Prevention of accidental exposure in radiotherapy: the risk matrix approach

Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.

Diversity and seasonal patterns of ticks parasitizing wild birds in western Portugal

The diversity and abundance of questing ticks and ticks parasitizing birds was assessed during 1 year in two recreational forests in western Portugal, a suburban forest and an enclosed game area. The aim of this study was to assess the distribution and seasonality of tick species and to understand the role of bird species as hosts for ticks. Ixodes ricinus was the most abundant questing tick collected in the enclosed game area, whereas in the suburban forest, only three ticks were collected by blanket dragging. Tick species parasitizing birds included I. ricinus, I. frontalis, I. arboricola, I. acuminatus, Haemaphysalis punctata, Hyalomma marginatum and H. lusitanicum. This is the first record of I. arboricola in Portugal. Tick prevalence and intensity of infestation differed between study areas and was higher in birds from the game area where a large population of deer and wild boar may support tick populations. Ground and shrub dwelling bird species such as Turdus merula, Erithacus rubecula and Sylvia melanocephala were the most heavily parasitized by ticks, but the importance of different bird species as hosts of larvae and nymphs of I. ricinus and I. frontalis differed. Therefore, different bird species may contribute differently for tick population maintenance.

Granulomatosis with polyangiitis initially misdiagnosed as lung cancer

Granulomatosis with Polyangiitis (GPA), which was formerly named Wegener's Granulomatosis (WG) is a systemic disease characterized by necrotizing granulomatous inflammation and vasculitis that primarily involves upper and lower respiratory tract, as well as kidneys. Diagnosing GPA on the basis of transthoracic fine needle aspiration (TFNA) may be problematic, as it can be misdiagnosed as cancer. We describe a patient with a probable GPA which was originally diagnosed as malignancy, but who responded to lung cancer chemotherapy.

Physico-chemical properties of chars obtained in the co-pyrolysis of waste mixtures

The present work aims to perform a multistep upgrading of chars obtained in the co-pyrolysis of PE, PP and PS plastic wastes, pine biomass and used tires. The quality of the upgraded chars was evaluated by measuring some of their physico-chemical properties in order to assess their valorisation as adsorbents' precursors. The crude chars were submitted to a sequential solvent extraction with organic solvents of increasing polarity (hexane, mixture 1:1 v/v hexane:acetone and acetone) followed by an acidic demineralization procedure with 1M HCl solution. The results obtained showed that the upgrading treatment allow the recovery of 63-81% of the pyrolysis oils trapped in the crude chars and a reduction in the char's ash content in the range of 64-86%. The textural and adsorption properties of the upgraded chars were evaluated and the results indicate that the chars are mainly mesoporous and macroporous materials, with adsorption capacities in the range of 3.59-22.2 mg/g for the methylene blue dye. The upgrading treatment allowed to obtain carbonaceous materials with quality to be reused as adsorbents or as precursors for activated carbon.

Characterization of chars produced in the co-pyrolysis of different wastes: decontamination study

The present work is devoted to the study of the decontamination of chars obtained in the co-pyrolysis of plastics, biomass and tyre wastes. The chars were extracted with several organic solvents of different polarities either individually or in sequence. The ability of each selected extractant to remove toxic pollutants was evaluated by comparing the extraction yields and by characterizing the crude extracts with a combination of chemical analysis and toxicity bioassays. Also, the mineral composition of the treated and non-treated chars was assessed. The results obtained in this study indicate that hexane is the more efficient extraction solvent to be used in the organic decontamination of chars obtained in the co-pyrolysis of plastics, tyres and biomass. A sequential extraction with solvents of increasing polarity can provide a better decontamination of the raw pyrolysis char than any individual extraction. The compounds removed from the char during the decontamination process are mainly aliphatic hydrocarbons and aromatic hydrocarbons, therefore a material that may be upgraded to be used as a fuel and/or as raw material for the organic chemical industry.

Efeito do óleo de arroz na ração sobre a produção e composição química do leite de ovelhas corriedale

Foi avaliada a influência da adição de óleo de arroz, sobre a produção e a composição química do leite de ovelhas Corriedale multíparas alimentadas com ração comercial sem e com adição de óleo de arroz contendo respectivamente 4,36% e 6,56% de extrato etéreo. A ordenha mecânica foi realizada uma vez por semana, pela manhã. Além da produção de leite foram avaliados: gordura, proteína, lactose e sólidos totais. A produção de leite, bem como dos componentes químicos lactose, proteína, gordura e sólidos totais, não foram influenciadas pelo aumento do extrato etéreo da ração com a adição de óleo de arroz.

