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Quillaia extract (E 999) was re-evaluated in 2019 by the EFSA Panel on Food Additives and Flavourings (FAF). EFSA derived an acceptable daily intake (ADI) of 3 mg saponins/kg bw per day for E 999. Following a European Commission call for data to submit data to fill the data gaps, the present follow-up opinion assesses data provided by interested business operators (IBOs) to support an amendment of the EU specifications for E 999. Additionally, this opinion deals with the assessment of the proposed extension of use for E 999 in food supplements supplied in a solid and liquid form, excluding food supplements for infants and young children and, as a carrier in botanical nutrients. The Panel concluded that the proposed extension of use, if authorised, could result in an exceedance of the ADI at the maximum of the ranges of the mean for children, adolescents and the elderly, and for all populations at the 95th percentile. An additional proposed extension of use for E 999 to be used as a carrier for glazing agents on entire fresh fruits and vegetables has been received. Since no information on the proposed use levels of E 999 on a saponins content basis has been provided by this applicant, the Panel was not able to evaluate the safety of this extension of use. Considering the technical data submitted, the Panel recommended some modifications of the existing EU specifications for E 999, mainly to lower the limits for lead, mercury and arsenic and to include a maximum limit for cadmium and for calcium oxalate. The Panel also recommended that the limits would be expressed on a saponins basis. The Panel proposed to revise the definition of E 999 to better describe the composition in a qualitative way.
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INTRODUCTION: Capsular contracture remains the most common complication following device-based breast reconstruction, occurring in up to 50% of women who also undergo adjuvant radiotherapy either before or after device-based reconstruction. While certain risk factors for capsular contracture have been identified, there remains no clinically effective method of prevention. The purpose of the present study is to determine the effect of coating the implant with the novel small molecule Met-Z2-Y12, with and without delayed, targeted radiotherapy, on capsule thickness and morphologic change around smooth silicone implants placed under the latissimus dorsi in a rodent model. METHODS: Twenty-four female Sprague Dawley rats each had 2 mL smooth round silicone breast implants implanted bilaterally under the latissimus dorsi muscle. Twelve received uncoated implants and twelve received implants coated with Met-Z2-Y12. Half of the animals from each group received targeted radiotherapy (20 Gray) on postoperative day ten. At three and 6 months after implantation, the tissue surrounding the implants was harvested for analysis of capsular histology including capsule thickness. Additionally, microCT scans were qualitatively analyzed for morphologic change. RESULTS: Capsules surrounding Met-Z2-Y12-coated implants were significantly thinner (P = 0.006). The greatest difference in capsule thickness was seen in the irradiated 6-month groups, where mean capsule thickness was 79.1 ± 27.3 µm for uncoated versus 50.9 ± 9.6 µm for Met-Z2-Y12-coated implants (P = 0.038). At the time of explant, there were no capsular morphologic differences between the groups either grossly or per microCT. CONCLUSIONS: Met-Z2-Y12 coating of smooth silicone breast implants significantly reduces capsule thickness in a rodent model of submuscular breast reconstruction with delayed radiotherapy.
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Implante Mamário , Implantes de Mama , Contratura , Mamoplastia , Ratos , Animais , Feminino , Roedores , Ratos Sprague-Dawley , Contratura Capsular em Implantes/etiologia , Contratura Capsular em Implantes/prevenção & controle , Contratura Capsular em Implantes/patologia , Mamoplastia/efeitos adversos , Implantes de Mama/efeitos adversos , Silicones , Contratura/complicações , Implante Mamário/efeitos adversosRESUMO
Inhalable particulate matter (PM) is a health concern, and people living in large cities such as Bangkok are exposed to high concentrations. This exposure has been linked to respiratory and cardiac diseases and cancers of the lung and brain. Throughout 2018, PM was measured in northern Bangkok near a toll road (13.87°N, 100.58°E) covering all three seasons (cool, hot and rainy). PM10 was measured in 24- and 72-h samples. On selected dates aerodynamic size and mass distribution were measured as 3-day samples from a fixed 5th floor inlet. Particle number concentration was measured from the 5th floor inlet and in roadside survey measurements. There was a large fraction of particle number concentration in the sub-micron range, which showed the greatest variability compared with larger fractions. Metals associated with combustion sources were most found on the smaller size fraction of particles, which may have implications for associated adverse health outcomes because of the likely location of aerosol deposition in the distal airways of the lung. PM10 samples varied between 30 and 100 µg m-3, with highest concentrations in the cool season. The largest metal fractions present in the PM10 measurements were calcium, iron and magnesium during the hot season with average airborne concentrations of 13.2, 3.6 and 2.0 µg m-3, respectively. Copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony and lead had large non-crustal sources. Principal component analysis (PCA) identified likely sources of the metals as crustal minerals, tailpipe exhaust and non-combustion traffic. A health risk analysis showed a higher risk of both carcinogenic and non-carcinogenic health effects in the drier seasons than the wet season due to ingestion of nickel, arsenic, cadmium and lead.
