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The Concept of Biocompatibility
Published in Antonietta Morena Gatti, Stefano Montanari, Advances in Nanopathology From Vaccines to Food, 2021
Antonietta Morena Gatti, Stefano Montanari
The actual LD50 value may be, and often is, different for a certain substance, depending on the route of exposure (e.g. ingestion, transdermal, inhalation, etc.). These different values are obtained testing the chemicals on laboratory animals. Special calculations are used when translating animal LD50 values to possible lethal dose values for humans. Safety factors of 10,000 or 1000 are usually included in such calculations to allow for the variability between individuals and how they react to a chemical, and for the uncertainties of experiment test results.
Hormesis
Published in T. D. Luckey, Radiation Hormesis, 2020
Many radiobiologists naively assumed that the effects of low doses of ionizing radiation could be derived by simple interpolation from high doses to ambient doses. That assumption is invalid because high and low doses of ionizing radiation give qualitatively opposite results in living organisms. Biostaticians called such practices “statistical fantasy” and “scientific malpractice”.383–385,486 Some agencies and physicians argue that the linear models provide safety factors against all possible harm from ionizing radiation. This viewpoint is counterproductive when their recommendations eliminate all biopositive effects. This deprives individuals and populations of the optimum conditions for health. Realistic safety factors which take into account the biopositive effects of ionizing radiation would be more humane. The hormetic model provides the ZEP as a definitive dividing point between biopositive and bionegative effects.
Properly Relating Radiation Protection Requirements to Relative Radiotoxicity and Risk *
Published in Kenneth L. Miller, Handbook of Management of Radiation Protection Programs, 2020
We must recognize that there is a need for adequate safety factors in the design and planning of radiation protection measures. The author has always advocated safety factors of at least 100 in designing protection against internal exposure, since some materials stay in the body for relatively long times after intake, and the dose delivered will be variable and uncertain. Safety facotrs are not unique to the health physics profession. Safety factors have been employed by structural engineers in building bridges and buildings for many hundreds of years. This author considers that the safety factors built into the selection of the values in Table 1 are already sufficient to take into account any changes that might occur as a result of the adoption of the proposed revisions to 10CFR part 20, which incorporate the newer DACS of the ICRP.22,23,33 Any additional safety factors should be related to uncertainties in probabilities or fractions of intake of materials in specific processes or operations. These uncertainties will in general be considerably larger than even those encountered in estimating internal dose commitments per unit intake (“dose conversion factors”23).
Modeling of occupational safety and health factors in production organizations and the formation of measuring scales of occupational safety climate
Published in International Journal of Occupational Safety and Ergonomics, 2022
Violeta Stefanović, Andrea Dobrosavljević, Snežana Urošević, Ivana Mladenović-Ranisavljević
One of the ways of understanding and defining the concept of the OSH climate can be seen in the work by Dollard et al. [31], who state that the OSH climate refers to the perceptions that employees form in terms of management commitment (MC) and performance in monitoring safety policy, procedures and practices. The OSH climate enables the flow of information to employees about the priority method of protection during the production process, taking into account psychological and health risks. This results in the application of adapted behavior by employees. Also, a positive OSH climate is considered to increase the frequency of safety behavior among employees working in potentially hazardous WC [32]. Kines et al. [30] claim that safety factors are the starting point in the study and formation of safety models at work, although their number and impact are still not clearly defined [11].
Pharmacokinetics and pharmacodynamics of MT-1207, a novel multitarget blocker of α1 receptor, 5-HT2A receptor, and calcium channel, in healthy subjects
Published in Expert Opinion on Investigational Drugs, 2021
Hong Zhang, Min Wu, Yue Hu, Cuiyun Li, Wenbo zheng, Jingrui Liu, Xiaojiao Li, Xiaoxue Zhu, Yanhua Ding
MT-1207 administered at doses of 2.5–10 mg/kg caused a dose-dependent decrease in blood pressure in rats. The absolute blood pressure reduction ranged from 13 to 36 mmHg, and instead of increasing the heart rate, the heart rate showed a slight decrease. Subsequently, the dosage was converted into a human dose of 29 mg as the starting dose, using the body surface area normalization method to directly convert into the corresponding human equivalent dose (HED). The No Observed Adverse Effect Level (NOAEL) was 5 mg in Beagle dogs and 15 mg in Sprague Dawley (SD) rats. The maximum recommended starting dose is 17.4 mg, with a 10-fold safety factor [8]. Based on the above pre-clinical empirical data about the effect and toxicity of the drug, a dosage of 5–40 mg was selected for use in clinical trials. This is the first study designed to investigate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of MT-1207 in Chinese healthy subjects.
Validation and initial results of surveys exploring perspectives on risks and solutions for diagnostic and medication errors in primary care in Sweden
Published in Scandinavian Journal of Primary Health Care, 2020
Rita Fernholm, Caroline Wachtler, Karolina Malm-Willadsen, Martin J. Holzmann, Axel C. Carlsson, Gunnar H. Nilsson, Karin Pukk Härenstam
The Yorkshire Contributory Factors Framework (YCFF) is an evidence-based framework of factors contributing to patient safety incidents in hospital settings [10]. A qualitative study with patients and carers explored patient safety factors in primary care compared to YCFF [11]. Furthermore, General Practitioner (GP) perspectives on patient safety incidents have been explored [12]. However, it is still unknown what contributing factors or risks are considered important for mitigation from both health care professionals’ (HCPs’) and patients’ perspectives. Our group has earlier conducted a qualitative study to identify factors important for understanding risks and solutions for patient safety issues in PHC [13]. These results were used in the present study to guide the design of the surveys for HCPs and patients. There is an instrument for assessing patient safety culture in primary care (Manchester Patient Safety Framework) but no instrument for assessing which patient safety issues should be prioritised to address.