Determination of alkylphenols in eluates from pyrolysis solid residues using dispersive liquid-liquid microextraction

Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was applied for the determination of 11 alkylphenols in eluates of chars produced in the co-pyrolysis of different wastes. The optimized DLLME procedure, 4 mL of sample solution, 15 microL of trichloroethylene as extraction solvent, 1 mL of acetone as dispersion solvent and addition of 15% (w/v) of NaCl, was validated. Under the optimum conditions, the enrichment factors were in the range of 82-180. Calibration curves were constructed for each analyte in pure water in the concentration range of 0.5-8 microg/L with correlation coefficients higher than 0.999. The limits of detection were between 0.07 and 0.17 microg/L. The repeatability of the method was evaluated using water samples fortified with the analyte mixture at two concentration levels: the relative standard deviation (RSD) values were between 3.7% and 8.0% for a concentration of 0.5 microg/L, and between 4.2% and 6.4% for a concentration of 3 microg/L. The recoveries of the analytes evaluated by fortification of real eluate samples were in the range of 67.9-97.9% for eluate 1 (obtained from a decontaminated char) and in the range of 61.9-101.4% for eluate 2 (obtained from the untreated char). o-Methylphenol presented low recoveries for both eluates showing a possible matrix effect. The results obtained show that this method is adequate for the determination of alkylphenols in environmental aqueous samples and presents itself as a fast and inexpensive technique, using minor amounts of organic solvents.

Toxicity of char residues produced in the co-pyrolysis of different wastes

Char residues produced in the co-pyrolysis of different wastes (plastics, pine biomass and used tyres) were characterized using chemical and toxicity assays. One part of the solid chars was submitted to extraction with dichloromethane (DCM) in order to reduce the toxicity of the char residues by removing organic contaminants. The different volatility fractions present in the extracted char (Char A) and in the raw char (Char B) were determined by progressive weight loss combustion. A selected group of heavy metals (Cd, Pb, Zn, Cu, Hg and As) was determined in both chars. The chars were subjected to the leaching test ISO/TS 21268 - 2, 2007 and the resulting eluates were further characterized by determining a group of inorganic parameters (pH, conductivity, Cd, Pb, Zn, Cu, Hg and As contents) and the concentrations of several organic contaminants (volatile aromatic hydrocarbons and alkyl phenols). An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the Council Decision 2003/33/CE and the criteria on the evaluation methods of waste ecotoxicity (CEMWE). The results obtained in this work indicated that the extraction with DCM is an effective method for the removal of organic contaminants of high to medium volatility from pyrolysis solid residues, thus decreasing their toxicity potential. Zn can be leached from the chars even after the DCM extraction treatment and can contribute to the ecotoxicity of the eluates obtained from chars. Both chars (treated and non treated with DCM) were classified as hazardous and ecotoxic wastes.

The effects of the Brazilian regulatory inspection programme on nuclear medicine facilities

This paper aims to demonstrate the importance of the regulatory inspections carried out by the Brazilian regulatory body in the area of nuclear medicine. The main aspects observed during the inspections are presented as well as the time evolution of the non-compliances, according to their occurrence by type. We also evaluate factors concerning the working of the nuclear medicine facility responsible for solving the non-compliances. The results suggest a decrease of occurrence of non-compliances with time that can be related to the strictness of the inspections and the awareness of the personnel in the nuclear medicine facilities. An analysis of radiation dose exposure levels for the professionals involved in nuclear medicine was carried out; although dose values are below regulatory dose limits, their occurrence is not decreasing satisfactorily. Results indicate the need for staff training and commitment of the responsible nuclear medicine facility staff to the radiological protection procedures. Our results also emphasise the importance of continuous coercive actions to improve the level of radiological protection in nuclear medicine facilities in compliance with the standards established by the national regulatory authority and international recommendations.

Chemical and ecotoxicological characterization of solid residues produced during the co-pyrolysis of plastics and pine biomass

A mixture of 70% (w/w) pine biomass and 30% (w/w) plastics (mixture of polypropylene, polyethylene, and polystyrene) was subjected to pyrolysis at 400 degrees C, for 15 min, with an initial pressure of 40 MPa. Part of the solid residue produced was subjected to extraction with dichloromethane (DCM). The extracted residue (residue A) and raw residue (residue B) were analyzed by weight loss combustion and submitted to the leaching test ISO/TS 21268-2 using two different leachants: DCM (0.2%, v/v) and calcium chloride (0.001 mol/L). The concentrations of the heavy metals Cd, Cr, Ni, Zn, Pb and Cu were determined in the eluates and in the two residues. The eluates were further characterized by determining their pH and the concentrations of benzene, toluene, ethylbenzene and xylenes (BTEX). The presence of other organic contaminants in the eluates was qualitatively evaluated by gas chromatography, coupled with mass spectrometry. An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). Residue A was not considered to be ecotoxic by the ecotoxicological criterion (EC(50) (30 min) >or=10%), but it was considered to be ecotoxic by the chemical criterion (Ni>or=0.5mg/L). Residue B was considered to be ecotoxic by the ecotoxicological criterion: EC(50) (30 min)<or=10%. Besides that, residue B was considered to be hazardous according the European legislation (BTEX concentrations higher than 100 ppb). The results indicate that volatile organic contaminants can be present in sufficient amounts in these residues and their eluates to induce ecotoxicity levels. The extraction of the pyrolysis residue with DCM was an efficient method for removing lighter organic contaminants.

