Prevention of vertical transmission of hepatitis B virus infection

Hepatitis B virus (HBV) is the leading cause of chronic viral hepatitis. Annually, almost two million children younger than 5 years acquire the infection, mostly through vertical or horizontal transmission in early life. Vertical transmission of HBV is a high efficacy phenomenon ranging, in the absence of any preventive interventions, from 70% to 90% for hepatitis e antigen positive mothers and from 10% to 40% for hepatitis e antigen-negative mothers. Maternal viraemia is a preeminent risk factor for vertical transmission of HBV. Maternal screening is the first step to prevent vertical transmission of HBV. Hepatitis B passive and active immunoprophylaxis at birth together with antiviral treatment of highly viraemic mothers are the key strategies for global elimination of HBV infection. Strategies are needed to promote implementation of birth-dose vaccination and hepatitis B immunoglobulins in low- and middle-income countries where the prevalence of the infection is at the highest

Hoffa’s fat pad thickness: a measurement method with sagittal MRI sequences

Background: Hoffa’s fat pad is a structure located within the fibrous joint capsule of the knee joint, but outside the synovial cavity. It plays an important biomechanical and metabolic role in knee joint, reducing the impact of forces generated by loading and producing cytokines. Changes in its size can induce modifications in the knee homeostasis. However, a great variability exists regarding its measurements. This work aims to evaluate the reliability of a measurement method of Hoffa’s fat pad dimensions through MRI. Methods: 3T sagittal IW 2D TSE fat-suppressed MRI sequences, taken from the OAI (Osteoarthritis initiative) database, of 191 male and female patients, aged between 40 and 80 years, were analysed; a manual measurement of the thickness of Hoffa’s fat pad of each subject was then performed by two different readers. The interobserver reliability and intraobserver reliability of the measurements were described by coefficient of variation (CV), Pearson correlation and Bland–Altman plots. Results: All statistical analyses have shown that not significant intra- or interobservers differences were evident (intraobserver CV % for the first observer was 2.17% for the right knee and 2.24% for the left knee, while for the second observer 2.31% for the right knee and 2.24% for the left knee; linear correlation was for the first observer r = 0.96 for the right knee and r = 0.96 for the left knee, while for the second observer r = 0.97 for the right knee and r = 0.96 for the left knee; in addition, the interobserver CV % was 1.25% for the right knee and 1.21% for the left knee and a high interobserver linear correlation was found: r = 0.97 for the right knee and r = 0.96 for the left knee). All results suggest that this manual measurement method of Hoffa’s fat pad thickness can be performed with satisfactory intra- and interobserver reliability. Conclusions: Hoffa’s fat pad thickness can be measured, using sagittal MRI images, with this manual method that represents, for his high reliability, an effective means for the study of this anatomical structure

Phenol compounds as new materials for Electron Paramagnetic Resonance dosimetry in clinical photon and electron beams,

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Paramagnetic Resonance (EPR) dosimetry to radiotherapy with different types of radiation beams. EPR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through EPR technique. The use of alanine as a dosimetric material gave the possibility to apply EPR spectroscopy for high-dose standardization and dose control in radiation processing (Marrale 2016). The EPR dosimetric method has many advantages such as simple and rapid dose evaluation, the readout procedure is non-destructive, linear response of many organic and inorganic compounds. EPR detectors show a behavior that suggest possible applications for various kinds of beams used for radiation therapy. Nowadays, the most widely used organic compound as a dosimeter is the alanine. However, many researches are in progress with the aim at improving sensitivity of EPR dosimetry for doses much smaller than 1 Gy. More sensitive materials than alanine are needed to make the EPR dosimeter competitive with other dosimetry systems. Our research group has started an investigation of the EPR response of some phenols compounds for possible EPR dosimetric applications suitable features, such as high efficiency of radiation-matter energy transfer and radical stability at room temperature. Phenols are compounds possessing a benzene ring attached to a OH group. After irradiation the final product is a stable phenoxy radical. The stability of such radical can be improved by adding other alkyl chains which can be attached to the benzene ring. The phenol octadecyl-3-(3,5-di-tert.butyl-4-hydroxyphenyl)-propionate gave interesting results. Moreover, its high molecular weight, the low volatility and the compatibility with the dosimeter binding material (wax) are advantages with respect to lower molecular weight phenols. In this work we report the EPR investigation of phenols exposed to clinical photon and electron beams (Gallo, 2016). The dosimetric features of these EPR dosimeters (dependence on microwave power and modulation amplitude, their response after gamma and electron irradiations, dependence on beam type and energy, the detection limits for both beam typologies, signal stability after irradiation) were investigated and the results are reported

