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1.
Pediatr Radiol ; 54(7): 1197-1204, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38769141

RESUMEN

BACKGROUND: Reports comparing field lens doses between helical scans with a 40-mm detector width and axial scans with a 160-mm detector width using different computed tomography (CT) scanners are currently scarce. OBJECTIVE: To compare scatter doses for lenses between a helical scan with a 40-mm detector width and an axial scan with a 160-mm detector width when using different CT scanners in the context of pediatric chest examinations. MATERIALS AND METHODS: Two different CT machines were used: Revolution CT (GE Healthcare, Waukesha, WI) with a 256-row, 0.625-mm multidetector; and Aquilion ONE GENESIS Edition (Canon Medical Systems, Otawara, Japan) with a 320-row, 0.5-mm multidetector. Three pediatric anthropomorphic phantoms were used, with optically stimulated luminescence dosimeters (OSLDs) placed on the left and right lenses. The scatter dose values measured by the OSLDs were compared between a helical scan with a 40-mm detector width and an axial scan with a 160-mm detector width during pediatric chest CT examinations. RESULTS: Median equivalent doses for the helical and axial scans were 0.12 and 0.12 mSv/mGy for the newborn, 0.17 and 0.16 mSv/mGy for the 1-year-old, and 0.18 and 0.15 mSv/mGy for the 5-year-old, respectively, when using the Revolution CT. With the Revolution CT, no significant differences were observed in the scatter doses between helical and axial scans in the newborn and 1-year-old phantoms. However, the lens scatter dose for the helical scan was approximately 20-35% higher than that for the axial scan in the 5-year-old phantom (P<0.01). The median equivalent doses of eye lenses for the helical and axial scans were 0.12 and 0.07 mSv/mGy for the newborn, 0.07 and 0.05 mSv/mGy for the 1-year-old, and 0.14 and 0.12 mSv/mGy for the 5-year-old, respectively, when using the Aquilion ONE. With the Aquilion ONE, lens scatter doses for the helical scan were approximately 70%, 40%, and 30% higher in the newborn, 1-year-old, and 5-year-old phantoms, respectively, than those for the axial scan (P<0.01). CONCLUSIONS: When using the Aquilion ONE, lens scatter doses for the helical scan were significantly higher in all three phantoms than those for the axial scan. In contrast, when using the Revolution CT, the lens scatter dose for the helical scan was significantly higher in the 5-year-old phantom than that for the axial scan. These results suggest that although scattered doses may vary with respect to the CT scanner and body size, they are generally lower in the case of axial scans.


Asunto(s)
Cristalino , Dosis de Radiación , Dispersión de Radiación , Tomografía Computarizada por Rayos X , Humanos , Masculino , Femenino , Cristalino/diagnóstico por imagen , Cristalino/efectos de la radiación , Tomografía Computarizada Espiral/métodos , Tomografía Computarizada por Rayos X/métodos , Fantasmas de Imagen , Radiometría , Exposición a la Radiación , Recién Nacido , Lactante , Preescolar
2.
Pediatr Radiol ; 54(5): 758-763, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38308740

RESUMEN

BACKGROUND: Adaptive collimation reduces the dose deposited outside the imaged volume along the z-axis. An increase in the dose deposited outside the imaged volume (to the lens and thyroid) in the z-axis direction is a concern in paediatric computed tomography (CT). OBJECTIVE: To compare the dose deposited outside the imaged volume (to the lens and thyroid) between 40-mm and 80-mm collimation during thoracic paediatric helical CT. MATERIALS AND METHODS: We used anthropomorphic phantoms of newborns and 5-year-olds with 40-mm and 80-mm collimation during helical CT. We compared the measured dose deposited outside the imaged volume using optically stimulated luminescence dosimeters (OSLD) at the surfaces of the lens and thyroid and the image noise between the 40-mm and 80-mm collimations. RESULTS: There were significant differences in the dose deposited outside the imaged volume (to the lens and thyroid) between the 40-mm and 80-mm collimations for both phantoms (P < 0.01). CONCLUSION: Compared with that observed for 80-mm collimation in helical CT scans of the paediatric thorax, the dose deposited outside the imaged volume (to the lens and thyroid) was significantly lower in newborns and 5-year-olds with 40-mm collimation.


