Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

A method to improve radioactive waste drum activity estimation in Segmented Gamma Scanning (SGS) systems was developed for homogenous content. We describe a method to quantify the activity of spatially distributed gamma-emitting isotopes (‘hot spots’) in homogenous content waste drums without the use of a collimator. Instead of averaging all the detector's readings we treat it as many different spatial samples as if we have multiple detectors surrounding the waste drum ("virtual detectors"). From these readings, we form a general linear model. Next, we derive the Maximum Likelihood Estimator (MLE) for the multiple sources position and activity. We solve this hyper-dimensional search problem using an Alternating Projections (AP) technique which transforms the problem into a simpler one-dimensional maximization problem. We tested this method using a mathematical simulation with a various number of sources, at random activities and positions for several energy bands. The preliminary results are consistent and show large improvement of the accuracy with comparison to industrial SGS systems and the same accuracy as new methods which exploits the spatial samples. Furthermore, since this method eliminates the need for heavy led collimator, none of the sources is blocked for the whole measurement period, which provides increased count rates and decreases the total measurement time

Improving Activity Estimation in Passive Gamma Scanning for Radioactive Waste Drums

A method to improve radioactive waste drum activity estimation in Segmented Gamma Scanning (SGS) systems was developed for homogenous content. We describe a method to quantify the activity of spatially distributed gamma-emitting isotopes (‘hot spots’) in homogenous content waste drums without the use of a collimator. Instead of averaging all the detector's readings we treat it as many different spatial samples as if we have multiple detectors surrounding the waste drum ("virtual detectors"). From these readings, we form a general linear model. Next, we derive the Maximum Likelihood Estimator (MLE) for the multiple sources position and activity. We solve this hyper-dimensional search problem using an Alternating Projections (AP) technique which transforms the problem into a simpler one-dimensional maximization problem. We tested this method using a mathematical simulation with a various number of sources, at random activities and positions for several energy bands. The preliminary results are consistent and show large improvement of the accuracy with comparison to industrial SGS systems and the same accuracy as new methods which exploits the spatial samples. Furthermore, since this method eliminates the need for heavy led collimator, none of the sources is blocked for the whole measurement period, which provides increased count rates and decreases the total measurement time

Reduced atherosclerosis and inflammatory cytokines in apolipoprotein-E-deficient mice lacking bone marrow-derived interleukin-1alpha.

Item does not contain fulltextOBJECTIVE: Interleukin (IL)-1alpha and IL-1beta are products of macrophages, endothelial cells and vascular smooth muscle cells; moreover, each of these cell types is affected by the pro-inflammatory properties of both IL-1's. Whereas several studies demonstrate the proatherogenic properties of IL-1beta, the role of IL-1alpha in atherogenesis remains unclear. We assessed whether IL-1alpha and IL-1beta from tissue resident vascular cells or emigrating bone marrow-derived cells promote the development of atherosclerosis in apoE-/- mice and determined the effect of selective macrophage IL-1alpha or IL-1beta deficiency on degradation of LDL and cytokine production. METHODS: We generated strains of double knock-out (KO) mice (apoE-/-/IL-1alpha-/- and apoE-/-/IL-1beta-/-) and created chimeras consisting of apoE-/- mice reconstituted with bone marrow-derived cells from apoE-/-/IL-1+/+, apoE-/-/IL-1alpha-/- and apoE-/-/IL-1beta-/-. RESULTS: The areas of aortic sinus lesions were lower in either double KO mice compared to solely apoE-/- mice, despite higher non-HDL cholesterol levels. Importantly, selective deficiency of IL-1alpha or IL-1beta in bone marrow-derived cells inhibited atherogenesis to the same extent as in double KO mice without affecting plasma lipids. Aortic sinus lesions in apoE-/- mice transplanted with IL-1beta-/- or IL-1alpha-/- cells were 32% and 52% lower, respectively, than in IL-1+/+ transplanted mice. Ex vivo, isolated IL-1alpha-/- macrophages from atherosclerotic mice degraded LDL and secreted IL-6, TNFalpha and IL-12 similarly to IL-1+/+ macrophages; however, IL-1alpha deficient macrophages secreted reduced levels of IL-1beta (-50%) and 2-3-fold higher levels of the anti-inflammatory cytokine IL-10. CONCLUSION: We show for the first time that it is IL-1alpha from bone marrow-derived cells that accelerates atherogenesis in apoE-deficient mice rather than constitutive IL-1alpha in vascular cells, possibly by increasing the inflammatory cytokine profile of macrophages

Lack of interleukin-1alpha or interleukin-1beta inhibits transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice.