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Poluentes Atmosféricos , Arsênio , Selênio , Humanos , Poluentes Atmosféricos/análise , Cádmio/análise , Níquel/análise , Arsênio/análise , Antimônio/análise , Cobre/análise , Magnésio/análise , Selênio/análise , Molibdênio/análise , Cálcio/análise , Tailândia , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Zinco/análise , Ferro/análise , Tamanho da PartículaRESUMO
[Table: see text] This guidance describes the scientific data required to allow an evaluation of the safety of new substances that are proposed for use as sources of nutrients in food supplements, foods for the general population or foods for specific groups and an assessment of the bioavailability of the nutrient from the proposed source. This guidance describes the scientific data required to allow an evaluation of the safety of the source within the established framework for risk assessment of food additives and novel food ingredients and the bioavailability of the nutrient from this source. This document is arranged in five main sections: one on technical data aimed at characterising the proposed source and at identifying potential hazards resulting from its manufacture and stability in food; one on existing authorisations and evaluation, providing an overview of previous assessments on the proposed source and their conclusions; one on proposed uses and exposure assessment section, allowing an estimate of the dietary exposure to the source and the nutrient based on the proposed uses and use levels; one on toxicological data, describing approaches which can be used to identify (in conjunction with data on manufacture and composition) and to characterise hazards of the source and any relevant breakdown products; the final section on bioavailability focuses on determining the extent to which the nutrient from the proposed source is available for use by the body in comparison with one or more forms of the same nutrient that are already permitted for use on the positive lists. This guidance was adopted by the Panel on Food Additives and Nutrient Sources added to Food (ANS Panel) on 16 May 2018. Upon request from EFSA, the present guidance has been revised to inform applicants of new provisions set out in Regulation (EC) No 178/2002, as amended by Regulation (EU) 2019/1381 on the transparency and sustainability of the EU risk assessment in the food chain.
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OBJECTIVE: The aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses. METHODS: In a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity. RESULTS: Mean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N ⢠m, and right peak torque by 0.14 (0.05-0.23) N ⢠m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (Pâ¯=â¯.002), and EMG at the downward force (right; Pâ¯=â¯.020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (-8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participantâ¯×â¯Intervention interaction: Pâ¯=â¯.044; response heterogeneity standard deviationâ¯=â¯34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes. CONCLUSION: After spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes.
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Exercício Físico/fisiologia , Músculos Isquiossurais/fisiologia , Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Força Muscular/fisiologia , Adulto , Estudos Cross-Over , Eletromiografia , Humanos , Região Lombossacral , Masculino , Torque , Adulto JovemRESUMO
The Panel on Food Additives and Flavourings (FAF) provided a scientific opinion re-evaluating the safety of acetic acid, lactic acid, citric acid, tartaric acid, mono- and diacetyltartaric acids, mixed acetic and tartaric acid esters of mono- and diglycerides of fatty acids (E 472a-f) as food additives. All substances had been previously evaluated by the Scientific Committee for Food (SCF) and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Hydrolysis of E472a,b,c,e was demonstrated in various experimental systems, although the available data on absorption, distribution, metabolism, excretion (ADME) were limited. The Panel assumed that E472a-f are extensively hydrolysed in the GI tract and/or (pre-)systemically after absorption into their individual hydrolysis products which are all normal dietary constituents and are metabolised or excreted intact. No adverse effects relevant for humans have been identified from the toxicological database available for E472a-f. The Panel considered that there is no need for a numerical acceptable daily intake (ADI) for E 472a,b,c. The Panel also considered that only l(+)-tartaric acid has to be used in the manufacturing process of E472d,e,f. The Panel established ADIs for E 472d,e,f based on the group ADI of 240 mg/kg body weight (bw) per day, expressed as tartaric acid, for l(+)-tartaric acid-tartrates (E334-337, 354) and considering the total amount of l(+)-tartaric acid in each food additive. Exposure estimates were calculated for all food additives individually, except for E 472e and f, using maximum level, refined exposure and food supplements consumers only scenarios. Considering the exposure estimates, there is no safety concern at their reported uses and use levels. In addition, exposure to tartaric acid released from the use of E 472d,e,f was calculated. The Panel also proposed a number of recommendations.