Asunto(s)
Cristalino , Fantasmas de Imagen , Dosis de Radiación , Radiografía Torácica , Glándula Tiroides , Humanos , Glándula Tiroides/diagnóstico por imagen , Recién Nacido , Cristalino/diagnóstico por imagen , Cristalino/efectos de la radiación , Radiografía Torácica/métodos , Radiografía Torácica/instrumentación , Preescolar , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada Espiral/métodos
3.
J Antimicrob Chemother ; 76(1): 189-198, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33035324

RESUMEN

BACKGROUND: Baloxavir acid, the active form of the orally available prodrug baloxavir marboxil, is a novel cap-dependent endonuclease inhibitor of influenza virus. Baloxavir marboxil has been shown to rapidly reduce virus titres compared with oseltamivir in clinical studies. OBJECTIVES: We investigated the relationship between pharmacokinetic (PK) parameters and antiviral activity of baloxavir acid based on virus titre reduction in lungs of infected mice. METHODS: BALB/c mice infected with a sub-lethal dose of influenza A(H1N1), A(H1N1)pdm09, A(H3N2) or type B virus were treated on day 5 with oral baloxavir marboxil (0.5-50 mg/kg q12h), subcutaneous baloxavir acid (0.25-8 mg/kg/day), oseltamivir phosphate (5 or 50 eq mg/kg q12h) or other antivirals for 1 day. Lung virus titres were assessed 24 h after initial antiviral dosing. PK testing was performed at up to 24 h post-dosing of baloxavir marboxil or baloxavir acid in A/WSN/33-infected mice and the PK/pharmacodynamic (PD) relationship was evaluated for baloxavir acid. RESULTS: Oral baloxavir marboxil administration showed dose-dependent virus titre reductions in lungs of mice infected with the different types/subtypes of influenza viruses 24 h post-dosing. Baloxavir marboxil at 15 mg/kg q12h resulted in ≥100-fold and ≥10-fold reductions in influenza A and B virus titres, respectively, compared with oseltamivir phosphate. PK/PD analysis showed that the plasma concentration at the end of the dosing interval (Cτ) or the plasma concentration at 24 h after initial dosing (C24) was the PK parameter predicting the virus titres at 24 h post-dosing of baloxavir acid. CONCLUSIONS: PK/PD analysis of baloxavir acid based on virus titre reduction in this mouse model could be helpful in predicting and maximizing virological outcomes in clinical settings.


Asunto(s)
Dibenzotiepinas , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Animales , Antivirales/uso terapéutico , Dibenzotiepinas/uso terapéutico , Modelos Animales de Enfermedad , Endonucleasas , Humanos , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/tratamiento farmacológico , Ratones , Ratones Endogámicos BALB C , Morfolinas/uso terapéutico , Oxazinas , Piridonas , Triazinas
4.
Clin Infect Dis ; 71(4): 971-981, 2020 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-31538644

RESUMEN

BACKGROUND: We assessed the safety and effectiveness of baloxavir marboxil administration in Japanese children with influenza. METHODS: This open-label study administered 1 weight-adjusted dose of baloxavir to 107 children aged 1-11 years with laboratory-confirmed, febrile influenza virus infection of ≤48 hours duration. RESULTS: Adverse events (AEs) were reported in 34.6% of patients, most commonly vomiting (7.5%); no serious AEs or AEs causing discontinuation occurred. The median time to alleviation of influenza illness was 44.6 hours (95% confidence interval, 38.9-62.5 hours), to resolution of fever was 21.4 hours, and to sustained cessation of infectious viral shedding was 24.0 hours. However, viruses with amino acid substitutions in the viral polymerase acidic protein at position I38 (PA/I38T/M) emerged in 18 of 77 (23.4%) patients. Emergence was associated with longer infectious virus detectability (median time, 180.0 hours) and time to illness alleviation (median, 79.6 vs 42.8 hours in patients without PA/I38T/M-substituted viruses). Among patients with PA/I38T/M-substituted virus emergence, those with baseline hemagglutinin inhibition (HAI) antibody titer <40 experienced delay in time to illness alleviation (median, 85.4 vs 56.0 hours in patients with higher baseline HAI antibody titer). CONCLUSIONS: A single, oral dose of baloxavir marboxil was well tolerated and rapidly reduced viral titers, but the common emergence of PA/I38T/M-substituted viruses warrants consideration of alternative dosing regimens in young children. CLINICAL TRIALS REGISTRATION: Japan Pharmaceutical Information Center Clinical Trials Information (Japic CTI-163417).