Rare earth doped silica optical fibre sensors for dosimetry in medical and technical applications

Radioluminescence optical fibre sensors are gaining importance since these devices are promising in several applications like high energy physics, particle tracking, real-time monitoring of radiation beams, and radioactive waste. Silica optical fibres play an important role thanks to their high radiation hardness. Moreover, rare earths may be incorporated to optimise the scintillation properties (emission spectrum, decay time) according to the particular application. This makes doped silica optical fibres a very versatile tool for the detection of ionizing radiation in many contexts. Among the fields of application of optical fibre sensors, radiation therapy represents a driving force for the research and development of new devices. In this review the recent progresses in the development of rare earth doped silica fibres for dosimetry in the medical field are described. After a general description of advantages and challenges for the use of optical fibre based dosimeter during radiation therapy treatment and diagnostic irradiations, the features of the incorporation of rare earths in the silica matrix in order to prepare radioluminescent optical fibre sensors are presented and discussed. In the last part of this paper, recent results obtained by using cerium, europium, and ytterbium doped silica optical fibres in radiation therapy applications are reviewed

Dexamethasone and oxygen therapy in care home residents with diabetes: a management guide and algorithm for treatment: a rapid response action statement from the European Diabetes Working Party for Older People (EDWPOP) and European Geriatric Medicine Society (EuGMS)

This statement addresses the need to provide clinically relevant and practical guidance for long-term care staff working in care homes and other stakeholders engaged in the care of residents who require consideration for dexamethasone and oxygen therapy. It had been provided following a series of consensus discussions between the EDWPOP and the EuGMS in January and February 2021. Its main aim is to minimise morbidity and mortality from serious acute illnesses including COVID-19 requiring these treatments within the long-term care sector. © 2021, The Author(s)

The association of grip strength with depressive symptoms and cortisol in hair: A cross-sectional study of older adults

BACKGROUND: Low handgrip strength has been shown to be associated with higher levels of depressive symptoms. One area of mental health that is understudied in relation to grip strength is chronic stress, which can exist independently to depression, or as a comorbidity or precursor to this condition. The present study examined cross-sectional associations between grip strength, an established marker of physical function, and (a) depressive symptoms and (b) chronic stress utilizing hair cortisol concentrations, while accounting for multiple pertinent confounding variables. // METHOD: Data were used from wave 6 (2012/13) of the English Longitudinal Study of Aging, a panel study of older (≥50 years) community-dwelling men and women. Grip strength was measured in kg using a hand-held dynamometer. Depressive symptoms were assessed using the 8-item Center for Epidemiologic Studies Depression scale. Hair cortisol concentrations (pg/mg) were determined from samples of scalp hair and log-transformed for analysis to correct skewness. Associations of grip strength with depressive symptoms and hair cortisol concentration were tested using linear regression models adjusted for age, sex, ethnicity, wealth, smoking status, physical activity, body mass index, limiting long-standing illness, arthritis, diabetes, and hair treatment. // RESULTS: The sample comprised of 3741 participants (mean age 68.4 years, 66.4% female). After adjustment for age and sex, grip strength was significantly and negatively associated with both depressive symptoms (B = -0.038, SE = 0.004, P < 0.001) and hair cortisol (B = -0.003, SE = 0.001, P = 0.029). However, in the fully-adjusted models, both associations were attenuated and only the association with depressive symptoms remained statistically significant (B = -0.015, SE = 0.004, P < 0.001; hair cortisol B = -0.002, SE = 0.001, P = 0.088). // CONCLUSION: In a large sample of older adults in England, grip strength was negatively associated with depressive symptoms. Results were inconclusive regarding the association between grip strength and chronic stress. Further research examining the longitudinal relationships between muscular strength and specific aspects of mental health, while also exploring the neurobiological mechanisms underlying these associations, is warranted before recommendations for policy and practice can be made