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The Panel on Food Additives and Flavourings (FAF) provided a scientific opinion re-evaluating the safety of Sodium aluminium silicate (E 554) and potassium aluminium silicate (E 555) as food additives. The Scientific Committee for Food (SCF) assigned these food additives together with other aluminium-containing food additives a provisional tolerable weekly intake (PTWI) of 7 mg aluminium/kg body weight (bw). In 2008, EFSA established a tolerable weekly intake (TWI) of 1 mg aluminium/kg bw per week. Sodium aluminium silicate was shown in rats to be absorbed to a limited extent at 0.12 ± 0.011%. The Panel considered that potassium aluminium silicate would be absorbed and become systemically available similarly to sodium aluminium silicate. No information on the physicochemical characterisation of sodium aluminium silicate and potassium aluminium silicate when used as food additives has been submitted and only very limited toxicological data were available for sodium aluminium silicate. Exposure to E 554 was calculated based on the reported use levels in food supplements. Exposure to aluminium from this use of E 554 was calculated to exceed the TWI for aluminium. Based on the data provided by interested business operators, the Panel considered that E 555 is not being used as a carrier, but as an inseparable component of 'potassium aluminium silicate-based pearlescent pigments'. The Panel calculated the regulatory maximum exposure to E 555 as a carrier for titanium dioxide (E 171) and iron oxides and hydroxides (E 172). Exposure to aluminium from this single use at the maximum permitted level could theoretically far exceed the TWI. Considering that only very limited toxicological data and insufficient information on the physicochemical characterisation of both food additives were available, the Panel concluded that the safety of sodium aluminium silicate (E 554) and potassium aluminium silicate (E 555) could not be assessed.
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Historically, failure rates in drug development are high; increased sophistication and investment throughout the process has shifted the reasons for attrition, but the overall success rates have remained stubbornly and consistently low. Only 8% of new entities entering clinical testing gain regulatory approval, indicating that significant obstacles still exist for efficient therapeutic development. The continued high failure rate can be partially attributed to the inability to link drug exposure with the magnitude of observed safety and efficacy-related pharmacodynamic (PD) responses; frequently, this is a result of nonclinical models exhibiting poor prediction of human outcomes across a wide range of disease conditions, resulting in faulty evaluation of drug toxicology and efficacy. However, the increasing quality and standardization of experimental methods in preclinical stages of testing has created valuable data sets within companies that can be leveraged to further improve the efficiency and accuracy of preclinical prediction for both pharmacokinetics (PK) and PD. Models of Quantitative structure-activity relationships (QSAR), physiologically based pharmacokinetics (PBPK), and PK/PD relationships have also improved efficiency. Founded on a core understanding of biochemistry and physiological interactions of xenobiotics, these in silico methods have the potential to increase the probability of compound success in clinical trials. Integration of traditional computational methods with machine-learning approaches and existing internal pharma databases stands to make a fundamental impact on the speed and accuracy of predictions during the process of drug development and approval.
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Desenvolvimento de Medicamentos/métodos , Modelos Biológicos , Modelos Químicos , Animais , Inteligência Artificial , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos , Humanos , Aprendizado de Máquina , Farmacocinética , Relação Quantitativa Estrutura-AtividadeRESUMO
Acute otitis media (AOM) is the most common diagnosis in childhood acute sick visits. By three years of age, 50% to 85% of children will have at least one episode of AOM. Symptoms may include ear pain (rubbing, tugging, or holding the ear may be a sign of pain), fever, irritability, otorrhea, anorexia, and sometimes vomiting or lethargy. AOM is diagnosed in symptomatic children with moderate to severe bulging of the tympanic membrane or new-onset otorrhea not caused by acute otitis externa, and in children with mild bulging and either recent-onset ear pain (less than 48 hours) or intense erythema of the tympanic membrane. Treatment includes pain management plus observation or antibiotics, depending on the patient's age, severity of symptoms, and whether the AOM is unilateral or bilateral. When antibiotics are used, high-dose amoxicillin (80 to 90 mg per kg per day in two divided doses) is first-line therapy unless the patient has taken amoxicillin for AOM in the previous 30 days or has concomitant purulent conjunctivitis; amoxicillin/clavulanate is typically used in this case. Cefdinir or azithromycin should be the first-line antibiotic in those with penicillin allergy based on risk of cephalosporin allergy. Tympanostomy tubes should be considered in children with three or more episodes of AOM within six months or four episodes within one year with one episode in the preceding six months. Pneumococcal and influenza vaccines and exclusive breastfeeding until at least six months of age can reduce the risk of AOM.