Determination of aromatic compounds in eluates of pyrolysis solid residues using HS-GC-MS and DLLME-GC-MS

A method for the determination of 15 aromatic hydrocarbons in eluates from solid residues produced during the co-pyrolysis of plastics and pine biomass was developed. In a first step, several sampling techniques (headspace solid phase microextraction (HS-SPME), static headspace sampling (HS), and dispersive liquid-liquid microextraction (DLLME) were compared in order to evaluate their sensitivity towards these analytes. HS-SPME and HS sampling had the better performance, but DLLME was itself as a technique able to extract volatiles with a significant enrichment factor. HS sampling coupled with GC-MS was chosen for method validation for the analytes tested. Calibration curves were constructed for each analyte with correlation coefficients higher than 0.999. The limits of detection were in the range of 0.66-37.85 ng/L. The precision of the HS method was evaluated and good repeatability was achieved with relative standard deviations of 4.8-13.2%. The recoveries of the analytes were evaluated by analysing fortified real eluate samples and were in the range of 60.6-113.9%. The validated method was applied in real eluate samples. Benzene, toluene, ethylbenzene and xylenes (BTEX) were the compounds in higher concentrations. The DLLME technique coupled with GC-MS was used to investigate the presence of less volatile contaminants in eluate samples. This analysis revealed the presence of significant amounts of alkyl phenols and other aromatic compounds with appreciable water solubility.

Leg muscles recruitment pattern in soccer players and active individuals during isometric contractions

This study aimed to compare the torque, torque ratio (Hamstrings: Quadriceps - H:Q), electromyographic (EMG) activity and EMG ratio (knee flexors: knee extensors EMG) in soccer players (SG, N = 10) and active subjects (AG, N = 10). Subjects performed three maximal voluntary isometric knee extensions and flexions at 45 degrees and 90 degrees to determine the peak torque and EMG activity. Torque and EMG activity of the knee flexor (biceps femoris [BF] and semitendinosus [ST]) were divided by the torque and EMG activity of the knee extensor (vastuls lateralis [VL] and rectus femoris [RF]) to calculate torque ratios (H:Q) and EMG ratios (BF:VL, BF:RF, ST:VL, ST:RF). The flexion torque was significantly higher for SG (p < 0.05) in 45 degrees and 90 degrees. EMG activity for SG was significantly higher in agonist contractions for VL, RF and ST and significantly lower in antagonist contractions for RF and ST when compared to AG. Torque and EMG ratios were similar between groups and there were good correlations between torque ratio and BF:VL ratio (r = 0.71, p = 0.02) and BF:RF ratio (r = 0.81, p = 0.004) at 45. The EMG results could overestimate the joint balance calculated using torque ratios. Differences in recruitment pattern between soccer players and non-athletes can be related to the training routines and the EMG ratios presents applicable in trained populations.

Sentinel lymph node biopsy: technique validation at the Setúbal Medical Centre, Portugal

Aims:

To evaluate the accuracy of sentinel lymph node biopsy in breast cancer patients at this institution, using combined technetium-99m (^99mTc) sulphur colloid and patent blue vital dye.

Methods:

From March 2007 to July 2008, 50 patients with a tumour of less than 3 cm and with clinically negative axillary lymph nodes underwent sentinel lymph node biopsy (SLNB), followed by axillary lymph node dissection (ALND). Sub-areolar ^99mTc sulphur colloid injection was performed the day before surgery, and patent blue vital dye was also injected sub-areolarly at least 5 minutes before surgery. Sentinel lymph node was identified during the surgical procedure, using a gamma probe and direct vision. All sentinel nodes underwent frozen section analysis. Later haematoxylin and eosin staining and immunohistochemical analysis were performed. Finally, SLNB was compared with standard ALND for its ability to accurately reflect the final pathological status of the axillary nodes.

Results:

The sentinel lymph node (SLN) was identified in 48 of 50 patients (96%). The number of sentinel lymph nodes ranged from one to four (mean 1.48) and non-sentinel nodes ranged from seven to 27 (mean 14.33). Of the 48 patients with successfully identified SLNs, 29.17% (14/48) were histologically positive. Sensivity of the SLN to predict axilla was 93.75%; accuracy was 97.96%. The SLN was falsely negative in one patient—6.25% (1/16).

Conclusions:

The SLNB represents a major advance in the surgical treatment of breast cancer as a minimally invasive procedure predicting the axillary lymph node status. This validation study demonstrates the accuracy of the SLNB and its reasonable false negative rate when performed in our institute. It can now be used as the standard method of staging in patients with early breast cancer at this institution.