Asunto(s)
Dibenzotiepinas , Gripe Humana , Antivirales/efectos adversos , Niño , Preescolar , Dibenzotiepinas/uso terapéutico , Humanos , Lactante , Gripe Humana/tratamiento farmacológico , Japón , Morfolinas/uso terapéutico , Piridonas/uso terapéutico , Triazinas
5.
Artículo en Inglés | MEDLINE | ID: mdl-32312784

RESUMEN

Baloxavir marboxil, a prodrug of cap-dependent endonuclease inhibitor baloxavir acid, reduces the time to improvement of influenza symptoms in patients infected with type A or B influenza virus. To characterize its pharmacokinetics, a population pharmacokinetic model for baloxavir acid was developed using 11,846 plasma concentration data items from 1,827 subjects, including 2,341 plasma concentration data items from 664 patients at high risk of influenza complications. A three-compartment model with first-order elimination and first-order absorption with lag time well described the plasma concentration data. Body weight and race were found to be the most important factors influencing clearance and volume of distribution. The exposures in high-risk patients were similar to those in otherwise healthy patients, and no pharmacokinetic difference was identified regarding any risk factors for influenza complications. Exposure-response analyses were performed regarding the time to improvement of symptoms and the reduction in the influenza virus titer in high-risk patients. The analyses suggested that body weight-based dosage, 40 mg for patients weighing <80 kg and 80 mg for patients weighing ≥80 kg, can shorten the time to improvement of influenza symptoms and reduce virus titer for both type A and B influenza virus regardless of the exposure levels of the high-risk patients as well as for the otherwise healthy influenza patients. The results of our population pharmacokinetic and exposure-response analyses in patients with risk factors of influenza complications should provide useful information on the pharmacokinetic and pharmacodynamic characteristics of baloxavir marboxil and also for the optimization of dose regimens.


Asunto(s)
Dibenzotiepinas , Gripe Humana , Antivirales/uso terapéutico , Humanos , Gripe Humana/tratamiento farmacológico , Morfolinas , Piridonas/uso terapéutico , Triazinas/uso terapéutico
6.
Biochem Biophys Res Commun ; 522(4): 965-970, 2020 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-31810604

RESUMEN

Molecular hydrogen (H2) is recognized as a medical gas applicable to numerous diseases including neurodegenerative diseases, metabolic disorders, and rheumatoid arthritis. Although the efficacy of H2 is reportedly attributed to its scavenging capability against the hydroxyl radical, the mechanisms underlying its therapeutic efficacy are not fully understood. Herein, we estimated the role of H2 in the energy converting system of the mitochondria, the source of reactive oxygen species. To investigate the effects of H2 on mitochondrial function, direction of electron flow, superoxide generation, and mitochondrial membrane potential were investigated. Forward electron transport (FET) or reverse electron transport (RET) was assessed by monitoring the decrease or increase of ß-nicotinamide adenine dinucleotide hydrate (NADH, - or +, µM, respectively) in the presence of ß-nicotinamide adenine dinucleotide (NAD+) and/or succinate in the isolated mitochondria. H2O2 converted from superoxide by superoxide dismutase (SOD) was measured to estimate electron leakage in the mitochondria. The effects of H2 on mitochondrial membrane potential were observed by staining cells with the fluorescence probe, teramethylrhodamine ethyl ester (TMRE). Despite the absence of succinate, a distinct RET was observed (from +0.0313 ± 0.0106 µM to +1.20 ± 0.302 µM) by adding 25 µM H2. In the presence of 5 µM NADH, RET by succinate inverted to FET from +1.62 ± 0.358 µM to -1.83 ± 0.191 µM, accompanied by a suppression of superoxide generated predominantly from complex I by 51.1%. H2 solely reduced mitochondrial membrane potential of the cultured cells by 11.3% as assessed by TMRE. The direction of electron flow was altered by H2 depending on the NAD+/NADH ratio, accompanied by suppression of superoxide generation H2 could suppress superoxide generation in complex I in vitro and reduce membrane potential in vivo. H2 may also neutralize semiquinone radicals to reduce superoxide produced in complex III. H2 may function as a rectifier of the electron flow affecting the mitochondrial membrane potential to suppress oxidative damage in mitochondria.