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Otite Média/terapia , Doença Aguda/terapia , Adulto , Amoxicilina/administração & dosagem , Antibacterianos/administração & dosagem , Criança , Pré-Escolar , Medicina Baseada em Evidências , Medicina de Família e Comunidade/normas , Feminino , Humanos , Lactente , Masculino , Ventilação da Orelha Média/métodos , Otite Média/diagnóstico , Otite Média/prevenção & controle , Manejo da Dor/métodos , Índice de Gravidade de DoençaRESUMO
The recent Scientific Committee on Health, Environmental and Emerging Risks Final Opinion on "The need for nonhuman primates in biomedical research, production and testing of products and devices" (2017 SCHEER) highlights approaches that could significantly contribute to the replacement, reduction, and refinement of nonhuman primate (NHP) studies. Initiatives that have the potential to affect NHP welfare and/or their use are expected to be appropriate, fair, and objective and publicly disseminated information focused on NHPs in biomedical research, which includes toxicologic and pathologic research and testing, should be objectively evaluated by stakeholder scientists, researchers, and veterinarians. Thus, IQ Consortium member companies convened to develop an informed and objective response, focusing on identifying areas of agreement, potential gaps, or missing information in 2017 SCHEER. Overall, the authors agree that many positions in the 2017 SCHEER Opinion generally align with industry views on the use of NHPs in research and testing, including the ongoing need of NHPs in many areas of research. From the perspective of the IQ Consortium, there are several topics in the 2017 SCHEER that merit additional comment, attention, or research, as well as consideration in future opinions.
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Alternativas ao Uso de Animais/tendências , Pesquisa Biomédica/métodos , Avaliação Pré-Clínica de Medicamentos/tendências , Primatas , Alternativas ao Uso de Animais/ética , Alternativas ao Uso de Animais/legislação & jurisprudência , Bem-Estar do Animal , Animais , Bioética , Pesquisa Biomédica/ética , Pesquisa Biomédica/legislação & jurisprudência , Avaliação Pré-Clínica de Medicamentos/ética , Avaliação Pré-Clínica de Medicamentos/métodos , União Europeia , Regulamentação GovernamentalRESUMO
High red meat intake is associated with the risk of colorectal cancer (CRC), whereas dietary fibers, such as resistant starch (RS) seemed to protect against CRC. The aim of this study was to determine whether high-amylose potato starch (HAPS), high-amylose maize starch (HAMS), and butyrylated high-amylose maize starch (HAMSB)-produced by an organocatalytic route-could oppose the negative effects of a high-protein meat diet (HPM), in terms of fermentation pattern, cecal microbial composition, and colonic biomarkers of CRC. Rats were fed a HPM diet or an HPM diet where 10% of the maize starch was substituted with either HAPS, HAMS, or HAMSB, for 4 weeks. Feces, cecum digesta, and colonic tissue were obtained for biochemical, microbial, gene expression (oncogenic microRNA), and immuno-histochemical (O6-methyl-2-deoxyguanosine (O6MeG) adduct) analysis. The HAMS and HAMSB diets shifted the fecal fermentation pattern from protein towards carbohydrate metabolism. The HAMSB diet also substantially increased fecal butyrate concentration and the pool, compared with the other diets. All three RS treatments altered the cecal microbial composition in a diet specific manner. HAPS and HAMSB showed CRC preventive effects, based on the reduced colonic oncogenic miR17-92 cluster miRNA expression, but there was no significant diet-induced differences in the colonic O6MeG adduct levels. Overall, HAMSB consumption showed the most potential for limiting the negative effects of a high-meat diet.