Análise espectral de dados SMMR para estudo de padrões de Inundação do Pantanal.

Inundation seasonal patterns are important in the understanding of tropical floodplain ecosystems dynamics. In this study, we have analyzed data derived from 37-GHz polarization differences observed by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR). The passive microwave observations, for 10 Pantanal subregioes, provide an robust signature of inundation dynamics in large wetlands such as the Pantanal. The time series was obtained taking into account the differences between vertically and horizontally polarized brightness temperatures providing a sensitive indicator of the surface water against a vegetation land surface background. Each time series was analyzed by applying the gradient pattern analysis on a multiresolution representation obtained from wavelet decomposition /reconstrution technique. The main result have shown similar variability patterns for the following groups of subregions: (i) Miranda and Piquiri; (ii) Negro and Nhecolandia; (iii) Corixo, Paraguay, Cuiabá and Taquari fan; and (iv) Taquari river and Nabileque. Some hydrological aspects are discussed in order to understand the clusterization found from our results

Temperature behavior of radiochromic poly(vinyl-alcohol)&#8211;glutaraldehyde Fricke gel dosimeters in practice

The use of synthetic gel matrices prepared with poly(vinyl-alcohol) (PVA) cross-linked by glutaraldehyde (GTA) contributed to enhance the interest toward radiochromic Fricke gel (FG) dosimeters. As it occurs in several chemical dosimeters, the response of PVA-GTA Fricke gels could be affected by temperature. Aim of this work is to study the dependence of the dosimetric properties of PVA-GTA Fricke gel dosimeters both on the irradiation temperature and on temperature changes possibly occurring between the irradiation and readout phases. Such effects were investigated by means of magnetic resonance imaging (MRI) and optical absorbance (OA) measurements. The results did not reveal any significant dependence of the sensitivity of the dosimeters on the irradiation temperature in the investigated interval 20\ub0C-35\ub0C. By contrast, auto-oxidation phenomena confirmed to be a critical aspect for FG dosimeters, also in case of use of PVA matrix. The extent such phenomena, that might impair the accuracy of dose estimations, proved to critically depend on the temperature at which FG dosimeters are subjected before and after irradiation, as well as on the duration of possible thermal-stress

In silico validation of MCID tool for voxel dosimetry applied to 90Y radioembolization of liver malignancies

The aim of this work is validating the Monte Carlo Internal Dosimetry (MCID) tool for internal dosimetry, which allows personalized treatment planning starting from patient-specific images and direct Monte Carlo (MC) simulations. The absorbed dose for different computational phantoms, calculated with MC and with conventional MIRD methods at both organ and voxel level, were compared, obtaining differences of about 0.3% and within 3%, respectively, whereas differences increased (up to 14%) introducing tissue heterogeneities in phantoms. The absorbed dose of spheres with different radius (10 mm ≤ r ≤ 30 mm), calculated from MC code and from OLINDA/EXM was also compared, obtaining differences varying in the range 2–9% after correcting for partial volume effects (PVEs) from imaging. This work validated the MCID tool which allows the fast generation of input macros for MC simulations, starting from patient-specific images. It also shows the impact of tissue inhomogeneities on dosimetric results and their relevance for an accurate dosimetric plan