Asunto(s)
Complejo I de Transporte de Electrón/metabolismo , Hidrógeno/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/metabolismo , Superóxidos/metabolismo , Células A549 , Supervivencia Celular/efectos de los fármacos , Transporte de Electrón/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/metabolismo , Mitocondrias/efectos de los fármacos , NAD/metabolismo
7.
Artículo en Inglés | MEDLINE | ID: mdl-27795374

RESUMEN

Cefiderocol, a novel parenteral siderophore cephalosporin, exhibits potent efficacy against most Gram-negative bacteria, including carbapenem-resistant strains. Since cefiderocol is excreted primarily via the kidneys, this study was conducted to develop a population pharmacokinetics (PK) model to determine dose adjustment based on renal function. Population PK models were developed based on data for cefiderocol concentrations in plasma, urine, and dialysate with a nonlinear mixed-effects model approach. Monte-Carlo simulations were conducted to calculate the probability of target attainment (PTA) of fraction of time during the dosing interval where the free drug concentration in plasma exceeds the MIC (Tf>MIC) for an MIC range of 0.25 to 16 µg/ml. For the simulations, dose regimens were selected to compare cefiderocol exposure among groups with different levels of renal function. The developed models well described the PK of cefiderocol for each renal function group. A dose of 2 g every 8 h with 3-h infusions provided >90% PTA for 75% Tf>MIC for an MIC of ≤4 µg/ml for patients with normal renal function, while a more frequent dose (every 6 h) could be used for patients with augmented renal function. A reduced dose and/or extended dosing interval was selected for patients with impaired renal function. A supplemental dose immediately after intermittent hemodialysis was proposed for patients requiring intermittent hemodialysis. The PK of cefiderocol could be adequately modeled, and the modeling-and-simulation approach suggested dose regimens based on renal function, ensuring drug exposure with adequate bactericidal effect.


Asunto(s)
Antibacterianos/farmacocinética , Cefalosporinas/farmacocinética , Sideróforos/farmacocinética , Humanos , Riñón/metabolismo , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Método de Montecarlo , Diálisis Renal , Cefiderocol
8.
Antimicrob Agents Chemother ; 59(11): 6755-62, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26282420

RESUMEN

UNLABELLED: Peramivir is an intravenous anti-influenza agent that inhibits viral growth by selectively inhibiting neuraminidase in human influenza A and B viruses. To characterize its pharmacokinetics, a population pharmacokinetic analysis of peramivir was performed using 3,199 plasma concentration data samples from 332 subjects in six clinical studies in Japan and the United States, including studies with renal impairment subjects, elderly subjects, and influenza patients. A three-compartment model well described the plasma concentration data for peramivir, and creatinine clearance was found to be the most important factor influencing clearance. Age and body weight were also found to be covariates for clearance and the volume of distribution, respectively. No difference in pharmacokinetics was found between genders or between Japanese and U.S. SUBJECTS: Small differences in pharmacokinetics were observed between uninfected subjects and influenza patients (clearance was 18% higher and the volume of distribution was 6% lower in influenza patients). Monte Carlo simulations indicated that single adjusted doses of 1/3- and 1/6-fold for patients with moderate and severe renal impairment, respectively, would give areas under the curve comparable to those for patients with normal renal function. The population pharmacokinetic model developed for peramivir should be useful for understanding its pharmacokinetic characteristics and for dose adjustment on the basis of renal function.


Asunto(s)
Ciclopentanos/sangre , Ciclopentanos/farmacocinética , Guanidinas/sangre , Guanidinas/farmacocinética , Gripe Humana/sangre , Ácidos Carbocíclicos , Voluntarios Sanos , Humanos , Japón , Modelos Teóricos , Método de Montecarlo , Estados Unidos
9.
J Infect Chemother ; 21(2): 123-9, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25487084

RESUMEN

Integrated analysis of all plasma concentration data obtained from phase 1 studies in Japanese subjects, including a high dose study and special population studies, was conducted to thoroughly re-investigate the pharmacokinetics of doripenem by means of a population approach. Dose adjustments for patients with renal impairment were assessed by Monte-Carlo pharmacokinetics/pharmacodynamics simulation. The population pharmacokinetics of doripenem was evaluated using 921 plasma concentration data from 92 subjects from eight phase 1 studies in Japan. The two-compartment model could well describe the plasma concentration profile of doripenem after intravenous infusion. Creatinine clearance and age were found to be covariates of doripenem clearance, and creatinine clearance was the most important factor influencing the pharmacokinetics of doripenem, which is consistent with the fact that doripenem is mainly excreted via the urine. Simulations suggest that exposures (AUC) to 1 g every 8 h for patients with normal renal function would be similar to those expected at 1 g every 12 h, 0.5 g every 8 h and 0.25 g every 8 h for patients with mild, moderate and severe renal impairment, respectively. These dosing regimens also provide sufficient exposure to doripenem from the viewpoint of the percentage of time above the minimum inhibitory concentration.


