regression models to estimate the effect of admission time, one adjusted for age, sex, comorbidities, and number of beds; and the second adjusted for the effect of consciousness levels and the above variables at admission. The percentage of severe disabilities/death at discharge increased for patients admitted outside of regular hours (22.8%, 27.2%, and 28.2% for working-hour, off-hour, and nighttime; P<0.001). These tendencies were significant in the bivariate and multivariable models without adjusting for consciousness level. However, the effects of off-hour or nighttime admissions were negated when adjusted for consciousness levels at admission (adjusted OR, 1.00 and 0.99; 95% CI, 1.00 to 1.13 and 0.89 to 1.10; P=0.067 and 0.851 for off-hour and nighttime, respectively, versus working-hour). The same trend was observed when each stroke subtype was stratified. CONCLUSIONS: The well-known off-hour effect might be attributed to the severely ill patient population. Thus, sustained stroke care that is sufficient to treat severely ill patients during off-hours is important.


Asunto(s)
Atención Posterior , Estado de Conciencia/fisiología , Mortalidad Hospitalaria , Admisión del Paciente/estadística & datos numéricos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/mortalidad , Anciano , Anciano de 80 o más Años , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/mortalidad , Hemorragia Cerebral/terapia , Estudios de Cohortes , Intervalos de Confianza , Femenino , Escala de Coma de Glasgow , Humanos , Japón , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Alta del Paciente/estadística & datos numéricos , Evaluación del Resultado de la Atención al Paciente , Estudios Retrospectivos , Medición de Riesgo , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/terapia , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/mortalidad , Hemorragia Subaracnoidea/terapia , Análisis de Supervivencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...