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Amilose/metabolismo , Neoplasias Colorretais/dietoterapia , Dieta Rica em Proteínas/efeitos adversos , Carboidratos da Dieta/metabolismo , Fermentação , Microbioma Gastrointestinal , Intestino Grosso/metabolismo , Amilose/química , Amilose/farmacologia , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Butiratos/química , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/prevenção & controle , Carboidratos da Dieta/farmacologia , Carboidratos da Dieta/uso terapêutico , Intestino Grosso/efeitos dos fármacos , Intestino Grosso/microbiologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Ratos , Ratos Sprague-Dawley , Solanum tuberosum/química , Zea mays/químicaRESUMO
INTRODUCTION: The PK optimization of drug candidates is one of the most resource-intensive tasks in pharmaceutical research and development. With the increasing availability of in silico, in vitro and mechanistic in vivo ADME models, drug discovery scientists have progressively learned to recognize common SAR patterns and engineer data-driven strategies to accelerate the resolution of ADME issues in lead optimization. Many of these strategies gravitate toward the concept of drug-likeness, which defines a number of optimal holistic physicochemical parameters (such as lipophilicity) that idealized oral drugs possess. Areas covered: Herein, the authors discuss the interplay of lipophilicity with in vitro and in vivo ADME data in order to refine existing thought around drug half-life optimization. Strategies to prolong the half-life of oral drugs via formulation are beyond the scope of this review. Expert opinion: Optimizing active properties such as potency, selectivity, and intrinsic metabolic clearance is an unambiguously beneficial strategy for small molecules within or beyond the Lipinski rule of five chemical space. The data that we present in this work suggests that emphasis should be primarily placed on optimizing active properties such as potency, selectivity, and metabolic stability.
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Descoberta de Drogas/métodos , Modelos Biológicos , Preparações Farmacêuticas/metabolismo , Simulação por Computador , Meia-Vida , Humanos , Preparações Farmacêuticas/química , Relação Estrutura-AtividadeRESUMO
During joint action tasks, expectations for outcomes of one's own and other's actions are collectively monitored. Recent evidence suggests that trait empathy levels may also influence performance monitoring processes. The present study investigated how outcome expectation and empathy interact during a turn-taking piano duet task, using simultaneous electroencephalography (EEG) recording. During the performances, one note in each player's part was altered in pitch to elicit the feedback-related negativity (FRN) and subsequent P3 complex. Pianists memorized and performed pieces containing either a similar or dissimilar sequence as their partner. For additional blocks, pianists also played both sequence types with an audio-only computer partner. The FRN and P3a were larger in response to self than other, while P3b occurred only in response to self, suggesting greater online monitoring of self- compared to other-produced actions during turn-taking joint action. P3a was larger when pianists played a similar sequence as their partner. Finally, as trait empathy level increased, FRN in response to self decreased. This association was absent for FRN in response to other. This may reflect that highly-empathetic musicians during joint performance could use a strategy to suppress exclusive focus on self-monitoring.
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Estimulação Acústica/métodos , Comportamento Cooperativo , Eletroencefalografia/métodos , Potenciais Evocados P300/fisiologia , Música/psicologia , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: The mechanisms that initiate and sustain persistent atrial fibrillation are not well characterized. Ablation results remain significantly worse than in paroxysmal atrial fibrillation in which the mechanism is better understood and subsequent targeted therapy has been developed. The aim of this study was to characterize and quantify patterns of activation during atrial fibrillation using contact mapping. METHODS: Patients with persistent atrial fibrillation (n=14; mean age, 61±8 years; ejection fraction, 59±10%) underwent simultaneous biatrial contact mapping with 64 electrode catheters. The atrial electrograms were transformed into phase, and subsequent spatiotemporal mapping was performed to identify phase singularities (PSs). RESULTS: PSs were located in both atria, but we observed more PSs in the left atrium compared with the right atrium (779±302, 552±235; P=0.015). Although some PSs of duration sufficient to complete >1 rotation were detected, the maximum PS duration was only 1150 ms, and the vast majority (97%) of PSs persisted for too short a period to complete a full rotation. Although in selected patients there was evidence of PS local clustering, overall, PSs were distributed globally throughout both chambers with no clear anatomic predisposition. In a subset of patients (n=7), analysis was repeated using an alternative established atrial PS mapping technique, which confirmed our initial findings. CONCLUSIONS: No sustained rotors or localized drivers were detected, and instead, the mechanism of arrhythmia maintenance was consistent with the multiple wavelet hypothesis, with passive activation of short-lived rotational activity. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01765075.