Asunto(s)
Antibacterianos/farmacocinética , Carbapenémicos/farmacocinética , Modelos Biológicos , Modelos Estadísticos , Insuficiencia Renal/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Área Bajo la Curva , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/metabolismo , Carbapenémicos/administración & dosificación , Carbapenémicos/sangre , Simulación por Computador , Doripenem , Humanos , Japón , Persona de Mediana Edad , Método de Montecarlo , Adulto Joven
11.
Radiat Prot Dosimetry ; 200(3): 251-258, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38088430

RESUMEN

The study investigated radiation dose, vascular computed tomography (CT) enhancement and image quality of cardiac computed tomography angiography (CCTA) with and without bolus tracking (BT) methods in infants with congenital heart disease (CHD). The volume CT dose index (CTDIvol) and dose length product (DLP) were recorded for all CT scans, and the effective dose was obtained using a conversion factors. The CT number for the ascending aorta (AO) and pulmonary artery (PA), image noise of muscle tissue and contrast-to-noise ratio (CNR) were measured and calculated. The median values in the groups with and without BT were 2.20 mGy versus 0.44 mGy for CTDIvol, 8.10 mGy·cm versus 6.20 mGy·cm for DLP, and 0.66 mSv versus 0.51 mSv for effective dose (p < 0.001). There were no statistical differences in vascular CT enhancement, image noise, and CNR. CCTA without BT methods can reduce the radiation dose while maintaining vascular CT enhancement and image quality compared to CCTA with BT methods.


Asunto(s)
Angiografía por Tomografía Computarizada , Cardiopatías Congénitas , Lactante , Humanos , Angiografía por Tomografía Computarizada/métodos , Tomografía Computarizada por Rayos X/métodos , Angiografía , Cardiopatías Congénitas/diagnóstico por imagen , Cintigrafía , Dosis de Radiación
12.
Radiat Prot Dosimetry ; 200(2): 143-148, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-37987195

RESUMEN

To determine whether using lower-tube voltage reduces the scattered dose for the lens during paediatric thoracic computed tomography (CT). Two paediatric anthropomorphic phantoms (ATOM Phantom, CIRS, Norfolk, Virginia, USA) representing a newborn and 5-year-old were placed on the gantry of CT scanner, and optically stimulated luminescence dosemeters were placed on the left and right lenses, in front of the left and right thyroid glands, in front of the left and right mammary glands, and in front of and behind the mammary gland level and we measured scattered dose of the optically stimulated luminescence dosemeter was compared for each phantom between 80 and 120 kVp. Significant differences were observed in the scatter doses for the lens between 80 and 120 kVp (p < 0.01). Compared with the 120 kVp scan, the scatter doses for the lens were ~15-40% lower in newborn and 5-year-olds using the 80 kVp scan during paediatric CT.


Asunto(s)
Cristalino , Tomografía Computarizada por Rayos X , Recién Nacido , Niño , Humanos , Preescolar , Dosis de Radiación , Tomografía Computarizada por Rayos X/métodos , Fantasmas de Imagen , Cintigrafía
13.
Artículo en Inglés | MEDLINE | ID: mdl-38997113

RESUMEN

Equivalent doses for the eye lenses, thyroid, and mammary glands were measured and compared between one adult and three pediatric anthropomorphic phantoms during chest computed tomography (CT) using 40 mm volume helical scan on the Aquilion ONE GENESIS Edition CT equipment. Placing an optically stimulated luminescence dosemeter (OSLD) on the eye lenses, thyroid, and mammary gland, we measured and compared the equivalent dose of OSLD among different phantoms during chest CT using a helical scan. Compared with adults, the equivalent doses to the eye lens, thyroid, and mammary glands were ~81%, 77%, and 63% lower in newborns, 1-year-olds, and 5-year-olds using comparable image noise during chest CT.

