Breast cancer induced by X-ray mammography screening? A review based on recent understanding of low-dose radiobiology

Screening mammography offers the possibility of discovering malignant diseases at an early stage, which is consequently treated early, thereby reducing the mortality rate. However, ionizing radiation as used in low-dose X-ray mammography may be associated with a risk of radiation-induced carcinogenesis. In the context of the harmful effects of ionizing radiation, this article reviewed novel radiobiological data and provided a simulation of the relative incidence of radiation-induced breast cancer due to screening against a background baseline incidence in a population of 100,000 individuals. The use of modern digital mammographic technology was assumed, giving rise to a glandular dose of 2.5 mGy from a 2-view per breast image. Assuming no latency time, this led to a ratio of induced incidence rate over baseline incidence rate of about 1.6‰ for biennial screening in women aged 50-74 years, although it cannot be excluded that the dose and dose rate effectiveness factor values relying on new radiobiological insights may lower this number to about 0.7‰. This carcinogenic risk is considered small in relation to the potential beneficial effects of screening, especially as latency time was not taken into consideration. However, individuals who are known to be carriers of risk-increasing genetic variations and/or have an inherited disposition of breast cancer should avoid ionizing radiation as much as possible and should be referred to ultrasound or magnetic resonance imaging. In addition, a significant, but difficult to quantify, risk of cancer is present for individuals who suffer from hypersusceptibility to ionizing radiation

Twenty-four-hour pattern in French firemen of lag time response to out-of-hospital cardiac arrest and work-related injury.

Circadian cognitive and physical rhythms plus 24 h patterns of accidents and work-related injuries (WRI) have been verified in numerous studies. However, rarely, if ever, have 24 h temporal differences in both work performance and risk of WRI been assessed in the same group of workers. We explored in a homogenous group of French firemen (FM) 24 h patterns of both lag time (LT) response duration to emergency calls for medical help (ECFM) for life-threatening out-of-hospital cardiac arrests (OHCA), used as a non-specific index of work performance, and WRI. Our studies demonstrate rather high amplitude statistically significant 24 h patterns of the two variables. The LT response duration was twice as long ~0500 h (slowest response) than ~1600 h (fastest response). In the same group of FM, the actual number WRI/h was greatest ~1600 h and lowest in the early morning hours. However, the 24 h pattern of the relative risk (RR) of WRIs, i.e., per clock hour number of WRI/(total number of responses to emergency calls x number of FM at risk per response), was very different, the RR being greatest ~0200 h and lowest in the afternoon. The 24 h pattern in LT response duration to ECMH for OHCA and RR of WRI was strongly correlated (r=+0.85, P<0.01), with the nocturnal trough (slowest response) in LT response duration coinciding with the nocturnal peak RR of WRI. These findings indicate the requirement for circadian rhythm-based interventions to improve the nocturnal compromised work performance and elevated risk of WRI of shift-working FM.

Radiation dose features and solid cancer induction in pediatric computed tomography

Over the past two decades technical advances and improvements have made computed tomography [CT] a valuable and essential tool in the array of diagnostic imaging modalities. CT uses ionizing radiation [X-rays] which may damage DNA and increase the risk of carcinogenesis. This is especially pertinent in pediatric CT as children are more radiosensitive and have a longer life expectancy than adults. The purpose of this paper is to review and elucidate the potential harmful effects of ionizing radiation in terms of solid cancer induction from pediatric CT scanning. In the light of scientific and technical developments, we will also discuss the possible strategies and ongoing efforts to reduce CT radiation exposure in pediatric patients. In this context, we will not ignore the fact that a well-justified CT scan may exceed its risk and have a favorable impact

Comparison of the flavonoid aglycone contents of Apis mellifera propolis from various regions of Brazil

Forty-six specimens of propolis which were collected by Apis mellifera were obtained from various regions of Brazil and extracted with 80 per cent aqueous ethanol(ethanolic extract of propolis, EEP). The extracts were analysed by using determination of total flavonoid concentrations using the aluminum nitrate method, UV-spectrophotometry, reversed phase-high performance thin layer chromatography (HPTLC), and reversed phase-HPLC. Six samples of EEP, which contained high total flavonoid concentrations, were selected for futher investigation. HPTLC indicated that the quality of flavonoid aglycones of EEP from the States of Minas Gerais and Säo Paulo (Southeastern Brazil), Goias and Mato Grosso do Sul (closely to Southeastern) were similar, but were different compared to those of EEP's from Paraná and Rio Grande do Sul, which are located in Southern Brazil. Reversed Phase-HPLC analysis of EEP's from Southern Brazil identified 7 flavonoid aglycones, whereas there were 9 from Säo Paulo and Minas Gerais and 7 from Goiás and Mato Grosso do Sul. These results indicate that the plant ecology of Southeastern and Southern Brazil are different. It was also observed that all samples of EEP's demonstrated inhibition of growth of Staphylococcus aureus coagulase positive, whereas Escherichia coli was not inhibited

Estudo comparativo entre atracúrio e vecurônio em dose única / Comparative study between atracurium and vecuronium using single dose

O estabelecimento do bloqueio neuromuscular do músculo adutor do polegar foi comparado após injeçäo única de atracúrio na dose de 0,6 mg kg e vecurônio na dose de 0,1 mg.kg em 23 pacientes ASA I e II sob anestesia geral. Foram avaliados os parâmetros de tempo desde o momento da injeçäo até a recuperaçäo da seqüência de quatro estímulos a 75% (Figura 1). Houve um aumento estatisticamente significativo de cerca de 10 min na duraçäo de açäo do atracúrio (p <0,05) em relaçäo ao vecurônio, assim como de outros parâmetros de tempo (Quadro 2). Näo ocorreram alteraçöes cardiocirculatórias (FC e PAM) nos 5 min subseqüentes às injeçöes de atracúrio e vecurônio. Foi observado um caso de eritema sobre o trajeto venoso no grupo que recebeu atracúrio. O atracúrio e o vecurônio säo bloqueadores neuromusculares indicados para cirurgias com duraçäo igual ou menor que 1 h