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Potenciais de Ação , Fibrilação Atrial/diagnóstico , Técnicas Eletrofisiológicas Cardíacas , Idoso , Fibrilação Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de TempoRESUMO
Aims: Conducting gaps in lesion sets are a major reason for failure of ablation procedures. Voltage mapping and pace-capture have been proposed for intra-procedural identification of gaps. We aimed to compare gap size measured acutely and chronically post-ablation to macroscopic gap size in a porcine model. Methods and results: Intercaval linear ablation was performed in eight Göttingen minipigs with a deliberate gap of â¼5 mm left in the ablation line. Gap size was measured by interpolating ablation contact force values between ablation tags and thresholding at a low force cut-off of 5 g. Bipolar voltage mapping and pace-capture mapping along the length of the line were performed immediately, and at 2 months, post-ablation. Animals were euthanized and gap sizes were measured macroscopically. Voltage thresholds to define scar were determined by receiver operating characteristic analysis as <0.56 mV (acutely) and <0.62 mV (chronically). Taking the macroscopic gap size as gold standard, error in gap measurements were determined for voltage, pace-capture, and ablation contact force maps. All modalities overestimated chronic gap size, by 1.4 ± 2.0 mm (ablation contact force map), 5.1 ± 3.4 mm (pace-capture), and 9.5 ± 3.8 mm (voltage mapping). Error on ablation contact force map gap measurements were significantly less than for voltage mapping (P = 0.003, Tukey's multiple comparisons test). Chronically, voltage mapping and pace-capture mapping overestimated macroscopic gap size by 11.9 ± 3.7 and 9.8 ± 3.5 mm, respectively. Conclusion: Bipolar voltage and pace-capture mapping overestimate the size of chronic gap formation in linear ablation lesions. The most accurate estimation of chronic gap size was achieved by analysis of catheter-myocardium contact force during ablation.
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Potenciais de Ação , Ablação por Cateter/efeitos adversos , Técnicas Eletrofisiológicas Cardíacas , Átrios do Coração/cirurgia , Frequência Cardíaca , Animais , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Modelos Animais , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Suínos , Porco Miniatura , Falha de TratamentoRESUMO
PURPOSE: Volume of distribution at steady state (Vdss) is a fundamental pharmacokinetic (PK) parameter driven predominantly by passive processes and physicochemical properties of the compound. Human Vdss can be estimated using in silico mechanistic methods or empirically scaled from Vdss values obtained from preclinical species. In this study the accuracy and the complementarity of these two approaches are analyzed leveraging a large data set (over 150 marketed drugs). METHODS: For all the drugs analyzed in this study experimental in vitro measurements of LogP, plasma protein binding and pKa are used as input for the mechanistic in silico model to predict human Vdss. The software used for predicting human tissue partition coefficients and Vdss based on the method described by Rodgers and Rowland is made available as supporting information. RESULTS: This assessment indicates that overall the in silico mechanistic model presented by Rodgers and Rowland is comparably accurate or superior to empirical approaches based on the extrapolation of in vivo data from preclinical species. CONCLUSIONS: These results illustrate the great potential of mechanistic in silico models to accurately predict Vdss in humans. This in silico method does not rely on in vivo data and is, consequently, significantly time and resource sparing. The success of this in silico model further suggests that reasonable predictability of Vdss in preclinical species could be obtained by a similar process.
