RESUMO
Low levels of N-nitrosamines (NAs) were detected in pharmaceuticals and, as a result, health authorities (HAs) have published acceptable intakes (AIs) in pharmaceuticals to limit potential carcinogenic risk. The rationales behind the AIs have not been provided to understand the process for selecting a TD50 or read-across analog. In this manuscript we evaluated the toxicity data for eleven common NAs in a comprehensive and transparent process consistent with ICH M7. This evaluation included substances which had datasets that were robust, limited but sufficient, and substances with insufficient experimental animal carcinogenicity data. In the case of robust or limited but sufficient carcinogenicity information, AIs were calculated based on published or derived TD50s from the most sensitive organ site. In the case of insufficient carcinogenicity information, available carcinogenicity data and structure activity relationships (SARs) were applied to categorical-based AIs of 1500 ng/day, 150 ng/day or 18 ng/day; however additional data (such as biological or additional computational modelling) could inform an alternative AI. This approach advances the methodology used to derive AIs for NAs.
Assuntos
Nitrosaminas , Animais , Nitrosaminas/toxicidade , Carcinógenos , Relação Estrutura-Atividade , Preparações FarmacêuticasRESUMO
BACKGROUND: Neuroendocrine neoplasias (NENs) are a rare type of malignancy that arise from the cells of the neuroendocrine system. Most patients present with advanced, unresectable disease, typically with metastases to the liver. The presence of liver metastases dictates prognosis and there has been a number of studies investigating therapies that reduce the burden of liver disease. Selective Internal Radiation Therapy (SIRT) allows the delivery of targeted high dose radiation directly to tumours, with relative sparing of the surrounding liver tissue. Here, we describe the design and rationale of ArtTisaN, a phase II study to assess efficacy and tolerability of SIRT using TheraSpheres for the management of liver metastases secondary to NENs. METHODS: Twenty-four eligible participants will be recruited to receive SIRT with TheraSpheres. The primary objective is to determine the objective response rate to treatment, defined as the rate of best overall response in the treated liver volume. In addition, total hepatic response and overall response will be assessed according to RECIST 1.1. The second co-primary objective is to determine the incidence of adverse and serious adverse device events. The secondary objectives are progression free survival, overall survival and quality of life. Additional exploratory objectives include investigation of circulating biomarkers of response and identification of a radiomic signature of response. DISCUSSION: This trial will provide prospective evidence on the efficacy of SIRT using TheraSpheres for the management of liver metastases. TRIAL REGISTRATION: NCT04362436 .
Assuntos
Neoplasias Hepáticas , Tumores Neuroendócrinos , Humanos , Ensaios Clínicos Fase II como Assunto , Neoplasias Hepáticas/patologia , Tumores Neuroendócrinos/patologia , Estudos Prospectivos , Qualidade de Vida , Compostos Radiofarmacêuticos/uso terapêutico , Resultado do Tratamento , BraquiterapiaRESUMO
The FMR1 premutation (PM:55-199 CGG) is associated with fragile X-associated tremor/ataxia syndrome (FXTAS) and when maternally transmitted is at risk of expansion to a hypermethylated full mutation (FM: ≥ 200 CGG) that causes fragile X syndrome (FXS). We describe a maternally transmitted PM (77 CGG) that was passed to a son (103 CGG), and to a daughter (220-1822 CGG), who were affected with FXTAS and FXS, respectively. The male with the PM showed low-level mosaicism for normal size of 30 and 37 CGG. This male had two offspring: one female mosaic for PM and FM (56, 157, >200 CGG) and another with only a 37 CGG allele detected in multiple tissues, neither with a clinical phenotype. The female with the 37 CGG allele showed normal levels of FMR1 methylation and mRNA and passed this 37 CGG allele to one of her daughters, who was also unaffected. These findings show that post-zygotic paternal retraction can lead to low-level mosaicism for normal size alleles, with these normal alleles being functional when passed over two generations.