14.
Nucleic Acids Res ; 39(20): 8972-83, 2011 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-21768126

RESUMEN

Human NUDT5 (hNUDT5) hydrolyzes various modified nucleoside diphosphates including 8-oxo-dGDP, 8-oxo-dADP and ADP-ribose (ADPR). However, the structural basis of the broad substrate specificity remains unknown. Here, we report the crystal structures of hNUDT5 complexed with 8-oxo-dGDP and 8-oxo-dADP. These structures reveal an unusually different substrate-binding mode. In particular, the positions of two phosphates (α and ß phosphates) of substrate in the 8-oxo-dGDP and 8-oxo-dADP complexes are completely inverted compared with those in the previously reported hNUDT5-ADPR complex structure. This result suggests that the nucleophilic substitution sites of the substrates involved in hydrolysis reactions differ despite the similarities in the chemical structures of the substrates and products. To clarify this hypothesis, we employed the isotope-labeling method and revealed that 8-oxo-dGDP is attacked by nucleophilic water at Pß, whereas ADPR is attacked at Pα. This observation reveals that the broad substrate specificity of hNUDT5 is achieved by a diversity of not only substrate recognition, but also hydrolysis mechanisms and leads to a novel aspect that enzymes do not always catalyze the reaction of substrates with similar chemical structures by using the chemically equivalent reaction site.


Asunto(s)
Pirofosfatasas/química , Adenosina Difosfato Ribosa/química , Biocatálisis , Cristalografía por Rayos X , Nucleótidos de Desoxiguanina/química , Proteínas de Escherichia coli/química , Guanosina Monofosfato/análogos & derivados , Guanosina Monofosfato/química , Humanos , Hidrólisis , Modelos Moleculares , Unión Proteica , Especificidad por Sustrato
15.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 69(10): 1119-29, 2013 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-24140900

RESUMEN

PURPOSE: Massive calcification complicates the diagnosis of the blood vessel lumen in computed tomography angiography (CTA) of the arteries of the lower extremities. The purpose of this study was to evaluate subtraction CTA with the use of orbital synchronized helical scanning (OS-SCTA). METHOD: Phantom study: We performed OS-SCTA and non-OSCTA of a calcified vessel phantom (ψ2.5 mm), and compared them with a non-calcified vessel phantom as the reference by full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of maximum intensity projection (MIP) images. Clinical study: 58 patients with peripheral artery disease who were referred for angiography also underwent OS-SCTA. OS-SCTA was produced using MIP images. Findings were graded according to three categories: (1) stenosis greater than 50% or occluded; (2) stenosis less than 50%; (3) not detected due to insufficient image quality. OS-SCTA findings were compared with the angiographic findings for each arterial segment. RESULTS: In the phantom study, FWHM showed no significant difference between OS-SCTA and the reference (P=0.135), whereas FWTM showed a significant difference (P<0.001). FWHM and FWTM showed a significant difference between non-OS-SCTA and the reference (P<0.001), due to misregistration with helical artifacts. In a clinical study comparing OS-SCTA with angiography, the sensitivity and specificity were 93.3% and 95.1% in calcified segments, 91.8% and 93.9% in non-calcified segments, and 92.2% and 94.6% in all segments. There was no significant difference between calcified segments and non-calcified segments (sensitivity: P=0.568, specificity: P=0.549). CONCLUSION: OS-SCTA is beneficial for the diagnosis of lower extremity arteries with vessel wall calcification, since it shows detection accuracy comparable to that of angiography.


Asunto(s)
Angiografía de Substracción Digital/métodos , Pierna/irrigación sanguínea , Tomografía Computarizada Espiral/métodos , Anciano , Arterias , Femenino , Humanos , Masculino , Fantasmas de Imagen , Sensibilidad y Especificidad , Calcificación Vascular/diagnóstico por imagen
16.
Radiat Prot Dosimetry ; 199(10): 1082-1089, 2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37092251