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Simulação por Computador , Avaliação Pré-Clínica de Medicamentos , Modelos Biológicos , Pesquisa Farmacêutica/métodos , Absorção Fisiológica , Conjuntos de Dados como Assunto , Taxa de Depuração Metabólica , Software , Distribuição TecidualAssuntos
Potenciais de Ação , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Taquicardia Ventricular/etiologia , Ablação por Cateter , Diagnóstico Diferencial , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/cirurgia , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgia , Fatores de Tempo , Resultado do TratamentoRESUMO
Aims: Local activation time (LAT) mapping forms the cornerstone of atrial tachycardia diagnosis. Although anatomic and positional accuracy of electroanatomic mapping (EAM) systems have been validated, the effect of electrode sampling density on LAT map reconstruction is not known. Here, we study the effect of chamber geometry and activation complexity on optimal LAT sampling density using a combined in silico and in vivo approach. Methods and results: In vivo 21 atrial tachycardia maps were studied in three groups: (1) focal activation, (2) macro-re-entry, and (3) localized re-entry. In silico activation was simulated on a 4×4cm atrial monolayer, sampled randomly at 0.25-10 points/cm2 and used to re-interpolate LAT maps. Activation patterns were studied in the geometrically simple porcine right atrium (RA) and complex human left atrium (LA). Activation complexity was introduced into the porcine RA by incomplete inter-caval linear ablation. In all cases, optimal sampling density was defined as the highest density resulting in minimal further error reduction in the re-interpolated maps. Optimal sampling densities for LA tachycardias were 0.67 ± 0.17 points/cm2 (focal activation), 1.05 ± 0.32 points/cm2 (macro-re-entry) and 1.23 ± 0.26 points/cm2 (localized re-entry), P = 0.0031. Increasing activation complexity was associated with increased optimal sampling density both in silico (focal activation 1.09 ± 0.14 points/cm2; re-entry 1.44 ± 0.49 points/cm2; spiral-wave 1.50 ± 0.34 points/cm2, P < 0.0001) and in vivo (porcine RA pre-ablation 0.45 ± 0.13 vs. post-ablation 0.78 ± 0.17 points/cm2, P = 0.0008). Increasing chamber geometry was also associated with increased optimal sampling density (0.61 ± 0.22 points/cm2 vs. 1.0 ± 0.34 points/cm2, P = 0.0015). Conclusion: Optimal sampling densities can be identified to maximize diagnostic yield of LAT maps. Greater sampling density is required to correctly reveal complex activation and represent activation across complex geometries. Overall, the optimal sampling density for LAT map interpolation defined in this study was â¼1.0-1.5 points/cm2.
Assuntos
Função Atrial , Técnicas Eletrofisiológicas Cardíacas , Átrios do Coração/fisiopatologia , Taquicardia Supraventricular/diagnóstico , Potenciais de Ação , Animais , Estimulação Cardíaca Artificial , Simulação por Computador , Modelos Animais de Doenças , Frequência Cardíaca , Humanos , Modelos Cardiovasculares , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Suínos , Porco Miniatura , Taquicardia Supraventricular/fisiopatologia , Fatores de TempoRESUMO
The present scientific opinion deals with the safety of orthosilicic acid-vanillin complex (OSA-VC) as a novel food ingredient for use as a source of silicon (Si) in food supplements and with the bioavailability of Si from this source. OSA-VC is stable in liquid solution at low pH values. OSA from OSA-VC was available as revealed by the increase in plasma Si concentrations after oral ingestion in human volunteers. The toxicological data provided in support of the current application were not in accordance with the Tier 1 requirement of the 'Guidance for submission for food additive evaluations'; however, this was considered justified by the Panel given that OSA-VC at pH 6.8 dissociates into orthosilicic acid and vanillin. The daily consumption of OSA-VC at the dose recommended by the applicant would provide a supplemental intake of Si of approximately 10-18 mg Si/day which would result in an estimated total intake of roughly 30-70 mg Si/day. The maximum vanillin intake resulting from the consumption of OSA-VC would be less than 5% of the acceptable daily intake (ADI) value for vanillin of 10 mg/kg body weight (bw) per day established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 2002. The Panel concluded that there would be no safety concern with the proposed use and use level of OSA-VC as a novel food ingredient intended to be used as a source of Si in food supplements for the adult population. The Panel concluded that OSA, measured as Si, is bioavailable following ingestion of OSA-VC and appears similar to values reported in the literature for other established sources of OSA.
RESUMO
The present scientific opinion deals with the evaluation of the safety of di-calcium malate (DCM) proposed as a novel food ingredient and as a source of calcium for use in foods for the general population, food supplements, total diet replacement for weight control and food for special medical purposes (FSMP), and with the bioavailability of calcium from this source. The structural formula of the proposed complex is based on expert judgement and not supported by any analytical data. On the basis of the available data, the Panel concluded that there was insufficient scientific evidence of a difference between the proposed novel food ingredient named as di-calcium malate (DCM) and calcium malate already authorised as a source of calcium included in Annex II to Directive 2002/46/EC. Accordingly, the Panel was unable to assess the safety of DCM as a novel food ingredient. On the basis of the results provided, the Panel considered that DCM does not completely dissociate into calcium and malic acid. The Panel concluded that when DCM dissociates, calcium would be available following ingestion of DCM and the bioavailability would appear similar to values reported for other sources of calcium already permitted. Furthermore, the Panel concluded that on the basis of the information available it was not possible to calculate the exposure to DCM as a source of calcium to foods for the general population, food supplements, total diet replacement for weight control and FSMP.