Assuntos
Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil , Alelos , Metilação de DNA , Feminino , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/diagnóstico , Síndrome do Cromossomo X Frágil/genética , Humanos , Masculino , Mutação , Expansão das Repetições de TrinucleotídeosRESUMO
The ICH M7(R1) guideline describes a framework to assess the carcinogenic risk of mutagenic and carcinogenic pharmaceutical impurities following less-than-lifetime (LTL) exposures. This LTL framework is important as many pharmaceuticals are not administered for a patient's lifetime and as clinical trials typically involve LTL exposures. While there has been regulatory caution about applying LTL concepts to cohort of concern (COC) impurities such as N-nitrosamines, ICH M7 does not preclude this and indeed literature data suggests that the LTL framework will be protective of patient safety for N-nitrosamines. The goal was to investigate if applying the LTL framework in ICH M7 would control exposure to an acceptable excess cancer risk in humans. Using N-nitrosodiethylamine as a case study, empirical data correlating exposure duration (as a percentage of lifespan) and cancer incidence in rodent bioassays indicate that the LTL acceptable intake (AI) as derived using the ICH M7 framework would not exceed a negligible additional risk of cancer. Therefore, controlling N-nitrosamines to an LTL AI based on the ICH M7 framework is thus demonstrated to be protective for potential carcinogenic risk to patients over the exposure durations typical of clinical trials and many prescribed medicines.
Assuntos
Dietilnitrosamina/toxicidade , Mutagênicos/toxicidade , Carcinógenos , Relação Dose-Resposta a Droga , Humanos , Mutagênese , Nitrosaminas/toxicidade , Testes de ToxicidadeRESUMO
Manufacturing of cell therapy products requires sufficient understanding of the cell culture variables and associated mechanisms for adequate control and risk analysis. The aim of this study was to apply an unstructured ordinary differential equation-based model for prediction of T-cell bioprocess outcomes as a function of process input parameters. A series of models were developed to represent the growth of T-cells as a function of time, culture volumes, cell densities, and glucose concentration using data from the Ambr®15 stirred bioreactor system. The models were sufficiently representative of the process to predict the glucose and volume provision required to maintain cell growth rate and quantitatively defined the relationship between glucose concentration, cell growth rate, and glucose utilization rate. The models demonstrated that although glucose is a limiting factor in batch supplied medium, a delivery rate of glucose at significantly less than the maximal specific consumption rate (0.05 mg 1 × 106 cell h-1 ) will adequately sustain cell growth due to a lower glucose Monod constant determining glucose consumption rate relative to the glucose Monod constant determining cell growth rate. The resultant volume and exchange requirements were used as inputs to an operational BioSolve cost model to suggest a cost-effective T-cell manufacturing process with minimum cost of goods per million cells produced and optimal volumetric productivity in a manufacturing settings. These findings highlight the potential of a simple unstructured model of T-cell growth in a stirred tank system to provide a framework for control and optimization of bioprocesses for manufacture.
Assuntos
Reatores Biológicos , Técnicas de Cultura de Células/métodos , Terapia Baseada em Transplante de Células e Tecidos , Linfócitos T/citologia , Contagem de Células , Proliferação de Células , Células Cultivadas , Custos e Análise de Custo , Humanos , CinéticaRESUMO
Large-scale manufacture of human embryonic stem cells (hESCs) is prerequisite to their widespread use in biomedical applications. However, current hESC culture strategies are labor-intensive and employ highly variable processes, presenting challenges for scaled production and commercial development. Here we demonstrate that passaging of the hESC lines, HUES7, and NOTT1, with trypsin in feeder-free conditions, is compatible with complete automation on the CompacT SelecT, a commercially available and industrially relevant robotic platform. Pluripotency was successfully retained, as evidenced by consistent proliferation during serial passage, expression of stem cell markers (OCT4, NANOG, TRA1-81, and SSEA-4), stable karyotype, and multi-germlayer differentiation in vitro, including to pharmacologically responsive cardiomyocytes. Automation of hESC culture will expedite cell-use in clinical, scientific, and industrial applications.
Assuntos
Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Células-Tronco Embrionárias , Células-Tronco Pluripotentes , Biomarcadores/análise , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Desenho de Equipamento , Humanos , Cariotipagem , Microscopia de Fluorescência , Robótica , Tripsina/químicaRESUMO
To avoid liver insufficiency following major hepatic resection, portal vein embolisation (PVE) is used to induce liver hypertrophy pre-operatively. Associating liver partition with portal vein ligation for staged hepatectomy assisted with radiofrequency (RALPPS) was introduced as an alternative method. A randomized controlled trial comparing PVE with RALPPS for the pre-operative manipulation of liver volume in patients with a future liver remnant volume (FLRV) ≤25% (or ≤35% if receiving preoperative chemotherapy) was conducted. The primary endpoint was increase in size of the FLRV. The secondary endpoints were length of time taken for the volume gain, morbidity, operation length and post-operative liver function. Between July 2015 and October 2017, 57 patients were randomised to RALPPS (n = 29) and PVE (n = 28). The mean percentage of increase in the FLRV was 80.7 ± 13.7% after a median 20 days following RALPPS compared to 18.4 ± 9.8% after 35 days (p < 0.001) following PVE. Twenty-four patients after RALPPS and 21 after PVE underwent stage-2 operation. Final resection was achieved in 92.3% and 66.6% patients in RALPPS and PVE, respectively (p = 0.007). There was no difference in morbidity, and one 30-day mortality after RALPPS (p = 0.991) was reported. RALPPS is more effective than PVE in increasing FLRV and the number of patients for surgical resection.