Item does not contain fulltextBACKGROUND & AIMS: The identification of the cellular and molecular pathways that mediate the development of non-alcoholic steatohepatitis is of crucial importance. Cytokines produced by liver-resident and infiltrating inflammatory cells, play a pivotal role in liver inflammation. The role of the proinflammatory cytokines IL-1alpha and IL-1beta in steatohepatitis remains elusive. METHODS: We employed IL-1alpha and IL-1beta-deficient mice and transplanted marrow cells to study the role of liver-resident and bone marrow-derived IL-1 in steatosis and its progression to steatohepatitis. RESULTS: Atherogenic diet-induced steatohepatitis in wild-type mice was associated with 16 and 4.6 fold-elevations in mRNA levels of hepatic IL-1alpha and IL-1beta, respectively. In mice deficient in either IL-1alpha or IL-1beta the transformation of steatosis to steatohepatitis and liver fibrosis was markedly reduced. This protective effect in IL-1alpha-deficient mice was noted despite increased liver cholesterol levels. Deficiency of IL-1alpha markedly reduced plasma serum amyloid A and steady-state levels of mRNA coding for inflammatory genes (P-selectin, CXCL1, IL-6, and TNFalpha) as well as pro-fibrotic genes (MMP-9 and Collagen) and particularly a 50% decrease in TGFbeta levels (p = 0.004). IL-1alpha mRNA levels were two-folds lower in IL-1beta-deficient mice, and IL-1beta transcripts were three-folds lower in IL-1alpha-deficient compared to wild-type mice. Hepatic cell derived IL-1alpha rather than from recruited bone marrow-derived cells was required for steatohepatitis development. CONCLUSIONS: These data demonstrate the critical role of IL-1alpha and IL-1beta in the transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice. Therefore, the potential of neutralizing IL-1alpha and/or IL-1beta to inhibit the development of steatohepatitis should be explored.1 november 201

Organisational model and coverage of at-home COVID-19 vaccination in an Italian urban context

The COVID-19 pandemic called for a reorganisation of the methods for providing health services. The aim of this paper is to describe the organisational model implemented by one of Rome’s Local Health Units (LHU), ASL Roma 1, for the “at-home COVID-19 vaccination campaign” dedicated to a target population and to outline data related to vaccination coverage stratified by health districts. A cross-sectional study was designed to describe the strategies implemented by LHU to deliver at-home vaccination programmes. People eligible for the at-home vaccination programme included patients living in the area of the LHU, being assisted by the district home care centre or not transportable or individuals with social situations that make traveling difficult. Priority for vaccination was given to (I) age > 80 years, (II) ventilated patients with no age limit, (III) very seriously disabled people with no age limit. Patients’ data were acquired from regional and LHU databases. From 5 February until the 16 May, 6127 people got at least one dose of Pfizer-Biontech Comirnaty® vaccine, while 5278 (86.14%) completed the necessary two doses. The highest number of vaccines was administered during the first week of April, reaching 1296 doses overall. The number of vaccines administered were similar across the districts. The average number of people vaccinated at home was 6 per 1000 inhabitants in the LHU. This model proved to be extremely complex but effective, reaching satisfying results in terms of vaccination coverage

A mutation and expression analysis of the oncogene BRAF in pituitary adenomas.

OBJECTIVE: BRAF is an oncogene that is commonly mutated in both melanomas and papillary thyroid carcinomas, usually at position V600E that leads to constitutive activity in the Ras-mitogen-activated protein kinase (MAPK) pathway. We speculated that this same gene may be either mutated at this site, or overexpressed, in pituitary adenomas. DESIGN AND MEASUREMENTS: We sequenced 37 pituitary adenomas for a mutation at the V600E position. In addition, we investigated B-Raf mRNA expression in normal pituitary (n = 5) and nonfunctioning pituitary adenomas (NFPA) (n = 6) by semiquantitative PCR, and in a further 27 pituitary adenomas of various types and 10 normal pituitaries using real-time quantitative PCR. Finally, we explored B-Raf protein expression in 10 normal pituitaries and 12 NFPAs. RESULTS: No sequence mutations for the substitution V600E were identified. B-Raf mRNA was overexpressed in pituitary adenomas compared to normal pituitary, and this was entirely due to overexpression in NFPAs. NFPAs also showed very variable expression of B-Raf protein, but those tumours showing highest levels of B-Raf mRNA expressed the most B-Raf protein. CONCLUSIONS: Mutations previously seen in the majority of melanomas and a substantial minority of papillary thyroid carcinomas are not a frequent finding in pituitary adenomas. However, overexpression of B-Raf mRNA and protein may be a feature of NFPAs, highlighting overactivity of the Ras-B-Raf-MAP kinase pathway in these tumours