RESUMEN

To propose reference values for air-kerma at the reference point (Ka,r), air-kerma area product (PKA), fluoroscopy time (FT) and number of cine images (CI) for four age groups in Japan, a nationwide questionnaire was posted to 132 pediatric catheterisation of certified facility in Japan, using the conventional post system, to which 43 facilities responded. For diagnostic cardiac angiography, reference values were as follows: Ka,r: 86, 102, 165 and 264 mGy; PKA: 9.3, 9.5, 16 and 34 Gy.cm2; FT: 33, 29, 26 and 30 min and CI: 1904, 1966, 2405 and 1871 images. For therapeutic cardiac angiography, reference values were as follows: Ka,r: 107, 163, 103 and 202 mGy; PKA: 7.5, 18, 7 and 24 Gy.cm2; FT: 56, 52, 42 and 30 min and CI: 3886, 3232, 2212 and 4316 images for less than 1, 1-5, 6-10 and 11-15 y, respectively. To optimal patient exposure from diagnostic and therapeutic cardiac catheterisation, it is therefore necessary to establish reference values for pediatric cardiac catheterisation examinations for four age groups.


Asunto(s)
Cateterismo Cardíaco , Radiografía Intervencional , Humanos , Niño , Dosis de Radiación , Japón , Encuestas y Cuestionarios , Fluoroscopía
17.
Antimicrob Agents Chemother ; 56(1): 369-77, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22024821

RESUMEN

Peramivir is a new neuraminidase inhibitor for intravenous administration that was first introduced in clinical practice in Japan. We conducted a multicenter, open-label, uncontrolled study in children with influenza virus infection ranging in age from ≥28 days to <16 years during the 2009 pandemic A (H1N1) influenza epidemic to evaluate the efficacy, safety, and pharmacokinetics of peramivir in children after intravenous infusion of 10 mg/kg (600 mg maximum) once daily. Among the 106 children (125 days to 15 years old) confirmed to have been infected with the pH1N1 virus by the PCR who were treated with peramivir, the median time to alleviation of symptoms was 29.1 h (95% confidence interval = 22.1 to 32.4), and the proportion of the 106 children who were virus positive was 78.2% on day 2 after the start of treatment and had decreased to 7.1% on day 6. The results of the safety evaluation among 117 patients enrolled in this study showed that adverse events and adverse drug reactions were reported in 62.4 and 29.1%, respectively, of the patients. All of the adverse events and adverse drug reactions resolved or improved rapidly. A population pharmacokinetic analysis was performed on the basis of 297 observed plasma concentration data obtained from 115 children with influenza virus infection. Peramivir exposure in children was within the range of levels within which the efficacy and safety was confirmed in adults, and it is considered that peramivir is clinically and virologically effective and safe in children with pH1N1 virus infection.


Asunto(s)
Antivirales/farmacocinética , Ciclopentanos/farmacocinética , Inhibidores Enzimáticos/farmacocinética , Guanidinas/farmacocinética , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Gripe Humana/tratamiento farmacológico , Neuraminidasa/antagonistas & inhibidores , Pandemias , Proteínas Virales/antagonistas & inhibidores , Ácidos Carbocíclicos , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Subtipo H1N1 del Virus de la Influenza A/enzimología , Gripe Humana/epidemiología , Gripe Humana/virología , Japón/epidemiología , Masculino , Neuraminidasa/metabolismo , Reacción en Cadena de la Polimerasa , Resultado del Tratamiento , Proteínas Virales/metabolismo
18.
Radiat Prot Dosimetry ; 198(1-2): 16-22, 2022 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-35021232

RESUMEN

To propose typical values for the arrhythmia region between pulmonary vein isolation (PVI) and nonpulmonary vein isolation (non-PVI) in Japan. A nationwide questionnaire was posted to 343 facilities, to which 125 facilities (36.4%) responded. Results is the median for PVI and non-PVI were in terms of Ka,r (317 and 196 mGy), PKA (40.8 and 26.3 Gy.cm2), FT (43.0 and 27.3 min), and CI (326 and 102 images). When comparing PVI and non-PVI procedures, there were significant differences in Ka, r, PKA, FT, and CI (p < 0.05). In other words, by classifying into two types, PVI and non-PVI, we contributed to the establishment of typical values in Japan's RFCA.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Exposición a la Radiación , Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Humanos , Japón , Venas Pulmonares/cirugía , Encuestas y Cuestionarios , Resultado del Tratamiento
19.
J Pediatric Infect Dis Soc ; 10(4): 477-484, 2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33340316