RESUMO
PURPOSE: To determine if fine art perception training improved performance in novice radiology trainees. METHODS: On the first day of their residency, 15 radiology residents underwent a basic radiology perception test in which they were shown 15 different radiographs that each had a significant abnormality. This was followed by a focused session of interpretation training at a local art gallery where art experts taught the trainees how to thoroughly analyze a painting. After this fine art session, the residents were once again shown 15 different radiographs and asked, in the same manner as before, to identify the location of the abnormality. The results of both radiograph assessments were then compared. RESULTS: The 15 residents correctly identified the areas of abnormality on 35 of 225 cases pre-art training with a mean score of 2.33 and a SD of 1.4. After art training, the figure for correctly identifying the area of abnormality rose to 94 of 225 cases with a mean score of 6.27 and a SD of 1.79 (P < .0001). CONCLUSION: The implementation of a focused teaching session on perception improved first-year residents' ability to localize imaging abnormalities. This improvement was significant (P < .0001). Most errors in radiology occur due to failures of perception rather than failures to correctly interpret a finding and, as such, it behooves the profession to ensure that perception training is adequately addressed as part of a radiology training curriculum. Using an art gallery may be a novel, effective transitional starting point for novice radiology trainees.
Assuntos
Competência Clínica , Pinturas , Radiologia/educação , Percepção Visual , Adulto , Connecticut , Currículo , Erros de Diagnóstico/prevenção & controle , Avaliação Educacional , Feminino , Humanos , Internato e Residência , MasculinoRESUMO
Artificial light at night (ALAN) is gaining recognition as having an important anthropogenic impact on the environment, yet the behavioural and physiological impacts of this stressor are largely unknown. This dearth of information is particularly true for freshwater ecosystems, which are already heavily impacted by anthropogenic pressures. Atlantic salmon (Salmo salar L.) is a species of conservation and economic importance whose ecology and behaviour is well studied, making it an ideal model species. Recent investigations have demonstrated that salmon show disrupted behaviour in response to artificial light; however, it is not yet clear which physiological processes are behind the observed behavioural modifications. Here, two novel non-invasive sampling methods were used to examine the cortisol stress response of dispersing salmon fry under different artificial lighting intensities. Fish egg and embryos were reared under differing ALAN intensities and individual measures of stress were subsequently taken from dispersing fry using static sampling, whereas population-level measures were achieved using deployed passive samplers. Dispersing fry exposed to experimental confinement showed elevated cortisol levels, indicating the capacity to mount a stress response at this early stage in ontogenesis. However, only one of the two methods for sampling cortisol used in this study indicated that ALAN may act as a stressor to dispersing salmon fry. As such, a cortisol-mediated response to light was not strongly supported. Furthermore, the efficacy of the two non-invasive methodologies used in this study is, subject to further validation, indicative of them proving useful in future ecological studies.
RESUMO
Despite its importance to ocean-climate interactions, the metabolic state of the oligotrophic ocean has remained controversial for >15 years. Positions in the debate are that it is either hetero- or autotrophic, which suggests either substantial unaccounted for organic matter inputs, or that all available photosynthesis (P) estimations (including (14)C) are biased. Here we show the existence of systematic differences in the metabolic state of the North (heterotrophic) and South (autotrophic) Atlantic oligotrophic gyres, resulting from differences in both P and respiration (R). The oligotrophic ocean is neither auto- nor heterotrophic, but functionally diverse. Our results show that the scaling of plankton metabolism by generalized P:R relationships that has sustained the debate is biased, and indicate that the variability of R, and not only of P, needs to be considered in regional estimations of the ocean's metabolic state.