RESUMEN

BACKGROUND: Baloxavir marboxil has demonstrated safety and efficacy in treating adult and adolescent outpatients with acute influenza (CAPSTONE-1 trial). Here, we report a subgroup analysis of outcomes in adolescents from the trial. METHODS: CAPSTONE-1 was a randomized, double-blind, placebo-controlled study. Eligible adolescent outpatients (aged 12-17 years of age) were randomized in a ratio of 2:1 to a single dose of baloxavir 40/80 mg if less than/greater than or equal to 80 kg or placebo. The main outcomes were the time to alleviation of symptoms (TTAS), duration of infectious virus detection, and incidence of adverse events (AEs). RESULTS: Among 117 adolescent patients, 90 (77%) comprised the intent-to-treat infected population (63 baloxavir and 27 placebo; 88.9% A(H3N2)). The median TTAS was 38.6 hours shorter (95% confidence interval: -2.6, 68.4) in the baloxavir group compared with placebo (median TTAS, 54.1 hours vs 92.7 hours, P = .0055). The median time to sustained cessation of infectious virus detection was 72.0 hours for baloxavir compared with 120.0 hours for placebo recipients (P < .0001). Treatment-emergent PA/I38X-substituted viruses were detected in 5 of the 51 (9.8%) baloxavir recipients. In the safety population (76 baloxavir and 41 placebo), AEs were less common in baloxavir than placebo recipients (17.1% vs 34.1%; P = .0421). In the baloxavir group, no AEs except for diarrhea were reported in 2 or more patients. CONCLUSIONS: Baloxavir demonstrated clinical and virologic efficacy in the otherwise healthy adolescents with acute influenza compared with placebo. There were no safety concerns identified. These results were similar to the adult population in CAPSTONE-1 and support baloxavir as a treatment option in adolescents.


Asunto(s)
Dibenzotiepinas , Gripe Humana , Adolescente , Adulto , Antivirales/efectos adversos , Dibenzotiepinas/uso terapéutico , Método Doble Ciego , Humanos , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/tratamiento farmacológico , Morfolinas/uso terapéutico , Piridonas/uso terapéutico , Triazinas
20.
PLoS One ; 15(5): e0233484, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32470022

RESUMEN

BACKGROUND: Measurement of the reactive hyperemia index (RHI) using peripheral arterial tonometry (PAT) has shown benefits in the evaluation of vascular endothelial function and prediction of cardiovascular disease prognosis. Thus, it is important to examine the factors that promote the RHI. In this study, we aimed to investigate the effect of molecular hydrogen (H2) on reactive hyperemia-PAT of the small arteries of fingers in healthy people. METHODS: To determine the efficacy of H2 for improving peripheral vascular endothelial function, water containing high H2 concentrations was administered to participants, and the Ln_RHI was measured in the finger vasculature. Sixty-eight volunteers were randomly divided into two groups: a placebo group (n = 34) that drank molecular nitrogen (N2)-containing water and a high H2 group (n = 34) that drank high H2 water (containing 7 ppm of H2: 3.5 mg H2 in 500-mL water). The Ln_RHI was measured before ingesting the placebo or high H2 water, 1 h and 24 h after the first ingestion, and 14 days after daily ingestion of high H2 water or the placebo. The mixed effects model for repeated measures was used in data analysis. RESULTS: The high H2 group had a significantly greater improvement in Ln_RHI than the placebo group. Ln_RHI improved by 22.2% (p<0.05) at 24 h after the first ingestion of high H2 water and by 25.4% (p<0.05) after the daily consumption of high H2 water for 2 weeks. CONCLUSIONS: Daily consumption of high H2 water improved the endothelial function of the arteries or arterioles assessed by the PAT test. The results suggest that the continuous consumption of high H2 water contributes to improved cardiovascular health.


Asunto(s)
Endotelio Vascular/fisiología , Hidrógeno/administración & dosificación , Hiperemia/etiología , Adulto , Factores Biológicos/agonistas , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/fisiopatología , Enfermedades Cardiovasculares/prevención & control , Método Doble Ciego , Endotelio Vascular/efectos de los fármacos , Femenino , Dedos/irrigación sanguínea , Voluntarios Sanos , Humanos , Hiperemia/fisiopatología , Masculino , Manometría/métodos , Persona de Mediana Edad , Modelos Cardiovasculares , Óxido Nítrico/agonistas , Óxido Nítrico/fisiología , Factores de Riesgo , Agua/análisis
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